• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.106-113
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• 2014

This work proposes an analytic framework to estimate the capacity of the link in an M2M gateway that multiplexes a massive number of machine type communication devices. First, we specify the network architecture for M2M communications. Next, we summarize the characteristics of M2M traffic, from which we extract an area about the problem that has to be resolved in the dimensioning of the link capacity. After that we propose a new method to determine the capacity of the link in an M2M gateway. Via numerical experiment reflecting the realistic environment of M2M traffic, we illustrate the validity of the proposed model.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.478-483
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• 2002

Presently metro in our county has higher rate of passengers as a public transportation of urban area than other transportations. And road is under very restrictive condition to be expanded in many aspects because the streets are completely choked. Therefore increase of capacity in metro and reduction of headway has been seriously required and utmost efforts has been taken by related fields to meet the requirements. The concept of CBTC system came out from this background. CBTC system can be implemented to detect the train location without using the track circuits. It has many advantages in aspects of signalling equipments build-up and maintenance. This study investigated examples of radio communication system and applicable standard norms in other countries. And it also reviewed the suggestion for the establishment of radio frequency and radio network to be considered for application train control system by radio under Korean metro environment.

• Annual Conference of KIPS
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• 2006.11a
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• pp.463-466
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• 2006

오늘날 기술의 발전으로 차량 시스템에 대한 고객의 요구가 다양해져 차량내의 시스템이 복잡해지고 있다. 이에 따라, 배선양을 줄이기 위해 Controller Area Network(CAN)이 개발되었다. 그러나 CAN 을 사용한 시스템이 제대로 동작하는지 또는 안전한지에 대한 안전성 문제가 중요시되면서 시스템을 실제로 어떠한 CAN 네트워크에 연결할 경우 그 시스템이 제대로 동작하는지는 자체 테스트와 효과적인 테스트가 필요하다. 본 논문은 CAN 네트웍 통신상태를 자동 테스트 할 수 있는 시뮬레이션 알고리즘을 소개하며 또한 fault packet을 생성하여 CAN 네트웍을 테스트하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.183-183
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• 2007

Bimodal Tram is a new public transportation system combined subway with bus and consists of variable electric equipment to accomplish the comfortness, reliability, safety and so on. One of them is VCU(Vehicle Control Unit) for Performing driver's cmmand and monitoring the state of other equipment. To lessen the wiring and the interference of outer electromagnetic noises is very important things for bimodal tram with complicated configuration of electric equipments. This paper has investigated the application of CAN(Controller Area Network) communication method for VCU which has display, central unit and several nodes that are connected with other electric equipments(HVAC, door controller etc). We designed and manufactured the prototype of VCU which eventually will be installed on bimodal tram being developed in KRRI at present.

• Journal of information and communication convergence engineering
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• v.16 no.2
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• pp.93-98
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• 2018

The Internet of Things (IoT) is a form of the emerging 4th industry in the 5G era. IoT is expected to develop naturally in our daily life in the 5G era in which high-speed communication will be completed. Along with the rise of IoT, concerns about security and malicious attacks are also increasing. This paper examines DoS attacks, which are one of the representative security threats of IoT and proposes a local detection and blocking system that are suitable for response to such attacks. First, systems of the LoRaWAN type, which are most actively researched in the IoT system field and DoS attacks that can occur in such systems were examined. Then, the inverse order tree algorithm using regional characteristics was designed as a cluster analysis form. Finally, a system capable of defending denial-of-service attacks in the 5G IoT system using local detection and blocking with the Euclidean distance was designed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.687-693
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• 2011

In this paper, problems and solutions are proposed for applying IEC 61850 to Distribution Automation System(DAS). Communication protocol integration in power automation system have issued by IEC standards, IEC 61850 of them has researched for applying IEC 61850 to many areas of power system in spite of that it was made for substation automation system. Especially, DAS is just about to apply IEC 61850 by communication network change from serial to ethernet although DNP 3.0 is used. But it's impossible to apply directly IEC 61850 to DAS by difference of environment which unfixed wide area and separated nodes in power distribution system unlike concept of IEC 61850 is made by Substation Automation System(SAS) environment of limited space. Thus, this paper proposed applications of three types which conceptual, practical, and future to consider problems and solutions when apply IEC 61850 to Ethernet based DAS.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.26-36
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• 2009

ad-hoc network is self-constructed by mobile hosts without any infrastructure. And the hosts collaborate with each other for routing packet by means of multi-hop communication. But it is too hard to deploy ad hoc network at the large area because of the salability problem caused by low network throughput. network throughput decrease is due to contention on the air among the neighbor host and single interface limitation, and broadcast flooding through overall network. In this paper, to solve the ad hoc scalability problem, we propose mesh network based scalable hierarchical ad hoc architecture, and also propose the adaptation methods for inter-working with the host not including ad hoc functions and the legacy infra-network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1238-1244
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• 2001

Earlier efforts on optical access concentrated on the design of PONs for the collection and distribution portion of the access network. In these networks the optical hardware in the RN is very simple, but a multiple access protocol is needed for upstream traffic control. On the other hand, the role of communications is already well established in the office environment. With the advent of cheap, affordable broadband communications and the increasing complexity of consumer electronics, it seems natural to extend the network into the home. As the application of Home Area Network is ever increasing, we therefore consider connectivity between access network and home network which generates various traffic to design MAC protocol over residential network. Global-FIFO is quite simple and allows dynamic upstream bandwidth assignment on the basis of a request-and-permit mechanism. It has good bandwidth efficiency and being cell-based, it does not consider the various traffic from home network. In this paper, we design and analyze the new MAC resource assignment algorithm called MQ-FIFO (Multiple Queue-FIFO) that provides good performance under the environment of ATM-PON and Home Network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3672-3679
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• 2012

Vehicle Ad hoc Network (VANET) is next-generation network technology to provide various services using V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure). In VANET, many researchers proposed various studies for the safety of drivers. In particular, using the emergency message to increase the efficiency of traffic safety have been actively studied. In order to efficiently transmit to moving vehicle, to send a quick message to as many nodes is very important via broadcasting belong to communication range of vehicle nodes. However, existing studies have suggested a message for transmission to the communication node through indiscriminate broadcasting and broadcast storm problems, thereby decreasing the overall performance has caused the problem. In addition, theses problems has decreasing performance of overall network in various form of road and high density of vehicle node as urban area. Therefore, this paper proposed Clustering based Routing Algorithm (CBRA) to efficiently transmit emergency message in high density of vehicle as urban area. The CBRA managed moving vehicle via clustering when vehicle transmit emergency messages. In addition, we resolve linkage problem between vehicles according to various form of road. The CBRA resolve link brokage problem according to various form of road as urban using clustering. In addition, we resolve broadcasting storm problem and improving efficacy using selection flooding method. simulation results using ns-2 revealed that the proposed CBRA performs much better than the existing routing protocols.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.209-216
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• 2022

The modern development of higher education in Ukraine is the result of two main factors. One of them - the factor of social progress - reflects the transformations inherent in modern Ukrainian society. These include, first of all, the processes of democratization and the development of civic responsibility. European the choice of Ukraine, the integration of our state into the European space determine accordingly, the second factor influencing the development of domestic higher education - the trends that guide the progress of the European Higher Education Area (European Higher Education Area (hereinafter - EHEA) and the European Research Area Research Area, hereinafter - ERA). The strategy of information support of the educational process (approved by the European Commission in 2010) recognizes the leading role of higher education as a driver of social progress, accordingly states the priority - the development of free economic education and identifies indicators of such progress - the achievement and international attractiveness of European free economic education. The information support of modernization challenges in higher education are aimed at the educational process, the leadership position of students, in particular through promotion and implementation of leading achievements and best practices in the context of globalization.