• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1051-1052
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• 2006

This paper deals with mathmatical of an induction motor, considering non-linearity in the torque balance equation under closed loop operation with a reference speed. A controller based on Adaptive Nuro-Fuzzy Inference System (ANFIS) is developed to minimize overshoot and settling time following sudden changes in load torque. The overall system is modeled and simulated using the Matlab/simulink and Fuzzy Logic Toolbox. The advantages of fuzzy logic and neural network based fuzzy logic controller. Required training data the ANFIS controller is generated by simulation of the anti-windup PI controller is eliminated using the ANFIS controller. The transient deviation of the response from the set reference following variation in load torque is found to be negligibly samll along with a desirable reduction in settling time for the ANFIS controller.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.501-503
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• 2005

The improvement of load following operation of the thermal power plant is influenced to the electrical quality. Analysis of boiler, turbine, and governor system, and the study of control algorithm are preceded. The thermal power plant is operated by various control systems. In the case of faulty governor system, it takes long days to solve the problem and impossible to repair the mechanism without outage. A non-planned out-age is taken into consideration because of economical power production. In this paper, to clear the continuous swings of an old turbine governor system(YEOSU #1), the trend, the control logic, and the hydraulic mechanism are analyzed, and then the control circuit with ADAPT function and the 1st order lag circuit are inserted and modified. After that, the power plant comes to automatic governor control operation.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.1026-1030
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• 2011

This paper presented here contains development of variable stability system(VSS) control laws for the KIFS (Korean In-Flight Simulator) aircraft to simulate the dynamics of F-16 aircraft. Development of VSS Control law for pitch rate, roll rate, yaw rate simulation for three specified flight conditions using Model Following Technique with rate feedback autopilot for stability provision. The direct lift force controller was also added to the developed VSS control law to simulate the pitch rate and normal g-load simultaneously. The simulation results show high accuracy of F-16 aircraft's pitch, roll, yaw rate and g-load simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.102-105
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• 2005

A Effective wall following plays important role for the mapping behaviors which determine the entire memory size and the shape of map before building a map. In case of wall following, attacking those cause by curved wall or obstacles brings a bad stuff that makes ripples on the moving trajectory. These types of ripples come to an end with problems that increase the load of calculation and sensing errors. In this paper, a new sensing method and its corresponding controller are suggested for problems. It minimizes the occurrence of the trajectory ripples.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1986년도 하계학술대회논문집
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• pp.145-148
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• 1986

• 대한조선학회지
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• 제20권4호
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• pp.1-8
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• 1983

This paper describes the application of the finite element method to the large deflection elastic plastic analysis and ultimate load calculation of axisymmetric shell of revolution with initial imperfection subjected to external pressure. The nonlinear equilibrium equations are linearized by the successive incremental method and are solved by the combination of load increment and iteration scheme with considering plastic deformation theory. To get the more realistic effect of large deflection, corrected coordinats and directions of applied load ar every load increment steps are used. The effects of the plasticity, initial imperfection and the shape of shells on the ultimate load of clamped circular cap under external pressure are investigated. Consequently, the following conclusions are obtained; (1) At same geometric parameter $\lambda$, each shape of clamped circular caps yield same elastic ultimate loads in both cases, i.e. with and without initial imperfections, whereas, in the case of elastic-plastic state the shell becomes thicker, the ultimate loads are getting smaller. (2) The effects of initial imperfection to ultimate load are most significant in the elastic case and are more senstive in the elastic-plastic state with the thinner shells.

• 오토저널
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• 제4권3호
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• pp.56-68
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• 1982

This paper presents analytic solutions of defection and their resonance diagrams for a uniform beam of infinite length subjected to an constant axial force and moving transverse load simultaneously. Steady solutions are obtained by a time-independent coordinate moving with the load. The supporting foundation includes damping effects. The influences of the axial force, the damping coefficient and the load velocity on the beam response are studied. The limiting cases of no damping and critical damping are also investigate. The profiles of the deflection of the beam are shown graphically for several values of the load speed, the axial force and damping parameters. Form the results, following conclusions have been reached. 1. The critical velocity .THETA.cr decreases as the axial compressive force increases, but increases as the axial tensile force increase. 2. At the critical velocity .THETA.cr the deflection have a tendency to decrease as the axial tensile force increases and to increase gradually as the axial compressive force increases. 3. In case if relatively small dampings, the deflection increases suddenly as the velocity of the moving load approaches the critical velocity, and it reachs its maximum at the critical velocity, and it decreases and become greatly affected by the axial force as the velocity increases further. 4. in case of relatively large dampings, as the velocity increases the deflection decreases gradually and it is affected little by the axial load.

• Geomechanics and Engineering
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• 제20권4호
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• pp.359-370
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• 2020

Prestressed ground anchors are important structural elements in geotechnical engineering. Despite their widespread usage, the design process is often significantly simplified. One of the major drawbacks of commonly used design methods is the assumption that skin friction is mobilized uniformly along an anchor's fixed length, one consequence of which is that a progressive failure phenomenon is neglected. The following paper introduces an alternative design approach - a computer algorithm employing the load-transfer method. The method is modified for the analysis of anchors and combined with a procedure for the derivation of load-transfer functions based on commonly available laboratory tests. The load-transfer function is divided into a pre-failure (hardening) and a post-failure (softening) segment. In this way, an aspect of non-linear stress-strain soil behavior is incorporated into the algorithm. The influence of post-grouting in terms of radial stress update, diameter enlargement, and grout consolidation is included. The axial stiffness of the anchor body is not held constant. Instead, it gradually decreases as a direct consequence of tensile cracks spreading in the grout material. An analysis of the program's operation is performed via a series of parametric studies in which the influence of governing parameters is investigated. Finally, two case studies concerning three investigation anchor load tests are presented.

• 전자공학회논문지A
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• 제29A권11호
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• pp.1-13
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• 1992

In this DQDB networks, erasure nodes may be allocated on the bus and release slots which already had been read by destination nodes. An important function of the erasure node must be to eliminate as many requests as erased slots used by downstream nodes. In the networks with priorities, following two additional issues must be solved : (1) accurately to guess for which priority the erased slots is to be used, and (2) to find in a short period a request of that priority to cancel. In this paper, we propose two erasure node algorithms based on elimination of the requests. In these algorithms, the requests are eliminated excessively at low load but optimum elimination can be achieved at full load. Simulation results show that these two algorithms have similar access delay to that of existing algorithms at low load and better performance at high load.

• Journal of Advanced Marine Engineering and Technology
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• 제17권1호
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• pp.26-32
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• 1993

The loads exerted on electro-hydraulic servo system are classified into inertial, viscous, and spring load. The additional load called disturbances is also exerted on system but is generally not modeled. To deal with these kinds of loads, it is necessary to maintain the continuous signal transfer, so we can construct compensator to satisfy control specifications using feedback signal such as displacement, velocity, acceleration and pressure known as state variables. In case of controlling the speed of hydraulic motor, we must keep up robust performance for the various loads and disturbances acted on the system. However, the load flow rate in the valve is characterized by nonlinearity so that traditional theory of linear control could not be expected to give the desired performance. In this paper, it is shown that speed controller of hydraulic motor gives a good command following and disturbance rejection performance by applying sliding mode theory as a way of robust control to the nonlinearity, variation of loads and disturbances.