• Journal of KIISE
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• v.43 no.9
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• pp.1052-1059
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• 2016

A key role in cloud computing systems that is becoming an issue is implementing a database on untrusted cloud servers requiring the complexity of key management. This study proposes a key management system using Self Proxy Servers to minimize key executions and improve the performance of cloud services by generating Self-Creating Algorithms where the data owner is not directly concerned with related keys when a user sends an encrypted database a query. The Self Proxy Server supports active and autonomous key managements as a distributed server if any trouble should arise from a cloud key server and for an efficient cloud key management. Therefore, the key management system provides secure cloud services by supporting confidentiality of a cloud server database.

• Journal of Internet Computing and Services
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• v.8 no.3
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• pp.85-98
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• 2007

In distributed computing paradigm, mobile surrogate systems have not gained wide acceptance because of security concerns that have not been suitably addressed yet. Currently even the widely used Grid middleware, Globus, does not have a host authentication mechanism, which makes it hard to provide high performance Grid computing capabilities to mobile clients. In this paper, a mobile Grid service framework is designed and implemented in order to provide Grid services to mobile host such as PDA. The surrogate host-based system allows mobile hosts to be provided with Grid services while moving. The implemented mobile Grid services system has been applied to mobile healthcare system which utilizes Grid computing for ECG signal processing. The presented system framework can be used as a secure enterprise mobile healthcare system for hospital physicians.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.9
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• pp.918-926
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• 2010

A widget is a small application running by the users' favorite services, so they are provided with web contents without explicitly visiting the web site. Although widgets can be easily implemented with Open APIs, only a few web sites provide them because of refactoring the structures of web resource to supply Open APIs to the widget developers. This paper presents an Open API Proxy Server System for widget services. The system consists of two components: an Open API Source Code Generator and an Open API Proxy Server. The Open API Source Code Generator provides a Graphical User Interface (GUI) for users to generate the Open APIs of user's choice and sends the Open API source code generation request to the Open API Proxy Server. The Open API Proxy Server using the HTML Table Processing Library receives the HTML web page from web site and extracts useful information from the target HTML table. The proxy server converts the extracted data into the corresponding XML document which becomes available through the Open API. We verify the operation of the proposed system through experiments with the HTML tables in the example web sites.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.4
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• pp.337-350
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• 2004

Because of a security problem and not enough IPv4 address space, the home network has been made up of private network, and it has been separated from Internet. This fact prevents people in Internet from controlling and monitoring home appliances. So, this paper designs and Implements the UPnP Proxy System which offers functions for users to control and monitor home appliances. When users are in the outside of the home network, they do not know which devices were connected in the home network because the advertisement messages of UPnP devices would not be delivered to the outside of the home network. Also, users cannot access devices directly, and their control messages are not delivered into the home network. So, this paper designs and implements the UPnP Proxy System to solve these problems. The merit of the system is that users can control and monitor home appliances in realtime using presentation web documents with the HTTP push technology.

• Journal of Korea Multimedia Society
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• v.7 no.6
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• pp.832-840
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• 2004

In ubiquitous environments, context is any information that can be used to characterize the situation of an entity such as a person or an object. Many sensors and small computers collect contexts and provide applications with them. Thus, ubiquitous applications need to represent contexts and exploit them effectively. In this paper, we design and implement a context-aware messaging system, called UMS (Ubiquitous Messaging System), based on Java and Jini. UMS can represent various contexts using XML scripts, and communicate text messages regardless of user's location using the proxy mechanism of Jini.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.325-326
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• 2011

전력선 통신기반 기술이 발전됨에 따라 원격검침시스템의 설치 및 유지관리에 필요한 망관리시스템기술도 함께 개발되어 운영되고 있으나 통합검침서비스를 제공하기 위해서 추가되는 무선통신노드의 관리에 대해서는 아직 적용된 바가 없다. 국내 구축된 전력선통신망의 셀 중심에는 칩 셋 벤더가 제공하는 망 관리유닛으로 망관리 정보를 모으고 SNMP기반으로 서버로 전송하는 Proxy agent 망관리구조를 가진다. 본 논문에서는 통합검침을 위한 주요 무선통신 노드인 댁내집속장치와 무선계량미터기관리를 위한 방안을 제시하고자 한다.

• Journal of Information Processing Systems
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• v.9 no.2
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• pp.287-300
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• 2013

Cloud storage is provided as a service in order to keep pace with the increasing use of digital information. It can be used to store data via networks and various devices and is easy to access. Unlike existing removable storage, many users can use cloud storage because it has no storage capacity limit and does not require a storage medium. Cloud storage reliability has become a topic of importance, as many users employ it for saving great volumes of data. For protection against unethical administrators and attackers, a variety of cryptography systems, such as searchable encryption and proxy re-encryption, are being applied to cloud storage systems. However, the existing searchable encryption technology is inconvenient to use in a cloud storage environment where users upload their data. This is because this data is shared with others, as necessary, and the users with whom the data is shared change frequently. In this paper, we propose a searchable re-encryption scheme in which a user can safely share data with others by generating a searchable encryption index and then re-encrypt it.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.991-1000
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• 2004

This paper presents an application layer multicast tree constructing algorithm to minimize the average time delay from the sender to end-systems for the effective real-time media delivery. Simultaneously, the proposed algorithm takes into account the computing power and the network condition of each end-system as a control variable and thus avoids the undesirable case that loads are concentrated to only several end-systems. The multicast tree is constructed by clustering technique and modified Dijkstra's algorithm in two steps, i.e. tree among proxy-senders and tree in each cluster. By the experimental results, we show that the proposed algorithm can provide an effective solution.

• The Journal of Society for e-Business Studies
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• v.12 no.2
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• pp.1-16
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• 2007

Recently the computing environment has been moved to open architectures that include Web technologies. Web Service is one of import component of the new paradigm. This paper presents a design and implementation of GIS Web Service for mobile devices. As many mobile devices are equipped with GPS (Global Positioning System), it is required to handle the position information more effectively. We have extended the proxy program in the client device to actively send the context information to the server. Based on the context information the server determines the optimal service mode to a particular client. A working example of location?based GIS Web Service is also presented. By using Web Service standards and XML messages we can achieve the maximal interoperability for heterogeneous mobile devices.

• Journal of Internet Computing and Services
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• v.12 no.2
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• pp.123-133
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• 2011

This paper introduces security problems on the video surveillance systems where the network cameras are equipped at remote places and isolated from the updated and secure environment and proposes a framework for a proxy server that is delegated to connect to network cameras by providing a secure connections from the clients. The server in the framework is deployed within a secure network, secretes the information for connection to cameras and authenticates the clients. Additionally, it provides a secure video service incorporating multi-level privileges for both images and clients through a encryption key distribution and management facility. Through an implementation of the server and a its deployment, it was proved that In this server implement to multi network camera and we confirm compare direct access to network camera equal video quality of service and it can be protection network camera. We expect that can be secure and integral management about traditional network camera through experimental result.