Acoustical Ranging Techniques in Embedded Wireless Sensor Networked Devices

Location sensing provides endless opportunities for a wide range of applications in GPS-obstructed environments; where, typically, there is a need for higher degree of accuracy. In this article, we focus on robust range estimation, an important prerequisite for fine-grained localization. Motivated by the promise of acoustic in delivering high ranging accuracy, we present the design, implementation and evaluation of acoustic (both ultrasound and audible) ranging systems.We distill the limitations of acoustic ranging; and present efficient signal designs and detection algorithms to overcome the challenges of coverage, range, accuracy/resolution, tolerance to Doppler’s effect, and audible intensity. We evaluate our proposed techniques experimentally on TWEET, a low-power platform purpose-built for acoustic ranging applications. Our experiments demonstrate an operational range of 20 m (outdoor) and an average accuracy 2 cm in the ultrasound domain. Finally, we present the design of an audible-range acoustic tracking service that encompasses the benefits of a near-inaudible acoustic broadband chirp and approximately two times increase in Doppler tolerance to achieve better performance

Insights into carbonate environmental conditions in the Chukchi Sea

Healthy Arctic marine ecosystems are essential to the food security and sovereignty, culture, and wellbeing of Indigenous Peoples in the Arctic. At the same time, Arctic marine ecosystems are highly susceptible to impacts of climate change and ocean acidification. While increasing ocean and air temperatures and melting sea ice act as direct stressors on the ecosystem, they also indirectly enhance ocean acidification, accelerating the associated changes in the inorganic carbon system. Yet, much is to be learned about the current state and variability of the inorganic carbon system in remote, high-latitude oceans. Here, we present time series (2016–2020) of pH and the partial pressure of carbon dioxide (pCO2) from the northeast Chukchi Sea continental shelf. The Chukchi Ecosystem Observatory includes a suite of subsurface year-round moorings sited amid a biological hotspot that is characterized by high primary productivity and a rich benthic food web that in turn supports coastal Iñupiat, whales, ice seals, walrus (Odobenus rosmarus), and Arctic cod (Boreogadus saida). Our observations suggest that near-bottom waters (33 m depth, 13 m above the seafloor) are a high carbon dioxide and low pH and aragonite saturation state (Ωarag) environment in summer and fall, when organic material from the highly productive summer remineralizes. During this time, Ωarag can be as low as 0.4. In winter, when the site was covered by sea ice, pH was &lt;8 and Ωarag remained undersaturated under the sea ice. There were only two short seasonal periods with relatively higher pH and Ωarag, which we term ocean acidification relaxation events. In spring, high primary production from sea ice algae and phytoplankton blooms led to spikes in pH (pH &gt; 8) and aragonite oversaturation. In late fall, strong wind-driven mixing events that delivered low-CO2 surface water to the shelf also led to events with elevated pH and Ωarag. Given the recent observations of high rates of ocean acidification and a sudden and dramatic shift of the physical, biogeochemical, and ecosystem conditions in the Chukchi Sea, it is possible that the observed extreme conditions at the Chukchi Ecosystem Observatory are deviating from the carbonate conditions to which many species are adapted.</p

Decoupling and context in new media art

This dissertation presents a novel characterization of new media art, centered on media appropriation: the dialectal insertion of technological knowledge into the art practice. The thesis identifies some defining characteristics of new media art’s language, and indicates the defining role that explicitation plays. While media appropriation is not necessarily linked to the digital realm, it provides a natural substratum for it and so this thesis analyzes some aspects of the relationship between art and technology, where it introduces the user–programmer continuum and the perceptual cloud, a new paradigm of human–computer interaction that emerges from the functional and geographical decoupling of the computational and perceptual layers of interactive systems. Next, it analyzes the sociopolitical inscription of new media art, integrating the economic and political contexts of its practice into the analysis and providing a new reflection on new media art production from the geopolitical periphery. This thesis is proposed as a hybrid research–practice. A selected subset of the artworks created are presented and analyzed within the dissertation’s conceptual framework.Esta disertación presenta una nueva caracterización del new media art, centrada en la apropiación de los medios, es decir, en la inserción dialéctica de conocimiento tecnológico dentro de la práctica artística. La tesis identifica algunas características definitorias del lenguaje del new media art, e identifica el rol fundamental que la explicitación juega. Aunque la apropiación de los medios no está necesariamente unida a lo digital, éste provee un substrato natural para ella. Por ello, esta tesis analiza algunos aspectos entre el arte y la tecnología digital, introduciendo el continuo usuario\2013programador y la nube perceptual, un nuevo paradigma de interacción humano\2013computadora que emerge del desacople funcional y geográfico de las capas computacionales y perceptuales de los sistemas interactivos. A continuación, se analiza la inscripción sociopolítica del new media art, integrando los contextos económico y político, proveyendo una nueva reflexión acerca de la producción artística desde la periferia geopolítica. Esta tesis se propone como un híbrido investigación\2013producción. Un subconjunto seleccionado de las obras creadas durante el programa son presentadas y analizadas desde el marco conceptual de la disertación

A survey on acoustic positioning systems for location-based services

Positioning systems have become increasingly popular in the last decade for location-based services, such as navigation, and asset tracking and management. As opposed to outdoor positioning, where the global navigation satellite system became the standard technology, there is no consensus yet for indoor environments despite the availability of different technologies, such as radio frequency, magnetic field, visual light communications, or acoustics. Within these options, acoustics emerged as a promising alternative to obtain high-accuracy low-cost systems. Nevertheless, acoustic signals have to face very demanding propagation conditions, particularly in terms of multipath and Doppler effect. Therefore, even if many acoustic positioning systems have been proposed in the last decades, it remains an active and challenging topic. This article surveys the developed prototypes and commercial systems that have been presented since they first appeared around the 1980s to 2022. We classify these systems into different groups depending on the observable that they use to calculate the user position, such as the time-of-flight, the received signal strength, or the acoustic spectrum. Furthermore, we summarize the main properties of these systems in terms of accuracy, coverage area, and update rate, among others. Finally, we evaluate the limitations of these groups based on the link budget approach, which gives an overview of the system's coverage from parameters such as source and noise level, detection threshold, attenuation, and processing gain.Agencia Estatal de InvestigaciónResearch Council of Norwa

Audio-based localization for ubiquitous sensor networks

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2005.Includes bibliographical references (p. 97-101).This research presents novel techniques for acoustic-source location for both actively triggered, and passively detected signals using pervasive, distributed networks of devices, and investigates the combination of existing resources available in personal electronics to build a digital sensing 'commons'. By connecting personal resources with those of the people nearby, tasks can be achieved, through distributed placement and statistical improvement, that a single device could not do alone. The utility and benefits of spatio-temporal acoustic sensing are presented, in the context of ubiquitous computing and machine listening history. An active audio self-localisation algorithm is described which is effective in distributed sensor networks even if only coarse temporal synchronisation can be established. Pseudo-noise 'chirps' are emitted and recorded at each of the nodes. Pair-wise distances are calculated by comparing the difference in the audio delays between the peaks measured in each recording. By removing dependence on fine grained temporal synchronisation it is hoped that this technique can be used concurrently across a wide range of devices to better leverage the existing audio sensing resources that surround us.(cont.) A passive acoustic source location estimation method is then derived which is suited to the microphone resources of network-connected heterogeneous devices containing asynchronous processors and uncalibrated sensors. Under these constraints position coordinates must be simultaneously determined for pairs of sounds and recorded at each microphone to form a chain of acoustic events. It is shown that an iterative, numerical least-squares estimator can be used. Initial position estimates of the source pair can be first found from the previous estimate in the chain and a closed-form least squares approach, improving the convergence rate of the second step. Implementations of these methods using the Smart Architectural Surfaces development platform are described and assessed. The viability of the active ranging technique is further demonstrated in a mixed-device ad-hoc sensor network case using existing off-the-shelf technology. Finally, drawing on human-centric onset detection as a means of discovering suitable sound features, to be passed between nodes for comparison, the extension of the source location algorithm beyond the use of pseudo-noise test sounds to enable the location of extraneous noises and acoustic streams is discussed for further study.Benjamin Christopher Dalton.S.M

Cryomobilities: Vessel mobilities amidst the ice-prone waters of the Bering Strait

In recent years, the overall decrease in sea ice and the increase in vessel traffic in the Arctic has raised questions over how to conceptualise vessel mobilities in icy ocean spaces. Drawing on the mobilities literature, this research turns to oceans and seas that sustain annual cycles of sea ice as an arena for exploring interactions between vessel mobilities and the mobilities of the (partially) frozen ocean amidst which they move. This thesis engages with the cryomobilities of the Bering Strait region through an interdisciplinary approach across human and physical geography, whereby “cryomobilities” refers not just to the mobile interactions between vessels and sea ice, but also points to the ways in which the vibrant and distinct materialities of our planet’s frozen oceans (as well as other cryoscapes) warrant dedicated and specific conceptualisations. Specifically, turning to icy ocean spaces raises questions for conceptualising entities in motion within an environmental that is itself also in motion. The Bering Strait region, located between Alaska and Siberia, comprises the ice-prone waters of the Bering and Chukchi Seas. By analysing interactions between vessels and sea ice in the Bering Strait region, this thesis explores how vessel mobilities are entangled with sea ice mobilities, and how these are experienced by people who engage with these mobilities in various ways. In order to analyse these multiple aspects of cryomobilities in the Bering Strait region, this thesis employs a mixed methods approach, combining spatial data analysis and interviews. Spatial data analysis uses sea-ice concentration and vessel traffic data from remote sensing to map and compare the interactions between the mobilities of sea ice and the mobilities of vessels between 2013 and 2022. Interviews with sea-ice scientists, sea-ice forecasters and people with on-ice and sailing experience explore the knowledge-making practices surrounding cryomobilities through embodied experience. The findings reveal how cryomobilities in the Bering Strait region are characterised by an avoidance of sea ice, with 95% of vessel traffic operating in open water. However, not all ships and not all sea-ice conditions are the same, as there are many diverse users of these varied and ever mobile icy-watery spaces, who all relate to sea-ice conditions in different ways. For example, tourist cruise ships, fishing vessels, drifting scientific stations and icebreaker vessel mobilities all rely in various ways on the presence – rather than the absence – of sea ice and its mobilities. Technological advances in shipbuilding are also enhancing the ice capabilities of ships and icebreakers such that, over the past decade (2013-2022), vessel traffic in ice-covered areas has been increasing at a faster rate than vessel traffic in open water. Cryomobilities are also influenced by the ways in which knowledge emerges through a combination of highly specific personal expertise, embodied experiences, and rigorous collection and analysis of scientific data about sea ice and vessel activities. By presenting a multifaceted and interdisciplinary perspective on cryomobilities in the Bering Strait region, this research pushes the boundaries of the existing mobilities literature, often dominated by terracentric and liquid-ocean accounts of mobilities. It also contributes to understanding vessel behaviour in ice-prone waters for informing present and future management of icy ocean spaces, especially in view of a warming climate

Environmental Biophysics

Ця книга призначена для студентів, які вивчають навколишнє середовище. Буде корисна для студентів, для яких англійська не є рідною мовою і які прагнуть покращити знання професійної англійської термінології, що дозволить краще зрозуміти сучасну наукову літературу, приймати активнішу участь в наукових міжнародних конференціях, симпозіумах, семінарах.This text-book: 1) provides a description of physical surrounding of living organisms; 2) elucidates the ability of living organisms to respond to the change of external factors due to receptor systems and to choose optimal conditions of survival; 3) gives information on the principles of operation of modern instrumentation for measure-ment of the environmental parameters with special emphasis on automated system and remote sensing of environmental components; 4) reviews transfer phenomena and processes which characterise the interaction of living or-ganisms with the environment; 5) considers the main principles of the solar radiation budget and the energy balance of physical and biological systems with the environment. This text-book is based on the concept of transfer phenomena – irreversible processes which are important from the point of view of viability of living organisms; the spatial transfer of physical values such as entropy, mass, energy, momentum, electric charges in the envi-ronment occurs due to these phenomena. Such an approach makes it possible to unite all bio-physical processes that characterise the interaction of living organisms with the environment. This text-book is intended for the students of Environmental Sciences. It will be useful for those students whose native language is not English and who want to improve the knowledge of professional English terminology that will make it possible to better understand modern literature, take a more active role in scientific missions abroad, get into contact with foreign colleagues, and enhance attendance at international conferences, symposiums, seminars, etc.Participation of Prof. Yuriy Posudin in research program in Japan was possible due to Fellowship of the Japan Society for the Promotion of Science, Fellow’s ID No.: S-07117 in 2007