• Title/Summary/Keyword: Mean Value Reliability Method

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Market Segmentation Based on Types of Motivations to Visit Coffee Shops (커피전문점 방문동기유형에 따른 시장세분화)

  • Lee, Yong-Sook;Kim, Eun-Jung;Park, Heung-Jin
    • The Korean Journal of Franchise Management
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    • v.7 no.1
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    • pp.21-29
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    • 2016
  • Purpose - The primary purpose of this study is to employ effective marketing methods using market segmentation of coffee shops by determining how motivations to visit coffee shops have different impacts on demographic profile of visitors and characteristics of coffee shop visits, so as to draw out a better understanding of customers of coffee market. Research design, data, and methodology - Data were collected using surveys of self-administered questionnaires toward coffee shop users in Daejeon, Korea. A number of samples used in data analysis were 253 excluding unusable responses. The data were analyzed through frequency, reliability, and factor analysis using SPSS 20.0. Factor analysis was conducted through the principal component analysis and varimax rotation method to derive factors of one or more eigen values. In addition, the cluster analysis, multivariate ANOVA, and cross-tab analysis were used for the market segmentation based on the types of motivation for coffee shop visits. The process of the cluster analysis is as follows. Four clusters were derived through hierarchical clustering, and k-means cluster analysis was then carried out using mean value of the four clusters as the initial seed value. Result - The factor analysis delineated four dimensions of motivation to visit coffee shops: ostentation motivation, hedonic motivation, esthetic motivation, utility motivation. The cluster analysis yielded four clusters: utility and esthetic seekers, hedonic seekers, utility seekers, ostentation seekers. In order to further specify the profile of four clusters, each cluster was cross tabulated with socio-demographics and characteristics of coffee shop visits. Four clusters are significantly different from each other by four types of motivations for coffee shop visits. Conclusions - This study has empirically examined the difference in demographic profile of visitors and characteristics of coffee shop visits by motivation to visit coffee shops. There are significant differences according to age, education background, marital status, occupation and monthly income. In addition, coffee shops use pattern characterization in frequency of visits to coffee shops, relationships with companion, purpose of visit, information sources, brand type, average expense per visit, important elements of selection attribute were significantly different depending on motivations for coffee shop visits.

The Bone Mineral Density Value According to the Operating Time of the Dual Energy X-ray (이중 에너지 엑스레이 흡수기의 가동 시간에 따른 골밀도 값의 평가)

  • Lee, Hae-Jung;Kim, Ho-Sung;Kim, Eun-Hye
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.40-45
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    • 2010
  • Purpose: Recently, the performance of the X-ray tube was very much improved by the power generation of the technology. However, the overload of equipment is occurred by the increment of the equipment operating time according to the increment of the examination number of cases. The X-ray dose can change by heat occurrence of the X-ray tube due to this. Moreover, the change of the bone mineral density value is possible to occur. Therefore, We tries to whether the change of the bone mineral density value of each equipment according to the difference of the examination number of cases and operating time occur or not. Materials and Methods: The BMD value was measured by the Aluminum Spine Phantom and the European Spine Phantom in each equipment, in order to find out about the difference of the time general classification bone mineral density value by using the Dual energy X-ray absorptiometry. And after scanning each phantom by using X-ray dose meter (Unfors Mult-O-Meter), a dose was measured by the same condition. As to, an average and standard deviation were found and the change of each equipment much BMD value was compared and it evaluated. Results: $Mean{\pm}SD$ of each equipment by using the Aluminum Spine Phantom, A equipment was $1.174{\pm}0.002$, $1.171{\pm}0.005$, $1.173{\pm}0.005$, B equipment was $1.186{\pm}0.003$, $1.187{\pm}0.003$, $1.185{\pm}0.003$, C equipment was $1.180{\pm}0.003$, $1.182{\pm}0.004$, $1.183{\pm}0.002$, D equipment was $1.188{\pm}0.004$, $1.185{\pm}0.003$, $1.185{\pm}0.004$. By using the European Spine Phantom, A equipment was $1.143{\pm}0.006$, $1.153{\pm}0.009$, $1.161{\pm}0.003$, B equipment was $1.134{\pm}0.004$, $1.13{\pm}0.008$, $1.127{\pm}0.015$, C equipment was $1.143{\pm}0.006$, $1.134{\pm}0.01$, $1.133{\pm}0.006$, D equipment was $1.14{\pm}0.001$, $1.122{\pm}0.002$, $1.131{\pm}0.008$, altogether included in the normal range. Conclusion: There was no significant change of the BMD value of using a phantom by time zones. Therefore, if the quality control is made to use the extent management method of the equipment for beginning in the present application, the reliability of the BMD equipment will be able to be enhanced.

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Human Error Probability Determination in Blasting Process of Ore Mine Using a Hybrid of HEART and Best-Worst Methods

  • Aliabadi, Mostafa Mirzaei;Mohammadfam, Iraj;Soltanian, Ali Reza;Najafi, Kamran
    • Safety and Health at Work
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    • v.13 no.3
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    • pp.326-335
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    • 2022
  • Background: One of the important actions for enhancing human reliability in any industry is assessing human error probability (HEP). The HEART technique is a robust tool for calculating HEP in various industries. The traditional HEART has some weaknesses due to expert judgment. For these reasons, a hybrid model is presented in this study to integrate HEART with Best-Worst Method. Materials Method: In this study, the blasting process in an iron ore mine was investigated as a case study. The proposed HEART-BWM was used to increase the sensitivity of APOA calculation. Then the HEP was calculated using conventional HEART formula. A consistency ratio was calculated using BWM. Finally, for verification of the HEART-BWM, HEP calculation was done by traditional HEART and HEART-BWM. Results: In the view of determined HEPs, the results showed that the mean of HEP in the blasting of the iron ore process was 2.57E-01. Checking the full blast of all the holes after the blasting sub-task was the most dangerous task due to the highest HEP value, and it was found 9.646E-01. On the other side, obtaining a permit to receive and transport materials was the most reliable task, and the HEP was 8.54E-04. Conclusion: The results showed a good consistency for the proposed technique. Comparing the two techniques confirmed that the BWM makes the traditional HEART faster and more reliable by performing the basic comparisons.

Stochastic fracture behavior analysis of infinite plates with a separate crack and a hole under tensile loading

  • Khubi Lal Khatri;Kanif Markad
    • Computers and Concrete
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    • v.32 no.1
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    • pp.99-117
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    • 2023
  • The crack under the influence of the higher intensities of the stresses grows and the structure gets collapsed with the time when the crack length reaches to critical value. Therefore, the fracture behavior of a structure in terms of stress intensity factors (SIF) becomes important to determine the remaining fracture strength and capacity of material and structure for avoiding catastrophic failure, increasing safety and further improvement in the design. The robustness of the method has been demonstrated by comparing the numerical results with analytical and experimental results of some problems. XFEM is used to model cracks and holes in structures and predict their strength and reliability under service conditions. Further, XFEM is extended with a stochastic method for predicting the sensitivity in terms of output COVs and fracture strength in terms of mean values of stress intensity factors (SIFs) of a structure with discontinuities (cracks and holes) under tensile loading condition with input individual and combined randomness in different system parameters. In stochastic technique, the second order perturbation technique (SOPT) has been used for the predicting the fracture behavior of the structures. The stochastic/perturbation technique is also known as Taylor series expansion method and it provides the reliable results if the input randomness is less than twenty percentage. From the present numerical analysis it is observed that, the crack tip near to the hole is under the influence of the stress concentration and the variational effect of the input random parameters on the crack tip in terms of the SIFs are lesser so the COVs are the less sensitive. The COVs of mixed mode SIFs are the most sensitive for the crack angles (α=45° to 90°) for all the values of c1 and d1. The plate with the shorter distance between hole and crack is the most sensitive with all the crack angles but the crack tip which is much nearer to the hole has the highest sensitivity.

Validation Technique of Simulation Model using Weighted F-measure with Hierarchical X-means (WF-HX) Method (계층적 X-means와 가중 F-measure를 통한 시뮬레이션 모델 검증 기법)

  • Yang, Dae-Gil;HwangBo, Hun;Cheon, Hyun-Jae;Lee, Hong-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.2
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    • pp.562-574
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    • 2012
  • Simulation validation techniques which have been employed in most studies are statistical analysis, which validate a model with mean or variance of throughput and resource utilization as an evaluation object. However, these methods have not been able to ensure the reliability of individual elements of the model well. To overcome the problem, the weighted F-measure method was proposed, but this technique also had some limitations. First, it is difficult to apply the technique to complex system environment with numerous values of interarrival time because it assigns a class to an individual value of interarrival time. In addition, due to unbounded weights, the value of weighted F-measure has no lower bound, so it is difficult to determine its threshold. Therefore, this paper propose weighted F-measure technique with cluster analysis to solve these problems. The classes for the technique are defined by each cluster, which reduces considerable number of classes and enables to apply the technique to various systems. Moreover, we improved the validation technique in the way of assigning minimum bounded weights without any lack of objectivity.

A Method to Evaluate Rate of 'Soft-Hard' In a Drawing (그림의 '부드러운-딱딱한' 정도의 평가 방법)

  • Yoon, Seok-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.12
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    • pp.3963-3970
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    • 2009
  • This study proposes a method to evaluate the level of 'soft-hard' of color quantitatively by evaluating the shape with edge sharpness automatically and by evaluating color in the color image scale in a drawing in art therapy using a computer. The dependent variable is the rank for the color experts to rate the level of 'soft-hard'. The mean and standard deviation of Value(V), and Chroma(C), colors, main color, clusters, length of edge, and sharp line rate of edge are considered as the independent variable. The appropriate independent variables to explain the dependent variable are selected through the step wise regression analysis. The inter-rater reliability of two raters is checked and the validity of developed system is verified by the rank correlations coefficient between the ranks of rater's and system's. This system can be used to evaluate of the shape or color in a drawing objectively and quantitatively for art therapy assessment, and to give the useful information to the fashion, textile, interior industry as well as color psychology and art therapy.

Rank Decision of Ecological Environment Assessment Field Introducing Fuzzy Integral (퍼지적분을 도입한 생태환경평가부문의 순위결정)

  • You, Ju-Han;Jung, Sung-Gwan;Choi, Won-Young;Lee, Woo-Sung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.5 s.118
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    • pp.39-51
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    • 2006
  • This study was carried out to provide guidance to environmental policy makers when deciding which assessment fields (biotic, abiotic, qualitative, functional) should have priority for ecological preservation and to develop an objective and scientific methodology by introducing the engineering concept of the fuzzy integral. The grant of weights was used the eigenvalues calculated by factor analysis, and the converted values of indicators were obtained in multiplying the arithmetic values and eigenvalues. The results of the appropriateness and reliability of assessment fields were examined over 0.6, and the results showed that the design of questionnaire presented no great problems. When the fuzzy integral was calculated to determine the rankings at ${\lambda}$=1, 2, 3, 4, 5, respectively, they were 0.646, 0.630, 0.943, 1.423, and 1.167 for the biotic field, 1.298, 1.400, 0.901, 0.580, and 1.456 for the abiotic field, 0.714, 0.674, 0.346, 0.674, and 1.610 in the qualitative field and 1.000, 0.973, 0.943, 1.024, and 1.008 in the functional field. The sensitivity to ${\lambda}$ value showed that ${\lambda}=4$ was the most suitable. In comparison with ${\lambda}=0$ (the arithmetic mean), the range of change was narrow. Because the range for ${\lambda}=4$ was narrower than my other values, ${\lambda}=4$ was sure to be available in ranking-decision. The fuzzy integral is expected to be a method for analyzing and filtering human thoughts. In the future, in order to overcome linguistic uncertainty and subjectivity, other fuzzy integral models including Sugeno's method, AHP, and so forth should be used.

A Study on Analyzing the Validity between the Predicted and Measured Concentrations of VOCs in the Atmosphere Using the CalTOX Model (CalTOX 모델에 의한 휘발성유기화합물의 대기 중 예측 농도와 실측 농도간의 타당성 분석에 관한 연구)

  • Kim, Ok;Lee, Minwoo;Park, Sanghyun;Park, Changyoung;Song, Youngho;Kim, Byeongbin;Choi, Jinha;Lee, Jinheon
    • Journal of Environmental Health Sciences
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    • v.46 no.5
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    • pp.576-587
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    • 2020
  • Objectives: This study calculated local residents exposures to VOCs (Volatile Organic Compounds) released into the atmosphere using the CalTOX model and carried out uncertainty analysis and sensitivity analysis. The model validity was analyzed by comparing the predicted and the actual atmospheric concentrations. Methods: Uncertainty was parsed by conducting a Monte Carlo simulation. Sensitivity was dissected with the regression (coefficients) method. The model validity was analyzed by applying r2 (coefficient of determination), RMSE (root mean square error), and the Nash-Sutcliffe EI (efficiency index) formula. Results: Among the concentrations in the atmosphere in this study, benzene was the highest and the lifetime average daily dose of benzene and the average daily dose of xylene were high. In terms of the sensitivity analysis outcome, the source term to air, exposure time, indoors resting (ETri), exposure time, outdoors at home (ETao), yearly average wind speed (v_w), contaminated area in ㎡ (Area), active breathing rate (BRa), resting breathing rate (BRr), exposure time, and active indoors (ETai) were elicited as input variables having great influence upon this model. In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. To supplement this value, the regression formula was derived for benzene with y=0.002+15.48x, ethylbenzene with y ≡ 0.001+57.240x, styrene with y=0.000+42.249x, toluene with y=0.004+91.588x, and xylene with y=0.000+0.007x. Conclusions: In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. This will be able to be used as base data for securing the accuracy and reliability of the model.

Perceptions of eco-friendly young-children's wear and selection criteria for young-children's wear and stores - A comparison of eco-friendly and ordinary children's wear purchasers - (친환경 유아복에 대한 인식이 유아복 구매시의 제품과 점포 선택기준에 미치는 영향 - 친환경 유아복 구매자와 비 구매자 비교 -)

  • Hong, Eun Bee;Hwang, Choon Sup
    • The Research Journal of the Costume Culture
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    • v.20 no.6
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    • pp.895-911
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    • 2012
  • The purpose of this study was to examine consumers' perceptions of eco-friendly children's-wear and their impact on the selection criteria for children's-wear and stores. A descriptive survey method using a self-administered questionnaire was employed. The sample consisted of mothers with children under the age of 13 residing in Seoul and the Gyeonggi area. Data were collected from September 2011 to October, 2011. The collected data were analyzed to find the differences between purchasers and non-purchasers of eco-friendly children's-wear in terms of their perceptions of eco-friendly children's-wear, as well as the influence of these perceptions on the consideration degree of criteria for the selection of children's wear and store. The results indicate that perceptions of eco-friendly children's-wear implied five key factors related to quality reliability, expected value, style, degree of recognition, and dissatisfaction with design and price. The results also revealed some differences between the group purchasing eco-friendly children's-wear and the group not purchasing eco-friendly children's-wear. These different perceptions were related to the aspects of quality reliability, expected value, style, degree of recognition. In general, the non-purchasing group displayed a lower mean score than the purchasing group. Both groups showed a low interest in aesthetic appreciation and the degree of recognition factor. The results showed that consumer's perceptions of eco-friendly children's-wear had an influence on the criteria for the selection of children's-wear and store type in both groups. Considering the findings of the study, it is clear that both purchasers and non-purchasers of eco-friendly children's-wear showed differences in their perceptions and purchasing behavior. Therefore, marketing strategies to appeal to the non-purchasing group should be differentiated from strategies used to ensure the loyalty of the purchasing group.

A Study on the Relation between the Number of First Aid Training and the Performance of Facilities Security Personnel (시설보안요원의 응급처치교육이수와 직무수행 관계에 관한 연구)

  • Kim, Sin-Hye;Han, I-Jun
    • Korean Security Journal
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    • no.59
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    • pp.91-108
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    • 2019
  • The purpose of this study is to investigate the relationship between the number of first aid training and safety performance. The researcher's questionnaire consisted of three variables: necessity of first aid education, application to security practice, and improvement of job satisfaction. In this study, Chronbach's Alpha coefficients were calculated to measure the internal validity for the reliability of the questionnaire. In order to verify the validity of the measured variables, exploratory factor analysis was carried out using the Berimax rotation method. The mean variance extracted AVE and the conceptual reliability CR value of the measurement result variables were both above the allowable reference value of 0.5 and it was judged to be a good test in terms of intensive validity. As a result of the hypothesis test, the standardization coefficient was 1.106 for 'necessity of first aid education ⇒ applied to security practice work', and 'applied to security work practice ⇒ improvement of job satisfaction' was 1.063 and the relationship of hypothesis 1 hypothesis 2 was significant (+), Respectively. Therefore, in order to increase the job satisfaction of security related workers, it is necessary to support first aid education and to receive first aid education.