• Electric Engineers Magazine
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• s.350
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• pp.13-15
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• 2011

본고에서는 메시법과 회전구체법의 관계, 메시법의 뇌보호 효과 등을 분석한 분석 모델을 소개하고, IEC62305규격에서 정하고 있는 메시법의 관련내용을 살펴보았다. 메시 사이즈의 선정과 배치방법을 검토하고 지붕에 메시망을 구축할 때 회전구체에 의해 침투하는 깊이를 계산해 제시했으며 고층 건물의 측뢰에 대한 메시법 적용과 그에 따른 문제와 대책 등을 검토했다. 그리고 메시법의 적용사례를 통해 메시 도체 배치방법 등을 고찰했다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.4 s.334
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• pp.7-14
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• 2005

Earlier researches have typically concentrated on discovering IP network topology, which implies that the connectivity of all Ethernet devices is ignored. But automatic discovery of Physical topology Plays a crucial role in enhancing the manageability of modem Metro Ethernet mesh networks due to the benefits of Ethernet services, including: Ease of use, Cost Effectiveness and flexibility. Because of proprietary solutions targeting specific product families and related algorithm which depends on Layer 2 forwarding table information it is impossible to discover physical topology in the Ethernet mesh networks. To cope with these shortcomings, in this paper we propose a novel and practical algorithmic solution that can discover accurate physical topology in the Ethernet mesh networks. Our algorithm divides the Ethernet mesh networks into bridged networks and host networks and those bridges located in boundary are named edge bridges. Our algorithm uses the standard spanning tree protocol MIB information for the bridged networks and uses the standard Layer 2 forwarding table MIB information for the host networks. As using the standard MIB information to discover physical topology we can offer interoperability guarantee in the Ethernet mesh networks composed of the various vendors' products.

• Convergence Security Journal
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• v.23 no.1
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• pp.3-8
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• 2023

Multi-domain optical transport networks are not fundamentally interoperable and require an integrated orchestration mechanism and path provision mechanism at the entire network level. In addition, ensuring network survivability is one of the important issues. MPLS-TP (Multi-Protocol Label Switching-Transport Profile) defines various protection/recovery methods as standards, but does not mention how to calculate and select protection/recovery paths. Therefore, an algorithm that minimizes protection/recovery collisions at the optical circuit packet integrated network level and calculates and sets a path that can be rapidly protected/recovered over the entire integrated network area is required. In this paper, we proposed an algorithm that calculates and sets up a path that can be rapidly protected and restored in a T-SDN network composed of multiple ring-mesh topology.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.1
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• pp.1-9
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• 2017

With the Development of Wireless Network Technology and Wireless Link Technology, Wireless Mesh Network (WMN) is Attracting Attention as a Key Technology to Construct the Wireless Transit Network. The WMN has been Studied for a Long Time in Various Fields, however there are still many Problems that have not been solved yet. One of them is the Routing Problem to find an Optimal path in a Multi-hop Network Composed of Wireless Links. In the Hybrid-WMN, which is one of the Three Types of WMN, Optimal Path Selection Requires Research on Path Search Protocols that Effectively use the Infrastructure Mesh as a Transit Network, Together with Research for a Routing Metric with Excellent Performance. Therefore, this Paper Proposes a Dual Mode-AODV(Ad hoc On-demand Distance Vector) for Hybrid-WMN. Simulation result shows that the Path Selection Delay was Reduced by 52% than AODV when the Proposed Dual Mode-AODV was applied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2422-2429
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• 2013

WMN is considered as a core methodology to provide mobile wireless network service with multi-hop routing feature. It has a merit that can be easily deployed by utilization of protocols for MANET. However, it has differences in supporting multiple networks and channels, network architecture, and so on. Especially, in case of routing protocols, to apply them intactly to WMN can be a cause of low performance because of do not moving mesh routers. AODV seems like suitable for WMN among the various routing protocols for MANET. However, it has a defect in scalability. In this paper, an enhanced AODV routing method for WMN was proposed. The proposed method was designed to be suitable to the architecture of WMN by use of layering and localizing the broadcasting domain.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.3
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• pp.158-170
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• 2009

In this paper, we propose the new torus network which has the hypercube Q3 as the basic module. The proposed Hyper-torus has the degree 4, and is the network which has the scalability, and the fine diameter. If we compare the class of the torus in the viewpoint of network cost, the hyper-torus with $1.4{\sqrt{N}}$+ 16 is proved to be approximately 65% than the torus with $4{\sqrt{N}}$ and 50% than the honeycomb with $2.45{\sqrt{N}}$. This result means that hyper-torus is better for the class of the existing mesh in the viewpoint of network cost.

• Journal of the Korea Society of Computer and Information
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• v.17 no.10
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• pp.99-105
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• 2012

ZigBee is the low power, low cost and low data rate wireless personal area network(LR-WPAN) standard. The Directed-Messaging is the protocol which improves the energy efficiency through reducing the redundant message transmission by transmitting messages with directional information toward the specified sub-network area in wireless sensor network using broadcasting. In this paper, we design and implement the experimental grid sensor network using ZigBee modified by the Directed-Messaging for the energy efficiency improvement. The experimental sensor network in this paper is configured with Nano24 supporting the ADV message and the routing management module modified to use the directional information. The energy efficiency improvement of the experimental sensor-network by evaluating the experimental results according to transmitting ADV message.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.150-153
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• 2008

현재 무선 랜 기반의 WMN은 도심지와 같은 통화량이 많은 지역('핫존')에서 서비스 되고 있다. 다수 핫존을 서비스하는 엑세스 포인트(AP)별로 인터넷 망에 유선 접속할 경우, 망 접속 비용이 높지만, WMN 기술을 이용하면 핫존별로 산재한 트래픽의 집중을 통해 자원을 대폭 줄일 수 있다. 또한, IEEE 802.11 표준은 가용한 채널이 다양한 직교주파수로 되어있어 IEEE 802.11b에서는 2.4GHz에서 간섭 없는 3개의 채널을 제공하고 IEEE 802.11a는 5GHz에서 간섭 없는 12개의 채널을 제공한다. 근접한 access point (AP)주변에는 다른 채널을 할당함으로써 근접한 AP사이에서의 간섭을 막을 수 있다. IEEE 802.11 표준은 동시 사용에 1개의 채널만 사용하게 되어있어 가용한 채널을 동시에 간섭 없이 사용함으로써 전체적인 throuput을 증대 시킬 수 있어 IEEE 802.11 표준 기반의 MAC 프로토콜의 수정만으로 상, 하 레이어의 수정 없이 향상된 멀티채널을 위한 MAC 프로토콜을 제시한다.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.259-267
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• 2012

Internet telephony is an Internet service which supports voice telephone using VoIP technology on the IP-based Internet. It has some advantages in that voice telephone services can be accompanied with multimedia services such as video communication and messaging services. Recently, the introduction of smart phones has led to a growth in social networking services and thus, the research and development of Internet telephony has been actively progressed and has the potential to become a replacement for the telephone service that is currently being used. In this paper we designed and implemented an Internet telephony network system which is developed by using Asterisk and open source softwares. It is developed on the linux system and has some features such as VoIP telephony service between SIP phones, voice mail, and call recording. It also supports web-based functions such as SIP users and server system management that is implemented by Apache web server and PHP programs. Afterwards, this system will be applied as VoIP network base technology for small sized companies and organizations. It will paly a role for encouraging companies to use open source softwares.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.235-242
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• 2014

Internet telephony is an Internet service which supports voice telephone using VoIP technology on the IP-based Internet. It has some advantages in that voice telephone services can be accompanied with multimedia services such as video communication and messaging services. In this paper we suggested an Asterisk-based Internet telephony system which can be easily scalable. Most current systems use text files to manage their configuration: SIP users, dialplans, IVR service and etc. But we designed the management system which introduces database tables for efficiency and scalability. It also supports web-based functions developed by using Asterisk, Apache, MySQL, jQuery, PHP and open source softwares.