• Title/Summary/Keyword: adaptive changes

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Performance Analysis of Adaptive Extended Kalman Filter in Tracking Radar (추적 레이더에서 적응형 확장 칼만 필터의 성능 분석)

  • Song, Seungeon;Shin, Han-Seop;Kim, Dae-Oh;Ko, Seokjun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.4
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    • pp.223-229
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    • 2017
  • An angle error is a factor obstructing to track accurate position in tracking radars. And the noise incurring the angle error can be divided as follows; thermal noise and glint. In general, Extended Kalman filter used in tracking radars is designed with considering thermal noise only. The Extended Klaman filter uses a fixed measurement error covariance when updating an estimate state by using ahead state and measurement. But, a noise power varies according to the range. Therefore we purposes the adaptive Kalman filter which changes the measurement noise covariance according to the range. In this paper, we compare the performance of the Extended Kalman filter and the proposed adaptive Kalman filter by considering KSLV-I (Korean Satellite Launch Vehicles).

A Design of Fuzzy Controllers of HVDC System Using Adaptive Evolutionary Algorithm (적응진화알고리즘을 이용한 HVDC 계통의 퍼지제어기 설계)

  • Choi, Jae-Kon;Hwang, Gi-Hyun;Park, Je-Young; Park, June-Ho
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.160-162
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    • 1999
  • This paper presents an optimal design method for fuzzy controllers of HVDC system using adaptive evolutionary algorithm(AEA). We have proposed an adaptive evolutionary algorithm which uses a genetic algorithm and an evolution strategy in an adaptive manner in order to take merits of two different evolutionary computations. AEA is used for tuning fuzzy membership functions, scaling constants and PD gains. The simulation results show that the disturbances are well damped by both controllers and the dynamic performances of fuzzy controllers have better responses than those of PD controllers when mechanical torque changes suddenly.

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Effective Reconstruction of Stereoscopic Image Pair by using Regularized Adaptive Window Matching Algorithm

  • Ko, Jung-Hwan;Lee, Sang-Tae;Kim, Eun-Soo
    • Journal of Information Display
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    • v.5 no.4
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    • pp.31-37
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    • 2004
  • In this paper, an effective method for reconstruction of stereoscopic image pair through the regularized adaptive disparity estimation is proposed. Although the conventional adaptive disparity window matching can sharply improve the PSNR of a reconstructed stereo image, but there still exist some problems of overlapping between the matching windows and disallocation of the matching windows, because the size of the matching window tend to changes adaptively in accordance with the magnitude of the feature values. In the proposed method, the problems relating to the conventional adaptive disparity estimation scheme can be solved and the predicted stereo image can be more effectively reconstructed by regularizing the extimated disparity vector with the neighboring disparity vectors. From the experimental results, it is found that the proposed algorithm show improvements the PSNR of the reconstructed right image by about 2.36${\sim}$2.76 dB, on average, compared with that of conventional algorithms.

Activity-dependent plasticity in skeletal muscle (골격근의 활동 의존적 가소성)

  • Kim, Sik-Hyun
    • PNF and Movement
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    • v.6 no.1
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    • pp.41-51
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    • 2008
  • Purpose : This paper reviews evidence supporting adaptive plasticity in skeletal muscle fibers induced by various exercise training and neuromuscular activity. Result : Skeletal muscle fiber demonstrates a remarkable adaptability and can adjust its physiologic and contractile makeup in response to alterations in functional demands. This adaptive plasticity results from the ability of muscle fibers to adjust their molecular, functional, and contractile properties in response to altered physiological demands, such as changes in exercise patterns and mechanical loading. The process of activity-dependent plasticity in skeletal muscle involves a multitude of signalling mechanisms initiating replication of specific genetic sequences, enabling subsequent translation of the genetic message and ultimately generating a series of myosin heavy chain isoform. Conclusions : Knowledge of the mechanisms and interaction of activity-dependent adaptive pathways in skeletal muscle is important for our understanding of the synthesis of muscle myosin protein, maintenance of metabolic and functional capacity with physical activity, and therapeutic intervention for functional improvement.

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Nonlinear structural modeling using multivariate adaptive regression splines

  • Zhang, Wengang;Goh, A.T.C.
    • Computers and Concrete
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    • v.16 no.4
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    • pp.569-585
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    • 2015
  • Various computational tools are available for modeling highly nonlinear structural engineering problems that lack a precise analytical theory or understanding of the phenomena involved. This paper adopts a fairly simple nonparametric adaptive regression algorithm known as multivariate adaptive regression splines (MARS) to model the nonlinear interactions between variables. The MARS method makes no specific assumptions about the underlying functional relationship between the input variables and the response. Details of MARS methodology and its associated procedures are introduced first, followed by a number of examples including three practical structural engineering problems. These examples indicate that accuracy of the MARS prediction approach. Additionally, MARS is able to assess the relative importance of the designed variables. As MARS explicitly defines the intervals for the input variables, the model enables engineers to have an insight and understanding of where significant changes in the data may occur. An example is also presented to demonstrate how the MARS developed model can be used to carry out structural reliability analysis.

Adaptive Linear Predictive Coding of Time-varying Images Using Multidimensional Recursive Least-squares Ladder Filters

  • Nam Man K.;Kim Woo Y.
    • Journal of the military operations research society of Korea
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    • v.13 no.1
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    • pp.1-18
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    • 1987
  • This paper presents several adaptive linear predictive coding techniques based upon extension of recursive ladder filters. A 2-D recursive ladder filter is extended to a 3-D case which can adaptively track the variation of both spatial and temporal changes of moving images. Using the 2-D/3-D ladder filter and a previous farme predictor, two types of adaptive predictor-control schemes are proposed in which the prediction error at each pel can be obtained at or close to a minimum level. We also investigate several modifications of the basic encoding methods. Performance of the 2-D/3-D ladder filters, their adaptive control schemes, and variations in coding methods are evaluated by computer simulations on a real sequence and compared to the results of motion compensation and frame differential coders. As a validity test of the ladder filters developed, the error signals for the different predictors are compared and evaluated.

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A Study on the Space Reconstitution Reflecting the Characteristics of Adaptive Reuse: Focusing on High-rise Building Regeneration as a Complex Cultural Space

  • Myung-Sik Lee;Dong Hyuk Son
    • International Journal of High-Rise Buildings
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    • v.13 no.1
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    • pp.69-83
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    • 2024
  • In this study, we focused on 'Adaptive Reuse', which has the concepts of space reconstitution and social and cultural regeneration, so that previously constructed highrise buildings can accommodate various changes in modern society, and new spatial design was developed based on the characteristics of adaptive reuse. We sought to present the concept and direction, detailed strategies, and architectural response elements of space reconstitution for the purpose of realizing the typical spatial reorganization required by modern society and seeking directions and methods of space reconstitution that can be applied to future society. The purpose is to do so.

Requirements Elicitation and Specification Method for the Development of Adaptive User Interface (적응형 사용자 인터페이스 개발을 위한 요구사항 도출 및 명세 기법)

  • Park, Kibeom;Lee, Seok-Won
    • Journal of KIISE
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    • v.44 no.1
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    • pp.27-35
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    • 2017
  • Many studies have addressed 'Adaptive User Interface (AUI)', wherein the user interface changes in accordance with the situation and the environment of each user at runtime. Nevertheless, previous papers for AUI barely reflected the viewpoints from requirements engineering field, since most of them focused on proposing the architecture and design. In this study, we outline AUI with the perspective of requirements engineering and propose the requirements elicitation and specification method based on concepts which have been researched in the area of self-adaptive system. Step by step, we first redefine and reinterpret the well-known concepts of self-adaptive software, after which the AUI requirements are elicited and specified. Finally, we illustrate a case study, which demonstrates the effectiveness of our method.

A Study on The Adaptive Control of the Rotational Systems by Means of the Normal Model Tracking Method (규범모델 추종방식에 의한 회전계통의 적응속도제어에 관한 연구)

  • 하주식;송문현
    • Journal of Advanced Marine Engineering and Technology
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    • v.19 no.3
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    • pp.77-83
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    • 1995
  • Recently, in the field of industrial servo-systems, several methods have been proposed for tracking the reference input fastly and finely without overshoot. These methods, however, are established under hypothesis that structure and parameters of the plant are known accurately and they are time invariant. In practice, it is difficult to obtain the values of plant's parameters accurately and usually plants change with time and operation conditions. In this paper a method to construct the nominal model tracking adaptive control system is proposed. The system is composed of the nomial model which produces a ideal response and the model tracking system with the fuzzy adaptive controller. If the actual plant is equal to the controlled object in the nominal model, the output of the plant is the same as that of the nominal model and the fuzzy adaptive controller becomes idle. However, when the plant changes, the fuzzy adaptive controller of the tracking system operates in order for the output of the plant to track the ideal response. Through the computer simulations under various conditions, it is confirmed that the proposed model tracking system is very effective.

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Adaptive Management of Water Supply Systems to Deal with Climate Changes: A Gwangdong Dam Case Study (기후 변화 대응을 위한 상수도 시설 적응형 관리의 필요성: 2008-2009 광동댐 취수 제한 사례 연구)

  • Lee, Sangeun;Choi, Dongjin;Park, Heekyung
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.5
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    • pp.583-598
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    • 2009
  • From the engineering standpoint, this study puts a special emphasis on application of adaptive management. To do this, we analyze the recent issue about water scarcity of the Gwangdong dam. Using the system dynamics model, we defined the system including water balance in the dam, dam manager's operation rules, regional water supply and local water distribution, and customer damage. It was expected that the model is useful to explain the real case, and also water scarcity of Gwangdong led to total damage of about 2.56 billion won, mainly to customers in the Taebaeck city. Two adaptive management options (i.e., optimal allocation of limited water resources, and early control of dam storage) were applied to the model in order to examine whether adaptive management is effective to mitigate the damage, it is concluded that the case study could largely reduce or entirely avoid the damage with adaptive engineering options.