• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.59-72
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• 2008

Computing systems in the modern era are expanding rapidly to include mobile-based businesses that make us of the various convergence distributed business process. This has lead to growing interest in the field of mobile embedded software development methodology, which has in turn lead to the proliferation of the embedded mobility. The use of CBD (Component Based Development) provides reusability, maintainability and portability, all of which are very important and focus issues to the business process. It also comes with the inherent productivity, quality and reliability of CBD. To make efficient use of CBD, though, clarified interface definitions for component integration are necessary. These definitions should be made up of collaborative hierarchical and horizontal architecture layers. Successful definitions should apply an effective framework made up of the architecture and process. In this paper, we describe an interface specification for small grained mobile embedded components(MEC) for the mobile embedded domain to meet maximum user requirements. We build and deploy the reconfigurable design patterns and components (in business domain categories) to make a component hierarchy and business logics for mobile embedded software. Proposed components specification plays a major role in development of the software for handling inconsistency in existing specification. It also includes plenty of specification information, using semantics and modeling based mechanisms to support business processes. We propose a development model of mobile embedded software using CBD for very complex and dynamic mobile business. We can apply it in a plug and play manner to develop the software. We verify that our framework supports very good productivity, quality and maintainability to meet the user's requirements in mobile business.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.121-129
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• 1999

When continuous media are transmitted over the communication networks, asynchrony which can not maintain temporal relationships among packets may occur due to a random transit delay. There exist two types of synchronization schemes ; for guaranteed or non-guaranteed resource networks. The former which applies a resource reservation technique maintains delay characteristics, however, the latter supply a best-effort service. In this paper, I propose a intra-media synchronization scheme to transmit continuous media on general networks not guaranteeing a bounded delay tome. The scheme controls transmission times of the packets by estimating next delay time with the delay distribution. So, the arriving packets may be maintained within a limited delay boundary, and playout will be performed after buffering to smoothen small delay variations. The continually increasing delay due to network overload causes buffer underflow at the receiver. To solve it, the transmitter is required to speed up instantaneously. Too much increase of transmission-rate may cause network congestion. At that time, the transmitter drops the current packet when informed excessive delay from the receiver.

• The KIPS Transactions:PartC
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• v.17C no.6
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• pp.441-450
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• 2010

Recently, a lot of interest is increased in sensor network which gathers various data through many sensor nodes deployed in wired and wireless network environment. However, because of the limitation in memory, computation, and energy of the sensor nodes, security problem is very important issue. In sensor network, not only the security problem, but also computing power should be seriously considered. In this paper, considering these characteristics, we make the sensor network consist of normal sensor nodes and clusterheaders with enough space and computing power, and propose a group key rekeying scheme adopting PCGR(Predistribution and local Collaborationbased Group Rekeying) for secure group communication. In our proposal, we enhance the security by minimizing the risk to safety of the entire network through verifying the new key value from clusterheader by sensor nodes. That is, to update the group keys, clusterheaders confirm sensor nodes through verifying the information from sensor nodes and send the new group keys back to authentic member nodes. The group keys sent back by the clusterheaders are verified again by sensor nodes. Through this mutual authentication, we can check if clusterheaders are compromised or not. Qualnet simulation result shows that our scheme not only guarantees secure group key rekeying but also decreasesstorage and communication overhead.

• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.11-19
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• 2004

P2P network environments provide users with direct data transmission and sharing facilities and those environments can be classified into hybrid P2P network environments and pure P2P network environments according to the arbitration mechanism among the peers in the network. In hybrid P2P network environments, there exists a server that maintains index information for the data to be shared and network isolation does not occur because every peer always keeps connection to the server. In pure P2P network environments, however, each peer directly connects to another peer and gets services without server intervention, and so, network isolation can occur when the mediating peer fails to work. In this paper. we propose a scheme for each peer to keep connection to other peers continuously by maintaining IP addresses of its neighbor peers and connecting to the peers when the mediating peer fails to work. Although the P2P application that uses our proposed framework should obtain one or more IP addresses of the neighbor peers manually, after instantiation, the application can do its job while maintaining connection to the network continuously and automatically. To evaluate our proposed scheme, we measured and analyzed the time for a peer to reconnect to the network when the mediating peer fails and the network isolation occurs.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.200-215
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• 2018

This research refers to the importance of health care in relation to the establishment of health care facilities and health care facilities in the rapidly changing health care environment, and the influence of health care in relation to the customer's satisfaction with health care. Orthographic analysis First, a hypothesis was adopted that the attractiveness of building materials will affect the positive (+) impact of the customer's satisfaction. Second, the hypothesis that the transport infrastructure will have a significant impact on the customer's satisfaction with the customer's satisfaction has been denied. Third, the hypothesis that the building appeal will have a significant effect on the health of the medical industry is adopted. Fourth, the hypothesis that the transport infrastructure will have a significant impact on health care is adopted. Fifth, the hypothesis that medical integration will have a significant impact on the customer's satisfaction with the customer's satisfaction is adopted. Sixth, the hypothesis that the relationship between the building and the customer's satisfaction in relation to the relationship between the client and the client was found to be partly attributable to the fact that there was a partial role. The assumption that the relationship between the transport infrastructure and the customer's satisfaction in relation to the traffic infrastructure was established has been identified as a complete parameter. The results of this study could be applied to provide the basis for selecting the location for future health care facilities.

• Science of Emotion and Sensibility
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• v.12 no.4
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• pp.481-488
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• 2009

The SNS(Social Network Service or Social Network Sites), the concept which came along with the Web2.0 is on-line service which focuses on building social network communities of people which used to be established off-line. Foreign SNS sites such as Facebook, MySpace and Twitter and domestic SNS sites such as Cyworld, Me2Day are getting popularity continuously and became one of the most important application in internet environments. Since these SNS sites have the purpose of providing infrastructure which enable all the people to share his/her interests with all the other people, it is necessary to appraise whether these sites provide convenient interfaces with proper accessibility to handicapped people and old people who are considered having difficulties in using internet. Web accessibility refers to the practice of providing equal access to people of all abilities and disabilities. If the web accessibility of a SNS site is so low that handicapped people and old people cannot use it properly, those gaps between user groups may become social problems. Therefore, the paper appraised web accessibility of Facebook and Cyworld using automatic tool, KADO-WAH 2.0 and Standard guideline, WCAG 2.0 and suggested the improvement opportunities based on the results of the appraisal.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.373-383
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• 2015

Spatial information has been widely used for efficient land use and management, disaster management, environment management, infrastructure management, corporate marketing, and cultural assets management, and the need for spatial information is expected to be increased. For this reason, central government, local government and public institutions must establish a National Spatial Information System (Fifteen systems related to spatial information managed by National Spatial Data Infrastructure Policy office, NSIS) framework that guarantees high accuracy and quality. The NSIS will provide convenience usage of spatial information in the field of decision-making or civil support. However the current National Spatial Information System is mainly established with separate processes, which causes data redundancy, deterioration of information, passive opening, and sharing of the spatial data. This study suggests 4 standards, which has been derived by applying value-chain model to NSIS data flow, and they are ‘Production and Establishment’, ‘Integration and Sharing’, ‘Application and Fusion’ and ‘Release and Opening’. Based on these standards, the 15 NSIS were analyzed to draw out implications and reforming directions were suggested. By following these suggestions we expect more recent, consist, accurate, and connected National Spatial Information Service which will be more open to public and then satisfy the demands.

• Journal of KIISE:Software and Applications
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• v.29 no.10
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• pp.726-735
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• 2002

E-mail service has been a general method for communication as internet is widely used instead of post mails. Many companies have invested in e-mail advertisement as e-mail service is spread. E-mail advertisement has an advantage that it can consider personal characters. A lot of e-mail users have been given e-mails that they did not want to receive because their e-mail addresses were opened out to companies on internet. Therefore, they need junk mail checking systems and several e-mail service providers have supported junk mail filters. However, the junk mail filters can check the junk mail with constraint because they don't check the junk degree of mails by the contents of e-mail. This paper suggests a content-based junk mail checking model using fuzzy relational products. The process of the junk mail checking model using fuzzy relational products is as following: (1) analyzes semantic relation between junk words-base and e-mails, (2) checks the junk degree of the e-mail using the semantic relation, (3) checks the mails with SVJ(Standard Value of Junk) if those are junk mail or non-junk mail. The efficiency of the proposed technique is proved by comparing the junk degree of the e-mail and the number of junk mails that was checked by e-mail users and checked by the proposed junk mail checking model.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.583-594
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• 2002

Assuring the security of group communications such as tole-conference and software distribution requires a common group key be shared among the legal members in a secure manner. Especially for large groups with frequent membership change, efficient rekey mechanism is essential for scalability. One of the most popular ways to provide sealable rekey is to partition the group into several subgroups. In this paper, we propose a two-layered key management scheme which combines DEP and CBT, a protocol in which subgroup manager cannot access the multicast data and another that has a multi-core, respectively. We also select sub-group key management protocols suitable for our structure and design new rekey protocols to exclude the subgroup managers from the multicast data. Compared to previous protocols based on CBT, our scheme provides forward secrecy, backward secrecy and scalability. This would reduce the number of encryption and decryption for a rekey message and would improve the efficiency number of rekey messages and the amount of information related to group members that group managers must maintain compared to DEP.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.309-318
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• 2005

In order to present wireless Internet users with previously created HTML contents and applications, it is essential to research and develop the technology to efficiently convert HTML documents into documents and further provide a way to edit the WML documents. This paper describes the design and development of a WML converter and WML editor The WML converter can convert HTML pages in real time into WML documents that are suitable for the WAP environment. The WML editor enables creation and modification of WML documents in a WYSIWYG fashion. These tools enable the previous services based on HTML documents to be easily adapted to the wireless environment. The developed WML converter can be installed on a proxy server to support real time conversion of Web contents. It is superior to other converters in terms of the various image formats it supports and the improvements on the conversion of the link and frame tags. Users can continuously browse via links and also view frames. Automatic dividing of large WML documents into WML cards md user defined conversion rules are also supported. The WML editor is also integrated with the converter and provides an integrated WYSIWYG environment for creating, converting and publishing WML documents.