• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.283-290
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• 2012

In this paper, a system for wake-up method for T-DMB AEAS is introduced. Wake-up function is important in emergency alert service. But there was no AEAS receiver that has the method. Google C2DM is efficient method for wake-up in android platform. So this paper suggests wake-up method in android smartphone with T-DMB by C2DM. This method will be an alternative plan until native broadcasting wake-up technology.

• International Journal of Industrial Entomology and Biomaterials
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• v.20 no.1
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• pp.19-24
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• 2010

Bumblebees are widely used to pollinate crops in greenhouses and fields. Here, we investigated whether different wake-up treatments during a short period of 1~3 days just before indoor rearing has any effects on oviposition and colony development of $CO_2$-treated Bombus ignitus queens and artificially hibernated B. terrestris queens The wake-up regimes were defined as 16L for 1 day (16L-1), 16 L per day for 3 days (16L-3), 24L for 1 day (24L-1), or 24D for 1 day (24D-1). Among these wake-up treatments, the oviposition rate and preoviposition period of B. ignitus queens reared at 24L-1 were 16.7~25.1% higher and 1.0~3.5 days shorter than other wake-up treatments. B. terrestris queens reared at 24L-1 also showed the best results for egg-laying characteristics, which were 8.9~18.8% higher for oviposition and 0.6~3.5 days shorter for preovipostion period than other wake-up treatments. Furthermore, B. terrestris queens reared at 24L-1 were 17.5% and 13.8% higher in rate of colony foundation and queen production, respectively, than other wake-up treatments. These results show that the most favorable wake-up treatment just before rearing for egg-laying and colony developmental characteristics of B. ignitus and B. terrestris queens was 24L-1. Overall, our findings indicate that a wake-up treatment just before rearing was effective for colony initiation and colony development of bumblebee queens.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.187-192
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• 2017

In dense deployments of sensor nodes in Wireless Sensor Networks, the MAC protocol has challenges to solve problems such as reducing delivery delay and reducing energy consumption. To solve these problems lots of protocols are suggested. This paper proposed a sensor nodes' residual energy based wake-up control mechanism, in which each node decides whether it wakes up or stays in sleep mode to save energy consumption by reducing unnecessary idle listening. The main idea of the wake-up control mechanism is to save node's energy consumption. The proposed wake-up control mechanism is based on the RI-MAC protocol, which is one of the receiver-initiated MAC protocols. A receiver node in the proposed mechanism periodically wakes up and broadcasts a beacon signal based on the energy status of the node. A receiver node also adjusts wake-up period based on the traffics. Results have shown that the proposed MAC protocol outperformed RI-MAC protocol in the terms of energy consumption.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.1
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• pp.1-12
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• 2000

The wake geometries of a two-bladed rotor in axial flights using a time-marching free-wake method without a non-physical model of the far wake are calculated. The computed free-wake geometries of AH-1G model rotor in climb flight are compared with the experimental visualization results. The time-marching free-wake method can predict the behavior of the tip vortex and the wake roil-up phenomena with remarkable agreements. Tip vortices shed from the two-bladed rotor can interact with each other significantly. The interaction consists of a turn of the tip vortex from one blade rolling around the tip vortex from the other. Wake expansion of wake geometries in radial direction after the contraction is a result of adjacent tip vortices begging to pair together and spiral about each other. Detailed numerical results show regular pairing phenomenon in the climb flights, the hover at high angle of attack and slow descent flight too. On the contrary, unstable motions of wake are observed numerically in the hover at low angle of attack and fast descent flight. It is because of the inherent wake instability and blade-vortex-interaction rather then the effect of recirculation due to the experimental equipment.

• Journal of Internet of Things and Convergence
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• v.8 no.2
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• pp.1-6
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• 2022

This paper presents a regionalized time slotted channel hopping (TSCH) slotframe-based aerial data collection using wake-up radio. The proposed scheme aims to minimize the delay and energy consumption when an unmanned aerial vehicle (UAV) collects data from sensor devices in the large-scale service area. To this end, the proposed scheme divides the service area into multiple regions, and determines the TSCH slotframe length for each region according to the number of cells required by sensor devices in each region. Then, it allocates the cells dedicated for data transmission to the TSCH slotframe using the ID of each sensor device. For energy-efficient data collection, the sensor devices use a wake-up radio. Specifically, the sensor devices use a wake-up radio to activate a network interface only in the cells allocated for beacon reception and data transmission. The simulation results showed that the proposed scheme exhibited better performance in terms of delay and energy consumption compared to the existing scheme.

• ETRI Journal
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• v.38 no.5
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• pp.799-806
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• 2016

In this paper, we propose an emergency wake-up alert system (EWAS) for providing accurate and rapid emergency information. The proposed system can provide an emergency wake-up alert service without an additional frequency allotment by utilizing the guard band of the Advanced Television Systems Committee (ATSC) Terrestrial Digital Television (DTV) system. The design target of the proposed system is to match the indoor reception coverage of EWAS with the outdoor reception coverage of the ATSC DTV system. To achieve this, the proposed system should be about 35.65 dB more robust than the ATSC DTV system. The simulation results show that the proposed system offers an emergency wake-up alert service supporting a data rate of up to 23 bps.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.377-383
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• 2012

In this paper, a new design of a planar rectenna system and its application to a wake-up receiver operating for incoming signal with a specified frequency are proposed for low-power sensor system applications. The planar and integrable rectenna system is designed with DGSs(Defected Ground Structures) at 2.4 GHz. The DGSs reject harmonic components of 4.8 and 7.2 GHz and eliminate 2.4 GHz fundamental frequency for DC-path filtering. The rectenna system has been evaluated for the conversion output voltages, and applied to the switching of a power supply at the low-power sensor receivers. The proposed system has been evaluated for the wake-up performance by testing a lownoise amplifier operation. From the experimental results, the proposed receiver system presents excellent operation performances.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.77-83
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• 2004

In low-power VLSI systems, it is effective to suppress leakage current by shutting down megablocks in idle states. Recently, multi-threshold voltage CMOS (MTCMOS) is widely accepted to shutdown power supply. However, it requires short wake-up time as operating frequency increases. This causes large current surge during wake-up process, and it often leads to system malfunction due to severe Power line noise. In this paper, a novel wake-up scheme is proposed to solve this problem. It exploits pipelined wake-up strategy in several stages that reduces maximum current on the power line and its corresponding power line noise. To evaluate its efficiency, the proposed scheme was applied to a multiplier block in the Compact Flash memory controller chip. Power line noise in shutdown and wake-up process was simulated and analyzed. From the simulation results, the proposed scheme was proven to greatly reduce the power line noise compared with conventional schemes.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.76-81
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• 2002

A numerical simulation of wake behavior behind three-dimensional wings in ground effect is done using an indirect boundary element method (Panel Method). An integral equation is obtained by applying Green's 2nd Identity on all surfaces of the flow domain. The AIC is constructed by imposing the no penetration condition on solid surfaces, and the Kutta at the wing's trailing edge. The ground effect is included using an image method. At each time step, a row of wake panels from wings' trailing edge are convected downstream following the force-free condition. The roll-up of wake vortices behind wings in close proximity is simulated.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.3
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• pp.152-156
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• 2009

This paper designs and implements wake up module for WBAN/USN sensor node which is using dynamic reference voltage demodulation circuit. When a comparator is used in a system for detecting received voltage level, comparator must have a reference voltage. However, the reference voltage is fixed, the system can communicate only a few range because received voltage level is changing widely due to distance of the wireless sensor nodes. Therefore, the proposed wake up module employs a dynamic reference voltage demodulation circuit for increasing communication range.