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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers A
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Journal DOI :
The Korean Society of Mechanical Engineers
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Volume & Issues
Volume 36, Issue 12 - Dec 2012
Volume 36, Issue 11 - Nov 2012
Volume 36, Issue 10 - Oct 2012
Volume 36, Issue 9 - Sep 2012
Volume 36, Issue 8 - Aug 2012
Volume 36, Issue 7 - Jul 2012
Volume 36, Issue 6 - Jun 2012
Volume 36, Issue 5 - May 2012
Volume 36, Issue 4 - Apr 2012
Volume 36, Issue 3 - Mar 2012
Volume 36, Issue 2 - Feb 2012
Volume 36, Issue 1 - Jan 2012
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Electrical and Fluidic Characterization of Microelectrofluidic Bench Fabricated Using UV-curable Polymer
Youn, Se-Chan ; Jin, Young-Hyun ; Cho, Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 475~479
DOI : 10.3795/KSME-A.2012.36.5.475
We present a novel polymer fabrication process involving direct UV patterning of a hyperbranched polymer, AEO3000. Compared to PDMS, which is the most widely used polymer in bioMEMS devices, the present polymer has advantages with regard to electrode integration and fast fabrication. We designed a four-chip microelectrofluidic bench having three electrical pads and two fluidic I/O ports. We integrated a microfluidic mixer and a cell separator on the bench to characterize the interconnection performance and sample manipulation. Electrical and fluidic characterization of the microfluidic bench was performed. The measured electrical contact resistance was
, which is small enough for electrical applications, and the pressure drop was 8.3 kPa, which was 39.3% of the value in the tubing method. By performing yeast mixing and a separation test in the integrated module on the bench, we successfully showed that the interconnected chips could be used for bio-sample manipulation.
Large-Displacement Electromagnetic Actuators with the Meander Springs Partially Exposed to Magnetic Field
Seo, Dae-Geon ; Han, Won ; Cho, Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 481~486
DOI : 10.3795/KSME-A.2012.36.5.481
We discuss the design, fabrication, and testing of a large-displacement electromagnetic actuator with the meander springs partially exposed to a magnetic field. We compared two prototypes: a prototype (F) of the conventional actuator with the meander springs fully exposed to a magnetic field and a prototype (P) of the proposed actuator with the meander springs partially exposed to a magnetic field. For a 5 Hz square input current varying from 10.40 mA, P showed an increase of
in the amplitude, which was greater than the increase in the case of F. Thus, we experimentally demonstrated the large-displacement actuation performance of the proposed actuator in a small volume and at low currents (below 40 mA). The proposed electromagnetic actuator can be used for low-power and large-displacement manipulation of optical switches and optical choppers.
Analysis of Mechanical Loads During Yawing
Nam, Yoon-Su ; Choi, Han-Soon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 487~495
DOI : 10.3795/KSME-A.2012.36.5.487
The yaw control, a major part of the wind turbine, is closely related to the efficiency of electric power production and the mechanical load. The yaw error, which results from the nacelle not being appropriately aligned in the wind direction, not only decreases the power output but also reduces the lifetime of the wind turbine as a result of large fatigue loads. However, the yawing rate cannot be increased indefinitely because of constraints on mechanical loads. This paper investigates the characteristics of an active yaw control system, the basic principle of the system, and mechanical loads around the yaw axis during yawing.
Dynamic Response Optimization of a Mobile Harbor Crane with a Moving Support
Kim, Hyun-Bum ; Lee, Jae-Jun ; Jang, Hwan-Hak ; Park, Gyung-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 497~504
DOI : 10.3795/KSME-A.2012.36.5.497
The mobile harbor is a new innovative system that delivers containers from a containership to a harbor without good infrastructure. A crane is installed on the deck of the mobile harbor and transfers the containers. The structure of the crane is influenced by the inertia force that occurs from a moving support. Thus an accurate safety verification considering the moving support is required. Lightweight of the crane structure is also significant in the design for low production cost and efficient operation. Dynamic response optimization can be exploited to achieve these two requirements. Equivalent static loads method is employed for dynamic response optimization of the crane. The equivalent static loads method transforms dynamic loads to equivalent static loads, and static response structural optimization with the transformed equivalent static loads are solved. The process proceeds in a cyclic manner. A new method is proposed to consider the moving supports and the structure of the mobile harbor is optimized using the proposed method.
Development of Structured Hybrid Illumination System and Optimum Illumination Condition Selection for Detection of Surface Defects on Silicon Wafer in Solar Cell
An, Byung-In ; Kim, Gyung-Bum ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 505~512
DOI : 10.3795/KSME-A.2012.36.5.505
In this study, an inspection system based on an optical scanning mechanism is developed for the inspection of silicon wafers in solar cells. In particular, a structured hybrid illumination system that can satisfy the illumination requirement for the detection of various defects is designed. In the hybrid illumination system, the optimum illumination conditions are selected by considering the design of experiment in master glass and silicon wafer. The illumination conditions available are B-high, BG-high, BR-high, and BGR-high for master glass and R-middle-B-medium for silicon wafers. By using the illumination conditions for silicon wafers, numerous surface defects like pinhole, scratch, and chipping, can be accurately detected. The hybrid illumination system is expected to be widely used for the inspection of silicon wafers in solar cells.
Estimation of Brittle Fracture Behavior of SA508 Carbon Steel by Considering Temperature Dependence of Damage Model
Choi, Shin-Beom ; Jeong, Jae-Uk ; Choi, Jae-Boong ; Chang, Yoon-Suk ; Ko, Han-Ok ; Kim, Min-Chul ; Lee, Bong-Sang ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 513~521
DOI : 10.3795/KSME-A.2012.36.5.513
The aim of this study was to determine the brittle fracture behavior of reactor pressure vessel steel by considering the temperature dependence of a damage model. A multi-island genetic algorithm was linked to a Weibull stress model, which is the model typically used for brittle fracture evaluation, to improve the calibration procedure. The improved calibration procedure and fracture toughness test data for SA508 carbon steel at the temperatures
were used to decide the damage parameters required for the brittle fracture evaluation. The model was found to show temperature dependence, similar to the case of NUREG/CR-6930. Finally, on the basis of the quantification of the difference between 2- and 3-parameter Weibull stress models, an engineering equation that can help obtain more realistic fracture behavior by using the simpler 2-parameter Weibull stress model was proposed.
Moisture Diffusion Analysis for Bendable Electronic Module Under Autoclave Test Condition
Han, Chang-Woon ; Oh, Chul-Min ; Hong, Won-Sik ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 523~528
DOI : 10.3795/KSME-A.2012.36.5.523
A bendable electronic module is developed for a mobile application by using a low-cost roll-to-roll manufacturing process. In the module, a thin silicon chip is embedded in a polymer-based encapsulating adhesive between flexible copper clad polyimide layers. A set of tests are conducted for the purpose of qualification: thermal shock, high temperature storage, and autoclave tests. During the autoclave test, delamination occurs at many places within the module layers. To investigate the failure mechanism, moisture diffusion analysis is conducted for the interior of the module under the autoclave test condition. For the analysis, the hygroscopic characteristics of the encapsulating materials are experimentally determined. Analysis results indicate the moisture saturation process in the interior of the module under the autoclave test condition.
Determination of Mechanical Properties of Galvanized Steel Sheets Using Instrumented Indentation Technique and Finite Element Analysis
Jin, Ji-Won ; Kwak, Sung-Jong ; Kim, Tae-Seong ; Noh, Ki-Han ; Kang, Ki-Weon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 529~535
DOI : 10.3795/KSME-A.2012.36.5.529
This paper deals with the determination of mechanical properties of various galvanized steel sheets that are used for fabricating automobile bodies; the instrumented indentation technique and finite element analysis were used for the determination. First, tensile tests were conducted to obtain the true stress-true strain curves of galvanized steel sheets with various thicknesses. Load-deformation curves were then obtained by using the instrumented indentation testing machine, and they were compared with load-deformation curves obtained by finite element analysis. Further, true stress-true strain curves were obtained at the optimal observation point by finite element analysis.
Analysis of the Relation Between Machining Accuracy of Internal Gear and Noise in Reduction Gears
Park, Sung-Pil ; Kim, Woo-Hyung ; Chung, Jin-Tai ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 537~543
DOI : 10.3795/KSME-A.2012.36.5.537
In this study, we experimentally investigate a noise mechanism related to the machining accuracy of the reducer in the driving state. We fabricate a planetary reducer and four types of gears for use in the planetary reducer. We use signal analysis to determine the noise and vibration of the reducer at different motor speeds; the motor speed is increased from 0 rpm to the maximum speed in a stepwise manner. In addition, we obtain the sound level by using a sound level meter. The machining accuracy of gears is evaluated by public organizations, Korea Testing Laboratory (KTL), on the basis of the Japanese Industrial Standard (JIS). We analyze and compare the results with the noise and vibration of the reducer.
Design and Implementation of an Automatic System for Mixing Offset Ink
Choi, Sung-Hac ; Lee, Joon-Yeol ; Lee, Bong-Su ; Lee, Sang-Yoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 545~553
DOI : 10.3795/KSME-A.2012.36.5.545
This paper reports the development of an automatic system for mixing offset printing ink. The ink mixing process is important in industrial fields where paint and ink are used. In particular, there is a demand for automating the process of producing spot colors, which involves mixing a small quantity of high-viscosity ink. The authors designed, fabricated, and experimentally tested an automatic mixing system that employs the revolution and rotation of ink and the transmission by belts. The performance of the ink mixing system was verified by conducting numerous experiments to determine the effect of rotation direction, speed, ink container axis angle, and ink amount. Conditions suitable for mixing offset ink are presented for use as guidelines for producing spot colors.
A Study on Algorithm for Gear Profile Measurement Using a Standard Gear
Lee, Min-Ki ; Lee, Eung-Suk ; Kim, Kuang-Jung ; Park, Hyun-Yoong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 555~561
DOI : 10.3795/KSME-A.2012.36.5.555
In this paper, a method to control the noise and vibration of a standard gear transmitting mechanical power in the transmission insides, to things regarding a way to inspect the gear which was processed minutely. In an algorithm used to accurately measure a work gear, the measurements of the master gear are considered as the basis. The existing method considers one rotation of the standard gear and monitor gear, and that carried out mastering work in frequency ways. In this study, an algorithm to measure standard gear and monitor gear is proposed along with methods to calculate an error of the monitor gear and to significantly increase the precision of gear measurement. Further, the algorithm is fast and is expected to be capable of accurately measuring for mastering processing.
Temperature Prediction Method for Superheater and Reheater Tubes of Fossil Power Plant Boiler During Operation
Kim, Bum-Shin ; Song, Gee-Wook ; Yoo, Seong-Yeon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 563~569
DOI : 10.3795/KSME-A.2012.36.5.563
The superheater and reheater tubes of a heavy-load fossil power plant boiler can be damaged by overheating, and therefore, the degree of overheating is assessed by measuring the oxide scale thickness inside the tube during outages. The tube temperature prediction from the oxide scale thickness measurement is necessarily accompanied by destructive tube sampling, and the result of tube temperature prediction cannot be expected to be accurate unless the selection of the overheated point is precise and the initial-operation tube temperature has been obtained. In contrast, if the tube temperature is to be predicted analytically, considerable effort (to carry out the analysis of combustion, radiation, convection heat transfer, and turbulence fluid dynamics of the gas outside the tube) is required. In addition, in the case of analytical tube temperature prediction, load changes, variations in the fuel composition, and operation mode changes are hardly considered, thus impeding the continuous monitoring of the tube temperature. This paper proposes a method for the short-term prediction of tube temperature; the method involves the use of boiler operation information and flow-network-analysis-based tube heat flux. This method can help in high-temperaturedamage monitoring when it is integrated with a practical tube-damage-assessment method such as the Larson-Miller Parameter.
A Study on Design of Vacuum Silo for Batch Treatment System for Dredged Soil
Kim, Yong-Seok ; Yang, Hae-Rim ; Kim, Hac-Sun ; Jeoung, Chan-Se ; Yang, Soon-Yong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 571~577
DOI : 10.3795/KSME-A.2012.36.5.571
In this study, a small movable batch treatment system for dredging soil deposited in a rain water tube is proposed; further, a vacuum silo sorting separation device with a vacuum silo, first-stage sorting separator, and conveyor is designed. The vacuum silo sorting separation device also consists of a storage tank, transferring screw, vacuum gate, screen bar, screen bar cleaner, and vacuum discharging device. In view of the fact that the flow of drawn air in the storage tank is a major factor influencing the sorting separation performance, the optimum shape of the tank is determined by CFD flow analysis. In addition, by using CAE structure analysis, the safety of a storage tank made of boards is examined. The specifications of the vacuum silo sorting separation device are determined by conducting mechanical and dynamic simulations of the driving mechanism of the vacuum silo sorting separation device through 3D-CAD modeling. Following this study, we will design a drum-screen-type second sorter, a decanter-type dehydration device, and waste water tank and pump as a secondary device. Further, on the basis of this design, we will construct a prototype model and carry out a field test.
Weight Reduction of an Urban Railway Axle Based on EN Standard
Han, Soon-Woo ; Son, Seung-Wan ; Jung, Hyun-Seung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 36, issue 5, 2012, Pages 579~590
DOI : 10.3795/KSME-A.2012.36.5.579
Weight reduction of a railway axle, which is one of heaviest parts in an urban railway vehicle, is discussed in this paper. A wheelset of a railway vehicle is very important with regard to railway safety, and its structural strength should always be considered when attempting to reduce the railway axle weight. In this work, the weight of the axles of a trailer bogie and a motor bogie of the Korean EMU was reduced by replacing solid axles with hollow axles. On the basis of the EN standard for railway axle design, the strength of existing solid axles was analyzed and the required bore size of a hollow axle was determined. It is shown that the weight of the concurrent axle of the Korean EMU can be reduced by up to 20% with a very small decrease in the structural strength. Finite element analyses were also carried out to verify the design result for lightweight hollow axles.