Localized evaluation of actuator tracking for real-time hybrid simulation using frequency-domain indices

Weijie Xu,Tong Guo,Cheng Chen 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.5

Accurate actuator tracking plays an important role in real-time hybrid simulation (RTHS) to ensure accurate and reliable experimental results. Frequency-domain evaluation index (FEI) interprets actuator tracking into amplitude and phase errors thus providing a promising tool for quantitative assessment of real-time hybrid simulation results. Previous applications of FEI successfully evaluated actuator tracking over the entire duration of the tests. In this study, FEI with moving window technique is explored to provide post-experiment localized actuator tracking assessment. Both moving window with and without overlap are investigated through computational simulations. The challenge is discussed for Fourier Transform to satisfy both time domain and frequency resolution for selected length of moving window. The required data window length for accuracy is shown to depend on the natural frequency and structural nonlinearity as well as the ground motion input for both moving windows with and without overlap. Moving window without overlap shows better computational efficiency and has potential for future online evaluation. Moving window with overlap however requires much more computational efforts and is more suitable for post-experiment evaluation. Existing RTHS data from Network Earthquake Engineering Simulation (NEES) is utilized to further demonstrate the effectiveness of the proposed approaches. It is demonstrated that with proper window size, FEI with moving window techniques enable accurate localized evaluation of actuator tracking for real-time hybrid simulation.

Acoustic Analysis with Moving Window in Normal and Pathologic Voices

Choi Seong Hee,Lee JiYeoun Jiang,J. Jack 한국음성학회 2010 말소리와 음성과학 Vol.2 No.3

In this study, the most stable portion was identified using 5% moving window during /a/ sustained phonation in normal and pathologic voice signals and the perturbation values were compared between normal and pathologic voices at the mid-point and at the most stable portion using moving window, respectively. The results revealed that some severe pathologic voice signals can be eligible for perturbation analysis by identifying the most stable portion with Err less than 10. In addition, the perturbation acoustic parameters did not differentiate the pathologic voice signals from the normal voice signals when the mid-point was selected to measure the perturbation analysis(p>0.05). However, significantly higher %shimmer and lower SNR values were observed in pathologic voices (p<0.05) when the most stable portion was selected by moving window. In conclusion, moving window could identify the most stable portion objectively which can allow toget the minimum perturbation values (%jitter, %shimmer) and maximum SNR values. Thus, moving window technique can be applicable for more reliable and accurate perturbation acoustic analysis.

Moving Window 기반 굴삭기용 과부하 검출 알고리즘

유창호(Chang Ho Yu),최재원(Jae Weon Choi),서영봉(Young Bong Seo) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

In this paper, an overload detecting algorithm for an excavator is presented. The proposed overload detecting algorithm is based on the time series analysis especially moving window. The main purpose of this paper is to prevent a damage or crack from the fatigue in advance. 16 channel sensors data are considered and maximum stress is computed by a sensor fusion method every moving window. After the maximum stress every window is compared with a given threshold, this overload detecting algorithm decides overload or not.

Moving Window를 이용한 굴삭기용 과부하 검출 알고리즘

유창호(Chang Ho Yu),최재원(Jae Weon Choi),서영봉(Young Bong Seo) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.6

In this paper, an overload detecting algorithm for an excavator is presented. The proposed overload detecting algorithm is based on the time series analysis especially moving window. The main purpose of this paper is to prevent a damage or crack from the fatigue in advance. 16 channel sensors data are considered and maximum stress is computed by a sensor fusion method every moving window. After the maximum stress every window is compared with a given threshold, this overload detecting algorithm decides overload or not.

새로운 CAM-shift 알고리즘을 이용한 이동 객체 추적

오현경(Hyun Kyung Oh),주영훈(Young Hoon Joo) 대한전기학회 2019 전기학회논문지 Vol.68 No.12

In this paper, we propose an algorithm that controls the expansion of the search window due to similar color background and moving objects, which is a disadvantage of CAM-shift. The proposed method designates the moving object to be tracked by using the search window designation method of the existing CAM-shift, extracts the feature points of the moving object by dividing the upper body and the lower body inside the designated search window, and finds the histogram. The feature points extracted from the upper and lower bodies are compared with the pixels of the histogram to determine the final feature points of the object by dividing the upper and lower bodies. Finally, we apply the RANSAC algorithm to find the histogram average of the extracted feature points and create a new search window. and constantly updates new search windows to keep track of objects. Finally, several experiments demonstrate the feasibility and applicability of the proposed method.

한국 자동차 시장 내 주요 기업간 다집단 경쟁 다이나믹스 모델링 및 분석

송영한,김영,정기선,김윤배 한국시뮬레이션학회 2020 한국시뮬레이션학회 논문지 Vol.29 No.4

Since the European Union–South Korea Free Trade Agreement entered into force in 2011, the Korean automobile market has grown rapidly, resulting in intensifying competition among companies in the market. European automakers gained price competitiveness, which intensified competition with Korean automakers. In such a situation, various studies on the Korean automobile market have been conducted, but studies such as market influencing factor analysis and consumer analysis have mainly been conducted, and there is no research on the analysis of competitive dynamics in the market. In this study, the competitive dynamics between Hyundai Motors, Kia Motors, Mercedes- Benz, and BMW, which are major automakers in the Korean automobile market, are analyzed. The competitive relationship between major automakers are modeled using the Lotka-Volterra (LV) model and the competitive dynamics over time are analyzed by applying the Moving Window. In order to explain the competitive dynamics effectively, we analyze it by subdividing it based on various influencing factors. 2011년 한-EU 자유무역협정 발효 이후, 한국 자동차 시장은 급성장하였으며 시장 내 기업 간 경쟁 양상은 심화되고 있다. 유럽산 자동차 기업은 가격 경쟁력을 보유하게 되었고, 이로 인해 한국 자동차 기업과의 경쟁이 격화되었다. 이와 같은 상황 속에서 한국 자동차 시장에 관한 다양한 연구가 수행되어왔으나, 시장 영향요인 분석과 소비자 분석 등의 연구가 주를 이루었고 시장 내 경쟁 다이나믹스 분석에 관한 연구는 전무한 상황이다. 본 연구에서는 한국 자동차 시장 내 주요 기업인 현대자동차, 기아자동차, 메르세데스-벤츠, BMW의 경쟁 다이나믹스를 분석하였다. Lotka-Volterra(LV) 모형을 사용하여 주요 기업들의 경쟁 관계를 모델링하였고, Moving Window 기법을 적용하여 시간의 흐름에 따른 기업 간 경쟁 다이나믹스를 분석하고 이를 정량적으로 도출하였다. 효과적인 해석을 위해, 도출된 경쟁 다이나믹스는 다양한 영향요인을 바탕으로 세분화되어 분석하였다.

TRIGGER ALGORITHM OF VEHICLE AUTOMATIC CRASH NOTIFICATION SYSTEM

W. XIAO,Z. LI,W. CHEN,Y. LU,H. JIANG 한국자동차공학회 2016 International journal of automotive technology Vol.17 No.2

The Automatic Crash Notification (ACN) system is an effective technology to decrease the crash response time, improve the level of post-accident rescue and alleviate the severity of injuries. To realize this system, a vehicle terminal is developed. And based on a moving window integral algorithm, the trigger algorithm of ACN system is designed. By comparing the effect of different window widths on the trigger algorithm, we select the window width of the moving window integral algorithm as 8 ms. After system is triggered, different notify types was determined according to the change of velocity in the moving window. A sled impact simulation test shows that the impact can be identified rapidly and also the notify types can be judged by the trigger algorithm. A vehicle road test proves that the ACN system has no false trigger cases. The outcomes of this study support identifications of accidents and crash severities for both occupants and emergency centers.

우리글 읽기에서 지각 폭 연구

최소영(Soyoung Choi),고성룡(Sungyrong Koh) 한국인지과학회 2009 인지과학 Vol.20 No.4

이 연구에서는 McConkie와 Rayner(1975)에서 소개된 움직이는-창(moving-window) 방법으로 우리글읽기에서 지각 폭, 즉 한 고정에서 유용한 정보가 추출되는 범위에 대해 알아보았다. 실험 1에서는 창의 크기를 좌우 대칭인 3, 5, 7, 9, 11, 13, 15자로 조작하여 창이 없는 통제 조건과 수행을 비교했다. 분당 읽을 수 있는 어절의 수(읽기율)를 비교했을 때는 15자 조건은 통제 조건과 수행차이가 없었으나, 나머지 다른 조건들은 통제 조건보다 수행이 저조했다. 고정의 수에서는 15자 조건과 통제 조건은 차이가 없었고, 13자 조건은 통제 조건보다 고정의 수가 많은 경향을 보였고, 다른 조건들은 통제 조건보다 많았다. 빈칸을 한 자로 취급한 글자 도약 거리에서는 결과는 읽기율에서와 같았고, 화소에 기초한 화소 도약 거리에서는 결과 양상이 고정의 수에서와 동일했다. 고정시간에서도 다른 결과들과 비슷했는데, 15자, 13자 및 11자 조건들은 차이가 없었고, 9자 조건들은 통제 조건보다 짧은 경향을 보였으며, 나머지 다른 조건들은 통제 조건보다 대체로 짧았다. 실험 2에서는 지각 폭의 비대칭성을 알아보기 위해 고정 좌측의 창 크기를 0, 1, 2, 3, 4자로 조작하였다. 그 결과, 읽기율, 고정 수, 고정 시간 등에서 1자 조건만 통제 조건과 차이가 나타났고 도약 거리는 조건별로 차이가 나지 않았다. 이 연구에서는 우리글 읽기에서 처음으로 지각 폭의 크기를 여러 지표에서 나타나는 왼쪽으로 1자, 오른쪽으로 6-7자로 추정했다. The present study investigated the perceptual span during reading Korean, using the moving-window display change technique introduced by McConkie and Rayner(1975). Eight different window sizes were used in Experiment 1. They were 3, 5, 7, 9, 11, 13, 15 characters in size and the full line. Reading rate, number of fixation, saccadic distance, fixation duration were compared between each window-size condition and the full line condition. The reading rate was no higher in the full line condition than in the 15 character condition but was higher than in the other conditions. The number of fixations was no larger in the full line condition than in the 15 character condition, had a tendency to be larger than in the 13 characters condition, and was more than in the other conditions. The result pattern of the saccadic distance based on character was the same as that of the reading rate, and the saccadic distance based on the pixel was the same as that of the number of fixation. Similarly, for fixation duration, there was no differences between whole line condition and 15, 13, and 11 characters condition. The fixation duration had a tendency to be shorter in the 9 characters, and was shorter in the 7, 5, and 3 characters conditions than whole line condition. In Experiment 2, based on asymmetry of perceptual span, the 6 different window sizes(0, 1, 2, 3, 4 characters in size and the full line) were used. There was a difference only between the 0 condition and the other conditions in the reading rate, number of fixations, fixation duration. Considering the pattern of eye-movement measures above, the perceptual span of Korean readers extends about 6-7 characters to the right of fixation and 1 character to the left of fixation.

움직이는 창을 이용한 고성능 무손실 데이터 삽입 방법

강지홍(Jihong Kang),Honglin Jin(Honglin Jin),최윤식(Yoonsik Choe) 한국방송·미디어공학회 2011 방송공학회논문지 Vol.16 No.5

This paper proposes a new lossless data embedding algorithm on spatial domain of digital images. A single key parameter is required to embed and extract data in the algorithm instead of embedding any additional information such as the location map. 3×3 window slides over the cover image by one pixel unit, and one bit can be embedded at each position of the window. So, the ideal embedding capacity equals to the number of pixels in an image. For further increase of embedding capacity, new weight parameters for the estimation of embedding target pixels have been used. As a result, significant increase in embedding capacity and better quality of the message-embedded image in high capacity embedding have been achieved. This algorithm is verified with simulations.

일반화 극단치분포에 기초한 태풍 최량진로자료에 대한 재현수준 추정

손건태,Xianglong Liang 한국자료분석학회 2014 Journal of the Korean Data Analysis Society Vol.16 No.3

본 연구에서는 비상구역을 통과한 태풍의 연간빈도와 최대풍속에 대하여 일반화 극단치분포를 적합하고, 추정된 분포를 바탕으로 추정된 재현수준의 동적 특성을 조사하였다. 연구를 위하여 RSMC-Tokyo에서 제공하는 최량진로자료를 사용하였다. 해당 시계열에 대하여 자기상관성 검정을 수행하고, 일반화 극단치분포에 대한 적합도 검정을 수행하였다. 모수에 대한 최대가능도추정량을 산출한 후 재현수준을 추정하였다. 두 인자에 대하여 일반화 극단치분포가 잘 적합되었다. 분포의 동적변화를 알아보기 위하여 30년 이동창 방법을 사용하였으며, 변화에 따른 재현수준의 동적변화를 조사하였다. 태풍 빈도의 재현수준은 감소하고 있는 것으로 나타났다. 최대풍속 경우 30년 이동창에서는 검벨형 일반화 극단치분포가 적합한 것으로 나타났으며 30년 이동창 방법으로 추정된 재현수준은 초기에 증가하다가 안정적으로 변화된 것으로 나타났다. 재현수준의 동적변화가 있는 경우 최근 30년 자료를 사용하여 추정된 재현수준을 사용할 것을 제안한다. The objectives of present study are to apply an generalized extreme value distribution (GEVD) to two climatic factors, annual frequency and wind speed of typhoons which pass over the emergency area, and to examine the dynamic pattern of parameters in GEVD and return levels. For this study, the best track data offered by RSMC-Tokyo are used. According to autocorrelation test and goodness-of-fit test, GEVD fits well to two factors. Return levels are generated from the estimated GEVD. Dynamic characteristics of parameters in GEVD and return levels are examined based on 30-year moving-window method. Return levels for annual typhoon frequency are slowly decreasing and those for maximum wind speed seem to be stable.