• Title/Summary/Keyword: Variance of Analysis

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Study on threshold values of a intensity-of-congestion measure for operations evaluation at signalized intersections based on traffic flow information (교통소통 정보기반 신호교차로 운영평가를 위한 혼잡강도 지표 임계값 연구)

  • Kim, Jin-Tae;Cho, Yongbin
    • International Journal of Highway Engineering
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    • v.20 no.3
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    • pp.85-92
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    • 2018
  • PURPOSES : In this study, analyze the characteristics of IOC indicator 'threshold' which is needed when evaluating the traffic signal operation status with ESPRESSO in various grade road traffic environment of Seoul metropolitan city and derive suggested value to use in field practice. METHODS : Using the computerized database program (Postgresql), we extracted data with regional characteristics (Arterial, Collector road) and temporal characteristics (peak hour, non-peak hour). Analysis of variance and Duncan's validation were performed using statistical analysis program (SPSS) to confirm whether the extracted data contains statistical significance. RESULTS : The analysis period of the main and secondary arterial roads was confirmed to be suitable from 14 days to 60 days. For the arterial, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 25 km/h as the critical speed for AM peak hour and night non peak hour. As for the collector road, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 30 km/h as the critical speed for AM peak hour and night non peak hour. CONCLUSIONS : It is meaningful from a methodological point of view that it is possible to make a reasonable comparative analysis on the signal intersection pre-post analysis when the signal operation DB is renewed by breaking the existing traffic signal operation evaluation method.

A Comparative Study on the Competitiveness of the Alignment Zones in the Capital Area (수도권 정비 권역별 입지 경쟁력 비교 연구)

  • Kim, Dong-Yoon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.3
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    • pp.79-88
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    • 2011
  • In the context of sustainability which is understood as equilibrium among three elements; human, space and time, the imbalance within the Seoul metropolitan area hinders its own area or the nation from development. Claims for the balanced development in the area are set up on the premise that there is a locational order of priority among the zones named 'overpopulation suppression', 'growth management' and 'conservation'. Based on the systematic consideration of competitiveness this study adopts the premise as a research hypothesis. Factor scales derived from the factor analysis, a kind of multivariate dependence analysis play an important role in this research process since they are measured by interval-ratio level and can be used for dependent variables in the statistical analysis. The hypothesis test carried out by means of the analysis of variance(ANOVA) concludes that the hypothesis assuming no difference in the competitiveness is rejected but the alternative hypothesis of the locational order mentioned above should be adjusted. Eigenvalues derived from the factor analysis could be used as weights for aggregate factor scales and the scales show that the priority is in the order of growth management - overpopulation suppression - conservation zones. This finding has also a significant implication that the countermeasures to cope with the lowering of the competitiveness resulted from the continuous and absolute restraints should be provided. And strategic approaches which are composed of key factors for each zone are deducted from in-depth review. (1) overpopulation suppression zone; health-welfare, educational base, public service factors, focusing on health-welfare one, (2) growth management zone; public service factor and (3) conservation zone; health-welfare, educational base factors, also focusing on health-welfare one.

Pareto Analysis of Experimental Data by L18(2 X 37) Orthogonal Array (L18(2 X 37) 직교배열표 실험자료에 대한 파레토 그림 분석)

  • 임용빈
    • The Korean Journal of Applied Statistics
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    • v.17 no.3
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    • pp.499-505
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    • 2004
  • The Pareto diagram analysis of the experimental data by the two level orthogonal arrays has been used widely in practice since it is a graphical, quick and easy method to analyze experimental results, which does not use the analysis of variance to screen significant effects. For the analysis of the experimental data by $L_{18}(2 \times 3^7)$ orthogonal array, Park(1996) proposed Pareto ANOVA in which the size of effects is defined by the mean squares of effects and the Pareto principle is used. In this paper, a new approach of the Pareto diagram analysis of the experimental data by $L_{18}(2 \times 3^7)$ orthogonal array is proposed. The main idea is to partition the size of three level effects by that of linear and quadratic orthogonal contrasts of those effects.

A Study on the Effect of the Archivist's Expert Power on the Job Engagement and Job Satisfaction of Record Management Personnel (기록물관리 전문요원의 전문적 영향력이 기록관리 담당자의 직무몰입과 직무만족에 미치는 영향에 관한 연구)

  • Kim, Seok-Joon;Kim, Ji-Hyun
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.29 no.4
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    • pp.161-178
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    • 2018
  • The purpose of this study is to explore how the Expert Power of archivists has influence on the job engagement and job satisfaction of record management personnel. The data were collected by survey with 103 record management personnel of office of education in Gwangju from September 2017 to October 2017. To analyze the research data, this study adopted several statistical analysis methods such as factor analysis, reliability analysis, correlation analysis, multiple regression analysis, independent sample T-test, and one-way analysis of variance. Results revealed that professionalism and influence tactics among professionalism, influence tactics, influence requirement be to the archivists Expert Power factors affect the job engagement and job satisfaction of record management personnel. Based on the results of the research, this study suggested the extension of educational training about record management and communication with record mangement personnel.

Effects of Ultra-high Pressure Homogenization on the Emulsifying Properties of Whey Protein Isolates under Various pH

  • Lee, Sang-Ho;Subirade, Muriel;Paquin, Paul
    • Food Science and Biotechnology
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    • v.17 no.2
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    • pp.324-329
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    • 2008
  • The effect of ultra-high pressure homogenization on the emulsifying properties of whey protein was investigated in a model emulsion made with whey protein isolate and soya oil under various pH. The emulsifying properties, the average diameter of the oil droplets ($d_{vs}$), and the protein load, were measured for each emulsion produced at different homogenization pressures (50 to 200 MPa) and pH values (4.6 to 8.0). According to the results of variance analysis and response surface, the pH had more influence on oil droplet size and protein load than homogenization pressure. The model equations, which were obtained by response surface analysis, show that pH and homogenization pressure had the major effect on oil droplet size and protein load. Higher homogenization pressure decreased the average droplet size and the protein load. Homogenization at high pressure, as opposed to low pressure, causes no overprocessing, but the effect was pH-dependent. The average diameter of the oil droplets increased slightly by decreasing the pH from 8.0 to 6.5 and then increased dramatically toward the isoelectric point of whey protein (i.e., at pH 4.6). Moreover associated droplets were found at acidic pH and their size was increased at high temperature.

Relationship of Illness Perception, Self-efficacy, and Self-care among Pulmonary Tuberculosis Patients (폐결핵 환자의 질병지각, 자기효능감과 자가간호 행위와의 관계연구)

  • Seong, Yeon-Sil;Lee, Young-Whee
    • Korean Journal of Adult Nursing
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    • v.23 no.1
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    • pp.31-39
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    • 2011
  • Purpose: A descriptive study was conducted to examine the relationship of illness perception, self-efficacy, and self-care of patients who were diagnosed pulmonary tuberculosis. Methods: The study was conducted using a convenient sample from two hospitals in Incheon and Seoul. One hundred forty four patients completed a questionnaire which included questions on general characteristics, a Brief Illness Perception Scale, a Self-efficacy Scale and a Self-care Scale. Data were analyzed by using descriptive statistics, t-test, ANOVA, Pearson Moment Correlations and stepwise multiple regression analysis. Results: There was a statistically significant positive correlation between illness perception and self-care (r=.335, p=.000) and between self-efficacy and self-care (r=.687, p=.000). Stepwise multiple regression analysis revealed that among the three variables the most powerful predictor was self-efficacy. Self-efficacy and illness perception were significant factors and accounted for 54.2% of the variance of self care in pulmonary tuberculosis patients. Conclusion: Self-efficacy and illness perception were influencing factors in self care among patients with pulmonary tuberculosis. Hence further interventional researches are needed that consider these two variables.

Exact Error Rate of Dual-Channel Receiver with Remote Antenna Unit Selection in Multicell Networks

  • Wang, Qing;Liu, Ju;Zheng, Lina;Xiong, Hailiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.8
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    • pp.3585-3601
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    • 2016
  • The error rate performance of circularly distributed antenna system is studied over Nakagami-m fading channels, where a dual-channel receiver is employed for the quadrature phase shift keying signals detection. To mitigate the Co-Channel Interference (CCI) caused by the adjacent cells and to save the transmit power, this work presents remote antenna unit selection transmission based on the best channel quality and the maximized path-loss, respectively. The commonly used Gaussian and Q-function approximation method in which the CCI and the noise are assumed to be Gaussian distributed fails to depict the precise system performance according to the central limit theory. To this end, this work treats the CCI as a random variable with random variance. Since the in-phase and the quadrature components of the CCI are correlated over Nakagami-m fading channels, the dependency between the in-phase and the quadrature components is also considered for the error rate analysis. For the special case of Rayleigh fading in which the dependency between the in-phase and the quadrature components can be ignored, the closed-form error rate expressions are derived. Numerical results validate the accuracy of the theoretical analysis, and a comparison among different transmission schemes is also performed.

A Study on tool life in the high speed machining of small-size end mill by factorial design of experiments and regression model (요인 실험계획법 및 회귀분석을 이용한 소경 엔드밀의 공구수명에 대한 연구)

  • Lim P.;Park S.Y.;Yang G.E.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.993-996
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    • 2005
  • High speed machining(HSM) technique is widely used in the appliance, automobile part and mold industries, which has many advantages such as good quality, low cost and rapid machining time. but it also has problems like tool break, smooth tool path, and so on. In particular, small size end mill is easy to break, so it must be changed before interrupting operation. Generally, the tool life of small size end mill is effected by the milling conditions whose evaluated parameters are spindle, feedrate, and width of cut. The experiments are carried out by full factorial design of experiments using and orthogonal array. This paper shows optimal combination and mathematical model for tool life, and the analysis of variance(ANOVA) is employed to analyze the main effects and the interactions of these milling parameters and the second-order polynomial regression model with three independent variables is estimated to predict tool life by multiple regression analysis.

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Reliability Design using Asymptotic Variance of Inverse Cumulative Distribution Function (분위수의 점근적 분산을 이용한 신뢰성 설계)

  • Cho H.J.;Baek S.H.;Hong S.H.;Cho S.S.;Joo W.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1682-1685
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    • 2005
  • System algorithms estimated by deterministic input may occur the error between predicted and actual output. Especially, actual system can't predict the exact outputs due to uncertainty and tolerance of input parameters. A single output to a set of inputs has a limited value without the variation. Hence, we should consider various scatters caused by the load assessment, material characteristics, stress analysis and manufacturing methods in order to perform the robust design or estimate the reliability of structure. The system design with uncertainty should perform the probabilistic structural optimization with the statistical response and the reliability. This method calculated the probability distributions of the characteristics such as stress by combining stress analysis, response surface methodology and Monte-Carlo Method and got the probabilistic sensitivity. The sensitivity of structural response with respect to inconstant design variables was estimated by fracture probability. Therefore, this paper proposed the probabilistic reliability design method for fracture of uncorved freight end beam and the design criteria by fracture probability.

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Probabilistic Approach for Fatigue Life of Composite Materials with Impact-Induced Damage (충격손상 복합재료의 피로수명에 대한 통계적 해석 연구)

  • Kang, Ki-Weon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3148-3154
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    • 2010
  • This paper presents the probabilistic analysis for fatigue life of Glass/Epoxy laminates with impact-induced damage. For this, a series of impact tests were perfomed on the Glass/Epoxy laminates using instrumented impact testing machine. Then, tensile and fatigue tests carried out so as to generate post-impact residual strength and fatigue life. Two Parameter Weibull distribution was used to fit the residual strength and fatigue life data of Glass/Epoxy composite laminates. The residual strength was affected by impact energy and their variance decreased with increasing of impact energy. The fatigue life of impacted laminates was greatly reduced by impact energy and this trend depended on applied stress amplitude. Additionally, the variation of fatigue life was gradually decreased with the applied stress amplitude.