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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
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Volume & Issues
Volume 23, Issue 12 - Dec 2006
Volume 23, Issue 11 - Nov 2006
Volume 23, Issue 10 - Oct 2006
Volume 23, Issue 9 - Sep 2006
Volume 23, Issue 8 - Aug 2006
Volume 23, Issue 7 - Jul 2006
Volume 23, Issue 6 - Jun 2006
Volume 23, Issue 5 - May 2006
Volume 23, Issue 4 - Apr 2006
Volume 23, Issue 3 - Mar 2006
Volume 23, Issue 2 - Feb 2006
Volume 23, Issue 1 - Jan 2006
Selecting the target year
Challenging issues of Piezo Drop-On-Demand Inkjet Printing Technology
Shin Dong-Youn ; Lee Won-Hee ; Kang Tae-Goo ; Kim Dong-Soo ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 7~14
Ink-jet Printing Technology for Paradigm Shift in Mass Production
Kim Seog-Soon ; Kim Dong-Soo ; Lee Won-Hee ; Shin Dong-Yun ; Kim Choung-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 15~21
DoD Metal-Jet Printing System
Lee Taik-Min ; Kang Tae-Goo ; Yang Jeong-Soon ; Jo Jeong-Dai ; Kim Kwang-Young ; Choi Byung-Oh ; Kim Dong-Soo ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 22~26
Micro/Nano Printing Technology Using ElectroSpray Deposition(ESD)
Kim Dong-Soo ; Lee Won-Hee ; Shin Dong-Yun ; Lim Hyun-Eui ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 27~32
Three Dimensional Printing Process Using Ink Jet Technology
Lee Won-Hee ; Kim Jung-Su ; Kim Dong-Soo ; Lee Min-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 33~38
Fabrication of Micro Diamond Tip Cantilever for AFM-based Tribo-Nanolithography
Park Jeong-Woo ; Lee Deug-Woo ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 39~46
Nano-scale fabrication of silicon substrate based on the use of atomic force microscopy (AFM) was demonstrated. A specially designed cantilever with diamond tip, allowing the formation of damaged layer on silicon substrate by a simple scratching process, has been applied instead of conventional silicon cantilever for scanning. A thin mask layer forms in the substrate at the diamond tip-sample junction along scanning path of the tip. The mask layer withstands against wet chemical etching in aqueous KOH solution. Diamond tip acts as a patterning tool like mask film for lithography process. Hence these sequential processes, called tribo-nanolithography, TNL, can fabricate 2D or 3D micro structures in nanometer range. This study demonstrates the novel fabrication processes of the micro cantilever and diamond tip as a tool for TNL using micro-patterning, wet chemical etching and CVD. The developed TNL tools show outstanding machinability against single crystal silicon wafer. Hence, they are expected to have a possibility for industrial applications as a micro-to-nano machining tool.
The Effect of Injection Angle and Pressure on Etch of Invar Plate Using Industrial Etch-Nozzle
Jeong Heung-Cheol ; Kim Dong-Wook ; Choi Gyung-Min ; Kim Duck-Jool ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 47~53
The purpose of this study was to investigate the significant characteristics in spray of industrial etch-nozzle for the design of process. The experiment was carried out with different spray pressure and industrial nozzle in wet etch. The characteristics of liquid spray, such as axial velocity and sauter mean diameter measurements were obtained by PDA. And impact force was calculated from spray characteristics. It was found that the fluid with higher spray pressure resulted in the smaller SMD and the higher droplet velocity and impact force. The depth of etch was increased in case of high spray pressure. In the case of injection angle oscillated between
, the result indicated constant effect of etch. The correlation between the spray characteristics and etch ones were analyzed. The depth of etch had good positive correlation with axial velocity and impact force. The result clearly shows that the characteristics in wet etch are strongly related to the spray characteristics with process.
Improvement of Sensitivity to In-plane Strain/Deformation Measurement by Micro-ESPI Technique
Kim Dong-Iel ; Kee Chang-Doo ; Huh Yong-Hak ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 54~63
Enhancement methods of sensitivity to in-plane strain measurement by micro-ESPI(Electronic Speckle Pattern Interferometry) technique were proposed using TiN and Au thin films. Micro-tensile strain over the micro-tensile specimens, prepared in micro-scale by those films, was measured by micro-tensile loading system and micro-ESPI system developed in this study. The subsequent measurement of in-plane tensile strain in the micro-sized specimens was introduced using the micro-ESPI technique, and the micro-tensile stress-strain curves for these films were determined. To enhance the sensitivity to measurement of in-plane tensile strain, algorithms of the phase estimation by using curve fitting of inter-fringe and the discrete Fourier Transform with object-induced dynamic phase shifting were developed. Using these two algorithms, the micro-tensile strain-stress curves were generated. It is shown that the algorithms for enhancement of the sensitivity suggested in this study make the sensitivity to measurement of the in-plane tensile strain increase.
Development of Compact Phase-difference Controller for an Ultrasonic Rotary Motor
Yi Dong-Chang ; Lee Myoung-Hoon ; Lee Eu-Hark ; Lee Sun-Pyo ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 64~71
In this paper, a uniform speed controller for an ultrasonic rotary motor is developed using the phase-difference method. The phase difference method uses traveling waves to drive the ultrasonic motor. The traveling waves are obtained by adding two standing waves that have a different phase to each other. A compact phase-difference driver system is designed and integrated by combining VCO(Voltage Controlled Oscillator) and phase shifter. Theoretically the relationship between the phase difference in time and the rotational speed of the ultrasonic motor is sine function, which is verified by experiments. Then a series of experiments under various loading conditions are conducted to characterize the motor's performance that is the relationship between the speed and torque. Proportional-integral control is adopted for the uniform speed control. The proportional control unit calculates the compensating phase-difference using the rotating speed which is measured by an encoder and fed back. Integral control is used to eliminate steady-state errors. Differential control for reducing overshoot is not used since the response of ultrasonic motor is prompt due to its low inertia and friction-driving characteristics. The developed controller demonstrates reasonable performance overcoming disturbing torque and the changes in material properties due to continuous usage.
Measurement of Grating Pitch Standards using Optical Diffractometry and Uncertainty Analysis
Kim Jong-Ahn ; Kim Jae-Wan ; Park Byong-Chon ; Kang Chu-Shik ; Eom Tae-Bong ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 72~79
We measured grating pitch standards using optical diffractometry and analyzed measurement uncertainty. Grating pitch standards have been used widely as a magnification standard for a scanning electron microscope (SEM) and a scanning probe microscope (SPM). Thus, to establish the meter-traceability in nano-metrology using SPM and SEM, it is important to certify grating pitch standards accurately. The optical diffractometer consists of two laser sources, argon ion laser (488 nm) and He-Cd laser (325 nm), optics to make an incident beam, a precision rotary table and a quadrant photo-diode to detect the position of diffraction beam. The precision rotary table incorporates a calibrated angle encoder, enabling the precise and accurate measurement of diffraction angle. Applying the measured diffraction angle to the grating equation, the mean pitch of grating specimen can be obtained very accurately. The pitch and orthogonality of two-dimensional grating pitch standards were measured, and the measurement uncertainty was analyzed according to the Guide to the Expression of Uncertainty in Measurement. The expanded uncertainties (k = 2) in pitch measurement were less than 0.015 nm and 0.03 nm for the specimen with the nominal pitch of 300 nm and 1000 nm. In the case of orthogonality measurement, the expanded uncertainties were less than
. In the pitch measurement, the main uncertainty source was the variation of measured pitch values according to the diffraction order. The measurement results show that the optical diffractometry can be used as an effective calibration tool for grating pitch standards.
Classification of Surface Defect on Steel Strip by KNN Classifier
Kim Cheol-Ho ; Choi Se-Ho ; Kim Gi-Bum ; Joo Won-Jong ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 80~88
This paper proposes a new steel strip surface inspection system. The system acquires bright and dark field images of defects by using a stroboscopic IR LED illuminator and area camera system and the defect images are preprocessed and segmented in real time for feature extraction. 4113 defect samples of hot rolled steel strip are used to develop KNN (k- Nearest Neighbor) classifier which classifies the defects into 8 different types. The developed KNN classifier demonstrates about 85% classifying performance which is considered very plausible result.
Shape Reconstruction from Unorganized Cloud of Points using Adaptive Domain Decomposition Method
Yoo Dong-Jin ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 89~99
In this paper a new shape reconstruction method that allows us to construct surface models from very large sets of points is presented. In this method the global domain of interest is divided into smaller domains where the problem can be solved locally. These local solutions of subdivided domains are blended together according to weighting coefficients to obtain a global solution using partition of unity function. The suggested approach gives us considerable flexibility in the choice of local shape functions which depend on the local shape complexity and desired accuracy. At each domain, a quadratic polynomial function is created that fits the points in the domain. If the approximation is not accurate enough, other higher order functions including cubic polynomial function and RBF(Radial Basis Function) are used. This adaptive selection of local shape functions offers robust and efficient solution to a great variety of shape reconstruction problems.
A Study on Electromagnetic Interference Shielding Effectiveness of the Metal Powders and Nano Carbon black /Fiber Reinforced Epoxy composites
Han Gil-Young ; Kim Jin-Seok ; Ahn Dong-Gyu ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 100~107
The objective of this research is to investigate the electromagnetic interference(EMI) shielding characteristics of fiber reinforced composites. We fabricated glass and carbon fiber reinforced composites filled with metal powder and nano carbon black. The measurements of shielding effectiveness(SE) were carried out frequency range 300MHz - 1GHz for commercial purposes such as electric or telecommunication devices. The return loss and loss due to absorption were also measured as a function of frequency in the micro wave(300MHz-1GHz) region. It is observed that the SE of the composites is the frequency dependent, increase with the increases in filler loading. The Mg metal powder filled composite showed higher SE compared to that of carbon black. The Mg metal powder/epoxy composite was shown to exhibit up to 40dB of SE. The results indicates that the composite having higher filler loading can be used for the purpose of EMI shielding as well as for some microwave applications.
Development of the Design Guideline to Increase the Reusing Rate of Cellular Phone Parts
Kim Chan-Seok ; Yi Hwa-Cho ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 108~118
Reusing is one of the most environmentally friendly recycling methods. For the economical remanufacturing of used cellular phone, the cellular phones should be design for easy disassembly. In this paper, we analyzed the components and connecting elements of cellular phones and developed a guideline for the design of the cellular phones. A software for the disassembly assessment was also developed. Redesigned cellular phone by the developed guideline and its original phone was analyzed by the disassembly assessment software. Disassembly time could be reduced about 40% and reusing rate could be improved about 37%.
Optimization of a Gate Valve using Orthogonal Array and Kriging Model
Kang Jin ; Lee Jong-Mun ; Kang Jung-Ho ; Park Hee-Chun ; Park Young-Chul ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 119~126
Kriging model is widely used as design DACE(analysis and computer experiments) model in the field of engineering design to accomplish computationally feasible design optimization. In this paper, the optimization of gate valve was performed using Kriging based approximation model. The DACE modeling, known as the one of Kriging interpolation, is introduced to obtain the surrogate approximation model of the function. In addition, we describe the definition, the prediction function and the algorithm of Kriging method and examine the accuracy of Kriging by using validation method.
Formulation of Optimal Design Parameters and Failure Map for Metallic Sandwich Plates with Inner Dimpled Shell Structure Subject to Bending Moment
Seong Dae-Yong ; Jung Chang-Gyun ; Yoon Seok-Joon ; Ahn Dong-Gyu ; Yang Dong-Yol ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 127~136
Metallic sandwich plates with inner dimpled shell subject to 3-point bending have been analyzed and then optimized for minimum weight. Inner dimpled shells can be easily fabricated by press or roll with high precision and bonded with same material skin sheets by resistance welding or adhesive bonding. Metallic sandwich plates with inner dimpled shell structure can be optimally designed for minimum weight subject to prescribed combination of bending and transverse shear loads. Fundamental findings for lightweight design are presented through constrained optimization. Failure responses of sandwich plates are predicted and formulated with an assumption of narrow sandwich beam theory. Failure is attributed to four kinds of mechanisms: face yielding, face buckling, dimple buckling and dimple collapse. Optimized shape of inner dimpled shell structure is a hemispherical shell to minimize weight without failure. It is demonstrated that bending stiffness of sandwich plate is 2 or 3 times larger than solid plates with the same strength. Failure mode boundaries and iso-strength lines dependent upon the geometry and yield strain of the material are plotted with respect to geometric parameters on the failure map. Because optimal parameters of maximum strength for given material weight can be selected from the map, analytic solutions for maximum strength are expressed as a function of only material property and proposed strength. These optimal parameters match well with numerical optimal parameters.
A Study on the Prediction Method of Belt Edge Separation due to the Belt Width Variation of a Tire
Kim Seong-Rae ; Sung Ki-Deug ; Kim Son-Joo ; Cho Choon-Tack ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 137~144
This study is concerned with the relation between steelbelt width and belt edge separation of a tire. Belt edge separation causes tire burst and threatens passenger's safety. For the reason, it is important to predict durability caused by belt edge separation in the early stage of the tire structure design. Usually, passenger car tires have two layers of steelbelts having opposite steel cord's angles, which makes a shear behaviour between each belt layer. Shear behaviour is one of reason to cause belt edge separation. In this study, to predict belt edge separation, we suggested the prediction method of belt edge separation and evaluated the effect of steelbelt width on the belt edge separation using FEM. We also studied on main parameters to affect shear behaviour at the belt edge area.
Structural Design of the Door Frame of a Microwave Oven to Decrease Its Twisting Deformation Using Dynamic Analysis
Lee Boo-Youn ; Koo Jin-Young ; Kim Won-Jin ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 145~153
To minimize the possible leakage of microwave when one opens the door of a microwave oven during its operation, a structural design of the reinforcing brackets for the door frame is presented. Twisting deformation of the door frame resulting from a dynamic pulling force is analyzed by harmonic and transient response analyses. Several types of the reinforcing brackets weldable to the right flange of the door frame is taken into consideration, and their effects to the twisting deformation of the door frame are compared and evaluated. As a conclusion, a thick step-shaped bracket, which is welded to whole length of the right flange, is favorable.
A Study on Design Improvement and Strength Evaluation of Shafting System for Washing Machine
Kim Eui-Soo ; Kim Sang-Uk ; Kim Byung-Min ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 154~162
By laying its drum horizontally, front-loaded washing machine mostly used in Europe that uses the head of the water to launder was appropriate for washing only small amount of laundry. However, the demands of customers are requiring front-loaded washing machine to handle big capacity laundry as well, and have faster rotation speed to increase drying ability. To meet such demands, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Flange is located between the drum and shaft, transferring power from the shaft to drum, and acting as a supporter of the back of the drum. Shaft is connected from the flange to insert production, transferring power from the motor to drum, and mainly acting as stiffness against the horizontal weight of the shafting system. In this paper, strength analysis and experiment were executed on both the shaft and flange of front-loaded washing machine to suggest the design improvement of shafting system for big capacity, high-rotation drying. Also, verification of this evaluation was executed on fracture strength and fatigue life for studied shaft system.
Alleviating Deformation of MEMS Structure in Surface Micromachining
Hong Seok-Kwan ; Kweon Soon-Cheol ; Jeon Byung-Hee ; Shin Hyung-Jae ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 163~170
By removing sacrificial layer through ashing process, movable MEMS structure on substrate can be fabricated in surface micromachining. However, MEMS structure includes, during the ashing process, the warping or buckling effects due to stress gradient along the vertical direction of thin film. In this study, we presented method for counteracting the unwanted deflection of MEMS structure and designed using character of deposit process to overcome limited design conditions. Unit cell patterns were designed with character of deposit shape, and their final shapes were adopted using Finite Element Method. Finally, RF MEMS switch was fabricated by surface micro machining as test vehicles. We checked out that alleviation effect for deformation of switch improved by 35%.
A Study on Nano/Micro Pattern Fabrication of Metals by Using Mechanical Machining and Selective Deposition Technique
Cho Sang-Hyun ; Youn Sung-Won ; Kang Chung-Gil ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 171~177
This study was performed as a part of the research on the development of a maskless and electroless process for fabricating metal micro/nanostructures by using a nanoindenter and an electroless deposition technique.
-deep indentation tests on Ni and Cu samples were performed. The elastic recovery of the Ni and Cu was 9.30% and 9.53% of the maximum penetration depth, respectively. The hardness and the elastic modulus were 1.56 GPa and 120 GPa for Ni and 1.51 GPa and 104 GPa for Cu. The effect of single-point diamond machining conditions such as the Berkovich tip orientation (0, 45, and
) and the normal load (0.1, 0.3, 0.5, 1, 3, and 5 mN), on both the deformation behavior and the morphology of cutting traces (such as width and depth) was investigated by constant-load scratch tests. The tip orientation had a significant influence on the coefficient of friction, which varied from 0.52-0.66 for Ni and from 0.46- 0.61 for Cu. The crisscross-pattern sample showed that the tip orientation strongly affects the surface quality of the machined are a during scratching. A selective deposition of Cu at the pit-like defect on a p-type Si(111) surface was also investigated. Preferential deposition of the Cu occurred at the surface defect sites of silicon wafers, indicating that those defect sites act as active sites for the deposition reaction. The shape of the Cu-deposited area was almost the same as that of the residual stress field.
4 Inch Wafer-Scale Replicability Enhancement in Hot Embossing by using PDMS-Cushioned Si Mold
Kim Heung-Kyu ; Ko Young-Bae ; Kang Jeong-Jin ; Heo Young-Moo ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 178~184
Hot embossing is to fabricate desired pattern on the polymer substrate by pressing the patterned mold against the substrate which is heated above the glass transition temperature, and it is a high throughput fabrication method for bio chip, optical microstructure, etc. due to the simultaneous large area patterning. However, the bad pattern fidelity in large area patterning is one of the obstacles to applying the hot embossing technology for mass production. In the present study, PDMS pad was used as a cushion on the backside of the micro-patterned 4 inch Si mold to improve the pattern fidelity over the 4 inch PMMA sheet by increasing the conformal contact between the Si mold and the PMMA sheet. The pattern replicability improvement over 4 inch wafer scale was evaluated by comparing the replicated pattern height and depth for PDMS-cushioned Si mold against the rigid Si mold without PDMS cushion.
Biomechanical Evaluation of the Vertebroplasty Based on Bone Density
Kim Dong-Ryul ; Lee Tae-Soo ; Park Jung-Yul ; Suh Jung-Gun ; Choi Kui-Won ; Chae Soo-Won ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 185~194
In this paper, three dimensional finite element analyses have been performed to investigate the biomechanics of vertebroplasty in patient accurate FE models have been constructed from CT images of a PMMA injected vertebra. In order to apply various material properties of the spine(T12), the functional relation between the well known apparent density and HU(Hounsfield unit) from CT image were employed and thus real material properties can be assigned to each element of FE model. The FE analysis showed similar results with the experiments. With this approach accurate analysis of the vertebroplasty and its clinical applications can be expected.
Rapid Manufacturing of 3D Thin-walled Products using Plastics and Metals
Shin Bo-Sung ; Kang Bo-Sik ; Park Jae-Hyun ; Rho Chi-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 195~202
High-speed machining (HSM) with excellent quality and dimensional accuracy has been widely used to create 3D structures of metal and plastics. However, the high-speed machining process is not suitable for the rapid realization of 3D thin-walled product because it consumes considerably long time in fixturing process of a work piece. In this paper, an effective rapid manufacturing process is proposed to fabricate 3D thin-walled products directly using HSM, phase change filling and ultrasonic welding. The filling process is useful to hold the thin-walled product during the machining step. The ultrasonic welding process is introduced to make one piece product from two piece parts that are machined by HSM and filling process. The proposed rapid manufacturing (RM) process has been shown that the RM process enables to fabricate the 3D thin-walled products using ABS plastics and aluminum metals from 3D CAD data to functional parts.
Rapid Tooling Technology for Producing Functional Prototypes using Ceramic Shell Investment Casting and Patterns Produced Directly from ThermoJet 3D Printer
Kim Ho-Chan ; Lee Seok ; Lee Seok-Hee ;
Journal of the Korean Society for Precision Engineering, volume 23, issue 8, 2006, Pages 203~210
This paper focuses on the development of RT technology suitable for manufacturing a small quantity of metal prototype of a precise part from an RP master. Dimensional accuracy and surface roughness are evaluated from Thermojet part of a 3D printer, and effective post-processing method is introduced. Investment casting is done using a prototype built from 3D printer as a wax pattern. Ceramic shell investment casting technique is developed to build a prototype with materials mostly wanted. Also, experimental result shows this research is very useful in manufacturing of a small quantity of functional part or a test part of a specific material.