• Korean Journal of Mathematics
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• v.21 no.3
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• pp.331-344
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• 2013

In the present article, we describe specific elements in a motivic cohomology group $H^1_{\mathcal{M}}(Spec\mathbb{Q}({\zeta}_l),\;\mathbb{Z}(2))$ of cyclotomic fields, which generate a subgroup of finite index for an odd prime $l$. As $H^1_{\mathcal{M}}(Spec\mathbb{Q}({\zeta}_l),\;\mathbb{Z}(1))$ is identified with the group of units in the ring of integers in $\mathbb{Q}({\zeta}_l)$ and cyclotomic units generate a subgroup of finite index, these elements play similar roles in the motivic cohomology group.

• Journal of Biosystems Engineering
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• v.37 no.4
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• pp.215-224
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• 2012

Purpose: This study was conducted to classify the energy efficiency of 131 tractor models tested during from 2006 to 2010 in Korea. Methods: Four sub-indexes were developed using the fuel consumptions at 60% and 90% of rated speed with partial loads and at pull speeds of 3.0 km/h and 7.5 km/h with maximum drawbar pull. Weighting factors of the sub-indexes were also considered to reflect the characteristics of tractor's actual working hours in Korea. Four sub-indexes were integrated into a classification index. Using the developed classification index, a five-classification system was made on the basis of normal distribution of tractors over the classification range. Percentage of $1^{st}$ grade interval was expected to be close to 15%, $2^{nd}$ grade 20%, $3^{rd}$ grade 30%, $4^{th}$ grade 20%, $5^{th}$ grade 15%. Results: Number of $1^{st}$ grade was 21, $2^{nd}$ grade 23, $3^{rd}$ grade 39, $4^{th}$ grade 33, $5^{th}$ grade 15 among 131 models. Conclusions: Classification index was developed by integrating four sub-indexes. By the classification method using developed index, distribution of classified tractors was acceptable for practical application.

• Journal of Environmental Science International
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• v.24 no.7
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• pp.907-915
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• 2015

The tap water is generally known to be corrosive in the pH range at 6.5 ~ 7.5. And the degree of corrosion varies depending on the types of raw water such as river surface water or lake water of the dam. Although several corrosion index represents the corrosivity of tap water, the typical corrosion indexes such as Langelier saturation index (LI) and calcium carbonate precipitation potential (CCPP) were calculated to monitoring the corrosive water quality about raw and tap water in water distribution system. To control the corrosive water quality, the correlation between corrosion index and water quality factors were examined. In this study, corrosion index (LI, CCPP) and the pH was found to be most highly correlated.

• Journal of Information Science Theory and Practice
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• v.9 no.3
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• pp.56-75
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• 2021

We introduce a new research assessment measure, called the research excellence index. The measure, which we denote by RE-index, accurately assesses the research performance of a researcher. The methodology used in deriving the RE-index tackles many of the flaws of popular research performance indicators such as publication counts, citation counts, and the h and g indices. A dataset is introduced, which takes advantage of the wide coverage of Scopus and the Library of Congress, and, at the same time, deals with the Scopus database depth problem. For an academic publication x, a prestige-type and length scores are assigned, and if x is published in an academic periodical publication J, the stature of J is identified through a quartile score. The three scores are used to assign a value score to every academic publication, and cited academic publications are given citation scores that encompass both cases of including and excluding self-citations. The foregoing scores are used to derive another set of scores measuring the combined qualitative and quantitative aspects of the creative work, citations of creative work, informative work and citations of informative work of a researcher. The scores take into consideration co-authorship. From these scores, two versions of the RE-index for a researcher are derived, covering the cases of including and excluding self-citations. The new measure is calculated for two mathematicians.

• Journal of The Korean Astronomical Society
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• v.55 no.2
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• pp.59-66
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• 2022

Stellar magnetic activity is important for formulating the evolution of the star. To represent the stellar magnetic activity, the S index is defined using the Ca II H+K flux measure from the Mount Wilson Observatory. Mg II lines are generated in a manner similar to the formation of Ca II lines, which are more sensitive to weak chromospheric activity. Mg II flux data are available from the International Ultraviolet Explorer (IUE). Thus, the main purpose of this study was to analyze the magnetic activity of stars. We used 343 high-resolution IUE spectra of 14 main-sequence G stars to obtain the Mg II continuum surface flux and Mg II line-core flux around 2,800 Å. We calculated S index using the IUE spectra and compared it with the conventional Mount Wilson S index. We found a color (B - V ) dependent association between the S index and the Mg II emission line-core flux. Furthermore, we attempted to obtain the magnetic activity cycles of these stars based on the new S index. Unfortunately, this was not successful because the IUE observation interval of approximately 17 years is too short to estimate the magnetic activity cycles of G-type stars, whose cycles may be longer than the 11 year mean activity cycle of the sun.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.367-374
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• 2005

This paper proposes a sound quality index to evaluate the vehicle interior noise. The index was developed using a correlation analysis of an objective measurement and a subjective evaluation data. First, the objective set of measurements was obtained at two specified driving conditions. One is from a wide-open test condition and the other is from a constant-speed test condition. At the same time, subjective evaluation was carried out using a score of ten scale where 17 test engineers participated in the experiment. The correlation analysis between the psycho-acoustic parameters derived from the objective measurement and the subjective evaluation was performed. The most critical factors at both test conditions were determined, and the corresponding equations for the sound quality were obtained from the multiple factor regression method. Finally, a comparative work between previous index and present index was performed to validate the effectiveness of the proposed index.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.306-312
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• 2008

This study investigated the influence of pH on the color development of melanoidins formed from amino acid enantiomer model systems. For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry. The browning and browning index showed no difference according to the type of amino acid enantiomers, while that formed from the D-Asn system was the only difference according to pH level. The tristimulus value of melanoidins formed from all model systems was located on a dominant wavelength of 475 nm, the blue zone of the diagram. In addition, the $L^*$, $a^*$, $b^*$, $C^*_{ab}$ values, and ${\Delta}E^*$ index on the basis of the type of amino acid enantiomers, the differences were markedly found at pH 4.0. At pH 7.0, significantly differences were found in the $L^*$, $a^*$, $b^*$ values, and ${\Delta}E^*$ index and not in the case of the lysine enantiomers. In addition, at pH 10.0, the differences were found in the $a^*$ and $b^*$ values from the lysine enantiomers and $C^*_{ab}$ value from the asparagine enantiomers. Therefore, the color development of melanoidins was influenced by the type of amino acid enantiomers and pH levels. Especially, it is thought that the $a^*$ and $b^*$ values can be used to explain the differences among the amino acid enantiomers in the color development of melanoidins.

• Korean Journal of Acupuncture
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• v.28 no.4
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• pp.79-89
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• 2011

Objectives : The aim of this study is to propose the W area of pulse (AW) as a new index which can confirm the arteriosclerosis by analyzing parameters of 5-level pressure pulse waveform measurement system for normotensive group according to aging. Methods : We measured radial pulse waveforms of normotensive group (20 to 60 years old) using 3-dimensional pulse imaging analyser (DMP-3000, DAEYOMEDI Co., Korea). And then we analyzed various parameters for sclerosis of the arteries such as Height (h1, h2, h3, h4, h5), Time (t1, t2, t3, t4, t5), AW, AW rate, Total area of pulse (At) and Augmentation Index (AIx). Results : As a result of analyzing parameters according to the aging, h2, h3, AS (systolic area rate to AT), AIx and AW were increased but t2/t, t3/t, t5/t and AD (diastolic area rate to AT) were decreased. Conclusions : We checked blood vessel conditions for normotensive group according to aging and confirmed various parameters. Also, we found that AW was analogous to AIx which has been used for diagnosing arteriosclerosis. Furthermore, we confirmed the usefulness of AW as a new parameter for checking vessel condition and characteristic compared with the AIx.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.298-305
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• 2017

This study aimed to compare chair-side test results for caries risk assessment and evaluate how well the tests reflect caries experience. The study was conducted on children aged < 6 years in primary dentition. Dental examination of children was conducted to determine the dmft index and subjects were divided into two groups : group I (dmft < 6), group II (dmft > 6). This study used four kinds of test kits (Plaque-check PH kit, Saliva-check buffer kit, Saliva-check mutans kit, Cytoperio analysis system). Saliva buffer capacity was significantly low in the high caries experience group (dmft > 6) and correlated with dmft index. Saliva pH level correlated significantly with saliva buffer capacity. The results showed that plaque pH and saliva pH levels had no correlation with dmft index. The Streptococcus mutans level measured by using the Saliva-check mutans and Cytoperio analysis system did not correlate with dmft index.

• Journal of Oral Medicine and Pain
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• v.1 no.1
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• pp.8-13
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• 1973

The authors had studied the oral environmental changes by salivary salivary pH, amount, periodontal Index in patient with active pulmonary tuberculosis patients. Among the subjects, The experimental group was consisted of 100 patients (50 males and 50 females) of 20-29 years and 100 persons of control group (50 males and 50 females) of 20-29 years. The measurement of salivary amount was performed with wide mouthed plastic (2 Inches) bottle for avoidance of Ionization of SiO2 by using of glass bottle and salivary pH was checked by pH meter 27 radiometer Copenhagen. The results are as follows : 1. The slivary pH does not appear to be characteristic of tuberculous paticents. 2. The obtained salivary amount indicated no significant to the tuberculous patients as compared to the obtained supposedely wealthg individuals. 3. The Russel Index wasfound higher and there had found more periodontal involvement(3 times than normal) in the experimental group.