• Title/Summary/Keyword: flow-feedback

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EasyLab : An Avatar Robot for Algorithm Education (알고리즘 교육을 위한 아바타 로봇 : EasyLab)

  • Park Young-Mok;Kim Ho-Yong;Seo Yeong-Geon
    • Journal of Digital Contents Society
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    • v.5 no.1
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    • pp.35-40
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    • 2004
  • Today`s education is in the 7th education curriculum. But, there is nothing that can be used in the classroom as a tool for education supplement. Easylab is a GUI-programing tool for students who not good at using computers. EasyLab is used in the classroom as a kind of tool to give a rise to ingenuity and creation which need at present education curriculum. When use it, first, learners think of programming-ideas, then program through icon-based software-EasyLab. After programing, the leaner can see the result directly thorough the programing code which are delivered by EasyRobot. So, leaner can study and discuss with the robot`s result. If, the result is incorrect, the robot will do a feedback as a kind of rule. One of the EasyLab`s specific property is that consisted icon-based flow-chart model. And leaner can practice with the robot that have input and output sense.

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PLL Control Method for Precise Speed Control of Slotless PM Brushless DC Motor Using 2 Hall-ICs (2 Hall-ICs를 이용한 Slotless PM Brushless DC Motor의 정밀속도제어를 위한 PLL 제어방식)

  • Yoon Y.H;Lee S.J;Kim Y.R;Won C.Y;Choe Y.Y
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.2
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    • pp.109-116
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    • 2005
  • The high performance drives of the slotless Permanent Magnet Brushless DC(PM BLDC) motor can be achieved by the current control, where the currents flow according to the rotor position and the current phase is suitably controlled according to the operational condition. Rotor position information can be provided by Hall-IC or sensorless algorithm. So, the Hall-ICs are set up in this motor to detect the main flux from the rotor. Instead of using three Hall-ICs and encoder, this paper uses only two Hall-ICs for the permanent magnet rotor position and the speed feedback signals, and uses a micro-controller of 16-bit type (80C196KC). Also because of low resolution obtained by using Hall-IC even low-cost and simple structure, to improve the wide range of speed response characteristic more exactly, we propose the rotor position signal synthesizer using PLL circuit based on two Hall-ICs.

Layer-specific serotonergic induction of long-term depression in the prefrontal cortex of rats

  • Shin, Dongchul;Cho, Kwang-Hyun;Joo, Kayoung;Rhie, Duck-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.6
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    • pp.517-527
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    • 2020
  • Layer 2/3 pyramidal neurons (L2/3 PyNs) of the cortex extend their basal dendrites near the soma and as apical dendritic tufts in layer 1, which mainly receive feedforward and feedback inputs, respectively. It is suggested that neuromodulators such as serotonin and acetylcholine may regulate the information flow between brain structures depending on the brain state. However, little is known about the dendritic compartment-specific induction of synaptic transmission in single PyNs. Here, we studied layer-specific serotonergic and cholinergic induction of long-term synaptic plasticity in L2/3 PyNs of the agranular insular cortex, a lateral component of the orbitofrontal cortex. Using FM1-43 dye unloading, we verified that local electrical stimulation to layers 1 (L1) and 3 (L3) activated axon terminals mostly located in L1 and perisomatic area (L2/3). Independent and AMPA receptor-mediated excitatory postsynaptic potential was evoked by local electrical stimulation of either L1 or L3. Application of serotonin (5-HT, 10 μM) induced activity-dependent longterm depression (LTD) in L2/3 but not in L1 inputs. LTD induced by 5-HT was blocked by the 5-HT2 receptor antagonist ketanserin, an NMDA receptor antagonist and by intracellular Ca2+ chelation. The 5-HT2 receptor agonist α-me-5-HT mimicked the LTD induced by 5-HT. However, the application of carbachol induced muscarinic receptor-dependent LTD in both inputs. The differential layer-specific induction of LTD by neuromodulators might play an important role in information processing mechanism of the prefrontal cortex.

A Development of Query-Answer Learning Tool based on LTSA (LTSA 기반의 질의 응답 학습 도구 개발)

  • Kim, Haeng-Kon;Kim, Jung-Soo
    • The KIPS Transactions:PartA
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    • v.10A no.3
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    • pp.269-278
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    • 2003
  • The popularity of the web based education has come the need for variety learning methods and for business to exploit the web not only for interoperability but also standardization. This way of standardization has come to researched for environments, contents and practical uses in ISO. The IEEE has special]y established five technical classes for LTSA which provide advanced e-learning environments. Feedback functions would not be supported and specified in standardization for Query Answer on LTSA. In this paper, we describe the query and answer model which we have developed on layer three of LTSA. We develop the redefined model for transforming data flow oriented into object or component based model. We have developed the Query Answer Metadata (QAM) based on Learning Object Metadata (LOM). We design and showed thing a prototyping implementation the Query Answer Learning Tool (QALT). We have used the QALT to address the problem of efficiency of web based education. We also used it to develop the related tools with quality and productivity.

Adaptive V1-MT model for motion perception

  • Li, Shuai;Fan, Xiaoguang;Xu, Yuelei;Huang, Jinke
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.1
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    • pp.371-384
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    • 2019
  • Motion perception has been tremendously improved in neuroscience and computer vision. The baseline motion perception model is mediated by the dorsal visual pathway involving the cortex areas the primary visual cortex (V1) and the middle temporal (V5 or MT) visual area. However, few works have been done on the extension of neural models to improve the efficacy and robustness of motion perception of real sequences. To overcome shortcomings in situations, such as varying illumination and large displacement, an adaptive V1-MT motion perception (Ad-V1MTMP) algorithm enriched to deal with real sequences is proposed and analyzed. First, the total variation semi-norm model based on Gabor functions (TV-Gabor) for structure-texture decomposition is performed to manage the illumination and color changes. And then, we study the impact of image local context, which is processed in extra-striate visual areas II (V2), on spatial motion integration by MT neurons, and propose a V1-V2 method to extract the image contrast information at a given location. Furthermore, we take feedback inputs from V2 into account during the polling stage. To use the algorithm on natural scenes, finally, multi-scale approach has been used to handle the frequency range, and adaptive pyramidal decomposition and decomposed spatio-temporal filters have been used to diminish computational cost. Theoretical analysis and experimental results suggest the new Ad-V1MTMP algorithm which mimics human primary motion pathway has universal, effective and robust performance.

The effect of acute diaphragmatic breathing exercise using DiP Belt on diaphragm motion and forced vital capacity (딥벨트를 이용한 일회성 가로막 호흡운동이 가로막 움직임과 노력성 폐활량에 미치는 영향)

  • Lee, Jae Seok;Kang, Tae Wook
    • Journal of Korean Physical Therapy Science
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    • v.29 no.2
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    • pp.57-65
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    • 2022
  • Background: This study was to determine whether the diaphragmatic breathing exercise using a DiP Belt(Diaphragmatic Pressure Belt) is effective in increasing the diaphragmatic motion and forced vital capacity. Design: Pretest-Posttest design. Methods: A total of 44 subjects(15 male, 29 female) participated in this study. All subjects were measured the diaphragmatic motion with a sonography and the Forced Vital Capacity(FVC) was measured with a digital spirometer. After 4 weeks, the subjects were intervened the diaphragmatic breathing exercise using a DiP belt and were remeasured for diaphragm motion and FVC. Results: After exercise intervention, quiet breathing significantly increased with the change in diaphragmatic motion and showed a moderate effect size (p<.01, Cohen's d = -0.53). In addition, it was significantly increased in deep breathing and showed a high effect size (p<.001, Cohen's d = -1.32). The mean diaphragmatic contraction pressure increased, but there was no significant difference and the peak diaphragmatic contraction pressure increased significantly (p<.05). Both diaphragmatic contraction pressure showed small effect sizes (respectively Cohen's d = -0.28, -0.33). In spirometry, FVC, Forced Expiratory Volume in 1 second (FEV1), and FEV1/FVC% all increased, but there was no significant difference. Only peak expiratory flow increased significantly and showed a small effect size (p<.05, Cohen's d = -0.41). Conclusion: The DiP belt diaphragmatic breathing exercise that the principle of visual feedback can correct diaphragm breathing in a short time, so it is a useful breathing exercise device that can help the diaphragm breathing exercise in the right way in clinical practice.

EFFECT OF INSTRUMENT COMPLIANCE ON THE POLYMERIZATION SHRINKAGE STRESS MEASUREMENTS OF DENTAL RESIN COMPOSITES (측정장치의 compliance 유무가 복합레진의 중합수축음력의 측정에 미치는 영향)

  • Seo, Deog-Gyu;Min, Sun-Hong;Lee, In-Bog
    • Restorative Dentistry and Endodontics
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    • v.34 no.2
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    • pp.145-153
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    • 2009
  • The purpose of this study was to evaluate the effect of instrument compliance on the polymerization shrinkage stress measurements of dental composites. The contraction strain and stress of composites during light curing were measured by a custom made stress-strain analyzer, which consisted of a displacement sensor, a cantilever load cell and a negative feedback mechanism. The instrument can measure the polymerization stress by two modes: with compliance mode in which the instrument compliance is allowed, or without compliance mode in which the instrument compliance is not allowed. A flowable (Filtek Flow: FF) and two universal hybrid (Z100: Z1 and Z250: Z2) composites were studied. A silane treated metal rod with a diameter of 3.0 mm was fixed at free end of the load cell, and other metal rod was fixed on the base plate. Composite of 1.0 mm thickness was placed between the two rods and light cured. The axial shrinkage strain and stress of the composite were recorded for 10 minutes during polymerization. and the tensile modulus of the materials was also determined with the instrument. The statistical analysis was conducted by ANOVA. paired t-test and Tukey's test (${\alpha}<0.05$). There were significant differences between the two measurement modes and among materials. With compliance mode, the contraction stress of FF was the highest: 3.11 (0.13). followed by Z1: 2.91 (0.10) and Z2: 1.94 (0.09) MPa. When the instrument compliance is not allowed, the contraction stress of Z1 was the highest: 17.08 (0.89), followed by FF: 10.11 (0.29) and Z2: 9.46 (1.63) MPa. The tensile modulus for Z1, Z2 and FF was 2.31 (0.18), 2.05 (0.20), 1.41 (0.11) GPa, respectively. With compliance mode. the measured stress correlated with the axial shrinkage strain of composite: while without compliance the elastic modulus of materials played a significant role in the stress measurement.

Porewater Pressure Buildup Mode Induced in Near-field of Open-ended Pipe Pile during Earthquake and Sequake (지진과 해진시 개단강관말뚝 주변에 유발된 간극수압의 발생 양상)

  • 최용규
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.4
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    • pp.23-30
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    • 1998
  • During an earthquake, there are three components of excitation : horizontal excitation of the ground, vertical excitation of the pile due to superstructure feedback produced by vertical excitation of the ground, and the seawater excitation by the vertical ground shaking, that is, "the seaquake." These excitations could have effects on the pore pressure buildup mode induced in the near-field of open-ended pile and the soil plugs in open-ended pipe piles installed at offshore sites. While the ground and pile excitation could be modeled by exciting the soil and pile with simulated motions, seaquake excitation induced by the vertical ground shaking can be modeled by pulsing the water pressure at the seabed. The objectives of this study were to observe buildup trend for the porewater pressures developed in near-field of open-ended pipe pile installed in the calibration chamber during the simulated earthquake and seaquake and, also to confirm the cause for reduction of soil plugging according to pore pressure buildup. During the simulated horizontal seismic motion, there was no upward flow through soil plug because the similar magnitude of excess porewater pressure were occurred at the top and under the toe of soil plug. During the horizontal seismic motion, relatively higher hydraulic gradients caused upward flow in the soil plug and then the degradation of plugging resistance was about 20%. During seaquake, in the case of the open-ended pile installed in a deep sea with more than 220m of water depth, soil plug failed completely because of high upward hydraulic gradients through soil plug.soil plug.

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An Algorithm for Real-Traffic Signal Control at An Isolated-Intersection (실시간 신호제어알고리즘 개발에 관한 연구)

  • Shin, Eon-Kyo;Kim, Young-Chan;Lee, Jong-Man
    • Journal of Korean Society of Transportation
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    • v.22 no.7 s.78
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    • pp.161-167
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    • 2004
  • While most or fixed-time control systems such as UTCS produce the signal timing plans that either maximizing bandwidth or minimizing a disutility index of delay and stops, cannot consider the fluctuation of traffic flow. One category of the traffic-response control systems, which make small changes on a predefined signal plan such as SCOOT, cannot be easily modified for feedback real-time control schemes based on observation of variables other than traffic flow. The other category, which decide to whether switch the traffic lights or not at each step of time as in PRODYN, does not adequately consider the relations between traffic flows and traffic lights at each step of time. In this paper we present a complete formulation that adequately consider the relations between traffic flows and traffic lights at each step of time. The formulation is a binary mixed integer linear programing (BMILP) that obtain traffic lights at each step for minimizing delay. Since numarical examples for application of the proposed model illustrated that the model adequately produced dynamic traffic signal plans minimizing delay at each step, the model may be expected to contribute to advanced transportation management systems (ATMS) for dynamic traffic signal control.

A Integrated Model of Land/Transportation System

  • 이상용
    • Proceedings of the KOR-KST Conference
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    • 1995.12a
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    • pp.45-73
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    • 1995
  • The current paper presents a system dynamics model which can generate the land use anq transportation system performance simultaneously is proposed. The model system consists of 7 submodels (population, migration of population, household, job growth-employment-land availability, housing development, travel demand, and traffic congestion level), and each of them is designed based on the causality functions and feedback loop structure between a large number of physical, socio-economic, and policy variables. The important advantages of the system dynamics model are as follows. First, the model can address the complex interactions between land use and transportation system performance dynamically. Therefore, it can be an effective tool for evaluating the time-by-time effect of a policy over time horizons. Secondly, the system dynamics model is not relied on the assumption of equilibrium state of urban systems as in conventional models since it determines the state of model components directly through dynamic system simulation. Thirdly, the system dynamics model is very flexible in reflecting new features, such as a policy, a new phenomenon which has not existed in the past, a special event, or a useful concept from other methodology, since it consists of a lots of separated equations. In Chapter I, II, and III, overall approach and structure of the model system are discussed with causal-loop diagrams and major equations. In Chapter V _, the performance of the developed model is applied to the analysis of the impact of highway capacity expansion on land use for the area of Montgomery County, MD. The year-by-year impacts of highway capacity expansion on congestion level and land use are analyzed with some possible scenarios for the highway capacity expansion. This is a first comprehensive attempt to use dynamic system simulation modeling in simultaneous treatment of land use and transportation system interactions. The model structure is not very elaborate mainly due to the problem of the availability of behavioral data, but the model performance results indicate that the proposed approach can be a promising one in dealing comprehensively with complicated urban land use/transportation system.

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