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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Manufacturing Technology Engineers
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Journal DOI :
The Korean Society of Manufacturing Technology Engineers
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Volume & Issues
Volume 24, Issue 6 - Dec 2015
Volume 24, Issue 5 - Oct 2015
Volume 24, Issue 4 - Aug 2015
Volume 24, Issue 3 - Jun 2015
Volume 24, Issue 2 - Apr 2015
Volume 24, Issue 1 - Feb 2015
Selecting the target year
An Evaluation on the Accuracy of a 3D Scanning Device Using Spherical Coordinate Mechanisms
Maeng, Hee-Young ; Park, Sangwook ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 1~6
DOI : 10.7735/ksmte.2015.24.1.001
To improve the efficiency of a reverse engineering process, many researches have recently tried to develop efficient, automatic 3D scanning devices. A new automatic 3D scanning device using a spherical coordinate system mechanism is introduced in this study. This device incorporates a guide motion along the spherical coordinate to compound each 3D data point automatically. The experiments correlating the system assembling tolerance with the form accuracy were conducted to verify the efficiency of the system for the scanning of an object, including complex shapes and manifold sections. In addition, the required time and system accuracy, taken during the scanning process of complicated artifact models, were investigated. Further, based on these empirical results, it was ascertained that the superior productivity of this new device offers a more precise and efficient scan when compared to conventional methodologies.
Development of an Electro-mechanical Driven Broaching Machine
Park, Hong-Seok ; Park, In-Soo ; Dang, Xuan-Phuong ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 7~14
DOI : 10.7735/ksmte.2015.24.1.007
The machine tools builders are trying to improve the efficiency and performance of the machine tools. The electro-mechanical driven broaching machine has many advantages such as lower noisy operating, higher energy efficiency, and smaller space of installation. This paper presents the structural and mechanical development of an electro-mechanical driven broaching machine that is replaced for traditional hydraulic one. The servo motor, ball screw and roller linear guide are used instead of hydraulic cylinder and translation frictional sliding guides. The simulation method based on FEM was applied to analyze the stress, deformation of the machine for static analysis. The dynamic analysis was carried out for verifying and assessing the mechanical behavior of the developed broaching machine. This work helps broaching machine developer make a better product at the early design stage with lower cost and development time.
Evaluation of Residual Stresses in 12%-Cr Steel Friction Stir Welds by the Eigenstrain Reconstruction Method
Jun, Tea-Sung ; Korsunsky, Alexander M. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 15~22
DOI : 10.7735/ksmte.2015.24.1.015
In the present paper we report the results of a study into Friction Stir Welds (FSWs) made in 13 mm-thick 12%-Cr steel plates. Based on residual strains obtained by diffraction techniques, eigenstrain analysis was performed using the Eigenstrain Reconstruction Method (ERM), which is a novel methodology for the reconstruction of full-field residual strain and stress distributions within engineering components. Significant eigenstrain distributions were found at around Thermo-Mechanically Affected Zone (TMAZ) where the most severe plastic deformation was occurred. Microstructure analysis was used to elucidate this phenomenon showing that the grain structure in TMAZ was bent and not successfully recrystallised, resulting in severe deformation behaviour. The reconstructed residual strain distributions by the ERM agree well with the experimental results. It was found that the approach based on theory of eigenstrain is a powerful basis for reconstructing the full-field residual strain/stress distributions in engineering components and structures.
Improvement of Optical 3D Scanner Performance Using Atomization-Based Spray Coating
Valinasab, Behzad ; Rukosuyev, Maxym ; Lee, Jason ; Ko, Junghyuk ; Jun, Martin B.G. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 23~30
DOI : 10.7735/ksmte.2015.24.1.023
The scanning quality can be influenced by reflective abilities of a surface. Transparency and glossiness of a surface can highly limit the scanning results. Various techniques have been developed to solve problems of reflective and transparent surfaces. As one of the most feasible and convenient solutions, a thin layer of coating with proper specifications is sprayed on surface for eliminating the problems of the surfaces. As the main goal is to keep the object geometry unchanged, then it is important to coat the surface with layers less than one micrometer in thickness. For this purpose, a newly designed atomization-based spray system has been developed and tested in sets of experiments to study its efficiency on scanning results while objects with the surface are in use. This paper presents the spray design process and then studies and compares the 3D scanning results of the surfaces coated with atomization-based and aerosol sprays.
Laser Line Welder for Continuous Operation of Cold-rolled Steel Coil
Choi, Jun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 31~37
DOI : 10.7735/ksmte.2015.24.1.031
A laser line welder using a solid-state laser (Yb:YAG) has been manufactured for joining ultra-thin cold-rolled steel coils in steelworks. The coils to be welded primarily range from 0.15 to 0.3 mm in thickness and 800 to 1,100 mm in width. Because the steel plate is extremely thin, it is very important to control the stop positions of the clamp at cutting and welding points. In this study, both hydraulic proportional control valves and LVDT sensor embedded cylinders were used to precisely control and monitor the positions of clamps with complementary stoppers. As a result, the positions could be controlled within an error of
. Erichsen cupping tests on the welded joints show that the Erichsen index ranges from 4.4 to 4.6 mm. Furthermore, the tensile strength of welding points is comparable to that of the base metal.
Fabrication of Nanopatterned PDMS Elastic Stamp Mold Using Surface Treatment of Nanotemplate
Park, Yong Min ; Seo, Sang Hyun ; Seo, Young Ho ; Kim, Byeong Hee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 38~42
DOI : 10.7735/ksmte.2015.24.1.038
Polydimethylsiloxane (PDMS) is a widely used material for replicating micro-structures because of its transparency, deformability, and easy fabrication. At the nanoscale, however, it is hard to fill a nanohole template with uncured PDMS. This paper introduces several simple methods by changing the surface energy of a nanohole template and PDMS elastomer for replicating 100nm-scale structures. In the case of template, pristine anodic aluminum oxide (AAO), hydrophobically treated AAO, and hydrophillically treated AAO are used. For the surface energy change of the PDMS elastomer, a hydrophilic additive and dilution solvent are added in the PDMS prepolymer. During the molding process, a simple casting method is used for all combinations of the treated template and modified PDMS. The nanostructured PDMS surface was investigated with a scanning electron microscope after the molding process for verification.
Silver Nanowire Anode-Based, Large-Area Indium Tin Oxide-Free Organic Photovoltaic Cells Fabricated by the Knife Coating Method
Han, Kyuhyo ; Kim, Gunwoo ; Lee, Jaehak ; Seok, Jaeyoung ; Yang, Minyang ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 43~48
DOI : 10.7735/ksmte.2015.24.1.043
Silver nanowire (AgNW) is a material that is increasingly being used for transparent electrodes, as a substitute for indium tin oxide (ITO), owing to its flexibility, high transmittance to sheet resistance ratio, and simple production process. This study involves manufacturing large-area organic photovoltaic cells (OPVs) deposited on AgNW electrodes. We compared the efficiency of OPVs with ITO and AgNW electrodes. The results verified that an OPV with an AgNW electrode performed better than that with an ITO electrode. Furthermore, by using the knife coating method, we successfully fabricated large-area OPVs without the loss of efficiency. Use of AgNW instead of ITO demonstrated that an OPV could be produced on various substrates by the solution process method, dropping the productions costs significantly. Additionally, by using the knife coating method, the process time and amount of wasted solution are reduced. This leads to an increase in the efficient fabrication of the OPV.
Indium Tin Oxide-Free Large-Area Flexible Organic Light-Emitting Diodes Utilizing Highly Conductive poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) Anode Fabricated by the Knife Coating Method
Seok, JaeYoung ; Lee, Jaehak ; Yang, MinYang ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 49~55
DOI : 10.7735/ksmte.2015.24.1.049
This paper reports solution-processed, high-efficiency organic light-emitting diodes (OLEDs) fabricated by a knife coating method under ambient air conditions. In addition, indium tin oxide (ITO), traditionally used as the anode, was substituted by optimizing the conductivity enhancement treatment of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films on a polyethylene terephthalate (PET) substrate. The transmittance and sheet resistance of the optimized PEDOT:PSS anode were 83.4% and
., respectively. The root mean square surface roughness of the PEDOT:PSS anode, measured by atomic force microscopy, was only 2.95 nm. The optimized OLED device showed a maximum current efficiency and maximum luminous density of 5.44 cd/A and
, respectively. As a result, the OLEDs created using the PEDOT:PSS anode possessed highly comparable characteristics to those created using ITO anodes.
A Study on Electrostatic Powder Coating for 3D Scanning of Diffused Surfaces
Maeng, Heeyoung ; Lee, Myoung Sang ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 56~62
DOI : 10.7735/ksmte.2015.24.1.056
Using an optical 3D scanning device to collect data from a diffused reflection surface is very difficult. To solve this problem, there are many applications including a spray-type developer and silicon molds. However, using a developer can cause chemical reactions between objects and particles of the developer and uneven surfaces on the object. To overcome these problems, we suggest an electrostatic powder coating method for even coating of particles onto surfaces for collecting 3D shape data. We have developed an automatic, electrostatic powder-coating machine and performed three different experiments to compare this system with a laser interferometer and a T-scan 3D scanner. As a result, we could ascertain the various characteristics of this new method, including good sensitivity for the various surface states of the bare surface, developer, and electrostatic powder coating. Finally, we verified the outstanding scanning performance and were able to demonstrate that this method achieves quality than traditional methods.
Study on Hybrid Search Method Using Neural Network and Simulated Annealing Algorithm for Apparel Pattern Layout Design
Jang, Seung Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 63~68
DOI : 10.7735/ksmte.2015.24.1.063
Pattern layout design is very important to the automation of apparel industry. Until now, the genetic algorithm and Tabu search method have been applied to layout design automation. With the genetic algorithm and Tabu search method, the obtained values are not always consistent depending on the initial conditions, number of iterations, and scheduling. In addition, the selection of various parameters for these methods is not easy. This paper presents a hybrid search method that uses a neural network and simulated annealing to solve these problems. The layout of pattern elements was optimized to verify the potential application of the suggested method to apparel pattern layout design.
Numerical Analysis Study on the Fluid Flow Characteristics of Hydraulic Retarder for Heavy Vehicles
Park, In-Sung ; Jang, Hyun ; Suh, Jeong-Se ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 69~74
DOI : 10.7735/ksmte.2015.24.1.069
This study examined the fluid flow characteristics of a hydraulic retarder adapted as an auxiliary brake for heavy vehicles. The commercial computational fluid dynamics (CFD) software STAR-CCM+ was used to investigate the torque performance and flow characteristics of the hydraulic retarder. The numerical results showed that the pressure distribution was higher near the inner wall surface of the rotor and stator. The pressure of the working fluid increased in the radial direction of the rotor and stator. The variation in the fluid velocity intensity showed a similar trend to that of the fluid pressure, but the maximum velocity appeared near the outer wall surface of the rotor and stator interface. The numerical results showed that increasing the revolution speed of the retarder greatly increased the rate of torque generation.
Selective Electrodeposition Using Laser Masking and DC Voltage
Shin, Hong Shik ; Kim, Sung Yong ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 75~80
DOI : 10.7735/ksmte.2015.24.1.075
This paper proposes a selective electrodeposition process that uses laser masking and a DC voltage. Selective electrodeposition using laser masking and a DC voltage is more efficient than that using laser masking and a pulse voltage. In other words, electrodeposition with a DC voltage allows for precise selective deposition without the limitation of the deposition region. Also, a selective electrodeposition method that uses laser masking and DC voltage can reduce the electrodeposition time. The characteristics of a copper layer deposited by laser masking and DC voltage were examined under various conditions. A selective copper layer with various micro patterns of
thickness was successfully fabricated.
Microfluidic Suction Pump based on Restoring Force of Elastomer for Liquid Transportation in Microfluidic System
Byun, Kang Il ; Han, Eui Don ; Kim, Byeong Hee ; Seo, Young Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 81~86
DOI : 10.7735/ksmte.2015.24.1.081
This paper presents a disposable passive suction pump that uses the restoring force of an elastomeric chamber for liquid transportation in a microfluidic system. The proposed suction pump can be operated by finger pressure without any peripheral equipment. To adjust the generated suction pressure, five different displacements of the suction chamber ceiling, two different chamber shapes, and five different elastic moduli of the elastomer were considered. For a cylindrical chamber with a 5 mm height and 5 mm radius, the generated suction pressure and flow rate increased almost linearly up to about 31 kPa and
, respectively, depending on the chamber deformation. A maximum suction pressure of
was obtained for a hemispherical chamber with a 2.1 mm height and 5 mm radius.
Dynamic Response Assessment of Space Use Telescope
Cho, Hee Keun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 87~93
DOI : 10.7735/ksmte.2015.24.1.087
The dynamic responses of a telescope loaded on an STSAT-3 satellite were analyzed, and environmental tests were conducted to verify the reliability of the design. The space use telescope COMIS (compact imaging spectrometer) is a major payload of the STSAT-3 launched on November 21, 2013. Vibration responses such as the acceleration, displacement, and velocity with respect to random vibration and shock impulse inputs were obtained based on theoretical fundamentals in conjunction with finite element analysis. The main focus of this study was on developing technology for accurate and/or favorable modeling and analysis of the structure and fitting the results to that of experiments. Cutting-edge technology for manipulating the vibrations of a space use telescope is suggested.
A Study of the Yellowing Phenomenon in the Laser Patterning of Silver Nanowire
Hwang, June Sik ; Park, Jong Eun ; Yang, Min Yang ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 94~97
DOI : 10.7735/ksmte.2015.24.1.094
In this study, we introduce a yellowing phenomenon in silver nanowire laser patterning and attempt to understand the cause of this phenomenon. Silver nanowire is a promising alternative to indium tin oxide as a transparent electrode owing to its flexibility. Additionally, silver nanowire can be easily patterned by laser ablation, which is free of dangerous chemicals. However, a yellowish color change reducing visibility is observed on the patterned area of the silver nanowires, and this yellowing phenomenon prevents the use of silver nanowire as a transparent electrode material. We concluded that resolidified debris of melted and evaporated silver nanowires after laser ablation causes the color change of the electrode. Further research is needed to determine a means of mitigating this yellowing phenomenon.
Autonomous Navigation of Nonholonomic Mobile Robots Using Generalized Voronoi Diagrams
Shaoa, Minglei ; Shin, Dongik ; Shin, Kyoosik ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 98~102
DOI : 10.7735/ksmte.2015.24.1.098
This paper proposes an autonomous navigation method for a nonholonomic mobile robot, based on the generalized Voronoi diagram (GVD). We define the look-ahead point for a given motion constraint to determine the direction of motion, which solves the problem of a minimum turning radius for the real nonholonomic mobile robot. This method can be used to direct the robot to explore an unknown environment and construct smooth feedback curves for the nonholonomic robot. As the trajectories can be smoothed, the position of the robot can be stabilized in the plane. The simulation results are presented to verify the performance of the proposed methods for the nonholonomic mobile robot. Furthermore, this approach is worth drawing on the experience of any other mobile robots.
Development of Multi-purpose Smart Sensor Using Presence Sensor
Cha, Joo-Heon ; Yong, Heong ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 103~109
DOI : 10.7735/ksmte.2015.24.1.103
This paper introduces a multi-purpose smart fusion sensor. Normally, this type of sensor can contribute to energy savings specifically related to lighting and heating/air conditioning systems by detecting individuals in an office building. If a fire occurs, the sensor can provide information regarding the presence and location of residents in the building to a management center. The system consists of four sensors: a thermopile sensor for detecting heat energy, an ultrasonic sensor for measuring the distance of objects from the sensor, a fire detection sensor, and a passive infrared sensor for detecting temperature change. The system has a wireless communication module to provide the management center with control information for lighting and heating/air conditioning systems. We have also demonstrated the usefulness of the proposed system by applying it to a real environment.
Influence of Torque Fluctuation on the Stability of a Rotating Disk
Shin, Eung-Soo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 110~116
DOI : 10.7735/ksmte.2015.24.1.110
This study investigates the whirling stability of a rotating shaft-disk system under parametric excitation using periodically varying torque. The equations of motion were derived using a lumped-mass model, and the Floquet method was employed to find the effects of torque fluctuation, internal and external damping, and rotational speed on whirling stability. Results indicated that the effect of torque fluctuation was considerable on the instability around resonance, but minimal on supercritical instability. Stability diagrams were sensitive to the parametric excitation frequency; critical torque decreased upon increasing excitation frequency, with faster response convergence or divergence. In addition, internal and external damping had a considerable effect on unstable regions, and reduced the effects of the parametric excitation frequency on critical torque and speed. Results obtained from the Floquet approach were in good agreement with those obtained by numerical integration, except for some cases with Floquet multipliers very close to unity.
Prediction of the Impact Lifetime for Board-Leveled Flip Chips by Changing the Design Parameters of the Solder Balls
Lee, Soo Jin ; Kim, Seong Keol ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 117~123
DOI : 10.7735/ksmte.2015.24.1.117
The need for drop simulations for board-leveled flip chips in micro-system packaging has been increasing. There have been many studies on flip chips with various solder ball compositions. However, studies on flip chips with Sn-1.0Ag-0.5Cu and Sn-3.0Ag-0.5Cu have rarely been attempted because of the unknown material properties. According to recent studies, drop simulations with these solder ball compositions have proven feasible. In this study, predictions of the impact lifetime by drop simulations are performed considering Cu and Cu/Ni UBMs using LS-DYNA to alter the design parameters of the flip chips, such as thickness of the flip chip and size of the solder ball. It was found that a smaller chip thickness, larger solder ball diameter, and using the Cu/Ni UBM can improve the drop lifetime of solder balls.
Vehicle Voltage Stabilizing Module Using Supercapacitors
Park, Sukhee ; Jeong, Kyuwon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 124~129
DOI : 10.7735/ksmte.2015.24.1.124
The performance of a passenger vehicle has been greatly improved recently owing to the intensive use of electronic controllers. Many components of a vehicle, including the engine, are controlled by electronic systems installed in the vehicle. Therefore, the electrical power required for such electronics has increased significantly. However, the electrical power generated by the vehicle`s alternator, operated by the engine, is limited, and when the vehicle is started, a large instantaneous current is required. The voltage of the vehicle electrical system fluctuates to a very low level, then, it is gradually recovered. This case is very severe and can even cause damage to electronic systems. In this study, a voltage-stabilizing module comprising electric double layer supercapacitors, which could alleviate the voltage variation, was developed and tested.
Development of Auto-Correction Monitoring System for Stud Bolts
Yun, Sung-Un ; Kim, Jae-Yeol ; Kang, Hyung-Seon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 130~134
DOI : 10.7735/ksmte.2015.24.1.130
The automobile industry is ubiquitous and involved in the handling of metal, machines, electricity, electron, and chemistry including the products of many types of processes. In the process of installing engines as a part of the car assembly line, the measurement and correction of the position of the stud bolts consumes a great deal of time. Additionally, defective parts must be manually removed. In the process of engine installation, the speed of the operation, related to the economics of vehicle assembly, is dependent upon measuring the precise position of the stud bolt, reducing the length of correction time, and increasing the working rate. This paper deals with securing the economic feasibility of the manufacturing process, increasing the safety by removing risk factors in the working area, and improving and equalizing the quality by developing an automatic system for the process involving a stud bolt.
Laser Sintering of Silver Nanoparticle for Flexible Electronics
Jia, Seok Young ; Park, Won Tea ; Noh, Yong-Young ; Chang, Won Seok ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 1, 2015, Pages 135~139
DOI : 10.7735/ksmte.2015.24.1.135
We present a fine patterning method of conductive lines on polyimide (PI) and glass substrates using silver (Ag) nanoparticles based on laser scanning. Controlled laser irradiation can realize selective sintering of conductive ink without damaging the substrate. Thus, this technique easily creates fine patterns on heat-sensitive substrates such as flexible plastics. The selective laser sintering of Ag nanoparticles was managed by optimizing the conditions for the laser scan velocity (1.0-20 mm/s) and power (10-150 mW) in order to achieve a small gap size, high electrical conductivity, and fine roughness. The fabricated electrodes had a minimum channel length of
and conductivity of
(bulk Ag has a conductivity of
) on the PI substrate. This method was used to successfully fabricate an organic field effect transistor with a poly(3-hexylthiophene) channel.