• The Korean Journal of Applied Statistics
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• v.27 no.5
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• pp.809-818
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• 2014

Multivariate skew-normal distribution(distribution that includes multivariate normal distribution) has been recently applied to many application areas. We consider saddlepoint approximation for a statistic of linear combination based on a multivariate skew-normal distribution. This approach can be regarded as an extension of Na and Yu (2013) that dealt saddlepoint approximation for the distribution of a skew-normal sample mean for a linear statistic and multivariate version. Simulations results and examples with real data verify the accuracy and applicability of suggested approximations.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.1-20
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• 2004

Bone scan is one of the most frequently peformed studios in nuclear medicine. In bone scan, the amount of radiolsotope taken up by lesion depends primarily on the local rate of bone turnover rather than on the bone mass. Bone scan is extremely sensitive for defecting bony abnormalities. However, abnormalities that appear on bone scan may not always represent disease. The normal scan appearances may be affected not only by skeletal physiology and anatomy but also by a variety of technical factors which can influence image quality. Many normal variants and artifacts may appear on bone scan. They could simulate a pathologic process and could mislead into the wrong diagnostic interpretation. Therefore, their recognition is necessary to avoid misdiagnosis. A nuclear medicine physician should be aware of variable appearance of the normal variants and artifacts on bone scan. In this article, a variety of normal variants and artifacts mimicking real pathologic lesion in bone scan interpretation are discussed and illustrated.

• Journal of the Korean Wood Science and Technology
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• v.21 no.4
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• pp.55-59
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• 1993

한국의 중서부 지역에서 주로 벌채한 잣나무 간벌 제재목을 경기도 광주 소재 제재소에서 무작위로 추출하여 구입하였다. 본 연구는 휨강도 시험을 표준 시험 방법에 의하여 실시하였다. 각 무결점 시편으로부터 측정한 영 계수와 휨 강도에 대하여 이론적 통계 분포인 정상 분포, Log-normal 분포, Weibull 분포를 계산하여 비교하였다. Weibull 분포가 휨영계수 및 휨강도 모두에 적합하였으며, Log-normal 분포는 영계수 분포에 대한 이용에 적합하였다. 휨강도 분포에서는 Normal 분포가 Log-normal 분포보다 적합하다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.314-319
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• 2008

Near infrared (NIR) spectroscopy was used to classify normal and artificially aged nonviable corn (Zea mays L., cv. 'Suwon19') seeds. The spectra at 1100-2500nm were scanned with normal and artificially aged single seeds and analyzed by principle component analysis (PCA). To discriminate normal seeds from artificially aged seeds, a calibration modeling set was developed with a discriminant partial least square 2 (PLS 2) method. The calibration model derived from PLS 2 resulted in 100% classification accuracy of normal and artificially aged (aged) seeds from the raw, the 1st and 2nd derivative spectra. The prediction accuracy of the unknown normal seeds was 88, 100 and 97% from the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, and that of the unknown aged seeds was 100% from all the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, respectively. The results showed a possibility to separate corn seeds into viable and non-viable using NIR spectroscopy.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.7 no.1
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• pp.32-38
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• 1996

The preservation of the voice-producing mechanism is an important feature in the management of laryngeal cancer by radiotherapy. But, radiation therapy has certain side effects such as mucositis, tissue edema, necrosis and fibrosis which could effect on normal voice production. Several subjective studies that used questionnaires and auditory perceptual judgements of voice have been interpreted to mean that radiation results in a normal or near-normal voice. Objective evidence of the status of vocal function after radiation treatment, however, is still lacking. We analyzed the changes that occur in voice parameters in a group of patients undergoing radiation therapy, in order to determine the effect of radiation on voice quality. In this study acoustic, aerodynamic measures of vocal function were used to determine the characteristics of voice production. We found that voice parameters in early glottic cancer changed meaningfully comparing to normal larynx with or without radiation and radiation therapy has an little effect on normal larynx.

• Bulletin of the Korean Chemical Society
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• v.29 no.11
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• pp.2119-2124
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• 2008

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.139-146
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• 2002

The characteristics and prediction model for the shear strength of unsaturated residual soils was studied. In order to investigate the influence of the net normal stress on the shear strength, unsaturated triaxial tests and SWCC tests were carried out varying the net normal stress, and the experimental data for unsaturated shear strength tests were compared with predicted shear strength envelopes using existing prediction models. It was shown that the soil - water characteristic curve and the shear strength of the unsaturated soil varied with the change of the net normal stress. Therefore, to achieve a truly descriptive shear strength envelope for unsaturated soils, tile effect of the normal stress on the contribution of matric suction to the shear strength has to be taken into consideration. In this paper, a modified prediction model for the unsaturated shear strength was proposed.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.23 no.3
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• pp.267-282
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• 2019

This paper examines how one can build a block tridiagonal structure for k-almost normal matrices and also for k-almost conjugate normal matrices. We shall see that these representations are created by unitary similarity and unitary congruance transformations, respectively. It shall be proven that the orders of diagonal blocks are 1, k + 2, 2k + 3, ${\ldots}$, in both cases. Then these block tridiagonal structures shall be reviewed for the cases where the mentioned matrices satisfy in a second-degree polynomial. Finally, for these processes, algorithms are presented.

• Korean Journal of Community Nutrition
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• v.25 no.5
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• pp.396-405
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• 2020

Objectives: This study was conducted to compare the nutrient intake of normal healthy adults with those having hypercholesterolemia. Methods: We analyzed data from the 6th Korea National Health and Nutrition Examination Survey (KNHANES VI). A total of 12,636 adults (5,223 males and 7,413 females) aged 19 or older were included in the study. Results: Males with hypercholesterolemia were older and had a higher waist circumference, body mass index, fasting blood sugar levels (FBS) and serum triglyceride (TG) concentrations compared to the normal group. Females with hypercholesterolemia were older and had higher FBS levels and serum TG concentrations compared to the normal group. While comparing nutrient intake by the 24-hour recall method, the male normal group showed a higher intake of fat, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), vitamin A and thiamin compared to the hypercholesterolemic group. However, the male normal group had a lower intake of iron and vitamin C compared to the hypercholesterolemic group. The female normal group had a higher intake of energy, protein, fat, SFA, MUFA, polyunsaturated fatty acids, cholesterol, riboflavin, and niacin compared to the hypercholesterolemic group, but had a lower intake of iron compared to the hypercholesterolemic group. A comparison of nutrient intake by food frequency questionnaire (FFQ) showed the following: There was no significant difference in nutrient intake between the normal men and women and those with hypercholesterolemia. After adjustment for confounding factors, nutrient intake by FFQ of the male normal group showed higher levels of n-3 fatty acid and vitamin C compared to the group with hypercholesterolemia. However, there was no significant difference in nutrient intake between the two groups of women. Conclusions: The average intake of n-3 fatty acids and vitamin C of the male group with hypercholesterolemia was lower than that of the normal group. However, since KNHANES is a cross-sectional study, prospective cohort studies are required to analyze the risk factors of hypercholesterolemia.

• Korean Journal of Health Education and Promotion
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• v.19 no.4
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• pp.19-31
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• 2002

Purpose : This study examines the differences in self-efficacy and health promoting behavior between obese students and normal weight students by gender; it tries to obtain basic data for the health guidance of obese students. Methods : Data were collected from 360 students (90 normal weight males, 90 obese males, 90 normal weight females, 90 obese females) using questionnaires about general characteristics, self-efficacy, and health promoting behavior. There were analyzed with descriptive statistics (frequency, percentage, mean, standard deviation), and a x$^2$ test, ANCOVA, and a Pearson's correlation of coefficient at the 0.05 significance level by using the SAS (version 8.01) Win Program. Results : The score of self-efficacy appears that in the case of boys, obese students are significantly lower than their normal weight counterparts (F=25.85, p=<.0001), while in the case of girls there is no significant difference between the two groups (F=.01, p=.9118). The score of health promoting behavior appears that in the case of boys, obese students are significantly lower than their normal weight counterparts (F=28.61, p=<.0001), while in the case of girls there is no significant difference between the two groups (F=1.25, p=.2643). The relation of self-efficacy and health promoting behavior shows a statistically significant correlation in all cases: obese boys (r=.69, p=<.0001), normal weight boys (r=.51, p=<.0001), obese girls (r=.67, p=<.0001), and normal weight girls (r=.49, p=<.0001). Conclusions : An evaluation study needs to see whether a program to encourage the self-efficacy of obese boys can be effective in health promoting behavior or weight control in the long run. As in this study more than half of the obese girls have mild-level obesity, a follow-up study should be conducted to examine the self-efficacy and health promoting behavior between middle or highly obese students and normal weight students.