• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.33-39
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• 2020

Interest in 5G communication security has been growing recently amid growing expectations for 5G technology with faster speed and stability than LTE. However, 5G has so far included disparate areas, so it has not yet fully supported the issues of security. This paper proposes a blockchain-based IoT management model in order to efficiently provide the authentication of users using IoT in 5G In order to efficiently fuse the authentication of IoT users with probabilistic theory and physical structure, the proposed model uses two random keys in reverse direction at different layers so that two-way authentication is achieved by the managers of layers and layers. The proposed model applied blockchain between grouped IoT devices by assigning weights to layer information of IoT information after certification of IoT users in 5G environment is stratified on a probabilistic basis. In particular, the proposed model has better functions than the existing blockchain because it divides the IoT network into layered, multi-layered networks.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.110-118
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• 2003

The paper describes a design process of the connection control function that performs overall procedures of optical network control system in the Next Generation - Synchronous Digital Hierarchy (NG-SDH) based transport system. Here, the NG-SDH means a new SDH technology that could perform automatic connection control with a granularity of VC-3 (about 50M) or VC-4 (about 150M) according to the increase and decrease of traffic, which is different from the existing technology that could perform connection control only with a granularity of a physical SDH link (STM-l, STM-4, STM-16, STM-64, STM-256 etc). The NG-SDH based connection control allows an ingress NG-SDH node to control the appropriate connection establishment process according to connection types such as Permanent Connection (PC), Soft Permanent Connection (SPC), Switched Connection (SC) over various SDH and Ethernet line cards.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1063-1068
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• 2002

Polyimide/silica(PI/silica) hybrid materials having physical or chemical bonds between the PI and silica network were prepared using sol-gel process through hydrolysis and polycondensation of tetraethoxysilane with the polyamic Acid(PAA) or end-capped PAA solution. PAA solution was synthesized by ring opening reaction of pyromellitic dianhydride and oxydianiline monomers in dimethyl acetamide solution. End-capped PAA solution was synthesized by the addition of 3-aminopropyltriethoxysilane in PAA solution. PI/silica hybrid samples were characterized by infrared spectroscopy, differential thermogravimetry, X-ray diffractometry, scanning electron microscopy, and tensile tester. It has been demonstrated that the properties of hybrid samples were affected by the silica content and the bond type between PI and silica.

• IMMUNE NETWORK
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• v.13 no.5
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• pp.213-217
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• 2013

Enterotoxigenic Bacteroides fragilis (ETBF) is a human gut commensal bacteria that causes inflammatory diarrhea and colitis. ETBF also promotes colorectal tumorigenesis in the Min mouse model. The key virulence factor is a secreted metalloprotease called B. fragilis toxin (BFT). BFT induces E-cadherin cleavage, cell rounding, activation of the ${\beta}$-catenin pathway and secretion of IL-8 in colonic epithelial cells. However, the precise mechanism by which these processes occur and how these processes are interrelated is still unclear. E-cadherin form homophilic interactions which tethers adjacent cells. Loss of E-cadherin results in detachment of adjacent cells. Prior studies have suggested that BFT induces IL-8 expression by inducing E-cadherin cleavage; cells that do not express E-cadherin do not secrete IL-8 in response to BFT. In the current study, we found that HT29/C1cells treated with dilute trypsin solution induced E-cadherin degradation and IL-8 secretion, consistent with the hypothesis that E-cadherin cleavage causes IL-8 secretion. However, physical damage to the cell monolayer did not induce IL-8 secretion. We also show that EDTA-mediated disruption of E-cadherin interactions without E-cadherin degradation was sufficient to induce IL-8 secretion. Finally, we determined that HT29/C1 cells treated with LiCl (${\beta}$-catenin activator) induced IL-8 secretion in a dose-dependent and time-dependent manner. Taken together, our results suggest that BFT induced IL-8 secretion may occur by the following process: E-cadherin cleavage, disruption of cellular interactions, activation of the ${\beta}$-catenin pathway and IL-8 expression. However, we further propose that E-cadherin cleavage per se may not be required for BFT induced IL-8 secretion.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.36.3-37
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• 2015

4C39.25 (0923+392) is a distant radio loud AGN placed at redshift 0.695. The motivation of our work is peculiar properties 4C39.25. Firstly, it has a conspicuous distinction of jet direction between kilo-parsec scale observation made by VLA (Kollgaard et al. 1990) and the parsec scale observation by VLBA (Kellermann et al. 1998). This might indicate episodic-jet activity which recently turned on. This object currently shows two stationary compact parsec-scale components which are bright jet component on east and less luminous core on west. Also, it is known that there have been superluminal jet components which are flowing from the core toward east, and then merging with the bright jet component (Marscher et al. 1991, Alberdi et al. 2000, Lister et al. 2013). Although 4C39.25 seems to be a blazar-like source having broad emission lines (SDSS) and superluminal motion, its property that jet component is brighter than the core is different from ordinary blazars. Furthermore, it has young radio galaxy-like properties such as non-variation in total flux (Alberdi et al. 1997, 2000, MOJAVE database) and high frequency peak at spectral energy distribution (Orienti et al 2007). Such complex properties led us to make recent observations to reveal precise properties and new changes of the source. We used Korean VLBI Network (KVN) and VLBI Exploration of Radio Astronomy (VERA) Array (KaVA) which provide high-frequency (23GHz and 43GHz) and high spatial resolution (1.2mas and 0.6mas). Therefore, this system is suitable for morphological and physical research on parsec scale structure. We present results for several epochs observed during 2013 to 2014, mainly focusing on morphological changes of 4C39.25 using KaVA images.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.1
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• pp.1-18
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• 2011

This paper explores changing concept of city in the context of globalization with innovation city and examines the characteristics of innovation city along with regional and national competitiveness. It is agreed that construction of innovation city by relocation of public institutions for balanced development of the country has valid logic. However, there are weak possibilities of innovation within the innovation city. Further more it is not a proper solution for the level up of national and regional competitiveness through this policy. The main logic is that physical relocation of institutions do not guarantee innovation of region through integration into globalization network resulting from the scale difference between nation and globe. Rather this paper suggests that regional innovation policy should performed in accordance with regional conditions and for the better competitiveness of nation and region, decentralization of power is needed. Then a region could have connection with global pipeline based on endogenous development power.

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.307-313
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• 2017

Objectives: Chemicals derived from various environment media contaminates food across the food supply chain. In Korea, levels of contaminants in food have been sporadically measured by monitoring programs of different government agencies. There is difficulty with data compilation and integrated analysis across media. Therefore, the aim of this study was to propose an overall integrated database and analytical platform design for the 'ECO-FOOD NET (Environmental COntaminant reduction platform for FOOD through an interagency collaboration NETwork)', a tool to support the reduction of environmental contaminants in food. Methods: We developed a new data structure and standardized protocols for the compilation of integrated data. In addition, we conducted subject-oriented logical and physical relational database modeling and created the architecture design of the platform. Results: We established a standardized code system related to exposure media and route, analysis method and food matrix. In addition, we designed the seven software modules of 'About the System', 'Introduction to Interagency Work', 'Media-Chemicals Profiles', 'Method Bank', 'Monitoring Data Base', 'Integrated Media Analysis', and 'Risk-Benefit Analysis'. Conclusions: This study will contribute to decision-making as a tool for executing risk management, such as sustainable reduction policies of contaminants in food.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.281-293
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• 2011

Server consolidation and virtualization have become an integral part of IT planning to reduce TCO cost and ensure the high availability for customer, enlarge the flexibility to computing resource in today' enterprise data centers. In spite of having the variety advantages of server consolidation and virtualization, they cause many problems such as the software licensing issues, virtual server sprawl, network complexity issues, hardware start-up costs, and failover costs. In particular, software licensing problem brings about the serious results in operating of data center and also presents a significant challenge to virtualization because many vendors have realized that licensing policies applicable to physical systems are not compatible with virtual machines. So, the IT planers must be considering this problem before they conducts the server consolidation and virtualization. In this paper, we proposed the efficiency strategy of SW licensing for server consolidation and virtualization analyzing the N-Datacenter case in Korea. As a result, we suggest the two strategies as technical and management/contract aspect. First, as the technical aspect, we propose i) the adaptation of suitable licensing for virtualization, ii) differentiation of license according to the characteristics of server, iii) the core distribution of licenses to minimizing. Second, as the management/contract aspect, we suggest following three things. i) The existing license agreement is changed to the right licensing for virtualization. ii) The license agreement is contracts the active focused. iii) When a new contract should be added to virtualization provisions.

• Water for future
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• v.28 no.5
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• pp.117-127
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• 1995

The application and analysis for the scale considering GIUH model proposed by the authors in this issue have been performed for the leemokjung sub-basin in the Pyungchang basin one of IHP representative basin in Korea. Scales of topographic maps for model application and fractal analysis are 1:25,000, 1:50,000 and 1:100,000. The ratio between successive scales is therefore constant. Link lengths were measured using a curvimeter with the resolution of 1 mm. Richardson's method was employed to have fractal dimension of streams. Apparent alternations of parameters were found in accordance with variations of map scale. And this tendency could mislead physical meanings of parameters because model parameters had to preserve their own value in spite of map scale change. It was found that uses of fractal transform and Melton's law could help to control the scale problem effectively. This methodlogy also could emphasize the relationship between network and basin to the model. To verify the applicability of GIUH proposed in this research, the model was compared with the exponential GIUH model. It is proven that proposed 2-parameter gamma GIUH model can better simulate the corresponding runoff from any given flood events than exponential GIUH model. The result showed that 2-parameter gamma GIUH model and fractal theory could be used for deriving scale considered IUH of the basin.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.1051-1061
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• 2005

This paper proposes a ubiquitous robot, Ubibot, as an integration of three forms of robots: Software robot (Sobot), Embedded robot (Embot) and Mobile robot (Mobot). A Sobot is a virtual robot, which has the ability to move to any place or connect to any device through a network in order to overcome spatial limitations. It has the capacity to interpret the context and thus interact with the user. An Embot is embedded within the environment or within physical robots. It can recognize the locations of and authenticate the user or robot, and synthesize sensing information. Also it has the ability to deliver essential information to the user or other components of Ubibot by using various types of output devices. A Mobot provides integrated mobile service. In addition, Middleware intervenes different protocols between Sobot, Embot, and Mobot in order to incorporate them reliably. The services provided by Ubibot will be seamless, calm and context-aware based on the combination of these components. This paper presents the basic concepts and structure of Ubibot. A Sobot, called Rity, is introduced in order to investigate the usability of the proposed concepts. Rity is a 3D synthetic character which exists in the virtual world, has a unique IP address and interacts with human beings through Vision Embot, Sound Embot, Position Embot and Voice Embot. Rity is capable of moving into a Mobot and controlling its mobility. In doing so, Rity can express its behavior in the virtual world, for example, wondering or moving about in the real world. The experimental results demonstrate the feasibility of implementing a Ubibot in a networked environment.