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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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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
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Position Control Algorithm and Experimental Evaluation of an Omni-directional Mobile Robot
Chu, Baeksuk ; Cho, Gangik ; Sung, Young Whee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 141~147
DOI : 10.7735/ksmte.2015.24.2.141
In this study, a position control algorithm for an omni-directional mobile robot based on Mecanum wheels was introduced and experimentally evaluated. Multiple ultrasonic sensors were installed around the mobile robot to obtain position feedback. Using the distance of the robot from the wall, the position and orientation of the mobile robot were calculated. In accordance with the omni-directional velocity generation mechanism, the velocity kinematics between the Mecanum wheel and the mobile platform were determined. Based on this formulation, a simple and intuitive position control algorithm was suggested. To evaluate the control algorithm, a test bed composed of artificial walls was designed and implemented. While conventional control algorithms based on normal wheels require additional path planning for two-dimensional planar motion, the omni-directional mobile robot using distance sensors was able to directly follow target positions with the simple proposed position feedback algorithm.
Computer Aided Process Planning for 3D Printing
Park, Hong-Seok ; Tran, Ngoc-Hien ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 148~154
DOI : 10.7735/ksmte.2015.24.2.148
Computer aided process planning (CAPP) keeps an important role between the design and manufacturing engineering processes. A CAPP system is a digital link between a computer aided design (CAD) model and manufacturing instructions. CAPP have been researched and applied in manufacturing filed, however, one manufacturing area where CAPP has not been extensively researched is rapid prototyping (RP). RP is a technique for creating directly a three dimensional CAD data into a physical prototype. RP enables to build physical models automatically and to use to reduce the time for the product development cycle as well as to improve the final quality of the designed product. Three-dimensional (3D) printing is one kind of RP that creates three-dimensional objects from CAD models. The paper presents a computer aided process planning system for printing medical products. 3D printing has been used to solve complex medical problems such as surgical instruments, bioengineered products, medical implants, and surgical guides.
Design of Alignment Mark Stamper Module for LED Post-Processing
Hwang, Donghyun ; Sohn, Young W. ; Seol, Tae-ho ; Jeon, YongHo ; Lee, Moon G. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 155~159
DOI : 10.7735/ksmte.2015.24.2.155
Light emitting devices (LEDs) are widely used in the liquid crystal display (LCD) industry, especially for LCD back light units. Therefore, much research has been performed to minimize manufacturing costs. However, the current process does not process LED chips from broken substrates even though the substrate is expensive sapphire wafer. This is because the broken substrates lose their alignment marks. After pre-processing, LED dies are glued onto blue tape to continue post-processing. If auxiliary alignment marks are stamped on the blue tape, post-processing can be performed using some of the LED dies from broken substrates. In this paper, a novel stamper module that can stamp the alignment mark on the blue tape is proposed, designed, and fabricated. In testing, the stamper was reliable even after a few hundred stamps. The module can position the stamp and apply the pattern effectively. By using this module, the LED industry can reduce manufacturing costs.
Effects of Molecular Weight and Temperature on Fiber Diameter of Poly(ε-caprolactone) Melt Electrospun Fiber
Ko, Junghyuk ; Jun, Seungwon ; Lee, Jason Keonhag ; Lee, Patrick C. ; Jun, Martin B.G. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 160~165
DOI : 10.7735/ksmte.2015.24.2.160
The 14k, 45k, and 70k Mw PCL have different crystallization temperatures and therefore have slightly different characteristics affecting the fiber diameter. To observe these behaviors, the fiber was produced at every step of
for each molecular weights and the diameter was measured. Moreover, the fiber was fabricated over the cooled ground plate to observe the change in fiber diameter in comparison to the normal ground plate. In case of molecular Mw 14k PCL, the diameter increased as the temperature increased. For Mw 45k PCL, the fiber diameter decreased as the temperature increased. As of Mw 70k PCL, the fiber diameter decreased with increasing temperature as well. When the experiment was conducted over the cooled collector plate, the data did not change significantly from the previous lexperiments.
Development of an Automation Tool for the Three-Dimensional Finite Element Analysis of Machine Tool Spindles
Choi, Jin-Woo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 166~171
DOI : 10.7735/ksmte.2015.24.2.166
In this study, an automation tool was developed for rapid evaluation of machine tool spindle designs with automated three-dimensional finite element analysis (3D FEA) using solid elements. The tool performs FEA with the minimum data of point coordinates to define the section of the spindle shaft and bearing positions. Using object-oriented programming techniques, the tool was implemented in the programming environment of a CAD system to make use of its objects. Its modules were constructed with the objects to generate the geometric model and then to convert it into the FE model of 3D solid elements at the workbenches of the CAD system using the point data. Graphic user interfaces were developed to allow users to interact with the tool. This tool is helpful for identification of a near optimal design of the spindle based on, for example, stiffness with multiple design changes and then FEAs.
Development of a Tool to Automate One-Dimensional Finite Element Analysis of Machine Tool Spindles
Choi, Jin-Woo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 172~176
DOI : 10.7735/ksmte.2015.24.2.172
In this research, a tool was developed to automate one-dimensional finite element analysis (1D FEA) for design of a machine tool spindle. Based on object-oriented programing, this tool employs the objects of a CAD system to construct a geometric model and then to convert it into the FE model of 1D beams at the workbenches of the CAD system with minimum data to define the spindle such as bearing positions and cross-sections of the shaft. Graphic user interfaces were developed for users to interact with the tool. This tool is helpful in identifying a near optimal design of the spindle with the automation of the FEA process with numerous design changes in minimum time and efforts. It is also expected to allow even design engineers to perform the FEA in search of an optimal design of the machine tool spindle.
Lightweight Design of Car Bodies for Double Deck High-Speed Trains
Kang, SeungGu ; Shin, KwangBok ; Ko, TaeHwan ; You, WonHee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 177~185
DOI : 10.7735/ksmte.2015.24.2.177
This paper describes a weight-reduction design method for the car bodies of a double deck high-speed train (service speed of 300 km/h). The method uses lightweight materials and a topology optimization technique. In this study, aluminum extrusions and sandwich composites were selected as the best materials to reduce the weight of the car body. The topology optimization technique was used to determine which car body parts could be made of the sandwich composites to achieve additional weight savings. The results of the topology optimization analysis showed that sandwich composites could be used for secondary car body members such as the roof and the second underframe. Also, it was found that a car body composed of aluminum extruded parts and sandwich composites could weigh up to 14% less than a car body made of only aluminum extrusions.
Approximate Optimization of the Power Transmission Drive Shaft Considering Strength Design Condition
Shao, Hailong ; Lee, Jongsoo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 186~191
DOI : 10.7735/ksmte.2015.24.2.186
Presently, rapidly changing and unstable global economic environments demand engineers. Products should be designed to increase profits by lowering costs and provide distinguished performance compared with competitors. This study aims to optimize the design of the power-transmission drive shaft. The mass is reduced as an objective function, and the stress is constrained under a constant value. To reduce the number of experiments, CCD (central composite design) and D-Optimal are used for the experimental design. RSM (response surface methodology) is employed to construct a regression model for the objective functions and constraint function. In this problem, there is only one objective function for the mass. The other objective function gives 1; thus, NSGA-II is used.
Approximate Multi-Objective Optimization of Stiffener of Steel Structure Considering Strength Design Conditions
Jeon, Eungi ; Lee, Jongsoo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 192~197
DOI : 10.7735/ksmte.2015.24.2.192
In many fields, the importance of reducing weight is increasing. A product should be designed such that it is profitable, by lowering costs and exhibiting better performance than other similar products. In this study, the mass and deflection of steel structures have to be reduced as objective functions under constraint conditions. To reduce computational analysis time, central composite design(CCD) and D-Optimal are used in design of experiments(DOE). The accuracy of approximate models is evaluated using the
value. In this study, the objective functions are multiple, so the non-dominant sorting genetic algorithm(NSGA-II), which is highly efficient, is used for such a problem. In order to verify the validity of Pareto solutions, CAE results and Pareto solutions are compared.
Development of Continuous and Scalable Nanomanufacturing Technologies Inspired by Traditional Machining Protocols Such as Rolling, Pullout, and Forging
Ok, Jong G. ; Kwak, Moon Kyu ; Guo, L. Jay ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 198~202
DOI : 10.7735/ksmte.2015.24.2.198
We present a series of simple but novel nanopatterning methodologies inspired by traditional mechanical machining processes involving rolling, pullout, and forging. First, we introduce roll-to-roll nanopatterning, which adapts conventional rolling for continuous nanopatterning. Then, nano-inscribing and nano-channel lithography are demonstrated, whereby seamless nanogratings can be continuously pulled out, as in a pullout process. Finally, we discuss vibrational indentation micro- and nanopatterning. Similarly to the forging/indentation process, this technique employs high-frequency vertical vibration to indent periodic micro/nanogratings onto a horizontally fed substrate. We discuss the basic principles of each process, along with its advantages, disadvantages, and potential applications. Adopting mature and reliable traditional technologies for small-scale machining may allow continuous nanopatterning techniques to cope with scalable and low-cost nanomanufacturing in a more productive and trustworthy way.
Case Study of Intermittent Poor Acceleration Fault Diagnosis by Brake Switch Fault
Kim, Sung Mo ; Jo, Haeng Deug ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 203~210
DOI : 10.7735/ksmte.2015.24.2.203
This paper investigates the failure of a car with a 2.5-liter CRDi engine of the Hyundai Company. The failure is caused by intermittent poor acceleration while driving. To analyze the cause, we investigated the air intake volume, the fuel injection, and the air-fuel ratio, which were determined to be normal. The brake switch signal error was discovered while analyzing the function that limits the output of the engine. While investigating the cause, we discovered the corrosion of the pins on the connector of the brake switch. We determined that it was generated by soapy water flowing in the solar film. Therefore, the cause of the failure was the brake switch signal errors. Additionally, we determined that ECM was the normal fail-safe mode that implemented the override device for safety during normal acceleration. Based on these results, further solar film experiments must be conducted to fully elucidate the causes.
Approximate Multi-Objective Optimization of Bike Frame Considering Normal Load
Chae, Yunsik ; Lee, Jongsoo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 211~216
DOI : 10.7735/ksmte.2015.24.2.211
Recently, because of the growth in the leisure industry and interest in health, the demand for bicycles has increased. In this research, considering the vertical load on a bike frame under static state conditions, the deflection and mass of the bike frame were minimized by satisfying the service condition and performing optimization. The thickness of the bicycle-frame tube was set to a design variable, and its sensitivity was confirmed by an analysis of means (ANOM). To optimize the solution, a response-surface-method (RSM) model was constructed using D-Optimal and central composite design(CCD). The optimization was performed using a non-dominant sorting genetic algorithm (NSGA-II), and the optimal solution was verified by finite-element analysis.
Study on Design Parameters of LED Secondary Lens with Very Close Range
Kim, Jang Yun ; Hyun, Dong Hoon ; Hong, Cheol Ui ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 217~223
DOI : 10.7735/ksmte.2015.24.2.217
In this paper, the performance of a system was analyzed according to the design parameters of a LED secondary lens that can be applied at a very close range, e.g., for direct lighting or display systems. We designed the secondary lens of the very-close-range LED using an aspheric equation and analyzed its performance-particularly the angle of the beam spread, central luminous intensity, and light uniformity-with respect to the thickness of lens, radius, conic constant, and asphericity (4th). Our analysis shows that four parameters affect the performance. The simulation results indicate an optimal thickness of 1 mm and show that a larger radius yields higher performance. The optimal range for the conic constant was determined as -1.21 to -1.25, the optimal range for the asphericity was determined as 0.0047xx to 0.0049xx (4th).
Machinability Evaluation of Sapphire Glass Using Powder Blasting
Kang, Eun Ji ; Kim, Jung Ho ; Jang, Ho Su ; Park, Dong Sam ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 224~230
DOI : 10.7735/ksmte.2015.24.2.224
In this study, the machinability of sapphire glass is tested using the powder blasting method under various blasting conditions. The thickness and diameter of the sapphire glass samples were 0.4 mm and 50.8 mm (2 inch), respectively. The machined patterns from each sample were a circle, a square, and a rectangle. The powder we used was GC #400 and #800. The blasting pressures of the powders were 2, 4, and 6 bar. The scanning time of the nozzle was 20 and the scanning speeds of the nozzle were 80, 100, and 120 mm/s. Experimental results showed that machining depths increased in proportion to blasting pressure. The machining depth of GC #800 was much higher than that of GC #400, while surface roughness was worst with GC #400. These results imply that the blasting pressure and size of the blasting powder are the most important parameters for machining sapphire glass.
Contact Stress of Slewing Ring Bearing with External Pinwheel Gear Set
Kwon, Soon-man ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 231~237
DOI : 10.7735/ksmte.2015.24.2.231
The pin-gear drive is a special form of fixed-axle gear mechanism. A large wheel with cylindrical pin teeth is called a pinwheel. As pinwheels are rounded, they have a simple structure, easy processing, low cost, and easy overhaul compared with general gears. They are also suitable for low-speed, heavy-duty mechanical transmission and for occasions with more dust, poor lubrication, etc. This paper introduces a novel slewing ring bearing with an external pinwheel gear set (e-PGS). First, we consider the exact cam pinion profile of the e-PGS with the introduction of a profile shift. Then, the contact stresses are investigated to determine the characteristics of the surface fatigue by varying the shape design parameters. The results show that the contact stresses of the e-PGS can be lowered significantly by increasing the profile shift coefficient.
Performance of Assembled-type Drills
Yang, Hae-Jeong ; Lee, Jai-Hak ; Seo, Jeong-Hwan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 238~243
DOI : 10.7735/ksmte.2015.24.2.238
Recently, the use of assembled-type drills as environmentally friendly products has expanded because the shanks of drills can be reused by replacing the tip when the tools are worn or cut. In addition to their precision and endurable stiffness with respect to the cutting force, assembled-type drills need no stricture because of thermal deformation, which makes replacement easily. In this study, we developed novel assembled-type drills and compared their characteristics, such as the precision, stiffness, and thermal deformation, with those of conventional drills. The new drills exhibited a precision over IT 8 class and no changes in dimensions due to thermal deformation, such that we can change the assembly easily with durability.
Study of Pressure and Flux Pulsation to Design Optimum Valve-Plate Notch and Pulsation-Variables Analysis of Swash-Plate-Type Piston Pump
Bae, Jun-Hyeong ; Chung, Won-Jee ; Jang, Jun-Ho ; Yoon, Young-Hwan ; Jeon, Ju-Yeol ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 244~250
DOI : 10.7735/ksmte.2015.24.2.244
We propose a simulation technique to estimate the reduction effect of the pressure/flow pulsation by analysis of the pulsation variables and notch shape of the valve plate of a swash-plate-type variable piston pump. First, using SimulationX
, we perform a theoretical kinematic analysis according to the variable swash-plate angle and rotational velocity in order to design a single-piston pump. In designing the notch shape of the valve plate of the swash-plate-type variable piston pump as one of the pulsation variables, we investigate the effect of the pulsation by comparing two notch types (circular type and V type). Then, we extend our analysis to a nine-piston pump model. This paper not only confirms the effect of the pressure/flow pulsation according to pulsation variables but can also be applied to the development of a SimulationX
-based simulation technique for notch-shape optimization for a swash-plate-type variable piston pump.
Study on the Thermal Deformation of the Air-conditioner Indoor Unit Assembly Using 3D Measurement and Finite Element Analysis
Hong, Seokmoo ; Hwang, Jihoon ; Kim, Cheulgon ; Eom, Seong-uk ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 251~255
DOI : 10.7735/ksmte.2015.24.2.251
Thermal deformation, such as bending and twisting, occurs among the polymer parts of air-conditioner indoor units because of repetitive temperature change during heating operation. In this study, a numerical method employing finite-element analysis to efficiently simulate the thermal deformation of an assembly is proposed. Firstly, the displacement of an actual assembly produced by thermal deformation was measured using a 3D optical measurement system. The measurement results indicated a general downward sag of the assembly, and the maximum displacement value was approximately 1 mm. The temperature distribution was measured using a thermographic camera, and the results were used as initial-temperature boundary conditions to perform temperature-displacement analysis. The simulation results agreed well with the measured data. To reduce the thermal deformation, the stiffness increased 100%. As the results, the maximum displacement decreased by approximately 5.4% and the twisting deformation of the holder improved significantly.
Development of Production System for Eco-friendly Ocher Tiles
Han, Jae-Ho ; Kim, Hang-Woo ; Lee, Yeon-Shin ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 2, 2015, Pages 256~262
DOI : 10.7735/ksmte.2015.24.2.256
This study has an innovative improvement of the ocher tiles production system that aims to resolve social issue of industrial waste and to meet the customer needs for environmental-friendly building materials. By changing a wet type cutting method to a dry type of ocher tiles production system, the three processes such as cleaning, dehydration, and drying can be removed in existing overall process of 17 steps. Accordingly, the application of the wet type cutting method, which is proposed in this study, makes an increase in ocher tiles production from 1,500 to 1,850 pieces per hour. In particular, industrial wastewater that was emerging as the biggest problem in environmental pollutants in the wet cutting method has been removed. In addition, the most serious problems of noise and dust from the operator side, while developing a device for the dry cutting method, are eliminated through the development of additional equipment.