• 전자공학회논문지B
• /
• 제30B권6호
• /
• pp.93-99
• /
• 1993

In previous paper we proposed a multi-layer bidirectional associative memory (MBAM) which is an extended model of the bidirectional associative memory (BAM) into a multilayer architecture. And we showed that the MBAM has the possibility to have binary storage for easy implementation. In this paper we present a MOdified MBAM(MOMBAM) with high performance compared to MBAM and multi-layer perceptron. The contents will include the architecture, the learning method, the computer simulation results for MOMBAM with MBAM and multi-layer perceptron, and the convergence properties shown by computer simulation examples.. And we will show that the proposed model can be used as classifier with a little restriction.

• 성인간호학회지
• /
• 제12권1호
• /
• pp.17-29
• /
• 2000

The purpose of this study is to find out the effects of depression on older adults' metamemory and memory performances. The subjects of the study consisted of 103 older adults over the age of 60 who are living in Kangwon Province. Some data were collected by means of the interview method, using questionnaires for metamemory (MIA questionnaire by Hultsch, et al., 1988), and depression(GDS by Yesavage and Sheikl, 1986). Other data were collected by a testing method on the memory performance, such as the immediate word recall task, the delayed word recall task, the word recognition task(Elderly Verbal Learning Test by Kyung Mi Choi, 1998), and the face recognition task(Face Recognition Task tool developed by this study). The results of this study were as follows: 1) The average point of depressed older persons' metamemory is 3.2 on a 5 point scale and was significantly lower than nondepressed older persons' point of 3.6. Looking into each sub-concept of metamemory, depressed persons' points are higher in terms of task(4.1), but are lower in terms of change(2.3), locus(2.6), and strategy(2.9) in comparison with nondepressed persons' points. 2) Depressed older persons' memory performances are all significantly lower than nondepressed person's, especially in terms of face recognition task(t=7.26, p<.0082) and word recognition task(t=6.58, p<.01). 3) In both depressed and nondepressed persons, metamemory has a close correlation with all memory tasks. In particular, depressed older persons' correlation is higher across the board, especially in memory self-efficacy of metamemory(r=.36 - .49) in comparison with nondepressed persons. 4) According to the results of analysis on the relations between metamemory and memory performances of each memory task using canonical analysis, in the case of depressed older persons, strategy, locus, capability and task have high correlation with word recognition task and delayed word recall task. Also in the case of nondepressed persons, achievement, strategy, change and locus variable have high correlation with face recognition task and immediate word recall task. As mentioned above, depression variables have a negative effect on older persons' metamemory and memory performance. In conclusion, when we care for depressed older persons with less memory ability, we have to consider the outcomes of this study are relevant. In addition, it is necessary to develop nursing intervention in order to prevent memory loss and improve memory performance in depressed older persons.

• 정보보호학회논문지
• /
• 제28권4호
• /
• pp.847-857
• /
• 2018

악성코드의 수가 가파르게 증가하면서 기업 및 공공기관, 금융기관, 병 의원 등을 타깃으로 한 사이버 공격 피해 사례가 늘어나고 있다. 이러한 흐름에 따라 학계와 보안 업계에서는 악성코드 탐지를 위한 다양한 연구를 진행하고 있다. 최근 들어서는 딥러닝을 비롯해 머신러닝 기법을 적용하는 형태의 연구가 많이 진행되는 추세다. 이 중 합성곱 신경망(CNN: Convolutional Neural Network), ResNet 등을 이용한 악성코드 분류 연구의 경우에는 기존의 분류 방법에 비해 정확도가 크게 향상된 것을 확인할 수 있다. 그러나 타깃 공격의 특징 중 하나는 사용된 악성코드가 불특정 다수를 상대로 광범위하게 퍼뜨리는 형태가 아닌, 특정 대상을 타깃으로 한 맞춤형 악성코드라는 점이다. 이러한 유형의 악성코드는 그 수가 많지 않기 때문에 기존에 연구되어온 머신러닝이나 딥러닝 기법을 적용하기에 한계가 있다. 본 논문은 타깃형 악성코드와 같이 샘플의 양이 부족한 상황에서 악성코드를 분류하는 방법에 대해 다루고 있다. 메모리가 추가된 신경망(MANN: Memory Augmented Neural Networks) 모델을 이용하였고 각 그룹별 20개의 소량 데이터로 구성되어 있는 악성코드 데이터셋에 대해 최대 97%까지 정확도로 분류할 수 있음을 확인하였다.

• 성인간호학회지
• /
• 제16권4호
• /
• pp.636-647
• /
• 2004

Purpose: This study aimed at developing the problem-based learning packages on the respiratory and cardiac system of an adult-health nursing course, and to examine the effect of PBL on the knowledge, learning attitude and motivation in nursing students. Method: A total of 7 PBL packages were developed through the analysis of learning contents and integration of concepts. Clinical scenarios used in 7 PBL packages were selected and composed at a respiratory and a cardiovascular unit, a medical ICU and a chest-surgery unit of C university hospital in G-city. The PBL method was implemented 3 hours a week for 12 weeks to 35 students of an experimental group, and the conventional lecture was implemented to 38 students at C college of C province from Sept. to Dec. 2002. A pretest-posttest experimental design was used. Result: The PBL students (n=35) scored significantly higher knowledge than conventional students (n=38) in the area of problem solving (t=3.418, p=. 001). But, there is no significant difference in the memory-dependent knowledge. Also, The level of learning attitude (t=3.570, p=. 001) and learning motivation (t=3.446. p=. 001) was significantly higher in PBL students. Conclusion: PBL method appears to be effective in improving nursing students' problem-solving knowledge and positive learning attitude and motivation.

• 로봇학회논문지
• /
• 제18권4호
• /
• pp.427-435
• /
• 2023

This paper proposes a method of estimating the pose of a mobile robot by using a learning model. When estimating the pose of a mobile robot, wheel encoder and inertial measurement unit (IMU) data are generally utilized. However, depending on the condition of the ground surface, slip occurs due to interaction between the wheel and the floor. In this case, it is hard to predict pose accurately by using only encoder and IMU. Thus, in order to reduce pose error even in such conditions, this paper introduces a pose estimation method based on a learning model using data of the wheel encoder and IMU. As the learning model, long short-term memory (LSTM) network is adopted. The inputs to LSTM are velocity and acceleration data from the wheel encoder and IMU. Outputs from network are corrected linear and angular velocity. Estimated pose is calculated through numerically integrating output velocities. Dataset used as ground truth of learning model is collected in various ground conditions. Experimental results demonstrate that proposed learning model has higher accuracy of pose estimation than extended Kalman filter (EKF) and other learning models using the same data under various ground conditions.

• Toxicological Research
• /
• 제17권
• /
• pp.47-57
• /
• 2001

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, and its pathology is characterized by the presence of numerous numbers of senile plaques and neurofibrillary tangles. Several genetic and transgenic studies have indicated that excess amount of $\beta$-amyloid protein (A$\beta$) is produced by mutations of $\beta$TEX>$\beta$-amyloid precursor protein and causes learning impairment. Moreover, $A\beta$ has a toxic effect on cultured nerve cells. To prepare AD model animals, we have examined continuous (2 weeks) infusion of $A\beta$ into the cerebral ventricle of rats. Continuous infusion of $A\beta$ induces learning impairment in water maze and passive avoidance tasks, and decreases choline acetyltransferase activity in the frontal cortex and hippocampus. Immunohistochemical analysis revealed diffuse depositions of $A\beta$ in the cerebral cortex and hippocampus around the ventricle. Furthermore, the nicotine-evoked release of acetylcholine and dopamine in the frontal cortex/hippocampus and striatum, respectively, is decreased in the $A\beta$-infused group. Perfusion of nicotine (50 $\mu\textrm{M}$) reduced the amplitude of electrically evoked population spikes in the CA1 pyramidal cells of the control group, but not in those of the $A\beta$-infused group, suggesting the impairment of nicotinic signaling in the $A\beta$-infused group. In fact, Kd, but not Bmax, values for ［$^3H$］ cytisine binding in the hippocampus significantly increased in the $A\beta$-infused rats. suggesting the decrease in affinity of nicotinic acetylcholine receptors. Long-term potentiation (LTP) induced by tetanic stimulations in CA1 pyramidal cells, which is thought to be an essential mechanism underlying learning and memory, was readily observed in the control group, whereas it was impaired in the $A\beta$-infused group. Taken together, these results suggest that $A\beta$ infusion impairs the signal transduction mechanisms via nicotinic acetylcholine receptors. This dysfunction may be responsible, at least in part, for the impairment of LTP induction and may lead to learning and memory impairment. We also found the reduction of glutathione- and Mn-superoxide dismutase-like immunoreactivity in the brains of $A\beta$-infused rats. Administration of antioxidants or nootropics alleviated learning and memory impairment induced by $A\beta$ infusion. We believe that investigation of currently available transgenic and non-transgenic animal models for AD will help to clarify the pathogenic mechanisms and allow assessment of new therapeutic strategies.

• Journal of Microbiology and Biotechnology
• /
• 제21권8호
• /
• pp.874-883
• /
• 2011

Many studies have shown that the steamed root of Rehmannia glutinosa (SRG), which is widely used in the treatment of various neurodegenerative diseases in the context of Korean traditional medicine, is effective for improving cognitive and memory impairments. The purpose of this study was to examine whether SRG extracts improved memory defects caused by administering scopolamine (SCO) into the brains of rats. The effects of SRG on the acetylcholinergic system and proinflammatory cytokines in the hippocampus were also investigated. Male rats were administered daily doses of SRG (50, 100, and 200 mg/kg, i.p.) for 14 days, 1 h before scopolamine injection (2 mg/kg, i.p.). After inducing cognitive impairment via scopolamine administration, we conducted a passive avoidance test (PAT) and the Morris water maze (MWM) test as behavioral assessments. Changes in cholinergic system reactivity were also examined by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) and the reactivity of acetylcholinesterase (AchE) in the hippocampus. Daily administration of SRG improved memory impairment according to the PAT, and reduced the escape latency for finding the platform in the MWM. The administration of SRG consistently significantly alleviated memory-associated decreases in cholinergic immunoreactivity and decreased interleukin-$1{\beta}$ (IL-$1{\beta}$) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) mRNA expression in the hippocampus. The results demonstrated that SRG had a significant neuroprotective effect against the neuronal impairment and memory dysfunction caused by scopolamine in rats. These results suggest that SRG may be useful for improving cognitive functioning by stimulating cholinergic enzyme activities and alleviating inflammatory responses.

• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제23권8호
• /
• pp.466-472
• /
• 2017

하드웨어 트랜잭셔널 메모리(HTM)는 트랜잭션 처리를 위한 병렬 프로그래밍 패러다임을 크게 바꾸었으며, 최근 Intel에서 TSX를 제안함에 따라 HTM에 기반한 다수의 연구들이 수행되었다. 그러나 기존 연구들은 트랜잭션 처리에서 하나의 원인에 대한 충돌 예측만을 지원하며, 모든 워크로드에 대해 획일화된 TSX 환경을 제공한다. 이러한 문제점을 해결하기 위해, 본 논문에서는 멀티코어 인메모리 환경에서 트랜잭션을 처리하기 위한 효율적인 HTM 기법을 제안한다. 첫째, 제안하는 기법은 과거 트랜잭션 처리 정보를 수집한 매트릭스를 이용하여, HTM 실패시의 대비책 경로로써 STM 혹은 single lock을 선택한다. 둘째, 머신러닝 알고리즘 기반 재시도 정책을 제공함으로써, 워크로드 특성에 맞는 효율적인 트랜잭션 처리를 수행한다. 마지막으로 STAMP를 이용한 성능평가를 통해, 제안하는 기법이 기존 연구에 비해 10~20%의 성능 향상이 있음을 보인다.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2022년도 학술발표회
• /
• pp.35-35
• /
• 2022

최근에 딥 러닝(Deep learning) 기반의 많은 방법들이 수문학적 모형 및 예측에서 의미있는 결과를 보여주고 있지만 더 많은 연구가 요구되고 있다. 본 연구에서는 수자원의 가장 대표적인 모델링 구조인 강우유출의 관계의 규명에 대한 모형을 Long Short-Term Memory (LSTM) 기반의 변형 된 방법으로 제시하고자 한다. 구체적으로 본 연구에서는 반응변수인 유출량에 대한 직접적인 고려가 아니라 그의 1차 도함수 (First derivative)로 정의되는 Delta기반으로 모형을 구축하였다. 또한, Attention 메카니즘 기반의 모형을 사용함으로써 강우유출의 관계의 규명에 있어 정확성을 향상시키고자 하였다. 마지막으로 확률 기반의 예측를 생성하고 이에 대한 불확실성의 고려를 위하여 Denisty 기반의 모형을 포함시켰고 이를 통하여 Epistemic uncertainty와 Aleatory uncertainty에 대한 상대적 정량화를 수행하였다. 본 연구에서 제시되는 모형의 효용성 및 적용성을 평가하기 위하여 미국 전역에 위치하는 총 507개의 유역의 일별 데이터를 기반으로 모형을 평가하였다. 결과적으로 본 연구에서 제시한 모형이 기존의 대표적인 딥 러닝 기반의 모형인 LSTM 모형과 비교하였을 때 높은 정확성뿐만 아니라 불확실성의 표현과 정량화에 대한 유용한 것으로 확인되었다.

• 사상체질의학회지
• /
• 제20권3호
• /
• pp.151-163
• /
• 2008

1. Objective This study was done to identify the anti-stress effect of Hyeongbangdojeok-san (HDS), Yanggyeoksanhwa-tang(YST) in Soyangin. 2. Methods Experimental animals were composed of YST, HDS+stress groups which were administered each by 200mg/kg, 400mg/kg and the Saline+stress group. On the 1st day, making the rats forced swim and on the 2nd day, applying Forced swimming test to the rats. After FST, the levels of Corticosterone in the blood were measured. For the study of learning retardation, memory ability and anxiety reaction, experimental animals were composed of YST, HDS+restraint stress groups which were administered each by 400mg/kg, no stress group and the Saline+restraint stress group. Restraint stress were applied 2 hours a day for 3 weeks. On the last day of the 3rd week, Elevated Plus Maze(EPM) was applied to the groups and Morris Water Maze(MWM) was applied to the groups for 7 days. 3. Results 1. As the results of measuring FST which reflects depression, the YST+stress group and the HDS+stress group showed significant effect in comparison with the Saline+stress group. The levels of Corticosterone in the blood were decreased only in the 400mg/kg YST+stress group. 2. As the results of measuring how long EPM which reflects anxiety reaction stayed in the open arm, there was the trend which can suppress anxiety reaction in the HDS+restraint stress group bur no statistical significance. But there was any suppression of anxiety reaction in the YST+restraint stress group. 3. According to the result of MWM, the saline+restraint stress group showed the learning retardation which means increased time arriving at goal compared to the normal group at the second and third day of measurement. On the contrary, a learning retardation was significantly decreased in the YST+restraint stress group at the third day of measurement. 4. Among the Probe trial test a memory loss occurred in the saline+restraint stress group, but memory ability was significantly increased in the YST+restraint stress group. 4. Conclusion: As the results above, Soyangin Yanggyeoksanhwa-tang has significant influence to the antidepression effect, the learning retardation, the anxiety reaction and also in the Hormone level. Hyeongbangdojeok-san has significant influence to the antidepression effect, in the Hormone level, bur not to the learning retardation and anxiety reaction. prefer to drink cold water, and who are suffering from chronic gastritis.