• 대한기계학회논문집A
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• 제26권2호
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• pp.275-282
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• 2002

Tensile residual stress happen by difference of coefficients of thermal expansion between fiber and matrix is one of the serious problems in metal matrix composite(MMC). In this study, TiNi fiber was used to solve the tensile residual stress as the reinforced material. TiNi fiber improves the tensile strength of composite by occurring compressive residual stress in matrix using shape memory effect of it. Pre-strain was added to generate compressive residual stress inside TiNi/A16061 composite. It was also evaluated the effect of compressive residual stress corresponding to pre-strains variation. AE technique was used to clarify the microscopic damage behavior at high temperature and the effect of pre-strain difference of TiNi/A16061 shape memory alloy composite.

• 대한본초학회지
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• 제27권5호
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• pp.27-35
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• 2012

Objectives : The purpose of this study was to characterize the effect of the fraction of Taraxacum officinale and T.coreanum on the learning and memory impairments induced by scopolamine. Methods : The cognition-enhancing effect of Taraxacum officinale and T.coreanum was investigated using a passive avoidance test, the Morris water maze test and Y-maze test in mice. Drug-induced amnesia was induced by treating animals with scopolamine (1 mg/kg, i.p.). Results : The results showed that the Aug harvested T.offiicinale extract-treated group (200 mg/kg, p.o.) and the tacrine-treated group (10 mg/kg, p.o.) significantly ameliorated scopolamine-induced amnesia based on the Passive avoidance Y-maze test and Watermaze test. And these results are same manner in DPPH radical scavenger effect and Acetylcholineseterase inhibition effect. Conclusions : These results suggest that Taraxacum officinale extract maybe a useful cognitive impairment treatment, and its beneficial effects are depending on the collecting time and origin plants. As a result, Taraxacum officinale harvested in August improve memory most.

• 대한기계학회논문집A
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• 제25권1호
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• pp.25-31
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• 2001

The theoretical modeling to predict the modulus of elasticity by the shape memory effect of dispersed particles in a metal matrix composite was studied. The modeling approach is based on the Eshelbys equivalent inclusion method and Mori-Tanakas mean field theory. The calculation was performed on the TiNi particle dispersed Al metal matrix composites(PDMMC) with varying volume fractions and prestrains of the particle. It was found that the prestrain has no effect on the Yonugs modulus of PDMMC but the volume fraction does affects it. This approach has an advantage of definite control of Youngs modulus in PDMMCs.

• 동의신경정신과학회지
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• 제10권2호
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• pp.105-113
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• 1999

The purpose of this study was to investigate the effect of Sunhyangjungkisan on the learning and memory ability in rats. For this purpose we have evoked cerebral dysfunction in rats with NOS inhibitor and then performed the Morris water maze task for each rat. We have found that Sunghyangjungkisan have some improving effedts on impaired learning and memort ability in the NOS inhibitor treated rat. In these improving effects, memory effect was more evident then learning effect. This result implies that Sunghyangjungkisan may be one of useful prescriptions for treatment of vascular dementia after cerebral ischemia.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.557-561
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• 2008

Shape memory alloys (SMA) have interesting features which are the superelastic effect (SE), shape memory effect (SME), two-way SME (TWSME), and so on. These are utilized in actuation factor. The thermo-mechanical constitutive equations of SMA proposed by Lagoudas et al. were employed in the present study for simulating SMA truss structures. The constitutive equation includes the necessary internal variables to account for the material transformations and is utilized in the non-linear finite element procedure of three dimensional truss structures that composed SMA bar (wholly or partially). In this study, we observed which element should be actuated to get a desired shape (actuation shape) from computational analysis. To reach this goal, we apply SMA constitutive equation to non-linear finite element formulation. And then, we simulate two-way shape memory effect as well as superelastic effect of various three dimensional truss using SMA.

• 인지과학
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• 제9권1호
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• pp.47-60
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• 1998

이중언어자의 언어구조를 기억정보의 위계적 특성으로 설명하는 위계모형의 적합성을 외현기억검사와 암묵기억검사를 사용하여 살펴보았다. 위계모형에 따르면 단어의 기억표상은 모국어와 외국어의 심성어휘집 정보와 두 언어와 공유하는 개념표상 정보로 구성되어 있으며, 개념표상 정보의 활성화는 심성어휘집 활성화를 통해 이루어지고, 과제의 종류와 번역의 방향성에 따라 심성어휘집과 개념표상의 정보가 별개로 인출될 수 있다. 기억검사중에서 개념 정보의 활성화에 민감한 외현기억검사와 지각 정보의 활성화에 민감한 암묵기억검사는 심성어휘집 정보와 개념표상 정보의 활성화에 상이한 민감성을 보일 것이다. 실험 1에서는 명명과제의 단어들을 의미적으로 범주화하여 제시한 후에 암묵기억검사와 외현기억검사를 실시했고, 실험 2에서는 의미적으로 범주화된 단어목록을 순행 및 역행 번역을 하도록 한 후에 암묵기억검사와 외현기억검사를 했다. 명명과제와 역행번역 및 암묵기억검사에는 목록의 의미적 범주효과가 나타나지 않았고, 순행번역 및 외현기억검사에는 목록의 의미적 범주효과가 나타났다. 이런 결과를 이중언어자의 언어구조가 언어에 따르는 별개의 심성어휘집과 공통의 개념표상을 지니고 있다는 위계모형을 지지하는 것으로 해석하였다.

• 한국융합학회논문지
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• 제11권2호
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• pp.101-107
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• 2020

본 연구는 명화 활용 방식(변형 vs. 재해석)과 상호작용성 수준(고 vs. 저)을 독립변인으로, '제품 속성 기억정보(PRM: Product-Related Memory)'와 '광고 이미지 관련 기억정보(IRM: Image Related Memory)', 광고태도(Aad)를 종속 변인으로 하는 Two-Way MANOVA 분석을 통해 실험연구를 진행하였다. 본 연구는 명화를 활용한 마케팅이 증가하고 있으나 기억과 태도 간의 구조적 관계를 실증적으로 규명하고자 한다. 연구 결과, 첫째, 변형 광고의 경우 상호작용성이 낮으면 광고 이미지 관련 기억정보(IRM)가 더 많이 기억되어 판단에 영향을 미치는 것으로 나타났다. 둘째, 재해석 광고의 경우 상호작용성 수준과 상관없이 제품 속성 관련 기억정보들이 낮은 수준으로 기억되는 것으로 나타났다. 셋째, 명화 활용 광고에 대한 광고 태도는 변형 광고는 상호작용성 수준이 낮은 경우 긍정적인 태도가 형성되었으나 상호작용성 수준이 높으면 재해석 광고의 태도가 긍정적이었다.

• Journal of Ginseng Research
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• 제33권2호
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• pp.132-138
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• 2009

Previous studies suggest that even low-dose irradiation can lead to progressive cognitive decline and memory deficits, which implicates, in part, hippocampal dysfunction in both humans and experimental animals. In this study, whether red ginseng (RG) could attenuate memory impairment was investigated through a passive-avoidance and object recognition memory test, as well as the suppression of hippocampal neurogenesis, using the TUNEL assay and immunohistochemical detection with markers of neurogenesis (Ki-67 and doublecortin (DCX)) in adult mice treated with a relatively low-dose exposure to gamma radiation (0.5 or 2.0 Gy). RG was administered intraperitonially at a dosage of 50 mg/kg of body weight, at 36 and 12 h pre-irradiation and at 30 minutes post-irradiation, or orally at a dosage of 250 mg! kg of body weight/day for seven days before autopsy. In the passive-avoidance and object recognition memory test, the mice that were trained for one day after acute irradiation (2 Gy) showed significant memory deficits compared with the sham controls. The number of TUNEL-positive apoptotic nuclei in the dentate gyrus (DG) was increased 12 h after irradiation. In addition, the number of Ki-67- and DCX-positive cells was significantly decreased. RG treatment prior to irradiation attenuated the memory defect and blocked apoptotic death as well as a decrease in the Ki-67- and DCX-positive cells. RG may attenuate memory defect in a relatively low-dose exposure to radiation in adult mice, possibly by inhibiting the detrimental effect of irradiation on hippocampal neurogenesis.

• Journal of Ginseng Research
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• 제20권3호
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• pp.226-232
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• 1996

This study was performed to investigate the effect of red ginseng extract including some vitamin B groups as test drug on learning and memory in mice. Single and repeated administrations of the test drug improved the acquisition and the process of consolidation in the tests using step-through and step-down apparatus, indicating this test drug improved learning and memory. However, the test drug did not improve scopolamine-induced amnesia. These results suggest that test drug may be useful as a nootropic agent.

• 생약학회지
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• 제45권1호
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• pp.48-54
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• 2014

Alzheimer's disease is progressive neurodegenerative disorder by the loss of memory and learning abilities. Codonopsis lanceolata (C. lanceolata) is traditional medicinal plant used for the treatment of inflammatory diseases. The aim of study was to evaluate the effect of steamed C. lanceolata on scopolamine-induced memory impairment in the Morris water maze test and passive avoidance test. In addition, this study investigated the neuroprotective effects of steamed C. lanceolata on glutamate-induced cell death in HT22 cells using MTT assay. The results showed that steamed C. lanceolata (500 mg/kg body weight, p.o.) reversed spatial memory impairment by scopolamine in Morris water maze test and passive avoidance test. Steamed C. lanceolata attenuated memory impairment by scopolamine compared with common C. lanceolata. In addition, administration of steamed C. lanceolata significantly also reduced cell death. We suggest that steaming process more improve cognitive enhancing and neuroprotective effect of C. lanceolata than common C. lanceolata.