• The Journal of the Acoustical Society of Korea
• /
• v.32 no.2
• /
• pp.131-137
• /
• 2013

In this paper we propose an improved voice activity detection (VAD) algorithm using statistical models in the signal subspace domain. A uncorrelated signal subspace is generated using embedded prewhitening technique and the statistical characteristics of the noisy speech and noise are investigated in this domain. According to the characteristics of the signals in the signal subspace, a new statistical VAD method using GGD (Generalized Gaussian Distribution) is proposed. Experimental results show that the proposed GGD-based approach outperforms the Gaussian-based signal subspace method at 0-15 dB SNR simulation conditions.

• Journal of Navigation and Port Research
• /
• v.32 no.3
• /
• pp.207-213
• /
• 2008

Ship-handling simulation system has been used for maritime traffic safety assessment for harbor and fairway. There exist various environmental conditions under which ship may navigate along a fairway or in harbor. Due to the time and budget limitations, however, ship-handling simulations are usually carried out for very limited number of environmental conditions. In this paper, statistical method for effective and systematic determination of real time simulation conditions is suggested and applied to the maritime traffic safety assessment problems. In the empirical study, the principal component analysis method and the concept of empirical cumulative distribution function are suggested to estimate synthetic navigational difficulty and to select simulation conditions which would impose high difficulty on shiphandling.

• Journal of the Korea Society for Simulation
• /
• v.21 no.3
• /
• pp.11-16
• /
• 2012

Simulation is the imitation of the operation of a real-world process or system over time. It concerns the study of the operating characteristics of real systems. Typically, a simulation project consists of several steps such as data collection, coding, model verification, model validation, experimental design, output data analysis, and implementation. Among these steps of a simulation study this paper focus on statistical analysis methods of simulation output data. Specially, we explain how to develop confidence interval estimators for mean ${\mu}$ in terminating and non-terminating simulation cases. We, then, explore the estimation techniques for $f({\mu})$, where the function $f({\bullet})$ is a nonlinear that is continuously differentiable in a neighborhood of ${\mu}$ with $f'({\mu}){\neq}0$.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.12
• /
• pp.31-36
• /
• 2007

This paper presents a novel statistical characterization for accurate timing analysis in Partially-Depleted Silicon-On-Insulator (PD-SOI) circuits in BSIMSOI3.2 100nm technology. The proposed timing estimate algorithm is implemented in Matlab, Hspice, and C, and it is applied to ISCAS85 benchmarks. The results show that the error is within 5% compared with Monte Carlo simulation results.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.2
• /
• pp.211-219
• /
• 2000

This paper simulated surface grinding process with statistically simulated grinding wheel topography, considering ridge formation phenomenon when grain scratch workpiece. Wheel grain is modeled as hybrid sphere and cone. Grinding wheel characteristic was evaluated with stylus by expanding the scanning region of the profilometer from a straight line to a plane. Each grain's diameter and semi-angle are assumed as normal distribution, each grain's protrusion height from wheel plane is assumed gamma distribution. So grinding wheel is simulated with grain's position randomly distributed without overlapping. Ground surface is 3-dimensionally simulated considering ridge formation of workpiece by each grain's cutting, and then surface profile and surface roughness parameters are compared with real ground workpiece.

• Proceedings of the Korean Statistical Society Conference
• /
• 2004.11a
• /
• pp.117-121
• /
• 2004

분석용 정밀 워게임 시뮬레이션 모형에서는 '모형운영 결과와 실제(또는 실험) 결과를 비교' 하는 통상적인 타당성 척도의 적용이 불가능함에 따라 워게임모형 운영환경에 적합한 새로운 개념의 타당성 척도로서 VEA(Validity for Exploratory Analysis), VSA(Validity subject to Assumption) 등의 개념을 도입하고 이를 탐색적으로 점검하는 방안을 제시한다. 분석용 워게임모형 활용에 있어 또 하나의 걸림돌은 1)시나리오 및 상황의 가변성, 2)무기체계 및 장비 성능에 대한 불확실성, 3)묘사범위 제한 및 논리의 부정확성으로 인한 오류 등으로 엄청난 불확실성(uncertainty)을 기본적으로 내포함에 따라 구체적 의사결정을 위한 종합적 결론 도출이 어렵다는 점이다. 본 연구에서는 이를 메타모델(Meta model) 즉 워게임모형 입출력 자료의 관계를 묘사한 통계적 모형을 구축하고 이를 기반으로 다양한 불확실성 하에서 관심변수간의 관계를 종합적으로 도출하고자 하는 '관련공간모의(Relevant Simulation)' 방안을 제시한다. 이와 같은 방안들은 SVAP(Statistical Validation and Aggregation Procedure)라는 하나의 종합된 절차로서 제시된다.

• Communications of Mathematical Education
• /
• v.12
• /
• pp.265-280
• /
• 2001

고등학교 수학 I 의 확률 및 통계영역의 교육내용을 정리한 후, 고등학생들에게 확률 및 통계영역에 관한 흥미를 돋구기 위하여 2002년 월드컵을 소재로 한 문제들을 활용하여 비주얼 베이직으로 프로그램한 ‘확률상자’ 라는 확률모형을 개발하였다. 확률상자에는 확률의 역사, 경우의 수, 순열, 같은 것이 있는 순열, 원순열, 조합, 이항계수, 통계적 확률, 조건부 확률, 배반사건 등 모두 10가지 모듈을 포함한다. 확률상자의 초기화면에서 메뉴를 선택하면 선택된 내용에 관한 간단한 정의와 함께 문제가 제시되어 정답을 적도록 하였고, 오답일 때는 힌트를 누르면 정답을 이해할 수 있도록 풀이과정을 제시하였다. 특히, 메뉴가운데서 경우의 수, 순열, 같은 것이 있는 순열, 원순열, 조합, 통계적 확률의 경우에는 풀이과정 중에 애니메이션 또는 시뮬레이션이 실행되도록 하여 이해를 돕도록 하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.830-832
• /
• 2014

In this study, friction stick-slip vibration're interpretation of the phenomenon, we used a statistical model of friction. In a previous study using a definite friction factor, but to a dynamic simulation using a constantly changing during the integration time by a Monte Carlo simulation method, not the average coefficient of friction and the dynamic friction coefficient and a constant value in this study.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.23 no.7
• /
• pp.1689-1698
• /
• 1998

In this paper, we present a new method for estimating the parameters of transient-type signal in additive white Gaussian noise. This method makes use of the truncated singular value decomposition of an extended-order auto-correlation-like matrix based on the linear-prediction model. The method is tested on data consisting of two exponentially dampled sinusoidal signals with the same damping factor and different damping factor. Simulation results are illustrated to demonstrate the better performance of the method applied to the auto-correlation-like matrix than that applied to the data matrix.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.1 no.1
• /
• pp.47-55
• /
• 1998

In this paper, authors try to assess the marine traffic environment from the viewpoint of the degree of congestion. First, the marine traffic flow simulation is carried out to get the information related to the assessment. The simulation is performed based on the wide investigation of marine traffic environment and some statistical methods. Then the degree of congestion is reasoned by using the reasoning methods of the degree of collision risk made to develop collision avoidance system. The quantified degree of congestion reasoned by this method provides much information needed to the design and the evaluation of marine traffic environment.