• Journal of information and communication convergence engineering
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• v.9 no.5
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• pp.530-538
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• 2011

Performance of TCP can be severely degraded in Mobile IP-based wireless networks where packet losses not related to network congestion occur frequently during inter-subnetwork handoffs by user mobility. To solve such a problem in the networks using Mobile IP, the packet buffering method at a base station(BS) recovers those packets dropped during handoff by forwarding the buffered packets at the old BS to the mobile users. But, when the mobile user moves to a congested BS in a new foreign subnetwork, those buffered packets forwarded by the old BS are dropped and TCP transmission performance of a mobile user degrades severely. In this paper, we propose a Modified BLUE(MBLUE) buffer required at a BS to increase TCP throughput in Mobile IP-based networks. When a queue length exceed a threshold and congestion grows, MBLUE increases its packet drop probability. But, when a TCP connection is added at new BS by a handoff, the old BS marks the buffered packets. And new BS receives the marked packets without dropping. Simulation results show that MBLUE buffer reduces congestion during handoffs and increases TCP throughputs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1166-1174
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• 2004

In this paper, a design of RISC-based transmission wrapper processor for TCP/IP protocol stack is described. The processor consists of input and output buffer memory with dual bank structure, 32-bit RISC microprocessor core, DMA unit with on-the-fly checksum capability, and memory module. To handle the various modes of TCP/IP protocol, hardware-software codesign approach based on RISC processor is used rather than the conventional state machine design. To eliminate large delay time due to sequential executions of data transfer and checksum operation, DMA module which can execute the checksum operation along with data transfer operation is adopted. The designed processor exclusive of variable-size input/output buffer consists of about 23,700 gates and its maximum operating frequency is about 167MHz under 0.35${\mu}m$ CMOS technology.

• Transactions on Control, Automation and Systems Engineering
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• v.1 no.2
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• pp.141-146
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• 1999

This paper describes the communication method of an auto-startup system. The Auto-Startup system is designed to operate a nuclear power plant automatically during the startup operation . In general , the operations during startup in existing plant have only been manually controlled by the operator. The manual operation caused to the operator mistake. The Auto-Startup system consists of the Distributed Control System(DCS) and G2 (Expert System). Also, Functional Test Facility(FTF) provides the plant's real-data for an Auto-Startup system. So, it is necessary to develop the communication method between these systems. We developed two methods ; one is a network and the other is a hardwire line. To communicate between these systems (DCS-G2 and DCS-FTF) , we developed the communication program. In case of DCS-FTF, we used the TCP/IP and VXI. BUt, in case of DCS-G2 , we , what it called , developed the bridge program using the GSI(G2 Standard Interface). We test to check the function of the important parameter, in time, for analysis of the developed communication method. The results are a good performance when we check the communication time of important parameter. We conclude that Auto-startup system could save heat-up time about at least 5 hours and reduced the change of the reactor operation and trip.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1077-1082
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• 2007

The necessity of the high speed exclusive use server that connect digital measure instrument flag to internet and CPU use rate of measure flag uses other imbedded operating system with many general servers to verification & proofreading system in remotion. This research is objective that embody high speed network module for Site-Based remote verification & proofreading system and through internet digital measure instrument flag to remote verification & proofreading, TCP/IP Offload Engine processing and improved that is Imbedded TCP/IP stack for high speed networking.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.625-630
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• 2010

With regard to the examples of establishing various sorts of information security, it can be seen that there are gradual, developmental procedures including Firewall and VPN (Virtual Private Network), IDS (Intrusion Detection System), or ESM(Enterprise Security Management). Each of the security solutions and equipments analyzes both defense and attack for information security with the criteria of classifying the problems of security policies by TCP/IP layers or resulted from attack patterns, attack types, or invasion through specialized security technology. The direction of this study is to examine latency time vulnerable to invasion which occurs when L2-stratum or lower grade equipments or policies are applied to the existing network through TCP/IP layer's L3-stratum or higher grade security policies or equipments and analyze security holes which may generate due to the IP preoccupation in the process of establishing policies to limit particular IP area regarding the policies for security equipments to figure out technological problems lying in it.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.3
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• pp.86-92
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• 2000

In this paper, we develop protocol analyzer that can analyze and monitor LAN(Local Area Network)-based TCP/IP protocol using the OOP(object-oriented programming) in Windows98/NT environment. TCP/IP(Transmission Control Protocol/Internet Protocol) protocol analyzer is consist of interface hardware, protocol analysis software and GUI(Graphic User Interface). It is designed for the real-time analysis using the real-time object. In results of Performance test, TCP/IP Protocol analyzer is showed that it can analyze and monitor without frame error in LAN-based. Also, developed protocol analyser operates better than conventional protocol analyzer in performance. It can be used in maintenance fields of communication and network.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.1-8
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• 2020

Communication between system modules is applied using the Modbus protocol in industrial sites including smart factories, industrial drones, building energy management systems, PLCs, ships, trains, and airplanes. The existing Modbus was used for serial communication, but the recent Modbus protocol is used for TCP/IP communication.The Modbus protocol supports RTU, TCP and ASCII, and implements and uses protocols in embedded systems. However, the transmission I/O devices for RTU, TCP, and ASCII-based protocols may differ. For example, RTU and ASCII communications transmit on a serial-based communication protocol, but in some cases, Ethernet TCP/IP transmission is required. In particular, since the C language (object-oriented) is used in embedded systems, the complexity of source code related to I/O registers increases. In this study, we designed software that can logically separate I/O functions from embedded devices, and designed the execution logic of each instance requiring I/O processing through a delegate class instance with Modbus RTU, TCP, and ASCII protocol generation. We designed and experimented with software that can separate communication I/O processing and logical execution logic for each instance.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1045-1054
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• 2020

In this paper, we designed a TCP/IP based ring buffer system that can stably transfer bulk data streams in the unstable network environments. In the scheme we proposed, The observation data stream generated and output by each radio observatory's backend system as a UDP frame is stored as a UDP packet in a large capacity ring buffer via a socket buffer in the client system. Thereafter, for stable transmission to the remote destination, the packets are processed in TCP and transmitted to the socket buffer of server system in the correlation center, which packets are stored in a large capacity ring buffer if there is no problem with the packets. In case of errors such as loss, duplication, and out of order delivery, the packets are retransmitted through TCP flow control, and we guaranteed that the reliability of data arriving at the correlation center. When congestion avoidance occurs due to network performance instability, we also suggest that performance degradation can be minimized by applying parallel streams.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.119-126
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• 2017

Developing the TCP/IP standard IBA which is higher organization of IETF decided to attach the TCP/IP protocol stack to small things, such as sensor. This means small object is also considered as on of the communication node, it has symbolic meaning that expand smart object has all five layer. Under this background, IoT/WoT configure the intelligent network between objects based on the internet to communication was introduced. Things has own IP address on IoT environment and are smart object that a lot of people communicate over the internet on Application Layer. In other words, IoT is that smart object are commercialized space. According to the interest of IoT, IETF establish CoAP for use as IoT protocol. CoAP is expected that standard protocols created by things is connected to the Internet protocol that can be used within a constrained environment. Accordingly, in this paper, we proposed Middleware API that can manage and collect the data of objects that connected CoAP network.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.359-360
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• 2010

In smart grid system which uses photovoltaic system, fuel cells and so on, a program implemented with C language is used for control and measurement. When using programs implemented with C language GUI is difficult to watch control and monitor the smart grid system. But LabVIEW is a graphical programming language and it is easy to design GUI screen and to manage many variables such as real-time output of electric power including solar cell, wind power system and fuel cell. This paper suggests LabVIEW and C-language TCP/IP communication for smart grid monitoring system i mplemented with C-language.