• Journal of KIISE:Information Networking
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• v.36 no.2
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• pp.118-129
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• 2009

The ISO 18000-7 Active RFID standard, a single channel system operating in the 433Mhz, faces technical difficulties in supporting some recently introduced application demands because of its low transmission rates and radio interference between readers. We propose a new multi-channel active RFID system operating in the 2.4Ghz. The special feature of the proposed system is that a reader makes use of multiple interfaces to improve its performance like a multi-core processor. However if only a small part of interfaces are actually used, the performance improvement would not meet the expectation. To overcome this problem, a new multi-channel multi-interface active RFID protocol, which balances communication loads among all available interfaces, is necessary. 3 protocols, named as "Aggregated", "LP-Combined", "AP-Balanced", are proposed. Through simulation, we compare them for various conditions by changing number of tags, number of interfaces, tag data size. AP-Balanced shows the best performance and its performance increases almost linearly as the number of interface increases, which meets our expectation.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.67-74
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• 2016

This paper presents a novel multiple orthogonal subcarrier modulation based UHF band RFID communication system. In tag-to-reader communication, the demonstration system can deliver 1.6 Mbps through four subcarriers. To improve data rate while suppressing increase in circuit complexity, tag employs square-waves as the subcarriers and uses individual load modulators for each subcarrier. By using multiple orthogonal subcarrier based modulation, proposed communication system can be operated under existing UHF band RFID regulation. In reader, an OFDM demodulator is used. Since the tag backscatters the reader's CW carrier, carrier frequency offset compensation is not necessary in reader demodulator. Experimental results show that the demonstration system achieves a bit error rate of 10-5 at an Eb/N0 of 10.8 dB.

• Annual Conference on Human and Language Technology
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• 2017.10a
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• pp.333-337
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• 2017

본 논문에서는 개체명 인식과 언어 모델의 다중 학습을 이용한 한국어 개체명 인식 방법을 제안한다. 다중 학습은 1 개의 모델에서 2 개 이상의 작업을 동시에 분석하여 성능 향상을 기대할 수 있는 방법이지만, 이를 적용하기 위해서 말뭉치에 각 작업에 해당하는 태그가 부착되어야 하는 문제가 있다. 본 논문에서는 추가적인 태그 부착 없이 정보를 획득할 수 있는 언어 모델을 개체명 인식 작업과 결합하여 성능 향상을 이루고자 한다. 또한 단순한 형태소 입력의 한계를 극복하기 위해 입력 표상을 자소 및 형태소 품사의 임베딩으로 확장하였다. 기계 학습 방법은 순차적 레이블링에서 높은 성능을 제공하는 Bi-directional LSTM CRF 모델을 사용하였고, 실험 결과 언어 모델이 개체명 인식의 오류를 효과적으로 개선함을 확인하였다.

• The Journal of Society for e-Business Studies
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• v.13 no.1
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• pp.21-32
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• 2008

RFID systems provide technologies of automatic object identification through wireless communications in invisible ranges and adaptability against various circumstances. These advantages make RFID systems to be applied in various fields of industries and individual life. However, it is difficult to use tags with distinction as tags are increasingly used in life because a tag usually stores only one object identifier in common RFID applications. In addition, RFID systems often make serious violation of privacy caused by various attacks because of their weakness of radio frequency communication. Therefore, information sharing methods among applications are necessary for expansive development of RFID systems. In this paper, we propose efficient RFID scheme. At first, we design a new RFID tag structure which supports many object identifiers of different applications in a tag and allows those applications to access them simultaneously. Secondly, we propose an authentication protocol to support the proposed tag structure. The proposed protocol is designed by considering of robustness against various attacks in low cost RFID systems. Especially, the proposed protocol is focused on efficiency of authentication procedure by considering security levels of applications. In the proposed protocol, each application goes through one of different authentication procedures according to their security levels. Finally, we prove efficiency of th proposed scheme compared with the other schemes through experiments and evaluation.

• KIISE Transactions on Computing Practices
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• v.23 no.6
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• pp.386-391
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• 2017

In this paper, we propose a system that automatically assigns user's experience-based emotion tags from wearable sensor data collected in real life. Four types of emotional tags are defined considering the user's own emotions and the information which the user sees and listens to. Based on the collected wearable sensor data from multiple sensors, we have trained a machine learning-based tagging system that combines the known auxiliary tools from the existing affective computing research and assigns emotional tags. In order to show the usefulness of this multi-modality-based emotion tagging system, quantitative and qualitative comparison with the existing single-modality-based emotion recognition approach are performed.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2006.06a
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• pp.1-4
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• 2006

본 논문에서는 보다 높은 보안 체계를 요구하는 환경에서 개인의 얼괄 인증과 RFID의 인증을 통한 다중 보안 시스템을 제안하고자 한다. 이 시스템은 추출된 얼굴 영상의 특징 벡터들을 각각 사용자의 태그에 저장하고 개인 인증 시 얼굴 영상의 입력과 비교 및 판독에 사용하도록 한다. 태그의 생체정보와 입력 얼굴영상에서 추출한 특징벡터가 일치하여야만 Database에 접근이 가능하며, 만약 하나라도 만족하지 못하면 인증은 실패한다. 이것은 사람의 얼굴뿐만 아니라 지문, 홍채 등의 생체인증 기술과 RFID와의 결합으로 보다 안전하고 효과적인 개인 인증 기술로 사용될 수 있을 것이다.

• Annual Conference on Human and Language Technology
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• 2015.10a
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• pp.99-103
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• 2015

최근 딥러닝 기술의 발전에 힘입어 이미지로부터 자동으로 관련된 단어 혹은 문장을 생성하는 연구들이 진행되고 있는데, 많은 연구들은 이미지와 단어가 1:1로 대응된 잘 정련된 학습 집합을 필요로 한다. 한편 스마트폰 보급의 확산으로 인스타그램, 폴라 등의 이미지 기반 SNS가 급속하게 성장함에 따라 인터넷에는 한 이미지의 복수개의 단어(태그)가 부착되어있는 데이터들이 폭증하고 있는 것이 현실이다. 본 논문에서는 소규모의 잘 정련된 학습 집합뿐 아니라 이러한 대규모의 다중 레이블 데이터를 같이 활용하여 이미지로부터 태그를 생성하는 개선된 CNN구조 및 학습알고리즘을 제안한다. 기존의 분류 기반 모델에 은닉층을 추가하고 새로운 학습 방법을 도입한 결과, 어노테이션 성능이 기존 모델보다 11% 이상 향상되었다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.1
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• pp.99-108
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• 2010

RFID(Radio Frequency IDentification) is a technology that automatically identifies objects containing the electronic tags by using radio wave. When there are some tags in the domain of the RFID reader, the mechanism that can solve a collision between the tags occurs is necessary. The multi tag identification problem is the core issue in the RFID and could be resolved by the anti-collision algorithm. However, RFID system has another problem. The problem id user information security. Tag response easily by query of reader, so the system happened user privacy violent problem by tag information exposure. In the case, RFID system id weak from sniffing by outside. In this paper, We study of security robustness for tree-walking algorithm, query tree algorithm and advanced query tree algorithm of tree based memoryless algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.807-812
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• 2015

In RFID system, when multiple tags respond simultaneously, a collision can occur. A method that solves this collision is referred as anti-collision algorithm. In 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. The PS algorithm divides the tags within the identification range of reader into smaller groups by increasing the transmission power incrementally and identifies them. In this paper, we propose a STAC/PS algorithm that the PS algorithm is applied in the STAC protocol. Through simulations, it is demonstrated that the collision rate for the proposed algorithm is about 50% lower than STAC protocol. Therefore, the STAC/PS algorithm can achieve faster tag identification speed compared with STAC protocol due to the low collision rate.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1443-1451
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• 2018

The genre of digital games is not a fixed and invariable system, but a generative system of revisions and changes. The purpose of this study is to define a concept of alternative genre for digital games. The alternative genre of digital games should be presented in combinations of various genre elements and reflected the genre awareness of the user. In this context, user tags of the game transform the classical genre concept into a family resemblance based categorization and establish a user-driven bottom-up genre system. User tags as the form of alternative genre can spread the 'small' genre through multiplicity of genre elements and strengthen the communicative function of the genre.