• Journal of the Korean Operations Research and Management Science Society
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• v.10 no.2
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• pp.1-14
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• 1985

This problem of product selection and princing are considered in congested and uncongested markets. In a congested market, such as a computer service market, product quality (the level of congestion) is partly a function of the amount of usage, which in turn depands on user choice. In an uncongested market, product qualities are set solely by providers. A model of quality and capacity variation is developed using a state equation description to represent user optimizing behavior. The model is used to study the problem of scarce resources among competing user demands through quality-dependent pricing.

• Journal of Species Research
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• v.2 no.2
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• pp.223-226
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• 2013

Pennisetum flaccidum Griseb. (Poaceae) is native to Central Asia. While monitoring Poaceae weeds nationwide in Korea, we found its new naturalized distribution in Gunsan, Jeonrabuk-do. The species is distinguished from P. alopecuroides var. alopecuroides by subsessile involucres and plumose bristles. We provide the first documented record of P. flaccidum Griseb. for Korea with the description and illustration. We also provide a taxonomic key to the species of Pennisetum in Korea.

• Journal of Species Research
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• v.6 no.3
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• pp.291-294
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• 2017

Two fungivorous Korean erotylid beetles-Triplax ainonia Lewis, 1887 and Triplax nagaoi Nakane, 1977 in the tribe Tritomini-were recorded for the first time from Korea. All Korean Triplax members are associated with the fruiting bodies of higher fungi and fungus-grown bark. Re-description, key to the species of Korean Triplax, photographs of adults, and line drawings of diagnostic characters and host fungi records are provided.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.100-108
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• 2022

We found Urtica dioica L., an unrecorded alien plant, in the Han River basin of Korea. U. dioica is considered to be native to Europe, much of temperate Asia and western North Africa. This plant has been introduced to many other parts of the world. In Particularly, it reported as an invasive species from East Asia (Japan), Oceania and South America. This species is distinguished from related Korean taxa of the genus by its unisexual flower and dioecious plant species. In the Neighbor-Joining tree, U. dioica samples from the Han River Park (Sangam-dong, Mapo-gu, Seoul) and Yangjaecheon Stream (Daechi-dong, Gangnam-gu, Seoul) clustered into a clade consisting of a U. dioica s.s. Here, we provide a precise description, illustrations, a key to the related taxa, and photographs of its habitat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.594-597
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• 2013

Two leptocephali [total length (TL) 68.2-80.5 mm] from the family Ophichthidae, collected from the waters south of Jeju Island, Korea, were identified using morphology. The two ophichthid leptocephali were identified as belonging to the genus Ophichthus based on morphological characters: 131-132 myomeres; nine gut swellings; dorsal fin origin above the middle of the body; five postanal pigments present from the anus to the caudal margin. Ultimately, both leptocephali were identified as Ophichthus asakusae, as the total number of myomeres was consistent with those of adult O. asakusae. Here, we first describe the morphological characteristics of the O. asakusae leptocephalus, and suggest diagnostic characters for leptocephali belonging to the genus Ophichthus.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.289-298
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• 2020

As part of the research program "2018 Rapid screening and identification of freshwater microorganisms using MALDI-TOF/MS library" freshwater samples were collected from a branch of the Nakdong River. Almost 300 antibiotic-resistant bacterial strains were isolated from freshwater samples and subsequently identified by 16S rRNA gene sequencing. Seventeen strains among the isolates shared high 16S rRNA gene sequence similarity (>99.0%) with known species that were not previously recorded in Korea, and each of the isolates also formed a robust phylogenetic clade with the closest species. These species were phylogenetically diverse, belonging to four phyla, seven classes, 10 orders, and 13 genera. At the genus and class level, the previously unrecorded species belonged to Rhodovarius, Xanthobacter, and Shinella of the class Alphaproteobacteria; Ottowia, Simplicispira, and Zoogloea of Betaproteobacteria; Pseudomonas, Acinetobacter, and Shewanella of Gammaproteobacteria; Arcobacter of Epsilonproteobacteria; Sphingobacterium of Sphingobacteriia; Trichococcus of Bacilli; and Leucobacter of Actinobacteria. The previously unrecorded species were further characterized by examining their gram-staining, colony and cell morphology, biochemical properties, and phylogenetic position.

• Journal of the Korea Safety Management & Science
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• v.7 no.1
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• pp.127-135
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• 2005

In general one can find an enormous number of studies about the productivity of land, labor and capital, very little has been done so far to communicate about the productivity of corporate information creating and information-consuming resources in ways that are useful to business executives. In view of the enormous share of corporate spending on information resources it would be useful in planning, budgeting, as well as in performance evaluation to measure how information resources are used in creating EVA(economic value-added). The effectiveness in deploying information resources has potentially a greater effect on corporate financial performance than any other economic influence. That in because corporate executives have greater discretion in directing what their information management staffs will do than in setting the terms for materials purchases, employee compensation, taxes or interest rates. The expenses for information are mostly in the form of overhead costs. Because expenses for information are mostly overhead costs and not for costs of goods, the prudent decision-maker should have a wide array of discretionary options available for allocating this resource. This study is intended for analysis the factors that having effects on the enterprise information productivity and is to description the factor using a foreign enterprise case study.

• Journal of Species Research
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• v.9 no.1
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• pp.1-10
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• 2020

A new dragonfly species, Nannophya koreana sp. nov., is described from Korea on the basis of morphology and mitochondrial cytochrome oxidase c subunit I (COI) gene sequences. Nannophya materials from Korea and other areas in Southeast Asia were compared. The new species was previously recognized in Korea as the endangered pygmy dragonfly Nannophya pygmaea Rambur, 1842, which is widely distributed in insular and peninsular Southeast Asia. However, male adults of the Nannophya population in Korea could be distinguished from other N. pygmaea populations by the presence of a thick, incomplete black stripe on the lateral synthorax that terminated at half-length (vs. continuous to wing base), light orange (vs. red) anal appendages, and 4-5 (vs. 2-3) black teeth on the ventral superior appendages. In addition, the body length of N. koreana was generally larger (1.2-1.4 times) than that of N. pygmaea, regardless of life stage. COI gene sequences from the two groups exhibited substantial genetic differences (>12%), thereby sufficiently substantiating their differentiation. The taxonomic status, distribution, and habitat of the new species are discussed.

• Geomechanics and Engineering
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• v.6 no.6
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• pp.613-624
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• 2014

The fractures in coal are the main migration and output channels of coalbed methane, directly influencing the permeability of the coal seams. It is of great significance to study the effect of fracture distribution in coals on the permeability of coal seam. The development rules of endogenetic and exogenetic fractures are different among various coal lithotypes. There is also difference in the fracture density for the same lithotype with different thicknesses. Through the observation and description of the macroscopic fractures in coal and the origin of fractures in coal, the effect of the coal lithotype and its thickness on fracture development in coal was discussed. It was found through the study that the density of fractures in vitrain band was the maximum for the same coal rank and thickness, followed by clarain band. There were few fractures developed in the durain band. However, the changes of fracture density in three types of bands presented different declining trends for low, medium and high coal rank. There were no fractures developed in the fusain. There were three variation patterns for the fracture densities at the same coal rank and coal lithotype: linear decrease, nonlinear decrease, and first decrease then remaining unchanged. However, the overall trend was that the fracture density decreased with the increase of thickness of coal band for the same coal rank and coal lithotype.

• Journal of Species Research
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• v.7 no.3
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• pp.240-247
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• 2018

Though several wood decay fungi have been reported in the world-wide, only about 600 wood decay fungi have been reported in Korea to date. Thus, the objective of this study was to secure resources for the wood decay fungi in Korea. We investigated wood decay fungi in Yeoninsan Provincial Park, Korea, and the collected specimens were identified based on ITS sequence analysis. Two species were unrecorded species in Korea: Postia hirsuta (Polyporales, Basidiomycota) and Hyphodontia reticulata (Hymenochaetales, Basidiomycota). Another species was previously reported without detailed description: Ceriporia alachuana (Polyporales, Basidiomycota). Here, we provided additional detailed microscopic features and phylogenetic analysis of these species.