• Journal of agriculture & life science
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• v.50 no.4
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• pp.59-71
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• 2016

The occurrence and growth of grass and sedge weed species were investigated in the transplanted rice fields that have different transplanting dates from Apr. 30 to Jun 19 with 10-day interval. The growth and yield of rice plant grown without weed control examined in each plot that has different transplanting dates. Both grass and sedge weeds showed greater plant numbers in the early transplanted plots(Apr. 30 and May 10) than late transplanted plots. Based on the occurring number and dry weight of weeds, the experimental plots were classified into two groups, early group and late group. Weed occurrence and growth were not dramatically different within a group even the occurrence was enhanced as delayed transplanting. Echinochloa spp. that was the most problematic weed showed higher dry weight in early-transplanted field until July, however, the greater dry weight was observed in the late-transplanted plots after August. Sedge weeds including Eleocharis kuroguwai and Scirpus juincoides showed persistently higher value of dry weight in early-transplanted plots than late plots over the experimental period. As the puddling was conducted earlier, emergences of grass and sedge weeds were occurred early and weed growth rate became greater. Therefore, growth and yield of rice that transplanted early decreased more strongly due to the strong suppression by grass and sedge weeds showing the enhanced weed growth rates in early-transplanted plots. Based on the weed growth rate, the adverse effects of grass weeds was maintained for longer period than sedge weeds that showed higher growth rates before heading date of rice plant.

• Life and Agrochemicals
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• s.259
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• pp.38-39
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• 2010

• Korean Journal of Construction Engineering and Management
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• v.25 no.3
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• pp.27-36
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• 2024

The effective control of cost overrun is a crucial issue for construction companies to secure profitability. Especially in situations where cost pressures are significant due to factors such as rising raw material prices and increased financial costs due to high-interest rate policies, cost overruns resulting from project failures have a highly detrimental impact on the profitability of construction firms. The objective of this study is to analyze the current status of cost overrun control measures adopted by construction companies using the IPA technique and provide key characteristics and implications. The IPA analysis results showed that practitioners in general contractors exhibit a high level of interest and effort regarding cost overrun while the performance level is relatively low. Nevertheless, the measures considered important to control cost overruns generally show a high tendency for execution as well. Cost overrun control measures that show high importance but low execution are primarily related to collaboration and communication sectors. To effectively control cost overruns, enhancing collaboration and communication with construction supervisors/CM, headquarters, and regulatory authorities emerged as the most urgent need. Through this study, the current status and areas for improvement regarding cost overrun control measures in general contractors can be identified. This can be valuable for deriving directions and enhancements for future cost overrun control strategy development.

• Agrochemical news magazine
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• v.22 no.3 s.166
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• pp.41-43
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• 2001

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.313-335
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• 2005

Many plants take up soluble silica from the soil, and they deposit in plant tissues. Silica bodies are most commonly found in the leaf epidermis. Silica body is important factor in growth and development of plant. It help to maintain rigidity in stem and linear leaves, and its content may be correlated with resistance to fungal disease. In this study, several morphologically distinctive forms of silica bodies on Cyperaceae in Korea are recognized, which are eventually classified into two groups. Silica body type of first group (Rhynchospora, Fuirena, Scleria, Carex, Eriophorum) is A-type, which is conical in shape. Silica body type of second group (Cyperus, Scirpus, Eleocharis, Fimbristylis, Kyllinga, Bulbostylis, Lipocarpha) is B-type, which is conical in shape with numerous satellite body. These types are consistent enough to use as characters in taxonomic studies within genus. Silica body type may be associated with habitat: the species in dry region have A-type, whereas the species in wet region have B-type. These results suggested that shapes and presence or absence of silica body might be valuable to systematic analysis.

• Korean Journal of Weed Science
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• v.1 no.1
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• pp.30-43
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• 1981

On unwedded paddy fields, six cropping patterns of rice cultivation, namely direct broadcast seeding, direct row seeding, machine transplanting, early season hand transplanting, standard season hand transplanting, and late season hand transplanting, were detected with two representative rice cultivars (Milyang 23 and Sadominori) to estimate the comparative fluctuation patterns of weed flora. As a result, number of emerged weed species, most crowding stages, differences of weed growth among cropping patterns, possible tendencies of competition in plant heights among plant groups, variations in Importance Values, and Simpson's Index analysis were discussed, respectively.

• The monthly packaging world
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• s.141
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• pp.90-91
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• 2005

• Korean Journal of Plant Taxonomy
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• v.40 no.3
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• pp.179-182
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• 2010

We report S. caricina (R. Br) Benth. (Cyperaceae) as an unrecorded species from Sinan-gun, Jeollanam Province on the Korean peninsula. This taxon was known to be distributed mainly in southeast Asia, China, Japan, and the northern part of Australia. S. caricina is distinguished from other species of the genus Scleria in Korea by having congested inflorescences, 3-toothed pistillate scales at the apex, and enclosed achenes in 2 scales. The new Korean common name, 'Ae-gi-gae-ol-mi', is given considering the small-size of the plants. A description based on the morphological characters and the illustrations of this species are provided with a taxonomic key to the species of Scleria in Korea.

• Korean Journal of Plant Taxonomy
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• v.50 no.1
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• pp.84-88
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• 2020

Fimbristylis fimbristyloides (F. Muell.) Druce (Cyperaceae) belonging to Fimbristylis sect. Fuscae Ohwi, which has been ambiguous in terms of its distribution and taxonomic substance in Korea, was found on Amtae-do Island, Sinan-gun, Jeollanam-do in Korea. F. fimbristyloides is a small species that is approximately 5-15 cm tall and differs greatly from most taxa in that the spikelets are laterally compressed. In particular, F. fimbristyloides is similar to F. ovata but is distinguished by the height of the plants, falcated leaves, the number and size of spikelets per inflorescence, glabrous styles, the size of the achenes, and the presence of achene stalks. A description, differences from related species, a key to the taxa and photographs of Korean F. fimbristyloides are provided in this paper.

• Korean Journal of Plant Taxonomy
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• v.44 no.4
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• pp.247-249
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• 2014

A newly naturalized plant, Carex scoparia Schkuhr ex Willd. var. scoparia, was found in Mt. Hanseok, Injegun, Gangwon-do, Korea. It belongs to sect. Ovales Kunth and had been known from North America, and was introduced into Europe and New Zealand. This species distinguished from related taxa in Asia, Carex maackii Maxim. and Carex leporina L., by pistillate scales lanceolate and having large perigynia. We propose the new Korean name, 'Han-seok-sa-cho', based on its first collecting place. We also provide descriptions for morphological characters, illustrations, photographs and keys to allied taxa.