• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.1-5
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• 2005

While the rusty-colored root is common in ginsengs culture and, often results in a severe economic loss, the major factors have not been found. This study was focused on the determination of a potential relationship between rusty root and endophytic bacteria. The number of endophytes was $9.6\;{\times}\;10^1{\sim}1.5\;{\times}\;10^2\;cfu/g$ fw in normal ginseng roots compared to $3.7\;{\times}\;10^6{\sim}5.1\;{\times}\;10^7\;cfu/g$ fw in rusty ones. Of 31 isolates from rusty ginseng roots, twenty-four isolates repeatedly induced severe to moderate rust on root while seven isolates induced slight rust. The bacteria responsible for rusty ginseng roots were mainly Gram negative aerobic. Rust inducing bacteria were identified as Agrobacterium tumefaciens, A. rhizogenes, Burkholderia phenazinium, Ensifer adharens, Lysobacter gummosus, Microbacterium luteolum, M. oxydans, Pseudomonas marginalis, P. veronii, Pseudomonas sp., Rhizobium leguminosarum, R. tropica, Rhodococcus erythropolis, Rh. globerulus, Variovorax paradoxus on the basis of bacteriological characters and 16S rDNA sequences analysis. The results in this study strongly suggested that the rusty ginseng roots were produced by infection and growth of endophytic bacteria.

• Journal of KIISE:Information Networking
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• v.31 no.3
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• pp.269-279
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• 2004

The most important factor influencing the robustness of the Internet Is the end-to-end TCP congestion control. However, the congestion control scheme of TCP Reno, the most popular TCP version on the Internet, employs passive congestion indication. It makes worse the network congestion. Recently, Brakmo and Peterson have proposed a new version of TCP, which is named TCP Vegas, with a fundamentally different congestion control scheme from that of the Reno. Many studies indicate that the Vegas is able to achieve better throughput and higher stability than the Reno. But there are two unfairness problems in Vegas. These problems hinder the spread of the Vegas in current Internet. In this paper, in order to solve these unfairness problems, we propose a new congestion control algorithm called TCP PowerVegas. The existing Vegas depends mainly only on the rtt(round trip time), but the proposed PowerVegas use the new congestion control scheme combined the Information on the rtt with the information on the packet loss. Therefore the PowerVegas performs the congestion control more competitively than the Vegas. Thus, the PowerVegas is able to solve effectively these unfairness problems which the Vegas has experienced. To evaluate the proposed approach, we compare the performance among PowerVegas, Reno and Vegas under same network environment. Using simulation, the PowerVegas is able to achieve better throughput and higher stability than the Reno and is shown to achieve much better fairness than the existing Vegas.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.9
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• pp.603-614
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• 2013

The popularity of mobile devices provides their users with a circumstance that services and information can be accessed wherever and whenever users need. Accordingly, various studies have been proposed personalized methods to improve accessibility of mobile users to information. However, since these personalized methods require users' private information, they gives rise to problems on security. An efficient way to resolve security problems is to estimate user information by using their online and offline behavior. In this paper, for this purpose, it is proposed a novel user information identification system that identifies users' personal and social information by using both his/her behavior on social network services and proximity patterns obtained from GPS data. In the proposed system, personal information of a user like age, gender, and so on is estimated by analyzing SNS texts and POI (Point of Interest) patterns, while social information between a pair of users like family and friend is predicted with proximity patterns between the users. Each identification module is efficiently designed to handle the characteristics of user data like much noise in SNS texts and missing signals in GPS data. In experiments to evaluate the proposed system, our system shows its superiority against ordinary identification methods. This result means that the proposed system can efficiently reflect the characteristics of user data.

• Journal of KIISE:Databases
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• v.35 no.6
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• pp.505-517
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• 2008

This paper proposes a rewriting algorithm of OWL-DL ontology query in SPARQL. Currently, to obtain inference results of given SPARQL queries, Web ontology repositories construct inference ontology models and match the SPARQL queries with the models. However, an inference model requires much larger space than its original base model, and reusability of the model is not available for other inferrable SPARQL queries. Therefore, the aforementioned approach is not suitable for large scale SPARQL query processing. To resolve tills issue, this paper proposes a novel SPARQL query rewriting algorithm that can obtain results by rewriting SPARQL queries and accomplishing query operations against the base ontology model. To achieve this goal, we first define OWL-DL inference rules and apply them on rewriting graph pattern in queries. The paper categorizes the inference rules and discusses on how these rules affect the query rewriting. To show the advantages of our proposal, a prototype system based on lena is implemented. For comparative evaluation, we conduct an experiment with a set of test queries and compare of our proposal with the previous approach. The evaluation result showed the proposed algorithm supports an improved performance in efficiency of the inferrable SPARQL query processing without loss of completeness and soundness.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.337-347
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• 2018

The government has been operating residential improvement projects through the "Act on the Maintenance and Improvement of Urban Areas and Dwelling Conditions for Residents" as a type of a remedial measure for deteriorated residential areas. However, in recent years, the residential improvement projects have experienced difficulties due to the effects of various factors including the slowdown in economic growth. After observing the depression in a number of projects, various studies have been carried out to investigate the causality and improve the promotion of the residential improvement projects. In the trend of research, this study aims to analyze the effects of land and building characteristics on the improvement projects of Busan Metropolitan City. The dependent variables of the study represent different phases of improvement project as specified in the "Act on the Maintenance and Improvement of Urban Areas and Dwelling Conditions for Residents". The independent variables represent land and building characteristics which refer to the criteria used in the designation process of maintenance area according to the act. The empirical analysis uses the ordered logit model. The results from the analysis suggest that geographical condition, factors related to the number of union members, factors related to the parcel price and condition of a location have impact on the promotion of the improvement project. The results of the analysis show that majority of the factors are related to the economic feasibility of the projects. Residential improvement project is a part of urban planning projects that rehabilitates deteriorated residential environment, and it is closely associated with the quality of life of public. Accordingly, we hope that such projects are reasonable and take effective approach to those with urgent needs rather than to focus on profitability. Also, potential administrative and economical loss should be avoided by taking necessary planning measures in advance.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.122-131
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• 2007

This study estimates how soil loss in a basin has been occurred according to the change of land cover, and analyzes which type of land cover has the largest soil loss by classifying the land-cover type into each area and a whole basin. Musimcheon, the second branch stream of GeumGang, is chosen as a research area. The result of analysis shows that the average soil loss occurs most largely in a crop land and a paddy field. The yearly soil loss of watershed estimates approximately 14,000 ton/yr in case of using 100-year-frequency rainfall data. A forest area, which takes the largest area in watershed, shows the soil loss occurs approximately 1,000ton/yr. A crop field shows that soil loss increased most largely 4,900 ton/yr (34.6%) in 1985 to 8,100 ton/yr (56.1%) in 2000. The change of land cover in a crop land increased 8% to 14%, and this change influences on the increase of soil loss. As a result of analyzing the area over $200ton/km^2/yr$, the soil loss in a crop field accounts for 74% to 96%.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.262-269
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• 2019

References at the end of an academic paper are information that helps authors keep their research ethics, readers refer to related prior studies. Also references are useful information for linking citations and citations between articles. As bibliography metrics develops, bibliographic data is used as an important data for assessing the academic influence of countries, institutions and individual researchers. However, it is not easy to identify and link the reference data due to the diversity of the bibliographic citation formats, the loss of information due to the abbreviation of journal names and author names, and typos by authors. This study investigated the method of improving the bibliographic data mapping rate by analyzing the unmapped cases. As a result, it was found that the main cause of the article-reference mapping failure was the similarity of abbreviated journal names. Research team suggested that continuous management of journal title authority data and improving the DOI registration rate as ways to improve the identification and mapping rate. This study is differentiated from other studies in used database. Bibliography mapping was attempted for domestic and foreign integrated journal database that is mainly subscribed, used, published and cited in Korea. Through reference construction volume and mapping rate improvement, it can be used as citation analysis and service database reflecting domestic situation that is different from overseas citation index database.

• The Journal of Engineering Geology
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• v.5 no.1
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• pp.1-20
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• 1995

A train overturn accident occurred on March 1993 in the Gupo area, northern part of Pusan, unfortunately had taken a heavy toll of lives and caused a great loss of property as well. The reasons for the subsidence of the basement under the railroads, which presumed to be the main cause of the accident, have been investigated from many different angles, including conventional geotechnical investigation methods. The deduced nuin reasons of the subsidence were: 1. blasting for tunnel excavation (NATM) at about 39 meter under the railroads, and 2. unexpected change of bedrock conditions along the direction of tunnel. But this accident was derived nrranlv from the lack of geological and geotechnical information under railroad area because it was impossible to drill beneath the railroads. This paper introduces a new geophysical survey techniqueseisrnic geotomography, and shows some results of the method applying to investigate the underground structure of the accident area. This method not only overcomes the unfavourable environment which many conventional investigation methods cannot face, but produces an image of underground structure with high resolution. Furthermore, the outputs from geotomogaphic analysis could provide very valuable in-situ basic parameters (like seismic velocities, elastic moduli, etc.) which is essential to the design and construction.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.1
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• pp.1-9
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• 2000

Vertical temperature distributions in muddy intertidal sediments near the Jebu Island on the west coast of Korea were obtained during the period of ebb tide which occurred in day time. The observations of mud temperature were made with thermistor embedded probe at 2cm interval for 18cm-layer of sediment for five different months of the year. Temporal changes in the vertical profile of the sediment temperature are strongly depend on the air temperature, the previous time of flood tide and the time of ebb tide. Heat exchanges in the surface layer (0-2 cm) in terms of magnitude and direction are greater than and opposite to those in the deeper sediment layer (8-12 cm), respectively and do not show any significant seasonal variations. In general, the surface layer gains heat while the deeper layer loses the heat. By using the 1-D diffusion equation temporal vertical profiles of the sediment temperature were obtained and were compared with the observed ones. The results show that in the sediment layer below 4 cm-depth the heat transport is predominantly by molecular diffusion. The average magnitude of heat flux into the sediment layer (0-18 cm) during the ebb tide when the mudflats were exposed in the middle of the day were between 4.1 and $28.9\;W/m^2$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1048-1057
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• 2004

WCDMA system is 3rd generation wireless mobile system specified by 3GPP. In WCDMA downlink, two power control schemes are operated. One is inner loop power control operated m every slot Another is outer loop power control based on one frame time. Base staion (BS) can estimate proper transmission power by these two power control schemes. However, because each MS's transmission power makes a severe effect on BS's performance, BS cannot give excessive transmission power to the speclfic user 3GPP defined Power Control Dynamic Range (PCDR) to guarantee proper BS's performance. In this paper, we propose Adaptive PCDR algorithm. By APCDR algorithm, Radio Network Controller (RNC) can estimate each MS's current state using received signal to interference ratio (SIR) APCDR algorithm changes MS's maximum code channel power based on frame. By proposed scheme, each MS can reduce wireless channel effect and endure outages in cell edge. Therefore, each MS can obtain better QoS. Simulation result indicate that APCDR algorithm show more attractive output than fixed PCDR algorithm.