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        검색결과 322

        83.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The current study examined the validity of classroom-based English assessment in the elementary school context using a validity analysis framework, which includes cognitive, instructional, and inferential validity components. As a case study, it evaluated two unit achievement tests administered to 142 6th grade students. Three types of data (i.e., the curricular learning goals, instructional contents covered for the two units, and two unit achievement tests and scores) were collected and analyzed for the classroom-based assessment validity argument. Results revealed that the two tests were relevant to the curriculum and instruction; however, there was a lack of correspondence between the two tests and the curriculum (cognitive validity); moreover, the instructional contents were not sufficiently covered with representative test items (instructional validity). While the test items functioned as expected, students showed a wide range of achievement, which was not expected in the achievement test context (inferential validity). The findings suggest implications for the development and use of classroom-based assessment for young language learners.
        6,400원
        84.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The kidney is a highly complex organ, and acute or chronic renal diseases can occur with various complications such as diabetes and hypertension. So far, no target specific treatment is available in acute or chronic renal failure, necessitating the development of alternative therapeutic strategy. Recent experimental findings suggest that the renal function and structure can be restored after being treated with various sources of stem/progenitor cells. In this review, we discuss up-to-date findings of the potential of renal progenitor/stem cells in alleviating renal injuries with a focus on preclinical studies. We also review cellular mechanisms underlying the therapeutic function of these cells.
        4,000원
        85.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 보편적으로 복잡한 문제로 정의되던 테트리스 게임을 강화학습을 통해 해결하기 위한 아키텍처를 구현하였다. 테트리스 게임은 무작위로 나타나는 블록의 모양과 회전의 형태를 고려해서 블록을 최적의 위치에 신속하게 쌓아야 하므로, actor의 빠른 판단능력과 반응속도를 요구한다. 또한, 다양한 블록의 형태와 순서로 인해 매우 많은 경우의 수가 나타나기 때문에 수행의 주체가 사람이라면 단순히 기억력과 암기에 의존하는 방법으로는 수행에 한계가 있다. 따라서 본 연구에서 구현한 강화학습 아키텍처의 경우 학습 모델의 구현뿐 아니라 의사결정의 정확성을 높일 수 있는 휴리스틱을 보상에 가중치로 활용하는 방식으로 접목하였고, 그 결과 사람이 직접 게임을 수행하는 것에 비해 보편적으로 높은 점수를 얻을 수 있었다. 아직은 해당 분야를 완전히 정복하였다고 표현할 수는 없지만, 여러 번의 실험에서도 일반적인 사람에 비해서 더욱 좋은 플레이를 할 수 있었다. 하지만 성능에 가장 큰 영향을 미치는 요소가 학습 모델보다 휴리스틱에서 비롯되고 있다는 단점도 식별하였다. 이에 본 논문에서는 이러한 아키텍처의 구조와 사용한 기술들과 알고리즘에 대해 자세히 기술하였으며 접근 방향을 제시한다.
        4,500원
        87.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of negotiation in the process of providing written corrective feedback (WCF) by comparing three different patterns: non-negotiation, minimal negotiation, and extended negotiation. The data were collected from three intermediate academic English classes at a university in Korea. Each class was exposed to different degrees of negotiation while they received WCF for two target forms, the past verb forms and the English articles, in their written production (text re-construction tasks). Their accuracy improvement was measured by text-reconstruction writing tasks and error correction tests. The study found that the use of negotiation affected accuracy improvement of the target forms; however, its effectiveness varied depending on the target forms and measurements. For the past tense, negotiation, regardless of its amount, resulted in more accuracy improvement than non-negotiation in both text re-construction tasks and error correction tests. However, for the English articles, negotiation operated differently: extended negotiation significantly brought about more accuracy development in both measurements, but the difference between minimal negotiation and non-negotiation was only observed in the error correction test, not in the text re-construction task.
        6,000원
        88.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 이 연구는 안경과 선글라스에서 테와 렌즈의 형태와 색상에 대한 한국인과 중국인 소비자 집단의 선호도 차이를 조사하기 위하여 실시되었다. 방법: 한국에 유학 중인 중국인 학생 150명과 한국인 대학생 150명을 대상으로 설문조사를 실시하고 그 결과를 분석하였다. 안경광학 관련 전공자는 설문 대상에서 배제되었다. 중국인 학생들에게는 중국어 간체자로 번역된 설문지를 제공하였으며, 제공된 설문지는 한국 대학 석사과정에 유학 중인 중국인 원어민 학생이 한국어 설문지를 바탕으로 번역한 것이다. 결과: 중국인 소비자 집단은 안경보다 선글라스에서 글로벌 유명 브랜드를 더 선호하였으며, 한국산 안경 제품을 상대적으로 선호하는 것으로 나타났다. 또한, 무테 또는 반무테, 금색테, 투톤컬러 렌즈 항목에서 한국인 소비자 집단보다 높은 선호도를 나타냈다. 결론: 이 연구의 결과는 한국 안경 제조․유통 업체의 중국 시장 진출이나 중국인 고객 비율이 높은 안경원 의 판매 전략 수립에 기여할 수 있을 것으로 기대된다.
        4,000원
        89.
        2018.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The study investigated the effects of recasts and prompts on learning language forms that arose incidentally in dyadic interaction, focusing on the degree of explicitness of each type of feedback and learner proficiency levels. The data were collected from 64 beginning and upper-intermediate English learners of Korean. Thirty-one beginning learners were randomly assigned to a feedback group and to a control group, and thirtythree upper-intermediate learners were also assigned to a feedback group and to a control group. Each learner was paired with an English speaker and worked on a picture-sequencing task. The learners in the feedback groups received recasts or prompts on their erroneous utterances while the learners in the control groups did not. The effects of feedback were measured by pre-interaction picture descriptions and immediate and delayed post-interaction correction tasks. The study found that both recasts and prompts had some effects on learning the targeted forms, and more explicit forms of each feedback resulted in a higher rate of correction. The beginning learners took more advantages of recasts relative to the upper-intermediate learners, and explicit prompts worked better for the upper-intermediate learners. The effects of prompts sustained longer than recasts in both levels.
        6,400원
        91.
        2018.11 구독 인증기관·개인회원 무료
        Acute kidney injury (AKI) is a disorder that is manifested by a sudden decrease of renal function within several hours, and AKI remains a significant cause that can lead to increasing morbidity and mortality. Although AKI has been extensively studies in animal models, translating the results from animal studies into clinical use has not been successful due to various factors including basal etiology of kidney deficiency and comorbidities and the complexity of this pathology. As a golden parameter, measuring serum creatinine (SCr) and blood urea nitrogen (BUN) has been conventionally used for determining the renal function, however, these biomarkers has been regarded suboptimal to identify renal injuries in early stages. In this study, we attempted to screen other serum biomarkers in early AKI event using cynomolgus monkeys. Two male monkeys, aged 60 months, were subjected to ischemic injury by unilateral clamping of renal pedicles for forty five minutes and then subsequently reperfused; the unclamped kidney was regarded as non-injured controls. Compared with control kidneys, we have found that the concentration of several inflammatory proteins including MCP1, TGFα, GSTα, were higher in the renal vein of injured kidney compared with control side after 24 and 48 hours of AKI. However, changes of serum level of KIM-1, which is one of the most-widely studied marker in rodent studies, were not different after AKI. Our results provide an useful information while developing a novel marker in AKI.
        92.
        2018.11 구독 인증기관·개인회원 무료
        Cryopreservation of bovine embryos is used to efficiently implant surrogate mothers. It has been widely accepted that high lipid content in the oocyte interrupts its survival during freeze-thaw cycles. Serum component in the culture medium is thought to increase the embryo`s lipid contents. Conversely, L-carnitine stimulates lipid metabolism by transporting long chain fatty acids into the mitochondria. Objective of this study was to analyze the effect of L-carnitine supplementation in IVM medium and defined IVC medium on the development, lipid contents and the cryosurvival of bovine IVF embryos. 0.0, 1.5, 3.0 and 6.0 mM L-carnitine was supplemented in IVM medium, respectively (IVM-LC 0.0, LC 1.5, LC 3.0 and LC 6.0). Development rate from the 2cell to the morula stages was higher in IVM-LC 3.0 groups than those of IVM-LC 6.0 (p<0.05). But there were no significant differences among the other groups in the blastocyst rates and lipid content results. When 0.0, 1.5, 3.0 and 6.0 mM L-carnitine were supplemented in IVC medium (IVC-LC 0.0, LC 1.5, LC 3.0 and LC 6.0), development competence was not significantly different between those embryos. Lipid contents of embryos treated L-carnitine (IVC-LC 1.5, 3.0 and 6.0) were significantly lower than embryos of non-treated group. L-carnitine was supplemented 0.0, 1.5, 3.0, 6.0 mM during IVM and 3.0 mM during IVC (LC 0.0 - 3.0, LC 1.5 – 3.0, LC 3.0 – 3.0, LC 6.0 – 3.0) and cryosurvival of blastocysts confirmed after freezing-thawing. There were no significant differences on development, but LC 3.0 – 3.0 was significantly lower lipid contents than other groups. And LC 3.0 – 3.0 had better survival rates and hatched rates of blastocysts than LC 0.0 – 0.0. In conclusion, supplementation of L-carnitine in defined IVC medium decreases lipid contents. And L-carnitine supplementation improves cryosurvival and developmental ability of bovine IVF embryos.
        93.
        2018.11 구독 인증기관·개인회원 무료
        The early-onset familial Alzheimer's disease (EOFAD/ FAD), the less common type of Alzheimer's disease (AD) currently affects a vast number of individuals worldwide. This type is being inherited as an autosomal dominant fashion. Missense mutations on Amyloid precursor protein (APP) and Presenilins 1 and 2 (PSEN1 & PSEN2) are known as major genetic factors in FAD. Conversely, missense mutations on microtubule-associated protein tau (MAPT) are also thought to involve. Up to date, several triple-transgenic animal models with muted forms of the human APP, PSENs and MAPT have been reported. Compared to other animals, canines are more emotional and their disease signs can be easily diagnosed. This attempt was to develop a triple transgenic canine model for the AD. We have obtained the coding sequences of APP, PSEN1 and MAPT from Dana-Farber/Harvard Cancer Center DNA resource core at HMS and incorporated several common AD mutations. The transgenic construct is composed of hNSE (ENO2) promoter-driven three AD genes fused together with modified 2A sequences. It was transfected into the canine fetal fibroblasts which were then used to perform somatic cell nuclear transfer (SCNT). The viable transgenic embryos were obtained after in vitro culture and the GFP was detected. In this study, we have successfully produced viable triple transgenic canine cloned embryos using SCNT technique. These transgenic canine embryos will be further developed into canines with FAD. The transgenic canines will be a good candidate in the AD research field.
        97.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 부모의 스마트폰 중독이 유아의 놀이성에 미치는 영향에서 유아의 스마트기기 이용수준의 매개효과를 밝히고자 했다. 이를 위해 만 3∼5세 유아와 그들의 어머니 259명을 대상으로 설문조사를 실시하였다. 수집된 자료는 R version 3.5.1과 Mplus Version 7.4 Base Program Single-User을 이용하여 분석했다. 본 연구의 결과는 다음과 같다. 첫째, 부모의 스마트폰 중독은 유아의 놀이성에 부적인 영향을 미쳤으나 유아의 미디어기기 이용수준에는 정적인 영향을 미쳤다. 그리고 유아의 놀이성에 대해 유아의 미디어기기 이용수준은 부적인 영향을 미쳤다. 둘째, 부모의 스마트폰 중독과 유아의 놀이성의 관계에서 유아의 미디어기기 이용수준도 부분 매개역할을 하는 것으로 나타났다. 본 연구결과는 스마트 기기를 사용할 수밖에 없는 현대인의 삶에서 유아의 스마트기기 이용 수준이 유아의 놀이성에 긍정적인 영향을 미치는 주요한 요인임을 시사한다.
        4,000원
        98.
        2018.06 구독 인증기관 무료, 개인회원 유료
        4,000원
        99.
        2018.05 구독 인증기관·개인회원 무료
        The infrastructure that man absolutely needs creates a lot of environmental load. The environmental load is quantified global environment pollution. So we can use LCA method for assess and control environmental load. In this study, we developed the environmental load estimating model to evaluate quickly in design stage when maintaining infrastructures facilities. Especially, we chose NATM tunnel because it is economical and there are many example of construction on public roads and expressway. First, we made a list of the breakdown cost by using collected unit cost of Korea Expressway Corporation and Seoul-Si about tunnel maintenance. So we chose major work classification. We selected the major classification such as pavement repairing inside tunnel, leaked surface treatment of tunnel, attached tile repairing inside tunnel and tunnel cleaning etc. We excluded concrete repairing because it is not easy to define maintenance factor about concrete repairing. Next, we made data bases of standard supply and resources need by specialist work classification. Using data bases, we was able to estimate environmental load by designating an input variable such as lane, pavement, length, tile repairing, leaked surface treatment and cleaning method. Lastly, we made environmental load estimating model after it is verified by comparing the results with the actual environmental load and estimated environmental load. Finally, our goal of this study is to develop the methodology that easily estimates the environmental load. Accordingly, the environmental load will be decreased by using this model in stage of planning, design and maintenance. Also, it is expected that the maintenance management estimating model developed from this study will be possible to do eco-friendly management of the road and tunnel construction.
        100.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 김치 제조시 철저한 재료 세척의 필요성을 확인하고, 더불어 비가열 식품인 김치의 위생 안전성 실태를 파악하여 효율적 미생물 저감화 방안을 마련하고자 국내에서 유통되는 김치 원·부재료 200건의 세척 전과 후의 비교분석과 시판 김치 100건에 대하여 미생물 분석을 실시하였다. 김치 원·부재료 및 완제품에 대하여 일반 세균수, 대장균 및 대장균군을 모니터링 하였으며, 병원성 미생물 9종(Bacillus cereus, Clostridium perfringens 정성·정 량, Staphylococcus aureus, Enterohemorrhagic Escherichia coli, Campylobacter jejuni/coli, Yersinia enterocolitica, Salmonella spp., Vibrio parahaemolyticus, Listeria monocytogenes 정성)을 분석 하였다. 모니터링 결과, 김치 원· 부재료 및 완제품에서 일반세균은 1.4~9.0 log CFU/g 수준 으로 확인되었으며, 원·부재료 중 생강에서 8.8 log CFU/g, 완제품 중 총각김치에서 9.0 log CFU/g으로 일반세균이 가장 높게 나타났다. 대장균군은 0.5~7.3 log CFU/g으로 확 인되었으며, 생강에서 7.3 log CFU/g으로 가장 높게 나타 났고, 병원성 미생물 9종의 분석결과, Bacillus cereus를 제 외한 나머지 8종의 식중독균은 모든 시료에서 검출되지 않았다. 김치 제조 시 사용되는 김치 원·부재료들의 세척 공정 후 미생물 수는 일반세균수 0.2~3.2 log CFU/g, 대장 균군 0.3~2.7 log CFU/g, Bacillus cereus 1.0~3.9 log CFU/g 감소하였다. 따라서, 김치 원·부재료의 세척 공정으로 미생물 오염도를 감소 시켰으며, 이 결과를 통하여 김치 완 제품의 위생 및 저장성 증진에 기여 할 수 있을 것으로 확인되었다.
        4,000원
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