• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.831-838
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• 2001

Mobile information service aims to provide some degree of effective information for real life activities of mobile users. Due to the user mobility and actual realism, it becomes very important technical issue to support an adaptive information service methodology to current situations of the terminal and/or user. This paper deals with a prefetching scheme for location-aware, out of the various context-aware which can be considered in mobile information service. It makes use of the velocity-based mobility model to shape the terminal and/or user's mobility behavior. Based on the moving speed and direction, the prefetching zone is proposed to define the number of prefetched information, so as to limit effectively the prefetched information whilst to preserve the location-aware adaptability. Using a simulator, the proposed scheme has been evaluated in the effectiveness point of view. The idea in this paper is expected to be able to extended to the other mobile service contexts, such as service time, I/O types of mobile terminals, network bandwidth.

• The Journal of Art Theory & Practice
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• no.3
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• pp.67-84
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• 2005

Since the evaluation of its intellectual activities and abilities is done by curator's capabilities, planning exhibition is very important as the final result achieved by their own knowledge, information, and research. ARPA(Advanced Research Project on Arts) is suggested as the system which enables curators responding simultaneously to the society in the times, based on its special characteristics. If this system settles well, which means that the curators at NMCA(National Museum of Contemporary Art, Korea) play their roles as the professionals in each of their fields, the goal of consolidating the status of museum as the representative national museum, and building up competent department of curators, will be achieved at the same time. To clarify above, the curators set up the various assignments of research about the types of arts such as painting, Korean painting, sculpture, installation, new-media, design, craft, photogarphy, architecture, etc. And they establish the art objects classified by the regions, such as the Northern American, Southern American, European, Asian, and other Third World countries. They elaborate art objects more on the history, the work, the artist, and the issue of contemporary art. Furthermore, when the curators devote deeper study to those research subjects, they can have the opportunities to design an exhibition upon the research. Today, the museum of art is 'The Place for Communication and Encounter', it is regarded important to share the aesthetical, creative values with current artists, and to understand mutually with the spectators. It is needed to improve the curator's work, in order to meet the demands of the times and even to advance. Because the form of 'exhibition' is the tool that reveals the identity NMCA aiming at, the motivation, the development, and the realization should be leaded by the curators, who are the mainstream of the museum. ARPA is a system for identifying the exhibition like mentioned above. The main purpose of this system is to produce synergy effect, having the researching, collecting work in liaison with planning exhibition. ARPA will be able to improve the quality of exhibition through the way of developing the exhibition, passing through the stable process in the long run. So far, I have referred to a new paradigm of the exhibition design at NMCA via ARPA. Yet, there still remain missions in reality, such as analyzing the previous exhibition and reshuffling personnel and system, which should be done. When these matters settled, these plans would be suggested practically. At this point, it is the most significant that NMCA is attempting to let others aware of the importance of exhibition planning based on research. when the ARPA and exhibition planning is conjoined together successfully, the competent exhibition will be achieved, which can offer a meaningful exhibition to the art world, strengthen infra structure thru exchanging with public museum in the region, and eventually, establish a network with museum in foreign countries.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.141-147
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• 2019

Recently, the biggest issue in the electricity industry is the increase in renewable energy, and various technologies are being developed to ensure the capacity of the power system. In addition, super-grids linking power systems are being pushed to utilize eco-friendly energy between countries and regions worldwide. The HVDC transmission technology is required to link the power network between regions with different characteristics of the power system such as frequency and voltage. Until now, Korea has applied HVDC transmission technology that connects mainland and Jeju Island with submarine cables. But, the HVDC transmission technology is still developing for long-distance high-capacity power transmission from power parks on the east coast to load-tight areas near the metropolitan area. Considering the high population density and mountainous domestic environment, it is pushing for commercialization of the design technology of the ${\pm}500kV$ Double Bipole with metallic return wire transmission line to transmit large-scale power of 8 GW using minimal right of ways. In this paper, the insulation characteristics were studied for the design of double-bipole transmission tower with metallic return wire, which is the first time in the world. And the air insulation characteristics resistant to the various overvoltage phenomena occurring on transmission lines were verified through a full-scale impulse voltage test.

• The Journal of Korean Institute of Next Generation Computing
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• v.15 no.3
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• pp.7-15
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• 2019

Cloud computing markets are rapidly growing as cost savings and business innovation are being carried out through ICT worldwide. In line with this paradigm, the nation is striving to introduce cloud computing in various areas, including the public sector and defense sector, through various research. In the defense sector, DIDC was established in 2015 by integrating military, naval, air and military computing centers, and it provides cloud services in the form of IaaS to some systems in the center. In DIDC and various future cloud defense systems, It is an important issue to ensure availability in cloud defense systems in the defense sector because system failures such as network delays and system resource failures are directly linked to the results of battlefields. However, ensuring the highest levels of availability for all systems in the defense cloud can be inefficient, and the efficiency that can be gained from deploying a cloud system can be reduced. In this paper, we classify and define the level of availability of defense cloud systems step by step, and propose the strategy of introducing Erasure coding and failure acceptance systems, and disaster recovery system technology according to each level of availability acquisition.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.2
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• pp.377-391
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• 2019

Recently, system studies using tokens and block chains for authentication, access control, etc in IoT environment have been going on at home and abroad. However, existing token-based systems are not suitable for IoT environments in terms of security, reliability, and scalability because they have centralized characteristics. In addition, the system using the block chain has to overload the IoT device because it has to repeatedly perform the calculation of the hash et to hold the block chain and store all the blocks. In this paper, we intend to manage the access rights through tokens for proper access control in the IoT. In addition, we apply the Tangle to configure the P2P distributed ledger network environment to solve the problem of the centralized structure and to manage the token. The authentication process and the access right grant process are performed to issue a token and share a transaction for issuing the token so that all the nodes can verify the validity of the token. And we intent to reduce the access control process by reducing the repeated authentication process and the access authorization process by reusing the already issued token.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.839-850
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• 2018

The flood damage in urban areas due to torrential rain is increasing with urbanization. For this reason, accurate and rapid flooding forecasting and expected inundation maps are needed. Predicting the extent of flooding for certain rainfalls is a very important issue in preparing flood in advance. Recently, government agencies are trying to provide expected inundation maps to the public. However, there is a lack of quantifying the extent of inundation caused by a particular rainfall scenario and the real-time prediction method for flood extent within a short time. Therefore the real-time prediction of flood extent is needed based on rainfall-runoff-inundation analysis. One/two dimensional model are continued to analyize drainage network, manhole overflow and inundation propagation by rainfall condition. By applying the various rainfall scenarios considering rainfall duration/distribution and return periods, the inundation volume and depth can be estimated and stored on a database. The Rainfall-Duration-Flooding Quantity (RDF) relationship curve based on the hydraulic analysis results and the Self-Organizing Map (SOM) that conducts unsupervised learning are applied to predict flooded area with particular rainfall condition. The validity of the proposed methodology was examined by comparing the results of the expected flood map with the 2-dimensional hydraulic model. Based on the result of the study, it is judged that this methodology will be useful to provide an unknown flood map according to medium-sized rainfall or frequency scenario. Furthermore, it will be used as a fundamental data for flood forecast by establishing the RDF curve which the relationship of rainfall-outflow-flood is considered and the database of expected inundation maps.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.926-929
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• 2014

In Korea MVNO was introduced in 2011 when twenty seven years had passed since Korea Mobile Telecom started mobile phone service in 1984. Whithout having its frequency bands and network facilities MVNO can resell the mobile telecom services to the consumers by purchasing MNO's service. That can bring competition more efffective that can lower communication costs through the alternatives. In the early 2000s, the need for the introduction of the MVNO has been raised already by scholars in Korea. But it wasn't until the late 2000s, rate cuts appeared to be a major policy issue, and in 2011 Korean government begin to try to introduce its own MVNO's. In may 2014, MVNO's mobile communication market share reached 6%, but Korea dose not have a firm system yet. However, if government authorities did not insist 3 mobile telecom companies system and recognize global MVNO flow quickly the national cost would be significantly reduced. In the mean time mobile telecom companies have maintained similar billing system and level of service but competed to attract consumers only. It looks like some level of mutual collision and the government cannot help recognizing the situation but it did not do any effective policy improvement effort and government only levied penalties.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.239-247
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• 2019

An accurate prediction of emotion is a very important issue for the sake of patient-centered medical device development and emotion-related psychology fields. Although there have been many studies on emotion prediction, no studies have applied the heart rate variability and neuro-fuzzy approach to emotion prediction. We propose ANFEP(Adaptive Neuro Fuzzy System for Emotion Prediction) HRV. The ANFEP bases its core functions on an ANFIS(Adaptive Neuro-Fuzzy Inference System) which integrates neural networks with fuzzy systems as a vehicle for training predictive models. To prove the proposed model, 50 participants were invited to join the experiment and Heart rate variability was obtained and used to input the ANFEP model. The ANFEP model with STDRR and RMSSD as inputs and two membership functions per input variable showed the best results. The result out of applying the ANFEP to the HRV metrics proved to be significantly robust when compared with benchmarking methods like linear regression, support vector regression, neural network, and random forest. The results show that reliable prediction of emotion is possible with less input and it is necessary to develop a more accurate and reliable emotion recognition system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.36-46
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• 2019

The number of hosts connected to the Internet has increased dramatically, introducing the Domain Name System(DNS) in 1984. DNS is now an important key point for all users of the Internet by allowing them to use a convenient character address without memorizing a series of numbers of complex IP address. However, relative to the importance of DNS, there still exist many problems such as the authorization allocation issue, the disputes over public registration, security vulnerability such as DNS cache poisoning, DNS spoofing, man-in-the-middle attack, DNS amplification attack, and the need for many domain names in the age of hyper-connected networks. In this paper, to effectively improve these problems of existing DNS, we proposed a method of implementing DNS using distributed ledger technology, blockchain, and implemented using a Ethereum-based platform. In addition, the qualitative analysis performance comparative evaluation of the existing domain name registration and domain name server was conducted, and conducted security assessments on the proposed system to improve security problem of existing DNS. In conclusion, it was shown that DNS services could be provided high security and high efficiently using blockchain.

• Korean Journal of Medical Ethics
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• v.21 no.4
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• pp.316-329
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• 2018

Although the use of social media by doctors raises important issues concerning medical professionalism, the relevant professional bodies in South Korea have failed to issue clear guidelines on social media usage. The Korean Medical Association's newly revised ethics guidelines do require members to maintain dignity while using social media, but the idea of "maintaining dignity" is far from clear, and its premodern connotation prevents it from being reliably used in professional codes of conduct. The authors of this article examine the concept of maintaining dignity and conclude that once it is clarified and redefined it can and should be used as a viable ethical standard in a variety of contexts, including the use of social media. Social media's unpredictability and uncontrollability, and the blurred distinction between professional/public and personal/private can be a threat to medical professionalism. In order to deal with this threat, the concept of dignity is important. We present three examples in which the dignity of medical professionals is undermined and explain why these jeopardize public trust. We conclude that in order to maintain public trust the Korean Medical Association should provide more detailed guidelines on the use of social media by its members.