• 전자공학회논문지B
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• 제30B권2호
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• pp.51-58
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• 1993

This paper describes the development of a speaker-dependent isolated word recognizer as applied to voice dialing in a car noise environment. for this purpose, several methods to improve performance under such condition are evaluated using database collected in a small car moving at 100km/h The main features of the recognizer are as follow: The endpoint detection error can be reduced by using the magnitude of the signal which is inverse filtered by the AR model of the background noise, and it can be compensated by using variants of the DTW algorithm. To remove the noise, an autocorrelation subtraction method is used with the constraint that residual energy obtainable by linear predictive analysis should be positive. By using the noise rubust distance measure, distortion of the feature vector is minimized. The speech recognizer is implemented using the Motorola DSP56001(24-bit general purpose digital signal processor). The recognition database is composed of 50 Korean names spoken by 3 male speakers. The recognition error rate of the system is reduced to 4.3% using a single reference pattern for each word and 1.5% using 2 reference patterns for each word.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 추계 학술대회논문집
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• pp.121-125
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• 2004

The preprocessor - solver - postprocessor software for 2D/Axisymmetric CSCM Upwind Flux Difference Splitting Navier-Stokes code has been developed for undergraduate educational purpose. This computational fluid dynamics (CFD) software allows students to setup, solve, visualize and control dynamically server for their own fluid problems via Internet. The preprocessor Is capable of generating geometry and grid, initial solution data and required solver control parameters. The postprocessor shows vector plot and contour plot with different options while residual plot shows root-mean-square (RMS) error history graphically and retrieves the data from solver interactively. Special feature of the preprocessor is grid generation part which is based on MFC/Visual C++ application and FORTRAN single block grid generator process. Many users can access solver via Internet from client computers and solve desired problems using locally installed pre- and postprocessor and remote powerful solver part.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.416-419
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• 2006

Numerical analysis is carried out to identify the wall thinning effect inside the feed water valve. The finite volume method is applied to make analysis for the viscous flows. The commercial cock FLUENT is used for the simulation and the GAMBIT for the grid generation. The RNG $\kappa-\varepsilon$ model is used for the turbulence and the tet-hybrid grid is applied for the modeling. The velocity vector, the pressure contour, the change of residual along the iteration number, and the dynamic head are predicted for the hydrodynamic investigation.

• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.270-276
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• 2002

An integrated robust fault diagnosis and fault accommodation strategy for a class of linear stochastic systems subjected to unknown disturbances is presented under the assumption that only a single fault may occur at a given time. The strategy is based on the fault isolation and estimation using a bank of robust two-stage Kalman filters and introduction of the additive compensation input for cancelling out the fault's effect on the system. Each filter is set up such that the residual is decoupled from unknown disturbances and fault with the influence vector designed in the filter. Simulation results for the simplified longitudinal flight control system with parameter uncertainties, process and sensor noises demonstrate the effectiveness of the present approach.

• Management Science and Financial Engineering
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• 제5권1호
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• pp.51-71
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• 1999

Performance of the group cumulative sum (CUSUM) control scheme using multiple univariate CUSUM charts is more sensitive to the change of quality control (QC) characteristics than the control chart schemes based on the Hotelling statistic We vexamine three group charts for multivariate normal data sets simulated with various correlation structures and shift directions in the mean vector. These group schemes apply the original measurement vectors, the scaled residual vectors from the re-gression of each variable on all others and the principal component vectors respectively to calculat-ing the CUSUM statistics. They are also compared to the multivariate QC charts based on the Ho-telling statistic by estimating average run lengths, coefficients of variation of run length and ranks in signaling order. On the basis of simulation results, we suggest a control chart scheme appropriate for specific quality control environment.

• 생명과학회지
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• 제9권5호
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• pp.531-536
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• 1999

As an attempt to preserve resources in marine biological organisms, we first constructed a cDNA library from the red alga Porphyra yezoensis. The library construction method from P. yezoensis consists of three steps; those include protoplast presparation, RNA isolation, and phage library construction. Protoplast was prepared in order to remove much of the carbohydrate compounds which are characteristics of algal cell walls. Carbohydrate contamination in the purified RNA may inhibit further enzyme reactions, those carbohydrates should be removed. RNA samples prepared from protoplast still seemed to contain residual amount of carbohydrate because mRNA isolation with conventional method failed. We therefore developed a method with Poly ATtract mRNA isolation system. The constructed phage library was tested by analyzing cDNA insert in phage vector from randomly picked ten independent white plagues. All of the phages contained cDNA inserts with sizes ranging 0.5kb and 2.0kb.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 추계학술발표논문집 (중)
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• pp.1317-1320
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• 2002

We present in this paper a new version of AODV that incorporates with "Minimizing Maximum node cost" by formulating that metric as a cost function of residual energy of nodes. An additional parameter is added to the cost function to consider the routing performance along with power-efficiency. The motivation of adding that new parameter is originated from the trace off between power-saving behaviors and routing performance.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 추계 학술대회논문집
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• pp.76-81
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• 2003

전산유체공학에서 그래픽 인터페이스를 이용한 후처리 기법은 수렴된 해의 물리적 구조 및 특성을 이해하는데 있어 매우 중요하다. 따라서 본 연구에서는 그래픽 환경을 이용하여 압축성 유동 해석 코드인 CSCM 수치해석 코드의 후처리 과정을 개발함으로서 코드전체의 완전성을 높이고자 하였다. Visual C++프로그램을 이용하여 Mesh plot, XY plot, 벡터 plot 및 contour plot이 가능한 후처리 프로그램을 개발하였으며 실시간으로 수치해석의 수렴정도를 파악할 수 있는 잔류항에 대한 그래픽 기능을 제공하게 하였다. 개발된 후처리 과정을 2차원 Compression ramp 및 Bump 문제의 해석결과에 대해 본 연구결과와 현재 유체해석의 후처리 프로그램으로 많은 사용자를 확보하고 있는 AMTEC사의 Tecplot 8.0 버전의 결과를 서로 비교해 본 결과 좋은 일치성을 보여주었다.

• Structural Engineering and Mechanics
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• 제42권3호
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• pp.425-448
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• 2012

In this paper, a new damage detection and quantification method has been presented to perform detection and quantification of structural damage under ambient vibration loadings. To extract modal properties of the structural system under ambient excitation, natural excitation technique (NExT) and eigensystem realization algorithm (ERA) are employed. Sensitivity matrices of the dynamic residual force vector have been derived and used in the parameter subset selection method to identify multiple damaged locations. In the sequel, the steady state genetic algorithm (SSGA) is used to determine quantified levels of the identified damage by minimizing errors in the modal flexibility matrix. In this study, performance of the proposed damage detection and quantification methodology is evaluated using a finite element model of a truss structure with considerations of possible experimental errors and noises. A series of numerical examples with five different damage scenarios including a challengingly small damage level demonstrates that the proposed methodology can efficaciously detect and quantify damage under noisy ambient vibrations.

• 응용통계연구
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• 제5권2호
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• pp.283-292
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• 1992

개인용 컴퓨터의 보급이 급격히 늘어남에 따라 자료의 통계분석에 개인용 컴퓨터가 많이 이용되고 있다. 컴퓨터의 하드웨어가 하루가 다르게 발전하고 있음으로 웬만큼 많은 양의 자료를 분석하는 데에는 컴퓨터의 기억용량이나 처리속도등이 문제되지는 않는다. 자료가 축차적(sequentially)으로 주어질 때 어떤 통계량을 계산하기 위하여 매번 전체 자료를 다시 읽어야 한다면 이는 번거로운 작업이 될 것이며 기억용량의 낭비임에 틀림없다. 이러한 문제점을 S/W 적인 입장에서 해결하고자 하는 노력이 바로 갱신 알고리즘(Updating Algorithm)이다. 이 연구에서는 몇가지 통계량에 대한 갱신 알고리즘들을 알아보고 그들의 특성을 밝힘으로써 소형 및 개인용 컴퓨터를 이용하여서도 많은 양의 자료분석이 가능하도록 하고자 한다.