• Journal of Advanced Navigation Technology
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• v.24 no.5
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• pp.438-443
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• 2020

To transfer files between nodes on network based on Ethernet, file transfer protocol (FTP) on TCP/IP and trivial file transfer protocol (TFTP) on UDP/IP are mostly used. Due to the lack of resources (processor, memory and so on) in the embedded system where we generally use for simple works with small firmware like ones; many of the systems implement only UDP/IP for their network stacks. Thus, TFTP is greatly to be preferred. For examples, environmental sensor devices for sensor networks, Boot Loader for general embedded device and preboot execution environment (PXE) boot for PC provide the TFTP. The logic of TFTP is simple for file transmission but, there is Stop-And-Wait problem during the process which occurs long blocking time. In this paper, we propose an algorithm which called QuTFTP(Quick UDP Trivial File Transfer Protocol) to reduce the length of the blocking time and to be compatible with the legacy TFTP.

• Journal of the Korea Computer Industry Society
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• v.2 no.2
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• pp.131-140
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• 2001

In this paper file transfer efficiencies of satellite and terrestrial links are analyzed, and a simulator that satellite links are supplementarily expanded to SARA(System ARchitect’ Apprentice) model, a terrestrial model of CSDN interface, is constructed. And in satellite transmission an interpretative method and a simulator of file transfer are proposed to evaluate the efficiency of file transfer. The parameters used are the message length and transmission time, and the optimum message length by transmission speed of satellite links. From the results of evaluation, in satellite transfer, it is found that when the length of message is shorter than 512 byte, the file transfer time becomes extremely long and when the length of message is set at 1,024 byte the file transfer time becomes minimum, and if the length of message is set more longer, the file transfer time abruptly increases from 2,048 byte. Therefore, from the results of file transfer simulation in the case of utilizing satellite transmission, it is found that the optimum massage length in the minimum transfer time is present closely at 1,024 byte.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.557-565
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• 2005

This paper presents the development and implementation of a zero-copy file transfer mechanism that improves the efficiency of file transfers for PC cluster systems using hardware-based VIA(Virtual Interface Architecture) network adapters. VIA is one of the representative user-level communication interfaces, but because there is no library for file transfer, one copy occurs between kernel buffer and user boilers. Our mechanism presents a file transfer primitive that does not require the file system to be modified and allows the NIC to transfer data from the kernel buffer to the remote node directly without copying. To do this, we have developed a hardware-based VIA network adapter, which supports the PCI 64bit/66MHz bus and Gigabit Ethernet, as a NIC, and implemented a zero-copy file transfer mechanism. The experimental results show that the overhead of data coy and context switching in the sender is greatly reduced and the CPU utilization of the sender is reduced to $30\%\~40\%$ of the VIA send/receive mechanism. We demonstrate the performance of the zero-copy file transfer mechanism experimentally. and compare the results with those from existing file transfer mechanisms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.3
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• pp.187-196
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• 1990

This paper presents the design and implementation of a File Transfer Protocol between PC's which are connected through public network. The file handling system was implemented under 3B20S/UNIX which has connections to IBM-PC under MS-DOS. In designing the Protocol we use Kerimit Protocol which supports a file transfer between several kinds of PC's, and we extended the Kermit Protocol to have window function and file managing system. Users prepare data at PC and are able to send it to host computer and can receive, inquire, and delete file in host computer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.7
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• pp.545-552
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• 1990

This paper is concerned with the file protection in the file transfer systems. In the existing file transfer systems, passwords are used in the protection but do not provide any data protection and can only provide some protection against unauthorized access. Even provided with this protection, we cannot be free form computer hackers. In order to achieve higher standards of protection for our privacy (protection for data themselves, authentication of senders...) analternative technical system should be developed in using of pulic key cryptography by choosing the public key method (RSA public key) in the file transfer. A new system suggested in the paper can achieve some higher standards of protection for our privacy. We a result thie system will be easily applied to various document handling systems as in the data base.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.614-618
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• 2002

Although there are a lot of file sharing mechanisms in the Internet such as NFS and P2P, FTP is one of the most common mechanisms used until now. In this paper, we propose a more enhanced file sharing mechanism, the Distributed File Server (DFS) method. The most remarkable feature of DFS is that it can be simply adopted in the current Internet FTP services by locating a DFS node between existing FTP servers and clients without changing any existing file transfer environment. To verify the proposed mechanism we implemented a DFS prototype on RedHat 7.2 system and we finally show that it can reduce the file storage problem caused by big-sized multimedia data.

• 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 KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.525-533
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• 2009

Staging technique is used to provide files for a job in the Grid. If a staged file has large volume, the start time of the job is delayed and the throughput of job in the Grid may decrease. Therefore, removal of staging overhead helps the Grid operate more efficiently. In this paper, we present two methods for efficient file provisioning to clear the overhead. First, we propose RA-RFT, which extends RFT of Globus Toolkit and enables it to utilize RLS with replica information. RA-RFT can reduce file transfer time by doing partial transfer for each replica in parallel. Second, we suggest Remote Link that uses remote I/O instead of file transfer. Remote link is able to save storage of computational nodes and enables fast file provisioning via prefetching. Through various experiments, we argue that our two methods have an advantage over existing staging techniques.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.20-23
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• 2013

Recently for the transfer of large size video file between sites for high-definition craft editing used by broadcasting company the Public Network is used a lot. In the IP Public Network with QoS(Quality-of-Service) not guaranteed, degradation of performance has several causes. In this paper, we have analyzed the causes of low performance to transfer a large size HD video file in long distance, in order to maximize the effectiveness, the high efficiency network could be implemented enabling the highspeed of HD video file using the connection with networks between hosts through packet creation and multi-session of Parallel TCP. We survey the result of high speed transfer system and verify the efficient transfer method using Public IP Network for large HD video file transfer in broadcasting cooperation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.2
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• pp.53-59
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• 2020

Malicious file upload attacks mean that the attacker to upload or transfer files of dangerous types that can be automatically processed within the web server's environment. Uploaded file content can include exploits, malware and malicious scripts. An attacker can user malicious content to manipulate the application behavior. As a method of detecting a malicious file upload attack, it is generally used to find a file type by detecting a file extension or a signature of the file. However, this type of file type detection has the disadvantage that it can not detect files that are not encoded with a specific program, such as PHP files. Therefore, in this paper, research was conducted on how to detect and block any program by using essential commands or variable names used in the corresponding program when writing a specific program. The performance evaluation results show that it detected specific files effectively using the suggested method.