• 충청수학회지
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• 제6권1호
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• pp.113-130
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• 1993

In this paper, we introduce certain subgroups $E^{Rel}_n$ (X, Y, K, G) of the relative homotopy groups ${\sigma}_n$(X, Y, K, G) of a transformation group and examine the algebraic properties of these groups.

• 충청수학회지
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• 제5권1호
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• pp.9-21
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• 1992

We define a certain subgroup $E_n$ (X, K, G) of the relative homotopy groups of a transformation group ${\sigma}_n$(X, K, G). The algebraic properties of these groups are examined.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.878-883
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• 2001

The effects of external excitation with various frequencies and amplitudes on the flame behavior and pollution emission characteristics from a laminar jet flame are experimentally investigated. Measurements of $NO_{x}$ emission indices($EINO_{x}$), performed in unconformed and vertical lifted flame at resonance frequency by strong excitation, have been conducted experimentally. It was also conducted to investigate the effects of excited frequency on $NO_{x}$ emissions with a various frequency ranged 0Hz to 2kHz. From the vertical lifted flame like turbulent of the excited jet with resonance frequency was shown that the dependence of $NO_{x}$ emission could be categorized into three groups: Group 1 of intermediate flame length and relative narrow flame volume yielding low $NO_{x}$ emission, Group 2 of short flame length but large flame volume yielding high $NO_{x}$ emission and Group 3 of long flame length with low temperature contours yielding high $NO_{x}$ emission.

• 복식
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• 제48권
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• pp.37-52
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• 1999

The purpose of this study was to find out the clothing-consumption propensity(CCP) and to classify consumption types in CCP and to classify consumption types in CCP and to compare the classfied groups on their consumer characteristics among Korean female X-generation. The survey method was conducted for this study. The subjects are 477 Koran femal X-generation whose age ranges from 18 to 29 and who reside in Seoul and its adjoined areas. The span of the survey was February through March in 1998. the results were analyzed by using of SPSS/PC+package. 1. The clothing consumption motives among the female X-generation were the sensuous satisfaction for posession motive the were practical necessity of the purcahse successively in order. The clothing consumption attitude were the practical electicism the effective value the favorable attitude on low price goods toward sale items and the self-control over their consumption. 2. According to the CCP consumers were classified into five groups: electice and practical group ostentatious and extravagant group passive and economical group sensuous and practical group and sale-fond group. The respective group showed significant difference in the nine factors of the CCP. 3. Consumtion type group had significantly difference in lifestyle among consumer factor and materialistic propensity influence of economic recession follow consumption among social influence factors.

• International Journal of Oral Biology
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• 제46권2호
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• pp.94-97
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• 2021

The purpose of this study was to introduce a new in vitro method for evaluating the antimicrobial activity of toothpaste, reflecting the actual toothbrushing time and the dilution of toothpaste by salivation. We designed three experimental groups and one negative control group. The experimental groups were (1) 90 μL of toothpaste + 10 μL 1X phosphate-buffered saline (PBS, 9/10 dilution group), (2) 50 μL of toothpaste + 40 μL 1X PBS (1/2 dilution group), and (3) 25 μL of toothpaste + 65 μL 1X PBS (1/4 dilution group). During toothbrushing, saliva is continuously secreted into the oral cavity and the toothpaste concentration is diluted over time during toothbrushing. Therefore, the 1/2 and 1/4 dilution experimental groups were added. The negative control group was toothpaste diluted 20,000-fold with 1X PBS. Miracle Fresh Doctor toothpaste and Streptococcus mitis KCOM 1350, Prevotella intermedia KCOM 1107, Fusobacterium nucleatum subsp. polymorphum KCOM 1322, and Aggregatibacter actinomycetemcomitans KCOM 1306 were used as the toothpaste and target bacterial strains, respectively. The number of bacterial cells plated on agar plates in the negative control group was 1,000 CFU. If the number of colonies on the experimental group plate was less than one, the treatment was considered to have > 99.9% bactericidal activity. These results suggest that this new in vitro method for antimicrobial evaluation could be used as the standard method for testing the antimicrobial activity of toothpaste.

• 한국전기전자재료학회논문지
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• 제21권6호
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• pp.544-551
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• 2008

We have studied the dielectric characteristics of low-k interlayer dielectric materials fabricated by PECVD for various precursor's flow rates. BTMSM precursor was introduced with the flow rates from 42 sccm to 60 sccm by 2 sccm step in the constant flow rate of 60 sccm $O_2$. The absorption intensities of Si-O-$CH_x$ bonding group and Si-$CH_x$ bonding group changed synchronously for the variation of precursor flow rate, but the intensity of Si-O-Si(C) responded asynchronously with the $CH_x$ combined bonds. The heat treatment reduced the FTIR absorption intensity of Si-O-$CH_x$ bonding group and Si-$CH_x$ bonding group but increased the intensity of Si-O-Si(C). The nanopore and free space formed by the increasement of caged link mode and cross link mode of Si-O-Si(C) group implied the origin of low-k SiOCH films.

• Journal of Welding and Joining
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• 제32권6호
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• pp.1-7
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• 2014

For the resistance spot welds of CR1180 and GA1180 TRIP steels, the weld quality evaluation method using the digitalized X-ray transmission imaging apparatus was investigated in comparison with the crosssectional examination method. In the case of the resistance spot welding of CR1180, three circular regions, such as WZ(white zone), GZ(grey zone) and DZ(dark zone), appeared on X-ray image and they corresponded to the diameters of indentation mark, nugget and corona bond, respectively. The variation of X-ray transmission thickness due to the thickness variation of the weld seemed to be mainly responsible for the formation of those contrasts. The X-ray image contrast formed from the variation of transmission thickness at the outer border line of DZ could also enable the inspections of the notch shape, nonuniformity of the welding pressure and spatter from its sharpness, concentricity and the normal straight line, respectively. The X-ray image of the resistance spot weld of galvannealed GA1180 TRIP steel was very similar to that of CR1180 TRIP steel except the crown shaped outer border line of DZ which was considered to be due to the melting behavior of zinc having the boiling temperature even lower than the melting temperature of steel.

• Kyungpook Mathematical Journal
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• 제61권1호
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• pp.23-32
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• 2021

Let D be an integral domain with quotient field K, X an indeterminate over D, ∗ a star operation on D, and Cl∗ (D) be the ∗-class group of D. The ∗w-operation on D is a star operation defined by I∗w = {x ∈ K | xJ ⊆ I for a nonzero finitely generated ideal J of D with J∗ = D}. In this paper, we study two star operations {∗} and [∗] on D[X] defined by A{∗} = ∩P∈∗w-Max(D) ADP [X] and A[∗] = (∩P∈∗w-Max(D) AD[X]P[X]) ∩ AK[X]. Among other things, we show that Cl∗(D) ≅ Cl[∗](D[X]) if and only if D is integrally closed.

• Journal of Acupuncture Research
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• 제32권2호
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• pp.187-195
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• 2015

Objectives : The purpose of this study is evaluating the effect of Poria cocos pharmacopuncture (PCP) at $SP_6$(Sameumgyo) and $ST_{36}$(Joksamni) on chronic stress model(CSM) rats. Methods : The experimental rats were assigned to five groups: normal, CSM(control), PCP1X, PCP2.5X and PCP5X. The experimental rats in CSM(control), PCP1X, PCP2.5X and PCP5X were put through a timetable to cause CSM. PCP($20{\mu}l$) was administered at $SP_6$, $ST_{36}$ to groups PCP1X, PCP2.5X and PCP5X once every three days for a total of six times. The weight of the rats was measured by an electronic scale after PCP injection, once every three days for a total of six times. Blood samples were taken from the rats for analysis of aspartate aminotransferase(AST) and alanine aminotransferase(ALT). Serotonin and norepinephrine were measured by enzyme-linked immunosorbent assay(ELISA) kit. Results : The experimental groups(PCP1X, 2.5X, 5X) showed significant body weight increase compared to the control group. Regarding AST and ALT changes in serum, the experimental groups(PCP2.5X, 5X) showed a significant decrease compared to the control group. For Serotonin changes in serum, the experimental group(PCP5X) showed a significant increase compared to the control group. For Norepinephrine changes in serum, the experimental groups(PCP2.5X) showed a significant decrease compared to the control group. Conclusions : These data suggest that PCP at $SP_6$, $ST_{36}$ has therapeutic effects on CSM rats.

• 충청수학회지
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• 제22권3호
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• pp.497-506
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• 2009

This work studies about the composition polynomial f(g(x)) that preserves certain properties of f(x) and g(x). We shall investigate necessary and sufficient conditions of f(x) and g(x) to be f(g(x)) is separable, solvable by radical or split completely. And we find relationship of Galois groups of f(g(x)), f(x) and of g(x).