• Nuclear Engineering and Technology
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• v.23 no.2
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• pp.174-182
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• 1991

Effects of human error relevant to the periodic test are incorporated in the evaluations of the unavailability and optimal test interval of a safety system. Two types of possible human error with respect to the test and maintenance are considered. One is the possibility that a good safety system is inadvertently left in a bad state after test（Type A human error) and the other is the possibility that a bad safety system is undetected upon the test（Type B human error). An event tree model is developed for the steady-state unavailability of a safety system in order to determine the effects of human errors on the system unavailability and the optimal test interval. A reliability analysis of the Safety Injection System (SIS) was peformed to evaluate the effects of human error on the SIS unavailability. Results of various sensitivity analyses show that ; (1) the steady-state unavailability of the safety system increases as the probabilities of both types of human error increase and it is far more sensitive to Type A human error, (2) the optimal test interval increases slightly as the probability of Type A human error increases but it decreases as the probability of Type B human error increases, and (3) provided that the test interval of the safety injction pump is kept unchanged, the unavailability of SIS increases significantly as the probability of Type A human error increases but slightly as the probability of Type B human error increases. Therefore, to obtain the realistic result of reliability analysis, one should take shorter test interval (not optimal test interval) so that the unavailability of SIS can be maintained at the same level irrespective of human error. Since Type A human error during test & maintenance influeces greatly on the system unavailability, special efforts to reduce the possibility of Type A human error are essential in the course of test & maintenance.

• Journal of Veterinary Clinics
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• v.36 no.1
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• pp.53-61
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• 2019

Total hip arthroplasty (THA) is a successful surgical treatment for both patients with chronical lameness and dogs who are nonresponsive to medical treatments, providing excellent joint function for returning dogs to the normal gait in 80% to 98% of hip dysplasia (HD) patients. The THA surgical implant system manufactured by BioMedtrix and Kyon are today widely accepted. When comparing the BioMedtrix biological fixation (BFX) system to the BioMedtrix cemented fixation (CFX) system, the many advantages of BFX, which include longer potential implant life, decreased risk of postoperative or later infection, and better implant stability, become evident. However, BFX implies a greater risk of femoral fracture during reaming and requires a more precise surgical technique to achieve good implant fit, given the press-fit nature of cementless THA. The purposes of this study are to both describe the mistakes and complications during stem implantation for beginner surgeons with both the BFX and the CFX systems and to document the initial result of 12 implantations in canine cadavers. Given the detailed evaluations of 3 specialists, who are Diplomate American College of Veterinary Surgeons (DACVS), only 3 of 11 stems were appropriately sized. Specifically, 6 stems were anteverted rather than being retroverted; further, although 7 stems were coaxial with the femoral long axis in the frontal plane, the other stems were in the varus at the frontal plane, with the proximal medial stem adjacent to the medial femoral cortex. Moderate angulation from the cranial to the caudal directions was found in 4 cases in the sagittal plane. Additionally, 1 case of femoral fissure and 1 case of perforated femoral cortex were reported. It is not easy for surgeons performing cementless THA for the first time to achieve a good result, even though they completed an educational course about it and given that catastrophic complications often occurred during early surgical clinical cases. Therefore, ex-vivo studies are sincerely required to get an expertise by rehearsing the preparation of the femoral envelop in isolated bones. Further studies should be conducted to achieve both highly accurate implant size and correct orientation during the preoperative planning. Additionally, surgeons' learning curve should be examined in future investigations.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.105-113
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• 2021

Due to the recent coronavirus outbreak, many universities in Korea have started to implement remote education. Accordingly, the Ministry of Education has stated its plans to continuously encourage and maintain remote learning as the future innovation model for education and suggested the need for a diverse range of remote learning models. However, studies on the development of practical learning models have not been carried out actively until now. Particularly, there are not many case studies in the field of design, especially regarding mobile website development. As means to improve the newly designed practice environment, this study therefore proposes the "modoo" project that offers domain creation and online marketing services. As a result of this study, the researcher suggests the use of a mixed(blending) teaching method and realized that the effectiveness of education multiplies when project-based learning and flipped learning is combined appropriately. The research methodology was divided into two big sections, education content and operations, and the effect was evaluated using the course evaluations. The study results confirmed that the applicability will increase given that learning satisfaction levels increased by more than 5% compared to face-to-face learning.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.608-619
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• 2022

Purpose This study aimed to evaluate the natural growth of subepithelial tumors of the small bowel detected on CT. Materials and Methods Consecutive patients who were suspected of having subepithelial tumors of the small bowel between January 2005 and December 2020 were reviewed. Eligible patients with suspected small (< 30 mm) subepithelial tumors on at least two CT evaluations were included in the analysis. The patients' data on demographic characteristics, tumoral characteristics, and tumoral size changes during the follow-up were collected. Results This study included 64 patients with suspected small subepithelial tumors (n = 64) of the small bowel. After a median follow-up of 15.8 months, the diameter and volume growth rates were 0.02 mm/month and 1.5 mm³/month, respectively. A significant correlation was observed between the initial size and the growth rate of the small bowel subepithelial tumors. The group of large-sized tumors (initial diameter ≥ 10 mm) tended to show lobulated contours, heterogeneous enhancement, and necrotic changes more frequently than the group of small-sized tumors (initial diameter < 10 mm). Conclusion Small bowel subepithelial tumors measuring less than 10 mm grew more slowly than those measuring 10-30 mm.

• Journal of The Korean Association For Science Education
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• v.22 no.2
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• pp.299-313
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• 2002

A web-based instruction program for the enriched course under the 7th Revised National Curriculum of Biology in Korea was developed and the application effects to learners were analyzed. For the development of the web-based instruction program, five topics of biology from the enriched courses through 7th to 10th grades in the middle and high school science textbooks were selected and modulated with interrogative sentences. Each topic of programs was divided into four activity sections according to the learners' activity procedures supplemented with explanations and evaluations. Each activity was hyper-linked to multi-layers and animations. Further, a virtual experiment was also developed and an evaluation section designed by Java Script was attached. Among five topics, one topic of 'Reproduction and development' at 9th grade level was selected to examine the effects on students' learning. Among 247 9th grade students in the research subject school, only 67 students were able to accessible to ultra-thin Internet cables with their computers at home and they became an experimental group. A control group was assigned to those who are similar level of school science achievement to the experiment group and did not use the web-based program. It was found that most of 9th grade students are able to use Internet at home, however, they do not prefer to use Internet for homework or task project. Rather, most of students used Internet for e-mail or information navigation. Students used internet to solve problems of science and perceived the benefits of Internet for science learning. However, there are not many students to utilize Internet for science homework or task project. Students expressed that they do not prefer to use a web-based learning program for science learning due to lack of interests in science. The effects on students who studied with this program appeared to be significantly high compared to those who did not study with this program. Students who studied with this program positively evaluated this program, in particular, they enjoyed animation effect and virtual experiments. It was concluded that a web-based program for science learning should be developed and distributed through Internet in an attractive and interesting format for students. It was also concluded that various web-based programs for science learning with animation effect and virtual experiments should be developed to increase students' interests in science as well as to improve students' science achievements.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.394-400
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• 2006

Purpose : This study was design and performed for evaluations of resent clinical pattern of bronchiolitis caused by RSV infection with children under 2 year of age for 5 years, who were admitted to pediatric ward. Methods : The inclusion criteria of the patients were children under 24 month-of-age, clinical manifestations of lower respiratory tract infection, and RSV antigen that was detected by a direct immunofluorescence test from the nasal secretions. The additional laboratory and simple chest X-ray findings were reviewed from the medical records of children who were admitted Wonkwang university hospital from Jan. 1999 to Dec. 2003. Results : In the 5 year study duration, 127 patients were enrolled and outbreak of RSV bronchiolitis took place in 2001. The 80 cases(63 percent) of RSV infection were concentrated in later autumn and winter. Number of the cases show coughing were 120(94.5 percent), but rale was audible in 78 cases(61.4 percent). Dyspnea, wheezing, and intercostal retraction were noticed in 27(21.3 percent), 21(16.5 percent), and 4(3 percent) cases respectively. The most common chest X-ray finding was hyperinflation of the lung that was noticed in 110 cases(86.6 percent). Care with mechanical ventilator for more than 2 days required in 5 cases. Conclusion : Lower respiratory tract infection by RSV was common in late autumn and winter season but year-round infection was noticed. The severity of RSV respiratory tract infectiontakes in some degree a grave course. So we suggest that population-based surveillance of acute respiratory infection due to RSV is necessary for assessment of prevalence and epidemiology of this disease.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.193-200
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• 2000

Purpose : This study was designed and performed for evaluations of clinical manifestation and course of the children under 2 year of age with respiratory tract infection and positive respiratory syncytial virus(RSV) antigen. Methods : The selection criteria of the patients were children under 24 month-of-age, Clinical manifestation of respiratory tract infection, and positive RSV antigen that was detected by Vitek ImmunoDiagnostic Assay System(VIDAS) from nasal cavity. The additional laboratory and simple chest X-ray findings were reviewed from the chart of children who were admitted Wonkwang university hospital from October 1999 to March 2000. Results : Total number of patients enrolled on this study was 102. The 48(47%) children were RSV antigen positive by VIDAS method. Abnormal chest X-ray findings were noticed in 38 cases. The male to female sex ratio of 48 RSV antigen positive cases was 1.2 : 1. The mean and range of age was $10.2{\pm}5.9$ and 1.0~24 months. The peak outbreak of cases was noticed on November, 1999. All of the cases shows coughing but rale was audible in 30 cases(60%). Dyspnea, wheezing, and intercostal retraction were noticed 11(23%), 15(31%), and 10(21%) cases respectively. The most common chest X-ray finding was scattered patch infiltration that was noticed in 30 cases(63%). The mean total white blood cell counts in peripheral blood was $12,608{\pm}4,686/mm^3$. The mean blood level of IgA and IgE were $50.8{\pm}20.9$ and $72.1{\pm}98.3mg/dL$ respectively. The C-reactive protein was $16.0{\pm}18.5mg/L$. Total 5 cases need a mechanical respiraton. The duration of admission was under 7 days in 36 cases(75%). Conclusion : The RSV antigen was detected commonly in late fall and winter season. The severity of children under 2 years old with RSV respiratory tract infection take in some degree a gave courses.

• Cross-Cultural Studies
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• v.48
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• pp.67-106
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• 2017

This study focuses on two specific history of Korean literature in Chinese: the outline of The History of Joseon Literature (2010) by Li Yan and The History of Joseon Literature (1988, 2008) by Wei Xu-sheng; it was conducted to compare narrative viewpoints to the history of South and North Korean literature and therefore identify distinguishable characteristics. As a result, the following was concluded. First, The History of Korean Literature by Cho Dong-il and The History of Korean Literature in North Korea (15 volumes) include thorough discussions on division of historical eras, concept of genres as well as individual literary works and applied such discussions on writing literary history. However, Wei Xu-sheng and Li Yan's The History of Korean Literature did not illuminate theoretical discussion of South and North Korea. Li Yan's outline of The History of Joseon Literature was published in 2010 and the first edition of Wei Xu-sheng's The History of Joseon Literature was published in 1986 and later was published as revised editions in 2000 and 2008. Regarding published dates, it is a matter of course to reference Cho Dong-il's The History of Korean Literature, published in the 1980s, or The History of Korean Literature in North Korea (15 volumes), published in the 1990s; nevertheless, neither Wei Xu-sheng nor Li Yan used those texts in their works. Their works were heavily influenced by the narrative tradition of the history of national literature and therefore, entailed unsophisticated discussion on the division of historical eras or the concept of genres. Second, those two texts also emphasized external factors such as politics, society, economy and culture and explicitly mention these factors in historical overview of each chapter. Such an approach is commonly used in narratives of literary history under socialist regimes, including The History of Korean Literature in North Korea (15 volumes). Accordingly, evaluations based on 'political standards' - stress of people, nationality, practicality and so forth - in main texts are particularly accentuated, akin to narratives of literary history under socialist regimes. Finally, since those two Korean literature history works are written by Chinese scholars, they focus on correlation between Chinese literature history and Korean literature history. However, several genre-related terminologies such as Xiaopin (a kind of essay), Yuefu (a kind of popular song/poem), Yuyan (fable), Shuochang (telling of popular stories with the interspersal songs), Shizhuan (biography or/and memoirs in history) were adopted directly from Chinese literature. In analyzing Korean literature using terminologies introduced from Chinese literature, differences between original and alternative definitions were not examined in detail. While some terminologies and concepts were adopted directly without further consideration as to state of the two nations, it is also interesting to note that dichotomy, mainly used in Korean literature history, was used to discuss the genre of Cheonki (romance tale), relevant to Suyichon and Keumosinhua, rather than follow traditions of Chinese literature history.