• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.491-494
• /
• 1995

In this study, we presented a system to measure inside diameters of parts of compressor. This system solved problems of air micrometer and improved measurement accuracy by using linear variable differential transformer. The system was designed for production line which require accurate and reliable measuring system. And the system is easier and faster to use than air micrometer and can be applied various measuring area.

• Journal of the Korean Society for Precision Engineering
• /
• v.4 no.3
• /
• pp.52-59
• /
• 1987

The flatness of a precision surface plate is generally measured by using precision angular measuring instruments such as laser interferometers, autocollimators and electronic levels. Since these instruments are expensive and measurement procedures are complex, such methods are not widely used in industries. In this study, an electronic micrometer that is easy to use and inexpensive to produce was developed in order to solve this problem. The flatness of a black granite surface plate, measured using this device was compared with the values obtained by using the conventional three methods. The results were consistent within ${\pm}1{\mu}m$. It proves that the flatness measuring method using electronic micrometers can be utilized for quantitative measurement. An accessory device that can improve the precision of measurement by attaching to the electronic micrometer was also designed and fabricated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.495-497
• /
• 1999

In order to determine what influences the interfacial breakdown in EPDM/XLPE laminates, We made the breakdown test ceil and this was pressure controllable breakdown test cell. We make the needle electrode (tip radius: about 10 micrometer) using electrochemical method. We studied the interfacial silicone oil was higher than that with silicone grease. As a function of heat treatment time in a vacuum, interfacial breakdown strength increased much in XLPE/EPDM laminates pasted with silicone grease but increased a little in that with silicone oil.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.35 no.4
• /
• pp.342-347
• /
• 2022

In-situ analyzation and detection of real-time chemical reactions can be a significant part in interpreting the underlying mechanism in very reactive chemical reactions. To do this, first we have designed a microfluidic device (MFD) pattern for observation of synthesis of hierarchical nanostructures based on graphene oxide (GO), conjugating the well-known coupling reaction by which the solution of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling is enhanced in the presence of n-hydroxysuccinimide (NHS) to make amide bonding, hereafter called as the EDC coupling. Then, we have manufactured microfluidic devices with multiple tens of micrometer-sized channels that can circulate those nanomaterials to be chemically reacted in the channels. These microfluidic devices were made by negative photo lithography and soft lithography. We showed the possibility of using Raman spectroscopy to reveal the basic mechanism of the energy storage applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.285-286
• /
• 2008

Recently, epoxy based nano-composites are being increasingly investigated for their electrical properties, since the introduction of nano fillers demonstrate several advantages in their properties when compared with the similar properties obtained for epoxy systems with micrometer sized fillers. We calculated scale and shape parameter using dielectric strength. In this paper, it is investigated that the allowable' breakdown probability of specimens is stable at some value using Weibull statistics. Therefore we found that breakdown probability of specimens is stable until 20 [%].

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1021-1024
• /
• 2003

In this work, we fabricated various 2D metallic and polymeric nanopatterns with the feature resolution of sub-micrometer scale by using the method of microcontact printing ($\mu$ P) based on soft lithography. Silicon masters for the micromolding were made by e-beam lithography. Composite poly(dimethylsiloxane) (PDMS) molds were composed of a thin, hard layer supported by soft PDMS layer. Finally, monodisperse metal or polymer particles could be obtained in the prepared pattern for the application of electronic devices.

• Journal of Welding and Joining
• /
• v.20 no.4
• /
• pp.544-550
• /
• 2002

Arc-spot welding is generally used in joining of precise parts such as case and core in electronic compressor. It is important to control joining deformation in electronic compressor because clearance control in micrometer order is needed for excellent airtightness and anti-nose. The countermeasures far this deformation in field have mainly been dependent on the rule of try and error by operator's experience because of productivities. For control this deformation problem without influence on productivities, development of exact simulation model should be needed. In this study, to solve this deformation problem in arc-spot welded structure with case and core, we intend to make a simulation model that is able to predict deformation in precise order by tuning and feedback between sensing data and simulation results. This paper include development of heat input model for arc-spot welding, temperature monitoring and make a heat transfer model using sensing data in product.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.9
• /
• pp.1594-1598
• /
• 2008

The ionic air pump can be used towards the thermal management of micro-electronic devices, since the size of pump can be reduced to micrometer orders. In addition, an air pump allows air flow control and generation with low noise and no moving parts. These ideal characteristics of the pump give rise to variety applications. However, all of these applications would benefit from maximizing the flow velocities of the pumps. In this study a surface discharge type air pump, with a third electrode, has been investigated by focusing on elevating the wind velocity and efficiency. As a result, the enhanced ionic wind velocity could be obtained with the third electrode of the proposed air pump.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.92.1-92.1
• /
• 2013

Molecular electronics has been the subject of intese research for many years because of the fundamental interest in molecular charge transport and potential applications, such as (bio)nanosensors and molecular memory devices. Molecular electronics requires a method for making reliable eletrical contacts to singlemolecules. To date, several approaches have been reported: scanning-probe microscopy, mechanical break junctions, nano patterning, and direct deposition of electrode on a self-assembled monolayers. However, most methods are laborious and difficult for large-scale application and more importantly, cannot control the number of moleucles in the junction. Recently, DNA has been used as a template for metallic nanostructures (e.g., Ag, Pd, and Au nanowires) through DNA metallization process. Furthermore, oligodeoxynucleotides have been tethered to organic molecules by using conventional organic reactions. Collectively, these techniques should provide an efficient route toward reliable and reproducible molecular electronic devices with large-scale fabrication. Therefore, I will present a paradigm for the fabrication of moleuclar electronic devices by using micrometer-sized DNA-singe organic molecule and DNA triblock structures.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1091-1097
• /
• 2008

Roll-to-roll based manufacturing plays an important role in producing devices at high speed with lower production cost in printed electronics and publishing industry. Web lateral control is one of the most important factors in improving the quality of product and contributes a considerable point in making devices at micrometer-level accuracy. In recent years, most algorithms proposed for web lateral control base on the Shelton‘s model for designing the feedback control system using the PI controller. Experimental results showed that the existing models do not fully describe the characteristics of the lateral dynamics for some typical operating conditions and so result in poor control algorithms. In this paper, a new lateral control algorithm is proposed for web lateral control system based on back-stepping approach. The outcome of this study proves the reliability throughout simulation results in Matlab/Simulink and comparison with the algorithms based on the existing results.