• Korean Journal of Medicinal Crop Science
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• v.17 no.4
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• pp.233-237
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• 2009

Astragalus membranaceus has a long history of medicinal use in Chinese herbal medicine. It has been shown to have immunostimulant, tonic, antioxidant, antiperspirant, diuretic, anti-diabetic, expectorant properties, and a supplementary medicine during cancer therapy. In this study, we investigated the effect of anti-oxidation of Astragalus membranaceus root extract. The anti-oxidative activities of water, 80% methanol, and 100% methanol extracts from Astragalus membranaceus were analyzed by DPPH free radical scavenging activity, Superoxide dismutase-like activity, reducing power, and crude ash. The water extract demonstrated to be more effective than methanol extract for a DPPH radicals scavenging activities and reducing power. Superoxide dismutase-like activity showed higher efficiency in 80% methanol extract. Our results indicate that Astragalus membranaceus extracts could be used as a source of antioxidant ingredients in the food industry.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.166-171
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• 2004

Since early 1950's fracture mechanics has brought significant impact on structural integrity assessment in a wide range of industries such as power, transportation, civil and petrochemical industries, especially in nuclear power plant industries. For the last two decades, significant efforts have been devoted in developing defect assessment procedures, from which various fitness-for-purpose or fitness-for-service codes have been developed. From another aspect, recent advances in IT (Information Technologies) bring rapid changes in various engineering fields. IT enables people to share information through network and thus provides concurrent working environment without limitations of working places. For this reason, a network system based on internet or intranet bas been appeared in various fields of business. Evaluating the integrity of structures is one of the most critical issues in nuclear industry. In order to evaluate the integrity of structures, a complicated and collaborative procedure is required including regular in-service inspection, fracture mechanics analysis, etc. And thus, experts in different fields have to cooperate to resolve the integrity problem. In this paper, an internet-based cooperative system for integrity evaluation system which adapts IT into a structural integrity evaluation procedure for reactor pressure vessel is introduced. The proposed system uses Virtual Reality (VR) technique, Virtual Network Computing (VNC) and agent programs. This system is able to support 3-dimensional virtual reality environment and to provide experts to cooperate by accessing related data through internet.

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.32-40
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• 2013

This study was objected to evaluate the potential impact on the groundwater environment of the coal bottom ash used as fill materials on the land surface. From four coal-fired power plants, bottom-ashes were collected and analyzed through sequential extraction and column leaching tests following the meteoric water mobility procedure. The column tests shown leaching heavy metals including Pb, As, B, Cu, Zn, Mn, Ni, Ba, Sr, Sb, V, Cr, Mo, and Hg. The relatively high concentrations of B, Sr, Ba, and V in leachate were attributed to both the higher concentrations in the bottom ash and the relatively higher portion of leachable state, sorbed state, of metals. Bottom-ash samples from the D-plant only show high leaching potential of sulfate ($SO_4$), probably originated from the coal-combustion process, called the Fluidized Bed Combustion. Consequently, to manage recycling bottom ashes as fill materials, an evaluation system should be implemented to test the leaching potentials of metals from the ashes considering the absolute amount of metals and their state of existence in ashes, and the coal-combustion process.

• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.915-920
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• 2005

This paper is aimed to survey threats of employment in Korean shipping industry, review the importance and speciality of women power, and diagnose its sexual discrimination and the actual condition of that. Therefore, this survey research will provide substantial data concerning issues in the employment and the significance of women power in the shipping firms, and give solutions for problems in managing women resource in the shipping companies. In conclusion, this study is able to identify the fact that threats of female employment are social costumes and prejudice, the speciality of work in shipping firms, and the shortage of occupations for women. This result of survey shows that the exclusive recognition about female employment in unique shipping industry should be revised as soon as possible.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.1
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• pp.75-88
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• 2004

Condor is a distributed batch system for sharing the workload among the computers connected by a network. Condor distributed system was developed on the basis that every machine in a Condor pool is always connected by a network to run a Condor Job. Due to advances in wireless communication and mobile computing technology, conventional distributed computer systems can now include “mobile” clients as well as “fixed” clients. Moreover, mobile users want to lower their power consumption by off-loading potentially power and resource consuming jobs. In this paper, we describe the design and implementation of mobile interface for mobile clients in Condor distributed batch system. The main purpose of this work is to enable users on mobile computers to interact with Condor environment any time anywhere regardless of their connection to a Condor pool. The mobile Condor distributed system also aims to provide mobile users the same Condor services without making any significant changes to the existing Condor system.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.55-60
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• 2018

In this study investigated the Controlled Low Strength Materials using coal ash and steel slag(KR slag) as the main material in the thermal power plant classified as waste resource. Bottom ash and KR slag are mixed at a ratio of 7: 3 to expand the use of industrial by-products through carbonate($CO_2$-fixation) reactions and inhibit the exudation of heavy metals. The results showed that the water content increased as the content of bottom ash increased. It was confirmed that as the powder content increased, the bleeding ratio decreased. Also, as the content of one kind of ordinary portland cement (OPC) decreased, activation of hydration reaction decreased and compressive strength decreased. However, when the mixed composition is appropriately adjusted, the compressive strength of 2.0 MPa required for the controlled low-strength material can be satisfied.

• Journal of Korea Technology Innovation Society
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• v.14 no.4
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• pp.1050-1072
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• 2011

It is well known that international cooperation is considerably more difficult because of the difference of interests, level of technology of the partners, social and culture as well as various macro-environmental conditions. This case study aims to investigate the success factors of international R&D collaboration between two firms. For it, an in-dept interview was conducted to the Etri-Microsoft Information Security Lab. A comprehensive research on theories, such as resource-based theory, network theory, relationship marketing theory and market power perspective was done as well. The results show clear objectives, communications based on trust, core competence on which the counterpart can rely on, consideration on the government decision process as well as the environment are important for success.

• Korean Journal of Medicinal Crop Science
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• v.24 no.1
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• pp.31-37
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• 2016

Background : We studied the anti-oxidant activity and anti-inflammatory effects of Spiraea fritschiana Schneid extract (SFSE). Methods and Results : The SFSE was prepared using methanol and was evaluated for its total phenol and flavonoid content, DPPH (1,1-diphenyl-2-picrylhydrazyl) free-radical scavenging activity, reducing power, and effect on nitric oxide (NO) production, and cell viability by using real-time polymerase chain reaction (PCR). The total phenol content was $212.78{\mu}g{\cdot}galli$c acid equivalent (GAE)/mg and the total flavonoid content was $66.84{\mu}g{\cdot}quercetin$ equivalent (QE)/mg. The extract showed antioxidant activity (DPPH free-radical scavenging activity) with $RC_{50}$ value of $76.61{\mu}g/m{\ell}$. The reducing power of the extract was Abs 0.58 at $250{\mu}g/m{\ell}$. Cell viability was determined using the MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. To evaluate anti-inflammatory activity, we examined the inhibitory effects on lipopolysaccharide-(LPS)-induced NO production in RAW 264.7 cells. The NO inhibition rate was 90% at $200{\mu}g/m{\ell}$ SFSE. At the same concentration, the expression of pro-inflammatory genes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 also decreased. Conclusions : Our results suggest that SFSE is a novel resource for the development of foods and drugs that possess anti-oxidant and anti-inflammatory activity.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.38-43
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• 2017

Sensor Networks (WSNs) can be defined as a self-configured and infrastructure-less wireless networks to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location or base-station where the data can be observed and analyzed. Typically a wireless sensor network contains hundreds of thousands of sensor nodes. The sensor nodes can communicate among themselves using radio signals. A wireless sensor node is equipped with sensing and computing devices, radio transceivers and power components. The individual nodes in a wireless sensor network (WSN) are inherently resource constrained: they have limited processing speed, storage capacity, communication bandwidth and limited-battery power. At present time, most of the research on WSNs has concentrated on the design of energy- and computationally efficient algorithms and protocols In order to extend the network life-time, in this paper we are looking into a routing protocol, especially LEACH and LEACH-related protocol. LEACH protocol is a representative routing protocol and improves overall network energy efficiency by allowing all nodes to be selected to the cluster head evenly once in a periodic manner. In LEACH, in case of movement of sensor nodes, there is a problem that the data transmission success rate decreases. In order to overcome LEACH's nodes movements, LEACH-Mobile protocol had proposed. But energy consumption increased because it consumes more energy to recognize which nodes moves and re-transfer data. In this paper we propose the new routing protocol considering nodes' mobility. In order to simulate the proposed protocol, we make a scenario, nodes' movements randomly and compared with the LEACH-Mobile protocol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.651-659
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• 2014

In this paper, we consider a two way relay network for ship-to-ship communications in a fleet, where two communicating ships exchange the information with the help of a multi-antenna relay ship. For the network, we propose a rate-aware three-phase analog network coding to improve the reliability of the information exchange with asymmetric rates. The proposed scheme allows low-complex implementation of the relay without channel estimation by generating an improved analog network coded signal with the orthogonally received signals from two ships by using only the received signal power at each antenna. In addition, the proposed scheme reduces outages in the data exchange at asymmetric rates by adopting a rate-aware relay power allocation, which is confirmed by evaluating the outage performance via simulation.