• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1C
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• pp.90-95
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• 2002

Though the FTP(File Transfer Protocol) has been used widely and stable, It has the structural weakness that can't support current file transmissions so that we have to wait the completion of previous file transmission when try to transmit another file. If try to transmit multiple files concurrently using this FTP, It has to forking multiple FTP servers and clients in each user's PC and ISP's host machine it would result in the waist of memory, resource of network and the high workload of system. In order to solving previous problem, in this paper I have designed the new model of FTP which based on multi-thread and created NFTP(Next-Generation FTP)protocol so that may reduce the workload of system and support current file transmission effectively. I have implemented NFTP and also applied to real service, as a result It have provided reliable service by reducing the workload of system and saved the waiting time which would happened.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.37-51
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• 2010

In this paper, we discuss the program implementation and system optimization for the effective transfer of huge amount of data. In VLBI which is observing the celestial bodies by using radio telescope hundreds thousands km apart, it is necessary for each VLBI observatory to transfer up to terabytes of observed data. For this reason, e-VLBI research based on advanced network is being actively carried out for the transfer of data efficiently. Following this trend, in this paper, we discuss design & implementation of system for the high speed Gbps data transfer rates. As a data transfer protocol, we use UDP for designing data transmission program with much higher speeds than currently available via VTP(VLBI Transport Protocol). Tsunami-UDP algorithms is applied to implementing data transfer program so that transmission performance could be maximize, also we make it possible to transfer observed data more fast and reliable through optimization of computer systems in each VLBI statopm.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.7
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• pp.303-312
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• 2006

This paper proposes the architecture and protocol of a data communication network for the safety system in nuclear power plants. First, we establish four design criteria with respect to determinability, reliability, separation and isolation, and verification/validation. Next we construct the architecture of the safety network for the following systems: PPS (Plant Protection System), ESF-CCS (Engineered Safety Features-Component Control System) and CPCS (Core Protection Calculator System). The safety network consists of 12 sub-networks and takes the form of a hierarchical star. Among 163 communication nodes are about 1600 origin-destination (OD) pairs created on their traffic demands. The OD pairs are allowed to exchange data only during the pre-assigned time slots. Finally, the communication protocol is designed in consideration of design factors for the safety network. The design factors include a network topology of star, fiber-optic transmission media, synchronous data transfer mode, point-to-point link configuration, and a periodic transmission schedule etc. The resulting protocol is the modification of IEEE 802.15.4 (LR-WPAN) MAC combined with IEEE 802.3 (Fast Ethernet) PHY. The MAC layer of IEEE 802.15.4 is simplified by eliminating some unnecessary (unctions. Most importantly, the optional TDMA-like scheme called the guaranteed time slot (GTS) is changed to be mandatory to guarantee the periodic data transfer. The proposed protocol is formally specified using the SDL. By performing simulations and validations using Telelogic Tau SDL Suite, we find that the proposed safety protocol fits well with the characteristics and the requirements of the safety system in nuclear power plants.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.229-237
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• 2005

One of the important issues of in this research is effective usage of energy to increase life time of nodes which form a network. Existing LEEM protocol causes unnecessary active time due to small packets with shorter transfer time than active interval period of node and packets with transfer time of more than twice of active interval period of node. In this paper, we propose Energy-Efficient MAC by Reservation (EEMR) protocol which can increase energy effectiveness in wireless sensor network environment by reducing unnecessary active time using a method that reserves next-hop depend upon the size of packet. We evaluated effectiveness of our proposed method through experiments. The result showed that using EEMR protocol had better energy effectiveness than existing LEEM protocol by 15%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.2
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• pp.288-299
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• 1993

This paper proposes the new bus protocol in the tightly coupled multiprocessor system. The bus protocol uses the pipelined data transfer and block transfer scheme to increase the bus bandwidth, The bus also has the independent transfer lines for the address and data respectively, and it can transfer the data up to maximum 264 Mbytes /sec. This paper also models the multiprocessor system where each processor boards have the private cache. Simulation evaluates the bus and system performance according to hit ratio of the reference data in cache memory, In the case of using this bus, the bus is evaluated not to be saturated when up to 10 processor boards are connected to the bus. As for up to 4 memory interleavng, the performance increases linearly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1075-1081
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• 2008

The growth of digital content market inducted to develope consuming device of various content. And through this, digital content consuming is more Promoted. But digital content cryption tool need to handle to protect and consume digital content safely. Also, interoperability of cryption tool management is impossible, because of not standardized transfer protocol between device. In this paper, we defined transfer protocol of cryption tool for protecting and consuming digital content. And in this base, we designed and implemented transfer server/client system.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.396-405
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• 2009

An interlocking equipment of railway signalling systems should have very high functional safety and reliability properties because of its vital railway protection functionality. In order to achieve the required safety and reliability level, an engineer, in general, designs and implements the interlocking equipment to operate under RTOS(Realtime Operating System) environment, and the control hardware architecture redundant to cope with the random failures of system or subsystem. In such an architecture, it's very difficult to implement the interlocking equipment to communicate with various interface systems including the signal operator's terminal. In this paper, we propose a dual ethernet network topology and dual packet seamless transfer protocol algorithm for railway signaling system such as the interlocking equipment. We verify in this paper that the proposed DPST protocol algorithm has the evidence of its robust properties against the random hardware faults and communication errors. The proposed communication structure and algorithm is implemented in the electronic interlocking equipment for the private railway system of Hyundai Steel Company and its performance and properties are validated on the guideline of European Railway Standard EN50159.

• Journal of Korean Clinical Nursing Research
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• v.29 no.1
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• pp.75-84
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• 2023

Purpose: This study developed a protocol for nursing care after death for adult patients in hospitals. Methods: This was a methodological study to develop a care after death protocol. The preliminary protocol was developed based on a literature review, guidelines, and practice recommendations from groups of experts and clinical nurses. Content validity was evaluated by a group of experts (n=6) and nurses (n=30) in two hospitals. Results: The preliminary protocol recommendations were modified by validation and the open-question analysis results. The final protocol comprised three general recommendations and 43 recommendations in five steps that are verification and notification of a death, personal care of the body, viewing the patient, patient transfer, and documentation and self-care. Conclusion: This study result provides nurses with a consensus information on patient care after death and family support in a hospital setting. This nursing protocol is expected to improve the quality of care after death for adult patients and their families, and can be used for developing educational and emotional support for nurses to accomplish their important role.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9B
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• pp.589-597
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• 2007

In this paper, a WDM metro ring consisting of access nodes with $FT-FR^n$ (Fixed Transmitter - n Fixed Receivers) is considered. A trade-off exists between node throughput and transmission fairness because the access nodes share wavelength channels. In order to eliminate the transmission unfairness and to increase throughput, the p-persistent medium access control (MAC) protocol is proposed: each node uses an empty optical slot to transmit a packet and make it available with the extraction of a transferred packet at the source access node, called source-stripping. The local empty slot can be used to transfer a head-of-line packet in the local buffer with probability p or it is used for the next downstream nodes with 1-p. The proposed MAC protocol provides better node throughput than the non-persistent protocol and exhibits better fairness index than the 1-persistent protocol in WDM ring networks. In addition, numerical analysis shows that the proposed MAC protocol maximizes the node throughput under uniform traffic conditions. For more detailed results, we use the network simulation under Poisson and self-similar traffic. Furthermore, unpredictable traffic constructed by the combination of the former and the latter is also considered. The reasonable probability of the p-persistent protocol for a given architecture can be determined through simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.2
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• pp.751-765
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• 2012

Key establishment protocols are fundamental for establishing secure communication channels over public insecure networks. Security must be given the topmost priority in the design of a key establishment protocol. In this work, we provide a security analysis on two recent key establishment protocols: Harn and Lin's group key transfer protocol and Dutta and Barua's group key agreement protocol. Our analysis shows that both the Harn-Lin protocol and the Dutta-Barua protocol have a flaw in their design and can be easily attacked. The attack we mount on the Harn-Lin protocol is a replay attack whereby a malicious user can obtain the long-term secrets of any other users. The Dutta-Barua protocol is vulnerable to an unknown key-share attack. For each of the two protocols, we present how to eliminate their security vulnerabilities. We also improve Dutta and Barua's proof of security to make it valid against unknown key share attacks.