• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.75-79
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• 2001

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity, The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.47-52
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• 2003

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented fir its performance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.755-758
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• 1997

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research of dynamic characteristics is very deficient. In this paper, the helical spring is fabricated with NiTi SMA wire of high resistivity The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA actuator is analyzed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.346-351
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• 2003

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMT is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.223-224
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• 2019

스마트폰 애플리케이션 시장은 단기간 비약적인 성장을 거듭했다. 여러 각종 분야에서 애플리케이션 개발을 원하는 곳이 많아졌고 그만큼 앱 개발자들을 원하는 시장이 늘어나고 있다. 본 연구는 앱 개발을 도전하려는 1인 혹은 소규모 아마추어 개발자 입장에서 관련 실력을 효과적으로 늘릴 수 있는 방법을 제공하고 전반적인 애플리케이션 개발과 환경에 관한 유익한 정보들을 쉽게 접근함으로써 조금 더 애플리케이션 개발에 관심을 갖게 되는 계기가 될 것이다. 또한 본 연구의 게임 애플리케이션은 사용자들의 명시적 기억과 암묵적 기억 훈련에 도움을 줄 수 있도록 개발하였다.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.270-270
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• 2004

이 연구는 Ⅰ) 혈관 폐색에 의한 인지 및 기억장애 동물모델에서 뇌졸중 치료제로써 인간배아줄기 세포의 신경세포 보호효과 및 작용기간을 밝히며, Ⅱ) 행동 약리학적 연구를 통해 기억력증진에 미치는 효과에 대해 밝히고 혈관 폐색에 의한 동물모델에서의 기억기능 증진 및 세포효과를 검증하고자 실시하였다. 중대 뇌동맥 폐색에 의한 쥐의 동물모델은 Sprague Dawley계 흰 쥐(260∼300 g)의 국소 중대뇌동맥을 일시적으로 폐색시켜 만들었다. 본 연구(미국 국립보건원에 등록된 MB03세포)에 사용된 인간배아줄기세포는 3×10⁴ cells/㎠ 밀도의 배양접시 내에서 4일 동안 embryoid bodies(EBs)의 형성을 위해 집합체를 이루도록 유도하였다. (중략)

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2000.05a
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• pp.87-92
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• 2000

이 연구에서는 단어를 지각하게 되면 그 단어에 대한 의미가 자동적으로 활성화되고 그림표상까지도 활성화되지만, 그림을 지각하고 난 후에는 의미표상체계는 활성화되지만 단어의 지각적 표상체계는 활성화되지 않는지를 살펴보고자 하였다. 실험 1과 2에서는 지연시간을 달리하여 그림을 지각적으로 처리를 하게 한 후 단어에 대한 점화효과를 보았으며, 실험 3 에서는 그림을 개념주도적 처리를 하게 한 후 단어에 대한 점화효과 및 암묵적 기억과 재인기억을 비교해 보았다. 실험결과 지각적 판단과제에서는 조건간의 아무런 차이가 없었지만, 의미적 판단과제에서는 동일조건과 그림조건에서의 반응시간이 통제조건을 포함한 기타 조건들에서보다 빠른 것으로 나타났다. 이러한 결과는 의미적 표상체계로부터 단어의 지각적 표상체계까지의 상호작용 통로가 존재하지 않으며, 그림자극이 단어자극의 점화효과에 영향을 주는 이유는 동일한 의미적 표상체계의 활성화가 단어자극의 지각적 표상체계까지 확산되기 때문이 아니라, 그림자극에 대한 의미적 표상체계가 활성화되기 때문이라는 점을 시사한다.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.92-98
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• 1988

The present study was performed to find the effects of ginseng and its saponins. which is written in Chung Yao Ta Tsu Tien as anti-amnesia in its chief indication. on experimental amnesia in mice. In the step through test. ginsenoside $Rb_1\;(GRb_1)\;and\;GRg_1$ facilitated the registration of memory and antagonized the electroconvulsive shock (ECS)-induced inhibition of the retention of memory. Moreover. $GRg_1$ antagonized the EtOH-induced inhibition of the retrieval of memory. In the step down test. $GRb_1\;GRb_2\;and\;GRg_1$ antagonized the ECS-induced inhibition of the retention of memory. Moreover. $GRg_1$ antagonized the EtOH-induced inhibition of the retrieval of memory and facilitated the acquisition of short term memory. In the shuttle hox and lever press tests. they have no effects on acquisition and retrieval of memory. except $GRb_1\;GRb_1$ depressed the retrieval of conditioned avoidance response in the shuttle box test. After the end of four tests. the effects of these orally administered drugs on sedative. analgesic. antipyretic and anticonvulsant actions. and on spontaneous and exploratory movements were tested in doses of less than 500mg/kg. but they had none of these effects. Present study may indicate that $GRg_1$ had effects on the retrieval of memory and on the acquisition process of learning response. The recent research on the role of NGF for the survival. regeneration and regulation of brain in adult animals. indicated the importance of NGF on dementia and amnesia. During our research on the specificity of the neurite out growth induced by NGF. we found that the effect of NGF was potentiated by $GRb_1$ in organ cultures of chick embryonic dorsal root ganglia. Then. the effect of $GRb_1$ on neuronal cell survivalin cell culture system was studied. $GRb_1$ potentiated the NGF-mediated increase of neurofilaments in cell cultures of chick embryonic sensory and sympathetic neurons. NGF with $GRb_1$ also showed a tendency to increase the number of surviving neurons of rat embryonic cerebral cortex. NGF increased choline acetyl transferase activity in cell cultures of rat embryonic septum area neurons. but $GRb_1$ did not potentiate NGF activity in cell cultures of rat embryonic septum area neurons. Present study may indicate that $GRb_1$ plays an important role for the survival or regeneration of neurons in the brain.

• Informatization Policy
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• v.31 no.1
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• pp.32-52
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• 2024

This study investigates the effectiveness of virtual reality agents as foreign language instructors with focus on the impact of different native language backgrounds and instructional roles. The agents were first distinguished as native or non-native speakers treated as a between-subject factor, and then assigned roles as either teachers or salespersons considered within-subject factors. An immersive virtual environment was developed for this experiment, and a 2×2 mixed factorial design was carried out. In an experimental group of 72 university students, statistically significant interactions were found in learning satisfaction, memory, and recall between the native/non-native status of the agents and their roles. With regard to learning confidence and presence, however, no statistically significant differences were observed in both interaction effects and main effects. Contextual learning in a virtual environment was found to enhance learning effectiveness and satisfaction, with the nativeness and the role of agents influencing learners' memory; thus highlighting the effectiveness of using virtual reality agents in foreign language learning. This suggests that varied approaches can have positive cognitive and emotional impacts on learners, thereby providing valuable theoretical and empirical implications.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.428-433
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• 2012

Probiotics and their products, such as yogurt and cheese have been widely consumed in many countries with proven health benefits including anti-microbial activity and anti-diarrheal activity. LHFM (Lactobacillus helveticus - fermented milk) is a processed skim milk powder, fermented by a probiotics, L. helveticus IDCC3801. In the present study, we aimed to investigate the neuroprotective effects and the cognitive improvements of LHFM. LHFM itself did not show any cytotoxicity to the human neuroblastoma cell line, SH-SY5Y; however, it dose-dependently protected against glutamate-induced neuronal cell death. LHFM also attenuated scopolamine-induced memory deficit in Y-maze and Morris-water maze. In the analysis of hippocampus after a behavior test, LHFM significantly increased the acetylcholine level and also inhibited acetylcholine esterase activity. Therefore, the raised acetylcholine release partially contributes to the improvement of learning and memory by a treatment with LHFM. These results suggest that LHFM is an effective material for prevention or improvement of cognitive impairments caused by neuronal cell damage and central cholinergic dysfunction.