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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
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Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 25, Issue 12 - Dec 2008
Volume 25, Issue 11 - Nov 2008
Volume 25, Issue 10 - Oct 2008
Volume 25, Issue 9 - Sep 2008
Volume 25, Issue 8 - Aug 2008
Volume 25, Issue 7 - Jul 2008
Volume 25, Issue 6 - Jun 2008
Volume 25, Issue 5 - May 2008
Volume 25, Issue 4 - Apr 2008
Volume 25, Issue 3 - Mar 2008
Volume 25, Issue 2 - Feb 2008
Volume 25, Issue 1 - Jan 2008
Selecting the target year
Importance of Inkjet Reliability and Calibration toward a New De Factor Industry Standard
Shin, Dong-Youn ; Kim, Dong-Soo ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 9~16
Novel Combination Technology of the Printing and Self-aligned Process for Organic Thin Film Transistor
Kim, Kang-Dae ; Jo, Jeong-Dai ; Lee, Taik-Min ; Kim, Chung-Hwan ; Shin, Dong-Youn ; Kim, Dong-Soo ; Choi, Byung-Oh ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 17~20
A Study on the Tower type Fizeau Interferometer System with a Fold Minor for Measuring Large Optical Lens Profile
Lee, Eung-Suk ; Lee, Ki-Am ; Kim, Ok-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 21~28
Fizeau interferometer is used for inspecting the lens surface profile accurately. This study is focused on the design and optical measuring techniques for large optical components, such as a reflection mirror for large area lithography or astronomical purpose. A tower type Fizeau interferometer is designed and set up in horizontally with a 45
fold mirror which makes easy to align the optical path of heavy interferometer system. To align the optical path, a five-axes stage for the interferometer is required. This study shows a method of the 45
fold mirror alignment by using a three-axis stage instead of adjusting the interferometer itself or measuring object. This system will be installed on the large optics polishing machine during the manufacturing process as an on-machine inspection system.
Development of an Algorithm for Detecting Angular Bisplacement with High Accuracy Based on the Dual-Encoder
Lee, Se-Han ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 29~36
An optical rotary encoder is easy to implement for automation system applications. In particular, the output of the encoder has a digital form pulse, which is also easy to be connected to a popular digital controller. By using an incremental encoder and a counting device, it is easy to measure angular displacement, as the number of the output pulses is proportional to the rotational displacement. This method can only detect the angular placement once a pulse signal comes out of the encoder. The angular displacement detection period is strongly subject to the change of the angular displacement in case of ultimate low velocity range. They have ultimate long detection period or cannot even detect angular displacement at near zero velocity. This paper proposes an algorithm for detecting angular displacement by using a dual encoder system with two encoders of normal resolution. The angular displacement detecting algorithm is able to keep detection period moderately at near zero velocity and even detect constant angular displacement within nominal period. It is useful for motion control applications in case of changing rotational direction at which there occurs zero velocity. In this paper, various experimental results are shown for the angular displacement detection algorithm.
Implementation of AR based Assembly System for Car C/pad Assembly
Park, Hong-Seok ; Choi, Hung-Won ; Park, Jin-Woo ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 37~44
Nowadays, the increasing global competition forces manufacturer to reduce the cost and time for implementation of manufacturing system. The AR(augmented reality) technology as a new human-machine interface introduces a noteworthy perspective for a new manufacturing system design. Using AR technology, a physically existing production environment can be superimposed with virtual planning objects. Therefore, the planning tasks can be validated without modeling the surrounding environment of the production domain during short process planning time. In this paper, we introduce the construction of AR browser and determine the optimal environment parameters for field application of AR system through lots of tests. And, many methods such as multi-marker coordinate system, division of virtual objects and so on, are proposed in order to solve the problems suggested from initial field test. Based on these tests and results, the test-bed of C/Pad assembly system is configured and robot program for C/Pad assembly is generated based on AR system.
Development of a Test Stand for Measuring Ink Jetting Performance
Kwon, Kye-Si ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 45~50
An ink jetting measurement system has been developed such that the velocity as well as the volume of ink droplets can be measured. In order to measure the ink droplet, a strobe LED light was synchronized to the droplet firing signal in order to obtain frozen droplet images. Then, a LabVIEW based software was developed for the analysis of the droplet image. For the efficient droplet analysis, a user generated rectangular shaped ROI (Region of Interest) was used. By using ROI, the ink droplet image can be easily isolated from the other structures such as printhead and the processing area can be minimized.
A Study on the Fracture Toughness of Plasma-treated Aluminum/Aluminum Foam Composites using Nitrogen Gas
Chung, Hyup-Jae ; Rhee, Kyong-Yop ; Han, Beom-Suck ; Ryu, Yong-Mun ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 51~56
Aluminum foam material has unique properties that make them useful in applications to the automobile, construction and railroad industries. In this study, aluminum was plasma-treated using nitrogen gas to improve fracture behavior between aluminum and aluminum foam material. SLS specimens were used for fracture tests. They were performed using plasma-treated and untreated aluminum/aluminum foam specimens. It was shown that the fracture strength and the tincture toughness of aluminum/aluminum foam were improved
, respectively when the aluminum was plasma-treated using nitrogen gas.
Equivalent Beam Modeling Technique and Experimental Verification of Corrugated Flexible Joint Bend Considering Strain Energy
Kim, Jin-Gon ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 57~64
Corrugated flexible joint with bellows shape is widely used in many industrial fields as it provides a relatively simple means of absorbing mechanical vibration and deformation due to its inherent flexibility. In this study, an effective equivalent beam modeling technique of corrugated flexible joint bend using a commercial CAE software is proposed to reduce the excessive efforts and costs required for three dimensional shell modelling in vibration analysis of bellows shape structure. When this simple and practical technique, based on the strain energy concept, is employed to modify the beam sectional properties of the flexible joint bend, quite satisfactory results can be obtained.
Transient Heat Transfer Analysis of Brake Drum Shape
Kim, Yang-Sul ; An, Su-Chul ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 65~71
This paper presents a transient heat transfer analysis of a drum brake shape. The transient heat transfer analysis of automotive drum brakes with frictional contact is performed by using the finite element method. The drum brake type studied in the page is the internally expanding one in which two shoes fitted externally with frictional material are forced outward against surface a rotating drum on the wheel unit. In this case, the braking power is produced by the friction force between a drum and a lining, and is converted into heat. The brake drum has constant material properties. The air inside the drum has temperature-dependent thermal conductivity and enthalpy. Radiation effects are ignored. The result explains the reason why hair crack and cause of drum failure occur. The temperature of drum is in proportion to the drum thickness and nonlinear changes at every points of drum. It's necessary for the decrease of the drum temperature to make the air inside drum flow.
The Shape Optimal Design of Shaft Serration Using Design of Experiment and Finite Element Method
Kim, Eui-Soo ; Kim, Byung-Min ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 72~79
To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Shaft and flange connected by inserting shaft serration into flange on the process of die casting. When the system is operating, the gap is formed between serration and flange. But, Serration has various design factors and the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), this study was performed investigating the interaction effect between the various design factors as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using box-behnken method among response surface derived from regression equation of simulation-based DOE.
Investigation into Low Velocity Impact Characteristics of the Stainless Steel Sheet with Thickness of 0.7 mm on the Stretching Condition using Three-Dimensional Finite Element Analysis
Ahn, Dong-Gyu ; Moon, Kyung-Je ; Jung, Chang-Gyun ; Yang, Dong-Yol ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 80~87
This paper investigated into the impact characteristics of the stainless sheet with thickness of 0.7 mm on the stretching boundary condition through three-dimensional finite element analysis. High speed tensile tests were carried out to obtain strain-stress relationships with the effects of the strain rate. The FE analysis was performed by the ABAQUS explicit code. In order to improve an accuracy of the FE analysis, the hyper-elastic model and the damping factor were introduced. Through the comparison of the results of the FE analyses and those of the impact tests, a proper FE model was obtained. The results of the FE analyses showed that the absorption rate of energy maintains almost 82.5-83.5% irrespective of the impact energy level and the diameter of the impact head. From the results of FE analyses, variations of stress, strain, dissipation energy, strain energy density, and local deformation characteristics in the stainless sheet during the collision and the rebound of the impact head were quantitatively examined. In addition, it was shown that the fracture of the specimen occurs when the plastic strain is 0.42 and the maximum value of the plastic dissipation energy of the specimen is nearly 1.83 J.
Sensitivity of Electroplating Conditions on Young's Modulus of Thin Film
Kim, Sang-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 88~95
Young's modulus of electroplated nickel thin film is systematically investigated using the resonance method of atomic force microscope. Thin layers of nickel to be measured are electroplated onto the surface of an AFM silicon cantilever and Young's modulus of plated nickel film is investigated as a function of process conditions such as the plating temperature and applied current density. It is found that Young's modulus of plated nickel thin film is as high as that of bulk nickel at low plating temperature or low current density, but decreases with increasing plating temperature or current density. The results imply that the plating rate increases as increasing the plating temperature or current density, therefore, slow plating rate produces a dense plating material due to the sufficient time fur nickel ions to form a dense coating.
Biomechanical Fatigue Analysis of Cervical Plate Systems by using a Computer Simulation Based on Finite Element Method
Kim, Sung-Min ; Yang, In-Chul ; Cho, Sung-Youn ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 96~103
In this study, we performed the biomechanical analysis of cervical plate systems by using a computer simulation based on finite element method to derive reliable model by analysis of design variables and fatigue behavior. To simulate the cervical spine movement in-vivo state by surgery, we modeled the cervical plate system which consisted of screws, rings, rivets, and plate and Ultra High Molecular Weight Polyethylene (UHMWPE) Block. The experiment of cervical plate system followed the ASTM F1717 standards that covered the materials and methods for the static and fatigue testing. The result of computer simulation is compared with experimented test. We expected this study is to derive reliable results by analysis of design variables and fatigue behavior for developing a new model.
Comparison of Energy Consumption of Reciprocating Gait Orthosis(RGO) and Powered Gait Orthosis(PGO) during Gait
Kang, Sung-Jae ; Ryu, Jei-Cheong ; Mun, Mu-Seong ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 8, 2008, Pages 104~110
The aim of this study ultimately is verifying that PGO gait is more efficient than RGO fur paraplegics because the air muscle assists hip flexion power in heel off movement. The gait characteristics of the paraplegic wearing the PGO or RGO are compared with that of a normal person. PGO with air muscles was used to analyze the walking of patients with lower-limb paralysis, and the results showed that the hip joint flexion and pelvic tilt angle decreased in PGO. In comparison to RGO gait, which is propelled by the movements of the back, PGO uses air muscles, which decreases the movement in the upper limb from a stance phase rate of 79
4%(RGO) to 68
8%. The energy consumption rate was 8.65
3.3 (ml/min/Kg) for RGO, while it decreased to 7.21t2.5(ml/min/Kg) for PGO. The results from this study show that PGO decreases energy consumption while providing support for patients with lower-limb paralysis, and it is helpful in walking for extended times.