• 제목/요약/키워드: control threshold

검색결과 1,147건 처리시간 0.028초

Robust Visual Odometry System for Illumination Variations Using Adaptive Thresholding (적응적 이진화를 이용하여 빛의 변화에 강인한 영상거리계를 통한 위치 추정)

  • Hwang, Yo-Seop;Yu, Ho-Yun;Lee, Jangmyung
    • Journal of Institute of Control, Robotics and Systems
    • /
    • 제22권9호
    • /
    • pp.738-744
    • /
    • 2016
  • In this paper, a robust visual odometry system has been proposed and implemented in an environment with dynamic illumination. Visual odometry is based on stereo images to estimate the distance to an object. It is very difficult to realize a highly accurate and stable estimation because image quality is highly dependent on the illumination, which is a major disadvantage of visual odometry. Therefore, in order to solve the problem of low performance during the feature detection phase that is caused by illumination variations, it is suggested to determine an optimal threshold value in the image binarization and to use an adaptive threshold value for feature detection. A feature point direction and a magnitude of the motion vector that is not uniform are utilized as the features. The performance of feature detection has been improved by the RANSAC algorithm. As a result, the position of a mobile robot has been estimated using the feature points. The experimental results demonstrated that the proposed approach has superior performance against illumination variations.

The Efficient Bandwidth Control Method for Variable Data using ATM-GFR Service (ATM-GFR 서비스를 이용한 가변 데이터의 효과적인 대역폭 관리)

  • Kim Jung-Gyu;Lee Young-Dong
    • Journal of Digital Contents Society
    • /
    • 제2권2호
    • /
    • pp.129-138
    • /
    • 2001
  • With the explosive growth and pervasive of the Internet, dynamic bandwidth allocation is nessary for ATM streams that carry various traffic. In order to provide quality of service(QoS) guarantees and to give the minimum cell rate, new bandwidth allocation scheme requires to be implemented. DFBA(Differential Fair Buffer Allocation) scheme is one of the methods for ATM GFR(Guaranteed Frame Rate) services. DFBA scheme treats cells selectively in a region between low buffer occupancy threshold and high buffer occupancy threshold. A big unbalance is introduced when the value being selected by DFBA scheme is greater than minimum rate. In a try to reduce the unbalance modified DFBA scheme is proposed. Selecting parameter according to the situation of network, this scheme is very effective to control the bandwidth in the various network situation.

  • PDF

A Study on Distributed Power Control for Energy Efficiency in Multicast Routing (멀티캐스트 라우팅에서의 전력 분산 제어(DPC)에 관한 연구)

  • Chung, Hyun-Gi;Yang, Seung-In
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • 제17권10호
    • /
    • pp.985-992
    • /
    • 2006
  • The classic routing algorithms try to minimize the number of hops to reach a destination. In our DPC(Distributed Power Control) this hop-by-hop power level selection is also used to select the path guaranteeing low energy consumption. The main goal is to realize a dynamic protocol able to be aware of mobility and to automatically set security threshold in order to get the best performance in every situation. In conclusion, the simulation DPC has improved energy gain of the AMRIS routing algorithm at the narrow area, and ODMRP routing algorithm has improved energy gain at the wide area.

Comparison of Electrical Coupling of Monolithic 3D Inverter with MOSFET and JLFET (MOSFET와 JLFET의 3차원 인버터 전기적 상호작용의 비교)

  • Ahn, Tae-Jun;Choi, Bum Ho;Yu, Yun Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 한국정보통신학회 2018년도 춘계학술대회
    • /
    • pp.173-174
    • /
    • 2018
  • This paper compared the electrical coupling of the monolithic 3D inverter consisting of MOSFET and JLFET. In the case of both the MOSFET and the JLFET, MOSFET and JLFET have a small threshold voltage variation when the thickness of inter-layer dielectric (ILD) = 100 nm. However, when the thickness of ILD = 10 nm, the threshold voltage variation is larger and the JLFET is twice as much as the MOSFET.

  • PDF

Threshold Voltage control of Pentacene Thin-Film Transistor with Dual-Gate Structure

  • Koo, Jae-Bon;Ku, Chan-Hoe;Lim, Sang-Chul;Lee, Jung-Hun;Kim, Seong-Hyun;Lim, Jung-Wook;Yun, Sun-Jin;Yang, Yong-Suk;Suh, Kyung-Soo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
    • /
    • pp.1103-1106
    • /
    • 2006
  • We have presented a comprehensive study on threshold voltage $(V_{th})$ control of organic thin-film transistors (OTFTs) with dual-gate structure. The fabrication of dual-gate pentacene OTFTs using plasma-enhanced atomic layer deposited (PEALD) 150 nm thick $Al_2O_3$ as a bottom gate dielectric and 300 nm thick parylene or PEALD 200 nm thick $Al_2O_3$ as both a top gate dielectric and a passivation layer is reported. The $V_{th}$ of OTFT with 300 nm thick parylene as a top gate dielectric is changed from 4.7 V to 1.3 V and that with PEALD 200 nm thick $Al_2O_3$ as a top gate dielectric is changed from 1.95 V to -9.8 V when the voltage bias of top gate electrode is changed from -10 V to 10 V. The change of $V_{th}$ of OTFT with dual-gate structure has been successfully understood by an analysis of electrostatic potential.

  • PDF

A Comparison of Threshold Anxieties According to the Existence of Information Prior to Electrical Stimulation (통전 전 설명 유무에 따른 불안감 역치비교)

  • Ahn, Duck-Hyun;Song, Young-Hee;Na, Jung-Su;Lee, Su-Young;Kim, Ji-Sun
    • Physical Therapy Korea
    • /
    • 제6권3호
    • /
    • pp.38-50
    • /
    • 1999
  • The purpose of this study was to investigate whether or not the physical therapist's explanation of the treatment prior to electrical stimulation affects the subjects level of anxiety. Eighty healthy subjects participated in this study and were assigned either to the experimental group receiving information on the treatment ($n_1$=40) or to the control group not receiving information on the treatment ($n_2$=40). Transcutaneus Electrical Nerve Stimulation (TENS), a sphygomamometer and the Spielberger State Anxiety Scale Questionnaire were used to investigate the threshold of anxiety. Analysis of data revealed significant differences in pulse and diastolic blood pressure compared to the control group when the subjects were stimulated electrically after receiving information on the treatment. We found significant differences between the two groups. The results of the study indicate that the patient's anxiety can be reduced by the physical therapist's explanation on the treatment.

  • PDF

An Automatic Threshold Control Circuit Adaptive to Burst Optical signal Levels (버스트 광 신호 레벨 적응형 기준레벨 자동 발생회로)

  • 기현철
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • 제40권12호
    • /
    • pp.24-30
    • /
    • 2003
  • In this paper, we proposed an adaptive ATC(Automatic Threshold Control) circuit with more decreased settling time by improving the structure of the peak detector. We showed that it could reduce a good deal of the settling time because it showed less than half the error voltage ratio that the ATC circuit with conventional structure showed in analysis. We also designed a burst-mode ATC circuit for the 1.25Gbps EPON system using a commercial foundry. It produced the reference levels in very short time, 6㎱ in 40 ㏈ input dynamic range.

A Burst-Mode Limiting Amplifier with fast ATC Function (고속 ATC 기능을 갖는 버스트-모드 제한 증폭기)

  • Ki, Hyeon-Cheol
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • 제46권10호
    • /
    • pp.9-15
    • /
    • 2009
  • In this paper, we invented a new structure of fast ATC(Automatic Threshold Control) circuit. Using the structure we made a new burst-mode limiting amplifier with fast ATC function using commercial $0.8{\mu}m$ BiCMOS technology. It's ATC function worked so fast that even the first bit of burst-data could be detected, which confirmed that the new structure was useful for fast ATC. However, in the beginning of a burst, distortions in duty-cycle occurred and increased up to 59% of duty-cycle as amplitude of input signal increased. But we confirmed that after 10 cycles passed, duty-cycles was staying below 52% of duty-cycle for any magnitude of input signal.

Study on Sound Quality Improvement in Bluetooth Headset (블루투스 헤드셋에서의 음질 향상에 관한 연구 - 개인 청각손실 방지측면 고려 -)

  • Kim, Hyun-Tae;Park, Jang-Sik;Song, Jong-Kwan
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • 제13권6호
    • /
    • pp.1188-1193
    • /
    • 2009
  • Todays, many young people suffer from noise-induced hearing loss by using wearable hearing devices, such as Bluetooth headset. This paper present hearing loss reduction and more natural volumn control algorithms considering individual hearing characteristics and threshold of feeling for Bluetooth headset. Experimental results using CSR Bluetooth headset example design board(DEV-PC-1645) show that individuals maybe able to perceive without the inconvenience at the less sound intensity and the more sensitive frequency bands. As a result, we may prevent hearing loss to reduce excessive sound energy in each frequency bands.

Effects of McKenzie Cervical Exercise Program on Cervical Pressure Pain and Balance in Industrial Workers (맥캔지 경부 운동프로그램이 산업체 근로자의 경부압통과 균형에 미치는 영향)

  • Lee, Hyongsoo;Kim, Yoonhwan
    • Journal of The Korean Society of Integrative Medicine
    • /
    • 제6권2호
    • /
    • pp.107-115
    • /
    • 2018
  • Purpose : The purpose of this study was to determine the effects of the McKenzie cervical exercise program on cervical pressure pain and balance in industrial workers. Method : The subjects, who consisted of 26 industrial workers, were randomly divided into two groups. The control group (n=13) went about their daily living routines. The other group (n=13) used the McKenzie cervical exercise program for 6 weeks (2 to 3 times/day). Pressure threshold and balance ability tests were completed before and after the experiment. The balance test was performed both with the eyes open and closed in a standing position. Result : There were significant improvements in the pressure threshold and balance ability test for the McKenzie cervical exercise program group (p<.05), while the control group showed no significant changes (p>.05). Conclusion : The above results revealed that the McKenzie cervical exercise program is effective in improving balance and cervical pressure pain.