• Title/Summary/Keyword: $<_+$-stable

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The Study on a Biomechanical Model for Automotive Seat Design (자동차 SEAT DESIGN을 위한 BIOMECHANICAL MODEL 연구)

  • 신학수;최출헌
    • Proceedings of the ESK Conference
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    • 1998.04a
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    • pp.149-154
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    • 1998
  • The design of seat is maintaining to final stable posture. The final stable posture is the seated posture in which the force of the pad and spring supporting the body is balanced with the body weight and the bodydoes not sink anyfurther intothe seat. With poorly designed seated seats, your behind maygradually move forward, or localized pressure may result in congestion of the blood or numbness, making you want to move. Therefore, the final stable posture is not maintained. A number of ideas were used in this study will eliminate this problem. In automobile seat design, primary attention has forcused on providing the occupant with a comfortable seat that has sufficient padding and adjuxtments toaccomodate different sizes and postures of people. First of all, whether the process is design-oriented or technology-oriented, the design concept must be human-oriented. The fatigue-alleviating seats which were the primary purpose of this research were studied with a human-oriented approach.

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Use of Support Vector Regression in Stable Trajectory Generation for Walking Humanoid Robots

  • Kim, Dong-Won;Seo, Sam-Jun;De Silva, Clarence W.;Park, Gwi-Tae
    • ETRI Journal
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    • v.31 no.5
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    • pp.565-575
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    • 2009
  • This paper concerns the use of support vector regression (SVR), which is based on the kernel method for learning from examples, in identification of walking robots. To handle complex dynamics in humanoid robot and realize stable walking, this paper develops and implements two types of reference natural motions for a humanoid, namely, walking trajectories on a flat floor and on an ascending slope. Next, SVR is applied to model stable walking motions by considering these actual motions. Three kinds of kernels, namely, linear, polynomial, and radial basis function (RBF), are considered, and the results from these kernels are compared and evaluated. The results show that the SVR approach works well, and SVR with the RBF kernel function provides the best performance. Plus, it can be effectively applied to model and control a practical biped walking robot.

Improvement of Tansient Response Characteristics of a Position Control Hydraulic Servosystem Using Observer (II) -Experimental Results Using Analog Observer- (觀測器를 利용한 位置制御 油壓 서보 시스템의 過度應答 特性 改善 (II) -애널로그 관측기를 이용한 실험결과-)

  • 이교일;조승호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.2
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    • pp.215-220
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    • 1988
  • The oscillatory hydraulic servosystem and the stable hydraulic servosystem under proportional control were feedback-controlled respectively using the estimated states of the observer. The observer was constructed in the analog computer and then it was interfaced with the real hydraulic servosystem to excute the experiment. As a result of experiment, the system that had been stable under proportional control responded more rapidly than before and the system that had shown oscillatory phenomenon under proportional control became stable with the same maximum acceleration and velocity that it had started under proportional control.

Development of Highly Efficient and Stable Blue Organic Electroluminescent Devices

  • Lee, Meng Ting;Chen, Hsia Hung;Tsai, Chih Hung;Liao, Chi Hung;Chen, Chin H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.265-268
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    • 2004
  • We have developed a highly efficient and stable blue organic electroluminescent device (OLED) based on the blue fluorescent p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-Ph) dopant in a morphologically stable high-bandgap host material, 2-methyl-9,10-di(2-naphthyl)anthracene (MADN), which achieved an EL efficiency of 9.7 cd/A and 5.5 lm/W at 20 mA/$cm^2$ and 5.7 V with a Commission Internationale d'Eclairage coordinates of(x = 0.16, y = 0.32). This sky blue device which could also alleviate the problematic current induced quenching at high current achieved a half-decay lifetime ($t_{1\;2}$) of 46,000 h at an initial brightness of 100 cd/$m^2$.

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A study on the Design of a stable Substrate Bias Generator for Low power DRAM's (DRAM 의 저전력 구현을 위한 안정한 기판전압 발생기 설계에 관한 연구)

  • 곽승욱;성양현곽계달
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.703-706
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    • 1998
  • This paper presents an efficient substrate-bias generator(SBG)for low-power, high-density DRAM's The proposed SBG can supply stable voltage with switching the supply voltage of driving circuit, and it can substitude the small capacitance for the large capacitance. The charge pumping circuit of the SBG suffere no VT loss and is to be applicable to low-voltage DRAM's. Also it can reduce the power consumption to make VBB because of it's high pumping efficiency. Using biasing voltage with positive temperature coefficient, VBB level detecting circuit can detect constant value of VBB against temperature variation. VBB level during VBB maintaining period varies 0.19% and the power dissipation during this period is 0.16mw. Charge pumping circuit can make VBB level up to -1.47V using VCC-1.5V, and do charge pumping operation one and half faster than the conventional ones. The temperature dependency of the VBB level detecting circuit is 0.34%. Therefore the proposed SBG is expected to supply a stable VBB with less power consumption when it is used in low power DRAM's.

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A Study on the Permissible Gain Ranges of the P and PI Controllers for the Retarded Processes (시간지연을 갖는 제어대상에 대한 P. PI제어의 유효 게인 조정 범위에 관한 연구)

  • 강인철;최순만;최재성
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.5
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    • pp.1086-1090
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    • 2001
  • In this paper, a method deciding the permissible gains of the P and PT controllers for a retarded process under stable condition is proposed. For analysis, the controlled process is assumed to be first-order system with time delay. At first, the adjustable parameter sets causing stability limit are obtained based on the frequency domain condition which makes the roots of the characteristic equation locate on the imaginary axis. And the cut-in frequency ${\omega}_p$ to bring the parameter set to P control from PI control is derived is derived in terms of L and $T_m$ then ${\omega}_p$ is used to compute the maximum gain with stable condition. The results indicate that the permissible controller gains can be described by a unique if parameters L and $T_m$ are know.

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Relationship of Information Technology User Personality, Security and Control (보안 및 통제와 정보기술 사용자의 성격의 관계)

  • Lee, Jang-Hyung;Kim, Jong-Won
    • The Journal of Information Systems
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    • v.19 no.3
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    • pp.1-12
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    • 2010
  • Personality is comprehensive nature of the mood and attitude of people, most clearly revealed in the interaction with other people. This study is a analysis on personality type to information system security and control from financial institute employee. Based on 'The Big Five' personality model, this study develops hypothetical causal relationships of potential organization member's personality and their information system security and control. Research hypotheses are empirically tested with data collected from 901 employees. Results show that employees of high level security mind are the owner of conscientious and emotional stable personality and the employees of high level control mind are the owner of agreeable and emotional stable personality. Therefore the owner of agreeable and stable personality is higher security and control than others.

STABILITY PROPERTIES OF A DELAYED VIRAL INFECTION MODEL WITH LYTIC IMMUNE RESPONSE

  • Song, Fang;Wang, Xia;Song, Xinyu
    • Journal of applied mathematics & informatics
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    • v.29 no.5_6
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    • pp.1117-1127
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    • 2011
  • In this paper, a class of more general delayed viral infection model with lytic immune response is proposed by Song et al.[1] ([Journal of Mathematical Analysis Application 373 (2011), 345-355). We derive the basic reproduction numbers $R_0$ and $R_0^*$ 0 for the viral infection, and establish that the global dynamics are completely determined by the values of $R_0$ and $R_0^*$. If $R_0{\leq}1$, the viral-free equilibrium $E_0$ is globally asymptotically stable; if $R_0^*{\leq}1$ < $R_0$, the immune-free equilibrium $E_1$ is globally asymptotically stable; if $R_0^*$ > 1, the chronic-infection equilibrium $E_2$ is globally asymptotically stable by using the method of Lyapunov function.

Walking Pattern Generation for a Biped Robot Using Polynomial Approximation (다항식 근사를 이용한 이족보행 로봇의 보행패턴 생성)

  • Kang, Yun-Seok;Park, Jung-Hun;Yim, Hong-Jae
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.567-572
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    • 2004
  • In this research, a stable walking pattern generation method for a biped robot is presented. A biped robot is considered as constrained multibody system by several kinematic joints. The proposed method is based on the optimized polynomial approximation of the trunk motion along the moving direction. Foot motions can be designed according to the ground condition and walking speed. To minimize the deviation from the desired ZMP, the trunk motion is generated by the fifth order polynomial approximation. Walking simulation for a virtual biped robot is performed to demonstrate the effectiveness and validity of the proposed method. The method can be applied to the biped robot for stable walking pattern generation.

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On the Stability and Performance Limits of the Force Reflecting Haptic Manipulator (가상반발력을 생성하는 햅틱장비의 안정성과 성능한계에 관한 연구)

  • ;Greg R. Luecke
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.12
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    • pp.180-187
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    • 1998
  • The stability and theoretical performance limits of the feedback controlled force reflecting haptic manipulator have been discussed. All the virtual environment which interact physically with the haptic system have its own stable performance limit. Three different realization of the interfaces have been compared using the driving point admittance. The haptic system which is separated from the human hand or finger is superior to its stable interaction provided that there is a means to apply a direct damping between the haptic manipulator and the human finger Electro-magnetic force is used for its digital implementation of the simple separated type haptic device. The stable limits of a virtual wall is calculated and experimental results show that there is performance limits in this implementation.

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