• Journal of Soil and Groundwater Environment
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• v.6 no.4
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• pp.41-50
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• 2001

The use of clay has been the favored method of reducing or eliminating hazardous contaminants in the leachate from landfills. But, neither natural clays nor organoclays modified with surfactants are able to effectively sorb both heavy metals and organic contaminants. Therefore, the objective of this study is to determine the optimal amount of surfactant added on the clay mineral to effectively remove both of them. For this purpose, Na-Bentonite as the natural clay, and hexadecyltrimethylammonium (HDTMA) as the cationic surfactant were used, Chlorobenzene and lead ($Pb^{2-}$) were selected as representative contaminants. Experimental result showed that chlorobenzene sorption increased with increasing HDTMA to bentonite, ratios. On the contrary, the removal rate of lead decreased as the amount of HDTMA increased. The removal of chlorobenzene was influenced by the amount of HDTMA added to the bentonites rather than initial concentration of chlorobenzene, but the removal of lead was much more influenced by the initial concentration of lead. The adsorption of lead was not affected by chlorobenzene, and vice versa. The competitive sorption between the heavy metal and the organic contaminant was not present.

• Korean Journal of Veterinary Research
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• v.47 no.3
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• pp.273-279
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• 2007

Swine influenza is an acute, infectious respiratory disease caused by type A influenza viruses in pigs. In the previous studies, serological surveys have indicated the presence of H3N2 swine influenza virus (SIV) since 1995 in Korea. And the percentage of the antibody-positive rate was 39.12% in the survey determining the prevalence of H1N1 SIV antibodies in 2002. The purpose of this study was therefore to investigate the sero-prevalence of SIV regard to the age of the pig and the season between June 2004 and May 2005. In this study, a total of 932 sera were used. These sera were randomly selected from blood samples, which were submitted to Department of Veterinary Pathology, Kangwon National University and Department of Veterinary Virology, Seoul National University from June 2004 to May 2005. These sera have been tested by ELISA test kit (IDEXX Lab, USA) for the SIV H3N2, H1N1 respectively. SAS version 9.1 was used for the statistical analysis based on the age of the pig and the season. The overall sero-prevalence of the antibody against H3N2 SIV was 20.82% (194/932). The overall sero-prevalence of the antibody against H1N1 SIV was 37.23% (347/932). The overall dual sero-prevalence of the antibody against H3N2 and H1N1 SIV was 10.62% (99/932). H3N2 has significant difference in statistically regarding the age of the pig and the season (p<0.0001). H1N1 has significant difference in statistically regarding the age of the pig (p<0.0001) but has not significant difference in statistically regarding the season (p=0.5882).

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.20.1-20.1
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• 2011

We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual-channel imaging spectrograph (S channel 900-1150 ${\AA}$, L channel 1350-1750 ${\AA}$, ${\lambda}/{\Box}{\lambda}$ ~ 550) with large image fields of view (S: $4^{\circ}.0{\times}4'.6$, L: $7^{\circ}.5{\times}4'.3$, angular resolution 5'-10') optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) was observed with a scanning survey mode when it was located around the perihelion between 8 and 15 May 2004. Several important emission lines were detected including S I (1425, 1474 ${\AA}$), C I (1561, 1657 ${\AA}$) and several emission lines of CO $A1{\cap}-X1{\sum}+$ system in the L channel. We estimated QCO = ($2.58\;{\pm}\;0.64)\;{\times}\;1028$ s-1 from the production rate of CO 1510 ${\AA}$. We obtained L-channel image which have map size of $5^{\circ}{\times}5^{\circ}$. The image was constructed for the wavelength band of L-channel (1350-1750 ${\AA}$).We also obtained radial profile of S I, C I, CO with line fitting from central coma.

• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.107-119
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• 2005

The Mobile IP has evolved from providing mobility support for portable computers to support wireless handheld devices with high mobility patterns. The Mobile IP secures mobility, but does not guarantee security, In this paper, the Mobile IP has been adapted to allow AM protocol that supports authentication, authorization and accounting for authentication and collection of accounting information of network usage by mobile nodes, For this goal, we propose a new security handoff mechanism to intensify the Mobile IP security and to achieve fast handoff. In the proposed mechanism, we provide enough handoff achievement time to maintain the security of mobile nodes, According to the analysis of modeling result, the proposed mechanism composed the basic Mobile IP along with AM protocol is up to about $60\%$ better in terms of normalized surcharge for the handoff failure rate that considers handoff time.

• Journal of Labour Economics
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• v.40 no.2
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• pp.31-68
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• 2017

This study examined the moonlighting behavior in Korea, to which relatively less attention has been paid. Based on the wage earners of 25 to 65 year old married, the results show that about 1.4% of the sample have dual jobs, working very long hours, on average 60 hours for a week combining both the primary job and the secondary job. The results of the fixed effects logit model on the moonlighting participation indicate that the wage rate and the hours of work in the primary job have a negative effect on moonlighting participation while the insecurity of the primary job appears to lead to a higher probability of taking a secondary job. The results of the moonlighting hours analysis suggest that hours worked in the primary job have a negative effect on moonlight hours while the wage of the primary job does not appear to have any significant effect on moonlighting hours. Interestingly enough, the wage of the secondary job appears to have a negative impact on moonlighting hours, which might be very plausible considering the long working hours moonlighters are engaged in.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.9-15
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• 2017

Natural gas fuel has known to be very promising in terms of abundancy and economic value. Therefore it is widely treated as research topics in a variety field of production, storage and utilization. Natural gas has become one of the major sources for the power generation by using internal combustion engines(ICE). Development of natural gas fuel injection device should be preceded to realize a reliable natural gas fuel supply system for a MW class power generation reciprocating ICE. In this research, an injection valve which consists of solenoid and body part with a moving plate was designed and its dynamic performance was experimented in the engine-like environment. Displacement length and diameter of an armature and diameter of a solenoid coil were tested at former study. In this research the effect of materials of solenoid core, size of main housing inlet and supply gas pressure are examined.

• The Plant Pathology Journal
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• v.33 no.6
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• pp.608-613
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• 2017

The full-length sequence of a new isolate of Apple chlorotic leaf spot virus (ACLSV) from Korea was divergent, but most closely related to the Japanese isolate A4, at 84% nucleotide identity. The full-length cDNA of the Korean isolate of ACLSV was cloned into a binary vector downstream of the bacteriophage T7 RNA promoter and the Cauliflower mosaic virus 35S promoter. Chenopodium quinoa was successfully infected using in vitro transcripts synthesized using the T7 promoter, detected at 20 days post inoculation (dpi), but did not produce obvious symptoms. Nicotiana occidentalis and C. quinoa were inoculated through agroinfiltration. At 32 dpi the infection rate was evaluated; no C. quinoa plants were infected by agroinfiltration, but infection of N. occidentalis was obtained.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.81-91
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• 2013

A novel design process of a parallel multi-flow type air-cooled condenser of a dual-loop waste heat recovery system with Rankine steam cycles for improving the fuel efficiency of gasoline automobiles has been investigated focusing on reduction of the pressure drop inside the micro-tubes. The low temperature condenser plays a role to dissipate heat from the system by condensing the low temperature loop working fluid sufficiently. However, the refrigerant has low evaporation temperature enough to recover the waste from engine coolant of about $100^{\circ}C$ but has small saturation enthalpy so that excessive mass flow rate of the LT working fluid, e.g., over 150 g/s, causes enormously large pressure drop of the working fluid to maintain the heat dissipation performance of more than 20 kW. This paper has dealt with the scheme to design the low temperature condenser that has reduced pressure drop while ensuring the required thermal performance. The number of pass, the arrangement of the tubes of each pass, and the positions of the inlet and outlet ports on the header are most critical parameters affecting the flow uniformity through all the tubes of the condenser. For the purpose of the performance predictions and the parametric study for the LT condenser, we have developed a 1-dimensional user-friendly performance prediction program that calculates feasibly the phase change of the working fluid in the tubes. An example is presented through the proposed design process and compared with an experiment.

• The Korean Journal of Pharmacology
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• v.15 no.1_2 s.25
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• pp.45-56
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• 1979

With a view to searching after a new antihypertensive or hypotensive agents in the botanical crude plants, authors intended to reevaluate several natural products caltivated in Korea. This experiment was undertaken to compare pharmacogical actions of Machilus thunbergii Siebold et Zuccarini with those of Magnolia obovata Thunberg in anesthetized rats and in normal mice. Machilus thunbergii Sieb. et Zucc., a tree belonging to the Lauraceae family, is caltivated at Ull-ung Do, and their cortecies have been used as folk medicine mingled with those of Magnolia obovata Thunberg. These two cortecies have teen also applied in chinese medicine, it was advocated that these cortecies exerted good therapeutic effects on gastritis, convulsive abdominal pain, nausea, vomiting and urinary tract disorders. Therefore, we intended to determine the pharmacological action of two palnt of different family each other, especially their effects on blood pressure and heart rate, and also their mechanism of action were observed. We studied their action with extracts of hexane(MTHE), ether(MTEE), methanol(MTME) and water(MTWE) from Machilus thunhergii Sieb. et Zucc., and also fractionations of methanol(MOME), chloroform(MOCE) and water(MOWE) from Mapolia obovata Thunberg. The results of this experiment were as follows; 1) MTME, when intravenously administered to rats, elicited the significant hypotensive responses dependent on the administered dosage. 2) MOWE was also exhibited the hypotensive effect dependent on the treated dose. 3) Depressor effect of MTME was blocked by pretreatment with hexamethonium. 4) The hypotensive response of MOWE was blocked by pretreatment with hexamethonium or hrdralazine. 5) HTME and MOWE were also observed the anticonvulsive effect and sedative effect. These results suggested that MTME may induce the hypotensive response via central sympathetic effect, but the site of action in brain are not clarified, and the hypotensive effect of MOWE may be due to dual mechanism of central sympathetic action and direct vasodilation of blood vessel.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.62-66
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• 2017

In this paper, we present the development of communication and data processing strategy for the electromagnetic wave precipitation gauge system. The electromagnetic wave precipitation gauge system is a small system for deriving area rainfall rates within 1 km radius through dual polarization radar observation at 24GHz band. It is necessary to take consider for measurement of accurate precipitation under limited computing resources originating from small systems and to minimize the use of network for the unattended operation and remote management. To overcome computational resource limitations, we adopted the fuzzy logic for quality control to eliminate non-precipitation echoes and developed the method by weighted synthesis of various rain rate fields using multiple radar QPE formulas. Also we have designed variable data packets rules to minimize the network traffic.