• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.213-219
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• 2013

Recently, with the rapid advancement in information and communication technology, indoor location-based services(LBSs) that require precise position tracking have been actively studied with outdoor-LBS using GPS. However, in case of a ship which consists of steel structure, it is difficult to measure a precise localization due to significant ranging error by the diffraction and refraction of radio waves. In order to reduce location measurement errors that occur in these indoor environments, this paper presents distance compensation algorithms that are suitable for a narrow passage such as ship corridors without any additional sensors by using UWB(Ultra-wide-band), which is robust to multi-path and has an error in the range of a few centimeters in free space. These improvement methods are that Pythagorean theory and adjacent node technique are used to solve the distance error due to the node deployment and distance variation analysis technique is applied to reduce the ranging errors which are significantly fluctuated in the corner section. The experimental results show that the number of nodes and the distance error are reduced to 66% and 57.41%, respectively, compared with conventional CSS(Chirp spread spectrum) method.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.31-37
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• 2021

Recently, in the market of home appliances, the technical differentiation of products using convergence technology has been receiving a lot of response to satisfy consumer demand. However, air-conditioner products are an area that requires research and development in the early stages of convergence technology. In this paper, it is developed that a non-contact bio-signal(respiration, movement) collection technology using IR-UWB(Impulse-Radio Ultra Wideband) technology, which controls the air-conditioner direction according to the user's location and also monitors sleep to provide an optimal sleep environment. In addition, emotional lighting and ASMR are developed to provide a comfortable and emotional place of life. Finally, based on the developed convergence technology, we develop intelligent smart air-conditioning services for the convenience of daily life and a comfortable resting space.

• Journal of Korea Multimedia Society
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• v.15 no.10
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• pp.1228-1235
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• 2012

In this Paper, we propose an energy efficient localization technique based on WUSB (Wireless USB) over WBAN (Wireless Body Area Networks) protocol required for Wearable Computer systems. For this purpose, the proposed localization algorithm minimizes power consumption and estimates location without range information. It is executed independently on the basis of WUSB over WBAN protocol at each sensor node comprising peripherals of a wearable computer system. And it minimizes power consumption by estimating locations of sensor nodes with range-free method fast.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.129-132
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• 2019

본 기술의 발달에 따라 실내 공간이 점차 대형화되면서 실내공간은 복잡해졌으며, 이로 인해 원하는 장소를 찾기가 어려워졌다. 4차 산업혁명에 힘입어 앞서 언급한 문제들을 해결하기 위해 실내 내비게이션을 도입하려는 시도가 활발히 이루어지고 있다. 실내 내비게이션의 기술들로는 Wi-Fi, Bluetooth, Beacon, RFID, UWB 등이 있지만, 실내 건물 구조 특성상 여러 장애물들에 의해 신호 정보의 오차가 심하여 사용하기에 어려움이 있다. 이러한 문제점을 해결하기 위해 스마트폰에 내장된 IMU 센서 및 카메라 센서를 이용하여 동시적 위치 인식 및 지도 작성을 하는 SLAM 알고리즘으로 실내 내비게이션을 구현하고, 사용자가 보다 쉽게 길을 찾을 수 있게 접근성이 높은 스마트폰과 AR을 이용하여 어플리케이션을 설계하였다.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.231-238
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• 2022

In this paper, among short-range wireless communication technologies such as Beacon, Bluetooth, UWB (Ultra-wideband), ZigBee, NFC (Near Field Communication), Z-Wave, 6LoWPAN (IPv6 over Low power WPAN), D2D (Device to Device), etc., proposed an IoT service platform based on a beacon that can provide indoor positioning. And, a beacon-linked web server was designed by blocking indiscriminate beacon spam signals and applying REST web service technology with flexibility and scalability. Data accessibility between different devices was verified by testing the success rate of data transmission, the success rate of blocking beacon push, the success rate of IoT interlocking processing, the accuracy of location positioning, and the success rate of REST web service-based data processing. Through the designed IoT service platform, various proposals and research on short-distance-based business models and service platforms will be conducted in the future.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.270-275
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• 2012

This paper describes design of a variable-N frequency synthesizer for RF PLL with $0.13{\mu}m$ silicon CMOS technology being used as an application of the UWB system like MBOA. To get good performance of speed and noise super dynamic circuits was used, and to get variable-N division ratio MOSFET switching circuits was used. Especially to solve narrow bandwidth problem of the dynamic circuits load resistance value of unit divider block was varied. Simulation results of the designed circuit shows very fast and wide operation characteristics as 5~26GHz frequency range.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.1
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• pp.56-61
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• 2011

This paper describes design of a programmable frequency synthesizer for RF PLL with $0.18{\mu}m$ silicon CMOS technology being used as an application of the UWB system like MBOA. To get good performance of speed and noise super dynamic circuits was used, and to get programmable division ratio switching circuits was used. Especially to solve narrow bandwidth problem of the dynamic circuits load resistance value of unit divider block was varied. Simulation results of the designed circuit shows very fast and wide operation characteristics as 1~14GHz frequency range.

• Electronics and Telecommunications Trends
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• v.22 no.2 s.104
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• pp.48-57
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• 2007

본 고에서 다루고자 하는 지능형 로봇 공간(intelligent robotic space)은 이동성(mobility), 조작성(manipulability)으로 대표되는 로봇의 독특한 기능을 분산센싱, 분산처리환경을 구축하여 고기능화함으로써 자연스러운 이동, 조작기능의 구현이 가능한 공간으로 정의할 수 있다. 이는 개념적으로 가상 공간(virtual space), 추론 공간(semantic space), 물리 공간(physical space)으로 구성된다. 가상 공간은 로봇-센서간 융합을 통한 환경지도 작성 및 표현을 위한 플랫폼 기술이고 추론 공간은 로봇 및 로봇과 연동된 사람이나 사물의 상태 해석을 위한 객체 모델 기술이다. 물리 공간은 지능형이동성과 로봇 조작 능력의 향상을 위한 지능형 하드웨어 공간이다. 본 고에서는 물리공간에서 가장 핵심적인 이슈인 실내 측위기술에 대해서 알아본다. 측위기술은 사람이나 사물의 위치를 정밀하게 결정하여 로봇이 인간과 공존할 수 있도록 안정적이고 신뢰성 있는 측위 정보를 제공하는 것을 목적으로 한다. 지능형 로봇을 위한 측위기술은 크게 무선 센서네트워크 기반의 광역(coarse) 위치 결정과 RFID 및 로봇 비전(vision)을 기반으로 하는 정밀(fine) 위치 결정으로 나뉘어진다. 본 고에서는 Wi-Fi, ZigBee, UWB를 이용하는 무선 센서네트워크 기반의 실내 위치 측정에 관한 연구 개발 동향을 분석하고 각각의 기술이 가지는 장단점을 비교한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.42-52
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• 2012

In this paper, a waveguide antenna is designed and fabricated for side and rear radar sensor of vehicles in UWB (Ultra Wide Band) high band (center frequency : 9.5 GHz, -10 dB bandwidth : 600 MHz (6.4 %)). For the radar antenna, a probe fed rectangular waveguide antenna having simple structure and wide bandwidth is used. An important performance factor in this antenna is the isolation between transmitting (TX) and receiving (RX) waveguide antennas because this radar system uses TX and RX antennas separately. Thus the isolation between two antennas was simulated for E-plane and H-plane array. As a result, it was verified that the isolation of the H-plane array of the antennas is better than E-plane array, due to the TE10 mode. Therefore, H-plane arrayed waveguide antennas were mounted on a T-shaped radar module and performance of antennas was investigated. The -10 dB bandwidth of the TX and RX antenna mounted on T-shaped radar module was measured as 1000 MHz (10.52 %) and 1090 MHz (11.47 %) respectively and the isolation is less than -50 dB in the operation band. The peak gain is 7.65 dBi for the TX antenna and 7.26 dBi for the RX antenna and the beamwidth of H-plane of TX and RX antenna was measured as $64^{\circ}$ and $65^{\circ}$ respectively. Consequently, we verified that the proposed waveguide antenna is appropriate for a vehicle radar applications.

• Journal of Korea Multimedia Society
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• v.15 no.7
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• pp.885-890
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• 2012

In this Paper, we propose a Real-Time Localization Platform Built on WUSB (Wireless USB) over WBAN (Wireless Body Area Networks) protocol required for Wearable Computer systems. Proposed Real-Time Localization Platform Technique is executed on the basis of WUSB over WBAN protocol at each sensor node comprising peripherals of a wearable computer system. In the Platform, a WUSB host calculates the location of a receiving sensor node by using the difference between the times at which the sensor node received different WBAN beacon frames sent from the WUSB host. And the WUSB host interprets motion of the virtual object.