• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.10a
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• pp.824-827
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• 1996

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.5
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• pp.53-58
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• 2002

A recent development, a concrete-filled steel(CFS) pier is an alternative to a reinforced concrete bridge pier in an urban area, because of its fast construction and excellent ductility against earthquakes. The capacity of CFS piers has not been used to a practical design, because there is no guide of a seismic design for CFS piers. Therefore, the guide of a seismic design value is derived from tests of CFS piers in order to apply it to a practical seismic design. Steel piers and concrete-filled steel piers are tested with constant axial load using quasi-static cyclic lateral load to check ductile capacity and using the real Kobe ground motion of pseudo-dynamic test to verify seismic performance. The results prove that CFS piers have more satisfactory ductility and strength than steel piers and relatively large hysteretic damping in dynamic behaviors. The seismic performance of steel and CFS piers is quantified on the basis of the test results. These results are evaluated through comparison of both the response modification factor method by elastic response spectrum and the performance-based design method by capacity spectrum and demand spectrum using effective viscous damping. The response modification factor of CFS piers is presented to apply in seismic design on a basis of this evaluation for a seismic performance.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.543-561
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• 2020

This paper is the result of the study on the effect of the support structure of the tunnel steel rib. In tunnel excavation, the top and bottom half excavation methods result in subsidence of steel rib reinforcement due to insufficient support of steel rib reinforcement when the ground is poor after excavation. The foundation of the steel rib installed in the upper half excavates the bottom part of the base, causing the subsidence to occur due to various effects such as internal load and lateral pressure. As a result, the tunnel is difficult to maintain and its safety is problematic. To solve these problems, steel rib support structures have been developed. For the purpose of verification, the behavior of the supporting structure is verified by model experiments reduced to shotcrete and steel rib material similarity, the numerical analysis of ΔP and ΔP generated by bottom excavation by Terzaghi theoretical equation. As a result, it was found that the support structure of 20.100~198.423 kN is required for the 10~40 m section of the depth for each soil of weathered soil~soft rock. In addition, as a result of the reduced model experiment, a fixed level of 50% steel rib deposit of steel rib support structure was installed. The study shows that the installation of steel rib support structures will compensate for uncertainties and various problems during construction. It is also thought that the installation of steel rib support structure will have many effects such as stability, economy, and air reduction.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.63-73
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• 2009

Purpose : To investigate the effects of various intracranial volume (ICV) measurement methods on the sensitivity of hippocampal volumetry and modulated voxel-based morphometry (mVBM) in female patients with major depressive disorder (MDD). Materials and Methods : T1 magnetic resonance imaging (MRI) data for 41 female subjects (21 MDD patients, 20 normal subjects) were analyzed. Hippocampal volumes were measured manually, and ICV was measured manually and automatically using the FreeSurfer package. Gray and white matter volumes were measured separately. Results : Manual ICV normalization provided the greatest sensitivity in hippocampal volumetry and mVBM, followed by FreeSurfer ICV, GWMV, and GMV. Manual and FreeSurfer ICVs were similar in normal subjects (p = 0.696), but distinct in MDD patients (p = 0.000002). Manual ICV-corrected total gray matter volume (p = 0.0015) and Manual ICV-corrected bilateral hippocampal volumes (right, p = 0.014; left, p = 0.004) were decreased significantly in MDD patients, but the differences of hippocampal volumes corrected by FreeSurfer ICV, GWMV, or GMV were not significant between two groups (p > 0.05). Only manual ICV-corrected mVBM analysis was significant after correction for multiple comparisons. Conclusion : The method of ICV measurement greatly affects the sensitivity of hippocampal volumetry and mVBM. Manual ICV normalization showed the ability to detect differences between women with and without MDD for both methods.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.527-530
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• 2014

A 7-year-old neutered male Korean domestic short-haired cat was referred to our clinic to treat constipation which had persisted for 6 months. The rectal examination revealed narrowing of the right lateral portion of the pelvic canal. A reduced pelvic canal diameter by pelvic fracture malunion was revealed on radiography. The pelvic canal diameter ratio measured from preoperative was 0.68. Based on rectal and radiographic examinations, constipation caused by pelvic canal narrowing was confirmed. Pelvic symphyseal distraction-osteotomy and iliac wedge osteotomy were performed. An iliac osteotomy of the ilium was performed to ease the pelvic symphyseal distraction. After the symphysis was split longitudinally, pelvic symphyseal distraction was maintained by using a spacer made of poly-methyl-methacrylate. The osteotomy of the ilium was fixed using a bone plate and screws. Increased pelvic canal diameter was confirmed on post-operative radiography and the postoperative pelvic canal diameter ratio was 0.91. The patient received antibiotics, NSAIDs, crystalloids and Lactulose for post-operative care. The cat recovered normal defecation abilities and did not have constipation at one week postoperatively. No episodes of constipation persisting longer than 6 months have been reported by owners in previous studies. Pelvic symphyseal distraction osteotomy and iliac wedge osteotomy may prove to be a useful surgical procedure to treat pelvic canal stenosis that is caused by pelvic fracture malunion.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.911-917
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• 2021

Severe Acute Respiratory Syndrome is being impacted worldwide by the prolonged COVID-19 situation. Due to the impact of COVID-19, domestic educational institutions have also changed their teaching methods. Domestic universities traditionally aim for face-to-face lectures, but due to the pandemic, they are conducting non-face-to-face lectures. This study aims to evaluate the effect of non-face-to-face lectures on radiology students. The subjects of this study are students of the Department of Radiology at University D in Daegu. As for the contents of the study, satisfaction with non-face-to-face lecture delivery, concentration, and comprehension was evaluated. Data analysis was performed in SPSS Ver. 26 was used, and the reliability measurement was found to be Cronbach's alpha coefficient = 0.805. In the results of this study, the satisfaction of non-face-to-face lecture delivery, concentration, and comprehension was overall high. However, satisfaction with theoretical subjects (2.08±0.88) was significantly different from that of practical subjects (2.51±1.10) (t=-9.880, p<.001). Satisfaction by grade level was highest in the first grade. As a result, it is judged that non-face-to-face theoretical lectures require more careful preparation from lecture planning than practical lectures, and further research is expected in the future.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.397-404
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• 2021

This study examined how different types of remote video lectures, which universities are using in earnest now due to the COVID-19 pandemic, impact the academic achievement of learners. Zoom-based remote video lectures were divided into two types-general lecture-centered and group task-oriented-and experimental and control groups were set up accordingly. An achievement test and a questionnaire were conducted to determine how academic achievement differed between these two approaches. The achievement test revealed no significant differences in achievement scores between the two groups. Meanwhile, the questionnaire regarding satisfaction with Zoom-based video lectures indicated that both groups were highly satisfied. Participants in the general lecture-centered type group cited the effect of learning, their instructors' class preparation and attitudes towards the class, and the promotion of participation in learning activities as the causes of their satisfaction, while participants in the task-oriented type group highlighted communication and sharing, the efficiency of group discussions, and the moderate difficulty level of group tasks as the reasons for their satisfaction with the video lectures. Remote video lectures in the untact era are becoming increasingly common, and educators will need to develop various Zoom-based teaching strategies to maximize their efficiency.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.778-787
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• 2022

This study was performed to obtain basic data in relation to instructional design and teaching strategy according to instructional modes. For the purpose of this study, participants evaluated the qualities of the instructions they attended and the results of the evaluation were compared according to 4 instructional modes(content class, online real-time class, online and face-to-face mixed class, and face-to-face class). As a result of the study, there were differences in the evaluation regarding the appropriateness of the course according to instructional modes. That is, satisfaction with lecture progress was lower in the online real-time classes than in content classes, mixed classes, and face-to-face classes. As a result of the descriptive lecture evaluation analysis, in the content class type, students answered that they were satisfied with the easily understandable and interesting explanations. In the case of the online real-time classes, it was found that they were satisfied with thorough preparation and effective communication. In the mixed class type, they said they were satisfied with the systematic class and passionate lecture, and in the face-to-face classes, the pleasure of interaction and the enthusiasm of the instructor were identified as the main reasons for satisfaction. It was analyzed that the satisfaction characteristic commonly derived from the four class types was the enthusiasm of the instructor. The results of this study are expected to provide implications for instructional design and teaching strategy establishment according to each instructional mode.

• Journal of the Korea Society of Computer and Information
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• v.27 no.10
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• pp.255-265
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• 2022

We compared and analyzed the factors affecting the lecture evaluation of IT subjects, which are mandatory for all students of H University. The purpose of this study is to determine whether lecture satisfaction has a significant correlation with academic achievement, attendance rate, and categories of courses. In this study, we check whether the lecture satisfaction of IT liberal arts subjects that require a lot of computer-based practice differs from that of other liberal arts subjects. We used the 2,149 evaluation data of 12 lectures submitted by 2,322 students in the first and second semesters of year 2019 at University H. As for the lecture evaluation results, in addition to the evaluation scores of the multiple choice questions, the subjective questions were also quantified by classifying the statements submitted by the students into positive and negative types to make the results of the lecture evaluation objective. Our research results show that student group who have the higher attendance rates and academic achievements have higher level of lecture satisfaction and they also use more positive words than negative words in subjective evaluation questions. Students with the lower score use the more negative words, but the ratio between positive and negative words does not differ between groups. Higher attendance rates groups in the basic programming courses and software applications courses have higher lecture satisfaction ratio. But in the intermediate programming courses, the higher attendances rate and the lecture satisfaction do not have any significant relationship. Also students in the intermediate programming courses use more negative words than those in the basic programming courses.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.169-171
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• 2013

본 연구는 초등학생을 대상으로 전자교육 학습자의 학습이력에 따른 중도탈락 원인들을 규명하고 재수강 의사 결정에 차이를 보이는지 분석을 통해 학습자의 재수강을 높일 수 있는 방안을 검토하고 효율적인 전자교육 프로그램을 운영할 수 있도록 시사점을 제공하기 위한 것이다. 구체적으로는 초등 전자교육에서 학습이력별 중도탈락 원인을 규명하고 재수강 의사 결정에 차이가 있는지 분석하였다. 연구결과 첫째, 초등전자교육에서 학습자의 학습이력 중 특히 학습자의 이수율이 중도탈락율과 관련 있으며, 유의한 원인은 시간부족, 교육내용 방법 평가로 나타났다. 둘째, 시간이 부족하거나 교육내용 방법 평가 방법이 적절하지 않아 중도탈락한 학습자들의 50% 이상이 재수강 의사를 밝혔으며, 중도탈락 원인 중 학업능력은 재수강을 결정하는데 유의한 원인으로 파악되었다. 셋째, 중도 탈락자의 재수강을 유도하는 방안으로서는 초등 전자교육 수강자는 온라인 플래너를 활용하여 매일 1시간씩 학습 시간을 관리하는 것이 필요하며, 선행학습은 한 학기 전까지 다루는 것이 좋은 것으로 나타났다.