• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.11a
• /
• pp.677-681
• /
• 2002

Several multi-user online applications which are operated by the existing fixed terminals(PC) are being changed into online application based on multi-platform operated by the several PC, PDA and mobile phones to perform concurrent works due to the popularization of mobile devices recently. This paper proposed the infrastructure for network applications based on multi-platform. We also proposed the methods of consistency control based on multi-platform, update propagation protocols among diverse clients which take the asymmetry of computing power and network bandwidth among each client into account. Moreover, we implemented a chatting application based on multi-platform and it showed the proposed infrastructure and methods perform well.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.1010-1012
• /
• 2015

Interest in fossil fuels, alternative energy development in the world has increased significantly. That interest in solar systems increase significant and technology for efficiency and effective operation of PV technology, we expect to continue. This section provides the necessary information to users, and introduce the client system for mobile monitoring real-time solar system information, without the constraints of location or time, and leverage real-time information transmitted tell me about the expected effects that you can get to evaluate.

• The KIPS Transactions:PartD
• /
• v.15D no.5
• /
• pp.699-704
• /
• 2008

By the dependence on Web from popularization of internet and increasing number of users, web services capability and security problem of communication is becoming a great issue. Existing web services technology decrease the capability of web application server by limiting the number of synchronous client, decreasing the processing load and increasing average response time. The encryption process to secure communication and the early expense of handshake decrease transmission speed and server capability by increasing the calculation time for connecting. Accordingly, this paper executes an encryption procedure by elliptical encryption algorithm to satisfy secure demands, improve the overload of server for web services and get reliability and security of web server architecture and proposes an improved mobile web sever which provides better ability and the techniques for deferred processing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.459-461
• /
• 2010

Ad-Hoc VoIP system is an important IP phone technique used in MANET networks. In small-scale networks, VoIP system could be built easily while keeping the Qos on a acceptable level. Although Ad-Hoc VoIP system is designed as 'Client-Server' model, due to the property of MANETs that no Base Stations working as servers, we have the SIP Server with promary funtions worked on mobile terminals instead. In this paper, we explored how to build VoIP systems in MANETs and achieved the construction from within linux.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.8B
• /
• pp.716-729
• /
• 2003

As the public Internet and private internet have grown from small networks into large infrastructures, the need to more systematically manage the large number of network components within these networks has grown more important as well. The rapid growth of network size has brought into question the salability of the existing centralized model, such as SNMP(Simple Network Management Protocol) and CMIP(Common Management Information Protocol). Thus, for efficient network management, researches about mobile agent have also been performed recently. This paper presents analytical models of centralized approach based on SNMP protocol, distributed approach based on mobile agent, and mixed mode to make up for shortcomings of SNMP and mobile agent. We compare the performance of these analytical models based on network management response time. Experiment results show that performance of mobile agent and the nixed mode is less sensitive to the delay in WAN network environment. However, SNMP is more efficient for the simple network environment like LAN. We also propose an adaptive network management algorithm in consideration of network t environment. delay, task, and the number of nodes based on the results of analytical models. The results show that the adaptive network management algorithm can reduce the network management response time by 10% compared with either mobile agent or mixed mode network management algorithm.

• Journal of Korea Society of Industrial Information Systems
• /
• v.13 no.2
• /
• pp.69-79
• /
• 2008

Due to popularization of the wireless Internet and mobile devices the infrastructure of the ubiquitous environment, where users can get information whatever they want anytime and anywhere, is created. Therefore, a variety of fields including the education studies methods for efficiency of information transmission using on-line and off-line contents. In this paper, we propose the Mixed Mobile Education system(MME) that improves educational efficiency using on-line and off-line contents on mobile devices. Because it is hard to input new data and cannot use similar off-line contents in systems used additional tags, the proposed system does not use additional tags but recognizes of-line contents as we extract feature points in the input image using the mobile camera. We use the Scale Invariant Feature Transform(SIFT) algorithm to extract feature points which are not affected by noise, color distortion, size and rotation in the input image captured by the low resolution camera. And we use the client-server architecture for solving the limited storage size of the mobile devices and for easily registration and modification of data. Experimental results show that compared with previous work, the proposed system has some advantages and disadvantages and that the proposed system has good efficiency on various environments.

• KIISE Transactions on Computing Practices
• /
• v.21 no.6
• /
• pp.403-411
• /
• 2015

Nowadays, in the so-called 'smart era', people are likely to feel more comfortable in on-line meetings than in off-line meetings. However, on-line meetings are often considered unimportant and it is difficult for participants to share their feelings. This paper suggests a mobile application that can revitalize off-line meetings to address these problems. Wecok Application, which suggests the best meeting place by applying users' preferences and their locations, provides a function-oriented user interface and simple touch flow. Wecok consists of a client/server software, and currently supports only three users simultaneously. It enables exchange of off-line and on-line communication by expanding meetings from on-line to off-line. By using Wecok, users can easily decide on an off-line meeting place.

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.3
• /
• pp.131-140
• /
• 2007

A general medical information service in hospitals recently has been rapidly developed in the effective patient management due to the digitalization. In addition, the hospitals make an effort to support the medical information service in ubiquitous environment. A key requirement in ubiquitous environment is the ability to communicate between the image viewer system using the DICOM standard and a server system to support the medical information service. This paper describes a remote networking system based on the mobile terminal with RFID technology for the medical information service. In order to apply the overall configuration, we first implemented the DICOM viewer system, configured the database to store the patient information, and realized the server/client networking system in mobile terminal environment. In particular, this paper showed the capability for the medical image-based communication as well as the text-based communication.

• The KIPS Transactions:PartB
• /
• v.13B no.5 s.108
• /
• pp.569-578
• /
• 2006

The present study implemented AAC(Augmentative and Alternative Communication) system using images that speech defectives can easily understand. In particular, the implementation was focused on the portability and mobility of the AAC system as well as communication system of a more flexible form. For mobility and portability, we implemented a system operable in mobile devices such as PDA so that speech defectives can communicate as food as ordinary People at any Place using the system Moreover, in order to overcome the limitation of storage space for a large volume of image data, we implemented the AAC system in client/server structure in mobile environment. What is more, for more flexible communication, we built an image dictionary by taking verbs as the base and sub-categorizing nouns according to their corresponding verbs, and regularized the types of sentences generated according to the type of verb, centering on verbs that play the most important role in composing a sentence.

• Journal of the Korean Geographical Society
• /
• v.42 no.5
• /
• pp.788-807
• /
• 2007

To better publish geographical information on the Web, it is important to capture how Web technologies are changing. For a recent decade, Semantic Web has been developed by incorporating ontologies into the current Web, with an aim to make computers understand rather than simply display. Ontology, an explicit specification of a conceptualization, and the Semantic Web grounded on the ontology, have the potential for effective sharing and appropriate retrieval of geographical information. This paper describes a Semantic Web Service over the mobile Web that can offer pertinent tourism information according to user contexts. To do this, a tourism ontology was formalized in the PARA(Place-Attraction-Resource-Activity) ontology model by organizing tourist places, tourist attractions, tourism resources, and activities. Locational relationships between tourist places were also included in the PARA ontology model to take into account the movements of tourists on a railway network. The XML(Extensible Markup Language) Web Service in the middle tier manages the client-side request for information retrieval and the corresponding server-side response from the data provider. The PARA ontology was integrated into the XML Web Service for the concept-based discovery of tourism information. The applicability of the proposed system was tested through a simulation experiment for Tokyo tourism.