• 제목/요약/키워드: analysis methods

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Blind Source Separation via Principal Component Analysis

  • Choi, Seung-Jin
    • Journal of KIEE
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    • 제11권1호
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    • pp.1-7
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    • 2001
  • Various methods for blind source separation (BSS) are based on independent component analysis (ICA) which can be viewed as a nonlinear extension of principal component analysis (PCA). Most existing ICA methods require certain nonlinear functions (which leads to higher-order statistics) depending on the probability distributions of sources, whereas PCA is a linear learning method based on second-order statistics. In this paper we show that the PCA can be applied to the task of BBS, provided that source are spatially uncorrelated but temporally correlated. Since the resulting method is based on only second-order statistics, it avoids the nonlinear function and is able to separate mixtures of several colored Gaussian sources, in contrast to the conventional ICA methods.

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Graphical Methods for the Sensitivity Analysis in Discriminant Analysis

  • Jang, Dae-Heung;Anderson-Cook, Christine M.;Kim, Youngil
    • Communications for Statistical Applications and Methods
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    • 제22권5호
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    • pp.475-485
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    • 2015
  • Similar to regression, many measures to detect influential data points in discriminant analysis have been developed. Many follow similar principles as the diagnostic measures used in linear regression in the context of discriminant analysis. Here we focus on the impact on the predicted classification posterior probability when a data point is omitted. The new method is intuitive and easily interpretable compared to existing methods. We also propose a graphical display to show the individual movement of the posterior probability of other data points when a specific data point is omitted. This enables the summaries to capture the overall pattern of the change.

일렉트론홀로그래피와 주사정전용량현미경 기술을 이용한 2차원 도펀트 프로파일의 측정 (Measurement of 2-Dimensional Dopant Profiles by Electron Holography and Scanning Capacitance Microscopy Methods)

  • 박경우;;현문섭;유정호;양준모;윤순길
    • 대한금속재료학회지
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    • 제47권5호
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    • pp.311-315
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    • 2009
  • 2-dimensional (2D) dopant profiling in semiconductor device was carried out by electron holography and scanning capacitance microscopy methods with the same multi-layered p-n junction sample. The dopant profiles obtained from two methods are in good agreement with each other. It demonstrates that reliability of dopant profile measurement can be increased through precise comparison of 2D profiles obtained from various techniques.

A STUDY ON THE RATE OF RETURN OF PRIVATE INFRASTRUSTURE INVESTMENT PROJECT

  • Young-Min Park;Soo-Yong Kim;Hyo-Soo Hwang
    • 국제학술발표논문집
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    • The 1th International Conference on Construction Engineering and Project Management
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    • pp.1244-1249
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    • 2005
  • Present PII(Private Infrastructure Investment) in Korea has increased up to 11% compared to the year 2003 and is expected to increase in the future. In spite of its rapid increase, we don't have any definite standard or system which distinctly presents the rate of return for domestic PII yet, and practical and scientific research is not sufficient compared to its necessity and importance. Hence, in this study we suggests methods to estimate the rate of return of PII to promote SOC PII to last successfully and present the proper level of rate of return of PII which is appropriate for domestic situations through diverse analysis. Therefore, to present reasonable rate of return, we have used 5 methods: previous research analysis, case study, financial index analysis, analysis of investor's rate of return, and analysis of rate of return in a real estate market. After comparing and analyzing these methods, at the end, we have presented the appropriate level of rate of return of PII, which can be applied in the domestic market.

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Model-Ship Correlation Study on the Powering Performance for a Large Container Carrier

  • Hwangbo, S.M.;Go, S.C.
    • Journal of Ship and Ocean Technology
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    • 제5권4호
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    • pp.44-50
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    • 2001
  • Large container carriers are suffering from lack of knowledge on reliable correlation allowances between model tests and full-scale trials, especially at fully loaded condition, Careful full-scale sea trial with a full loading of containers both in holds and on decks was carried out to clarify it. Model test results were analyzed by different methods but with the same measuring data to figure out appropriated correlations factors for each analysis methods, Even if it is no doubt that model test technique is one of the most reliable tool to predict full scale powering performance, its assumptions and simplifications which have been applied on the course of data manipulation and analysis need a feedback from sea trial data for a fine tuning, so called correlation factor. It can be stated that the best correlation allowances at fully loaded condition for both 2-dimensional and 3-dimensional analysis methods are fecund through the careful sea trial results and relevant study on the large size container carriers.

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언어 네트워크 분석 방법을 활용한 학술논문의 내용분석 (A Content Analysis of Journal Articles Using the Language Network Analysis Methods)

  • 이수상
    • 정보관리학회지
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    • 제31권4호
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    • pp.49-68
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    • 2014
  • 본 연구의 목적은 국내 학술논문 데이터베이스에서 검색한 언어 네트워크 분석 관련 53편의 국내 학술논문들을 대상으로 하는 내용분석을 통해, 언어 네트워크 분석 방법의 기초적인 체계를 파악하기 위한 것이다. 내용분석의 범주는 분석대상의 언어 텍스트 유형, 키워드 선정 방법, 동시출현관계의 파악 방법, 네트워크의 구성 방법, 네트워크 분석도구와 분석지표의 유형이다. 분석결과로 나타난 주요 특성은 다음과 같다. 첫째, 학술논문과 인터뷰 자료를 분석대상의 언어 텍스트로 많이 사용하고 있다. 둘째, 키워드는 주로 텍스트의 본문에서 추출한 단어의 출현빈도를 사용하여 선정하고 있다. 셋째, 키워드 간 관계의 파악은 거의 동시출현빈도를 사용하고 있다. 넷째, 언어 네트워크는 단수의 네트워크보다 복수의 네트워크를 구성하고 있다. 다섯째, 네트워크 분석을 위해 NetMiner, UCINET/NetDraw, NodeXL, Pajek 등을 사용하고 있다. 여섯째, 밀도, 중심성, 하위 네트워크 등 다양한 분석지표들을 사용하고 있다. 이러한 특성들은 언어 네트워크 분석 방법의 기초적인 체계를 구성하는 데 활용할 수 있을 것이다.

주성분회귀와 고유값회귀에 대한 감도분석의 성질에 대한 연구 (A study on the properties of sensitivity analysis in principal component regression and latent root regression)

  • 신재경;장덕준
    • Journal of the Korean Data and Information Science Society
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    • 제20권2호
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    • pp.321-328
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    • 2009
  • 회귀분석에서 설명변수들 사이에 상관이 높으면 최소제곱추정법에서 구한 회귀계수들의 정도가 떨어진다. 다중공선성이라 불리는 이 현상은 실제 자료분석에서 심각한 문제를 야기시킨다. 이 다중공선성의 문제를 극복하기 위한 여러 가지 방법이 제안되었다. 능형회귀, 축소추정량 그리고 주성분분석에 기초한 주성분회귀와 고유값회귀등이 있다. 지난 수십 년간 많은 통계학자들은 일반적인 중 회귀에서 감도분석에 관해 연구하였으며, 주성분회귀, 고유값회귀와 로지스틱 주성분회귀에 대해서도 같은 주제로 연구하였다. 이 모든 방법에서 주성분분석은 중요한 역할을 하였다. 또한, 많은 통계학자들이 주성분분석과 관련된 다변량 방법에서 감도분석에 대해 연구를 하였다. 본 연구논문에서는 주성분회귀와 고유값회귀를 소개하고, 또한 주성분회귀와 고유값회귀에서 감도분석의 방법을 소개하고, 마지막으로 이들두방법에 대한 감도분석의 성질에 대해 논의하였다.

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간호행정학회지 게재논문의 연구동향 분석(2013~2015년): 텍스트 네트워크 분석의 적용 (Analysis of Research Articles Published in the Journal of Korean Academy of Nursing Administration for 3 Years (2013~2015): The Application of Text Network Analysis)

  • 이태화;박광옥;서문경애;김미영;황지인;유소영;정석희;정민;문미경
    • 간호행정학회지
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    • 제23권1호
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    • pp.101-110
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    • 2017
  • Purpose: This study aimed to identify research trends in the Journal of Korean Academy of Nursing Administration from 2013 to 2015. Methods: For this study, 171 articles were analyzed. Research designs, participants, research settings, sampling, and data analyses methods were reviewed using established analysis criteria. Keyword centrality and clusters were generated by keyword network analysis. Results: Most of studies used quantitative methods (82.5%), and sampling mainly focused on nurses (68.8%). The most commonly used data analyses methods were t-test, ANOVA, correlation, and regression. The most central keywords were turnover and empowerment. Network analysis generated four network groups: 1) burnout; 2) turnover; 3) happiness; and 4) nursing professionalism. Conclusion: The results of this study identify current trends and interests in Korean nursing administration research. The findings from this study suggest that future studies include a variety of research methods and maintain appropriate research ethics.

A Retrospective Statistical Analysis of Miniscalpel Needle Therapy for Herniated Intervertebral Disc or Spinal Stenosis

  • Kim, Jae Ik;Jeong, Jeong Kyo;Kim, Myung Kwan;Jeon, Ju Hyun;Kim, Eun Seok;Kim, Young Il
    • Journal of Acupuncture Research
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    • 제35권4호
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    • pp.226-237
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    • 2018
  • Background: This study examined the characteristics and prognosis of patients admitted to the Dunsan Korean medicine hospital for treatment of herniated intervertebral disc (HIVD) or spinal stenosis with Miniscalpel needle therapy (MSN). Methods: Patients were admitted to the Dunsan Korean medicine hospital from January 01, 2016 to September 30, 2017 for the treatment of HIVD or spinal stenosis with MSN. Crossover analysis, Independent sample t test, one-way ANOVA, multiple linear regression analysis, and binary logistic regression analysis were performed. Results: Crossover analysis showed statistically significant differences in treatment methods according to gender, current pain according to the disease duration, satisfaction of MSN according to disease duration, treatment methods, and intention of re-treatment with MSN according to treatment methods. Independent t test and one-way ANOVA showed that there was a difference in current Numeric Rating Scale (NRS) according to disease duration, and difference between discharge and current NRS, and number of MSN according to disease. Multiple linear regression analysis showed that age, disease duration, and number of MSN affect discharge NRS, disease duration, and number of MSN affect current NRS, and Western medical treatment after MSN, discharge NRS, and current NRS affect satisfaction of MSN. Binary logistic regression analysis showed that discharge NRS affects current pain, and gender, discharge NRS, and treatment methods affect intention of re-treatment with MSN. Conclusion: Characteristics, prognosis, satisfaction and variables affecting prognosis of MSN were statistically significant, indicating that more systematic studies are required to further examine the effects of MSN on HIVD or spinal stenosis.

Methods of Automated Analysis of Curricula According to the Higher Education Standard

  • Liudmyla Omelchuk;Andrii Kryvolap;Taras Panchenko;Nataliia Rusina;Olena Shyshatska;Oleksii Tkachenko
    • International Journal of Computer Science & Network Security
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    • 제23권11호
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    • pp.32-42
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    • 2023
  • The paper describes the new approaches to the automated analysis of curricula according to the higher education standard. The analysis process is proposed to carry out in two ways: (a) the analysis of completeness and sufficiency of curricula according to the standard of higher education; (b) the comparison of curricula of the same qualification and specialty. The problem of improving the quality of university students' training launches the process of monitoring and analyzing educational curricula and their correspondence to the higher education standard. We developed the rules and methods to compare curricula. In addition, we implemented the automated system of curricula comparison. The paper reveals the use of these methods based on the analysis of the curriculum bachelor level of higher education "Informatics", specialty "Computer science", at the Faculty of Computer Science and Cybernetics of the Taras Shevchenko National University of Kyiv. The findings put towards the idea that the implementation of developed methods as well as the automated system of curricula analysis will improve the educational services by higher education institutions.