• 한국CDE학회논문집
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• 제19권2호
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• pp.103-110
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• 2014

Engineering changes are indispensable engineering and management activities for manufactures to develop competitive products and to maintain consistency of its product data. Analysis of engineering changes provides a core functionality to support decision makings for engineering change management. This study aims to develop a method for analysis of engineering changes based on On-Line Analytical Processing (OLAP), a proven database analysis technology that has been applied to various business areas. This approach automates data processing for engineering change analysis from product databases that follow an international standard for product data management (PDM), and enables analysts to analyze various aspects of engineering changes with its OLAP operations. The study consists of modeling a standard PDM database and a multidimensional data model for engineering change analysis, implementing the standard and multidimensional models with PDM and data cube systems and applying the implemented data cube to core functions of engineering change management, the evaluation and propagation of engineering changes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1847-1852
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• 2004

This article provides the connection between feedback stabilization and interpolation conditions for n-D linear systems (n > 1). In addition to internal stability, if one demands performance as a design goal, then there results an n-D matrix Nevanlinna-Pick interpolation problem. Application of recent work on Nevanlinna-Pick interpolation on the polydisk yields a solution of the problem for the 2-D case. The same analysis applies in the n-D case (n > 2), but leads to solutions which are contractive in a norm (the "Schur-Agler norm") somewhat stronger than the $H^{\infty}$ norm. This is an analogous version of the connection between the standard $H^{\infty}$ control problem and an interpolation problem of Nevanlinna-Pick type in the classical 1-D linear time-invariant systems.

• Communications for Statistical Applications and Methods
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• 제26권4호
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• pp.371-383
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• 2019

Panel data sets have been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Maximum likelihood (ML) may be the most common statistical method for analyzing panel data models; however, the inference based on the ML estimate will have an inflated Type I error because the ML method tends to give a downwardly biased estimate of variance components when the sample size is small. The under estimation could be severe when data is incomplete. This paper proposes the restricted maximum likelihood (REML) method for a random effects panel data model with a censored dependent variable. Note that the likelihood function of the model is complex in that it includes a multidimensional integral. Many authors proposed to use integral approximation methods for the computation of likelihood function; however, it is well known that integral approximation methods are inadequate for high dimensional integrals in practice. This paper introduces to use the moments of truncated multivariate normal random vector for the calculation of multidimensional integral. In addition, a proper asymptotic standard error of REML estimate is given.

• 한국학교ㆍ지역보건교육학회지
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• 제7권
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• pp.1-17
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• 2006

Background: School is a primary health education setting for adolescents and the continuous support should be provided to renew school health education curriculum correspondent to cultural changes in Korean society. Objectives: This study was conducted to identify the principals and teachers' health education needs for their students and to analyze their conceptual map for health education curriculum at school. Methods: The sample size of the preliminary study was 321 of the teachers in elementary, middle, and high school, and that of the main study was 355 middle school principals and teachers over the country. The self-administered mailing survey was conducted to collect the available health education topics in the preliminary study, to identify the factor structure of the health education topics and to analyze the conceptual properties on health education with exploratory factor analysis and multidimensional scaling analysis in SPSS 12.0. Results: A total of 21 health education topics were collected from the preliminary survey and 31 topics were, comprehensively, generated for the main survey. In exploratory factor analysis, seven factors were generated in 1.0 or greater Eigen value standard. The seven factors were 'life health promotion,' 'disease prevention and drug control,' 'bulling and aggression prevention,' 'injury and sexual harassment prevention,' human-efficacy and regulation,' 'health protection for adolescence,' and 'alcohol and tobacco control.' The educational need scores were the highest in 'human-efficacy and regulation' and 'injury and sexual harassment prevention.' The two-dimensional cooperates were generated for the 31 health education topics and the two dimensional properties which divided the conceptual space were 'health-safety' for one and 'public/environmental-individual/personal' for the other. That is, middle school principals and teachers primarily, understand the health education curriculum in the sense of 'health vs. safety' and 'public/environmental vs individual/personal.' Conclusions: Health education curriculum and textbook should be developed based on teachers' needs and conditions for health education in school fields. The field-based health education programs or textbook would make more possible problem-solving health education for youth in real school fields.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3298-3302
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• 2012

Although offline enrichment of phosphorylated peptides is widely used, enrichment for phosphopeptides using $TiO_2$ is often performed manually, which is labor-intensive and can lead to irreproducible results. To address the problems associated with offline enrichment and to improve the effectiveness of phosphopeptide detection, we developed an automated online enrichment system for phosphopeptide analysis. A standard protein mixture comprising BSA, fetuin, crystalline, ${\alpha}$-casein and ${\beta}$-casein, and ovalbumin was assessed using our new system. Our multidimensional system has four main parts: a sample pump, a 20-mm $TiO_2$-based column, a weak anion-exchange, and a strong cation-exchange (2:1 WAX:SCX) separation column with LC/MS. Phosphorylated peptides were successfully detected using the $TiO_2$-based online system with little interference from nonphosphorylated peptides. Our results confirmed that our online enrichment system is a simple and efficient method for detecting phosphorylated peptides.

• 한국자기공명학회논문지
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• 제24권1호
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• pp.30-37
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• 2020

Quantitative nuclear magnetic resonance (qNMR) has been gaining attention as a purity assessment method. In particular, qNMR is recognized as the primary method to realize the Internal System of Units (SI) in organic analysis. The capability of quantitative analysis is recognized as the beginning of NMR development. NMR signals are proportional to the number of nuclei and qNMR has been used in various fields, such as metabolomics and food and pharmaceutical analysis. However, careful sample preparation and thorough optimization of measurement parameters are required to obtain accurate and reliable results. In this review, quantitative methods used in qNMR are discussed, and the important factors to be considered also introduced. The recent development of qNMR techniques including combination with chromatography and, multidimensional NMR are also presented.

• 한국산학기술학회논문지
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• 제11권6호
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• pp.2054-2061
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• 2010

본 논문에서는 최적 포지셔닝을 정의하고, 직교변환행렬을 이용하여 포지셔닝의 축을 직교회전 시키는 방법을 제시하고, 최적 포지셔닝 구현을 위한 최적의 회전 각도를 찾아, 궁극적으로는 최적 포지셔닝을 구현하는데 그 목 적이 있다. 또한 최적의 회전 각도를 찾는 최적화 각도 알고리즘을 제안한다.

• Safety and Health at Work
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• 제7권2호
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• pp.124-129
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• 2016

Background: Work-related fatigue has a strong impact on performance and safety but so far, no agreed upon method exists to detect and quantify it. It has been suggested that work-related fatigue cannot be quantified with just one test alone, possibly because fatigue is not a uniform construct. The purpose of this study is therefore to measure work-related fatigue with multiple tests and then to determine the underlying factorial structure. Methods: Twenty-eight employees (mean: 36.11; standard deviation 13.17) participated in five common fatigue tests, namely, posturography, heart rate variability, distributed attention, simple reaction time, and subjective fatigue before and after work. To evaluate changes from morning to afternoon, t tests were conducted. For further data analysis, the differences between afternoon and morning scores for each outcome measure and participant (${\Delta}$ scores) were submitted to factor analysis with varimax rotation and each factor with the highest-loading outcome measure was selected. The ${\Delta}$ scores from tests with single and multiple outcome measures were submitted for a further factor analysis with varimax rotation. Results: The statistical analysis of the multiple tests determine a factorial structure with three factors: The first factor is best represented by center of pressure (COP) path length, COP confidence area, and simple reaction time. The second factor is associated with root mean square of successive difference and useful field of view (UFOV). The third factor is represented by the single ${\Delta}$ score of subjective fatigue. Conclusion: Work-related fatigue is a multidimensional phenomenon that should be assessed by multiple tests. Based on data structure and practicability, we recommend carrying out further studies to assess work-related fatigue with manual reaction time and UFOV Subtest 2.

• 한국간호교육학회지
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• 제23권4호
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• pp.378-388
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• 2017

Purpose: The aim of this study was to identify the status of performance on standard precautions among nursing students and to examine the mediating effects of internal health locus of control on the relationship between awareness and performance on standard precautions of hospital-acquired infection control. Methods: The participants in this study were 134 nursing students. The measurements included a standard precautions awareness and performance scale, and a multidimensional health locus of control scale. Data were analyzed using independent t-test, one-way ANOVA, $Scheff{\acute{e}}$ test, Pearson correlation coefficient, and simple and multiple regression techniques. Mediation analysis was performed by the Baron and Kenny's method and Sobel test. Results: The mean score of standard awareness, standard performance, and internal health locus of control about standard precaution were $174.30{\pm}9.08$; $169.48{\pm}12.04$; and $20.43{\pm}2.82$; respectively. There was a positive correlation between standard awareness and performance (r=.414, p<.001). Also, standard awareness was significantly correlated with internal health locus of control (r=.413, p=.014). Internal health locus of control showed partial mediating effects in the relationship between awareness and performance. Conclusion: The results indicate a need to improve the internal health locus of control of nursing students. Therefore, an internal health locus of control improvement program should improve performance on standard precautions for patients and themselves.

• 감성과학
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• 제12권4호
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• pp.501-510
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• 2009

본 연구는 다차원척도법에 의한 그루밍 사용자의 2차원 감성 모델을 정의함에 따라 터치폰의 GUI 요소를 결정하는 것이 목적이다. 본 연구는 다음과 같은 단계로 진행되었다. 첫 번째 단계로 그루밍(Grooming) 사용자들의 라이프스타일을 조사하여 Norman(2002)에 의거한 감각적, 행태적, 그리고 심볼적 레벨의 감성요소를 추출하였다. 두 번째 단계로 요인분석을 이용하여 대표 감성 어휘를 도출한다. 세 번째 단계로 도출된 대표감성 어휘는 다차원척도분석을 통해 2차원 감성 모델링을 하였다. 마지막으로 매핑 된 그루밍 사용자의 감성과 터치폰 GUI 요소의 관계성을 설문 한 후 정규화를 통해 0~1사이의 정량적 수치로 디자인에 반영될 주요감성 어휘를 도출하였다. 본 연구 결과 터치폰의 43개 디자인 요소에 해당하는 그루밍 사용자의 6개의 대표감성으로 '특이한', '주관이 뚜렷한', '세련된', '자유로운' '열정적인', '깔끔한'을 제시하였다. 또한 정규화를 통해 각각의 GUI 요소를 디자인 할 때 중요하게 고려되어야 할 감성을 제시하였다.