• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.222-229
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• 2000

Malty bridges are severely damaged by the overloaded heavy vehicle and tile trend will become more serious because the traffic volume is continuously increasing. Currently, the vehicles with gross weights over 40 tons or axle weight over 10 tons are not allowed on the public road. However, this regulation is not based on a systemetic study on the bridge capacityand assumed to be much too conservative depending on the vehicle types ans bridge types. In this study, the permit weights of heavy vehicles of diverse axle spacings and axle load distribution are calculated considering the structural characteristics of bridge superstructures. In order to consider the various load effects of heavy weight vehicle crossings, three conditions are considered in the calculation of permit vehicle load. From the results, the permit vehicle weights of bridges are calculated and simplified formulas which can be used in the case when only the vehicle dimension are known are presented.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.504-509
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• 1993

A heavy load driving system for the gun laying control is designed with the analysis of performance in pointing accuracy and speed. To eliminate the firing noise and high frequency system noise, a .PI. filter is implemented in conjunction with the PI velocity control. To incorporate the gunner's commands in the PID position control loop easily, a .mu.-processor is utilized in the position control loop. Main difficulties in the heavy load driving system exist in the design of motor drivers and heat sinkers. With an appropriate design of the motor drivers and heat sinkers, the performance of the gun laying system is analyzed by the simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.436-440
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• 1996

In this study, underdeveloping heavy-load driving servo control system, which are composed of controller, electro-hydraulic servo-valve, hydraulic motor, reduction gear box, turret slew bearing and turret structure, are investigated to simplify the control system. To estimate the effect of each component, modeling and simulation of linear and nonlinear system are carried out. In the first stage, to prove the reliability of performance estimation program, simulation results are compared with experimental results. In the second stage, the effect of each component of control system is evaluated and then a simplified control system is suggested.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.261-267
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• 2000

In this study, a heavy-load servo-control driving system, which are composed of controller, electro-hydraulic servomechanism, hydraulic motor, reduction gearbox, turret slew bearing and turret structure, are investigated to simplify the servo-control system. To estimate the effect of each component, nonlinear modeling and simulation are carried out. In the first stage, to prove the validity of the performance estimation program, simulation results are compared with experimental results. In the second stage, the effect of each component of the control system is evaluated and then a simplified control system is suggested.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.364-368
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• 1992

The conventional loading process of workpieces for a CNC lathe is performaed either by human or by a general robot. It is not suitable for a general robot to load workpieces because of high price and inefficiency. Starting from the description of the environment around CNC lathes and the analysis ofloading process, we have developed the task-oriented loading manipulator. The characteristics of a loading manipulator are the following: to load/unload heavy workpieces, to decrease the whole porcess time. The air-chuck to load heavy workpiece has high clamping force and light weight. A loading manipulator has accomplished both the integration of independent automation techniques and cost-down effect of product. A loading manupulator developed in this project has been designed for general loading process. The loading manipulator is capable of carrying heavy payload with respect to weight of robot in short cycle time.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.55-63
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• 2004

This paper presents neural network based controller using the feedback error loaming technique for a heavy load pointing system. Also the mathematical model was developed to analyze heavy load pointing system. The control scheme consists of a feedforward neural network controller and a fixed-gain feedback controller. This neural network controller is trained so as to make the output of the feedback controller zero. The proposed controller is compared with the conventional PI controller through simulations, and the results show that the pointing accuracy of the proposed control system are improved against the disturbance induced by vehicle running on the bump course.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.1005-1009
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• 2017

In this study, the shock resistance of a gas turbine package subjected to a shock load caused by non-contact underwater explosion was investigated using numerical analysis. To perform shock analysis, the time-history shock load was calculated according to BV-043 (German Navy Regulation). The direct transient response analysis in the time domain for the simplified Whole Engine Model (WEM) was performed using the calculated shock load. In addition, the structural integrity of a detailed model was evaluated by considering the shock load transferred to each component. As a result, it was confirmed that the safety factor was at least 1.0 as compared with the reference stress. Finally, the structural and functional integrity of the Engine Management System (EMS) of the gas turbine package was verified through an actual shock test.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.78-80
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• 2005

The load flow calculation is one of the most critical issues in electrical power systems. Generally, load flow has been calculated by Gauss-Seidel method and Newton-Raphson method but these methods have some problems such as non-convergence due to heavy load and initial value. In this paper, to overcome such problems, the power flow is calculated by genetic algorithm. At the heavy load, the solution for problem can not be obtained by the Newton-Raphson method. However, it can be solved in case of using genetic algorithm. In this paper, the strong point of this method would be demonstrated in application to an example system.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.13-17
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• 2015

There are many vinyl houses in rural areas. These vinyl houses have occasionally been collapsed due to heavy snow load in winter. If these vinyl houses are collapsed, many farmers get a lot of economical damages. So it is very important to built safe vinyl house that is able to withstand the applied heavy snow load. In this study, compressive buckling and flexural tests were performed to investigate the strength increase of circular mortar filled pipes. The results showed that buckling load and flexural moment of mortar filled pipes were increased 42 % ~ 82 %, 40 % ~ 44 % respectively more than only pipe without mortar. It is recommended that mortar filled pipes as main members of vinyl house have to be used to prevent collapsing due to the severe snow load.

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.1-7
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• 2017

It has been developed large mooring fittings having the capacity of 160 tons and 180 tons installed on 170K LNG FSRU. The finite element analysis for the mooring fittings was carried out in order to check the structural integrity and to confirm satisfaction of the rule requirements. The 3 kinds of mooring fittings such as chock, bollard and universal fairlead are selected for FE analysis and load test. According to the FE analysis results, all the stress levels satisfied the acceptance criteria guided by the IACS UR A2, ISO standard, ship rules and OCIMF. As test results under design load, no structural defects were found.