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

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1023-1026
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• 2005

In the ubiquitous computing environment, an intelligent vehicle is defined as a sensor node with a capability of intelligence and communication in a wire and wireless network space. To make it real, a lot of problems should be addressed in the aspect of vehicle mobility, in-vehicle communication, common service platform and the connection of heterogeneous networks to provide a driver with several intelligent information services beyond the time and space. In this paper, we present an intelligent information system for managing in-vehicle sensor network and a vehicle gateway for connecting the external networks. The in-vehicle sensor network connected with several sensor nodes is used to collect sensor data and control the vehicle based on CAN protocol. Each sensor node is equipped with a reusable modular node architecture, which contains a common CAN stack, a message manager and an event handler. The vehicle gateway makes vehicle control and diagnosis from a remote host possible by connecting the in-vehicle sensor network with an external network. Specifically, it gives an access to the external mobile communication network such as CDMA. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixed place, 707ms at rural area and 910ms at urban area.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.7-12
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• 2014

IETF (Internet Engineering Task Force) CoAP (Constrained Application Protocol) protocol is supported communication between sensor or actuator nodes by in a constrained environment, such as small amount of memory, and low power. CoAP and HTTP protocol can convert easily, and can use to monitor or controll the infrastructure utility through low-power sensor and actuator networks in IoT (Internet of Thing) and M2M (Machine-to-Machine) environment. IETF CoRE(Constrained RESTful environments) Working Group proposed CoAP protocol in 2010, and began to standardize it. Recently, CoAP protocol is published RFC (Request for Comments) 7252. In this paper, we design and implement of CoAP protocol for testing the interoperability in heterogeneous operating environments. For this experiment, we developed the CoAP client program based on Windows environment and CoAP server program in Linux environment to test the interoperability.

• Journal of The Korean Association of Information Education
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• v.9 no.1
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• pp.79-86
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• 2005

With the rapid advance of computer and communication technology, the amount of data transferred is also increasing more than ever. The recent trend of education systems is connecting related information semantically in different systems in order to improve the utilization of computerized information Therefore, Web-based teaching-learning is developing in the ubiquitous learning direction that learners select and organize the contents, time and order of learning by themselves. That is, it is evolving to provide teaching-learning environment adaptive to individual learners' characteristics (their level of knowledge, pattern of study, areas of interest). This paper proposes the efficient evaluation method of learning contents in a mediator for the integration of heterogeneous information resources. This means that the autonomy of a remote server can be preserved to the highest degree. In addition, this paper proposes the adaptive optimization of learning contents such that available storage in a mediator can be highly utilized at any time. In order to differentiate the recent usage of a learning content from the past, the accumulated usage frequency of a learning content decays as time goes by.

• Journal of The Korean Association of Information Education
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• v.1 no.1
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• pp.74-81
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• 1997

The World Wide Web (Web) is one of the most popular internet tool on now, In this reason most of common user, they understand the Web is internet and Web content is also important issues on this side. However, commonly Web content created by one of Web content creator and sometime they refer the another document and link. In these kinds of environments cause tile delivery of incorrect information or linking to another Web user. There are lots of way to protect the incorrect information deliveries to Web user and the most famous one is Computer Supported Cooperation Work (CSCW). This supports the multi-user environment on single system environment, but this needs more additional things in the current internet environment Current internet defined as distributed information network not tile traditional client-server environment. Specially, Intranet environments need to support the heterogeneous system environment like several Rinds of database, systems like PC, Mac and UNIX workstation, and etc. In this reason, we need collaboration and this would serve the common user interface to all of Web user. In these paper, we review the current concept of CSCW and grouoware that are major concept of collaboration and definition, classification and problem analysis of the collaboration. Finally, we suggest the construction method of collaboration environment for Web.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.51-60
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• 2004

In open GIS environment, a GIS client can access spatial data in different types of GIS sowers with the same Interfaces. This means that open GIS components software ensures the interoperability throughout the heterogeneous GIS servers. The user response time, however, tends to be increased, if the client makes use of the standard interfaces for data accesses that can ensure interoperability. This is because the format of spatial data accessed from a specific GIS server must be transformed into common format, such as Rowset in OLE/DB, which is compatible with the standard interfaces. In this paper, we develop efficient techniques for data buffering in GIS client to reduce the response time. We design the buffer management method, which Is based on the space partitioning, and Integrate buffer management components into MapBase, an open GIS component software. And we also, show that buffer management proposed in this paper yields significant performance improvement in GIS client.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.769-778
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• 2002

The LEX system is a XML-based framework for medical information consolidation. The Lex makes it possible for heterogeneous HISs(Hospital Information Systems) exchange and share HL7 messages by storing the messages into a single Central Clinical Database. In this paper, we propose a HL7 message server independently interoperable from existing HIS to generate HL7 messages, and design an XML database schema suitable for storing and manipulating such data. We also propose a new DTD for efficient transformation of HL7 messages to XML documents for storage saving as well as supporting patient-oriented information retrieval.

• Journal of Information Processing Systems
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• v.2 no.2
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• pp.76-81
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• 2006

A PDA is used mainly for downloading data from a stationary server such as a desktop PC in an infrastructure network based on wireless LAN. Thus, the overall performance depends heavily on the performance of such downloading with PDA. Unfortunately, for a PDA the time taken to receive data from a PC is longer than the time taken to send it by 53%. Thus, we measured and analyzed all possible factors that could cause the receiving time of a PDA to be delayed with a test bed system. There are crucial factors: the TCP window size, file access time of a PDA, and the inter-packet delay that affects the receiving time of a PDA. The window size of a PDA during the downstream is reduced dramatically to 686 bytes from 32,581 bytes. In addition, because flash memory is embedded into a PDA, writing data into the flash memory takes twice as long as reading the data from it. To alleviate these, we propose three distinct remedies: First, in order to keep the window size at a sender constant, both the size of a socket send buffer for a desktop PC and the size of a socket receive buffer for a PDA should be increased. Second, to shorten its internal file access time, the size of an application buffer implemented in an application should be doubled. Finally, the inter-packet delay of a PDA and a desktop PC at the application layer should be adjusted asymmetrically to lower the traffic bottleneck between these heterogeneous terminals.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.206-218
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• 2002

In this paper, we design and implement a system that presents a method for selecting and providing personalized services independently without unifying the existing system platform with shopping malls joined in the hub site. This system provides a mechanism for gathering information left behind by many clients visiting Web sites for analysis of customers property, vector model for selecting personalized services, and mechanism for providing them to customers who visited in a shopping mall joined to the hub site. In a position of shopping mall site, this kind of personalization system can provide target advertisement, point marketing, and point share service etc. without changing existing shopping mall's environment through wrapper web server. Hub site customers can get personalized services from many shopping mall sites with only once registration for the hub site.

• The Journal of Society for e-Business Studies
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• v.10 no.2
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• pp.43-57
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• 2005

The web services concept is rising as a standard to integrate heterogeneous systems in distributed environment based on XML messaging. Recently, for that reason, many companies are trying to use web services for their B2C and B2B business. In order to successfully introduce the web services, it is required to guarantee a differentiated quality of web services. However, most of the current web services cannot provide differentiated policies for requested messages and the existing web servers cannot consider appropriately the quality factors of web services in the service level agreement between provider and consumer. In this paper, we analyzed appropriate quality factors of web services in application level and suggested priority allocation strategy for processes dealing with messages of web services using those factors. This strategy can allocate dynamically a priority to satisfy the service level agreement.