• Journal of Communications and Networks
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• v.15 no.5
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• pp.504-513
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• 2013

Communication in delay tolerant networks (DTNs) relies on message transport by mobile nodes, and a correct understanding of the node mobility characteristics is therefore crucial to the design of an efficient DTN routing protocol. However, previous work has mainly focused on uncovering all behaviors of node movement, which is not conducive to accurately detecting the specific movement characteristics of a different node. In this paper, we seek to address this problem based on a consideration of social relationships. We first consider social ties from both static and dynamic perspectives. For a static perspective, in addition to certain accidental events, social relations are considered for a long time granularity and tend to be stable over time. For a dynamic perspective, social relations are analyzed in a relatively short time granularity and are likely to change over time. Based on these perspectives, we adopted different efficient approaches to dividing node pairs into two classes, i.e., familiar and unfamiliar pairs. A threshold approach is used for static social ties whereas a density-based aggregation method is used for dynamic social relationships. Extensive experimental results show that both familiar and unfamiliar node pairs have the same inter-contact time distribution, which closely follows a power-law decay up to a certain point, beyond which it begins to exponentially decay. The results also demonstrate that the inter-contact time distribution of familiar pairs decays faster than that of unfamiliar pairs, whether from a static or dynamic perspective. In addition, we also analyze the reason for the difference between the inter-contact time distributions of both unfamiliar and familiar pairs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.80-84
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• 2015

We investigated the dielectric relaxation properties $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics with CuO addition. With increasing CuO addition, the lattice parameter was increased by substitution of small amount $Cu^{2+}$ ion in B-site of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics. Also the grain size and the maximum dielectric constant of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics was decreased with increasing amounts of CuO addition. Moreover, the diffused phase transition properties (${\gamma}$) of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics was increased by compositional fluctuation with increasing of CuO amount, changed from 1.45 at 1 wt% CuO addition to 1.94 at 7 wt% CuO addition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.12
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• pp.953-962
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• 2018

Recently, the Ministry of Internal Affairs and Communications of Japan has reported on a plan for the "effective use of radio waves" to be promoted in the 2020s. This includes promotion of the effective use of public frequencies, reviews of frequency allocation and transition systems, and spectrum usage fee system. Based on the proposals in this study, concrete systems for revising related laws, such as the Radio Law, will be designed and implemented. In addition, the government will jointly conduct research and development as well as verification tests in cooperation with industry, academia, and government. A plan to improve the system for the effective use of radio waves will then be devised. This study examines the policy directions of the frequency utilization system that Japan plans to use for radio waves in the 2020s. The policy directions are analyzed selectively while considering the radio waves utilization system in Korea, and implications for domestic applications are derived. Based on the research from this study, analyzing the radio policies of advanced countries, including those of England and the United States, and utilizing them to establish an effective use plan of radio waves in Korea are deemed necessary.

• Convergence Security Journal
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• v.19 no.2
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• pp.21-28
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• 2019

The emergence of a hyper-connected-super-intelligence society, called the era of the Fourth Industrial Revolution, brought about a new change in the security environment. With ICT (Information Communication Technology) convergence and high-tech technologies introduced across the board, the person-centered driving force that moved the real space is replaced by the code-oriented cyberspace, and its dependency is constantly increasing. Paradoxically, however, these technological changes serve as another security vulnerability that threatens our society, and have brought about the justification for building a cyber defense system while simultaneously facing the opportunities and challenges brought by technology. In this study, the theory of self-defense was put forward on the basis of the theoretical basis for actively responding to the increasingly intelligent and mass-evolving cyberattacks, and firstly, the need to enact a cybersecurity law, secondly, and thirdly, the need to develop a response cooperation system with the U.S. and other cyber powers.

• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.54-61
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• 2019

Objectives: In this study, we investigated an assessment for exposure levels of hazardous substances to kids cafes that unregulated by law. Methods: Heavy metals, volatile organic compounds, formaldehyde, pesticides and phthalate were measured at 20 kids cafes in Gyeonggi-do and Incheon. Samplings were conducted from April to July in 2018. Results: Heavy metals were detected over the standard mainly around the floor and walls in the 19 kids cafes. Pesticides were detected in 7 locations with chlorpyrifos, diazinon and cypermethrin, and showed the highest detection level of chlorpyrifos. The concentrations of DEHP in all kids cafes were exceeded with standard. The risk assessment results showed that HCHO as carcinogen had a safety level and DEHP as non-carcinogens had a safety level as assessed to be under than 0.1. Conclusions: Considering the exposure investigation results and the importance of child health protection, kids cafe should be included in the legal management list of children's activities zones.

• Journal of Platform Technology
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• v.9 no.4
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• pp.32-41
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• 2021

The EU enacted a law strongly regulating the GDPR to protect the privacy of its citizens on 25 May 2018. Compliance with GDPR is an essential prerequisite for companies to enter the European market in the global economic era. In this paper, Step-by-step measures have been defined to conclude DPA agreements for the appropriate level of protection against EU personal data transfer. To explore the benefits and expected effects of determining appropriateness at the government level. As a result, enterprises benefit from simplifying processes, reducing time, and reducing costs when entering the EU. Government-level support in response to personal data breach and communication with the EU Commission will have a positive impact, However, even after the adequacy decision, the entity continues to need activities to secure personal data through compliance with GDPR principles and obligations. Major operations of companies that comply with GDPR are also maintained as important tasks that must be observed in most cases except for the Data Protection Agreement.

• Journal of the Korean Society of Safety
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• v.37 no.3
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• pp.34-44
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• 2022

This study analyzed the smart construction safety cost included in safety management plans that are approved before construction. Specifically, it refers to the cost incurred in constructing and operating a safety management system using wireless communication and facilities. Based on the obtained statistical results, an activation policy for the inclusion of the smart construction safety cost in building safety management plans was proposed. The smart construction safety cost must be included in the safety management cost; notably, this is mandated by the Construction Technology Promotion Act. However, there are some problems with the inclusion of smart construction safety costs. To analyze the problems encountered when calculating the smart construction safety cost and including it in safety management plans, in this study, statistical analysis was performed using the data of 1,334 safety management plans received at the Construction Safety Management Integrated Information (CSI) from June to August 2021. The results show that only 50.7% of the safety management plans included the smart construction safety cost although the current law mandates 100% inclusion of these costs. Thus, it is apparent that the smart construction safety costs are only included in a low proportion of sites. In addition, the calculated smart construction safety costs were shown to have a small correlation with the construction cost; moreover, they appeared to be distributed at a constant cost level. In this context, it is believed that perfunctory cost calculations were performed at most sites since the effect of the construction cost on the smart construction safety cost was negligible. Therefore, it is necessary to improve the inclusion of smart construction safety costs by strengthening the authorization process of the approval institute of safety management plans. In addition, institutional support, such as guidelines that promote the calculation and inclusion of appropriate smart construction safety costs according to the characteristics of sites, are needed.

• Journal of Korean Society of Rural Planning
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• v.29 no.4
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• pp.27-34
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• 2023

Recently, worldwide to respond to climate change and secure sustainability. Korea aimed to increase water use efficiency by implementing integrated management according to the water management unification policy. Therefore, the necessity of establishing and operating governance is expanding to ensure the sustainability of agricultural water. In this study aims to evaluate the importance of agricultural water governance components and provide essential data for the participation of stakeholders in the efficient use of agricultural water in Korea. For this study, a total of 19 respondents to the ANP survey for this study were composed of experts in agricultural water and governance in Korea. As a result, the ranking for the main components was in the order of law, policy, and systems(0.222), core subjects(0.191), information sharing and communication(0.180), budget support(0.178), mutual learning(0.124), and external experts(0.105). The most important components for the operation of agricultural water governance are laws, policies, and systems. Since Korea's agricultural water management is a public management system, national standards are considered the first priority. This study, which is the purpose of the agricultural water governance model, evaluated the importance of the constituent components for participating in demand management with a sense of responsibility. Moreover, if agricultural water governance is expanded nationwide by reflecting agricultural and water resource policies in the future, it is believed that positive effects can be achieved in increasing utilization efficiency and securing sustainability through agricultural water saving.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.103-108
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• 2016

The size of urban areas is currently growing and the functions of cities are becoming increasingly complicated. Furthermore, more people are living in cities. The life of urban is getting closer and linked with neighboring people in many parts. In particular, people are making artificial noise, even though it might not consciously be noticed, in their daily live. Seoul is the most crowded place in Korea and the noise levels are 73dB or higher. People living in cities are exposed to noise pollution. In particular, loudspeakers used during demonstrations or to generate publicity, cause considerable noise, which in turn can be related to stress. Moreover, the noise restrictions defined by law are not adhered to. If enhanced noise regulations, no matter how residents are not forced to be a great stress field close to the noise and reduces the loudness -5dB do not feel well if the difference. Limiting the duration of noise rather than reducing the volume thus is a much more plausible way of reducing the damage caused by noise pollution. If the stress caused by the noise, you will see people or vehicles holding a megaphone at the roadside is not good for health if it may be a wise way to live that is getting rid of the noise pollution so quickly out of the area.

• Korean journal of communication and information
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• v.34
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• pp.132-160
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• 2006

The main purpose of this study is based on the comparative analysis over news framing of the family headship(Hoju) abolition in Korean society. This study examined the newspaper articles involving the Hoju abolition, which had been printed on the three major dailies, Chosun, Kukmin, Hankyoreh through February of 1990 to July of 2005. First, the news articles were analyzed and classified on the basis of their lengths, news types, main characters, news framing and systematic framing. Second, the articles that this study looked into were divided into the five major periods when the issue of the Hoju abolition in Korean society surfaced as a main social agenda to be discussed. Third, the main differences between the noticeable frame and unnoticeable frame in each period were analyzed through the three different perspectives which can also can be sub-divided into the six different attributes. This study found that the Hoju abolition as an attribute had developed into political, legal and social fields. The analysis of the research shows that the articles related to the patriarchy abolition showed more dominant frame which reflected the social change or the general tendency of the times. However, the analysis indicates that the articles in the level of an attribute included more dominant frame which mirrored a male chauvinism society. It also points out that the articles contained more dominant frame which was be used as a standard to find out the readers' political inclination. The articles also showed the dominant frame which included the revision and legal process of family laws before presidential or general election campaigns. The study also found that there were major differences among the three dailies. First of all, Chosun, regarded the Hoju as a custom by stressing that 'it is necessary to keep Hoju system to intensify the role and crisis of family if the Hoju will be abolished'. However, Hankyoreh recognized the issue as an important one to improve feminism and female rights by maintaining that 'it is the time to balance the inequality out between men and women with the abolition of patriarchy'. Finally, Kukmin treated the issue as an first step to acknowledge the dignity of females by emphasizing that 'a revision of the law is essential to accept the changing ethics of the times'.