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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 23, Issue 6 - Dec 2014
Volume 23, Issue 5 - Oct 2014
Volume 23, Issue 4 - Aug 2014
Volume 23, Issue 3 - Jun 2014
Volume 23, Issue 2 - Apr 2014
Volume 23, Issue 1 - Feb 2014
Selecting the target year
Fabrication of Superoleophobic Surface with Anisotropic Wettability Using Silicon Wafer
Lee, Dong-Ki ; Lee, Eun-Haeng ; Cho, Younghak ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 533~538
DOI : 10.7735/ksmte.2014.23.6.533
We fabricated grooved mushroom structures with anisotropic wettability on silicon substrates using basic MEMS processes. The geometry of these grooved mushroom structures could be changed by controlling the additional IPA solution during Si etching by TMAH solution. To understand anisotropic wettability, contact angles (CAs) of hexadecane droplets were measured in the orthogonal and parallel directions to grooved lines. The CA measurement results displayed anisotropic wetting on the grooved mushroom structures. However, specimens with
distance between top layers displayed isotropic and superoleophobic wetting. This study demonstrates that the thickness of the top layer is more critical than the width or height of the ridge when determining the wettability of organic solvent. Despite the wide distance between top layers (
), the specimen with a thin top layer (100 nm) showed highly anisotropic wetting and low CA due to the pinning of droplets at the edge of the top layer.
An Ultra-precision Electronic Clinometer for Measurement of Small Inclination Angles
Tan, Siew-Leng ; Kataoka, Satoshi ; Ishikawa, Tatsuya ; Ito, So ; Shimizu, Yuuki ; Chen, Yuanliu ; Gao, Wei ; Nakagawa, Satoshi ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 539~546
DOI : 10.7735/ksmte.2014.23.6.539
This paper describes an ultra-precision electronic clinometer, which is based on the capacitive-based fluid type, for detection of small inclination angles. The main parts of the clinometer low-noise electronics are two capacitance measurement circuits for converting the capacitances of the capacitors of the clinometer into voltages, and a differential amplifier for obtaining the difference of the capacitances, which is proportional to the input inclination angle. A 16 bit analog to digital (AD) converter is also embedded into the same circuit board, whose output is sent to a PC via RS-232C, for achieving a small noise level down to tens of
. A compensation method, which is referred to as the delay time method for shortening the stabilization time of the sensor was also discussed. Experimental results have shown the possibility of achieving a measurement resolution of
as well as the quick measurement with the delay time method.
Nano-precision Polishing of CVD SiC Using MCF (Magnetic Compound Fluid) Slurry
Wu, Yongbo ; Wang, Youliang ; Fujimoto, Masakazu ; Nomura, Mitsuyoshi ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 547~554
DOI : 10.7735/ksmte.2014.23.6.547
CVD SiC is a perfect material used for molds/dies in hot press molding of glass lens. In its fabrication process, nano-precision polishing is essential finally. For this purpose, a novel polishing method using MCF (Magnetic Compound Fluid) slurry is proposed. In this method, MCF slurry is supplied into a given gap between the workpiece and a MCF slurry carrier, and constrained within the polishing zone by magnetic forces from permanent magnet. In this paper, after an experimental rig used to actually realize the proposed method has been constructed, the fundamental polishing characteristics of CVD SiC such as the effects of process parameters including MCF slurry composition on work-surface roughness were experimentally investigated. As a result, nano-precision surface finish of CVD SiC was successfully attained with MCF slurry and the optimum process parameters for obtaining the smoothest work-surface were determined.
Microparticle Separator based on Dean Vortex in Spiral Microchannel
Byun, Kang Il ; Kim, Hyung Jin ; Kim, Byeong Hee ; Seo, Young Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 555~560
DOI : 10.7735/ksmte.2014.23.6.555
This paper presents a microparticle separator using a spiral microchannel. A particle separator based on the dean vortex was designed, fabricated, and characterized. Two different spiral microchannels were fabricated. Width and initial radius of rotation in the spiral microchannel were fixed to
and 1.75 mm, respectively. Two different depths of the microchannels were designed at
. In this experimental study, the equilibrium position of microparticles was monitored by using fluorescent microbeads. In the case of a low dean number (<1.0), lift force and dean drag force were similar, indicating that microbeads were distributed to almost all areas across microchannels. However, in the case of a high dean number (>1.0), dean drag force rather than lift force was dominant, indicating that microbeads moved toward the inner wall of the spiral microchannel.
Study on Improving Flow Balance and Clamp Force of Family Mold for Refrigerator Shelf
Park, Je-Hong ; Yoon, Kyeong-Won ; Ko, Chang-Oh ; Seo, Sang-Won ; Kim, Su-Jin ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 561~568
DOI : 10.7735/ksmte.2014.23.6.561
Injection molding industries realize the necessity of developing family molds to improve competitiveness. One of the primary causes of manufacturing defective products is the imbalance of flow in a family mold. In this study, the family mold of a shelf for refrigerators is analyzed by using CAE software. First, the flow balance, clamping force, and injection pressure are analyzed for different gate diameters of two cavities. Second, the flow balance, clamping force, and injection pressure are improved when the two gate valves are open at different times. Finally, the results of filling analysis are compared with the test injection product.
Analysis of Cutting Edge Geometry Effect on Surface Roughness in Ball-end Milling Using the Taguchi Method
Cho, Chul Yong ; Ryu, Shi Hyoung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 569~575
DOI : 10.7735/ksmte.2014.23.6.569
In this study, the effect of cutting edge geometry, such as helix and rake angles, on surface roughness in ball-end milling is investigated by using the Taguchi method. A set of experiments adopting the
design with an orthogonal array are conducted with special WC ball-end mills having different helix and rake angles. Analysis of variance (ANOVA) is performed to analyze the effects of tool geometry and machining parameters, such as cutting speed, feed per tooth, and depth of cut, on surface roughness. The ANOVA results reveal that helix and rake angles are critical factors affecting surface roughness; the interaction of helix angle and cutting speed is also important. This research can contribute to novel cutting edge designs of ball-end mills and optimization of cutting parameters.
Feasibility Study for Wear Resistance of Rails
Chang, Seky ; Pyun, Young Sik ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 576~579
DOI : 10.7735/ksmte.2014.23.6.576
Rails are continuously exposed to severe environments due to increases in train service frequency, passing tonnage, and speed. Wear is one of the most common types of damage observed on rails. The surface of railsis heat treated to secure safety at critical sites, such as curved tracks or turnouts. Ultrasonic nanocrystal surface modification (UNSM), a new approach for rails, was examined to strengthen the rail surface. The effect of UNSM on the wear resistance of rail specimens was compared with that of heat treatment. Wear resistance was improved after UNSM treatment due to increased hardness and surface compressive residual stress.
Automation of Cell Production System for Cellular Phones based on Multi-dual-arm Robots
Do, Hyun Min ; Kim, Doo Hyeong ; Kyung, Jin Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 580~589
DOI : 10.7735/ksmte.2014.23.6.580
Demands for automation in the cell production process of IT products are becoming increasingly sophisticated. In particular, the dual-arm robot has drawn attention as a solution because it has a flexibility and works similarly to humans. In this paper, we propose an automation system for cellular phone packing processes using two dual-arm robots. Applied robots are designed with specifications to meet the requirements of cellular phone packing jobs. In addition, a robotic cell production system is proposed by applying a method of task allocation for efficient packing of cellular phones. Specifically, a task is assigned to reduce takt-time and to avoid collision between two robots. Finally, we discuss some experimental results that include the packing job of five unit boxes with seven kinds of accessories.
Investigation of Asymmetric Aspherical Triangular Prism Optical System for Video Information Display
Youn, Gap-Suck ; Yoo, Kyung-Sun ; Hyun, Dong-Hoon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 590~595
DOI : 10.7735/ksmte.2014.23.6.590
We have investigated anamorphic prism lenses with distortions of 0.3-0.5%. We designed the plastic triangular lens and confirmed the minimum resolution using MTF graphs. Also we confirmed that the SVGA optical system can realize a resolution of
56 megapixels. A distortion of about 0.5% aberration appears in the maximum field, and a finite beam aberration of about
is confirmed. We made a mold based on the design data and completed the prism lens through exodus molding. We confirmed the shape error (<
) and surface roughness (> 40 nm) of the three sides. We made the video-information-display prototype glasses using prism lens by measuring the performance, we determined the distortion aberration (0.3%) and SVGA resolution. Our approach will enable fabrication of a portable large-screen display device for glasses and sunglasses for the domestic market and, after 2015, for the world market.
Flow Analysis of Mounting Gradient of Protective Glass Around Motorcycle
Han, Moonsik ; Cho, Jaeung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 596~601
DOI : 10.7735/ksmte.2014.23.6.596
In this study, driving efficiency and the safety of motorcycle drivers due to the mounting gradient of motorcycle protective glass are investigated through flow analysis. Mounting gradients of motorcycle protective glass in models 1, 2, and 3 are
, respectively. Wind velocity of 100 km/h is applied to the protective glass installed at the front of each model. The flow resistance values of models 2 and 3 are 1.2 and 1.5 times, respectively, that of model 1. The driving efficiency of model 1 is the highest among the three models. Pressure to the driver`s face in models 2 and 3 is 1.2 times higher than in model 1. Because the pressure to the driver`s face in model 1, with mounting gradient of
, is the lowest among the three models, model 1 is the safest. This result can be applied to improve the safety of motorcycle drivers.
Experimental Study of New Welding Assembly Technology Applied with Mixed-Model Production Method
Park, Dong Hwan ; Gu, Ja Jun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 602~608
DOI : 10.7735/ksmte.2014.23.6.602
Mixed-model production lines are often used in manufacturing systems. In production lines, different product types are simultaneously manufactured by processing small batches. This paper describes a new welding assembly technology involving the development of experimental models for a mixed-model production line in an automobile company. Due to the extensive number of models, the design of a welding assembly system is complicated. Performance evaluation is an important phase in the design of welding assembly lines in a mixed-model production environment. In this study, a new welding assembly technology for a mixed-model production method was used to weld the package tray and dash panel of a vehicle.
Investigation of the Angular Distribution of Luminous Intensity in the Symmetric Optical System of a COB LED High Bay
Yoo, Kyung-Sun ; Lee, Chang-Soo ; Hyun, Dong-Hoon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 609~617
DOI : 10.7735/ksmte.2014.23.6.609
We have studied a chip-on-board LED lighting optical system for various luminous-intensity-distribution angles of the LED. An optical system that can accept different LEDs was made to reduce the systems`s weight and size as we selected the chip-on-board LED, which is easy to apply to optical systems, unlike existing package-on-board LEDs. The luminous-intensity-distribution angles were
. We researched these four types of optical systems. The
units were developed into reflectors, and the
units, into lenses. We checked the performance of the designed optical system through simulation and made a mock-up. Then we made a prototype of the chip-on-board LED high bay for use with the mock-up. After measuring its performance, we tested the luminous-intensity-distribution angles and compared them with simulation data. The resulting prototype was developed considering brightness, light uniformity, age, and economics which are suitable for a factory environment.
Analysis on the Characteristic of Current Waveform and Welding for SM45C Using FCAW According to Gas Mixture Ratio
Lee, JongHun ; Lim, ByungChul ; Park, SangHeup ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 618~623
DOI : 10.7735/ksmte.2014.23.6.618
This study, analyzed the waveform and mechanical properties of flux cored arc Welding on SM45C.
10% + Ar 90% shows the lowest standard deviation and shunt ratio at which the arc was most stable.
10% + Ar 90% is equal to
20% + Ar 80%. therefore,
20% + Ar 80% is the best of mixture gases. The hardness test result for the gas mixture ratio of
10% + Ar 90% was HV 249.7 which is the highest measured value. According to tensile test results, the tensile strength increased with increasing Ar in the mixture gas. This was because of the inertness of the argon, which does not combine with other elements, causing
to combine with pearlite and ferrite and decreasing the maximum tensile strength. Microstructural examination results show that with increasing Ar, ferrite generation decreases while the mild microstructure increases which influences the hardness.
Case Study of Intermittent Engine Hesitation Fault Diagnosis By CKPS Fault
Kim, Sung Mo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 624~629
DOI : 10.7735/ksmte.2014.23.6.624
The purpose of this study is to carry out the task of engine hesitation which occurred intermittently in driving due to the defective CKPS of LPI vehicles. As the result of the wrong data from the equipment of D-logger, the signal error of CKPS caused the engine hesitation. We performed a study in the followings to analyze and investigate the cause effectively. First, we have investigated the control wiring harness and connector pin contact defect inspection. Second, we have inspected the defection of CKPS separately. From this study, it was found that the engine hesitation were caused by the bad durability and we have showed how to diagnosis the fault of the engine hesitation intermittently while driving. Therefore, it is determined that we have to improve the durability of the CKPS through a strict quality control and to increase the reliability.
Characteristics of a PZT-Driven Micro Depth Adjustment Device for Cutting Coated Film
Ryu, Sang-Oh ; Kim, Hwa-Young ; Ahn, Jung-Hwan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 630~635
DOI : 10.7735/ksmte.2014.23.6.630
This study aims to develop a PZT-driven depth adjustment device with a flexure hinge and to investigate its static/dynamic characteristics. This device will be applied to rapidly and accurately trace a flat surface with slight waviness of up to several hundreds of micrometers in magnitude. One typical example is to cut a film coated on a steel plate. A depth control system composed of PMAC, PZT/PZT amplifier, flexure hinge/knife, and laser displacement sensor is implemented on a desktop three-axis machine and an actual cutting test is conducted on a steel workpiece with a sinusoidal-wavy surface. It is verified that the dynamic characteristics of the device limit the maximum cutting speed and depth precision.
Development of Nipkow Disk for High-Speed Confocal Probe Using Micro-lens and Pinhole Disks
Kim, Gee Hong ; Lee, Hyung Seok ; Kim, Chang Kyu ; Lim, Hyung Jun ; Lee, Jae Jong ; Choi, Kee Bong ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 636~641
DOI : 10.7735/ksmte.2014.23.6.636
This paper discusses the fabrication process for a Nipkow disk using micro-lens and pinhole disks. The confocal measuring system that uses the Nipkow disk has the advantage in measuring speed, because the Nipkow disk can simultaneously provide confocal images of all pixels in a CCD camera without requiring a lateral scanning unit. A micro-lens configuration, which focuses illumination on a pinhole, overcomes the low optical efficiency of the Nipkow disk system and allows its use in practical applications. This paper describes how to design the Nipkow disk in terms of numerical aperture, particularly for measuring the height of solder bumps in packaging application and for hybrid processes combining mechanical and semiconductor processes.
Parallelism Measurement of Rolls by Using a Laser Interferometer
Choi, Jong Geun ; Kim, Seongeun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 23, issue 6, 2014, Pages 642~646
DOI : 10.7735/ksmte.2014.23.6.642
This research describes the measurement of roll parallelism by a laser interferometer. Parallelism among rolls is an important factor for improving the precision of printing devices. A laser interferometer, which is a device for the precise measurement of distance, can be utilized to measure parallelisms between rolls. To measure distance between two rolls by using a laser interferometer, the laser must not be severed during measurement. To achieve this condition, a linear motion guide was installed to each roll being measured, and continuous measurement of distance between two rolls was implemented by the simultaneous control of two mirrors installed on the guides. The method to measure parallelism between two rolls presented in this research can be utilized to improve printing precision by enhancing parallelism between rolls in printing devices.