• 대한수학회지
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• 제55권4호
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• pp.797-808
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• 2018

In [1], the authors generalize the concept of the class group of an integral domain $D(Cl_t(D))$ by introducing the notion of the S-class group of an integral domain where S is a multiplicative subset of D. The S-class group of D, $S-Cl_t(D)$, is the group of fractional t-invertible t-ideals of D under the t-multiplication modulo its subgroup of S-principal t-invertible t-ideals of D. In this paper we study when $S-Cl_t(D){\simeq}S-Cl_t(D_T)$, where T is a multiplicative subset generated by prime elements of D. We show that if D is a Mori domain, T a multiplicative subset generated by prime elements of D and S a multiplicative subset of D, then the natural homomorphism $S-Cl_t(D){\rightarrow}S-Cl_t(D_T)$ is an isomorphism. In particular, we give an S-version of Nagata's Theorem [13]: Let D be a Krull domain, T a multiplicative subset generated by prime elements of D and S another multiplicative subset of D. If $D_T$ is an S-factorial domain, then D is an S-factorial domain.

• 대한수학회논문집
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• 제32권2호
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• pp.353-359
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• 2017

Starting from a t-norm T, it is possible to construct a class of new t-norms, so-called T-generalized t-norm. The purpose of this paper is to describe some properties of this class of generalized t-norms. An algebraic structure as well as a binary relation among t-norms are also investigated. Some open problems are discussed as well.

• 대한치과교정학회지
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• 제48권1호
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• pp.63-70
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• 2018

Objective: The aim of this study is to quantitatively evaluate the stability of the skeletal and dental widths using cone-beam computed tomography (CBCT) after segmental Le Fort I osteotomy in adult patients with skeletal Class III malocclusion requiring maxillary expansion. Methods: In total, 25 and 36 patients with skeletal Class III malocclusion underwent Le Fort I osteotomy (control group) and segmental Le Fort I osteotomy (experimental group), respectively. Coronal CBCT images were used to measure the dental and skeletal widths before (T1) and after (T2) surgery and at the end of treatment (T3). The correlation between the extent of surgery and the amount of relapse in the experimental group was also determined. Results: In the control group, the dental width exhibited a significant decrease of $0.70{\pm}1.28mm$ between T3 and T2. In the experimental group, dental and skeletal expansion of $1.83{\pm}1.66$ and $2.55{\pm}1.94mm$, respectively, was observed between T2 and T1. The mean changes in the dental and skeletal widths between T3 and T2 were $-1.41{\pm}1.98$ and $-0.67{\pm}0.72mm$, respectively. There was a weak correlation between the amount of skeletal expansion during segmental Le Fort I osteotomy and the amount of postoperative skeletal relapse in the experimental group. Conclusions: Maxillary expansion via segmental Le Fort I osteotomy showed good stability, with a skeletal relapse rate of 26.3% over approximately 12 months. Our results suggest that a greater amount of expansion requires greater efforts for the prevention of relapse.

• 대한치과교정학회지
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• 제45권5호
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• pp.226-235
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• 2015

Objective: The purpose of this retrospective study was to investigate short-term and long-term skeletodental outcomes of Class III activator treatment. Methods: A Class III activator treatment group (AG) comprised of 22 patients (9 boys, 13 girls) was compared with a Class III control group (CG) comprised of 17 patients (6 boys, 11 girls). The total treatment period was divided into three stages; the initial stage (T1), the post-activator treatment or post-mandibular growth peak stage (T2), and the long-term follow-up stage (T3). Cephalometric changes were evaluated statistically via the Mann-Whitney U-test and the Friedman test. Results: The AG exhibited significant increases in the SNA angle, ANB angle, Wits appraisal, A point-N perpendicular, Convexity of A point, and proclination of the maxillary incisors, from T1 to T2. In the long-term follow-up (T1-T3), the AG exhibited significantly greater increases in the ANB angle, Wits appraisal, and Convexity of A point than the CG. Conclusions: Favorable skeletal outcomes induced during the Class III activator treatment period were generally maintained until the long-term follow-up period of the post-mandibular growth peak stage.

• 문화기술의 융합
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• 제7권3호
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• pp.277-284
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• 2021

본 연구는 간호대학생을 대상으로 기본간호학 실습교육에 플립러닝 수업을 적용하여 자기효능감과 비판적 사고능력에 미치는 효과를 확인하고자 시행되었다. 연구 대상자는 연구 참여를 허락한 실험군 42명과 대조군 40명을 대상으로 하였으며, 자료분석은 SPSS/WIN 24.0 프로그램을 이용하여 통계처리 하였다. 본 연구 결과 플립러닝을 적용한 수업을 받은 실험군의 자기효능감 점수는 수업 전에 비해 수업 직후(t=3.49, p=.001) 유의하게 증가하였으며, 수업 후 10주(t=-0.75, p=.456)에 효과가 지속되었다. 실험군의 비판적 사고능력 점수는 수업 전에 비해 수업 직후(t=3.49, p=.001) 유의하게 증가하였으며, 수업 후 10주(t=0.11, p=.913)에 효과가 지속되었으나, 강의식 수업을 받은 대조군의 자기효능감과 비판적 사고능력 점수는 유의한 차이가 없었다. 즉, 플립러닝을 적용한 기본간호학실습 수업은 간호대학생의 자기효능감과 비판적 사고능력을 향상시키는데 효과가 있다는 것이 본 연구결과에서 확인되었다. 본 연구를 토대로 간호학 전공교과목에서 플립러닝 교수법 적용을 확대해야 함을 제언한다.

• 대한치과교정학회지
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• 제50권3호
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• pp.170-180
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• 2020

Objective: To compare short- and long-term dentoalveolar, skeletal, and rotational changes evaluated by Björk's structural method of superimposition between children with Class II malocclusion treated by functional appliances and untreated matched controls. Methods: Seventy-nine prepubertal or pubertal children (mean age, 11.57 ± 1.40 years) with Class II malocclusion were included. Thirty-four children were treated using an activator with a high-pull headgear (Z-activator), while 28 were treated using an activator without a headgear (E-activator). Seventeen untreated children were included as controls. Lateral cephalograms were obtained before treatment (T1), after functional appliance treatment (T2), and after retention in the postpubertal phase (T3). Changes from T1 to T2 and T1 to T3 were compared between the treated groups and control group using multiple linear regression analysis. Results: Relative to the findings in the control group at T2, the sagittal jaw relationship (subspinale-nasion-pogonion, p < 0.001), maxillary prognathism (sella-nasion-subspinale, p < 0.05), and condylar growth (p < 0.001) exhibited significant improvements in the Z- and E-activator groups, which also showed a significantly increased maxillary incisor retraction (p < 0.001) and decreased overjet (p < 0.001). Only the E-activator group exhibited significant backward rotation of the maxilla at T2 (p < 0.01). The improvements in the sagittal jaw relationship (p < 0.01) and dental relationship (p < 0.001) remained significant at T3. Condylar growth and jaw rotations were not significant at T3. Conclusions: Functional appliance treatment in children with Class II malocclusion can significantly improve the sagittal jaw relationship and dental relationships in the long term.

• 한국컴퓨터정보학회논문지
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• 제27권8호
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• pp.253-261
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• 2022

본 연구에서는 컴퓨터 비전공자 대상의 인공지능 교양 교육을 위한 프로젝트 학습법을 적용한 후 교육적 효과를 파악하고자 한다. 실험집단과 통제집단 각각의 학습몰입, 인공지능 효능감의 향상 정도를 파악하기 위하여 각 집단 내에서 대응표본 t-검정을 실시하였고, 수업 후 실험집단과 통제집단의 학습몰입과 인공지능 효능감에 대한 사전검사와 사후검사의 통계적 효과를 알아보기 위해 독립표본 t-검정을 실시하였다. 그 결과 실험집단과 통제집단은 각각 수업 전과 후 학습몰입과 인공지능 효능감에서 유의미한 향상을 보였다. 인공지능 수업에서 프로젝트 학습방법을 적용한 실험군과 이론과 실습만 진행한 통제집단 간의 학습몰입은 통계적으로 유의한 차이가 없었지만, 프로젝트 학습방법을 적용한 실험집단은 이론과 실습만 진행한 통제집단에 비해 인공지능의 효능감이 유의미한 수준으로 향상되었음을 확인하였다.

• 한국학교수학회논문집
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• 제4권2호
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• pp.103-113
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• 2001

The teaching-learning method utilizing Web makes it possible for the students take the initiative in any field and offers the teaching strategy, methodology and teaching-learning materials suitable for students' ability and standard. The purpose of this study is to investigate the characteristics of WBI in mathematics class for the effective teaching and learning focusing on the unit 'Function' in the 1st grade of middle school and verify its effectiveness by developing the WBI programs which can progress learning achievement and applying them to math class. Two hypotheses were established for this study. Hypothesis 1 : There will be meaningful difference between the group that studies under WBI and the one that doesn't, Hypothesis 2 : There will be meaningful difference in the attitude and interest toward learning between the group that studies under WBI and the one that doesn't. In order to find out the result, I have made a comparative analysis through t-verification on the object of two classes of the 1st grade in P middle school that I have been working for. The result shows that the class utilizing WBI is more effective than the traditional lecture-oriented class since there is a meaningful difference between the control group and experimental one and also that the class based on WEB has a great influence on students' interest and positive attitude toward math class.

• 한국간호교육학회지
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• 제16권2호
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• pp.202-212
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• 2010

Purpose: The purpose of this study was to identify the effectiveness of the JigsawⅣ cooperative learning in a facilitative communication class of nursing students. Achievement, communication skill, self-directed learning and experience during the class were measured. Method: This study was a pretest and posttest design with two subject groups. 43 students were in experimental (JigsawⅣ) group and 47 ones were in control (general small discussion) group. Classes were conducted over a 6-week period. The collected data was analyzed by the SPSS 12.0 program. Result: After taking part in the educational program, the experimental group had significantly more improvement in communication skill (F=6.81, p=.002) and self-directed learning (F=11.81, p=.000). In addition, the experimental group showed significantly higher scores for concentration in the class (t=2.26, p=.27), positive emotional state (t=3.01, p=.003) and active participation (t=2.78, p=.007) compared to the control group. However, the achievement between the two groups was not significantly different (F=3.29, p=.073). Conclusion: The findings of this study show that JigsawⅣ cooperative learning has positive effects in improvement of communication skill and self-directed learning. Also, students were excited and interested in the class during cooperative learning. Based on these findings, the author suggests developing additional educational programs focusing on nursing students.

• 사물인터넷융복합논문지
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• 제9권2호
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• pp.33-40
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• 2023

본 연구는 간호대학생을 대상으로 아로마 블렌딩 오일 흡입이 학업스트레스와 수업집중력에 미치는 효과를 검정하기 위한 비동등성 플라시보 대조군 전후 시차설계의 유사실험연구이다. 연구의 대상자는 Y시에 소재하는 K대학교 간호학과 2학년 학생으로 처치군 24명, 플라시보 대조군 24명이었다. 2022년 11월 4일부터 2022년 12월 3일까지 자료를 수집하였고, 자료는 SPSS 23.0 Program을 이용하여 분석하였다. 동질성 검정은 chi-square test, independent t-test, 실험 후 집단 간 종속변수의 차이는 independent t-test, 집단 내 종속변수의 차이는 paired t-test로 분석하였다. 10일간 아로마 블렌딩 오일을 흡입한 처치군은 호호바 오일을 흡입한 플라시보 대조군보다 학업스트레스는 유의하게 감소하였고(t=-8.79, p<.001), 수업집중력 유의하게 증가하였다(t=24.44, p<.001).