An evaluation of earcons for use in auditory human-computer interfaces

An evaluation of earcons was carried out to seee whether they are an effective means of communicating information in sound. An initial experiment showed that earcons were better than unstructured bursts of sound and that musical timbres were more effective than simple tones. A second experiment was then carried out which improved upon some of the weaknesses shown up in Experiment 1 to give a significant improvement in recognition. From the results of these experiments some guidelines were drawn up for use in the creation of earcons. Earcons have been shown to be an effective method for communicating information in a human-computer interface

Parallel earcons: reducing the length of audio messages

This paper describes a method of presenting structured audio messages, earcons, in parallel so that they take less time to play and can better keep pace with interactions in a human-computer interface. The two component parts of a compound earcon are played in parallel so that the time taken is only that of a single part. An experiment was conducted to test the recall and recognition of parallel compound earcons as compared to serial compound earcons. Results showed that there are no differences in the rates of recognition between the two groups. Non-musicians are also shown to be equal in performance to musicians. Some extensions to the earcon creation guidelines of Brewster, Wright and Edwards are put forward based upon research into auditory stream segregation. Parallel earcons are shown to be an effective means of increasing the presentation rates of audio messages without compromising recognition rates

The design and evaluation of an auditory-enhanced scrollbar

A structured method is described for the analysis of interactions to identify situations where hidden information may exist and where non-speech sound might be used to overcome the associated problems. Interactions are considered in terms of events, status and modes to find any hidden information. This is then categorised in terms of the feedback needed to present it. An auditory-enhanced scrollbar, based on the method described, was then experimentally tested. Timing and error rates were used along with subjective measures of workload. Results from the experiment show a significant reduction in time to complete one task, a decrease in the mental effort required and an overall preference for the auditory-enhanced scrollbar

Effect of row spacings on yields of spring and winter wheats in central and northern Saskatchewan

Non-Peer ReviewedThe effect of row spacings on yields of HY320 and Neepawa spring wheats and Norstar and Norwin winter wheats was investigated at several locations in central and northern Saskatchewan. These results, although preliminary, indicated that yields increased as row spacings decreased. The effect of row spacing appeared to be greatest where yields were highest although significant row spacing effects were also noted at those sites where yields were lower. Data from a limited number of sites where counts of head numbers per m^2 were made indicated that much of the difference in yields between row spacings could be accounted for by increased numbers of heads being produced at narrower spacings

An evaluation of the vacuum/pressure moisturization technique of seed grains and oilseeds

Non-Peer Reviewe

The empirical relevance of the competitive storage model

"The empirical relevance of models of competitive storage arbitrage in explaining commodity price behavior has been seriously challenged in a series of pathbreaking papers by Deaton and Laroque (1992, 1995, 1996). Here we address their major criticism, that the model is in general unable to explain the degree of serial correlation observed in prices of twelve major commodities. First, we present a simple numerical version of their model which, contrary to Deaton and Laroque (1992), can generate the high levels of serial correlation observed in commodity prices, if it is parameterized to generate realistic levels of price variation. Then, after estimating the Deaton and Laroque (1995, 1996) model using their data set, model specification and econometric approach, we show that use of a much finer grid to approximate the equilibrium price function yields quite different estimates for most commodities. Results are obtained for coffee, copper, jute, maize, palm oil, sugar and tin that support the specifications of the storage model with positive constant marginal storage cost and no deterioration as in Gustafson (1958a). Consumption demand has low response to price and, except for sugar, there are infrequent stockouts. Observed magnitudes of serial correlation of price match those implied by the estimated model." [author's abstract

Do we know the mass of a black hole? Mass of some cosmological black hole models

Using a cosmological black hole model proposed recently, we have calculated the quasi-local mass of a collapsing structure within a cosmological setting due to different definitions put forward in the last decades to see how similar or different they are. It has been shown that the mass within the horizon follows the familiar Brown-York behavior. It increases, however, outside the horizon again after a short decrease, in contrast to the Schwarzschild case. Further away, near the void, outside the collapsed region, and where the density reaches the background minimum, all the mass definitions roughly coincide. They differ, however, substantially far from it. Generically, we are faced with three different Brown-York mass maxima: near the horizon, around the void between the overdensity region and the background, and another at cosmological distances corresponding to the cosmological horizon. While the latter two maxima are always present, the horizon mass maxima is absent before the onset of the central singularity.Comment: 11 pages, 8 figures, revised version, accepted in General Relativity and Gravitatio

Associations between sole ulcer, white line disease and digital dermatitis and the milk yield of 1824 dairy cows on 30 dairy cow farms in England and Wales from February 2003–November 2004

The milk yields of 1824 cows were used to investigate the effect of lesion-specific causes of lameness, based on farmer treatment and diagnosis of lame cows, on milk yield. A three level hierarchical model of repeated test day yields within cows within herds was used to investigate the impact of lesion-specific causes of lameness (sole ulcer, white line disease, digital dermatitis and other causes) on milk yield before and after treatment compared with unaffected cows. Cattle which developed sole ulcer (SU) and white line disease (WLD) were higher yielding cattle before they were diagnosed. Their milk production fell to below that of the mean of unaffected cows before diagnosis and remained low after diagnosis. In cattle which developed digital dermatitis (DD) there was no significant difference in milk yield before treatment and a slightly raised milk yield immediately after treatment. The estimated milk loss attributable to SU and WLD was approximately 570kg and 370kg respectively. These results highlight that specific types of lameness vary by herds and within herds they are associated with higher yielding cattle. Consequently lesion-specific lameness reduction programmes targeting the cow and farm specific causes of lameness might be more effective than generic recommendations. They also highlight the importance of milk loss when estimating the economic impact of SU and WLD on the farms profitability

Land resource assessment of Northern Belize (NRI Bulletin 43, Volume 1 of 2)

The land resource assessment was undertaken from July 1989 to June 1990 by the Natural Resources Institute (NRI) of the Overseas Development Administration (ODA), assisted by Mr. A. C. S. Wright, and Dr. M. Holder of Central Farm. The main object of the survey was to produce an updated land suitability assessment of Orange Walk, Corozal, Belize and Cayo districts which had not already been surveyed by Jenkin et al. (1976) and King et al. (1989). In addition, this survey would provide a land suitability assessment for the Belize Valley based on the soil mapping of )en kin et al. Thus, together with the land resource assessments of Toledo and Stann Creek districts (King et al., 1986, 1989 respectively), a land suitability assessment for the whole of Belize is now available