• Journal of KIISE
• /
• v.44 no.2
• /
• pp.115-123
• /
• 2017

A message processor is server software that receives non-realtime messages as well as realtime messages from clients that need to be processed within a deadline. With the recent advances of micro-processor technologies and Linux, the message processor is often implemented in Linux-based multi-core servers and it is important to use cores efficiently to maximize the performance of system in multi-core environments. Numerous research efforts on a real-time scheduler for the efficient utilization of the multi-core environments have been conducted. Typically, though, they have been conducted theoretically or via simulation, making a subsequent real-system application difficult. Moreover, many Linux-based real-time schedulers can only be used in a specific Linux version, or the Linux source code needs to be modified. This paper presents the design of a Linux-based message processor for multi-core environments that maps the threads to the cores at user level. The message processor is implemented through a modification of the traditional RM algorithm that consolidates the real-time messages into certain cores using a first-fit-based bin-packing algorithm; this minimizes the response-time delay of the non-real-time messages, while guaranteeing the violation rate of the real-time messages. To compare the performances, the message processor was implemented using the two multi-core-scheduling algorithms GSN-EDF and P-FP, which are provided by the LITMUS framework. The benchmarking results show that the response-time delay of non-real-time messages in the proposed system was improved up to a maximum of 17% to 18%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.6
• /
• pp.587-598
• /
• 2021

This study aims to develop a multi-camera based MMS (Mobile Mapping System) technology for building a HD (High Definition) map for autonomous driving and for quick update. To replace expensive lidar sensors and reduce long processing times, we intend to develop a low-cost and efficient MMS by applying multiple cameras and real-time data pre-processing. To this end, multi-camera storage technology development, multi-camera time synchronization technology development, and MMS prototype development were performed. We developed a storage module for real-time JPG compression of high-speed images acquired from multiple cameras, and developed an event signal and GNSS (Global Navigation Satellite System) time server-based synchronization method to record the exposure time multiple images taken in real time. And based on the requirements of each sector, MMS was designed and prototypes were produced. Finally, to verify the performance of the manufactured multi-camera-based MMS, data were acquired from an actual 1,000 km road and quantitative evaluation was performed. As a result of the evaluation, the time synchronization performance was less than 1/1000 second, and the position accuracy of the point cloud obtained through SFM (Structure from Motion) image processing was around 5 cm. Through the evaluation results, it was found that the multi-camera based MMS technology developed in this study showed the performance that satisfies the criteria for building a HD map.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.20 no.3
• /
• pp.281-286
• /
• 2007

An engineering design problem involving Multi-Disciplinary Analysis(MDA) generally requires a large amounts of computing time for the entire design process, and therefore it is essential to introduce a Multiple Processor System (MPS) for reducing the computing time. However, when applying conventional parallel processing techniques, all of the CAE S/W requited for the MDA should be installed on all the servers making up MPS because of characteristic of MDA and it would be a great expense in CAE S/W licenses. To solve this problem, we propose a Weight-based Multiqueue Load Balancing algorithm for a heterogeneous MPS where performance of servers and CAE S/W installed on each server are different of each other. To validate the performance, a Computational experiments comparing the First Come First Serve algorithm and our proposed algorithm was accomplished.

• Journal of Digital Convergence
• /
• v.13 no.8
• /
• pp.245-251
• /
• 2015

If a digital signage system is operated in PC mounted in the Window OS then the implementing price is very high. For resolving this problem, we used the Smartphone mounted in ARM Cortex family of multi-core processor-based mobile platform. We developed a low-power low-cost digital signage system and a remote convergence content management program based on web server. This convergence system manages advertising content to a remote control device anywhere using remote control technology. This system is one integrated system with display and is a low-power consumed and is developed in very efficient hardware interface. And condition sensors(intensity of illumination, temperature, weather, GPS etc) is equipped in the developed system. Automatic contents builder and Context-aware SMIL module is also implemented in the convergence system. We achieved over 50% power savings comparing with conventional Window OS system and 16 points multi-touch in our system.

• Journal of Internet Computing and Services
• /
• v.16 no.3
• /
• pp.13-20
• /
• 2015

This paper proposes a Near Field Communication (NFC) communication system that exchanges information of digital business cards efficiently for many to many communication to solve inconvenience of one-to-one communication when people exchanges business cards each other in meetings such as conference, forum, seminar. The proposed system can provide people to exchange contact information one-to-one as well as multiple members at once using a digital business card system that consists a server and a database based on NFC communication. The system has been developed to collect business card information from a NFC reader and to transfer it directly to a smartphone application effectively. The system can manage business card information with the application effectively and provide security in order to prevent from leakage of private information when transferring contact data.

• The Journal of the Korea Contents Association
• /
• v.10 no.10
• /
• pp.26-35
• /
• 2010

Recently, multi client PC technologies that several users can use one set of computer at the same time are being designed to use the surplus computer resource. In general, as the existing PC management system considers only a single client PC that only one user uses a computer, various kinds of complicated problems may be arisen. This paper designs and realizes a remote management system that can monitor and control the information used in the windows based OS multi-client using WMI technology. The proposed system herein uses WMI technology and newly defined client management protocol and provides the monitoring and control functions on individual resource use information of multi-client. As well, it provides a communication function between the server and the client, and locking setting and access control functions.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.4
• /
• pp.828-834
• /
• 2009

To get a better profit, standalone mobile game market shifts network-based mobile game. Currently, most of the game platform are separated into mobile to mobile, desktop to desktop, and console to console. Multi platform network game has a diverse problems including consistency control, object management technique, and bandwidth inconsistency. n this paper, we will introduce a multi-platform arcade game "Push-Push", which is played on desktop to mobile environment. The game guarantees realtime play between heterogeneous machine users and game item sharing between two platforms. e will focus n the issues of the 3rd generation multi platform games and propose some techniques or solving these problems. Our server database is implemented on MS SQL database, also the desktop programming tool is Visual Basic, and WIPI(Wireless Internet Platform or Interoperability) as a mobile platform.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.6
• /
• pp.152-161
• /
• 2014

In this paper, a multi-node real-time diagnostic and management system based on zigbee sensor network is proposed, which is to monitor and diagnose multiple nodes as well as to control the data generated from the various multiple sensors collectively. The proposed system is designed to transmit the collected wireless and wired data to the server for monitoring and controling efficiently the condition for multi-nodes by taking the corresponding actions according to the analysis. The system is implemented to make it possible to manage the sensor data by classifying them, of which data are issued from the clustered sources with a number of the remote sensors. In order to evaluate the performance of the proposed system, we measure and analyze both the transmission delay time according to the distance and the data loss rate issued from multiple sensors. The results shows that the proposed system has a good performance.

• Journal of Broadcast Engineering
• /
• v.13 no.6
• /
• pp.930-940
• /
• 2008

This paper proposes a prototype realization of multi-view HD video transport system with synchronized multiplexing over IP networks. The proposed synchronized multiplexing considers the synchronization during video acquisition and the multiplexing for the interactive view-selection during transport. For the synchronized acquisition from multiple HDV camcorders through IEEE 1394 interface, we estimate the timeline differences among MPEG-2 compressed video streams by using global time of network between the cameras and a server and correct timelines of video streams by changing the time stamp of the MPEG-2 system stream. Also, we multiplex a selected number of acquired HD views at the MPEG-2 TS (transport stream) level for the interactive view-selection during transport. Thus, with the proposed synchronized multiplexing scheme, we can display synchronized HD view.

• Journal of Korea Multimedia Society
• /
• v.9 no.10
• /
• pp.1322-1331
• /
• 2006

Concurrency control is one of the important factors to maintain consistent conditions of a game because most participants of the game should be shared information to play the game through a distributed network system. replay delay times should establish in every event and the received event should be saved and performed simultaneously for Concurrency Control. However, it is not easy to practice the event with same speed in environment having various moving speed. Therefore, expansion have to be provided. In other words, one of the most important factors of a game's efficiency is the process of bandwidth and delay. the process of concurrency control method based on scalable prediction for Multi-platform games would minimize the loss rate of a event and then would improve the interaction capacity of a game. It also might get reliability between clients. This paper analyzes some problems in terms of a layout of a game that integrates a cable and a wireless system. In addition, this paper provides methods to expand bandwidth and delay that might be an obstacle of a On-line game and to ensure reliability between a server and a client.