• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.41-55
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• 2015

Monitoring of $CO_2$ release through the ground surface is essential to confirm the safety of carbon storage projects. We conducted a feasibility study of the multi-channel surface-soil $CO_2$-concentration monitoring (SCM) system as a soil $CO_2$ monitoring tool with a small scale injection test. The background concentrations showed the distinct diurnal variation. The negative relation of $CO_2$ with temperature and the low $CO_2$ concentrations during the day imply that surface-soil $CO_2$ depends on photosynthesis and respiration. After 4.2 kg of $CO_2$ injection (1 m depth for 29 minutes), surface-soil $CO_2$ concentrations increased in the all five chambers, which were located less than 2.8 m of distance from each other. The $CO_2$ concentrations seem to be recovered to the background around 4 hours after the injection ended. To determine the leakage, the data from Chamber 2 and 5 with low increase rates were used for statistical analyses. Coefficient of variation for 30 minutes ($CV_{30min}$.) is efficient to determine a leakage signal, with reflecting the fast change in $CO_2$ concentrations. Consequently, SCM and $CV_{30min}$ could be applied for an efficient monitoring tool to detect $CO_2$ release through the ground surface. Also, this study provides ideas for establishing action steps after leakage detection.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.146-149
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• 2013

For in recently years, global cellular network service is changing rapidly to 4G. However, the fast introducing of 4G has been going with not enough research about security threat, it could be many kind of vulnerability. Therefore the research about security threat on 4G network is ongoing in external countries, but not sufficient in domestic. particularly in domestic situation of rapidly increased subscribers, The security threats which are hindering stability and usability could make a fatal effect on many users. 4G network should be considered about the feature of mobile network to protect 4G network stable. Mobile network has limited radio resources, it releases the radio resource which is not used in selected time and reallocate when detected the data transmission. Many signaling messages are transferred in the network entities to allocate or release the radio resource. In this paper, it will be introduced the technology to detect signaling DoS traffic hindering the stability and usability of network entities managing the radio resources by huge signaling message from the repetitive wireless connection/release message.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.1
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• pp.32-37
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• 2017

Cis-(1S,4S)-4-(3,4-dichlorophenyl)-1,2,3,4-tertrahydro-N-methyl-1-naphthalenamine (sertraline) hydrochloride from among selective serotonin reuptake inhibitors (SSRIs) is a treatment of major depression. For the differential diagnosis by metabolizing serotonin in a patient with neurological disorders, the radiolabeled $^{11}C$-sertraline was developed for non-invasive positron emission tomography in living brain and use the evaluation of new drug for SSRIs. We release the results of a fast and easy radiolabeling method applied a one-step loop method with $[^{11}C]CH_3OTf$ for routine clinical applications of $^{11}C$-sertraline. 1 mg of a precursor for $^{11}C$-sertraline in 0.1 mL DMF and $5{\mu}L$ of 1N NaOH, were injected into the loop of semi-prep high-performance liquid chromatography (HPLC). $[^{11}C]CH_3OTf$ was passed through the loop at room temperature (RT). The $^{11}C$-sertraline was separated by the semi-preparative HPLC. $^{11}C$-sertraline was eluted at 28.0 min was collected and evaluated by analytical HPLC and mass spectrometer. The total radiolabeling efficiency of $^{11}C$-sertraline was $30.7{\pm}8.7%$. The specific activity was $64.8{\pm}51.4GBq/{\mu}mol$. The radiochemical and chemical purities were higher than 99%. The mass spectrum of the product showed m/z peaks at 307.1 (M+1), indicating the mass of sertraline. By the one-step loop method with $[^{11}C]CH_3OTf$, $^{11}C$-sertraline could be quickly and easily prepared for clinical application.

• Fire Science and Engineering
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• v.31 no.5
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• pp.28-36
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• 2017

In this work, the effects of fire curtain and forced smoke ventilation on smoke spread to auditorium in the stage fire of theater were investigated using the Fire Dynamics Simulator (FDS). For the stage of 31 m (Width)${\times}$34 m (Depth)${\times}$32 m (Height) in dimension, the fast growth fire condition with 10 MW of heat release rate was applied. The forced smoke ventilation was set based on the National Fire Safety Code (NFSC) and previous research. The gap distances between the fire curtain and proscenium wall was established to be 0 m and 0.5 m. When the fire curtain was attached completely to the proscenium wall without any gap, no smoke spread from the stage to the auditorium occurred, independent of forced smoke ventilation. When the gap distance between the fire curtain and proscenium wall was 0.5 m, the smoke layer in the stage descended to the lower height from the bottom than the case without the fire curtain, which was because the smoke spread to auditorium was impeded by the fire curtain. Under the same fire curtain condition, the case with the forced smoke ventilation led to decreasing the mass flow rate of outflow through the gap between the fire curtain and proscenium wall, as compared to the case without the forced smoke ventilation. Based on this study, it was confirmed that the fire curtain and forced smoke ventilation were the effective tools to hold down the smoke spread to the auditorium in the stage fire of theater.

• Journal of Korea Trade
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• v.27 no.5
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• pp.113-136
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• 2023

Purpose - Global production chains and their impacts on economic growth have drawn extensive attention from researchers. Close relationships among global production chains, export and economic growth have been illuminated, as evidenced by the fast and stable economic growth of East Asian economies. These economies perform various roles within global production chains using offshoring, in which the impact of import on domestic gross output is as strong as that of export. The impact of import on economic growth would depend on whether imported inputs substitute or complement domestic inputs production, which is likely to vary according to individual countries' functions within global production chains. The economic growth of concerned countries would also be diverse. However, little attention has been paid to the impact brought by imports compared to its significance. Design/methodology - The principal methodology used in this paper is structural decomposition analysis (SDA), widely chosen to elucidate the impact of various factors on domestic gross output using input-output tables. This paper extracts trade data of six Asian economies from the World Input-Output Database (WIOD) 2016 release that covers 43 countries for the period 2000-2014. The extracted data is then categorised into 37 sectors. First, this paper calculates the Feenstra-Hanson Offshoring Index (OSI) of each country. It then applies SDA to measure the changes in each economy's gross output, export, import input coefficients, and domestic input coefficients. Finally, after taking the first difference from pooled time-series data, it estimates the correlations between imported input coefficients and OSI using the ordinary least square (OLS) method. Findings - The main findings of this paper can be summarised as follows. Firstly, all six countries have increasingly engaged in global production chains, as evidenced by the growing size of OSI. Secondly, there are negative correlations in five countries except Japan, with sectoral differences. Thirdly, changes in import input coefficients are not negative in all six countries, indicating that offshoring does not necessarily substitute for domestic inputs production but does complement it and, therefore, fosters their economic growth. This is observed in China, Indonesia, Korea and Taiwan. Offshoring has led to an increase in the use of imported inputs, which has, in turn, stimulated domestic inputs production in these countries. Originality/value - While existing studies focus on the role of export in evaluating the impact of participating global production chains, this paper explicitly examines the unexplored impact of import on domestic gross output by considering both the substitution and the complementary effect, using the WIOD. The findings of this paper suggest that Asian economies have achieved fast and stable economic growth not only through successful export management but also through effective import management within global production chains. This paper recommends that the Korean government and enterprises carefully choose offshoring strategies to minimise disruption to domestic production chains or foster them.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.9C
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• pp.842-852
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• 2002

The fast advance in the VoIP technologies gives a rich opportunity to create different kind of VoIP applications such as IP telephony services. The application level call signaling protocols such as ITU-T H.323 and IETF SIP provide the communication functions of end-to-end call setup and release. Currently, there is a lot of H.323 based VoIP products in the market, however SIP is considered as a suitable protocol for supporting applications in IP environments, so SIP based VoIP products and services begin to appear. In this paper, firstly we present the characteristics of some possible SIP based applications and describe the design and implementation of a VoIP example service named PC-to-PC Internet telephony service using the developed SIP network components. The PC-to-PC Internet telephony service and User Agent are developed in MS window 98/2000 using visual C/C++, and Proxy server and Registrar in Linux 7.0 using C, respectively.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.135-147
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• 2004

This study was conducted to investigate the technical factors of Lu Yu Fu vault actually performed by three men gymnasts participated in artistic gymnastics competition of 2003 summer Universiade in Daegu through the DLT method of three dimensional cinematography. To analyze these vaults, the instant events of Lu Yu Fu were set in the board touchdown(BTD), the board takeoff(BTO), the horse touchdown(HTD), the horse takeoff(HTO), the peak height(PH), the mat touchdown(MTD) respectively and the phases of that vault were set in the board contact(BC), the preflight(PRF), the horse contact(HC), the postflight(POF), the grounding on mat(GM) respectively After calculating the performance times, the CG displacement velocity, the kinetic energy impulse reaction force moment arm torque at the horse, the released angle piked angle addressed angle, the angular momentum angular velocity of whole body in x axis, and the horizontal displacement between the feet and CG, the following conclusions were reached. To perform the better Lu Yu Fu vault, a gymnast must have the large horizontal velocity of whole body with fast run-up, decrease the duration time and the horizontal vertical displacement of whole body in PRF, have the enough time to judge the correct magnitude and direction of force to brake or push the horse so as to lengthen the HC duration time at any cost. Also it is desirable to increase the horizontal vertical displacement of whole body in POF if possible, maintain the adequate piked position to decrease the angular velocity of whole body in x axis, prepare the grounding on mat previously and delay the release of the hand from the body to keep the angular momentum.

• The Korean Journal of Pharmacology
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• v.26 no.2
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• pp.113-120
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• 1990

Influences of trigger calcium on myocardial contraction from several sources were investigated on the frequency reduction-induced changes of contraction in rat left atria driven by electrical field stimulation. Rat atria elicited characteristic three phase-changes according to frequency reduction: the first rapid rise in twitch tension, the second transient fast decrease in tension and the third maintenance of twitch tension at about 200% of resting tension during high frequency. Caffeine treatment enormously suppressed the frequency reduction-induced twitch tension increase. The atrial contraction during high frequency vanished after verapamil treatment. But, during low frequency, atrial contraction revived in the presence of verapamil. Ouabain treatment and sodium depletion in superfusing solution abolished the characteristic second phase with slow frequency. These results suggest that slow calcium channel is an indispensable calcium entry route and calcium release from sarcoplasmic reticulum is an major source for trigger calcium in cardiac contraction. And sodium-calcium exchange has a modulatory roles in the regualtion of trigger calcium according to the changes of intracellular sodium concentration.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.518-525
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• 2016

This paper presents the characteristics of non-fundamental multi-mode combustion instability and the effects of high-harmonic components on the Rayleigh criterion. Phenomenological observations of multi-harmonic-mode dynamic pressure waves regarding the intensity of harmonic components and the source of wave distortion have been explained by introducing examples of second- and third-order harmonics at various amplitudes. The amplitude and order of the harmonic components distorted the wave shapes, including the peak and the amplitude, of the dynamic pressure and heat release, and consequently the temporal Rayleigh index and its integrals. A cause-and-effect analysis was used to identify the root causes of the phase delay and the amplification of the Rayleigh index. From this analysis, the skewness of the dynamic pressure turned out to be a major source in determining whether multi-mode instability is driving or damping, as well as in optimizing the combustor design, such as the mixing length and the combustor length, to avoid unstable regions. The results can be used to minimize errors in predicting combustion instability in cases of high multi-mode combustion instability. In the future, the amount of research and the number of applications will increase because new fuels, such as fast-burning syngases, are prone to generating multi-mode instabilities.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.1028-1037
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• 2015

Unique organoleptic characteristics such as rich flavors and chewy texture contribute to the higher popularity of native chicken in many Asian areas, while the commercial broilers are well-accepted due to their fast-growing and higher yields of meat. Sensory attributes of foods are often used to evaluate food eating quality and serve as references during the selection of foods. In this study, a three-phase descriptive sensory study was conducted to evaluate the sensory attributes of commercial broiler (BR) and Taiwan native chicken (TNC) breast meat, and investigate correlations between these sensory attributes and instrumental measurements. The results showed that for the first bite (phase 1), TNC meat had significantly higher moisture release, hardness, springiness, and cohesiveness than BR meat. After chewing for 10 to 12 bites (phase 2), TNC meat presented significantly higher chewdown hardness and meat particle size, whereas BR meat had significantly higher cohesiveness of mass. After swallowing (phase 3), TNC meat had higher chewiness and oily mouthcoat and lower residual loose particles than BR meat. TNC meat also provided more intense chicken flavors. This study clearly demonstrates that descriptive sensory analysis provides more detailed and more objectively information about the sensory attributes of meats from various chicken breeds. Additionally, sensory textural attributes vary between BR and TNC meat, and are highly correlated to the shear force value and collagen content which influence meat eating qualities greatly. The poultry industry and scientists should be able to recognize the sensory characteristics of different chicken meats more clearly. Accordingly, based on the meat's unique sensory and physicochemical characteristics, future work might address how meat from various breeds could best satisfy consumer needs using various cooking methods.