• 생명과학회지
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• 제9권5호
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• pp.548-555
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• 1999

Long-term effects of Ganoderma lucidum (GL) on memory and oxidative stress of senescence-accelerated mice (SAM) were investigated. Senescence-resistant (R1) and prone (P8) strains of SAM were fed GL diets, premixed with low (20 mg/kg/day, T1) or high (200 mg/kg/day, T2) levels of GL powder for 9 months starting from young (3 months of age) or for 5 months starting from old (7 months of age). After the final feeding at 12 months of age, all animals were subjected to passive avoidance test for the evaluation of memory function. In addition, the changes in hepatic thiobarbituric acid-reactive substance (TBARS) and glutathione were analyzed. SAMP8 fed GL diets from old age (7 months) exhibited the improvement of memory, although GL rather inhibited the memory function of both SAMR1 and SAMP8 mice fed diets from young (3 months of age). Hepatic TBARS contents were decreased in SAMP8 fed high GL diet for 9 months and in SAMR1 fed low GL diet for 5 months. Hepatic glutathione content was also remarkably increased in SAMR1 following both feeding periods, and less extent in SAMP8 fed diet for 5 months of age. Taken together, it is proposed that GL extracts may play an anti-aging role through antioxidant action, and thereby may improve the senescence-related memory dysfunction.

• 로봇학회논문지
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• 제16권2호
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• pp.137-146
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• 2021

When controlling manipulator, degree of freedom is lost in singularity so specific joint velocity does not propagate to the end effector. In addition, control problem occurs because jacobian inverse matrix can not be calculated. To avoid singularity, we apply Deep Deterministic Policy Gradient(DDPG), algorithm of reinforcement learning that rewards behavior according to actions then determines high-reward actions in simulation. DDPG uses off-policy that uses 𝝐-greedy policy for selecting action of current time step and greed policy for the next step. In the simulation, learning is given by negative reward when moving near singulairty, and positive reward when moving away from the singularity and moving to target point. The reward equation consists of distance to target point and singularity, manipulability, and arrival flag. Dual arm manipulators hold long rod at the same time and conduct experiments to avoid singularity by simulated path. In the learning process, if object to be avoided is set as a space rather than point, it is expected that avoidance of obstacles will be possible in future research.

• 동의생리병리학회지
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• 제19권1호
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• pp.254-261
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• 2005

The effects on memory and learning ability of the Korean herbal medicine, Xingyo-tang(XGT, 神交湯), which consists of Ginseng Radix(人蔘) 4 g, Liriopis Tuber(麥門冬) 40 g, Morindae Officinalis Radix(巴戟天) 40 g, Biotae Semen(柏子仁) 20 g, Dioscoreae Rhizoma(山藥) 40 g, Euryales Semen(?實) 20 g, Scrophulariae Radix(玄蔘) 40 g, Salviae Miltiorrhizae Radix(丹蔘) 12 g, Poria(茯神) 12 g, Cuscutae Semen(免絲子) 40 g, was investigated. The effects of XGT on learning and memory performance were examined in normal or memory impaired mice by using avoidance tests, Pentobarbital -induced sleep test, fear conditioning task, novel object recognition task, and water maze task. Hot water extract from XGT was used for the studies. Learning ability and memory are based on modifications of synaptic strength among neurons that are simultaneously active. Enhanced synaptic coincidence detection leads to better learning and memory. The XGT-treated (30 mg/100 g and 60 mg/100 g, p.o.) mice exhibit superior ability in learning and memorizing when performing various behavioral tasks. XGT did not affect the passive avoidance responses of normal mice in the step through and step down tests, the conditioned and unconditioned avoidance responses of normal mice in the shuttle box, lever press performance tests, and the ambulatory activity of normal mice in normal condition. In contrast, XGT produced ameliorating effects on the memory retrieval impairment induced by ethanol. XGT also improved the memory consolidation disability induced by electric convulsive shock (ECS). XGT extended the sleeping time induced by pentobarbital dose-dependently, suggesting its transquilizing or antianxiety action. These results suggest that XGT has an improving effect on the impaired learning through the effects on memory registration and retrieval.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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• pp.290-300
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• 2000

One of the most important topics in attentional and emotional modulation of cardiac responses is time course of cardiac chronotropic response. The reason lies in dual innervation of heart, which leads to occurrence of several phases of cardiac response during exposure to affective stimuli, determined by the balance of sympathetic and parasympathetic influences. Cardiac chronotropic reactivity thus represents quite effective measure capable to trace the moment when attending and orienting processes (i.e., sensory intake of stimulus) prime relevant behavioral response (ile., emotion with approach or avoidance tendencies). The aim of this study was to find the time course of heart rate (HR) responses typical for negative (disgust, surprise, fear, anger) and positive (happiness, pleasant erotic) affective pictures and to identify cardiac response dissociation for emotions with different action tendencies such as "approach" (surprise, anger, happiness) and "avoidance" (fear, sadness, disgust). Forty college students participated in this study where cardiac responses to slides from IAPS intended to evoke basic emotions (surprise, fear, anger, sadness, disgust, happiness, pleasant-erotic). Inter-beat intervals of HR were analyzed on every 10 sec basis during 60 sec long exposure to affective visual stimuli. Obtained results demonstrated that differentiation was observed at the very first 10s of exposure (anger-fear, surprise-sad, surprise-erotic, surprise-happiness paris), reaching the peak of dissociation at 30s (same pairs plus surprise-disgust and surprise-fear) and was still effective for some pairs (surprise-erotic, surprise-sad) even at 50s and 60s. discussed are potential cardiac autonomic mechanisms underlying attention and emotion processes evoked by affective stimulation and theoretical considerations implicated to understand the role of differential cardiac reactivity in the behavioral context (e.g., approach-avoidance tendencies, orienting-defense responses).

• 해양환경안전학회지
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• 제24권1호
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• pp.10-17
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• 2018

종합 안전관리체계인 e-navigation을 준비하기 위해 선박의 의도된 경로를 선박 대 선박, 그리고 선박 대 육상 간에 공유하는 경로교환에 대한 연구가 활발히 진행 중이다. 하지만 경로교환을 위한 기술적인 측면에서의 연구 개발은 진행되고 있으나, 그 효과나 문제점 등 도입 필요성에 대한 연구는 부족한 실정이다. 본 연구는 선박조종 시뮬레이션을 통해 경로교환이 항해 안전에 미치는 영향을 정량적으로 분석하고, 시뮬레이션 수행자들의 주관적인 평가를 종합하여 경로교환의 효과를 검증하였다. 선박 간 경로교환을 할 경우 최초 충돌회피 시점은 평균 3.43분 더 빨라졌으며, 충돌회피 방향은 60 %가 변경되었다. 또한 타선 A와의 최근접점은 31 % 더 가까워지고, 평균 타 사용지수는 57 % 줄어들었다. 그리고 설문 응답자의 95 %는 경로교환이 충돌회피 의사결정에 영향, 85 %는 안전운항에 긍정적인 영향, 90 %는 사고예방 효과, 70 %는 항해사의 심리적 부담 경감, 70 %는 경로교환을 실무에 도입해야한다고 답하였다.

• 한국콘텐츠학회논문지
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• 제18권1호
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• pp.517-526
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• 2018

본 연구는 $G{\acute{a}}mez$, Chmielewski, Kotov, Ruggero와 Watson이 개발한 다차원적 체험회피 질문지를 한국어로 번안하여 신뢰도 및 타당도를 검증하기 위해 수행되었다. 대학생 285명을 대상으로 다차원적 체험회피 질문지를 실시하여 탐색적 요인분석을 실시한 결과, 6개 요인, 50문항이 확인되었다. 50문항 전체의 내적 합치도 계수는 .91이었다. 대학생 315명에게 다차원적 체험회피 질문지를 실시하여 확인적 요인분석을 실시한 결과, 6개 요인이 적합한 것으로 나타났다. 이 중 275명에게 수용 행동 질문지II, 사고억제 질문지, Toronto 감정표현 불능증 척도, 신경증, 회피적 대처, 한국판 CES-D, 한국판 Beck 불안 척도, 한국판 심리적 안녕감 척도, 삶의 만족도 척도를 함께 실시하여 다차원적 체험회피와의 상관을 살펴본 결과, 다차원적 체험회피 질문지는 수렴, 변별, 준거타당도를 가지는 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3444-3457
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• 2021

In the field of anti-jamming based on dynamic spectrum, most methods try to improve the ability to avoid jamming and seldom consider whether the jammer would perceive the user's signal. Although these existing methods work in some anti-jamming scenarios, their long-term performance may be depressed when intelligent jammers can learn user's waveform or decision information from user's historical activities. Hence, we proposed a hidden anti-jamming method to address this problem by reducing the jammer's sense probability. In the proposed method, the action correlation between the user and the jammer is used to evaluate the hiding effect of the user's actions. And a deep reinforcement learning framework, including specific action correlation calculation and iteration learning algorithm, is designed to maximize the hiding and communication performance of the user synchronously. The simulation result shows that the algorithm proposed reduces the jammer's sense probability significantly and improves the user's anti-jamming performance slightly compared to the existing algorithms based on jamming avoidance.

• 수산해양교육연구
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• 제21권1호
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• pp.52-58
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• 2009

항행중에 두 선박이 접근하여 충돌의 위험이 있을 경우 안전한계접근거리 즉 피항을 시작해야할 시점에 대해서 실선시험을 통한 자료에 근거를 하여 조종성지수를 산출하고 안전한계접근거리를 계산하여 제공함으로써 항행중에 선박의 조선자들이 상대선박과 피항동작을 취해야 할 경우에 경험이나 감각에만 의존함으로써 생기는 착오를 방지하고자 하였다. 앞의 논의 과정을 요약하면 다음과 같다. 1. 조우각도가 같을 경우에도 타각을 10도사용하면 타각을 30도 사용할 때보다도 안전한계접근거리는 최소 1.3배에서 최대 1.8배정도 더 증가하므로 해상상태, 자선의 적하상태를 고려해서 대타각의 전타가 어려울 경우 특히 피항개시 시점을 충분히 주의해야한다. 2. 선박의 크기에 상관없이 조우각도가 90도 부근에서 충돌의 위험이 가장 커서 안전한계접근거리는 소형선(300톤급)에서는 자선 길이의 5.0배에서, 대형선(100,000톤급)에서는 10.7배로서 대형선일수록 피항개시 시기를 놓치지 않도록 해야 한다. 3. 조우각도가 적을 경우가 클 경우보다도 안전한계접근거리가 훨씬 크게 나타났고 대형선에서 더욱 두드러지게 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2568-2574
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• 2005

Control architecture of the action based robot engineering can be divided into two types of deliberate type - and reactive type- controller. Typical deliberate type, slow in reaction speed, is well suited for the realization of the higher intelligence with its capability to forecast on the basis of environmental model according to time flow, while reactive type is suitable for the lower intelligence as it fits to the realization of speedy reactive action by inputting the sensor without a complete environmental model. Looking at the environments in the application areas in which robots are actually used, we can see that they have been mostly covered by the uncertain and unknown dynamic changes depending on time and place, the previously known knowledge being existed though. It may cause, therefore, any deterioration of the robot performance as well as further happen such cases as the robots can not carry out their desired performances, when any one of these two types is solely engaged. Accordingly this paper aims at suggesting Goal-oriented Geometric Model(GGM) Based Intelligent System Architecture which leads the actions of the robots to perform their jobs under variously changing environment and applying the suggested system structure to the navigation issues of the robots. When the robots do perform navigation in human life changing in a various manner with time, they can appropriately respond to the changing environment by doing the action with the recognition of the state. Extending this concept to cover the highest hierarchy without sticking only to the actions of the robots can lead us to apply to the algorithm to perform various small jobs required for the carrying-out of a large main job.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.888-891
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• 1991

In this paper, we have shown a new approach of neural networks for mobile robot motion control under an indoor refracted environment. The vehicle has two powered wheels and four passive casters which support a free motion. And it also uses sonar sensors, infrared sensors, Internal odometer, and contact sensors. Two experiments were conducted to demonstrate our objectives. The first one is that the vehicle executes a reflexive motor control to maintain a constant distance to the boundary. The second one is that as well as the boundary following, the vehicle makes a block obstacle avoidance during its path. Without prior knowledge of external environment. we have accomplished the tasks by employing a simple, reactive stimulus-response neural network scheme associating sensor data with the vehicle's action.