• 한국통신학회논문지
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• 제29권12B호
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• pp.1052-1062
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• 2004

지금의 high-speed TCP 프로토콜은 공정성과 TCP friendliness에 심각한 문제가 있으며, 이는 high-speed TCP의 도입에 있어 중요한 문제가 된다. 본 논문에서는 high-speed TCP의 버스터한 특성을 줄여 TCP friendliness와 공평성 향상시키는 방안으로 high-speed TCP에 pacing 적용을 제시하고 성능 분석을 수행하였다. Pacing은 TCP 송신원의 수정만으로 적용 가능하며 TCP 혼잡 제어 방식과는 독립적으로 동작하기 때문에 도입이 쉽다는 장점을 가진다. 시뮬레이션 결과 제안된 방안은 high-speed TCP의 버스터한 특성을 효과적으로 줄이고 성능 저하 없이 기존의 high-speed TCP에 비해 향상된 TCP friendliness와 RTT에 따른 공정성을 제공함을 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권5호
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• pp.1597-1610
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• 2022

At present, the main method of high-speed train chassis detection is using computer vision technology to extract keypoints from two related chassis images firstly, then matching these keypoints to find the pixel-level correspondence between these two images, finally, detection and other steps are performed. The quality and accuracy of image matching are very important for subsequent defect detection. Current traditional matching methods are difficult to meet the actual requirements for the generalization of complex scenes such as weather, illumination, and seasonal changes. Therefore, it is of great significance to study the high-speed train image matching method based on deep learning. This paper establishes a high-speed train chassis image matching dataset, including random perspective changes and optical distortion, to simulate the changes in the actual working environment of the high-speed rail system as much as possible. This work designs a convolutional neural network to intensively extract keypoints, so as to alleviate the problems of current methods. With multi-level features, on the one hand, the network restores low-level details, thereby improving the localization accuracy of keypoints, on the other hand, the network can generate robust keypoint descriptors. Detailed experiments show the huge improvement of the proposed network over traditional methods.

• 한국통신학회논문지
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• 제38B권3호
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• pp.180-189
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• 2013

본 연구의 목적은 농어촌 지역의 정보격차 해소를 위한 초고속정보통신 인프라 구축 확대에 대해 경제성을 분석하여 정부 및 민간 통신사업자에게 정보화사업 확대의 당위성과 추진 전략을 제안하는 데에 있다. 초고속 인터넷 망에 대한 접근성이 결여된 상태에서 도시와 농어촌 지역 간에 정보격차가 발생될 수밖에 없는 상황을 살펴보고, 농어촌 지역의 마을 형태별 FTTH 망 구성을 위해 가입자 댁내 인입 구간인 1.3Km~1.5Km 범위를 대상으로 경제성 분석을 하였다. 통신 인프라 망의 구축을 통하여 창출되는 유무형의 사회적 편익요소의 가치를 고려할 때 중앙정부에서 주도적으로 정보화 사업을 추진할 필요가 있으며, 이를 위해 효과적으로 정보격차를 해소시킬 수 있는 방안을 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.483-485
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• 1999

Recently, distributed control network system has been widely applied to on-board control system than conventional relay logic with control wire. This paper presents two configuration of driver's desk system using TCN(Train Communication Network). One is configured with TCN, the other is partial adoption of TCN.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제2권3호
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• pp.135-149
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• 2008

Traditional attack detection schemes based on packets or flows have very high computational complexity. And, network based anomaly detection schemes can reduce the complexity, but they have a limitation to figure out the pattern of the distributed global scale network attack. In this paper, we propose an efficient and fast method for detecting distributed global-scale network attack symptoms in high-speed backbone networks. The proposed method is implemented at the aggregate traffic level. So, our proposed scheme has much lower computational complexity, and is implemented in very high-speed backbone networks. In addition, the proposed method can detect attack patterns, such as attacks in which the target is a certain host or the backbone infrastructure itself, via collaboration of edge routers on the backbone network. The effectiveness of the proposed method are demonstrated via simulation.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.247-252
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• 2000

본 논문은 국내 5GHz 대역에서 초고속 무선접속 망을 위한 주파수의 분배 및 공유조건에 관한 것이다. 본 논문에서는 초고속 무선접속 망과 기존 기상 레이더 사이의 공유 가능성을 평가하기 위해서 최소결합손실(Minimum Coupling Loss) 방법과 Monte-Carlo 시뮬레이션을 이용하여 기상 레이더가 초고속 무선 접속용 기기에 미치는 전파간섭을 분석하였다. 그리고 실험 결과에 의하면 기상레이더와 초고속 무선접속 망의 주파수 공유를 위해서는 DFS(Dynamic Frequency Selection) 기법을 사용하는 것이 필수적이다.

• 한국정보통신학회논문지
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• 제4권4호
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• pp.751-758
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• 2000

본 논문은 국내 5GHz 대역에서 초고속 무선접속 망을 도입하기 위한 주파수의 분배 및 공유조건에 관한 것이다. 본 논문에서는 초고속 무선접속 망과 기존 기상 레이더 사이의 공유 가능성을 평가 하기 위해서 최소결합손실(Minimum Coupling Loss) 방법과 Monte-Carlo 시뮬레이션을 이용하여 기상 레이더가 초고속 무선 접속용 기기에 미치는 전파간섭을 분석하였다. 그리고 시뮬레이션과 실제 측정 결과에 의하면 기상 레이더와 초고속 무선접속 망의 주파수 공유를 위해서는 DFS(Dynamic Frequency Selection)기법을 사용하는 것이 필수적이라는 결론을 얻었다.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.211-214
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• 2005

There are emerging many eScience applications. More and more scientists want to collaborate on their investigation with international partners without space limitation by using these applications. Since these applications have to analyze the massive raw data, scientists need to send and receive the data in short time. So today's network related requirement is high speed networking. The key point of network performance is transport protocol. We can use TCP and UDP as transport protocol but we use TCP due to the data reliability. However, TCP was designed under low bandwidth network, therefore, general TCP, for example Reno, cannot utilize the whole bandwidth of high capacity network. There are several TCP variants to solve TCP problems related to high speed networking. They can be classified into two groups: loss based TCP and delay based TCP. In this paper, I will compare two approaches of TCP variants and propose a hybrid approach for high speed networking.

• 전기학회논문지
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• 제60권9호
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• pp.1700-1707
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• 2011

Interior permanent magnet synchronous motor(IPMSM) adjustable speed drives offer significant advantages over induction motor drives in a wide variety of industrial applications such as high power density, high efficiency, improved dynamic performance and reliability. Since the fuzzy neural network(FNN) is recognized general approximate method to control non-linearities and uncertainties, the development of FNN control systems have also grown rapidly. The FNN controller is compounded of fuzzy and neural network. It has an advantage that is the robustness of fuzzy control and the ability to adapt of neural network. However, the FNN has static problem due to their feed-forward network structure. This paper proposes high performance speed control of IPMSM drive using the recurrent FNN(RFNN) which improved conventional FNN controller. The RFNN has excellent dynamic response characteristics because of it has internally feed-back structure. Also, this paper proposes speed estimation of IPMSM drive using ANN. The proposed method is analyzed and compared to conventional FNN controller in various operating condition such as parameter variation, steady and transient states etc.

• 한국국방경영분석학회지
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• 제23권2호
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• pp.171-191
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• 1997

In this paper, we design and construct a high speed LAN(Local Area Network) using FDDI(Fiber Distributed Data Interface) and Frame Relay in order to support our multimedia communication services. A program of this communication network is divided into requirement analysis, design, establishment and test. First, we propose an optimal communication method that compares various network techniques in the requirement analysis phase. Second, we design the physical network configuration, secure method, and address in the LAN and WAN. Finally, we establish and test the communication devices and lines. Ultimately, we minimized mistakes and satisfied user requirements using this program. We constructed efficiently a high speed data communication network using FDDI and Frame Relay.