One-Sample Tests in Regional Archaeological Analysis: New Possibilities through Computer Technology

1990 ◽  
Vol 55 (2) ◽  
pp. 367-381 ◽  
Author(s):  
Kenneth L. Kvamme

Archaeologists commonly employ two-sample statistical tests in regional locational analyses that compare environmental measurements obtained at site locations against measurements taken at random locations from the background environment. One-sample tests that compare a site sample against a background standard are conceptually and statistically superior, but have been difficult to implement for continuous data types. This situation now is changed owing to a relatively new computer technology known as Geographic Information Systems (GIS). GIS can provide a complete description of the nature of the background environment of entire regions for categorical and continuous data types, thereby allowing the ready application of one-sample testing strategies. Examples of several GIS-based one-sample tests are given using data from east-central Arizona. Such conventional tests only should be applied, however, when the observations can be shown to be statistically independent through tests for spatial autocorrelation.

Author(s):  
Wang Ren ◽  
Xin Tong ◽  
Jing Du ◽  
Na Wang ◽  
Shancang Li ◽  
...  

AbstractThe Internet of Things (IoT) and Industrial 4.0 bring enormous potential benefits by enabling highly customised services and applications, which create huge volume and variety of data. However, preserving the privacy in IoT and Industrial 4.0 against re-identification attacks is very challenging. In this work, we considered three main data types generated in IoT: context data, continuous data, and media data. We first proposed a stream data anonymisation method based on k-anonymity for data collected by IoT devices; and then privacy enhancing techniques for both continuous data and media data were proposed for different IoT scenarios. The experiment results show that the proposed techniques can well preserve privacy without significantly affecting the utility of the data.


Author(s):  
Dhamanpreet Kaur ◽  
Matthew Sobiesk ◽  
Shubham Patil ◽  
Jin Liu ◽  
Puran Bhagat ◽  
...  

Abstract Objective This study seeks to develop a fully automated method of generating synthetic data from a real dataset that could be employed by medical organizations to distribute health data to researchers, reducing the need for access to real data. We hypothesize the application of Bayesian networks will improve upon the predominant existing method, medBGAN, in handling the complexity and dimensionality of healthcare data. Materials and Methods We employed Bayesian networks to learn probabilistic graphical structures and simulated synthetic patient records from the learned structure. We used the University of California Irvine (UCI) heart disease and diabetes datasets as well as the MIMIC-III diagnoses database. We evaluated our method through statistical tests, machine learning tasks, preservation of rare events, disclosure risk, and the ability of a machine learning classifier to discriminate between the real and synthetic data. Results Our Bayesian network model outperformed or equaled medBGAN in all key metrics. Notable improvement was achieved in capturing rare variables and preserving association rules. Discussion Bayesian networks generated data sufficiently similar to the original data with minimal risk of disclosure, while offering additional transparency, computational efficiency, and capacity to handle more data types in comparison to existing methods. We hope this method will allow healthcare organizations to efficiently disseminate synthetic health data to researchers, enabling them to generate hypotheses and develop analytical tools. Conclusion We conclude the application of Bayesian networks is a promising option for generating realistic synthetic health data that preserves the features of the original data without compromising data privacy.


2015 ◽  
Vol 206 (4) ◽  
pp. 332-338 ◽  
Author(s):  
Jay C. Fournier ◽  
Robert J. DeRubeis ◽  
Jay Amsterdam ◽  
Richard C. Shelton ◽  
Steven D. Hollon

BackgroundDepression can adversely affect employment status.AimsTo examine whether there is a relative advantage of cognitive therapy or antidepressant medication in improving employment status following treatment, using data from a previously reported trial.MethodRandom assignment to cognitive therapy (n = 48) or the selective serotonin reuptake inhibitor paroxetine (n = 93) for 4 months; treatment responders were followed for up to 24 months. Differential effects of treatment on employment status were examined.ResultsAt the end of 28 months, cognitive therapy led to higher rates of full-time employment (88.9%) than did antidepressant medication among treatment responders (70.8%), χ21 = 5.78, P = 0.02, odds ratio (OR) = 5.66, 95% CI 1.16–27.69. In the shorter-term, the main effect of treatment on employment status was not significant following acute treatment (χ21 = 1.74, P = 0.19, OR = 1.77, 95% CI 0.75–4.17); however, we observed a site×treatment interaction (χ21 = 6.87, P = 0.009) whereby cognitive therapy led to a higher rate of full-time employment at one site but not at the other.ConclusionsCognitive therapy may produce greater improvements in employment v. medication, particularly over the longer term.


Author(s):  
Emmanuel Adugu

Research indicates that individual consumers with food safety, environmental and ethical concerns regarding the provisioning of food may be motivated to use the marketplace as a site for political action to promote social change—a phenomenon known as political consumption (PC). Using data from Ohio 2007 Survey of Food, Farming and Environment, this research examined individual level attributes shaping engagement in PC and conventional political action. Findings based on logistic regression analyses, reveal that engagement in conventional political behavior is positively related to the likelihood of engagement in political consumption. This suggests that engagement in conventional political action and political consumption are not mutually exclusive. The main factors associated with engagement in political consumption are: knowledge about food production, environmental and food safety concerns. These findings suggest that consumers with concerns about the organization and character of food production believe they can create social changes via their consumptive decisions.


Cryptography ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 11
Author(s):  
Mitchell Martin ◽  
Jim Plusquellic

Physical Unclonable Functions (PUFs) are primitives that are designed to leverage naturally occurring variations to produce a random bitstring. Current PUF designs are typically implemented in silicon or utilize variations found in commercial off-the-shelf (COTS) parts. Because of this, existing designs are insufficient for the authentication of Printed Circuit Boards (PCBs). In this paper, we propose a novel PUF design that leverages board variations in a manufactured PCB to generate unique and stable IDs for each PCB. In particular, a single copper trace is used as a source of randomness for bitstring generation. The trace connects three notch filter structures in series, each of which is designed to reject specific but separate frequencies. The bitstrings generated using data measured from a set of PCBs are analyzed using statistical tests to illustrate that high levels of uniqueness and randomness are achievable.


2017 ◽  
Vol 21 (4) ◽  
pp. 2127-2142 ◽  
Author(s):  
Tesfay G. Gebremicael ◽  
Yasir A. Mohamed ◽  
Pieter v. Zaag ◽  
Eyasu Y. Hagos

Abstract. The Upper Tekezē–Atbara river sub-basin, part of the Nile Basin, is characterized by high temporal and spatial variability of rainfall and streamflow. In spite of its importance for sustainable water use and food security, the changing patterns of streamflow and its association with climate change is not well understood. This study aims to improve the understanding of the linkages between rainfall and streamflow trends and identify possible drivers of streamflow variabilities in the basin. Trend analyses and change-point detections of rainfall and streamflow were analysed using Mann–Kendall and Pettitt tests, respectively, using data records for 21 rainfall and 9 streamflow stations. The nature of changes and linkages between rainfall and streamflow were carefully examined for monthly, seasonal and annual flows, as well as indicators of hydrologic alteration (IHA). The trend and change-point analyses found that 19 of the tested 21 rainfall stations did not show statistically significant changes. In contrast, trend analyses on the streamflow showed both significant increasing and decreasing patterns. A decreasing trend in the dry season (October to February), short season (March to May), main rainy season (June to September) and annual totals is dominant in six out of the nine stations. Only one out of nine gauging stations experienced significant increasing flow in the dry and short rainy seasons, attributed to the construction of Tekezē hydropower dam upstream this station in 2009. Overall, streamflow trends and change-point timings were found to be inconsistent among the stations. Changes in streamflow without significant change in rainfall suggests factors other than rainfall drive the change. Most likely the observed changes in streamflow regimes could be due to changes in catchment characteristics of the basin. Further studies are needed to verify and quantify the hydrological changes shown in statistical tests by identifying the physical mechanisms behind those changes. The findings from this study are useful as a prerequisite for studying the effects of catchment management dynamics on the hydrological variabilities in the basin.


2014 ◽  
Vol 14 (4) ◽  
pp. 815-829 ◽  
Author(s):  
G. Anderson ◽  
D. Klugmann

Abstract. The Met Office has operated a very low frequency (VLF) lightning location network since 1987. The long-range capabilities of this network, referred to in its current form as ATDnet, allow for relatively continuous detection efficiency across Europe with only a limited number of sensors. The wide coverage and continuous data obtained by Arrival Time Differing NETwork (ATDnet) are here used to create data sets of lightning density across Europe. Results of annual and monthly detected lightning density using data from 2008–2012 are presented, along with more detailed analysis of statistics and features of interest. No adjustment has been made to the data for regional variations in detection efficiency.


1990 ◽  
Vol 68 (4) ◽  
pp. 773-781 ◽  
Author(s):  
Conrad Richter ◽  
Jack Dainty

Selective cation binding by Sphagnum russowii cell walls was investigated using data from bicationic potentiometric titrations of isolated cell walls. Selectivity measurements were interpreted in the context of Manning condensation. In titrations with cations of different valency, selectivity favoured the higher valency cation, as expected in Manning condensation. This selectivity generally increased with bathing pH until the wall-bound polyuronic acids became fully ionized (pH > 5). The selectivity coefficient order at full ionization was Na+–Ca2+ > Na+–La3+ > Ca2+–La3+, as predicted by the weak acid Donnan–Manning (WADM) model. Other phenomena also appear to influence binding selectivity. A small population of isolated binding sites are more effectively neutralized by univalent (or divalent) than divalent (or trivalent) cations. High selectivity for cations of lower valency at low pH also suggests a site isolation effect. In bicationic titrations involving divalent cations only, Sr24+ and Ca2+ were bound by the cell wall with approximately equal effectiveness, as predicted by the WADM model. However, cation or binding site specificities probably account for the favoured binding of Ca2+ over Mg2+ by the cell wall. Key words: ion exchange, cell wall, selectivity.


1982 ◽  
Vol 11 (2) ◽  
pp. 201-216 ◽  
Author(s):  
M. R. Levy ◽  
T. S. E. Maibaum
Keyword(s):  

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