• 경영과학
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• 제28권1호
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• pp.159-167
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• 2011

The theory of random utility maximization (RUM) defines the probability of an alternative being chosen as the probability of its utility being perceived as higher than those of all the other competing alternatives in the choice set (Marschak 1960). According to this theory, consumers perceive the utility of an alternative not as a constant but as a probability distribution. Over the last two decades, there have been an increasing number of studies on the effect of utility variance on choice probability. The common result of the previous studies is that as the utility variance increases, the effect of the mean value of the utility (the deterministic component of the utility) on choice probability is reduced. This study provides a theoretical investigation on the effect of utility variance on choice probability without any assumptions on the specific forms of probability distributions. This study suggests that without assumptions of the probability distribution functions, firms cannot apply the marketing strategy of maximizing choice probability (or market share), but can only adopt the strategy of maximizing the minimum or maximum value of the expected choice probability. This study applies the Chebyshef inequality and shows how the changes in utility variances affect the maximum of minimum of choice probabilities and provides managerial implications.

• 한국간호교육학회지
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• 제17권3호
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• pp.536-544
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• 2011

Purpose: The purpose of this descriptive study was to investigate the level of nursing professionalism and influencing factors of professionalism in nursing students. Method: A convenience sample of 207 subjects were recruited from two universities in I city and one university in S city. The subject for this survey were senior students who finished all clinical practicum to be done before graduation. Results: The mean scores of the nursing professionalism and the satisfaction with clinical practice were 3.43 and 3.28 individually. The mean of self-efficacy and image of nurses were 3.60 and 3.71 individually. Mean of major satisfaction score was 3.88. There were significant correlations among nursing professionalism, satisfaction with clinical practice, self-efficacy, image of nurses and major satisfaction. The most strong factor affecting nursing professionalism was the image of nurses and accounted 52.0 percentage of the variance. Sixty point one percentage of the variance was explained by image of nurses, major satisfaction, religion and satisfaction with clinical practice. Conclusion: To make students have more positive nursing professionalism, strategies enhancing the positive nurse image, clinical satisfaction, and major satisfaction need to be developed during school years.

• 대한간호학회지
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• 제35권3호
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• pp.585-592
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• 2005

Purpose: The purpose of this study was to identify the relationship between self efficacy (SE), health promoting behaviors (HPB) and symptoms of stress (SOS) among university students. Method: Data was collected by questionnaires from 369 university students in Seoul, Korea. Data was analyzed using descriptive statistics, pearson correlation coefficients, and stepwise multiple regression. Results: The mean score for SE was 3.42, the mean score for HPB was 2.48, and the mean score for SOS was 2.31. The score of SOS showed a significantly negative correlation with the score of SE (r=-.24, p=.00) and HPB (r=-.13, r=.00). Also, SOS showed a significantly negative correlation with diet HPB (r=-.15, p=.00), spiritual growth HPB (r=-.17, p=.00), interpersonal relationship HPB (r=-.17, p=.00), and stress management HPB (r=-.10, p=.04). The most powerful predictor of SOS was SE and the variance was $10\%$. A combination of SE, diet, problems related to drinking, and responsibility for health HPB account for $16\%$ of the variance in SOS among university students. Conclusion: This study suggests that SE and HPB are significant influencing factors on SOS among university students.

• 한국멀티미디어학회논문지
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• 제22권12호
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• pp.1376-1384
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• 2019

The cosmetic and behavioral aspects of aging have become increasingly evident over the years. Physical aging in people can easily be observed on their face, posture, voice, and gait. In contrast, bone aging only becomes apparent once significant bone degeneration manifests through degenerative bone diseases. Therefore, a more accurate and timely assessment of bone aging is needed so that the determinants and its mechanisms can be more effectively identified and ultimately optimized. This study proposed a deep learning approach to assess the bone age of an adult using whole-body bone scintigraphy. The proposed approach uses multiple inputs deep neural network architectures using a loss function, called mean-variance loss. The data set was collected from Chonnam National University Hwasun Hospital. The experiment results show the effectiveness of the proposed method with a mean absolute error of 3.40 years.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.625-633
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• 2013

본 다중반응표면 최적화는 다수의 반응변수(품질특성치)를 동시에 고려하여, 입력변수의 최적 조건을 찾는 것을 목적으로 한다. 지금까지 다중반응표면 최적화를 위하여 다양한 방법이 제안되어 왔는데, 그 중 평균제곱오차 최소화법은 다수의 반응변수의 평균과 표준편차를 동시에 고려하여 최적화하는 방법이다. 이 방법은 기본적으로 평균과 표준편차가 동일한 가중치를 가지고 있다는 것을 전제로 하고 있다. 그러나 문제의 상황에 따라 평균과 표준편차에 서로 다른 가중치를 부여해야 하는 경우도 있다. 이에 본 논문에서는 기존의 평균제곱오차를 확대하여 평균과 표준편차에 서로 다른 가중치도 부여할 수 있도록 가중평균제곱오차 최소화법을 제안하고자 한다.

• 한국통신학회논문지
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• 제32권11C호
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• pp.1127-1133
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• 2007

제안된 알고리즘은 QR 형태의 LMS 알고리즘이 입력의 분산에 비례하게 되어있어 입력의 분산을 평균적인 측면에서 입력의 분산을 정규화하는 알고리즘중 하나이다. 본 논문에는 정규화 알고리즘의 수렴 특정 분석이 되어있다. 제안한 알고리즘의 성능분석을 위하여 간단한 FIR 시스템의 시스템 식별을 수행하였다. 이때 성능 비교에 참여한 알고리즘은 LMS, NLMS(normalized least mean square) 알고리즘이다. 그 결과 제안한 알고리즘은 NLMS 알고리즘과 매우 유사한 성능을 가짐을 확인하였다.

• 응용통계연구
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• 제23권2호
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• pp.317-323
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• 2010

Measures are very useful tools for comparing the shape variability in statistical shape analysis. For examples, the Procrustes statistic(PS) is isolated measure, and the mean Procrustes statistic(MPS) and the root mean square measure(RMS) are overall measures. But these measures are very subjective, complicated and moreover these measures are not statistical for comparing the shape variability. Therefore we need to study some tests. It is well known that the Hotelling's $T^2$ test is used for testing shape variability of two independent samples. And for testing shape variabilities of several independent samples, instead of the Hotelling's $T^2$ test, one way analysis of variance(ANOVA) can be applied. In fact, this one way ANOVA is based on the balanced samples of equal size which is called as BANOVA. However, If we have unbalanced samples with unequal size, we can not use BANOVA. Therefore we propose the unbalanced analysis of variance(UNBANOVA) for testing shape variabilities of several independent samples of unequal size.

• 응용통계연구
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• 제18권1호
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• pp.197-210
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• 2005

본 연구에서는 중등학교 통계교육을 위하여, 제7차 수학과 교육과정 중 고등학교에서 사용하는 검정교과서 수학 1과 국정교과서 확률과 통계의 확률통계 영역을 중심으로 용어와 개념 및 표현을 비교, 연구하였다. 검정과 국정교과서의 표본표준편차의 정의가 일치되지 않았으며, 표분평균의 분산과 중심극한정리에 대한 개념설명이 교과서마다 상이하였다. 또한, 확률변수 개념 설명이 불분명 한 교과서도 발견되었다. 본 연구에서는 오류의 수정과 더불어 표본분산으로 불편추정량을 사용할 것을 제안하였다.

• 대한기계학회논문집
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• 제12권1호
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• pp.137-151
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• 1988

본 논문에서는 아래 평판은 높은 온도 $T_{h}$로 유지되고, 위의 평판은 낮은 온도 $T_{i}$로 유지되어 있을 때 온도차에 의하여 발생하는 난류 열대류 문제를 난류모델 방정식을 사용하여 수치적으로 해석하고자 한다.다.다.

• 대한원격탐사학회지
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• 제26권3호
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• pp.305-316
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• 2010

The MODerate Resolution Imaging Spectroradiometer (MODIS) sensor has 36 bands at 250m, 500m, 1km spatial resolution. However, 500m or 1km MODIS data exhibits a few limitations when low resolution data is applied at small areas that possess complex land cover types. In this study, we produce seven 250m spectral bands by fusing two MODIS 250m bands into five 500m bands. In order to recommend the best fusion method by which one acquires MODIS data, we compare seven fusion methods including the Brovey transform, principle components algorithm (PCA) fusion method, the Gram-Schmidt fusion method, the least mean and variance matching method, the least square fusion method, the discrete wavelet fusion method, and the wavelet-PCA fusion method. Results of the above fusion methods are compared using various evaluation indicators such as correlation, relative difference of mean, relative variation, deviation index, peak signal-to-noise ratio index and universal image quality index, as well as visual interpretation method. Among various fusion methods, the local mean and variance matching method provides the best fusion result for the visual interpretation and the evaluation indicators. The fusion algorithm of 250m MODIS data may be used to effectively improve the accuracy of various MODIS land products.