• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.5-14
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• 2014

Searchable encryption systems provide search on encrypted data while preserving the privacy of the data and the search keywords used in queries. Recently, interest on data outsourcing has increased due to proliferation of cloud computing services. Many researches are on going to minimize the trust put on external servers and searchable encryption is one of them. However, most of previous searchable encryption schemes provide only a single keyword boolean search. Although, there have been proposals to provide conjunctive keyword search, most of these works use a fixed field which limit their application. In this paper, we propose a field-free conjunctive keyword searchable encryption that also provides rank information of search results. Our system uses prime tables and greatest common divisor operation, making our system very efficient. Moreover, our system is practical and can be implemented very easily since it does not require sophisticated cryptographic module.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.143-154
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• 2005

This paper proposes the location acquisition methods and LBS(location-based services) system using RFID(radio frequency identification) tags with location information in ubiquitous city. Location information is checked using RFID tags attached to various buildings. stores and road signs. And various LBSs are provided based on the location information. Traditionally, when the location information is obtained by a GPS, the precision of the location information may deteriorate due to geographical displacement of a satellite and GPS receivers, for example shadow zone by building, in-door environment, and heavy cloud. The objective of this paper is to provide a ULID(universal location identification) data structure, a ULID-based location acquisition method and an LBS system, in which precise location information is extracted using RFID tags attached to various buildings, stores and road signs and ULID and also danger of information leakage is minimized so that an LBS of ubiquitous environment can be provided to a user.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.93-99
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• 2017

The elevator system combines various convergence technologies with the development of ICT technology. Emergency call devices which are safety related devices is applied as an obligation of the elevator and those scope also varies. In this paper, we propose an integrated model that overcomes the limitations of existing voice emergency call devices and efficiently manages and manages video call based service structures in VoIP based on wired and wireless environments. This method effectively manages and operates various lift data and video records in the elevator between the manager, the server and the user. And also It is possible to secure the quality of video call in VoIP and cloud service environment and increase the reliability of safety management and enhance various service environment by creating an integrated structure utilizing various data and additional services in the elevator.

• The Journal of Society for e-Business Studies
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• v.16 no.3
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• pp.211-224
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• 2011

Since appearance of smart devices and cloud computing services, the social and economical values of administrative information have been magnified as valuable information. In order to make better use of various administrative information by diverse government organizations efficiently and effectively, information sharing based on legal systems is essential because of several obstacles including privacy. To suggest practical ways for using administrative information, this study categorized the administrative information sharing process, and analyzed the regulations and legal systems that are contradictory to the regulations. The result of analysis appears that there is a need of legislative base for well-defined business use of information, and a need of the organizations, that available to collect and manufacture the information. The results of this study can be expected to make legislation contributions not only for industries, but also by suggesting the policy making and guidelines to protect privacy and improve the quality of citizens' life.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.29-38
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• 2012

Nowadays, most remote sensing image processing systems are on client-based ones. But in the view of information technology, a web-based system is predominant, being closely related to cloud computing and services. The web-based system in remote sensing is somewhat limited in the area of data sharing or dissemination, but it is necessary to extend. This study is to implement a web-based system and its component modules for SAR data processing. First, the previous cases dealt with both web computing and SAR information are investigated. InSAR information processing and concerned modules for a web-based system among SAR research domains are the main points in this work. It is expected that this approach contributes to the first attempt to link web computing technology such as HTML5 and satellite image processing.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.251-258
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• 2016

Recently, the demand for fast storage devices is rapidly increasing in cloud platforms, social network services, etc. Despite the development of fast storage devices, the traditional Linux I/O stack is not able to exploit the full extent of the performance improvement since it has been optimized for disk-based storage devices. In this paper, we propose an optimized I/O stack which can fully utilize the I/O bandwidth and latency of fast storage devices. To this end, we design a new I/O interface to replace the current block I/O interface and optimize our I/O interface. Our optimized I/O interface bypasses operations/layers in block I/O subsystems of the current Linux I/O stack to fully exploit fast storage devices. We also optimize the Linux file systems such as ext2 and ext4 to run on our I/O interface. We evaluate our I/O stack with multiple benchmarks and the experimental results show that our I/O stack achieves 1.7 times better throughput compared to traditional Linux I/O stack.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.78-83
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• 2017

Linux was born under the influence of Unix except for the kernel, Linux was used to bring the Unix system and relevant program package, commands, etc. However, the latest version of Enterprise Linux, RHEL 7 was adopted systemd instead of init to boot program and management services. The adoption of systemd was building its own Linux system, the system only. Also noteworthy point is that given the considerable number of features specific to a particular package and instructions. As Linux has been recognized as a subtype of Unix itself as a catch all this time the turn of the tide in the cloud era and there on their own to try various changes, the start of the adoption of these changes can be called systemd. Linux is the future beyond the confines of Unix is noteworthy not attempt any changes.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.91-99
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• 2013

While there is the active integration of various industries, a convergence of the software and knowledge service industries including software used in finance and counseling products is creating the necessity to include software industry utilization sectors aside from covering only software products and service production activities. Furthermore, to cope with the radical environment changes in the software industry when it comes to categorizing mobile and cloud computing areas into a software and classification system, we are at a point where there is a need to establish a directional nature on what should be included. In order to establish an integrated classification of newly introduced technologies, products and services, this paper aims to discover areas not included in the classification standard because of the ecological characteristics of the software. It also wants to differentiate the classification system and identify its incomplete areas such as the lack of connections within the system to ultimately establish such for newly surfacing software fields.

• Convergence Security Journal
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• v.16 no.7
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• pp.21-29
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• 2016

Our society is currently exposed to environment of various information that is exchanged real time through networks. Especially regarding medical policy, the government rushes to practice remote medical treatment to improve the quality of medical services for citizens. The remote medical practice requires establishment of medical information based on big data for customized treatment regardless of where patients are. This study suggests establishment of regional medical cluster along with defense and protection cooperation models that in case service availability is harmed, and attacks occur, the attacks can be detected, and proper measures can be taken. For this, the study suggested forming networks with nationwide local government hospitals as regional virtual medical cluster bases by the same medical information system. The study also designed a mutual cooperation security model that can real time cope with IP Spoofing attack that can occur in the medical cluster and DDoS attacks accordingly, so that the limit that sole system and sole security policy have can be overcome.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.5
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• pp.19-28
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• 2012

Recently a grid and cloud computing collaboration have become a social issue. These collaborative network system, the P2P system based on this system. Distingui shed from the client/server systems, P2P systems in order to exchange information, its purpose and functions are divided according to the morphological Category. In accordance with the purposes and functions of information and data retrieval, remote program control and integration services for the offers. Most P2P systems client/server scalability, and management takes the form, but to overcome the disadvantages in terms of applying the mixed-mode system is increasing. And recently the distributed computing aspects of the service to users in order to provide suitable to accommodate the diverse needs of various types of mobile agent technology is needed. In this paper, as required by the mobile agent access to a remote resource access control and agent for the execution and management capabilities and improve the reliability of the mobile agent system designed to suggest.