• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1009-1012
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• 2005

e-러닝의 활용도와 역할이 커져 가면서, 온톨로지(Ontology)나 컨셉맵(Concept Map)을 이용하여 e-러닝의 학습효과를 높이는 방안들이 연구되고 있다. 그러나 아직까지 e-러닝에 온톨로지나 컨셉맵 개념을 적용한 연구 사례는 미미한 수준이며, 이들간의 연계에 대한 고려 없이 별개의 대상으로 다루어져 왔다. 본 연구는 온톨로지와 컨셉맵의 상호 연관 관계와 각각의 장점들을 분석하여 학습에 있어서 시너지(Synergy)를 가져올 수 있는 새로운 e-러닝 시스템 구축 방안을 제안한다. 제안 시스템에서 온톨로지와 컨셉맵 간의 연계는 컨셉맵 에이전트에 의해 이루어진다. 컨셉맵 에이전트는 학습자의 수준이나 관심영역(주제와 범위)에 맞게 온톨로지로부터 추출한 학습 콘텐츠를 재구성해 준다. 학습자는 제안 시스템의 사용자 인터페이스를 통해 자신이 이해하고 있는 지식을 컨셉맵 형태로 표현할 수 있고, 컨셉맵 에이전트에게 요청하여 제공 받은 모범답안 컨셉맵과 자신이 표현한 컨셉맵을 비교하여 학습자가 스스로 자기 평가를 할 수 있다. 본 e-러닝 시스템이 제공하는 이러한 새로운 형태의 학습 환경은 학습자가 학습 지식에 대해 보다 체계적으로 접근하여 효과적으로 학습할 수 있게 해준다. 또한, 학습에 있어서 컨셉맵을 이용하므로 학습 형태의 특성상 보다 원천적으로 암기 위주의 학습에서 탈피하여 구성주의적인 학습을 가능하게 한다.

• Journal of the Korea Society for Simulation
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• v.29 no.2
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• pp.35-47
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• 2020

Immediate and serious attention on CGF(computer generated forces) behavior modeling for defense M&S (modeling & simulation) is required in response to the reduction in the number of troops and development of 4^th industrial technologies. It is crucial for both military person and engineer to understand such technologies. The research aims to provide guidelines for establishment of research direction on CGF behavior modeling. We investigate traditional and/or novel methodologies such as rule-based, agent-based, and learning-based method. Discussions on future direction of applicable area and strategies are followed. We expect that the research plays a key role for understanding CGF behavior modeling.

• Advances in robotics research
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• v.2 no.1
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• pp.59-68
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• 2018

Autonomous mobile service medical robots (AMSMRs) are one of the promising developments in contemporary medical robotics. In this study, we consider the essential technical and intellectual abilities needed by AMSMRs. Based on expert analysis of the behavior exhibited by AMSMRs in clinics under basic scenarios, these robots can be classified as intellectual dynamic systems acting according to a situation in a multi-object and multi-agent environment. An AMSMR should identify different objects that define the presented territory (rooms and paths), different objects between and inside rooms (doors, tables, and beds, among others), and other robots. They should also identify the means for interacting with these objects, people and their speech, different information for communication, and small objects for transportation. These are included in the minimum set required to form the internal world model in an AMSMR. Recognizing door handles and opening doors are some of the most difficult problems for contemporary AMSMRs. The ability to recognize the meaning of human speech and actions and to assist them effectively are other problems that need solutions. These unresolved issues indicate that AMSMRs will need to pass through some learning and training programs before starting real work in hospitals.

• Korean Journal of Pharmacognosy
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• v.48 no.2
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• pp.119-124
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• 2017

Taraxacum platycarpum H. Dahl. (Compositae) has been used as an anti-inflammatory or anti-cancer agent in the clinic. Although its antidepressant effect has been reported, however, its cognitive function is not investigated until yet. In the present study, we investigated whether the water extract of T. platycarpum (WETP) could improve cognitive function in cholinergic blockade-induced amnesia mouse model using the passive avoidance or Y-maze task. WETP (12.5, 25 or 50 mg/kg) significantly ameliorated the scopolamine-induced cognitive impairment both in the passive avoidance test and the Y-maze test. In addition, WETP significantly inhibited acetylcholinesterase (AChE) activity measured by an ex vivo study using the mouse whole brain. These results suggest that WETP alleviates the cognitive dysfunction caused by the cholinergic blockade, in part, via AChE inhibition, and that it may be a useful for treating cognitive dysfunction.

• Journal of Ginseng Research
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• v.30 no.2
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• pp.57-63
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• 2006

One of the various signaling agents in the animal cells is the simple ion called calcium, $Ca^{2+}$.$Ca^{2+}$ controls almost everything that animals do, including fertilization, secretion, metabolism, muscle contractions, heartbeat, learning, memory stores, and more. To do all of this, $Ca^{2+}$ acts as an intracellular messenger, relaying information within cells to regulate their activity. In contrast, the maintenance of intracellular high $Ca^{2+}$ concentrations caused by various excitatory agents or toxins can lead to the disintegration of cells (necrosis) through the activity of $Ca^{2+}$-sensitive protein-digesting enzymes. High concentrations of calcium have also been implicated in the more orderly programs of cell death known as apoptosis. Because this simple ion, acts as an agent for cell birth, life and death, to coordinate all of these functions, $Ca^{2+}$ signalings should be regulated precisely and tightly. Recent reports have shown that ginsenosides regulate directly and indirectly intracellular $Ca^{2+}$ level with differential manners between neuronal and non-neuronal cells. This brief review will attempt to survey how ginsenosides differentially regulate intracellular $Ca^{2+}$ signaling mediated by various ion channels and receptor activations in neuronal and non-neuronal cells.

• Korean Journal of Childcare and Education
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• v.19 no.2
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• pp.119-141
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• 2023

Objective: This study aimed to investigate Pre-service early childhood teachers' perceptions and roles regarding young children's free play time. Methods: The study utilized the photovoice method and involved 21 pre-service early childhood teachers who expressed interest in participating. Participants were enrolled in an infants teaching methodology class in B city. The study involved four virtual meetings conducted via untact teams, and the automatic recordings of these meetings were transcribed for analysis. Results: The results revealed that pre-service early childhood teachers recognized young children's free play time as a period to enjoy full freedom, develop as the main agent of their lives, and express their imagination. Furthermore, pre-service early childhood teachers perceived their roles during young children's free play time as a specialist infant observer, a connector between play and learning, and a versatile supporter. Conclusion/Implications: The findings suggest the need for a systematic curriculum to provide pre-service early childhood teachers with a balanced perspective and awareness of the meaning of free play and teacher roles. The study highlights the importance of expanding pre-practice courses for observation of play and field-oriented curriculum for incumbent teachers.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.819-822
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• 2021

AI World Cup 환경은 다수 가상 에이전트들이 팀을 이뤄서 서로 상호작용하며 대전이 가능한 가상 축구 환경이다. 본 논문에서는 AI World Cup 환경에서 멀티 에이전트기반 학습/추론 기술을 사용하여 다양한 전략과 전술을 구사하는 가상 축구 에이전트 구현과 시뮬레이션 결과를 소개한다. 먼저, 역할을 바탕으로 협동하여 상대방과 대전할 수 있는 논리 기반 추론형 멀티 에이전트 기술이 적용된 Dynamic planning 축구 에이전트 9 세트를 구현하였다. 이후, 강화학습 에이전트 기반, 단일 에이전트를 조합한 Independent Q-Learning 방식의 학습형 축구 에이전트를 구현한 후, 이를 멀티 에이전트 강화학습으로 확장하여 역할 기반 전략 학습이 가능한 가상 축구 에이전트를 구현하고 시뮬레이션 하였다. 구현된 가상 축구 에이전트들 간 대전을 통해 승률을 확인하고, 전략의 우수성을 분석하였다. 시뮬레이션 예제는 다음에서 확인할 수 있다 (https://github.com/I-hate-Soccer/Simulation).

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.309-318
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• 2024

Compared to other organs, the brain has limited antioxidant defenses. In particular, the hippocampus is the central region for learning and memory and is highly susceptible to oxidative stress. Glial cells are the most abundant cells in the brain, and sustained glial cell activation is critical to the neuroinflammation that aggravates neuropathology and neurotoxicity. Therefore, regulating glial cell activation is a promising neurotherapeutic treatment. Quinic acid (QA) and its derivatives possess anti-oxidant and anti-inflammatory properties. Although previous studies have evidenced QA's benefit on the brain, in vivo and in vitro analyses of its anti-oxidant and anti-inflammatory properties in glial cells have yet to be established. This study investigated QA's rescue effect in lipopolysaccharide (LPS)-induced behavior impairment. Orally administering QA restored social impairment and LPS-induced spatial and fear memory. In addition, QA inhibited proinflammatory mediator, oxidative stress marker, and mitogen-activated protein kinase (MAPK) activation in the LPS-injected hippocampus. QA inhibited nitrite release and extracellular signal-regulated kinase (ERK) phosphorylation in LPS-stimulated astrocytes. Collectively, QA restored impaired neuroinflammation-induced behavior by regulating proinflammatory mediator and ERK activation in astrocytes, demonstrating its potential as a therapeutic agent for neuroinflammation-induced brain disease treatments.

• Journal of Ginseng Research
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• v.24 no.1
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• pp.8-17
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• 2000

Estrogen can influence on the expression of behaviors not associated directly with reproduction, including learning and memory. Recently estrogen has received considerable attention for its effects on neuroprotection and neural circuits in brain areas associated with cognition. Although estrogen replacement therapy may be helpful to postmenopausal women, it also results in a number of harmful side effects. Ginseng also has steroidal qualities and contains several ginsenoside components which have similar backbone structure to estrogen. The objectives of this experiment were 1) to examine the effects of estrogen and 2) to investigate the effects of ginsenosides as estrogenic agent on learning and memory using the Morris water maze, a traditional experimental task for spatial memory. In the experiments designed here, ovariectomized mice were implanted subcutaneously with Sila, itic capsules containing 17${\beta}$-estradiol (100∼250 $\mu\textrm{g}$/$m\ell$), panaxadiol (PD) and panaxatriol (PT) saponins (15∼100 $\mu\textrm{g}$/$m\ell$) diluted with sesame oil. In the first set of experiment, the effects of estradiol on learning and memory during the Morris water maze was examined. When estradiol was delivered via Silastic capsules following training improved spatial memory performance in ovariectomized female mice. In the second set of experiment, three different PD and PT saponin concentrations were delivered via Silastic implants to ovariectomized female mice and their effects were compared with estrogenic effects. Results of three separate experiments demonstrated that estradiol, PD and PT administrated by Silastic implants for 2 weeks prior to water maze training significantly improved spatial memory performance compared to ovariectomized (OVX) mice, as indicated by lower escape latency over trial. The positive effect of estradiol suggests that estrogen can affect performance on learning and memory. In addition, the positive effect of PD and PT saponins suggest that ginsenosides have an estrogen-like effects in mediating learning and memory related behavior action.

• Journal of the Korea Society for Simulation
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• v.33 no.2
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• pp.37-44
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• 2024

The Korean Helicopter Development Program has successfully introduced the Surion helicopter, a versatile multi-domain operational aircraft that replaces the aging UH-1 and 500MD helicopters. Specifically designed for maneuverability, the Surion plays a crucial role in low-altitude tactical maneuvers for personnel transportation and specific missions, emphasizing the helicopter's survivability. Despite the significance of its low-altitude tactical maneuver capability, there is a notable gap in research focusing on multi-mission tactical maneuvers that consider the risk factors associated with deploying the Surion in the presence of enemy air defenses. This study addresses this gap by exploring a method to enhance the Surion's low-altitude maneuvering paths, incorporating information about enemy air defenses. Leveraging the Proximal Policy Optimization (PPO) algorithm, a reinforcement learning-based approach, the research aims to optimize the helicopter's path planning. Visualized experiments were conducted using a Surion model implemented in the Unity environment and ML-Agents library. The proposed method resulted in a rapid and stable policy convergence for generating optimal maneuvering paths for the Surion. The experiments, based on two key criteria, "operation time" and "minimum damage," revealed distinct optimal paths. This divergence suggests the potential for effective tactical maneuvers in low-altitude situations, considering the risk factors associated with enemy air defenses. Importantly, the Surion's capability for remote control in all directions enhances its adaptability in complex operational environments.