• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.350-351
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• 2017

스마트폰과 같은 모바일 기기의 발달과 함께 사용자의 위치에 기반한 다양한 서비스가 출현하고 있다. 그중 사용자의 위치를 기준으로하는 길안내 서비스가 가장 대표적이다. GPS에 기반한 실외 중심의 길안내는 다양한 비콘과 WiFi 등의 기술과 함께 실내에서도 길안내 서비스가 가능하도록 해주고 있다. 하지만, 상기의 사용자 위치에 대한 길안내 서비스는 거리에 대한 인식 단계가 세밀하지 못하기에 해당거리별 상세 서비스가 어려운 것이 현실이다. 이에 본 논문에서는 기존 BLE 비콘의 Immediate, Near, Far의 3단계 거리인식을 6단계까지 확장하여 보다 상세한 안내가 가능한 실내 길안내 서비스를 제안한다. 또한 편의적 기능을 위해 목적지 입력 및 길안내가 음성에 기반하여 구동될 수 있도록 구현하였다.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.501-502
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• 2018

ICT기술은 소프트웨어와 하드웨어의 모든 분야에서 비약적으로 발전을 거듭하고 있다. 이에 따라, 기업에서 전통적으로 사용되어 오는 경영정보시스템들도 다양한 형태로 개선되거나 융합되어지고 있다. 특히, 재택근무, 이동근무, 원격 협업 등의 ICT기술 활용하여 시간과 장소에 얽매이지 않고 업무를 수행하는 스마트워크는 기업의 근무행태에 대한 패러다임을 바꿀 것으로 기대를 받고 있다. 본 논문에서는 이러한 스마트워크의 일환으로 BLE(Bluetooth Low Energy Beacon)을 이용한 모바일 형태의 그룹웨어 시스템을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.05a
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• pp.445-446
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• 2018

최근 무인항공기 (Unmanned Aerial Vehicle, UAV)에 장착한 카메라를 활용하여 사용자의 눈높이가 아닌 새로운 시각에서 사용자를 촬영한 영상을 제공한다. 사용자를 추적하며 촬영하기 위해 저전력 블루투스 (Bluetooth Low Energy, BLE) 신호, 영상, 그리고 Natural User Interface/Natual User Experience(NUI/NUX) 기술을 활용한다. BLE 신호로 사용자를 추적하는 경우 사용자의 후방에서 추적하며 사용자만을 추적하며 촬영 가능한 문제가 있다. 하지만 복수의 사용자를 전방에서 추적하며 촬영하는 방법이 필요하다. 본 논문에서는 복수의 사용자를 추적하며 전방에서 촬영하기 위해 UAV의 비행방향을 결정하는 방법을 설명한다. 복수의 사용자로부터 측정 가능한 BLE 신호들을 UAV에서 측정한다. 복수개의 BLE 신호의 변화를 활용하여 UAV의 비행방향을 결정한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.520-522
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• 2015

저전력 블루투스(BLE, Bluetooth Low Energy)를 이용해 사람이나 사물의 위치를 파악하는 근거리 무선 통신 기술을 제공한다. 과거에는 GPS로 건물 밖의 이동 데이터만 확인 가능 했다면, Beacon은 실내에서의 객체 이동 위치 데이터와 이동 경로를 측정 할 수 있는 기술이다. 본 애플리케이션에서는 BLE를 통한 비콘셀이 항시 ID를 주변으로 뿌리고, 이를 인식한 단말기가 수신한 ID를 통해 Beacon 서비스 서버에 접속하여 정보를 받는 방식으로, Beacon이 설치된 장소에서 특정 범위 안에 있는 단말기기는 Beacon 서버를 통하여 관광지의 정보 서비스를 제공한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1172-1177
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• 2008

To compensate voltage error of the channel selecting filter, a current comparison type voltage tuning circuit is designed. Because the proposed current comparison type voltage tuning circuit is not need to attach another subcircuit, the chip size can be reduced, therefore the proposed circuit is very useful in the low voltage and low power channel filter. We used three channels including bluetooth communication system as application circuits of the proposed tuning circuit. As the results of HSPICE simulation using $0.18{\mu}m$ CMOS technology verify that the proposed tuning circuit respectively can be operated in $12{\mu}s$, $13{\mu}s$ and $15{\mu}s$ in three channel.

• Journal of IKEEE
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• v.24 no.3
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• pp.838-844
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• 2020

In this paper, we propose an efficient Viterbi processor using Joint Viterbi detection and decoding (JVDD) algorithm for a for bluetooth low energy (BLE) system. Since the convolutional coded Gaussian minimum-shift keying (GMSK) signal is specified in the BLE 5.0 standard, two Viterbi processors are needed for detection and decoding. However, the proposed JVDD scheme uses only one Viterbi processor by modifying the branch metric with inter-symbol interference information from GMSK modulation; therefore, the hardware complexity can be significantly reduced without performance degradation. Low-latency and low-complexity hardware architecture for the proposed JVDD algorithm was proposed, which makes Viterbi decoding completed within one clock cycle. Viterbi Processor RTL synthesis results on a GF55nm process show that the gate count is 12K and the memory unit and the initial latency is reduced by 33% compared to the modified state exchange (MSE).

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.2
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• pp.104-111
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• 2008

The ECG is biomedical electrical signal occurring on the surface of the body due to the contraction and relaxation of the heart. This signal represents an extremely important measure for health monitoring, as it provides vital information about a patient's cardiac condition and general health. ECG signals are contaminated with high frequency noise such as power line interference, muscle artifact and low frequency nose such as motion artifact. But it is difficult to filter nose from ECG signal, and errors resulting from filtering can distort a ECG signal. The present study implemented a small-size and low-power ECG measurement system that can remove motion artifact for convenient health monitoring during daily life. The implemented ECG monitoring system consists of ECG amplifier, a low power microprocessor, bluetooth module and monitoring program. Amplifier was designed and implemented using low power instrumentation amplifier, and microprocessor was interfaced to the ECG amplifier to collect the data, process, store and feed to a transmitter. And bluetooth module used to wirelessly transmit and receive the vital sign data from the microprocessor to an PC at the receiving site. In order to evaluate the performance of the implemented system, we assessed motion artifact rejection performance in each situation with artificially set condition using adaptive filter.

• Journal of Digital Contents Society
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• v.18 no.5
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• pp.803-810
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• 2017

Currently, every person possesses a smart phone due to the development of the IT industry. There is an improper situation in which a smart phone is not set in silent mode, such as a lecture room, a library, and a theatre hall. The proposed system automatically automates the function of smart phones where they are designated as a public place or etiquette area and automatically return the function of the smartphone if they deviate from the location of the site. It is also equipped with a combination of autonomous devices and services, based on Bluetooth communications, which are applied to ultra-light low-power IoT(Internet of Things) devices, and has features that allow diverse types of features and services to be added without requiring deformation of the hardware.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.160-172
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• 2018

The method of estimating a position using a GPS has been applied to various fields including a navigation system of an automobile. However, since it is difficult to measure GPS signals indoors, it is difficult to locate specific objects indoors such as a building or factory. To overcome these limitations, this study proposes a system for object location estimation based on Bluetooth5 for the management of materials in factories. The object position estimation system consists of a Bluetooth signal generator, a receiver, and a database server. A signal generator based on Bluetooth Low Energy(BLE) is attached to the material and a receiver is appropriately arranged inside the factory. In this study, we propose "Diagonal Survey Method", a 4 - axis survey algorithm using four receivers to reduce the error of existing trilateration method. The proposed algorithm showed good performance compared to the conventional trilateration and we verified the effectiveness of the proposed system and algorithm by performing the experiment by installing the system in the factory.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.137-143
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• 2009

Through the development of techniques, robots are becomes smaller, and many of robots needed for application are greater and greater. Method of coordinating large number of autonomous robots through local interactions has becoming an important research issue in robot community. Swarm Robot System is a system that independent autonomous robots in the restricted environment infer their status from preassigned conditions and operate their jobs through the coorperation with each other. Within the SRS,a robot contains sensor part to percept the situation around them, communication part to exchange information, and actuator part to do a work. Specially, in order to cooperate with other robots, communicating with other robot is one of the essential elements. In such as Bluetooth has many adventages such as low power consumption, small size module package, and various standard procotols, it is rated as one of the efficent communcating system for autonomous robot is developed in this paper. and How to construct and what kind of procedure to develop the communicatry system for group behavior of the SRS under intelligent space is discussed in this paper.