• Journal of Communications and Networks
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• v.18 no.2
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• pp.246-260
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• 2016

A major challenge achieving scalable access control for a large number of subscribers in a public broadcast is to distribute key update messages reliably to all stateless receivers. However, in a public broadcast, the rekeying messages can be dropped or compromised during transmission over an insecure broadcast channel, or transmitted to receivers while they were off-line. In this study, we propose a novel group key management scheme. It features a mechanism to allow legitimate receivers to recover the current group key, even if they lose key update messages for long-term sessions. The scheme uses short hint messages and member computation. Performance analysis shows that the proposed scheme has the advantages of scalability and efficient rekeying compared to previous reliable group key distribution schemes. The proposed key management scheme targets a conditional access system in a media broadcast in which there is no feedback channel from receivers to the broadcasting station.

• Journal of Information Processing Systems
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• v.1 no.1 s.1
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• pp.55-61
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• 2005

In this paper we propose a distributed location management scheme to reduce the bottleneck problem of HLR in Large Mobile Networks (LMN). Using analytical modeling and numerical simulation, we show that replicating location information is both appropriate and efficient for small mobile networks. Then, we extend the scheme in a hierarchical environment to reduce the overhead traffic and scale to LMN. In numerical results, we show the superiority of our scheme compared to the current IS-95 standard scheme in IMT-2000 networks.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.82-88
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• 2021

In this paper, we propose an automatic detection scheme of work distraction for remote management of telecommuting. The proposed scheme periodically captures two consequent computer screens and generates the difference image of these two captured images. The scheme applies the difference image to our deep learning model and makes a decision of abnormal patterns in the difference image. Our deep learning model is designed with the transfer learning technique of VGG16 deep learning. When the scheme detects an abnormal pattern in the difference image, it hides all texts in the difference images to protect disclosure of privacy-related information. Evaluation shows that the proposed scheme provides about 96% detection accuracy.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.191-193
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• 2005

Flash memories are one of best media to support portable computer's storages. However, we need to improve traditional data management scheme due to the relatively slow characteristics of flash operation as compared to RAM memory. In order to achieve this goal, we devise a new scheme called Flash Two Phase Locking (F2PL) scheme for efficient data processing. F2PL improves transaction performance by allowing multi version reads and efficiently handling slow flash write/erase operation in lock management process.

• Korean Management Science Review
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• v.10 no.1
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• pp.1-22
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• 1993

Systemetic classification of a technology is critical to the development of technology strategy. This paper suggests a new technology classification scheme for computer and communication : a two-level scheme. Technology is first classified by its role and function in the upper level which forms a 2 * 2 matrix. The technology is then further classified into the lower level of 3 classes by associations among technology elements. Thus, a new classification scheme of 2 * 2 * 3 matrix is proposed for the computer and communication technology.

• ETRI Journal
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• v.36 no.1
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• pp.80-88
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• 2014

Recently, the idea of the smart grid has been gaining significant attention and has become a hot research topic. The purpose of this paper is to present a novel smart grid management scheme that uses game theory principles. In our proposed scheme, power appliances in the smart grid adaptively form groups according to the non-cooperative hedonic game model. By exploiting multi-appliance diversity, appliances in each group are dynamically scheduled in a cooperative manner. For efficient smart grid management, the proposed coopetition game approach is dynamic and flexible to adaptively respond to current system conditions. The main feature is to maximize the overall system performance while satisfying the requirements of individual appliances. Simulation results indicate that our proposed scheme achieves higher energy efficiency and better system performance than other existing schemes.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.50-58
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• 2007

We design a filtering management scheme with synchronization function under a realtime RFID middleware system for larger-scale data processing. The application interface(AI) is to support a various access protocol, HTTP, XML, JMS, and SOAP for the RFID applications. Generally, the synchronization problem is occurred in multiple accessing of clients for single filtering file. In this paper, we implement a filtering management scheme supporting the synchronization using the filter management process, and then demonstrate the RFID middleware filtering scheme.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.98-106
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• 2009

Process Control Systems (PCSs) or Supervisory Control and Data Acquisition (SCADA) systems have recently been added to the already wide collection of wireless sensor networks applications. The PCS/SCADA environment is somewhat more amenable to the use of heavy cryptographic mechanisms such as public key cryptography than other sensor application environments. The sensor nodes in the environment, however, are still open to devastating attacks such as node capture, which makes designing a secure key management challenging. In this paper, a key management scheme is proposed to defeat node capture attack by offering both forward and backward secrecies. Our scheme overcomes the pitfalls which Nilsson et al.'s scheme suffers from, and is not more expensive than their scheme.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1279-1289
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• 2000

Recently, research activities for combining portable computer technology and wireless communication technology are in progress to realize mobile computing environment that designed to support mobile hosts in the existing network environments. For PCN environments, the location management strategies are particularly emphasized among various strategies necessary for the mobile computing environment. Location management strategy for PCN environment, which is mostly based on the IS-41 standards brings an issue that additional network traffics are generated to deliver updata messages to home location server whenever a mobile host changes its location server. In this paper, we propose an innovative updata strategy and a search strategy that resolves the problem shown in the IS-41 scheme for HLR/VLR structure of CDMA environments. Also, this paper presents the performance comparison of proposed scheme and scheme used in IS-41 obtained from a simulation. The simulation was conducted based on the number of messages, the rate of database accesses, and the number of hops visited when the location management scheme is executed.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.216-223
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• 2002

This paper proposes an efficient location management scheme for next-generation cellular mobile networks. In the proposed scheme, the users are classified into two classes according to their mobility patterns; high mobility users (HMU) and low mobility users (LMU). We design the intelligent location management strategy based on theme user mobility classes. The performance of the proposed scheme is compared with that of pure intelligent paging scheme by computer simulation. As a result, it is shown that the proposed scheme provides the better performance than the pure intelligent paging scheme.