• Convergence Security Journal
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• v.24 no.1
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• pp.21-26
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• 2024

The security model in the previous network environment has a vulnerability in which resource access control for trusted users is not properly achieved using the Perimeter model based on trust. The Zero Trust is an absolute principle to assume that the users and devices accessing internal data have nothing to trust. Applying the Zero Trust principle is very successful in reducing the attack surface of an organization, and by using the Zero Trust, it is possible to minimize damage when an attack occurs by limiting the intrusion to one small area through segmentation. ZTNA is a major technology that enables organizations to implement Zero Trust security, and similar to Software Defined Boundary (SDP), ZTNA hides most of its infrastructure and services, establishing one-to-one encrypted connections between devices and the resources they need. In this study, we review the functions and requirements that become the principles of the ZTNA architecture, and also study the security requirements and additional considerations according to the construction and operation of the ZTNA solution.

• Smart Media Journal
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• v.12 no.11
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• pp.36-47
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• 2023

Industrial Control System(ICS), which controls facilities at major industrial sites, is increasingly connected to other systems through networks. With this integration and the development of intelligent attacks that can lead to a single external intrusion as a whole system paralysis, the risk and impact of security on industrial control systems are increasing. As a result, research on how to protect and detect cyber attacks is actively underway, and deep learning models in the form of unsupervised learning have achieved a lot, and many abnormal detection technologies based on deep learning are being introduced. In this study, we emphasize the application of preprocessing methodologies to enhance the anomaly detection performance of deep learning models on time series data. The results demonstrate the effectiveness of a Wavelet Transform (WT)-based noise reduction methodology as a preprocessing technique for deep learning-based anomaly detection. Particularly, by incorporating sensor characteristics through clustering, the differential application of the Dual-Tree Complex Wavelet Transform proves to be the most effective approach in improving the detection performance of cyber attacks.

• The Journal of Engineering Geology
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• v.10 no.3
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• pp.247-261
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• 2000

The geostatistical analyses for the chemical components of pH, TS, KMnO4 Demand, Cl, SO$_4$ and NO$_3$-N are carried out to understand the groundwater contamination in Pusan. The average values of each component are 7.2 for pH, 336.4mg/$\ell$ for TS, 2.3mg/$\ell$ for KMnO$_4$ Demand, 44.3mg/$\ell$ for Cl, 36.0mg/$\ell$ for SO$_4$, and 4.6mg/$\ell$ for NO$_3$-N. The ratios over the drinking standard of each component are 0.34% for pH, 2.27% for TS, 1.55% for KMnO$_4$ Demand, 1.59% for Cl, 0.57% for SO$_4$, and 3.7% for NO$_3$-N. The highest ratio of NO$_3$-N results from the municipal sewage and exhaust gas of vehicles. The isopleth maps of 6 chemical components show that the high values of groundwater contamination come from the inland of Pusan, and that some high values appear at the coastal area. The isopleth maps of Cl and SO$_4$ related with seawater intrusion also show that the high values appear only at the particular coastal area, not at the whole area. On the isopleth maps of Cl and SO$_4$, the anomalies of the concentration contours were compared with the directions of two large fault zones, the Ilkwang Fault and the Dongrae Fault. Apparently, they don't have the particular correlation. Therefore, it is concluded that the main source of groundwater contamination in Pusan is not the seawater, but the municipal sewage and other sources such as the exhaust gas of vehicles, the contaminated surface water, the waste water of factories, and the leachate of waste landfills.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.203-214
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• 2018

The purpose of this study is to estimate the concentrated distribution area of nutria (Myocastor coypus) and potential suitable habitat and to provide useful data for the effective management direction setting. Based on the nationwide distribution data of nutria, the cross-validation value was applied to analyze the distribution density. As a result, the concentrated distribution areas thatrequired preferential elimination is found in 14 administrative areas including Busan Metropolitan City, Daegu Metropolitan City, 11 cities and counties in Gyeongsangnam-do and 1 county in Gyeongsangbuk-do. In the potential suitable habitat estimation using a MaxEnt (Maximum Entropy) model, the possibility of emergency was found in the Nakdong River middle and lower stream area and the Seomjin riverlower stream area and Gahwacheon River area. As for the contribution by variables of a model, it showed DEM, precipitation of driest month, min temperature of coldest month and distance from river had contribution from the highest order. In terms of the relation with the probability of appearance, the probability of emergence was higher than the threshold value in areas with less than 34m of altitude, with $-5.7^{\circ}C{\sim}-0.6^{\circ}C$ of min temperature of the coldest month, with 15-30mm of precipitation of the driest month and with less than 1,373m away from the river. Variables that Altitude, existence of water and wintertemperature affected settlement and expansion of nutria, considering the research results and the physiological and ecological characteristics of nutria. Therefore, it is necessary to reflect them as important variables in the future habitable area detection and expansion estimation modeling. It must be essential to distinguish the concentrated distribution area and the management area of invasive alien species such as nutria and to establish and apply a suitable management strategy to the management site for the permanent control. The results in this study can be used as useful data for a strategic management such as rapid management on the preferential management area and preemptive and preventive management on the possible spreading area.

• Journal of Environmental Impact Assessment
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• v.25 no.5
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• pp.319-332
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• 2016

Alien turtles belonging to Genus Trachemys have been designated as Invasive Alien Species since 2001 and their import has been banned in Korea. However, current status of import and distribution of the other alien turtles have not been reported. In this study, we aimed to investigate the taxa of alien turtles introduced into Korea, to assess their potential risks to the natural ecosystems and to suggest the future management directions of them in Korea. We identified 73 species of alien turtles belonging to 9 families. Since 2008, more than 6,000 kg of turtles have been imported annually and widely distributed through the pet shops, traditional markets and individual transactions. From the survey of natural habitats, we found that 8 species belonging to 3 families including Chrysemys picta, Pseudemys concinna, P. nelsoni, P. peninsularis, P. rubriventris, Mauremys sinensis, Macrochelys temminckii and Trachemys scripta have inhabited in 12 study sites. Out of 73 alien turtles, the potential adverse impacts of 13 species to ecosystems are serious when we considered status of designation of invasive alien species in other countries. For the management of alien turtles, it is required to register alien turtles in the import list and share general information such as import purpose, distribution and management condition among relevant authorities. The breeders and distributors must be obliged to identify turtles and to record management. The government must check transfer and migration of turtles periodically to prevent their introduction and spread into natural environments. The change of alien turtle populations in natural habitats should be monitored and their management plan should be developed to control the alien turtles in areas where the impacts are significant.

• The Korean Journal of Mycology
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• v.36 no.2
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• pp.153-162
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• 2008

Pinewood nematode (PWN) trapping by nematophagous fungi, Arthrobotrys conoides, A. dactyloides and A. oligospora and the fungal growth were characterized. The three Arthrobotrys species each was inoculated into the PWN cultured on Botrytis cinera fungal colony on potato dextrose agar (PDA). The effects of temperature, pH, PWN inoculation density and nutrients on the growth of the three Arthrobotrys spp were measured. A. conoides grew fast, 13.9 mm/day while A. dactyloides grew slow, 3 mm/day. PDA medium was the best for the fungal growth at $25^{\circ}C$ and pH 4.5. The Arthrobotrys spp growth was stimulated by 500 nematodes inoculation but not by 1000 inoculation. A. dactyloides did not grow below pH 4.5 and at high PWN density. A. conoides and A oligospora formed trapping organs with thick constricting hyphal network only when PWN present, while A. dactyloides formed the organ with circular hyphae constitutively. A. conoides formed trapping organs faster than A. oligospora did. The nematode trapping hyphae of the fungi penetrated into PNW inside to form many tiny infection bulbs and to digest the nematode. However, A. dactyloides formed a few trapping organs but no trapping was observed. Infection rate of PWN was 95% by A. conoides, 80% by A. oligospora and 92% by the combination inoculation of A. conoides and A. oligospora. In contrast A. dactyloides increased PWN density without infecton. There was no interaction effect in any combination inoculation of the three Arthrobotrys spp. A. conoides enhanced PWN infection rate by rapid hyphal growth and early trapping, while A. oligospora did it by increasing hyphal density. In conclusion A. conoides is the most effective in both hyphal growth and infection, and thus these characteristics can be utilized as a biological control of PWN.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.372-395
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• 2020

This study aimed to elucidate the distribution of vascular plants in Mt. Goryeo in Ganghwa-gun, Korea. The results of 14 field surveys from March 2018 to August 2019 identified 629 total taxa, representing 568 species, 10 subspecies, 45 varieties, two forms, and four hybrids in 371 genera and 112 families. The plant formation of Mt. Goryeo is the deciduous broad-leaved and conifer mixed forest, which is the common one in the middle part of the Korean Peninsula. Most parts of the mountain are covered with a young secondary forest, mainly composed of Quercus and Pinus spp. Out of the 629 taxa, 314 were first recorded in the region, six were endemic to Korea, four were listed on the Korean Red List of threatened species, 63 were floristic target plants, and 58 were invasive alien plants. The percentages of the naturalized index (NI) and urbanization index (UI) were 9.2% and 15.5%, respectively. The area showed a high plant diversity with many rare plants and phytogeographically important plants. This study discussed in detail conservation strategies to ensure biodiversity and effective management of Mt. Goryeo. The study results can be used as the reference for the preparation of biodiversity conservation and the establishment of management measures.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.147-151
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• 2007

Laboratory tests were conducted to determine the susceptibility of the alfalfa weevil, Hypera postica to Korean entomopathogenic nematodes, Steinernema carpocapsae GSN1 strain (ScG), S. glaseri Dongrae strain (SgD), Heterorhabditis bacteriophora Hamyang strain (HbH), and Heterorhabditis sp. Gyeongsan strain (HeG) at the petri dish assay. The larval mortality of H. postica was significantly different depending on nematode species and treatment concentration. SgD and HeG strain were more effective against H. postica larva than ScG and HbH strain. When SgD and HeG strain were treated with the rate of >20 infective juveniles (ijs) per alfalfa weevil larva, mortality was ca. 77.5-100% at the late instars of H. postica in 3 days. The number of established nematode was significantly different depending on nematode species, whereas number of progeny was not significantly different. The mean number of established us of SgD strain in a host was the highest at 80 ijs by 30.2. The highest progeny number of HeG strain was 2,671.5 with 80 ijs. All nematode strains were not parasitic entirely to H. postica adults. These results show that alfalfa weevil late larva is highly susceptible to Korean entomopathogenic nematodes in the laboratory.

• Journal of Life Science
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• v.19 no.2
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• pp.284-288
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• 2009

The innate immune system is important for the first line of host defence against infectious agents, which have penetrated the mechanical barriers. Mannose-binding lectin (MBL or mannan-binding protein, MBP) is a serum protein that is synthesized in the liver as a part of the acute phase response. MBL binds to carbohydrate structures presented by a wide range of pathogenic bacteria, viruses, fungi, and parasites. MBL is synthesized as a monomer that has a carboxy-terminal carbohydrate recognition domain, a neck region and a collagen region. Low MBL level was reported to be the most frequent immuno-deficiency syndrome. Although extensive studies have yielded detailed information on the structure of MBL, functions of the MBL complex are not fully understood yet. We, here, present cloning process of MBL cDNA from the rat liver and production of truncated recombinant MBL protein using a bacterial expression system in order to produce anti-MBL polyclonal antibody. Anti-MBL polyclonal antibody was raised in a New Zealand rabbit and its affinity was tested against recombinant protein using western blot technique. MBL cDNA, recombinant protein and anti-MBL antibody could be used as great arsenals to dissect cellular biochemistry of MBL.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.90-95
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• 2001

Kinetic Analysis of Cathepsin B Inhibitor Using a Spectrophotometric Assay. Han, Kil-Hwan and SangDal Kim*. Department of Applied MicrobioJ0f5Yt Yeungnam UniversitYt Kyongsan 77 2-749, Korea - The KHS 10, C4Hl10~6 formula produced from Streptomyces luteogriseus KT-] 0 effectively inhibited a lysosomal cysteine proteinase, cathepsin B. It inhibited the enzyme activity of cathepsin B competitively when the N a-CBZ-Llysine p-nitrophenyl ester HC] (CLN) was used as a substrate. The inhibition const:mt (Ki) of KHS 1 0 for cathepsin B detennined by spectrophotometeric assay was 430 nM. The effective inhibition of cathepsin B was observed at $25^{\circ}C$ :md pH 6.0. The cathepsin B inhibitor, KHSlO needed a preincubation of cathepsin B with the inhibitor for over 5 min. The KHS 10 preserved over 80% inhibition activity even after heat-treatment at $100^{\circ}C$ for ] hr.