• Journal of Institute of Control, Robotics and Systems
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• v.10 no.5
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• pp.464-474
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• 2004

This paper proposes a middleware structure for the module-based personal robot, which can run on heterogeneous network interfaces and provides users easy interface-method regardless of underlying heterogeneous interfaces and convenient exchange of modules. The proposed middleware is divided into three layers of a streaming layer (SL), a network adaptation layer (NAL) and a network interface layer (NIL). The streaming layer manages application transactions using middleware services and provides user a uniform interfaces to the proposed middleware. The network adaptation layer manages a message-routing and provides naming service and it is a core of the proposed middleware. And the network interfaces layer manages dependent parts of heterogeneous network interfaces such as IEEE1394, USB, Ethernet, and CAN (Control Area Network). This paper implements the proposed middleware structure, where 3 types of interfaces of IEEE 1394, USB and Ethernet are used, and measures response times among those interfaces.

• Journal of information and communication convergence engineering
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• v.18 no.2
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• pp.82-87
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• 2020

This paper discusses how to design a game server that is scalable, adaptable, and re-buildable with components. Furthermore, it explains how various implementation issues were resolved. To support adaptability, the server comprises three layers: network, user, and database. To ensure independence between the layers, each layer was designed to communicate with each other only via message queues. In this architecture, each layer can have an arbitrary number of threads; thus, scalability is guaranteed for each layer. The network layer uses input/output completion ports(IOCP), which shows the best performance on the Windows platform, it can handle up to 5,000 simultaneous connections on a typical entry-level computer, despite being built with a single-threaded user layer. To completely separate the database from the game server, the SQL code was not directly embedded in the database layer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1969-1975
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• 2015

The Internet of Things (IoT), in which resource constrained devices communicate with each other, requires a lightweight security protocol. In this paper, we propose a new message authentication scheme using a hash tree for lightweight message authentication in the Datagram Transport Layer Security (DTLS) protocol. The proposed scheme provides lightweight secure operations compared with those of the DTLS protocol. Besides, it provides more suitable performance than the DTLS protocol for an IoT environment, thanks to the reduced use of message authentication code.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.520-523
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• 1989

MAP(Manufacturing Automation Protocol), Network Protocol for FA has 7 Layer Structure of OSI. Being an Application Layer Protocol for Communication Interfaced with the Actual Programmable Devices, MMS(Manufacturing Message Specification) Consists of Three Factors of Services, Interfaces, and Protocol. For Details, It Classifies with the Followings ; Connection/Context Management, Remote Variable Access, Semaphore Management, File transfer and Management, Program UP/DOWN Load, Remote Program Fxecution. In this Paper Designing MAP Network Station of Programmable Device, we Analyze the Protocol of MMS, and Realize the State Diagram of each Services and Propose the Model of MMS Function Call Instructions.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.761-766
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• 1990

Manufacturing Message Specification(MMS) was sewed as an International Standard by International Standardization Organization(ISO). MMS is being accepted throughout the world as a solution to communications among multi vendor factory floor environments. This paper describes an implementation of MMS which operates on Application Layer of Open Systems Interconnection(OSI) 7 layer model. MMS was implemented on MSDOS in apersonal computer environment.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.9-18
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• 2009

This paper proposes a Ubiquitous Henhouse Monitoring System (UHMS) that can not only monitor henhouse's conditions and raising environments, but also control the henhouse remotely by using sensor network technology. The system consists of three layers. The physical layer connects sensors with facilities. The middleware layer processes and manages data collected from the physical layer. And the application layer provides the user with the user requested services. The system provides a real-time monitoring service, a facility controlling service, an expert service, a consumer safety service, and a mobile message service via interacting with components of each layer. Finally, a henhouse model is defined and the relevant system components and the application GUIs are implemented.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.14-20
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• 2017

In this paper, we discuss physical layer security techniques in downlink networks, including eavesdroppers. The main objective of using physical layer security is delivering a perfectly secure message from a transmitter to an intended receiver in the presence of passive or active eavesdroppers who are trying to wiretap the information or disturb the network stability. In downlink networks, based on the random feature of channels to terminals, opportunistic user scheduling can be exploited as an additional tool for enhancing physical layer security. We introduce user scheduling strategies and discuss the corresponding performances according to different levels of channel state information (CSI) at the base station (BS). We show that the availability of CSI of eavesdroppers significantly affects not only the beamforming strategy but also the user scheduling. Eventually, we provide intuitive information on the effect of CSI on the secrecy performance by considering three scenarios: perfect, imperfect, and absence of eavesdropper's CSI at the BS.

• Journal of the Korea Society of Computer and Information
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• v.21 no.3
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• pp.25-32
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• 2016

Mobile Ad Hoc Networks(MANETs) consists of mobile nodes which communicate with each other without any centralized infrastructure. Message broadcasting by flooding for route discovery in MANET can result in high redundant retransmission, contention and collision of broadcasting packet, known as the broadcast storm problem collectively. The cross-layer design is adopted in this paper, which lets routing layer share the received signal strength information at MAC layer. Also this paper proposes a new probabilistic approach that dynamically adjusts the rebroadcasting probability of a node for routing request packets (RREQs) according to the received signal strength. The simulation results show that the proposed approach demonstrates better performance than blind flooding, fixed probabilistic broadcasting approaches.

• The Transactions of the Korea Information Processing Society
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• v.2 no.3
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• pp.397-405
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• 1995

In order to operate the automatic devices of manufacturing process more efficiently and to solve the needs of the resource sharing,network technology is applied to the unit control devices located in common manufacturing zone and operated by connecting them.In this paper,functional standard of the network operation layer is set as MAP standard application layer of MMS(manufacturing message standard)for the cell or group,which is suggested by CIM (computer integrated manufacturing) standardization as common manufacturing zone.MMS is composed of abstract message which is not consider specific devices.Then,specific message standard must be defined to operate MMS.It is designed as VMD (virtual manufacturing device)objects which are abstract objects to perform group management based on the companion standard.Also they are operated in the group management model system.Group management operation takes multicast communication method which is the communication from single source to the multiple sinks, and the group management system and unit control devices are performed as VMD and real device mapping.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.2
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• pp.149-156
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• 2005

The HLA is the simulation architecture standard that the civilian and military simulation communities are deeply interested in. We can find various successful practices applying HLA to constructive simulations such as war games in domestics and overseas. However, any case of real-time distributed simulations has not been reported. The reason is that a message transmission period via RTI in a network layer varies according to computing power, simulation nodes, transmission types, and packet size; further a message processing time in an application layer depends on its processing methods, thus too difficult to set up real-time constraints for the enhancement of a real-time resolution. Hence, in this paper we have studied the real-time constraints of RTI for the development of the M-SAM simulator. Thus we have developed a HLA based pilot simulator using 6 PC's in LAN and then measured and analysed the performance of the RTI. As the results of our work, we could obtain the quantitative values for message delay, RTI overhead and RTI packet transmission ratio by a real operation scenario and loads, which are not shown in the previous works. We also expect that the results can be used as a guideline to set up the number of targets, transmission frequency and message processing method in the development of the M-SAM simulator and similar applications.