• 전력전자학회논문지
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• 제18권5호
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• pp.501-506
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• 2013

A hold-up time compensation circuit is proposed to get high efficiency of the front-end phase-shifted full bridge DC/DC converter. The proposed circuit can make the phase-shifted full bridge front-end DC/DC converter built with 0.5 duty ratio so that the conduction loss of the primary side and voltage stress across rectifier in the secondary side are reduced and the higher efficiency can be obtained. Furthermore, the requirement of an output filter significantly can diminish due to the perfect filtered waveform. A 12V/100A prototype has been made and experimental results are given to verify the theoretic analysis and detailed features.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.978-983
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• 2009

This paper analyzed longitudinal end effect occurred in linear induction motor by using I-d direct solution and its result is verified by 2-d Finite Element Method(FEM). Longitudinal end effect of linear induction motor caused by magnetic discontinuity in primary core and electric discontinuity in armature winding has been investigated by many researchers. In this paper, 1-d direct solution and boundary conditions proposed by Yamamura and Nasar is used to analyze end effect of linear induction motor and its solution is verified by 2-d FEM.

• 대한소아치과학회지
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• 제26권2호
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• pp.207-217
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• 1999

본 연구의 목적은 어린이에게 사용되고 있는 가철식 교정장치를 위한 clasp에 대하여 각 디자인간 유지력의 차이를 평가하고자 함이다. 상악 유견치와 제 1, 2유구치 및 제 1 대구치를 단일 치아모형과 두 개의 인접 치아 형태로 금속 주모형을 제작한 후 clasp를 종류에 따라 형성하여 각 모형에 대한 clasp의 유지력을 측정하였다. Clasp의 종류에 따른 유지력을 서로 비교하여 다음과 같은 결론을 얻었다. 1. 단일치아에서 유지력을 얻는 clasp중 Jackson clasp와 Adams clasp는 다른 clasp에 비하여 높은 유지력을 나타냈으며, C clasp는 가장 낮은 유지력을 나타냈다(p<0.05). 2. 두개 이상 치아의 치간부 undercut을 이용하는 clasp중 eyelet clasp가 가장 큰 유지력을 보여주었고 triangular clasp, ball clasp순으로 낮은 유지력을 보여주었다(p<0.05).

• Advances in pediatric surgery
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• 제13권2호
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• pp.105-111
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• 2007

We reviewed the records of 25 patients who were re-operated upon after primary repair of esophageal atresia with or without fistula at the Department of Pediatric Surgery, Seoul National University Children's Hospital, from January 1997 to March 2007. Types of the esophageal atresia anomalies were Gross type A in 5 patients, C in 18, and E in 2. The indications for re-operation were anastomosis stricture (n = 14), tracheo-bronchial remnant (n = 4), persistent anastomosis leakage (n = 3), recurrent tracheo-esophageal fistula (n = 2) and esophageal web (n = 2). The interval between primary and secondary surgery was from 48 days to 26 years 5 months (mean: 2 years and 4 months). Four patients required a third operation. The interval between the second and third operation was between 1 year 1 month and 3 year 10 month (mean: 2 years 5 months). Mean follow up period after last operation was 35 months (1 years-8 years 6 months). The secondary surgery was end-to-end esophageal anastomosis in 15, esophagoplasty in 5, gastric tube replacement in 5. After secondary operation, 6 patients had anastomosis stricture (4 patients were relieved of the symptoms by balloon dilatation, 2 patients underwent tertiary operation). Five patients had leakage (sealed on conservative management in all). Two patients had recurrent tracheo-esophagel fistula (1 patient received chemical cauterization and 1 patient underwent tertiary operation). Currently, only one patient has feeding problems. There were no mortalities. Secondary esophageal surgery after primary surgery for esophageal atresia was effective and safe, should be positively considered when complications do not respond to nonoperative therapy.

• 동의신경정신과학회지
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• 제34권4호
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• pp.359-368
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• 2023

Objectives: This study aims to establish a Korean medicine doctor's range of services in the dementia relief primary care system based on the previously developed dementia clinical practice guidelines (CPGs). Developing a dementia relief primary care Clinical Pathway (CP) can aid clinically when the Korean medicine primary care doctor conducts treatment. Methods: We analyzed Dementia Korean Medicine Primary Care Model Data and then applied CP Methodology to develop the configuration of the Korean Medicine Primary Care Model. For patients with Alzheimer's dementia (AD), vascular dementia (VD), and mild cognitive impairment (MCI), the Korean Medicine Primary Care Model focuses on improving cognitive function, everyday living abilities and easing symptoms through interventions described in CPGs. The contents of the draft model later include references to already-existing CPs. Results: The study sites were chosen as Korean medical clinics connected to primary care physicians in the dementia-friendly model. The CP used a time task matrix version to arrange the clinical chronology, which included all examinations, diagnoses, and treatment procedures, from the initial appointment to follow-ups and the end of therapy. Conclusions: It anticipates that Korean primary care doctors familiar with dementia can use the offered therapies for the first time by creating the dementia Korean medicine primary care model in this study. This is expected to maximize the range of medical services provided by Korean medicine and improve the standard of medical treatment.

• Journal of Species Research
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• 제5권1호
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• pp.31-48
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• 2016

Twelve new species of two genera Smenospongia and Cacospongia (Demospongia: Dictyoceratida: Thorectidae) are described from Gageodo Island and Ulleungdo Island, Korea. Of these, ten new species of the Smenospongia are distinguished from the other nine reported species of the genus by the skeletal structure and sponge colour. Primary fibres of the genus Smenospongia are mostly dense, dark colour, and invisible inside of fibres, but they are mostly cored detritus and echinated with spicules. Especially, the end of primary fibres at the surface shows densely cored with spicules. All these new species changed the colour. Two new species of the genus Cacospongia are compared with nine other reported species. In skeletal structure, primary fibres of the genus Cacospongia are light colour, visible inside and more heavily cored with spicules and sands. The skeleton of this genus has large meshes. The colour of the genus Cacospongia does not change.

• 대한소아치과학회지
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• 제8권1호
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• pp.47-53
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• 1981

Author have studied with electron microscope on the effect of biscuit solution dissolved in natural saliva on the enamel surface of the primary teeth. Four of the teeth were natural primary teeth and the other four teeth were treated in acidulated phosphate fluoride during four minute. The obtained results were as follows; 1. The pH value of the solution was decreased according to the time passed, and gradually became 3.75 at the end of 48 hours. 2. Natural teeth appeared normal enamel surface appearance during first 12 hours, and at 24 hours, it appeared some degree of decalcified appearance near the enamel rods and surfaces. 3. The decalcified appearances of the enamel surfaces of the fluoride treated teeth were not significant compared with the fluoride untreated teeth. 4. Streptococci of the enamel surface were increased according to the time passed.

• Asian-Australasian Journal of Animal Sciences
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• 제25권5호
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• pp.629-634
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• 2012

This study was conducted to improve the yield of mature oocytes from in vitro-culture of ovarian primary follicles by optimizing follicle retrieval from neonatal mice of different ages. Primary follicles of 75 to $99{\mu}m$ in diameter were collected daily from 7- to 14-day-old neonatal mice, and subsequently cultured in ${\alpha}$-MEM medium. Number of primary follicles isolated, growth of the follicle during in vitro-culture and maturation of intrafollicular oocytes were monitored. Overall, mean number of preantral follicles per animal was improved from 10.7 to 88.7 as the age of follicle donors was increased from 7 to 14-day-old. Number of primary follicles was increased gradually up to 11-day-old (35.7 follicle per an animal), then reduced to 29 in 14-day-old (p = 0.0013). More follicles retrieved from 10-day-old or 11-day-old females maintained their morphological normality at the end of primary culture than the follicles retrieved from 9-day-old. Of those cultured, primary follicles retrieved from 11-day-old mice yielded largest larger number of early secondary follicles than the follicles retrieved from in the other ages (39 vs. 13 to 29%). More than 3.3-times increase (0.86 to 2.86; p<0.05) in an average number of mature oocytes per animal was observed in the group of 11-day-old, compared with 9-day-old. However, no difference was found in the percentage of primary follicles developing into the pseudoantral stage (21 to 30%; p = 0.5222) and in the percentage of oocytes mucified (32 to 39%; p = 0.5792). In conclusion, a positive correlation between retrieval time and follicle growth was detected, which influences the efficiency to derive mature oocytes by follicle culture.

• Journal of Korean Neurosurgical Society
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• 제63권3호
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• pp.327-337
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• 2020

Junctional neurulation represents the most recent adjunct to the well-known sequential embryological processes of primary and secondary neurulation. While its exact molecular processes, occurring at the end of primary and the beginning of secondary neurulation, are still being actively investigated, its pathological counterpart -junctional neural tube defect (JNTD)- had been described in 2017 based on three patients whose well-formed secondary neural tube, the conus, is widely separated from its corresponding primary neural tube and functionally disconnected from corticospinal control from above. Several other cases conforming to this bizarre neural tube arrangement have since appeared in the literature, reinforcing the validity of this entity. The cardinal clinical, neuroimaging, and electrophysiological features of JNTD, and the hypothesis of its embryogenetic mechanism, form part of this review.

• International journal of advanced smart convergence
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• 제13권2호
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• pp.258-266
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• 2024

E-learning systems have proliferated in recent years, particularly in the wake of the global COVID-19 pandemic. For kids, there isn't a specific online learning platform available, though. To do this, new conceptual models of training and learning software that are adapted to the abilities and preferences of end users must be created. Young pupils: those in kindergarten, preschool, and elementary school are unique subjects with little research history. From the standpoint of software technology, young students who have never had access to a computer system are regarded as specific users with high expectations for the functionality and interface of the software, social network connectivity, and instantaneous Internet communication. In this study, we suggested creating an electronic learning management system that is web-based and appropriate for primary school pupils. User-centered design is the fundamental technique that was applied in the development of the system that we are proposing. Test findings have demonstrated that students who are using the digital environment for the first time are studying more effectively thanks to the online learning management system.