• 제목/요약/키워드: G2019S

검색결과 840건 처리시간 0.033초

The Effects of a Circle-based Early Childhood Science Education Program Using Physical Movement on Young Children's Scientific Inquiry Ability, Scientific Attitude, Object Manipulation Ability and Spatial Ability (신체움직임을 활용한 순환학습기반 유아과학교육 프로그램이 유아의 과학적 탐구능력, 과학적 태도, 물체조작능력 및 공간능력에 미치는 효과)

  • Chung, Gibun;Kim, Jihyun
    • Korean Journal of Childcare and Education
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    • 제15권6호
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    • pp.139-167
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    • 2019
  • Objective: This study aims to investigate the effects of a learning cycle model-based early childhood education program using physical motion on young children's scientific inquiry ability, scientific attitude, object manipulation ability and spatial ability. Methods: The subjects of this study were 60 five-year-old children who were attending K-G City Childcare Center. The SPSS Window 21.0 program and content analysis method were used, and post-validation Tukey was conducted to examine the differences between the one-way ANOVA and the group. Results: Activities using body movement were practiced systematically based on the circle learning. Children could revise their pre-concept and concept of error by interacting with other children, teachers and the environment. Furthermore, children were attaining new knowledge while they were doing body movement activities, assessing and applying them to actual activities. Conclusion/Implications: This study is investigated a cyclic learning-based early childhood science education program using physical motion, which has significance in systematic and practical early childhood centered education for young children.

Flexural analysis of thermally actuated fiber reinforced shape memory polymer composite

  • Tiwari, Nilesh;Shaikh, A.A.
    • Advances in materials Research
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    • 제8권4호
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    • pp.337-359
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    • 2019
  • Shape Memory Polymer Composites (SMPC) have gained popularity over the last few decades due to its flexible shape memory behaviour over wide range of strains and temperatures. In this paper, non-linear bending analysis has been carried out for SMPC beam under the application of uniformly distributed transverse load (UDL). Simplified C0 continuity Finite Element Method (FEM) based on Higher Order Shear Deformation Theory (HSDT) has been adopted for flexural analysis of SMPC. The numerical solutions are obtained by iterative Newton Raphson method. Material properties of SMPC with Shape Memory Polymer (SMP) as matrix and carbon fibre as reinforcements, have been calculated by theory of volume averaging. Effect of temperature on SMPC has been evaluated for numerous parameters for instance number of layers, aspect ratio, boundary conditions, volume fraction of carbon fiber and laminate stacking orientation. Moreover, deflection profile over unit length and behavior of stresses across thickness are also presented to elaborate the effect of glass transition temperature (Tg). Present study provides detailed explanation on effect of different parameters on the bending of SMPC beam for large strain over a broad span of temperature from 273-373K, which encompasses glass transition region of SMPC.

Numerical Analysis of Heat Transfer and Fabrication of Carbon Material for Heat Dissipation in Solar Panel (태양광 패널 적용 방열용 탄소소재의 제조 및 열전달 수치해석)

  • Park, Hun-Su;Kang, Chul-Hee;Kim, Hong-Gun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • 제18권12호
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    • pp.82-90
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    • 2019
  • This analysis demonstrates the effective removal of heat generated from a solar panel's output degradation factor solar cells (the solar panel's output deterioration factor), and solves the problems of oxidation and corrosion in existing metal heat sinks. The heat-dissipating test specimen was prepared using carbon materials; then, its thermal conductivity and its effectiveness in reducing temperatures were studied using heat transfer numerical analysis. As a result, the test specimen of the 30g/㎡ basis weight containing 80% of carbon fiber impregnated with carbon ink showed the highest thermal conductivity 6.96 W/(m K). This is because the surface that directly contacted the solar panel had almost no pores, and the conduction of heat to the panels appeared to be active. In addition, a large surface area was exposed to the atmosphere, which is considered advantageous in heat dissipation. Finally, numerical analysis confirmed the temperature reduction effectiveness of 2.18℃ in a solar panel and 1.08℃ in a solar cell, depending on the application of heat dissipating materials.

A Rapid and Effective Colony PCR Procedure for Screening Transformants in Several Common Mushrooms

  • Wang, Yuanyuan;Xu, Danyun;Liu, Dongmei;Sun, Xueyan;Chen, Yue;Zheng, Lisheng;Chen, Liguo;Ma, Aimin
    • Mycobiology
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    • 제47권3호
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    • pp.350-354
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    • 2019
  • In the post-genomic era, gene function analysis has attracted much attention. Transformation is often needed to investigate gene function. In this study, an easy, rapid, reliable, and cost-effective colony polymerase chain reaction (PCR) method for screening mushroom transformants was developed: picking up a suitable amount of transformant's tissue ($1-10{\mu}g$) to $20{\mu}l$ 0.25% Lywallzyme solution, and vortexing for 10 s followed by incubation at $34^{\circ}C$ for 15 min. Finally, $2{\mu}l$ of the suspension was used as templates to perform PCR and single target bands were successfully amplified from respective transformants of Tremella fuciformis, Pleurotus ostreatus, and Pleurotus tuber-regium. This procedure could be widely employed for screening transformants in mushroom transformation experiments.

A Reinforcement Learning Framework for Autonomous Cell Activation and Customized Energy-Efficient Resource Allocation in C-RANs

  • Sun, Guolin;Boateng, Gordon Owusu;Huang, Hu;Jiang, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권8호
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    • pp.3821-3841
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    • 2019
  • Cloud radio access networks (C-RANs) have been regarded in recent times as a promising concept in future 5G technologies where all DSP processors are moved into a central base band unit (BBU) pool in the cloud, and distributed remote radio heads (RRHs) compress and forward received radio signals from mobile users to the BBUs through radio links. In such dynamic environment, automatic decision-making approaches, such as artificial intelligence based deep reinforcement learning (DRL), become imperative in designing new solutions. In this paper, we propose a generic framework of autonomous cell activation and customized physical resource allocation schemes for energy consumption and QoS optimization in wireless networks. We formulate the problem as fractional power control with bandwidth adaptation and full power control and bandwidth allocation models and set up a Q-learning model to satisfy the QoS requirements of users and to achieve low energy consumption with the minimum number of active RRHs under varying traffic demand and network densities. Extensive simulations are conducted to show the effectiveness of our proposed solution compared to existing schemes.

First Korean case of factor V Leiden mutation in pregnant woman with a history of recurrent pregnancy loss

  • Han, Sung Hee;Seo, Jung Jae;Kim, Eun Seol;Ryu, Jae Song;Hong, Seong Hyeon;Hwang, Seung Yong
    • Journal of Genetic Medicine
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    • 제16권1호
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    • pp.23-26
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    • 2019
  • Thrombophilia refers to inherited or acquired hemostatic disorders that result in a predisposition to blood clot formation. When combined with the hypercoagulable state that is characteristic of pregnancy, there is an increased risk of severe and recurrent pregnancy complications. Activated protein C resistance caused by factor V Leiden (FVL) mutation is known to be the most common cause of inherited thrombophilia in Caucasian population. FVL mutation has been related to pregnancy complications associated with hypercoagulation, e.g. miscarriage, intrauterine fetal demise, placental abruption, and intrauterine growth retardation. Although the FVL mutation is easily detected using molecular DNA techniques, patients who are heterozygous for this disorder often remain asymptomatic until they develop a concurrent prothrombotic condition. Because there are potentially serious effects of FVL mutation for pregnancy, and because effective treatment strategies exist, early detection and treatment of this condition might be considered.

FE modeling for geometrically nonlinear analysis of laminated plates using a new plate theory

  • Bhaskar, Dhiraj P.;Thakur, Ajaykumar G.
    • Advances in aircraft and spacecraft science
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    • 제6권5호
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    • pp.409-426
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    • 2019
  • The aim of the present work is to study the nonlinear behavior of the laminated composite plates under transverse sinusoidal loading using a new inverse trigonometric shear deformation theory, where geometric nonlinearity in the Von-Karman sense is taken into account. In the present theory, in-plane displacements use an inverse trigonometric shape function to account the effect of transverse shear deformation. The theory satisfies the traction free boundary conditions and violates the need of shear correction factor. The governing equations of equilibrium and boundary conditions associated with present theory are obtained by using the principle of minimum potential energy. These governing equations are solved by eight nodded serendipity element having five degree of freedom per node. A square laminated composite plate is considered for the geometrically linear and nonlinear formulation. The numerical results are obtained for central deflections, in-plane stresses and transverse shear stresses. Finite element Codes are developed using MATLAB. The present results are compared with previously published results. It is concluded that the geometrically linear and nonlinear response of laminated composite plates predicted by using the present inverse trigonometric shape function is in excellent agreement with previously published results.

Ultrahigh-Speed Photonic Devices and Components Technologies for Optical Transceivers (초고속 광송수신 소자·부품 기술)

  • Kim, J.H.;Han, Y.T.;Kim, D.J.;Kim, D.C.;Choe, J.S.;Lee, D.H.;Lee, S.Y.
    • Electronics and Telecommunications Trends
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    • 제34권5호
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    • pp.81-90
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    • 2019
  • The data rate for transmission through fiber-optic cables has increased to 400 Gbps in single-wavelength channels. However, speeds up to 1 Tbps are required now to meet the ever-increasing bandwidth demand driven by the diverse requirements of contemporary applications for high-quality on-demand video streaming, cloud services, various social media, and emerging 5G-enabled applications. Because the data rates of the per-channel optical interfaces depend strongly on the operational speed of the optoelectronic devices used in optical transceivers, ultrahigh-speed photonic devices and components, and eventually, chip-level transmitter and receiver technologies, are essentially required to realize futuristic optical transceivers with data rates of 1 Tbps and beyond. In this paper, we review the recent progress achieved in high-speed optoelectronic devices, such as laser diodes, optical modulators, photodiodes, and the transmitter-receiver optical subassembly for optical transceivers in data centers and in metro/long-haul transmission.

Cognitive dysfunctions in individuals with diabetes mellitus

  • Kim, Hye-Geum
    • Journal of Yeungnam Medical Science
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    • 제36권3호
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    • pp.183-191
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    • 2019
  • Some patients with type 1 and type 2 diabetes mellitus (DM) present with cognitive dysfunctions. The pathophysiology underlying this complication is not well understood. Type 1 DM has been associated with a decrease in the speed of information processing, psychomotor efficiency, attention, mental flexibility, and visual perception. Longitudinal epidemiological studies of type 1 DM have indicated that chronic hyperglycemia and microvascular disease, rather than repeated severe hypoglycemia, are associated with the pathogenesis of DM-related cognitive dysfunction. However, severe hypoglycemic episodes may contribute to cognitive dysfunction in high-risk patients with DM. Type 2 DM has been associated with memory deficits, decreased psychomotor speed, and reduced frontal lobe/executive function. In type 2 DM, chronic hyperglycemia, long duration of DM, presence of vascular risk factors (e.g., hypertension and obesity), and microvascular and macrovascular complications are associated with the increased risk of developing cognitive dysfunction. The pathophysiology of cognitive dysfunction in individuals with DM include the following: (1) role of hyperglycemia, (2) role of vascular disease, (3) role of hypoglycemia, and (4) role of insulin resistance and amyloid. Recently, some investigators have proposed that type 3 DM is correlated to sporadic Alzheimer's disease. The molecular and biochemical consequences of insulin and insulin-like growth factor resistance in the brain compromise neuronal survival, energy production, gene expression, plasticity, and white matter integrity. If patients claim that their performance is worsening or if they ask about the effects of DM on functioning, screening and assessment are recommended.

A Study on Orientation and Position Control of Mobile Robot Based on Multi-Sensors Fusion for Implimentation of Smart FA (스마트팩토리 실현을 위한 다중센서기반 모바일로봇의 위치 및 자세제어에 관한 연구)

  • Dong, G.H;Kim, D.B.;Kim, H.J;Kim, S.H;Baek, Y.T;Han, S.H
    • Journal of the Korean Society of Industry Convergence
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    • 제22권2호
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    • pp.209-218
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    • 2019
  • This study proposes a new approach to Control the Orientation and position based on obstacle avoidance technology by multi sensors fusion and autonomous travelling control of mobile robot system for implimentation of Smart FA. The important focus is to control mobile robot based on by the multiple sensor module for autonomous travelling and obstacle avoidance of proposed mobile robot system, and the multiple sensor module is consit with sonar sensors, psd sensors, color recognition sensors, and position recognition sensors. Especially, it is proposed two points for the real time implementation of autonomous travelling control of mobile robot in limited manufacturing environments. One is on the development of the travelling trajectory control algorithm which obtain accurate and fast in considering any constraints. such as uncertain nonlinear dynamic effects. The other is on the real time implementation of obstacle avoidance and autonomous travelling control of mobile robot based on multiple sensors. The reliability of this study has been illustrated by the computer simulation and experiments for autonomous travelling control and obstacle avoidance.