• Journal of Ecology and Environment
• /
• v.45 no.3
• /
• pp.97-104
• /
• 2021

Background: Asarum sieboldii Miq., a species of forest understory vegetation, is an herbaceous perennial belonging to the family Aristolochiaceae. The metapopulation of A. sieboldii is distributed sparsely and has a short seed dispersal distance by ants as their seed distributor. It is known that many flowers of A. sieboldii depend on self-fertilization. Because these characteristics can affect negatively in genetic structure, investigating habitat structure and assessment of genetic structure is needed. A total of 27 individuals in a valley were sampled for measuring genetic diversity, genetic distance, and genetic differentiation by RAPDPCR. Results: The habitat areas of A. sieboldii metapopulation were relatively small (3.78~33.60 m²) and population density was very low (five to seven individuals in 20×20 m quadrat). The habitat of A. sieboldii was a very shady (relative light intensity = 0.9%) and mature forest with a high evenness value (J = 0.81~0.99) and a low dominance value (D = 0.19~0.28). The total genetic diversity of A. sieboldii was quite high (h = 0.338, I = 0.506). A total of 33 band loci were observed in five selected primers, and 31 band loci (94%) were polymorphic. However, genetic differentiation along the valley was highly progressed (G_st = 0.548, N_m = 0.412). The average genetic distance between subpopulations was 0.387. The results of AMOVA showed 52.77% of variance occurs among populations, which is evidence of population structuring. Conclusions: It is expected that a small-scale founder effect had occurred, an individual spread far from the original subpopulation formed a new subpopulation. However, geographical distance between individuals would have been far and genetic flow occurred only within each subpopulation because of the low density of population. This made significant genetic distance between the original and new population by distance. Although genetic diversity of A. sieboldii metapopulation is not as low as concerned, the subpopulation of A. sieboldii can disappear by stochastic events due to small subpopulation size and low density of population. To prevent genetic isolation and to enhance the stable population size, conservative efforts such as increasing the size of each subpopulation or the connection between subpopulations are needed.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.23 no.1
• /
• pp.87-102
• /
• 2021

The purpose of this study is to consider effective digital marketing strategies through analysis of luxury fashion brands. This study conducted both quantitative analysis and case studies of the brands Louis Vuitton, Gucci, Burberry, and Chanel. To measure the brand image of the luxury fashion brands, the survey was distributed to Millennials, and total of 277 responses were used for the final analysis by using SPSS 25.0 statistical program. Other than survey, this paper analyzed digital marketing strategies of luxury fashion brands through brand-related papers, website and social media of each brand, Samsung Designnet's database, and news posted on search engines. The results of this study are as follows: First, according to the result of examining brand image of luxury fashion brands, there was no significant difference between brands, except Gucci. Second, this study analyzed each luxury fashion brand to understand the characteristics of digital marketing, and common characteristics were identified. Third, by analyzing the brand image and digital marketing strategies of luxury fashion brands, it was confirmed that Gucci's brand image and digital marketing strategies were consistent, while there was a difference between Burberry's brand image and digital marketing strategy. Therefore, this article proposes the following digital marketing strategies that are suitable for luxury fashion brands. First, is the connection of on/offline channels. Second, is the use of AI technology. Third, is a blockchain-based platform.

• International Journal of Computer Science & Network Security
• /
• v.21 no.6
• /
• pp.107-118
• /
• 2021

The deployment of 5G is in full swing, with a significant yearly growth in the data traffic expected to reach 26% by the year and data consumption to reach 122 EB per month by 2022 [10]. In parallel, the idea of smart cities has been implemented by various governments and private organizations. One of the main objectives of 5G deployment is to help develop and realize smart cities. 5G can support the enhanced data delivery requirements and the mass connection requirements of a smart city environment. However, for specific high-demanding applications like tactile Internet, transportation, and augmented reality, the cloud-based 5G infrastructure cannot deliver the required quality of services. We suggest using multi-access edge computing (MEC) technology for smart cities' environments to provide the necessary support. In cloud computing, the dependency on a central server for computation and storage adds extra cost in terms of higher latency. We present a few scenarios to demonstrate how the MEC, with its distributed architecture and closer proximity to the end nodes can significantly improve the quality of services by reducing the latency. This paper has surveyed the existing work in MEC for 5G and highlights various challenges and opportunities. Moreover, we propose a unique framework based on the use of MEC for 5G in a smart city environment. This framework works at multiple levels, where each level has its own defined functionalities. The proposed framework uses the MEC and introduces edge-sub levels to keep the computing infrastructure much closer to the end nodes.

• International Journal of Computer Science & Network Security
• /
• v.21 no.5
• /
• pp.243-255
• /
• 2021

This study aimed to identify the effectiveness of the use of distance-evaluation tools and methods among students with learning difficulties from the teachers' point of view, to achieve this goal. A scale was built, and the psychometric characteristics were validated. It consisted, in its final form, of 17 items distributed on four axes, in addition to three open questions. It was applied to a random sample of (149) teachers of students with learning difficulties in Makkah Region. The results showed that teachers' keenness to encourage students with learning difficulties, so that they would not feel frustrated with the distance learning process. It was also evident that teachers did not use achievement portfolios in the evaluation process. In connection with the appropriate evaluation methods, the majority indicated the use of work sheets and visual evaluation methods that rely on audio and visual skills, such as presenting videos, pictures, audio and games, and applying short objective tests. Among the proposals to improve evaluation methods and tools: Individual evaluation, attention to individual treatment, obligating personal attendance of students to school, splitting the required tasks, and not increasing the skills required to be mastered. As for the obstacles that teachers face: Lack of time, difficulty in communicating with students with distance learning difficulties and problems related to the Internet such as interruption, weakness, or lack of availability.

• The Journal of the Korea Contents Association
• /
• v.22 no.3
• /
• pp.296-308
• /
• 2022

In the COVID-19 crisis, the elderly over 60 have various psychological health problems such as depression, anxiety, and fear, and the community has become the only space for senior activities. To this end, this study presented a therapeutic aging-friendly community environmental design evaluation system using theoretical review, FGI interview, and hierarchical analysis AHP. The evaluation system is a three-dimensional space, with 10 upper layers and 68 lower layers. In addition, the weight of each index of the evaluation system was distributed through expert survey and SPSS program analysis. First, the material space environment design must satisfy the comfort and health of the elderly when they are active in a common space for their daily life. Second, the design of social space environment is designed to promote exchange and social connection among the elderly. Third, the operating space environment design considers the operating system of the community operating company as important. Through this, it is expected to improve the psychological health of the elderly by providing systematic technical basis and action guidelines for the development of the residential environment of the elderly.

• KEPCO Journal on Electric Power and Energy
• /
• v.8 no.1
• /
• pp.43-48
• /
• 2022

Although the distribution system has been structured as complicated as a mesh in the past, the connection points for each line are always kept open, so that it is operated as a radial distribution system (RDS). For RDS, the line utilization rate is determined according to the maximum load on the line, and the utilization rate is usually kept low. In addition, when a fault occurs in the RDS, a power outage of about 3 to 5 minutes occurs until the fault section is separated, and the healthy section is transferred to another line. To improve the disadvantages of the RDS, research on the construction of a networked distribution system (NDS) that linking multiple lines is in progress. Compared to the RDS, the NDS has advantages such as increased facility utilization, load leveling, self-healing, increased capacity connected to distributed generator, and resolution of terminal voltage drop. However, when a fault occurs in the network distribution system, fault current can flow in from all connected lines, and the direction of fault current varies depending on the fault point, so a high-precision fault current direction determination method and high-speed communication are required. Therefore, in this paper, we propose an accurate fault current direction determination method by comparing the peak value polarity of the fault current in the event of a fault, and a communication-based protection coordination method using this method.

• Journal of IKEEE
• /
• v.26 no.1
• /
• pp.1-9
• /
• 2022

In order to secure the reliability of the power system and to increase the penetration level of distributed energy resources (DERs), requirements such as IEEE 1547 have been revised to strengthen the grid connection standards for DER. This paper proposes a control scheme for smart inverter functions based on IEEE 1547-2018 that satisfy these standards, and introduces a power HILS-based test platform built for verification of smart inverter. Among the smart inverter functions, Volt-var and Frequency-watt allow the curve to be set from the upper level to comply with the interoperability and operation time of enable signals for each function are controlled by references from the upper level. According to the requirement, Volt-var and Frequency-watt are performed via power HILS platform and verified through the measurement results that all of the specified type tests were satisfied.

• 한국노년학
• /
• v.39 no.1
• /
• pp.61-72
• /
• 2019

The purpose of this study was to find ways to reduce old age anxiety by identifying the differences between old age anxiety, grandparents' connection, filial piety, and characteristics, and by identifying factors that affect old age anxiety. The study participants conveniently labeled college students residing in Seoul, Gyeonggi and Chungcheong provinces, and collected data from 2 April to 15 June 2018 and distributed a total of 250 structured questionnaires and retrieved 235 copies to use part 213 for the final analysis. The analysis used SPSS 20.0 Version to obtain frequency, percentage, average, and standard deviation, and age anxiety according to the characteristics of the subject, grandparents and sense of filial piety were analyzed with t-test and ANOVA, and the correlation between aging anxiety, grandparents' bond and filial consciousness was confirmed as Pearson correlation co-efficient. To check the effects of aging anxiety, polylinearity was diagnosed and analyzed with Stepwise multiple regression. Research found that there were statistically significant differences in age insecurity according to majors, grandparents and ties by gender and filial piety by religion and grandparents. And the lower the bond with grandparents, the higher the filial piety, the higher the anxiety was.

• Convergence Security Journal
• /
• v.23 no.4
• /
• pp.43-52
• /
• 2023

Many businesses and organizations use smartcard-based user authentication for remote access. In the meantime, through various studies, dynamic ID-based remote user authentication protocols for distributed multi-server environments have been proposed to protect the connection between users and servers. Among them, Qiu et al. proposed an efficient smart card-based remote user authentication system that provides mutual authentication and key agreement, user anonymity, and resistance to various types of attacks. Later, Andola et al. found various vulnerabilities in the authentication scheme proposed by Qiu et al., and overcame the flaws in their authentication scheme, and whenever the user wants to log in to the server, the user ID is dynamically changed before logging in. An improved authentication protocol is proposed. In this paper, by analyzing the operation process and vulnerabilities of the protocol proposed by Andola et al., it was revealed that the protocol proposed by Andola et al. was vulnerable to offline smart card attack, dos attack, lack of perfect forward secrecy, and session key attack.

• The Korean Journal of Quaternary Research
• /
• v.19 no.1
• /
• pp.1-17
• /
• 2005

This study aims to study the distribution and formation age of Quaternary deposits in the downstream of Yeongsan Estuarine River, encompassing Muan, Illo and Donggang counties. For this purpose the authors examine several borehole data, and step trench survey for excellent profiles was studied in connection with grain size population and magnetic susceptibility. As a result, it is interpreted that the coastal plain of the Yeongsan River was formed by sea level rise after Last Glacial Maximum(LGM). The fore edge/escarpment of coastal terraces distributed 7-10 m asl is assumed to be formed during the last glacial period, while the coastal terraces distributed above 7-10m asl formed during MIS 5a. In addition, the fore edge/escarpment of coastal terraces distributed above 15 m asl is presumed to be have been formed during the stadial of last interglacial period, while the formation age of coastal terraces distributed above 15m(asl) is assumed to be MIS 5e. This formation age can be estimated by the coastal terrace ages of the southeastern coast of Korean Peninsula. The characteristics of Quaternary deposits linked to paleolithic culture will eventually lead to the reconstruction of ecosystem environment of paleolithic peoples.