The factors affecting attitudes toward HSDPA service and intention to use:a cross-cultural comparison between Asia and Europe

HSDPA (High-Speed Downlink Packet Access) is a 3.5-generation asynchronous mobile communications service based on the third generation of W-CDMA. In Korea, it is mainly provided in through videophone service. Because of the diffusion of more powerful and diversified services, along with steep advances in mobile communications technology, consumers demand a wide range of choices. However, because of the variety of technologies, which tend to overflow the market regardless of consumer preferences, consumers feel increasingly confused. Therefore, we should not adopt strategies that focus only on developing new technology on the assumption that new technologies are next-generation projects. Instead, we should understand the process by which consumers accept new forms of technology and devise schemes to lower market entry barriers through strategies that enable developers to understand and provide what consumers really want.

The attenuation surface for contrast sensitivity has the form of a witch’s hat within the central visual field

Over the full visual field, contrast sensitivity is fairly well described by a linear decline in log sensitivity as a function of eccentricity (expressed in grating cycles). However, many psychophysical studies of spatial visual function concentrate on the central ±4.5 deg (or so) of the visual field. As the details of the variation in sensitivity have not been well documented in this region we did so for small patches of target contrast at several spatial frequencies (0.7–4 c/deg), meridians (horizontal, vertical, and oblique), orientations (horizontal, vertical, and oblique), and eccentricities (0–18 cycles). To reduce the potential effects of stimulus uncertainty, circular markers surrounded the targets. Our analysis shows that the decline in binocular log sensitivity within the central visual field is bilinear: The initial decline is steep, whereas the later decline is shallow and much closer to the classical results. The bilinear decline was approximately symmetrical in the horizontal meridian and declined most steeply in the superior visual field. Further analyses showed our results to be scale-invariant and that this property could not be predicted from cone densities. We used the results from the cardinal meridians to radially interpolate an attenuation surface with the shape of a witch's hat that provided good predictions for the results from the oblique meridians. The witch's hat provides a convenient starting point from which to build models of contrast sensitivity, including those designed to investigate signal summation and neuronal convergence of the image contrast signal. Finally, we provide Matlab code for constructing the witch's hat.

Theory and data for area summation of contrast with and without uncertainty:evidence for a noisy energy model

Contrast sensitivity improves with the area of a sine-wave grating, but why? Here we assess this phenomenon against contemporary models involving spatial summation, probability summation, uncertainty, and stochastic noise. Using a two-interval forced-choice procedure we measured contrast sensitivity for circular patches of sine-wave gratings with various diameters that were blocked or interleaved across trials to produce low and high extrinsic uncertainty, respectively. Summation curves were steep initially, becoming shallower thereafter. For the smaller stimuli, sensitivity was slightly worse for the interleaved design than for the blocked design. Neither area nor blocking affected the slope of the psychometric function. We derived model predictions for noisy mechanisms and extrinsic uncertainty that was either low or high. The contrast transducer was either linear (c1.0) or nonlinear (c2.0), and pooling was either linear or a MAX operation. There was either no intrinsic uncertainty, or it was fixed or proportional to stimulus size. Of these 10 canonical models, only the nonlinear transducer with linear pooling (the noisy energy model) described the main forms of the data for both experimental designs. We also show how a cross-correlator can be modified to fit our results and provide a contemporary presentation of the relation between summation and the slope of the psychometric function.

Pattern integration in the normal and abnormal human visual system

The processing conducted by the visual system requires the combination of signals that are detected at different locations in the visual field. The processes by which these signals are combined are explored here using psychophysical experiments and computer modelling. Most of the work presented in this thesis is concerned with the summation of contrast over space at detection threshold. Previous investigations of this sort have been confounded by the inhomogeneity in contrast sensitivity across the visual field. Experiments performed in this thesis find that the decline in log contrast sensitivity with eccentricity is bilinear, with an initial steep fall-off followed by a shallower decline. This decline is scale-invariant for spatial frequencies of 0.7 to 4 c/deg. A detailed map of the inhomogeneity is developed, and applied to area summation experiments both by incorporating it into models of the visual system and by using it to compensate stimuli in order to factor out the effects of the inhomogeneity. The results of these area summation experiments show that the summation of contrast over area is spatially extensive (occurring over 33 stimulus carrier cycles), and that summation behaviour is the same in the fovea, parafovea, and periphery. Summation occurs according to a fourth-root summation rule, consistent with a “noisy energy” model. This work is extended to investigate the visual deficit in amblyopia, finding that area summation is normal in amblyopic observers. Finally, the methods used to study the summation of threshold contrast over area are adapted to investigate the integration of coherent orientation signals in a texture. The results of this study are described by a two-stage model, with a mandatory local combination stage followed by flexible global pooling of these local outputs. In each study, the results suggest a more extensive combination of signals in vision than has been previously understood.

Income distribution dependence of poverty measure:a theoretical analysis

Using a modified deprivation (or poverty) function, in this paper, we theoretically study the changes in poverty with respect to the 'global' mean and variance of the income distribution using Indian survey data. We show that when the income obeys a log-normal distribution, a rising mean income generally indicates a reduction in poverty while an increase in the variance of the income distribution increases poverty. This altruistic view for a developing economy, however, is not tenable anymore once the poverty index is found to follow a pareto distribution. Here although a rising mean income indicates a reduction in poverty, due to the presence of an inflexion point in the poverty function, there is a critical value of the variance below which poverty decreases with increasing variance while beyond this value, poverty undergoes a steep increase followed by a decrease with respect to higher variance. Identifying this inflexion point as the poverty line, we show that the pareto poverty function satisfies all three standard axioms of a poverty index [N.C. Kakwani, Econometrica 43 (1980) 437; A.K. Sen, Econometrica 44 (1976) 219] whereas the log-normal distribution falls short of this requisite. Following these results, we make quantitative predictions to correlate a developing with a developed economy. © 2006 Elsevier B.V. All rights reserved.

[Fe(μ-btzmp)2(btzmp)2](ClO4)2:a doubly-bridged 1D spin-transition bistetrazole-based polymer showing thermal hysteresis behaviour

The reaction of btzmp (1,2-bis(tetrazol-1-yl)-2-methylpropane) with Fe(ClO4)2 generates a 1D polymeric species, [Fe(μ-btzmp)2(btzmp)2](ClO4)2, showing a steep spin transition (T½↑ = 136 K and T ½↓ = 133 K) with a 3 K thermal hysteresis. The crystal structure at 100 and 200 K reveals that, in contrast to other bistetrazole based spin-transition systems such as [Fe(endi)3](BF4)2 and [Fe(btzp)3](ClO4)2, the present compound has only two ligands bridging the metallic centres, while the other two coordination positions are occupied by two mono-coordinated (non-bridging) btzmp ligands. This peculiarity confers an unprecedented crystal packing in the series of 1D bistetrazole based polymers. The change in spin state is accompanied by an order/disorder transition of the ClO4- counterion. A careful examination of the structural changes occurring upon the spin transition indicates that this order/disorder is most likely affected by the modification of the [tetrazole-centroid]-ND-Fe angle (which is typical of bistetrazole spin-transition materials). Apart from X-ray analysis, also magnetic susceptibility, Mössbauer and UV-vis spectroscopies have been used to characterise the HS and the LS states of [Fe(µ-btzmp)2(btzmp)2](ClO4)2. © The Royal Society of Chemistry.

Optimal time following fluorescein instillation to evaluate rigid gas permeable contact lens fit

PURPOSE: To examine the optimum time at which fluorescein patterns of gas permeable lenses (GPs) should be evaluated. METHODS: Aligned, 0.2mm steep and 0.2mm flat GPs were fitted to 17 patients (aged 20.6±1.1 years, 10 male). Fluorescein was applied to their upper temporal bulbar conjunctiva with a moistened fluorescein strip. Digital slit lamp images (CSO, Italy) at 10× magnification of the fluorescein pattern viewed with blue light through a yellow filter were captured every 15s. Fluorescein intensity in central, mid peripheral and edge regions of the superior, inferior, temporal and nasal quadrants of the lens were graded subjectively using a +2 to -2 scale and using ImageJ software on the simultaneously captured images. RESULTS: Subjectively graded and objectively image analysed fluorescein intensity changed with time (p<0.001), lens region (centre, mid-periphery and edge: p<0.05) and there was interaction between lens region with lens fit (p<0.001). For edge band width, there was a significant effect of time (F=118.503, p<0.001) and lens fit (F=5.1249, p=0.012). The expected alignment, flat and steep fitting patterns could be seen from approximately after 30 to 180s subjectively and 15 to 105s in captured images. CONCLUSION: Although the stability of fluorescein intensity can start to decline in as little as 45s post fluorescein instillation, the diagnostic pattern of alignment, steep or flat fit is seen in each meridian by subjective observation from about 30s to 3min indicating this is the most appropriate time window to evaluate GP lenses in clinical practice.

Kérdőjelek a közgazdaságtanban és oktatásában = Challenges in economic research and education

Ez az esszé a teljesség igénye nélkül kísérli meg áttekinteni azt, hogy mire vezetett a közgazdaságtan világméretekben megindult és a 2008-2009. évi válság lezáratlansága miatt vélhetően évtizedes szinten zajló önvizsgálata. A tudományszak egészét egyszerre jellemzi egyfajta tartalmi kiüresedés és a társtudományokkal való erőteljesebb kapcsolatkeresés, a módszertanok és az iskolák egymás mellett élése - ami egyáltalán nem békés -, valamint a gyakorlat által felvetett kérdések elméleti általánosításának igénye. A magyar közgazdaságtan hagyományos követő szerepe megmaradt, viszont a képzésben szerzett negyedszázados tapasztalatok és az új globális kihívások lényegi átalakításokat indokolnának a mai, túlságosan egységesített képzésben. _____ This essay joins the soul-searching that has developed globally among economists since the financial crisis of 2008-2009, whose still open-ended outcomes make it likely that such self-critical reassessments will continue in the years to come. Economics is marked by the parallel existence of substantive hollowing and in-creased reliance on interfaces with neighbouring disciplines. So the plurality and none-too-peaceful coexistence of schools and methodologies is likely to persist. Similarly abundant are the attempts to theorize and generalize new phenomena in policy and business practices. Hungarian economics continues to be a follower - a trend-taker rather than trend-setter - as it was in the inter-war period. Experience has been accumulating for over 25 years in introducing Western-style higher education in economics. The increase of student numbers and steep decrease in public funding thereof call for major restructuring in curricula, institutions and teaching methods and styles alike.

Tracking rates of ecotone migration due to salt-water encroachment using fossil mollusks in coastal South Florida

We determined the rate of migration of coastal vegetation zones in response to salt-water encroachment through paleoecological analysis of mollusks in 36 sediment cores taken along transects perpendicular to the coast in a 5.5 km2 band of coastal wetlands in southeast Florida. Five vegetation zones, separated by distinct ecotones, included freshwater swamp forest, freshwater marsh, and dwarf, transitional and fringing mangrove forest. Vegetation composition, soil depth and organic matter content, porewater salinity and the contemporary mollusk community were determined at 226 sites to establish the salinity preferences of the mollusk fauna. Calibration models allowed accurate inference of salinity and vegetation type from fossil mollusk assemblages in chronologically calibrated sediments. Most sediments were shallow (20–130 cm) permitting coarse-scale temporal inferences for three zones: an upper peat layer (zone 1) representing the last 30–70 years, a mixed peat-marl layer (zone 2) representing the previous ca. 150–250 years and a basal section (zone 3) of ranging from 310 to 2990 YBP. Modern peat accretion rates averaged 3.1 mm yr)1 while subsurface marl accreted more slowly at 0.8 mm yr)1. Salinity and vegetation type for zone 1 show a steep gradient with freshwater communities being confined west of a north–south drainage canal constructed in 1960. Inferences for zone 2 (pre-drainage) suggest that freshwater marshes and associated forest units covered 90% of the area, with mangrove forests only present along the peripheral coastline. During the entire pre-drainage history, salinity in the entire area was maintained below a mean of 2 ppt and only small pockets of mangroves were present; currently, salinity averages 13.2 ppt and mangroves occupy 95% of the wetland. Over 3 km2 of freshwater wetland vegetation type have been lost from this basin due to salt-water encroachment, estimated from the mollusk-inferred migration rate of freshwater vegetation of 3.1 m yr)1 for the last 70 years (compared to 0.14 m yr)1 for the pre-drainage period). This rapid rate of encroachment is driven by sea-level rise and freshwater diversion. Plans for rehydrating these basins with freshwater will require high-magnitude re-diversion to counteract locally high rates of sea-level rise.

Can Permaculture Design Save the World?

This project will create a blueprint for an eco-settlement in the South Florida area that will house a total of ten people on a five acre plot of land. Using a combination of permaculture design principles and simple tech solutions, this settlement will be capable of supporting its inhabitants “off the grid”, or with no reliance on outside public utilities. More specifically, the settlement will be capable of supporting its inhabitants by producing a minimum of 80% of its resources on site using only all natural farming techniques, proper water management, companion planting and various other techniques. Instead of using modern agricultural practices that damage the land in the long term, all of the principles that will be used in this design will allow the land to heal over time while still producing most of what is needed for any inhabitants. This project is significant because all of the principles used are time-tested and capable of adapting to any type of environment. The principles used do not have a steep learning curve. In fact, anyone ranging from a kindergartener to a 90-year-old will be able to learn and teach the required skill sets in as little as one week. By contrast, in order to fully utilize GMO crops, first a scientist must spend a minimum of eight years getting degrees in various fields of study to even reach a textbook understanding of the exact science. In addition, several years must be spent in sterile lab environments to see the results of complex experiments that may not even be used, thus wasting time, money, and resources. I am certain that this will be successful because similar goals have already been reached by people around the world without access to modern utilities. The only major difference is that my approach will be documented scientifically, and show that not only is this way of life healthy, but also easy and practical. Because of this, my project will bring permaculture design into the spotlight, and will hopefully see widespread adoption. This will result in cities designed with the intent to live with nature instead of conquering it, and will hopefully aid the earth in healing for future generations.

Results of analysis and model simulation of the bed profiles

Bedforms such as dunes and ripples are ubiquitous in rivers and coastal seas, and commonly described as triangular shapes from which height and length are calculated to estimate hydrodynamic and sediment dynamic parameters. Natural bedforms, however, present a far more complicated morphology; the difference between natural bedform shape and the often assumed triangular shape is usually neglected, and how this may affect the flow is unknown. This study investigates the shapes of natural bedforms and how they influence flow and shear stress, based on four datasets extracted from earlier studies on two rivers (the Rio Paraná in Argentina, and the Lower Rhine in The Netherlands). The most commonly occurring morphological elements are a sinusoidal stoss side made of one segment and a lee side made of two segments, a gently sloping upper lee side and a relatively steep (6 to 21°) slip face. A non-hydrostatic numerical model, set up using Delft3D, served to simulate the flow over fixed bedforms with various morphologies derived from the identified morphological elements. Both shear stress and turbulence increase with increasing slip face angle and are only marginally affected by the dimensions and positions of the upper and lower lee side. The average slip face angle determined from the bed profiles is 14°, over which there is no permanent flow separation. Shear stress and turbulence above natural bedforms are higher than above a flat bed but much lower than over the often assumed 30° lee side angle.

Expressão geofísica-estrutural do lineamento transbrasiliano na porção central da Bacia do Parnaíba (Maranhão-Piauí)

The objective of this study was to characterize the structural-geophysical expression of the Transbrasiliano Lineament (TBL) in the east-central portion of the Parnaíba Basin. The TBL corresponds to a major Neoproterozoic NE-trending shear zone related to the Brasiliano orogenic cycle, with dextral strike-slip kinematics, underlying (but also laterally exposed in the NE and SW basin edges) the sedimentary section of the Parnaíba Basin. In this study, the interpretation of gravity and magnetic anomaly maps is consistent with the TBL kinematics, the signature of the geophysical anomalies corresponding to the high (plastic behaviour) and subsequent declining temperature (ductile to brittle behaviour) stages during Brasiliano and late Brasiliano times. The pattern of residual gravity anomalies is compatible with an S-C dextral pair shaping the geological bodies of an heterogeneous basement, such as slices of gneisses and granulites (positive anomalies), granitic and low-medium grade metasedimentary rocks (negative anomalies). Such anomalies curvilinear trends, ranging from NNE (interpreted as S surfaces) to NE (C surfaces), correspond to flattening surfaces (S), while the NE rectilinear trend must represent a C band. The narrower magnetic anomalies also display NNE to NE (S surfaces) trends and should correspond to similar (although narrower and more discontinuous) sources in the equivalent anomaly patterns. Pre-Silurian pull-apart style grabens may contribute to the NE negative gravimetric anomalies, although this interpretation demands control by seismic data analysis. On the other hand, the curvilinear anomalies associated to contractional trends are incompatible with their interpretation as pre-Silurian graben, in both maps. In the (reduced to the pole) magnetic anomalies map, most of these are again associated to low-temperature shear zones (C planes) and faults, juxtaposing distinct blocks in terms of magnetic properties, or eventually filled with basic bodies. It is also possible that some isolated magnetic anomalies correspond to igneous bodies of late-Brasiliano or Mesozoic age. The basement late discontinuities pattern can be interpreted in analogy to the Riedel fractures model, with steep dipping surfaces and a sub-horizontal movement section. This study also explored 2D gravity modeling controlled by the interpretation of a dip seismic line as regards to the Transbrasiliano Lineament. The rock section equivalent to the Jaibaras Group occupying a graben structure (as identified in the seismic line) corresponds to a discrete negative anomaly superimposed to a gravimetric high, once again indicating a stronger influence of older crystalline basement rocks as gravimetric sources, mainly reflecting the heterogeneities and anisotropies generated at high temperature conditions and their subsequent cooling along the TBL, during the Brasiliano cycle.

Expressão geofísica-estrutural do lineamento transbrasiliano na porção central da Bacia do Parnaíba (Maranhão-Piauí)

The objective of this study was to characterize the structural-geophysical expression of the Transbrasiliano Lineament (TBL) in the east-central portion of the Parnaíba Basin. The TBL corresponds to a major Neoproterozoic NE-trending shear zone related to the Brasiliano orogenic cycle, with dextral strike-slip kinematics, underlying (but also laterally exposed in the NE and SW basin edges) the sedimentary section of the Parnaíba Basin. In this study, the interpretation of gravity and magnetic anomaly maps is consistent with the TBL kinematics, the signature of the geophysical anomalies corresponding to the high (plastic behaviour) and subsequent declining temperature (ductile to brittle behaviour) stages during Brasiliano and late Brasiliano times. The pattern of residual gravity anomalies is compatible with an S-C dextral pair shaping the geological bodies of an heterogeneous basement, such as slices of gneisses and granulites (positive anomalies), granitic and low-medium grade metasedimentary rocks (negative anomalies). Such anomalies curvilinear trends, ranging from NNE (interpreted as S surfaces) to NE (C surfaces), correspond to flattening surfaces (S), while the NE rectilinear trend must represent a C band. The narrower magnetic anomalies also display NNE to NE (S surfaces) trends and should correspond to similar (although narrower and more discontinuous) sources in the equivalent anomaly patterns. Pre-Silurian pull-apart style grabens may contribute to the NE negative gravimetric anomalies, although this interpretation demands control by seismic data analysis. On the other hand, the curvilinear anomalies associated to contractional trends are incompatible with their interpretation as pre-Silurian graben, in both maps. In the (reduced to the pole) magnetic anomalies map, most of these are again associated to low-temperature shear zones (C planes) and faults, juxtaposing distinct blocks in terms of magnetic properties, or eventually filled with basic bodies. It is also possible that some isolated magnetic anomalies correspond to igneous bodies of late-Brasiliano or Mesozoic age. The basement late discontinuities pattern can be interpreted in analogy to the Riedel fractures model, with steep dipping surfaces and a sub-horizontal movement section. This study also explored 2D gravity modeling controlled by the interpretation of a dip seismic line as regards to the Transbrasiliano Lineament. The rock section equivalent to the Jaibaras Group occupying a graben structure (as identified in the seismic line) corresponds to a discrete negative anomaly superimposed to a gravimetric high, once again indicating a stronger influence of older crystalline basement rocks as gravimetric sources, mainly reflecting the heterogeneities and anisotropies generated at high temperature conditions and their subsequent cooling along the TBL, during the Brasiliano cycle.

Lithology, micropaleontology and isotope record of sediments from the Nordic Seas

On the basis of various lithological, mircopaleontological and isotopic proxy records covering the last 30,000 calendar years (cal kyr) the paleoenvironmental evolution of the deep and surface water circulation in the subarctic Nordic seas was reconstructed for a climate interval characterized by intensive ice-sheet growth and subsequent decay on the surrounding land masses. The data reveal considerable temporal changes in the type of thermohaline circulation. Open-water convection prevailed in the early record, providing moisture for the Fennoscandian-Barents ice sheets to grow until they reached the shelf break at ~26 cal. kyr and started to deliver high amounts of ice-rafted debris (IRD) into the ocean via melting icebergs. Low epibenthic delta18O values and small-sized subpolar foraminifera observed after 26 cal. kyr may implicate that advection of Atlantic water into the Nordic seas occurred at the subsurface until 15 cal. kyr. Although modern-like surface and deep-water conditions first developed at ~13.5 cal. kyr, thermohaline circulation remained unstable, switching between a subsurface and surface advection of Atlantic water until 10 cal. kyr when IRD deposition and major input of meltwater ceased. During this time, two depletions in epibenthic delta13C are recognized just before and after the Younger Dryas indicating a notable reduction in convectional processes. Despite an intermittent cooling at ~8 cal. kyr, warmest surface conditions existed in the central Nordic seas between 10 and 6 cal. kyr. However, already after 7 cal. kyr the present day situation gradually evolved, verified by a strong water mass exchange with the Arctic Ocean and an intensifying deep convection as well as surface temperature decrease in the central Nordic seas. This process led to the development of the modern distribution of water masses and associated oceanographic fronts after 5 cal. kyr and, eventually, to today's steep east-west surface temperature gradient. The time discrepancy between intensive vertical convection after 5 cal. kyr but warmest surface temperatures already between 10 and 6 cal. kyr strongly implicates that widespread postglacial surface warming in the Nordic seas was not directly linked to the rates in deep-water formation.

Sedimentology of cores from the Bellingshausen Sea, Antarctic

On the continental rise west of the Antarctic Peninsula there are nine large mounds interpreted as sediment drifts, separated by turbidity current channels. Drift 7 is 150 km long, 70 km wide and up to 700 m high and is asymmetric, with steep sides on the south-east (towards the continent) and south-west, and gentle slopes to north-west and north-east. Cores on the gentle sides of the drift show a cyclicity between brown, bioturbated, diatom-bearing mud with foraminifera and radiolarians, and grey, laminated, barren mud. Biostratigraphic evidence is consistent with a Late Quaternary age. Detailed lithostratigraphy and magnetic susceptibility data allow precise correlation over distances of tens of kilometres. On the basis of chemostratigraphy, the brown sediment is interpreted as interglacial (isotope stages 1 and 5) and the grey as glacial (stages 2-4 and 6). Sedimentation rates are 3.0-5.5 cm/ka. Cores on the steep sides of the drift recovered a condensed section with thinner cycles and hiatuses. Fine grain size, very poor sorting and the absence of a mode in the silt size range indicate deposition from suspension with only weak current activity, There is little evidence for cyclic changes in bottom current strength. Supply of sediment to the benthic nepheloid layer was by entrainment ofmud from turbidity currents, and by settling ofpelagic material (biogenic grains, IRD, sediment suspended in meltwater plumes). Cyclic changes in sediment supply include more biogenic supply in interglacials with less sea ice cover, more terrigenous supply from turbidites in glacials with ice sheets grounded to the shelf edge, and changes in IRD content.