• Journal of the Korean Society for Precision Engineering
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• v.27 no.8
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• pp.84-90
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• 2010

In focused ion beam (FIB) fabrication processes the ion beam intensity with Gaussian profile has a drawback for high resolution machining. In this paper, the fabrication method to modify the beam profile at substrate using silt mask is proposed to increase the machining resolution at high current. Slit mask is utilized to block the part of beam and transmit only high intensity portion. A nano manipulator is utilized to handle the silt mask. Geometrical analysis on fabricated profile through silt mask was conducted. By utilizing proposed method, improvement of machining resolution was achieved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.489-490
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• 2006

To establish fabrication techniques for nano structure understanding of focused ion beam (FIB) milling process is required. In this study the mathematical model containing the factors related to FIB milling is developed to acquire the optimal fabrication condition. Then, the model is verified by comparison with various nano pattern fabricated in actual FIB system. Consequently, it is demonstrated that the nano patterns with the smallest pitch can be fabricated using developed FIB milling model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.495-496
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• 2006

Electrostatically actuated nanoscale tweezers are fabricated on micro processed electrodes using FIB-CVD. Heavily doped electrode works as interconnection platform for controlling nanoscale devices. Short bent pillars are deposited to control the gap distance of main tweezers fabricated on bent ones. Two types of tweezers which have different gap distances are fabricated and tweezing motion was successfully demonstrated. The threshold voltages at snap-down of the pillars are dependent on the initial gap distance of the unactuated pillars, and the measured values were 93V for 3.6um and 30V for 2.2um. The dimension of nano tweezers and initial gap distances are controllable as demonstrated and we expect more complicated 3-dimensional shapes are also possible.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.929-936
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• 1995

LOMI 제염제의 전기화학적 제조공정 중 전하운반체의 역할 및 V$^{3+}$ 이온의 침전현상을 방지하기 위하여 첨가되는 과량의 formic acid 는 제염제 제조시에는 중요한 역할을 하지만 제염 폐기물의 양을 증가시키는 요인이 되기도 한다. EPRI 공정에서는 formate : V 의 비율(FVR)이 10:1 인 조건에서 V$^{2+}$-formate 를 제조한 후 음이온 교환 수지를 이용하여 과량의 formate 를 제거하는 공정을 사용한다. 이러한 방법으로 줄일 수 있는 FVR의 한계가 약 2.5 : 1 이다. 본 연구에서는 제염제 중 formate 의 양을 더욱 줄일 수 있는 방법으로써 V$^{2+}$-formate 제조시 용액 중에 picolinic acid를 미리 첨가하는 영향을 조사하였다. V$^{2+}$ 이온의 농도가 0.1 M 일 때 FVR 를 1.5:1 까지도 줄일 수 있음을 확인하였다.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.152-169
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• 2018

The purpose of this study was to analyze the effect of adjacentroads on the concentration of negative air ions in urban neighborhood park. The measured factors were negative air ion concentration, positive airion concentration, airtemperature,relative humidity, wind speed, green formation volume factor (GVZ) and distance from highway and general road. The mean negative air ion concentration was $206ea/cm^3$ and the positive air ion concentration was $416ea/cm^3$ in the influence zone of roads. On the other hand, the mean negative air ion was $339ea/cm^3$ and the positive air ion was $229ea/cm^3$ in the unaffected zone of roads, which are inner areas of the park. The difference of the negative air ion concentration according to the influence of the road was statistically significant. The negative air ion concentration model was presented by integrating the correlation analysis with the influence factors, and the explanatory power of the model was increased by adding the influence factor of the road.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.650-655
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• 1996

In order to investigate the effects of added magnetized water on the callus induction and plant regeneration in rice, 700G(G=Gauss) magnetized water were used. The callus in-duction and plant regeneration of rice in magnetized water treatment are different from the callus induction and plant regeneration in ionic water treatment. The rates of callus induction in magnetized water media were 27.3% in solid media and 15.4% in liquid which were compared to that of callus induction in the ionic water media 21 and 13.3%. Also plant regeneration frequency in the magnetic water media is 5.4% better than that of the ionic water media. And dissolved oxgen amount of magnetic culture media is from 0.1 ppm to 0.9 ppm more than that of ionic culture media. The pH value was increased with rising of water temperature, and the magnetic water was effected at increasing of pH value.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.171-172
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• 2012

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.05a
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• pp.171-176
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• 1998

공업의 고도 성장과 이로 인하여 유출되는 산업폐기물의 함유된 각종 중금속류가 무한한 잔류독성을 가지므로 이를 제거하려는 관심이 높아지고 있다. 오염원 중 특히 카드뮴, 수은, 니켈, 크롬, 납등에 의한 환경오염은 자연의 생태계를 변화시켜 우리의 생활권까지 위협을 주고 있어 더욱 문제가 되고 있다. (중략)

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.881-883
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• 1998

We fabricated IMI-O polymer containing imidazole group that can be form a complex structure between the monolayer and the metal ions at the air-water interface. Also, the monolayer behavior at the air-water interface and Langmuir-Blodget films by complexes formation have been investigated by $\pi$-A isotherms, Brewster Angle Microscopy and the scanning Maxwell-stress microscopy.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2004.11a
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• pp.102-102
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• 2004