• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.353-362
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• 2009

This study attempted to compare the litter decomposition rate of Arundinella hirta and Miscanthus sinensis var. purpurascens which collected from serpentine soil acting potentially toxic concentration of heavy metals and non-serpentine soil by using the microcosm method for 192 days under constant humidity and $23^{\circ}C$. The contents of Ni, Fe, Mg and Cr in the serpentine and nonserpentine soil originated litter showed high differences between them. The litter samples from serpentine site have lower C/N than non-serpentine litter, but the soluble carbohydrate content was shown almost similar between two plant litter. The mass loss rates of leaf litter from serpentine area were slower than those from non-serpentine site. During the experimental period, the remained dry weight of A. hirta and M. sinensis var. purpurascens litter collected from serpentine site were 64.7%, 65.0% of initial dry weight and litter samples from non-serpentine site showed 54.2%, 50.7%, respectively. K and Na were leached rapidly at the initial decomposition periods, but Ca showed immobilization and other metal elements reserved at the decomposing litter for a long time. The decomposing A. hirta litter from non-serpentine soil showed higher values of $CO_2$ evolution, microbial biomass-C, and microbial biomass-N than those in serpentine soil originated litter acting nutrient stresses and exhibited rapid decay rate. The microbial biomass and microbial respiration of decaying litter were positively correlated with litter decomposition rate, and these relationships showed more rapid slope in non-serpentine soil originated litter than that in serpentine soil.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.847-864
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• 1995

In this paper we present an integrated methodology for strategic planning in telecommunications standardization. Especially this paper focuses on the method of setting priorities for telecommunications SWAs(Standardization Work Areas) and related SWls(Standardization Work Items). To make a strategic plan for telecommunications standardization in which usually includes prioritization, resource allocation, standardization schedule for each SWA is based on prioritization of SWAs. Our methodology integrated various existing methods including the Analytic Hierarchy Process(AHP) and a modified Delphi technique. Recently, rapid technology evolution in telecommunications fields increases the necessity of developing more and more new standards. Also increased complexity of those technologies makes standards more complicated, more specified and more thick than the past ones. As a result, the number of SWAs and SWIs are being increased constantly. Furthermore, rapid telecommunication environment changes such as deregulation, liberalization, privatization, regionalization, and globalization surrounding standardization bring about new challenges and opportunities. Due to all these trends, strategic planning for telecommunications standardization grows more and more important. To cope with these challenges and also to make the more efficient use of the limited standardization resources including time, financial, human resources, we suggest more logical and rational approach that will be a backbone of strategic plan for telecommunications standardization. The telecommunications standardization planning process involves a MCDM(Multi-Criteria Decision Making) process. The Analytic Hierarchy Process(AHP) is a kind of MCDM approaches. Our method is based on a combination of a modified Delphi technique and an application of AHP(Liberator's spreadsheet model). Analyzed data from Delphi technique is used as inputs to ABP. In addition, we also focus on the technique how to combine group judgments and to handle a large number of comparisons. We present analyzed results including Pilot and Full Scale Survey according to the proposed process. The result of this study will be useful input for telecommunications standardization policy making and practical implementation.

• 한국균학회소식:학술대회논문집
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• 2018.05a
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• pp.37-37
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• 2018

Mating type of Lentinula edodes is determined by two unlinked genetic loci, A and B. To better understand mating behavior of L. edodes, we investigated variations in mating type genes in129 dikaryotic strains collected from East Asia. Through sequence analysis of A locus, we discovered that hypervariable region spanning N-term of HD2-intergenic region-N-term of HD1 could represent A mating type. Mating and hypervariable region analyses revealed 70 unique A mating types: 27 from 98 cultivated strains, 53 from 31 wild strains, and 10 commonly found. It was also revealed that only a few A mating type alleles such as A1, A4, A5, and A7 were prevalent in cultivated strains. Contrarily, A mating type in wild strains was highly diverse: 23 unique A alleles were discovered in small mountainous area in Korean peninsula, suggesting rapid evolution of A mating type in nature. The B locus was assessed by allelic variations in pheromone (PHB) and pheromone receptor (RCB) pairs which constituted subloci Ba and Bb. Sequence analyses and mating assay revealed 5 alleles of RCB1 with 9 associated PHBs in Ba sublocus and 3 alleles of RCB2 with 5 associated PHBs in Bb sublocus. Each RCB was primarily associated with two PHBs. Each PHB-RCB pair was always discovered as a distinct unit. This allowed us to propose 15 B mating types via combinations of five Ba and three Bb subloci. Further investigation on 129 strains confirmed that the B locus, unlike the A locus, was indeed restricted to 15 mating types. Thus, the total number of mating types became 1,050 in L. edodes through a combination of 70 A and 15 B. This number will further increase because of rapid diversification of A mating type. Our findings provide a comprehensive and practical knowledge on mating behaviors of L. edodes.

• Journal of Powder Materials
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• v.17 no.3
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• pp.190-196
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• 2010

In this paper, rapid solidified Mg-4.3Zn-0.7Y (at.%) alloy powders were prepared using an inert gas atomizer, followed by a severe plastic deformation technique of high pressure torsion (HPT) for consolidation of the powders. The gas atomized powders were almost spherical in shape, and grain size was as fine as less than $5\;{\mu}m$ due to rapid solidification. Plastic deformation responses during HPT were simulated using the finite element method, which shows in good agreement with the analytical solutions of a strain expression in torsion. Varying the HPT processing temperature from ambient to 473 K, the behavior of powder consolidation, matrix microstructural evolution and mechanical properties of the compacts was investigated. The gas atomized powders were deformed plastically as well as fully densified, resulting in effective grain size refinements and enhanced microhardness values.

• Smart Structures and Systems
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• v.31 no.2
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• pp.101-111
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• 2023

Structural health monitoring (SHM) covers a range of damage detection strategies for buildings. In real-time, SHM provides a basis for rapid decision making to optimise the speed and economic efficiency of post-event response. Previous work introduced an SHM method based on identifying structural nonlinear hysteretic parameters and their evolution from structural force-deformation hysteresis loops in real-time. This research extends and generalises this method to investigate the impact of a wide range of flag-shaped or pinching shape nonlinear hysteretic response and its impact on the SHM accuracy. A particular focus is plastic stiffness (K_p), where accurate identification of this parameter enables accurate identification of net and total plastic deformation and plastic energy dissipated, all of which are directly related to damage and infrequently assessed in SHM. A sensitivity study using a realistic seismic case study with known ground truth values investigates the impact of hysteresis loop shape, as well as added noise, on SHM accuracy using a suite of 20 ground motions from the PEER database. Monte Carlo analysis over 22,000 simulations with different hysteresis loops and added noise resulted in absolute percentage identification error (median, (IQR)) in K_p of 1.88% (0.79, 4.94)%. Errors were larger where five events (Earthquakes #1, 6, 9, 14) have very large errors over 100% for resulted K_p as an almost entirely linear response yielded only negligible plastic response, increasing identification error. The sensitivity analysis shows accuracy is reduces to within 3% when plastic drift is induced. This method shows clear potential to provide accurate, real-time metrics of non-linear stiffness and deformation to assist rapid damage assessment and decision making, utilising algorithms significantly simpler than previous non-linear structural model-based parameter identification SHM methods.

• The Plant Pathology Journal
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• v.39 no.2
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• pp.191-206
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• 2023

Ground cherry (Physalis pubescens) is the most prominent species in the Solanaceae family due to its nutritional content, and prospective health advantages. It is grown all over the world, but notably in northern China. In 2019 firstly bacterial leaf spot (BLS) disease was identified on P. pubescens in China that caused by both BLS pathogens Xanthomonas euvesicatoria pv. euvesicatoria resulted in substantial monetary losses. Here, we compared whole genome sequences of X. euvesicatoria to other Xanthomonas species that caused BLS diseases for high similarities and dissimilarities in genomic sequences through average nucleotide identity (ANI) and BLAST comparison. Molecular techniques and phylogenetic trees were adopted to detect X. euvesicatoria on P. pubescens using recQ, hrpB1, and hrpB2 genes for efficient and precise identification. For rapid molecular detection of X. euvesicatoria, loop-mediated isothermal amplification, polymerase chain reaction (PCR), and real-time PCR techniques were used. Whole genome comparison results showed that the genome of X. euvesicatoria was more closely relative to X. perforans than X. vesicatoria, and X. gardneri with 98%, 84%, and 86% ANI, respectively. All infected leaves of P. pubescens found positive amplification, and negative controls did not show amplification. The findings of evolutionary history revealed that isolated strains XeC10RQ, XeH9RQ, XeA10RQ, and XeB10RQ that originated from China were closely relative and highly homologous to the X. euvesicatoria. This research provides information to researchers on genomic variation in BLS pathogens, and further molecular evolution and identification of X. euvesicatoria using the unique target recQ gene through advance molecular approaches.

• Journal of The Korean Astronomical Society
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• v.56 no.1
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• pp.11-22
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• 2023

We report the result of a high-resolution spectroscopic study on seven magnesium (Mg) enhanced stars. The high Mg abundances in these stars imply that they were born in an environment heavily affected by the nucleosynthesis products of massive stars. We measure abundances of 16 elements including Mg and they show various abundance patterns implying their diverse origin. Three of our program stars show a very high Mg to Si ratio ([Mg/Si] ≈ 0.18-0.25), which might be well explained by fall-back supernovae or by supernovae with rapid rotating progenitors having an initial mass higher than about 20 M_⊙. Another three of our program stars have high light to heavy s-process element ratios ([Y/Ba] ≈ 0.30-0.44), which are consistent with the theoretical prediction of the nucleosynthesis in rapidly rotating massive stars with an initial mass of about M = 40 M_⊙. We also report a star having both high Y ([Y/Fe] = 0.2) and Ba ([Ba/Fe] = 0.28) abundance ratios, and it also shows the highest Zn abundance ratio ([Zn/Fe] = 0.27) among our sample, implying the nucleosynthesis by asymmetric supernova explosion induced by very rapid rotation of a massive progenitor having an initial mass between 20 M_⊙ ≲ M ≲ 40 M_⊙. A relative deficiency of odd-number elements, which would be a signature of the pair-instability nucleosynthesis, is not found in our sample.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.58-62
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• 2006

Rapid assay of enzyme is a primary requirement for successful application of directed evolution technology. Halo generation on a turbid plate would be a method of choice for high throughput screening of enzymes in this context. Here we report a new approach to prepare turbid plates, by controlling the crystallization of tyrosine to form needle-like particles. In the presence of tyrosine phenol-lyase (TPL), the needle-like tyrosine crystals were converted to soluble phenol rapidly than the usual rectangular tyrosine crystals. When an error-prone PCR library of Citrobacter freundii TPL was spread on the turbid plate, approximately 10% of the colonies displayed recognizable halos after 24 hours of incubation at $37^{\circ}C$. Representative positives from the turbid plates were transferred to LB-medium in 96-wellplates, cultivated overnight, and assayed for the enzyme activity with L-tyrosine as the substrate. The assay results were approximated to be proportional to the halo size on turbid plates, suggesting the screening system is directly applicable to the directed evolution of TPL. Actually, two best mutants on the turbid plates were identified to be $2{\sim}2.5$ and 1.5-fold improved in the activity.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.4
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• pp.509-526
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• 2008

This paper aims to examine the evolutionary dynamics of the Korea's footwear industry by adopting evolutionary perspectives. To explain the evolutionary dynamics of an industry, evolutionary perspectives have paid a particular attention to exploring a variety of factors for influencing the evolution of the industry, such as the selection and imitation of the firm, the mechanism of firm's entry and exit, technological characteristics and innovation processes. The majority of existing research tend to explain that the decline of the Korea's footwear industry since 1990 was mostly due to the rapid rising of wage and the structural changes in labor-intensive industries. On the contrary, this paper attempts to explain the decline of the Korea's footwear industry, in terms of the path of selection and imitation, the dominant technological paradigm, regulatory frameworks and the meso trajectory of industry evolution. This paper concludes that the decline of the Korea's footwear industry since 1990 was appeared as a result of the evolutionary selection processes of the firms in order to adapt to changes in the environment of competition and the regime of market selection in the global footwear industry.

• The Journal of the Petrological Society of Korea
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• v.17 no.1
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• pp.1-15
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• 2008

The metasedimentary rocks of the Nampo Croup consisting of metaconglomerates, metasandstones, phyllites are exposed in the area of the Daechcon beach and Maryangri, Seocheon-gun. Their typical metamorphic assemblages of Bt-Mus-Grt-Qtz (${\pm}Pl{\pm}Chl$) and Bt-Mus-Qtz (${\pm}Pl{\pm}Chl$) indicate that they have been under intermediate P/T type metamorphism and were metamorphosed to garnet zone grade of amphibolite-facies during the Daebo Orogeny. Pressure-temperature conditions of peak metamorphism estimated from geothermobarometries are $560{\sim}595^{\circ}C$, $6.9{\sim}8.2\;kb$ respectively. The results of K-Ar biotite age determination are $143.2{\pm}3.6\;Ma$, $122.6{\pm}2.4\;Ma$ and $124.8{\pm}2.4\;Ma$ and the last two ages are considered as the results of later-stage thermal perturbation. On the bases of the formation age of Daedong Supergroup of $187{\sim}172\;Ma$ (Han et al., 2006; Jeon et al., 2007) combined with the results of this study, the hypothetical model of tectonometamorphic evolution of the study area during Daebo Orogeny is proposed. Crustal thickening resulted from folding and duplexing of thrusts in the area initiated at around 175 Ma just after sedimentation of Nampo Croup. And then rapid cooling by normal faulting due to crustal extention followed immediately after the peak metamorphism to the closure temperature of biotite.