• Journal of KIISE:Computing Practices and Letters
• /
• v.9 no.1
• /
• pp.13-24
• /
• 2003

MPEG-4 is a standard for multimedia applications and provides a set of technologies to satisfy the needs of authors, service providers and end users alike. In this paper, we suggest a Real-time Multiple Circular Buffer (M4RM Buffer) model, which is suitable for streaming these MPEG-4 contents efficiently. M4RM buffer generates each structure of the buffer, which matches well with each object composing an MPEG-4 content, according to the transferred information, and manipulates multiple read/write operations only by its reference. It divides the decoder buffer and the composition buffer, which are described in the standard, by the unit of frame allocated to minimize the range of access. This buffer unit of a frame is allocated according to the object description. Also, it processes the objects synchronization within the buffer and provides APIs for an efficient buffer management to process the real-time user events. Based on the performance evaluation, we show that M4RM buffer model decreases the waiting time in a buffer frame, and so allows the real-time streaming of an MPEG-4 content using the smaller size of the memory block than IM1-2D and Window Media Player.

• Korean Journal of Environmental Biology
• /
• v.37 no.4
• /
• pp.585-591
• /
• 2019

Most insect-resistant LMOs have been produced by applying Cry and Vip3Aa proteins. Vip3Aa protein is activated during the vegetative stage of Bacillus thuringensis (Bt) and the inhibitory activity of the Vip3Aa protein against pathogenic attacks from lepidopteran insect species is well known. However, a risk assessment of the Vip3Aa protein compared to the Cry protein has not been conducted in South Korea. This study demonstrates a possible risk assessment method for Vip3Aa protein against honeybees (Apis mellifera). For the risk assessment of the protein, we purified the recombinant Vip3Aa protein in Escherichia coli. The survival rate and symptoms of general intoxication of 4 months honeybees were measured after Vip3Aa exposure. These results indicated that there was no significant difference in the survival rate and the symptom between Vip3Aa and the control buffer. In this study, we established standard methods of Vip3Aa protein purification and oral adult toxicity test using A. mellifera as an LMO risk assessment technique for preserving the natural ecosystem of South Korea.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.19 no.2
• /
• pp.75-82
• /
• 2009

In this paper, we test for security targeting on APIs of Windows as that is used by many people worldwide. In order to test APIs in DLL fils of Windows OS, we propose Automated Windows API Fuzz Testing(AWAFT) that can execute fuzz testing automatically and implemented the practical tool for AWAFT. AWAFT focuses on buffer overflows and parsing errors of function parameters. Using the tool, we found 177 errors in the system folder of Windows XP SP2. Therefore, AWAFT is useful for security testing of Windows APIs. AWAFT can be applied to libraries of third party software in Windows OS for the security.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.6
• /
• pp.326-336
• /
• 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 Microbiology and Biotechnology
• /
• v.27 no.1
• /
• pp.84-91
• /
• 2017

The concern over the use of melittin in honey bee venom due to its adverse reaction caused by allergens such as phospholipase A2 ($PLA_2$) and hyaluronidase (HYA) has been an obstacle towards its usage. We developed a novel single-step method for melittin purification and the removal of $PLA_2$ and HYA. This study explores the influence of pH, buffer compositions, salt concentration, and types of cation-exchange chromatography resins on the recovery of melittin and the removal of both HYA and $PLA_2$. Melittin was readily purified with a strong cation-exchange resin at pH 6.0 with sodium phosphate buffer. It resulted in a recovery yield of melittin up to 93% (5.87 mg from a total of 6.32 mg of initial melittin in crude bee venom), which is higher than any previously reported studies on melittin purification. $PLA_2$ (99%) and HYA (96%) were also successfully removed. Our study generates a single-step purification method for melittin with a high removal rate of $PLA_2$ and HYA, enabling melittin to be fully utilized for its therapeutic purposes.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.19 no.5
• /
• pp.189-194
• /
• 2009

Most of anti-virus programs detect and compare the signature of the malicious code to detect buffer overflow malicious code. Therefore most of anti-virus programs can't detect new or unknown malicious code. This paper introduces a new way to detect malicious code traces memory executable of essentials APIs by malicious code. To prove the usefulness of the technology, 7 sample codes were chosen for compared with other methods of 8 anti-virus programs. Through the simulation, It turns out that other anti-virus programs could detect only a limited portion of the code, because they were implemented just for detecting not heap areas but stack areas. But in other hand, I was able to confirm that the proposed technology is capable to detect the malicious code.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.1 no.2
• /
• pp.90-103
• /
• 2006

There are many file systems in various operating systems. Those are usually designed for server environments, where the common cases are usually 'multiple active users', 'great many small files' And they assume a big main memory to be used as buffer cache. So the existing file systems are not suitable for resource hungry embedded systems that process multimedia data streams. In this study, we designed and implemented a new file system which efficiently stores and retrieves multimedia data steams. The proposed file system has a very simple disk layout, which guarantees a quick disk initialization and file system recovery. And we introduced a new indexing-scheme, called the time-based indexing scheme, with the file system. With the indexing scheme, the file system maintains the relation between time and the location for all the multimedia streams. The scheme is useful in searching and playing the compressed multimedia streams by locating exact frame position with given time, resulting in reduction of CPU processing and power consumption. The proposed file system and its APIs utilizing the time-based indexing schemes were implemented firstly on a Linux environment, though it is operating system independent. In the performance evaluation on a real DVR system, which measured the execution time of multi-threaded reading and writing, we found the proposed file system is maximum 38.7% faster than EXT2 file system.