• Korean Journal of Environmental Biology
• /
• v.24 no.3
• /
• pp.248-257
• /
• 2006

Total naturalized plant species in the streams of Jeonju were listed as 109 taxa; 24 families, 75 genera, 106 species, 3 varieties. Dividing by stream, Jeonju stream has 75 taxa; 20 families, 55 genera, 73 species, 2 varieties. Samcheon stream has 86 taxa; 19 families, 64 genera, 84 species, 2 varieties. Soyang stream has 80 taxa; 21 families, 60 genera, 77 species, 3 varieties. Urbanization Index (UI) of total streams (109 taxa) was 40.2%. UI was 27.7% in Jeonju stream (75 taxa), 31.7% in Samcheon stream (86 taxa), 29.5% in Soyang stream (80 taxa). Dividing by degree of naturalization classification, 25 taxa (9.2%) were found in class 5, 17 taxa (6.2%) in class 4, 32 taxa (11.8%) in class 3, 27 taxa (9.9%) in class 2 and 8 taxa (2.9%) in class 1. Dividing by introduction period, 48 taxa (44%) aye in period I, 19 taxa (17%) in period II, 42 taxa (39%) in period III. Dividing by growth type, 48 taxa (44%) are annuals, 25 taxa (23%) are biennials, 33 taxa (30%) are perennials. Dividing by the place of origin, 39 taxa (35%) are from Euyope, 33 taxa (30%) from North America, 11 taxa (10%) from Tropic America, 9 taxa (8%) from Europe Asia,5 taxa (5%) from South America, 5 taxa (5%) from China.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.11
• /
• pp.1908-1915
• /
• 2018

Upon viral infection, the host cell recognizes the invasion through a number of pattern recognition receptors. Melanoma differentiation associated gene 5 (MDA5) and retinoic acid-inducible gene-I (RIG-I) recognize RNA molecules derived from invading viruses, activating down-stream signaling cascades, culminating in the induction of the type I interferon. On the other hand, viruses have evolved to evade type I interferon-mediated inhibition. Hepatitis E virus has been shown to encode a few antagonists of type I interferon and it is not surprising that viruses encode multiple mechanisms of viral evasion. In the present study, we demonstrated that HEV PCP strongly down-regulates MDA5-mediated activation of interferon ${\beta}$ induction in a dose-dependent manner. Interestingly, MDA5 protein expression was almost completely abolished. In addition, polyinosinic polycytidylic acid (poly(I:C))- and Sendai virus-mediated activation of type I interferon responses were similarly abrogated in the presence of HEV PCP. Furthermore, HEV PCP down-regulates several molecules that play critical roles in the induction of type I IFN expression. Taken together, these data collectively suggest that HEV-encoded PCP is a strong antagonist of type I interferon.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.26 no.4
• /
• pp.333-340
• /
• 1990

The authors carried out a visiualizational model test by the hydrogen bubble method to examine the pattern of the fluid flow besides the simple camber type and plane type otter board in circulation water channel. The experimental conditions are velocity of flow 0.05 and 0.1m/sec, angle of attack 0$^{\circ}$~45$^{\circ}$(5$^{\circ}$step). The results obtained are as follows: 1. In the case of the simple camber type otter board located angle of attack 25$^{\circ}$, vortex at the leading edge was geneated at 1/2 of chord length. 2. Size of the vortex generated in the trailing edge was about 2~3 times larger then that of the leading edge. 3. In the case of the simple camber type otter board located angle of attack 30$^{\circ}$, separation of stream-line at leading edge was generated at 1/3 of chord length. 4. Nearest stream-line in the back side of the simple camber type otter board was bent in the direction of otter board when the angle of attack was 25$^{\circ}$ and 30$^{\circ}$, and in the case of plane type otter board was expanded outside of the flow direction. 6. Area separated of the simple camber type otter board at the angle of attack 30$^{\circ}$ was smaller then that of plane type otter board. 7. Flow speed in the back side of the simple camber type otter board was about 1.4 times faster then that in the front side, and in the case of the plane otter board about 1.2 times faster.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.5
• /
• pp.382-393
• /
• 2000

The principal indicators contributing to water qualities was screened by factor analyses, based on the monitored chemical parameters of water quality for various water resources from 1995 to 1999 in the small agricultural catchments of the Han River Basin. Water samples of streams, groundwaters, and reservoirs were taken four times a year from upper (Daegwanryong), middle (Dunnae and Chunchon) and lower (Guri) reaches of Han River Basin. In these areas, the respective type of farming practiced was alpine agriculture and livestocks raising, typical upland and paddy cultivation, and intensive cropping in the plastic film house. Water quality was monitored for twenty-one water quality parameters, including pH, EC, SS, T-N, T-P, COD, cations, anions, and heavy metals. pH, EC and COD of the stream waters were suitable for the Korea irrigation water quality guidelines. However, T-N and T-P concentrations of water samples in four catchments far exceeded the irrigation water guideline. Concentrations of canons and heavy metals in Wangsuk stream in Guri area were higher than those in streams in other areas. Factor analysis revealed that significant correlation was observed for 81 pairs out of 231 water quality indicators of stream water among the $21\;{\times}\;21$ cross correlation matrix of stream water quality indicators. The first factor accounted for 27.01% of the total variation in stream water quality indicators, and high positive factor loadings were shown on EC, K, Na, $NH_4\;^+-N$, $PO_4\;^{3-}$, $SO_4\;^{2-}$, and COD. Fifty-three water quality indicator pairs were significant out of 190 ground water quality parameters. The first factor accounted for 28.54% of the total variation in ground water quality indicators, and high loadings were revealed on EC, Ca, Mg, K, Na, $NH_4\;^+-N$, and $SO_4$. Twenty-nine pairs of reservoir water quality indicators were significant out of 66 pairs. The first factor accounted for 37.06% of the total variation in reservoir water quality indicators, and high loadings were shown on EC, Mg, K, Na, SS, T-P, Cl, and COD. These results demonstrate that EC was the first factor contributing to water quality.

• Journal of the Korean Chemical Society
• /
• v.36 no.5
• /
• pp.638-643
• /
• 1992

The analytical response properties of two types of continuous flow-through electrode system as fulfide ion detectors are examined and directly compared their reponse characteristics under the optimal conditions. In both detection systems, observed peak potentials are logarithmically related to the sulfide ion concentration and at least twenty samples per hour can be determined. In the pH electrode method, the pH of the flowing recipient stream leaving the dialyzer was monitored. The designed system involves the use of continuous flow gas dialyzer in conjunction with the tubular polymer membrane electrode. In this method, optimal experimental conditions are recipient of mixture of $5.0 {\times} 10^{-5} M NaOH ＋ 5.0 {\times} 10^{-3} M$ NaCl and diluent of 0.10 M $H_2SO_4$, and all flow rates of recipient stream, diluent stream, and sample are 1.0 ml/min. In the sulfide ion electrode method, a commercially available sulfide ion-selective electrode was used to detect sulfide ion in the flow-through cell. The optimal flow rates of sulfide anti-oxidant buffer (3.5 g ascorbic acid and 7.6 g $Na_2EDTA$ dissolved in 1.0 M NaOH solution 1 l) and sample were 1.4 ml/min and 1.0 ml/min, respectively.

• Journal of Wetlands Research
• /
• v.17 no.4
• /
• pp.359-369
• /
• 2015

Stream ecosystems are highly valued natural resources, however, stream environments are currently under threat in several respects. We evaluated vegetation and ecological characteristics according to different revetment types. The distribution of vegetation differed with revetment type, with a 42~45 taxa found in natural revetments, and 23~38 taxa in vertical revetments. Thus, natural revetments host more diverse vegetation than vertical revetments. We also found more plants belonging to the families Labiatae and Cyperaceae growing in natural revetments than in vertical revetments. We proposed that habitat space be apportioned to introduce annual plants as part of stream restoration projects. And, we identified 7 families and 18 taxa of naturalized plants, majority taxa were either biennial or perennial. Moreover, naturalized ratio was higher in vertical(14.3%) than natural(12.1%), we proposed a plan to promote and improve natural streams and revetments. Furthermore, we applied a waterfront evaluation method developed by the Natural Resources Conservation Service of the USDA-NRCS, which confirmed that stream health can be improved in most regions by controlling naturalized plants and ensuring shrub and tree growth. We adopted a new method to remove naturalized plants and establish natural revetments to ensure shrub and tree growth to aid in small-stream restoration and improvement. In future studies, we hope to develop methods for small-stream restoration projects in rural areas.

• Journal of Korea Water Resources Association
• /
• v.40 no.6 s.179
• /
• pp.447-458
• /
• 2007

In this study, the coastal urban flood prediction and warning system based on HEC-RAS and SWMM were investigated to evaluate a watershed of On-Cheon stream in Busan which has characteristics of costal area cased by flooding of coastal urban areas. The basis of this study is a selection of various geological data from the numerical map that is a watershed of On-Cheon stream and computation of hydrologic GIS data. Thiessen method was used for analyzing of rainfall on the On-Cheon stream and 6th regression equation, which is Huff's Type II was time-distribution of rainfall. To evaluate the deployment of flood prediction and warning system, risk depth was used on the 3 selected areas. To find the threshold runoff for hydraulic analysis of stream, HEC-RAS was used and flood depth and threshold runoff was considered with the effect of tidal water level. To estimate urban flash flood trigger rainfall, PCSWMM 2002 was introduced for hydrologic analysis. Consequently, not only were the criteria of coastal urban flood prediction and warning system decided on the watershed of On-Cheon stream, but also the deployment flow charts of flood prediction and warning system and operation system was evaluated. This study indicates the criteria of flood prediction and warning system on the coastal areas and modeling methods with application of ArcView GIS, HEC-RAS and SWMM on the basin. For the future, flood prediction and warning system should be considered and developed to various basin cases to reduce natural flood disasters in coastal urban area.

• Korean Journal of Environment and Ecology
• /
• v.20 no.4
• /
• pp.415-424
• /
• 2006

This study was carried out to analyze the characteristics of forest watershed factors by using the quantification theory(I) for evaluation and prediction of the failure hazard area. Present $sediment(m^3/yr/ha)$ of erosion control dams were investigated in 95 sites of erosion control dam constructed during 1986 to 1999 in Gyeongnam province. The results obtained from this study were summarized as follows; General condition of class I(Very hazard area) were as follow; Igneous rock in parent rock, coniferous in forest type, below 20year in stand age, below 30cm in soil depth, SCL in soil texture, $31{\sim}40%$ in gravel contents, $S{\sim}E$ in aspect, $2,501{\sim}3,600m$ in length of main stream, $26{\sim}30$ in number of total streams, $6,601{\sim}10,000m$ in length of total streams, over 3 in stream order, over 16 in number of first streams order and over $31^{\circ}$ of slope gradient. General condition of class IIl(hazard area) were as follow; Metamorphic rock in parent rock, hardwood in forest type, over $21{\sim}24year$ in stand age, $31{\sim}40cm$ in soil depth, SiCL or SCL in soil texture, $11{\sim}20%$ in gravel contents, $S{\sim}W$ in aspect, $1,501{\sim}2,600m$ in length of main stream, $6{\sim}10$ in number of total streams, $3,501{\sim}5,500m$ in length of total streams, 2 in stream order, $6{\sim}10$ in number of first streams order and over $31^{\circ}$ of slope gradient. General condition of class III(Un hazard area) were as follow; Sedimentary rock in parent rock, mixed in forest type, over 25year in stand age, $41{\sim}50cm$ in soil depth, SiCL in soil texture, below 10% in gravel contents, $N{\sim}W$ in aspect, below 500m in length of main stream, below 5 in number of total streams, below 1,000m in length of total treams, below 1 in stream order, below 2 in number of first streams order and below $25^{\circ}$ of slope gradient. The prediction method of suitable for failure hazard area divided into class I, II, and III for the convenience of use. The score of class I evaluated as a very hazard area was over 4.8052. A score of class II was 4.8051 to 2.5602, it was evaluated as a hazard area, and class III was below 2.5601, it was evaluated as a un hazard area.

• Water for future
• /
• v.27 no.2
• /
• pp.97-109
• /
• 1994

Parameters for the Synthetic Unit Hydrograph(SUH) using SCS and v methods(including modified type) are derived by regression analysis of the Representative Unit Hydrograph(RUH) of 22 basins in Korea. These derived SUHs were compared with the RUHs and those of Snyder and HYMO given by the Korea Institute of Construction Technology (KICT) for selected 4 basins. In SCS method, when correlated with the lag time of SUHs based on the whole basin rather than on the riverwise basins the peak discharge(excluding Bocheng stream) is close to that of RUH. BUt the peak time given by riverwise basins agrees closer to the RUH than by the whole basins. The modified Nakayasu type SUH(excluding Wi stream) associated with lag time based on riverwise basins gives better agreements to the RUH than that of Nakayasu method. And the modified Nakayasu type SUH gives much better agreement to the RUH than that of Nakayasu method for the case of both whole and riverwise basins.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.28 no.4
• /
• pp.28-35
• /
• 2010

'Byeolseo(別墅)' means a kind of building that is built where is separated from main house. From the results of our field investigation, we could see that every type of the Jungja(亭子) a kind of Byeolseo-building in Gyoungnam Province. And the types of building plan found are center-focused room, eccentric room, seperated room, and the one without room. And also, we could find that the most representative location type of Byeolseo is on the hill where the cliff is on the riverside. That is, both waterscape and rockscape play an important role in the composition of landscape treatment of Byeolseo in Gyoungnam Province. In waterscape, "waterfall+swamp+fast-flowing stream" structure which is connected with river or mountain stream is found prominently, and in the case of rockscape, bedrocks, boulders, and Dae(臺) that are present in nature are used prevalently rather than an artificial hill or disposing rocks on purpose. Treating and disposing landscape of Byeolseo in Gyoungnam Province, the perspective view(average perspective distance is 5.6km) and several axes of view are used.