• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1B
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• pp.99-107
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• 2002

Broadcast disks are suited for disseminating information to a large number of clients in mobile computing environments. In broadcast disks, the server continuously and repeatedly broadcasts all data items in the database to clients without specific requests. The clients monitor the broadcast channel and retrieve data items as they arrive on the broadcast channel. The broadcast channel then becomes a disk from which clients can retrieve data items. In this paper, we propose a cache conscious concurrency control ($C^4$) scheme to preserve the consistency of client transactions, when the values of broadcast data items are updated at the server. $C^4$ scheme is novel in the sense that it can reduce the response time of client transactions with minimal control information to be broadcast from the server. This is achieved by the judicious caching strategy of the clients.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.4
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• pp.264-274
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• 2006

Recently, a variety of organizations including enterprises tend to try to use reporting tools as a data analysis tool for decision making support because reporting tools are capable of formatting data flexibly. Traditional reporting tools have thin-client structure in which all of dynamic documents are generated in the server side. This structure enables reporting tools to avoid repetitive process to generate dynamic documents, when many clients intend to access the same dynamic document. However, generating dynamic documents for data analysis doesn't consider a number of potential readers and increases requests to the server by making clients input various parameters at short intervals. In the structure of the traditional reporting tools, the increase of these requests leads to the increase of processing load in the server side. Thus, we present the reporting tool that can generate dynamic documents at the client side. This reporting tool has a processing mechanism to deal with a number of data despite the limited memory capacity of the client side.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.607-616
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• 2008

By the advancement of computer & network technology, the paridigm of 'Network Computer' has been realizing`. In what is called network computer, computer system and computing resource is incomparably seem to be expanded compared with conventional network technology[1]. Network connected computer system consitute a massive virtual computer, it is possible for people to use an enourmous amout of computing resource distributed widely through the network. It is also possible that we make client lightweight by the use of computer system & all shared computing resources on the network in our computer processing and we call this type of client system as thin-client. Thin-client and network computer are on and the same network paradigm in that both paradigm featuring the active use of computer system and resource on the network[2]. In network computer paragem, network itself is regarded as a basic platform for the transfer of application, so it is possible that client access remote serve system to run remote applications through the network[3]. In this paper, we propose the system architecture for the implementation of network computer by the use of Web browser, X window system and Pyjamas. By the use of network computer proposed in this paper, it is possible for people to run application on the server system as if he run local application, and it is expected to improve the security and maintenance efficiency.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.115-126
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• 2008

VNC(Virtual Network Computing) is a desktop sharing system based on the RFB(Remote Framebuffer) protocol which allows you to control a remote computer running a VNC server through a VNC client(or viewer) on a local computer. To exchange information between the two computers, VNC provides the functionality of sharing the clipboard contents. Unfortunately, the current VNC softwares support only the clipboard text contents, not providing methods for sharing the clipboard multimedia contents such as images. In this paper, we extend the RFB protocol to share the clipboard contents composed of text and images. Also, to support the developed protocol. we extend both the UltraVNC server and the JavaViewer VNC client which are free open-source softwares. Through the developed VNC softwares, users can exchange the clipboard contents including texts and images between the remote computer and the local computer.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.5
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• pp.607-617
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• 2002

IETF has proposed CNRP that is a protocol exchanging CNRP objects between server and client for resolving a common name to URIs of the desired Internet resouces. CNRP enables users to access various services via the integrated interface, to easily get the desired resources, and to reuse the results not as the data but as the information. Whereby these advantages, CNRP will be generally used for the integration of the various Internet services or the applications where the resolution of common name is needed. But, CNRP specification doesn't describes the practical implementation method for server and client. Though a few prototype systems are developed in some researches using CNRP, they are not enough to be generally used for the various Internet applications because they doesn't include all objects specified in CNRP specification or they construct systems with one server. So, this Paper proposes the practical implementation method for CNRP server/client through analyzing and solving the problems occurred when implementing them, and implements all objects specified in CNRP specification. This paper also verifies the feasibility of the proposed method by developing the prototype system of the company name resolution service using the CNRP server/client implemented in this study. The CNRP server/client implemented in this paper are used to develop various CNRP application systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5B
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• pp.317-323
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• 2005

Broadcast disks are suited for disseminating information to a large number of clients in mobile computing environments. In broadcast disks, the server continuously and repeatedly broadcasts all data items in the database to clients without specific requests. The clients monitor the broadcast channel and retrieve data items as they arrive on the broadcast channel. The broadcast channel then becomes a disk from which clients can retrieve data items. This paper proposes a Timestamp based Concurrency Control (TCC) scheme to preserve the consistency of read-only client transactions, when the values of broadcast data items are updated at the server. Previous schemes tried to reduce transaction aborts by consuming considerable amount of downlink communication from the server to clients for transferring control information. On the other hand, the TCC uses a timestamp field of each data item to describe execution order of server transactions. Clients can allow more transaction executions by checking consistency of their read-only transactions with timestamps of data items. As a result, the TCC can reduce the abort ratio of client transactions with minimal control information to be broadcast from the server.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.6
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• pp.1111-1116
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• 2009

For expression of contour lines in mobile GIS environments, the client needs to receive the numerical data with the topographical map from a server. At this point, a client can't get the entire raw data because of the mobile characteristics. The approach to get representative points and to make isogram by interpolation methods, has some problems. The approach requires huge computing overhead at the client and doesn't guarantee the correctness of the isogram. In this paper, a data structure, algorithm and implementation results for efficient transmission of contour information to a client which is constructed from elevation information at a server, are proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.151-154
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• 2008

For expression of isogram in mobile GIS environments, the client needs to receive the value data with the topographical map from a server. At this point, a client can't get the entire raw data because of the mobile characteristics. The approach to get representative points and to make isogram by interpolation methods, has some problems. The approach requires huge computing overhead at the client and doesn't guarantee the correctness of the isogram. In this paper, a data structure, algorithm and implementation results for efficient transmission of contour information to a client which is constructed from a elevation information at a server, are proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.08a
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• pp.79-82
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• 2008

For expression of isogram in mobile GIS environments, the client needs to receive the value data with the topographical map from a server. At this point, a client can't get the entire raw data because of the mobile characteristics. The approach to get representative points and to make isogram by interpolation methods, has some problems. The approach requires huge computing overhead at the client and doesn't guarantee the correctness of the isogram. In this paper, a data structure and algorithm for efficient transmission of contour information to a client which is constructed from a elevation information at a server, arc proposed. A proposed methods are focused at minimizing the transmission data volume and time.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1016-1019
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• 1996

This paper discribes automobile processes and introduction for process monitoring and control system for engine plant, truck automobile industries using the MES(Manufacturing Execution Systems) functions.