• 한국공간구조학회논문집
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• 제23권2호
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• pp.29-36
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• 2023

Reinforcement learning (RL) is widely applied to various engineering fields. Especially, RL has shown successful performance for control problems, such as vehicles, robotics, and active structural control system. However, little research on application of RL to optimal structural design has conducted to date. In this study, the possibility of application of RL to structural design of reinforced concrete (RC) beam was investigated. The example of RC beam structural design problem introduced in previous study was used for comparative study. Deep q-network (DQN) is a famous RL algorithm presenting good performance in the discrete action space and thus it was used in this study. The action of DQN agent is required to represent design variables of RC beam. However, the number of design variables of RC beam is too many to represent by the action of conventional DQN. To solve this problem, multi-agent DQN was used in this study. For more effective reinforcement learning process, DDQN (Double Q-Learning) that is an advanced version of a conventional DQN was employed. The multi-agent of DDQN was trained for optimal structural design of RC beam to satisfy American Concrete Institute (318) without any hand-labeled dataset. Five agents of DDQN provides actions for beam with, beam depth, main rebar size, number of main rebar, and shear stirrup size, respectively. Five agents of DDQN were trained for 10,000 episodes and the performance of the multi-agent of DDQN was evaluated with 100 test design cases. This study shows that the multi-agent DDQN algorithm can provide successfully structural design results of RC beam.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.984-988
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• 2003

The actinomycete strain KH-6l4 possessed strong antifungal activity, especially antagonistic to the rice blast fungus, Pyricularia oryzae. Diaminopimelic acid (DAP) type and morphological and physiological characteristics, examined by scanning electron microscopy (SEM), indicated that KH-614 belonged to the genus Streptomyces. Antifungal agent produced by this strain was found to be most active, when the strain was cultured in the presence of glucose, polypeptone, and yeast extract (PY) medium for 6 days at $27^{\circ}C$. Based on the spectral report data, MS and NMR, the antifungal agent was identified as cyclo(L-leucyl-L-prolyl). According to the antimicrobial activity test measured by minimal inhibitory concentration (MIC), the cyclo(1eu-pro) exhibited the activity against Candida albicans IAM 4905, Mucor ramannianus IAM6218, Rhizoctonia solani IFO 6218, Aspergilus fumigatus ATCC 42202, Glomerella cingulata IFO 9767, Trichophton mentagrophytes ATCC 18749, and Trichophyton rubrum ATCC 44766, the order of MIC values were 50, 12.5, 5, 50, 25, 5, $5\;\mu\textrm{g}/ml$, respectively. Specifically, cyclo(1eu-pro) was one of the most effective elements against Pyricularia oryzae IFO 5994 with the MIC value of $2.5\;\mu\textrm{g}/ml$, thus indicating that cyclo(leu-pro) is a potential antifungal agent.

• 한국수산과학회지
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• 제42권5호
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• pp.468-475
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• 2009

This study was conducted to examine the bleaching of an anti-inflammatory agent containing Undaria pinnatifida extract (AIAU). Brown-colored AIAU was irradiated with $^{60}CO$ gamma rays at doses ranging from 10-200 kGy. Discoloring of the anti-inflammatory agent was achieved by gamma irradiation, with significantly removal by 50 kGy irradiation. The main active compound of the agent consisted of 4% U. pinnatifida extract, which inhibited inflammatory symptoms in mouse ear edema by 93%. There was no change in effects against edema, erythema, blood flow and radical scavenging activity by irradiation.

• 컴퓨터교육학회논문지
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• 제7권1호
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• pp.97-106
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• 2004

최근 학습자의 요구에 맞는 코스웨어의 주문이 증가하고 있는 추세이며 그에 따라 웹 기반 교육 시스템에 효율적이고 자동화된 교육 에이전트의 필요성이 인식되고 있다. 본 논문에서는 취약성 분석 알고리즘을 이용한 학습자 중심의 코스 스케쥴링 멀티 에이전트 시스템을 제안한다. 제안한 시스템은 먼저 학습자의 학습 평가 결과를 분석하고 학습자의 학습 성취도를 계산하며, 이 성취도를 에이전트의 스케줄에 적응하여 학습자에게 적합한 코스를 제공하고, 학습자는 이러한 코스에 따라 능력에 맞는 반복된 학습을 통하여 적극적인 완전학습을 수행하게 된다.

• 정보처리학회논문지D
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• 제8D권5호
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• pp.623-630
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• 2001

최근 인터넷 솔루션 시장은 전자상거래의 필요성과 효과에 대한 논의를 벗어나 전자상거래 내에서의 경쟁에 초점이 맞추어져 있다. 본 논문에서는 전자상거래 시장을 활성화에 기여할 수 있는 정책지향 매칭 에이전트(policy-oriented matching agent) 시스템을 제안한다. 제안된 정책지향적 솔루션은 정책을 객체화하였기 때문에 다양한 프로모션을 구현할 수 있으며, 기존의 룰 기반 시스템의 장점에 정책이 실기되는 공간 개념(release post)을 추가하였기 때문에 정책의 수립, 실시, 추적 평가 등을 일관되게 처리할 수 있다. 정책지향 솔루션을 구현함에 있어 전자상거래를 위한 기초 플랫폼에 적합한 컴포넌트 기반 구조를 채택하고, 기존의 여타 시스템에 연동되어 마케팅 활동을 쉽게 지원할 수 있도록 한다. 또한 정책 담당자가 정책을 직관적으로 편집할 수 있는 인터페이스를 갖도록 한다.

• Journal of Pharmaceutical Investigation
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• 제2권1호
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• pp.18-30
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• 1972

Renal pathways for excretion of sulfadiazine has been studied by standard clearance technique in the rabbit. 1. Large part of sulfadiazine filtered in the glomeruli is reabsorbed in the tubules, as visualized from the fact that Csd (clearance of sulfadiazine) amounts only a fraction of simultaneously measured Ccr (GFR). 2. Csd changed linearly with the rate of urine flow, whether it is increased by the duir etics or decreased by clamping u reter. 3. Csd remained unchanged until the plasma level of the Csdremained unchanged drug reached 10.0 mg%, and the amount transported in the tubules increased linearly with the increase in the load, exhibiting No maximum capacity for transport. 4. Csd was increased by 2,4-dinitrophenol which is an uncoupling agent of oxidative phosphorylation and decreased by probenecid which is on uricosuric agent. 5. During sodium bicarbonate infusion net secretion of sulfadiazine by tubules observed. All the evidences obtained in the rabbit indicated that sulfadiazine was reabsorbed by active, energy-requiring, or passive, simple diffusion, process, and secreted simultaneously by a probenecid-sensitive, active procss.

• Structural Engineering and Mechanics
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• 제65권6호
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• pp.707-719
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• 2018

In this article, a new method is introduced to improve the local search capability of meta-heuristic algorithms using the projection of the path on the border of constraints. In a mathematical point of view, the Gradient Projection Method is applied through a new approach, while the imposed limitations are removed. Accordingly, the gradient vector is replaced with a new meta-heuristic based vector. Besides, the active constraint identification algorithm, and the projection method are changed into less complex approaches. As a result, if a constraint is violated by an agent, a new path will be suggested to correct the direction of the agent's movement. The presented procedure includes three main steps: (1) the identification of the active constraint, (2) the neighboring point determination, and (3) the new direction and step length. Moreover, this method can be applied to some meta-heuristic algorithms. It increases the chance of convergence in the final phase of the search process, especially when the number of the violations of the constraints increases. The method is applied jointly with the authors' newly developed meta-heuristic algorithm, entitled Star Graph. The capability of the resulted hybrid method is examined using the optimal design of truss and frame structures. Eventually, the comparison of the results with other meta-heuristics of the literature shows that the hybrid method is successful in the global as well as local search.

• 말소리와 음성과학
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• 제4권2호
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• pp.127-134
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• 2012

The purpose of this study is to present evidence for a particular processing approach based on the language-specific characteristics of Korean. To compare individuals' sentence-comprehension abilities, this study measured the accuracy and reaction times (RT) of 12 aphasic patients (AP) and 12 normal controls (NC) during a sentence-picture matching task. Four versions of a sentence were constructed with the two types of voice (active/passive) and two types of word order (agent-first/patient-first). To examine the effects of increased processing demand, picture stimuli were manipulated in such a way that they appeared immediately after the sentence was presented. As expected, the AP group showed higher error rates and longer RT for all conditions than the NC group. Furthermore, Korean speakers with aphasia performed above a chance level in sentence comprehension, even with passive sentences. Aphasics understood sentences more quickly and accurately when they were given in the active voice and with agent-first order. The patterns of the NC group were similar. These results confirm that Korean adults with aphasia do not completely lose their knowledge of sentence comprehension. When the processing demand was increased by delaying the picture stimulus onset, the effect of increased processing demands on RT was more pronounced in the AP than in the NC group. These findings fit well with the idea that the computational system for interpreting sentences is intact in aphasics, but its ability is compromised when processing demands increase.

• Journal of Electrochemical Science and Technology
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• 제10권2호
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• pp.244-249
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• 2019

SiO has a high theoretical capacity as a promising anode material candidate for high-energy-density Li-ion batteries. However, its practical application is still not widely used because of the large volume change that occurs during cycling. In this report, an active material containing a mixture of SiO and graphite was used to improve the insufficient energy density of the conventional anode with the support of multidimensional conducting agents. To relieve the isolation of the active materials from volume changes of SiO/graphite electrode, two types of conducting agents, namely, 1-dimensional VGCF and 0-dimensional Super-P, were introduced. The combination of VGCF and Super-P conducting agents efficiently maintained electrical pathways among particles in the electrode during cycling. We found that the electrochemical performances of cycleability and rate capability were greatly improved by employing the conducting agent combinations of VGCF and Super-P compared with the electrode using only single VGCF or single Super-P. We investigated the detailed failure mechanisms by using systematic electrochemical analyses.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.243.1-243.1
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• 2003

The pharmacokinetics of eupatilin (an active components of Stillen, a new antigastritic agent) were investigated using UV-HPLC method. The quantitation limit of eupatilin was 10 ng/ml in plasma. After intravenous administration of eupatiln, 30 mg/kg to rats, the plasma concentrations of unchanged eupatilin declined rapidly with the mean terminal half-life of 0.101 hr. Total body clearance was 121 ml/min/kg, and fractions of dose excreted in urine and feces for 24 hr were only 2.5% and 0.919%, respectively. (omitted)