• KIPS Transactions on Computer and Communication Systems
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• v.9 no.11
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• pp.247-249
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• 2020

In the era of the 4th industrial revolution, the demand for convergence between ICT technologies is increasing in various fields. Accordingly, a new term that combines data, network, and artificial intelligence technology, DNA (Data, Network, AI) is in use. and has recently become a hot topic. DNA has various potential technology to be able to develop intelligent application in the real world. Therefore, this paper introduces the reviewed papers on the service image placement mechanism based on the logical fog network, the mobility support scheme based on machine learning for Industrial wireless sensor network, the prediction of the following BCI performance by means of spectral EEG characteristics, the warning classification method based on artificial neural network using topics of source code and natural language processing model for data visualization interaction with chatbot, related on DNA technology.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.434-437
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• 2010

본 논문에서는 현재 연구 개발이 활발히 진행되고 있는 공공 무선망 서비스 제공을 위한 Binary CDMA기술이 적용된 Guardian 모뎀 칩셋에 대하여 알아 본 후, 무선 데이터 전송 시험을 통해 데이터 율과 SNR, BER, PER에 대한 성능을 분석한다.

• IE interfaces
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• v.16 no.2
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• pp.195-200
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• 2003

In this paper, the selective use of RTS and CTS frames is considered to analyze the capacity of IEEE 802.11 WLAN (Wireless Local Area Network). The RTS and CTS frames are used to transmit the data frames longer than dot11RTSThreshold according to IEEE 802.11 specification. The analysis of the optimal RTS-CTS threshold is derived to maximize the capacity of IEEE 802.11 WLAN. And, numerical examples are also presented for IEEE 802.11 a and b WLANs.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.168-172
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• 2003

건물의 대형화로 인하여 건물의 이력관리 및 자재관리 둥 설비관리 시스템이 중요해지고 있다. 이에 따라, 건물 내의 모든 것의 자동화가 이루어지고 있지만, 기기의 자동화에 비해 업무의 자동화는 미흡한 실정이다 기존의 시스템은 설비업무의 특성상 외부 업무가 많은데 네트워크 지역에서만 전송이 가능하였다. 이로 인하여 문서의 누락이 많았고 업무의 효율성에 문제가 있었다. 본 논문에서는 기존의 설비관리 시스템의 문제점인 네트워크 음영지역에서의 업무의 단절을 극복하기 위하여 모바일 기기에 Oracle Lite를 탐재해서 음영지역에서도 문서를 저장할 수 있게 하여 업무의 효율성을 높이는 것을 목적으로 한다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.4
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• pp.41-49
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• 2016

Smart Grid is a next generation of new power growth electrical grid which provide high quality of electrical service by using Information Technologies to increase intelligence and performance. By using Smart Grid system, it can support energy management such as increase quality of electrical power, decrease energy and decrease emissions. However, Smart Grid uses information of energy consumption and when Smart Grid collects information, it will create private information. In this thesis, it will address issues of security private information which caused by Smart Grid for administrative measure and efficiency of Smart Grid in domestic. Also, cryptographic module algorithm, latest security solutions and strong wireless security policy for network environment such as wireless communication Iinternet are require for Smart Grid perform successfully and protect national power network equipment from cyber-attack and can stop leakage of user's personal information. Finally, it is urgent to prepare protection measures of National industrial facilities and power grid which can prepare for a cyber terrorism and penetration attacks and build emergency countermeasure management team for Smart Grid are require for safe Smart Grid environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1C
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• pp.1-7
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• 2012

At the industrial work site, the manufacturing process is being automated to improve work efficiency. However, it is often difficult to automate the entire manufacturing process, and there are spaces in which workers there are constantly exposed to danger. To protect such workers from the danger, this paper studied a worker safety management system for the industrial work site which uses a location recognition system and which is based on the Ubiquitous-Wireless Sensor Network (U-WSN). Using wireless signals, the distance between two devices can be measured and the location of a worker can be calculated using triangularization in 3-D. But at the industrial work sites where there are a lot of steel and structures, errors occur due to signal reflection and multi-path, etc., which makes it difficult to get the accurate location. To address this problem the following was done: first, a circular polarization patch antenna appropriate to the work site was used to reduce the degree of error that may occur from the antenna emission pattern and the particular Line of Sight (LOS); second, a 3-D localization technique and a filtering algorithm were used to improve the accuracy of location determination. The developed system was tested by using it on a wharf crane to validate its accuracy and effectiveness. The proposed location recognition system is expected to contribute greatly in ensuring the safety of workers at industrial work sites.

• International journal of advanced smart convergence
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• v.3 no.2
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• pp.1-5
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• 2014

Sensor nodes depend on batteries for energy source in Wireless Sensor Networks (WSNs). Low Energy Adaptive Clustering Hierarchy (LEACH) is a representative cluster-based routing protocol designed to ensure energy use efficiency whereas the virtual cluster exchange routing (VCR) information only with its closest node to build a network. In this paper, a protocol scheme was proposed wherein member nodes are designed to compare the currently sensed data with the previously sensed one and to switch to sleep mode when a match is achieved. The design is to help improve the transmission energy efficiency too.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.287-289
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• 2009

무선 메쉬 네트워크(WMN, Wireless Mesh Network)에서의 전체적인 성능은 채널의 간섭을 최소화함으로써 개선될 수 있다. 본 논문은 3개의 멀티 채널을 지원하는 IEEE 802.11b/g 기반 WMNs를 위해 제안된 클러스터 기반 채널 할당 기법인 CB-CA(Cluster-Based Channel Assignment)[3] 알고리즘을 멀티 라디오 멀티 채널 WMN 환경에 적합하게 개선시키고자 한다. CB-CA 알고리즘에서는 메쉬 라우터들중에 선택된 클러스터 헤드(CH, Cluster Head) 노드들과 클러스터들 간의 에지 게이트웨이(EG, Edge Gateway) 노드들 간에는 모두 동일 채널을 사용함으로써 채널 스캐닝과 채널 스위칭을 수행하지 않는다. 그러나 이러한 모든 CH들과 EG들 간의 동일 채널의 사용은 많은 노드들에서 채널 간섭을 발생 시키는 문제점이 발생한다. 본 논문에서는 이를 해결하기 위하여 송수신 인터페이스를 구분하고 각 인터페이스에서의 채널을 랜덤하게 설정하고 이를 통신 범위 내에 인접한 이웃 클러스터들에게 알림으로써 서로 간섭이 발생하지 않는 채널들이 설정되도록 한다. 이로써 각 클러스터 간의 채널 간섭을 최소화 할 수 있음과 동시에 다중 인터페이스와 다중 채널을 모두 활용할 수 있어서 QoS를 향상시킬 수있다.

• IE interfaces
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• v.14 no.3
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• pp.227-235
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• 2001

There is a rapidly growing demand for wireless telecommunication. However, the number of usable channel is very limited. Therefore, the problem of channel assignment becomes more and more important to use channels as efficiently as possible. The objective of this paper is to develop an evolution program (EP) to find an efficient dynamic channel assignment method for minimum interference among the channels within reasonable time. The series of specific channel number is used as a representation of chromosome. The only changed chromosomes by crossover and mutation are evaluated in each generation to save computation time and memory for the progress of improved EP. We can easily differentiate the fitness value of each chromosome using proposed evaluation function. We also control the weighting factor of the mutation rate and the used number of elitist chromosomes for the speed of convergence to the optimal solution.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.326-329
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• 2008

현재 IEEE 802.11p 규격은 기존의 IEEE 802.11a 규격을 기반으로 하여 표준화가 진행되고 있다. 기존의 IEEE 802.11a 규격은 무선랜 (WLAN: Wireless Local Area Network) 규격으로서 고속으로 이동하는 차량 통신환경 즉 WAVE (Wireless Access for Vehicular Environment) 환경에 그대로 작용할 경우 수신 성능이 급격히 떨어지게 되 는 문제점이 있다. 본 논문에서는 긴 훈련 심볼 (LTS: Long Training Sequence)을 이용하는 기존의 채널 추정 기법을 기반으로 하되 WAVE 채널처럼 빠르게 변화하는 채널에 대응하기 위해 일정한 심볼 주기 마다 미드엠블 (Mid-Amble)을 삽입하는 전송구조를 제안한다. 또한, 미드엠블 사이의 심볼들의 위상과 크기를 3차원 스플라인 보간법을 적용하여 추정하는 알고리듬을 제안한다. 제안된 알고리듬의 성능실험을 위해 WAVE 채널을 모델링하였으며 이러한 채널에서 성능실험을 수행하였다. 실험결과에 의하면 제안된 알고리듬은 빠른 시변 채널에서도 매우 우수한 성능을 나타냄을 알 수 있다.