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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
Editor in Chief :
Volume & Issues
Volume 19, Issue 12 - Dec 2002
Volume 19, Issue 11 - Nov 2002
Volume 19, Issue 10 - Oct 2002
Volume 19, Issue 9 - Sep 2002
Volume 19, Issue 8 - Aug 2002
Volume 19, Issue 7 - Jul 2002
Volume 19, Issue 6 - Jun 2002
Volume 19, Issue 5 - May 2002
Volume 19, Issue 4 - Apr 2002
Volume 19, Issue 3 - Mar 2002
Volume 19, Issue 2 - Feb 2002
Volume 19, Issue 1 - Jan 2002
Selecting the target year
Mechanical Properties of Soft Connective Tissues
Chun, Keyoung-Jin ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 7~17
The Mechanical Properties of Bone Tissues
Choe, Gwi-Won ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 18~24
Overview of the Spine Biomechanics
Kim, Young-Eun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 25~33
Hemodynamics and Vascular Diseases
Rhee, Kyehan ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 34~43
Exercise of Paralyzed Muscles and Paraplegic Walking Induced by FES
Khang-, Gon ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 44~51
Prosthetic Gait and Socket Biomechanical Analyses of Transfemoral Amputee
Hong, Jung-Hwa ; Mun, Mu-Seong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 52~72
Estimation of Surface Roughness using Neural Network in Polishing Operation of Mold and Die
Cho, Kyu-Kab ; Kang, Yong-Woo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 73~78
This paper presents a neural network approach to estimate the surface roughness by considering the relationship between the polishing operation parameters and the surface roughness. The neural network model predicts the post-machining surface roughness by using several factors such as pre-machining surface roughness, pressure, feed rate, spindle speed, and the number of polishing as inputs. In this paper, the several neural network models are implemented to estimate the surface roughness by using actual experimental data. The experimental results show that the neural network approach is more appropriate to represent the polishing characteristics of mold and die compared with the results obtained by the approach using exponential function.
The Development of CAM Software for Ultra-precision Aspheric Surface
Yang, Min-Yang ; Lee, Taik-Min ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 79~86
As consumer electronics, information, and aero-space industry grow, the demand for aspheric lens increases higher. To enhance the precision and productivity of aspheric surface, a CAM system for ultra-precision aspheric surface needs to be realized. In this study, the developed CAM system can generate NC code fur various aspheric surfaces fast and precisely by a new bi-arc interpolation method that the location of maximum error is fixed at an efficient point. The newly developed bi-arc meets the given tolerance more precisely, performs faster calculation. The cutting condition input module and the NC code verification module are adequate to ultra-precision machining, so that a operator can obtain products fast and easily.
Modeling and Parameter estimation of Antilock Braking System
Song, Chang-Sub ; Rho, Hyoung-Woo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 87~92
By using the signal error test, model structure of total antilock braking system consisting of electromagnetic system and hydraulic system is determined as 9th order system. For determining parameters of the ABS, using time discrete model of parametric method, parameters in time discrete model are searched by least square method. By bilinear transform, we have found the model of ABS in s domain. Afterward, experimental output data is compared with simulated output data by MATLAB haying identified parameter. As the result, experimental data is agreed with simulated data very well.
Analysis of the Characteristics of the Feed motor Current for the Estimation of the Cutting Force in General Cutting Environment
Jeong, Young-Hun ; Yun, Seong-Hyun ; Cho, Dong-Woo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 93~100
The current from the feed motor of a machine tool contains substantial information about the machining state. There have been many researches that investigated the current as a measure for the cutting farces. However it has been reported that this indirect measurement of the cutting farces from the feed motor current is only feasible in low frequency. In this research, it was presented that the bandwidth of the current monitoring can be expanded to 130 Hz. And the unusual behavior of the current was examined in this bandwidth. The cross-feed directional cutting force influences the machined surface of the workpiece, which makes it necessary to estimate this force to control the roughness of the machined sulfate. The current exists in the stationary feed motor, and it can give the useful information on the quality of the machined surface. But the unpredictable behavior of the current prevents applying the current to prediction of the cutting state. Empirical approach was conducted to resolve the problem. As a result, the current was shown to be related to the accumulation of the accumulation of the infinitesimal rotation of the motor. rotation of the motor. Subsequently the relationship between the current and the cutting force was identified.
A Study on the Electrochemical Micro-machining for Fabrication of Micro Grooves
Park, Jeong-Woo ; Lee, Eun-Sang ; Moon, Young-Hun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 101~108
A specially-built EMM (Electrochemical Micro Machining) / PECM (Pulse Electrochemical Machining) cell, a electrode tool filled with non-conducting material, a electrolyte flow control system and a small & stable gap control unit are developed to achieve accurate dimensions of recesses. Two electrolytes, aqueous sodium nitrate and aqueous sodium chloridc arc applied in this study. The farmer electrolyte has better machine-ability than the latter one because of its appropriate changing to the transpassive state without pits on the surface of workpiece. It is easier to control the machining depth precisely by micrometer with pulse current than direct current. This paper also presents an identification method for the machining depth by in-process analysis of machining current and inter electrode gap size. The inter electrode gap characteristics, inc1uding pulse current, effective volumetric electrochemical equivalent and electrolyte conductivity variations, are analyzed based on the model and experiments.
Aircraft Wing Spar Cross-section Area Optimization with Response Surface Method
Park, Chan-Woo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 109~116
The solution of the aircraft wing spar cross-section area optimization problem is obtained by the response surface method. The object function of the problem is wing total weight, design variables are spar cross-section areas, constraints are the conditions that the stresses at the each spar is less than the allowable stress. D-Optimal condition is utilized to obtain the experimental points to construct the response surfaces. D-Optimal experimental points are obtained by the commercial software "Deign-Expert". Response values for the object function and constraints for each experimental point are calculated by the NASTRAN. Response surfaces for object function and constraints are approximated from the response values by the least square method. The optimization solution is obtained by the DOT for the response surfaces of object function and constraints. The optimization results obtained from the response surface are compared with the results obtained by the NASTRAN SOL200.
The Study on the Quantitative Analysis of Accident Fracture Surface by X-ray Diffraction
Choi, Seong-Dae ; Kweon, Hyun-Kyu ; Cheong, Seon-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 117~123
X-ray diffraction observation of fracture surfaces yields useful information to analyze the causes of failure accidents of engineering structures. This experimental technique, named X-ray fractography, has been developed especially in metal and mechanical engineering fields. The distributions of the residual stress and the half value breadth of diffraction profiles beneath the fatigue fracture surface were measured with SNCM 439, HT100 and Ti-6Al-4V alloy. The size of the maximum plastic zone was successfully determined on the basis of the measured distributions. This size was correlated to maximum stress intensity factor. The distributions of the half value breadth of diffraction profiles on the fatigue fracture surfaces were measured with SNCM 439. HT100. The equations of x-ray parameter distribution were possible to estimated fracture parameters of fatigue fracture surfaces.
A Generalized Volumetric Error Modeling Considering Backlash in Machine Tools
Ahn, Kyoung-Gee ; Cho, Dong-Woo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 124~131
In this paper, an extended volumetric error model considering backlash in a three-axis machine tool was proposed and utilized for calculating the volumetric error of the machine tool at any position in three-dimensional workspace. Backlashes are interrelated; i.e. the angular backlash affects the straightness errors which then affect talc calculated squareness errors. Therefore, a new concept was introduced to define the backlash of squareness errors to incorporate the backlash of squareness error into the volumetric error, and the characteristics of the backlash of squareness error were investigated. The effects of backlash errors were assessed, by experiments. for 21 geometric errors of a machine tool. The backlash error was shown to be one of the systematic errors of a machine tool. And a generalized volumetric error model formulator for three-axis machine tools was developed, which allowed us to formulate machine tool synthesis error models far all possible machine tool configurations only with machine tool topology information. Based on these volumetric error model and model formulator, a computer-aided volumetric error analysis system was developed for a three-axis machine tool in this paper. Then the volumetric error at an arbitrary position can be obtained, and displayed in a three-dimensional graphic form.
Development of Inference Algorithm for Bead Geometry in GMAW
Kim, Myun-Hee ; Bae, Joon-Young ; Lee, Sang-Ryong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 132~139
In GMAW(Gas Metal Arc Welding) processes, bead geometry (penetration, bead width and height) is a criterion to estimate welding quality. Bead geometry is affected by welding current, arc voltage and travel speed, shielding gas, CTWD (contact-tip to workpiece distance) and so on. In this paper, welding process variables were selected as welding current, arc voltage and travel speed. And bead geometry was reasoned from the chosen welding process variables using neuro-fuzzy algorithm. Neural networks was applied to design FL(fuzzy logic). The parameters of input membership functions and those of consequence functions in FL were tuned through the method of learning by backpropagation algorithm. Bead geometry could be reasoned from welding current, arc voltage, travel speed on FL using the results learned by neural networks. On the developed inference system of bead geometry using neuro-furzy algorithm, the inference error percent of bead width was within
4%, that of bead height was within
3%, and that of penetration was within
8%. Neural networks came into effect to find the parameters of input membership functions and those of consequence in FL. Therefore the inference system of welding quality expects to be developed through proposed algorithm.
A Study on the Active Balancing for High-Speed Rotors (I): Development of the Active Balancing System
Kim, Jong-Soo ; Park, Hyun-Kyu ; Lee, Soo-Hun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 140~146
High speed rotating machines can be very sensitive to rotating mass unbalance that is a major source of harmful vibration for many types of rotating machinery. So, the balancing procedure is needed for all high-speed rotating system. To save the time and cost of off-line balancing, many researchers have developed the on-line balancing devices and methods. In this paper, an active balancing device, which is an electro-magnetic type, is developed and the active balancing algorithm using influence coefficient method is also proposed. The active balancing experiment for flexible rotors during operation is performed by an active balancing device. As a result, controlled unbalance responses are below the vibration limit at all rotating speed ranges with critical speed.
A Study on the Active Balancing for High-Speed Rotors (II): Control Stability and Application
Kim, Jong-Soo ; Moon, Jong-Duk ; Lee, Soo-Hun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 147~153
In the preceding research, the active balancing device, which is an electro-magnetic type, has been developed and active balancing method using influence coefficient method is also proposed. The stability of active balancing control is studied in this paper. A stable condition for active balancing control is derived by estimating errors of influence coefficients. A gain scheduling control using influence coefficients of the reference model is proposed when dynamic characteristic of rotor system is changed. The stability of the balancing method is verified by experiments.
Evaluation of Tool Wear of P/M High Speed Steel Flat Endmill
Jung, Ha-Seung ; Ko, Tae-Jo ; Kim, Hee-Sool ; Bae, Jong-Soo ; Kim, Yong-Jin ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 154~160
Powder metallurgy(P/M) process has been used for the production of high performance high-speed steels. P/M high speed steel has more uniform and fine microstructure than those of conventional wrought products. Therefore, it offers distinct advantages over conventional tool steels. The superior uniformity of composition and fine microstrucure lead to excellent toughness and less distortion during heat treatment, which in turn can reduce total grinding costs and provides other benefits, such as uniform hardness and increased tool life. From these reasons, milling, hole machining, broaching, and gear manufacturing tools are major applications of P/M high-speed steels. In this research, we evaluated tool wear of flat endmill which is made of P/M high-speed steel from the view point of cutting tool performance.
Characterization of Electrostrictive Polyurethane Films for Micro-Actuators
Jeong, Eun-Soo ; Park, Han-Soo ; Jeong, Hae-Do ; Jo, Nam-Ju ; Jae, Woo-Seong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 161~167
For the purpose of applying to micro-actuator, thermal properties and displacement of electrostrictive polyurethane(PU) elastomers have been measured. In order to understand an effect of PU component, crosslinking agent are controlled by 0.5 wt% and 1 wt%. DMPA and anther chain extenders were used. PU sample that chain extenders are DMPA is added NaOH for comprehension of effect of ionic groups. The deposited electrode sire on PU films is equal to acrylic holder size when the displacement was measured. Dynamic response according to frequency, displacement and recovery time according to PU thickness were measured. 1 wt% crosslinking agent contents PU samples have higher displacement and lower recovery time than 0.5 wt% crosslinking agent contents PU. If the PU thickness is increased, the actuating voltage for generating of same displacement is increased, too.
Model of Remote Service and Intelligent Fault Diagnosis for CNC Machine Tool
Kim, Sun-Ho ; Kim, Dong-Hoon ; Han, Gi-Sang ; Kim, Chan-Bong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 168~178
The CNC machine toots has two kinds of fault. One is the fault due to degraded parts and the other is the fault due to operation disability. The phenomena of degradation is predictable but the operational fault is unpredictable because it occurred without any warning. The major faults of CNC machine tool are operational faults which are charged over 70%. This paper describes the model of remote service and the intelligent fault diagnosis system to diagnosis operational faults of CNC machine tools. To generalize fault diagnosis, two diagnosis models such as SF(Switching Function) and SSF(Step Switching Function) are proposed. The SF is static model and SSF is dynamic model for expression of fault. The SF and SSF model can be generated using SFG(Switching Function Generator) which is developed in this research. The three major operational faults such as emergency stop error, cycle start disability and machine ready disability are applied to experiment of fault modeling. To remote service of faults fur CNC machine tool, the web server and client system based internet are proposed as the suitable environment. The developed two technologies are implemented with the internal function of open architecture controller. The implemental results for two technologies are presented to validate the proposed scheme.
A Study on Improving The Coefficient of Utilization of Material in Deep Drawing Process
Lee, Kyung-Won ; Ban, Jae-Sam ; Park, Young-Jin ; Cho, Kyu-Zong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 179~186
This paper is the study on improving the coefficient of utilization of material in deep drawing process. Cylindrical cup drawing process is widely used in sheet metal forming process. The blank shape is one of the important things in sheet metal forming process. It is produced for the bridge of blank in a blanking process. The coefficient of utilization of material is much effected by this bridge of blank. This study offered a new process method to reduce the loss of material. The new blank shape offered and manufactured by new process method is investigated by a finite element method and the experiment. Then the wrinkling, the punch load, the thickness distribution is observed. This result is different from the result of circular blank process. And it is got that the Max strain, the wrinkle and the height of the wrinkle are effected by the holding farce and the punch load. As a result. if the processing optimum condition is found, the loss of material will be reduced. It is necessary to research systematically about determining the optimum vague of process variables.
An Obstacle-Avoidance Algorithm for a Redundant Robot Arm Using Fuzzy Control and Performance-Function Optimization
Lee, Byung-Ryong ; Hwang, Jae-Suk ; Park, Chan-Ho ; Yang, Soon-Yong ; Ahn, Kyung-Kwan ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 187~194
In this paper, a motion control algorithm is developed using a fuzzy control and the optimization of performance function, which makes a robot arm avoid an unexpected obstacle when the end-effector of the robot arm is moving to the goal position. During talc motion, if there exists no obstacle, the end-effector of the robot arm moves along the predefined path. But if these exists an obstacle and close to talc robot arm, the fuzzy motion controller is activated to adjust the path of the end-effector of the robot arm. Then, the robot arm takes the optimal posture far collision avoidance with the obstacle. To show the feasibility of the developed algorithm, numerical simulations are carried out with changing both the positions and sites of obstacles. It was concluded that the proposed algorithm gives a good performance for obstacle avoidance.
A High-Resolution Heterodyne Interferometer using Beat Frequency between Two-Axial Modes of a HeNe Laser
Kim, Min-Seok ; Kim, Seung-Woo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 195~201
We propose a new scheme of high-resolution heterodyne interferometer that employs the two-axial mode He-Ne laser with an inter-mode beat frequency of 600~1000 MHz. An electronic RF-heterodyne circuit lowers the beat frequency down to 5 MHz, so that the phase change of the interferometer output is precisely measured with a displacement resolution of 0.1 nanometer without significant loss of dynamic bandwidth. A thermal control scheme is adopted to stabilize the cavity length with ainus to suppress frequency drifts caused by the phenomena of frequency pulling and polarization anisotropy of the two-axial made laser to a stability level of 2 parts in
. The two-axial mode HeNe laser yields a high output power of 2.0 mW, which allows us to perform multiple measurements of up to 10 machine axes simultaneously.
Robust Force Control of a 6-Link Electro-Hydraulic Manipulator
Ahn, Kyoung-Kwan ; Cho, Yong-Rae ; Yang, Soon-Yong ; Lee, Byung-Ryong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 4, 2002, Pages 202~208
An electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous assembly tasks using hydraulic manipulators. In this report, we applied a compliance control which is based on the position control by a disturbance observer for our manipulator system. And a reference trajectory modification method is proposed in order to achieve accurate force control even though the stiffness and position of environment change. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved under various environment conditions.