• 대한수학회보
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• 제32권2호
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• pp.179-189
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• 1995

Let $V \subset R^n$ be a convex homogeneous cone which does not contain straight lines, so that the automorphism group $$ G = Aut(R^n, V)^\circ = { g \in GL(R^n) $\mid$ gV = V}^\circ $$ ($\circ$ denoting the identity component) acts transitively on V. A convex cone V is called "self-dual" if V coincides with its dual $$ (1.1) V' = { x' \in R^n $\mid$ < x, x' > > 0 for all x \in \bar{V} - {0}} $$ where $\bar{V}$ denotes the closure of V.sure of V.

• 대한수학회지
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• 제42권4호
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• pp.635-653
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• 2005

We study the distribution of a dense orbit of a lattice A acting by the right multiplication on the space $\Gamma/G$ where G is a connected simple Lie group and $\Gamma$ its lattice. We show that for $G=SL_n(\mathbb{R})$, every dense orbit is equidistributed with respect to the Euclidean norm.

• 한국수자원학회논문집
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• 제43권1호
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• pp.15-24
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• 2010

최근에는 확률강우량을 산정할 경우 지점빈도해석의 단점을 보완한 지역빈도해석법이 자주 실무에 적용되고 있으나, 가뭄에 관련한 연구에서는 대부분 아직까지 지점자료를 이용한 가뭄분석을 실시하고 있다. 본 연구에서는 가뭄의 지역적 특성 분석을 실시하기 위하여 필요한 동질한 가뭄특성을 지닌 지역을 구분하는 연구를 수행하였다. 본 연구에서는 기상청 강우관측 지점자료 중 30년 이상의 강우자료를 보유한 58개의 관측지점을 대상으로 표준강수지수(SPI)를 산정하여 가뭄의 심도, 지속기간, 강도, 발생빈도 등과 같은 가뭄특성인자를 생성하였다. 가뭄특성인자는 수문학적으로 동질한 특성을 지닌 지역을 구분하는데 중요한 정보를 제공한다. 본 연구에서는 다양한 가뭄특성인자를 효율적으로 활용하여 K-means 기법을 적용한 군집분석을 실시하여 동질한 가뭄특성을 지닌 지역을 6개 지역으로 구분하였다. 이러한 지역구분은 가뭄 특성의 공간적 해석을 가능하게 할 수 있고, 지점빈도 해석의 단점을 보완하는 지역빈도 해석도 가능하게 할 수 있다.

• 대한간호학회지
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• 제42권3호
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• pp.405-413
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• 2012

Purpose: The aim of this study was to explore the effects of A-solution on halitosis and oral status in preoperative NPO patients. Methods: A nonequivalent control group, non-synchronized pretest-posttest design was used in this study. The participants in this study were 66 patients who were admitted for gynecologic surgery. The experimental treatment was to give oral gargling with A-solution, blended essential oils and diluted with distilled water. To identify the experimental treatment effects, halitosis, salivary pH, and oral status were measured by a portable halitosis detector, visual analogue scale, Bromo Thymol Blue (BTB), Bromo Cresol Purple (BCP) test paper and oral assessment guide. Data were analyzed using $X^2$-test, t-test with PASW 18.0 version. Results: Participants were homogeneous before experimental treatment. Objective halitosis in the experimental group, measured by a portable halitosis detector (t=-8.34, p<.001) was significantly lower than the control group. Subjective halitosis was significantly lower in the experimental group (t=-9.29, p<.001). Salivary pH was significantly different between two groups (t=8.81, p<.001). Oral status was significantly better in the experimental group (t=-13.31, p<.001). Conclusion: These findings indicate that oral gargling using A-solution is effective in reducing patient halitosis, and improving oral status.

• 한국수학교육학회지시리즈A:수학교육
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• 제56권1호
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• pp.1-17
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• 2017

The purpose of this study is to analyze the differences between the cognitive load of mathematics textbooks based on storytelling and traditional mathematics textbooks that are presented to students. In order to verify this, we have selected two 4th grade classes in elementary school that were identified as a homogeneous group through prior testing, and thus were separated into experimental group and comparative group. Then, without the teacher's lessons, the experimental group learned from mathematics textbooks based on storytelling and the comparative group learned from traditional mathematics textbooks. Afterwards, the two groups' cognitive load was measured through a questionnaire, and the following results were obtained: In the 'mental effort' and 'self evaluation' categories, the students that learned from the mathematics textbook based on storytelling showed higher scores than the students that learned from the traditional mathematics textbook. also there was statistically significant difference in some items. However, no statistically significant difference was found in the remaining categories 'task difficulty', 'self evaluation', and 'material design'.

• BMB Reports
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• 제28권1호
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• pp.33-39
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• 1995

The Gelatinases (typeIV collagenases) are metalloproteinases that may play an important role in tumor invasion and metastasis. Progelatinase A was purified from a conditioned medium of T98G human glioblastoma cells. TIMP-2 complexed progelatinase A and free progelatinase A were separated by heparin affinity HPLC. The final product was homogeneous on SDS-PAGE, with a molecular weight of 64,000 daltons without reduction. TIMP-2 and free progelatinase A were separated from TIMP-2 complexed progelatinase A by reverse-phase HPLC in the presence of trifluoroacetic acid. TIMP-2 complexed progelatinase A was resistant to activation by p-aminophenyl mercuric acetate (APMA), and showed less than 20% of the activity of the TIMP-2 free active enzyme. TIMP-2 free progelatinase A was easily activated to the mature form with a molecular weight of 57,000 daltons by APMA and showed high activity compared to the TIMP-2 complexed enzyme.

• Journal of Korean Biological Nursing Science
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• 제16권2호
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• pp.141-149
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• 2014

Purpose: The purpose of this study was to compare the effects of gargling with A-Solution and 0.9% normal saline on xerostomia, halitosis, and salivary pH among nursing students. Methods: The study design was a randomized, controlled trial. The experimental group received oral gargling treatment for 15 seconds with A-solution while the control group received oral gargling treatment for the same time with 0.9% normal saline. Outcome variables were measured at baseline, 60 minutes, and 120 minutes. Results: The groups were homogeneous in general characteristics, and the outcome variables before the treatment between the experimental group and the control group. 1) There were no significant differences in xerostomia, halitosis, and salivary pH between the two groups. 2) There were no significant differences in xerostomia, halitosis, and salivary pH based on the time. 3) There were significant interactions between group and time in subjective halitosis (F=3.766, p=.034) only. Conclusion: These findings indicate that oral gargling with Aroma solution and 0.9% normal saline could have the same effect of reducing xerostomia and halitosis in nursing students.

• 보건교육건강증진학회지
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• 제27권4호
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• pp.17-27
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• 2010

Objectives: The aim of this study was to compare the knowledge and attitudes about AIDS between an activity-oriented and a lecture-oriented AIDS prevention education in middle school boys. Methods: Each of 60 middle school boys in M city, Gyeongsangnam-do, was assigned to the experimental or control group. The activity-oriented AIDS prevention education in experimental group and the lecture-oriented education in control group were provided for a 45 minutes class per week for 4 weeks, respectively. Date were collected with questionnaires and analyzed through $x^2$-test, t-test, and repeated measures ANOVA. Results: The experimental group and control group were homogeneous in knowledge and attitudes about AIDS prevention before the study. In AIDS prevention knowledge, there was no significant interaction of times by groups (F=0.033, p=.930); but the main effect of times was significant (F=63.950, p<.001). In attitudes toward AIDS, there was a significant interaction of times by groups (F=8.892, p<.001). Conclusion: The activity-oriented AIDS prevention education was an effective teaching strategy to foster positive attitudes toward AIDS prevention in middle school boys. Therefore, systematic and sustained development of AIDS prevention education reflecting learners' characteristics is required.

• 한국분말재료학회지
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• 제18권3호
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• pp.269-276
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• 2011

The synthesis behavior of nanoporous silica aerogel in the macroporous ceramic structure was observed using TEOS as a source material and glycerol as a dry control chemical additive (DCCA). Silica aerogel in the macroporous ceramic structure was synthesized via sono-gel process using hexamethyldiazane (HMDS) as a modification agent and n-hexane as a main solvent. The wet gel with a modified surface was dried at $105^{\circ}C$ under ambient pressure. The addition of glycerol appears to give the wet gel a more homogeneous microstructure. However, glycerol also retarded the rate of surface modification and solvent exchange. Silica aerogel completely filled the macroporous ceramic structure without defect in the condition of surface modification (20% HMDS/nhexane at 36hr).

• 한국세라믹학회지
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• 제46권2호
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• pp.131-136
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• 2009

Radio frequency (RF) plasma treatment is studied for the size reduction and the spheroidization of coarse particles to change them into nano-sized powders of spherical shape in MLCC fields. The uni-nanoadditives manufactured by RF plasma processing for high dispersion have been investigated for the effect on core-shell structure in dielectrics of MLCC. Microstructures have been characterized using scanning electron microscope (SEM), transmission electron microscope (TEM) and Electron Probe Micro Analyzer (EPMA). We compared the distribution of core-shell grains between specimens manufactured using uni-nanoadditive and using mixed additive. In addition, the uniformity of rare earth elements in the core-shell structured grains was analyzed. It was shown, from TEM observations, that the sintered specimen manufactured using uni-nanoadditives had more dense small grains with well-developed core-shell structure than the specimen using mixed additives, which had a homogeneous microstructure without abnormal grain growth and shows broad temperature coefficient of capacitance (TCC) curves in all temperature ranges because of well dispersed additives.