• Applied Science and Convergence Technology
• /
• 제23권2호
• /
• pp.83-89
• /
• 2014

Adsorption of residual gas molecules damped the emission current of a W (310) field electron emission (FE) emitter. The damping speed was linearly proportional to the pressure gauge readings at pressure ranging from ${\sim}10^{-8}Pa$ to ${\sim}10^{-9}Pa$, and the proportionality constant was employed to measure pressure in the $10^{-10}Pa$ range. A time plot of FE current revealed the existence of an "initial stable region" after the flash heating of W(310) FE, during which the FE current damps very slowly. The presence of non-hydrogen gas removed this region from the plot, supplying a means of qualitatively analysing the gas species.

• 천문학회보
• /
• 제36권1호
• /
• pp.52.2-52.2
• /
• 2011

The correlation between black hole mass and galaxy stellar velocity dispersion gives an important clue on the black hole growth and galaxy evolution. In the case of AGN, however, it is extremely difficult to measure stellar velocity dispersions in the optical spectra since AGN continuum dilutes stellar absorption features. In contrast, stellar velocity dispersions of active galaxies can be measured in the near-IR, where AGN-to-star flux ratio is much smaller, particularly with the laser-guide-star adaptive optics. However, it is crucial to test whether the stellar velocity dispersion measured from the near-IR spectra is consistent with that measured from the optical spectra. Using the TripleSpec at the Palomar 5-m Telescope, we obtained high quality spectra ranging from 1 to 2.4 micron for a sample of 35 nearby galaxies, for which dynamical black hole masses and optical stellar velocity dispersion measurements are available, in order to calibrate the stellar velocity dispersion in the near-IR. In this poster, we present the initial results based on 10 galaxies, with the stellar velocity dispersion measured in the H-band.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제8권4호
• /
• pp.221-226
• /
• 2003

With the current rapid development of nanotechnology and synthesis technology for designed oligonucleotides or oligonucleotide-modified nanoparticle conjugates, the combined strategies have become one of the most valuable methods in detection technology for DNA analysis. Using the uniquely recognizable interactions of pre-designed DNA molecules in assembling nanoparticles, various novel approaches have been recently developed towards detecting specific DNA sequences. Here we describe the key fundamentals and issues of this promising strategies ranging from the initial findings of rationally designed DNA-based assembly of nanoparticles to the extended chip-based detection system. Some limitations of these new strategies and possible approaches will be also discussed for the practical application in the area of DNA microarray detection.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2011년도 추계학술논문집 1부
• /
• pp.326-329
• /
• 2011

Mortality associated with maxillofacial infection is relatively low due to the development of antibiotics, and improved oral care. However, inappropriate treatment, delayed treatment, old age, underlying systemic disease, and drug-resistant micro-organisms can potentially result in life threatening situations such as cavernous sinus thrombosis, mediastinitis, and sepsis. Sepsis is the most dangerous state with high mortality, ranging from 20~60%. The treatment of sepsis involves properly monitoring vital functions, fluid resuscitation, surgical drainage, and empirical use of high doses of antibiotics until culture results are available. Ventilatory support maybe be required as well. We encountered a 64-year-old patient who died from sepsis that developed as the result of an odontogenic infection. The initial diagnosis was right temporal, infraorbital, buccal, pterygomandibular space abscess. Despite surgical and medical supportive care, the condition progressed to sepsis and after four days the patient died due to multiple organ failure.

• Bulletin of the Korean Chemical Society
• /
• 제21권4호
• /
• pp.383-388
• /
• 2000

Multiblock copolymers consisting of poly( g-benzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) as the hydrophilic part (GEG) were synthesized and characterized. GEG polymeric micelles were prepared by the dialysis technique. Particle size distributions based on intensity,volume, and number-average were 22.6 $\pm$ 11.9 nm, 23.5 $\pm$ 4.6 nm, and 23.7 $\pm$ 37 nm, respectively. It was observed that par-ticle size and size distribution of GEG polymeric micelles changed significantly with the choice of initial sol-vent. Transmission electron micrographs (TEM) showed the polymeric micelles to be spherically shaped, with sizes ranging from 20 nm to 40 nm in diameter. Fluorescence spectroscopy measurements suggested that GEG block copolymers wereassociated in water to form polymeric micelles, and the critical micelle concentrations (CMC) value of the block copolymers was 0.0094 g/L. Further evidenceof micelle formation of GEG block copolymers and limited mobility of the PBLG chain in the core ohe micelle was obtained with 1 H NMR in D2O.

• 통합자연과학논문집
• /
• 제12권1호
• /
• pp.1-8
• /
• 2019

Smart pole is one of mega trend in smart city development. It has multi-function to get as much as data from the street to better city management. And smart street lighting of smart pole as core part of smart city development is being implemented by many cities in globally. Refer to the latest edition of Navigant Research's Smart City Tracker includes smart city projects in 221 cities, a quarter of which are deploying smart street lighting ranging from initial pilots to citywide and regional deployments that span tens and even hundreds of thousands of lights. The most important feature of smart street lighting solution is "Connectivity" through the IoT technology. In order to implement the smart city, we should have so-called intelligent watchdog and mesh networked post for keeping the various smart city technology development progress and operation properly. Smart street lighting solution could be main infrastructure as an enabler for a range of smart city applications. We can talk about the expected role of smart street lighting for the smart city development on this paper.

• 천문학회보
• /
• 제43권2호
• /
• pp.36.3-37
• /
• 2018

By utilizing large-scale graph analytic tools in the modern Big Data platform, Apache Spark, we investigate the topological structures of five different multiverses produced by cosmological n-body simulations with various cosmological initial conditions: (1) one standard universe, (2) two different dark energy states, and (3) two different dark matter densities. For the Big Data calculations, we use a custom build of stand-alone Spark cluster at KIAS and Dataproc Compute Engine in Google Cloud Platform with the sample sizes ranging from 7 millions to 200 millions. Among many graph statistics, we find that three simple graph measurements, denoted by (1) $n_\k$, (2) $\tau_\Delta$, and (3) $n_{S\ge5}$, can efficiently discern different topology in discrete point distributions. We denote this set of three graph diagnostics by kT5+. These kT5+ statistics provide a quick look of various orders of n-points correlation functions in a computationally cheap way: (1) $n = 2$ by $n_k$, (2) $n = 3$ by $\tau_\Delta$, and (3) $n \ge 5$ by $n_{S\ge5}$.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.28-29
• /
• 2015

The tire production facility is a large-scale construction with the complexity of a manufacturing process. The process utilities should be wide-ranging as an effective arrangement of them is highly important. All the necessary information should be clarified together with the manufacturer at the basic planning stage, and this design should be developed to comply with the local culture and regulations. It is important to carry out more advanced engineering in terms of process, cost and quality, even if it is difficult to standardize due to the cultural and geographical conditions and regulations. The key point is to reflect all the given conditions and make a clear design during the design stage, to eliminate the problems after the construction has begun. Another key point is the delivery system, which must be totally managed from the initial design stage until the construction stage by proven companies. Flexibility, quick action, and single responsibility will be the fundamental features in all the steps of the project.

• 소성∙가공
• /
• 제8권3호
• /
• pp.241-241
• /
• 1999

With the aim of assessing the degradation of Zr-2.5Nb pressure tubes operating in the Wolsong unit-1 nuclear power plant, characterization tests are being conducted on irradiated Zr-2.5Nb tubes removed after 10-year operation. The examined tube had been exposed to temperatures ranging from 264 to 306℃ and a neutron fluence of 8.9×$10^{21}$ n/cm²(E>1 MeV) at the maximum. Tensile tests were carried out at temperatures ranging from RT to 300℃. The density of a-type and c-type dislocations was examined on the irradiated Zr-2.5Nb tube using a transmission electron microscope. Neutron irradiation up to 8.9×$10^{21}$ n/cm²(E>1 MeV) yielded an increase in a-type dislocation density of the Zr-2.5Nb pressure tube to 7.5×$10^{14} m^{-2}$, which was highest at the inlet of the tube exposed to the low temperature of 275℃. In contrast, the c-component dislocation density did not change with irradiation, keeping an initial dislocation density of 0.8×$10^{14} m^{-2}$ over the whole length of the tube. As expected, the neutron irradiation increased mechanical strength by about 17-26% in the transverse direction and by 34-39% in the longitudinal direction compared to that of the unirradiated tube at 300℃. The change in the mechanical properties with irradiation is discussed in association with the microstructural change as a function of temperature and neutron fluence.

• 한국농공학회지
• /
• 제34권3호
• /
• pp.33-42
• /
• 1992

The shear strength of cohesionless Soils results from particle-to-particle friction and structural resistance by interlocking. And, the shear strength of soils is subjected to vary depending on the internal states and external condtions. If the volume change occurring in the soils and stress-strain relationships under the internal and external changes can accrurately he described, it is possible to predict the behaviors of soils. To accomplish these objectives a series of drained triaxial compression tests and isotropic compression test was performed on the Banwol sand at different relative densities ranging from 20% to 80% and different confining pressures ranging from 0.4kgf/cm$^2$ to l2kgf/cm$^2$. The results and main conclusions of the study are summarized as follows; 1.When the relative density or the confining pressure is increased, the maximum deviator stress is increased. The ratio of the maximum deviator stress and the confining pressure is linearly proportional to the relative density. 2.It is observed that the dilatancy depends not only upon its relative density but also the confining stress, and that the maximum deviator stress is obtained after the diatancy occurs. 3.The volume of sands undergoes initial contraction prior to the dilatancy occurred by strain softening. The dilatancy rate eventually approaches the critical state or a constant volume. 4.At lower strains, Poisson's ratio approaches a certain minimum value regadless of the state of materials. At larger strains, however, the ratio is increased as the relative density is increased. 5.It is observed that the modulus of elasticity is linearly proportional to the relative density and the pressure. 6.When the relative density is increased, the friction angle of sands is linearly increased. 7.When the relative density is increased, the expansion index and the compression index are linearly decreased, and the ratio of the two is about 1/3.