• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.2
• /
• pp.357-364
• /
• 2001

The Instant Messenger(IM) is the most popular personal communication tool today. IM is a tool that can substitute E-mail for a person, and can secure the user for a company. Further, it is claimed as it has a limitless potential. However, there has been several reports on security issues. It has known that the transmitting message is not secured for the attacks, and hacking tools has been developed. In addition, several reports has been made regards to the vulnerability. In other words, anyone can peep through and manipulate the messages that are sent or received via IM. This is a barrier for the IM to be developed as a corporate's strategic tool, and furthermore, it will create serious personal privacy issue. IETF IMPP Working (:roup is preparing a standard mutual relationship between IM. However, it is complicated due to the American On-Lines's absence, whom has ensured the most number of IM users. There was a discussion only about the form of the transmitting data, but it is insufficient state to discuss the security service for general. In this paper, 1 design and implement the Secure Instant Messaging System, to solve the IM's vulnerability and the security issue presented above.

• Journal of The Korean Association of Information Education
• /
• v.8 no.3
• /
• pp.335-349
• /
• 2004

Recently, there is change the environment of education due to development of Science Technology Specially, As education information on web increased by internet, using education web data by mean of medium that aids learning by computer. Also It studied method that used the Computer as learning medium through the CAI(Computer Assisted Instruction), ICAI(Intelligent CAI), and ITS(Intelligent Tutoring System). But legacy system are not support efficient method that learns to vary learner suitable learning method by individual level. Specially It is not suitable the education course to direct current course of education, and not consider different of student capability, aptitude, need, interesting, not maximized the individual growable power and effect of education. To solve the this problem, our paper suggest the web-based self-directed MITS(Multimedia ITS) that supply the needed the information on web, make the environment that can self-directed learning. To maximized effect of individual learning, our paper structured coursed, characterized, related learning contents in region of numeral at mathematics of primary school. And then integrated contents and class, design and implement the web-based MITS that consist of 4 module to escape from limitation of learner grade, learning time, learning place.

• Journal of Korea Port Economic Association
• /
• v.25 no.1
• /
• pp.63-86
• /
• 2009

With increasing uncertainty of energy market in the world, the policies for the energy resource security have become crucial Several countries with poor energy resource like Netherlands and Singapore have pursued the policy for becoming an oil hub in the region. Singapore has been an oil hub in East Asia for a long time not only because it is well located with a large number of countries exporting and importing oil but it has also pursued strong policies to become an oil hub while establishing favourable institutional, regulatory and business environment for accommodating major refineries and petro-chemical companies. However with growing trading volume of petroleum products in Northeast Asia and a record high price of oil in these days, the necessities of another oil hub in the region are considered in order to reap benefits of the security of economical and stable oil. South Korea is situated astride the main North Pacific shipping route, with deep water ports and proximity to Chinese and Japanese industrial centres that make tank terminal operators Ideal choices for the oil hub in Northeast Asia although it has several disadvantages such as lack of independent storage facilities, underdeveloped oil trading market and unfavourable business friendly climates etc. This study is focused on examining the globalization strategies of tank terminal operators such as Vopak, Oiltanking and Odfjell in order to suggest the policy implications for becoming an oil tub in Northeast Asia.

• Journal of Gifted/Talented Education
• /
• v.26 no.4
• /
• pp.721-746
• /
• 2016

The purpose of this study was to investigate the effects of science experience with their children on mothers who have children who are science gifted children and how they perceive what kind of parenting methods are appropriate for the growth and development of children who are science gifted children. To do this, we interviewed 13 mothers of the gifted education center of the Ministry of Education and conducted two in - depth interviews with them. Results, mothers who have scientific gifted children have various science experiences with children who are scientific gifted. In this process, mothers of gifted children understand the gifted children through science experience with their children, I have come to realize that it is necessary to provide an educational environment that can express my child's talents and help to determine the direction of my career. For this purpose, leadership education that reminds the importance of relationships between people, providing opportunities for various experiences so that they can decide their life, career education through inquiry of deep science experience and meeting with senior scientists, humanities for integrated thinking And the arts. In this way, it is possible to provide in-depth research results to the mothers of the gifted and talented to provide specific directions for the various supportive methods and teaching methods that the gifted children should provide for intellectual and emotional growth and development. Development of educational programs is necessary.

• The Journal of the Korea Contents Association
• /
• v.19 no.10
• /
• pp.685-697
• /
• 2019

The study aimed to analyze the structure of China's passenger railway network in the years of 2008, 2013, and 2018, respectively. At the same time, it tried to investigate its derivative impact on the patterns of Chinese urban network. The analytical tool was based on the NetMiner4.0. In order to measure network characteristics of China's passenger railway network, it primarily focused on the degree centrality, betweenness centrality, and closeness centrality. First of all, the higher degree centralities, with a few exceptions, were observed in BeiJing, ShangHai, GuangZhou, WuHan, XiAn, ChengDu, HaErBin, and ShenYang over a decade. In contrast, the higher betweenness centralities were recorded in cities of higher development potential including WuLuMuQi, GuiYang, ShenYang, and KunMing. The closeness centrality analyses confirmed the fact that most metropoles like BeiJing, ShangHai, and GuangZhou kept the highest train accessibility during the same research period. At the same time, the opening up of a new stretch of high speed railway network has consecutively strengthened connectivity between BeiJing and TianJin. Owing to unprecedented development of railway traffic and its extensive operations, this study believes that Chinese major cities, without interruption, would pursue a series of urban policy alternatives geared towards railway stations-oriented networking and competitively try to extend their network ranges.

• Membrane Journal
• /
• v.31 no.2
• /
• pp.101-119
• /
• 2021

The demand for clean water is virtually present in all modern human societies even as our society has developed increasingly more advanced and sophisticated technologies to improve human life. However, as global climate change begins to show more dramatic effects in many regions in the world, the demand for a cheap, effective way to treat wastewater or to remove harmful bacteria, microbes, viruses, and other solvents detrimental to human health has continued to remain present and remains as important as ever. Well-established synthetic membranes composed of polyaniline (PANI), polyvinylidene fluoride (PVDF), and others have been extensively studied to gather information regarding the characteristics and performance of the membrane, but recent studies have shown that making these synthetic membranes conductive to electrical current by doping the membrane with another material or incorporating conductive materials onto the surface of the membrane, such as allotropes of carbon, have shown to increase the performance of these membranes by allowing the adjustability of pore size, improving antifouling and making the antibacterial property better. In this review, modern electrically conductive membranes are compared to conventional membranes and their performance improvements under electric fields are discussed, as well as their potential in water filtration and wastewater treatment applications.

• The Journal of the Korea Contents Association
• /
• v.21 no.7
• /
• pp.363-373
• /
• 2021

The purpose of this research is to analyze the Spill-over economic effect of the cultural and creative industries(CCI) in Henan Province, China. The research object is the CCI of Henan Province, which is mainly based on five sectors out of 42 industries in the industrial association table of the Statistical Bureau of Henan Province, China in 2017 (culture, sports; recreation and research sector; experimental development and integrated technical services sector; information transmission, computer services and software sector; education sector, etc), and is analyzed through secondary integration and redefinition of the CCI of Henan Province. Through the analysis of Henan Province Industry Association Table, this paper provides some enlightenment to the future direction of the cultural and creative industries. The main analysis results are as follows. The total production inducement of the CCI in Henan province is 48,848 billion yuan, and in particular, the production inducement coefficient of the industry in Henan province is 2.72809, 2.23909 (total of columns and rows), Index of the power of dispersion is 0.26325, and the index of the sensitivity of dispersion is 0.87535. Income induction coefficient is 0.55211, production tax induction coefficient is 0.09291. Because CCI of Henan Province has full development potential, the government needs to provide active support and policy support, in addition to the need for legal provisions and supervision of market management. In order to improve the innovative development of the CCI, it is necessary to develop a new model of "CCI+X".

• Journal of Elementary Mathematics Education in Korea
• /
• v.22 no.4
• /
• pp.385-403
• /
• 2018

Fraction division can be categorized as partitive division, measurement division, and the inverse of a Cartesian product. In the contexts of quotitive division and the inverse of a Cartesian product, the multiply-by-the-reciprocal algorithm is drawn well out. In this study, I analyze the potential and significance of the method of using $1{\div}$(divisor) as an alternative way of developing the multiply-by-the-reciprocal algorithm in the context of quotitive division. The method of using $1{\div}$(divisor) in quotitive division has the following advantages. First, by this method we can draw the multiply-by-the-reciprocal algorithm keeping connection with the context of quotitive division. Second, as in other contexts, this method focuses on the multiplicative relationship between the divisor and 1. Third, as in other contexts, this method investigates the multiplicative relationship between the divisor and 1 by two kinds of reasoning that use either ${\frac{1}{the\;denominator\;of\;the\;divisor}}$ or the numerator of the divisor as a stepping stone. These advantages indicates the potential of this method in understanding the multiply-by-the-reciprocal algorithm as the common structure of fraction division. This method is based on the dual meaning of a fraction as a quantity and the composition of times which the current elementary mathematics textbook does not focus on. It is necessary to pay attention to how to form this basis when developing teaching materials for fraction division.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.46 no.6
• /
• pp.1-16
• /
• 2018

The decline in the construction industry has led to a decrease the profitability of small and medium-sized landscape contractors. To relieve this situation, small and medium-sized landscape contractors have continued to proactively find ways to enter global construction markets. However, many small and medium-sized landscape contractors face risks due to their lack of capacity and insufficient preparations to extend the business abroad. Thus, this study aims to analyze the current condition of the Vietnamese construction market and the related risk factors. It then suggests strategies to improve the small and medium-sized landscape contractors' competitiveness in that market. We investigated the business climate and analyzed risk factors. Finally, we developed expansion strategies and conducted in-depth interviews with six overseas construction professionals. The study results first showed that efforts to improve infrastructure and the increased demand for housing in Vietnam will lead to more opportunities for small and medium-sized landscape contractors entering the Vietnamese construction market. However, changes in the Vietnamese business climate may act as a variable. Second, we found that small and medium-sized landscape contractors' risk factors are mainly related to laws and regulations, government finance, market fluctuations, public administration system, minimum wage increases, financing and bonds, contracting, trees and materials, and design errors. Finally, small and medium-sized landscape contractors are required to consider the following when seeking to enter the Vietnamese construction market: short-term strategy and mid-to-long-term strategy. This study will be used as the basis for small and medium-sized landscape contractors to plan to enter the Vietnamese construction market and to contribute to the expansion of the global construction market in the landscape industry.

• Journal of Life Science
• /
• v.30 no.12
• /
• pp.1128-1139
• /
• 2020

Over recent years, it has become evident that food and agricultural products are easily contaminated by fungi of Aspergillus, Fusarium, and Penicillium due to rapid climate change, which is not only a global food quality concern but also a serious health concern. Owing to consumers' interest in health, resistance to preservatives such as propionic acid and sorbic acid (which have been used in the past) is increasing, so it is necessary to develop a substitute from natural materials. In this review, the role of lactic acid bacteria as a biological method for controlling the growth and toxin production of fungi was examined. According to recent studies, lactic acid bacteria effectively inhibit the growth of fungi through various metabolites such as organic acids with low molecular weight, reuterin, proteinaceous compounds, hydroxy fatty acids, and phenol compounds. Lactic acid bacteria effectively reduced mycotoxin production by fungi via adsorption of mycotoxin with lactic acid bacteria cell surface components, degradation of fungal mycotoxin, and inhibition of mycotoxin production. Lactic acid bacteria could be regarded as a potential anti-fungal and anti-mycotoxigenic material in the prevention of fungal contamination of food and agricultural products because lactic acid bacteria produce various kinds of potent metabolic compounds with anti-fungal activities.