Studies into the detection of buried objects (particularly optical fibres) in saturated sediment. Part 2: design and commissioning of test tank

This report is the second in a series of five, designed to investigate the detection oftargets buried in saturated sediment, primarily through acoustical or acoustics-relatedmethods. Although steel targets are included for comparison, the major interest is intargets (polyethylene cylinders and optical fibres) which have a poor acousticimpedance mismatch with the host sediment. This particular report details theconstruction of a laboratory-scale test facility. This consisted of three maincomponents. Budget constraints were an over-riding consideration in the design.First, there is the design and production of a tank containing saturated sediment. Itwas the intention that the physical and acoustical properties of the laboratory systemshould be similar to those found in a real seafloor environment. Particularconsideration is given to those features of the test system which might affect theacoustic performance, such as reverberation, the presence of gas bubbles in thesediment, or a suspension of particles above it. Sound speed and attenuation wereidentified as being critical parameters, requiring particular attention. Hence, thesewere investigated separately for each component of the acoustic path.Second, there is the design and production of a transducer system. It was the intentionthat this would be suitable for an investigation into the non-invasive acousticdetection of buried objects. A focused reflector is considered to be the most costeffectiveway of achieving a high acoustic power and narrow beamwidth. Acomparison of different reflector sizes suggested that a larger aperture would result inless spherical aberration, thus producing a more uniform sound field. Diffractioneffects are reduced by specifying a tolerance of much less than an acousticwavelength over the reflector surface. The free-field performance of the transducerswas found to be in agreement with the model prediction. Several parameters havebeen determined in this report that pertain to the acoustical characteristics of the waterand sediment in the laboratory tank in the 10 – 100 kHz frequency range.Third, there is the design and production of an automated control system wasdeveloped to simplify the data acquisition process. This was, primarily, a motordrivenposition control system which allowed the transducers to be accuratelypositioned in the two-dimensional plane above the sediment. Thus, it was possible forthe combined signal generation, data acquisition and position control process to be coordinatedfrom a central computer.This series of reports is written in support of the article “The detection by sonar ofxdifficult targets (including centimetre-scale plastic objects and optical fibres) buriedin saturated sediment” by T G Leighton and R C P Evans, written for a Special Issueof Applied Acoustics which contains articles on the topic of the detection of objectsburied in marine sediment. Further support material can be found athttp://www.isvr.soton.ac.uk/FDAG/uaua/target_in_sand.HTM

Hermeneutic Relations in VR: Immersion, Embodiment, Presence and HCI in VR Gaming

The emergence of Virtual Reality (VR) as a viable consumer medium for gaming offers an opportunity toreconceptualise understandings of immersion, embodiment and presence in gaming. However, many of thediscourses and attempts to conceptualise experience in VR games conflate these terms rather thanunderstanding each as a state of engagement with a VR environment or game. This results in a lack ofunderstanding of the importance of design and intentionality in the VR game with regards to immersion,embodiment and presence. Using a post-phenomenological approach, this paper differentiates immersion,embodiment and presence as three kinds of relation utilising the I – technology – world schema. Thisapproach allows for an understanding of these states of engagement as layered and hierarchical rather thaninstantly emergent on the part of the technology. The hermeneutic relation between the user and VR game[I → (technology – world)] that indicates presence can be understood as a feeling of place or placehood inVR and is intentionally the state aimed for as optional in VR games. The importance of technologicalintentionality as a co-constructor of embodiment and presence is exemplified through an analysis of userreviews of VR games either built-for VR or ported to VR. Built-for VR games create the possibility of asense of place for the games by incorporating the possibility of embodiment and presence into the designof control and movement while ported VR games fail to immerse because of a lack of technologicalintentionality towards these goals

‘The embodied empathy revolution … ’: pornography and the contemporary state of consumer virtual reality

Virtual Reality (VR) has been proposed as a potentially revolutionary medium for pornography. The notion of VR as a an ‘empathy machine’ has led to predictions that VR will facilitate more empathetic relationships between pornography and the viewer, and pornographic actors and viewers. This affective turn in VR pornography is contingent upon the use of teledildonic technology and VR to facilitate new embodied relations for the viewer. However, the current state of VR pornography is very far from this vision. Currently, VR pornography is dominated by a variation on the point-of-view genre of pornography where the viewer is embodied in a stationary, subject position – often that of a straight, white male while a female actor submits to the desire of the actor. The promise of VR pornography is currently some way from being realised, and the material currently available recycles debates on heteronormativity and hegemonic masculinity in eroticism

Barriers to VR use in HE

VR promises revolutionary changes in the levels of immersion that users can experience, and if applied successfully in educational contexts thisdeep immersion could have significant effects on both teaching and learning. To utilise VR effectively in the higher education (HE) space, theremust be some consideration given to what might prevent the use of VR in this sector and why these barriers exist—and how they can be mitigatedagainst. Based on an extensive research project involving qualitative interviews with 21 VR makers and designers in autumn 2017, following athematic analysis of the interview data, this paper identifies 5 major barriers to the uptake of VR in a wider cultural sense and in a specific, educationalcontext. These identified barriers are: the materiality of VR and issues with headsets and cables; interfaces within VR and issues with haptictechnology; the ‘language of VR’ and the difficulty in communicating the benefits of VR; cybersickness and gender issues with VR use, and, thecost of VR. The preparation of educational VR materials requires an acknowledgement of these sometimes-concealed barriers to VR use, and it isproposed that through knowledge-transfer and sharing of best practice the use of VR in higher education could become a model of best practicefor designing inclusive VR experiences that avoid major barriers to participation in VR

Authenticity Online: Using Webnography to Address Phenomenological Concerns

In this paper, I will aim to describe a webnography-based approach to exploring issues of the authenticity of being in online spaces. Early studies held the prevailing view that online communities were exotic places and fundamentally different to the norms of everyday communication, but the issue of authenticity still demands inquiry, and using Heidegger's categories of angst and resoluteness as moods of authentic existence, it will be argued that the extent of authenticity in being online can be assessed using ethnography

How to Build a Map for Free: immaterial labour and location-based social networking

In April 2011, I happened to find myself in the beautiful city of York, Northern England, on a Wednesday evening, ready to deliver a paper to a conference the next morning. While there is much to admire in York – beautiful architecture, plentiful culture and wonderful scenery – I had only one objective in mind. On this evening, I wanted to watch Manchester United play Chelsea in the quarterfinals of the Champions League. I support neither team – and downright loathe Chelsea – but I really wanted to watch the match: I wanted to watch it in a bar, with other football supporters, with cheap beer and plentiful screens to see the action. In the past, this would have involved tiresome seeking out of bars in the city, walking from place to place and possibly missing the action. On this evening though, I missed nothing and found the perfect place, and I achieved this in seconds with the use of my iPhone and the application Foursquare: I hit the Foursquare app button; pulled up the list of places near to my location in the centre of York; started going through the venues to find bars, and read the comments and tips left by other customers; and found a nice place with student discounts for beer and lots of screens. The game was a routine 1-0 win for Manchester United, but the bar was great, a hidden gem in York, and found by utilising the power of smartphone technology and the social tips left by other likeminded people. I used the check-ins and comments of other users, stored in a database, to make decisions about somewhere I didn’t know anything about, and when I checked-in there and left a comment – “a great place to watch football and great offers on beer!” – I contributed to this database and map of places as well. This is the world of location-based social networking (LBSN), a map of places created by users: what is called a “bottom-up” system, where users create the information rather than being given the information from above in a “top-down” system. This type of mapping has been incredibly useful to me, but it poses a very important question to be considered: what happens to the data I produce for the LBSN? This essay looks at how the data produced by user-generated databases of places is a very valuable commodity produced for free by the users, and while the database or map is very useful, we should also be aware of how our activities using such services are made into commodities for the companies that provide these services