• The KIPS Transactions:PartC
• /
• v.13C no.7 s.110
• /
• pp.813-820
• /
• 2006

The advance of computer and communication technologies enables the embedded systems to be equipped with the network communication interfaces. Their appearance in network leads to security issues on the embedded systems. An easy way to overcome the security problem is to adopt the packet filter that is implemented in the general computer systems. However, general packet filters designed for host computers are not suitable to embedded systems because of their complexity. In this paper, we propose a lightweight packet filter for embedded systems. The lightweight packet filter is implemented in the kernel code. And we have installed a Web-GUI interface for user to easily set the filtering policies at remote space. The experimental results show that the proposed packet filter decreases the packet delivery time compared to the packet filter designed for host computers and it is comparable to the systems without packet filter.

• Journal of Korea Multimedia Society
• /
• v.21 no.3
• /
• pp.358-368
• /
• 2018

The mobile characteristics of the smart phone are well suited to on-the-site oriented services and are being utilized in a variety of ways. However, since most applications operate on a central server basis, Internet access is inevitable, and there are various problems such as an increase in server maintenance cost and security deterioration. Although researches have been proposed to utilize the smart phone itself as a server to improve it, these methods are based on downsizing the PC-based web server or modifying the smart phone kernel. These methods have the problems that a end user has to use the rooting, and they are not able to effectively utilize various communication means of a smart phone. In this paper, we propose a design and implementation of an application level smart phone web server. The server receives the document request from the remote via the Internet and in the local area using the WPAN. At this time, the web document is stored as an internal file structure of the smart phone application. We proposed the phttp protocol which uses server's phone number as ID for document request. Through the implementation, we analyzed the capacity and latency of stored data and its effectiveness is evaluated.

• KIPS Transactions on Computer and Communication Systems
• /
• v.6 no.1
• /
• pp.43-50
• /
• 2017

Use-After-Free security problem is rapidly growing in popularity, especially for attacking web browser, operating system kernel, local software. This security weakness is difficult to detect by conventional methods. And if local system or software has this security weakness, it cause internal security problem. In this paper, we study ways to remove this security weakness in software development by summarize the cause of the Use-After-Free security weakness and suggest ways to remove them.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11a
• /
• pp.385-388
• /
• 2003

인터넷 인구의 폭주로 트래픽을 줄이려는 노력이 일고 있는 가운데, 우리는 기존에 웹 서버의 성능를 리눅스 커널 단에서 향상시키는 방법을 제안하였다. 사용자 영역의 스레드를 사용하지 않고 커널 영역의 스레드를 사용하고 CPU 개수와 동일한 스레드만 사용함으로서 스레드간의 컨텍스트 스위칭과 시스템 콜 사용의 오버헤드를 줄일수 있었다. 이번에는 이 구조를 CPN(Coloured Petri-Net)을 사용하여 논리적으로 분해하고 그 동작특성을 이해하여 모델링과 실제 데이터를 비교함으로서 프로그램 동작에 관한 논리적 문제점을 발견할 수 있고, 동작특성의 시간특성을 알 수 있다.

• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2429-2431
• /
• 2004

In this paper, we have designed a remote controlable HDR System using all embedded linux board. The system is composed of three parts - a HDR System, a PC client program for remote control and a Nameserver for registering and aquisition of the IP address. The system is built in an embedded board using a linux kernel. With the Linux the system can support networking and file system for a hard disk management In addition, the system embeds a web-server and a ftp-server for remote manipulation and file transfer. And the hardwares of the system are controlled by the linux device driver mechanism. MPEG1/2 technique is used to compress TV tuner signal and external analog video/audio signal. And compressed data is stored in a hard disk. The data stored in the system is accesable through lan or internet. And RTP protocol is used to enable the system to service live stream of instant video/audio input.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.5 s.248
• /
• pp.488-495
• /
• 2006

The demand for the use of 3D CAD data over the Internet environment has been increased. However, transmission of 3D CAD data has delayed the communication effectiveness because of the CAD data size. Lightweight CAD file design methodology is required for rapid transmission in the distributed environment. In this paper, to derive lightweight CAD files from commercial CAD systems, a file translation system producing a native file is constructed first by using the InterOp and API of the ACIS kernel. Using the B-rep model and mesh data extracted from the native file, the lightweight CAD file with topological information is constructed as a binary file. Since the lightweight CAD file retains topological information, it is applied to the dimensional verification, digital mock-ups and visualization of CAD files. Effectiveness of the proposed lightweight CAD file is confirmed through various case studies.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.489-492
• /
• 2002

인터넷 전자 상거래의 폭발적 증가와 더불어 개인 및 기업의 정보가 온라인 상으로 유출되는 경우가 증가하고 있다. 이에 따라. 새로운 하드웨어의 추가 없이 프로토콜 및 알고리즘의 변화에 유연한 인터넷 보안방법이 요구되고 있다. 본 논문에서는 사용자 영역과 상관없는 커널 스레드를 사용하고 커널 영역으로 포팅된 라이브러리를 참조하여 사용자의 웹 페이지 요청을 처리함으로써 응답시간과 서버 부하를 감소시키는 새로운 SSL(Secure Socket Layer) 처리 구조를 제안한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04a
• /
• pp.781-783
• /
• 2001

최근 정보가전과 홈네트워크산업이 급속히 발전됨에 따라 가정이 하나의 네트워크망을 형성하고 있다. 이에 홈네트워크에서도 보안의 필요성을 인식하게 되었으며, 유해사이트 차단은 필수가 되었다. 이러한 사이트 차단을 위해 기존의 유닉스, 리눅스는 lib9pcap 라이브러리 윈도우즈는 NDIS의 API를 이용한 응용계층에서의 패킷 필터링방법을 지원한다. 하지만 이와 같은 방법은 가정의 시스템 성능과 지속적으로 추가되는 홈서버의 기능으로 인해 시스템에 많은 부하를 발생시킨다. 본 논문은 이러한 부하를 최소화하기 위해 시스템 성능이 좋은 커널 모듈을 이용한 패킷 필터링 방법을 제시하고 이를 활용한 유해사이트 차단 시스템의 구현 예를 보인다.

• Journal of Information Processing Systems
• /
• v.1 no.1 s.1
• /
• pp.1-8
• /
• 2005

Embedded systems are used in many fields such as home appliances, terminals, controls, communications, etc. So, to manage, control, and test these embedded systems, monitoring programs have been developed variously. In this paper, to overcome the characteristic faults of embedded systems which have resource restrictions, we implemented a development environment based on NFS and designed a monitoring tool that can evaluate and analyze kernel performance in embedded equipment by using LTT(Linux Trace Toolkit). Also, we designed a method to show monitoring data collected by using a monitoring tool, called MONETA 2.0, through the web-page.

• International Journal of Contents
• /
• v.1 no.2
• /
• pp.26-30
• /
• 2005

According to the fast growth of information on the Internet, it is becoming increasingly difficult to find and organize useful information. To reduce information overload, it needs to exploit automatic text classification for handling enormous documents. Support Vector Machine (SVM) is a model that is calculated as a weighted sum of kernel function outputs. This paper describes a document classifier for web documents in the fields of Information Technology and uses SVM to learn a model, which is constructed from the training sets and its representative terms. The basic idea is to exploit the representative terms meaning distribution in coherent thematic texts of each category by simple statistics methods. Vector-space model is applied to represent documents in the categories by using feature selection scheme based on TFiDF. We apply a category factor which represents effects in category of any term to the feature selection. Experiments show the results of categorization and the correlation of vector length.