scholarly journals A framework for attenuation method selection evaluated with ice-penetrating radar data at South Pole Lake

2020 ◽  
Vol 61 (81) ◽  
pp. 176-187 ◽  
Author(s):  
Benjamin H. Hills ◽  
Knut Christianson ◽  
Nicholas Holschuh
Keyword(s):  
Survey Design ◽  
Radar Data ◽  
South Pole ◽  
Empirical Methods ◽  
Arrhenius Model ◽  
Method Selection ◽  
Methodological Comparison ◽  
Measured Power ◽  
Do So ◽  
Conductivity Models

AbstractAll radar power interpretations require a correction for attenuative losses. Moreover, radar attenuation is a proxy for ice-column properties, such as temperature and chemistry. Prior studies use either paired thermodynamic and conductivity models or the radar data themselves to calculate attenuation, but there is no standard method to do so; and, before now, there has been no robust methodological comparison. Here, we develop a framework meant to guide the implementation of empirical attenuation methods based on survey design and regional glaciological conditions. We divide the methods into the three main groups: (1) those that infer attenuation from a single reflector across many traces; (2) those that infer attenuation from multiple reflectors within one trace; and (3) those that infer attenuation by contrasting the measured power from primary and secondary reflections. To assess our framework, we introduce a new ground-based radar survey from South Pole Lake, comparing selected empirical methods to the expected attenuation from a temperature- and chemistry-dependent Arrhenius model. Based on the small surveyed area, lack of a sufficient calibration surface and low reflector relief, the attenuation methods that use multiple reflectors are most suitable at South Pole Lake.

scholarly journals ERRATUM: “THE SPITZER SOUTH POLE TELESCOPE DEEP FIELD: SURVEY DESIGN AND INFRARED ARRAY CAMERA CATALOGS” (2013, ApJS, 209, 22)

2014 ◽  
Vol 212 (1) ◽  
pp. 16 ◽  
Author(s):  
M. L. N. Ashby ◽  
S. A. Stanford ◽  
M. Brodwin ◽  
A. H. Gonzalez ◽  
J. Martinez-Manso ◽  
...  
Keyword(s):  
Field Survey ◽  
Survey Design ◽  
South Pole ◽  
South Pole Telescope ◽  
Array Camera ◽  
Infrared Array

scholarly journals On the psychological consequences of unemployment in South-Africa

2012 ◽  
Vol 15 (3) ◽  
pp. 235-252 ◽  
Author(s):  
Hans De Witte ◽  
Sebastiaan Rothmann ◽  
Leone TB Jackson
Keyword(s):  
South Africa ◽  
Survey Design ◽  
Psychological Consequences ◽  
Negative Experiences ◽  
Unemployed People ◽  
North West ◽  
The North ◽  
Job Application ◽  
Affective Experiences ◽  
Do So

The objective of this study was to investigate the affective experiences, attitudes to work, and job application behaviour of unemployed people. A survey design was used and samples (N = 381) were drawn from unemployed people in the North West Province. The Experiences of Unemployment Questionnaire was administered. Regarding affective experiences, being unemployed was described as very unpleasant and it was associated with boredom, loneliness, uncertainty about the future, concerns about financial matters, emptiness and conflict. When it came to the participants’ attitudes to work, the results showed that almost 96 per cent of them regarded work as important, particularly because it provides meaning. Regarding job application behaviour, the results showed that most of the participants would like to find a job within the month, and they expected to do so. Almost 78 per cent of the participants were asking people for a job at least once a week or more often. Most of them asked friends and acquaintances for employment information, but unemployed people also reported that they looked out for advertisements. People with poor education had the most negative experiences of unemployment and saw work as more important than did those with better education.

scholarly journals E-learning Delivery Platforms for Improving Teaching/Learning During COVID-19 Lockdown in Private Universities, South-South Nigeria

2021 ◽  
Vol 2 (3) ◽  
pp. 160-163
Author(s):  
Effiong Edet Asuquo ◽  
Rosemary Young Godwin
Keyword(s):  
Sample Size ◽  
Survey Design ◽  
Private Universities ◽  
Sampling Technique ◽  
Cluster Sampling ◽  
Learning Platform ◽  
E Learning ◽  
Research Questions ◽  
Teaching Learning ◽  
Do So

The purpose of this study was to examine the extent to which e-learning delivery platforms were utilized to improve teaching/learning during Covid-19 lockdown in Private Universities in South-South Nigeria. To achieve this, three specific objectives and three research questions were asked to guide the study. An expost facto survey design was adopted for the study. The study was conducted in South-South Nigeria. The population consisted of 4305 students of five private universities in South-South Nigeria. A sample size of 366 was selected using the Taro Yamane formula and a cluster sampling technique was used for the study. An instrument titled “Utilization of E-learning Platform for teaching/Learning during the Covid-19 Lockdown Questionnaire” (UEPTLDCOVID19LQ) was used for the study. The finding of the study shows that Private Universities utilized e-learning facilities during the Covid-19 lockdown because they had the facilities to do so.

scholarly journals The National Longitudinal Survey of Children and Youth - Overview and Changes After Three Cycles

2001 ◽  
Vol 28 (2) ◽  
pp. 391 ◽  
Author(s):  
Sylvie Michaud
Keyword(s):  
Survey Design ◽  
Well Being ◽  
Longitudinal Survey ◽  
Children And Youth ◽  
National Longitudinal Survey ◽  
Term Study ◽  
Long Term Study ◽  
Future Direction ◽  
Do So

The National Longitudinal Survey of Children and Youth is a long-term study to monitor child development and well being of Canada’s children as they grow from infancy to adulthood. To do so, a representative sample of Canadian children aged between 0-11 years old was selected and interviewed in 1994- 1995. Interviews are conducted every two years and the current plans are to follow that cohort of children until they reach the age of 25. The survey has now gone through three collection cycles and already a number of changes have been observed. The paper will give an overview of the objectives of the survey, the survey design, the collection methodology, the survey content and the products and research that has already been done on the survey. The last section will present the future direction of the survey.

scholarly journals First results from radar profiles collected along the US-ITASE traverse from Taylor Dome to South Pole (2006–2008)

2009 ◽  
Vol 50 (51) ◽  
pp. 35-41 ◽  
Author(s):  
Brian C. Welch ◽  
Robert W. Jacobel ◽  
Steven A. Arcone
Keyword(s):  
Flow Regimes ◽  
Radar Data ◽  
East Antarctica ◽  
South Pole ◽  
The West ◽  
Ice Flow ◽  
The Us ◽  
First Results ◽  
Subglacial Lakes ◽  
Deformation Layer

AbstractThe 2006/07 and 2007/08 US-ITASE traverses from Taylor Dome to South Pole in East Antarctica provided opportunities to survey the subglacial and englacial environments using 3 MHz and 200MHz radar. We present first results of these new ground-based radar data. A prominent basal deformation layer indicates different ice-flow regimes for the northern and southern halves of the Byrd Glacier drainage. Buried dune stratigraphy that appears to be related to the megadunes towards the west occurs at depths of up to 1500 m. At least two new water-filled subglacial lakes were discovered, while two recently drained lakes identified from repeat ICESat surface elevation surveys appear to be devoid of water.

Motivation for Achievement and Structural Workplace Empowerment among Palestinian Healthcare Professionals

2013 ◽  
Vol 12 (5-6) ◽  
pp. 543-560 ◽  
Author(s):  
Randa Nasser ◽  
Belal A. Saadeh
Keyword(s):  
Achievement Motivation ◽  
Survey Design ◽  
Personal Characteristics ◽  
Personal Characteristic ◽  
Hospital Nurses ◽  
Personal Factors ◽  
Structural Determinants ◽  
Workplace Empowerment ◽  
Self Administered Questionnaire ◽  
Do So

AbstractThis study tests Kanter’s theory of structural workplace empowerment. It maintains that previous research that attempted to do so failed to account for the effect of an important personal characteristic—i.e. employees’ achievement motivation. This body of research also failed to uncover the mechanisms by which personal characteristics of employees influence their perceived empowerment. Data was collected from a sample of 154 hospital nurses, in two major Palestinian hospitals, through a survey design and self-administered questionnaire. The results of multivariate regression analyses and path-analysis indicate that perceived empowerment is indirectly influenced by personal factors (including educational qualifications, experience, position, and motivation towards achievement) through more direct structural determinants (access to formal and informal lines of power). More significantly, motivation has a direct—albeit weak—impact on perceived empowerment, after the effects of the more proximate structural determinants are controlled for.

Conductivity models for Archie rocks

Geophysics ◽  
2012 ◽  
Vol 77 (3) ◽  
pp. WA109-WA128 ◽  
Author(s):  
W. David Kennedy ◽  
David C. Herrick
Keyword(s):  
Predictive Power ◽  
A Priori ◽  
Geometrical Factor ◽  
Data Set ◽  
Archie’S Law ◽  
Resistivity Model ◽  
Noise Data ◽  
Brine Volume ◽  
Do So ◽  
Conductivity Models

The petroleum industry’s standard porosity-resistivity model (i.e., Archie’s law), although it is fit for its purpose, remains poorly understood after seven decades of use. This results from the choice of the graphical display and trend formula used to analyze Archie’s seminal porosity-resistivity data, taken in the Nacatoch sandstone, a petroliferous clastic formation in the Gulf of Mexico coastal area. Archie’s model accurately predicts the conductivity-brine volume trend for this sandstone. Not all rocks follow the same porosity-resistivity trends observed in the Nacatoch sandstone, but those that do are defined as Archie rocks. Archie’s Nacatoch sandstone data set has significant irreducible scatter, or noise. Data with significant scatter cannot be used to uniquely define a trend. Alternative graphical analyses of Archie’s Nacatoch sandstone data indicates that Archie could have analyzed these data differently had it occurred to him to do so. A physics-based porosity-conductivity model, a “geometrical factor theory” (GFT), is preferred as an alternative to the Archie model because it has a physical interpretation. In this model, the bulk conductivity of an Archie rock is the product of three factors: brine conductivity, fractional brine volume, and an explicit geometrical factor. The model is offered in the form of a theorem, proved in three steps, to make our arguments as explicit and transparent as possible. The model is developed through its culmination as a saturation equation to illustrate that it is a complete theory for Archie rocks. The predictive power of the Archie model and GFT are similar, but unlike the adjustable parameters of the Archie model ([Formula: see text], [Formula: see text], and [Formula: see text]), all of the parameters of GFT have a priori physical interpretations. Through a connection to site percolation theory, GFT has promise to connect porosity-conductivity interpretation to circuit theory first principles.

scholarly journals THE SPITZER SOUTH POLE TELESCOPE DEEP FIELD: SURVEY DESIGN AND INFRARED ARRAY CAMERA CATALOGS

2013 ◽  
Vol 209 (2) ◽  
pp. 22 ◽  
Author(s):  
M. L. N. Ashby ◽  
S. A. Stanford ◽  
M. Brodwin ◽  
A. H. Gonzalez ◽  
J. Martinez-Manso ◽  
...  
Keyword(s):  
Field Survey ◽  
Survey Design ◽  
South Pole ◽  
South Pole Telescope ◽  
Array Camera ◽  
Infrared Array

scholarly journals Reanalysis of Clementine bistatic radar data from the lunar South Pole

1999 ◽  
Vol 104 (E2) ◽  
pp. 3845-3862 ◽  
Author(s):  
Richard A. Simpson ◽  
G. Leonard Tyler
Keyword(s):  
Radar Data ◽  
Bistatic Radar ◽  
South Pole ◽  
Lunar South Pole

scholarly journals Spatial and Temporal Characteristics of Polarimetric Tornadic Debris Signatures

2014 ◽  
Vol 53 (10) ◽  
pp. 2217-2231 ◽  
Author(s):  
Matthew S. Van Den Broeke ◽  
Sabrina T. Jauernic
Keyword(s):  
Land Cover ◽  
Radar Data ◽  
Areal Extent ◽  
Polarimetric Radar ◽  
Property Damage ◽  
Lower Altitude ◽  
Vertical Extent ◽  
Urban Land Cover ◽  
Spatial And Temporal Characteristics ◽  
Do So

AbstractNonmeteorological scatter, including debris lofted by tornadoes, may be detected using the polarimetric radar variables. For the 17 months from January 2012 to May 2013, radar data were examined for each tornado reported in the domain of an operational polarimetric Weather Surveillance Radar-1988 Doppler (WSR-88D). Characteristics of the tornadic debris signature (TDS) were recorded when a signature was present. Approximately 16% of all tornadoes reported in Storm Data were associated with a debris signature, and this proportion is shown to vary regionally. Signatures were more frequently seen with tornadoes that were rated higher on the enhanced Fujita (EF) scale, with tornadoes causing higher reported total property damage, with tornadoes that were closer to the radar and thus intercepted by the beam at lower altitude, and associated with tornadoes with greater total pathlength. Tornadic debris signatures were most common in spring, when more strong tornadoes occur, and in autumn, when natural debris is more available. Debris-signature areal extent is shown to increase consistently with EF-scale rating and tornado longevity. Vertical extent of a TDS is shown to be greatest for strong, long-lived tornadoes with large radii of damaging wind. Land cover is also shown to exhibit some control over TDS characteristics—in particular, a large percentage of tornadoes with substantial track over urban land cover exhibited a TDS and do so very quickly after reported tornadogenesis, as compared with tornadoes over other land-cover classifications. TDS characteristics over grassland and cropland tended to be similar.

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