• Journal of Communications and Networks
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• v.12 no.3
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• pp.209-215
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• 2010

In an asymmetrical speed channel environment like asymmetric digital subscriber line, the up-link bandwidth is normally smaller than the down-link bandwidth, which will lead to extremely low utilization of down-link bandwidth when current P2P video transmission is applied. To overcome this, a new fast P2P video transmission method applied in an asymmetrical speed channel environment is proposed in this paper. On the basis of the many-to-one concept, the proposed method uses a new multipeer aggregation technique to enhance the utilization of down-link bandwidth. In addition, an adaptive peer assignment algorithm is also introduced in order to minimize the overall transmission time. Experimental results show that by using our proposed method, the utilization of down-link bandwidth is significantly improved, and the overall transmission time is greatly reduced.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.344-354
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• 2020

Identification of the target species of 2-MIB (2-methyllisoborneol) production is crucial in the management of off-flavor problem in the freshwater system. This study was conducted to identify 2-MIB-producing Pseudanabaena strains occurring in the North Han River system using molecular genetic method. Eleven phenotypes of Pseudanabaena were isolated from several mainstream sites of the North Han River, including Sambong-ri, Joam-myun, and Lake Uiam areas. Despite of morphological similarity of the strains, the phylogenetic analysis using 16S rDNA classified them into different species with low genetic similarity (40~55%). Isolated Pseudanabaena strains were converged to four species; Pseudanabaena cinerea, P. yagii, P. mucicola, and P. redekei. Among them, the 2-MIB synthesizing gene (mibC) was detected in P. cinerea, P. yagii, and P. redekei. However, actual 2-MIB production was detected only in P. cinerea and P. redekei based on gas chromatography analysis. This study is the first report of the molecular identification of Pseudanabaena strains and their 2-MIB production potential in Korea. The results of this study provides an evidence of species diversity of Pseudanabaena occurring in the North Han River.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.229-235
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• 2024

Background: Plant health is directly related to the change in native microbial diversity and changes in soil health have been implicated as one of the main cause of root rot. However, scarce information is present regarding allelopathic relationship of Panax notoginseng root exudates and pathogenic fungi Fusarium oxysporum in a continuous cropping system. Methods: We analyzed P. notoginseng root exudate in the planting soil for three successive years to determine phenolic acid concentration using GC-MS and HPLC followed by effect on the microbial community assembly. Antioxidant enzymes were checked in the roots to confirm possible resistance in P. notoginseng. Results: Total 29 allelochemicals in the planting soil extract was found with highest concentration (10.54 %) of p-hydroxybenzoic acid. The HPLC showing a year-by-year decrease in p-hydroxybenzoic acid content in soil of different planting years, and an increase in population of F. oxysporum. Moreover, community analysis displayed negative correlation with 2.22 mmol. L^-1 of p-hydroxybenzoic acid correspond to an 18.1 % population of F. oxysporum. Furthermore, in vitro plate assay indicates that medium dose of p-hydroxybenzoic acid (2.5-5 mmol. L^-1) can stimulate the growth of F. oxysporum colonies and the production of macroconidia, as well as cell wall-degrading enzymes. We found that 2-3 mmol. L^-1 of p-hydroxybenzoic acid significantly increased the population of F. oxysporum. Conclusion: In conclusion, our study suggested that p-hydroxybenzoic acid have negative effect on the root system and modified the rhizosphere microbiome so that the host plant became more susceptible to root rot disease.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.44-47
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• 2015

In this paper, P2P VLC Sound Transmission Technology between Underwater Object of 5cm Distance. It proposed a P2P VLC sound transmission technology, and developed a P2P VLC sound transmission technology between LED transmitter and PD(Photo Detector) receiver of 15cm distance. Under the assumption that the underwater environment, it performs a P2P VLC sound transmission experiment between LED transmitter and PD receiver for sound transmission, and demonstrated the usefulness of the proposed technology. In this paper, P2P VLC Sound Transmission Technology between Underwater Object of 5cm Distance, and proposed technology is expected to be widely used in various fields because it can use P2P VLC sound transmission technology between underwater object in the underwater environment.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.3
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• pp.81-86
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• 2014

According to the development of streaming services with P2P and mobile network technologies, researches to enhance the service quality in mobile environment have been proposed. However, streaming services considering high-speed mobile environment and characteristics of heterogenous terminals have been hindered from being provided with the required quality from user because of bandwidth congestion between selfish peers of existing P2P system. It is also prone to long delay and loss in accordance with the repeated traffic amounts because there are no optimized solution for traffic localization. The structure to enhance peer contribution for service differentiation and peer selection with clustering scheme with location information of terminal can satisfy both users and service providers with service quality and efficiency. In this paper, we propose an incentive mechanism and resource distribution scheme with user contribution and traffic cost information based on user location, which make mobile users increase the satisfaction of service quality in LTE environments.

• The Korean Journal of Quaternary Research
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• v.16 no.2
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• pp.39-56
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• 2002

The results of geoarchaeological studies of the prehistoric cultural complexes on the Russian Far East (Primorye, or Maritime Province; the Amur River basin; and Sakhalin Island) are presented. Upper Palaeolithic sites are dated to ca. 40,000-10,500 B.P. They existed during the mild climate of the Chernoruchie interstadial (ca. 40,000-21,000 B.P.); during harsh climate at the Last Glacial Maximum, ca. 20,000-18,000 B.P., in several places on the Russian Far East (Primorye, Amur River basin, and Sakhalin); and during climatic amelioration in the Late Glacial time, ca. 16,000-10,500 B.P. The earliest Neolithic sites, represented by Osipovka and Gromatukha cultures, existed at ca. 13,000-10,000 B.P. in the environment of coniferous forests with admixture of broadleaved taxa. Since ca. 8000 B.P., Neolithic cultures appeared in all of the Russian Far East. They existed until ca. 3000 B.P., first during the Holocene Climatic Optimum, ca. 8000-5000 B.P., in the environment of coniferous-broadleaved forests, and later, at ca. 5000-3000 B.P., in the environment of birch-oak and coniferous forests.

• Child Health Nursing Research
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• v.6 no.2
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• pp.132-143
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• 2000

The purpose of this correlational study was to find the correlation between the infant temperament, mother-infant interaction, and child-rearing environment. The subjects of this study were 37 dyads of healthy mothers and healthy infants. Data were collected from 15th of March to 3rd of September, 1999. Convenient sampling was done at Obstetric wards of one University hospital, and demographic data were collected before discharge. At one month and three month postpartum, we visited subject's home, and collected the data on the infant temperament, and also video taped the mother-infant interaction during feeding. In addition, child-rearing environment was checked by researcher according to HOME(Home Observation for Measurement of the Environment) at three months postpartum. Mother-infant interactions were rated according to the NCAST Feeding Scale later. Data were analyzed by window SPSS program, and correlations between the infant temperament, mother-infant interaction, and child-rearing environment were analyzed by Pearson's correlational coefficient. The results were as follows: 1. Infant temperament. 1) Among the subscales of infant temperament, mothers perceived cuddliness and amenability most positively at one month, and responsivity and amenability most positively at three months. 2) In subscale analysis of stability, amenability, responsivity, and persistence were stable with the time. 3) Significant relationships were found between the malleability and amenability, between the malleability and responsivity at one month, and also between the malleability and amenability, and between the malleability and cuddliness at three months. 2. Correlations of infant temperament and mother-infant interaction. 1) There was no significant relationship between the infant temperament and mother-infant interaction at one month. 2) There was a significant relationship between the infant temperament and mother-infant interaction at three months(r=.335, p<.05). In subscale analysis, there were significnt relationships between the total score of infant temperament and maternal sensitivity to infant's cues(r=.372, p<.05), and between the total score of infant temperament and maternal response to infant's distress (r=.331, p<.05). 3. Correlations of infant temperament and child-rearing environment. 1) There was no significant relationship between the total score of infant temperament at one month and total score of HOME at three months. In subscal analysis, the total score of infant temperament at one showed significant relationships with the organization of environment(r=.413, p<.05), and the emotional, verbal response at three months(r=.337, p<.05). 2) There was a significant relationship between the total score of infant temperament at three months and the total score of HOME at three months (r=.599, p<.01). In subscal analysis, the total score of infant temperament at three months showed significant relationships with the organization of environment(r=.410, p<.05), maternal involvement(r=.482, p,.01), and the emotional, verbal response(r=.695, p<.01) at three months. 4. Correlations of mother-infant interaction and child-rearing environment. There was a significant relationship between the maternal score of mother-infant interaction at one month and three months and the total score of HOME at three months (r=.474, p<.01; r=.452, p<.01). In conclusion, it was proved that infant temperament had significant relationships with mother-infant interaction and child-rearing environment, especially when the infants were getting older. This showed the possibility for changeability of infant teperament by the maternal factors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.7
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• pp.1120-1125
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• 2002

According as progress by information society, computer network use and enlargement of scale are accelerated more. Also, with good physician increase of information that is exchanged through computer network, security of network is embossed to controversial point that is new. Because P2P as that remove or weakens center server function is open network that can participate between each user, problem about authentication between each users is risen. If certain user in network i3 in open environment, this user must authenticate request about service to user who is admitted between each user to limit connection. This treatise proposed method to keep security in P2P environment to solve this and designed certification mechanism that quote Kerberos certification mechanism to mechanism that can share information safety in P2P environment.

• Journal of Industrial Convergence
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• v.6 no.1
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• pp.57-72
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• 2008

In this study, general outline of P2P(peer to peer) application was analyzed dealing with security attacks and threats on the P2P environment. Information security service was studied to provide secure P2P service under the information threats. This study proposes two methods to provide secure information security service. One is a method to use personal firewall software on the peer. The other is a method to use key distribution protocol for confidentiality and integrity.

• Journal of the Korean housing association
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• v.8 no.2
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• pp.107-112
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• 1997

This thesis is dealt with the thermal environment, the indoor air environment, the sound environment and the light environment in P.C apartment house. The purpose of this study is to analyze degrees of 'the cognition'. 'the importance', and ‘the satisfaction' on indoor environmental factors and to evaluate comfort of indoor environment based on residents' responses. The questionnaire survey was given to the residents at P.C apartment complex in Rowon-Gu, Seoul. The following are the results obtained in this thesis. The results of Path analysis on comfort revealed that factors of direct effect to comfort were the satisfaction on indoor air environment and sound environment and the cognition on indoor air environment and sound environment. The satisfaction on indoor air environment was the biggest variable which decided the comfort. By the survey of P.C apartment residents' responses, the level of P.C apartment indoor comfort was found uncomfortable. It is meaningful to su99est the model evaluating comfort by residents' responses .