• 한국자동차공학회논문집
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• 제18권2호
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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.

• 한국통신학회논문지
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• 제30권10B호
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• pp.660-668
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• 2005

최근에는 인터넷 기반의 통신 방식이 원격 제어와 데이터 수집 분야에서도 널리 채택되어지고 있다. 현재의 인터넷에서 대부분의 네트워크 애플리케이션들은 Client-Sever 모델로 개발되고 있다. 본 논문에서는 인터넷상에서 Client와 Server의 역할을 교환하여, 다양한 산업용 디바이스를 위해 단일화된 디바이스 인터페이스를 제공해 주는 DCP(Device Configuration Protocol) 프로토콜을 제안한다. 제안된 프로토콜은 TCP/IP 표준 프로토콜 상에서 돌아가는 응용 계층 프로토콜로 동작한다. 또한 DCP 프로토콜을 확장하여 실시간 처리 기능을 추가하고, IPv6의 QoS(Quality of Service) 지원기능인 FlowLabel과 연동하여 실시간 처리가 사용자 수준에서 가능하도록 하였다. 시뮬레이션 수행 결과 실시간 처리가 요구되는 패킷과 일반적인 패킷을 비교하였을 때, 지연시간 측면에서 보면 실시간 처리가 요구되는 패킷은 처리율과 무관하게 마감 시간 전에 처리됨을 알 수 있다.

• 한국멀티미디어학회논문지
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• 제20권5호
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• pp.808-826
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• 2017

Most of conventional DSS's(Digital Signage Systems) have been built based on LAMP framework. Recent researches have shown that MEAN or MERN stack framework is simpler, more flexible, faster and more suitable for web-based application than LAMP stack framework. In this paper, we propose a design and implementation of MEARN (ME(A+R)N) stack-based real-time digital signage system, MR-DSS, which supports handing real-time tasks like urgent/instant messaging, system status monitoring and so on, efficiently in addition to conventional digital signage CMS service tasks. MR-DSCMS, CMS of MR-DSS, is designed to provide most of its normal services by REST APIs and real-time services like urgent/instant messaging by Socket.IO base under MEARN stack environment. In addition to architecture description of components composing MR-DSS, design and implementation issues are clarified in more detail. Through experimental testing, it is shown that 1) MR-DSS works functionally well, 2) the networking load performance of MR-DSCMS's REST APIs is better compared to a well-known open source Xibo CMS, and 3) real-time messaging via Socket.IO works much faster than REST APIs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권2호
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• pp.932-945
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• 2018

Everything in the world is becoming connected and interactive due to the Internet. The future of interactive smart environments such as smart cities, smart industries, or smart farms demand high network bandwidth, high network flexibility, and self-organization systems without costly hardware upgrades, and they provide a sustainable, scalable, and replicable smart environment backbone infrastructure. This paper presents a new Hybrid Software-Defined architecture for integrating Internet-of-Things technologies that are essential technologies for smart environments. It combines a software-defined networking infrastructure and a real-time distributed network framework with an advanced optimization to enable self-configuration, self-management, and self-adaption for providing seamless communication and efficiently managing a vast number of smart heterogeneous devices.

• 제어로봇시스템학회논문지
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• 제6권10호
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• pp.911-917
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• 2000

As many sensors and actuators are used in various automated systems, the application of network to real-time distributed control system is gaining acceptance in many industries. In order to take advantages of networking, however, the network should be carefully designed to satisfy real-time distributed control. This paper presents an implementation method of closed-loop control using Profibus-FMS. In order to implement a closed-loop control system, we used industrial computers with Profibus-FMS network cards and a DC servo motor. Through various experiments, the step response of the control system with network was compared with the reference response without network.

• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.12-20
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• 2002

As numerous sensors and actuators are used in many automated systems, various industrial networks are adopted for real-time distributed control. In order to take advantages of the networking, however, the network implementation should be carefully designed to satisfy real-time requirements considering network induced delays. This paper presents an implementation scheme of a networked control system via Profibus-DP network fur real-time distributed control. More specifically, the effect of the network induced delay on the control performance is evaluated on a Profibus-DP testbed. Also, two conventional PID gain tuning methods are slightly modified fur fouling controllers fur the networked control system. With appropriate choices for gains, it is shown that the networked control system can perform almost as well as the traditional control system.

• 한국정밀공학회지
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• 제18권5호
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• pp.120-129
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• 2001

As many sensors and actuators are used in many automated systems, various industrial networks are adopted for real-time distributed control. In order to take advantages of the networking, however, the network implementation should be carefully designed to satisfy real-time requirements considering network delays. This paper presents the implementation of a remote feedback control system via Profibus-DP net work for real-time distributed control More specifically, the effect of the network delay on the control performance evaluated on Profibus-DP testbed. Also, the traditional PID gain tuning methods are used to demonstrate the feasibility of the remote feedback control.

• 한국자동차공학회논문집
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• 제14권3호
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• pp.28-34
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• 2006

An ACC driving simulator is a virtual reality device which designed to test or evaluate vehicle control algorithm. It is designed and built based on the rapid control prototyping(RCP) concept. Therefore this simulator adopt RCP tools to solve the equation of a vehicle dynamics model and control algorithm in real time, rendering engine to provide real-time visual representation of vehicle behavior and CAN communication to reduce networking load. It can provide also many different driving test environment and driving scenarios.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.689-694
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• 2006

Wireless LAN is getting more popularity and plays a main role in electronic and telecommunication field. Wireless LAN is more convenient than wired LAN when mobility is required, and are sometimes the only feasible choice. Wireless LAN can also pose a significant security risk when not properly installed and maintained. Thus, this paper studies real-time message transmission using existing mobile telecommunication network and describes considerations and procedures when introducing wireless LAN concept and wireless LAN systems. It also studies integrated wired and wireless networking including wireless LAN bridge and AP technology of International Organization for Standardization, and especially real-time dynamic image data transmission in a moving train.

• 대한임베디드공학회논문지
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• 제2권2호
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• pp.82-94
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• 2007

Wireless sensor networking technology is one of the basic infrastructures for ubiquitous environment. It enables us to gather various sensory data such as temperature, humidity, gas leakage, and speed from the remote sensor devices. To support these networking functions, IEEE WPAN working group makes standards for PHY and MAC, while ZigBee Alliance defines the standards for the network, security, and applications. The low-rate WPAN was emerged to have the characteristics of network resilience, low cost, and low power consumption. It has a broad range of applications including, but not limit to industrial control and monitoring, home automation, disaster forecast and monitoring, health care. In order to provide more intelligent and robust services, users want voice-based solutions to accommodate to low-rate WPAN. In this paper, we have evaluated voice quality of an IEEE 802.15.4 standard compliant voice node. Specifically, it includes the design of a voice node and experiments based on the prediction of voice quality using the E-model suggested by ITU-T G.107, and the network communication mechanisms considering beacon-enabled and nonbeacon-enabled networks for real-time voice communications.