• International Commerce and Information Review
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• v.10 no.4
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• pp.153-169
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• 2008

The purpose of this paper is to review the major issues of between electronic trade and Ubiquitous computing. The rapidly developed environment by ubiquitous computing make the paradigm form e-trade to u-trade. This Article suggests an a-trade performance framework based on both field and literatures surveys. We propose some research subjects as well as practical implications for improving the performance of global c-trade under ubiquitous.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.347-347
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• 2006

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.2 s.344
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• pp.27-38
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• 2006

When an RFID reader attempts to read tags, interference might occur if the neighboring readers also attempt to communicate with the same tag at the same time or the neighboring readers use the same frequency at the same time. These interferences cause the RFID reader collision. When the RFID reader collision occirs, either the command from the reader can not be transmitted to the tags or the response from the tags can not be received by the reader correctly. RFID reader anti-collision algorithms have been developed to reduce it. One of the best blown reader anti-collision algorithms is the Colorwave algorithm proposed by MIT. The Colorwave algorithm reduces the reader collisions by having the readers operate at different times. In Colorwave the time is divided into frames and a frame is divided into a number of slots. Each reader can access the tags using the slot time assigned to it. Depending on the probability of the interference, the colorwave adjusts the frame size to improve the efficiency. In this paper, we analyze the operations and the performance of the Colorwave algorithm and identify the problems of the algorithm. We also show that by adding some modifications to the algorithm the performance can be improved significantly.

• Journal of electromagnetic engineering and science
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• v.7 no.1
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• pp.47-52
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• 2007

We investigated the effects of substrate, metal-line, and surface material on the performance of radio frequency identification(RFID) tag antenna using a tag antenna with a meander line radiator and T-matching network. The results showed that readability of the tag antenna with a thin high-loss substrate could be increased so that it was similar to that of a low-loss substrate if the substrate was very thin. The readability of the tag antenna decreased significantly when the metal line was thinner than the skin depth. The readability of the tag also decreased drastically when the tag was attached to high-permittivity high-loss target objects.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.519-523
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• 2010

In Gen-2 RFID system, the initial value of $Q_{fp}$, which is the slot-count parameter of Q-algorithm, is not defined in the standard. In this case, if the number of tags within the reader's identification range is small and we let the initial $Q_{fp}$ be large, the number of empty slot will be large. On the other hand, if we let the initial $Q_{fp}$ be small in spite of many tags, almost all the slots will be collided. As a result, the performance will be declined because the frame size does not converge to the optimal point quickly during the query round. In this paper, we propose a scheme to allocate the optimal initial $Q_{fp}$ through the tag number estimation before the query round begins. Through computer simulations, it is demonstrated that the proposed scheme achieves more stable performance than Gen-2 Q-algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.529-531
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• 2011

In Gen-2 Q-algorithm, the values of weight C, which is the parameter for incrementing or decrementing the slot-count size, are not defined in the standard. In this case, if the reader selects an inappropriate weight, there are a lot of empty or collided slots. As a result, the performance will be degraded because the frame size does not converge to the optimal point quickly during the query round. In this paper, we analyze how the performances of Gen-2 Q-algorithm will be affected by the weight value.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.677-681
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• 2010

This paper proposes a transmission probability control scheme for enhancing the performances of FSA-based RFID system. In order to maximize the system performance, the number of tags attempting to transmit their identifiers in a frame should be kept at a proper level. The reader calculates the transmission probability according to the number of tags within the identification range of reader and then broadcasts it to tags. Tags, in which their slot counter values reach to zero, attempt to transmit their identifiers with the received probability. Simulation results show that the proposed scheme can offer better throughput and delay performance than the conventional one regardless of the number of tags.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3997-4015
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• 2014

Radio frequency identification (RFID) is an emerging wireless communication technology which allows objects to be identified automatically. The tag anti-collision is a significant issue for fast identifying tags due to the shared wireless channel between tags and the reader during communication. The EPCglobal Class-1 Generation-2 which uses Q algorithm for the anti-collision is widely used in many applications such as consumer electronic device and supply chain. However, the increasing application of EPCglobal Class-1 Generation-2 which requires the dynamic environment makes the efficiency decrease critically. Furthermore, its frame length (size) determination and frame termination lead to the suboptimal efficiency. A new anti-collision algorithm is proposed to deal with the two problems for large-scale RFID systems. The algorithm has higher performance than the Q algorithm in the dynamic environment. Some simulations are given to illustrate the performance.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.209-216
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• 2013

RFID/USN, are recognized as the new growth engines for the future, regardless of the advanced and developing countries. RFID, in particular, already entered practical stage by global companies. EPCIS, which is the one of the EPC golabal network components, makes a huge load on the system due to the large amount of entering data by following events. In this study, a data model developed based on ER-WIN by collecting four kind information that occurred in the EPC global networks. This model supports both in processing of high performance and huge capacity of data by a considerable storage capacity and input speed. A simulation was developed in order to verify the performance. Each model tested several times and results were compared.

• ETRI Journal
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• v.33 no.3
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• pp.458-461
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• 2011

With the introduction of the new generation RFID technology, EPCglobal Class-1 Generation-2, there is considerable interest in improving the performance of the framed slotted Aloha (FSA)-based tag collision arbitration protocol. We suggest a novel time-optimal anti-collision algorithm for the FSA protocol. Our performance evaluation demonstrates that our algorithm outperforms other tag collision arbitration schemes.