• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.1057-1063
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• 1994

An instantaneous frequency analysis is a technique to examine a signature for the rotating machinery if the signal has several transitions within a cycle. This paper discusses the conditions of existing negative frequency components in the instantaneous frequency. By using a signal consisted of two frequency components, the instantaneous frequency analysis is conducted while the amplitude ratio between two frequency components has been changed. The analysis shows that, depending on the amplitude ratio, the instantaneous frequencies have averaged, zero-valued, or negative components. It turns out that the negative-valued instantaneous frequencies, which have been regarded as the noise effect, are the consequence of the calculation process for the multisignal components. The criteria of existing the negative values in instantaneous frequencies is given in terms of the relative amplitude ratio and the frequency difference. Especially when the amplitude ratio approaches to 1, the instantaneous frequency fluctuates ${\pm}\infty$ in theory, which implies that instantaneous frequency has unstable region around the amplitude ratio, 1.Also, as the frequency difference between major signal components is increased, the region of existing negative instantaneous becomes broader. In an instantaneous frequency analysis, therefore, a narrow band analysis is suggested, with extreme care if the amplitude ratio approaches to 1. In this paper, a vibration signal monitored from a rotating machinery is also examined as an application example in order to show the existence of negative instantaneous frequencies components.

• The Journal of Korean Society for School & Community Health Education
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• v.16 no.2
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• pp.17-31
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• 2015

Objectives: This study aimed to analyze the relationship between metabolic syndrome and cataract in a middle-aged men over the age of 40's by using the data from the 5th Korean National Health and Nutrition Examination Survey(2010~2012). Methods: The subjects for the analysis were comprised of 5,808 patients who were at least 40 years or more with metabolic syndrome and cataract. The comparison between the metabolic syndrome and ophthalmic diseases according to the health demographic characteristics, health behavior and health conditions was analyzed with ${\chi}^2-test$. The complex samples logistic regression analysis was used to calculate the odds ratio of cataract according to the health demographic characteristics, health behavior and health conditions and the combination of the comprising factors of the metabolic syndrome. Results: After controlling the confounding factors, the odds ratio of cataract in the metabolic syndrome group was OR 1.30, which was significantly high (p<0.01). Furthermore, the odds ratio of cataract was significantly high in the case of males, as the age increased, educational level decreased, with exercising habits of less than 3 days a week, sun exposure of at least 5 hours, with hypertension and diabetes (p<0.01). The results of analyzing the odds ratio for the occurrence of cataract with the components of metabolic syndrome were OR 1.36 (concurrent high fasting blood glucose, high triglycerides, low HDL cholesterol), OR 1.63 (concurrent high fasting blood glucose, high triglycerides, high waist circumference) and OR 1.33 (high triglycerides, low HDL cholesterol, high waist circumference), which showed significantly high odds ratio for cataract occurrence (p<0.05). Conclusions: We come to know that the relation between metabolic syndrome and components are associate with cataract. Therefore the thorough management of metabolic syndrome and components is needed to prevent cataract.

• Journal of Conservation Science
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• v.33 no.2
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• pp.75-83
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• 2017

This study produced smelting slag through the reproduction of an ancient iron manufacturing technique, with the aim of facilitating a comprehensive understanding of the process by analyzing the slag components. The research suggests an interpretation method using the ratio of the subcomponents relative to the main slag components as an alternative to existing methods. We investigated the component source within the smelting furnace from which the slag is derived by developing an understanding of the tendency between slags. Based on bivariate graph and triangular coordinate data analysis, it was found that a slag can be categorized according to its components. The groups were identified as the ore slag group(centered on the ore), and the clay slag group(centered on clay and granite soil). This research determined that it is possible to estimate the components derived from the slag, depending on which group they belong to or resemble, as shown in Figure 4~7. It was found that a comprehensive understanding of the ratio between the components was more accurate than a simple analysis of the contents, for the interpretation of ancient iron manufacturing processes. This is based on the fact that a higher ratio of $TiO_2$ was detected by the components analysis, and an analysis of all the slag showed that the value of $CaO/SiO_2$ ratio was lower than 0.4, which corresponds to the reproduction experiment condition in which flux was not used.

• The Journal of Internal Korean Medicine
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• v.27 no.1
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• pp.55-71
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• 2006

Objectives : To find out more pharmacologically efficient way of extraction of herbal dicoction, Gamichungsangbohatang (GMCSBHT). Methods : Several main components of GMCSBHT was compared and analysed between hot water extract of GMCSBHT and Alcohol(70% ethanol) extract of GMCSBHT via HPLC method. Results : Hot water extract of GMCSBHT showed relatively more component content than ethanol extract of GMCSBHT. Also weighted mean of main components of hot water extraction of GMCSBHT was higher than that of alcohol extract of GMCSBHT. But from chromatographic pattern analysis of matching ratio and similarity ratio showed that these two forms of extracts might have different chemical composition, and 3D PDA plot of alcohol extract of GMCSBHT showed high peaks near UV $190{\sim}220nm$ which was invisible in hot water extract of GMCSBHT. Conclusion : Alcohol extract of GMCSBHT may have some special components which do not exist in hot water extract of GMCSBHT.

• Journal of Korean Public Health Nursing
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• v.31 no.2
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• pp.376-388
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• 2017

Purpose: The triglyceride-to-high-density lipoprotein-cholesterol (TG/HDL-C) ratio is one of the main predictive indices for cardiovascular disease. This study was examined the relationship between TG/HDL-C ratio and metabolic syndrome (MetS) in male office workers. Methods: Secondary analysis was conducted to determine the risk between the TG/HDL-C ratio and MetS in male office workers. A total of 765 people underwent the 'regular workplace health checkups in 2014'. Among the subjects who were male and responded to the questionnaire and health lifestyle survey, 470 (61.4%) excluding those with missing and/or abnormal values were analyzed. The association between MetS, MetS components, and the TG/HDL-C ratio was examined by a Chi-square test, One-way ANOVA, Turkey post-hoc test and Logistic regression analysis. Results: The number of males with MetS was 70 (14.9%) and the number of MetS components increased with increasing TG/HDL-C ratio (p<.001). Logistic regression analysis with an adjustment for potential confounders revealed a 31.8 times higher odds ratio of the Quartile4 group for MetS than that of the Quartile1 group (p<.001). Conclusion: These results show that the likelihood of MetS, particularly the risk of MetS in the Quartile4, increases with increasing TG/HDL-C ratio.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.672-679
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• 1996

In order to examine the quality attributes of native-bee honey, proximate composition and mineral components were analysed by atomic absorption spectrometry, ion chromatography and high performance liquid chromatography. The analytical results showed that native-bee honey is higher in the contents of crude ash, crude protein and diastase activity than those of foreign-bee honey. The principal mineral components of honey were Ca, Mg, Na, K and Cl, which showed that almost all the mineral components were contained higher in the native-bee honey than the foreign-bee honey samples. When we calculated K/Na ratio, we could make a clear distinction between native-bee honey and foreign-bee honey. The K/Na ratio turned out to be more than 10 in 6 samples of native-bee honey, whereas the ratio of foreign-bee honey showed up less than 1.5 in all 3 samples.

• Journal of Korea Multimedia Society
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• v.23 no.12
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• pp.1586-1593
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• 2020

This study was conducted on the face ratio of mammals. It can also be applied to character automation by checking factors about the difference between animal and human face shapes. This paper used the face and face area data generated for Deep Learning learning. In detail, the proportion factors of the area comprising the faces of 20 species of animals and humans were defined and the average ratio was calculated. Next, the proportion of each animal was analyzed using the Principal Component Analysis (PCA). Through this, we would like to propose the golden ratio of mammals.

• Earthquakes and Structures
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• v.8 no.5
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• pp.1069-1089
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• 2015

This paper presents average numerical results of 2128 nonlinear dynamic finite element (FE) analyses of lightweight acceleration-sensitive non-structural components (NSCs) attached to the floors of one-bay three-storey reinforced concrete (RC) primary structures (P-structures) with different eccentricity ratios. The investigated parameters include the NSC to P-structure vibration period ratio, peak ground acceleration, P-structure eccentricity ratio, and NSC damping ratio. Appropriate constitutive relationships were used to model the behaviour of the RC P-structures. The NSCs were modelled as vertical cantilevers fixed at their bases with masses on the free ends and varying lengths so as to match the vibration periods of the P-structures. Full dynamic interaction was considered between the NSCs and P-structures. A set of seven natural bi-directional ground motions were used to evaluate the seismic response of the NSCs. The numerical results show that the acceleration response of the NSCs depends on the investigated parameters. The accelerations of the NSCs attached to the flexible sides of the P-structures increased with the increase in peak ground acceleration and P-structure eccentricity ratio but decreased with the increase in NSC damping ratio. Comparison between the FE results and Eurocode 8 (EC8) predictions suggests that, under tuned conditions, EC8 provisions underestimate the seismic response of the NSCs mounted on the flexible sides of the plan-irregular RC P-structures.

• Journal of Korean Elementary Science Education
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• v.26 no.1
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• pp.76-86
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• 2007

The purpose of this study is to investigate the characteristics of scientific argumentation and its development in the process of mutual discussion activities by elementary school students in the 5th grade. The results of this study can be summarized as below: First, students used diversity argumentation components for solving the given argumentation theme, however, most students used the assertion or the basis of a simple expression of their own thoughts as a high ratio, and components of a one directional explanatory argumentation process rather than components of a mutual communicative argumentation process. Second, an asymmetric group showed a high-use ratio of communicative argumentation components and achieved argumentation activities harmoniously between a symmetric group and an asymmetric group in organization of groups for solving argumentation themes. It was found that students in the transitional period showed the highest rate of participation within the discussion process. Moreover, they also showed the highest rate of development of discussion skills whilst in the process of using scientific problems. In conclusion, this phenomenon is caused by highlighting the mutual action between the teacher and the student rather than placing an emphasis on the mutual action among students during field instructions.

• Earthquakes and Structures
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• v.6 no.4
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• pp.351-373
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• 2014

This paper investigates the seismic response of lightweight acceleration-sensitive non-structural components (NSCs) mounted on irregular reinforced concrete (RC) primary structures (P-structures) using non-linear dynamic finite element (FE) analysis. The aim of this paper is to study the influence of NSC to P-structure vibration period ratio, peak ground acceleration, NSC to P-structure height ratio, and P-structure torsional behaviour on the seismic response of the NSCs. Representative constitutive models were used to simulate the behaviour of the RC P-structures. The NSCs were modelled as vertical cantilevers fixed at their bases with masses on the free ends and varying lengths so as to match the frequencies of the P-structures. Full dynamic interaction is considered between the NSCs and P-structures. A set of 21 natural and artificial earthquake records were used to evaluate the seismic response of the NSCs. The numerical results indicate that the behaviour of the NSCs is significantly influenced by the investigated parameters. Comparison between the FE results and Eurocode (EC8) predictions suggests that EC8 underestimates the response of NSCs mounted on the flexible sides of irregular RC P-structures when the fundamental periods and heights of the NSCs match those of the P-structures. The perceived cause of this discrepancy is that EC8 does not take into account the amplification in the dynamic response of NSCs induced by the torsional behaviour of RC P-structures.