• The Bulletin of The Korean Astronomical Society
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• 제42권2호
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• pp.79.3-80
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• 2017

Molecular clouds are the sites of stellar birth. Turbulence is a natural phenomenon in molecular clouds, which largely determines the density and velocity fields. Additionally turbulent energy dissipation can affect the gas kinetic temperature via shocks. Turbulence thus controls the mode and tempo of star formation. However, despite its important role in star formation, the properties of turbulence remain poorly understood. As part of the Taeduk Radio Astronomy Observatory (TRAO) Key Science Program (KSP), "Mapping turbulent properties of star-forming molecular clouds down to the sonic scale (PI: Jeong-Eun Lee)", we have been mapping two star-forming clouds, the Orion A and the ${\rho}$ Ophiuchus molecular clouds in 3 sets of lines (13CO 1-0/C18O 1-0, HCN 1-0/HCO+ 1-0, and CS 2-1/N2H+ 1-0) using the TRAO 14-m telescope. We apply a Principal Component Analysis (PCA), which is an useful tool to represent turbulent power spectrum. We will present the preliminary results of our TRAO KSP toward two regions: OMC 1-4 in the Orion A cloud, and L1688 in the ${\rho}$ Ophiuchus cloud.

• Toxicological Research
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• 제32권4호
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• pp.301-309
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• 2016

Due to undesirable hazardous interactions with biological systems, this investigation was undertaken to evaluate the effect of chronic exposure to silver on certain biochemical and some oxidative stress parameters with histopathological examination of brain, as well as the possible protective role of selenium and/or vitamin E as nutritional supplements. Thirty six male rats were divided into six groups of six each: the first group used as a control group. Group II given both vitamin E (400 mg/kg) of diet and selenium (Se) (1 mg/L) in their drinking water. Group III given silver as silver nitrate ($AgNO_3$) (20 mg/L). Group IV given vitamin E and $AgNO_3$. Group V given both $AgNO_3$ and selenium. Group VI given $AgNO_3$, vitamin E and Se. The animals were in the same exposure conditions for 3 months. According to the results which have been obtained; there was an increase in serum lactate dehydrogenase (LDH), lipase activities and cholesterol level, a decrease in serum total protein, calcium and alkaline phosphatase (ALP) activity in Ag-intoxicated rats. Moreover, the findings showed that $Ag^+$ ions affected antioxidant defense system by decreasing superoxide dismutase (SOD) activity and increasing vitamin E concentration with a high level of malondialdehyde (MDA) in brain tissue. The histological examination also exhibited some nervous tissue alterations including hemorrhage and cytoplasm vacuolization. However, the co-administration of selenium and/or vitamin E ameliorated the biochemical parameters and restored the histological alterations. In conclusion, this study indicated that silver could cause harmful effects in animal body and these effects can be more toxic in high concentrations or prolonged time exposure to this metal. However, selenium and vitamin E act as powerful antioxidants which may exercise adverse effect against the toxicity of this metal.

• Transactions of the Korean Society of Machine Tool Engineers
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• 제16권5호
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• pp.1-6
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• 2007

This paper presents a new experimental Servo-Parameter tuning technique for a 6-axes articulated robot manipulator, especially considering robot's dynamics. First of all, investigation for proportional gain of velocity control loop by using a Dynamic Signal Analyzer(DSA) is performed. Using the FUNCTION characteristic of DSA based on the Bode plot, the Bode plot of open loop transfer function can be obtained. In turn, the integral gain of a servo controller can be found out by using the integration time constant extracted from the Bode plot of open loop transfer function. In the meanwhile, the positional gain of the servo controller can be obtained by using the Bode plot of the closed loop transfer function. Using the experimental gain tuning technique proposed in this paper, the testing linear motion of DR6-II robot has been shown to be more accurate rather than the motion with a conventional(empirical) gain tuning technique in Doosan Mecatec Co., Ltd., by improving the dynamic response of the robot as well as synchronizing each joint velocity according to the positional command of an end-effector.

• Journal of the Institute of Electronics Engineers of Korea SP
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• 제39권1호
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• pp.70-76
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• 2002

In this paper, we proposed a personal identification algorithm using the iris region which has discriminant features. First, we acquired the eye image with the black and white CCD camera and extracted the iris region by using a circular edge detector which minimizes the search space for real center and radius of the iris. And then, we localized the iris region into several circles and extracted the features by filtering signals on the perimeters of circles with one dimensional Gabor filter We identified a person by comparing ,correlation values of input signals with the registered signals. We also decided threshold value minimizing average error rate for FRR(Type I)error rate and FAR(Type II)error rate. Experimental results show that proposed algorithm has average error rate less than 5.2%.

• Journal of the Korean Society of Environmental Restoration Technology
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• 제16권1호
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• pp.171-180
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• 2013

As the second-largest 1st degree of ecological zone in Kangwon Province, Pyeongchang County is expected to play an important role in expanding the protected areas of the Republic of Korea. However, Pyoungchang County is expected to experience an increase in demand for development due to the 2018 Winter Olympics. Problems related to various stakeholders and limited budget will arise regarding the issue of expanding the protected areas. In this study, in order to effectively control these problems, we designed expansion plans for the 1st degree ecological zoning map areas and the observed data of threatened species I and II in Pyoungchang County by using the MARXAN Software. As for the methods, we first set the planning units(PUs) for the spatial analysis. The PUs include boundary length, land cost, land status, etc. Then, we made the input data by controlling the conservation features, BLM(Boundary Length Modifier) and iteration numbers. There are two measures for the establishment of the protected areas, one of which only concerns with the ecological priority, and the other with combining the land cost on forest. The one illustrated shows that the larger patches that include the conservation feature was selected as a candidate of the protected areas. The other one presented shows that inexpensive land cost areas were selected. As this study produces visual results and enables an efficient application of various values in selecting protected areas, we believe that it will be useful to various stakeholders in spatial decision-making process.

• Korean Journal of Veterinary Service
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• 제30권1호
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• pp.51-66
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• 2007

The purpose of this study was to evaluate the effect of a subsequent infection of porcine reproductive and respiratory syndrome(PRRS) virus to pigs with A pleuropneumonia. Twenty three 7-week-old commercial pigs were infected intratracheally with PRRS virus and/or A pleuropneumoniae serotype 5. Serum antibody titers were examined by an enzyme-linked immunosorbent assay(ELISA) and proportion of porcine leukocyte subpopulations in peripheral blood was examined by flow cytometry. In this experiment, antibodies against PRRS virus and A pleuropneumoniae were detected at 2 weeks and 1 week postinfection and the number of antibody positive pigs were gradually increased. And in proportion to leukocyte subpopulations in peripheral blood of pigs infected with A pleuropneumoniae compared with pigs administrated with saline, the proportion of PoCD4 and N cells were increased(P<0.1). Furthermore, in proportion to leukocyte subpopulations in peripheral blood of pigs infected with PRRS virus followed by A pleuropneumoniae compared with pigs administrated with saline, the proportion of MHC class II, PoCD4 and B cells were significantly increased(P<0.1). The results indicated that dual infection with PRRS virus and A pleuropneumoniae induced the stronger immune responses associated with macrophages and Th cells in pigs than single infection with PRRS virus or A pleuropneumoniae.

• Korean Journal of Veterinary Research
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• 제55권4호
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• pp.233-240
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• 2015

Although the effects of the rice bran have recently been investigated, there is no information regarding platelet physiology available. However, it is well known that fermented natural plants have a beneficial effect on cardiovascular diseases. Therefore, this study was conducted to investigate whether fermented rice bran extract (FRBE) with several plants (Artemisia princeps, Angelica Gigantis Radix, Cnidium officinale, and Camellia sinensis) affected agonist-induced platelet aggregation, and if so, what the underlying mechanism of its activity was. We performed several experiments, including in vitro platelet aggregation, intracellular calcium concentration and adenosine triphosphate release. In addition, the activation of integrin ${\alpha}_{II}b{\beta}3$ was determined using fibrinogen binding. Thrombus formation was also evaluated in vivo using an arterio-venous shunt model. The FRBE inhibited collagen-induced platelet aggregation in a concentration-dependent manner. FRBE significantly and dose dependently attenuated thrombus formation using rat arterio-venous shunt. FRBE suppressed the intracellular calcium mobilization in collagen-stimulated platelets. We also found that FRBE inhibited extracellular stimuli-responsive kinase 1/2, p38-mitogen-activated protein kinases and c-Jun N-terminal kinase phosphorylation. These results suggested that FRBE inhibited collagen-induced platelet aggregation, which was mediated by modulation of downstream signaling molecules. In conclusion, FRBE could be developed as a functional food against aberrant platelet activation-related cardiovascular diseases.

• The Bulletin of The Korean Astronomical Society
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• 제43권1호
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• pp.66.1-66.1
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• 2018

Turbulence is a phenomenon which largely determines the density and velocity fields in molecular clouds. Turbulence can produce density fluctuation which triggers a gravitational collapse, and it can also produce a non-thermal pressure against gravity. Therefore, turbulence controls the mode and tempo of star formation. However, despite many years of study, the properties of turbulence remain poorly understood. As part of the Taeduk Radio Astronomy Observatory (TRAO) Key Science Program (KSP), "apping Turbulent properties In star-forming MolEcular clouds down to the Sonic scale (TIMES; PI: Jeong-Eun Lee)", we have mapped two star-forming clouds, the Orion A and the ${\rho}$ Ophiuchus molecular clouds, in 3 sets of lines (13CO 1-0/C18O 1-0, HCN 1-0/HCO+ 1-0, and CS 2-1/N2H+ 1-0) using the TRAO 14-m telescope. We aim to map entire clouds with a high-velocity resolution (~0.05 km/s) to compare turbulent properties between two different star-forming environments. We will present the preliminary results using a statistical method, Principal Component Analysis (PCA), that is a useful tool to represent turbulent power spectrum.

• Journal of the Korea Convergence Society
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• 제9권9호
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• pp.53-60
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• 2018

In order to manage energy efficiency by analyzing the amount of energy, it would determine the nature of the factors involved in the energy utilization. Therefore, accurate measurement of the energy consumption data is an important factor in the energy management. In this study, we are aware of the importance of the data measurement, and proposes the accuracy assessment of electric energy monitoring system. According to conventional statistical methods it is proceeded as follows; i)the measurement error value would be determined by a random variable, ii) setting the confidence interval to consider the distribution of the statistic and determines the confidence level of the measurement accuracy. And using the t-distribution CDF is used to facilitate even small sample data.

• Transactions of the Korean hydrogen and new energy society
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• 제25권2호
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• pp.105-113
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• 2014

Performance tests on $Ni/Ce-ZrO_2/Al_2O_3$ catalysts with additives (MgO, $La_2O_3$) were investigated in the combined reforming processes (SCR, ATR, TRM) in order to produce hydrogen and carbon monoxide (it is called "syngas".). The catalyst characterization was conducted using the BET surface analyzer, X-ray diffraction (XRD), SEM, TPR and TGA. The combined reforming process was developed to adjust the syngas ratio depending on the synthetic fuel (methanol, DME and GTL) manufacturing processes. Ni-based catalysts supported on alumina has been generally recommended as a combined reforming reaction catalyst. It was found that both free NiO and complexed NiO species were responsible for the catalytic activity in the combined reforming of methane conversion, and the $Ce-ZrO_2$ binary support employed had improved the oxygen storage capacity and thermal stability. The additives, MgO and $La_2O_3$, also seemed to play an important role to prevent the formation of the carbon deposition over the catalysts. The experimental results were compared with the equilibrium data using a commercial simulation tool (PRO/II).