• Title, Summary, Keyword: Reinforcement

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A Study on Performance Improvement of Evolutionary Algorithms Using Reinforcement Learning (강화학습을 이용한 진화 알고리즘의 성능개선에 대한 연구)

  • 이상환;심귀보
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • pp.420-426
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    • 1998
  • Evolutionary algorithms are probabilistic optimization algorithms based on the model of natural evolution. Recently the efforts to improve the performance of evolutionary algorithms have been made extensively. In this paper, we introduce the research for improving the convergence rate and search faculty of evolution algorithms by using reinforcement learning. After providing an introduction to evolution algorithms and reinforcement learning, we present adaptive genetic algorithms, reinforcement genetic programming, and reinforcement evolution strategies which are combined with reinforcement learning. Adaptive genetic algorithms generate mutation probabilities of each locus by interacting with the environment according to reinforcement learning. Reinforcement genetic programming executes crossover and mutation operations based on reinforcement and inhibition mechanism of reinforcement learning. Reinforcement evolution strategies use the variances of fitness occurred by mutation to make the reinforcement signals which estimate and control the step length.

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Assessment of Flexural Ductility in RC Beams with High-Strength Reinforcement (고장력 철근을 사용한 RC 보의 휨연성 평가)

  • 권순범;윤영수;이만섭;임철현
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.897-902
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    • 2001
  • Recently, structure performance is maximized by using high strength concrete. In design of structure, concrete need combination with reinforcement, but use of common strength reinforcement make member complex bar placement, so high strength concrete members require increased strength reinforcement. If common strength reinforcement replaced by equal tension area of high strength reinforcement, reinforcement ratio increase and brittle failure of member may occur by material change. So, adequate upper limit of strength ratio is required to affirm ductile behavior in application of high strength reinforcement. In this study, ductility behavior was analysed by factor of reinforcement ratio, strength of concrete and reinforcement. The result indicate that ductile failure is shown under 0.35 $\rho_{b}$ in any reinforcement strength of same section and high strength concrete of 800kg/$cm^{2}$ used commonly is compatible with reinforcement of 5500kg/$cm^{2}$.

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Punching Shear Performance Evaluation of Foundation by Enforcement-length of Shear Head Reinforcement (전단 보강재의 보강길이에 따른 기초판의 뚫림전단 성능평가)

  • Lee, Yong-Jae;Yi, Waon-Ho;Yang, Won-Jik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.2
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    • pp.60-68
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    • 2017
  • This study was made to examine the motion characteristics according to the reinforcement of the reinforcement length and stiffener reinforcement for shear reinforcement to the foundation structure reinforced with shear reinforcement steel plate. Experimental study was made after specimen was installed on the ground as the same as in the practical site. Reinforcement lengths of the steel for shear reinforcement are divided into 1,000 mm, 1,200 mm and 1,400 mm in the specimen and as for reinforcement method of the stiffener, 4 stiffeners with interval of 100mm reinforced with the same materials as the shear reinforcement were manufactured for the experiment. Considering result of the experiment, it is expressed that no effect of the stiffener reinforcement was found and regarding the reinforcement length of shear reinforcement material the crossed point of the two converted lines of the value that the shear force is expressed in the bearing power in the expanded dangerous section and the value that the shear capacity receivable by the reinforcement materials in the dangerous section is proposed as effective reinforcement length.

A study about determination of preliminary design & minimum reinforcement ratios

  • KOC, Varol;EMIROGLU, Yusuf
    • Computers and Concrete
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    • v.17 no.5
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    • pp.673-692
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    • 2016
  • In the standards, minimum reinforcement ratios are presented as the least reinforcement ratios that bearing elements should have in a way to include all systems and in general. However, naturally these general minimum ratios might be presented as being lower than the normally required reinforcement ratios by criteria such as system size, bearing system arrangement, section situation and distributions of the elements and earthquake effect. In this case, minimum reinforcement ratios may remain as meaningless restrictions. Then grouping the criterion that might affect reinforcement ratios according to certain parameters and creating minimum reinforcement ratios regarding preliminary design will provide ease and safety during the project designing. Moreover, it will enable fast and simple examinations in the beginning of project control and evaluation process. By means of the data which could be defined as "preliminary design & minimum reinforcement ratios", a more realistic and safe restriction compared to general minimum reinforcement ratios could be presented. As a result of numerous comprehensive studies, reinforcement ratios to include all certain systems might be obtained. Today, thanks to the development level of finite elements programs which can make reinforced concrete modelling, with the studies that are impossible to carry out beforehand, this deficiency in the minimum reinforcement ratios in the standarts may at least be partially made up with the advisory regulation of preliminary design & minimum reinforcement ratios. As the structure of the system to be examined and the diversity of the parameters range from the specific to the general, preliminary design & minimum reinforcement ratios will approximate to general minimum reinforcement ratios in real terms. By focusing on a more specific system structure and diversity of the parameters, preliminary design and even design reinforcement ratios will be approximated. In this preliminary study, a route between these two extremes was attempted to be followed. Today, it is possible to determine suggested practical ratios for project designs through carrying out numerous studies.

Assessment of Ductility for the RC Piers with Transverse Reinforcement and Application of Carbon-Fiber Red (횡방향 구속철근의 배근방법에 따른 철근콘크리트 교각의 연성 평가 및 탄소섬유 ROD의 적용)

  • 이영호;이학은
    • Journal of the Korea Concrete Institute
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    • v.14 no.1
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    • pp.8-15
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    • 2002
  • This paper presents a study carried out for the seismic capacity in reinforced concrete(RC) piers by the confinement effect of transverse reinforcement as such a hooked-tied, welded-tied and spiral reinforcement. In order to assess the seismic capacity with transverse reinforcement, experiment리 and analytical methods were adopted. A RC column survey was conducted based on eight one-fourth scale single circular column specimens designed and tested under slow horizontal cyclic loads. Two cases were analyzed. The confinement effect of concrete by transverse reinforcement is considered not in Case 1 but in Case 2. Also, we studied the propriety of making use of the method in which a carbon fiber rod replace spiral reinforcement in RC piers. In experimental tests, a welded-tied and spiral reinforcement has a good seismic capacity, but a carbon fiber rod presents low ductility in comparison with a hooked-tied reinforcement. In an analytical study, displacement ductility is approximate to the experimental result because of considering the confinement effect of the transverse reinforcement. Even if the confinement effect of the transverse reinforcement is considered, the analytical results for ductility of the specimens with welded-tied and spiral reinforcement show an excessive underestimation of the experimental results.

Reinforcement Effect Analysis of Geogrid by Model Test and Numerical Interpretation (모형실험 및 수치해석에 의한 지오그리드 보강효과 분석)

  • Ahn, Seung Jae;Cha, Ju Hee;Yoo, Se Eun;Jeon, Han Yong
    • Textile Science and Engineering
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    • v.53 no.5
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    • pp.372-377
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    • 2016
  • In order to minimize settlement of a shallow foundation, a model test is performed using geogrids for reinforcement. The optimal reinforcement is found by varying reinforcement length and changing reinforcement layer. From the test results, it is inferred that 2 layers and 4 times the foundation length is the most effective reinforcement condition obtained using geogrids. As a result of this tendency, 2 layers-4 times and 2 layers-5 times conditions are used to determine the reinforcement effect of two types of geogrids with the same tensile strength and of a single type of geogrid but with two tensile strengths. The reinforcement effect of the welded type is less than that of warp-knitted type. It can be seen that frictional resistance is developed at the soil-geogrid rib interface; therefore, the reinforcement capacity is reduced. It is inefficient to use reinforcement of high tensile strength under conditions of allowable bearing capacity, but it is necessary to choose reinforcement of suitable tensile strength under conditions of ultimate bearing capacity.

Evaluation of Reinforcement Effects According to Reinforcement Type and Grouting Method (지반보강재의 형상과 그라우팅 방법에 따른 보강효과 평가)

  • Park, Jongseo;Kim, Taeyeon;Lee, Bongjik
    • Journal of the Korean Geoenvironmental Society
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    • v.20 no.8
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    • pp.13-20
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    • 2019
  • In order to ground reinforcement, the chemical grouting, the anchor, the soil nailing system, the micropile, etc. can be mentioned by the methods widely used in domestic. The above ground reinforcement methods are developed by various methods depending on the type of reinforcement, installation method, presence of prestress, grouting method, etc. However, in common, the strength of reinforcement, the friction force of grout and reinforcement and the friction force of grout and ground are the main design variables. Therefore, the optimized ground reinforcement is a material with a high tensile strength of the reinforcement itself, the friction force between the reinforcement and the grout is high, and the application of an optimal grouting method is necessary to improve the friction force between the grout and the ground. In this study, a total of 20 model tests were conducted to analyze the reinforcement effects according to the shape of the reinforcement and the grouting method. As a result of the test, As a result of the experiment, it is judged that the reinforcing effect is superior to the perforated + wing type reinforcement and post grouting method.

The Interaction Design of Teaching Assistant Robots Based on Reinforcement Theory: With an Emphasis on the Measurement of Task Performance and Reaction Rate (강화 이론에 근거한 교사 보조 로봇 인터랙션 디자인: 수행도와 반응률 측정을 중심으로)

  • Kwak, So-Nya S.;Lee, Dong-Kyu;Lee, Min-Gu;Han, Jeong-Hye;Kim, Myung-Suk
    • The Journal of Korea Robotics Society
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    • v.1 no.2
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    • pp.142-150
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    • 2006
  • This study examines whether the reinforcement theory would be effectively applied to teaching assistant robots between a robot and a student in the same way as it is applied to teaching methods between a teacher and a student. Participants interact with a teaching assistant robot in a 3 (types of robots: positive reinforcement vs. negative reinforcement vs. both reinforcements) by 2 (types of participants: honor students vs. backward students), within-subject experiment. Three different types of robots, such as 'Ching-chan-ee' which gives 'positive reinforcement', 'Um-bul-ee' which gives 'negative reinforcement', and 'Sang-bul-ee' which gives both 'positive and negative reinforcement' are designed based on the reinforcement theory and the token reinforcement system. Participants' task performance and reaction rate are measured according to the types of robots and the types of participants. In task performance, the negative reinforcement robot is more effective than the other two types, but regarding the number of stimulus, the less the stimulus is, the more effective the task performance is. Also, participants showed the highest reaction rate on the negative reinforcement robot which implies that the negative reinforcement robot is most effective to motivate students. The findings demonstrate that the participants perceive the teaching assistant robot not as a toy but as a teaching assistant and the reinforcement interaction is important and effective for teaching assistant robots to motivate students. The results of this study can be implicated as an effective guideline to interaction design of teaching assistant robots.

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Modifying Inappropriate Behaviors of Nursery School Children through Token and Social Reinforcement (토오컨강화와 사회적강화를 이용한 유아원 아동의 부적절한 학습행동의 수정)

  • Kim, Jin Sook
    • Korean Journal of Child Studies
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    • v.8 no.2
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    • pp.61-71
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    • 1987
  • The effects of token and social reinforcement on inappropriate study behaviors of nursery school children were investigated. The subjects were three nursery school boys, and the target behaviors were : 1) out-of-seat behaviors, 2) bothering other children, and 3) disruptive behaviors. The ABAB(Reversal) design was used in this experiment. It consisted of four periods : baseline, reinforcement I, reversal, and reinforcement II. During the reinforcement period, social reinforcement as well as token reinforcement was applied. In all three subjects, inappropriate study behaviors decreased during the reinforcement periods (I, II), and increased during the reversal period, showing the effects of token and social reinforcement. The subjects showed stability in three post-experimental tests, indicating that modification of inappropriate study behaviors was being maintained.

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Effects of details of lattice reinforcement for punching shear strength of slab-column connections (슬래브-기둥 접합부의 뚫림 전단강도에 대한 래티스 보강상세의 영향)

  • Kim, You-Ni;Park, Hong-Gun
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.17-20
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    • 2006
  • A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In previous, experimental tests were performed to study the capacity of slab-column connections strengthened with various shear reinforcement, and the capacity of the specimens with lattice reinforcement are superior to the others. In present study, to study for effects of details of lattice reinforcement, experimental studies was performed. Main parameters are the amount of lattice shear reinforcement, arrangement of lattice and the effect of flexural re-bar. And capacity of the specimen with small amount of lattice reinforcement was higher than the capacity of other shear reinforcement.

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