• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.32 no.5
• /
• pp.14-25
• /
• 2000

In this investigation, a wavelet transform analysis was used to decompose beta-radiographic formation images into spectral and spatial components. Conventional formation analysis may use spectral analysis, based on Fourier transformation or variance vs. zone size, to describe the grammage distribution of features such as flocs, streaks and mean fiber orientation. However, these methods have limited utility for the analysis of statistically stationary data sets where variance is not uniform with position, e.g. paper machine CD profiles (especially those that contain streaks). A continuous wavelet transform was used to analyze formation data arrays obtained from radiographic imaging of handsheets and cross machine paper samples. The response of the analytical method to grammage, floc size distribution, mean fiber orientation an sensitivity to feature localization were assessed. From wavelet analysis, the change in scale of grammage variation as a function of position was used to demonstrate regular and isolated differences in the formed structure.

• Genomics & Informatics
• /
• v.20 no.3
• /
• pp.34.1-34.11
• /
• 2022

Multilevel analysis is an appropriate and powerful tool for analyzing hierarchical structure data widely applied from public health to genomic data. In practice, however, we may lose the information on multiple nesting levels in the multilevel analysis since data may fail to capture all levels of hierarchy, or the top or intermediate levels of hierarchy are ignored in the analysis. In this study, we consider a multilevel linear mixed effect model (LMM) with single imputation that can involve all data hierarchy levels in the presence of missing top or intermediate-level clusters. We evaluate and compare the performance of a multilevel LMM with single imputation with other models ignoring the data hierarchy or missing intermediate-level clusters. To this end, we applied a multilevel LMM with single imputation and other models to hierarchically structured cohort data with some intermediate levels missing and to simulated data with various cluster sizes and missing rates of intermediate-level clusters. A thorough simulation study demonstrated that an LMM with single imputation estimates fixed coefficients and variance components of a multilevel model more accurately than other models ignoring data hierarchy or missing clusters in terms of mean squared error and coverage probability. In particular, when models ignoring data hierarchy or missing clusters were applied, the variance components of random effects were overestimated. We observed similar results from the analysis of hierarchically structured cohort data.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2000.04a
• /
• pp.167-170
• /
• 2000

Recently the sub-micron structured substrates of 0.74 ${mu}ell$ track pitch and 800 $\AA$groove depth are required for DVD-RAM and the track pitch is expected to be narrower as the need for the information storage density is getting higher. For the accurate replication of the land-groove structure in the stamper to the plastic substrates it is important to control the injection -compression molding process such that the integrity of the replication for the land-groove structure is maximized. in the present study polycarbonate substrates were fabricated by injection comression molding and the land-groove structure regarded as one of mold temperature and the compression pressure on the integrity of the replication were examined experimentally. An efficient design methodology using the response surface method (RSM) the central composite design(CCD) technique and the analysis-of-variance (ANOVA) was developed to obtain the optimum processing conditions which maximize the integrity of the replication with a limited number of experiments.

• Journal of Welding and Joining
• /
• v.15 no.6
• /
• pp.66-77
• /
• 1997

In the present work, Taguchi method for electron beam welding(EBW) process in AISI 4130 steel plate has been adopted for investigating the contribution of effect of welding variables. $A L_8(2^7)$ orthogonal array is adopted to obtain the effect of adjustment parameters. The adjustment parameters consist of accelerating voltage, beam current, travel speed and focus currrent. And the quality features selected for the EBW process are bead width of weldment, reinforcement, penetration depth, undercut and area of weld metal. Variance analysis is performed in order to check the effect of adjustment parameters on EBW. The mechanical properties of electron beam welded joints for each heat treatment conditions are investigated in comparison with those of base metal, especially from the view point of tensile and impact properties.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.30
• /
• pp.3-26
• /
• 2006

Supply chain is viewed as a number of organizations(at least three) working cooperatively with at least some shared objectives. The concept of supply chain management represents the most advanced state in the evolutionary development of purchasing, procurement and other supply chain activities. This study aims to analyze and develop a measurement instrument for supply chain performance in international logistics. A measurement instrument for supply chain performance in international logistics are developed by Lai et al(2002). Supply chain reliability, customer service and cost are constructed reflecting service effectiveness and operations efficiency between shipper, forwarder and liner. The results of this study are as follow. We firstly tested the measurement properties of the sub-dimension of the supply chain performance construct using reliability test and confirmatory factor analysis follow by exploratory factor analysis. For each of the factor, reliability and validity are achieved because of the significant loading of the measurement items on their latent factors. Further research perform the analysis of variance by multi respondents within each firm and across partner firms in the supply chain. The result of analysis present the difference with shipper, forwarder and liner in statistics.

• Korean journal of food and cookery science
• /
• v.21 no.2 s.86
• /
• pp.155-162
• /
• 2005

The purpose of this study was to identify factors associated with sanitation and cleanliness regarding the importance of family restaurant employees in the Ulsan and Busan areas. Accordingly, this study conducted a suey questionnaire consisting of 28 measures of food-service as well as major subject descriptors. From the results, the frequency, descriptive, factor, correspondence analysis, major findings and marketing implications could be summarized as follows: First, 6 factors were extracted: cooking and control factor, food and tableware handling factor, personal cleanliness condition factor, purchase and receiving factor, unit food material store factor and Kitchen utensil sanitation factor. KMO and Bartlett' stest statistics showed that the data fitted the factor analysis well. Results of factor analysis, average variance extracted estimates and shared variance showed that the convergent and discriminant validity of 6 factors are supported and Cronbach's alpha showed that the internal consistency of the 6 factors was supported. Second, correspondence analysis indicated that statistically significant relationships existed between some of the family restaurant employee sanitation and cleanliness factors and the family restaurant enterprise.

• Animal Systematics, Evolution and Diversity
• /
• v.29 no.1
• /
• pp.18-22
• /
• 2013

A recent study on the mitochondrial genetic variation of the Carassius auratus population in South Korea suggested that there are 3 distinct mitochondrial lineages in the country, and that they are geographically separated between westward rivers and southward rivers, respectively. In this study, the population genetic structure of amplified fragment length polymorphism (AFLP) of Carassius auratus was investigated. The results of analysis of molecular variance (AMOVA) supported the geographic distinction between westward and southward river populations, but only 3.66% of total genetic variance lies among these populations. The panmicticity of the AFLP genetic variation is backed up by the results of the neighbor-joining dendrogram drawn from a linearized pairwise $F_{ST}$ matrix and Bayesian clustering analysis. The discordance of genetic structure between mitochondrial and AFLP genetic variation may come from difference in effective population size between these markers and/or gene flow between westward and southward river populations through river capture events.

• Korean Journal of Adult Nursing
• /
• v.14 no.4
• /
• pp.591-601
• /
• 2002

Purpose: This study was conducted to investigate the relationship of hardiness, job stress, and burnout in nurses, and to identify predictors of burnout. Method: Empirical data were collected from 154 staff nurses at one university hospital in Gwangju city. Self- reported questionnaires were composed of the Personal Views Survey(PVS), job stress scale, Tedium scale, and 7 items asking nurse's general characteristics. Data analysis was done with a SAS package. Result: In correlation analysis, hardiness, job stress, and nursing satisfaction had significant correlation with burnout. In stepwise multiple regression, 28.7% of the variance in burnout was accounted for by nursing satisfaction (19.9%), job stress (6.0%), and hardiness (2.8%). Among subscales of hardiness, only commitment was a significant predictor, so nursing satisfaction, job stress, and commitment explained 28.9% of variance in burnout. Conclusion: Based on the findings of this study, the development of program for nurses to increase nursing satisfaction is needed, and more studies to examine causal relationship between nursing satisfaction and burnout is also highly recommended.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.4
• /
• pp.133-139
• /
• 2008

With the increasing demand for higher production quality and growing competition in the global market, coordinate measuring machine(CMM) has been widely used in industry to improve the efficiency and effectiveness of measurement. In this paper the performance evaluation of coordinate measuring machine is proposed using design of experiments. A factorial design is applied to carry out the performance test proposed by ISO 10360 with a length bar and to investigate CMM measurement errors associated to orientation and length in the work volume. The determination of the significance of effects in an experiment is made through the analysis of variance(ANOVA). The results show that the proposed method is suitable to analyze the factors which affect the CMM measurement performance.

• The Korean Journal of Rehabilitation Nursing
• /
• v.13 no.2
• /
• pp.123-131
• /
• 2010

Purpose: This study was aimed at identifying the levels of parenting stress among mothers of children with cerebral palsy and factors influencing parenting stress. Method: The research design was cross-sectional survey. Data were collected from 122 mothers of hospitalized children (under 15 years of age) with cerebral palsy at the Y medical center using the questionnaires. The data were analyzed using one way analysis of variance with Scheffe test for post-hoc analysis or t-test, Pearson correlation, and stepwise multiple regression. Results: The mean score of parenting stress was 2.52 (SD=0.79; range: 1~4). The father's participation, mother's parenting hours, self-esteem and social support were significant predictors of parenting stress, significantly accounting for the 33.3% variance (F=16.118, p<.001). Conclusion: It is essential for health professionals to consider the aforementioned four factors when developing interventions to reduce parenting stress for mothers of children with cerebral palsy.