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Flow-based P2P Traffic Identification using SVM (SVM을 이용한 플로우 기반 P2P 트래픽 식별)

  • Um, Nam-Kyoung;Woo, Sung-Hee;Lee, Sang-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.3
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    • pp.123-130
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    • 2008
  • To avoid some protection systems such as firewall, P2P applications have recently used to apply dynamic port numbers. Reliable estimates of P2P traffic require examination of packet payload, a methodological land mine from legal, privacy technical, logistic, and fiscal perspectives. Indeed, access to user payload is often rendered impossible by one of these factors, inhibiting trustworthy estimation of P2P growth and dynamics. Despite various methods such as port-based and signature-based techniques, it still dose not satisfy the method which uses both qualitative and quantitative aspects. In this paper, a method using SVM mechanism which discriminate the P2P traffic from non-P2P traffics using differences between P2P and other application traffics is suggested. This is a systematic methodology to identify P2P networks, and without relying on packet payload.

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A Suggestion of P2P Search Algorithm for Multidirectional Processing (다방향 프로세싱을 위한 P2P 검색 알고리즘 제안)

  • Kim, Boon-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.7
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    • pp.109-115
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    • 2008
  • In the P2P distributed system, such peers don't always keep on-line status. P2P systems are different from the ordinary systems that such peers are organically operated as the elements of system. In this case, users using P2P system are able to loss the reliability. At this point, many P2P studies are tried to resolve these problems. In this paper, we suggest a P2P search algorithm for multidirectional processing about the resources to be downloading. In existing studies, the loading rate is very high to select new resources supported peer, so we suggest new solution in this study.

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우리나라 인공호의 부영양화 평가 및 예측에 관한 연구

  • 김재윤
    • Journal of Environmental Science International
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    • v.7 no.4
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    • pp.441-450
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    • 1998
  • The purpose of this study is to evaluate and to predict of eutrophication in lakes by using VollenweiderGECD model and total phosphorus concentration and inflow rate which were measurded in 1993-1996. The results of study was as follows. The annual total phosphorus loading from the watershed was calculated to be 181-195tP /yr at lake Soyang, 591-680tP/yr at lake Chungju, 420-466tP/yr at lake Taechong, 229-278tP/yr at lake Andong, 103-106tP/yr at lake Hapchon, 57-59tP/yr at lake Imha, 194-244tP/yr at lake Namgang, 8386tP /yr at lake Chuam, 99-109tP /yr at lake Somjin. These are discharged, for the most parts, from population and ftshfarm facility. TP loading on the surface area at lake Soyang was 3.0lgP/$m^2$/yr, 2.82gP/$m^2$/yr, 2.84gP/$m^2$/yr, 3. 03gP/$m^2$/yr, at lake Chungju 7.91gP/$m^2$/yr, 6.87gP/$m^2$/yr, 7.38gP/$m^2$/yr, 7.l8gP/$m^2$/yr, at lake Taechong 6.7lgP/$m^2$/yr, 7.25gP/$m^2$/yr, 7.24gP/$m^2$/yr, 6.53gP/$m^2$/yr and TP loading on the surface area of Nakdong river basin, that is, lake Andong, Imha, Hapchon and Namgang were 5.39gP/$m^2$/yr, 4.47gP/$m^2$/yr, 4. 56gP/$m^2$/yr, 4.45gP/$m^2$/yr and 2.20gP/$m^2$/yr, 2.23gP/$m^2$/yr, 2.24gP/$m^2$/yr, 2.l7gP/$m^2$/yr and 4.50gP/$m^2$/ yr, 4.50gP/$m^2$/yr, 4.54gP/$m^2$/yr, 4.43gP/$m^2$/yr and 8.25gP/$m^2$/yr, 8.48gP/$m^2$/yr, 8.48gP/$m^2$/yr, 10. 39gP/$m^2$/yr respectively. Also those of lake Chuam was 2.51gP/$m^2$/yr, 2.61gP/$m^2$/yr, 2.52gP/$m^2$/yr, 2. 54gP/$m^2$/yr and TP loading on the surface area at lake Somjin was analysed 4.09gP/$m^2$/yr, 4.l0gP/$m^2$/yr, 3.98gP/$m^2$/yr,3.73gP/$m^2$/yr. The tropic states of nine lakes can be assessed as eutrophy because phosphorus loading exceeds the critical phosphorus loading by Vollenwelder-GECD model.

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An Architecture of UPnP Bridge for Non-lP Devices with Heterogeneous Interfaces (다양한 Non-lP 장치를 위한 UPnP 브리지 구조)

  • Kang, Jeong-Seok;Choi, Yong-Soon;Park, Hong-Seong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12B
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    • pp.779-789
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    • 2007
  • This paper presents an architecture of UPnP Bridge for interconnecting Non-lP devices with heterogeneous network interfaces to UPnP devices on UPnP networks. The proposed UPnP Bridge provides a Virtual UPnP device that performs generic UPnP Device's functionalities on behalf of Non-lP device. This paper defines 3 types of descriptions, Device Description, Message Field Description, and Extended UPnP Service Description in order to reduce the amount of effort required to connect a non-lP device with a new interface or message format to UPnP network. By these three types of descriptions and Message conversion module, developers for Non-lP devices can easily connect the devices to UPnP network without additional programming. So UPnP control point controls Non-lP devices as generic UPnP device. Some experiments validate the proposed architecture, which are performed on a test bed consisting of UPnP network the proposed bridge, and non-lP devices with CAN and RS232 interfaces.

Comparison of the Forage Quality and Productivity According to Varieties and Plant Parts of Imported Silage Corn (Zea mays, L) (도입 사일리지용 옥수수의 품종과 식물체 부위에 대한 사료가치와 생산성 비교)

  • Kim, Jong Geun;Li, Yan Feng;Wei, Sheng Nan;Jeong, Eun Chan;Kim, Hak Jin
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.2
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    • pp.98-105
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    • 2020
  • This experiment was conducted to a comparison of the productivity according to variety and forage quality by plant parts of imported silage corn (Zea mays, L) in Pyeongchang. The corns evaluated in this experiment were 8 varieties (P1184, P1151, P1194, P1543, P1345, P1429, P1443, and P2105) introduced from the United States, Pioneer Hybrid Co. The harvested corn was divided into 5 plant parts (leaf, stem, cob, husk, and grain), and the ratio of each part was calculated using dry weight and the feed value was analyzed. The emergence rate of corn was generally good except for the P1151 and P2105 varieties. The average tasseling date was July 24th and the silking date was July 27th, but the P2105 variety was late to July 28th and August 1st, and the remaining varieties were similar. P1345 was the highest (289 and 123 cm), and P1151 varieties were the lowest (267 and 101 cm) in the plant and ear height. Disease resistance was low in P1184, P1443 and P1429, and P1197 and P1345 were high. In the case of stover, the dry matter (DM) content was the lowest at 19.6% in the P1151 and the highest at 24.9% in the P1429. DM content of ear was the highest in the P2105 (55.5%), and P1184 (54.2%) and P1345 (54.3%) were also significantly higher (p<0.05). The DM yield of stover of P2105, P1429 and P1194 varieties was significantly higher (p<0.05), and ear yield of P2105, P1345 and P1443 was higher. The proportions of each part of plants (leaf, stem, cob, husk, and grain) divided by 5 was high, with 50-60% of the ear(grain+cob) ratio. The ratio of husk and cob was roughly similar, and the leaf and stem part showed a ratio of about 20%. The crude protein (CP) content was highest in leaf, followed by grain. The CP content of the stem was the lowest, and the husk was not significantly different among the varieties (p>0.05). The acid detergent fiber (ADF) content was similar to the rest parts except grain, but the leaf part tended to be lower, and other parts except the stem and leaf showed no significant difference between varieties (p>0.05). There was no significant difference in NDF (neutral detergent fiber) content in husk, but there was a difference between varieties in other parts (p<0.05). In addition, there was a special difference by plant parts for each variety, P2015 on the stem, P1197 on the leaf, P1151 on the cob, P1197 on the husk, and P1197 on the grains with high NDF content. IVDMD (in vitro dry matter digestibility) was not significantly different between stems and grains, but there was a difference between varieties in cobs and husks. According to the results, DM yield of P2105 variety was the best in the experiment, and the ratio of grain was excellent in P1543 and P1345. In addition, it was found that the feed value was higher in the leaves and grains, and the leaf and stem had higher feed values than husk or cob.

Isolation and Characterization of the Smallest Bacteriophage P4 Derivatives Packaged into P4-Size Head in Bacteriophage P2-P4 System

  • Kim, Kyoung-Jin;Song, Jae-Ho
    • Journal of Microbiology
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    • v.44 no.5
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    • pp.530-536
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    • 2006
  • Bacteriophage P4, a satellite phage of coliphage P2, is a very useful experimental tool for the study of viral capsid assembly and cos-cleavage. For an in vitro cos-cleavage reaction study of the P2-P4 system, new shortened and selectable markers containing P4 derivative plasm ids were designed as a substrate molecules. They were constructed by swapping the non-essential segment of P4 DNA for either the kanamycin resistance (kmr) gene or the ampicillin resistance (apr) gene. The size of the genomes of the resulting markers were 82% (P4 ash8 delRI:: kmr) and 79% (P4 ash8 delRI:: apr) of the wild type P4 genome. To determine the lower limit of genome size that could be packaged into the small P4-size bead, these shortened P4 plasmids were converted to phage particles with infection of the helper phage P2. The conversion of plasmid P4 derivatives to bacteriophage particles was verified by the heat stability test and the burst size determination experiment. CsCl buoyant equilibrium density gradient experiments confirmed not only the genome size of the viable phage form of shortened P4 derivatives, but also their packaging into the small P4-size head. P4 ash8 delRI:: apr turned out to be the smallest P4 genome that can be packaged into P4-sized head.

A Design and Implementation of Dynamic Hybrid P2P System with Hierarchical Group Management and Maintenance of Reliability (계층적 그룹관리와 신뢰성을 위한 동적인 변형 P2P 시스템 설계 및 구현)

  • Lee, Seok-Hee;Cho, Sang;Kim, Sung-Yeol
    • The KIPS Transactions:PartD
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    • v.11D no.4
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    • pp.975-982
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    • 2004
  • In current P2P concept, pure P2P and Hybrid P2P structures are used commonly. Gnutella and Ktella are forms of pure P2P. and forms of Hybrid P2P are innumerable. File searching models exist in these models. These models provide group management for file sharing, searching and indexing. The general file sharing model is good at maintaining connectivity. However, it is defective in group management. Therefore, this study approaches hierarchical structure in file sharing models through routing technique and backup system. This system was designed so that the user was able to maintain group efficiency and connection reliability in large-scale network.

Phylogeny of Korean Isolates of Phytophthora Species Based on Sequence Analysis of Internal Transcribed Spacer of Ribosomal DNA

  • Hong, Seung-Beom;Jee, Hyeong-Jin;Kim, Sang-Hee;Go, Seung-Joo
    • The Plant Pathology Journal
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    • v.16 no.1
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    • pp.29-35
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    • 2000
  • The internal transcribed spacer regions (ITS I, 5.8S and ITS II) of the ribosomal DNAs were amplified from Korean isolates of Phytophthora spp. and sequenced to characterize them. Sequences from 33 isolates previously identified as P. boehmeriae, P. cactprum, P. cambivora, P. capsici, P. cinnamomi, P. erythroseptica, P. infestans, P. megasperma, P. melonis, P. nicotianae, P. palmivora and P. sojae were compared with published sequences, and a phylogenetic tree was produced. All isolates belonging to 10 species, P. cactorum, P. cambivora, P. capsici, P. cinnamomi P. citricola, P. infestans, P. nicotianae, P. palmivora and P. sojae were clearly clustered into published isolates of each species above 97% bootstrap value. Cucurbits isolates of Phytophthora previously identified as either P. melonis or P. drechsleri showed distinct evolutionary lineages from the P. megasperma was closely related to isolates of P. cryptogea-P. drechsleri showed distinct evolutionary lineages from the P. cryptogea-P. drechsleri complex group, indicating that P. melonis is a valid species. A Korean isolate of P. megasperma was closely related to isolates of P. erythroseptica showed distant genetic relationship with published isolates of P. erythroseptica (CBS 956.87). It is probable that the two Korean isolates could be genetically different from foreign isolates or misidentified. A grouping of species according to ITS sequence divergence matched, to some degree, the broad classification based on type of papilla. However, a separation of semi-papillate species and papillate species was not wvident in this study.

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A Comparative Study on the Growth Characteristics and Nutritional Components of Corn Hybrids for Silage at Paddy Field Cultivation (논토양에 사일리지용 옥수수 재배시 품종별 생육특성 및 영양성분 비교 연구)

  • Kim, Wan-Su;Hwang, Joo-Hwan;Lee, Jae-Hun;Kim, Eun-Joong;Jeon, Byong-Tae;Moon, Sang-Ho;Lee, Sang-Moo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.32 no.1
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    • pp.15-28
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    • 2012
  • This study was carried out to know adaptability and growth characteristics, yield, chemical compositions and nutrition yield of corn hybrids for silage at paddy field. The field experiments were conducted at Sangju province for one year (2009). The experimental design was arranged in a randomized block design with three replication. The treatments consisted of eleven corn hybrids. The planting date was on 1 May and harvested at 24 August. Stem diameter, stem hardness and number of ear were higher in P32P75 than other varieties. Ear height, dead leaf and green degree were highest in $NC^+$7117, but number of root system and Brix ($B^{\circ}$) were higher in P3394 than other varieties. Crude protein and crude fat (EE) were highest in P32K61 and P31P41, respectively (P<0.01). NDF and ADF were highest in KPO and KIO, respectively, but no significant differences were found among the varieties. Total mineral contents were the highest in Kwangpyongok (9,775 mg/kg), and P3394 (6,651 mg/kg) was the lowest as compared to other varieties (P<0.01). Crude protein yield, crude fat yield and mineral yield were highest in P3156, P31P41 and KPO, respectively (P<0.01). Total composition amino acid and total fatty acid were the highest in P32K61 and KIO, respectively (P<0.01). Yields of crude protein, fatty acid, composition amino acid and TDN were the highest in P3156 (P<0.01). But yields of crude protein and mineral were the highest in P31P41 and KPO, respectively (P<0.01). Total digestible nutrient (TDN) was higher in order of P3156 > $NC^+$7117 > P31N27 > KPO > P32K61 > P32T83 > P32P75 > P31P41 > P3394 > P32W86 > KIO. Based on the above results, corn hybrid varieties could be recommended in P3156, NC+7117 and P31N27 for growth characteristics, quantitative production and nutrition yield.

A Study on Composition of Inorganic phosphorus Forms and Methods of Determining Available Phosphorus in Volcanic Ash (제주도토양의 무기태인산(無機態燐酸) 조성(組成)과 유효인산의 정량법(定量法) 비교(比較))

  • Shin, Cheol-Woo;Ryu, In-Soo;Yoon, Jung-Hui
    • Korean Journal of Soil Science and Fertilizer
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    • v.13 no.3
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    • pp.93-97
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    • 1981
  • Laboratory experiment was carried out to investigate the changes in the amount of inorganic phosphorus fractions of native and applied phosphorus and to compare the some analytical methods of soil phosphorus in volcanic ash. The rates of inorganic phosphorus to total-pP were varied with the kinds of soil in the ranges of 6.9 to 28.8% for Al-P, 24.1 to 26.9% for Fe-P, 7.4 to 11.9% for Ca-P and 0.7 to 8.0% for available phosphorus. The composition of inorganic phosphorus after incubation for 60 days was in the order of Al-P>Fe-P>Ca-P in Black soil, Fe-P>Al-P>Ca-P in Very dark brown soil, Fe-P>Ca-P>Al-P in Dark brown soil and Fe-P Al-P>Ca-P on Red yellow soil. The amounts of phosphorus extracted from soil varied with the methods for available phosphorus estimation. The magnitute of available P measured by Bray No. 2 method was the greatest. In relationship between inorganic phosphorus forms and available phophorus, Bray No. 2 method was closely related to Ca-P only and Olsen method correlated to Al-P, Fe-P, Ca-P and Total-P.

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