• Title/Summary/Keyword: adaptive changes

Search Result 684, Processing Time 0.032 seconds

Neuro-fuzzy and artificial neural networks modeling of uniform temperature effects of symmetric parabolic haunched beams

  • Yuksel, S. Bahadir;Yarar, Alpaslan
    • Structural Engineering and Mechanics
    • /
    • v.56 no.5
    • /
    • pp.787-796
    • /
    • 2015
  • When the temperature of a structure varies, there is a tendency to produce changes in the shape of the structure. The resulting actions may be of considerable importance in the analysis of the structures having non-prismatic members. The computation of design forces for the non-prismatic beams having symmetrical parabolic haunches (NBSPH) is fairly difficult because of the parabolic change of the cross section. Due to their non-prismatic geometrical configuration, their assessment, particularly the computation of fixed-end horizontal forces and fixed-end moments becomes a complex problem. In this study, the efficiency of the Artificial Neural Networks (ANN) and Adaptive Neuro Fuzzy Inference Systems (ANFIS) in predicting the design forces and the design moments of the NBSPH due to temperature changes was investigated. Previously obtained finite element analyses results in the literature were used to train and test the ANN and ANFIS models. The performances of the different models were evaluated by comparing the corresponding values of mean squared errors (MSE) and decisive coefficients ($R^2$). In addition to this, the comparison of ANN and ANFIS with traditional methods was made by setting up Linear-regression (LR) model.

Adaptive Fuzzy Logic Control Using a Predictive Neural Network (예측 신경망을 이용한 적응 퍼지 논리 제어)

  • 정성훈
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.7 no.5
    • /
    • pp.46-50
    • /
    • 1997
  • In fuzzy logic control, static fuzzy rules cannot cope with significant changes of parameters of plants or environment. To solve this prohlem, self-organizing fuzzy control. neural-network-hased fuzzy logic control and so on have heen introduced so far. However, dynamically changed fuzzy rules of these schemes may make a fuzzy logic controller Fall into dangerous situations because the changed fuzzy rules may he incomplete or inconsistent. This paper proposes a new adaptive filzzy logic control scheme using a predictivc neural network. Although some parameters of a controlled plant or environment are changed, proposed fuzzy logic controller changes its decision outputs adaptively and robustly using unchanged initial fuzzy rules and the predictive errors generated hy the predictive neural network by on-line learning. Experimental results with a D<' servo-motor position control problem show that propnsed cnntrol scheme is very useful in the viewpoint of adaptability.

  • PDF

Analysis of Mobile System using Adaptive Modulation Method by Channel Forecast (채널예측에 의한 적응변조방식을 이용한 모바일 시스템 분석)

  • Lee, Myung-Soo;Cho, Dae-Jea
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.12 no.2
    • /
    • pp.895-900
    • /
    • 2011
  • To improve drawback of existing modulation method, in this paper, we propose the channel forecast method using adaptive modulation which can improve throughput of channel. This method adaptively changes modulation method to the change of channel environments. In proposed method, channel's characteristics are measured in realtime to determine code rate to the changes of demanded channel's bit error rate. If bit error rate is increased, this method reduce code rate to maintain maximum throughput. We analysis performance of proposed method by Matlab.

Density Change Adaptive Congestive Scene Recognition Network

  • Jun-Hee Kim;Dae-Seok Lee;Suk-Ho Lee
    • International journal of advanced smart convergence
    • /
    • v.12 no.4
    • /
    • pp.147-153
    • /
    • 2023
  • In recent times, an absence of effective crowd management has led to numerous stampede incidents in crowded places. A crucial component for enhancing on-site crowd management effectiveness is the utilization of crowd counting technology. Current approaches to analyzing congested scenes have evolved beyond simple crowd counting, which outputs the number of people in the targeted image to a density map. This development aligns with the demands of real-life applications, as the same number of people can exhibit vastly different crowd distributions. Therefore, solely counting the number of crowds is no longer sufficient. CSRNet stands out as one representative method within this advanced category of approaches. In this paper, we propose a crowd counting network which is adaptive to the change in the density of people in the scene, addressing the performance degradation issue observed in the existing CSRNet(Congested Scene Recognition Network) when there are changes in density. To overcome the weakness of the CSRNet, we introduce a system that takes input from the image's information and adjusts the output of CSRNet based on the features extracted from the image. This aims to improve the algorithm's adaptability to changes in density, supplementing the shortcomings identified in the original CSRNet.

Adaptive Mission Control Architecture with Flexible Levels of Autonomy (유연한 자율화 수준의 적응형 임무통제 아키텍처)

  • Wonik Park;Hojoo Lee;Joonsung Choi;Tokson Choe;Chonghui Kim
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.27 no.2
    • /
    • pp.265-276
    • /
    • 2024
  • The future battlefield operation concept does not focus on advanced and complete weapon systems, but requires a new battlefield operation concept that can effectively demonstrate offensive power by combining a large number of low-cost, miniaturized weapons. Recently, research on the autonomous application of major technologies that make up the mission control system is actively underway. However, since the mission control system is still dependent on the operator's operating ability when operating multiple robots, there are limitations to simply applying the automation technology of the existing mission control system. Therefore, we understand how changes in operator capabilities affect multi-robot operation and propose an adaptive mission control architecture design method that supports multi-robot integrated operation by adjusting the level of autonomy of the mission control system according to changes in operator capability.

Types and Changes in Adjustment Patterns to Childcare Centers Based on Infants' and Toddlers' Temperaments: A Latent Profile Analysis (영아의 기질에 따른 어린이집 적응의 유형 및 전이 양상: 잠재프로파일분석을 이용하여)

  • Seolhui Park;Nary Shin
    • Korean Journal of Childcare and Education
    • /
    • v.20 no.4
    • /
    • pp.35-58
    • /
    • 2024
  • Objective: The objectives of this research are to identify how infants and toddlers adjust to childcare at the beginning of the semester and to explore the effects of their temperament on this adjustment. Methods: Two surveys were conducted with 315 mothers and 134 teachers of infants and toddlers. Data from two rounds of teacher-reported assessments on infants' and toddlers' adjustment to childcare were analyzed using latent profile analysis(LPA) to examine change patterns and influencing factors. Results: Three types of adjustment to childcare were identified at the beginning of the semester, and two types were identified in the late middle. As the semester progressed, the most common transition was from the intial adaptive type to the later adaptive group. Children's temperament partially influenced the changes in adjustment patterns among infants and toddlers in childcare centers. Conclusion/Implications: The results of this study indicate that it may be beneficial to take children's temperaments into account when developing orientation programs with the aim of enhancing their adjustment to childcare.

On discrete nonlinear self-tuning control

  • Mohler, R.-R.;Rajkumar, V.;Zakrzewski, R.-R.
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1991.10b
    • /
    • pp.1659-1663
    • /
    • 1991
  • A new control design methodology is presented here which is based on a nonlinear time-series reference model. It is indicated by highly nonlinear simulations that such designs successfully stabilize troublesome aircraft maneuvers undergoing large changes in angle of attack as well as large electric power transients due to line faults. In both applications, the nonlinear controller was significantly better than the corresponding linear adaptive controller. For the electric power network, a flexible a.c. transmission system (FACTS) with series capacitor power feedback control is studied. A bilinear auto-regressive moving average (BARMA) reference model is identified from system data and the feedback control manipulated according to a desired reference state. The control is optimized according to a predictive one-step quadratic performance index (J). A similar algorithm is derived for control of rapid changes in aircraft angle of attack over a normally unstable flight regime. In the latter case, however, a generalization of a bilinear time-series model reference includes quadratic and cubic terms in angle of attack. These applications are typical of the numerous plants for which nonlinear adaptive control has the potential to provide significant performance improvements. For aircraft control, significant maneuverability gains can provide safer transportation under large windshear disturbances as well as tactical advantages. For FACTS, there is the potential for significant increase in admissible electric power transmission over available transmission lines along with energy conservation. Electric power systems are inherently nonlinear for significant transient variations from synchronism such as may result for large fault disturbances. In such cases, traditional linear controllers may not stabilize the swing (in rotor angle) without inefficient energy wasting strategies to shed loads, etc. Fortunately, the advent of power electronics (e.g., high-speed thyristors) admits the possibility of adaptive control by means of FACTS. Line admittance manipulation seems to be an effective means to achieve stabilization and high efficiency for such FACTS. This results in parametric (or multiplicative) control of a highly nonlinear plant.

  • PDF

A Study on the Hereafter Development in Universal Design Surveyed on the Case Studies of Kitchen Design (부엌디자인 사례연구를 중심으로 살펴본 유니버설디자인의 전개방향에 관한 연구)

  • Choi, Eun-Hee
    • Archives of design research
    • /
    • v.18 no.1 s.59
    • /
    • pp.81-90
    • /
    • 2005
  • Universal Design is comprised of three main concepts known as barrier-free, adaptive and life-span design. It does not focus on accessibility for the disabled, but rather expands its breadth to the comfortable use and easy access in ail physical environments and facilities. In this study, the researcher views the present and future of universal design through the cases of kitchen design. Based on the market changes in design guidelines and the changes of time uncovered from past studies, this researcher suggests that universal design would develop through mass customization for personalized use, application of new technology and consideration of psychological aspects. Additionally, for the diffusion of universal design appropriate solution in economic cost problem, social recognition and conversion of problem cognizance in designing is needed. In Korea design models of universal design concepts are not yet in production over various fields. In order to develop and study universal design which suits our country, cultural and regional characteristics should be considered as well as physical, perceptual, psychological aspects.

  • PDF

Adaptive Framework for Designing R&D Project Management Process Using Cloud Computing Technology (클라우드 컴퓨팅 기술을 활용한 적응형 연구개발 프로젝트 관리 프로세스 설계 프레임워크)

  • Shin, Kwang-Sup
    • The Journal of Society for e-Business Studies
    • /
    • v.18 no.4
    • /
    • pp.25-43
    • /
    • 2013
  • Two of the most important changes in the global market can be represented with Hyper-connection and Glocalization. To cope with these changes and secure the competitive advantages, it is essential to develop the standard organization, policy, processes and criteria for service management. In addition, the service management system is required to effectively support the R&D project management. In this research, an adaptive framework and system architecture for designing R&D project management process using cloud computing has been introduced. With the proposed system, it is able to overcome the limitations of traditional service management and treat the demand from the market in agility. Moreover, it may be possible to present more value than customers want and secure the competitive advantages in the global market with the proposed system.

An Adaptive Analysis in the Element-free Galerkin Method Using Bubble Meshing Technique (Bubble Mesh기법을 이용한 적응적 EFG해석)

  • 정흥진;이계희;최창근
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.15 no.1
    • /
    • pp.85-94
    • /
    • 2002
  • In this study an adaptive node generation procedure in the Element-free Galerkin (EFG) method using bubble-meshing technique is Proposed. Since we construct the initial configuration of nodes by subdivision of background cell, abrupt changes of inter-nodal distance between higher and lower error regions are unavoidable. This unpreferable nodal spacing induces additional errors. To obtain the smooth nodal configuration the nodal configurations are regenerated by bubble-meshing technique. This bubble meshing technique was originally developed to generate a set of well-shaped triangles and tetrahedra. In odder to evaluate the effect of abrupt changes of nodal spacing, one-dimensional problems with various nodal configurations mere investigated. To demonstrate the performance of proposed scheme, the sequences of making optimal nodal configuration with bubble meshing technique are investigated for several problems.