• ETRI Journal
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• 제36권5호
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• pp.704-713
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• 2014

Most natural language processing tasks depend on the outputs of some other tasks. Thus, they involve other tasks as subtasks. The main problem of this type of pipelined model is that the optimality of the subtasks that are trained with their own data is not guaranteed in the final target task, since the subtasks are not optimized with respect to the target task. As a solution to this problem, this paper proposes a consolidation of subtasks for a target task ($CST^2$). In $CST^2$, all parameters of a target task and its subtasks are optimized to fulfill the objective of the target task. $CST^2$ finds such optimized parameters through a backpropagation algorithm. In experiments in which text chunking is a target task and part-of-speech tagging is its subtask, $CST^2$ outperforms a traditional pipelined text chunker. The experimental results prove the effectiveness of optimizing subtasks with respect to the target task.

• Biomolecules & Therapeutics
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• 제16권4호
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• pp.320-327
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• 2008

Several lines of evidence indicate that adenosine $A_{2A}$ agonist disrupts spatial working memory. However, it is unclear which stages of learning and memory are affected by the stimulation of adenosine $A_{2A}$ receptor. To clarify these points, we employed CV-1808 as adenosine $A_{2A}$ agonist and investigated its effects on acquisition, consolidation, and retrieval phases of learning and memory using passive avoidance and the Morris water maze tasks. During the acquisition phase, CV-1808 (2-phenylaminoadenosine, 1 and 2 mg/kg, i.p.) decreased the latency time in passive avoidance task and the mean savings in the Morris water maze task, respectively. During the consolidation and retrieval phase tests, CV-1808 did not exhibited any effects on latency time in passive avoidance task and the mean savings in the Morris water maze task. These results suggest that CV-1808 as an adenosine $A_{2A}$ agonist impairs memory acquisition but not consolidation or retrieval.

• Biomolecules & Therapeutics
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• 제16권3호
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• pp.173-178
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• 2008

Several lines of evidence indicate that scopolamine as a nonselective muscarinic antagonist disrupts object recognition performance and spatial working memory when administered systemically. In the present study, we investigated the different effects of scopolamine on acquisition, consolidation, and retrieval phases of object recognition performance and spatial working memory using the object recognition and the Morris water maze tasks in mice. In the acquisition phase test, scopolamine decreased recognition index on object recognition task and the trial 1 to trial 2 differences on Morris water maze task. In the consolidation and retrieval phase tests, scopolamine also decreased recognition index on object recognition task, where as scopolamine did not exhibited any effects on the Morris water maze task.

• 수면정신생리
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• 제12권1호
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• pp.5-10
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• 2005

Study in the field of sleep and memory has greatly expanded recently and the number of publications supporting the association between sleep and memory consolidation is rapidly growing. This study presents evidence related to sleep-dependent memory consolidation, ranging from behavioral task-performing studies to molecular studies, and several arguments against the association. Basic researches show that many genes are upwardly regulated during sleep and patterns of brain activation seen during daytime task training are repeated during subsequent REM sleep. Several electrophysiological studies demonstrate the correlation between spindle density increase following training and subsequent improvement in performing the training task. Overnight improvement or deterioration in task performance correlates with REM or SWS sleep. In the end, a lot of issues remain to be studied and discussed further in the future in spite of supporting evidence now available.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.569-574
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• 1999

In Soft ground of south-western coast of our country necessity of marine indutrial complex and container facility has been remarkable. Site construction for habor facility is one of the most urgent problems. Consolidation of dredged fill has become important task. In addition, volume change of dredged fill should be examined carefully. This study dealt with consolidation of dredged fill by PCDDF and in order to secure trafficability of heavy equipment for surface treatment should be studied.

• 한국해안해양공학회지
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• 제17권1호
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• pp.16-20
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• 2005

고함수비상태로 준설투기된 준설점토지반에 지반개량을 위한 하중재하시 보통 점토지반에 비해 큰 압밀침하가 발생한다. 미소변형률을 전제로 하고 있는 기존의 열전도형 압밀방정식은 준설토지반과 같이 대변형이 발생하는 지반에 적용하기 어렵다. 따라서 준설토층과 같이 큰 변형이 발생하는 지반에서는 압밀과정 중 층 두께의 변화가 고려되어지는 압밀방정식을 적용해야한다. 본 연구에서는 층 두께의 변화를 고려한 압밀해석을 하고 이들의 결과와 층 두께의 변화를 고려하지 않은 기존 압밀해석의 결과와 비교·분석하였다. 이들로부터 변형률이 큰 지반에서의 압밀기간은 층 두께의 변화를 고려한 이론이 그렇지 않은 경우보다 실측치에 보다 근사하게 산정되었고, 압밀침하량의 경우는 압축지수에 의한 방법보다 변형률에 근거한 계산이 실측치에 매우 근접하게 산정되었다.

• PNF and Movement
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• 제6권3호
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• pp.19-28
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• 2008

Purpose : The objective of this study was to determine efficacy of sleep-dependent motor learning. Methods : This is a literature study with books and internet. We searched the PubMed, Science Direct, KISS and DBpia. Key words were Sleep-dependent, motor learning, RAM and LTP. Results : Procedural memory, like declarative memory, undergoes a slow, time-dependent period of consolidation. A process has recently been described wherein performance on some procedural task improves with the mere passage of time and has been termed "enhancement". Some studies have reported that the consolidation/enhancement of perceptual and motor skill is dependent on sleep. Specially, rapid-eye-movement(REM) sleep seems to benefit procedural aspects of memory. Conclusion : Motor learning is very important for CNS injury patients. And also distribution of practice sessions is important because REM sleep is to benefit procedural aspects of memory consolidation.

• Journal of Platform Technology
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• 제6권4호
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• pp.34-40
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• 2018

현재 인공신경망은 단일 작업에 대해선 뛰어난 성능을 보이나, 다른 종류의 작업을 학습하면 이전 학습 내용을 잊어버리는 단점이 있다. 이를 catastrophic forgetting이라고 한다. 인공신경망의 활용도를 높이긴 위해선 이 현상을 극복해야 한다. catastrophic forgetting을 극복하기 위한 여러 노력이 있다. 하지만 많은 노력이 있었음에도 완벽하게 catastrophic forgetting을 극복하지는 못하였다. 본 논문에서는 여러 노력 중 elastic weight consolidation(EWC)에 사용되는 핵심 개념을 이용하여, 순차적 반복학습을 제시한다. 인공신경망 학습에 많이 쓰이는 MNIST를 확장한 EMNIST 데이터 셋을 이용하여 catastrophic forgetting 현상을 재현하고 이를 순차적 반복학습을 통해 극복하는 실험을 진행하였으며, 그 결과 모든 작업에 대해서 학습이 가능하였다.

• 보존과학회지
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• 제26권4호
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• pp.361-370
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• 2010

Gameunsaji West Stone Pagoda;Filler;Consolidation;Pore;Injection;Materials; 석조문화재의 내부공극은 강화처리만으로 효과를 보기 어렵고 고분자합성수지를 이용한 충전의 경우 재료적 이질감과 높은 강도, 저점도에 따른 유동성 향상으로 내부벽면만 접착, 강화되는 단점이 있다. 따라서 본 연구는 무기질 바탕의 다양한 충전제를 검색하여 충전효과검증을 통해 감은사지삼층석탑 공극부 충전에 효과적인 충전제를 선정, 보존처리를 실시하였다. 충전실험 결과 부재와 동일하거나 매우 유사한 물성을 지닌 KSE 500 STE + KSE Filler A KSE Filler B 조합을 사용하여 충전하였다. 서탑 전체표면적은 $252.6m^2$이며 이중 내부공극이 발달한 부분은 $17.77m^2$(7.03%)로 내부를 충전($24,885m{\ell}$)하였다.

• 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.