• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.12
• /
• pp.618-629
• /
• 2007

In this paper, we propose an effective memory test environment, called a virtualized kernel, for 64bit multi-core computing environments. The term of effectiveness means that we can test all of the physical memory space, even the memory space occupied by the kernel itself, without rebooting. To obtain this capability, our virtualized kernel provides four mechanisms. The first is direct accessing to physical memory both in kernel and user mode, which allows applying various test patterns to any place of physical memory. The second is making kernel virtualized so that we can run two or more kernel image at the different location of physical memory. The third is isolating memory space used by different instances of virtualized kernel. The final is kernel hibernation, which enables the context switch between kernels. We have implemented the proposed virtualized kernel by modifying the latest Linux kernel 2.6.18 running on Intel Xeon system that has two 64bit dual-core CPUs with hyper-threading technology and 2GB main memory. Experimental results have shown that the two instances of virtualized kernel run at the different location of physical memory and the kernel hibernation works well as we have designed. As the results, the every place of physical memory can be tested without rebooting.

• The Journal of the Korea Contents Association
• /
• v.9 no.5
• /
• pp.13-23
• /
• 2009

One of the main purpose of multiple-view image processing technology is support realistic 3D image to device user by using multiple viewpoint display devices and compressed data restoration devices. This paper proposes a multiple view image synthesis scheme based on RAM disk which makes possible to browse 3D images generated by applying effective composing method to real time input stereo images. The proposed scheme first converts input images to binary image. We applies edge detection algorithm such as Sobel algorithm and Prewiit algorithm to find edges used to evaluate disparities from images of 4 multi-cameras. In addition, we make use of time interval between hardware trigger and software trigger to solve the synchronization problem which has stated ambiguously in related studies. We use a unique identifier on each snapshot of images for distributed environment. With respect of performance results, the proposed scheme takes 0.67 sec in each binary array. to transfer entire images which contains left and right side with disparity information for high quality 3D image browsing. We conclude that the proposed scheme is suitable for real time 3D applications.

• Journal of Advanced Navigation Technology
• /
• v.20 no.3
• /
• pp.232-237
• /
• 2016

As a possible standardization of wireless local area network (WLAN), IEEE 802.11 LRLP is under discussion in order to support long range and low power (LRLP) communication for internet of things (IoT) including drones and many other IoT devices. In this paper, an efficient adaptive resource unit allocation scheme for uplink multiuser transmission in IEEE 802.11 LRLP networks is proposed. In the proposed scheme, which adopts OFDMA random access based transmission scheme of IEEE 802.11ax, in order to enhance the efficiency of the slotted OFDMA random access, access point (AP) traces the history of the sizes of successfully transmitted uplink data, and adjusts the sizes of resource units for the next uplink multiuser transmission adaptively. Our simulation results corroborate that the proposed scheme significantly improves the system throughput.

• Proceedings of the Korea Contents Association Conference
• /
• 2009.05a
• /
• pp.915-920
• /
• 2009

In terms of development of intelligent information devices, the most important element is the function which is able to deliver the information user wants to input on the device without complexities. By using the mean such as our voice, expression, gesture and physical contact we use in our daily routine, we are able to interact with device easily and simply. In this paper, we are initiated to present interactive surface system, in which allows users to use their hand gesture as a function of mouse and keyboard free, to be interacted within the platform of web application.

• Journal of Korean Library and Information Science Society
• /
• v.22
• /
• pp.205-244
• /
• 1995

Originally the concept of the traditional resource sharing has been discussed in the context of bibliographic materials, and has been labor-intensive and high-cost activities. The technology has had a great impact on such pattern of the resource sharing, and has expanded the limited scope of the traditional concept into the sharing of library information in the levels of local, regional and national systems, and expertise, materials, facilities, equipments and personnels of the library system. While the traditional circulation service as a basic method to share library materials by users can provide the resource to a single person at a time, the electronic resource can be shared, by multi-users at a time anytime anywhere. The maximization of the electronic resource sharing requires that publishing process should be fundamentally changed and articles, books, chapters, speech manuscripts, music scores, maps, sound, and other formats of materials should be prepared in machine readable format. This study examined the positive effects of the technology on the resource sharing, but not investigate the concrete and complex problems as to the cost, guidelines, detailed procedures, design details, and intellectual properties and protection involved in the resource sharing. Some findings extracted from the study can be summarized as follows; (1) ILL will lose its meaning as a method to share the materials if they are all in the electronic format and the phrase 'networked information resource' becomes omnipresent. (2) The technology keeps on changing the concept of resource sharing. Today, the scope of resource sharing not only encompasses the sharing of the primary and secondary materials but also the sharing of the processings(eg. cataloging), expertise, user education, special facilities, and the integrated automated library systems. (3) The sharing of the networked resource will be a method to provide better services for library users in the low cost. (4) The a n.0, pplication of the technology to the resource sharing should be focus on the method which allows an end-users to do the direct access to the needed materials, and to be delivered the primary document as soon as possible.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.19 no.2 s.72
• /
• pp.161-169
• /
• 2006

The study proposes component models in developing an efficient platform for internet-based structural analysis. Since a structural analysis requires an operation of complicated algorithms, a client-side computation using X-Internet is preferred to a server-side computation to provide a flexible service for multi-users. To compete with the user-friendly interfaces of available commercial analysis programs, a window-based interface using Smart Client was applied. Also, component-based programming was performed with the considerations on reusability and expandability so that active Preparation for future change or modification could be feasible. The components describe the whole system by subdivision and simplification. In the relationship between upper-and lower-level components and also in the relationship between components and objects, a unified interface was used to clearly classify the connection between the libraries. By performing data communication between different types of platforms using XML WebService, a conner-stone of data transfer is proposed for the future integrated CAE. The efficiency of the developed platform has been examined through a sample structural analysis and design on planar truss structures.

• Journal of the Korea Convergence Society
• /
• v.1 no.1
• /
• pp.23-29
• /
• 2010

The various kinds of application is distributed for the Smart phone user recently. There is the advantage that the open source application on Android operating system based Smart phone supports a multi tasking service. Layar, Wikitude, and Sherpa and the other applications using the GPS location information like an a2b etc. were developed in the Smart phone environment. However, the existing Cell-ID based location information can be directly collected by the mobile ISP unit which the mobile carrier installs, the personal privacy problem occurs. Therefore, the personal location information is possible to be exposed publicly without any access control procedure. Therefore, in this research, the self-control mechanism on the GPS location information at the Smart phone is designed and presented. Through this, it is possible to develop diverse applications providing enhanced access control and GPS location management on the Android based Smart Phone.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.8 s.350
• /
• pp.15-24
• /
• 2006

We design and implement explicit mobile multicast, named XMIP, by enhancing explicit multicast for a great number of small group multicast communications. XMIP is a straightforward multicast mechanism without maintaining multicast states due to the inheritance from the explicit multicast based on a unicast routing. This research modifies and extends the functionality of each mobility agent of IETF Mobile IP for interworking XMIP XMIP Packets captured by an extended home agent are forwarded to each extended foreign agent through nested tunnels, named X-in-X tunnels, made by the binding table of the extended home agent. X-in-X tunneling mechanism can effectively solve the serious traffic concentration problems of Mobile IP multicast specifications. Finally heterogeneous mobile networks as an XMIP testbed including CDMA2000 1X EV-DO and WLAN are actually established, and a multi-user instant messenger system for small group communications is developed for verifying the feasibility of the proposed protocols.

• Journal of Digital Contents Society
• /
• v.9 no.4
• /
• pp.771-778
• /
• 2008

A Device performance analyzing method for appropriate level in hybrid rendering model is suggested. In recent research, we proposed a hybrid rendering model which is applying a proper shading method to each of polygons consisting of an object. The number of polygon for Gouraud shading and that for flat shading should be considered according to a current device performance and system environments. Therefore, this paper suggests the method to calculate automatically a proper resolution of a mesh of object and a proper level of mixture between Gouraud and a flat shading, considering a current device performance and a preference of end-user. The rendering model is so simple that it can be an efficient replacement to reduce a real-time rendering time since it provides automatically multi-level of rendering resolution to an executing environments. Moreover, it can be adopted in real-time adaptive service for 3D graphic contents like a graphic game under various device environments.

• The KIPS Transactions:PartC
• /
• v.10C no.1
• /
• pp.87-94
• /
• 2003

As the number of the Internet users increases explosively, a solution for this problem is web caching. So, many techniques on improving cache server performance have been suggested. In this paper, we analyze the cause of the bottleneck in cache servers, and propose an arbitral thread and delayed caching mechanism as a solution. We use an arbitral thread in order to provide a quick service to user requests through eliminating the ready multi-thread search problem in case of disk writing operation. We also use delayed caching in order to provide stable system operation through avoiding overloaded disk operation and queue threshold. Proposed cache server is implemented through modification on SQUlD cache server, and we compare its performance with the original SQUID cache server.