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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
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 24, Issue 12 - Dec 2007
Volume 24, Issue 11 - Nov 2007
Volume 24, Issue 10 - Oct 2007
Volume 24, Issue 9 - Sep 2007
Volume 24, Issue 8 - Aug 2007
Volume 24, Issue 7 - Jul 2007
Volume 24, Issue 6 - Jun 2007
Volume 24, Issue 5 - May 2007
Volume 24, Issue 4 - Apr 2007
Volume 24, Issue 3 - Mar 2007
Volume 24, Issue 2 - Feb 2007
Volume 24, Issue 1 - Jan 2007
Selecting the target year
The Current Status of Machine Tool Industry and Future Growth Direction
Kim, Kyung-Dong ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 7~13
Development Direction of Machine Tool Mechanical Technology
Gim, Tae-Won ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 14~19
The Trends of CNC Technology and Development Strategy of Industry
Seong, Dae-Jung ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 20~26
Development of 6-axis Ankle Force/Moment Sensor for an Intelligent Foot of a Humanoid Robot
Kim, Gab-Soon ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 27~36
This paper describes the development of 6-axis ankle force/moment sensor for the intelligent feet of a humanoid robot. When the robot walks on uneven terrain, the feet should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz from the attached 6-axis force/moment sensor on their ankles. Papers have already been published have some disadvantages in the size of the sensor, the rated output and so on. The rated output of each component sensor (6-axis ankle force/moment sensor) is very important to design the 6-axis force/moment sensor for precision measurement. Therefore, each sensor should be designed to get the similar rated output under each rated load. Also, the size of the sensor is very important for mounting to robot's feet. Therefore, the diameter should be below 100 mm and the height should be below 40mm. In this paper, first, the structure of a 6-axis ankle force/moment sensor was modeled for a humanoid robot's feet newly, Second, the equations to predict the strains on the sensing elements was derived, third, the size of the sensing elements was designed by using the equations, then, the sensor was fabricated by attaching straingages on the sensing elements, finally, the characteristic test of the developed sensor was carried out. The rated outputs from the derived equations agree well with the results from the experiments. The interference error of the sensor is less than 2.94%.
Development of Profilometer for Profile Measurement and Severity Analysis of Unpaved Test Courses
Yang, Jin-Saeng ; Goo, Sang-Hwa ; Bae, Cheol-Hoon ; Lee, Sang-Ho ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 37~46
The vibration environment essentially companied by vehicle operation on the ground is determined by the shape of road surface, which is called profile. This paper focuses on development of a profile and severity measurement system for unpaved test courses. In general, the profile and severity of unpaved road is an important issue in the reliability of endurance test. In order to measure unpaved road profile and severity, it is necessary to develop a profilometer system. The developed profilometer system is composed of data processing computer, power unit, air compressor and sensors(encoder, vertical gyro and laser displacement) This paper presents the measuring system configuration, measurement principle of road profile and analysis method of road characteristics used at CPG(Changwon Proving Ground) for this purpose.
Fabrication and Characterization of Micro parts by Mechanical Micro Machining: Precision and Cost Estimation
Kang, Hyuk-Jin ; Choi, Woon-Yong ; Ahn, Sung-Hoon ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 47~56
Recently, demands on mechanical micro machining technology have been increased in manufacturing of micro-scale precision shapes and parts. The main purpose of this research is to verify the accuracy and cost efficiency of the mechanical micro machining. In order to measure the precision and feasibility of mechanical micro machining, various micro features were machined. Aluminum molds were machined by a 3-axis micro stage in order to fabricate microchips with
wide channel for capillary electrophoresis, then the same geometry of microchip was made by injection molding. To evaluate the cost efficiency of various micro manufacturing processes, cost estimation for mechanical micro machining was conducted, and actual costs of microchips fabricated by mechanical micro machining, injection molding, and MEMS (Micro electro mechanical system) were compared.
Isothermal Pass Schedule to Prevent Delamination in the Dry Wire Drawing Process
Ko, Dae-Cheol ; Lee, Sang-Kon ; Kim, Min-An ; Kim, Byung-Min ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 57~63
Wire drawing process of the high carbon steel with a high speed is usually conducted at room temperature using a number of passes or reductions through consequently located dies. In the multi-pass drawing process, temperature rise in each pass affects the mechanical properties of the final product such as bending, torsion, and tensile property, etc. This temperature rise during the deformation promotes the occurrence of delamination, and deteriorates the torsion property and durability of wire. This study investigates the occurrence of delamination in the wire through the torsion test and the evaluation of wire temperature. The excessive wire temperature leads to the occurrence of the delamination. Based on the calculation of the wire temperature, a new pass schedule, which can prevent the delamination due to the excessive wire temperature rise, is designed through the isothermal pass schedule.
Fabrication of Sub-100 nm Embossing Patterns using Weakly-Polymerized Region via Long-Exposure Technique (LET) in Two-Photon Polymerization
Park, Sang-Hu ; Lim, Tae-Woo ; Yang, Dong-Yol ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 64~70
A long-exposing technique (LET) has been conducted to create nanoscale patterns applicable to diverse micro-devices using two-photon polymerization (TPP). By the weakly-polymerized region via the LET, double-layered embossing patterns can be fabricated simply in a single step. The LET makes possible a voxel and its surrounding to be fully grown into more than 500 nm in lateral size and weakly-polymerized region (WPR), respectively. In the WPR. interconnecting ribs between voxels are generated, and they lead to the creation of double-layered dot patterns. Moreover, by controlling the distance between voxels, various shapes of interconnecting rib can be fabricated when the LET is applied. Various embossing patterns were fabricated to evaluate the usefulness of the proposed technique as a novel nanopatterning technique in TPP.
Characteristics of SU-8 Mask for Abrasive Jet Machining
Ko, Tae-Jo ; Park, Dong-Jin ; Kim, Hee-Sool ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 71~78
Abrasive jet machining (AJM) has been traditionally used for removing rusts or paints. Nowadays, this is promising technology for micro bulk machining where brittle substrate materials are used. In order to get accurate details, masks such as metal, polymer or elastomer is inevitable. Among them, photo polymer which is sensitive to the light has been attractive for it's high accuracy using photolithography. In this research, SU-8 as a photo polymer is used since it is adequate for making thick mask. So, this paper describes how to make AJM masks using SU-8 with a photolithography process, and investigates the characteristics of SU-8 masks during AJM process. Also, an example of fabrication using AJM was shown.
Friction Property for Angles of Micro-crosshatch Grooved Surface Pattern under Lubricated Sliding Contact
Chae, Young-Hun ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 79~84
Some surface pattern of tribological application is an attractive technology of engineered surface. Therefore, friction reduction is considered to be necessary for improved efficiency of machine. This study investigated the effect of friction property for angles of micro-crosshatch groove surface pattern on bearing steel using pin-on-disk test. We obtain sample which can be fabricated by photolithography process. We discuss the friction property depend on an angle of crosshatch groove surface pattern. We can verify the lubrication mechanism as Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter under the lubrication condition. It was found that the friction coefficient was related to angle of crosshatch groove pattern on contact surface.
Gait Analysis on Unexpected Missing Foot Steps
Hwang, Sun-Hong ; Ryu, Ki-Hong ; Keum, Young-Kwang ; Kim, Young-Ho ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 85~92
In the present study, three-dimensional motion analyses were performed to determine biomechanics of the lower extremity in unexpected missing foot steps for ten healthy young volunteers. In unexpected missing foot steps, the whole plantar surface of the foot or the heel contacted to the ground. A rapid ankle dorsiflexion was found right after missing foot steps and an increased plantarflexion moment was noted during loading response. After the unexpected situation, the breaking force increased rapidly. At this time, both tibialis anterior and soleus were simultaneously activated. Moreover, the range of motion at ankle, knee and hip significantly decreased during stance. In pre-swing, rectus femoris and biceps femoris prevented the collapse of the lower limbs. During late stance, propulsive forces decreased and thus, both plantarflexion moment and power generation were significantly reduced. On the opposite side, hip extension and pelvic upward motion during terminal swing were significant. Due to the shortened pre-swing, the energy generation at the ankle to push sufficiently off the ground was greatly reduced. This preliminary study would be helpful to understand the biomechanics of unexpected dynamic perturbations and valuable to prevent frequent falling of the elderly and patients with gait disorders.
Shape Design of the Bristle for the Periodontally Involved Patients by Using 3D Scanner
Kim, Hyun-Jun ; Suh, Myung-Won ; Bae, Jong-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 93~100
In this study, an investigation was made on bristles for the prosthetic and periodontally involved patients based on the previous studies. The purpose of this study was to investigate the ideal location and dimensions of bristles for the patients who were installed with fixed prostheses and severely involved periodontitis. 3D scanner was used to develop 3D visual models of bristles and teeth. These models were developed to be used for designing the ideal bristles for the prosthetic and periodontally involved patients. For the ideal design of bristle, interproximal area of dental arch and bristle must get into maximum and standard teeth may have to be chosen from many gypsum molds. During the design process the factors should be considered that influence the removal of plaque by bristle.
Temporal-perceptual Judgement of Visuo-Auditory Stimulation
Yu, Mi ; Lee, Sang-Min ; Piao, Yong-Jun ; Kwon, Tae-Kyu ; Kim, Nam-Gyun ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 101~109
In situations of spatio-temporal perception about visuo-auditory stimulus, researches propose optimal integration hypothesis that perceptual process is optimized to the interaction of the senses for the precision of perception. So, when the visual information considered generally dominant over any other sense is ambiguous, the information of the other sense like auditory stimulus influences the perceptual process in interaction with visual information. Thus, we performed two different experiments to certain the conditions of the interacting senses and influence of the condition. We consider the interaction of the visuo-auditory stimulation in the free space, the color of visual stimulus and sex difference of testee with normal people. In first experiment, 12 participants were asked to judge the change in the frequency of audio-visual stimulation using a visual flicker and auditory flutter stimulation in the free space. When auditory temporal cues were presented, the change in the frequency of the visual stimulation was associated with a perceived change in the frequency of the auditory stimulation as the results of the previous studies using headphone. In second experiment, 30 male and 30 female were asked to judge the change in the frequency of audio-visual stimulation using a color of visual flicker and auditory flutter stimulation. In the color condition using red and green. Both male and female testees showed same perceptual tendency. male and female testees showed same perceptual tendency however, in case of female, the standard deviation is larger than that of male. This results implies that audio-visual asymmetry effects are influenced by the cues of visual and auditory information, such as the orientation between auditory and visual stimulus, the color of visual stimulus.
Detecting and Tracking Changes of Mechanical Characteristics of the Trabecular and Cortical Bone in the Lumbar Vertebrae of an OVX Rat - Use of In-Vivo Micro-CT and Micro-FE Analysis -
Ko, Chang-Yong ; Woo, Dae-Gon ; Lee, Tae-Woo ; Lee, Beob-Yi ; Tack, Gye-Rae ; Kim, Han-Sung ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 110~117
This study investigated changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the ovariectomised (OVX) rat. In previous researches, there were many studies for morphology of osteoporotic bones based on Micro-Computed Tomography (Micro-CT). However, there were few studies for detecting and tracking changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the OVX rat. For this study, the 4th lumbar of the OVX rat (female Sprague-Dawley) was utilized as a specimen. An OVX rat was scanned at week 0 (just before surgery), at week 4, and week 8 after surgery. Micro-finite element (
) analysis was used to investigate mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae for an OVX rat. When the OVX rat (at week 8) was compared with the OVX rat (at week 0), the structural modulus of cortical and trabecualr bone was decreased by 52% and 99%, respectively. This study showed the change of mechanical characteristics of cortical bone as well as trabecular bone of an OVX rat. Detecting and tracking changes of mechanical characteristics could greatly contribute to an experiment test for the trabecular and cortical bone in the lumbar vertebrae of an OVX rat by using In-vivo Micro-CT.
Plantar Shear Stress and Normal Pressure in Lateral Heel Diabetic Foot Patients During Walking
Hwang, Sung-Jae ; Park, Sun-Woo ; Yi, Jin-Bock ; Ryu, Ki-Hong ; Kim, Young-Ho ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 1, 2007, Pages 118~125
In this study, we analyzed the plantar shear stress and normal pressure in lateral heel diabetic foot patients during walking by using in-shoe local shear stress and plantar pressure measurement systems. The shear force transducer based on the magnetic-resistive principle, was a rigid 3-layer circular disc. Shear transducers were mounted on the locations of four metatarsal heads and heel in the insole. Twelve normal subjects and three diabetic foot patients with diabetic neuropathy in the lateral heel participated in this study. The center of pressure in lateral heel diabetic foot patients moved more medially and directed toward the first, medial to the second metatarsal heads, and the hallux during late stance, making pressure at the medial heel and the second metatarsal head significantly larger than in the normal. Shear stress at the heel changed significantly in early stance and the magnitude of shear stresses in each metatarsal head also changed. Further studies would be very helpful to design foot orthoses in patients with diabetic neuropathy or other diseases.