• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.553-555
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• 2013

본 논문은 HTML5의 새로운 표준인 웹소켓(WebSocket)을 이용하여 구현한 실시간 커뮤니케이션 시스템을 소개한다. 본 논문에서 구현한 시스템은 PC의 브라우저와 모바일 디바이스 모두를 통해 접근이 가능하다. 본 논문에서 구현한 실시간 커뮤니케이션 서비스 시스템은 이벤트 기반의 비동기 방식을 채택함으로써, 클라이언트가 리로드(reload)하지 않더라도 필요한 정보를 빠르게 제공한다. PC의 브라우저가 접근하는 부분은 Node.js를 사용하여 구현하였으며, 모바일 디바이스가 접근하는 부분은 PhoneGap 플랫폼을 사용하여 구현하였다. 본 논문에서는 시스템의 전체 구조와 관련 기술을 설명하고, 구체적인 구현 코드의 일부를 제시하며, 추후 확장 가능성과 비전을 제시한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2473-2481
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• 2014

The majority of next generation information systems will be working on portable mobile devices such as smartphones. REST Open API web services have quickly become popular among mobile application development. The use of REST web services are not only growing in popularity but totally changing the way of mobile applications development. This is because REST web services could be used in application development as a form of building blocks, which is completely independent, compatible, to any platforms. With this strength, REST web services encourage third party application to build add-on functionality. This research proposes the use of REST web service to replace the use of socket APIs into major internet communication APIs. To this end, this paper also provide performance evaluation of the REST web services compared to the conventional socket APIs, focusing on scalability by analytical and experimental evaluations. Finally, we summarize the possibility whether REST Open API web services have enough performance as future major internet communication primitive APIs.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.461-468
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• 2001

Large-scale distributed applications based on Internet and client/server applications have to deal with series of problems such as load balancing, unpredictable communication delays, partial errors, and networking failures. Therefore, sophisticated applications such as teleconferencing, video-on-demand, and concurrent software engineering require an abstracted communication. In this paper, we present our design, implementation and performance analysis of group communication using the CORBA ORB, JAVA RMI, Socket based on distributed computing. We anticipate our study may apply to the various field of applications such as fault-tolerant client/server system, groupware, scalable text retrieval system, and financial information systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1223-1230
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• 2021

Recently, energy resource management is a major concern around the world. Energy management activities minimize environmental impacts of the energy production. This paper presents design and prototyping of a home electric energy monitoring system that provides residential consumers with real time information about their electricity use. The developed system is composed of an in-house sensing system and a server system. The in-home sensing system is a set of wireless smart plug which have an AC power socket, a relay to switch the socket ON/OFF, a CT sensor to sense current of load appliance and a Kmote. The Kmote is a wireless communication interface based on TinyOS. Each sensing node sends its detection signal to a home gateway via wireless link. The home gateway stores the received signals into a remote database. The server system is composed of a database server and a web server, which provides web-based monitoring system to residential consumers. We analyzed and presented energy consumption data from electrical appliances for 3 months in home. The experimental results show the promising possibilities to estimate the energy consumption patterns and the current status.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.3
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• pp.289-300
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• 2003

Traditional kernel-level communication systems for clusters are dependent upon computing platforms. Futhermore, they are not easy to use and do not provide various functions for clusters. This paper presents an architecture and various implementation issues of a kernel-level communication system, KCCM(Kernel level Cluster Communication Module), for linux cluster. The KCCM provides asynchronous communication services as well as standard synchronous communication services using send and receive. The KCCM also automatically detects and recovers connection failures at runtime. This allows programmers to use KCCM when they build mission critical applications over TCP-based connection-oriented communication environments. Having developed using standard socket interfaces, it can be easily ported to various platforms. The experimental results show that the KCCM provides good performance for asynchronous communication patterns.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.6
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• pp.326-336
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• 2006

Due to the evolution of wired and wireless communication technologies and the Internet, multimedia services such as Internet broadcast and VOD have been prevalent recently. RTP is designed to be suitable for transmission of real-time multimedia data on the Internet by IETF While a variety of applications have utilized different RTPs implemented as a library, embeddedRTP is RTP-based kernel-level protocol that resolved performance issues of this kind of RTPs. This paper proposes the ExtendedERTP protocol based on existing embeddedRTP. This new protocol resolves a couple of issues such as packet processing overhead and buffer requirement and combines its APIs with BSD socket APIs which have been widely utilized in network applications. This paper demonstrates that this integration makes it possible to transmit real-time multimedia data through the accustomed interface of BSD socket APIs with nominal extra overhead. This paper also proposes a scheme for improving packet processing time by 15$\sim$20% and another scheme for reducing memory requirement for packet processing to about 3.5%, comparing with those of embeddedRTP.

• Journal of Internet Computing and Services
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• v.8 no.5
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• pp.11-20
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• 2007

This paper designs and implements a message passing library called JMPI (Java Message Passing Interface) which complies with MPJ (Message Passing in Java), the MPI standard Specification for Java language, This library provides some graphic user interface tools to enable parallel computing environments to be configured very simply by their administrators and JMPI applications to be executed very conveniently. Also in this paper, we implement two versions of systems using Socket and RPC which are both typical distributed system communication mechanisms and with three benchmark applications, compare performance of these systems with that of an existing system JPVM depending on the increasing number of the computers. Experimental results show that our systems outperform JPVM system in terms of various aspects and that the most efficient processing speedup can be obtained by increasing the number of the computers in consideration of network traffic through processing evaluation. Finally, we can see that, as the number of computers increases, using RMI to transmit a message is more effective than using object streams attached to sockets to transmit a message.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.475-482
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• 2001

In this paper, I describe the implementation of the distributed lists based on socket and on RMI(Remote Method Invocation). First, I describe and implement an interface of distributed list based on socket using object stream in a distributed environment, when encapsulating the message in the distributed list. Second, the major purpose to implement a distributed list in RMI is to compare advantages and disadvantages with other networking mechanisms by implementing complicated applications. The major advantage in using RMI is to implement simply the programs without using application-level protocol. In terms of program efficiency, the applications using HMI can degrade the performance due to many TCP/IP connections generated every update. TCP/IP connection requires much less cost than RMI. Even though RMI has the mechanism processing many method calls using a sing]e network connection, RMI is less efficient than the direct use of socket. However, RMI makes it possible to communicate beyond firewall using HTTP proxying mechanism. Consequently, I present a modeling of networking mechanism in finding out optimization solution by comparing and analyzing the two systems.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.65.1-70
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• 2000

최근 인터넷 사용자의 증가와 인터넷을 이용한 전자상거래가 활발해지면서 TCP/IP 통신 보안에대한 많은 연구들이 진행되고 있다. 이러한 연구들중 SSL(Secure Socket Layer) 은 인증 및 보안 프로토콜로서 인터넷을 이용한 통신 보안에 가장 많이 사용되고있는 방법이다. 본 논문에서는 국내 암호 알고리즘의 표준으로 채택된 SEED 알고리즘을 SSL에 적용하여 서버와 클라이언트의 통신을 128bits 암호화할 수 있는 SSL-Proxy 프로그램을 구현하였으며, Windows 와 Unix 시스템에 모두 적용 가능하도록 모듈화하였다.