• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.1-7
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• 2008

The general bus architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. Specially, as several masters do not concurrently receive the right of bus usage, the arbiter plays an important role in arbitrating between shared bus and masters. Fixed priority, round-robin, TDMA and Lottery methods are developed in general arbitration policies, which lead the efficiency of bus usage in shared bus. On the other hand, the bus architecture can be modified to maximize the system performance. In the paper, we propose the flying master bus architecture that supports the parallel bus communication and analyze its merits and demerits following various arbitration policies that are mentioned above, compared with normal shared bus. From the results of performance verification using TLM(Transaction Level Model), we find that more than 40% of the data communication performance improves, regardless of arbitration policies. As the flying master bus architecture advances its studies and applies various SoCs, it becomes the leading candidate of the high performance bus architecture.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.80-86
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• 2010

The conventional bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in arbitrating the bus. The efficiency of bus usage can be determined by the selection of arbitration method. Fixed Priority, Round-Robin, TDMA and Lottery arbitration policies are studied in the conventional arbitration method where the bus priority is primarily considered. In this paper, we propose the arbitration method that calculates the bus utilization of each master. Furthermore, we verify the performance compared with the other arbitration methods through TLM(Transaction Level Model). From the results of performance verification, the arbitration methods of Fixed Priority and Round-Robin can not set the bus utilization and those of TDMA and Lottery happen the error of 50% and 70% respectively compared with bus utilization set by user in more than 100,000 cycles. On the other hand, the bandwidth-award bus arbitration method remains the error of less than 1% since approximately 1000 cycles, compared with bus utilization set by user.

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.276-282
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• 2022

One of the most essential foundations upon which big institutions rely in delivering cloud computing and hosting services, as well as other kinds of multiple digital services, is the security of infrastructures for digital and information services throughout the world. Distributed denial-of-service (DDoS) assaults are one of the most common types of threats to networks and data centers. Denial of service attacks of all types operates on the premise of flooding the target with a massive volume of requests and data until it reaches a size bigger than the target's energy, at which point it collapses or goes out of service. where it takes advantage of a flaw in the Transport Control Protocol's transmitting and receiving (3-way Handshake) (TCP). The current study's major focus is on an architecture that stops DDoS attacks assaults by producing code for DDoS attacks using a cloud controller and calculating Round-Tripe Time (RTT).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.538-549
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• 2008

Recently IEEE 802.22 WG has considered Cognitive Radio (CR) technology to overcome shortage of communication channels. For using CR technology, accurate and rapid sensing method selection is extremely important. According to the channel sensing method, it is of the utmost importance because it can affect the incumbent system protection. So, optimum selection of channel sensing method is very important. IEEE 802.22 gives the solution, name of fine sensing, but the solution can not adapt to various networks. So in this paper we propose Policy-based Channel Sensing Architecture and Algorithms for Cognitive Radio Networks. The proposed channel sensing architecture and algorithms can reduce both primary system detection time and quiet time in our simulation. Among the proposed sensing algorithm, channel division round robin sensing reduce average detection time up to 70% compare to fine sensing method in IEEE 802.22.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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• pp.165-184
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• 2023

The ARX-based lightweight block cipher is widely used in resource-constrained IoT devices due to fast and simple operation of software and hardware platforms. However, there are three weaknesses to ARX-based lightweight block ciphers. Firstly, only half of the data can be changed in one round. Secondly, traditional ARX-based lightweight block ciphers are static structures, which provide limited security. Thirdly, it has poor diffusion when the initial plaintext and key are all 0 or all 1. This paper proposes a new dynamic ARX-based lightweight block cipher to overcome these weaknesses, called DABC. DABC can change all data in one round, which overcomes the first weakness. This paper combines the key and the generalized two-dimensional cat map to construct a dynamic permutation layer P1, which improves the uncertainty between different rounds of DABC. The non-linear component of the round function alternately uses NAND gate and AND gate to increase the complexity of the attack, which overcomes the third weakness. Meanwhile, this paper proposes the round-based architecture of DABC and conducted ASIC and FPGA implementation. The hardware results show that DABC has less hardware resource and high throughput. Finally, the safety evaluation results show that DABC has a good avalanche effect and security.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.54-61
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• 2017

Strengthening the protection and management of very old trees is an important aspect of urban site preservation, urban design and construction. Rating various danger factors to evaluate the degree of danger posed can help to create the correct protective countermeasures. In order to develop the danger evaluation index, this study performed four round surveys by using the Delphi method and collected opinions from experts in related fields. Necessary indexes were fully added in the first and second round while the indexes falling beyond the guidelines were deleted. From the final analysis results, five areas derived a total of forty-one indicators to create a degree of danger index from vigour status, growth and development status, diseases and insect pests, soil status, and management status. The degree of danger evaluation index can provide basic data for the protection of very old trees.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.42-47
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• 2011

This study aims to choose installation location of wind power system and analyze influence factors of wind power system by shape of super high-raise building by using CFD simulation. As a result of this study, wind power system is more applicable to streamlined building than normal building. Round openings are seemed to be the most efficient shape for building integrated wind power system in types applying venturi effect. Safety and vibration should be considered in the case of application of wind power system between the buildings.

• Journal of IKEEE
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• v.12 no.4
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• pp.246-254
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• 2008

This paper represents a design of a 4 way SIMD processor with multi-thread and dual phase instruction pipeline. 8 threads can be performing in round-robin order, so any hazards can’t occur. The dual phase pipeline makes a pipeline operate as two pipelines, and it can fetch maximum 4 unit instructions at once. This variable length instruction set divide into first phase and second phase instructions, and with this function, complex branch and addressing can be executed at one clock cycle. This processor reduces the code size to quarter, pull out the doubled performance improvement than normal SIMD architecture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.79-95
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• 2016

In order to improve the Quality-of-Service (QoS) of latency sensitive applications in next-generation cellular networks, multi-path is adopted to transmit packet stream in real-time to achieve high-quality video transmission in heterogeneous wireless networks. However, multi-path also introduces two important challenges: out-of-order issue and reordering delay. In this paper, we propose a new architecture based on Software Defined Network (SDN) for flow aggregation and flow splitting, and then design a Multiple Access Radio Scheduling (MARS) scheme based on relative Round-Trip Time (RTT) measurement. The QoS metrics including end-to-end delay, throughput and the packet out-of-order problem at the receiver have been investigated using the extensive simulation experiments. The performance results show that this SDN architecture coupled with the proposed MARS scheme can reduce the end-to-end delay and the reordering delay time caused by packet out-of-order as well as achieve a better throughput than the existing SMOS and Round-Robin algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.2009-2014
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• 2012

The general bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in bus arbitration. In compliance with the selection of arbitration method, The efficiency of bus usage can be determined. Fixed Priority, Round-Robin, TDMA, Lottery arbitration are studied in conventional arbitration method. In this paper, we draw the performance comparison of TDMA and Lottery bus arbitration policy developed recently due to farious conditions and propose the methods of performance improvement.