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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 18, Issue 12 - Dec 2001
Volume 18, Issue 11 - Nov 2001
Volume 18, Issue 10 - Oct 2001
Volume 18, Issue 9 - Sep 2001
Volume 18, Issue 8 - Aug 2001
Volume 18, Issue 7 - Jul 2001
Volume 18, Issue 6 - Jun 2001
Volume 18, Issue 5 - May 2001
Volume 18, Issue 4 - Apr 2001
Volume 18, Issue 3 - Mar 2001
Volume 18, Issue 2 - Feb 2001
Volume 18, Issue 1 - Jan 2001
Selecting the target year
Information Storage Devices Using Smart Materials
Choe, Seung-Bok ; Im, Su-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 11~21
Fabrication of 3-D MEMS using smart materials
Kim, Jae-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 22~29
Active Vibration Control of Smart Structure Using Piezoceramics
Gwak, Mun-Gyu ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 30~46
Optimal Design of a Variable-Speed Cam for Power Circuit Breaker
Kim, Jun-Hyeong ; An, Gil-Yeong ; Kim, Su-Hyeon ; Gwak, Yun-Geun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 47~53
Power Circuit Breaker uses a variable-speed cam mechanism actuated by pre-loaded spring force. This paper presents the optimal design procedure for a variable-speed cam mechanism based on the dynamic model of a complete spring-actuated cam system. The optimal cam is compared with an original cam. Simulation results show that the dynamic behaviors of the designed cam are superior to those of the original cam.
The Effect of the Area Ratio and Change of Location on the Buckling Stress of Two Rectangular Plates Spot-welded
Han, Geun-Jo ; An, Seong-Chan ; Sim, Jae-Jun ; Lee, Hyeon-Cheol ; Jang, Hwal-Su ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 54~59
The stability of a thin plate structure is very crucial problem which results buckling. Because the buckling strength of thin plates is lower than the yield strength of the material, reinforcement plate must be used to increase the buckling strength. And, in this case, spot welding is commonly used, however, the spot welded joints are practically designed by experimental decisions, so it is Inefficient and has the risks of buckling demolition. In this study, two parameters, such as the area ratio and the distance ratio of spot welding which have influence on the buckling strength, should be chosen. Under compressive and shearing load, the effect of two parameters on the critical stress is discussed.
Analysis for Filling Stage of Injection Molding Considering Compressibility and Phase Change
Lee, Sang-Chan ; Park, Chang-Eon ; Yang, Dong-Yeol ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 60~65
To simulate the real molding conditions, the effects of phase change and compressibility of the resin were considered in the present investigation. A modified Cross model with either an Arrhenius-type or WLF-type functional form was used for modeling viscosity of the resin. A double-domain Tait equation of state was employed to describe the compressibility of the resin during molding. The energy balance equation including latent-heat dissipation fur semi-crystalline materials was solved in order to predict the solidified layer and temperature profile. Injection molding experiments were carried out using polypropylene(PP) in the present study. Based on the comparison between experiments and simulations, it was found out the predicted pressure distributions and melt front propagations were accurate. Thus it was concluded that the program developed in this study was proved to be useful in simulations of injection molding process.
Position and Vibration Control of a Spatial Redundant Flexible Manipulator by using Pseudo-inverse of Jacobian
Kim, Jin-Su ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 66~72
In this paper, by using pseudo-inverse matrix of the spatial redundant flexible manipulators, a position control method and its effect in vibration suppression was presented. Vibration suppression control was developed using lumped mass spring model of the flexible manipulators. With 2 elastic links and 7 rotory joint manipulator ADAM, (1)position control for no redundancy, and (2)position control for one redundant DOF(degree of freedom) were tested. The objective of this experiment is to show the effect of position control, using pseudo-inverse matrix. toward the improvement of operation, and at the same time, to reduce the vibration of the link and the magnitude of the joint torque.
A Study on the Numerical Analysis of Magnetic Flux Density by a Solenoid for MIAB Welding
Choe, Dong-Hyeok ; Kim, Jae-Ung ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 73~81
The MIAB welding uses a rotating arc as its heat source and is known as an efficient method fur pipe butt welding. The arc is rotated around the weld line by the electro-magnetic force resulting from the interaction of arc current and magnetic field. The electro-magnetic force is affected by magnetic flux density, arc current, and arc length. Especially, the magnetic flux density is an important factor on arc rotation and weld quality. This paper presents a 2D finite element model for the analysis of magnetic flux density in the actual welding conditions. The magnetic flux density is mainly dependent on gap between two pipes, the position of coil from gap center, exciting current, and relative permeability. Thus, the relations between magnetic flux density and main factors were investigated through experiment and analysis. Experiments were performed for the steel pipes(48.1mm O.D and 2.0mm thickness). The analysis results of magnetic flux density reveal that it increases with increasing exciting current, increasing relative permeability, decreasing distance from gap center to coil, and decreasing gap size. It is considered that the results of this study can be used as important data on the design of coil system and MIAB welding system.
A Study on the Mirror Grinding for Mold of a Small Aspherical Lens
Lee, Joo-Sang ; Masaru Saeki ; Tsunemoto Kuriyagawa ; Katsuo Syoji ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 82~87
This paper deals with mirror grinding of a small-sized aspherical lens by the resin bonded diamond spherical wheel. Up to now, a spherical lens has been used for the lens of the optical communication optical part. However, recently, the aspherical optical parts are mainly used in order to attempt the improvement in image quality and miniaturization of the optical device. It is possible to manufacture the aspherical lens which is presently being used in optical instrument through ultra-precision machinery technology. Also, to realize compactability, efforts are being made to produce a micro aspherical lens, for which the development of a high-precision, micro molding die is inevitable. Therefore, extensive research is being done on methods of producing an micro aspherical surface by high-precision grinding. In this paper, the spherical wheel was trued by cup-type truer and tool path was calculated by the radius of curvature of wheel after truing and dressing. And then in the aspherical grinding experiment, WC material which is used as a molding die for the small-sized aspherical lens was ground. It results was that a form accuracy of 0.1918
P-V and a surface roughness of 0.064
An Analysis of Eigenvector Coefficient for V-notched Cracks in Pseudo-isotropic and Anisotropic Dissimilar Materials
Kim, Jin-Gwang ; Jo, Sang-Bong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 88~94
The V-notched crack problem in dissimilar materials can be formulated as an eigenvalue problem. The RWCIM(Reciprocal Work Contour Integral Method) is applied to the determination of the eigenvector coefficients associated with eigenvalues for V-notched cracks in pseudo-isotropic and anisotropic dissimilar materials. The RWCIM algorithm is programed by the commercial numerical program, MATHEMATICA. The numerical results obtained are shown that the RWCIM is a useful method for determining the eigenvector coefficients of V-notched cracks in pseudo-isotropic and anisotropic dissimilar materials.
Buckling of an Orthotropic Layer Bonded to a Half-Space with an Interface Crack
Jeong, Gyeong-Mun ; Beom, Hyeon-Gyu ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 95~103
The buckling of an orthotropic layer bonded to an orthotropic half-space with an interface crack subjected to compressive load under plane strain is analyzed. General solution to the stability equations describing the buckling behavior of both the layer and the half-space is expressed in terms of displacement functions. The displacement functions are represented by the solution of Cauchy-type singular integral equations, which are numerically solved. Numerical results of the critical buckling loads are presented fur various geometric parameters and material properties of both the layer and half-space.
Dynamic Characteristics Prediction of Rubber Mounts for Anti-Vibration of an Optical Disk Drive
Kim, Guk-Won ; Kim, Nam-Ung ; Im, Jong-Rak ; An, Tae-Gil ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 104~109
With the increase of storage density and data transfer rates in optical disk drive, mechanical issues, mainly noise and vibration, become critical. Rubber materials are extensively used in various machine design application, mainly for vibration/shock/noise control devices. However, there are still a lot of difficulties in the use of designing the rubber components with complex shape and under pre-deformed state. It was demonstrated in that the variation of rubber component stiffness with the pre-deformed state were calculated by the finite element method and the reliability of numerical results were checked by compared with the measuring the deflection values. This paper presents a efficient design method of rubber mounts for anti-vibration of an optical disk thrive. With an empirical equation to estimate elastic modulus from hardness, and dynamic characteristics of rubber material of a cylindrical shape, this method is capable of predicting the dynamic characteristics of rubber components at design stage.
Temperature Analysis of Each Coolant Level by a Multiple Comparison in Turning Process
Park, Tae-Jun ; Yang, Seung-Han ; Lee, Yeong-Mun ; Kim, Hui-Sul ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 110~115
In this paper, a multiple comparison was proposed to minimize the amount of coolant. And new coolant level, called "low level", was suggested to show usefulness of multiple comparison for experiments. The amount of this levee is about 1/4 of conventional coolant amount-called "high level", and dry cutting is called "none level". Using these coolant levels, the cutting temperatures of each coolant level in turning process were analyzed by analysis of variance(ANOYA)-test and a multiple comparison. As the result of ANOVA-test, we have just known that the average of temperature of each coolant level is not equal. However by Tukey's HSD, one of multiple comparison. it was analyzed that the average of temperature of low level is similar to that of high levee and different from that of none level.erent from that of none level.
Robust Design for Multiple Quality Attributes in Injection Molded Parts by the TOPSIS and Complex Method
Park, Jong-Cheon ; Kim, Gi-Beom ; Kim, Gyeong-Mo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 116~123
An automated injection molding design methodology has been developed to optimize multiple quality attributes, which are usually in conflict with each other, in injection molded parts. For the optimization, commercial CAE simulation tools and optimization techniques are integrated into the methodology. To decal with the multiple objective problem the relative closeness computed in TOPSIS(Technique for Order Preference by Similarity to Ideal Solution) is used as a performance measurement index for optimization multiple part defects. To attain robustness against process variation, Taguchi's quadratic loss function is introduced in the TOPSIS. Also, the modified complex method is used as an optimization tool to optimize objective function. The verification of the developed design methodology was carried out on simulation software with an actual model. Applied to production this methodology will be useful to companies in reducing their product development time and enhancing their product quality.
Rapid Manufacturing of Trial Molds and Prototypes by High Speed Machining
Sin, Bo-Seong ; Yang, Dong-Yeol ; Choe, Du-Seon ; Je, Tae-Jin ; Lee, Eung-Suk ; Hwang, Gyeong-Hyeon ; Lee, Jong-Hyeon ; J. H. ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 124~129
Recently, life cycle and lead-time of products have been shortened with the demand of customers. Therefore, it is important to reduce time and cost at the step of manufacturing trial molds. High speed machining can be applied for this kind of purpose with a lot of practical advantages. In our research, several fundamental experiments are carried out to obtain machining parameters such as cutting force, machining time and surface characteristics for tool paths that are appropriate to high-speed machining. Moreover, a trial mold for an automatic transmission knob is fabricated with aluminum-7075 material. Using automatic set-up equipments, an ABS rapid prototype of a trial product of an AT knob is also manufactured with a filling process.
Optimization of Cutting Parameters for Burr Minimization
Lee, Sang-Heon ; Lee, Seong-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 130~136
Burrs formed during face milling operations are very hard to characterize because there are many parameters that affect the cutting process. Many researchers have tried to predict burr characteristics including burr size and shapes with various experimental conditions such as cutting speed, feed rate, in-plane exit angle, number of inserts, etc., but it still remains as a challenging problem for the complex combined effects between the parameters. In this paper, the Taguchi method, which is a systematic optimization application in design and analysis of experiments, is introduced to acquire optimum cutting parameters for burr minimization in face milling. Also, analysis of variance (AVOVA) is employed to study the performance characteristics in more detail. Experimental verifications are provided to show the effectiveness of this approach.
Detection of Moving Position of AGV Using Rotating LSB(Laser Slit Beam)
Kim, Seon-Ho ; Park, Gyeong-Taek ; Park, Geon-Guk ; An, Jung-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 137~144
The major movement blocks of the container are the range between the apron and the designation points on yard in container terminals. The yard tractor drived by operator takes charge of it's movement in conventional container terminals. In automated container terminal, AGV(automatic guided vehicle) takes charge of a yard tractor's role and information of navigation path are ordered from upper control system. The automated container terminal facilities must have the docking system that guides landing zinc to execute high speed travelling and precision positioning. This paper describes the new docking method with the rotating LSB(laser slit beam) generator and two pair of photo receiver. The LSB generator is installed on the fixed ground and the photo receiver is implemented on the moving vehicle such as AGV. The proposed docking system is implemented to confirm it's function and accuracy. The accuracy of measured moving position is represented in ±5mm at 1 data sampling.
The Effect of Stress Ring for the Design of Precision Cold Forging Die
Heo, Gwan-Do ; Choe, Yeong ; Yeo, Hong-Tae ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 145~151
The dimensional accuracy of the cold forged part is depended on the elastic characteristics of the die. To increase the stiffness of the prestressed die, the first stress ring of the tungsten carbide alloy (WC) is considered. For the design, Lame's equation is used. Diameter ratios and interferences have been determinated by maximum inner pressure without yielding of materials. The design of the prestressed die has been compared with the conventional one. For the comparison, the FE-analysis using ANSYS has been performed. The results indicate that the prestressed die with the high stiffness can be obtained by the using the high stiffness material as the first stress ring.
A Study on the Performance Evaluation of a Voice Coil Actuator for Electro-Discharge Micro-Drilling Machine
Yang, Seung-Jin ; Baek, Hyeong-Chang ; Kim, Byeong-Hui ; Jang, In-Bae ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 152~158
In this paper, we have developed an electro discharge machine for micro drilling driven by a voice coil actuator. Because the voltage signal of the electro-discharging circuit shows a lot of peaks and valleys, the active type low-pass filtering technique is adopted to get the average of the signal. Since the motion of the voice coil is precisely controlled by the error value between the object voltage value and the measured one, it is possible to prevent the mechanical contact between the rotating electrode and the workpiece and to maintain the appropriate machining conditions during the process. The electro-chemical machining technology was also adopted to make small diameter electrodes. Pure water is used as a dielectric. The machining procedure is performed to verify the feasibility of the developed system. It takes about 10 seconds to drill the
hole to the 100
thickness stainless steel plate. The machining time depends on the values of the resister and the capacitor. There may exist the optimal values of time constant and the tendency is displayed In the appendix.
The Selection of the Improved Void Slab Applying the Impedance Method to the Floor-Impact Sound
Kim, U-Taek ; O, Jae-Eung ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 159~166
Recently, high story apartments are common to solve a housing problem especially in major cities. Apartments are considered as clean, sanitary and convenient to live. However, There are some problems because residents share walls, floors and ceilings with other people. Thus, the residents are often disturbed by neighbours since sound travels the building elements. Especially, impact noise through the floors causes the many complains. And so, it has been drawn attention to isolate by the impact sound. The purpose of this study is to analyze the characteristics of vibration response of 12-type void slabs in the improved void slab by impedance method, and is to find the best improveds void slab on the 12-type void slabs.
The Effects of the Annealing Heat Treatments and Testing Temperatures on the Mechanical Properties of the Invar Materials
Won, Si-Tae ; Kim, Jong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 167~176
The effects of heat treatments and testing temperatures on the mechanical properties of Invar materials were investigated through experiments, which call influence the formability in metal forming fields. Annealing temperatures were changed from
with an increment of
under two different furnace atmosphere(vacuum and H
gas). Microstructure and hardness tests were performed for annealed specimens at room temperature(RT) and tensile tests were also performed by changing annealing temperatures as well as testing temperatures from RT to
. The grain size of annealed materials increased with increasing annealing temperature, while micro-hardness distributions showed almost same hardness values regardless of annealing temperatures. Strength ratio (tensile/yield strength), which influences the forming characteristics of sheet metal, remained almost constant for various experimental conditions in case of unannealed specimens. However, it showed increasing tendency with increasing both annealing and testing temperatures, particularly at the testing temperature higher than
. Therefore it can be concluded that press formability of fully-annealed Invar material can be improved by warm forming technique.
A Study on The Burr Minimization by The Chemical Mechanical Micro Machining(C3M)
Lee, Hyeon-U ; Park, Jun-Min ; Jeong, Sang-Cheol ; Jeong, Hae-Do ; Lee, Eung-Suk ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 177~184
C3M(chemical mechanical micro machining) is applied for diminishing the size of burr and fabricating the massless patterning for aluminium wafer(thickness of 1
). It is difficult to perform the micro size machining with the radically increased shear stress. While the miniaturization and function-orientation of parts has been needed in the many field such as electronics, optics and medicine. etc., it is not enough to satisfy the industry needs in the machining technology. In this paper feasibility test of diminishing burr and fabricating maskless pattern was experimented and analyzed. In the experiment oxide layer was farmed on the aluminium with chemical reaction by
(10wt%), then the surface was grooved with tungsten carbide tool for the different condition such as the load and fred rate. The result was compared with the conventional machining to show the improvement of C3M with SEM for burr diminish and XPS for atomic existence, AFM for more precise image.
Detectibility of Internal Defects in Aluminum Die-casted Rotor Using Ultrasonic Technique
Lee, Jun-Hyeon ; Choe, Sang-U ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 185~191
The aluminum die-casting technique has been widely used to manufacture a rotor in motor industry because of its highly productivity, even though it sometime causes the various type of defects in the rotor, such as shrinkage, cavity, blow holes etc. which results in the decrease of the efficiency of system. Therefore the development of reliable technique to detect the flaws in the rotor is strongly needed not only to control quality assurance but to improve its efficiency. In this study, the wide variety of ultrasonic techniques have been applied to detect the flaws in the rotor and then to discuss the detectibility of the flaw and the applicability for NDE tool in the aluminum die-casting rotor.
The Study of Metal CMP Using Abrasive Embedded Pad
Park, Jae-Hong ; Kim, Ho-Yun ; Jeong, Hae-Do ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 12, 2001, Pages 192~199
Chemical mechanical planarization (CMP) has emerged as the planarization technique of choice in both front-end and back-end integrated circuit manufacturing. Conventional CMP process utilize a polyurethane polishing pad and liquid chemical slurry containing abrasive particles. There hale been serious problems in CMP in terms of repeatability and deflects in patterned wafers. Especial1y, dishing and erosion defects increase the resistance because they decrease the interconnection section area, and ultimately reduce the lifetime of the semiconductor. Methods to reduce dishing & erosion have recently been interface hardness of the pad, optimization of the pattern structure as dummy patterns. Dishing & erosion are initially generated an uneven pressure distribution in the materials. These defects are accelerated by free abrasives and chemical etching. Therefore, it is known that dishing & erosion can be reduced by minimizing the abrasive concentration. Minimizing the abrasive concentration by using CeO
is the best solution for reducing dishing & erosion and for removal rate. This paper introduce dishing & erosion generating mechanism and a method fur developing a semi-rigid abrasive pad to minimize dishing & erosion during CMP.