• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.11a
• /
• pp.995-998
• /
• 2007

무선 네트워크에서 사용되는 단말기는 이동성이라는 특징상 한정된 에너지를 사용하여 동작하게 된다. 따라서 무선 호스트에 의해 소모되는 에너지의 양을 감소시키기 위한 기술은 대단히 중요하다. 이러한 기술적 지원을 위해 IEEE 802.11 에서는 DCF (Distributed Coordination Function) 전력 절감 메카니즘을 제안하고 있다. 그런데, DCF 를 위한 IEEE 802.11 전력 절감 메카니즘에서는 ATIM 창 동안 노드들은 비콘 기간 동안 깨어 있는 상태로 있을 것인지를 결정하기 위해서 control packet 을 교환 하는데, 이러한 ATIM 창 크기는 각각의 노드들의 전력 절감에 상당한 영향을 미친다. 그래서 ATIM 창 크기를 효율적으로 할당하기 위해 DPSM 과 같은 기법들이 개발되었다. 본 논문은 ATIM 창 크기를 동적으로 증감시켜서 ATIM 창 시간동안 소모되는 에너지를 줄이도록 하였다. ATIM 창 크기를 동적으로 할당하기 위하여 통계적 예측 기법인 칼만 필터를 도입하여 예측시스템을 구축하였으며, 이 예측 시스템을 통해 다음 상태에서 적용할 ATIM 창 크기를 예측하여 동적으로 할당하도록 하였다. 실험 결과 네트워크 생존 시간을 28.6% 증가시켰고, ATIM 창 크기 예측값의 오차는 4.42%로 나타났다.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.9
• /
• pp.2815-2826
• /
• 2000

This paper describes the design and implementation of a CHILL Run-time System(CRS) that provides a running environments of real-time distributed software like as ATM switching software on host computers. To do this, we have proposed an execution model of real-time distributed CHILL proRrams and developed a CHS executinR the software of the execution model on host computers. Because CRS provides transparent runninR environments of target operating system, programmers are able to develop target system software without target system. As it provides an environment for multiple users running programs concurrently, it guarantees the improvement of program productivity. Originally, CRS has developed as a simulator of SROS. But it can be easily modified for other operating systems.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.1
• /
• pp.161-171
• /
• 1998

In this paper, we shows the implementation of Web based performance manager which analyze the traffic of a Web server to support the diagnostics of it. The manager monitors the HTIP traffic by polling and measures and presents is performance on demand. To enhance the adaptability of management interface Web based interfaces with JAVA is used. Recently, the need of traffic management on s Web has grown, because of increasing Web traffic. Therefore, the traffic management of Web service and the effective management of a Web server's performance are needed. We have designed interfaces with which is comprised of Collection-Request, Analysis-Request, Realtime-Monitoring, Comparison-Analysis on a client with Web Browser on a network, and implemented the server system that can analyze these requests. Also we have introduced some perfonnance indicator by referring a Web related MIB. Also, we have designed and developed a message format for communication between the Web client and the server system.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.7
• /
• pp.1855-1862
• /
• 1998

An Internet user obtains an IP address from DNS to access the host. But, Korean users must use English word order Domain that is not convenient for them. All existing systems have the reverse of the Korean word order and that is the obstacle to the spreading of Internet. So, the necessity of a Korean name system that well suited for Korean Internet user is increasing. In order to operate the proposed Korean Domain System with existing Domain Name Systems, we build a Korean to English transformation rule and Korean Domain Name composition rule. Also, we designed a STHOP for Korean word order processing. In a STROP, a SLDF transform a Korean SLD into English SLD, and a NFDNG makes this as an English word order. By using Korean Domain Name System proposed here, users could understand the embedded meaning of Domain Name with ease, and reluctance of Domain registration caused by similarity of organization names would be solved, Consequently. it could devote to the popularization of the Internet.

• Convergence Security Journal
• /
• v.8 no.1
• /
• pp.1-7
• /
• 2008

The hacking method came to be more complicated, became program ant it was automated. That is hacking trend of recent times. Before, The password crack, catch root authority is trend of hacking which uses the vulnerability of server. Hacker attack network or all of domain not some host. Web application system at hacking technique develops and improve transmitted data through the network shows many vulnerability. The massive data are transmitted through the network without encipherment filtering. It will be able to bring about the neck of a bottle actual condition which is serious in security system because of the network where the user comes to be many it leads and the data which is delivered comes to be many. In this paper, we propose web application system to prevent overload from bottleneck in encipherment system. It can solve security key trust problem in encoding and decoding with public key infrastructure.

• The KIPS Transactions:PartC
• /
• v.10C no.6
• /
• pp.727-738
• /
• 2003

Much research efforts are being exerted for the study of intrusion detection system(IDS). However little work has been for the communication medels and performance eveluation of the IDS. Here we present a communication framework for doing hybrid intrusion detection in which agents are used for local intrusion detections with a centralized data anaysis componenta for a global intrusion detection at multiple domains environment. We also assume the combination of host-based and network-based intrusion detection systems in the oberall framework. From the local domain, a set of information such as alert, and / or log data are reported to the upper level. At the root of the hierarchy, there is a global manager where data coalescing is performed. The global manager delivers a security policy to its lower levels as the result of aggregation and correlation of intrusion detection alerts. In this paper, we model the communication mechanisms for the hybrid IDS and develop a simular using OPNET modeller for the performance evaluation of transmission capabillities for the delivery of data and policy. We present and compare simulation results based on several scenarios focuding on communication delay.

• The KIPS Transactions:PartC
• /
• v.12C no.2 s.98
• /
• pp.191-200
• /
• 2005

The brilliant achievements in computers and the internet technology make it easy for users to get useful information. But at the same time, the damages caused by intrusions and denial of service attacks are getting more worse. Specially because denial of service attacks by internet worm incapacitate computers and networks, we should draw up a disposal plan against it. So far many rule-based intrusion detection systems have been developed, but these have the limits of these ability to detect new internet worms. In this paper, we propose a system to detect intrusion and generate detection rule against scan-based internet worm, paying attention to the fact that internet worms scan network to infect hosts. The system detects internet worms using detection rule. And if it detects traffic causing by a new scan-based internet worm, it generates new detection nile using traffic information that is gathered. Therefore it can response to new internet worms early. Because the system gathers packet payload, when it is being necessary only, it can reduce system's overhead and disk space that is required.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.2
• /
• pp.259-266
• /
• 2021

USB bus not only works with convenience but also transmits data fast and becomes a standard peripheral interface between FPGA development board and personal computer. In this paper FPGA verification system with slave FIFO interface for Cypress FX3 USB 3 bridge chip was implemented. The designed slave FIFO interface consists of host interface module based on FIFO structure, master bus controller and command decoder and supports streaming communication interface for FX3 bridge chip and memory-mapped input and output interface for user design circuit. The ZestSC3 board with Cypress FX3 USB 3 bridge chip and Xilinx Artix FPGA(XC7A35T-1C5G3241) was used to implement FPGA verification system. It was verified that the FPGA verification system for user design circuit operated correctly under various clock frequencies using GUI software developed by visual C# and C++ DLL. The designed slave FIFO interface for FPGA verification system has modular structure and can be applicable to the different user designs with memory-mapped I/O interface.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.48 no.7
• /
• pp.48-56
• /
• 2011

Recently, new storage device SSD(Solid State Disk) based on NAND flash memory is gradually replacing HDD(Hard Disk Drive) in mobile device and thus a variety of research efforts are going on to find the cost-effective ways of performance improvement. By increasing the NAND flash channels in order to enhance the bandwidth through parallel processing, DRAM buffer which acts as a buffer cache between host(PC) and NAND flash has become the bottleneck point. To resolve this problem, this paper proposes an efficient low-cost scheme to increase SSD performance by improving DRAM buffer bandwidth through scheduling techniques which utilize DRAM multi-banks. When both host and NAND flash multi-channels request access to DRAM buffer concurrently, the proposed technique checks their destination and then schedules appropriately considering properties of DRAMs. It can reduce overheads of bank active time and row latency significantly and thus optimizes DRAM buffer bandwidth utilization. The result reveals that the proposed technique improves the SSD performance by 47.4% in read and 47.7% in write operation respectively compared to conventional methods with negligible changes and increases in the hardware.

• Journal of Digital Convergence
• /
• v.18 no.3
• /
• pp.163-169
• /
• 2020

A smart key has been used in a variety of embedded environments and there also have been attacks from a remote place by amplifying signals at a location of a user. Existing studies on defence techniques suggest multiple sensors and hash functions to improve authentication speed; these, however, increase the electricity usage and the probability of type 1 error. For these reasons, I suggest an embedded security controller based on client authentication and user movement information improving the authentication method between a controller and a host device. I applied encryption algorithm to the suggested model for communication using an Arduino board, GPS, and Bluetooth and performed authentication through path analysis utilizing user movement information for the authentication. I found that the change in usability was nonsignificant when performing actions using the suggested model by evaluating the time to encode and decode. The embedded security controller in the model can be applied to the system of a remote controller for a two-wheeled vehicle or a mobile and stationary host device; in the process of studying, I found that encryption and decryption could take less then 100ms. The later study may deal with protocols to speed up the data communication including encryption and decryption and the path data management.