• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.368-373
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• 2010

Juniperus chinensis var. sargentii Henry is a short and creeping evergreen shrub which reaches about 60 cm in height and only occurs in the northeast Asia and in the top of high mountains over the Korea. The Korea Forest Service protects it strictly by law since J. chinensis var. sargentii is an eccentric plant and possibly may be exterminated soon in Korea. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of J. chinensis var. sargentii. The rooting responses of branch cuttings, obtained from hard(May) and semi-hard wood shoots (August) to four growth regulators, namely, IAA, IBA, NAA and Rooton(exceptionally powder method) applied at various concentrations(0, 100, 200, 500, 1000 and 2000 $mgL^{-1}$) were examined in mixed soil media. Rooting rate showed significant difference between cutting times, among kinds and among concentrations of growth regulators. The optimum cutting time was April to May in hardwood cutting. The application of IBA 1000 $mgL^{-1}$(rooting rate : 36.4%) was most effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was 30.4%. Root characteristics such as number, length and diameter of root were not significantly affected by kinds and concentrations of growth regulators in hardwood cutting.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.255-263
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• 2015

Biological invasion of alien plants is considered to be one of the most serious threats to biodiversity in riparian zones. The effects of two invasive alien plants, Sicyos angulatus and Paspalum distichum var. indutum, on the flora and community structure of the riparian vegetation were investigated at 22 sites at streams in Korea. Sicyos angulatus has invaded the central Korean Peninsula. This alien plant has caused problems to stream managers because of its aggressive vining growth. It had suppressed native vegetation such as trees, shrubs and tall grasses on bank slope and higher floodplains. Paspalum distichum var. indutum has become more widespread in the southern part of Korea. This invasive plant has shallow rhizomes and creeping, extensively branched stolons. It forms a dense mat over lotic or slowly-flowing water and threatens submerged and short emergent hydrophytes. In order to control the introduction and expansion of alien plants, limitation of artificial disturbances and appropriate alien plant management are needed in riparian areas.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.160-165
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• 2018

BACKGROUND: Mixed cropping of legume and grass was effective system in view point of providing organic matter and nitrogen or reducing the nitrogen starvation of following crop. The relation of the change of N and P constituents depending on the cropping types and those effects on the growth and nutrient uptake of the following crop were observed. METHODS AND RESULTS: Three cropping types, hairy vetch mono cropping, barley mono cropping, and mixed cropping of hairy vetch and barley were applied. Soil properties, growth characteristics, and nitrogen production of green manure crops were observed. In additions, the effect of cropping types on the growth pattern of corn as the following crop was observed. In the mixed cropping system, creeping type hairy vetch climbed to the erect type barely for light utilization resulting in improvement of light interception rate and higher LAI (Leaf Area Index) than in mono cropping. Mixed cropping showed higher biomass production and soil nitrogen availability among the cropping types, indicating relatively much more nutrient supply and higher yield production of following crop. CONCLUSION: Mixed cropping showed relatively higher LAI (dry matter) mainly because of intense competition for light utilization usually after flowering stage. Mixed cropping also showed relatively higher yield of corn, the following crop rather than other types, mainly due to the more biomass production potential and higher N and P production ability. Therefore, mixed cropping was adaptable method to reduce or replace chemical fertilizer application for environmentally-friendly agriculture.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.216-223
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• 2019

This study was conducted to measure the changes in the geological and soil properties following slow-moving landslide events in Yangbuk-myun and Gyungju-si, Gyeongsangbuk-do, South Korea. The geological characteristics of the study site comprised black shale in the Gyeongsang nodal group formed in the Cretaceous period and quartz feldspar carcinoma in the east side with conglomerate in the Yeonil group formed in the Quaternary period. The study site exhibited the geologic characteristics of a slow-moving landslide with severely weathered rocks. The maximum collapsing depth of the slow-moving landslide was 12.0 m with colluvial deposits. The strike and joint aspects in the slope areas of the slow-moving landslides were $N46^{\circ}E$ in lower slope and $N62^{\circ}E$ in upper slope, respectively. Soil hardness of ${\leq}20cm$ deep was not measured because of the completely disturbed soil resulting from soil creeping. Soil from 25 to 90 cm deep was 1.4-4.7 times softer in the slow-moving landslide areas than in the undisturbed or natural forests. Soil bulk density was $1.24-1.29g/cm^3$ in land creep areas. Soil bulk in both areas was 1.6 times denser than that in the natural forest. The soil pore space was 51.5-53.3% in the land creep areas. The values are 1.3-1.4 times lower than those within the natural forest. Black shale areas showed the lowest coefficient of permeability (8.75 E-06 cm/s) and mesopore ratio (pF 2.7: 9.8%) compared with those resulting from other study areas.

• Steel and Composite Structures
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• v.48 no.2
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• pp.207-233
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• 2023

Steel-concrete composite box girder bridges are widely used in the construction of highway and railway bridges both domestically and abroad due to their advantages of being light weight and having a large spanning ability and very large torsional rigidity. Composite box girder bridges exhibit the effects of shear lag, restrained torsion, distortion and interface bidirectional slip under various loads during operation. As one of the most commonly used calculation tools in bridge engineering analysis, one-dimensional models offer the advantages of high calculation efficiency and strong stability. Currently, research on the one-dimensional model of composite beams mainly focuses on simulating interface longitudinal slip and the shear lag effect. There are relatively few studies on the one-dimensional model which can consider the effects of restrained torsion, distortion and interface transverse slip. Additionally, there are few studies on vehicle-bridge integrated systems where a one-dimensional model is used as a tool that only considers the calculations of natural frequency, mode and moving load conditions to study the dynamic response of composite beams. Some scholars have established a dynamic analysis model of a coupled composite beam bridge-train system, but where the composite beam is only simulated using a Euler beam or Timoshenko beam. As a result, it is impossible to comprehensively consider multiple complex force effects, such as shear lag, restrained torsion, distortion and interface bidirectional slip of composite beams. In this paper, a 27 DOF vehicle rigid body model is used to simulate train operation. A two-node 26 DOF finite beam element with composed box beams considering the effects of shear lag, restrained torsion, distortion and interface bidirectional slip is proposed. The dynamic analysis model of the coupled composite box girder bridge-train system is constructed based on the wheel-rail contact relationship of vertical close-fitting and lateral linear creeping slip. Furthermore, the accuracy of the dynamic analysis model is verified via the measured dynamic response data of a practical composite box girder bridge. Finally, the dynamic analysis model is applied in order to study the influence of various mechanical effects on the dynamic performance of the vehicle-bridge system.

• The Korean Journal of Mycology
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• v.20 no.1
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• pp.37-43
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• 1992

Typhula incarnata grew over a temperature range of -5 to $20^{\circ}C$ with maximum growth at 10 to $15^{\circ}C$. Sclerotial production for T. incarnata was greatest at the higher temperature. Maximum mycelial growth of this pathogen occurred from pH 5.4 to 6.2. When carbon sources were added to a basal salt medium (Czapek's dox agar) at 5 g carbon sources/l, inulin, soluble starch, galactose, glucose, mannose, manitol, sucrose, maltose, cellobirose, trehalose, raffinose, and dextrin supported growth better than other carbon sources did. Of the twenty-three nitrogen sources tested, glycine, serine, ammonium sulfate, asparagine, asparatic acid, and ${\beta}-alanine$ were the most favorable for mycelial growth of T. incarnata. Cystine and cysteine were poor nitrogen sources. Ammonium salt of nitrogen sources supported growth better than nitrate salt of nitrogen sources. Potato dextrose agar, oat meal agar, and V-8 juice agar were the most favorable for mycelial growth and sclerotial formation. Appropriate addition of pepton to PDA decreased mycelial dry weight, but sucrose supported good growth of T. incarnata. Percent viable sclerotia of T. incarnate buried in bentgrass soil decreased from 2 months after treatment remarkably. Trichoderma riride and bacteria were isolated from non-germinated sclerotia. Live orchard grass leaf pieces within the soil were colonized by T. incarnata better than sterile and unsterile dead leaf pieces at $0^{\circ}C$. Saprophytic ability of T. incarnate on sterile leaf sheath occurred better at $0^{\circ}C$ than at $10^{\circ}C$. Saprophytic microflora consisting of Cladosporium sp., Fusarium sp., Mucor sp., Pythium sp., and unidentified fungi were the competitors for the sterilized and unsterilized substrate, but their colonization was not find on live leaf sheath buried in the soil at $0^{\circ}C$. In the effect of fungicides to Typhula snow mold disease of creeping bentgrass, mixture of polyoxin and thiram was the most effective, followed by iprodione, mixture of iprodione and oxine copper, thiophanate-methyl, myclobutanil, and tolclofos-methyl.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.567-573
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• 2010

Research was initiated to investigate early establishment characteristics and germination pattern of fine-textured fescues (FF). Six varieties from Chewings fescue ($Festuca$ $rubra$ L. ssp. $commutata$ Gaud., CF), creeping red fescue ($F.$ $rubra$ L. ssp. $rubra$ Gaud., CRF), hard fescue ($F.$ $ovina$ ssp. $longifolia$ Thuill., HF) and sheep fescue ($F.$ $ovina$ L., SF) were evaluated in the study. An alternative environmental condition requiring a FF germination test by International Seed Testing Association (ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Daily and cumulative germination patterns were measured and analyzed on a daily basis. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 60% germination, and germination rate. The final germination percentage was variable with species and varieties, being 40.25 to 82.00% at the end of study. There were considerable variations in early germination characteristics and germination pattern among FF species. The first germination in all entries except HF was initiated between 5 and 6 DAS (days after seeding) under ISTA conditions, while HF between 6 and 7 DAS, being 1 day later. It was 8 to 10 DAS in days to the 50% germination, which was 2 to 4 days after the first germination date. Days to the 60% germination were 9.10 to 14.80 DAS under ISTA conditions, being 5.70 days in differences among the entries. CF 'Jamestown II' and 'Shadow II' and HF 'Aurora Gold' were the fast varieties. The slowest one was HF 'Rescue 911'. Among FF species, turf establishment speed was becoming faster in CRF, SF, HF and CF in this order. Information on differences in germination characteristics and pattern from this study would be usefully applied for golf course design and construction, when established with FF.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.265-271
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• 1994

This study was conducted to determine the herbicidal activity, persistance, downward movement and effect on bentgrass of 7 dinitroaniline herbicides such as benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl) benzenamine], beslogine [N,N-dibutyl-2,6-dinitro-4-trifluoromethylaniline], prodiamine [2,4-dinitro-$N^3$,$N^3$-dipropyl-6-(trifluoromethyl)-1,3-benzenediamine], pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine], trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl) benzenamine], ethalfluralin [N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine], and oryzalin [4-(diprop-ylamino)-3,5-dinitrobenzene-sulfonamide) together with bensulide [O,O-bis(1-methylethyl) S-[2-[(phenyl-sulfonyl) amino]ethyl]phosphorodithioate] and siduron [N-(2-methylcyclohexyl)-N'-phenylurea) as the control. In addition, distribution of pendimethalin and benefin into bentgrass was also determined. Prodiamine, benefin, and pendimethalin at the 1/16 dose of the recommended rate showed very high herbicidal activity($LD_{90}$) on Digitaria sanguinalis, but ethalfluralin and bensulide showed $LD_{90}$ at the 1/4 dose of the recommended rate, showing difference in herbicidal activities among dinitroaniline herbicides. All the herbicides except for pendimethalin had the lower herbicidal activity in sandy soil than that of clay-loam soil. Benefin, beslogine, prodiamine, oryzalin, bensulide and siduron persisted in the soil for about 50 days, but pendimethalin persisted in the soil for about 35 days, and trifluralin and ethalfluralin for about 25 days. Ethalfluralin, oryzalin and bensulide were the most mobile(downward movement) of the 9 herbicides studied. Less mobility was observed in the turfgrass condition than that of the bare soil. Beslogine bensulide prodiamine and benefin had no injury effect on bentgrass(Agrastis atolonifera L., penncross creeping bent grass). However, herbicides like oryzalin, trifluralin and pendimethalin reduced the dry weight of bentgrass by 12%, 30% and 40%, respectively. No significant difference in distribution of pendimethalin and benefin into inner part of leaves, surface and wax layer of bentgrass was observed, and thus it seems that different phytotoxic effect between pendimethalin and benefin may be attributed to different metabolism and mode of action.

• Journal of Korean Home Economics Education Association
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• v.17 no.3 s.37
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• pp.83-96
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• 2005

To assess the food intake and diet quality of high school students who live in Chuncheon area, a dietary survey using 24-hour recall method was conducted with 318 subjects. $71.4\%$ of total food intake was in the form of plant foods and the rest on the form of animal food. Diet quality was assessed by food group pattern, dietary diversity score(DDS), and dietary variety score(DVS). When counting the major food groups consumed, $37.1\%$ of subjects had a DDS of 3 and $48.4\%$ of subjects had a DDS of 4. When investigating the consumption pattern of the major five food groups, only $14.5\%$ of subjects consumed foods from all five groups. On average, subjects habitually consumed 26.7 different foods daily, with the mean score of diet variety for males (27.3) being significantly higher than for females (25.8) . Correlation coefficients between nutrient adequacy ratio (NAR) and DVS ranged from r=0.39 for vitamin $B_2$ to r=0.61 for phosphorus. NAR also improved as the number or foods or rna groups consumed increased (p<0.001). Associations between the NAR and high level of DVS was more positive than those between the NAR with DDS. When assessing the dietary quality of subjects using DDS and DVS, many people appeared not to have a desirable food intake. Therefore, to lead them to have nutritionally balanced diet, educating students and their parents on nutrients and suggesting guidelines for a desirable diet is considered to be essential so that they can intake from all of major food group and have various foods in their diet.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.65-76
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• 2006

Scz1, an isolate of Sclerotinia homoeocarpa, was recently reported as a novel pathogen responsible for dollar spot disease in Zoysiagrass, a warm season turfgrass. Scz1 possessed different characteristics on mycelial pigment, mycelial affinity and host pathogenecity compared to those of Scb1, a typical isolate, obtained from creeping bentgrass, a cool season turfgrass. In this study, only three isolates, Scz1, Scz2(another analogous isolate of Sclerotinia homoeocarpa from zoysiagrass), and Scb1, were examined at the molecular level using the internal transcribed spacer(ITS) and random amplified polymorphic DNA(RAPD) assays to verify their identification and genetic variation. As a result of ITS assay, partial ITS sequences of three isolates showed 94-97% similarity with a standardized ITS sequence of S. homoeocarpa registered on BLAST. In the analysis of RAPD, range value through similarity matrix was 0.167 between Scz1 and Scb1, 0.139 between Scz2 and Scb1, and 0.713 between Scz1 and Scz2, respectively. Furthermore, tendegram analysis indicated that Scz1 and Scz2, unlike Scb1, were clustered together as accompanying a high genetic similarity. In in vitro fungicide bioassay, $EC_{50}$ value representing the sensitivity degree to propiconazole, a well-known fungicide for dollar spot disease, was 0.012 ${\mu}g/ml$ for Sczl, 0.003 ${\mu}g/ml$ for Scz2, and 0.030 ${\mu}g/ml$ for Scb1. From all data taken, we concluded that both Scz1 and Scz2 belonged to one group of S. homoeocarpa, since they exhibit the same host range and high level of genetic similarity, whereas their chemical competences to a fungicide were different. This study would provide further approach for assessing genetic diversity of S. homoeocarpa isolates as well as characterizing individual isolate against chemical exposure.