• Title/Summary/Keyword: Adaptive control system

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Implementation of Commercial IWB Interface using Image Processing (영상처리를 이용한 상업용 전자칠판의 인터페이스 구현)

  • Ko, Eunsang;Rhee, Yang Won;Lee, Chang Woo
    • Journal of Korea Society of Industrial Information Systems
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    • v.17 no.6
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    • pp.19-24
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    • 2012
  • In this paper we introduce a commercial interactive whiteboard (IWB) system named ImSensorTouch by ImSensor Inc. Using this interface system, we can control our computer through the interactive whiteboard screen just by touching it with your finger or a pen. The interface interacts with Windows operating system (OS) and is adaptable to changes of surroundings especially temperature, and illumination condition. The proposed system calculates the difference between a reference image and a current image captured by a camera in the optical receptive field. And the position making the difference is used to generate the position on Windows screen. Then, we send a mouse event on the position to Windows OS. We have implemented the system using a critical section(CS) with two threads for the reference frame update process in which an adaptive thresholding technique is periodically exploited to get reliable result. We expect the system is competitive and promises a bright future in the IWB market.

A Study on Optimization of Single-Channel Monopulse Tracking System using Phased Array Antenna (위상배열안테나를 이용한 단일 채널 모노펄스 추적 시스템의 최적화에 관한 연구)

  • Jung, Jin-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.4
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    • pp.705-712
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    • 2018
  • The radiation characteristics of a phased array antenna is changed according to the beam steering angle. The monopulse tracking system calculates the prediction angle using the radiation characteristics of antenna. Therefore, the monopulse ratio curve is changed according to the beam steering angle for the monopulse tracking system using a phase array antenna, and the tracking accuracy goes down. In the case of a single-channel monopulse system, the monopulse rate curve is controlled by the configuration variables of the system. In this paper, a simplified formula was presented for adaptive control of monopulse system configuration variables on beam steering angle. The presented formula can induce a uniform monopulse ratio curve for the beam steering angle as well as the phased array antenna design parameters.

Stereo Convergence Angle Disparity Extraction of the Moving Target using Optical JTC (광 JTC를 이용한 이동 물체의 스테레오 주시각 시차 추출)

  • 이재수;김성호;김규태;김은수;박순영;이용범
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.12
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    • pp.99-107
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    • 1998
  • A stereo vision system such as the structure of human's eyes has two cameras at separated positions from which we can obtain two input images and then put them together to create 3-D image. It can show more virtual effect than the conventional 2-D image system. But, the stereo image system has to control the convergence angle so that the stereo disparity could always be zero because observers can be fatigued and unconscious of stereo image in conditions that the stereo disparity is not zero for a long work. Therefore, in the paper, optical JTC system which can process adaptive tracking of a specific moving object is proposed as a new approach to keep the stereo disparity to be zero. In this method, optical JTC system obtains the values of the relative locations of a moving objects in left and right images and then these values are used for maintaining the stereo disparity to be zero. Through some optical experiments the proposed stereo vision system is proved to be insensitive to background noises and operate in real-time.

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Load-adaptive 180-Degree Sinusoidal Permanent-Magnet Brushless Motor Control Employing Automatic Angle Compensation

  • Kim, Minki;Oh, Jimin;Suk, Jung-Hee;Heo, Sewan;Yang, Yil Suk
    • IEIE Transactions on Smart Processing and Computing
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    • v.2 no.5
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    • pp.310-316
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    • 2013
  • This paper reports a sinusoidal $180^{\circ}$ drive for a permanent magnet (PM) brushless motor employing automatic angle compensator to suppress the driving loss during the wide-range load operation. The proposed drive of the sinusoidal $180^{\circ}$ PM Brushless motor reduced the amplitude of the 3-phase current by compensating for the lead-angle of the fundamental waves of the 3-phase PWM signal. The conventional lead-angle method was implemented using the fixed angle or memorized table, whereas the proposed method was automatically compensated by calculating the angle of the current and voltage signal. The algorithm of the proposed method was verified in a 30 W PM brushless motor system using a PSIM simulator. The efficiency of the conventional method was decreased 90 % to 60 %, whereas that of proposed method maintained approximately 85 % when the load shift was 0 to $0.02N{\cdot}m$. Using an FPGA prototype, the proposed method was evaluated experimentally in a 30 W PM brushless motor system. The proposed method maintained the minimum phase RMS current and 79 % of the motor efficiency under 0 to $0.09N{\cdot}m$ load conditions. The proposed PM brushless motor driving method is suitable for a variety of applications with a wide range of load conditions.

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A Study of Iterative QC-BC Method for AMSU-A in the KIAPS Data Assimilation System (KIAPS 자료동화 시스템에서 AMSU-A의 품질검사 및 편향보정 반복기법에 관한 연구)

  • Jeong, Han-Byeol;Chun, Hyoung-Wook;Lee, Sihye
    • Atmosphere
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    • v.29 no.3
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    • pp.241-255
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    • 2019
  • Bias correction (BC) and quality control (QC) are essential steps for the proper use of satellite observations in data assimilation (DA) system. BC should be calculated over quality controlled observation. And also QC should be performed for bias corrected observation. In the Korea Institute of Atmospheric Prediction Systems (KIAPS) Package for Observation Processing (KPOP), we adopted an adaptive BC method that calculates the BC coefficients with background at the analysis time rather than using static BC coefficients. In this study, we have developed an iterative QC-BC method for Advanced Microwave Sounding Unit-A (AMSU-A) to reduce the negative feedback from the interaction between BC and QC. The new iterative QC-BC is evaluated in the KIAPS 3-dimensional variational (3DVAR) DA cycle for January 2016. The iterative QC-BC method for AMSU-A shows globally significant benefits for error reduction of the temperature. The positive impacts for the temperature were predominant at latitudes of $30^{\circ}{\sim}90^{\circ}$ of both hemispheres. Moreover, the background warm bias across the troposphere is decreased. Even though AMSU-A is mainly designed for atmospheric temperature sounding, the improvement of AMSU-A pre-processing module has a positive impact on the wind component over latitudes of $30^{\circ}S$ near upper-troposphere, respectively. Consequently, the 3-day-forecast-accuracy is improved about 1% for temperature and zonal wind in the troposphere.

N-recognins UBR1 and UBR2 as central ER stress sensors in mammals

  • Ly Thi Huong Luu Le;Seoyoung Park;Jung Hoon Lee;Yun Kyung Kim;Min Jae Lee
    • Molecules and Cells
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    • v.47 no.1
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    • pp.100001.1-100001.8
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    • 2024
  • In eukaryotes, a primary protein quality control (PQC) process involves the destruction of conformationally misfolded proteins through the ubiquitin-proteasome system. Because approximately one-third of eukaryotic proteomes fold and assemble within the endoplasmic reticulum (ER) before being sent to their destinations, the ER plays a crucial role in PQC. The specific functions and biochemical roles of several E3 ubiquitin ligases involved in ER-associated degradation in mammals, on the other hand, are mainly unknown. We identified 2 E3 ligases, ubiquitin protein ligase E3 component N-recognin 1 (UBR1) and ubiquitin protein ligase E3 component N-recognin 2 (UBR2), which are the key N-recognins in the N-degron pathway and participate in the ER stress response in mammalian cells by modulating their stability. Cells lacking UBR1 and UBR2 are hypersensitive to ER stress-induced apoptosis. Under normal circumstances, these proteins are polyubiquitinated through Lys48-specific linkages and are then degraded by the 26S proteasome. In contrast, when cells are subjected to ER stress, UBR1 and UBR2 exhibit greater stability, potentially as a cellular adaptive response to stressful conditions. Although the precise mechanisms underlying these findings require further investigation, our findings show that cytoplasmic UBR1 and UBR2 have anti-ER stress activities and contribute to global PQC in mammals. These data also reveal an additional level of complexity within the mammalian ER-associated degradation system, implicating potential involvement of the N-degron pathway.

A Real-time Augmented Reality System using Hand Geometric Characteristics based on Computer Vision (손의 기하학적인 특성을 적용한 실시간 비전 기반 증강현실 시스템)

  • Choi, Hee-Sun;Jung, Da-Un;Choi, Jong-Soo
    • Journal of Korea Multimedia Society
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    • v.15 no.3
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    • pp.323-335
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    • 2012
  • In this paper, we propose an AR(augmented reality) system using user's bare hand based on computer vision. It is important for registering a virtual object on the real input image to detect and track correct feature points. The AR systems with markers are stable but they can not register the virtual object on an acquired image when the marker goes out of a range of the camera. There is a tendency to give users inconvenient environment which is limited to control a virtual object. On the other hand, our system detects fingertips as fiducial features using adaptive ellipse fitting method considering the geometric characteristics of hand. It registers the virtual object stably by getting movement of fingertips with determining the shortest distance from a palm center. We verified that the accuracy of fingertip detection over 82.0% and fingertip ordering and tracking have just 1.8% and 2.0% errors for each step. We proved that this system can replace the marker system by tacking a camera projection matrix effectively in the view of stable augmentation of virtual object.

Adaptive Load Balancing Algorithm and Its Performance Analysis Based on System-Level Simulations in Indoor Mobile Communication System (옥내용 모바일 통신 시스템을 위한 적응적 Load-Balancing 알고리즘 제안 및 시스템 레벨 시뮬레이션 기반 성능 분석)

  • Lee, Woongsup;Lee, Howon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.11
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    • pp.2563-2568
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    • 2013
  • Recently, various solutions to support explosively growing mobile data traffic have attracted intensive attentions. However, the range of spectrum which can be exploited for mobile communications is very limited. Small cell networks are actively investigated because they can efficiently offload mobile data traffic from macro cells without using additional spectrum. In this paper, we developed a system-level simulator considering small cell networks in the indoor environments. We compare the performance of outage probability when a load-balancing algorithm is utilized or not. We can reduce the outage probability of congested BS with the load-balancing algorithm. In addition, overall outage probability of whole wireless systems can be reduced by using the proposed load-balancing algorithm.

Application Behavior-oriented Adaptive Remote Access Cache in Ring based NUMA System (링 구조 NUMA 시스템에서 적응형 다중 그레인 원격 캐쉬 설계)

  • 곽종욱;장성태;전주식
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.9
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    • pp.461-476
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    • 2003
  • Due to the implementation ease and alleviation of memory bottleneck effect, NUMA architecture has dominated in the multiprocessor systems for the past several years. However, because the NUMA system distributes memory in each node, frequent remote memory access is a key factor of performance degradation. Therefore, efficient design of RAC(Remote Access Cache) in NUMA system is critical for performance improvement. In this paper, we suggest Multi-Grain RAC which can adaptively control the RAC line size, with respect to each application behavior Then we simulate NUMA system with multi-grain RAC using MINT, event-driven memory hierarchy simulator. and analyze the performance results. At first, with profile-based determination method, we verify the optimal RAC line size for each application and, then, we compare and analyze the performance differences among NUMA systems with normal RAC, with optimal line size RAC, and with multi-grain RAC. The simulation shows that the worst case can be always avoided and results are very close to optimal case with any combination of application and RAC format.

A Study on Design and Implementation of Speech Recognition System Using ART2 Algorithm

  • Kim, Joeng Hoon;Kim, Dong Han;Jang, Won Il;Lee, Sang Bae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.4 no.2
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    • pp.149-154
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    • 2004
  • In this research, we selected the speech recognition to implement the electric wheelchair system as a method to control it by only using the speech and used DTW (Dynamic Time Warping), which is speaker-dependent and has a relatively high recognition rate among the speech recognitions. However, it has to have small memory and fast process speed performance under consideration of real-time. Thus, we introduced VQ (Vector Quantization) which is widely used as a compression algorithm of speaker-independent recognition, to secure fast recognition and small memory. However, we found that the recognition rate decreased after using VQ. To improve the recognition rate, we applied ART2 (Adaptive Reason Theory 2) algorithm as a post-process algorithm to obtain about 5% recognition rate improvement. To utilize ART2, we have to apply an error range. In case that the subtraction of the first distance from the second distance for each distance obtained to apply DTW is 20 or more, the error range is applied. Likewise, ART2 was applied and we could obtain fast process and high recognition rate. Moreover, since this system is a moving object, the system should be implemented as an embedded one. Thus, we selected TMS320C32 chip, which can process significantly many calculations relatively fast, to implement the embedded system. Considering that the memory is speech, we used 128kbyte-RAM and 64kbyte ROM to save large amount of data. In case of speech input, we used 16-bit stereo audio codec, securing relatively accurate data through high resolution capacity.