• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1826-1829
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• 2005

Recent advancement in wireless communications and electronics has enabled the development of low power sensor network. Wireless sensor network are often used in remote monitoring control applications, health care, security and environmental monitoring. Wireless sensor networks are an emerging technology consisting of small, low-power, and low-cost devices that integrate limited computation, sensing, and radio communication capabilities. Sensor network platform for health care has been designed, fabricated and tested. This system consists of an embedded micro-controller, Radio Frequency (RF) transceiver, power management, I/O expansion, and serial communication (RS-232). The hardware platform uses Atmel ATmega128L 8-bit ultra low power RISC processor with 128KB flash memory as the program memory and 4KB SRAM as the data memory. The radio transceiver (Chipcon CC1000) operates in the ISM band at 433MHz or 916MHz with a maximum data rate of 76.8kbps. Also, the indoor radio range is approximately 20-30m. When many sensors have to communicate with the controller, standard communication interfaces such as Serial Peripheral Interface (SPI) or Integrated Circuit ($I^{2}C$) allow sharing a single communication bus. With its low power, the smallest and low cost design, the wireless sensor network system and wireless sensing electronics to collect health-related information of human vitality and main physiological parameters (ECG, Temperature, Perspiration, Blood Pressure and some more vitality parameters, etc.)

• 한국멀티미디어학회논문지
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• 제24권9호
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• pp.1211-1223
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• 2021

Internet of Things(IoT) services have increased the demand for connectivity among electronics devices. As a result, various types of novel wireless communication technologies have been standardized and developed. In this paper, we evaluate the performance of low power wireless communication technologies such as Bluetooth, IEEE 802.15.4, DASH 7, IEEE 802.15.4g, LoRa, and SigFox in various environments. This is the first experiment evaluating various low power wireless communication technologies in real testbed. We expect that the evaluation results will be useful data to other researchers in applying the IoT technology in the future.

• 전기전자학회논문지
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• 제12권1호
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• pp.27-33
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• 2008

The demand of wireless communication is increased rapidly due to the development of wireless communication systems, and many people have the great interest about the "RF system". The trend of the RF audio system is to design the system with less power consumption. In this paper, we explain the Software Algorithm Design of RF systems that is suitable for low power consumption.

• 반도체공학회 논문지
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• 제2권1호
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• pp.9-16
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• 2024

본 논문에서는 무선 센서 네트워크를 위한 생체이식형 초저전력 MICS RF 트랜시버 설게에 대해 다룬다. 400 MHz MICS 표준은 WBAN 무선 센서 시스템 구현을 위해, 인체 내 전파적 특성 및 주변 네트워크와의 간접 최소화하며 고려되었다. 본 논문은 MICS 표준에 부합하는 시스템 및 송수신기 설계를 위한 link budget 및 다양한 송수신 아키텍쳐, 초저전력 송수신기 회로기법을 포함한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.782-785
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• 2002

Power amplifier of wireless communication tranceiver can be effectually controlled output power. And small size and low power dissipation are indispensable to portable system. In this paper, to reduce the size of portable tranceiver, inductor is integrated in a single chip. And to reduce power dissipation, a power amplifier that can be digitally controlled output power, is proposed and designed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.1111-1130
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• 2016

Cooperative communications can significantly improve the wireless transmission performance with the help of relay nodes. In cooperative communication networks, relay selection and power allocation are two key issues. In this paper, we propose a relay selection and power allocation scheme RS-PA-PSACO (Relay Selection-Power Allocation-Particle Swarm Ant Colony Optimization) based on PSACO (Particle Swarm Ant Colony Optimization) algorithm. This scheme can effectively reduce the computational complexity and select the optimal relay nodes. As one of the swarm intelligence algorithms, PSACO which combined both PSO (Particle Swarm Optimization) and ACO (Ant Colony Optimization) algorithms is effective to solve non-linear optimization problems through a fast global search at a low cost. The proposed RS-PA-PSACO algorithm can simultaneously obtain the optimal solutions of relay selection and power allocation to minimize the SER (Symbol Error Rate) with a fixed total power constraint both in AF (Amplify and Forward) and DF (Decode and Forward) modes. Simulation results show that the proposed scheme improves the system performance significantly both in reliability and power efficiency at a low complexity.

• ETRI Journal
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• 제45권4호
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• pp.570-580
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• 2023

Sensor nodes are the most significant part of a wireless sensor network that offers a powerful combination of sensing, processing, and communication. One major challenge while designing a sensor node is power consumption, as sensor nodes are generally battery-operated. In this study, we proposed the design of a low-power, long range-based wireless sensor node with flexibility, a compact size, and energy efficiency. Furthermore, we improved power performance by adopting an efficient hardware design and proper component selection. The Nano Power Timer Integrated Circuit is used for power management, as it consumes nanoamps of current, resulting in improved battery life. The proposed design achieves an off-time current of 38.17309 nA, which is tiny compared with the design discussed in the existing literature. Battery life is estimated for spreading factors (SFs), ranging from SF7 to SF12. The achieved battery life is 2.54 years for SF12 and 3.94 years for SF7. We present the analysis of current consumption and battery life. Sensor data, received signal strength indicator, and signal-to-noise ratio are visualized using the ThingSpeak network.

• Journal of Magnetics
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• 제8권1호
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• pp.74-78
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• 2003

The largest advantage of magnetic micromachine is wireless operation. This advantage makes it suitable for medical micromachine working inside the human body. In the medical field, low invasion treatment is very important From this point of view, very small machines working in the body without power supply cables meet the needs of the medical field. In this paper, we report about magnetic wireless actuators for medical applications.

• 한국인터넷방송통신학회논문지
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• 제14권4호
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• pp.85-90
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• 2014

ZigBee를 이용한 개인영역망으로 구성된 무선 다중 통합 레이저 교전 시스템을 구현하였다. 무선 레이저 검출기는 아날로그 신호처리, 해독 및 무선통신 기능을 갖추어야하는 반면 병사의 신체에 부착될 수 있도록 저전력소모, 소형 및 경량화 되어야한다. 소형 및 경량화를 위해 해독기는 소프트웨어적으로 구현하였고, 협대역 광학 필터를 이용하여 시스템의 부하를 줄여줌으로써 저전력화를 꽤하였다. 제작된 무선 레이저 검출기는 광잡음 환경에서도 정상 작동하였다. 무선 개인영역망을 통한 PU(Player Unit)와의 통신은 무선 레이저 검출기의 부착 위치에 따라 다소 차이가 있었으나 -40.2dBm이상의 출력으로 송신할 경우 100%의 수신율을 확보할 수 있었다.

• International Journal of Contents
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• 제7권1호
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• pp.1-7
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• 2011

A new power control algorithm for wireless communication which can be applied to various near distance communications and USN/RFID systems is proposed. This technique has been applied and tested to lithium coin battery operated UHF/microwave transceiver systems to show extremely long communication life time without battery exchange. The power control algorithm is based on the dynamic prediction method of arrival time for incoming packet at the receiver. We obtain 16mA current consumption in the TX module and 20mA current consumption in the RX module. The advantage provided by this method compared to others is that both master transceiver and slave transceiver can be low power consumption system.