Investigating methods for measuring face recognition under lamps of different spectral power distribution

Face recognition is one of the interpersonal judgements carried out by pedestrians. Road lighting should enhance the visual component of such judgements after dark. This paper presents experiments carried out using two different procedures, identification and perceived recognition, to investigate why earlier studies have led to inconsistent conclusions about the influence of spectral power distribution (SPD) on face recognition. For the identification procedure, two observation durations were employed (1-s and 3-s). The two procedures led to similar conclusions regarding recognition ability at different distances. Review of these and past results suggests that an effect of lamp (SPD) is more likely to be found when the task is difficult, i.e. small size, brief observation and correctly naming the target rather than simply picking a face from a sample

Solar ultraviolet protection provided by human head hair

The solar erythemal UV irradiances through human hair and the protection from UV provided by human head hair have been investigated for a solar zenith angle (SZA) range of 17 to 51 degrees for the conditions of a head upright in full sun, a head upright in shade and a head in full sun tilted towards the sun. The two hair lengths investigated were 49.1+-7.1 mm for the short type and 109.5+-5.5 mm for the long type. For the head upright in full sun, the irradiances through the hair ranged from 0.75 to 1.4 SED/h for SZA less than 25 degrees and less than 0.6 SED/h in shade. The ultraviolet protection factor (UPF) ranged from approximately 5 to 17 in full sun, with the UPF increasing with higher SZA. The longer hair provided a lower UPF than the shorter hair and for the head oriented towards the sun, there was a marginally lower UPF than for the upright head. This research shows that the UV exposure limits to the scalp through hair can be exceeded within short timeframes and provides important information to assist employers to comply with Workplace Health and Safety legislation

Intelligent control for energy-positive street lighting

The paper investigates the application of solar energy in public lighting for realizing a street lighting sub-grid with positive yearly energy balance. The focus is given to the central controller, which ensures the adaptive behavior of the overall system and provides smart city services to the end users via its web-based user interface. A functionality of the controller of special interest is the optimization of the energy management of the system, i.e., determining when to sell and buy electricity to/from the grid, in order to minimize the cost of electricity (or to maximize the profit) subject to a given, time-of-use variable energy tariff. This requires precise forecasts of the energy produced and consumed, as well as appropriate robust optimization techniques that guarantee that the system bridges potential power outages of moderate duration in island mode

Measurements of the upper body ultraviolet exposure to golfers: non-melanoma skin cancer risk, and the potential benefits of exposure to sunlight

Background. Geographically, Queensland presents an extreme ultraviolet exposure climate to members of the public engaged in outdoor recreational activity. The risk of developing a skin cancer or an eye disease as a result of incidental exposure to naturally occurring ultraviolet radiation in the outdoor environment is proportionately high in a Queensland population compared to fair skinned population groups residing in comparable Northern Hemisphere latitudes. In contrast to these risks, elderly members of this high growth population group have been reported to be vitamin D deficient. The risks and potential benefits of exposure to sunlight in southern Queensland are assessed in this study with respect to recreational golfing. This sport is a popular recreational activity for the Queensland population and must be played during daylight hours. Methods. The erythemal and vitamin D effective ultraviolet exposure measured to the forearm, upper back and vertex are presented for individuals playing golf under various atmospheric conditions in a seven month period extending from summer to winter. Results. Mean summertime exposures were measured in the 2008 study period to be 1.4, 2.2 and 3.2 SED at forearm, upper back and vertex sites respectively compared to respective wintertime forearm, upper back and vertex exposures of 0.2, 0.3, 0.5 SED, where summertime exposures were recorded in the mean solar zenith angle ranges of 56o to 59o and wintertime exposures were recorded in the mean solar zenith angle range 74o to 83o. Vitamin D3 effective exposures were determined to vary from between 225 Jm-2, 325 Jm 2 and 475Jm-2 during summer and 48 Jm-2, 59 Jm-2 and 88 Jm-2 during winter for the respective forearm, upper back and vertex body sites measured in the above mean solar zenith angle ranges. Conclusion. Exposures to ambient UV during winter on the golf course between 3:00 pm and 5:30 pm could be beneficial for office workers for the production of vitamin D. Optimising exposure periods to late afternoon in the winter months and taking adequate sun protection measures in the summer months are important strategies that golfers can utilise for long term preventative health