• Journal of KIISE:Databases
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• v.32 no.4
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• pp.416-428
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• 2005

In the paper we propose an index method for XML streaming services, where a server broadcasts XML data to a lot of clients in wireless information systems. In order to control the access and tuning time of mobile clients, the proposed method constructs the XML stream through replicating partial index intermixed with parts of data. For this purpose, we propose a two-level tree structure for separating index and XML data into two parts: replicated vs. non-replicated. We analyze the performance of the proposed method with respect to access time and tuning time. With the analysis result, we derive the optimal level value.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.123-128
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• 2009

In ubiquitous computing environments, service discovery to search for an available service is an important issue. In this paper, we propose an efficient service discovery scheme that is combined a node id-based clustering service discovery scheme and a P2P caching-based information spreading scheme. To search quickly a service, proposed scheme store key information in neighbor's local cache and search services using it's information. We do not use a central look up server and do not rely on flooding. Through simulation, we show that the proposed scheme improves the performance of response time and network load compared to other methods.

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.432-438
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• 2010

In this paper, we propose a system which can perceive status of semiconductor equipment and evaluate its performance. The proposed system acquires the information such acceleration, pressure, temperature and gas sensors in the surrounding semiconductor equipment. After acquiring information, it is sent to server through multi hop transmission. The transmitted data generates 3 steps alarm using context-aware algorithm of unit or multiple event. From the experiment's result of the proposed system, we confirm that the reliability and efficiency of information is more improved about 80% than a system that doesn't use context-aware algorithm. Moreover, this system can be effective status monitoring of semiconductor equipment because lots of client nodes acquire surrounding information.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.6
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• pp.205-212
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• 2015

SSH provides a secure, encrypted communication channel between two end point systems using public key encryption. But SSH brute force attack is one of the most significant attacks. This kind of attack aims to login to the SSH server by continually guessing a large number of user account and password combinations. In this paper, we analyze logs of SSH brute force attacks in 2014 and propose a failed-log based detection mechanism in high performance computing service environment.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.1
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• pp.1-9
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• 2013

Performance of smart phones has increased to conduct simple PC functions that has become essential to modern people. With the development of smart phones, not only limited inner sensors but various sensors can be connected through USB. However, there is problem that app needs to downloaded when using each sensor. In this paper, a smart phone unified app structure for USB sensor Plug&Play is presented. The structure was designed to download web pages to use various sensors in one app. Unified app communicated with the platform through ADK accessory protocol and implements structure of delivering sensor ID to the web server and downloading device driver, web page. By measurement test, it was confirmed that download time of web page in unified app was 10 times faster than original download time of original app. By managing various sensors by one app, the app is searched every time the sensor changes in which there is no need for downloading several apps.

• Convergence Security Journal
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• v.4 no.3
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• pp.47-55
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• 2004

Currently used to manage a whole bunch of networks is the Client/Server Network Management Technique in which a central manager system supports a number of managed ones. Unfortunately it has a big drawback: wasting network resources, most of all bandwidth, which is mainly caused by too much traffic between the central manager system and the managed ones. In a way to overcome this weak point, we have designed a new type of system, a Configuration Management System (CMS), based on code mobility which has been used in distributed network management systems. In this thesis we have compared the CMS with the currently used network management system, identified class to make Mobile Code, and analyzed the techniques of other network management systems in order to verify the validity of the new system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.9
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• pp.3870-3884
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• 2020

The proposed framework of Four Layer Robust Storage in Cloud (FLRSC) architecture involves host server, local host and edge devices in addition to Virtual Machine Monitoring (VMM). The goal is to protect the privacy of stored data at edge devices. The computational intelligence (CI) part of our algorithm distributes blocks of data to three different layers by partially encoded and forwarded for decoding to the next layer using hash and greed Solomon algorithms. VMM monitoring uses snapshot algorithm to detect intrusion. The proposed system is compared with Tiang Wang method to validate efficiency of data transfer with security. Hence, security is proven against the indexed efficiency. It is an important study to integrate communication between local host software and nearer edge devices through different channels by verifying snapshot using lamport mechanism to ensure integrity and security at software level thereby reducing the latency. It also provides thorough knowledge and understanding about data communication at software level with VMM. The performance evaluation and feasibility study of security in FLRSC against three-layered approach is proven over 2³² blocks of data with 98% accuracy. Practical implications and contributions to the growing knowledge base are highlighted along with directions for further research.

• Journal of Digital Contents Society
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• v.9 no.1
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• pp.125-130
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• 2008

User web service is increasing by development of internet technology. Quantity of encrypted data that transmitted through the network are increasing by development of encipherment technology. We have many problems; it is caused by technical development and service increase of user requests. It is like that, we have reliability of contents and illegality copy problem of internet contents in web application system. It is contents protection skills in web that encipherment technology, authentication and digital signature. We need message encoding and secret key for solve vulnerability of encipherment in web application system. In this paper, we propose a distributed secure system that can data confidentiality and user authentication. It prevent performance degradation from bottle neck in encipherment server, and improve service quality.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.532-535
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• 2004

Architecture generation is the first step in the design of software systems. Most of the qualities that the final software system possesses are usually decided at the architecture development stage itself. Thus, if the final system should be usable, testable, secure, high performance, mobile and adaptable, then these qualities or non­functional requirements should be engineered into the architecture itself. In particular, adaptability is emerging as an important attribute required by almost all software systems. The machinery and tools in the remote site surveillance and connects intelligence information machinery and tools at Internet. We need the server which uses different embedded operating system to become private use. With the progress of information-oriented society, many device with advanced technologies invented by many companies. However, the current firmware technologies have many problems to meet such high level of new technologies. In this paper, we have successfully ported linux on an embedded system, which is based on intel StrongARM SA-1 1 10 processor, then written several network modules for internet-based network devices.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1655-1673
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• 2018

Mobile computing environment is subject to the constraints of bounded network bandwidth, frequently encountered disconnections, insufficient battery power, and system asymmetry. To meet these constraints and to gain high scalability, data broadcasting has been proposed on data transmission techniques. However, updates made to the database in any broadcast cycle are deferred to the next cycle in order to appear to mobile clients with lower data currency. The main goal of this paper is to enhance the transaction performance processing and database currency. The main approach involves decomposing the main broadcast cycle into a number of sub-cycles, where data items are broadcasted as they were originally sequenced in the main cycle while appearing in the most current versions. A concurrency control method AOCCRBSC is proposed to cope well with the cycle decomposition. The proposed method exploits predeclaration and adapts the AOCCRB method by customizing prefetching, back-off, and partial backward and forward validation techniques. As a result, more than one of the conflicting transactions is allowed to commit at the server in the same broadcast cycle which empowers the processing of both update and read-only transactions and improves data currency.