• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4640-4661
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• 2018

To cope with the explosive growth of Internet services, Service Function Chaining (SFC) based on Software-defined Networking (SDN) is an emerging and promising technology that has been suggested to meet this challenge. Determining the placement of Virtual Network Functions (VNFs) and routing paths that optimize the network utilization and resource consumption is a challenging problem, particularly without violating service level agreements (SLAs). This problem is called the optimal SFC placement problem and an Integer Linear Programming (ILP) formulation is provided. A greedy heuristic solution is also provided based on an improved two-step mapping algorithm. The obtained experimental results show that the proposed algorithm can automatically place VNFs at the optimal locations and find the optimal routing paths for each online request. This algorithm can increase the average request acceptance rate by about 17.6% and provide more than 20-fold reduction of the computational complexity compared to the Greedy algorithm. The feasibility of this approach is demonstrated via NetFPGA-10G prototype implementation.

• Convergence Security Journal
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• v.11 no.4
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• pp.37-42
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• 2011

In this paper, the design methodology of information security is analyzed to implement the ubiquitous city (u-City). The definition, concept, and main u-services of u-City are presented. The main components, functio ns and offering services of u-City management center are presented, and the laws and network security requirements related to protect the personal information in collecting, processing, and exchanging are also analyzed. Three step security levels of Router/Switch, Firewall/VPN, and IPS are applied where main functions of in terception of abnormal packets($1^{st}$ level), access control for each service($2^{nd}$ level), and real-time network monitoring($3^{rd}$ level) are performed. Finally, application cases are presented to validate the security of personal information in providing the u-City services.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.744-751
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• 2008

Ubiquitous computing is a new paradigm of telecommunication technology and is embedded with advanced computing technology to process a large amount of data in a normal environment. Generally, ail equipment is embedded with sensors and operating devices to interaction with communication functions. That is why ubiquitous computing must be able to access any devices anywhere at anytime in order to perform appropriate functions. Unfortunately, however, it is difficult to make an optimized design for applications which can effectively interaction with various functions in distributed environment like ubiquitous computing. Therefore, this paper is aimed at deploying interface with server nodules and virtual prototyping by utilizing LabVIEW and embedded application software with additional network function. In addition, given information about sensors collected from context-awareness and location-awareness, it will suggest the ideal ubiquitous application based on context-awareness and apply the advanced application to device control and monitoring through context awareness of lab.

• The Transactions of the Korea Information Processing Society
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• v.13 no.2
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• pp.48-59
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• 2024

As functions that support virtualization on their own in hardware are developed, user applications having various workloads are operating efficiently in the virtualization system. SR-IOV is a virtualization support function that takes direct access to PCI devices, thus giving a high I/O performance by minimizing the need for hypervisor or operating system interventions. With SR-IOV, network I/O acceleration can be realized in virtualization systems that have relatively long I/O paths compared to bare-metal systems and frequent context switches between the user area and kernel area. To take performance advantages of SR-IOV, network resource management policies that can derive optimal network performance when SR-IOV is applied to an instance such as a virtual machine(VM) or container are being actively studied.This paper evaluates and analyzes the network performance of SR-IOV implementing I/O acceleration is compared with Virtio in terms of 1) network delay, 2) network throughput, 3) network fairness, 4) performance interference, and 5) multi-network. The contributions of this paper are as follows. First, the network I/O process of Virtio and SR-IOV was clearly explained in the virtualization system, and second, the evaluation results of the network performance of Virtio and SR-IOV were analyzed based on various performance metrics. Third, the system overhead and the possibility of optimization for the SR-IOV network in a virtualization system with high VM density were experimentally confirmed. The experimental results and analysis of the paper are expected to be referenced in the network resource management policy for virtualization systems that operate network-intensive services such as smart factories, connected cars, deep learning inference models, and crowdsourcing.

• Archives of design research
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• v.12 no.4
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• pp.182-190
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• 1999

There has been the rapid change of paradigm with the overflow of terms related to computers such as information, digital, cyber, virtual world and the change of time concept on the ground that it is common to change the world into virtual time. This study is about cybercharacters working in air-broadcasting with rapidly-developing internet, The cybercharacters including 3D animation developed from 2D animation are know to be manufactured with use of electronic mediun and computers and to exist in electronics. Though the emergence of the cybercharacters has a lot of gflnetic roots according to their objectives, they have in common that they are made by 3D graphics and they work in the virtual space, The great traits of the cybercharaters lie in the extension of interfacial function and ecological growth. In the cyberspace the interface, the meeting point between a computer and its users is the most important, The cybercharacters as medium providing new ruman interface become effective with growing interest in virtual reality, The cybercharacters also keep the ecological traits, They can also bring about added value with infusion of image and development of the network, These cybercharacters can also play the important parts in the continually developing cyberspace, The successful birth of the cybercharacter are based on, the technological power. assistance of fund and the ctrltural background, The information-entertainment of the cybercharacters functions well with the accompinimene of these three things, The cybercharacters can make a subject which keeps single issue as a central point of the virtual realty, The cybercharacters can also be connected with equity of "Korean knowledge information society" in the cultural rule of the internet and sociocul tural identity, identity.

• Journal of KIISE:Information Networking
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• v.30 no.2
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• pp.270-281
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• 2003

ETF made the RFCs of MPLS technologies for providing the QoS of ATM or Frame Relay and the flexibility&scalability of IP on the Internet services. IETF has been expanding MPLS technologies as a common control component for supporting the various switching technologies called GMPLS. Also, IETF has standardized the signaling protocols based on such technologies, such as LDP, CR-LDP and RSVP-TE. ETRI developed the MPLS system based on ATM switch in order to provide more reliable services, differentiated services and value-added services like the VPN and traffic engineering service on the Korea Public Sector network. We are planning on deploying model services and commercial services on that network. This paper explains the basic functions of LDP, design and development of LDP on our system, and compares with LDP development and operation on other MPLS systems made by Cisco, Juniper, Nortel and Riverstone. In conclusion, this paper deduces the future services and applications by LDP through these explanation and comparison.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.499-510
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• 2012

An SNS(Social Network Service) is an online service that supports an effective way to share information over virtual communities. Recently, as SNSs such as Twitter, Facebook, and Me2day are getting bigger, the purposes of using popular SNSs are expanded to broadcastings, politics, marketings and so on. In this paper, we propose an API to integrate and manage open APIs for various SNSs, presenting a library as an implementation of the proposed API. Also, utilizing the developed library, a smartphone application is provided which supports integrated management of popular SNSs and personal schedules. Using the library, developers can reduce costs when they need to implement specific functions for managing various SNSs. With the developed application, we can read and write to/from the related SNSs on same screen, automatically reminding our schedule and sharing the schedule with friends over the SNSs.

• Journal of Korea Water Resources Association
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• v.38 no.3 s.152
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• pp.199-212
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• 2005

The study on the plan for rehabilitation project of domestic water distribution system - especially using Heuristic Algorithm as Genetic Algorithm which is expected to provide a more optimal solution effectively - has not been done sufficiently. The purpose of this study is the development of the optimal decision making system for the rehabilitation of the water distribution system considering economic and hydraulic influences using ReHS which is recent study of OR technique. Five different models with different objective functions are developed and tested to virtual pipe network according to various conditions considered in this study. These models provide more options for the rehabilitation of pipe network systems compared to previously suggested models in the literature.

• Journal of the Korea Society for Simulation
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• v.26 no.3
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• pp.105-113
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• 2017

This study considers an optimal investment planning for improving survivability from an air threat in the layered air defense system. To establish an optimization model, we first represent the layered air defense system as a network model, and then, present two optimization models minimizing the failure probability of counteracting an air threat subject to budget limitation, in which one deals with whether to invest and the other enables continuous investment on the subset of nodes. Nonlinear objective functions are linearized using log function, and we suggest dynamic programming algorithm and linear programing for solving the proposed models. After designing a layered air defense system based on a virtual scenario, we solve the two optimization problems and analyze the corresponding optimal solutions. This provides necessity and an approach for an effective investment planning of the layered air defense system.

• The Research Journal of the Costume Culture
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• v.23 no.6
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• pp.1097-1115
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• 2015

ICT in the IOT era is the core basis of modern society. This study investigated and analyzed the recent commercialization trends of smart fashion products internationally and domestically, to utilize them as the basis of data for developing user-friendly smart fashion products that can meet the needs of consumers. Keyword research using the most representative search engines, Google and Naver was conducted for searching for various wearable items commercialized actively since 2010. The final 78 products were classified by the physical area, and the key features and benefits were analyzed. Smart fashion products were classified as four physical types for the head and face, torso, arms and hands, and ankles and feet. Smart fashion products for each body part were developed in various ways, such as hats, glasses, lenses, virtual screens, earphones, headsets, clothing, watches, wrist bands, gloves, rings, wallets, bags, anklets, shoes, socks, and insoles. The main features were music playback, bluetooth, a camera based on NFC, virtual effects, health and safety protection through measuring heartbeat and momentum, and social network sharing of all kinds of information, based on inter-working with a smartphone. These functions represent the physical, social, and emotional interactions among users and their surroundings, as well as the users, themselves. The research results are expected to be used in future studies on planning user-friendly and marketable products through in-depth analysis of the design characteristics of smart fashion products as well as consumer responses.