• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.727-730
• /
• 2002

Most of battery industries are growing explosively as a core strategy industry for the development of the semi-conductor, the LCD, and the mobile communication device. Dynamic characteristic analysis consists of dynamic behavior analysis and finite element analysis and is necessary for effective design of machines. In the dynamic behavior analysis, the displacement, velocity, applied force and angular velocity of each components are simulated according to each part. In the FEA, stress analysis, mode analysis, and frequency analysis are performed far each part. The results of these simulations are used for the design specification investigation and compensation for optimal design of cell manufacturing line. Virtual Engineering of the separator inserting machine on the automatic cell assembly line systems are modeled and simulated. 3D motion behavior is visualized under real-operating condition on the computer window. Virtual Prototype make it possible to save time by identifying design problems early in development, cut cost by reducing making hardware prototype, and improve quality by quickly optimizing full-system performance. As the first step of CAE which integrates design, dynamic modeling using ADAMS and FEM analysis using NASTRAN are developed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.3
• /
• pp.308-313
• /
• 2006

The extent of impact dispersion is a function of parameters including gun geometry and tolerances, the foe control system, projectile manufacturing tolerances, etc. The study here investigates potential impact point accuracy improvement for a projectile realized by replacing the rigid nose cone wind screen with a passive nose. Toward this end, a nose projectile dynamic model is derived which consists of the standard six degrees of freedom similar to a rigid projectile plus three additional degrees of freedom associated with rotation of the nose with respect to the main projectile body. By Observing the pitch and yaw movement of the nose in the simulation results, it is believed to be possible to reduce the effects of uncertainties which is occurred at firing step.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.10
• /
• pp.1045-1053
• /
• 2009

Precision stages for 6-DOF positioning, actuated by PZT stacks, which are fed back by gap sensors and guided by flexure hinges, have enlarged their application territory in micro/nano manufacturing and measurement area. The precision stages inherently have such limitations as the nonlinearity between input and output in piezoelectric stacks, feedback signal noise in precision capacitive gap sensors and low material damping in precision kinematic linkages of mechanical flexures. To surmount these limitations, the precision stage is modeled with physics-based variables, which are identified by transient response correspondence, and a gain margin calculation algorithm using the Prandtl-Ishlinskii model and describing function is newly developed to assess system performance more precisely than linear controller design schemes. Based on such analyses, a precision positioning controller is designed. Excellent positioning accuracy with rapid settlement accomplished by the controller is shown in step responses of the closed-loop system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.10a
• /
• pp.68-74
• /
• 2001

This system is composed of fine and coarse apparatus, measurement system and control system. Piezoelectric actuator is designed for fine positioning. We make a study of precision apparatus that is used in the various industrial machine. The study was carried out to develope a precision positioning apparatus, consisting of servo motor and piezoelectric actuator. Coarse positioning using lead screw is drived by servo motor. Control system output a signal from laser interferometer to amplifier of servo motor and piezoelectric actuator after digital signal processing(DSP). Resolution of this apparatus measure with laser interferometer. In this study, design method and control system with ultra precision position apparatus are researched. As the first step, we have estimated for control performance and system stability before an actual apparatus is manufactured by MATLAB with SIMULINK including various functions those are composed of pre-design and system modeling.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.3
• /
• pp.199-205
• /
• 2016

A thin sheet of metal with corrugated structures has been utilized in various devices: heat exchangers, separators in fuel cells, and many others. However, it is not easy to fabricate thin corrugated structures using a single-step stamping process due to their geometrical complexity. To solve this problem, firstly, a plate type heat exchanger was redesigned to attain the optimal value of aspect ratio and the optimal shape of corrugated structures for the actual loading conditions. A forming analysis of the corrugated plate was then carried out to determine the process parameters. From this work, the optimal value of aspect ratio was found to be 4.6. In addition, the process parameters of heat exchanger forming were optimized using the optimal value of aspect ratio, and the analytical results were evaluated through experiments. The results obtained indicated good agreements between them.

• Journal of the Korean Society for information Management
• /
• v.24 no.1 s.63
• /
• pp.5-29
• /
• 2007

With the environmental changes around libraries and information centers, they need to develop various management techniques and apply them to library works and services. In this research a case study was conducted in a special library of If company. This study was aimed for reducing ineffective components and unnecessary processes in library works and services. This study applied the Six sigma technique to improve the process of purchasing overseas academic and strategic Information and users' a degree of satisfaction on information service. Specifically, this study used the live-step DMAIC(Define, Measure, Analyze, Improve, Control) method, mainly used in the manufacturing sector. As a result of this study, we could get epoch-making improvement.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.229-232
• /
• 2005

The study on the improvement of manufacturing process of RJ-4 liquid fuel that have high flash point, was carried out. In preparing of RJ-4 using commercially available MCPD, 1st, 2nd hydrogenation and isomerization reaction were enabled 1 step continuous process by combined use of heteropoly phosphoroustungstic cesium salt catalyst and 2nd stage-heat-controllable reactor. Also when heteropolyacid cesium salt was used as a isomerization catalyst instead of aluminum chloride, formation rate of exe-THDMCPD was higher, the catalyst could be easily separable from product and there was no production of waste acid, so this new reaction condition was confirmed as the environment friendly process.

• Journal of the Korean Applied Science and Technology
• /
• v.30 no.4
• /
• pp.740-753
• /
• 2013

It is valuable research area regarding to developing manufacturing process of biogas from organic wastes take a side view of alternative for fossil energy and to improve the environmental atmosphere leads to decrease the greenhouse gas be discharged. The regulation which is prepared by environmental department shows that biogas as a transportation fuel is required to purity of above 95%, while it of natural gas is above 88%. However, in this situation it is necessary to prepare the regulation which is distributed by department of transportation as for the fuel be connected to vehicles as well in order to take step forward, and it is suggest to develop the technics of biogas this country's own original one, not be the technics imported from foreign countries, and also to turn to higher practical use of biogas for transportation area, since it shows far much less ratio have compared to other application areas.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2006.11a
• /
• pp.169-174
• /
• 2006

This paper is related to a design of high pressure sub-scale combustor with regenerative reeling. As a previous step for the evaluation of thermal heat flux, a similar combustor with cooling water was manufactured. Design conditions with high combustion efficiency and cooling performance were verified through the hot firing tests of the water-cooled high pressure combustor. Finally the regeneratively cooled high pressure combustor has been designed based on these data. After manufacturing it, its practical utility will be tested and verified through hot firing tests.

• Journal of Environmental Health Sciences
• /
• v.37 no.1
• /
• pp.57-63
• /
• 2011

Crocidolite quality control (QC) sampling created by the wet generation method has been validated by validation tests such as the accuracy, precision, and storage tests. For this study we designed and developed a manufacturing apparatus and standard operating procedure for making these QC samples. The most important step in the procedure of making QC samples was the stage eliminating static electricity in asbestos fibers. This static electricity hampers the fibers clog functioning. In accuracy and precision tests by phase contrast microscopy analysis, the difference between the reference values and the studied values was at maximum 17.8%. This satisfies the AIHA proficiency analytical test criteria for asbestos. We could confirm the nearly even distribution of crocidolite fibers on the membrane filter. Also, there was no loss of fibers in the storage test after the one month.