Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Transactions of the Korean Society of Mechanical Engineers A
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
Editor in Chief :
Volume & Issues
Volume 34, Issue 12 - Dec 2010
Volume 34, Issue 11 - Nov 2010
Volume 34, Issue 10 - Oct 2010
Volume 34, Issue 9 - Sep 2010
Volume 34, Issue 8 - Aug 2010
Volume 34, Issue 7 - Jul 2010
Volume 34, Issue 6 - Jun 2010
Volume 34, Issue 5 - May 2010
Volume 34, Issue 4 - Apr 2010
Volume 34, Issue 3 - Mar 2010
Volume 34, Issue 2 - Feb 2010
Volume 34, Issue 1 - Jan 2010
Selecting the target year
Study on Microbiochip for Buccal Cell Lysis and DNA Purification
Ha, Seung-Mo ; Cho, Woong ; Ahn, Yoo-Min ; Hwang, Seung-Yong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1785~1791
DOI : 10.3795/KSME-A.2010.34.12.1785
This paper describes a separable microfluidic device fabricated with PDMS (polydimethylsiloxane) and glass. The device is used for sample preparation involving cell lysis and the DNA purification process. The cell lysis was performed for 2 min at
in a serpentine-type microreactor (
) using a Au microheater that was integrated with a thermal microsensor on a glass substrate. The DNA that was mixed with other residual products during the cell lysis process was then filtered through a new filtration system composed of microbeads (diameter:
) and PDMS pillars. Since the entire process (sample loading, cell lysis reaction, DNA purification, and sample extraction) was performed within 5 min in a microchip, we could reduce the sample preparation time in comparison with that for the conventional methods used in biochemistry laboratories. Finally, we verified the performance of the sample preparation chip by conducting PCR (polymerase chain reaction) analysis of the chip product.
Development of a Multiobjective Optimization Algorithm Using Data Distribution Characteristics
Hwang, In-Jin ; Park, Gyung-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1793~1803
DOI : 10.3795/KSME-A.2010.34.12.1793
The weighting method and goal programming require weighting factors or target values to obtain a Pareto optimal solution. However, it is difficult to define these parameters, and a Pareto solution is not guaranteed when the choice of the parameters is incorrect. Recently, the Mahalanobis Taguchi System (MTS) has been introduced to minimize the Mahalanobis distance (MD). However, the MTS method cannot obtain a Pareto optimal solution. We propose a function called the skewed Mahalanobis distance (SMD) to obtain a Pareto optimal solution while retaining the advantages of the MD. The SMD is a new distance scale that multiplies the skewed value of a design point by the MD. The weighting factors are automatically reflected when the SMD is calculated. The SMD always gives a unique Pareto optimal solution. To verify the efficiency of the SMD, we present two numerical examples and show that the SMD can obtain a unique Pareto optimal solution without any additional information.
Three-Dimensional Microstructures Fabricated by Multi-Step Electrochemical Aluminum-Foil Etching
Kim, Yoon-Ji ; Youn, Se-Chan ; Han, Won ; Cho, Young-Ho ; Park, Ho-Joon ; Chang, Byeung-Gyu ; Oh, Yong-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1805~1810
DOI : 10.3795/KSME-A.2010.34.12.1805
We present a simple, cost-effective, and fast fabrication process for three-dimensional (3D) microstructures; this process is based on multi-step electrochemical etching of metal foils which facilitates the mass production of 3D microstructures. Compared to electroplating, this process maintains uniform and well-controlled material properties of the microstructure. In the experimental study, we perform single-step electrochemical etching of aluminum foils for the fabrication of 2D cantilever arrays. In the single-step etching, the depth etch rate and bias etch rate are measured as
, respectively. Using the results of single-step etching, we perform two-step electrochemical etching for 3D microstructures with probe tips on cantilevers. The errors in height and lateral fabrication in the case of the fabricated structures are
, respectively; the surface roughness is
Preliminary Study on Nonlinear Static Response Topology Optimization Using Equivalent Load
Lee, Hyun-Ah ; Zeshan, Ahmad ; Park, Gyung-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1811~1820
DOI : 10.3795/KSME-A.2010.34.12.1811
Most components in the real world show nonlinear response. The nonlinearity may arise because of contact between the parts, nonlinear material, or large deformation of the components. Structural optimization considering nonlinearities is fairly expensive because sensitivity information is difficult to calculate. To overcome this difficulty, the equivalent load method was proposed for nonlinear response optimization. This method was originally developed for size and shape optimization. In this study, the equivalent load method is modified to perform topology optimization considering all kinds of nonlinearities. Equivalent load is defined as the load for linear analysis that generates the same response field as that for nonlinear analysis. A simple example demonstrates that results of the topology optimization using equivalent load are very similar to the numerical results. Nonlinear response topology optimization is performed with a practical example and the results are compared with those of conventional linear response topology optimization.
Sensitivity Analyses of Finite Element Parameters of Laser Shock Peening for Improving Fatigue Life of Metalic components
Kim, Ju-Hee ; Kim, Yun-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1821~1828
DOI : 10.3795/KSME-A.2010.34.12.1821
Laser shock peening(LSP) is an innovative surface treatment technique, and it has been successfully used to improve the fatigue performance of metallic components. It is widely known, that cracks caused by metal fatigue occur only at the location where the metal is subject to tension, and not at the location where the metal is subjected to compression. Therefore, LSP can be employed to improve fatigue life because it generates a high-magnitude compressive residual stress on the surface and interior of metallic components. In this study, we analyzed the applicability of the LSP method in improving fatigue performance and evaluated the various parameters that influence the compressive residual stress. Further, we analyzed the change in the mechanical properties such as surface dynamic stress and the compressive residual stress on the surface and interior of metallic components.
Study on Local Buckling of District Heating Pipes Using Limit State Design
Kim, Joo-Yong ; Lee, Sang-Youn ; Ko, Hyun-Il ; Cho, Chong-Du ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1829~1836
DOI : 10.3795/KSME-A.2010.34.12.1829
The district heating system distributes the heat generated from a cogeneration plant to wider locations. In this process, the district heating pipe (DHP) is subjected to internal and external loadings. The internal loadings are generally caused by the operating conditions such as water temperature and internal pressure. Frictional interactions between the pipes and the soil contribute to the external loadings. Thus, investigation of the mechanisms of failure of DHPs will help to guarantee both mechanical stability and heating efficiency. In this study, we investigate the local buckling of DHPs using limit state design (LSD). Two methods are considered: the use of the limit state for the width-thickness ratio and the use of the limit state for the strain. The results are used to confirm that the DHP is stable under local buckling. Finally, we suggest a minimum preheating temperature for avoiding local buckling.
Synthesis of Top Connector for Solar Cells by Using Silver Paste
Kim, Young-Kyu ; Jeong, Tae-Eui ; Oh, Dong-Hoon ; Kim, Nam-Soo ; Hong, Seong-Yeup ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1837~1842
DOI : 10.3795/KSME-A.2010.34.12.1837
Studies on alternative energy have been carried out for many decades because of the accelerated exhaustion of fuel. While the efficacy of solar cells is still low in comparison with that of nuclear power, solar cells have been highlighted as potential sources of alternative energy because they are environmentally friendly and have a source of unlimited energy, namely, the sun. In this study, the optimum efficiency of solar cells was simulated as a function of the incident angle of sunlight and the geometric shapes of patterns using MATLAB and MathCAD software. The foremost efficiency of the solar cell was found to be 1.10 when the thickness and width of the patterns were in the range 25-
, respectively. To achieve the 25 um thick layer, 100,000 cps silver paste and 500 um orifice tip has been successfully implemented with Micro-Dispensing Deposition Writing.
Study on Concept Design of the Motor Actuator of Outside Rear-View Mirror by Incomplete Coupled Design
Choi, Jun-Ho ; Lee, Kun-Sang ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1843~1848
DOI : 10.3795/KSME-A.2010.34.12.1843
This paper presents an analysis of the design hypothesis of integration of parts from the viewpoint of axiomatic design. In parts integration, parts with the same functions are integrated into a single part. For the analysis, a motor actuator of an outside rear-view mirror with the type of an uncoupled design was used. The parts within the actuator are checked for determining the possibility of integration, by adopting the design hypothesis of integration of parts. The design hypothesis of integration of parts is based on a type of coupled design. However, the type of incomplete coupled design that resembles the type of an uncoupled design would be better than the type of a coupled design.
Fracture Behavior of Glass/Resin/Glass Sandwich Structures with Different Resin Thicknesses
Park, Jae-Hong ; Lee, Eu-Gene ; Kim, Tae-Woo ; Yim, Hong-Jae ; Lee, Kee-Sung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1849~1856
DOI : 10.3795/KSME-A.2010.34.12.1849
Glass/resin/glass laminate structures are used in the automobile, biological, and display industries. The sandwich structures are used in the micro/nanoimprint process to fabricate a variety of functional components and devices in fields such as display, optics, MEMS, and bioindustry. In the process, micrometer- or nanometer-scale patterns are transferred onto the substrate using UV curing resins. The demodling process has an important impact on productivity. In this study, we investigated the fracture behavior of glass/resin/glass laminates fabricated via UV curing. We performed measurements of the adhesion force and the interfacial energy between the mold and resin materials using the four-point flexural test. The bending-test measurements and the load-displacement curves of the laminates indicate that the fracture behavior is influenced by the interfacial energy between the mold and resin and the resin thickness.
Fabrication and Characterization of Transparent Piezoresistors Using Carbon Nanotube Film
Lee, Kang-Won ; Lee, Jung-A ; Lee, Kwang-Cheol ; Lee, Seung-Seob ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1857~1863
DOI : 10.3795/KSME-A.2010.34.12.1857
We present the fabrication and characterization of transparent carbon nanotube film (CNF) piezoresistors. CNFs were fabricated by vacuum filtration methods with 65?92% transmittance and patterned on Au-deposited silicon wafer by photolithography and dry etching. The patterned CNFs were transferred onto poly-dimethysiloxane (PDMS) using the weak adhesion property between the silicon wafer and the Au layer. The transferred CNFs were confirmed to be piezoresistors using the equation of concentrated-force-derived resistance change. The gauge factor of the CNFs was measured to range from 10 to 20 as the resistance of the CNFs increased with applied pressure. In polymer microelectromechanical systems, CNF piezoresistors are the promising materials because of their high sensitivity and low-temperature process.
Self-Sensing Actuator Using an Ion-Polymer Metal Composite Based on a Neural Network Model
Yoon, Jong-Il ; Truong, Dinh Quang ; Ahn, Kyoung-Kwan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1865~1870
DOI : 10.3795/KSME-A.2010.34.12.1865
We develop an IPMC actuator with self-sensing behavior based on an accurate neural network model (NNM). The supplied voltage and voltage signals measured at two determined points on both sides of the IPMC sheet are used as inputs to the NNM. A CCD laser displacement sensor is installed in the rig for accurate measurement of the IPMC tip displacement that is used as the training output of the proposed NNM. Consequently, the NNM model is used to estimate the IPMC tip displacement; the NNM parameters are optimized by the collected input/output training data. The effectiveness of the model for the IPMC actuator is then verified by modeling results.
Sound Quality Evaluation Based on the Mahalanobis Distance for the Interior Noise of Driving Vehicles with Various the Tire Type
Jeong, Jae-Eun ; Yang, In-Hyung ; Park, Goon-Dong ; Lee, You-Yub ; Oh, Jae-Eung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1871~1876
DOI : 10.3795/KSME-A.2010.34.12.1871
The reduction of vehicle interior noise has been the main interest of NVH engineers. The driver's perception of the vehicle noise is strongly affected by the psychoacoustic characteristics of the noise and the SPL. The existing methods to evaluate the SQ for vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of subjective SQ values by neural network. However, these methods strongly depend on jury tests, this leads to difficulties. To reduce the important of the jury tests, we suggest a new method using the Mahalanobis distance for SQ evaluation. And, the optimal characteristic values that influenced the results of sound quality evaluation on the basis by main effect. Finally, we developed a new method based on the MD method to evaluate sound quality. The result of noise evaluation revealed that the sound quality could be well improved by changing the structural characteristics of the vehicle.
Acoustic Nonlinearity of Narrow-Band Surface Wave Generated by Laser Beam with Line-Arrayed Slit Mask
Choi, Sung-Ho ; Nam, Tae-Hyung ; Lee, Tae-Hun ; Kim, Chung-Seok ; Jhang, Kyung-Young ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1877~1883
DOI : 10.3795/KSME-A.2010.34.12.1877
We examined the mechanism of generation of higher harmonics by theoretically analyzing the frequency characteristics of a narrow-band surface wave generated by a laser beam with line-arrayed slit masks. We experimentally analyzed the effects of slit opening width and laser intensity on the acoustic nonlinearity of aluminum 6061-T6 alloy by using single-slit and line-arrayed slit masks. The magnitude of the harmonic wave depended on the slit opening width. In our experiment, we generated a 1.75-MHz surface wave by using an arrayed slit with intervals of 1.67 mm. The magnitude of the second harmonic component decreased about by 80% when the slit opening width was increased from 0.5 mm to 1.0 mm. In addition, the relationship between the magnitudes of the fundamental and the second harmonic wave showed good linearity, which agreed well with the typical behavior of acoustic nonlinearity.
Comparison of Response Properties Determined in Two Torque Control Methods for a 2.75-MW Wind Turbine Under Turbulence Wind Speed
Lim, Chae-Wook ; Seo, Kang-Yoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1885~1891
DOI : 10.3795/KSME-A.2010.34.12.1885
Torque control of wind turbines is important when the wind speed is below the rated speed. The main objective of torque control is to extract the maximum power from the potential aerodynamic power of the wind. Torque control methods for wind turbines are classified as torque-mode control and speed-mode control. In torque-mode control, which is well known and traditionally used in many wind turbines, the torque demand of the generator is proportional to the square of the generator speed. In speed-mode control, a PI controller is used to generate the appropriate torque demand of the generator. In this study, the two torque control methods mentioned above are applied to a 2.75-MW wind turbine; simulation results for real turbulence wind speeds are presented, and the response properties are compared.
Locomotion Characteristics of a Foxtail and a Foxtail-like Robot
Lee, Min-Su ; Kim, Yeong-Hyeok ; Leem, Sang-Huyck ; Kim, Byung-Kyu ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1893~1899
DOI : 10.3795/KSME-A.2010.34.12.1893
A foxtail moves forward on a flat surface when pushed by a vertical force. The distance moved by the foxtail depends on the degree of deformation. We experimentally investigated the main parameters that influence the distance moved while varying the pushing force, area, and velocity. We then fabricated a nylon barb that mimics the foxtail barb and performed theoretical and experimental analyses of the displacement according to the acting force and the deflection. In addition, we investigated the relation between the displacement and the angle of a foxtail-like robot's leg by varying the clearance between the robot body and the inner surface of the pipe. To find the design parameters of the barb of the robot for tubular-type digestive organs and blood vessels, we studied the relation between the acting force and the elastic modulus while varying the leg diameter.
A Study on the Durability Design of a Hydraulic Cylinder for an Excavator
Kim, Young-Bum ; Kim, Pan-Young ; Kim, In-Kyu ; Kwon, Hak-Soon ; Lee, Min-Hee ; Park, Jin-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1901~1907
DOI : 10.3795/KSME-A.2010.34.12.1901
A hydraulic cylinder is a primary component of an excavator and is used for activating attachments such as boom, arm, and bucket. Generally, the cylinder is prone to structural problems such as buckling and fatigue failure caused by cyclic high pressure. Therefore, the safety margin for fatigue, yield, and buckling during the design lifetime should be evaluated at the durability-design stage. The durability design includes basic and detailed stages. In the basic design, the principal dimensions of the rod and tube are determined by considering the working force, speed, and range with respect to yield and buckling. In the detailed design, the dimensions of the rod notch, welds, tube end, gland, orifice, and cushion ring are determined by considering the fatigue safety. We present and discuss the overall procedure for durability design and the related analysis techniques.
Changes in Material Properties of Used Gas Turbine Blade Made of Single- Crystal Superalloy
Yoo, Keun-Bong ; Lee, Han-Sang ; Song, Gyu-So ; Lee, Kyu-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1909~1915
DOI : 10.3795/KSME-A.2010.34.12.1909
The material properties of gas turbine components change during the daily start/stop thermal cycle because of exposure to the hot combustion gas. Recently, single-crystal Ni-based superalloys have been used to manufacture many hot-gas components for gas turbines. However, the user needs to depend on the manufacturer for maintenance issues because of the lack of data required for predicting blade life and material degradation. In this study, we investigate the time-dependent degradation of first-stage blades at various operating facilities to collect the basic data for life assessment and damage analysis. The blade material is a single-crystal Ni-based superalloy, CMSX-4, and the EOH (equivalent operating hours) are 25,000 and 52,000, respectively. We prepared the test specimen directly from used blades and carried out mechanical tests and microstructural observations.
Study on Model Identification and Pre-Differential 2-DOF PID Flow Control Algorithm for Cooling Processes
Hwang, I-Cheol ; Park, Cheol-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1917~1923
DOI : 10.3795/KSME-A.2010.34.12.1917
This study focuses on model identification and a 2-DOF PID control algorithm for cooling processes; a pneumatic butterfly-type control valve is used for this purpose. The mathematical model is a transfer function composed of a time delay and a second-order delay system. The control valve is identified as a first-order delay system with a time delay and included in the controlled plant. From the experimental data sets for a demo plant, the model parameters are identified, and the 2-DOF PID control gains are analytically derived by Kitamori's method. We show via a computer simulation and an experimental test that the performance of the proposed 2-DOF PID control system is better than that of a conventional 1-DOF PID control system.
Nonlinear Adaptive Control for Position Synchronization of a Gantry-Moving-Type Linear Motor
Han, Sang-Oh ; Kim, In-Keun ; Huh, Kun-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1925~1930
DOI : 10.3795/KSME-A.2010.34.12.1925
For high-speed/high-accuracy position control of a gantry-moving-type linear motor, we propose a nonlinear adaptive controller including a synchronization algorithm. Linear motors are easily affected by force ripple, friction, and parameter variations because there is no mechanical transmission to reduce the effects of model uncertainties and external disturbances. Synchronization error is also caused by skew motion, model uncertainties, and force disturbance on each axis. Nonlinear effects such as friction and ripple force are estimated and compensated for. The synchronization algorithm is used to reduce the synchronous error of the two side pillars. The performance of the controller is evaluated via computer simulations.
Sound Insulation Performance of Honeycomb Composite Panel for a Tilting Train
Kim, Seock-Hyun ; Seo, Tae-Gun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 12, 2010, Pages 1931~1936
DOI : 10.3795/KSME-A.2010.34.12.1931
In Korean tilting trains, honeycomb composite panels are used for high speed and light weight. The side wall of a tilting train consists of an aluminum honeycomb coated with carbon-fiber-reinforced epoxy skin and a nomex honeycomb panel as the main structure, with glass wool inserted between the panels. In this study, based on ASTM E2249-02, we measure the intensity sound transmission loss (TL) of the honeycomb composite panels. Using mass law deviation (MLD), we estimate the sound insulation performance of the honeycomb composite panels in terms of their weight and explore the feasibility of substituting a conventional corrugated steel panel. The transmission-loss data of the honeycomb composite panels obtained in the study will be used to establish noise-reduction measures for train compartments.