• Mycobiology
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• v.49 no.2
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• pp.142-150
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• 2021

The species within the family Cunninghamellaceae are widely distributed and produce important metabolites. Morphological studies along with a molecular phylogeny based on the internal transcribed spacer (ITS) and large subunit (LSU) of ribosomal DNA revealed two new species in this family from soils in China, that is, Absidia ovalispora sp. nov. and Cunninghamella globospora sp. nov. The former is phylogenetically closely related to Absidia koreana, but morphologically differs in sporangiospores, sporangia, sporangiophores, columellae, collars, and rhizoids. The latter is phylogenetically closely related to Cunninghamella intermedia, but morphologically differs in sporangiola and colonies. They were described and illustrated.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.6
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• pp.87-107
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• 2020

The purpose of this study is to present the basic data for maintenance and management of river ecosystem by surveying and analysing the kinds and their characteristics of vascular plants in Bukcheon stream, Gyeongju-si, South Korea. The numbers of vascular plants were summarized as 428 taxa including 92 families, 265 genera, 3 subspecies, 24 varieties, 6 forms, 5 hybrids and 5 cultivars. Among the identified taxa, there were 90 planted species. The endangered wild species was Cicuta virosa, and the rare plants were 5 taxa including Prunus × yedoensis, Juniperus chinensis L. var. sargentii and so on. The Korean endemic plants were 5 taxa Populus × tomentiglandulosa, Salix koriyanagi, Lespedeza maritima, Forsythia koreana and Aster pseudoglehni. The specific plants by floristic region were 26 taxa including 2 taxa of grade V, 3 taxa of grade IV, 2 taxa of grade III, 8 taxa of grade II and 11 taxa of grade I. The naturalized plants were 81 taxa including Euphorbia maculata, Erigeron strigosus, Vulpia myuros and so on. The invasive alien plants were 7 taxa including Humulus scandens, Rumex acetosella, Ambrosia artemisiifolia, Ambrosia trifida, Lactuca seriola, Symphyotrichum pilosum and Paspalum distichum.

• Journal of Environmental Science International
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• v.30 no.2
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• pp.173-184
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• 2021

Ecological disturbance plants distributed throughout the country are causing a lot of damage to us directly or indirectly in terms of ecology, economy and health. These plants are not easy to manage and remove because they have a strong fertility, and it is very difficult to express them quantitatively. In this study, drone hyperspectral sensor data and Field spectroradiometer were acquired around the experimental area. In order to secure the quality accuracy of the drone hyperspectral image, GPS survey was performed, and a location accuracy of about 17cm was secured. Spectroscopic libraries were constructed for 7 kinds of plants in the experimental area using a Field spectroradiometer, and drone hyperspectral sensors were acquired in August and October, respectively. Spectral data for each plant were calculated from the acquired hyperspectral data, and spectral angles of 0.08 to 0.36 were derived. In most cases, good values of less than 0.5 were obtained, and Ambrosia trifida and Lactuca scariola, which are common in the experimental area, were extracted. As a result, it was found that about 29.6% of Ambrosia trifida and 31.5% of Lactuca scariola spread in October than in August. In the future, it is expected that better results can be obtained for the detection of ecosystem distribution plants if standardized indicators are calculated by constructing a precise spectral angle standard library based on more data.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.111-119
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• 2021

This study was conducted to investigate the growth characteristics of artificially planted trees on top of the underground parking lots. The trees were planted 17 years ago and are now in good condition. The survey results are as follows. The planting depth of the trees was 0.9 - 1.3m. The horizontal roots of the trees were distributed in the depth of 0.2m ~ 0.6m, Growth condition was also considered to be good. Also, in the case of the straight root of the trees, the pine tree(Pinus densiflora) grew near the bottom but tree root was very thin, and the Japanese hackberry tree(Celtis sinensis) and the zelkova tree(Zelkova serrata) were seemed to bend at the bottom and to grow by changing direction. When trees were planted on artificial ground, the roots grew well horizontally, and the forces of growing vertically were much weakened. because the plants were planted in earth ball state. As a result, it was considered that the roots would hardly penetrate the bottom-pressing concrete floor.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4725-4747
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• 2020

Software defined networking (SDN) is considered to be one of the most promising paradigms in the future. To solve the scalability and performance problem that a single and centralized controller suffers from, the distributed multi-controller architecture is adopted, thus forms multi-domain SDN. In a multi-domain SDN network, it is of great importance to ensure a reliable control plane. In this paper, we focus on the reliability problem of multi-domain SDN against controller failure from perspectives of backup controller deployment and controller replication. We firstly propose a placement algorithm for backup controllers, which considers both the reliability and the cost factors. Then a controller replication mechanism based on shared data storage is proposed to solve the inconsistency between the active and standby controllers. We also propose a shared data storage layout method that considers both reliability and performance. Besides, a fault recovery and repair process is designed based on the controller backup and shared data storage mechanism. Simulations show that our approach can recover and repair controller failure. Evaluation results also show that the proposed backup controller placement approach is more effective than other methods.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.6
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• pp.15-34
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• 2021

Syntaxonomy and Synecology on Quercus variabilis forests in Daecheong-dam basin was carried out using the methods of Braun-Blanquet phytosociology. 6 syntaxa classified as species compositions described were Quercus variabilis community, Platycarya strobilacea-Quercus variabilis community(typicum subcommunity, dictamnus dasycarpus subcommunity), Quercetum variabili-serratae, Zelkova serrata-Quercus variabilis community and Dendranthema boreale-Quercus variabilis community. All syntaxa were shown habitat environmental conditions including steep inclination of more than 30°, high rock exposure rate of more than 50% and South-facing slope. These communities excepting Dendranthema boreale-Quercus variabilis community classified as natural vegetation were identified as low emergence rate of annual plants and species compositions composed native species, so it was confirmed that relatively natural succession were proceeding well. Quercetum variabili-serratae and Dendranthema boreale-Quercus variabilis community distributed forested hillslope of open water edge were representative Quercus variabilis syntaxa in Daecheong-dam basin.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.4011-4027
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• 2021

Cloud Computing has emerged as an extensively used technology not only in the IT sector but almost in all sectors. As the nature of the cloud is distributed and dynamic, the jeopardies present in the current implementations of virtualization, numerous security threats and attacks have been reported. Considering the potent architecture and the system complexity, it is indispensable to adopt fundamentals. This paper proposes a secure authentication and data sharing scheme for providing security to the cloud data. An efficient IPSO-KELM is proposed for detecting the malicious behaviour of the user. Initially, the proposed method starts with the authentication phase of the data sender. After authentication, the sender sends the data to the cloud, and the IPSO-KELM identifies if the received data from the sender is an attacked one or normal data i.e. the algorithm identifies if the data is received from a malicious sender or authenticated sender. If the data received from the sender is identified to be normal data, then the data is securely shared with the data receiver using SHA256-RSA algorithm. The upshot of the proposed method are scrutinized by identifying the dissimilarities with the other existing techniques to confirm that the proposed IPSO-KELM and SHA256-RSA works well for malicious user detection and secure data sharing in the cloud.

• Architectural research
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• v.24 no.4
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• pp.93-103
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• 2022

In contemporary housing design, this cultural value has been ignored. Contemporary design has adapted quickly to global trends and houses have gradually lost their cultural identity (GhaffarianHoseini & Dahlan, 2012; Lim, 2001). Nevertheless, traditional housing culture persists in people's behavior and thoughts. Therefore, there is currently a pressing need to rebuild cultural identity in housing for cultural sustainability. This study aimed to analyze the traditional culture which was maintained, then transformed and disappeared in housing design through the quantitative survey and explore the cultural identity of Malaysian housing as a result. A quantitative survey was distributed to mothers of 129 married households living in a metropolitan area of Kuala Lumpur in August 2019. As a result, it was found that hosting guest was important even though the designated space (serambi) was disappeared. The LD/K layout, separating kitchen from living and dining area was philosophical and practical culture, still strong among older generation, but weakened among younger generation. To accommodate the traditional habit of diverse household work, wet kitchen, utility space for washing machine & drying, and outdoor space were needed to design carefully. When applied to future housing design, the findings will contribute to enhancing quality of life by strengthening residents' sense of place and social cohesion and by providing a culturally inherent design that eases the effects of globalization.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.1-8
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• 2021

With the rapid growth of intelligent devices and communication technologies, 5G network environment has become more heterogeneous and complex in terms of service management and orchestration. 5G architecture requires supportive technologies to handle the existing challenges for improving the Quality of Service (QoS) and the Quality of Experience (QoE) performances. Among many challenges, traffic steering is one of the key elements which requires critically developing an optimal solution for smart guidance, control, and reliable system. Mobile edge computing (MEC), software-defined networking (SDN), network functions virtualization (NFV), and deep learning (DL) play essential roles to complementary develop a flexible computation and extensible flow rules management in this potential aspect. In this proposed system, an accurate flow recommendation, a centralized control, and a reliable distributed connectivity based on the inspection of packet condition are provided. With the system deployment, the packet is classified separately and recommended to request from the optimal destination with matched preferences and conditions. To evaluate the proposed scheme outperformance, a network simulator software was used to conduct and capture the end-to-end QoS performance metrics. SDN flow rules installation was experimented to illustrate the post control function corresponding to DL-based output. The intelligent steering for network communication traffic is cooperatively configured in SDN controller and NFV-orchestrator to lead a variety of beneficial factors for improving massive real-time Internet of Things (IoT) performance.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.5
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• pp.297-307
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• 2022

The simple procedural segment selection algorithm commonly used in Dynamic Adaptive Streaming over HTTP (DASH) reveals severe weakness to provide high-quality streaming services in the integrated mobile networks of various wired and wireless links. A major issue could be how to properly cope with dynamically changing underlying network conditions. The key to meet it should be to make the segment selection algorithm much more adaptive to fluctuation of network traffics. This paper presents a system architecture that replaces the existing procedural segment selection algorithm with a deep reinforcement learning algorithm based on the Asynchronous Advantage Actor-Critic (A3C). The distributed A3C-based deep learning server is designed and implemented to allow multiple clients in different network conditions to stream videos simultaneously, collect learning data quickly, and learn asynchronously, resulting in greatly improved learning speed as the number of video clients increases. The performance analysis shows that the proposed algorithm outperforms both the conventional DASH algorithm and the Deep Q-Network algorithm in terms of the user's quality of experience and the speed of deep learning.