• Mycobiology
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• v.47 no.3
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• pp.261-272
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• 2019

Oomycetes are widely distributed in various environments, including desert and polar regions. Depending upon different habits and hosts, they have evolved with both saprophytic and pathogenic nutritional modes. Freshwater ecosystem is one of the most important habitats for members of oomycetes. Most studies on oomycete diversity, however, have been biased mostly towards terrestrial phytopathogenic species, rather than aquatic species, although their roles as saprophytes and parasites are essential for freshwater ecosystems. In this study, we isolated oomycete strains from soil sediment, algae, and decaying plant debris in freshwater streams of Korea. The strains were identified based on cultural and morphological characteristics, as well as molecular phylogenetic analyses of ITS rDNA, cox1, and cox2 mtDNA sequences. As a result, we discovered eight oomycete species previously unknown in Korea, namely Phytopythium chamaehyphon, Phytopythium litorale, Phytopythium vexans, Pythium diclinum, Pythium heterothallicum, Pythium inflatum, Pythium intermedium, and Pythium oopapillum. Diversity and ecology of freshwater oomycetes in Korea are poorly understood. This study could contribute to understand their distribution and ecological function in freshwater ecosystem.

• Mycobiology
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• v.49 no.5
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• pp.476-490
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• 2021

Global temperatures are steadily increasing, leading to significant changes in microbial diversity and ecology. In the present study, we isolated high-temperature-growing fungi and fungi-like group (Oomycota) strains from freshwater environments of Korea and identified them based on cultural, morphological, and multilocus phylogenetic analyses. As a result, we introduce Saksenaea (Fungi) isolates as a new species, Saksenaea longicolla sp. nov. and record Phytophthora chlamydospora and P. lagoariana (Oomycota) new to Korea. In the growth experiments, they exhibited high-temperature tolerance, which can grow at 35-40 ℃ but become inactive at 4 ℃ and below. This study confirms the presence of high-temperature-tolerant fungi and oomycetes in Korea and suggests that the Korean climate conditions are changing in favor of these species. This indicates that climate warming is altering microbial distributions in freshwater environments.

• Animal Systematics, Evolution and Diversity
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• v.37 no.4
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• pp.322-329
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• 2021

A depressariid moth, Agonopterix issikii Clarke, 1962, feeing on Orixa japonica was newly recorded from Korea. Agonopterix issikii can be characterized by the brownish forewing mottled dark brown and black scales that show a dentate line at the base and three minute blackish dots in triangular at the median, and the basally pale gray hindwing. Agonopterix issikii is similar to A. ocellana Fabricius in external appearance but can be distinguished by the presence of brownish forewing with three blackish triangular dots at the median. The male genitalia of Agonopterix issikii can be characterized by the elliptic gnathos, the triangular socius, the rectangular valva with rather straight cuiller, and the stout phallus with a short basal process and the absence of cornutus. The female genitalia can be characterized by the funnel-shaped ostium bursae, the long ducuts bursae, and the ovate corpus bursae with a rounded patch of signa. To date, 12 species of the genus Agonopterix have been recorded in Korea.

• Knowledge Management Research
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• v.19 no.4
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• pp.99-118
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• 2018

Recently, individuals are interested in a variety of products and services based on artificial intelligence. Among those products and services, an intelligent personal assistants are attracting many attention from IT companies as a next generation platform. Thus, the main purpose of this study is to investigate effects of intelligent personal assistant's benefits on user's value formation and adoption behavior based on Value-based Adoption Model. In addition, the moderating effect of personal innovativeness is examined through empirical analysis. Based on the analysis with the data from actual users, the results show that usefulness, enjoyment, technicality and cost advantage have significant influences on perceived value and correspondingly have an effect on intention to adopt. Personal innovativeness is related to the relationship between perceived value and intention to adopt. These findings may provide important insights to the relevant field regarding the use and spread of intelligent personal assistants.

• Journal of the Korean Physical Society
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• v.73 no.11
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• pp.1787-1793
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• 2018

The power conversion efficiency of perovskite solar cells has reached 23.3%. Although significant developments have been made through intensive studies, the stability issue is still challenging. Passivation of perovskite solar cells with a transparent polymer provides better stability; however, there are a few disadvantages of organic polymer such as low thermal stability, weak adhesion and the lack of water retention ability. In this work, we prepared a dual Parylene-F/C layer with 3-methacryloxypropyltrimethoxysilane, A-174, to combine the advantages of organic and inorganic materials. As a result, A-174 treated dual Parylene-F/C layer demonstrated improved passivation effects compared to a single Parylene layer due to the strong binding of Parylene and the water retention ability by $SiO_2$ formed from A-174. This synergetic effects can be expanded to the combination of other organic materials and organosilane compounds.

• Journal of the Korean Physical Society
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• v.73 no.11
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• pp.1725-1728
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• 2018

We synthesized the gold nanoparticles (Au NPs)-embedded methylammonium lead iodide ($MAPbI_3$) film for the first time. The effects of metal nanoparticles on $MAPbI_3$ perovskite were systematically studied using UV-Vis absorption and photoluminescence (PL) measurements. As a result, the 20-nm-sized Au NPs-embedded $MAPbI_3$ film exhibited a 4.15% higher absorbance than the bare $MAPbI_3$ film. Moreover, the average PL intensity of the Au NPs-embedded $MAPbI_3$ film increased by about 75.25% over the bare $MAPbI_3$ film. Therefore, we have confirmed that addition of the Au NPs has a positive effect on the optical properties of $MAPbI_3$, and we believe that this study will provide a basic insight into the metal nanoparticles-embedded perovskite thin films for the future optoelectronic applications.

• Journal of the Korean Physical Society
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• v.73 no.11
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• pp.1675-1678
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• 2018

Methylammonium lead halide ($MAPbI_3$) perovskites are considered as promising materials owing to their excellent optical and electrical properties. However, perovskite materials suffer from degradation in air, which limits their practical applications. Here, we demonstrate successful passivation of the $MAPbI_3$ photodetectors through monochloro-para-xylylene (Parylene-C) deposition. The time-dependent photocurrent characteristics were systematically investigated, and we achieved significantly improved device performance and stability with Parylene-C passivation. Based on the excitation-power-dependent photoluminescence (PL) data, we confirmed that Parylene-C can reduce the carrier losses in $MAPbI_3$, leading to the enhancement of photocurrent and PL in $MAPbI_3$ photodetectors.

• Animal Systematics, Evolution and Diversity
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• v.38 no.4
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• pp.238-241
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• 2022

Two species of the Drepanidae are newly recorded from Korea. Habrosyne indica formosana Werny, 1966 and Neodaruma tamanukii Matsumura, 1933. Habrosyne indica formosana can be distinguished by the blackish forewing with a large inverse triangular medial band and the whitish pink subtermen running from the apex to tornus, and the blackish hindwing. Neodaruma tamanukii can be distinguished by the dark grayish forewing with a pair of parallel undulating, blackish antemedial and postmedial lines and a large, renal-shaped discal dot, and a pale grayish undulating subterminal line of the forewing, and the whitish hindwing with a darkly colored postmedial line and subtermen. We provide the diagnosis and figures of adult and genitalia.

• Animal Systematics, Evolution and Diversity
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• v.38 no.4
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• pp.260-262
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• 2022

One species of the Herminiinae, Hadennia nakatanii Owada is newly recorded from Korea. Hadennia nakatanii can be distinguished by the light blackish forewing with the relatively thick, transverse medial line, a large light yellowish discal dot, the thick blackish slanted band from the apex to the middle part of the dorsum, and the light blackish hindwing, basally suffused with black and medially broadly suffused with black. The female genitalia can be diagnosed by the simple antrum, the long strongly sclerotized ductus bursae, and the large rectangular corpus bursae with a small uplifted signa patch with minute spicules. We provided the figures of adult and the genitalia with short notes on distribution.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.6
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• pp.355-365
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• 2022

This paper addresses the problem of real-time tracking a high-speed ballistic target. Particle filters can be considered to overcome the nonlinearity in motion and measurement models in the ballistic target. However, it is difficult to apply particle filters to real-time systems because particle filters generally require much computation time. This paper proposes an accelerated particle filter using graphics processing unit (GPU) for real-time ballistic target tracking. The real-time performance of the proposed method was tested and analyzed on a widely-used embedded system. The comparison results with the conventional particle filter on CPU (central processing unit) showed that the proposed method improved the real-time performance by reducing computation time significantly.