• 대한수학회지
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• 제41권3호
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• pp.479-487
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• 2004

Let G be a finite group and N be a normal subgroup of G. We denote by ncc(N) the number of conjugacy classes of N in G and N is called n-decomposable, if ncc(N) = n. Set $K_{G}\;=\;\{ncc(N)$\mid$N{\lhd}G\}$. Let X be a non-empty subset of positive integers. A group G is called X-decomposable, if KG = X. In this paper we characterise the {1, 3, 4}-decomposable finite non-perfect groups. We prove that such a group is isomorphic to Small Group (36, 9), the $9^{th}$ group of order 36 in the small group library of GAP, a metabelian group of order $2^n{2{\frac{n-1}{2}}\;-\;1)$, in which n is odd positive integer and $2{\frac{n-1}{2}}\;-\;1$ is a Mersenne prime or a metabelian group of order $2^n(2{\frac{n}{3}}\;-\;1)$, where 3$\mid$n and $2\frac{n}{3}\;-\;1$ is a Mersenne prime. Moreover, we calculate the set $K_{G}$, for some finite group G.

• 한국가정과교육학회지
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• 제14권1호
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• pp.75-86
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• 2002

The purpose of this study is to analyze the effect of Web-based small group discussion on the achievement and satisfaction in the practice-planning phase of Technology and Home Economy. The subject of this study consists of 68 students of a middle school. The 7r7up is divided into two subgroup. the Web-based discussion croup and the face-to-face discussion grouts. each of which has 34 students. The achievement is estimated by individual reports. practice plans and the overall evaluation sheets. To estimate the satisfaction of students. the test sheets were used. together with the interviews of sampled students from both group. The results show that there is a statistically significant difference in the performance of practice between the two groups with the significant level of 0.05(p<0.05). There is also some difference in the satisfaction between the two groups.

• 한국안전학회지
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• 제13권1호
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• pp.85-91
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• 1998

Sol-gel derived silica films were prepared by dip-coating onto polymethylmethacylate with Tetraethoxysilane(TEOS) as starting materials. Film properties such as viscosity and thickness were investigated as a function of dip speed, waterprecursor ratio, sol aging time. IR spectra of the gel films prepared from TEOS at various R are given. At small values of R the absorption peaks assignable to C-H vibration in $-OC_2H_5$ groups are observed around 3000 and 1500-1300 $cm^{-1}$. These bands indicate that the -$-OC_2H_5$ groups are retained in the gel at small values of R because of incomplete hydrolysis of TEOS. Film behaviour was interpreted in terms of the dependence of hydrolysis and condensation rates on the interplay between sol pH and waterprecursor ratio. Film thickness was found to increase by approximately a factor of two as waterprecursor ratio increased from two to six. Film thickness also increased with sol prepolymerization time. Surface quality was correlated with processing conditions.

• 한국군사과학기술학회지
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• 제7권3호
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• pp.77-83
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• 2004

This paper focuses on a scheduling problem of military training. Repetitive and identical training over multiple serials is a common type of military education. A simple but systematic method is suggested to determine a training schedule for small groups divided from each serial. A satisfactory training schedule and the number of such small groups can be determined by iteratively solving assignment problems with additional constraints. With this method, loads of instructors can also be balanced without violating constraints associated with precedence and continuity relationships among lectures.

• Applied Microscopy
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• 제42권4호
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• pp.194-199
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• 2012

The anatomy and morphology of seeds from 10 Hawaiian Portulaca taxa were examined to explore patterns of variation among the taxa, and to evaluate their phylogenetic relationships. Features of seeds were assessed employing microtechnique procedures, statistical analysis, and scanning electron microscopy (SEM). Anatomically, the orientation of embryo was consistent across taxa, and all seeds examined had central nutritive tissue and integuments comprising the peripheral embryo. Seeds were generally small, circular to ovoid in shape, and either smooth or rough-surfaced, with tubercules. Variation in seed size was noted, although minimal within small seeded group. The size of seeds ranged from 0.50~1.26 mm in length, and 0.55~1.34 mm in width, with similar weights. Seeds were distinguished by the sculpture and arrangement of the testa epidermis and the way in which their stellulate-tessellate cells uniquely fit together. Using a multiple range test (ANOVA), two groups were established by seed characteristics. The SEM also demonstrated morphological differences in testa sculpturing. The results obtained confirm the usefulness of seed characteristics in the identification of the species examined, and furthermore, allow for the separation of the Hawaiian Portulaca into two groups.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2008년도 연합학회학술대회
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• pp.1-11
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• 2008

본 연구는 대기업과 중소기업의 전자상거래 도입요인 및 도입 이후의 실현이익에 대해 느끼는 영향요인의 차이를 비교해 보고자 한다. 본 연구는 실증분석을 위해 한국에서 기업활동 중인 중소기업과 대기업을 분류하여 데이터를 수집하였으며, 기존의 문헌 연구를 바탕으로 연구가설을 설정하고, 가설검증을 위해 설문지를 작성하였다.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1649-1654
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• 2003

We have investigated substituent effect on the stabilization energies, and nucleus-independent chemical shifts of pentafulvalenes and on the electronic structures of the corresponding polypentafulvalenes to design environmentally stable semiconductive or conductive polymers. Geometrical optimizations of the molecules were carried out at the density functional level of theory with B3LYP hybrid functional and 6-311+G(d) basis set. Stabilization energies were estimated using isodesmic and homodesmotic reactions. As a criterion of aromaticity nucleus-independent chemical shifts of the molecules were computed using GIAO approach. For the polymers the geometrical parameters were optimized through AM1 band calculations and the electronic structures were obtained through modified extended Huckel band calculations. It is found that strong electronwithdrawing substituents increase isodesmic and homodesmotic stabilization energies of pentafulvalene, though it does not increase the aromaticity. Nitro-substituted pentafulvalene is estimated to have stabilization energy as much as azulene. However, substitution either with electron-donating groups or with electronwithdrawing groups does not significantly affect the electronic structures of polypentafulvalene and poly (vinylenedioxypentafulvalene).

• 한국수학교육학회지시리즈D:수학교육연구
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• 제22권3호
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• pp.203-222
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• 2019

Despite its importance when it is employed in classrooms, scaffolding is limited in the classrooms. Many researchers have focused on contingent teaching, which is the first component of scaffolding. Given a lack of research on contingent teaching with prospective teachers (PSTs), this paper explores how PSTs intend to do contingent teaching in small groups when they engage in mathematics teaching. Building on research on contingent teaching, I analyzed 26 PSTs' written responses to scenarios in an online open-ended survey. The focus of the analysis was on how the PSTs would do contingent teaching that might support students to learn the subject matter. I present findings in relation to what the PSTs' responses showed in relation to contingent teaching with the subject matter. The findings will be discussed along with implications.

• 한국의류산업학회지
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• 제17권5호
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• pp.815-827
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• 2015

This study analyzes the characteristics by age and type for middle aged and elderly women foot shapes aged 40-69 years. ANOVA, factor, and cluster analyzed middle aged and elderly women's foot shapes. The results of the study are as follows. First, higher age groups tended to have smaller foot lengths, ball/instep circumferences, circumferences, and ball heights with larger heel height values and higher degrees of gathering of toe 1 and toe 5 toward the feet reference axis. Second, foot lengths were 220 mm-240 mm and the ball circumference's size symbol in high frequency sections were distributed from E to EEEE in the 40s and 60s groups and from D to EEEE in the 50s group. Third, eight factors were extracted through the factor analyses of middle aged and elderly women's foot measurement items. Fourth, a cluster analyses classified the subjects into four types. Type 1 is a normal foot type with medium foot length and small ball circumference and type 2 is a long and flat foot type with a type with large foot length and ball circumference values as well as small ball height values. Type 3 is a thick foot type with a medium foot length, large ball circumference, large ball height and type 4 is a toe deformation foot type with medium foot length, small ball circumference, and a high degree of toe gathering toward the center.

• 대한화학회지
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• 제44권4호
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• pp.356-362
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• 2000

협동적인 소집단 문제 해결 과정을 녹화/녹음하여 작성한 프로토콜에 대하여 언어적 행동의 빈도를 분석하고, 학생들의 사전 성취 수준에 따라 비교하였다. 각각의 소집단에서 학생들의 사전 성취 수준에 따라 언어적 상호작용에 대한 참여율도 조사하였다. 상위 수준 학생들은 중${\cdot}$하위 수준에 비해 '정보 주기' 범주에 속하는 행동들을 많이 나타내었고, '제공', '제공 반복', '정당화'에서의 차이가 통계적으로 유의미하였다. '정보 받기'나 '질문하기' 범주에서는 통계적으로 유의미한 차이를 나타내는 행동이 없었다. 12개 소집단 가운데 모든 수준의 학생들이 언어적 상호작용에 균형 있게 참여한 경우는 3개조에 불과했고, 중위 수준 학생들의 참여율이저조한 경우가 많았다.