scholarly journals Sound amplification by means of a horn-like roosting structure in Spix's disc-winged bat

2013 ◽  
Vol 280 (1772) ◽  
pp. 20132362 ◽  
Author(s):  
Gloriana Chaverri ◽  
Erin H. Gillam
Keyword(s):  
Sound Intensity ◽  
Sound Waves ◽  
Long Distance ◽  
Social Calls ◽  
Distance Communication ◽  
Group Members ◽  
Sound Amplification ◽  
Behavioural Experiments ◽  
Acoustic Horns ◽  
Thyroptera Tricolor

While sound is a signal modality widely used by many animals, it is very susceptible to attenuation, hampering effective long-distance communication. A strategy to minimize sound attenuation that has been historically used by humans is to use acoustic horns; to date, no other animal is known to use a similar structure to increase sound intensity. Here, we describe how the use of a roosting structure that resembles an acoustic horn (the tapered tubes that form when new leaves of plants such as Heliconia or Calathea species start to unfurl) increases sound amplification of the incoming and outgoing social calls used by Spix's disc-winged bat ( Thyroptera tricolor ) to locate roosts and group members. Our results indicate that incoming calls are significantly amplified as a result of sound waves being increasingly compressed as they move into the narrow end of the leaf. Outgoing calls were faintly amplified, probably as a result of increased sound directionality. Both types of call, however, experienced significant sound distortion, which might explain the patterns of signal recognition previously observed in behavioural experiments. Our study provides the first evidence of the potential role that a roost can play in facilitating acoustic communication in bats.

scholarly journals Social calls used by a leaf-roosting bat to signal location

2010 ◽  
Vol 6 (4) ◽  
pp. 441-444 ◽  
Author(s):  
Gloriana Chaverri ◽  
Erin H. Gillam ◽  
Maarten J. Vonhof
Keyword(s):  
Information Transfer ◽  
Mate Attraction ◽  
The Social ◽  
Social Calls ◽  
Group Members ◽  
Thyroptera Tricolor

Social calls in bats have many functions, including mate attraction and maintaining contact during flight. Research suggests that social calls may also be used to transfer information about roosts, but no studies have yet demonstrated that calls are used to actively attract conspecifics to roosting locations. We document the social calls used by Spix's disc-winged bat ( Thyroptera tricolor ) to actively recruit group members to roosts. In acoustic trials, we recorded two sets of calls; one from flying individuals termed ‘inquiry calls’, and another from roosting bats termed ‘response calls’. Inquiry calls were emitted by flying bats immediately upon release, and quickly (i.e. 178 ms) elicited production of response calls from roosting individuals. Most flying bats entered the roost when roosting individuals responded, while few bats entered the roost in the absence of a response. We argue that information transfer concerning roost location may facilitate sociality in T. tricolor , given the ephemeral nature of roosting structures used by this species.

scholarly journals A Long-Distance Communication Architecture for Medical Devices Based on LoRaWAN Protocol

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 940
Author(s):  
Nicoleta Cristina Gaitan
Keyword(s):  
Energy Consumption ◽  
Long Range ◽  
Medical Devices ◽  
Low Energy ◽  
Area Network ◽  
Wide Area Network ◽  
Long Distance ◽  
Communication Architecture ◽  
Low Energy Consumption ◽  
Distance Communication

Recent market studies show that the market for remote monitoring devices of different medical parameters will grow exponentially. Globally, more than 4 million individuals will be monitored remotely from the perspective of different health parameters by 2023. Of particular importance is the way of remote transmission of the information acquired from the medical sensors. At this time, there are several methods such as Bluetooth, WI-FI, or other wireless communication interfaces. Recently, the communication based on LoRa (Long Range) technology has had an explosive development that allows the transmission of information over long distances with low energy consumption. The implementation of the IoT (Internet of Things) applications using LoRa devices based on open Long Range Wide-Area Network (LoRaWAN) protocol for long distances with low energy consumption can also be used in the medical field. Therefore, in this paper, we proposed and developed a long-distance communication architecture for medical devices based on the LoRaWAN protocol that allows data communications over a distance of more than 10 km.

scholarly journals Quantum repeaters based on concatenated bosonic and discrete-variable quantum codes

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Filip Rozpędek ◽  
Kyungjoo Noh ◽  
Qian Xu ◽  
Saikat Guha ◽  
Liang Jiang
Keyword(s):  
Continuous Variable ◽  
Quantum Codes ◽  
Discrete Variable ◽  
Long Distance ◽  
Concatenated Code ◽  
Different Types ◽  
Optical Modes ◽  
Distance Communication ◽  
Quantum Repeaters ◽  
Quantum Error

AbstractWe propose an architecture of quantum-error-correction-based quantum repeaters that combines techniques used in discrete- and continuous-variable quantum information. Specifically, we propose to encode the transmitted qubits in a concatenated code consisting of two levels. On the first level we use a continuous-variable GKP code encoding the qubit in a single bosonic mode. On the second level we use a small discrete-variable code. Such an architecture has two important features. Firstly, errors on each of the two levels are corrected in repeaters of two different types. This enables for achieving performance needed in practical scenarios with a reduced cost with respect to an architecture for which all repeaters are the same. Secondly, the use of continuous-variable GKP code on the lower level generates additional analog information which enhances the error-correcting capabilities of the second-level code such that long-distance communication becomes possible with encodings consisting of only four or seven optical modes.

CONVERGENCE IMPROVEMENT OF ADAPTIVE LATTICE ALGORITHM WITH FUZZY BASED ADAPTIVE GAIN

1999 ◽  
Vol 09 (01n02) ◽  
pp. 125-132
Author(s):  
GEUN-TAEK RYU ◽  
DAE-SUNG KIM ◽  
DAE-YOUNG LEE ◽  
SUNG-HWAN HAN ◽  
HYEON-DEOK BAE
Keyword(s):  
Adaptive Filters ◽  
Communication Channel ◽  
Long Distance ◽  
Input And Output ◽  
Forward Prediction ◽  
Adaptation Procedure ◽  
Distance Communication ◽  
One Step ◽  
Input Variables ◽  
Lattice Algorithm

The choice of the adaptive gain is important to the performance of LMS-based adaptive filters. Depending on application areas, the realization structure of the filters is also important. This letter presents an adaptive lattice algorithm which adjusts the adaptive gain of LMS using fuzzy if-then rules determined by matching input and output variables during adaptation procedure. In each lattice filter stage, this filter adjusts the adaptive gain as the output of the fuzzy logic which has two input variables, normalized squared forward prediction error and one step previous adaptive gain. The proposed algorithm is applied to echo canceling problem of long distance communication channel. The simulation results are compared with NLMS on TDL and lattice structures.

Basic communication sciences

1969 ◽  
Vol 308 (1493) ◽  
pp. 183-198
Keyword(s):  
Long Distance ◽  
Earth Station ◽  
Early Communication ◽  
Technical Developments ◽  
Radiated Power ◽  
The Earth ◽  
Distance Communication ◽  
Quality Of Transmission ◽  
Communication Equipment

The feasibility and utility of long-distance communication via Earth-orbiting satellites has been demonstrated during recent years and it is appropriate therefore to focus attention on the more important scientific studies and technical developments that will be needed if full use is to be made of this valuable mode of communication in the future. The early communication satellites (the Telstar and Relay series) were pioneers in a relatively unknown propagation environment. The satellites themselves were conceptually simple and the communication equipment consisted essentially of a frequency-changing transponder with an r. f. power output of a few watts and a bandwidth some tens of megahertz. Carrier frequencies in the range 2 to 6 GHz were employed; typically either 2 or 6 GHz was used for transmission and 4 GHz for reception at the Earth station. To obtain an adequate signal/noise ratio at the output of the Earth station receiver, frequency modulation was employed, the frequency deviations being greater than those used on terrestrial microwave links. Launcher limitations and other factors meant that the satellites had to be placed in inclined elliptical orbits (see figure 1) with maximum heights of only a few thousand miles. Nevertheless, these satellites demonstrated that some hundreds of frequency-division multiplex telephony circuits, or a television channel, could be achieved with generally satisfactory quality of transmission. It is to be noted, however, that the satellite transponders accommodated only one, or at the most two, r. f. carriers at any time, and that the transmission performance was at times marginal due to limitations of the satellite effective radiated power. Furthermore, these relatively low orbit satellites provided communication in periods of generally less than an hour at a time and required continuous tracking by the Earth station aerials, due to movement of the satellites relative to the Earth.

scholarly journals Study of Optical Fiber Design Parameters in Fiber Optics Communications

2017 ◽  
Vol 2 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Salim Qadir Mohammed ◽  
Asaad M. Asaad M. Al-Hindawi
Keyword(s):  
Optical Fiber ◽  
Fiber Optics ◽  
Numerical Aperture ◽  
Design Parameters ◽  
Light Sources ◽  
Long Distance ◽  
Graded Index ◽  
Large Bandwidth ◽  
Telecommunication Infrastructure ◽  
Distance Communication

Fiber optics is an important part in the telecommunication infrastructure. Large bandwidth and low attenuation are features for the fiber optics to provide gigabit transmission. Nowadays, fiber optics are used widely in long distance communication and networking to provide the required information traffic for multimedia applications. In this paper, the optical fiber structure and the operation mechanism for multimode and single modes are analyzed. The design parameters such as core radius, numerical aperture, attenuation, dispersion and information capacity for step index and graded index fibers are studied, calculated and compared for different light sources.

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