• International Journal of Contents
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• 제13권3호
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• pp.25-31
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• 2017

With tremendous advancement of information and communication technologies, mobile learning systems have been widely adopted in language learning contexts, and several frameworks have been developed for identifying and categorizing different factors of mobile-assisted language learning (MALL). However, pre-existing frameworks have limitations when evaluating the importance level of criteria. The purpose of this study is to develop a comprehensive hierarchical framework for identifying and categorizing success factors of MALL and prioritizing them according to the importance level. To do that, AHP method is used to quantitatively estimate weight values of MALL criteria. Results reveal that the priority of MALL criteria is ordered as follows: content, system, learner, language learning. Local weights of each criterion are also analyzed; for example, usefulness, accuracy, and authenticity are critical factors for improving MALL contents. Ease of use and mobility of MALL systems are also considered more critical than other systematic factors. In addition, availability of immediate feedback and self-directness has the highest weight values of importance. The findings of the study are discussed regarding hierarchical orders of MALL criteria and conclude that successful MALL implementation may be achieved if related elements are diversely measured and evaluated. Pedagogical implications and suggestions for further research are also presented.

• 분석과학
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• 제30권2호
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• pp.96-101
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• 2017

This study investigated the effect of centrifugation on tryptic digestion. This was done by applying different centrifugation speeds (6,000, 8,000, 10,000, 20,000, and $30,000{\times}g$) over various durations (0, 10, 20, 30, 40, 50, and 60 min) to digest two model proteins - cytochrome c and myoglobin. The intact proteins and resulting peptides were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Centrifugation greatly improved the tryptic digestion efficiency of cytochrome c, where either an increase in centrifugation speed or in digestion duration significantly improved the digestion of cytochrome c. However, centrifugation did not noticeably improve the digestion of myoglobin; 16 h of centrifuge-assisted tryptic digestion at $30,000{\times}g$ barely removed the myoglobin protein peak. Similar results were also obtained when using conventional tryptic digestion with gentle mixing. When acetonitrile (ACN) was added to make 10% ACN buffer solutions, the myoglobin protein peak disappeared after 6 h of digestion using both centrifuge-assisted and conventional tryptic digestions.

• 한국안광학회지
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• 제9권1호
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• pp.161-166
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• 2004

본 연구에서는 이온빔 증착방법을 사용하여 스테인레스 스틸 기판 위에 TiN 박막을 성장하였다. $10^{-5}$ Torr의 질소 분위기에서 아르곤 가스를 보조 이온빔으로 사용하여 TiN 박막을 성장하였다. TiN 박막의 화학 조성, 색상, 밀착력 등을 En의(원자당 이용에너지) 변화에 따라서 측정하였다. En이 증가 할 때 질소와 Ti의 비율은 선형적으로 변화 하였고, 높은 En의 경우에는 질소와 Ti의 비율은 1.2를 가지며 포화되었다. 밝은 금색은 En이 어떤 임계값(Ecn)에 도달 하였을 때 얻어졌다. 이때의 질소와 Ti의 비율은 0.9 이다.

• Journal of Animal Science and Technology
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• 제61권6호
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• pp.379-387
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• 2019

The purpose of this study is to identify the effects of a group integrated intervention program that simultaneously conducts cognitive activities, physical activities, emotional activities and social interactions by integrating animal-assisted therapy (AAT) and integrated elderly play therapy based on the cognitive functions and depression of the elderly who live alone. This study follows a pre-test post-test design with a nonequivalent control group, to verify the effectiveness of a group integrated intervention. It applies a group integrated intervention program to 20 elderly people who live alone, aged 65 and above (10 in the experimental group, 10 in the control group), once a week for 90 minutes across eight weeks. The study went through MMSE-K, TMT-A and GDSSF-A to assess cognitive functions and the level of depression. The group integrated intervention increased the cognitive functions of the experimental group and decreased levels of depression. Therefore, this study verified that a group integrated intervention program of AAT and integrated play therapy of the elderly, is an effective for increasing cognitive functions and decreasing depression levels of the elderly who live alone. Based on these findings, the study suggests that there is a need to continuously expand group integrated intervention programs and provide relevant political support.

• Advances in nano research
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• 제5권3호
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• pp.203-214
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• 2017

In this study we present the reaction mechanism of $Cu_2ZnSnSe_4$ (CZTSe) nanoparticles synthesized by microwave-assisted chemical synthesis. We performed reactions every 10 minutes in order to identify different phases during quaternary CZTSe formation. The powder samples were analyzed by x-ray diffraction (XRD), Raman spectroscopy, energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results showed that in the first minutes copper phases are predominant, then copper and tin secondary phases react to form ternary phase. The quaternary phase is formed at 50 minutes while ternary and secondary phases are consumed. At 60 minutes pure quaternary CZTSe phase is present. After 60 minutes the quaternary phase decomposes in the previous ternary and secondary phases, which indicates that 60 minutes is ideal reaction time. The EDS analysis of pure quaternary nanocrystals (CZTSe) showed stoichiometric relations similar to the reported research in the literature, which falls in the range of Cu/(Zn+Sn): 0.8-1.0, Zn/Sn: 1.0-1.20. In conclusion, the evolution pathway of CZTSe synthesized by this novel method is similar to other synthesis methods reported before. Nanoparticles synthesized in this study present desirable properties in order to use them in solar cell and photoelectrochemical cell applications.

• 한국항행학회논문지
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• 제17권4호
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• pp.386-395
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• 2013

본 논문에서는 AOA (Angle of Arrival)기반의 재머위치 결정기법에 사용되는 DOA 추정 알고리즘을 대상으로 Root-MUSIC으로 1차 DOA 추정을 수행한 후 MUSIC을 이용한 2차 DOA 추정을 수행하는 성능 개선 알고리즘을 제시하였다. 또한 제안한 알고리즘을 검증하기 위해 소프트웨어 기반의 시뮬레이션 플랫폼을 구성하여 오차환경에 따른 DOA 추정 성능 분석을 수행하고, 본 논문에서 제시한 DOA 추정 알고리즘의 DOA 추정 정확도 및 분해능의 개선 정도를 분석하였다.

• Journal of Korean Neurosurgical Society
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• 제48권1호
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• pp.53-58
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• 2010

Objective : The purpose of this study was to review the safety and durability of aneurysms treated with stent-assisted coiling of ruptured anterior communicating artery aneurysms with small parent vessels (< 2.0 mm). Methods : Retrospective review of all ruptured aneurysm treated with stent assisted endovascular coiling between March 2005 and March 2009 at our institution was conducted. We report 11 cases of the Neuroform stent placement into cerebral vessels measuring less than 2.0 mm in diameter (range, 1.3-1.9 mm) in anterior cerebral artery. Clinical follow-up ranged from 3 to 12 months and imaging follow-up was performed with cerebral angiography at 6 months and 12 months after discharge. Results : Complete occlusion was achieved in 10 patients, and a remnant neck was evident in one. No stent displacement or no dislodgement occurred during stent placement. There was no evidence of thromboembolic complication, arterial dissection and spasm during procedure. We performed follow-up angiography in all patients at 6 months and/or 12 months from the first procedure. The follow-up angiographic data showed successfully results except one in-stent stenosis case. All patients improved clinical performances except one patient with severe vasospasm who showed poor clinical condition initially. Conclusion : We have safely and successfully treated 11 vessels smaller than 2.0 mm in diameter with self-expanding stents with good short and intermediate term results. More clinical data with longer follow-ups are needed to establish the role of stent-assisted coiling in ruptured aneurysms with small parent vessels.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 제33회 추계학술대회논문집
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• pp.173-176
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• 2009

박격포는 근거리 진지전이나 직사화기 곡사화기로는 사격할 수 없는 배사면의 적을 큰 낙각의 탄도를 그리는 포탄으로 공격할 수 있으므로 보병부대에서 효율적으로 운용되고 있다. 육군에서는 정확성, 기동성 및 사거리가 증대된 120미리 박격포의 도입 필요성을 제기하고 있으며, 관련 연구도 꾸준히 진행되고 있다. 본 연구에서는 120미리 박격포탄 중 사거리연장탄에 사용되는 로켓추진제의 조성을 설계하여 시제품을 제조한 후 지상연소시험과 발사시험을 통해 120미리 박격포용 사거리연장탄의 개발 가능성을 알아보았다.

• Journal of Chest Surgery
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• 제33권1호
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• pp.85-87
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• 2000

Patent ductus arteriosus(PDA) is a common congenital heart disease encountered in premature neonates infants and children. Patent ductus arteriosus was the first surgically managed congenital heart disease,. Classic surgical interruption of patent ducturs arteriosus was partially replaced by a transcatheter endovascular closure, After a 5-7 mm video-assisted thoracoscopic interruption of the patent ductus arteriosus first applied in 1991, this minimally invasive technique came to be used in many centers, Video-assisted thoracoscopic interruption of the patent ductus arteriosus is feasible in low-weight infants whereas transcatheter endovascular closure of the ductus is usually not possible. We experienced successful outcome for the treatment of patent ductus arteriosus with 2 mm video-assisted thoracoscopic titanium clipping, We believed that this technique is a simple safe and rapid method for closure of the patent arteriosus.

• Advances in pediatric surgery
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• 제19권2호
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• pp.130-139
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• 2013

The application of laparoscopic techniques for the surgical management of Hirschsprung's disease is the recent trend. We described the surgical technique and postoperative long-term outcomes of the one-stage, laparoscopic-assiseted endorectal pull-through operation for Hirschsprung's disease. The technique uses three to four small abdominal ports. Laparoscopic mobilization of the sigmoid colon and rectum is performed and marginal artery-preserving colon pedicle is prepared. The rectal mobilization is performed using a transanal endorectal sleeve technique. The anastomosis is performed 0.5~1 cm above the dentate line. The age at surgery ranged from 6 days to 4 years. The average operative time was 144 minutes. Almost all of the patients passed stool and flatus within 36 hours of surgery. The average hospital stay after surgery was 6.5 days. Among 42 patients, 32 patients older than 3 years old were evaluated for function on defecation. All 32 patients have been continent, of those who needed laxatives were 11 (34.3%) due to constipation and overflow incontinence. Four children (12.5%) have remained dependent on laxatives. Laparoscopic-assisted endorectal pull-through operation for Hirschsprung's disease appears to be safe, provides the less pain, shorter time to full feeding, shorter hospital stay, and excellent cosmetic outcomes. Helping patients and parents ensure the quality of life, they should be provided with counseling, education, and longer-term follow-up care.