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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 28, Issue 12 - Dec 2011
Volume 28, Issue 11 - Nov 2011
Volume 28, Issue 10 - Oct 2011
Volume 28, Issue 9 - Sep 2011
Volume 28, Issue 8 - Aug 2011
Volume 28, Issue 7 - Jul 2011
Volume 28, Issue 6 - Jun 2011
Volume 28, Issue 5 - May 2011
Volume 28, Issue 4 - Apr 2011
Volume 28, Issue 3 - Mar 2011
Volume 28, Issue 2 - Feb 2011
Volume 28, Issue 1 - Jan 2011
Selecting the target year
Recent Trends of the Development of Photobioreactors to Cultivate Microalgae
Kim, Jong-Tye ; Ahn, Dong-Gyu ; Park, Jong-Rak ; Park, Jeong-Woo ; Jeong, Sang-Hwa ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 125~132
This paper describes current status and future prospects of the mass production of microalgae biomass. Microalgae have attracted considerable attention since they not only effectively fix
gas during their metabolic process but also have the great potential to be utilized for producing valuable substances as a kind of efficient light-harvesting cell factories. In this review, we outline various types of photobioreactors employed for mass production of biomass by culturing microalgae in a well controlled way and give an overview about the present state of affairs, both domestic and international, in the field of the microalgal culturing technologies.
Design of Light Guide Plate for Photobioreactor
Park, Gi-Chan ; Kim, Hun ; Kim, Jong-Tye ; Park, Jeong-Woo ; Jeong, Sang-Hwa ; Park, Jong-Rak ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 133~139
We have performed optical design of light guide plates (LGPs) for a photobioreactor by using an illumination design tool. An LGP having light emitting diodes (LEDs) as a light source on the four sides was designed by optimizing the distribution of LGP patterns and design of another LGP, on top of which sunlight was focused by a Fresnel lens, was executed. Finally, a hybrid-solar-and-LED-lighting scheme was described. Detailed design process and optical performances of the designed LGPs are presented.
Design of Photobioreactor for Mass Production of Microalgae
Ahn, Dong-Gyu ; Cho, Chang-Gyu ; Jeong, Sang-Hwa ; Lee, Dong-Gi ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 140~153
The objective of this paper is to investigate into the design of photbioreactor for mass production of microalgae. Characteristics of previously developed photobioreactors were examined to obtain design factors, including light transfer, fluid dynamics and metabolic reactions, of the photobioreactor. Design technology of components related to the design factors, such as light sources, photobioreactor cases, spargers, mixer, etc., was discussed to improve the viability and the growth rate of microalgal and productivity of the photobioreactor. Finally a principle direction of the design for an airlift flat plane photobiorectors was investigated.
Development of Biorefinery Process using Microalgae
Shin, Hyun-Jae ; Park, Ju-Hyun ; Jung, Won-Kyo ; Cho, Hoon ; Kim, Si-Wouk ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 154~167
Recently, microalgae have been focused on potential biomass for bio-diesel and biorefinery process. The aim of this paper is to review the biorefinery process including biodesel using microalgae as a microreactor. The state-of-the-art of biodiesel and biorefinery research such as extraction and reaction process as well as byproducts utilization is described. In addition, we suggest possibility for develop bioactive substances and their industrial products from byproducts of microalgae massively obtained after bio-diesel extraction.
Improvement of Corner Contouring Accuracy of CNC Servo Systems with Communication Delay
Lim, Jong-Hyup ; Jee, Sung-Chul ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 168~175
Contouring accuracy of CNC machine tools is very important for high-speed and high-precision machining. In particular, large contour error may occur during corner tracking. In order to reduce the corner contouring error, acceleration and deceleration control or tool-path planning methods have been suggested. However, they do not directly control the corner contouring error. In the meantime, network servo systems are widely used because of their easiness of building and cost effectiveness. Communication latency between the master controller and servo drives, however, may deteriorate contouring accuracy especially during corner tracking. This paper proposes a control strategy that can accurately calculate and directly control the corner contouring error. A prediction control is combined with the above control to cope with communication latency. The proposed control method is evaluated through computer simulation and experiments. The results show its validity and usefulness.
Implementation of IEEE 1451 based ZigBee Smart Sensor System for Active Telemetries
Lee, Suk ; Song, Young-Hun ; Park, Jee-Hun ; Kim, Man-Ho ; Lee, Kyung-Chang ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 176~184
As modern megalopolises become more complex and huge, convenience and safety of citizens are main components for a welfare state. In order to make safe society, telemetrics technology, which remotely measures the information of target system using electronic devices, is an essential component. In general, telemetrics technology consists of USN (ubiquitous sensor network) based on a wireless network, smart sensor, and SoC (system on chip). In the smart sensor technology, the following two problems should be overcome. Firstly, because it is very difficult for transducer manufacturers to develop smart sensors that support all the existing network protocols, the smart sensor must be independent of the type of networking protocols. Secondly, smart sensors should be modular so that a faulty sensor element can be replaced without replacing healthy communication element. To solve these problems, this paper investigates the feasibility of an IEEE 1451 based ZigBee smart sensor system. More specifically, a smart sensor for large network coverage has been developed using ZigBee for active telemetrics.
The Basic Study on the Leak Test Method of the Hydrogen Exhaust Pipe for a Fuel Cell Vehicle
Suh, Ho-Cheol ; Park, Kyoung-Suk ; Seo, Kyung-Doo ; Yong, Gee-Joong ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 185~192
This study deals with a basic proposal to prove the safety for the exhausted fittings of the hydrogen fuel cell vehicle. First, this study was approached to numerical analysis solving to close the exact boundary condition (Axial, Bending, Lateral) and the second, this study produced the Lateral movement equipment for the vibration. For the numerical analysis, This study was considered with the exact solution of Lateral movement and the resonance effect for durability sample according to fitting positions. The second, This study was made for special equipment for displacement/gas leak and the frequency because the domestic samples were comparing with foreign fitting and foreign fitting for the hydrogen fuel cell vehicle. The result of this study was satisfied with domestic fittings for the basic reference but it need more test because of other situation for hydrogen fuel cell vehicle.
Development of Clamp Type Transferring Mechanism for Package Substrate's Wet Process
Ryu, Sun-Joong ; Heo, Jun-Yeon ; Cho, Seung-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 193~201
Clamp type transferring mechanism for package substrate's wet processes was newly developed instead of conventional roller type transferring mechanism. Clamp type transferring mechanism has the advantages of reducing the panel deflection and of minimizing the contact problem between the panel and the transferring mechanism. Individual clamp of the mechanism has two distinct mechanical functions which are perfectly fixing a panel during the transferring and generating adequate tension for the panel. To determine the mechanical parameters of the clamp, panel deflection simulation was conducted and the result was verified by the panel deflection measurement. Also, fixing angle of a clamp could be determined by the free body force analysis of individual clamp. Finally clamp type transferring mechanism was actually manufactured and the transferring performance was verified during the water spraying condition of the package substrate's wet processes.
Development of a Convective Sequential Production System for Aspheric Lens
Kuk, Kum-Hoan ; Kim, Gab-Soon ; Jung, Dong-Yean ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 202~210
The fabrication method of aspheric lens is changed from machining to press molding so as to improve the productivity. In the case of the press molding method, the temperature control of the molding die is most important, because the temperature of each molding die determines the quality of lens. But any practical method for direct measuring of the lens temperature and the die internal temperature is yet unknown. Besides, in the case of the press molding system in which the heating and pressing and cooing of a die is done at separate work stations, the lens productivity of the system for small lens is yet too low. The paper shows an improved structure of convective sequential system, the lens productivity of which is three times as many as the conventional convective system. To know the die internal temperature, numerical results are given using ANSYS. A new convective sequential system is developed and tested. Finally, the Taguchi method is applied in order to optimize the setting conditions of individual work station of the system.
The Study on Designing and Making Power Lifting Wheelchair using Mecanum Wheels
Jo, Jang-Hyen ; Hwang, Byung-Jun ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 211~218
We reported the design, prototype, test drive, and mechanical & electrical engineering analyses of a power-lifting wheelchair using mecanum wheels. Mecanum wheels enable translational and rotational movement of the device in any direction on the ground. The power-lifting capability enables the seated individual to reach the standing height of a non-disabled individual. This mecanum wheelchair is fully controlled by the joystick attached to the armrest. The motion of the wheelchair and lifting action of the seat were studied using statics and dynamics. We believe this mecanum wheelchair is a prime candidate for commercial production.
Finite Element Analysis of Residual Stress Evolution during Cure Process of Silicone Resin for High-power LED Encapsulant
Song, Min-Jae ; Kim, Heung-Kyu ; Kang, Jeong-Jin ; Kim, Kwon-Hee ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 219~225
Silicone resin is recently used as encapsulant for high-power LED module due to its excellent thermal and optical properties. In the present investigation, finite element analysis of cure process was attempted to examine residual stress evolution behavior during silicone resin cure process which is composed of chemical curing and post-cooling. To model chemical curing of silicone, a cure kinetics equation was evaluated based on the measurement by differential scanning calorimeter. The evolutions of elastic modulus and chemical shrinkage during cure process were assumed as a function of the degree of cure to examine their effect on residual stress evolution. Finite element predictions showed how residual stress in cured silicone resin can be affected by elastic modulus and chemical shrinkage behavior. Finite element analysis is supposed to be utilized to select appropriate silicone resin or to design optimum cure process which brings about a minimum residual stress in encapsulant silicone resin.
Optimum Structural Design of a Triaxial Load Cell for Wind Tunnel Test
Lee, Jae-Hoon ; Song, Chang-Kon ; Park, Seong-Hun ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 226~232
In this study, an optimized design of a triaxial load cell has been developed by the use of finite element analysis, design of experiment and response surface method. The developed optimal design was further validated by both stress-strain analysis and natural vibration analysis under an applied load of 30 kgf. When vertical, horizontal, and axial loads of 30 kgf were applied to the load cell with the optimal design, the calculated strains were satisfied with the required strain range of
. The natural vibration analysis exhibited that the fundamental natural frequency of the optimally designed load cell was 5.56 kHz and higher enough than a maximum frequency of 0.17 kHz which can be applied to the load cell for wind-tunnel tests. The satisfactory sensitivity in all triaxial directions also suggests that the currently proposed design of the triaxial load cell enables accurate measurements of the multi-axial forces in wind-tunnel tests.
A Seismic Stability Design by the KEPIC Code of Main Pipe in Reactor Containment Building of a Nuclear Power Plant
Yi, Hyeong-Bok ; Lee, Jin-Kyu ; Kang, Tae-In ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 233~238
In piping design of nuclear power plant facilities, the load stress according to self-weight is important for design values in test run(shutdown and starting). But sometimes it needs more studies, such as seismic analysis of an earthquake of power plant area and fatigue life and stress of thermal expansion and anchor displacement in operating run. In this paper, seismic evaluations were performed to nuclear piping system of Shin-Kori NO. 3&4 being built in Pusan lately. Results of seismic analysis are evaluated on basis of KEPIC MN code. The structural integrity on RCB piping system was proved.
A Study on Stamp Process Life Time in Thermal NIL
Cho, Cheon-Soo ; Lee, Moon-Jae ; Oh, Ji-In ; Lim, O-Kaung ; Jeong, Myung-Yung ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 239~244
Nano Imprint Lithography(NIL) is technique for copying a pattern from stamp with nano size pattern in order to replicated the materials. It is very important to demold in order to make NIL process effectively. Self Assembled Monolayers(SAM) coater is manufactured by means of decreasing surface energy with the stamp surface treatment to improve release characteristics. Manufactured device contains tilting and rotation option for increasing process life time by coating on the sidewall of the pattern in stamp. The stamp coated with optimized tilting angle
and rotation speed of 10rpm has more imprinting cycles than the stamping coated without tilting and rotation. Effective SAM coating on the sidewall of the pattern in stamp will improve by 50% of process life time.
Focused Ion Beam Milling for Nanostencil Lithography
Kim, Gyu-Man ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 245~250
A high-resolution shadow mask, a nanostencil, is widely used for high resolution lithography. This high-resolution shadowmask is often fabricated by a combination of MEMS processes and focused ion beam (FIB) milling. In this study, FIB milling on 500-nm-thin SiN membrane was tested and characterized. 500 nm thick and
mm large membranes were made on a silicon wafer by micro-fabrication processes of LPCVD, photolithography, ICP etching and bulk silicon etching. A subsequent FIB milling enabled local membrane thinning and aperture making into the thinned silicon nitride membrane. Due to the high resolution of the FIB milling process, nanoscale apertures down to 60 nm could be made into the membrane. The nanostencil could be used for nanoscale patterning by local deposition through the apertures.
Simulation of the Radial Overcut in Micro Electrochemical Machining
Kim, Bo-Hyun ; Shin, Hong-Shik ; Oh, Young-Tak ; Lee, Kang-Hee ; Chu, Chong-Nam ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 2, 2011, Pages 251~256
The radial overcut in micro electrochemical machining was investigated. The prediction of overcut is important not only for the machining accuracy but also for the shape control of micro structures. In micro ECM, machining gap or overcut depends on electrolyte, pulse voltage, pulse duration and dissolution time etc. Understanding of electrochemical dissolution rate is necessary for the overcut prediction. In this paper, the radial overcut of micro electrochemical machining according to pulse duration and dissolution time was simulated using electrochemical principles and also experimentally estimated.