• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.2
• /
• pp.88-93
• /
• 2004

The main objective of the research is to Propose an algorithm that to estimate the screwing torque from parameters of DC motor current without using any stain gage and torque cell. The auto screw drive system is divided into two parts, one is the DC motor ind the other is mechanical part in which the friction torque and damping ratio are a function of rotational of spindle electro motive force constant. The torque is estimated from the friction torque. The research is concerned with applying the method to an auto screw drive and the advantages and limitations are also discussed in this paper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.1195-1201
• /
• 2002

Researches on the FRF-based substructuring method have been mainly focused on vibratory response analysis. Present study Is concerned about the application of the method to the dynamic stress analysis of a air-conditioner compressor mounting bracket in a passenger car. This is performed by using reaction forces that can be obtained by the FRF-based substructuring method. The air-conditioner system, composed of a compressor and bracket, Is analyzed by using the FRF-based substructuring method. The experimental and numerical FRFs are combined to calculate the system responses and reaction forces at the connection point. The dynamic reaction forces plugged into the bracket FE model to compute the stresses of the bracket Dynamic strains by the present method are compared with those from strain-gage test for bracket system on shaker. The comparison shows possibility of practical usage of the method for the real problem

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.281-285
• /
• 2002

A new method of dynamic contact force measurement between a pantograph and a contact wire is proposed in this paper The method does not require design modification of an original pantograph in order to install sensors such as load cells. Contact forces can be expressed as the sum of vertical shear forces at the support points and inertial forces. Using specially-designed strain gage rosettes. vertical shear forces at the supported points can be measured without noise mixing and thermal effects. In order to obtain contact forces from shear forces, 3 inertial force compansation methods are proposed and compared in this paper. By validation process, the new proposed measurement method is verified to be applicable to the on-line current collection test.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.956-963
• /
• 2001

The measurement of residual stresses by the hole-drilling method has been commonly used to evaluate residual stresses in structural members. In this method, eccentricity can usually occur between the hole center and rosette gage center. In this study, the error due to the hole eccentricity is predicted using the artificial neural network. The neural network has trained training examples of stress ratio, normalized eccentricity, off-centered direction and stress error using backpropagation loaming process. The prediction results of the error using the trained neural network are good agreement with FE analyzed ones.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.6
• /
• pp.201-206
• /
• 2001

The hole-drilling method makes a little hole through the metal surface that has residual stress and measures the relieved stress with a strain gage. It is used widely in measuring the residual stress of surfaces. In this method, the inclined hole is one of the source of error. This paper presents a finite element analysis of influence of the inclined hole for the uniaxial residual stress field. The stress differences between measured and applied residual stress increase proportionally to inclined angle of the hole. The correction equations which easily obtain the residual stress taking account of the inclined angle and direction are derived. The measurement error of stress due to the inclined hole can be reduced to around 1% through this study.

• Journal of Chest Surgery
• /
• v.14 no.2
• /
• pp.168-174
• /
• 1981

Since cardiac pacemaker was first totally implanted by Chardack, Gage and Greatbatch [1966], the electrical circuity of the cardiac pacemaker has been improved, modified, and refined. The problem of transvenous electrodes, however, is still remained; this may be due to electrode displacement, exit and/or entrance block, lead fracture and insulation defects. In permanent cardiac pacing, Irreversible loss of function of the transvenous electrode catheter eventually requires insertion of new lead. Authors now report one case that disclosed easy displacement of electrode tip in early phase of implantation and then two years and five months later, malfunctioning electrode could not be withdrawn from the cardiovascular system because it has become firmly enclosed by fibrous tissue along its course from the vein tract to the right ventricle. Under such circumstances, the electrode catheter tip was left in tricuspid annulus after being sutured at its entrance and burying the loop of lead in generator pocket. New other one electrode was then reimplantation through left external jugular vein.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.1321-1325
• /
• 2004

The continuous monitoring of the runoff in the small-scaled urban watershed and easily accessible experiment catchment is necessary to investigate the overall status of the development in the urban catchment and the varying aspects of the discharge characteristics due to the urbanization. However, the research on the management and the characteristics of the small-scaled model basin for discharge tests has not been actively performed up to now. This study selects the Dong-Eui university basin, which locates at Gaya-dong in Busan, as the experiment catchment to monitor the discharge rate in the urban watershed. EMS(DEMS, DATA-PCS EMS, mini rain gage & AWS(AWS-DEU, DATA-PCS AWS) monitoring system installed for the collection of hydrological data such as the rainfall and the waterlevel. This experiment catchment is the typical urban catchment and is under development, and it is possible to analyze the varying aspects of the discharge rate during and after the development.

• International Journal of Precision Engineering and Manufacturing
• /
• v.4 no.3
• /
• pp.12-19
• /
• 2003

This paper describes the design of a robot's hand with two fingers for stably grasping an unknown object, and the development of a 3-axis force sensor for which is necessary to constructing the robot's fingers. In order to safely grasp an unknown object using the robot's fingers, they should measure the forces in the gripping and in the gravity directions, and control the measured forces. The 3-axis force sensor should be used for accurately measuring the weight of an unknown object in the gravity direction. Thus, in this paper, the robot's hand with two fingers for stably grasping an unknown object is designed, and the 3-axis force sensor is newly modeled and fabricated using several parallel-plate beams.

• Journal of Biosystems Engineering
• /
• v.18 no.1
• /
• pp.37-47
• /
• 1993

This study was conducted to develop the on-line monitoring system for plant growth responses. The system consisted of two parts. One system was the measuring system and the other was its controlling system. The established measuring systems were the ultrasonic wave sensor driver for height of plant, the potentiometer for diameter of plant stem, and the weighing system with strain gage application for plant weight. Also, computer program for measurement and controlling was developed, and the whole system was tested by the fabricated plant, and the actual plant growth responses were monitored by the system. When monitoring the actual plant growth responses, even the small amount of plant growth resposes could be measured by the system within tolerable error ranges.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.4 no.1
• /
• pp.75-85
• /
• 1996

The gas pressure acting on the rings in internal combustion engine influences the friction, wear and HC emission. In order to understand their characteristics, it is necessary to measure the interring gas pressure during engine operations. In this study, miniature type pressure transducer was developed to measure inter-ring gas pressure. And measurements of cylinder and inter-ring gas pressure were made on a gasoline engine running at full and part load conditions. Finally the characteristics of inter-ring gas pressure variation during engine operation were obtained form analysis of measured date.