• Journal of KIISE:Information Networking
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• v.33 no.5
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• pp.355-368
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• 2006

This paper introduces a new split-TCP approach for improving TCP performance over IEEE 802.11-based wireless LANs. TCP over wireless LANs differently from wired networks is not aggressive, which is a fundamental reason for poor performance. Therefore, we propose TAS (TCP-Aware Sub-layer) to migigate this problem. Our scheme extends the split-connection approach that divides a connection into two different connections at a split point such as an access point (AP). Using TAS, a wireless node emulates TCP ACK packets using MAC ACK frames, instead of receiving real TCP ACK packets. We compared TAS with both normal TCP and I-TCP (Indirect TCP) by NS2 simulation. Results show that TAS achieves higher throughput, more fair resource allocation and, in power-saving mode, shorter delays.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.184-191
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• 2008

NanoQplus, which is an embedded operating system for wireless sensor networks (WSNs) and developed by Electronics and Telecommunications Research Institute (ETRI), provides programmer-friendly preemptive multi-threading programming technique, but it has poor network protocol stack, as compared to TinyOS, one of the famous operating systems for WSNs. In this paper, we apply dynamic MANET on-demand routing (DYMO) protocol, which is being standardized in Internet Engineering Task Force (IETF), to NanoQplus. Since DYMO has been proposed for mobile ad-hoc networks (MANETs) and MANETs have less resource restrictions than WSNs, the basic DYMO protocol cannot be applied to WSNs without modifications. Moreover, coherence with MAC protocol should be considered in order to eliminate redundant data between MAC and network layers. Thus, we propose a modified version of the basic DYMO protocol for NanoQplus. The experimental results from a real sensor network test-bed show that the DYMO implementation using NanoQplus works efficiently in WSNs.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.217-224
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• 2008

EThis paper is study regarding banking institution and DoS attack regarding government organization which occurred in 2008. We used a tool aggressive actual DoS You install the N-IDS which used Snort in networks in order to detect a DoS attack. Storages of Winpcap and a packet to detect a packet and MySQL, HSC, to analyze. We install NET Framework etc. E-Watch etc. analyzes Packet regarding a DoS attack of a hacker and TCP, UDP etc. information, Port, MAC and IP information etc. through packet analysis tools. There is a meaning you analyze data regarding the cyber DoS, DDoS attack that is dysfunction of Ubiquitous Information Society, and it generates forensics data regarding an invader and back-tracking analysis data, and to ensure safe Internet information system through this paper study.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.275-281
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• 2012

Community network is a communication environment where heterogeneous devices can access and communicate with each other at any time and at any space to share information. To do so, mobile devices are required to be self-configured even in absence of communication infrastructures. Semi-infrastructured wireless ad-hoc network is a promising solution to meet with such a requirement. This paper proposes the VTC(virtual topology coordinator) system as an evaluation tool for examining network protocols that are intended to be deployed in the semi-infrastructured ad-hoc networks. VTC emulates multi-hops wireless network topology virtually using a mechanism of selective receiving MAC frame in a small area, where only a single hop communication is available. VTC system cannot consider all properties introduced in real wireless network, but do more wireless properties than verification through simulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.345-352
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• 2017

In this paper, we design and implement an educational robot system that can use scratch education with the function of user demanding to perform robot education in actual school site in an embedded environment. It is developed to enable physical education for sensing information processing, software design and programming practice training that is the basis of robotic system. The development environment of the system is Arduino Uno based product using Atmega 328 core, debugging environment based on Arduino Sketch, firmware development language using C language, OS using Windows, Linux, Mac OS X. The system operation process receives the control command of the server using the Bluetooth communication, and drives various sensors of the educational robot. The curriculum includes Scratch program and Bluetooth communication, which enables real-time scratch training. It also provides smartphone apps and is designed to enable education like C and Python through expansion. Teachers at the school site used the developed products and presented performance processing results satisfying the missionary needs of the missionaries.

• Journal of KIISE:Information Networking
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• v.33 no.1
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• pp.91-102
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• 2006

We analyze the performance of MAC-layer Reed-Solomon error recovery in the cdma2000 1xEV-DO Broadcast and Multicast Services (BCMCSs) environment, with respect to the size of the ECB (Error Control Block) and the air-channel condition, and establish the relationship between ECB size, error recovery capacity and service latency. From this we propose an adaptive error recovery scheme which adjusts the size of the ECB to reflect the environment of the mobile nodes so as to meet the required service quality (target bit error-rate), while reducing the latency of real-time applications. Extensive simulation results show the effectiveness of our approach compared to the current static scheme. Proposed adaptive schemes achieves near optimal solution with respect to service latency while satisfying the required service quality.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.373-379
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• 2019

AeroMACS spectrum is a national resource internationally allocated by ITU at WRC-07. AeroMACS is an airport broadband mobile communication infrastructure based on WiMAX-based IEEE 802.16e that enables real-time video, graphics, voice, and high-speed data transmission. With the approval of ICAO's development technology standards in 2008, 50 airports in 11 countries have already completed the testing of D-TAXI or A-SMGCS technology using the AeroMACS infrastructure in 2019, starting in the United States in 2009. With many advantages in safety and convenience in terrestrial telecommunications operations, the system is becoming an area of performance improvement for airport operations in accordance with ICAO's ASBU plan. This paper examines the current status of domestic development of AeroMACS and lists service areas applicable to airlines and operators. It also seeks to promote safe and efficient next-generation airport mobile communication system services by presenting feasible partners management in the mobile area and use of aircraft communication systems for active technology development.

• Journal of Korean Society of Archives and Records Management
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• v.3 no.2
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• pp.78-96
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• 2003

Nowadays, mass media innovates and has the great power of revolution of our lives. Marshall MacLuhan says new media is the new method of language and also, it is connecting to the real world possibly. The letters make media world a big different. At the end of voiceless age, the caption not only delivers means of the contents but also provides for the composition of the screen itself. In these kinds of composition elements contain explanations such as aesthetic, entertainment, and revival aspects. The caption as translation that used to use was as changing as new way of exploring method. To deliver means of contents, the letters of inside screen has extremely big changes and meaning as well. The design of lettering is the new aesthetic method of media world. Also, the elements of lettering is approaching as the new way of lives. Therefore, this study is to provide the aspects of the lettering to the mass media respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1705-1713
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• 2018

It is currently undergoing the fourth industrial revolution, which is the convergence of ICT and manufacturing, connecting both industrial equipment and production processes to one network and communicating with each other. The fact that they are connected to one network has the advantage of management, but there is a risk of security. In particular, Wi-Fi can be easily accessed by outsiders through a software change of the MAC address or password exposures. In this paper, by applying the method of Beacon using a Bluetooth Low Energy Add in Bluetooth 4.0, we propose a system of black-box approach to secure connections to wireless Internet, users do not have to know the password. We also implemented the proposed system using the raspberry pi and verified the effectiveness of a real-time system by testing the communication.

• ETRI Journal
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• v.14 no.4
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• pp.165-178
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• 1992

본 고는 Mini-MAP 네트워크의 접속장치를 구현한 내용이다. 이 접속장치는 공장자동화 네트워크 시스팀에서 Mini-MAP 노드로 동작하며, PLC, CNC, robot와 같은 프로그래머블 디바이스를 MAP 네트워크 환경에 접속하여 원격제어가 가능하도록 하는 네트워크 구축을 위한 핵심 장치이다. 이 접속장치는 MAP 3.0의 Mini-MAP으로 구현하고 실현하였다. MAC 부계층은 Token Bus Controller(TBC)가 담당하며, LLC 부계층은 class 3로 설계하였고, MMS는 implementaton class MAP3를 설계하였다. 구현된 모든 소프트웨어는 Mini-MAP의 실시간 정보 전송 성능을 보증하기 위해 real-time 멀티 태스크 OS로 운영하도록 설계하였으며, 보드에 firmware로 탑재하였다. 프로토콜 분석기를 이용하여 LLC 수준의 오류검출과 전송기능을 확인하였으며, MMS는 적합성 시험을 이미 받은 MMS를 탑재한 상용 제품과의 통신 실험을 통해 적합성을 확인하였다.