• 디자인학연구
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• 제19권5호
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• pp.255-268
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• 2006

본 연구에서는 '제품에 대한 사용자의 심리적 가치의식이 디자인 평가에 어떠한 작용을 하는가'에 문제의식을 제기하여 14가지의 제품 샘플을 대상으로 평가를 실시하였다. 이에 따른 주요내용은 '제품평가의 단계별 사고', '제품에 대한 가치의식', '조형이미지 생성과 디자인 평가' 등 크게 3가지 영역을 주요 골자로 하여 분석을 실시하였다. 결론 도출을 위해 먼저 4개의 연구가설을 설정하였고, 이를 검증하기 위하여 '종결적 조사'의 일환으로 사례연구를 실시하였다. 표본은 데이터의 정확성을 높이기 위하여 제품디자인을 전공으로 하는 20대 대학생 120명을 대상으로 선정하였다. 수집된 데이터는 '단순집계'에 의하여 전체적인 흐름을 파악하였고, 이를 토대로 3개의 평가항목에 대한 구체적인 분석을 실시하였다. 분석방법은 '요인분석(factor analysis)', '클러스터분석(duster analysis)' 등 '다변량분석(multivariate analysis)'에 의한 '정량적 분석'에 중점을 두었다. 본 연구의 실증분석은 유의수준 p<.05에서 검증하였고, 통계처리는 'SPSSWIN 12.0' 프로그램을 사용하였다. 그 결과 '제품에 대한 사용자의 가치의식에 따른 디자인 평가의 유형'에 관해 4가지 결론을 얻었다.

• 한국토양비료학회지
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• 제34권3호
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• pp.173-177
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• 2001

This study was conducted to investigate a potential utilitization of multivariate statistical analysis(Factor analysis, Discrimination analysis) on interpretation of rice plant lodging reason. Rice plants were sampled in paddy around Taegu city at from 25 to 29 of September in 2000. Mineral nutrient content(phosphate, potassium) of rice plant were significantly higher at 99% level, Silicate content were lower at 95% level in lodged samples than in normal. Plant characteristics associate with lodging(Culm length, second and third internode length, bight of center gravity) were significantly longer in lodged rice plant than in non lodged. Result of Factor analysis were that first principle component were culm length, second(N2) and third internode length(N3), second principle component were Ca content, first internode length(N1) and N3/culm length, third principle component were center gravity length(G) and G/culm length, fourth were nitrogen, phosphate, and potassium content, fifth were N2/culm length, N2+N3/culm length, Sixth was silicate content of rice plant. Linear discriminant equation distinguished lodged rice plants with non lodged rice plants very well. Prediction value was 100%, most explainable variable were phosphate content, culm length and third length.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2021-2026
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• 2014

Aim: Recent research suggests that nucleophosmin (NPM) may be a prognostic marker in colorectal carcinomas (CRC). We here tested its use to predict the survival of CRC patients. Methods: We investigated NPM expression by immunohistochemistry in histologically normal to malignant colorectal tissues and evaluated its association with clinicopathological variables. Overall and disease-free survival after tumor removal were calculated by the Kaplan-Meier method, and differences in survival curves were analyzed by the log-rank test. The Cox proportional hazards model was used for multivariate analysis of prognostic factors. Results: NPM expression was found significantly upregulated in CRC compared to adjacent colorectal tissue, villous adenoma, tubular adenoma and normal colorectal mucosa (p<0.05 for all). NPM expression was statistically linked to cancer embolus, lymph node metastasis, differentiation grade, and recurrence of CRC. Overall and disease-free survival of NPM-negative CRC patients tended to be better than those for patients with NPM-positive lesions (log-rank statistic, p<0.05 for all). Multivariate analysis indicated NPM expression as an independent prognostic indicator for CRC patients (p<0.05 ). Conclusion: Our results suggest that NPM expression can predict the survival of CRC patients. Prognosis of CRC is determined by not only many known prognostic factors but also by NPM expression.

• Journal of Gastric Cancer
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• 제15권4호
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• pp.262-269
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• 2015

Purpose: Intraabdominal abscess is one of the most common reasons for re-hospitalization after gastrectomy. This study aimed to develop a model for estimating the probability of intraabdominal abscesses that can be used during the postoperative period. Materials and Methods: We retrospectively reviewed the clinicopathological data of 1,564 patients who underwent gastrectomy for gastric cancer between 2010 and 2012. Twenty-six related markers were analyzed, and multivariate logistic regression analysis was used to develop the probability estimation model for intraabdominal abscess. Internal validation using a bootstrap approach was employed to correct for bias, and the model was then validated using an independent dataset comprising of patients who underwent gastrectomy between January 2008 and March 2010. Discrimination and calibration abilities were checked in both datasets. Results: The incidence of intraabdominal abscess in the development set was 7.80% (122/1,564). The surgical approach, operating time, pathologic N classification, body temperature, white blood cell count, C-reactive protein level, glucose level, and change in the hemoglobin level were significant predictors of intraabdominal abscess in the multivariate analysis. The probability estimation model that was developed on the basis of these results showed good discrimination and calibration abilities (concordance index=0.828, Hosmer-Lemeshow chi-statistic P=0.274). Finally, we combined both datasets to produce a nomogram that estimates the probability of intraabdominal abscess. Conclusions: This nomogram can be useful for identifying patients at a high risk of intraabdominal abscess. Patients at a high risk may benefit from further evaluation or treatment before discharge.

• 응용통계연구
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• 제31권6호
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• pp.721-732
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• 2018

잠재집단 모형은 다변량 범주형 자료 안에 숨겨진 집단을 찾는 매우 중요한 도구종의 하나이다. 하지만 실제 자료분석에서 너무 많은 관찰변수들을 포함시킨 모형은 모형을 복잡하게 만들고 또한 모수추정의 정확도에 영향을 주기 때문에 정보가 손실되지 않는 내에서 유용한 변수를 찾는 것은 중요한 문제이다. Dean과 Raftery (2010)은 잠재집단 모형에서의 변수선택을 위해 BIC를 이용한 Headlong search 알고리즘을 제시하였는데 본 논문에서는 이 방법을 대체할 수 있는 방법으로 적합한 모형으로부터 계산된 잠재집단에 속할 사후확률을 이용하여 변수 선택을 하는 방법을 제안하고자 한다. 이를 위하여 잠재집단 모형의 적합성을 측정할 수 있는 새로운 통계량과 이를 이용한 변수선택 알고리즘을 제시할 것이다. 또한 제안된 방법의 효율성을 모의실험과 실증자료 분석을 통해 살펴보고자 한다.

• 한국문헌정보학회지
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• 제40권1호
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• pp.119-138
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• 2006

본 연구는 국내외 문헌정보학분야의 대표적인 10개 학술지에서 2001부터 2004까지 발표된 1,768편의 연구논문을 대상으로 통계사용을 비교하였고, 그 중 추론통계를 사용한 345편의 논문에서 사용된 추론통계기법을 국내외, 학술지 주제영역별, 논문의 연구주제별, 연구방법별, 저자의 전공별로 분석하였다. 2001년 이후 기술통계와 추론통계의 사용은 증가하였으나, 외국에 비하여 국내에서의 사용률은 유의하게 낮은 차이를 보였다. 추론통계를 사용한 345편의 논문은 국내외, 학술지 주제영역별, 연구주제별, 연구방법별, 저자의 전공별 차이가 있었다. 사용된 추론통계기법은 국내외 간에, 학술지 주제영역 간에 차이가 있었다. 전체적으로 다변량분석이 가장 많이 사용되었다. 추론통계를 사용하는데는 가설 설정에서부터 가설을 검정하고, 검정통계량과 유의확률을 제시하고, 모형의 적합성을 해석하는데 보다 주의깊은 논의가 필요한 것으로 분석되었다.

• 생약학회지
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• 제39권3호
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• pp.179-185
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• 2008

Three species, such as Rheum palmatum L., R. tanguticum Maxim. and R. officinale Baillon are recognized as the source plants of Rhei Rhizoma in Korean Pharmacopeia. However, other herbal sources such as R. undulatum L. and Rumex crispus L. have been often misused as Rhei Rhizoma. A pattern analysis method to discriminate Rhei Rhizoma in Korean Pharmacopeia from other herbal plants using HPLC and TLC chromatograms was developed. The multivariate peak data of the chromatograms of methanol extracts of Rhei Rhizoma were used for hierarchical clustering analysis, principal components analysis and similarity calculation. Besides of the statistic analysis, TLC patterns of samples could be used as criteria of the discrimination. The developed pattern analysis method was specific and could be readily utilized for comprehensive evaluation of Rhei Rhizoma.

• 한국패션뷰티학회지
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• 제5권2호
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• pp.68-74
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• 2007

The purpose of this study was to find out the difference between high self-esteem and low self-esteem about the product. The study used the questionnaire method to find out the control effect of self-esteem on apparel brand types. The survey data was analyzed by SPSS Hangul 10.0 Statistic Package. 16 apparel brands that had been selected by a preliminary study were surveyed by using. Brand Mapping was performed in each group for brand classification, and ANOVA was conducted in order to compare the variables depending on brand types. The self-esteem was surveyed by using the self-esteem scale by Rosenberg was used. Multivariate analysis was conducted to identify brand preference, product involvement according to purchase intention and the interactive effects of the brand types that are divided into familiarity and control recognition. For the purpose of the study was to compare searched the results of the high self-esteem comparison with the low self-esteem. The results of the study found the differences on perception about the brand between the high self-esteem and the low self-esteem on the preference. People with high self-esteem liked the brand that was perceived obedience. But the low self-esteem liked the brand that was perceived control.

• Communications for Statistical Applications and Methods
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• 제25권3호
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• pp.283-296
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• 2018

Ranked set sampling, as introduced by McIntyre (Australian Journal of Agriculture Research, 3, 385-390, 1952), dealt with the estimation of the mean of one population. To deal with two or more variables, different forms of bivariate and multivariate ranked set sampling were suggested. For a technique to be useful, it should be easy to implement in practice. Bivariate ranked set sampling, as introduced by Al-Saleh and Zheng (Australian & New Zealand Journal of Statistics, 44, 221-232, 2002), is not easy to implement in practice, because it requires the judgment ranking of each of the combination of the order statistics of the two characteristics. This paper investigates two modifications that make the method easier to use. The first modification is based on ranking one variable and noting the rank of the other variable for one cycle, and do the reverse for another cycle. The second approach is based on ranking of one variable and giving the second variable the same rank (Concomitant Order Statistic) for one cycle and do the reverse for the other cycle. The two procedures are investigated for an estimation of the means of some well-known distributions. It is show that the suggested approaches can be used in practice and can be more efficient than using SRS. A real data set is used to illustrate the procedure.

• 한국컴퓨터정보학회논문지
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• 제28권5호
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• pp.179-187
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• 2023

본 논문은 크론바흐 알파 신뢰계수의 유의성 검정에서 이상치가 검정력에 미치는 영향을 연구한 것이다. 표본 크기, 문항들의 수, 이상치의 수, 모집단의 크론바흐 알파 레벨의 네 개의 변수들에 변화를 주었다. 데이터 시물에이션을 위해 다변량 정규분포를 사용했고 균일분포로부터 이상치를 추출하여 사용했다. 크론바흐 알파 신뢰도의 유의성 검정을 위해 모수적 검정(F 검정)과 퍼뮤테이션 검정을 사용하였다. 결과적으로 퍼뮤테이션 검정의 검정력은 F검정의 검정력 보다 크거나 같았고, 두 검정의 검정력은 모두 이상치의 수가 많아질수록 감소하였으며 이러한 이상치의 영향은 모집단의 알파 레벨이 증가할수록 크게 나타났다.