The Analysis of design and manufacturing tasks using haptic and immersive VR - Some case studies

The use of virtual reality in interactive design and manufacture has been researched extensively but the practical application of this technology in industry is still very much in its infancy. This is surprising as one would have expected that, after some 30 years of research commercial applications of interactive design or manufacturing planning and analysis would be widespread throughout the product design domain. One of the major but less well known advantages of VR technology is that logging the user gives a great deal of rich data which can be used to automatically generate designs or manufacturing instructions, analyse design and manufacturing tasks, map engineering processes and, tentatively, acquire expert knowledge. The authors feel that the benefits of VR in these areas have not been fully disseminated to the wider industrial community and - with the advent of cheaper PC-based VR solutions - perhaps a wider appreciation of the capabilities of this type of technology may encourage companies to adopt VR solutions for some of their product design processes. With this in mind, this paper will describe in detail applications of haptics in assembly demonstrating how user task logging can lead to the analysis of design and manufacturing tasks at a level of detail not previously possible as well as giving usable engineering outputs. The haptic 3D VR study involves the use of a Phantom and 3D system to analyse and compare this technology against real-world user performance. This work demonstrates that the detailed logging of tasks in a virtual environment gives considerable potential for understanding how virtual tasks can be mapped onto their real world equivalent as well as showing how haptic process plans can be generated in a similar manner to the conduit design and assembly planning HMD VR tool reported in PART A. The paper concludes with a view as to how the authors feel that the use of VR systems in product design and manufacturing should evolve in order to enable the industrial adoption of this technology in the future

Automated design analysis, assembly planning and motion study analysis using immersive virtual reality

Previous research work at Heriot-Watt University using immersive virtual reality (VR) for cable harness design showed that VR provided substantial productivity gains over traditional computer-aided design (CAD) systems. This follow-on work was aimed at understanding the degree to which aspects of this technology were contributed to these benefits and to determine if engineering design and planning processes could be analysed in detail by nonintrusively monitoring and logging engineering tasks. This involved using a CAD-equivalent VR system for cable harness routing design, harness assembly and installation planning that can be functionally evaluated using a set of creative design-tasks to measure the system and users' performance. A novel design task categorisation scheme was created and formalised which broke down the cable harness design process and associated activities. The system was also used to demonstrate the automatic generation of usable bulkhead connector, cable harness assembly and cable harness installation plans from non-intrusive user logging. Finally, the data generated from the user-logging allowed the automated activity categorisation of the user actions, automated generation of process flow diagrams and chronocyclegraphs

Exact Calculation of the Vortex-Antivortex Interaction Energy in the Anisotropic 3D XY-model

We have developed an exact method to calculate the vortex-antivortex interaction energy in the anisotropic 3D-XY model. For this calculation, dual transformation which is already known for the 2D XY-model was extended. We found an explicit form of this interaction energy as a function of the anisotropic ratio and the separation $r$ between the vortex and antivortex located on the same layer. The form of interaction energy is $\ln r$ at the small $r$ limi t but is proportional to $r$ at the opposite limit. This form of interaction energ y is consistent with the upper bound calculation using the variational method by Cataudella and Minnhagen.Comment: REVTeX 12 pages, In print for publication in Phys. Rev.

Pilot Study of a Haptic Soldering Environment

Soldering plays an important role in the electronics manufacturing industry, whether it is carried out manually, semi-automatically or fully-automatically. Even though it is straightforward to learn the fundamental techniques involved in manual soldering, it still requires a vast amount of time and effort to reach an expert level. The research presented here aims to simulate the manual soldering process in a haptics environment, and by logging the users' actions automatically and unobtrusively in the background, the aim is to investigate human hand dexterity and learn how novices and experts operate differently through knowledge capture. A pilot study was carried out in which the obtained log files were parsed and the capture of knowledge was demonstrated. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

Organogenesis of Phaseolus angularis L.: high efficiency of adventitious shoot regeneration from etiolated seedlings in the presence of N6-benzylaminopurine and thidiazuron

A step-wise procedure for the regeneration of fertile plants by organogenesis from cultures of the economically important Phaseolus angularis L., cultivars: KS-6, KS-7 and KS-8 using etiolated seedlings was established. Pre-culture of 5-day old seedling explants with MS (Murashige and Skoog (1962) Physiol Plant 15:473-493) + B-5-vitamins (Gamborg et al. (1968) Exp Cell Res 50:151-158) liquid medium containing either 5.0 mu M TDZ or 5.0 mu M BAP under dark condition was essential for organogenesis. Bud growth and shoot multiplication were stimulated by reducing the BAP concentrations from 5.0 to 2.5 mu M after 3 weeks. The maximum frequency of shoot induction was 65.2% (33.8 +/- 2.54 shoots/explant) in cultivar KS-8 followed by KS-7 34.6% (23.4 +/- 1.91 shoots/explant) and KS-6 30.6% (21.2 +/- 2.28 shoots/explant). The multiplied buds elongated after transferring to solid MSB5 medium supplemented with 4.0 mu M GA(3), 12.5 mu M AgNO3 and 0.4 mu M IBA. Up to 98% rooting efficiency of was obtained when the shoots were pulse-treated with liquid medium containing 4.5 mu M IBA for 10 min. The rooted plantlets were transferred to pots in the greenhouse, where they grew, mature, flowered and bared pod normally. The efficient shoot bud induction capability was found to be cultivar dependent. All the three cultivars tested formed multiple shoots. This efficient and rapid regeneration system may also be helpful for Agrobacterium- or particle gun-mediated transformation for this important legume crop

Using morphological diagnosis and molecular markers to assess the clonal fidelity of micropropagated Echinacea purpurea regenerants

Both morphological characteristics and amplified fragment length polymorphism (AFLP) markers were used to validate the genetic fidelity of 1 080 field-grown Echinacea purpurea plants regenerated from leaf explants of donor T5-9. Morphological diagnosis revealed that 1 067 out of 1 080 regenerants were normal, while 13 regenerants were aberrant. AFLP analysis was further performed to assess DNA variations among donor, 43 sampled normal regenerants and all 13 aberrant regenerants. Seven primer combinations generated 471 fragments among donor and normal regenerants, of which 9 fragments were polymorphic. The same primer pairs generated 484 fragments for aberrant regenerants, of which 417 fragments were polymorphic. UPGMA clustering indicated that 42 normal regenerants and donor fell into same cluster at similarity scale of > 0.99, while all 13 aberrant regenerants and one morphologically normal regenerant comprised the other clusters. AFLP analysis indicated that these 14 regenerants are off-types

Operator with large spin and spinning D3-brane

We consider the conformal dimension of an operator with large spin, using a spinning D3-brane with electric flux in AdS_5 x S^5 instead of spinning fundamental string. This spinning D3-brane solution seems to correspond to an operator made by taking trace in a large symmetric representation. The conformal dimension, the spin and the R-charge show a scaling relation in a certain region of parameters. In the small string charge limit, the result is consistent with the fundamental string picture. There is a phase transition when the fundamental string charge become larger than a certain critical value; there is no stable D3-brane solution above the critical value.Comment: 16 pages, 4 figures. v2: typos corrected, references added, series expansion of anomalous dimension added. v3: a reference added, comment on calculation in gauge theor

Phase Separation Based on U(1) Slave-boson Functional Integral Approach to the t-J Model

We investigate the phase diagram of phase separation for the hole-doped two dimensional system of antiferromagnetically correlated electrons based on the U(1) slave-boson functional integral approach to the t-J model. We show that the phase separation occurs for all values of J/t, that is, whether $0 < J/t < 1$ or $J/t \geq 1$ with J, the Heisenberg coupling constant and t, the hopping strength. This is consistent with other numerical studies of hole-doped two dimensional antiferromagnets. The phase separation in the physically interesting J region, $0 < J/t \lesssim 0.4$ is examined by introducing hole-hole (holon-holon) repulsive interaction. We find from this study that with high repulsive interaction between holes the phase separation boundary tends to remain robust in this low $J$ region, while in the high J region, J/t > 0.4, the phase separation boundary tends to disappear.Comment: 4 pages, 2 figures, submitted to Phys. Rev.

Environmental metabarcoding reveals heterogeneous drivers of microbial eukaryote diversity in contrasting estuarine ecosystems

Assessing how natural environmental drivers affect biodiversity underpins our understanding of the relationships between complex biotic and ecological factors in natural ecosystems. Of all ecosystems, anthropogenically important estuaries represent a �melting pot� of environmental stressors, typified by extreme salinity variations and associated biological complexity. Although existing models attempt to predict macroorganismal diversity over estuarine salinity gradients, attempts to model microbial biodiversity are limited for eukaryotes. Although diatoms commonly feature as bioindicator species, additional microbial eukaryotes represent a huge resource for assessing ecosystem health. Of these, meiofaunal communities may represent the optimal compromise between functional diversity that can be assessed using morphology and phenotype�environment interactions as compared with smaller life fractions. Here, using 454 Roche sequencing of the 18S nSSU barcode we investigate which of the local natural drivers are most strongly associated with microbial metazoan and sampled protist diversity across the full salinity gradient of the estuarine ecosystem. In order to investigate potential variation at the ecosystem scale, we compare two geographically proximate estuaries (Thames and Mersey, UK) with contrasting histories of anthropogenic stress. The data show that although community turnover is likely to be predictable, taxa are likely to respond to different environmental drivers and, in particular, hydrodynamics, salinity range and granulometry, according to varied life-history characteristics. At the ecosystem level, communities exhibited patterns of estuary-specific similarity within different salinity range habitats, highlighting the environmental sequencing biomonitoring potential of meiofauna, dispersal effects or both

Far-infrared transmission studies of c-axis oriented superconducting MgB2 thin film

We reported far-infrared transmission measurements on a c-axis oriented superconducting MgB$_{2}$ thin film in the frequency range of 30 $\sim$ 250 cm$^{-1}$. We found that these measurements were sensitive to values of scattering rate $1/\tau$ and superconducting gap $2\Delta$. By fitting the experimental transmission spectra at 40 K and below, we obtained $1/\tau =$ (700 $\sim$ 1000) cm$^{-1}$ and $2\Delta (0)\cong$ 42 cm$^{-1}$. These two quantities suggested that MgB$_{2}$ belong to the dirty limit.Comment: submitted at May