• 한국연초학회지
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• 제22권2호
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• pp.151-156
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• 2000

The variability of a ventilated filter cigarette depends on the details of its construction and on the variabilities of its components. Variations in filter ventilation arise from many sources, including variations in tobacco rod pressure drop, filter tip pressure drop, tipping paper permeability, and plugwrap permeability. To reduce the filter ventilation variability, the variability of filter ventilation levels in ventilated cigarettes is studied by Monte Carlo Analysis. For each trials a value is selected for tobacco rod pressure drop, filter tip pressure drop, tipping paper permeability, and plugwrap permeability. These values are selected randomly from a normal distribution based on the target and coefficient of variation for each input variable. The results of this analysis for filter ventilation variation suggest that the variations of filter ventilation are dependent on the details of cigarette designs studied and reducing the variability of any cigarette component will reduce filter ventilation variability. For typical cigarettes, variation in the permeability of tipping paper is usually the most significant contributor to filter ventilation variability. Results of a Monte Carlo Analysis could provide both general insights and specific practical guidance about the design of ventilated filter cigarettes.

• 대한한의진단학회지
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• 제12권2호
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• pp.84-95
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• 2008

Background and purpose: Health is characterized by variability and a loss variability is associated with aging and disease. Normal healthy respiratory patterns are characterized by breath to breath variability. The aim of this study is to analyze Correlation Analysis of 10 respiratory indices(include breath to breath variability) and K-POMS factors score. Method: Respiratory data were measured during 15 minutes and transferred to text file. We calculated 10 respiratory parameters in use of MATLAB7.1. After then do correlation analysis of 10 respiratory indices and K-POMS factors score. Result and conclusion: Respiratory variability is showed significant correlation with vigor factor. Respiratory rate is showed significant correlation with depression factor.

• 대한한의진단학회지
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• 제12권2호
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• pp.74-83
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• 2008

Background and purpose : Health is characterized by variability, and the loss of variability is associated with aging and disease. Normal healthy respiratory patterns are characterized by breath to breath variability. Cold-Heat scores are quantified indices in Korean Medicine. The aim of this study is to analyze relations between 9 respiratory indices (including breath to breath variability) and HRV(heart rate variability). Method : Respiratory data were measured during a period of 15 minutes and transferred to text file. We calculated 9 respiratory parameters using MATLAB 7.1. Afterwards we did correlation analysis of the 9 respiratory indices and HRV. Results and conclusion : Respiratory variability showed significant correlation with HRV.

• 전기학회논문지
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• 제65권7호
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• pp.1247-1251
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• 2016

This study aims to investigate the effect of sampling frequency to the time domain and frequency domain analysis of pulse rate variability (PRV). Typical time domain variables - AVNN, SDNN, SDSD, RMSSD, NN50 count and pNN50 - and frequency domain variables - VLF, LF, HF, LF/HF, Total Power, nLF and nHF - were derived from 7 down-sampled (250 Hz, 100 Hz, 50 Hz, 25 Hz, 20 Hz, 15 Hz, 10 Hz) PRVs and compared with the result of heart rate variability of 10 kHz-sampled electrocardiogram. Result showed that every variable of time domain analysis of PRV was significant at 25 Hz or higher sampling frequency. Also, in frequency domain analysis, every variable of PRV was significant at 15 Hz or higher sampling frequency.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.479-482
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• 2004

This paper proposes a new framework for variability analysis in QFD. The proposed framework considers the uncertainty of the information contained in the house of quality chart and analyzes the variability resulting in the outcome. A new framework provides a dominance index and a difference index for each pairwise ECs. The indices are helpful to evaluate priorities of each pairwise EC.

• 한국운동역학회지
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• 제18권4호
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• pp.49-57
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• 2008

이 연구는 고령자를 대상으로 탄성저항운동을 수행하였을 경우 운동 전 후로 보행 시 지면반력 신호 크기와 이들의 variability에 어떠한 영향을 미치는 가를 구명하고자 하였다. 이를 위하여 여성 고령자 12명을 대상으로 12주간 탄성저항운동을 실시하였으며, 운동 전 후로 보행 시 3방향 지면반력 신호의 주파수 크기와 variability 값을 산출하였다. FFT(fast Fourier transform)를 이용하여 주파수 분석을 하였으며, PSD(power spectral density)를 계산하였다. 총 대상자들의 변이 계수(SD/Mean*100)을 이용하여 집단 간 variability를 계산하였다. 그 결과 다음과 같은 결론을 얻었다. 지면반력 신호의 주파수 크기는 좌우 방향에서 운동 전보다 운동 후에 작은 값을 보였으며, 통계적으로도 유의한 차이(p<.05)가 나타났다. 지면반력 신호의 variability에서는 좌우 방향에서 운동 전보다 운동 후에 큰 값이 나타났으며, 통계적으로도 유의한 차이(p<.05)가 나타났다.

• 수산경영론집
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• 제48권2호
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• pp.1-17
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• 2017

This work studies the variability of flatfish sales revenue. The theoretical analysis draws functions for equilibrium price and quantity using expectation hypotheses. The functions include unpredictable phenomenon with dummy variable and GARCH. The equilibrium function, using adaptive expectation hypothesis, contains the independent variables of supply and demand, while the equilibrium function, embodying rational expectation hypothesis, includes only the independent variables of supply side, because the demand side disappears by the information extraction process theoretically, if economic subjects build the expectation rational. The empirical analysis shows: the variability of flatfish production has a spillover effect on the variability of revenue with the adaptive expectation hypothesis. In the case when the model has a rational expectation hypothesis, the variability of flatfish production has a spillover effect on the revenue (the mean equation of GARCH model). This study indicates that there is the variability in flatfish production and sales revenue, and the spillover effect between them. The result can help to build of the rational system for the fishery income stability.

• 한국운동역학회지
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• 제17권4호
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• pp.1-8
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• 2007

The purpose of this study was to investigate the difference in the stride-to-stride variability between two treadmill conditions; traditional treadmill and special treadmill whose speed can be adjusted automatically by subject's walking speed. Eight male subjects (25.1 years, 172.7 cm, 66.6 kg) were participated in treadmill walking experiment. First, preferred walking speed (PWS) of each subject was determined. Second, each subject performed walking experiment with fixed PWS condition and with free PWS condition for 10 minutes. 3D motion capture system (Motion analysis Corp., USA) with 6 cameras was used to collect motion data with sampling frequency of 120Hz. Temporal and spatial variables for stride-to-stride variability were calculated. Coefficient of variance (CV) which quantifies the amount of variability and Detrended Fluctuation Analysis (DFA) which explains the structure (self-similarity) of the variability were used for analysis. Results showed that the amount of variability during free PWS condition was greater than that of fixed PWS condition. DFA results showed that there was a statistical difference between two treadmill conditions for the variables of step length, stance time, and double support time. From these results, it is possible that traditional treadmill study might give incorrect conclusion about gait variability study. Further study is necessary to clarify these matters by considering the number of subjects, experimental time, and gait variables for the study of stride-to-stride variability.

• 정보처리학회논문지D
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• 제16D권6호
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• pp.927-934
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• 2009

본 논문에서는 UML CASE 도구 프레임워크 구축에 이용할 수 있는 공통성 및 가변성 분석 기법을 제안하고자 한다. 공통성 및 가변성 분석은 동일 도메인에서 어플리케이션 특성에 따라 변할 수 있는 영역과 변하지 않는 영역을 구분함으로써 확장과 재사용성을 향상시킬 수 있는 방법이다. 공통성 및 가변성 분석 기법으로 클래스에 기반한 분류기법을 제안하였으며, 이를 명시적으로 나타낼 수 있는 표기법을 제시하였다. 또한 분석 기법을 바탕으로 프레임워크를 구현하였으며, 결함 제거 효율성을 이용해 분석 기법의 검증을 수행하였다.

• 한국농공학회논문집
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• 제54권3호
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• pp.55-63
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• 2012

Soil properties are not random values which is represented by mean and standard deviation but show spatial correlation. Especially, soils are highly variable in their properties and rarely homogeneous. Thus, the accuracy and reliability of probabilistic analysis results is decreased when using only one random variable as design parameter. In this paper, to consider spatial variability of soil property, one-dimensional random fields of coefficient of consolidation ($C_v$) were generated based on a Karhunen-Loeve expansion. A Latin hypercube Monte Calro simulation coupled with finite difference method for Terzaghi's one dimensional consolidation theory was then used to probabilistic analysis. The results show that the failure probability is smaller when consider spatial variability of $C_v$ than not considered and the failure probability increased when the autocorrelation distance increased. Thus, the uncertainty of soil can be overestimated when spatial variability of soil property is not considered, and therefore, to perform a more accurate probabilistic analysis, spatial variability of soil property needed to be considered.