• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.101-106
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• 2003

This study is to capture autogenous shrinkage in reinforced concrete. The experiment was carried out on total 13 beams. The experiment parameters are a method of curing and reinforcement ratio. Autogenous shrinkage in reinforced concrete beam was experimentally measured. Also, the distribution of autogenous shrinkage and self stress on cross section in reinforced concrete beams were calculated. The experimental results showed that autogenous shrinkage of high strength concrete were significantly higher than that of nomal strength concrete.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.89-99
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• 2006

The PCRW (Precast Concrete Retaining Wall) has many advantages compared with cast in place concrete retaining wall : shorter construction period, excellency of quality and minimum interference with the adjacent structure and traffics. However, shallow foundation type of PCRW, which has comparatively better ground condition, has some disadvantages such as difficulty in transportation and higher cost due to the size of PCRW being expanded by resisting only with self-weight if there is no other supplementary reinforcement. The presented study, in order to complement such disadvantages of PCRW, have applied the micropile method. The micropile method has advantages like low-cost and high-efficiency and does not require huge space, because it can be executed with small size equipment. However, the mechanical behavior characteristics of the PCRW reinforced by micropile, which is installed to improve the reinforcement effect, is not yet clearly identified and there is no suggested standard as to the length, diameter, install angle and install position of micropiles. Hence, this method is yet being designed depend on engineer's experience. In this study, various laboratory model tests as to sliding and overturning were performed in order to identify and present the optimum type of reinforcement and reinforcement effect of the PCRW reinforced by micropiles. In addition, it also executed numerical analysis for the purpose of verifying the optimum type of reinforcement for micropiles based on the results of laboratory model tests. The optimum reinforcement type of micropiles was estimated by model test and numerical analysis. The length of micropiles is 0.4 times wall height and the diameter is 0.04 times wall length.

• Korean Journal of Child Studies
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• v.29 no.1
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• pp.169-188
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• 2008

This study analyzed the influences of child care accreditation system on the participants' successful experiences. Analysis of 20 protocols made by the participants showed three dimensions of effects (1) reinforcement of their speciality within the field of childcare, (2) psychological satisfaction; e.g. self-confidence and self-fulfillment, and (3) positive perspectives on child care accreditation. Conclusions were that child care accreditation is an effective system as long as it helps the participants achieve successful experiences. These data will be useful for understanding and publicity of the recently established child care accreditation system. Future research on this subject is needed not only to activate childcare study but also to contribute towards acceptance of the new system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.402-408
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• 1997

일정 학습계수와 이진 강화함수를 지닌 자기조직화 형상지도(Self-Organizing Feature Map)신경회로망을 FPGA위에 하드웨어로 구현하였다. 원래의 SOFM 알고리즘에서 학습계수가 시간 종속형인데 반하여, 본 논문에서 하드웨어로 구현한 알고리즘에서는 학습계수가 일정인 값으로 고정되며 이로 인한 성능저하를 보상하기 위하여 이진 강화함수를 부가하였다. 제안한 알고리즘은 복잡한 곱셈 연산을 필요로 하지 않으므로 하드웨어 구현시 보다 쉽게 구현 가능한 특징이 있다. 1개의 덧셈/뺄셈기와 2개의 덧셈기로 구성된 단위 뉴런은 형대가 단순하면서 반복적이므로 하나의 FPGA위에서도 다수의 뉴런을 구현 할 수 있으며 비교적 소수의 제어 신호로서 이들을 모두 제어 가능할 수 있도록 설계하였다. 실험결과 각 구성부분은 모두 이상 없이 올바로 동작하였으며 각 부분이 모두 종합된 전체 시스템도 이상 없이 동작함을 알 수 있었다.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.163-171
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• 2006

This paper introduces the research progress on the artificial brain in the Telerobotics and Control Laboratory at KAIST. This series of studies is based on the assumption that it will be possible to develop an artificial intelligence by copying the mechanisms of the animal brain. Two important brain mechanisms are considered: spike-timing dependent plasticity and dopaminergic plasticity. Each mechanism is implemented in two coding paradigms: spike-codes and rate-codes. Spike-timing dependent plasticity is essential for self-organization in the brain. Dopamine neurons deliver reward signals and modify the synaptic efficacies in order to maximize the predicted reward. This paper addresses how artificial intelligence can emerge by the synergy between self-organization and reinforcement learning. For implementation issues, the rate codes of the brain mechanisms are developed to calculate the neuron dynamics efficiently.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.73-77
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• 2001

본 논문에서는 부분적으로 관측 가능한 환경에서 사전의 모델 정보 없이 확률적인 행동 정책을 학습하는 상태 조직화 강화 학습 모델을 제안한다. 기존의 강화학습은 환경 모델을 사전에 필요로 하고 상태 전체의 관측이 필요하기 때문에 학습 이전에 문제에 대해 알아야 한다는 제약이 있다. 또한 작은 문제에 대해서는 잘 적용되지만 상태의 수가 매우 많고 부분적으로만 관측한 경우가 많은 실제 문제에는 그대로 적용하기가 불가능하다. 이러한 두 가지 단점을 해결하기 위해 본 논문에서는 사전의 모델 정보 없이 부분적인 관측값으로부터 상태와 행동 정책을 동시에 학습해 나가는 강화 학습 모델을 제안하고, 제안된 방법을 부분적으로만 관측이 가능한 미로 탐색 문제에 적용하였다.

• Journal of Information Technology Applications and Management
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• v.28 no.6
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• pp.97-116
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• 2021

Due to the decrease in the school-age population and government regulations, universities have made great efforts to secure their own competitiveness. In particular, the selection of universities with financial support based on the recent evaluation of the Ministry of Education has become a major concern enough to affect the existence of the university itself. This paper extracts three-year data from 124 major private universities nationwide, and quantitatively analyzes the variables of major universities selected as self-improvement universities, competency reinforcement universities, and universities with limited financial support. As a result of estimating the selection of self-powered universities using the ordered logit model by hierarchically inputting 12 variables, student competitiveness in the metropolitan area (1.318^**), Educational Restitution Rate (4.078^***), University operation expenditure index rate (1.088^***) values were found. Significant positive coefficient values were found in the admission enrollment rate (45.98^***) and the enrollment rate (13.25^***). As a result of analyzing the marginal effects, the increase in the rate of reduction of education costs has always been positive in the selection of self-powered universities, but it was observed that the rate of increase decreases in areas of increase of 150% or more. On the contrary, the probability of becoming a Em-powered university was negative in all sectors, but on the contrary, it was analyzed that marginal effects increased at the same time point. On the other hand, the employment rate of graduates was not able to find direct significance with the result of the selection of Self powered universities. Through this paper, it is expected that each university will analyze the possibility and shortcomings of the selection of Self powered universities in policy making, and in particular, the risk of dropout of selection for the vulnerable field can be predicted using marginal effects. It can be used as major research data for both university evaluators, university officials and students.

• Computers and Concrete
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• v.21 no.3
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• pp.249-259
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• 2018

The use of recycled aggregate in concrete is gaining much attention due to the growing need for sustainability in construction. In the present study, Self Compacting Concrete (SCC) is made using both natural and recycled aggregate (crushed recycled concrete aggregate from building demolished waste) and performance of recycled aggregate based SCC for the bond behaviour of reinforcement is evaluated. The major factors that influence the bond like concrete compressive strength (Mix-A, B and C), diameter of bar ($D_b=10$, 12 and 16 mm) and embedment length of bar ($L_d=2.5Db$, $5D_b$ and full depth of specimen) are the parameters considered in the present study in addition to type of aggregates (natural and recycled aggregates). The mix proportions of Natural Aggregate SCC (NASCC) are arrived based on the specifications of IS 10262. The mix proportions also satisfy the guidelines of EFNARC. In case of Recycled Aggregate SCC (RASCC), both the natural coarse and fine aggregates are replaced 100% by volume with that of recycled aggregates. These mixes are also evaluated for fresh properties as per EFNARC. The hardened properties like compressive strength, split tensile strength and flexural strength are also determined. The pull-out test is conducted as per the specifications of IS 2770 (Part-1) for determining the bond strength of reinforcement. Bond stress versus slip curves were plotted and a typical comparison of RASCC is made with NASCC. The fracture energy i.e., area under the bond stress slip curve is determined. With the use of recycled aggregates, reduction in maximum bond stress is noticed whereas, the normalised maximum bond stress is higher in case of recycled aggregates. Based on the experimental results, regression analysis is conducted and an equation is proposed to predict the maximum bond stress of RASCC. The equation is in good agreement with the experimental results. The available models in the literature are made use to predict the maximum bond stress and compare the present results.

• Research in Community and Public Health Nursing
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• v.26 no.4
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• pp.398-404
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• 2015

Purpose: This study was conducted to examine the effects of osteoporosis prevention education on Korean breast cancer patients' knowledge and health promoting behavior. Methods: The participants in this study included breast cancer patients who were registered at a self-help group organized by the Breast Cancer Center of a university hospital in Seoul, Korea. The intervention group received 60 minutes' didactic instruction followed by 30 minutes' interactive session, and reinforcement education with leaflets was given three weeks after the group intervention. In order to measure the effects of the intervention, this study used valid and reliable scales on the knowledge of osteoporosis and health promoting behavior for preventing osteoporosis. A post-test was conducted 12 weeks after the intervention. Results: The results showed significant improvement in three of the five factors of osteoporosis knowledge including bone physiology, the characteristics of osteoporosis, and preventive behaviors in the intervention group. Overall health promoting behavior for preventing osteoporosis had significantly increased in the intervention group compared to the control group. Conclusion: Osteoporosis preventive education improved breast cancer patients' knowledge of osteoporosis and health promoting behavior for preventing osteoporosis by inducing their voluntary participation in self-care activities.

• Composites Research
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• v.33 no.5
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• pp.256-261
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• 2020

In this study, the ignition temperature of the Al-Ti-C reaction system, the microstructure and the mechanical properties of the TiC/Mg composite which produced by the self-propagating high-temperature synthesis (SHS) followed by stir casting process were investigated. Mg based composite with uniformly dispersed 0, 10, 20, and 30 vol.% TiC were fabricated, and higher volume fraction of TiC reinforced composite showed superior compressive strength and wear resistance as compared with Mg matrix. It is attributed to the less contamination, defects, impurities in TiC/Mg composite by the in-situ SHS yield effective load transfer from the matrix to the reinforcement.