• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.766-769
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• 2005

In a ubiquitous environment made up of multiple sensors, most sensors participate in communications with limited battery, and the sensor node isn't able to participate in communications when all the battery is used up. When an existing authentication method is used for the sensor node which has to participate in a long term communication with limited battery, it creates a problem by making the length of network maintenance or sensor node's operation time relatively shorte. Therefore, a network structure where RM (Register Manager) node and AM (Authentication Manager) node are imported to solve the energy consumption problem during a communication process is presented in this thesis. This offers a low power protocol based on safety through a mutual authentication during communications. Through registration and authentication manager nodes, each sensor nodes are ensured of safety and the algorithm of key's generation, encryption/descramble and authentication is processed with faster operation speed. So the amount of electricity used up during the communications between sensor nodes has been evaluated. In case of the amount of electrical usage, an average of $34.783\%$ for the same subnet and 36.855 for communications with two different subnets, are reduced. The proposed method is a protocol which maintains the limited battery for a long time to increase the effectiveness of energy usage in sensor nodes and can also increase the participation rate of communication by sensor nodes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.5
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• pp.1735-1754
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• 2022

The reliability and performance of WiFi need optimization because of the rising number of WiFi users day by day. A highlighted point is saving power while transmitting and receiving packets using WiFi devices. Wake-on-Wlan (WoW) is also implemented to improve energy consumption, but it also needs betterment. This paper will introduce universal ideas to transmit and receive packets using low-power technology like Bluetooth or BLE (Bluetooth low energy). While looking for power-saving ways in this research, WiFi connection and maintenance also take care using lesser power-consuming technology. Identifying different use-cases where low power technology can help save energy and maintain 802.11 connection is part of the research. In addition, the proposed method discuss energy saving with unicast and broadcast/multicast data. Calculation of power-saving and comparison with standalone WiFi usage clearly shows the effectiveness of the proposed method.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.69-74
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• 2004

System-on-glass technology made with low temperature poly-Si TFT has been rapidly advancing in recent years. We have developed a low-power, narrow edged frame, 1.9inch system-on-glass LCD which fully integrates a 16-bit RGB interface driver and all power circuits required for driving the LCD. In this paper, the latest poly-Si TFT circuit technologies used in the newly developed LCD are discussed. The development trends are also reviewed.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.11
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• pp.497-505
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• 2001

The power system stabilizer(PSS) is important for the suppression of low-frequency oscillation and the improvement of system stability. In this paper, An Adaptive Neurofuzzy-based Power System Stabilizer(ANF PSS) is proposed as the new PSS type. The proposed PSS employs a multi-layer adaptive network. The network is trained directly from the input and the output of the generating unit. The algorithm combines the advantages of the Artificial Neural Network(ANN) and Fuzzy Logic Control(FLC) schemes. Studies show that the proposed ANF PSS can provide good damping of the power system over the wide range of operating conditions and improve the dynamic performance of the system.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.62-66
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• 2016

This paper presents a MedRadio-band low power low noise amplifier for Medical Devices. A proposed MedRadio-band low power low noise amplifier adopts a current-reuse resistive feedback topology to increase overall gm and reduce power consumption. The gain of the LNA increases by the Q-factor of the additional series RLC input matching network, and its noise figure is minimized by the similar factor. Furthermore, it consumes low power because of low supply voltage and current reuse technique. By exploiting the $g_m$-booting and matching network property, the proposed MedRadio-band low noise amplifier achieves a noise figure of 0.85 dB, a voltage gain of 30 dB, and IIP3 of -7.9 dBm while consuming 0.18 mA from a 1 V supply voltage in $0.13{\mu}m$ CMOS technology.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.184-187
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• 2000

A network is an important portion of communications in these days. Because of many inconveniences of a wired-network, wireless solutions have been studied for many years. One of the results of those efforts is IEEE 802.11, wireless LAN. This paper briefly summarizes wireless LAN and specially focuses on the design of a network processor for the wireless LAN system. The processor has 16-bit instruction set suitably selected for network processing and low-power consumption. It is implemented and verified with a wireless LAN system model. The wireless LAN system is modeled in RTL excluding the RF module. The processor can be used in many wireless systems as a controller and utilized as a test module for the research of low-power schemes.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.168-170
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• 2006

In this paper, authors realize water AMR(Automatic Meter Reading) network using low power ZigBee protocol included routing ability for improving wireless communitation error detection and network range. ZigBee wireless standard is an important standard of the field related Ubiquitous industry and recently has application to Home-Network. It's special features are to spend low power and to include routing ability each terminator. Because of these features, authors realize water AMR system on Embedded system using ZigBee protocol for applying to transfer data between a water meter and RF module equipped with a water meter in each house.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1599-1610
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• 2019

Intelligent services have expanded as Internet of Things (IoT) technology has evolved and new requirements emerge to accommodate various services. One new requirement is transmitting data over long distances with low-power. Researchers have developed low power wide area (LPWA) network technology to satisfy the requirement; this can improve IoT network infrastructure and increase the range of services. However, network coverage expansion causes several problems. The traffic load is concentrated at a specific gateway, which causes network congestion and leads to decreased transmission efficiency. Therefore, the approach proposed in this paper attempts to recognize and then avoid congestion through gateway channel hopping. The LPWA network employs multiple channels, so wireless channel hopping is available in a gateway. Devices that are not delay sensitive wait for the gateway to reappear on their wireless channel; delay sensitive devices change the wireless channel along the hopping gateway. Thus, the traffic load and congestion in each wireless channel can be reduced improving transmission efficiency. The proposed approach's performance is evaluated by computer simulation and verified in terms of transmission efficiency.

• Journal of Digital Contents Society
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• v.7 no.2
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• pp.103-108
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• 2006

Short-range wireless communication and networking technologies are becoming increasingly important in enabling useful mobile applications. for example, ZigBee technology is expected to provide low cost and low power connectivity for equipment that needs battery life as long as several months to several years. In addition, ZigBee can be implemented in mesh networks larger than is possible with Bluetooth. The main features of this ZigBee standard are network flexibility, low cost, very low power consumption, and low data rate in an adhoc self-organizing network among fixed, portable and moving devices. Home network/Home automation is one of the key market areas for Zigbee, with an example of a simple network This paper investigates the effect of short range wireless channel on the performance of Zigbee system and DSSS-BPSK signal transmission in AWGN, interference and Rician fading environments. And we investigate performance degradation due to interference and fading effects in short range wireless channel. In particular, the impacts of the fading and interference level on the bit error probability is shown in BER performance figures.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.6
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• pp.291-300
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• 2012

This paper deals with the design and implementation of wireless sensor network protocol for smart power outlet system capable of fire detection, power monitoring, standby power cutoff, and home automation. The proposed protocol integrates both the CSMA and the TDMA protocols for low power consumption and good scalability. A prototype smart power outlet system employing the proposed protocol and a simple home automation network including the power outlet system have been implemented for evaluating the feasibility of the proposed protocol The result shows that the proposed protocol allows the power outlet system to be scalable with high power efficiency.