• ETRI Journal
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• v.35 no.1
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• pp.146-149
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• 2013

We propose a reconciliation sublayer (RS)-based lane and traffic control protocol for energy-efficient 40-G/100-G Ethernet. The RS performs active/inactive lane control and data rate adaptation depending on active lane information received from the upper layer. This protocol does not result in a processing delay in the media access control layer, nor is an additional buffer required at the physical layer for dynamic lane control. It ensures minimal delay and no overhead for the exchange of control frames and provides a simple adaptive data rate.

• ETRI Journal
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• v.35 no.3
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• pp.414-424
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• 2013

We consider a new load balancing routing for delay-guaranteed services in the network in which the traffic is dynamic and network topologies frequently change. For such an ever-changing network, we propose a new online load balancing routing called AntLBR, which exploits the ant colony optimization method. Generally, to achieve load balancing, researchers have tried to calculate the traffic split ratio by solving a complicated linear programming (LP) problem under the static network environment. In contrast, the proposed AntLBR does not make any attempt to solve this complicated LP problem. So as to achieve load balancing, AntLBR simply forwards incoming flows by referring to the amount of pheromone trails. Simulation results indicate that the AntLBR algorithm achieves a more load-balanced network under the changing network environment than techniques used in previous research while guaranteeing the requirements of delay-guaranteed services.

• ETRI Journal
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• v.35 no.6
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• pp.1075-1083
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• 2013

This paper describes an ultra-wideband (UWB) antenna that uses a ring resonator concept. The proposed antenna can operate in the entire UWB, and the IEEE 802.11a frequency band can be rejected by inserting a notch stub into the ring resonator. The experiment results indicate that the measured impedance bandwidth of the proposed antenna is 17.5 GHz (2.5 GHz to at least 20 GHz). The proposed UWB antenna has omnidirectional radiation patterns with a gain variation of 3 dBi (1 dBi to 4 dBi).

• ETRI Journal
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• v.35 no.2
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• pp.253-258
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• 2013

We propose and demonstrate an efficient power-saving optical network unit (ONU) based on upstream traffic monitoring for 10-Gb/s wavelength division multiplexed passive optical networks (WDM-PONs). The power-saving mode controller uses a ${\mu}$-processor and traffic monitoring modules followed by the proposed power-saving processes to operate the sleep mode ONU. The power consumption of the ONU is effectively reduced from 19.3 W to 6.4 W when no traffic from the users is detected. In addition, we design a power-saving mechanism based on a cyclic sleep mode operation to allow a connectivity check between the optical line terminal and ONU. Our calculation results show that the WDM-PON ONU reduces the power consumption by around 60% using the proposed mechanism.

• Journal of Korea Technology Innovation Society
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• v.8 no.3
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• pp.1139-1156
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• 2005

The explosive growth in wireless networks and Internet services has created considerable demand for mobile Internet services based on the mobile phone. Mobile Internet has become the new business model in telecommunication market, therefore the open network policy for mobile Internet has been formulated and implemented by the government in Korea. In spite of the open network policy for mobile Internet, there has been no systematic analysis of the various interconnection issues, including pricing, in mobile Internet network. This paper aims to suggest the interconnection pricing methods for mobile Internet network by reviewing the current pricing models for various communications services, and adapting them to mobile Internet communications circumstances. Results of this paper can be used as a guideline for government policy directions and management decision making after the introduction of the open network policy for mobile Internet.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.50.4-50
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• 2002

$\textbullet$ Definition of TeleCare $\textbullet$ Motivations behind Internet TeleCare with Robots $\textbullet$ Framework of Robot Operation Management $\textbullet$ Database Structure $\textbullet$ Chat Room Conference $\textbullet$ Remote Robot Control by Softswitch $\textbullet$ Experimental Results and Conclusion

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1501-1506
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• 1999

DSRC(Dedicated Short Range Communications), which is a radio mobile communication protocol in ITS, is suited for traffic related information services. But in WAC(Wide-Area wireless communications), we could consider a conventional communication infrastructure in the case of supporting other applications besides ITS. Especially considering the current the trends to introduce wireless internet service into the mobile communication network, wireless internet service in ITS system is valuable. Although ITS LLC(Logical Link Control) protocols recommended by Europe and Japan are effective for traffic related services, it is not suitable for services related with geographical information, image or internet. That is because the data traffic characteristics is changed according to service types. Therefore we suggest a logical link control algorithm effective for traffic information related services as well as internet web service, and analyze its performance. As a result of numerical analysis and simulation, proposed algorithm shows larger performance improvements. For traffic information related services, the performance of DSRC LLC recommended by Europe and Japan is the same as that of proposed LLC protocol. However, for wireless internet web service, the performance of proposed protocol is much better than that of LLC protocol used in Europe and Japan.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.10
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• pp.3256-3274
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• 2022

With the rapid development of information and communications technology, the construction of efficient, reliable, and safe Internet of Things (IoT) is an inevitable trend in order to meet high-quality demands for the forthcoming 6G communications. In this paper, we study a secure intelligent reflecting surface (IRS)-assisted IoT system where malicious eavesdropper trying to sniff out the desired information from the transmission links between the IRS and legitimate IoT devices. We discuss the system overall performance and propose a hybrid resource allocation scheme for maximizing the secrecy capacity and secrecy energy efficiency. In order to achieve the trade-off between transmission reliability, communication security, and energy efficiency, we develop a quantum-inspired marine predator algorithm (QMPA) for realizing rational configuration of system resources and prevent from eavesdropping. Simulation results demonstrate the superiority of the QMPA over other strategies. It is also indicated that proper IRS deployment and power allocation are beneficial for the enhancement of system overall capacity.

• 한국경영정보학회:학술대회논문집
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• 2008.06a
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• pp.411-416
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• 2008

모바일을 통한 커뮤니케이션은 우리 생활에 밀접하게 관련되어 있고, 없어서는 안될 부분이다. 이 현상은 웹을 가진 인터넷보다도 더 중요한 삶의 부분이 되었으며, 미래까지도 계속적으로 아주 빠르게 중요성을 더욱 커질 것이다. 우리는 인간과 인간의 커뮤니케이션을 넘어, 존재하는 모든 사물들과 커뮤니케이션을 원하고 있다. 자연스럽게 "Internet of Things"의 시대로 우리는 나아갈 것이고, 인간과 사물, 사물과 사물간의 커뮤니케이션 발전 정도에 비례하여 유비쿼터스 세상이 얼마나 빠르게 도래되는지 결정될 것이다. 인간과 사물과의 단순한 커뮤니케이션은 우리가 의도적으로 목적을 가지고 사물과의 커뮤니케이션을 원할 때만 가능한 것이다. 하지만, Internet of Things의 사회가 도래도면 우리가 관여하지 않아도 사물들간의 커뮤니케이션을 자율적으로 유지되고 지속적으로 연결되어 있어야만 한다. 이를 위하여 각 사물은 다른 사물들과의 구별, 차이를 가지기 위해 자신만의 고유한 성질인 메타데이터를 가지고 있어야 하고, "Spime" 개념을 이용하여 이를 구체화하고 이해관계를 설명할 수 있을 것이다.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.330-339
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• 2007

We extracted English expressions that appear in Japanese sentences in newspaper articles and on the Internet. The results obtained from the newspaper articles showed that the preposition "in" has been regularly used for more than ten years, and it is still regularly used now. The results obtained from the Internet articles showed there were many kinds of English expressions from various parts of speech. We extracted some interesting expressions that included English prepositions and verb phrases. These were interesting because they had different word orders to the normal order in Japanese expressions. Comparing the extracted English and katakana expressions, we found that the expressions that are commonly used in Japanese are often written in the katakana syllabary and that the expressions that are not so often used in Japanese, such as prepositions, are hardly ever written in the katakana syllabary.