• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.587-597
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• 2017

Recently, the demand for real-time performance in mobile environment is increasing due to the improvement of hardware performance, however a GPOS(General-Purpose Operating System) such as Android and Linux do not provide real-time performance. We developed RTiK(Real-Time implant Kernel) for this problem, but it has the disadvantage of supporting only x86 Architecture. In this paper, we designed and implemented a RTiKA(Real-Time implanted Kernel for ARM) to support real-time in ARM Linux. We used MCT(Multi-Core Timer) timer which replaces Local APIC Timer for real-time support, and we measured the period of generated real-time task for performance verification and evaluation. As the recent the RTiKA can guarantee the operating of several real-time tasks based on the cycle of 1ms.

• The KIPS Transactions:PartA
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• v.12A no.7 s.97
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• pp.597-604
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• 2005

The paper describes implementation of smartphone edition based on embedded Linux, which is composed of smartphone middleware and basic applications. Existing smartphone platforms entails loyalty expenses and has difficulties on customization due to the closed policy of their source codes. Although GPE - based on embedded Linux has solved the loyalty issues, other problems are remained unsolved. Since GPE has been designed for relatively large PDA-level devices, applications are generally inoperable under the condition of small LCD size and input methods without touch-screen; the condition is typical limitations of the smartphones. In the implemented smartphone edition of the paper no loyalty is required, because the smartphone edition is based on embedded Linux. It also supports keypad-only operating functionality such as moving between folders or running applications with operations. Besides, it provides more user-friendly environment to use the smartphone editionscreen interfaces and indicatorsto those of the regular cellular phones.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.326-328
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• 2016

While hackers in early days intended to disable and devastate the system, these days people hack and attack the network in order to steal customer's private information from the big corporate, which changes the nature of the crime to cyber attack for money, eventually causing a lot of damages. One of the most efficient ways to protect this kind of network attack is VPN, referring to Virtual Private Network. VPN is a private networking technology that makes the public network available for only those who are concerned. This paper will suggest the VPN technology that can be applied to Linux server and related protocols and figure the applicable VPN out.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.796-800
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• 2006

In this paper, we developed an e-loaming contents for C programming language using Linux and open source software, not using commercial integrated development tool like Microsoft's Visual Studio. In most programming language courses, students study or practice the programming language by editing source code compiling and running the executable code by commercial software like Visual Studio which installed on each PC. This way of learning has some difficulties in total cost of purchasing software and using other PCs which donot have proper software installed. To overcome this situation and enable loaming anywhere, with any device, at anytime, we propose a way of utilizing Linux and open source software in Web-based learning environment. In this environment students can input their source code on the form of broweser and get the result instantly from the server.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.100-102
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• 2001

Intensive I/O bandwidth demand of the multimedia streaming service puts significant burden on file system. Different from the legacy text based or image data, the semantics of the data in multimedia format can be significantly affected if the data block is not delivered by the predefined deadline. The legacy file system used in Unix or Unix like environment is designed to efficiently handle the files who sizes range from few hundreds of byte to several tens of gigabytes. This fundamental design philosophy results in the file system based on multi level skewed tree structure. Multi level i-node structure has significant drawback when the application performs sequential read operation. In this article, we present the result of the performance study of the file system which is specifically designed for handling multimedia streams. We implemented the file system on Linux Operating System environment and examines the performance behavior of the file system under streaming I/O workload. The result of the study shows that the proposed file system performs much more efficiently than the ext2 file system of Linux does.

• The KIPS Transactions:PartA
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• v.11A no.5
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• pp.313-318
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• 2004

In this paper, we suggest a checkpoint and recovery facility for the fault-tolerable process which is expected to be executed for a long time. The basic concept of the suggested facility is to allow the process to be executed continuously, when the process was stopped due to a System fault, by storing the execution status of the process periodically and recovering the execution status prior to the fault was occurred. In the suggested facility, it does not need to modify the source code for the fault-tolerable process. It was designed for the user to specify directly the file name and the checkpoint frequency, and two system calls(save, recover) were added. finally, it was implemented on the Linux environment(kernel 2.4.18) for checking the feasibility.

• Journal of Information Processing Systems
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• v.4 no.4
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• pp.133-144
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• 2008

Clusters have become a popular alternative for building high-performance parallel computing systems. Today's high-performance system area network (SAN) protocols such as VIA and IBA significantly reduce user-to-user communication latency by implementing protocol stacks outside of operating system kernel. However, emerging parallel applications require a significant improvement in communication latency. Since the time required for transferring data between host memory and network interface (NI) make up a large portion of overall communication latency, the reduction of data transfer time is crucial for achieving low-latency communication. In this paper, Eager Data Transfer (EDT) mechanism is proposed to reduce the time for data transfers between the host and network interface. The EDT employs cache coherence interface hardware to directly transfer data between the host and NI. An EDT-based network interface was modeled and simulated on the Linux-based, complete system simulation environment, Linux/SimOS. Our simulation results show that the EDT approach significantly reduces the data transfer time compared to DMA-based approaches. The EDTbased NI attains 17% to 38% reduction in user-to-user message time compared to the cache-coherent DMA-based NIs for a range of message sizes (64 bytes${\sim}$4 Kbytes) in a SAN environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.355-357
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• 2014

Linux environment that is commonly used at embedded systems, supports various file systems as Ext2, FAT, NTFS, ets. The file system that is equiped on the embedded system is mostly implemented on mini hard disk or flash memory. The types of the file system of the system make an effect on the performance of a application programs. The factors of file system performance on a same media are block allocation and block free time. On these factors, block free time is not so different according to the type of file systems. This thesis performs the performance benchmark of a Ext2, FAT and NTFS file systems about block allocation performance. As the result, it is discussed that what file system is better at which case.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.581-583
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• 2012

In this paper, linux-based wireless terminals that receives packets from the AP(Access Point) were analyzed. Wireless terminals received a number of unnecessary packets from AP, and received unnecessary packets were discarded in the appropriate layer. Whenever Wireless terminals receive unnecessary packets from AP, wireless terminals repeatedly perform an inefficient operation.

• Journal of KIISE:Information Networking
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• v.34 no.2
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• pp.81-87
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• 2007

This paper proposes architecture of Linux-based Network Traffic Control Test-bed (NTCT) that easily implements reconfigurable network environment. The proposed NTCT consists of traffic generator that uses the simulation results of NS2 simulator, traffic controller using Linux kernel, and traffic monitor. This paper also includes the analysis example using the proposed NTCT.