bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Analysis of the Validity of Capital Asset Pricing Model: Evidence from Pakistan Stock Exchange
Authors: Akhtar Adeel , Malik Muhammad Shaukat , Nusrat Imran , Bakhsh Allah 
Published: September 2017

The aim of this study was to find evidence for the implementation of capital asset pricing model (CAPM) on companies listed at Pakistan StockExchange before, during and after financial crisis. The data of 50 companies were collected ranging from various sectors of Pakistan stockexchange. Data were divided into 3 different groups: year 2005-2007, 2008-2010 and 2011-2013. Regression analysis was conducted for testingthe hypotheses by taking Pakistan stock exchange 100 index as independent variable and individual stocks return as dependent variable.Three different levels of significance have been used: significance at 1%, significance at 5%, and significance at 10%. The results suggested that inPakistan different business organizations due to narrow scope of business are relatively less diversified and have relatively high flexibility ofresponding unexpected and uncertain events, influencing overall market performance. Similarly, large number of companies, specifically duringperiod of financial crisis, are affected and influenced by numerous risk factors. It was concluded that fair prices of stock cannot be determinedwith the help of CAPM in Pakistan.
Influence of Creative Accounting on Reliability and Objectivity of Financial Reporting (Factors Responsible For Adoption of Creative Accounting Practices in Pakistan).
Authors: Shahid Maria 
Published: September 2017

Purpose: Intellectual modifications (creative accounting) in financial reports to make them attractive are very emerging and vastly accepted practices around the globe. But these practices are deceiving and unethical. This study aims to explore the factors encourage the adoption of creative accounting practices like agency problem, corporate governance, company's ethical value, company's future orientation etc. as well as how these practices affect the reliability and objectivity of financial reporting.
Methodology: This research is an empirical research and data is collected from accounting and management professionals of manufacturing industry of Punjab via structured questionnaire. Convenient sampling technique used to select sample size and SPSS software used for data analysis.
Findings: Results of this research explored the positive association between agency problem and creative accounting while corporate governance, company's ethical value, company's future orientation have negative impact on creative accounting. It is also verified that creative accounting has significant negative impact on reliability as well as objectivity of financial reporting.
Implications: Results of this study will assist the company's management how to control adverse influence of these manipulative activities on reliability and objectivity of financial reports as well as provide literacy to investors to be aware of such extensively using speculative activities.
Limitations: Limitations of this study are that it is only considering few factors as well as manufacturing industry of Punjab.
Late Neogene Sirius Group strata in Reedy Valley, Antarctica: a multiple-resolution record of climate, ice-sheet and sea-level events
Authors: Wilson Gary S. , Harwood David M. , Askin Rosemary A. , Levy Richard H. 
Published: September 2017

AbstractLate Neogene Sirius Group strata from Tillite Spur and Quartz Hills in the Reedy Glacier area, Antarctica, demonstrate the variability in Sirius Group facies and contrasts Sirius Group strata deposited at high and low paleo-elevation, respectively. The Tillite Spur and Quartz Hills Formations (Pliocene) are formally defined here.The Tillite Spur Formation type section crops out on the edge of the Wisconsin Plateau overlooking Tillite Spur. It comprises 32m of alternating coarse gray conglomerate and muddy olive-brown diamictites. The Quartz Hills Formation type section crops out above the western margin of Reedy Glacier in a pre-existing cirque towards the southern end of the Quartz Hills. It comprises c.100m of alternating massive diamictites and rhythmically interbedded sandstone and laminated mudstones which were deposited close to sea level and subsequently rapidly uplifted (>500 m Myr−1) to their present elevation at c. 1500 m. Three orders of paleoclimatic variability are recorded in the Sirius Group strata from Reedy Valley: (1) recycled marine microfloras in glacial diamictites indicate intervals of marine incursion into the Antarctic cratonic interior co-occurring with reductions in the East Antarctic ice sheet; (2) an advancing and retreating paleo-Reedy Glacier deposited a glacial/interglacial sequence alternating on a 10-100 kyr scale; 3) Centimeter and millimeter stratification in strata of the Quartz Hills Formation record annual kyr scale variability.
Modelling the evolution of subglacial tunnels due to varying water input
Authors: Cutler Paul M. 
Published: September 2017

AbstractThe time evolution of a subglacial tunnel cross-section is examined usine a two-dimensional finite-element ice-flow model coupled to an idealized drainage system. Simulations are driven by physically based calculations of surface water-input variations at Slorgiaciaren, Sweden. Highlights of the model are its ability to handle unsteady conditions and irregular tunnel shapes. Agreement between modelled water pressure and borehole water levels is good. The following conclusions are reached: (i) Tunnels adapt to fluctuating inflow on time-scales of days. Storms, during which effective pressure ranges from 0 to 0.9 MPa, cause significant adjustments but daily fluctuations due solely to melt-water inflow are minor, (ii) Open-channel flow may become commonplace late in the ablation season, (iii) Initial tunnel shape influences subsequent tunnel evolution and seasonal water-pressure variation. Over the course of a summer, tunnels retain some of their initial shape, though in all experiments the width-to-height ratio increased with time, (iv) Tunnel contraction forms broad low tunnels. However, (v) given two tunnels of equal initial area, the higher narrower one expands more rapidly. Thus, more semi-circular tunnels may capture How from broader neighbours early in the summer.
Analysis of the 1993-95 Bering Glacier (Alaska) surge using differential SAR interferometry
Authors: Fatland Dennis R. , Lingle Craig S. 
Published: September 2017

AbstractDifferential spaceborne radar interferometry observations of West Bagley Icefield are used to measure surface velocity and topography. Bagley Icefield is the accumulation area fur Bering Glacier which surged in two phases from spring 1993 through summer 1905. The observations presented are based on data collected during the winter of 1992, prior to the surge, and during winter 1994 while the surge was in full progress. Both observation intervals correspond to 3 day repeat orbit phases of the ERS-I C-band SAR. This paper gives an overview of the algorithms used to derive surface-velocity vector fields and topography for valley glaciers from SAR images. The resulting high-resolution velocity data clearly show West Bagley Icefield accelerating from its quiescent pre-surge velocity by a factor of 2.7 in response to the Bering Glacier surge. Persistence of lnterfero-metric phase coherence and the relatively moderate degree of acceleration on the western arm of Bagley Icefield suggest that the velocity increase may have been caused by increased longitudinal stress gradients resulting from coupling to the surging main trunk of Bering Glacier.
Glaciohydraulic supercooling: a freeze-on mechanism to create stratified, debris-rich basal ice: II. Theory
Authors: Alley Richard B. , Lawson Daniel E. , Evenson Edward B. , Strasser Jeffrey C. , Larson Grahame J. 
Published: September 2017

AbstractSimple theory supports field observations (Lawson and others, 1998 that subGlaciol water flow out of overdeepenings can cause accretion of layered, debris-bearing ice to the bases of glaciers. The large meltwater flux into a temperate glacier at the onset of summer melting can cause rapid water flow through expanded basal cavities or other flow paths. If that flow ascends a sufficiently steep slope out of an overdeepèning, the water will supercool as the pressure-melting point rises, and basal-ice accretion will occur. Diurnal, occasional or annual fluctuations in water discharge will cause variations in accretion rate, debris content of accreted ice or subsequent diagenesis, producing layers. Under appropriate conditions, net accretion of debris-bearing basal ice will allow debris fluxes that are significant in the glacier sediment budget.
Errors in daily ablation measurements in northern Greenland, 1993-94, and their implications for glacier climate studies
Authors: Braithwaite Roger J. , Konzelmann Thomas , Marty Christoph , Olesen Ole B. 
Published: September 2017

AbstractAblation climate studies were made at two locations in northern Greenland in the summers of 1993 and 1994, respectively. Daily ablation was measured at ten stakes within a small area, and the data were compared with each other to detect gross errors. For example, high standard deviations for data taken on the same day, or low correlations between data series at different stakes, indicate erroneous data. After discarding data for one stake in 1993 and two stakes in 1994, random errors in daily ablation data for individual stakes are ± 5 kg m 2 d−1, which is further reduced to only about db 2 kg m−2d−1 by averaging over eight or nine stakes. Random errors in calculated energy balances using the present ablation data are much lower than found in earlier stuthes in West Greenland where ablation was only measured on three stakes without any attempt to detect gross errors. Aside from day-to-day errors, there are ±10% differences in mean ablation at different stakes, which are probably caused by small-scale variations in surface albedo. Such interstate differences give a ± 10% uncertainty in positive degree-day factors, which are 9.8 ± 0.9 and 5.9 ± 0.6 kg m 2 d −1 deg −1 for the two sites.
Migration of the Siple Dome ice divide, West Antarctica
Authors: Nereson N. A. , Raymond C. F. , Waddington E. D. , Jacobel R. W. 
Published: September 2017

AbstractThe non-linearity of the ice-flow law or a local accumulation low over an ice divide can cause isochrones (internal layers) to be shallower under the divide relative to the flanks, forming a “divide bump” in the internal layer pattern. This divide signature is analyzed using ice-flow models and inverse techniques to detect and quantify motion of the Siple Dome ice divide, West Antarctica. The principal feature indicating that migration has occurred is a distinct tilt of the axis of the peaks of the warped internal layers beneath the divide. The calculated migration rate is 0.05-0.50 m a−1 toward Ice Stream D and depends slightly on whether the divide bump is caused by the non-linearity of ice flow or by a local accumulation low. Our calculations also suggest a strong south-north accumulation gradient of 5-10 x 10−6 a−1 in a narrow zone north of the divide. A consequence of divide migration is that pre-Holocene ice is thickest about 0.5 km south of the present divide position. Divide motion indicates that non-steady processes, possibly associated with activity of the bounding ice streams, are affecting the geometry of Siple Dome. The migration rate is sufficiently slow that the divide bump is maintained in the internal layer pattern at all observable depths. This suggests that major asynchronous changes in the elevation or position of the bounding ice streams are unlikely over at least the past 103-104 years.
Thickening of the western part of the Greenland ice sheet
Authors: Thomas Robert H. , Csathó Beáta M. , Gogineni Sivaprasad , Jezek Kenneth C. , Kuivinen Karl 
Published: September 2017

AbstractNASA's Program for Arctic Regional Climate Assessment (PARCA) includes measurements of ice velocity and ice thickness along the 2000 m elevation contour line in the western part of the ice sheet. Here we use these measurements together with published estimates of snow-accumulation rates to infer die mass balance, or rate of thickening/thinning, of the ice-sheet catchment area inland from the velocity traverse. Within the accuracy to which we know snow-accumulation rates, the entire area is in balance, but localized regions inland from Upernavik Isstrom and Jakobshavn Isbra both appear to be thickening by about 10 cm a-1.
An improved coherent radar depth sounder
Authors: Gogineni S. , Chuah T. , Allen C. , Jezek K. , Moore R. K. 
Published: September 2017

AbstractThe University of Kansas developed a coherent radar depth sounder during the 1980s. This system was originally developed for glacial ice-thickness measurements in the -Antarctic. During the field tests in the Antarctic and Greenland, we found the system performance to be less than optimum. The field tests in Greenland were performed in 1993, as a part of the NASA Program for Arctic Climate Assessment (PARCA). We redesigned and rebuilt this system to improve the performance.The radar uses pulse compression and coherent signal processing to obtain high sensitivity and fine along-track resolution. It operates at a center frequency of 150 MHz with a radio frequency bandwidth of about 17 MHz., which gives a range resolution of about 5m in ice. We have been operating it from a NASA P-3 aircraft for collecting ice-thickness data in conjunction with laser surface-elevation measurements over the Greenland ice sheet during the last 4years. We have demonstrated that this radar can measure the thickness of more than 3 km of cold ice and can obtain ice-thickness information over outlet glaciers and ice margins.In this paper we provide a brief survey of radar sounding of glacial ice, followed by a description of the system and subsystem design and performance. We also show sample results from the held experiments over the Greenland ice sheet and its outlet glaciers.
Temperature history and accumulation timing for the snowpack at GISP2, central Greenland
Authors: Shuman C. A. , Alley R. B. , Fahnestock M. A. , Bindschadler R. A. , White J. W. C. , Winterle J. , Mconnell J. R. 
Published: September 2017

AbstractPrevious research has documented a close association between high-resolution snow-pit profiles of hydrogen and oxygen stable-isotope ratios and multi-year Special Sensor Microwave/lmager (SSM/I) 37 GHz brightness temperature data in central Greenland. Comparison of the SSM/I data to profiles obtained during the 1989-91 field seasons indicated that δD and δ18O data from the near-surface snow at the Greenland summit are a reliable, high-resolution temperature proxy. To test this new technique further, additional stable-isotope data were obtained from a 2 m snow pit constructed during late-June 1995 near the GISP2 site.This new profile, supported by pit stratigraphy and chemistry data, confirms the utility of comparing stable-isotope records with SSM/I brightness temperatures. The sub-annual variation of the δD record at the GISP2 site was determined using 15 match points, from approximately December 1991 through June 1995 and was guided in part by time-constrained hoar layers. The close association of these temperature proxies supports the assertion that snow accumulation occurs frequently through the year and that the isotope record initially contains temperature information from many times of the year. This is also independently confirmed by analysis of H2O2 data. The slope of the multi-year T vs δ correlation was evaluated along with the sub-annual variation in the amount, rate and timing of accumulation. These new results are consistent with those from the previous study and they also demonstrate that the snow in this area initially contains temperature and chemical records with sub-annual resolution. This encourages confident interpretation of the paleoclimatic signal variations in the GISP2 and GRIP deep cores.
Discrimination of glacier facies using multi-temporal SAR data
Authors: Partington K. C. 
Published: September 2017

AbstractGlacier facies from the Greenland ice sheet and the Wrangell-St Elias Mountains, Alaska, are analyzed using multi-temporal synthetic aperture radar (SAR) data from the European Space Agency ERS-1 satellite. Distinct zones and facies are visible in multi-temporal SAR data, including the dry-snow facies, the combined percolation and wet-snow facies, the ice facies, transient melt areas and moraine. In Greenland and south-central Alaska, very similar multi-temporal signatures are evident for the same facies, although these facies are found at lower altitude in West Greenland where the equilibrium line appears to be found at sea level at 71°30?N during the year analyzed (1992-93), probably because of the cooling effect of the eruption of Mount Pinatubo. In Greenland, both the percolation and dry-snow facies are excellent distributed targets for sensor calibration, with backscatter coefficients stable to within 0.2 dB. However, the percolation facies near the top of Mount Wrangell are more complex and less easily delineated than in Greenland, and at high altitude the glacier facies have a multi-temporal signature which depends sensitively on slope orientation.
Improving digital elevation models over ice sheets using AVHRR-based photoclinometry
Authors: Scambos Ted A. , Fahnestock Mark A. 
Published: September 2017

AbstractAdvanced very high-resolution radiometer (AVHRR) images and a radar-altimetry-based digital elevation model (DEM) covering part of the northeast Greenland ice stream are combined to create an improved topographic map of the area using photoclinometry. In this application of photoclinometry, a DEM is used to establish the photometric relationship for two AVHRR images of a snow surface. Slopes from the DEM are compared with AVHRR data that are filtered (i.e. blurred) to the resolution of the DEM to give an empirical photometric determination. This is then used to convert unfiltered AVHRR data into quantitative slope measurements of the surface in the along-sun direction in each image, resolving features not present (or poorly represented) in the DEM. Co-registration of the images is based on the assumption that the two slope fields from the images describe one continuous smooth surface. The combined slopes are then converted to topography. In the test case, the technique adds topographic details with spatial scales of ~3 to ~20 km. A comparison of our results with airborne laser elevation profiles demonstrates that the new technique recovers most of the topography that is missed by the DEM. The improved topographic map reveals a ten-fold increase in local surface relief over the ice-stream feature, and shows the presence of shallow troughs over the shear margins of the feature.
Radar reflections reveal a wet bed beneath stagnant Ice Stream C and a frozen bed beneath ridge BC, West Antarctica
Authors: Bentley C. R. , Lord N. , Liu C. 
Published: September 2017

AbstractDigital airborne radar data were collected during the 1987-88 Antarctic field season in nine gridded blocks covering the downstream portions of Ice Stream B (6km spacing) and Ice Stream C (11 km spacing), together with a portion of ridge BC between them. An automated processing procedure was used for picking onset times of the reflected radar pulses, converting travel times to distances, interpolating missing data, converting pressure transducer readings, correcting navigational drift, performing crossover analysis, and zeroing rémanent crossover errors. Interpolation between flight-lines was carried out using the minimum curvature method.Maps of ice thickness (estimated accuracy 20 m) and basal-reflection strength (estimated accuracy 1 dB) were produced. The ice-thickness map confirms the characteristics of previous reconnaissance maps and reveals no new features. The reflection-strength map shows pronounced contrasts between the ice streams and ridge BC and between the two ice streams themselves. We interpret the reflection strengths to mean that the bed of Ice Stream C, as well as that of Ice Stream B, is unfrozen, that the bed of ridge BC is frozen and that the boundary between the frozen bed of ridge BC and the unfrozen bed of Ice Stream C lies precisely below the former shear margin of the ice stream.
Mapping subglacial surfaces of temperate valley glaciers by two-pass migration of a radio-echo sounding survey
Authors: Welch B.C. , Pfeffer W.T. , Harper J.T. , Humphrey N.F. 
Published: September 2017

AbstractHigh-resolution maps of the glacier bed are developed through a pseudo-three-dimensional migration of a dense array of radio-echo sounding profiles. Resolution of three-dimensional maps of subglacial surfaces is determined by the radio-echo sounding wavelength, data sparing in the field, and migration. Based on synthetic radio-echo sounding profile experiments, the maximum resolution of the final map cannot exceed one half-wavelength. A methodology of field and processing techniques is outlined to develop a maximum-resolution map of the glacier bed. The field and processing techniques are used to develop a map of the glacier bed below part of Worthington Glacier, a temperate valley glacier in south-central Alaska. The field techniques and the processing steps used on the glacier result in a map of 20 m x 20 m resolution.
Precise dielectric profiling of ice cores: a new device with improved guarding and its theory
Authors: Wilhelms Frank , Kipfstuhl Josef , Miller Heinz , Heinloth Klaus , Firestone John 
Published: September 2017

AbstractDielectric profiling (DEP), a capacitive method for measuring an ice core’s electrical conductivity and permittivity, has been in use for several years. We have built an improved DEP instrument with a modified guarded-electrode geometry whose capacitance can be determined from potential theory. The new instrument can measure an ice core’s conductivity and permittivity to within a few per cent error, a high enough accuracy to infer its density using well-known models.
The Eclipse drill: A field-portable intermediate-depth ice-coring drill
Authors: Blake Erik W. , Wake Cameron P. , Gerasimoff Michael D. 
Published: September 2017

AbstractA derivative of the Danish tipping-lower intermediate-depth ice-coring drill system has been developed for use in remote areas. The system as described is capable of drilling to depths of 250 m, although the drill has been proven to 350 m. The drill system is designed to be transported by hand and consumes 700 W maximum power from a 24 V Ac. battery bank charged by solar panels or a small generator. A field test in the St Elias Mountains, Yukon, produced good-quality core to 161.6 m depth; drilling at 6500 m a.s.l. on Far East Rongbuk Glacier, Mount Everest, produced good core to 42 m depth.
Using the temporal variability of satellite radar altimetric observations to map surface properties of the Antarctic ice sheet
Authors: Legrésy Benoît , Rémy Frédérique 
Published: September 2017

AbstractThe problem of measuring surface height and snowpack characteristics from satellite radar altimeter echoes is investigated. In this paper, we perform an analysis of the ERS1 altimeter dataset acquired during a 3 day repeat orbit. The analysis reveals that there are temporal variations in shapes of the radar altimeter echo and that these variations are linked to meteorological phenomena. The time- and space-scales over which these variations apply are a few to tens of days and a few hundred kilometres, respectively. This phenomenon, if not accounted for, can create error in the height measurement. A numerical echo model is used to recover snowpack characteristics by taking advantage of the temporal variations of the radar echoes. A map of penetration depth of the radar waves in the Ku band over the Antarctic continent is obtained and suggests that grain-size produces the dominant effect on radar extinction in the snowpack at this frequency. Finally, a procedure is proposed to correct the height measurement within the context of ice-sheet mass-balance survey.