• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.47-50
• /
• 1995

This paper concerns an adaptive control scheme which is an extension of the simplified adaptive control. Originally, the SAC approach was developed based on the command generator tracker (CGT) theory for perfect model tracking. An attractive point of the SAC is that a control input can be synthesized without any prior knowledge about plant structure. However, a feedforward dynamic compensator of the CGT is removed from the basic structure of the SAC. This deletion of the compensator makes perfect model tracking difficult against even a step input. In this paper, an adaptive control system is redesigned to achieve perfect model tracking for as long as possible by reviving the dynamic compensator of the CGT. The proposed method is applied to slewing control of a flexible space structure and compared to the SAC responses.

• International Journal of Aeronautical and Space Sciences
• /
• v.2 no.1
• /
• pp.78-92
• /
• 2001

In this paper, several dynamic systems are modeled using the time domain finite element method. Galerkins' Weak Principle is used to model the general second-order mechanical system, and is applied to a simple pendulum dynamics. Problems caused by approximating the final momentum are also investigated. Extending the research, some dynamic analysis methods are suggested for the hybrid coordinate systems that have both slew and flexible modes. The proposed methods are based on both Extended Hamilton's Principle and Galerkin's Weak Principle. The matrix wave equation is propagated in space domain, satisfying the geometric/natural boundary conditions. As a result, the flexible motion can be obtained compatible with the applied control input. Numerical example is shown to demonstrate the effectiveness of the proposed modeling methods for the hybrid coordinate systems.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1999.06a
• /
• pp.23.1-28
• /
• 1999

InterSpaceTM is an advanced networked virtual reality system that presents shared three-dimensional computer graphics (CG) worlds via the Internet where multiple users can enjoy synchronous communications with voice, video and text. Users can control their avatars as a surrogate interface. In InterSpace users can walk around and interact with other people and interact with contents. In this paper, we describe the function-distributed architecture used in InterSpace. The architecture enables flexible configuration of server functions and load distribution. It also allows users to select media and client PCs to switch servers dynamically.

• International Journal of Advanced Culture Technology
• /
• v.11 no.2
• /
• pp.56-63
• /
• 2023

I proposed the architectural guideline for educational environment based on design thinking approach to integrate and enhance learners' activities and achievements. The physical environment of design education learning space should be applied by teaching methods and learning activities, especially for STEAM-based convergent education, the architectural space conditions should support the design process based on design thinking. The learning environment conditions influence design education with physical design factors and learners' communication, and the flexible environment based on design thinking, which is crucial for design education. The 3 steps of design thinking experiences also allow students to learn the context of ideas, skills and outcomes. Therefore, I argued that the learning surrounding based on design thinking needs flexible and mobile, connected, integrated, organized, and team-focused environments to support learners' understanding, participation, and collaboration, and to achieve the design process based on research findings. For spaces for convergent learning environments based on design thinking, common design principles should be reviewed, such as coexistence with technology, safety and security, transparency and spatial extension, multi-purpose space and outdoor learning.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.4
• /
• pp.364-375
• /
• 2012

This study investigates the effects of interior design elements on the satisfaction and preference for space. Field measurements and surveys were conducted in three coffeeshops where various interior design elements were applied. Results indicate that movable tables and chairs for two people were preferred in the space. They need to be placed flexibly according to the visitors' needs to improve satisfaction for convenience. To improve spatial satisfaction, the brightness of color applied to wall surfaces was recommended to be lower than that of color used for floor surfaces. The surfaces of space and interior design elements such as furniture also need to be kept clean. Lamps with lower color temperature were effective to enhance spatial satisfaction. Light sources should be shielded when a pendant lighting system with general diffuse type was used in space. Natural daylight through window was also required for better satisfaction level. Multiple linear regression implied that the cozy feeling by electric light, existence of daylight, flexible layouts for tables and chairs, color and quality of material for tables and floor were significant contributors to overall spatial satisfaction.

• Construction Engineering and Management
• /
• v.23 no.3
• /
• pp.17-22
• /
• 2022

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.547-550
• /
• 2005

In many machines handling lightweight and flexible media, such as automated teller machines and printers, the media must transit an open space. It is important to predict the static and dynamic behavior of the sheets with a high degree of reliability The nonlinear theory of the dynamic elastica has often been used to a nonlinear dynamic deflection model. In this paper, the governing equation is derived and simulated by the finite difference method. The analysis has to include aerodynamic effect for more exact behavior analysis, because the flexible media can be deformed drastically by a little force. Therefore aerodynamic force must be applied to the governing equation. Different results were obtained with and without aerodynamic effect and the resulted show that after contacting circular guide, the directions of flexible media of two cases are different.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.10
• /
• pp.2483-2490
• /
• 1993

This paper presents a systematic formulation for the kinematic and dynamic analysis of flexible multibody systems. The system equations of motion are derived in terms of relative and elastic coordinates using velocity transformation technique. The position transformation equations that relate the relative and elastic coordinates to the Cartesian coordinates for the two contiguous flexible bodies are derived. The velocity transformation matrix is derived systematically corresponding to the type of kinematic joints connecting the bodies and system path matrix. This matrix is employed to represent the equations of motion in relative coordinate space. Two examples are taken to test the method developed here.

• Journal of Mechanical Science and Technology
• /
• v.15 no.2
• /
• pp.143-151
• /
• 2001

In the paper, a robust control mechanism is presented to maneuver a flexible spacecraft with the deflection reduction during large slewing operation at the same time. For deflection reduction and maneuvering of the flexible spacecraft, a control mechanism is developed with the application of stochastic optimal sliding-mode control, a linear tracking model and input shaping technique. A start-coast-stop maneuver is employed as a slewing strategy. It is shown that the control mechanism with he strategic maneuver results in better performance and is more efficient than rigid-body-like maneuver, by applying to the Spacecraft Control Laboratory Experiment (SCOLE) system in a space environment.

• Journal of Mechanical Science and Technology
• /
• v.14 no.2
• /
• pp.188-196
• /
• 2000

In this paper, our aim is to develop a model for two cooperating flexible manipulators handling a rigid object by using lumped parameters. This model is in turn analyzed on MATLAB. In order to validate the model, a precise simulation model is developed using $ADAMS^{TM}$ (Automatic Dynamic Analysis of Mechanical System). Moreover, to clarify the discussion, the motions of a dual-arm experimental flexible manipulator are considered. Using the developed model, we control a robotic system with a symmetric hybrid position/force control scheme. Finally, experiments and simulations are performed, and a comparison of simulation results with experimental results is given to a rerify the validity of our model.