• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.383-383
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• 2011

Generally, field emitters can be categorized into two types according to the emitter shape, one is a planar field emitter and the other is a point emitter. The planar field emitter is used for displays, flat lamps and signage boards. On the other hands, the point field emitter is expected to play a significant role in x-ray sources and electron beam sources. Such applications of the point field emitters, especially, need large emission current and high emission stability with a small electron beam size. A few reports announced point emitters made by carbon nanotubes (CNTs). However, they still have suffered from poor reproducibility and low emission current. Here, we demonstrated high performance CNT point emitters by attaching CNTs onto graphite rod. Graphite rod exhibited good electrical conductivity and chemical stability. In this method, the shape of the point emitter could be easily controlled by changing the length and diameter of the graphite rod. The CNT point emitter showed emission current over 1 mA at an applied electric field of 1.4 V/${\mu}m$. We consider that the stable emission performance is attributed to the stable contact between CNTs and graphite rod.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.575-582
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• 2018

This article compared accuracy of 5 types of radionuclide activity meters that are being used in medical institutions and proposed the correction factor for each radionuclide activity meters type, using Ge-68/Ga-68 radiation sources for scanner setting, regular scanner correction, attenuation correction, and normalization. The calibration constant between baseline values and measured values by CRC-15R, CRC-15 PET, CRC-712M, CRC-15 Beta, and CRC-25PET was 0.99999(P<0.0001), which showed very high linearity. In the accuracy test, CRC-15R, CRC-15 PET, CRC-712M, CRC-15 Beta, and CRC-25PET model showed -3.232%, -1.342%, -2.815%, -2.913%, and -3.089% respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.171-175
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• 2010

Various soil characteristics for safe construction is necessary to understand the tests using the samples collected, and head in place an energy evaluation is conducted to evaluate the ground. In-Situ testing ground, Rod length and around the intrusive when the energy loss due to friction has been measured only in the head. Abstract The purpose of this agreement when increasing contract area of Rod agreement to transform the energy attenuation and the attenuation at the energy being delivered to evaluate. To this end, the same material used in the field test, laboratory test to apply Rod diameter and length have been considered, designed to perform the experiment was to use the Rod. Energy that raised at head of Rod, was increased and decreased by contracting type. The energy difference occurs in the head with the tip that shows the energy rating may be required at the tip is showing. Abstract The energy evaluation for the Rod field test to be at the basic sources and will be able to calculate the trusted information are measured from the tip.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.12
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• pp.1106-1112
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• 2000

In this paper, we present a vision system which measures the cross-section of a hot wire-rod in the steel plant. We developed a mobile vision system capable of accurate measurement, which is strong to vibration and jolt when moving. Our system uses green laser light sources and CCD cameras as a sensor, where laser sheet beams form a cross-section contour on the surface of the hot wire-rod and the reflected light from the wire-rode is imaged on the CCD cameras. We use four lasers and four cameras to obtain the image with the complete cross-section contour without an occlusion region. We also perform camera calibrations to obtain each cameras physical parameters by using a single calibration pattern sheet. In our measuring algorithm, distorted four-camera images are corrected by using the camera calibration information and added to generate an image with the complete cross-section contour of the wire-rod. Then, from this image, the cross-section contour of the wire-rod is extracted by preprocessing and segmentation, and its height, width and area are measured.

• Nuclear Engineering and Technology
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• v.29 no.3
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• pp.181-185
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• 1997

The ion sources for induction linac driven heavy ion fusion were fabricated and their omittance characteristics were investigated. For to kinds of ion sources, i. e. a carbon vacuum arc ion source and a cusp field rf ion source, the emittance was measured with a double slit beam scanner. The required normalized omittance of an ion source for heavy ion fusion is 10$^{-7}$ - 5$\times$10$^{-7}$ $\pi$ m-rod, and the measured emittances of the ion beams from carbon vacuum arc ion source and cusp field rf ion source (Ne$^{+}$) were 2$\times$10$^{-6}$ $\pi$ m-rad and 4$\times$10$^{-7}$ $\pi$ m-rad, respectively.y.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.2
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• pp.151-156
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• 2000

The variability of a ventilated filter cigarette depends on the details of its construction and on the variabilities of its components. Variations in filter ventilation arise from many sources, including variations in tobacco rod pressure drop, filter tip pressure drop, tipping paper permeability, and plugwrap permeability. To reduce the filter ventilation variability, the variability of filter ventilation levels in ventilated cigarettes is studied by Monte Carlo Analysis. For each trials a value is selected for tobacco rod pressure drop, filter tip pressure drop, tipping paper permeability, and plugwrap permeability. These values are selected randomly from a normal distribution based on the target and coefficient of variation for each input variable. The results of this analysis for filter ventilation variation suggest that the variations of filter ventilation are dependent on the details of cigarette designs studied and reducing the variability of any cigarette component will reduce filter ventilation variability. For typical cigarettes, variation in the permeability of tipping paper is usually the most significant contributor to filter ventilation variability. Results of a Monte Carlo Analysis could provide both general insights and specific practical guidance about the design of ventilated filter cigarettes.

• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.108-114
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• 1993

A new strain of acidophilic, acetogenic bacterium, Acetobacter sp. strain HA was isolated by selective enrichment from the traditionally fermented rice wine vinegar in Korea. It was a gram-negative, non-motile short rod and oxidized acetate and lactate. The optimal temperature and pH for growth were $28^{\circ}C$ and 4.0, respectively. The strain HA differed from other Acetobacter species by growing well on methanol, xylitol, inositol, dulcitol, D-xylose, L-arabinose, and D-mannose as sole sources of carbon and energy. The isolated strain HA did not produce $\gamma$-pyrones from glucose and did not produce ketone bodies from glycerol. The quinone system used in this study was an ubiquinone-9 isoprene unit. The guanine-plus-cytosine content of the DNA was 50.7 mol%, and the major cellular fatty acids were $C_{18:1} and C_{16:0}$.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.79-84
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• 1996

The robust controller for the nuclear reactor power control system is designed. The reactor model is set up by use of the point kinetics equations and the singly lumped energy balance equations. Since the model is different from the actual plant, the controller which makes the system robust is necessary. The perturbation of the actual plant is investigated with respect to several possible sources of uncertainty. Then the overall system is configured into the two port model and the $H_{\infty}$ controller is designed. The loop shaping and the permissible control rod speed are considered as the design constraints. The designed $H_{\infty}$ controller provides the sufficient margins for the robustness, and the system output as well as the control input satisfy their relevant requirements.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.724-727
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• 2000

A Phenanthrene-degrading bacterium, Strain 1-21 was isolated from oil-contaminated soil. This strain was a Gram-negative, aerobic, and rod-shaped bacterium, and exhibited a 99% sequence similarity of 16S rDNA to that of Sphingomonas subarctica. The major cellular fatty acid was a summed feature 7(18:1 w7c, 18:1 w9t, 18:1 s12t), which is a characteristic of the Sphingomonas species. When 200 and 1,000 ppm of phenanthrene was added as the sole carbon source, Strain 1-21 degraded 98% and 67% after 10 days of incubation, respectively. Futhermore, this strain was also able to utilized naphthalene and fluorene as sole carbon and energy sources.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.1-9
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• 1999

For the practical using of liquid spawn we carried out selection test of nutrient sources, cultural methods and cultural apparatus for liquid spawn production of oyster mushroom(ASTI 2001, ASTI 2018, ASTI 2072, ASTI 2016, ASTI 2070, ASTI 2180, ASTI 2183, ASTI 2042). The optimal temperature and pH range for mycelial growth of Pleurotus species were $25^{\circ}C\;to\;30^{\circ}C$ and 5.5 to 6.5, respectively. The effect of carbon sources, nitrogen sources and mineral salts on the mycelial growth was studied using petridish culture. Generally, the disaccharides and polysaccharides showed good effect for mycelial growth of Pleurotus species, and the polysaccharides were superior to the other classes of carbon sources for mycelial growth. For the mycelial growth of the 8 oyster mushroom stains, soybean flour was superior to the other kinds of nitrogen sources. On the other hand, addition of mineral salts did not affect, and even poor under certain mineral salts, the mycelial growth of the 8 oyster mushroom stains. The brown sugar selected out the carbon source of the agricultural medium. Also the soybean flour selected out the nitrogen source of agricultural medium. In the medium selection, we selected out agricultural optimum medium composed of brown sugar 3%, soybean flour 0.3%, potassium phosphate 0.05%, magnesium sulfate 0.05%. Under the 250 ml erlenmeyer culture, the effects of such factors as the inoculum rate, the working volume, cultural method and flask shapes on the mycelial growth were examined. The optimal inoculum rate and working volume on the mycelial growth of oyster mushroom was 2 mycelial disk (diameter 6 mm) and 100 ml, respectively. The shake flask culture was enhanced the mycelial growth than at the erlenmeyer flask. Pulp form growth of mycelium in the erlenmeyer flask culture was obtained in the culture with glass rod of length 50 mm, diameter 10 mm.