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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 11, Issue 6 - Dec 1994
Volume 11, Issue 5 - Oct 1994
Volume 11, Issue 4 - Aug 1994
Volume 11, Issue 3 - Jun 1994
Volume 11, Issue 2 - Apr 1994
Volume 11, Issue 1 - Feb 1994
Selecting the target year
중소기업용 제조관리 시스템 개발
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 11~19
생산자동화 시스템에서의 신경회로망
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 20~31
자동화 제조시스템의 유연성 펑가방법
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 32~43
A Study on the Cutting Characteristics of SCM440, SNCM21, STS 304 in Cryogenic Cutting(1st Report)
Kim, C.S. ; S.S. Oh ; Y.H. Lim ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 44~53
We experimented on cutting characteristics-cutting force, behavior of cutting temprature, surface foughness, behavior of chips-under low tempdeature, which generated by liquid nitrogen (77K). The workpieces were freezed to -195 .deg. C and liquid nitrogen was also sprinkled on cutting area in order to increase the efficiency of machining in low temperature. The workpiece was became to -195 .deg. C in 5 minutes, and cutting temperature in CC was lower about 170 .deg. C than NC. The cutting force trended to increase slighty in cooled cutting, but chip thickness was decreased, shear angle was however increased. The form of chips was in good conditions of long or short tubular chips in CC. In CC surface roughness of workpiece was better than NC. In NC surface hardness of chips trended to increase according to increasing of cutting speed, but in CC it trended to decrease. The power spectrum of vertical cutting force trended to increase according to increasing of feed, and in CC it was higher than NC.
Active Vibration Control of a Composite Beam Using Piezoelectric Films
Kim, S.H. ; Park, S.B. ; C.C. Cheong ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 54~62
This paper presents active control methodologies to suppress structural deflections of a composite beam using a distributed piezoelectric-film actuator and sensor. Three types of different controllers are employed to achieve vibration suppression. The controllers are established depending upon the information on the velocity components of the structrue and on the deflection magnitudes as well. They are constant-amplitude controller(CAC), constant-gain mcontroller(CGC), and constant-amplitude-gain controller(CAGC). For the minimization of the residual vibration (chattering in a settled phase), which is the practical shortcoming of the conventional CAC dur to time delay phenomenon of the hardware system, a new control algoritym CAGCis designed by selecting switching constants in an optimal manner with respect to the initial tip deflection and the applied voltage. The experimental investigations of the transient and forced vibration control for the first vibrational mode are undertaken in order to compare the suppression efficiency of each control algorithm. Moreover, simultaneous controllability of various vibrational modes through the proposed scheme is also experimentally verified by pressenting both the transfer function and the phase.
Accuracy Evaluation of a Non-Contact Rotational Torque Measurement System by Using Telemeter
Kim, G.S. ; J.W. Joo ; Y.H. Kwon ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 63~70
This paper presents manufacturing and evaluation of a non-contact rotational torque measurement system which consists of torque cell, telemeter system, transmitter and receiver coil, transmitter, receiver and telemeter indicator. Static calibration test results show that the system has a maximum uncertaintry of 05% or less. A standar calibration system for rotational torque is used to evaluate the measurement system, As a result, the maximum uncertainty for measuring rotational torque by this system is 2% or less. We may conclude that the measurement system is sufficient to measure rotational torque of shaft in industry.
Characteristics of tool wear and cutting temperature in machining of SUS 304
Kwon, Y.K. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 71~79
The aim of this study is to analyze the behavier of SUS 304 during the cutting process and the resulting cutting temperaturce. Since SUS 304 is a difficult-to-machine material, tool damage is largely affected by the suitability of cutting conditions. Therefore, in varying such cutting conditions, the experiment investigates the relations between cutting temperature and tool wear during the cutting process. All the cutting temperature data were manipulated successfully, and the tool temperature distributions were analyzed by a finite element method based on the acquisition data. In the results, the characteristics of cutting temperature are related to the difficulty of machining characteristics.
Identification of Contact State between Parts during Peg-in-Hole Process by Fuzzy Inference Method
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 80~88
In the automation of rigid parts mating process with the intelligent robots, Peg-In-Hole is the most available task since inserting is some analytic and needs suitable range of forces that can be controlled by induatrial manipulators. In this Peg-In-Hole process, it is very important to identify the contact state between tow parts, peg and hole, to build the strategies for robot motion that leads to avoid the jamming condition occurs during insertion process. In this paper, we adpopted 3 parameters for identification, lFzl, lFxy/Fzl, and lMxy/Fxyl, derived from axes value of Whitney's jamming diagram. Also, we defined the fuzzy membership functions for these parameters and developed the identification algorithm based on fuzzy inference method of max-product. As an experimental result, we obtained about 96% of identification ratio that could be raised up to industrial requirements by further research.
Experimental Study on Structural Characteristics of Machine Bed Model Using Epoxy-Granite Material
Maeng, H.Y. ; Park, Y.I. ; Won, S.T. ; Kim, J.H. ; Lee, H.S. ; Park, J.K. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 89~96
This study is to develop a new composite material, a mixture of epoxy resin and granite aggergates which is called Expoxy-Granite, to overcome the inherent disadvantages of conventional materials commonly used as a bed structure material of long-term dimensional/ thermal stability. Under the various manufacturing conditions which could be formulated through experimental investigation, we have constructed 6 kinds of Epoxy-Granite structure models having one fifth the size of the ultra-precision machine tool bed structure. They are compared with cast iron and pure granite models through the dynamic test and the thermal deformation test. Both in the steel ball dropping test and in the forced vibration test, three types of epoxy-granite models made in this study have shown much better dynamic characteristics than the cast iron model and almost the same characteristics as compared with the pure granite model. In the thermal deformation test the above composite materials have also represented lower thermal displacements in the vertical direction of each model as compared with other specimens. It is therefore seen that the epoxy-granite complsite material can be applied to the construction of high-precision machine tool bed, instead of cast iron or pure granite.
A Study on the Vibration Characteristics of Nonuniform Cross Section Propeller Blade
I.S. Chung ; H.C. Chae ; K.M. Kim ; H.S. Lee ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 97~107
The method is presented for determining the free vibration characteristics of a rotating blade having nonuniform spanwise properties and cantilever boundary condition. The equations which govern the coupled flapwise, chordwise and torsional motion of such a blade are solved using an integrating matrix method. By expressing the equation of motion in matrix notation, utilizing the integrating matrix as an operator, and applying the boundary condition, the equations are formulated into an eigenvalue problem whose solution may be determined by conventional method. Computed results are compared with experimental data.
Development of Active Noise Control System using DSP
Kim, H.S. ; Shin, J. ; Oh, J.E. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 108~113
Active noise control technique has superior performance in low frequency ranges(50 .approx. 400Hz) to the conventional passive noise control technique. For the feasibility of active noise control, it is required to develop a controller which can implement control algorithm on real-time. In this study, therefore, real-time controller is developed using TMS320c25, high speed digital processor. Unlike conventional DSP board of complete ADD ON type, it is possible for the developed controller to interface with the other computer system easily by series communication for the convenience of program development. Furthermore it is designes to be separated readily as a control device. Active noise control of duct system is implemented ti evaluate a performance of developed device. Active noise control of duct system is implemented to evaluate a performance of developed controller using filtered-x LMS algorithm.
A Study on the Measurement of two Dimensional Strain by ESPI Method and Image processing
K.S. Kim ; H.S. Kim ; C.W. Kim ; M.S. Hong ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 114~122
ESPE(Electonic-Speckle-Pattern-Interferometry) is very useful method for measuring In-plane displacement. Using the CW-Laser and Image processing system, it is possible to measure displacement and strain. Unlike traditional straingauge or moire' method, ESPI method requires no special surface preparation or attachments and can be measured In-plane displacement with no contact and real time. In this experimental specimen was loaded in paralled with loadcell, which provided loading step. The specimen was sheet plate, which was attached straingauge in x-y direction. In this study provides an example of how ESPI has been used to measure two dimensional displacement and strain distribution in this specimen. The results measured by ESPI compare with the data which was measured straingauge method in tensile testing at 1 ton range.
Air Cooling Characteristics of a High Speed Spindle System for Machine Tools
Park, D.B. ; Kim, S.I. ; J.B. Song ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 123~128
A high speed spindle system for machine tools can be used to reduce the machining time, to improve the machining accuracy, to perform the machining of light metals and hard materials, and to unite the cutting and grinding processes. In this study, a high speed spindle system is developed by applying the oil-air lubrication method, angular contact ball bearings, injection nozzles with dual orifices, cooling jacket and so on. And an air cooling experiment for evaluating the performance of the spindle system is carried out. Especially, in ofder to establish the air cooling conditions related to the development of a high speed spindle system, the effects of cooling air pressure, oil supply rate, air supply rate and rotational spindle speed are studied and discussed on the bearing temperature rise and frictional torque. Also the effects of cooling air pressure, rotational spindle speed and spindle system structure is investigated on the bearing temperature distribution. The experiment on the test model reveals the usefulness of the air cooling method.
Analysis of Superplastic Forming Process Design Using a Combined Stretch/Blow Process for Uniform Thickness Distribution
Hong, S.S. ; Lee, J.S. ; Kin, Y.H. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 129~137
A rigid-viscoplastic finite element method has been used for modeling superplastic stretch/blow process design to improve thickness distribution. Punch velocity-time relationship of the stretch forming and pressure-time cycle of the blow forming for a given strain rate are calculated. A superplastic material is assumed to be isotropic and a plane-strain line element based on membrane approximation is employed for the formulation. The effects of the width, corner radius and height of the punch during stretch forming are examined for the final thickness distribution, and the process design to improve thickness distribution can be established.
Adaptive Milling Process Modeling and Nerual Networks Applied to Tool Wear Monitoring
T.J. Ko ; D.W. Cho ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 138~149
This paper introduces a new monitoring technique which utilizes an adaptive signal processing for feature generation, coupled with a multilayered merual network for pattern recognition. The cutting force signal in face milling operation was modeled by a low order discrete autoregressive model, shere parameters were estimated recursively at each sampling instant using a parameter adaptation algorithm based on an RLS(recursive least square) method with discounted measurements. The influences of the adaptation algorithm parameters as well as some considerations for modeling on the estimation results are discussed. The sensitivity of the extimated model parameters to the tool state(new and worn tool)is presented, and the application of a multilayered neural network to tool state monitoring using the previously generated features is also demonstrated with a high success rate. The methodology turned out to be quite suitable for in-process tool wear monitoring in the sense that the model parameters are effective as tool state features in milling operation and that the classifier successfully maps the sensors data to correct output decision.
Measurement methodology for the alignment accuracy of wafer stepper
J.H. Lee ; W.I. Jang ; D.H. Kim ; B.H. Nam ; J.H. Kim ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 150~156
To meet the process requirement of semiconductor device manufacturing, it is necessary to improve the alignment accuracy in exposure equipments. We developed the excimer laser stepper and will describe the methodology for alignment measurement and experimental results. Our wafer alignment system consists of off-axis optics, TTL(Through The Lens) optics and high precision stage. Off-axis alignment utilizes the image processing and /or diffraction from thealign marks of off-centered chip area. On the other hand, TTL alignment can be used for the die-by-die alignment using dual beam interferometry. When only off-axis alignment was used, the experimental alignment error(lml+3 .sigma. ) was 0.26-0.29 .mu. m, and will be reduced down to 0.15 .mu. m by adding TTL alignment.
Development of a General-Purpose Program for Automatic Finite-Element Modelling with Quadrilateral Finite Elements
M.S. Joun ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 157~165
A general-purpose program for automatic two-dimensional finite-element modelling with quadrilateral elements was developed in this research. The conventional looping method employed in the program was introduced with emphasis on a new splitting criterion and a splitting scheme developed for improving the method. Some application examples were given, which show versatility and applicability of the developed program.
Effects of Source Correlation on Plates Driven by Multi-point Random Forces
Oh, S.G. ; Park, J.D. ; Kwak, C.S. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 166~176
The problem of reducing the vibration level of elastic plates driven by multiple random point forces is analyzed in this study. First, the analytical solution for the vibration level of finite thin plates with four simply supported edges under the action of multiple random point force is derived. By assuming the plates to be lightly damped, an approximate solution for the vibration level of the plate is obtained. A numerical study is carried out to determine an optimal spacing distance between the multiple point forces in order to produce a relative minimum in the plate's vibration level. The optimal spacing distance is shown to depend on the given excitation band. The effects of wave cancellation in the near field of the multiple point forces are discussed by using the equivalence of certain stationary random responses and deterministic pulse responese.
Finishing of Scupltured Surface through Cusp Pattern Control and Micro-ball End Milling
C.G. Sim ; M.Y. Yang ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 177~183
The ball-end milling process is widely used in the die/mold industries, and it is very suitable for the machining of free-from surfaces. However, cusps(or scallops) remaining at the machined part along the cutter paths require anothe finish process such as polishing or grinding. In this study, a high sped micro ball-end milling method has been suggested for the finish of free- form surfaces. A new tool path which makes the geometrical roughness of workpiece be constant through the machined surface has been developed. In the high speed machining of micro ball-end muling experimets, the developed tool paths have been successfully applied. And it was concluded that the surface roughness from this finish cuts of micro ball-end milling process was acceptable.
Development of Design Technology for Assembly Automation
H.S. Mok ; J.W. Ha ; D.K. Cha ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 184~191
In this study, the product design technology to facilitate the assembly automation is developed. First, checkistis are developed to analyse weakpoints which make assembly automation difficult. The weakpoints of assembly automation can be redesigned by using design rules for assemblability which are systematized in this research. In addition, the assemblability of product can be evaluated qualitatively with the new developed assembly evaluation method. This evaluation method is performed in the respect of the component parts, the assembly method and the assembly motion.
Probabilistic Fatigue Crack Growth Analysis under Random Loading
S.H. Song ; D.S. Chang ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 192~200
The methodology of a simple probabilistic fatigue crack under random loading is proposed. Using the crack closure concept, the crack opening stress is assumed to be constant during random loading. The loading history was analyzed to determine the probability density functions, probability distribution functions and other related parameters for the probabilistic fatigue crack growth analysis. Fatigue crack growth using the exisiting available data was predicted by the proposed probabilistic analysis and compared with experimental data.
Comparison of Theoretical model with Experiment in Bead Shape of Laser Welding
Kim, J.D. ; Kim, J.D. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 201~210
A theoretical heat-flow model incorporating with a constant moving CO
laser beam has been analyzed to predict depth and the shape of bead section during last beam welding. The laser beam is exponentially attenuated with an abosrption coefficient in the material. The solution can be expressed in terms of normalized variables. The experimental data were generated by usint CW 2 CO
laser with multi beam mode and CW 3 kW CO
laser with Gaussian mode. The specimens were made as bead-on-plate welds for SM 10C, STS 304, STS 316, STS 420 and pure Nickel. The maximum possible penetration depth and the shape of beas section for given sources of laser power, travel speed and beam spot size can be prdicted with this model in a given material.
Architecture of knowledge-Base and Management System for Grining Operations
Kim, G.H. ; I. Inasaki ; Lee, J.K. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 211~218
Grinding is considered as a very effective machining technology to attain high production rates and a good surface quality of hard and brittle components. However, the grinding operations till needs the skill and the experience of an operator because of a lack of scientific knowledge and engineering principles. This is the reason why grinding operations are not completley intergrated in CIMS(Computer Intergrated Manufacturing System. Recent develop- ment focus on expert system which deals with domain specific knowledge in order to solve this problem. Firstly, in this study, a basic strategy to develop the grinding knowledge-base for grinding is discussed. Next, the architecture of knowledge-base and management of the grinding knowledge-base(GKB) is described.
Architecture and Implementation of Database on the Cylindrical Grinding Utilizing the Fuzzy Regression Model
Kim, G.H. ; I. Inasaki ; Song, J.B. ;
Journal of the Korean Society for Precision Engineering, volume 11, issue 1, 1994, Pages 219~229
This paper describes an expert system on the cylindrical grinding operations in order to establish the optimum grinding conditions, which satisfy the maximum removal rates, considering the several constraints of grinding power, workpiece burn, chatter vibration and surface roughness. Specialized knowledge of the grinding operations are acquired from the actual operation database. Coefficientis in the experimental equations are obtaines through the fuzzy regression model based on the fuzzy set theory, and are stored in the actual operation database. The developed system is capable of determining the optimum grinding conditions taking into account some problems, and practical examples of implementaion are described.