• 한국수학교육학회지시리즈E:수학교육논문집
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• 제37권2호
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• pp.199-212
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• 2023

본 연구의 목적은 수학교과에서 학습하는 내용이 영역과 유형의 차이에 따라 구획연습과 교차연습의 성취도 차이가 나는지 알아보고 이 결과를 통해 수학학습에서의 교차연습의 효과가 '분산-연습 가설'에 의한 것인지 혹은 '구분-대조 가설'에 의한 것인지를 확인하는 것이다. 교차연습이 구획연습보다 효과적이라는 연구가 대부분이지만 그 원인에 대해서 선행 연구들은 일관된 결과를 보이고 있지 않다. 이에 본 연구에서는 D광역시 중학교 1학년 103명을 구획연습, 교차연습, 먼-구획연습, 먼-교차연습 집단으로 무작위 배치하여 4회에 걸쳐 학습활동을 하였고 일주일의 파지간격을 둔 후 최종검사를 실시하였다. 그 결과, 동일한 영역에서의 유사한 유형에서는 교차연습의 효과가 나타났고, 서로 다른 영역의 다른 유형에서는 교차연습의 효과가 나타나지 않았다. 또한, 이 결과를 통해 교차연습의 효과는 '분산-연습 가설'보다는 '구분-대조 가설'에 의한 것임을 확인할 수 있었다. 연구결과와 연구방법에 대한 논의를 통해 후속 연구가 필요한 연구문제를 제안하였다.

• The Journal of Korean Physical Therapy
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• 제23권3호
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• pp.65-70
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• 2011

Purpose: We investigated the changes in the stop-signal reaction time (SSRT) and the no-signal reaction time (NSRT) following motor sequential learning in the stop-signal task (SST). This study also determined which of the reduction0s of spatial processing time was better between blocked- and random-SST. Methods: Thirty right-handed healthy subjects without a history of neurological dysfunction were recruited. In all subjects, both the SSRT and the NSRT were measured for the SST. Tasks were classified into two categories based on the stop-signal patterns, the blocked-SST practice group and random-SST practice group. All subjects gave written informed consent. Results: In the blocked-SST group, both the SSRT and the NSRT was significantly decreased (p<0.05) but not significantly changed in the random-SST group. In the SSRT and the NSRT, the blocked-SST group was faster than the random-SST group (p<0.05). In the post-test SST after practice of each group, the SSRT was significantly decreased in the random-SST group (p<0.05), but the NSRT showed no significant changes in either group. Conclusion: These findings demonstrate that random-SST practice resulted in a decrease in internal processing times needed for a rapid stop to visual signals, indicating motor skill learning is acquired through improved response selection and inhibition.

• The Journal of Korean Physical Therapy
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• 제27권4호
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• pp.240-245
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• 2015

Purpose: The purpose of this study was to compare the blocked practice and random practice of task-oriented training in patients with chronic stroke to determine the effect of lower extremity muscle activity and balance ability. Methods: The thirty participants were randomly assigned to either the block practice group (BP) group or the random practice group (RP) and received the training three times per week, 30 minutes per day, for six weeks. Surface electromyography was used for measurement of lower extremity muscle activity. Static balance was to measured the stability index (SI) and weight distribution index (WDI) using the Tetrax. The four square step test (FSST) was used to measure dynamic balance. The paired t-test was used for determination of differences before and after intervention, and the independent t-test was used for determination of differences between groups. Results: Lower extremity muscle activity, RA and GCM was improved in the RP group after intervention and between groups. TA was significantly improved in the RP group compared with the BP group. In comparison of before and after interventions, SI was reduced in BP and RP. WDI in OS was reduced in comparison of BP and RP before and after intervention. CS was reduced in BP and RP. The OS and CS was improved in RP compared with BP. In comparison of before and after intervention, FSST was improved in BP and RP. Conclusion: Task-oriented training methods using random practice was found to be effective in promoting lower extremity muscle activity and balance ability in chronic stroke patients.

• 대한감각통합치료학회지
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• 제19권1호
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• pp.54-68
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• 2021

목적 : 본 연구는 뇌성마비 아동의 신체기능과 일상생활 향상을 위해 적용된 과제 중심 훈련 방법에 대해 정리하고 효과를 제시하고자 하였다. 연구방법 : 검색 기간은 2008년 1월부터 2020년 8월까지로 하였으며, 자료 검색을 위해 CINAHL, MEDLINE, PubMed의 데이터베이스를 이용하였다. 총 18편이 선정되었으며, PICO(Patient, Intervention, Comparison, Outcome) 방법을 적용하여 체계적으로 정리하였다. 과제 중심 훈련은 선행연구를 참고하여 운동학습 및 운동조절 이론의 전략인 과제(Task), 실행(Practice), 피드백(Feedback)으로 분류하여 제시하였다. 결과 : 그 결과 13편의 연구가 운동기술 영역에서 유의한 결과를 보였으며, 그 중 2편의 연구에서 일상생활 영역에서 유의한 결과를 보였다. 과제는 개별 과제(discrete task)와 닫힌 과제(closed task) 형태가 가장 많이 사용되었다. 실행은 전체 실행(whole practice) 유형이 가장 많이 사용되었으며, 부분 실행(part practice), 차단 실행(blocked practice) 순으로 사용되었다. 마지막으로 피드백은 구체적으로 제시하지 않은 경우가 가장 많았으며, 외재적 피드백(extrinsic feedback)이 사용되었다. 결론 : 본 연구를 바탕으로 향후에는 뇌성마비 아동의 운동조절을 촉진하는 기술의 체계적인 선택과 구체적인 방법의 제시를 통하여 과제 중심 훈련이 임상에서 더욱 효과적으로 사용될 수 있을 것이라 기대한다.

• Journal of Communications and Networks
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• 제18권3호
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• pp.364-374
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• 2016

With vast amounts of spectrum available in the millimeter wave (mmWave) band, small cells at mmWave frequencies densely deployed underlying the conventional homogeneous macrocell network have gained considerable interest from academia, industry, and standards bodies. Due to high propagation loss at higher frequencies, mmWave communications are inherently directional, and concurrent transmissions (spatial reuse) under low inter-link interference can be enabled to significantly improve network capacity. On the other hand, mmWave links are easily blocked by obstacles such as human body and furniture. In this paper, we develop a multi-hop relaying transmission (MHRT) scheme to steer blocked flows around obstacles by establishing multi-hop relay paths. In MHRT, a relay path selection algorithm is proposed to establish relay paths for blocked flows for better use of concurrent transmissions. After relay path selection, we use a multi-hop transmission scheduling algorithm to compute near-optimal schedules by fully exploiting the spatial reuse. Through extensive simulations under various traffic patterns and channel conditions, we demonstrate MHRT achieves superior performance in terms of network throughput and connection robustness compared with other existing protocols, especially under serious blockage conditions. The performance ofMHRT with different hop limitations is also simulated and analyzed for a better choice of the maximum hop number in practice.

• 재활치료과학
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• 제1권2호
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• pp.14-22
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• 2012

서론 : 뇌줄중 환자의 상지 운동 결손은 일상생활에서 수행하는 많은 활동에 큰 어려움을 겪게 만든다. 작업치료사들은 다양한 활동을 제공함으로써 일상생활의 참여를 돕기 위해서 노력하지만 학습자의 특성과 환경을 고려하지 않은 채 훈련이 이루어지고 있다. 따라서 본 연구는 운동 학습 이론과 원칙에 대해 알아보고 작업치료 영역에 적용하기 위한 임상적 고려에 대해 제언해보고자 한다. 본론 : 운동학습의 원칙으로는 학습의 단계, 과제의 형태, 실행 또는 연습, 피드백이 있는 학습의 단계에 따라 운동학습의 원칙을 적용할 수 있을 것이다. 초기단계에서는 학습목표와 작업환경에 대한 충분한 이해가 선행되어야 하며 지속적이며 차단된 연습, 전체 과제 연습이 학습을 촉진시킨다. 후기단계에서는 내제적 피드백에 의존하도록 유도하여야 하며 열린과제, 무작위 연습이 수행을 증진시킨다. 결론 : 치료기전으로 제공되는 다양한 운동학습의 원칙을 적용하기 위해서는 치료계획 수립 시에 체계적으로 결정되어야 할 것이다. 작업치료사들은 환자 각각의 평가결과를 바탕으로 환자의 수준에서 수행을 증진시킬 수 있는 효과적인 운동학습의 원칙을 계획하고 치료적 변화를 계속 모니터링하면서 변경시켜나가야 할 것이다.

• 대한조선학회논문집
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• 제46권5호
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• pp.460-470
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• 2009

In recent practice a half round prismatic bar has fillet welded or formed through foundry work along the centerline on rear concave surface of the horn to mitigate gap flow between fixed and movable part of the rudder system. When the gap clearance has been blocked with this practice, numerical simulations indicate that the practices are not only effective in reducing the gap flow but also in mitigating the cavitation. The blocking effects are remarkably improved when a pair of blocking bar is bisymmetrically attached with respect to centerline on the opposite convex surface of the movable part. The blocking bar could be placed on the exposed surface under maximum rudder angle. This implies that the blocking bar could be easily adopted not only in a design stage but also in a maintenance stage for mitigating rudder cavitation. In addition, the numerical simulations imply that more improvements could be anticipated through the selection of section shape of prismatic bar for gap flow blocking.

• Nutrition Research and Practice
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• 제3권3호
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• pp.192-199
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• 2009

Cadmium intoxication has been associated with the dysregulation of iron homeostasis. In the present study, we investigated the effect of cadmium on the expression of ferroportin 1 (FPN1), an important iron transporter protein that is involved in iron release from macrophages. When we incubated cadmium with J774 mouse macrophage cells, FPN1 mRNA levels were significantly increased in a dose- and time-dependent manner. Furthermore, the cadmium-induced FPN1 mRNA expression was associated with increased levels of FPN1 protein. On the other hand, cadmium-mediated FPN1 mRNA induction in J774 cells was completely blocked when cells were co-treated with a transcription inhibitor, acitomycin D. Also, cadmium directly stimulated the activity of the FPN1-promoter driven luciferase reporter, suggesting that the cadmium up-regulates FPN1 gene expression in a transcription-dependent manner. Finally, cadmium exposure to J774 macrophages increased intracellular reactive oxygen species (ROS) levels by ${\sim}2$-fold, compared to untreated controls. When J774 cells were co-treated with antioxidant N-acetylcystein, the cadmium-induced FPN1 mRNA induction was significantly attenuated. In summary, the results of this study clearly demonstrated that cadmium increased FPN1 expression in macrophages through a mechanism that involves ROS production, and suggests another important interaction between iron and cadmium metabolism.

• Nutrition Research and Practice
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• 제3권1호
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• pp.15-22
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• 2009

This study was performed to investigate the effect of chlorella on cadmium (Cd) toxicity in Cd-administered rats. Sixty male Sprague-Dawley rats (14 week-old) were blocked into 6 groups. Cadmium chloride was given at levels of 0 or 325 mg (Cd: 0, 160 ppm), and chlorella powder at levels of 0, 3 and 5%. Cadmium was accumulated in blood and tissues (liver, kidney and small intestine) in the Cd-exposed groups, while the accumulation of Cd was decreased in the Cd-exposed chlorella groups. Fecal and urinary Cd excretions were remarkably increased in Cd-exposed chlorella groups. Thus, cadmium retention ratio and absorption rate were decreased in the Cd exposed chlorella groups. Urinary and serum creatinine, and creatinine clearance were not changed in experimental animals. In addition, metallothionein (MT) synthesis in tissues was increased by Cd administration. The Cd-exposed chlorella groups indicated lower MT concentration compared to the Cd-exposed groups. Moreover, glomerular filtration rate (GFR) was not changed by dietary chI orella and Cd administration. According to the results above, this study could suggest that Cd toxicity can be alleviated by increasing Cd excretion through feces. Therefore, when exposed to Cd, chlorella is an appropriate source which counteracts heavy metal poisoning, to decrease the damage of tissues by decreasing cadmium absorption.

• 기본간호학회지
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• 제6권3호
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• pp.493-506
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• 1999

The purpose of the study is to evaluate the effectiveness and competence level of trainees of Cardiopulmonary resuscitation training targeted for nursing students. 70 nursing students of Y nursing college are recruited as subjects from Dec. 1st, 1998 through Dec. 8th. 1998. For the pre-test. demographic data related to CPR and knowledge of CPR were evaluated. For the post-test, the next week of pre-test, three difference groups of subjects were tested their knowledge of CPR. CPR training was designed by two components which were 90 mins lecture and demonstration by one professor and individual practice using two educational models with two professors. As the tool of measurement estimating pre or post knowledge of CPR. questionnaires were developed based on self-diagnosis questionnaires of American Heart Association(AHA). The questionnaires were multiple choices (50 questions) and open end questions regarding CPR process. Each multiple choices questions valued 2 points (Score varied min. 0 point to max 100 points.). Collected data were computerized and analyzed by SPSS-WIN. Frequency and percentage of each questions analyzed. The differences of the knowledge and competency level of subjects between pre and post test was analyses by paired t-test. The followings are research outcome. 1. In the pre-test, 95% of subjects answered that they already knew what CPR was. but only 82% described correctly what CPR was. 49% learned CPR before, and 80s5 of them learned at high school. 2. 37 questions scores increases, and 10 questions scores decreased. 3 questions didnt change their score. After getting training, ratio of 80% correct score significantly increased 4 times. 3. In post-test. knowledge level of trainees increased compared to that of pre-test. (t=-15.075, p=.000) 4. Competence level also increased (t=-14.86, p=.00). In result, after getting CPR training, most CPR knowledge increased except open the air tract, toddler CPR, and alternative behavior when the air tract is blocked. CPR training needs to extend the educational scope not only CPR lecture but also psychomotor skill practice. CPR trainees are in need of appropriate feedback as well as enough opportunities of skill practice.