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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
Ultrasonic Fatigue Test for a High Strength Steel Plate
Yeom, Hyunho ; Jung, Yongchan ; Kim, Chayeong ; Kang, Ki-Young ; Lee, Moon Gu ; Hong, Min-Sung ; Jeon, Yongho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 589~593
DOI : 10.7735/ksmte.2015.24.6.589
The demand of high cycle fatigue behavior on plate material is increasing because of its various applications. However, the high-cycle fatigue life data of the plate material is very rare compared to the rod material. Thus, in this study, a plate specimen is designed for the ultrasonic fatigue test because it is time efficient as compared to the conventional fatigue test. To apply the ultrasonic fatigue test, the specimen design is required to resonate at 20 kHz. Therefore, the dynamic elastic modulus was determined by measuring the resonance frequency with a piezoelectric element and laser doppler vibrometer (LDV). As a result, the plate specimen is designed and demonstrated using the ultrasonic fatigue testing machine. The ultrasonic fatigue test results were compared with the hydraulic fatigue test results.
Fabrication of WC-Ni-Si-B
C Composite and Diffusion Bonding with Stainless Steel
Won, Jong-Wun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 594~598
DOI : 10.7735/ksmte.2015.24.6.594
The effects of Ni on the mechanical properties of WC-Xwt.%Ni-1.5wt.%Si-1.1wt.%
composite (X = 21.6, 23.6, 25.6 and 27.6 wt.%) were investigated in order to replace Co with Ni as the binder metal for hard materials based on WC-Co system. Using X-ray diffraction, optical microscopy, field-emission scanning electron microscopy results, the microstructure, pore distribution and grain size of the composites sintered at
were examined with different fraction (X = 21.6, 23.6, 25.6 and 27.6 wt.%) of binder metal Ni. The average WC grain size of the
composites was about
. The Rockwell hardness : A (HRA) and transverse rupture strength were about 88HRA and
, respectively. The obtained sample was bonded with SM45C at a temperature of
. The thickness and mechanical properties of the bonded area were investigated with different dwell time at a bonding temperature of
Cyclone Type Filter for Preventing Clogging of High Pressure Coolant Pump
Kim, Jun-Hwan ; Kang, Ji-Hun ; Kang, Seong-Gi ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 599~604
DOI : 10.7735/ksmte.2015.24.6.599
Currently, the coolant system in industrial sites is an efficient process to keep clean cutting oils. However, the damage to a pump occurs due to a chip and debris when inhaled into the pump, and thus problems such as the reduction of both efficiency and lifespan might arise. In this study, a new type of filter was developed in order to primarily prevent the damage from the pump impeller and make it unnecessary to have the replacement and cleaning at the same time. This study found the problem reducing the suction volumetric efficiency and cavitation when inhaled, and conducted a method to solve the problem compared to the result of fluid analysis according to two velocity conditions. As a result, this study achieved the effect of lowering the pressure and meeting the suction flow rate by connecting the four filters.
Robot System Design Capable of Motion Recognition and Tracking the Operator's Motion
Choi, Yonguk ; Yoon, Sanghyun ; Kim, Junsik ; Ahn, YoungSeok ; Kim, Dong Hwan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 605~612
DOI : 10.7735/ksmte.2015.24.6.605
Three dimensional (3D) position determination and motion recognition using a 3D depth sensor camera are applied to a developed penguin-shaped robot, and its validity and closeness are investigated. The robot is equipped with an Asus Xtion Pro Live as a 3D depth camera, and a sound module. Using the skeleton information from the motion recognition data extracted from the camera, the robot is controlled so as to follow the typical three mode-reactions formed by the operator's gestures. In this study, the extraction of skeleton joint information using the 3D depth camera is introduced, and the tracking performance of the operator's motions is explained.
Experimental Study on a New Test Method for Pole Side Impact
Kim, Dea Up ; Woo, Chang Gi ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 613~618
DOI : 10.7735/ksmte.2015.24.6.613
In recent years, WorldSID has been continuously developed and investigated to be the representative biofidelic anthropomorphic test device (ATD) as well as the device for replacement of the current EuroSID-2. In Korea, the side impact accident is one of the major severe accidents in terms of the number of accidents and fatality. Since 2003, the side crash test with a speed of 50 kph in the perpendicular direction has been initiated as a safety standard with EuroSID-1 at the first stage. Simultaneously, a 55 kph impact test has been conducted as a part of Korean New Car Assessment (KNCAP). Currently, only EuroSIDE-2 is accepted as a regulatory tool for vehicle certification and KNCAP. The tests with WorldSID are conducted experimentally in order to use WorldSID of the KNCAP in near future.
Design of Optimal Kinetic Energy Harvester Using Double Pendulum
Lee, Chibum ; Park, Hee Jae ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 619~624
DOI : 10.7735/ksmte.2015.24.6.619
Owing to miniaturization and low-power electronics, mobile, implanted, and wearable devices have become the main trends of electronics during the past decade. There has been much research regarding energy harvesting to achieve battery-free or self-powered devices. The optimal design problems of a double-pendulum kinetic-energy harvester from human motion are studied in this paper. For the given form factor, the weight of the harvester, and the known human excitation, the optimal design problem is solved using a dynamic non-linear double-pendulum model and an electric generator. The average electrical power was selected as the performance index for the given time period. A double-pendulum harvester was proven to be more efficient than a single-pendulum harvester when the appropriate parameters were used.
Hardness Analysis of Surface Treated Magnesium Alloy using Laser Induced Breakdown Spectroscopy
Kang, Dongchan ; Kim, Joohan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 625~631
DOI : 10.7735/ksmte.2015.24.6.625
The hardness of surface treated magnesium alloy was evaluated using laser induced breakdown spectroscopy. The surface of the specimen was hardened mechanically, and the hardness profiles were measured using a traditional measurement technique. A laser beam was irradiated to generate a plasma, and the peaks of the components of the specimen were analyzed. A wavelength of 333.66 nm and 293.65 nm were selected as the atomic and ionic peaks, respectively. The ratios of the ionic peak to the atomic peak were obtained so as to compare the hardness profile. As the depth increased, the ratio decreased. These results are in good agreement with the previous hardness measurement results. It can be considered that this technique could be applied for remote and time-efficient hardness measurement.
Cause of Fatigue Failure of the First Blade of 100-MW Gas Turbine
Youn, Hee-Chul ; Woo, Chang-Ki ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 632~638
DOI : 10.7735/ksmte.2015.24.6.632
Many failures have been reported in gas turbine facilities owing to repeated startups and prolonged use of the turbines. In this study, the causes and mechanism of fatigue failure in the first blade of a gas turbine were analyzed using a finite element method to calculate the centrifugal force, bending force, and a modal analysis based on the stress-stiffening effect and harmonic response under the operating conditions. The results show that, fatigue damage was caused by the resonance conditions encountered, in which the first natural frequency declined along with an increase in the metal temperature of the blade. The position of the expected fatigue damage was shown to match the actual position of the cracking at the root area of the blade, which was on the concave side. In addition, the equivalence fatigue stress was observed to approach the fatigue limit.
Surface Characteristics based on Material and Process Changes in Surface Treatment using Fast Tool Servo
Kim, Mi Ru ; Lee, Deug Woo ; Lee, Seung Jun ; Liang, Li ; Kim, Jong Man ; Jang, Nam-Su ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 639~646
DOI : 10.7735/ksmte.2015.24.6.639
A treatment for improving the characteristics of a surface is very important in increasing the life of machine parts. Many studies have been carried out on the surface characteristics after such treatments. For enhanced eco-technology, an alternative to a conventional chemical surface treatment process is essential. Ultrasonic nano-crystal surface modification (UNSM) technology is a physical environmentally friendly surface treatment method. This technology was developed in domestic and currently being used. As the mechanism of UNSM technology, a ball tip attached to an ultrasonic vibration device strikes the metal surface at nearly 20,000 times per second. The resulting modified surface layer improves the surface characteristics. This paper describes a self-developed fast tool servo system applied to the UNSM process as a vibration module within a high-frequency bandwidth. After describing the surface modification process based on the material and process changes, the surface characteristics are compared.
Characterization of Probe Pin for LED Inspection System
Shim, Hee-Soo ; Kim, Sun Kyoung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 647~652
DOI : 10.7735/ksmte.2015.24.6.647
A probe pin is a key component of LED inspection equipment. The probe pin makes contact with the LED electrodes and supplies an electric current. Because the mechanical and electrical homogeneity of the probe surface affects the service life and reliability, its characterization is essential. For this study, the hardness was measured using a micro-Vickers hardness test. Moreover, the thicknesses of the plating at different locations and the elemental compositions were examined using an FE-SEM. The uniformity of the plating was found to be acceptable because palladium was detected consistently throughout the tested domain. In addition, the hardness of the surface was determined to be higher than that of the typical palladium range, which is attributed to the use of undercoated nickel.
Acceleration Life Prediction of the Capacitor on a Traction Inverter for a High-Speed Train
Maeng, Heeyoung ; Jung, Si-Kyo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 653~659
DOI : 10.7735/ksmte.2015.24.6.653
The aim of this study is to develop a technique for the accelerated life test of the capacitor in a propulsion control device of a traction inverter used for a high-speed train. Using this technique, the accelerated life test can possibly estimate the life cycle of a capacitor under various temperature conditions and irregularly applied voltage. The accelerated life test is conducted for the capacitor of the traction inverter. The common proceedings of this test are selection of failure mechanism, determination of accelerated stress, range determination of the accelerated stress, determination of the test condition, and distribution and determination of the sample. From this result, the continuous applied voltage was not considered for the acceleration factors anymore. Therefore, the final result having an acceleration factor of 9.4 (= 13,626/1,445) was observed. Furthermore, the life-shortening acceleration effect for the irregular applied voltage condition can be applied to various situations.
Design and Control of X-ray Permeable Teleoperated Stewart Platform for Fracture Surgery
Yoo, Byeongjun ; Kim, Hyemi ; Lee, Sung-Hak ; Lim, Sunho ; Park, Tae Gon ; Lee, Chibum ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 660~666
DOI : 10.7735/ksmte.2015.24.6.660
To avoid radiation exposure from repeated x-rays taken during orthopedic surgery, an x-ray permeable teleoperated Stewart platform for orthopedic fracture surgery was developed. This system is composed of a user interface device and a teleoperated operational robot, both of which use a Stewart platform mechanism. The links of the operational robot are made from an x-ray permeable material, polycarbonate, to minimize the interference. The forward and inverse kinematics algorithm applied and the structural reliability were both verified through an analysis using commercial engineering software. To monitor the operating status in real time and stop the device during an emergency, a monitoring software was developed. The performance of the x-ray permeable teleoperated Steward platform was validated experimentally.
Development of a Hexapod Robot for Multi-terrain Reconnaissance
Lim, Seoung-Yong ; Kim, Jong-Hyeong ; Kim, Hyeong-Gik ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 667~674
DOI : 10.7735/ksmte.2015.24.6.667
This paper describes the development of a prototype hexapod robot with six circular legs to overcome a variety of challenging terrains. The legs of the robot are very important for stability during walking, which are analyzed for determining the optimal design parameters through CAE tools. Its control system consists of three types of sensors, microprocessors, and communication modules for PC interface. The entire operation of the robot can be controlled and monitored using a PC. The experimental operations for three different roads verified the feasibility of the prototype robot for carrying out reconnaissance on multi terrain. In the near future, the prototype robot can be used for a military purpose of detecting and informing a potential risk in advance.
Design of Special-purpose Machine Tool Based on a Multi-spindle Head
Maeng, Heeyoung ; Park, Juwook ; Park, Hongkeun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 675~681
DOI : 10.7735/ksmte.2015.24.6.675
When many holes on a plane are machined simultaneously, the positional precision and machining efficiency are very important. Multi-spindle heads are typical order making products of which the number of shafts and hole positions vary depending on the size or form of the product. For the automatic design of multi-spindle heads, the design modules for power transmission systems for drive, idle, and spindle shafts were developed, and a design technique the determining the optimum position and number of idle shafts according to gear positions was developed. In addition, for the precise determination of the multi-spindle head, the design methods for the guide planes of columns, and feed mechanisms were devised. In addition, the design modules for accurate clamping and automatic transportation mechanisms were developed. Finally, in order to simplify and standardize the design process, the design analysis and simulation verification modules are integrated.
Validation of Turbulence Models for Analysis of a Single-Phase Turbulent Natural Convection
Song, Ik-Joon ; Shin, Kyung-Jin ; Kim, Jungwoo ; Park, Ik Kyu ; Lee, Seung-Jun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 682~686
DOI : 10.7735/ksmte.2015.24.6.682
The objective of this study is to validate the performance of the current
turbulence model for a single-phase turbulent natural convection, which has been considered an important phenomenon in nuclear safety. As a result, the natural convection problems in the 2D and 3D cavities previously studied are calculated by using the ANSYS Fluent software. The present results show that the current
turbulent model accounting for the buoyancy effect is in good agreement with the previous results for the natural convection problems in the 2D and 3D cavities although some improvements should be required to get better prediction.
An Experimental Study on the Automation of Semi-Hot-Air Coffee Roasting Process
Choi, Ho-Man ; Namkung, Hwang ; Kim, Dong-Won ; Park, Chang Yong ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 687~695
DOI : 10.7735/ksmte.2015.24.6.687
An experimental study on the automation of the coffee roasting process was conducted. For this study, a temperature sensor, controllers, and motors were added to a manually operated coffee roaster. The temperature, time, and exhausting damper control were selected as the control parameters. The thermocouple measurements were severely influenced by the thermocouple size and location of the roaster. As a result, the standard thermocouple size and location of the roaster were experimentally set to show a similar trend of temperature change by using a previously installed thermometer. A standard roasting process was chosen through repeated roasting experiments and the advice of a roasting expert. The automation of the roasting process was successfully executed using temperature criteria, such as the bean input and first and second crack occurrence, and by controlling the exhausting damper opening time. The control parameters and roaster skills can be used for similar types of roasters for process automation.
An Improvement of Navigation in Robot Soccer using Bezier Curve
Jung, Tae-Young ; Lee, Gui-Hyung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 696~702
DOI : 10.7735/ksmte.2015.24.6.696
This paper suggests a new method for making a navigation path by using Bezier curve in order to improve the navigation performance used to avoid obstacles during a robot soccer game. We analyzed the advantages and disadvantages of both vector-field and limit-cycle navigation methods, which are the mostly widely used navigation methods for avoiding obstacles. To improve the disadvantages of these methods, we propose a new design technique for generating a more proper path using Bezier curve and describe its advantages. Using computer simulations and experiments, we compare the performance of vector-field navigation with that of Bezier curve navigation. The results prove that the navigation performance using Bezier curve is relatively superior to the other method.
3D Object Location Identification Using Finger Pointing and a Robot System for Tracking an Identified Object
Gwak, Dong-Gi ; Hwang, Soon-Chul ; Ok, Seo-Won ; Yim, Jung-Sae ; Kim, Dong Hwan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 703~709
DOI : 10.7735/ksmte.2015.24.6.703
In this work, a robot aimed at grapping and delivering an object by using a simple finger-pointing command from a hand- or arm-handicapped person is introduced. In this robot system, a Leap Motion sensor is utilized to obtain the finger-motion data of the user. In addition, a Kinect sensor is also used to measure the 3D (Three Dimensional)-position information of the desired object. Once the object is pointed at through the finger pointing of the handicapped user, the exact 3D information of the object is determined using an image processing technique and a coordinate transformation between the Leap Motion and Kinect sensors. It was found that the information obtained is transmitted to the robot controller, and that the robot eventually grabs the target and delivers it to the handicapped person successfully.
Accuracy Improvement of Output in Projection Stereolithography by Optimizing Projection Resolution
Kim, Yeong-Heum ; Kim, Kyu-Eon ; Lee, Chibum ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 710~717
DOI : 10.7735/ksmte.2015.24.6.710
Projection stereolithography is an additive manufacturing method that uses beam projection to cure the photo-reactive resin used. The light source of a cross-section layer-form illuminates photo-curable resin for building a three-dimensional (3D) model. This method has high accuracy and a fast molding speed because the processing unit is a face instead of a dot. This study describes a Scalable Projection Stereolithography 3D Printing System for improving the accuracy of the stereolithography. In a conventional projection 3D printer, when printing a small sized model, many pixels are not used in the projection or curing. The proposed system solves this problem through an optical adjustment, and keeps using the original image as possible as filling the whole projection area. The experimental verification shows that the proposed system can maintain the highest level of precision regardless of the output size.
Design of Fusion Platform Robot for Ground and Aerial Reconnaissance
Jang, Dong-Hwi ; Ko, Hyun-Jun ; Kim, Jong-Hyeong ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 24, issue 6, 2015, Pages 718~723
DOI : 10.7735/ksmte.2015.24.6.718
This paper describes the conceptual platform design of a dual-capable robot for both driving on the ground and flying in the air. The dual-capable robot can move over all types of terrain for both ground and aerial reconnaissance. The main design problem of the robot is how to make a wheel for both driving and flying. The proposed key design concept is a hubless driving wheel that contains a propeller inside for flying in the air. The primary design parameters and initial specifications were confirmed through an examination of the conceptual design, and functional tests were then conducted using a real prototype robot for driving and flying modes. The test results show the feasibility of the proposed design concept.