• Title/Summary/Keyword: target model update

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Damage Detection Using Finite Element Model Updating (유한요소 모델 개선기법을 이용한 손상추정)

  • Min, Cheon-Hong;Choi, Jong-Su;Hong, Sup;Kim, Hyung-Woo;Yeu, Tae-Kyeong
    • Journal of Ocean Engineering and Technology
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    • v.26 no.5
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    • pp.11-17
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    • 2012
  • In this study, a damage detection method that uses sensitivity-based finite (FE) element model updating with the natural frequency and zero frequency was proposed. The stiffness matrix for a structure was modified using the sensitivity-based FE model updating method. A sensitivity analysis was used to update the FE model, and the natural frequencies and zero frequencies were considered as target parameters to supplement the information on the vibration characteristics. The locations and values of the damages were estimated from the modified stiffness matrix. Several numerical examples were considered to verify the performance of the proposed method.

Design of a Variable Sampling Rate Tracking Filter for a Phased Array Radar (위상배열 레이다를 위한 가변 표본화 빈도 추적 필터의 설계)

  • Hong, Sun-Mog
    • Journal of Sensor Science and Technology
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    • v.1 no.2
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    • pp.155-163
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    • 1992
  • The phased array antenna has the ability to perform adaptive sampling by directing the radar beam without inertia in any direction. The adaptive sampling capability of the phased array antenna allows each sampling time interval to be varied for each target, depending on the acceleration of each target at any time. In this paper we design a three-dimensional adaptive tracking algorithm for the phased array radar system with a given set of measurement parameters. The tracking algorithm avoids taking unnecessarily frequent samples, while keeping the angular prediction error within a fraction of antenna beamwidth so that the probability of detection will not be degraded during a track update illuminations. In our algorithm, the target model and the sampling rate are selected depending on the target range and the target maneuver status which is determined by a maneuver detector. A detailed simulation is conducted to test the validity of our tracking algorithm for encounter geometries under various conditions of maneuver.

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Data Dissemination Protocol Considering Target Mobility in Ubiquitous Sensor Network (유비쿼터스 센서 네트워크 환경에서 감지대상의 이동성을 고려한 데이터 전달 프로토콜)

  • Suh Yu-Hwa;Kim Ki-Young;Shin Young-Tae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3A
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    • pp.311-320
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    • 2006
  • This paper proposes DDTM for USN having end-point mobility. The existing network protocols did not consider target's and sink's mobility. So it requires flooding and path update whenever targets or sinks move. This can lead to drain battery of sensors excessively and decrease lifetime of USN. DDTM is the protocol based on TTDD considering sink's mobility. TTDD provides sink's mobility efficiently by using the grid structure, but it requires the high energy because of reconstructing the grid structure whenever targets move. In this way, the proposed protocol can decrease a consumption of energy, since it reuses the existing grid structure of TTDD, if the target moves in local cell. We compare DDTM with TTDD under the total message and the energy consumption by using a discrete analytical model for cost analysis. Analytical results demonstrated that our proposed protocol can provide the higher efficiency on target's mobility.

A New Intelligent Tracking Algorithm Using Fuzzy Kalman Filter (퍼지 칼만 필터를 이용한 새로운 지능형 추적 알고리즘)

  • Noh Sun-Young;Joo Young-Hoon;Park Jin-Bae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.5
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    • pp.593-598
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    • 2005
  • The standard Kalman filter has been used to estimate the states of the target, but in the presence of a maneuver, its error is occurred and performance may be seriously degraded. To solve this problem, this paper presents a new intelligent tracking algorithm using the fuzzy Kalman filter. In this algorithm, the unknown acceleration is regarded as an additive process noise by using the fuzzy logic based on genetic algorithm(GA) method. And then, the modified filter is corrected by the new update equation method which is a fuzzy system using the relation between the filter residual and its variation. To shows the feasibility of the suggested method with only one filter, the computer simulations system are provided, this method is compared with multiple model method.

Therapeutic applications of gene editing in chronic liver diseases: an update

  • Shin, Ji Hyun;Lee, Jinho;Jung, Yun Kyung;Kim, Kyeong Sik;Jeong, Jaemin;Choi, Dongho
    • BMB Reports
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    • v.55 no.6
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    • pp.251-258
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    • 2022
  • Innovative genome editing techniques developed in recent decades have revolutionized the biomedical research field. Liver is the most favored target organ for genome editing owing to its ability to regenerate. The regenerative capacity of the liver enables ex vivo gene editing in which the mutated gene in hepatocytes isolated from the animal model of genetic disease is repaired. The edited hepatocytes are injected back into the animal to mitigate the disease. Furthermore, the liver is considered as the easiest target organ for gene editing as it absorbs almost all foreign molecules. The mRNA vaccines, which have been developed to manage the COVID-19 pandemic, have provided a novel gene editing strategy using Cas mRNA. A single injection of gene editing components with Cas mRNA is reported to be efficient in the treatment of patients with genetic liver diseases. In this review, we first discuss previously reported gene editing tools and cases managed using them, as well as liver diseases caused by genetic mutations. Next, we summarize the recent successes of ex vivo and in vivo gene editing approaches in ameliorating liver diseases in animals and humans.

A New Design of Fuzzy Neural Networks Using Data Information (데이터 정보를 이용한 퍼지 뉴럴 네트워크의 새로운 설계)

  • Park, Keon-Jun;Oh, Sung-Kwun;Kim, Hyun-Ki
    • Proceedings of the KIEE Conference
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    • 2006.04a
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    • pp.273-275
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    • 2006
  • In this paper, we introduce a new design of fuzzy neural networks using input-output data information of target system. The proposed fuzzy neural networks is constructed by input-output data information and used the center of data distance by HCM clustering to obtain the characteristics of data. A membership function is defined by HCM clustering and is applied input-output dat included each rule to conclusion polynomial functions. We use triangular membership functions and simplified fuzzy inference, linear fuzzy inference, and modified quadratic fuzzy inference in conclusion. In the networks learning, back propagation algorithm of network is used to update the parameters of the network. The proposed model is evaluated with benchmark data.

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POSE-VIWEPOINT ADAPTIVE OBJECT TRACKING VIA ONLINE LEARNING APPROACH

  • Mariappan, Vinayagam;Kim, Hyung-O;Lee, Minwoo;Cho, Juphil;Cha, Jaesang
    • International journal of advanced smart convergence
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    • v.4 no.2
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    • pp.20-28
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    • 2015
  • In this paper, we propose an effective tracking algorithm with an appearance model based on features extracted from a video frame with posture variation and camera view point adaptation by employing the non-adaptive random projections that preserve the structure of the image feature space of objects. The existing online tracking algorithms update models with features from recent video frames and the numerous issues remain to be addressed despite on the improvement in tracking. The data-dependent adaptive appearance models often encounter the drift problems because the online algorithms does not get the required amount of data for online learning. So, we propose an effective tracking algorithm with an appearance model based on features extracted from a video frame.

Radome Slope Estimation using Mode Parameter Renewal Method of IMM Algorithm (IMM 알고리듬의 모드 계수 갱신 방법을 통한 레이돔 굴절률 추정)

  • Kim, Young-Mo;Back, Ju-Hoon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.5
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    • pp.763-770
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    • 2017
  • A radome mounted on the front of an aircraft can cause refraction errors for various reasons that occur during maneuver in seeking and tracking a target. This refraction error means that the microwave seeker is detecting apparent target. An Interactive Multiple Model (IMM) algorithm is applied to estimate radome slope mounted on an aircraft in 3D space. However, even though the parameter of uncertain system model such as radome slope can be estimated, the estimated performance can not be guaranteed when it exceeds the range of the predicted value. In this paper, we propose a method to update the predicted value by using the radome slope as the mode parameter of the IMM algorithm, and confirm the radome slope estimation performance of the proposed method.

Object Tracking Based on Color Centroids Shifting with Background Color and Temporal filtering (배경 컬러와 시간에 대한 필터링을 접목한 컬러 중심 이동 기반 물체 추적 알고리즘)

  • Lee, Suk-Ho;Choi, Eun-Cheol;Kang, Moon-Gi
    • Journal of Broadcast Engineering
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    • v.16 no.1
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    • pp.178-181
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    • 2011
  • With the development of mobile devices and intelligent surveillance system loaded with pan/tilt cameras, object tracking with non-stationary cameras has become a topic with increasing importancy. Since it is difficult to model a background image in a non-stationary camera environment, colors and texture are the most important features in the tracking algorithm. However, colors in the background similar to those in the target arise instability in the tracking. Recently, we proposed a robust color based tracking algorithm that uses an area weighted centroid shift. In this letter, we update the model such that it becomes more stable against background colors. The proposed algorithm also incorporates time filtering by adding an additional energy term to the energy functional.

Guidance Law for Agile Turn of Air-to-Air Missile During Boost Phase

  • Han, Seungyeop;Bai, Ji Hoon;Hong, Seong-Min;Roh, Heekun;Tahk, Min-Jea;Yun, Joongsup;Park, Sanghyuk
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.4
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    • pp.709-718
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    • 2017
  • This paper proposes the guidance laws for an agile turn of air-to-air missiles during the initial boost phase. Optimal solution for the agile turn is obtained based on the optimal control theory with a simplified missile dynamic model. Angle-of-attack command generating methods for completion of agile turn are then proposed from the optimal solution. Collision triangle condition for non-maneuvering target is reviewed and implemented for update of terminal condition for the agile turn. The performance of the proposed method is compared with an existing homing guidance law and the minimum-time optimal solution through simulations under various initial engagement scenarios. Simulation results verify that transition to homing phase after boost phase with the proposed method is more effective than direct usage of the homing guidance law.