• 한국정보전자통신기술학회논문지
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• 제10권1호
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• pp.16-22
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• 2017

본 논문에서는 먼저 최근 급격히 증가하는 모바일 데이터 트래픽을 오프로드(Offload)시키는 Local IP Access(LIPA) 기술을 펨토셀 네트워크와 함께 소개한다. 이후, 전형적인 이동통신 시스템, 펨토셀 기반 시스템, 그리고 펨토셀과 LIPA를 함께 이용하는 시스템에서 댁내 모바일 데이터 트래픽을 전송할 때, 트래픽 전송시간과 이동통신 사업자망으로 전송되는 모바일 데이터 트래픽 확률에 대한 성능을 분석한다. 분석결과를 통해 차세대 이동통신 시스템에서 펨토셀과 LIPA를 함께 이용하면 이동통신 사업자망으로 전송되는 모바일 데이터 트래픽 부하를 감소시킬 뿐만 아니라 댁내 모바일 트래픽의 전송시간을 크게 줄이는 효과도 얻을 수 있음을 보인다. 즉, 전형적인 이동통신 시스템과 펨토셀 기반 시스템은 펨토셀과 LIPA를 함께 이용하는 시스템보다 인터넷 지연시간이 10ms에서 약 3배와 4배 정도 길었고, 인터넷 지연시간이 100ms에서 약 14배와 26배 정도 긴 결과를 보였다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 춘계학술발표논문집
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• pp.245-247
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• 2008

교차로 교통시스템은 도로상에 깔린 루프검지기를 통해서 통과차량과 지체차량의 수를 누적하여 차량 통행주기를 결정하는 웹스터방정식의 방법을 따른다. 그러나 웹스터방정식은 현장 교차로상의 교통데이터를 주로 사용하는 방법이라 할 수 있으므로 이웃 교차로의 교통상황을 데이터로 받아서 교차로 연동제어를 할 수 없는 문제점을 갖고 있다. 따라서 교차로 원격지 제어를 시행 할 경우에 마땅한 제어 방법이 없고, 있어도 지역네트워크 단위인 고비용 시스템을 사용하여야 하므로 경제성이 없다. 따라서 인터넷을 사용하여 이웃 및 먼거리에 떨어져 있는 교차로의 교통상황을 참조하여 교차로 교통제어를 할 경우에는 저비용의 전문성 있는 교차로 교통제어를 할 수 있다.

• International Journal of Internet, Broadcasting and Communication
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• 제7권1호
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• pp.6-9
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• 2015

The use of Intelligent Transportation System (ITS) is promising to bring better solutions for managing and handling the city traffic. This system combines many fields in advanced technology such as Global Positioning System (GPS), Geographic Information System (GIS) and so on. The basement of applications in ITS is the effective collections and data integration tools. The purpose of our research is to propose solutions which involve the use of GPS time series data collected from GPS devices in order to improve the quality of output traffic data. In this study, GPS data is collected from devices attached to vehicles travelling on routes in Ho Chi Minh City (HCMC). Then, GPS data is stored in database system to serve in many transportation applications. The proposed method combines the data usage level and data coverage to improve the quality of traffic data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1975-1988
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• 2019

Short-term traffic flow prediction plays an important role in intelligent transportation systems (ITS) in areas such as transportation management, traffic control and guidance. For short-term traffic flow regression predictions, the main challenge stems from the non-stationary property of traffic flow data. In this paper, we design an ensemble cascading prediction framework based on extremely randomized trees (extra-trees) using a boosting technique called EET to predict the short-term traffic flow under non-stationary environments. Extra-trees is a tree-based ensemble method. It essentially consists of strongly randomizing both the attribute and cut-point choices while splitting a tree node. This mechanism reduces the variance of the model and is, therefore, more suitable for traffic flow regression prediction in non-stationary environments. Moreover, the extra-trees algorithm uses boosting ensemble technique averaging to improve the predictive accuracy and control overfitting. To the best of our knowledge, this is the first time that extra-trees have been used as fundamental building blocks in boosting committee machines. The proposed approach involves predicting 5 min in advance using real-time traffic flow data in the context of inherently considering temporal and spatial correlations. Experiments demonstrate that the proposed method achieves higher accuracy and lower variance and computational complexity when compared to the existing methods.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 1999년도 춘계학술발표회논문집
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• pp.93-105
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• 1999

In Vessel Traffic Service, the management information on marine traffic control is almost transported by VHF. It is so difficult to exchange a lot of the related information necessary for marine traffic control exactly and in real time. Aiming at improved visualized data transporting network, we examine the methods for transporting and displaying the data on marine traffic controls. In this paper, we design the information networks established by broadcasting method and by internet method using home page in order to manage marine traffics in Masan port.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.229-232
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• 2004

With the internet(World Wide Web) widespread among people after 1995, Information Communication Network, which is basic structure of the internet, is rapidly changing into fiber optics communication. Voice-centered Circuit Traffic is rapidly changing into Internet-centered Packet Traffic and Optics Communication Technology can transmit 1Tb/s thousands kilometers away. The information conveyed through the internet is being diversified - from simple information based on text to bulky multimedia information such as auido & video data. So the demand for higher speed, high storage Router is on the crease. With the continued increase of Internet Traffic, Router for Core Backbone System will be much more needed.

• 대한전자공학회논문지TC
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• 제39권6호
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• pp.19-19
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• 2002

본 고에서는 최선형 인터넷 서비스에 대해서 대역공유량의 변화가 가지는 특성을 이론적으로 모델링하는 방법을 제안한다. 그리고 유틸리티에 기반한 요금정책을 제안하고 수치실험을 통해 제안방법의 의의와 효과에 대해 검토한다.

• 대한전자공학회논문지TC
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• 제39권6호
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• pp.277-284
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• 2002

본 고에서는 최선형 인터넷 서비스에 대해서 대역공유량의 변화가 가지는 특성을 이론적으로 모델링하는 방법을 제안한다. 그리고 유틸리티에 기반한 요금정책을 제안하고 수치실험을 통해 제안방법의 의의와 효과에 대해 검토한다.

• 정보통신설비학회논문지
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• 제1권1호
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• pp.51-64
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• 2002

This paper analyzes performance measures of a Bluetooth_based mobile home network system. The home network system consists of terminals with Bluetooth interfaces, access points (AP), a home PC, and a gateway A mobile host in wireless terminals uses Mobile IP for supporting the mobility This paper considers four types of data traffic, which are new connection traffic, handoff traffic, Internet data traffic, and control data traffic and suggests a queueing system model of the home network system, where the AP and the home PC are modeled as M/G/1 with four priority queues and the gateway is modeled as M/G/1 with a single queue The generation rate and service time of individual traffic influence their performance measures. Based ell the suggested model, we propose the elapsed time of data traffic in terms of the number of cells, the number of Home PCs, arrival rates of four types of traffic and the service rates of AP/Home PCs/Gateway To analyze influences on the elapsed time with respect to arrival rate of four types of traffic, some examples are given.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.762-777
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• 2014

With the increasing usage of cloud applications such as MapReduce and social networking, the amount of data traffic in data center networks continues to grow. Moreover, these appli-cations follow the incast traffic pattern, where a large burst of traffic sent by a number of senders, accumulates simultaneously at the shallow-buffered data center switches. This causes severe packet losses. The currently deployed TCP is custom-tailored for the wide-area Internet. This causes cloud applications to suffer long completion times towing to the packet losses, and hence, results in a poor quality of service. An Explicit Congestion Notification (ECN)-based approach is an attractive solution that conservatively adjusts to the network congestion in advance. This legacy approach, however, lacks scalability in terms of the number of flows. In this paper, we reveal the primary cause of the scalability issue through analysis, and propose a new congestion-control algorithm called FaST. FaST employs a novel, virtual congestion window to conduct fine-grained congestion control that results in improved scalability. Fur-thermore, FaST is easy to deploy since it requires only a few software modifications at the server-side. Through ns-3 simulations, we show that FaST improves the scalability of data center networks compared with the existing approaches.