• 척추신경추나의학회지
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• 제4권1호
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• pp.85-94
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• 2009

Objects : This study was to report a clinical effect of Korean Treatment for a patient diagnosed by Computed Tomography as Cervical Spinal Stenosis with Ossification of posterior Longitudinal Ligament. Methods : In order to alleviate left shoulder pain and neck stiffness, the patient was treated by acupuncture therapy, herbal medicine, distilled herbal injection, cervical traction technique of Chuna treatment and conservative managements. To evaluate the effect of the treatment, Recovery rate of Hirabayashi, VAS(Visual Anlaogue Scale), NDI and ROM(Range of Motion) were used. Lhermitte's sign, Valsalva test, Distraction test, Compression test and Spurling test were carried out. Results : VAS, NDI and ROM were improved and Recovery rate was 100%. Conclusions : Korean Treatment can be effectively used for a patient with Cervical Spinal Stenosis with OPLL. Further clinical studies are needed to verify the findings.

• Advances in materials Research
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• 제1권1호
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• pp.93-107
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• 2012

Epoxy resin is widely used in high voltage apparatus as insulation. Fillers are often added to epoxy resin to enhance its mechanical, thermal and chemical properties. The addition of fillers can deteriorate electrical performance. With the new development in nanotechnology, it has been widely anticipated that the combination of nanoparticles with traditional resin systems may create nanocomposite materials with enhanced electrical, thermal and mechanical properties. In the present paper we have carried out a comparative study on dielectric properties, space charge and dielectric breakdown behavior of epoxy resin/nanocomposites with nano-fillers of $SiO_2$ and $Al_2O_3$. The epoxy resin (LY556), commonly used in power apparatus was used to investigate the dielectric behavior of epoxy resin/nanocomposites with different filler concentrations. The epoxy resin/nanocomposite thin film samples were prepared and tests were carried out to measure their dielectric permittivity and tan delta value in a frequency range of 1 Hz - 1 MHz. The space charge behaviors were also observed by using the pulse electroacoustic (PEA) technique. In addition, traditional epoxy resin/microcomposites were also prepared and tested and the test results were compared with those obtained from epoxy resin/nanocomposites.

• 한국생산제조학회지
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• 제18권6호
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• pp.565-575
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• 2009

A forklift (also called a lift truck) is a powered industrial truck that is used to lift and transport materials. It has become an indispensable piece of equipment in manufacturing and warehousing operations. The modem forklift is equipped with automatic transmission to meet the requirement of loading and easy operation of the vehicle. This paper proposes the design of TECU(Transmission Electronic Control Unit) which is applied to PSD322-Axle transmission. Garofalo's control technique is generally used to the automatic transmission. We consider the work quality and market requirement that does not want to control engine throttle. This paper proposes new controller system which guarantees efficient speed changes with simple system. This new system does not control the engine throttle spontaneously. But it has the load of engine and vehicle as a maximum disturbance. The scope of the disturbance is limited to the stoll area of the torque converter. This paper proposes a ideal control commander that converges relative velocity of the input and ouput of a clutch into a zero. We design linear controller to execute the idea control commander. We applied the control algorithm to the forklift of PSD322-Axle type and the performance of this controller was verified.

• 한국정밀공학회지
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• 제25권1호
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• pp.138-144
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• 2008

Micro-machining of a brittle material such as glass, silicon, etc., is important in micro fabrication. Particularly, micro-abrasive jet machining (${\mu}-AJM$) has become a useful technique for micro-machining of such materials. The ${\mu}-AJM$ process is mainly based on the erosion of a mask which protects brittle substrate against high velocity of micro-particle. Therefore, fabrication of an adequate mask is very important. Generally, for the fabrication of a mask in the ${\mu}-AJM$ process, a photomask based on the semi-conductor fabrication process was used. In this research a rapid mask fabrication technology has been developed for the ${\mu}-AJM$. By scanning the focused UV laser beam, a micro-mask pattern was fabricated directly without photolithography process and photomask. Two kinds of mask patterns were fabricated using SU-8 and photopolymer (Watershed 11110). Using fabricated mask patterns, abrasive-jet machining of Si wafer were conducted successfully.

• KIEAE Journal
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• 제2권1호
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• pp.3-10
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• 2002

The purpose of this study is make a proposal for application skill of Ecological communal. Ecological communal is Environmentally friendly lifestyle and an alternative plan of Environmental pollution. There is growing international scientific consensus that human activities are having a discernible effect on the global climate. The environment was polluted the cause by The Development of scientific technique and economy. Recently, Environmental pollution spreads through over the world over. Moreover, An increasing gulf between the rich and the poor. In result, rise to the emergency in cooperation with the whole world. We need to advance a new direction for society to take in order to suffer environmental problems which have emerged as the most serious. The development of ecological communal is directed toward realizing a sustainable society. If life styles are to become less dependent on ecological resources and reduce externalities, same as Ecological communal, then a wide range of renewable energy technologies and energy saving measures are required. Up to now, the development of ecological communal has been actively initiated and still continues by some venture farmers whit a vision and strong will. These study results are definitely very conducive to spread ecological communal knowledge among the public.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.473-476
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• 1997

Focused Ar ion laser beam can be utilized to fabricate microstructures on silicon substrate as well as other materials(e.g. such as ceramic). The laser using in this study is an argon ion laser with maximum power of 6 W, wavelength of 514 nm. This laser beam is focused by objectives with a high numerical aperture, a long working distance. We have achieved line width about 1 ${\mu}{\textrm}{m}$ with high scan speed. The resolution for Si machining is determined by the selectivity of the chemical reaction rather than the laser spot size. In this study, we have obtained the maximum etch rate of 434.7 ${\mu}{\textrm}{m}$/sec with high aspect ratio. The characteristics of etched groove was investigated by scanning electron microscope(SEM) and auger electron spectroscopy(AES). It is assumed that the technique using arson ion laser is applicab1e to fabricate microstructures.

• 한국전기전자재료학회논문지
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• 제28권9호
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• pp.593-597
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• 2015

Ni ink for electrohydrodynamic (EHD) continuous jet printing has been developed by using Ni nanoparticles mixed with conhesiveness provider. EHD continuous jet printing was used in order to realize $20{\mu}m$ pattern width. Ink stability was investigated by using Turbi-scan which monitors agglomeration and precipitation of nanoparticles in the ink for three days. The Turbi-scan results showed that the formulated Ni ink had been stable for 3 days without any indication of precipitation across the entire ink. Antireflection coating (ARC) layer in crystalline solar cell wafers was removed by laser ablation technique leading to the formation of 84 grooves where the Ni ink was printed by EHD continuous jet printing. The printability and microstructure of EHD-jet-printed Ni lines were investigated by using optical and electron microscopes. 84 Ni lines with the width less than $20{\mu}m$ were successfully printed by one-time printing without any misalignment and fill the laser-ablated ARC grooves.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3307-3309
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• 1999

Electrochemical discharge machining (ECDM) is a very recent technique in the fabrication of the micro-electro-mechanical system ( MEMS ) devices. This paper presents the experimental results of the machining of micro-holes on pyrex glass substrates by use of ECDM. Electrolyte is used with a KOH aqueous solution, cathode with copper, anode with platinum, and tool feed system is applied with gravity feed system. Already established experimental results were taken under the condition of constant voltage frequency. However in this paper, the effect of variation of the voltage frequency and duty ratio is considered. In this experiment, it is measured the ECDM performances with variation of the voltage frequency and duty ratio under the conditions of constant other machining variables. ECDM performances are described by the hole depth, and the top hole diameter.

• 한국주조공학회지
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• 제39권5호
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• pp.87-93
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• 2019

The effects of mold materials on the microstructure and tensile properties were investigated to develop a mass production technique of aluminum alloy parts with excellent mechanical properties using a lost foam casting method. The microstructures of the plate-shaped cast alloy showed a tendency to be finer in proportion to the thickness of the plate, and a remarkably fine structure was obtained by applying a steel chill or a ball as a mold material compared to general sand. When a steel ball was used, it was observed that the larger the ball, the finer the cast structure and the better the tensile properties. The microstructure and tensile properties of the cast parts with complex shapes were greatly affected by the gating system, but the positive effects of the steel chill and the steel ball as a mold material were clear.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.313-314
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• 2007

AlN is used a wide variety of applications such as electroacoustic devices, blue diode and metal-insulator-semiconductor structures. AlN thin films were deposited on Si substrates by rf sputter technique with low temperature process. The orientation and morphology of AlN thin films at various power in the range from 150 to 300 w was studied. X-ray diffraction (XRD), full width at half-maximum (FWHM) and field emission scanning electron microscopy were employed to characterize the deposited films. The c-axis orientation along (002) Plane at experimental results was enhanced with the increasing of the rf power from 150 to 300 w and the surface morphology of the films showed a homogeneous and nano-sized microstructure.