• 대한기계학회논문집
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• 제18권4호
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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.

• 한국학교ㆍ지역보건교육학회지
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• 제16권2호
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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.

• 보존과학회지
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• 제33권2호
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• pp.75-83
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• 2017

본 연구는 고대 제철로 재현실험의 제련 슬래그를 대상으로 성분을 분석하고, 기존의 연구방법 대신 슬래그의 주성분에 대한 다른 성분들의 상대적인 비율을 활용한 해석 방법을 제시하여 슬래그 간의 경향성을 파악함으로써 노(爐)내에서 슬래그가 기인된 성분 출처를 연구하고자 하였다. 분석 데이터를 이변량 및 삼각좌표 비교 분석 그래프로 작성한 결과 기준시료의 주요 성분에 따라 일정한 경향성을 띠며 그룹을 형성하는 것이 확인되었다. 기준시료인 광석을 중심으로 형성된 광석 슬래그군은 CaO와 $TiO_2$함량이 높았고, 점토와 마사토를 중심으로 형성된 점토 슬래그군은 $Al_2O_3$와 $SiO_2$함량이 높았다. 또한 그래프 상에서 군집에 속하지 못하는 경우 어느 군집에 더 근접한가에 따라 슬래그가 기인한 성분의 추정이 가능한 것으로 판단하였다. 실험에 사용된 광석 및 점토, 첨가제와 제련 슬래그에서 공통적으로 $TiO_2$함량이 1.6% 이상으로 비교적 높게 나타났고, 모든 슬래그 분석 결과에서 $CaO/SiO_2$값이 0.4 이하로 분석되었다. 복원실험이 철광석 제련이었다는 점과 조업 시 조재제를 첨가하지 않았다는 것을 고려했을 때, 슬래그를 해석하는데 있어 단순 함량보다 성분 간 비율을 종합적으로 파악하는 방법이 더욱 정확한 해석 방법이 될 수 있을 것으로 판단된다.

• 대한한방내과학회지
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• 제27권1호
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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.

• 한국보건간호학회지
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• 제31권2호
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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.

• 한국식품영양과학회지
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• 제25권4호
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• pp.672-679
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• 1996

토종꿀파 양봉꿀의 이화학적 특성을 비교, 분석하였고 벌꿀에 함유되 어 있는 무기성분 중 K/Na ratio를 이용하여 토종꿀의 판별가능성을 고찰하였다. 벌꿀의 이화학적 특성을 살펴 본 결과, 토종꿀과 양봉꿀의 일반성분 중에서 가장 차이가 두드러진 항목이 회분과 조 단백질이었는데 토종꿀의 함량은 평균 0.31% 및 0.28%, 양봉꿀의 평균 함량은 0.11%및 0.13%로서 토종꿀이 휠씬 높게 나타났다. 벌꿀 중의 proline과 diastase activity는 토종꿀이 평균 13.6mg%, 31.7unit, 양봉꿀은 평균 16.4mg%, 17.0unit로서 proline 함랑은 양봉꿀이 높았으며, diastase activity는 토종꿀이 더 높았다. 무기성분은 토종꿀이 양봉꿀에 비해 월등히 많이 함유하고 있는 성분이 었는데, 주요 무기성 분은 Ca, Mg, Na, K, Cl 등으로 토종꿀에서는 K가 가장 높은 함량을 보인 반면 양봉꿀에서는 Cl이 가장 높은 함량을 보였다. 본 실험에서 분석하였던 무기성분 중 K와 Na의 조성비를 이용하였더니 토종꿀과 양봉꿀의 특성이 분명하게 구분되었다. 토종꿀의 K/Na ratio는 실험 에 사용하였던 6점 모두 10 이상으로 나타난 반면 양봉꿀은 3점 모두 1.5 이하로 나타나 토종꿀을 판별할 수 있는 하나의 지표로서의 가능성이 있는 것으로 판단되었다.

• 한국멀티미디어학회논문지
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• 제23권12호
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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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• 제8권5호
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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.

• 한국초등과학교육학회지:초등과학교육
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• 제26권1호
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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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• 제6권4호
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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.