• 제목/요약/키워드: Mean-Variance Analysis

검색결과 1,106건 처리시간 0.026초

대학생의 쇼핑가치에 따른 신용카드인식 및 신용카드관리행동에 관한 연구 (A Study for the Perception and Management Behaviors on Credit Cards According to the Shopping Value Types of College Students)

  • 서인주
    • 가족자원경영과 정책
    • /
    • 제13권2호
    • /
    • pp.129-151
    • /
    • 2009
  • The first purpose of this study was to reveal the types of shopping value of college students. The second purpose was to examine the change in the perception and management behaviors related to credit cards according to the types of shopping value. The third purpose was to examine the effects of shopping value on perception and management behaviors on credit cards. The data were collected from 392 college students in Seoul by a self-administered questionnaire. Analyses including frequency, mean, factor analysis, Cronbach's alpha, Pearson's correlation analysis, Crosstabulation analysis, analysis of variance, K-means Cluster analysis and Multiple linear regression were conducted using SPSS WIN12.0. The major findings were as follows. First, college students can be categorized into 3 types of shopping values by K-means Cluster analysis of 14 items. The groups were entitled the hedonistic shopping value, the utilitarian shopping value, and the saving shopping value. Second, positive perception and management behaviors related to credit cards were different depending on the types of shopping value. The hedonistic shopping value group had a higher level of positive perception of credit cards and a lower level of credit card management, compared with the other groups. The saving shopping value group had higher levels of both positive perception and management of credit cards. Among the three groups, the utilitarian shopping group had the lowest level of positive perception of credit cards, despite having ahigher level of credit card management. Lastly, the most effective variance on credit card management was the utilitarian shopping value. These results suggest that a healthy shopping value is very important for having a healthy perception and management of credit cards, because shopping value is a critical variance to affect perception and management of credit cards.

  • PDF

임부의 산전애착에 영향을 미치는 변인 (Influencing Factors on Prenatal Attachment)

  • 정영숙
    • 부모자녀건강학회지
    • /
    • 제7권1호
    • /
    • pp.38-49
    • /
    • 2004
  • This study is to investigate the main factors influencing prenatal attachment. The research method is on the basis of descriptive correlational study, and data collecting period was from 11 to 29, November, 2003. The objects of this study were 100 pregnant women of two OBGY Hospitals in Masan. Using the SPSS/WIN 10.1 program the data were analyzed by t-test, ANOVA, Pearson correlation coefficient, stepwise multiple regression analysis. The result of this study was as follows : The mean score of prenatal attachment was 2.64, the mean score of physical discomforts, 1.61, the mean score of husband-wife attachment, 3.28, the mean score of psychosocial adjustment of pregnancy, 1.82. The degree of prenatal attachment according to general characteristics was significantly difference according to religion. The degree of prenatal attachment according to obstetrical characteristics was significantly difference according to Lamaze class, Taekyo. Significant correlations of prenatal attachment was found in both psychosocial adjustment of pregnancy, Taekyo, husband-wife attachment, Lamaze class, religion. Stepwise multiple regression analysis showed that 52% of the variance in prenatal attachment was significantly accounted by psychosocial adjustment of pregnancy(34%), Taekyo(6%), husband-wife attachment(5%), Lamaze c1ass(5%), and religion(3%). Further findings of this study support the development of creative strategies to enhance positive attachment relationship for pregnant woman.

  • PDF

혈액투석 환자의 음식갈망 영향요인 (Factors Affecting Food Carving among Hemodialysis Patients)

  • 김주연;주현실
    • 임상간호연구
    • /
    • 제23권3호
    • /
    • pp.398-406
    • /
    • 2017
  • Purpose: The purpose of this study was to evaluate food carving among hemodialysis patients and to identify factors affecting the food carving. Methods: A descriptive correlational study was conducted. Data were collected from 129 patients receiving hemodialysis between March 15 and April 15, 2017. Measurement instruments included the general food craving questionnaire trait, the center for epidemiological studies-depression scale, and stress response inventory-modified form. The statistical analysis included t-test, analysis of variance, pearson correlation analysis, and stepwise multiple regression analysis. Results: Mean food craving score was $53.00{\pm}12.36$. Food craving was higher in patients younger than 40 years (F=4.36 p=.006) and having occupation (t=2.18 p=.031). Patients receiving hemodialysis demonstrated higher levels of depression ($21.37{\pm}9.62$) and stress ($39.68{\pm}15.95$). Factors influencing food craving were depression (${\beta}=.52$, p<.001), stress (${\beta}=.65$, p<.001), and age 50~59 years old (${\beta}=-.28$, p=.001) and 60~69 years old (${\beta}=-.19$, p=.026), which accounted for 25.6% of total variance. Conclusion: Food craving among hemodialysis patients was influenced by patients' depression, stress and age. Assessment and management of depression and stress needs to be incorporated as a nursing strategy for dietary management for hemodialysis patients.

의약품 함량분석 정도관리에서의 변이 요인에 대한 통계분석 (Statistical Analysis on the Sources of Variance in Proficiency Test of Quantitative Analysis of Medicines)

  • 조정환
    • Journal of Pharmaceutical Investigation
    • /
    • 제37권1호
    • /
    • pp.27-37
    • /
    • 2007
  • Proficiency test is an essential tool far ensuring analytical ability of analytical chemists and analytical institutes. Usually, the standard protocol for proficiency test is focused on acceptability of reported analytical results of participants by calculating z-scores and related diagnostic parameters. The ultimate goal of this process is to reveal the sources of variability of analytical results and to find the way to reduce their influence. In this study, the method of analysis of variance (ANOVA) was applied to the analytical data collected from qualify control departments of pharmaceutical companies in KyungIn province in Korea in the year of 2000. As influencing factors of variability of analytical results, the use of internal standards for liquid and gas chromatograpy, the educational and professional background of participants, geological locations and yearly production sizes of participating companies were evaluated. To evaluate the variability in accuracy of analytical results, absolute differences from sample mean and sample median were used and to evaluate variability in precision of individual participants, the reported standard deviation of each participant was used. As a result, the use of internal standards in gas chromatographic analysis, participants' academic background and the yearly production sizes of pharmaceutical companies showed statistically significant influence to the accuracy and the precision of the reported analytical results used in this study.

A novel amnion-chorion allograft membrane combined with a coronally advanced flap: a minimally invasive surgical therapy to regenerate interdental papillary soft tissue recession - a six-month postoperative image analysis-based clinical trial

  • Pitale, Unnati;Pal, Pritish Chandra;Boyapati, Ramanarayana;Bali, Ashish;Varma, Manish;Khetarpal, Shaleen
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제47권6호
    • /
    • pp.438-444
    • /
    • 2021
  • Objectives: Loss of the interdental papilla is multi-factorial and creates a multitude of problems. Autogenous connective tissue/biomaterial-based regeneration has been attempted for decades to reconstitute the black space created due to the loss of papilla. The aim of this present study was to regenerate papillary recession defects using an amnion-chorion membrane (ACM) allograft and to evaluate the clinical outcome up to six months postoperatively. Materials and Methods: Twenty patients with 25 Nordland and Tarnow's Class I/II interdental papillary recession defects were treated with ACM and coronal advancement of the gingivo-papillary unit via a semilunar incision on the labial aspect followed by a sulcular incision in the area of interest. A photographic image analysis was carried out using the GNU Image Manipulation software program from the baseline to three and six months postoperatively. The black triangle height (BTH) and the black triangle width (BTW) were calculated using the pixel size and were then converted into millimeters. The mean and standard deviation values were determined at baseline and then again at three and six months postoperatively. The probability values (P<0.05 and P≤0.01) were considered statistically significant and highly significant, respectively. An analysis of variance and post hoc Bonferroni test were carried out to compare the mean values. Results: Our evaluation of the BTH and BTW showed a statistically and highly significant difference from the baseline until both three and six months postoperatively (P=0.01). A post hoc Bonferroni test disclosed a statistically significant variance from the baseline until three and six months postoperatively (P<0.05) and a non-significant difference from three to six months after the procedure (P≥0.05). Conclusion: An ACM allograft in conjunction with a coronally advanced flap could be a suitable minimally invasive alternative for papillary regeneration.

Stochastic failure analysis of [0/θ]s laminated composite plate containing edge crack and voids using XFEM

  • Ashok B. Magar;Achchhe Lal
    • Advances in materials Research
    • /
    • 제13권4호
    • /
    • pp.299-319
    • /
    • 2024
  • Due to higher strength-to-weight ratio of composite laminates, they find uses in many weight-sensitive applications like aerospace, automobile and marine structures. From a reliability point of view, accurate prediction of failure of these structures is important. Due to the complexities in the manufacturing processes of composite laminates, there is a variation in the material properties and geometric parameters. Hence stochastic aspects are important while designing the composite laminates. Many existing works of composite laminate failure analysis are based on the deterministic approach but it is important to consider the randomness in the material properties, geometry and loading to predict accurate failure loads. In this paper the statistics of the ultimate failure load of the [0/θ]s laminated composite plate (LCP) containing the edge crack and voids subjected to the tensile loading are presented in terms of the mean and coefficient of variance (COV). The objective is to better the efficacy of laminate failure by predicting the statistics of the ultimate failure load of LCP with random material, geometric and loading parameters. The stochastic analysis is done by using the extended finite element method (XFEM) combined with the second-order perturbation technique (SOPT). The ultimate failure load of the LCP is obtained by ply-by-ply failure analysis using the ply discount method combined with the Tsai-Wu failure criterion. The aim is to know the effect of the stacking sequence, crack length, crack angle, location of voids and number of voids on the mean and corresponding COV of the ultimate failure load of LCP is investigated. The results of the ultimate failure load obtained by the present method are in good agreement with the existing experimental and numerical results. It is observed that [0/θ]s LCPs are very sensitive to the randomness in the crack length, applied load, transverse tensile strength of the laminate and modulus of elasticity of the material, so precise control of these parameters is important. The novelty of the present study is, the stochastic implementation in XFEM for the failure prediction of LCPs containing crack and voids.

곶자왈휴양림 삼림욕 후 자율신경 활성의 변화 (Changes of Autonomous Nerves Activities after the Gyorae Gotjawal Forest Bathing)

  • 신방식;이근광
    • 한국자연치유학회지
    • /
    • 제7권2호
    • /
    • pp.39-46
    • /
    • 2018
  • 교래자연휴양림을 탐방한 대상자들이 삼림욕을 한 후에 자율신경의 활성도에 미치는 영향을 평가하는 것이 목적이었다. 방법: 삼림욕 전후에 유비맥파기를 이용하여 맥파를 측정하였다. 결과: 삼림욕 후에 교감신경 활성(LF)의 변화에서는 대조군의 사전과 사후의 평균치 차이는 유의성이 없었으나, 실험군에서는 사전보다 사후에는 증가하여 유의성이 있었으며(p<.038), 분산분석에서는 그룹간(p<.014), 전후 차( p<.026) 및 그룹과 전후 차에서도 유의하였다(p<.018). 부교감신경 활성도(HF)의 변화에서는 대조군과 실험군 간에 모두 유의성이 없었다. LF/HF 비율에서는 실험군에서는 사전보다 사후에 증가하여 유의성이 있었고(p<.019), 그리고 분산분석에서는 그룹간, 사전 및 사후 차간에서도 유의성이 있었다(p<.04). 평균맥박의 변화에서는 대조군은 사전보다 사후에 유의성이 없이 감소하였으나, 실험군에서는 사전보다 사후에 증가하여 유의성이 있었다(p<.026). 맥박표준편차(SDNN)의 변화에서는 대조군 및 실험군의 사전보다 사후의 평균치는 감소하였으나 유의성이 없었으나, 분산분석에서는 그룹간에서는 유의성이 있었다(p <.014). 심박변이평균편차(RMSSD)의 변화에서는 대조군 및 실험군의 사전과 사후의 평균치 차이는 유의성이 없었다. 결론: 교래곶자왈 숲 삼림욕 후에는 자율신경의 활성이 변화되고 평균맥박도 높아져서 자연치유의 장소로 유용하다고 판단한다.

  • PDF

이동-멱변환에 관한 연구 (Shift-Power Transformation)

  • 조기종;정석오;신기일
    • 응용통계연구
    • /
    • 제19권2호
    • /
    • pp.283-290
    • /
    • 2006
  • 일반적으로 Box-Cox변환과 같은 류의 멱변환은 분산 안정화 혹은 분포의 대칭성 향상 등을 목적으로 사용된다. 그러나 원 자료의 평균의 크기가 크면서 분산이 상대 적으로 작은 경우, 즉 변동계수가 작은 경우에는 제대로 작동하지 않는 것이 알려져 있다. 본 논문에서는 이러한 문제점을 해결하기 위한 이동-멱변환을 제안하고 모의실험과 실제 자료 분석을 통하여 그 효과를 확인하였다.

증가하는 스트레스에서의 최적가속수명시험 (Optimum Progressive-Stress Accelerated Life Test)

  • 윤원영;정성기
    • 대한산업공학회지
    • /
    • 제19권2호
    • /
    • pp.15-21
    • /
    • 1993
  • This paper considers the optimal design of accelerated life test in which the stress is linearly increased. It discusses the special case when the life distribution under constant stress follows an exponential distribution and the accelerated equation satisfies the inverse power law. It is assumed that cumulative damage is linear, that is, the remaining life of test units depends only on the current cumulative fraction failed and current stress(cumulative exposure model). The optimization criterion is the asymptotic variance of the maximum likelihood estimator of the log mean life at a design stress. The optimal increasing rate is obtained to minimize the asymptotic variance. Table of sensitivity analysis is given for the prior estimators of model parameters.

  • PDF

水質時系列의 週期性 分析 (Periodicity Analysis of Water Quality at Guii)

  • Ahn, Ryong-Me
    • 한국환경보건학회지
    • /
    • 제14권1호
    • /
    • pp.39-45
    • /
    • 1988
  • The stochastic variations were analyzed periodicity by autocorrelation, variance spectrum and Fourier series. These time series included hourly and hourly mean observations on DO, water temperature and air temperature which measured by automatic recording instrument at Guii from 1, Jan., 1986 to 23, Feb., 1986. The results of study were as follows: l. Autocorrelation coef. (lag time 120) DO($\varrho_1$= 0.9705), WT($\varrho_1$ = 0.9890), and AT($\varrho_1$ = 0.9874) were deeply related. DO and AT clearly showedr 24-hour periodicities while WT showed 23-26 hour periodicity. 2. Spectral density showed high at 24 hour in eech item and all of them showed weak peak at 12 hour. 3. The explained variance, which was a measure of the contribution of periodic function to the original time series, varied high 90.8 - 94.7%. This results showed that water qualities at Guii were affected deterministic components.

  • PDF