• Journal of IKEEE
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• v.18 no.3
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• pp.427-434
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• 2014

The Multihop Routing of vehicle communication environment is difficult to maintain due to heavy fluctuation of network topology and routing channel according to the movement of the vehicle, road property, vehicle distribution. We implemented GeoNetworking on the basis of ETSI(European Telecommunication Standard Institute) to maintain the vehicle safety service. GeoNetworking has its own way that delivers the data through the Unicast and Broadcast. In this paper, we compared performance index such as packet delivery ratio, end-to-end delay about GeoNetworking using the QualNet Network Simulator. Previous research assessed performance of GeoUnicast. This research has been additionally performed about GeoBroadcast, and we progressed algorithm performance through the comparison of CBF(Contention based Forwarding) of GeoUnicast with Greedy forwarding of GeoBroadcast.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.401-407
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• 2007

This paper proposes the ethernet-based in-vehicle networking method for "body" and "multimedia" domains. The ethernet-based in-vehicle networking method should modify the topology and the layer 2 for traffic shaping. In this paper, we simulate the two ring networking systems, the Media Oriented Systems Transport (MOST) and the proposed system with the shaping by the network simulator 2 and evaluate each performance. In addition, we demonstrate the proposed networking system to exchange two kinds of traffic, i.e., QoS data and best-effort data, on the ring network constituting of three nodes. Finally this paper expects to substitute the ethernet-based in-vehicle network for the MOST in advance.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.39-47
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• 2010

As vehicles become intelligent for convenience and safety of drivers, in-vehicle networking (IVN) systems are essential components of intelligent vehicles. Recently, the chassis networking system which require increased network capacity and real-time capability is being developed to expand the application area of IVN systems. Also, FlexRay has been developed for the chassis networking system. However, FlexRay needs a complex scheduling method of static segment, which is a barrier for implementing the chassis networking system. Especially, if we want to migrate from CAN network to FlexRay network using CAN message database that was well constructed for the chassis networking system by automotive vendors, a novel scheduling method is necessary to be able to reduce design complexity. This paper presents a node-based scheduling method for FlexRay network system. And, in order to demonstrate the method's feasibility, its performance is evaluated through an experimental testbed.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.155-163
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• 2003

As vehicles become more intelligent for convenience and safety of drivers, the in-vehicle networking(IVN) systems and smart modules are essential components for intelligent vehicles. However, for wider application of smart modules and IVN's, the following two problems should be overcome. Firstly, because it is very difficult that transducer manufacturers developed the smart module that supports all the existing IVN protocols, the smart module must be independent of the type of networking protocols. Secondly, when the smart module needs to be replaced due to its failure, only the transducer should be replaced these without the replacement of the microprocessor and network transceiver. To solve these problems, this paper investigates the feasibility of an IEEE 1451 based smart module. More specifically, a smart module for DC motor control has been developed. The module has been evaluated for its delay caused by the IEEE 1451 architecture. In addition, the time required for transducer replacement has been measured.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.168-171
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• 2003

As vehicles are more intelligent for convenience and safety of drivers, the in-vehicle networking systems and smart modules are essential components for intelligent vehicles. However, for the smart module to widely apply to the IVN systems, two problems are considered as follows. Firstly, because it is very difficult that transducer manufacturers developed the smart module that supports the existing all IVN protocols, the smart module must be independent to the type of networking protocols. Secondly, when the smart module is exchanged due to its failure, it is necessary how the transducer is only exchanged without exchange of the microprocessor and network transceiver. This paper deals with the IEEE 1451 based smart module that describes the digital interface between a network transceiver and sensor module. Finally. efficiency of the IEEE 1451 based smart module was evaluated on the experimental model.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.37-45
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• 2011

As vehicles become more intelligent, in-vehicle networking (IVN) systems such as controller area network (CAN) or FlexRay are essential for convenience and safety of drivers. To expand the applicability of IVN systems, attention is currently being focused on the communication between heterogeneous networks such as body networking and chassis networking systems. A gateway based on message mapping method was developed to interconnect FlexRay and CAN networks. However, this type of gateways has the following shortcomings. First, when a message ID was changed, the gateway must be reloaded with a new mapping table reflecting the change. Second, if the number of messages to be transferred between two networks increase, software complexity of gateway increases very rapidly. In order to overcome these disadvantages, this paper presents FlexRay-CAN gateway based on node mapping method. More specifically, this paper presents a node mapping based FlexRay-CAN gateway operation algorithm along with the experimental evaluation for ID change.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.99-100
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• 2009

자동차에 대한 IT 융합 기술이 증가함에 따라 소프트웨어가 자동차 전체에 차지하는 비중은 점점 증가 하고 있으며, 최근에는 자동차의 품질을 좌우하는 주 요인으로 부각되고 있다. 그러나 응용 서비스를 제공하는데 있어서는 여전히 자동차 제조사별, 차종 별로 특화되어 있는 정보가 많아 차량 정보를 활용하기 어려운 단점이 있다. 이에 본 논문에서는 차량 정보를 기반으로 서비스를 개발하는데 있어 반복적으로 재사용될 수 있는 차량-IT 용 차내망 컴포넌트에 대한 방안을 제시하고자 한다. 차내망 컴포넌트를 통한 차량 정보 이용은 자동차-IT 분야의 시장 진입 장벽을 낮추고, 제품의 개발 및 시험 기간 단축과 이에 따른 비용 절감 효과를 가져 올 수 있다.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.1018-1023
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• 2010

The CAN (Controller Area Network) system is the most dominant protocol for in-vehicle networking system because it provides bounded transmission delay among ECUs (Electronic Control Units) at data rates between 125Kbps and 1Mbps. And, many automotive companies have chosen the CAN protocol for their in-vehicle networking system such as chassis network system because of its excellent communication characteristics. However, the increasing number of ECUs and the need for more intelligent functions such as ADASs (Advanced Driver Assistance Systems) or IVISs (In-Vehicle Information Systems) require a network with more network capacity and the real-time QoS (Quality-of-Service). As one approach to enhancing the network capacity of a CAN system, this paper introduces a CAN system with dual communication channel. And, this paper presents a distributed message allocation method that allocates messages to the more appropriate channel using forecast traffic of each channel. Finally, an experimental testbed using commercial off-the-shelf microcontrollers with two CAN protocol controllers was used to demonstrate the feasibility of the CAN system with dual communication channel using the distributed message allocation method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.41-60
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• 2018

Recently, road traffic congestion is becoming a serious urban phenomenon, leading to massive adverse impacts on the ecology and economy. Therefore, solving this problem has drawn public attention throughout the world. One new promising solution is to take full advantage of vehicular ad hoc networks (VANETs). In this study, we propose a new traffic congestion detection and quantification method based on vehicle clustering and fuzzy assessment in VANET environment. To enhance real-time performance, this method collects traffic information by vehicle clustering. The average speed, road density, and average stop delay are selected as the characteristic parameters for traffic state identification. We use a comprehensive fuzzy assessment based on the three indicators to determine the road congestion condition. Simulation results show that the proposed method can precisely reflect the road condition and is more accurate and stable compared to existing algorithms.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.2
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• pp.69-78
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• 2013

As vehicles become more intelligent for safety and convenience of drivers, in-vehicle networking systems such as controller are network (CAN) have been widely used due to increasing number of electronic control unit (ECU). Recently, FlexRay was developed to replace CAN protocol in chassis networking systems, to remedy the shortage of transmission capacity and unsatisfactory real-time transmission delay of conventional CAN. However, it is difficult for vehicle network designers to calculate platform configuration registers (PCR) and determine a base cycle or slot length of FlexRay. To assist vehicle network designers for designing FlexRay cluster, this paper presents automatic field bus exchange format (FIBEX) generation algorithm from CANdb information, which is de-facto standard database format for CAN. To design this program, structures of FIBEX, CANdb and relationship among PCR variables are analyzed.