• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.679-686
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• 2005

Because EPON access network shares a medium and aggregates the traffic from EPON subscribers, scheduling media access control on EPON bandwidth allocation is very important. Furthermore DBA mechanism of EPON based on TDMA is out of specification and up to implementation. This paper deals with a DBA method to guarantee the QoS of the delay sensitive traffic on the base of best-effort service and delay priority queue management. The proposed method performs virtual scheduling algorithm for the integrated traffic. It uses the same MAC messages and tries to guarantee the QoS of higher priority traffic first with a simple DBA architecture. We evaluate the algorithm for traffic delay according to polling interval and traffic load of upstream and downstream. The results show that the proposed method can guarantee the QoS of the delay sensitive traffic with priority of the service classes.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.221-228
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• 2007

For the usage of the different standard technology among DRM vendors, the DRM technologies in today could not guarantee the interoperability between the digital contents and digital devices. While users have been guaranteed the protection of contents, they have to put up with the limitation and inconvenience. The Superdistribution methods that InterTrust has proposed is the content distribution technology which is possible to use the content only by the user authentication with the license regardless of the acquisition of the DRM contents. However, it need a additional license with re-authentication from DRM server when the original contents need to be moved to other devices from the own device. In this paper, to reduce the inconveniences of re-authentication and re-issue procedures of the license and continually to protect the rights of contents on the offline, we propose the DRM system that creates domain between home devices and enable users to freely transfer contents with the domain.

• The KIPS Transactions:PartA
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• v.11A no.1
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• pp.81-88
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• 2004

In this paper, we designed the outer encoder/decoder for the terrestrial DMB that is an advanced digital broadcasting standard, implemented, and verified by using ALTERA FPGA. In the encoder part, it was created the parity bytes (16 bytes) from the input packet (188by1e) of MPEG-2 TS and the encoded data was distributed output by the convolutional interleaver for Preventing burst errors. In the decoder part, It was proposed the algorithm that detects synchronous character suitable to DMB in transmitted data from the encoder. The circuit complexity in RS decoder was reduced by applying a modified Euclid's algorithm. This system has a capability to correct error of the maximum 8 bytes in a packet. After the outer encoder/decoder algorithm was verified by using C language, described in VHDL and implemented in the ALTERA FPGA chips.

• The KIPS Transactions:PartB
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• v.15B no.5
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• pp.465-476
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• 2008

To provide autonomous and dynamic services for users in a ubiquitous environment where heterogeneity, mobility and variability are main characteristics, an efficient service description/structuring mechanism and a service composition method are essential. Service composition can consider context in real-time and compose appropriate services. In this research, we propose a mechanism for extracting services from a specific domain and structuring them into hierarchical service ontology. Each service is described using the proposed service specification. Based on this service ontology, users can represent their goals using various abstraction levels of services, and then our service overloading method enables to invoke the most appropriate service at the execution time. Moreover, we present a method which can discovery an alternative service by referencing the service ontology, when the requested service is not available. The experimental result shows that our service ontology could improve the success probability of users' goals and reduce service binding time compare to using just an unstructured list of services.

• The KIPS Transactions:PartC
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• v.16C no.5
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• pp.637-644
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• 2009

A study about performance analysis of synchronization clock using measured clock noises is required. Therefore this paper executed the study for performance analysis of synchronization clock and acquirement of maximum number of network node with various clock states using measured clock noises in NG-SDH networks. Also this paper generated a suitable clock model using measured clock noises, and carried out simulations with various clock states. Through the simulation results, maximum numbers were 80 or more network nodes in normal state, and were below 37 nodes in short-term phase transient(SPT) state, and were 50 or more in long-term phase transient(LPT) state. Accordingly this study showed that maximum numbers to meet ITU-T specification were below 37 network nodes in three clock states. Also this study showed that when SPT or LPT states occur from NE network before DOTS system, synchronization source must change with other stable synchronization source of normal state.

• The KIPS Transactions:PartD
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• v.12D no.1 s.97
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• pp.63-72
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• 2005

In this paper we describe interoperability maturity measurement, due to highlight a momentous issue on interoperability between heterogeneous distributed component based systems. it also suggests one of various ways for supporting interoperability between each other different component based systems, that is, using web services based mechanism and also revises 'LISI (Level of information systems interoperability)' model to measure interoperability maturity. We also develop the interoperability questionnaire based on the interoperability factors considered at each phase of component based development process, which is possible to measure interoperability maturity between heterogeneous distributed component systems. Based on revised interoperability maturity model and questionnaire we measure each interoperability maturity on examples of two different implementations, that is, web services and distributed object based mechanism. As a result, we suggest an enhanced interoperability way based on analysing problems af these measured results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.175-182
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• 2011

In this paper, we implemented a high-performence memory controller which can accommodate processing blocks(multiple masters) in SoC for video signal processing. The memory controller is arbitrated by the internal arbiter which receives request signals from masters and sends grant and data signals to masters. The designed memory controller consists of Master Selector, Mster Arbiter, Memory Signal Generator, Command Decoder, and memory Signal Generator. It was designed using VHDL, and verified using the memory model of SAMSING Inc. For FPGA synthesis and verification, Quartus II of ATERA Inc. was used. The target device is Cyclone II. For simulation, ModelSim of Cadence Inc was used. Since the designed H/W can be stably operated in 174.28MHz, it satisfies the specification of SDRAM technology.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.79-88
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• 2015

This paper introduces surveillance equipment "ADS-B", the core subject of traffic control system and study of ADS-B 1090ES ground receiver. The standard is set not only for functional but also its reliability by analyzing international standard documents and existing products. The Bias circuit is designed for less power consumption, low noise and high gain for RF module. The signal processing is capable of overcoming its bad conditions. MCU part is configured with the latest CPU for high speed communication with external parts and SNMP is selected for remote control communication. The performance of developed receiver satisfies national and international standards and its functions are more advanced compared to foreign receivers.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.12
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• pp.481-490
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• 2016

Bluetooth utilizes a symmetric key that is exchanged at the first pairing to establish a secure channel. There are four authentication modes which enables device authentication, Just work, Passkey Entry, Out of Band, and Numeric Comparison. Up to now, Just work has been considered as the authentication mode that is vulnerable to Man-In-The-Middle (MITM) Attack. In addition, it is possible to intentionally change any authentication mode to Just work mode, in order to succeed in MITM Attack under Just work mode. However, this kind of attacks have just worked under the assumption that users should not notice that authentication mode was changed. In this paper, We analyze the specification of Secure Simple Pairing, LE Legacy Pairing and LE Secure Connection Pairing. When using Passkey Entry mode on each approach, it seems the MITM attack is possible. Also it offers Passkey Entry MITM attack that does not require assumptions about the user's fault, because it isn't change verification process of the authentication mode unlike traditional attacks. We implement the proposed MITM attacks. Also we presents a scenario in which an attack can be exploited and a countermeasure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.205-214
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• 2012

IDPF, which builds formats and copyright protection standards of eBooks, has announced ePUB 3.0 as a technical standard of eBooks in October, 2011. This standard includes methods how to represent eBooks and technical specifications to protect eBook content. While technical specifications for content protection describe how to represent encryption and digital signature techniques, they do not identify any technical standards for rights expression but just file names for storages of rights information. It does not provide any unification of copyright information representation and formats used by eBook service companies. When copyright protection techniques for eBooks are used, comparability among eBook readers cannot be expected, even though there is a standard of ePUB. This study suggests a method to maintain compatibility toward eBook DRM by using unified rights information process under circumstances where different eBook service companies use diverse methods. The standard reference software of the model proposed in this study, together with other results of this study, will be offered as a registered open software.