• Nutrition Research and Practice
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• 제12권3호
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• pp.191-198
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• 2018

BACKGROUD/OBJECTIVES: Neuroinflammation plays critical role in neurodegenerative disorders, such as Alzheimer's disease (AD). We investigated the effect of three licorice varieties, Glycyrhiza uralensis, G. glabra, and Shinwongam (SW) on a mouse model of inflammation-induced memory and cognitive deficit. MATERIALS/METHODS: C57BL/6 mice were injected with lipopolysaccharide (LPS; 2.5 mg/kg, intraperitoneally) and orally administrated G. uralensis, G. glabra, and SW extract (150 mg/kg/day). SW, a new species of licorice in Korea, was combined with G. uralensis and G. glabra. Behavioral tests, including the T-maze, novel object recognition and Morris water maze, were carried out to assess learning and memory. In addition, the expressions of inflammation-related proteins in brain tissue were measured by western blotting. RESULTS: There was a significant decrease in spatial and objective recognition memory in LPS-induced cognitive impairment group, as measured by the T-maze and novel object recognition test; however, the administration of licorice ameliorated these deficits. In addition, licorice-treated groups exhibited improved learning and memory ability in the Morris water maze. Furthermore, LPS-injected mice had up-regulated pro-inflammatory proteins, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2, interleukin-6, via activation of toll like receptor 4 (TLR4) and nuclear factor-kappa B ($NF{\kappa}B$) pathways in the brain. However, these were attenuated by following administration of the three licorice varieties. Interestingly, the SW-administered group showed greater inhibition of iNOS and TLR4 when compared with the other licorice varieties. Furthermore, there was a significant increase in the expression of brain-derived neurotrophic factor (BDNF) in the brain of LPS-induced cognitively impaired mice that were administered licorice, with the greatest effect following SW treatment. CONCLUSIONS: The three licorice varieties ameliorated the inflammation-induced cognitive dysfunction by down-regulating inflammatory proteins and up-regulating BDNF. These results suggest that licorice, in particular SW, could be potential therapeutic agents against cognitive impairment.

• 대한원격탐사학회지
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• 제35권5_1호
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• pp.681-692
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• 2019

이 논문에서는 작물 분류를 목적으로 작물의 시공간 특징을 고려할 수 있는 딥러닝 모델 2D convolution with bidirectional long short-term memory(2DCBLSTM)을 제안하였다. 제안 모델은 우선 작물의 공간 특징을 추출하기 위해 2차원의 합성곱 연산자를 적용하고, 추출된 공간 특징을 시간 특징을 고려할 수 있는 양방향 LSTM 모델의 입력 자료로 이용한다. 제안 모델의 분류 성능을 평가하기 위해 안반덕에서 수집된 다중시기 무인기 영상을 이용한 밭작물 구분 사례 연구를 수행하였다. 비교를 목적으로 기존 딥러닝 모델인 2차원의 공간 특징을 이용하는 2D convolutional neural network(CNN), 시간 특징을 이용하는 LSTM과 3차원의 시공간 특징을 이용하는 3D CNN을 적용하였다. 하이퍼 파라미터의 영향 분석을 통해, 시공간 특징을 이용함으로써 작물의 오분류 양상을 현저히 줄일 수 있었으며, 제안 모델이 공간 특징이나 시간 특징만을 고려하는 기존 딥러닝 모델에 비해 가장 우수한 분류 정확도를 나타냈다. 따라서 이 연구에서 제안된 모델은 작물의 시공간 특징을 고려할 수 있기 때문에 작물 분류에 효과적으로 적용될 수 있을 것으로 기대된다.

• 동력기계공학회지
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• 제2권1호
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• pp.52-58
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• 1998

An immune system has powerful abilities such as memory, recognition and learning to respond to invading antigens, and is applied to many engineering algorithm recently. In this paper, the combined optimization algorithm is proposed for multi-objective problem by introducing the capability of the immune system that controls the proliferation of clones to the genetic algorithm. The optimizing ability of the proposed algorithm is identified by using multi-peak function which have many local optimums and identification of the flexural rigidity for wire rope model.

• 정보과학회 논문지
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• 제44권1호
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• pp.51-56
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• 2017

질의응답 문제를 인공지능 모델을 통해 해결하는 연구는 메모리 네트워크의 등장으로 인해 방법론의 변화를 맞이하고 있으며, 그 중 동적 메모리 네트워크(DMN)는 인간 기억 체계에 착안하여 신경망 기반의 주의 기제를 적용하면서, 질의응답에서 일어나는 각 인지 과정들을 모듈화 했다는 특징들을 갖는다. 본 연구에서는 부족한 학습 데이터를 확장 시키고, DMN이 내포하고 있는 시간 인식의 한계를 개선해 정답률을 높이고자 한다. 실험 결과, 개선된 DMN은 1K-bAbI 문제의 테스트 데이터에서 89.21%의 정답률과, 95%를 질의응답 통과의 기준의 정답률으로 가정할 때 12개의 과제를 통과하는 성능을 보여 정확도 면에서 기존의 DMN에 비해 13.5%p 만큼 더 높고, 4개의 과제를 추가로 통과하는 성능 향상을 보여주었다. 또한 뒤이은 실험을 통해, 데이터 내에서 비슷한 의미 구조를 가지는 단어들은 벡터 공간상에서 강한 군집을 이룬다는 점과, 일화 기억 모듈 통과 횟수와 근거 사실 수의 성능에 큰 영향을 미치는 직접적인 연관성을 발견하였다.

• Nutrition Research and Practice
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• 제16권2호
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• pp.173-193
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• 2022

BACKGROUND/OBJECTIVES: Alzheimer's disease (AD) is one of the most representative neurodegenerative disease mainly caused by the excessive production of amyloid beta (Aβ). Several studies on the antioxidant activity and protective effects of Populus tomentiglandulosa (PT) against cerebral ischemia-induced neuronal damage have been reported. Based on this background, the present study investigated the protective effects of PT against cognitive impairment in AD. MATERIALS/METHODS: We orally administered PT (50 and 100 mg/kg/day) for 14 days in an Aβ_25-35-induced mouse model and conducted behavioral experiments to test cognitive ability. In addition, we evaluated the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum and measured the production of lipid peroxide, nitric oxide (NO), and reactive oxygen species (ROS) in tissues. RESULTS: PT treatment improved the space perceptive ability in the T-maze test, object cognitive ability in the novel object recognition test, and spatial learning/long-term memory in the Morris water-maze test. Moreover, the levels of AST and ALT were not significantly different among the groups, indicating that PT did not show liver toxicity. Furthermore, administration of PT significantly inhibited the production of lipid peroxide, NO, and ROS in the brain, liver, and kidney, suggesting that PT protected against oxidative stress. CONCLUSIONS: Our study demonstrated that administration of PT improved Aβ_25-35-induced cognitive impairment by regulating oxidative stress. Therefore, we propose that PT could be used as a natural agent for AD improvement.

• 해양환경안전학회지
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• 제27권5호
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• pp.574-583
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• 2021

해운 시황을 예측하는 것은 중요한 문제이다. 투자 방식의 결정, 선대 편성 방법, 운임 등을 결정하기 위한 판단 근거가 되며 이는 기업의 이익과 생존에 큰 영향을 미치기 때문이다. 이를 위해 본 연구에서는 기계학습 모델인 장단기 메모리 및 간소화된 장단기 메모리 구조의 Gated Recurrent Units를 활용하여 컨테이너선의 해상운임 예측 모델을 제안한다. 운임 예측 대상은 중국 컨테이너 운임지수(CCFI)이며, 2003년 3월부터 2020년 5월까지의 CCFI 데이터를 학습에 사용하였다. 각 모델에 따라 2020년 6월 이후의 CCFI를 예측한 후 실제 CCFI와 비교, 분석하였다. 실험 모델은 하이퍼 파라메터의 설정에 따라 총 6개의 모델을 설계하였다. 또한 전통적인 분석 방법과의 성능을 비교하기 위해 ARIMA 모델도 실험에 추가하였다. 최적 모델은 두 가지 방법에 따라 선정하였다. 첫 번째 방법으로 각 모델을 10회 반복 실험하여 얻은 RMSE의 평균값이 가장 작은 모델을 선정하는 것이다. 두 번째 방법으로는 모든 실험에서 가장 낮은 RMSE를 기록한 모델을 선정하는 것이다. 실험 결과 전통적 시계열 예측모델인 ARIMA 모델과 비교하여 딥러닝 모델의 정확도를 입증하였으며, 정확한 예측모델을 통해 운임 변동의 위험관리 능력을 제고시키는데 기여했다. 반면 코로나19와 같은 외부 효과에 따른 운임의 급격한 변화상황이 발생한 경우, 예측모델의 정확도가 감소하는 한계점을 나타냈다. 제안된 모델 중 GRU1 모델이 두 가지 평가 방법 모두에서 가장 낮은 RMSE(69.55, 49.35)를 기록하며 최적 모델로 선정되었다.

• Nutrition Research and Practice
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• 제10권3호
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• pp.274-281
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• 2016

BACKGROUND/OBJECTIVES: The accumulation of amyloid-${\beta}$ ($A{\beta}$) in the brain is a hallmark of Alzheimer's disease (AD) and plays a key role in cognitive dysfunction. Perilla frutescens var. japonica extract (PFE) and its major compound, rosmarinic acid (RA), have shown antioxidant and anti-inflammatory activities. We investigated whether administration of PFE and RA contributes to cognitive improvement in an $A{\beta}_{25-35}$-injected mouse model. MATERIALS/METHODS: Male ICR mice were intracerebroventricularly injected with aggregated $A{\beta}_{25-35}$ to induce AD. $A{\beta}_{25-35}$-injected mice were fed PFE (50 mg/kg/day) or RA (0.25 mg/kg/day) for 14 days and examined for learning and memory ability through the T-maze, object recognition, and Morris water maze test. RESULTS: Our present study demonstrated that PFE and RA administration significantly enhanced cognition function and object discrimination, which were impaired by $A{\beta}_{25-35}$, in the T-maze and object recognition tests, respectively. In addition, oral administration of PFE and RA decreased the time to reach the platform and increased the number of crossings over the removed platform when compared with the $A{\beta}_{25-35}$-induced control group in the Morris water maze test. Furthermore, PFE and RA significantly decreased the levels of nitric oxide (NO) and malondialdehyde (MDA) in the brain, kidney, and liver. In particular, PFE markedly attenuated oxidative stress by inhibiting production of NO and MDA in the $A{\beta}_{25-35}$-injected mouse brain. CONCLUSIONS: These results suggest that PFE and its active compound RA have beneficial effects on cognitive improvement and may help prevent AD induced by $A{\beta}$.

• Nutrition Research and Practice
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• 제15권2호
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• pp.173-186
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• 2021

BACKGROUD/OBJECTIVES: Alzheimer's disease (AD) is the most common cause of dementia in the elderly. Due to the increased incidence of dementia, there is a corresponding increase concerning the importance of AD. In this study, we investigated the protective effects conferred by Zizyphus jujuba (Zj) and Zizyphus jujuba fermented by yeast (Zj-Y), on cognitive impairment in an AD mouse model. MATERIALS/METHODS: AD was induced by injecting amyloid beta25-35 (Aβ25-35) in ICR mice, and subsequently 200 mg/kg Zj or Zj-Y was administered daily for 14 days. The cognitive ability of AD mice was observed through behavioral experiments in T-maze, novel object recognition, and Morris water maze tests. We subsequently measured the levels of malondialdehyde (MDA), nitric oxide (NO), aspartate aminotransferase, and alanine aminotransferase in either tissues or serum. RESULTS: In behavioral tests, deterioration was revealed in the short- and long-term learning and memory functions in the Aβ25-35-injected control group compared to the normal group, indicating that Aβ25-35 injection impairs cognitive functions. However, administration of Zj and Zj-Y improved cognitive function in mice, as compared to the Aβ25-35-injected control mice. In addition, the Aβ25-35 induced elevations of MDA and NO in the brain, kidney, and liver were suppressed after exposure to Zj and Zj-Y. Especially, Zj-Y showed stronger scavenging effect against MDA and NO, as compared to Zj. CONCLUSIONS: Results of the present study indicate that Zj-Y exerts a protective effect on cognitive impairment and memory dysfunction, which is exerted by attenuating the oxidative stress induced by Aβ25-35.

• 약학회지
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• 제58권5호
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• pp.287-293
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• 2014

Alzheimer's disease (AD), most common form of dementia is characterized that memory deficit and loss of cognitive function. This study was evaluated cognitive enhancing effect of water and ethanol extracts of Codonopsis lanceolata and compared using Morris water maze and passive avoidance test. The water and 70% ethanol extracts (100, 300 and 500 mg/kg) were administered to mice. The neuroprotective effect on glutamate-induced cell death in HT22 cells was additionally investigated using MTT assay. Results showed 70% ethanol extract of Codonopsis lanceolata enhanced cognitive function than water extract, as shown by decrease in escape latency time in Morris water maze test. In passive avoidance test, 70% ethanol extract also increased the latency time compared to the water extract. Furthermore, 70% ethanol extract significantly protected neuronal cell against glutamate cytotoxicity and showed higher than neuroprotective effect of water extract. These results indicate that 70% ethanol extract more improve spatial cognitive ability and protected neuronal cells than water extract.

• Clinical and Experimental Pediatrics
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• 제63권3호
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• pp.88-95
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• 2020

Accurate localization of the seizure onset zone is important for better seizure outcomes and preventing deficits following epilepsy surgery. Recent advances in neuroimaging techniques have increased our understanding of the underlying etiology and improved our ability to noninvasively identify the seizure onset zone. Using epilepsy-specific magnetic resonance imaging (MRI) protocols, structural MRI allows better detection of the seizure onset zone, particularly when it is interpreted by experienced neuroradiologists. Ultra-high-field imaging and postprocessing analysis with automated machine learning algorithms can detect subtle structural abnormalities in MRI-negative patients. Tractography derived from diffusion tensor imaging can delineate white matter connections associated with epilepsy or eloquent function, thus, preventing deficits after epilepsy surgery. Arterial spin-labeling perfusion MRI, simultaneous electroencephalography (EEG)-functional MRI (fMRI), and magnetoencephalography (MEG) are noinvasive imaging modalities that can be used to localize the epileptogenic foci and assist in planning epilepsy surgery with positron emission tomography, ictal single-photon emission computed tomography, and intracranial EEG monitoring. MEG and fMRI can localize and lateralize the area of the cortex that is essential for language, motor, and memory function and identify its relationship with planned surgical resection sites to reduce the risk of neurological impairments. These advanced structural and functional imaging modalities can be combined with postprocessing methods to better understand the epileptic network and obtain valuable clinical information for predicting long-term outcomes in pediatric epilepsy.