3,895 research outputs found
A cognitive approach to user perception of multimedia quality: An empirical investigation
Whilst multimedia technology has been one of the main contributing factors behind the Web's success, delivery of personalized multimedia content has been a desire seldom achieved in practice. Moreover, the perspective adopted is rarely viewed from a cognitive styles standpoint, notwithstanding the fact that they have significant effects on users’ preferences with respect to the presentation of multimedia content. Indeed, research has thus far neglected to examine the effect of cognitive styles on users’ subjective perceptions of multimedia quality. This paper aims to examine the relationships between users’ cognitive styles, the multimedia quality of service delivered by the underlying network, and users’ quality of perception (understood as both enjoyment and informational assimilation) associated with the viewed multimedia content. Results from the empirical study reported here show that all users, regardless of cognitive style, have higher levels of understanding of informational content in multimedia video clips (represented in our study by excerpts from television programmes) with weak dynamism, but that they enjoy moderately dynamic clips most. Additionally, multimedia content was found to significantly influence users’ levels of understanding and enjoyment. Surprisingly, our study highlighted the fact that Bimodal users prefer to draw on visual sources for informational purposes, and that the presence of text in multimedia clips has a detrimental effect on the knowledge acquisition of all three cognitive style groups
Age really is an issue
The majority of the source and reservoir rocks for the hydrocarbons in North Sea and the
North West Shelf are Jurassic (200–146 Ma) in age. In both the exploration and production
phases, the study of palynology, especially fossil dinoflagellate cysts, is one of the principal
techniques used in subdividing the hydrocarbon-bearing successions. High-resolution zonal
schemes have been developed for both these areas, and have been routinely applied for
around thirty years. The BGS has been a key player in the formulation and refinement of
the standard Jurassic scheme and we have shown that integrated studies using these
microfossils can resolve interregional geological problems
Measuring quality of perception in distributed multimedia: Verbalizers vs. imagers
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2008 ElsevierThis paper presents the results of a study which investigated the impact of cognitive styles on perceptual multimedia quality. More specifically, we examine the different preferences demonstrated by verbalizers and imagers when viewing multimedia content presented with different quality of service (QoS) levels pertaining to frame rates and color depth. Recognizing multimedia’s infotainment duality, we used the quality of perception (QoP) metric to characterize perceived quality. Results showed that in terms of low and high dynamisms clips, the frame rate at which multimedia content is displayed influences the levels of information assimilated by Imagers. Whilst black and white presentations are shown to be beneficial for both Biomodals and Imagers in order to experience enhanced levels of information assimilation, Imagers were shown to enjoy presentations in full 24-bit colour
An effective palynological preparation procedure using hydrogen peroxide
Most pre-Quaternary palynology samples are currently prepared by demineralization of the sediment/sedimentary rock matrix using hydrochloric and hydrofluoric acids (HCl and HF respectively). If a consistently effective alternative to this procedure can be developed, palynological processing will be made significantly less hazardous to both laboratory personnel, and to the wider environment. Furthermore, most non-acid processing methods are normally quicker and cheaper than matrix dissolution using acid. Some authors have previously used hydrogen peroxide (H2O2) to extract palynomorphs by the physico–chemical disaggregation of the clay fraction. However, H2O2 is a powerful oxidizing agent and hence can potentially destroy sedimentary organic material, including palynomorphs. A new method using hot H2O2, where exposure of the sample material to the H2O2 is minimized, has been developed. Crushed sample material in a suitable vessel is placed on a hot plate for one minute, treated with 15–30% H2O2 for 10 minutes, then the residue is diluted with cold distilled water. Disaggregated sample material tends to float, and is decanted into a large vessel containing distilled water to further dilute the H2O2. If any undisaggregated sample remains, the procedure is repeated several times if necessary. Relatively indurated sedimentary lithotypes normally require several treatments. The reason for this stepwise treatment is that the organic material is not exposed to H2O2 for sustained periods, thereby reducing the possibility of palynomorph damage/degradation due to oxidation. When the sample matrix has been fully disaggregated, the residue can be further processed as appropriate.
In this study, eight samples of Carboniferous, Jurassic, Paleogene, and Quaternary age were prepared quantitatively using the new H2O2 method. These were all prepared using 30% H2O2. For comparison, they were also prepared quantitatively using HCl/HF and/or sodium hexametaphosphate [(NaPO3)6]. Quantitative preparations allow the concentration of palynomorphs extracted to be determined, and therefore the effectiveness of the techniques used can be compared objectively. The palynomorph residues derived from these three techniques varied markedly. The H2O2 method does not consistently disaggregate all the sample material, particularly the older and more indurated lithotypes. Some evidence of oxidation effects was observed. Two samples of Mississippian mudstone from the U.S.A. were prepared using H2O2 and (NaPO3)6. Both methods produced abundant miospores, however the H2O2 procedure yielded far higher palynomorph concentrations than the (NaPO3)6 technique. Minor degradation of palynomorphs in the H2O2 preparation was noted. The H2O2 and HCl/HF methods were compared directly on a palynomorph-rich sample of Upper Carboniferous mudstone from offshore Scotland. Both preparations produced abundant miospores. The HCl/HF method had significantly higher recovery levels than the H2O2 procedure. It appears that the H2O2 method simultaneously macerates the matrix, and oxidizes any amorphous organic material (AOM) present. In this sample, the HCl/HF residue was relatively rich in AOM. By contrast, the H2O2 preparation is virtually clear of this phytoclast type, which partially obscures palynomorphs. Two samples of the Middle Jurassic Grantham Formation of eastern England were processed using H2O2 and HCl/HF. The two methods produced abundant palynofloras of similar palynomorph concentrations. Two dinoflagellate cyst acmes within the Danian (Paleogene) part of the López de Bertodano Formation of Seymour Island, Antarctica were also tested using H2O2, (NaPO3)6, and HCl/HF. TheH2O2 preparation completely destroyed the dominant taxon, Palaeoperidinium pyrophorum, in one sample. By contrast, the (NaPO3)6 and HCl/HF preparations produced abundant, fully representative palynofloras. In the other sample, the acme of Spinidinium spp. is completely unaffected by the H2O2 preparation procedure. The final sample of this study is an unconsolidated clay of Late Pleistocene age from offshore Scotland. Both the H2O2 and HCl/HF preparations proved similar in both taxonomic content and overall palynomorph yield.
The new method of preparation using hot H2O2 has proved to be extremely effective. In particular, it appears to be superior to the (NaPO3)6 procedure for indurated lithotypes. However care should be taken because H2O2 can destroy certain dinoflagellate cysts and kerogen macerals which are especially susceptible to oxidation. Further development work, and more comparative testing of the H2O2, (NaPO3)6, and HCl/HF procedures, should be undertaken
Between the Lines: documenting the multiple dimensions of computer supported collaborations
When we consider the possibilities for the design and evaluation of Computer Supported Collaborative Learning (CSCL) we probably constrain the CS in CSCL to situations in which learners, or groups of learners collaborate with each other around a single computer, across a local intranet or via the global internet. We probably also consider situations in which the computer itself acts as a collaborative partner giving hints and tips either with or without the addition of an animated pedagogical agent. However, there are now many possibilities for CSCL applications to be offered to learners through computing technology that is something other than a desktop computer, such as the TV or a digital toy. In order to understand how such complex and novel interactions work, we need tools to map out the multiple dimensions of collaboration using a whole variety of technologies. This paper discusses the evolution of a documentation technique for collaborative interactions from its roots in a situation where a single learner is collaborating with a software learning partner, through its second generation: group use of multimedia, to its current test-bed: young children using digital toys and associated software. We will explore some of the challenges these different learning situations pose for those involved in the evaluation of collaborative learning
New evidence for the age of the Athol Formation (Middle Jurassic : Bajocian) in the Tusk-1 and Tusk-2 wells, offshore Carnarvon Basin, Western Australia
The co-occurrence of ammonites with palynomorphs in the Athol Formation of the Tusk-1 and Tusk-2 wells drilled in the offshore Carnarvon Basin, Western Australia confirms the Early Bajocian (Middle Jurassic) age of the Dissiliodinium caddaense dinoflagellate cyst Oppel Zone. The macrofaunas refine this Early Bajocian age to the early Laeviuscula Chronozone. A belemnite from the Tusk-1 well has a strontium isotope (87Sr/86Sr) ratio consistent with the biostratigraphical age. All the identifiable ammonites belong to Pseudotoites robiginosus (Crick). Pseudotoites is prominent in the Early Bajocian of the Indo-Pacific Realm, being known mainly from onshore Western Australia and the Southern Andes, together with rare occurrences in Irian Jaya (west New Guinea); somewhat surprisingly, it is also rarely present in southern Alaska. The palynofloras studied from the Tusk-1 and Tusk-2 wells contain abundant specimens of the marine dinoflagellate cyst Dissiliodinium caddaense, and are assigned to the Dissiliodinium caddaense Oppel Zone. The Athol Formation is a correlative of the Newmarracarra Limestone of the onshore Perth Basin, Western Australia; the distribution of both these units indicates a marine transgression onto the Australian block during the Early Bajocian
The rating of educational aims by Greek and English student-teachers
60 Greek and 60 English Primary teacher-training students rated 25
educational aims on a five-point scale under three conditions: (a) representing their
estimates of the priorities of their own former Primary teachers; (b) representing what
they took to be the views of their present lecturers; and (c) indicating their own
intentions for their teaching career. The result showed the two sets of students to have
taken up very similar stances in nearly all respects and to be further united in the belief
that they had moved a long way from prevailing ideologies of their own schooldays.
The findings are discussed in relation to the patterns of Primary Schooling and Teacher
Education in both countries.peer-reviewe
Invoice from the Riding Club to Ogden Goelet
https://digitalcommons.salve.edu/goelet-personal-expenses/1022/thumbnail.jp
A latest Cretaceous to earliest Paleogene dinoflagellate cyst zonation of Antarctica, and implications for phytoprovincialism in the high southern latitudes
The thickest uppermost Cretaceous to lowermost Paleogene (Maastrichtian to Danian) sedimentary succession in the world is exposed on southern Seymour Island (65° South) in the James Ross Basin, Antarctic Peninsula. This fossiliferous shallow marine sequence, which spans the Cretaceous–Paleogene boundary, has allowed a high-resolution analysis of well-preserved marine palynomorphs. Previous correlation of Cretaceous–Paleogene marine palynomorph assemblages in the south polar region relied on dinoflagellate cyst biozonations from New Zealand and southern Australia. The age model of the southern Seymour Island succession is refined and placed within the stratigraphical context of the mid to high southern palaeolatitudes. Quantitative palynological analysis of a new 1102 m continuous stratigraphical section comprising the uppermost Snow Hill Island Formation and the López de Bertodano Formation (Marambio Group) across southern Seymour Island was undertaken. We propose the first formal late Maastrichtian to early Danian dinoflagellate cyst zonation scheme for the Antarctic based on this exceptional succession. Two new late Maastrichtian zones, including three subzones, and one new early Danian zone are defined. The oldest beds correlate well with the late Maastrichtian of New Zealand. In a wider context, a new South Polar Province based on Maastrichtian to Danian dinoflagellate cysts is proposed, which excludes most southern South American marine palynofloras. This interpretation is supported by models of ocean currents around Antarctica and implies an unrestricted oceanic connection across Antarctica between southern South America and the Tasman Sea
Late Miocene Mediterranean desiccation: topography and significance of the 'Salinity Crisis' erosion surface on-land in southeast Spain: Reply
We welcome this opportunity to amplify the results
of our studies of the Late Miocene Messinian
sequence in the Sorbas Basin of southeast Spain.
The Salinity Crisis concept has captured geological
imagination and found its way into textbooks, but
scrutiny reveals its details to be disturbingly elusive.
Our approach has been to read the history of this
important episode in Neogene history in well-exposed
on-land sections at Sorbas, Almería, near the western
end of the Mediterranean. The Salinity Crisis concept,
as it was first proposed (Hsü et al., 1973, 1977) and
has largely survived (Cita, 1991), is of deep-desiccation
and reflooding of the Mediterranean near the
close of the Miocene. Marine downdraw resulted in
marginal erosion; evaporites accumulated in depressions;
and final marine reflooding completed the
cycle. Our rationale is that if these principal tenets
of the concept are correct, then one or more of their
effects should be recorded throughout the region, both
on the deep Mediterranean floor and in marginal
basins that were contemporaneously connected to
the Mediterranean, including the Sorbas Basin. This
emphasis on the widespread effects of the Salinity
Crisis does not exclude the possibility that they
were overprinted by local conditions, which probably
differed considerably over a region as extensive and
diverse as the Mediterranean basins. Indeed, we have
interpreted the evaporites of the Sorbas Basin to be
local products of basin barring, related to the Salinity
Crisis but not coeval with deep Mediterranean evaporites.
At the same time, we have taken the view that the
regional result of the Salinity Crisis in all marginal
basins should be an erosion surface on the scale of the
massive sea-level fall implied by the concept. It is our
recognition of this erosion surface in the Sorbas Basin
that has drawn most criticism from Fortuin et al.
(2000). Here we provide further details of critical
localities so that our observations can be accurately
assessed
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