• Nuclear Engineering and Technology
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• 제49권6호
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• pp.1269-1286
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• 2017

This paper presents a newly developed resonance self-shielding method based on Tone's method in $APOLLO3^{(R)}$ for fast and thermal reactor calculations. The new method is based on simplified models, the narrow resonance approximation for the slowing down source and Tone's approximation for group collision probability matrix. It utilizes mathematical probability tables as quadrature formulas in calculating effective cross-sections. Numerical results for the ZPPR drawer calculations in 1,968 groups show that, in the case of the double-column fuel drawer, Tone's method gives equivalent precision to the subgroup method while markedly reducing the total number of collision probability matrix calculations and hence the central processing unit time. In the case of a single-column fuel drawer with the presence of a uranium metal material, Tone's method obtains less precise results than those of the subgroup method due to less precise heterogeneous-homogeneous equivalence. The same options are also applied to PWR UOX, MOX, and Gd cells using the SHEM 361-group library, with the objective of analyzing whether this energy mesh might be suitable for the application of this methodology to thermal systems. The numerical results show that comparable precision is reached with both Tone's and the subgroup methods, with the satisfactory representation of intrapellet spatial effects.

• 한국수학교육학회지시리즈A:수학교육
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• 제39권1호
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• pp.11-20
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• 2000

Compared with other subjects, mathematics has great differences in achievement. In hope of solving this problems, most schools the level-movement learning. Although they say it may have some effect because of its homogeneous group, the level groups still have differences in achievement in their students abilities. So, this study aims to present an appropriate tasks for the advanced intermediate and beginner groups and to help self-directed learning by selecting an appropriate tasks for the students' own level. To achieve thiese goals, a great deal of level tasks were developed and given to the students. After lettins them an select appropriate tasks for their own level and perform self-directed teaming, the tasks were measured carefully for their interest attitude and achievement in learning. Consequently, we tried a new method to improve uniformity and to turn teacher-centered learning into student-centered teaming. The following is the conclusion to this study. First self-directed teaming based on the selection of level tasks has meaningful effects on learning achievement in mathematics, especially for the beginner group. Second though the above method did not improve an interest for mathematics, but was very effective in the improvement of learning attitudes.

• Advances in nano research
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• 제10권3호
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• pp.271-280
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• 2021

The present work deals with an investigation on longitudinal wave propagation in nanobeams made of graphene sheets, for the first time. The nanobeam is modelled via a higher-order shear deformation theory accounts for both higher-order and thickness stretching terms. The general nonlocal strain gradient theory including nonlocality and strain gradient characteristics of size-dependency in order is used to examine the small-scale effects. This model has three-small scale coefficients in which two of them are for nonlocality and one of them applied for gradient effects. Hamilton supposition is applied to obtain the governing motion equation which is solved using a harmonic solution procedure. It is indicated that the longitudinal wave characteristics of the nanobeams are significantly influenced by the nonlocal parameters and strain gradient parameter. It is shown that higher nonlocal parameter is more efficient than lower nonlocal parameter to change longitudinal phase velocities, while the strain gradient parameter is the determining factor for their efficiency on the results.

• 대한지구과학교육학회지
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• 제9권3호
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• pp.323-340
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• 2016

이 연구의 목적은 지구와 달의 공전 궤도를 고려한 달의 위상 변화 관찰 교구의 효과를 알아보고자 하는 것이다. 이를 위하여 지구의 공전 궤도와 $5^{\circ}$ 기울어진 달의 공전 궤도를 나타내는 달의 위상 변화 관찰 교구를 개발하였다. 그리고 이 교구의 효과를 확인하기 위해 제주시내 초등학교 6학년 110명의 학생을 실험집단과 비교집단으로 나누어 연구를 실시하였다. 실험집단 55명의 학생은 이 연구에서 개발한 달의 위상 변화 관찰 교구를 활용하여 수업을 진행하였고 비교집단 55명의 학생은 현행 교과서 활동으로 수업을 진행하였다. 실험집단과 비교집단의 학생들에게 달의 위상 변화에 대한 사전, 사후, 지연 개념검사와 개념수준별 반구조화된 면담을 실시하였다. 학생들의 응답에 따라 '위상 인지', '우주적 관점', '지구적 관점', '인지 불가'로 개념 수준을 구분하였다. 사전개념검사에서 t-검정 결과 실험집단과 비교집단은 동질 집단임을 확인할 수 있었다. 사후개념검사와 지연개념검사에서 실험집단은 비교집단보다 통계적으로 유의미하게 높은 점수를 얻었다. 또한 실험집단은 비교집단보다 상위 개념 수준인 '위상 인지'에 속하는 학생 수가 많았다. 반구조화된 면담 결과 '위상 인지'와 '우주적 관점'에 속한 실험집단 학생들은 비교집단 학생들보다 달의 위상 변화에 대해 더 과학적으로 설명하였다. 이를 통해 지구와 달의 공전 궤도를 고려한 달의 위상 변화 관찰 교구가 효과가 있음을 확인할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.588-595
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• 2016

IFN-γ release assays (IGRAs) have been developed as viable alternative diagnostic tools for detecting latent tuberculosis infection (LTBI). A customized homogeneous sandwich luminescent oxygen channeling immunoassay (LOCI) was used to quantify IFN-γ levels in IGRAs. Samples were collected from healthy volunteers (n = 40) who were T-Spot-negative and T-Spot-positive patients (n = 32) at rest. Then the amount of IFN-γ in the supernatant of IGRAs was measured by LOCI. The results demonstrated a low background, and high sensitivity, specificity, accuracy, and reproducibility, and a short assay time (only 30 min) with LOCI for IFN-γ. The recovery range was 81.63-102.06%, the coefficients of variation were below 5%, and the limit of detection was 19.0 mIU/ml. Excellent agreement between LOCI IFN-γ and the T-SPOT.TB test was obtained (97.2% agreement, κ = 0.94). The LOCI IFN-γ concentrations were significantly higher in T-Spot-positive patients than in the healthy group (p < 0.001). Moreover, as observed for the comparative LOCI IFN-γ assay, IFN-γ concentrations were related to the numbers of T-SPOT.TB spots. We have established an in vitro blood test for LTBI diagnosis, defined as LOCI IFN-γ. A high level of agreement between the LOCI IFN-γ method and T-SPOT.TB assay was observed in clinical studies that showed the LOCI IFN-γ method could determine LTBI. This study shows acceptable performance characteristics of the LOCI IFN-γ assay to diagnose LTBI.

• Clinical Endoscopy
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• 제56권4호
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• pp.510-520
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• 2023

Background/Aims: We aimed to investigate (1) promising clinical findings for the recognition of focal type autoimmune pancreatitis (FAIP) and (2) the impact of endoscopic ultrasound (EUS)-guided tissue acquisition (EUS-TA) on the diagnosis of FAIP. Methods: Twenty-three patients with FAIP were involved in this study, and 44 patients with resected pancreatic ductal adenocarcinoma (PDAC) were included in the control group. Results: (1) Multivariate analysis revealed that homogeneous delayed enhancement on contrast-enhanced computed tomography was a significant factor indicative of FAIP compared to PDAC (90% vs. 7%, p=0.015). (2) For 13 of 17 FAIP patients (76.5%) who underwent EUS-TA, EUS-TA aided the diagnostic confirmation of AIPs, and only one patient (5.9%) was found to have AIP after surgery. On the other hand, of the six patients who did not undergo EUS-TA, three (50.0%) underwent surgery for pancreatic lesions. Conclusions: Homogeneous delayed enhancement on contrast-enhanced computed tomography was the most useful clinical factor for discriminating FAIPs from PDACs. EUS-TA is mandatory for diagnostic confirmation of FAIP lesions and can contribute to a reduction in the rate of unnecessary surgery for patients with FAIP.

• Advances in pediatric surgery
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• 제4권2호
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• pp.93-99
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• 1998

Anal endosonography has recently been popularized in adult patients in order to access staging of rectal cancer and other lesions of the anorectum. This study is not familiar to pediatric surgeons. We performed anal endosonography in 30 children without anorectal disease in order to determine the standard morphology of the anorectum. The internal anal sphincter(IAS) was clearly identified as a homogeneous hypoechoic circular band, extending caudally to a level just proximal to the anal verge. The external anal sphincter(EAS) showed mixed echogenicity and different architecture along the anal canal; the EAS was U-shape in the upper canal and it had a circular pattern in the lower canal. In the upper canal of girls, the perineal body and the vagina were found just anterior of the anal canal, which made the U shape of the EAS. In the male, the sphincter tapered anteriorly into two arcs that met in the midline. The perineal body was prominent in the female. Posteriorly, the anococcygeal ligament was represented by a triangular shadow in both sex. The thickness of the IAS was measured in 3 directions, left, right and posterior, at 3 levels, upper, middle and lower areas of the anal canal. The average thickness was 0.86-2.40 mm between 6 and 18 months of age(Group 1), 0.88-3.20 mm between 19 and 36(Group 2), 1.07-2.20 mm between 37 and 54(Group 3) and 1.18-2.42 mm more than 54-month-old(Group 4). The thickness was correlated with the age of the children only in the right upper(p=0.008) and the left middle portion(p=0.015). We were able to obtain standard morphologic features of the normal anal canal in children with anal endosonography. We believe that this technique is a safe and an effective procedure to evaluate anorectal lesions in children.

• Journal of Korean Biological Nursing Science
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• 제18권4호
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• pp.318-326
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• 2016

Purpose: The purpose of this study was to develop and conduct an intensive education program on infection control and investigated how the program influenced nursing students' knowledge, attitude, and confidence in the infection control. Methods: The program was conducted for four days between January 5 and 8, 2016, for seven hours per day. The program was conducted by the specialists in infectious diseases and the nurses specializing in infection, and the third year students enrolled in E University participated in the program. Knowledge, attitude, and confidence in infection control were measured before and after the program in the students that participated in the program and those who did not. The experimental group consisted of 33 students while the control group comprised 28 students. Results: The two groups were found to be homogeneous before the education program. After four days of intensive education program, the experimental group showed statistically significant improvements in knowledge (t=2.02, p=.048), attitude (t=2.04, p=.045), and performance confidence (t=2.75, p=.008) in infection control when compared to the control group. Conclusion: The present study showed that our intensive education program on hospital infection control was effective for the nursing students who will be professional nurses who will carry out autonomous roles in infection control in a near future.

• 한국과학교육학회지
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• 제33권7호
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• pp.1259-1272
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• 2013

본 연구는 탐구적 과학 글쓰기 실험수업이 중학생들의 창의적 사고와 비판적 사고에 미치는 효과를 알아보기 위한 것으로 이를 위해 Keys 등(1999)이 개발한 SWH 전략에 기초하여 탐구적 과학 글쓰기 프로그램을 개발하였다. 연구의 대상은 2개 학급 63명은 비교집단으로, 2개 학급은 실험집단으로 선정하였고, 소집단의 구성은 인지수준이 비슷한 동질집단으로 구성하였다. 프로그램의 처치는 2011년 3월부터 7월까지 9개의 활동 주제로 총 18차시를 투입하였다. 사후검사는 사전검사와 동일한 검사지를 사용하였으며, 검사 결과는 SPSS 20.0 프로그램을 사용하여 창의적 사고와 비판적 사고의 사전검사를 공변인으로 하는 공변량 분석(ANCOVA)으로 통계 처리하였다. 또한 설문지를 이용하여 학생들의 탐구적 과학 글쓰기 실험수업에 대한 인식을 알아보았다. 이러한 연구결과를 살펴보면, 탐구적 과학 글쓰기 실험수업이 창의적 문제해결력 향상에 효과적이므로, 지속적인 탐구적 과학 글쓰기 수업전략의 제시와 다양한 실험 주제 개발이 필요하다고 여겨진다.

• 한국멀티미디어학회논문지
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• 제5권1호
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• pp.68-76
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• 2002

이동 호스트에서의 멀티캐스트에는 호스트이동성, 멀티캐스트 결정 문제, 삼각라우팅, 터널 집중성 문제, 재전송의 폭주, 대역폭 낭비 등의 문제가 있다. 무선에서의 대역폭 낭비는 전송률을 떨어뜨리는 결정적 요인이다. 본 논문에서는 대역폭 낭비를 해결하는 방법으로 호스트 이동성, 그룹관리, 멀티 캐스트 라우팅 프로토콜을 통합하여 신뢰성 있는 패킷 손실 복구를 할 수 있는 FIM을 제안한다. FIM은 IP Mobility Support와 IGMP, DVMRP를 통합하고, FEC와 수신자 기반 지역복구방식을 사용하였다. 제안한 프로토콜의 성능은 동종 독립 손실, 이종 독립 손실, 상호 의존적 손실로 나누어 분석 하였다. 손실 모델에 대한 평가는 전송그룹의 크기가 일정크기를 넘어서면, 지역그룹의 크기와 비례하여 성능이 향상되고 있음을 세 모델 전체에서 확인할 수 있었다. 따라서 제안된 프로토콜은 이동 호스트에서 데이터의 양과 수신자의 수가 많은 환경에서 효율적 임을 나타내었다.