• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.649-656
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• 2007

Today, controller area network(CAN) is a field bus that is nowadays widespread in distributed embedded systems due to its electrical robustness, low price, and deterministic access delay. However, its use safety-critical applications has been controversial due to dependability limitation, such as those arising from its bus topology. Thus it is important to analyze the performance of the network in terms of load of data bus, maximum time delay, communication contention, and others during the design phase of the controller area network. In this paper, a simulation algorithm is introduced to evaluate the communication performance of the vehicle network and apply software base fault injection techniques. This can not only reduce any erratic implementation of the vehicle network but it also improves the reliability of the system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1448-1453
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• 2015

In this paper, we propose an alternative method of communication to improve the reliability of in-vehicle networks by jointly using wireless communication networks. Wired Communication networks have been used in vehicles for the monitoring and the control of vehicle motion, however, the disconnection of wires or hardware fault of networks may cause a critical problem in vehicles. If the network manager detects a disconnection or faults in wired in-vehicle network like the Controller Area Network(CAN), it can redirect the communication path from the wired to the wireless communication like the Zigbee network. To show the validity and the effectiveness of the proposed in-vehicle network architecture, we implement the Electronic Stability Control(ESC) system as ECU-In-the-Loop Simulation(EILS) and verify that the control performance can be kept well even if some hardware faults like disconnection of wires occur.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.175-180
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• 2002

In order to satisfy the requirements of time reduction and cost saving for development of electronic control systems(ECU) in automotive industry, the applications of a standardized real-time operating system(RTOS) and a communication protocol to ECUs are increased. In this study, a body control module(BCM) that employs OSEK/VDX(open system and corresponding interfaces for automotive electronics/vehicle distributed executive) OS tour the RTOS and a controller area network(CAN) fur the communication protocol is designed, and the performances of the system are evaluated. The BCM controls doors, mirrors, and windows of the vehicle through the in-vehicle network. To identify all the transmitted and received control messages, a PC connected with the CAN communication protocol behaves as a CAN bus emulator. The control system based upon in-vehicle network improves the system stability and reduces the number of wiring harness. Furthermore it is easy to maintain and simple to add new features because the system is designed based on the standards of RTOS and communication protocol.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.5
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• pp.218-225
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• 2001

This paper analyses the performance of network system using the CAN(Controller Area Network) protocol. Given messages are assumed to be scheduled by the DMS(Deadline Monotonic Scheduling) algorithm. The mathematical models for time-delay that can be occurred between CAN nodes are defined. The effectiveness of modeling is shown by comparing the difference of time-delay between simulations and practical experiments. We analyse the results according to the variation of factors, such as the number of nodes, the transmission speed, the message size and the number of aperiodic messages through simulation and confirm the real-time performance of lower priority messages. We also investigate the real-time performance of periodic messages when aperiodic message generates.

• The KIPS Transactions:PartC
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• v.15C no.3
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• pp.199-204
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• 2008

Controller Area Network was developed originally for in-vehicle communication network. But it is now widely used for factory automation because of its properties such as strong noise resistance and high reliabilities. With changing communication environments from peer to peer topology to bus topology, we should check each devices about not only mechanical operations but also electronic or software operations. In this paper, we suggest reliability test environment for CAN based system, which is divided two parts, data correctness and timely delivery.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.524-531
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• 2010

The automobile networks consist of the communication bus systems which become independent and heterogeneous each other. Most often, the CAN buses are implemented in a car in order to connect all the electronic control units in various ways. Thus, some gateways are necessary for exchanging the useful information between electronic control units on the buses. The automobile body networks group is divided into two kinds on a large scale, namely the low-speed bus and the high-speed bus. To interchange messages between the two, a CAN signal gateway is designed and implemented in a miniature scale. A network analyzer (called "Vehicle spy") and an oscilloscope monitor network situation to confirm the due operation of CAN signal gateway. The efficiency of the designed gateway is evaluated. The more message thread increased, the more efficiency decreased.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.60-66
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• 2009

A service network in the future ubiquitous environment can consist of a variety of elements, which include different protocols of the network transport. Interwoking different transport protocols can alleviate such problems occurred in accessing network as poverty of facilities, faults, and contention in a path of particular protocol communication. This paper schemes to improve performance of the network constituted of different protocols for the network transport. Interposing an interwork element, like SDR (Software Defined Radio), in the network can raise availability of transport paths, and then improve transport performance of the overall network Simulation analysis justifies such a scheme and this paper presents simulation results.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.80-85
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• 2021

This study is to analyze the structure of the networks of tourism marketing on Twitter, identifying the most prominent users, the flow of information about tourism marketing, and the interaction between the users posting tweets. This study employs NodeXL pro as a visualization software package for social network analysis. The number of vertices or nodes is 171, and the number of the unique edges or links is 128, but there are 101 edges with duplicates, so the total links are 229, which means that there are fewer Twitter accounts in the social network on tourism marketing, but they have a few close relationships by sharing information. The research can map the social network of communicators of tourism marketing using Twitter data. The network has a complicated pattern, including one independent network and some connected networks. Some mediators connect each network and can control the information flow of tourism marketing. More communicators are getting the information than the ones providing it, which means that there is likely to be the dependence of information among communicators that can cause an obstacle and distortion of the information flow system, especially in the independent network.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.333-340
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• 2002

Embedding is a mapping an interconnection network G to another interconnection network H. If a network G can be embedded to another network H, algorithms developed on G can be simulated on H. In this paper, we first propose a method to embed between Hierarchical Cubic Network HCN(n, n) and Hierarchical Folded-hypercube Network HFN(n, n). HCN(n, n) and HFN(n, n) are graph topologies having desirable properties of hypercube while improving the network cost, defined as degree${\times}$diameter, of Hypercube. We prove that HCN(n, n) can be embedded into HFN(n, n) with dilation 3 and congestion 2, and the average dilation is less than 2. HFN(n, n) can be embedded into HCN(n, n) with dilation 0 (n), but the average dilation is less than 2. Finally, we analyze the fault tolerance of HCN(n, n) and prove that HCN(n, n) is maximally fault tolerant.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.4
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• pp.295-302
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• 2013

In the network coding, throughput can be increased by allowing the transformation of the received data at the intermediate nodes. However, the adversary can obtain more information at the intermediate nodes and make troubles for decoding of transmitted data at the sink nodes by modifying transmitted data at the compromised nodes. In order to resist the adversary activities, various information theoretic or cryptographic secure network coding schemes are proposed. Recently, a secure network coding based on the cryptographic hash function can be used at the random network coding. However, because of the computational resource requirement for cryptographic hash functions, networks with limited computational resources such as sensor nodes have difficulties to use the cryptographic solution. In this paper, we propose a new secure network coding scheme which uses linear transformations and table lookup and safely transmits n-1 packets at the random network coding under the assumption that the adversary can eavesdrop at most n-1 nodes. It is shown that the proposed scheme is an all-or-nothing transform (AONT) and weakly secure network coding in the information theory.