• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1147-1161
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• 2015

Nowadays we are considering and analyzing not only classical data expressed by points in the p-dimensional Euclidean space but also new types of data such as signals, functions, images, and shapes, etc. Symbolic data also can be considered as one of those new types of data. Symbolic data can have various formats such as intervals, histograms, lists, tables, distributions, models, and the like. Up to date, symbolic data studies have mainly focused on individual formats of symbolic data. In this study, it is extended into datasets with both histogram and multimodal-valued data and a divisive clustering method for the mixed feature-type symbolic data is introduced and it is applied to the analysis of industrial accident data.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.3
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• pp.81-91
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• 2016

Purpose : This study is conducted to analyze the safe awarenece, its related health education and the employee's requirements in a prime supplier and its subcontractor company, suggesting the proper measure in employee education program. Method : The employees of 'S' construction company and its subcontractor are surveyed during the period of April 15 from May 15 in 2016. The 324 questionnaires are statistically analyzed with the version 21.0 of SPSS. The general characteristics were calculated through the frequency analysis and descriptive statistics. The difference in safe consciousness between prime and subcontractor employee group was analyzed using t-test. Result : The statistics shows the employees in the prime company tend to observe the safe rules rather than the subcontractor employees(p<.005), but the latter are more conscious of safety in working environment than the former(p<.005). In addition, the subcontractor company did not provide his employees with the site for the safety-health education. Conclusion : The small-sized subcontractor company should identify its employees' requirements and supplement the lack of the safety and health education for the prevention of the industrial disasters. In details, the hand-on and practice-oriented leaning and teaching program development are suggested.

• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.327-335
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• 2013

Purpose: The purpose of this study is to suggest the modified 'Korean Standard-Quality Excellence Index' model and analyze the improvement effect with survey data by comparing the properness between current and suggested model result. Methods: The collected data through the survey were analyzed using paired t-test and unbalanced ANOVA method for testing the consistency of two customer satisfaction evaluating categories and comparing the current model to suggested model for confirming the improvement of performance. Results: The statistical analysis result shows that adjusted model using prior information improves the consistency between two customer satisfaction in case of short life-cycle product. Also long life-cycle product case, the result shows difference gap decreasing with same direction. Conclusion: Considering statistical model for QEI reflecting the characteristic of product group such as life cycle seems to be meaningful. Since index may be compared yearly base for checking the trend, careful approaching without big change should be considered for application.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.125-130
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• 2012

According to the Korea National Statistical Office data in 2010, the population over ages of 65 years would possess to 11.3% whole population of Korea in 2011 denoting Korea is already in the aging society. Old age is associated with inevitable time-dependent losses in physical capabilities. However the maintenance of physical capabilities is essential for continuing independence in old age. The work ability index(WAI) was constructed to reveal how well a worker is able to perform his work. This study focused on the discovery of an industrial and age-related influences on the work ability and job stress of workers in the shipbuilding, house managing, apartment construction industry. For this, the study conducted a job stress test using the Korean Occupational Stress Questionnaire Short Form, and employee performance evaluations using the Work Ability Index (WAI) of the Finnish Institute of Occupational Health (FIOH) on 3,228 workers in the shipbuilding, house managing and apartment construction industry. SPSS 12.0 K statistics program was used for statistics analysis and significance was verified with the Kruskal-Wallis test, a corporate body of nonparametric statistical analysis. As a result, employee performance had significant differences, depending on age, an industrial and years of service. The mean WAI score of the shipbuilding industry was lower than that of the other industry. Additionally, it was found that employee work ability decreased more as job stress increased.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.17-25
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• 2009

This study was aimed to analyze of characteristics of Musculoskeletal disorders (MSDs) based on the industrial accident statistics which were extracted from the Ministry of Labor. In this study all MSDs cases in 2007, 7,723 cases, were investigated. First of all, for the analysis of a wide view point concerning the characteristics of MSDs, We have inspected characteristics of the user population (i.e. age, gender, employed periods, etc.). Secondly, work-related risk factors such as repetitive motions, awkward postures, manual material handling were analyzed in terms of disease code, injured part of body, types of business, etc. Next, characteristics of handling of heavy materials were analyzed according to weight, types of handling, agency of cause, etc. Finally, we have compared and analyzed the features between the period of hospitalization and other variables. In addition to that we also conducted statistics analysis. The study results showed that there were significant characteristics of MSDs that could be used as basis data for the MSDs prevention policy.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.2
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• pp.108-120
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• 2022

We considered qualitative behaviour of the generalization of Einstein's model of Brownian motion when the key parameter of the time interval of free jump degenerates. Fluids will be characterised by number of particles per unit volume (density of fluid) at point of observation. Degeneration of the phenomenon manifests in two scenarios: a) flow of the fluid, which is highly dispersing like a non-dense gas and b) flow of fluid far away from the source of flow, when the velocity of the flow is incomparably smaller than the gradient of the density. First, we will show that both types of flows can be modeled using the Einstein paradigm. We will investigate the question: What features will particle flow exhibit if the time interval of the free jump is inverse proportional to the density and its gradient ? We will show that in this scenario, the flow exhibits localization property, namely: if at some moment of time t₀ in the region, the gradient of the density or density itself is equal to zero, then for some T during time interval [t₀, t₀ + T] there is no flow in the region. This directly links to Barenblatt's finite speed of propagation property for the degenerate equation. The method of the proof is very different from Barenblatt's method and based on the application of Ladyzhenskaya - De Giorgi iterative scheme and Vespri - Tedeev technique. From PDE point of view it assumed that solution exists in appropriate Sobolev type of space.

• The Korean Journal of Applied Statistics
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• v.19 no.1
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• pp.135-148
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• 2006

Independent component analysis (ICA) is a statistical method for transforming an observed high-dimensional multivariate data into statistically independent components. ICA has been applied increasingly in wide fields of spectrum application since ICA is able to extract unknown components of a mixture from spectra. We focus on application of ICA for separating independent sources and predicting each composition using extracted components. The theory of ICA is introduced and an application to a metal surface spectra data will be described, where subsequent analysis using non-negative least square method is performed to predict composition ratio of each sample. Furthermore, some simulation experiments are performed to demonstrate the performance of the proposed approach.

• The Korean Journal of Applied Statistics
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• v.24 no.3
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• pp.465-475
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• 2011

In this paper, we have considered the problems of the estimation of the gross areas of a factory site relating to the areas of industrial complex lands based on a statistical forecasting model and the results of a sampling survey. In respect to the data of a gross areas of a factory site, we have only the sizes from 1981-2003. In 2009, the Korea Industrial Complex Corp. conducted a sampling survey to estimate its bulk size, and investigate the demands of its sizes for the next five years. In this study, we have adopted the sampling survey results, and have created a statistical growth model for the gross areas of a factory site to improve the prediction for the areas of a factory site. The three-different parts of data: the results of areas of a factory site by Korea National Statistical Office, imputation results by the statistical forecasting model, and sampling survey results have used as the basis for analysis. The combination of the three-different parts of data has created a new forecasting value of the areas of a factory site through the spline smoothing method.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1271-1281
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• 2015

Competing risk analysis is widely applied to analyze a failure time with more than two causes. This paper discusses the application of a competing risk model to a economic activity state of workers with occupational injuries. In particular, main interest is to estimate the distribution of restarting time two kinds of economic activities, (i) returning to original working place and (ii) finding a new job. In this paper, we applied a cumulative incidence function to evaluate their patterns under several individual factors and working place's factor. Furthermore, a subdistributional regression model is applied to estimate the effect of these factors on the returning time. According to result, worker with higher education, younger age and longer working period had a higher chance to return an original working place while one with more severe injuries and skilled laborer had longer returning time to an original working place.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6250-6257
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• 2014

This study examined the preparation for elderly life in terms of health for aging and the related factors in the community (part of Daegu). The data of 391 middle-aged women in this study were collected from 4 culture centers. The interviews were conducted from March 1 until March 25 in 2011 using a structured questionnaire. The data was analyzed by descriptive statistics and logistic regression analysis using the IBM SPSS Statistics 20 program. The variables in preparation for elderly life regarding their health were exercise, good nutrition, proper sleep, and health examination. From the data, the preparation for elderly life regarding middle-aged women's health for successful aging was identified. Therefore, health service programs and healthy environment should be varied based on the result of this study.