Use of three isotopes to calibrate human bone radiocarbon determinations from Kainapirina (SAC), Watom Island, Papua New Guinea

In archaeological dating, the greatest confidence is usually placed upon radiocarbon results of material that can be directly related to a defined archaeological event. Human bone should fulfill this requirement, but bone dates obtained from Pacific sites are often perceived as problematic due to the incorporation of ¹⁴C from a range of different reservoirs into the collagen via diet. In this paper, we present new human bone gelatin results for 2 burials from the SAC archaeological site on Watom Island, Papua New Guinea, and investigate the success of calibrating these determinations using dietary corrections obtained from δ³⁴S, δ¹⁵N, and δ¹³C isotopes

Hard-input-hard-output capacity analysis of UWB BPSK systems with timing errors

The hard-input-hard-output capacity of a binary phase-shift keying (BPSK) ultrawideband system is analyzed for both additive white Gaussian noise and multipath fading channels with timing errors. Unlike previous works that calculate the capacity with perfect synchronization and/or multiple-access interference only, our analysis considers timing errors with different distributions, as well as the interpath (IPI), interchip (ICI), and intersymbol (ISI) interferences, as in practical systems. The sensitivity of the channel capacity to the timing error is examined. The effects of pulse shape, the multiple-access technique, the number of users, and the number of chips are studied. It is found that time hopping is less sensitive to the pulse shape and that the timing error has higher capacity than direct sequence due to its low duty of cycle. Using these results, one can choose appropriate system parameters for different applications

Short-range ultrasonic communications in air using quadrature modulation

A study has been undertaken of ultrasonic communications methods in air, using a quadrature modulation method. Simulations were first performed to establish the likely performance of quadrature phase shift keying over the limited bandwidth available in an ultrasonic system. Quadrature phase shift keying modulation was then implemented within an experimental communication system, using capacitive ultrasonic sources and receivers. The results show that such a system is feasible in principle for communications over distances of several meters, using frequencies in the 200 to 400 kHz range

Underwater optical wireless communications : depth dependent variations in attenuation

Depth variations in the attenuation coefficient for light in the ocean were calculated using a one-parameter model based on the chlorophyll-a concentration Cc and experimentally-determined Gaussian chlorophyll-depth profiles. The depth profiles were related to surface chlorophyll levels for the range 0–4  mg/m2, representing clear, open ocean. The depth where Cc became negligible was calculated to be shallower for places of high surface chlorophyll; 111.5 m for surface chlorophyll 0.8<Cc<2.2  mg/m3 compared with 415.5 m for surface Cc<0.04  mg/m3. Below this depth is the absolute minimum attenuation for underwater ocean communication links, calculated to be 0.0092  m−1 at a wavelength of 430 nm. By combining this with satellite surface-chlorophyll data, it is possible to quantify the attenuation between any two locations in the ocean, with applications for low-noise or secure underwater communications and vertical links from the ocean surface

New observations on the stratigraphy and radiocarbon dates at the Cross Creek site, Opito, Coromandel Peninsula

This paper re-examines stratigraphy and radiocarbon dates at Cross Creek in Sarah's Gully. Three new radiocarbon dates are presented for Layer 9, the earliest, and previously undated, occupation. This investigation is part of a programme of archaeological work being carried out on the Coromandel Peninsula. Although there are several individual research projects underway, they have a common theme related to the Polynesian settlement period on the Coromandel Peninsula. The two seasons of excavation at Tairua are being written up by Matthew Campbell of CFG Heritage on behalf of Roger Green. Louise Furey, also CFG Heritage, is researching a thematic study on early sites for the Department of Conservation, Archaeological research in the Opito area includes documenting a pollen sequence for Opito under a grant obtained from the Green Foundation for Polynesian Research: Pam Chester, Louise Furey and Brenda Sewell are participants. In addition, positively identifying the Kaharoa Ash in the Opito-Sarah's Gully area is a priority

The marine ΔR For Nenumbo (Solomon Islands): A case study in calculating reservoir offsets form paired sample data

It is necessary to calculate location-specific marine ΔR values in order to calibrate marine samples using calibration curves such as those provided through the IntCal98 (Stuiver et al. 1998) data. Where known-age samples are available, this calculation is straightforward (i.e. Stuiver et al. 1986). In the case that a paired marine/terrestrial sample calculation is performed, however, the standard calculation (i.e. Stuiver and Braziunas 1993) requires that the samples are treated as relating to isochronous events. This may not be an appropriate assumption for many archaeological paired samples. In this paper, we present an approach to calculating marine ΔR values that does not require the dated events to be treated as isochronous. When archaeological evidence allows the dated events to be tightly temporally constrained, the approach presented here and that described by Stuiver and Braziunas (1993) give very similar results. However, where tight temporal constraints are less certain, the 2 approaches can give rise to differing results. The example analysis considered here shows that a ΔR of –81 ± 64 ¹⁴C yr is appropriate for samples in the vicinity of Nenumbo (Reef Islands, southeast Solomon Islands) around the period 2000–3000 BP

Multi-user indoor optical wireless communication system channel control using a genetic algorithm

A genetic algorithm controlled multispot transmitter is demonstrated that is capable of optimising the received power distribution for randomly aligned single element receivers in multiple fully diffuse optical wireless communications systems with multiple mobile users. Using a genetic algorithm to control the intensity of individual diffusion spots, system deployment environment changes, user movement and user alignment can be compensating for, with negligible impact on the bandwidth and root mean square delay spread. It is shown that the dynamic range, referenced against the peak received power, can be reduced up to 27% for empty environments and up to 26% when the users are moving. Furthermore, the effect of user movement, that can perturb the channel up to 8%, can be reduced to within 5% of the optimised case. Compared to alternative bespoke designs that are capable of mitigating optical wireless channel drawbacks, this method provides the possibility of cost-effectiveness for mass-produced receivers in applications where end-user friendliness and mobility are paramount

Beware of Mad John: Political Theology, Psychedelics and Literature

Using the discourse of Political Theology as a mode of enquiry we can overcome a longstanding tension between aesthetics and history that characterized much of twentieth century thought. Focusing on literary and occasionally musical works from the mid twentieth century, my aim is to show how works displaying psychedelic aesthetics are important venues for political deliberation with regard to citizenship. Through affective means, psychedelic aesthetics reimagine the boundaries of liberal subjectivity through a consciousness expansion and return from that expansion. The subject who returns from a psychedelic “experience” – which can be attained in various ways – comes to ethically realign and re-norm his or her “self” according to a moral authority beyond the authority of the nation state. While critical of liberalism on one level, this “expanded” citizenship ultimately offers liberalism political advice in crisis situations by performing a public sacrifice on the state and disseminating social responsibility to individuals. Psychedelic aesthetics perform this ‘public sacrifice’ through affective enchantment, using spiritual and religious rhetoric to change the relationship between citizen and state. Because artistic works of the mid twentieth century are essentially “ahead of the game” regarding states of exception and economic crises, it is to this period that we should look for methods of cultural recovery in current ones. But this requires that we take both aesthetic and religious enchantment seriously in a post-secular world