Spatially balanced sampling

2019 ◽  
pp. 240-268
Author(s):  
David G. Hankin ◽  
Michael S. Mohr ◽  
Ken B. Newman
Keyword(s):  
Spatial Structure ◽  
Software Package ◽  
Tree Mortality ◽  
Sample Survey ◽  
Simple Random Sample ◽  
Acceptance Sampling ◽  
Statistical Programming ◽  
High Degree ◽  
Total Tree ◽  
Selection Of

In many ecological and natural resource settings, there may be a high degree of spatial structure or pattern to the distribution of target variable values across the landscape. For example, the number of trees per hectare killed by a bark beetle infestation may be exceptionally high in one region of a national forest and near zero elsewhere. In such circumstances it may be highly desirable or even required that a sample survey directed at estimation of total tree mortality across a forest be based on selection of random locations that have good spatial balance, i.e., locations are well spread over the landscape with relatively even distances between them. A simple random sample cannot guarantee good spatial balance. We present two methods that have been proposed for selection of spatially balanced samples: GRTS (Generalized Random Tessellation Stratified Sampling) and BAS (Balanced Acceptance Sampling). Selection of samples using the GRTS approach involves a complicated series of sequential steps that allows generation of spatially balanced samples selected from finite populations or from infinite study areas. Selection of samples using BAS relies on the Halton sequence, is conceptually simpler, and produces samples that generally have better spatial balance than those produced by GRTS. Both approaches rely on use of software that is available in the R statistical/programming environment. Estimation relies on the Horvitz–Thompson estimator. Illustrative examples of running the SPSURVEY software package (used for GRTS) and links to the SDraw package (used for BAS) are provided at http://global.oup.com/uk/companion/hankin.

scholarly journals Spatial Structure Analysis of Leisure Agriculture in Suzhou

2020 ◽  
Vol 5 (3) ◽  
pp. 95
Author(s):  
Peng Chen ◽  
Chenchen Zhu
Keyword(s):  
Spatial Structure ◽  
Concentration Index ◽  
Tourism Planning ◽  
Geographic Concentration ◽  
Development Path ◽  
Sample Data ◽  
Suzhou City ◽  
High Degree ◽  
Agriculture Development ◽  
Selection Of

<p>Based on the analysis of the basic connotation of leisure agriculture, this paper takes the Suzhou city leisure agriculture as the research object to summarize the current situation of leisure agriculture development in Suzhou, the selection of the Suzhou city rural tourism planning (2016-2020) in the key construction project for the leisure agriculture point sample data, analyzes its spatial structure by means of geographic concentration index and Gini coefficient. Through the geographic concentration index is calculated . G is a little less than <em>G<sub>optimal</sub></em> at 44.721. Gini=0.371, C=0.629. According to the research results, leisure agriculture points in Suzhou show a moderate distribution trend, and the leisure agriculture is distributed in various administrative regions of Suzhou city with a high degree of equilibrium, which is conducive to the development of leisure in agriculture. Pertinent suggestions are appropriate to the optimal development path of leisure agriculture in Suzhou.</p>

APPLICATION OF OPTIMIZATION OF SPECIFIED PARAMETERS OF THE ACCIDENT-RESISTANT FUEL SYSTEM OF THE HELICOPTER IN SIMINTECH SOFTWARE PACKAGE

2020 ◽  
pp. 7-13
Author(s):  
D. I. Smagin ◽  
K. S. Napreenko ◽  
R. S. Savel’ev ◽  
S. V. Grachev
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Life Cycle ◽  
Software Package ◽  
Operation Mode ◽  
Design Stage ◽  
Fuel System ◽  
Software Complex ◽  
High Degree ◽  
Selection Of

The process of creating an accident-resistant fuel system (AFS) of a helicopter using mathematical modeling is considered. Possibility of applying optimization algorithms in mathematical modeling of parameters of units of accident-resistant fuel system of helicopter in domestic software complex SimInTech is studied. An approach to solving the problem of optimizing given parameters, both in theory and in practice, is described. Results of the simplest optimization of AFS parameters for nominal operation mode are covered, examples of algorithms for selection of unit parameters are shown. This method of researching the system will allow, with a high degree of accuracy, to determine the necessary parameters at the design stage of the system. It is worth noting that the functionality of the developed dynamic mathematical model in the SimInTech software package is sufficient to perform tasks not only of the conceptual design stage, but also of the subsequent stages of the AFS life cycle.

A Study of Different Methodologies Helpful in the Identification of Offline Handwritten Script

2018 ◽  
Vol 6 (6) ◽  
pp. 307
Author(s):  
Manish M. Kayasth ◽  
Bharat C. Patel
Keyword(s):  
Feature Extraction ◽  
Character Recognition ◽  
Recognition Rate ◽  
Recognition System ◽  
Post Processing ◽  
Classification Technique ◽  
Scanned Image ◽  
Gujarati Language ◽  
High Degree ◽  
Selection Of

The entire character recognition system is logically characterized into different sections like Scanning, Pre-processing, Classification, Processing, and Post-processing. In the targeted system, the scanned image is first passed through pre-processing modules then feature extraction, classification in order to achieve a high recognition rate. This paper describes mainly on Feature extraction and Classification technique. These are the methodologies which play an important role to identify offline handwritten characters specifically in Gujarati language. Feature extraction provides methods with the help of which characters can identify uniquely and with high degree of accuracy. Feature extraction helps to find the shape contained in the pattern. Several techniques are available for feature extraction and classification, however the selection of an appropriate technique based on its input decides the degree of accuracy of recognition. 

Development of a Performance-Related Framework for Asphalt Mixture Design for the Illinois Tollway

2021 ◽  
pp. 036119812110148
Author(s):  
Behnam Jahangiri ◽  
Punyaslok Rath ◽  
Hamed Majidifard ◽  
William G. Buttlar
Keyword(s):  
Asphalt Mixture ◽  
Field Performance ◽  
Compact Tension ◽  
T Test ◽  
Novel Approach ◽  
Final Adjustment ◽  
Development And Validation ◽  
High Degree ◽  
Selection Of

Various agencies have begun to research and introduce performance-related specifications (PRS) for the design of modern asphalt paving mixtures. The focus of most recent studies has been directed toward simplified cracking test development and evaluation. In some cases, development and validation of PRS has been performed, building on these new tests, often by comparison of test values to accelerated pavement test studies and/or to limited field data. This study describes the findings of a comprehensive research project conducted at Illinois Tollway, leading to a PRS for the design of mainline and shoulder asphalt mixtures. A novel approach was developed, involving the systematic establishment of specification requirements based on: 1) selection of baseline values based on minimally acceptable field performance thresholds; 2) elevation of thresholds to account for differences between short-term lab aging and expected long-term field aging; 3) further elevation of thresholds to account for variability in lab testing, plus variability in the testing of field cores; and 4) final adjustment and rounding of thresholds based on a consensus process. After a thorough evaluation of different candidate cracking tests in the course of the project, the Disk-shaped Compact Tension—DC(T)—test was chosen to be retained in the Illinois Tollway PRS and to be presented in this study for the design of crack-resistant mixtures. The DC(T) test was selected because of its high degree of correlation with field results and its excellent repeatability. Tailored Hamburg rut depth and stripping inflection point thresholds were also established for mainline and shoulder mixes.

Cybersecurity Standards in the Context of Operating System

2021 ◽  
Vol 54 (3) ◽  
pp. 1-36
Author(s):  
Syed Wasif Abbas Hamdani ◽  
Haider Abbas ◽  
Abdul Rehman Janjua ◽  
Waleed Bin Shahid ◽  
Muhammad Faisal Amjad ◽  
...  
Keyword(s):  
Organizational Context ◽  
Cyber Attacks ◽  
Fine Tuning ◽  
Security Vulnerabilities ◽  
Compliance Testing ◽  
Depth Analysis ◽  
Minimum Requirements ◽  
Security Standards ◽  
High Degree ◽  
Selection Of

Cyber threats have been growing tremendously in recent years. There are significant advancements in the threat space that have led towards an essential need for the strengthening of digital infrastructure security. Better security can be achieved by fine-tuning system parameters to the best and optimized security levels. For the protection of infrastructure and information systems, several guidelines have been provided by well-known organizations in the form of cybersecurity standards. Since security vulnerabilities incur a very high degree of financial, reputational, informational, and organizational security compromise, it is imperative that a baseline for standard compliance be established. The selection of security standards and extracting requirements from those standards in an organizational context is a tedious task. This article presents a detailed literature review, a comprehensive analysis of various cybersecurity standards, and statistics of cyber-attacks related to operating systems (OS). In addition to that, an explicit comparison between the frameworks, tools, and software available for OS compliance testing is provided. An in-depth analysis of the most common software solutions ensuring compliance with certain cybersecurity standards is also presented. Finally, based on the cybersecurity standards under consideration, a comprehensive set of minimum requirements is proposed for OS hardening and a few open research challenges are discussed.

Using Cluster Analysis to Improve Marketing Experiments

1971 ◽  
Vol 8 (3) ◽  
pp. 340-347 ◽  
Author(s):  
George S. Day ◽  
Roger M. Heeler
Keyword(s):  
Cluster Analysis ◽  
Space Representation ◽  
Reduced Space ◽  
High Degree ◽  
Degree Of Similarity ◽  
Sensitive Experiment ◽  
Selection Of

When the selection of a sample of stores or cities requires a high degree of similarity among the test units in order to ensure a sensitive experiment, the sample may no longer represent the market. These conflicting requirements can be satisfied by choosing the sample from clusters displayed in a reduced space representation of the market.

The In Vitro Sensitivities of 70 Strains of Shigella

PEDIATRICS ◽  
1964 ◽  
Vol 34 (5) ◽  
pp. 705-707
Author(s):  
WILLIAM D. DONALD
Keyword(s):  
Clinical Trials ◽  
Gastrointestinal Tract ◽  
Tetracycline Resistance ◽  
The Other ◽  
Drug Of Choice ◽  
High Degree ◽  
As Toxicity ◽  
Selection Of

In vitro sensitivities of 70 shigella strains isolated over a recent 18-month period are reported. The high degree of sulfadiazine resistance casts some doubt on the selection of this agent as the drug of choice in the treatment of shigellosis, at least in this community. Some of the other agents, although inhibiting the growth of the organisms in vitro, have disadvantages such as toxicity or failure of absorption from the gastrointestinal tract. Tetracycline resistance was found in only 7% of the organisms tested, but from this and other reports we may anticipate the occurrence of more organisms resistant to this agent. The results of the sensitivities to ampicillin are encouraging and further studies including clinical trials of this agent are in order.

Selection of the optimal hydraulic drive for the press

2021 ◽  
pp. 50-60
Author(s):  
A.A. Antsifirov ◽  
V.A. Krivoshein
Keyword(s):  
Technological Process ◽  
Electric Motor ◽  
Software Package ◽  
Hydraulic Drive ◽  
Hydraulic Press ◽  
Topological Model ◽  
Electric Motors ◽  
Engine Operation ◽  
The Press ◽  
Selection Of

The research presented in the article is devoted to the selection of the electric motor of the hydraulic press drive with a nominal force of 5MN. The article presents the main characteristics and the description of the press operation using the means of mechanization of the technological process of pressure treatment. Using the Deform-3D software package, the process of stamping the crosspiece of the ZIL-130 cardan shaft was simulated. Based on the presented hydraulic scheme of the press, its topological model was formed in the PA-9 software package. The deformation force obtained in the course of modeling the technological process of stamping was used in the topological model of the press. Using a tabular cyclogram, the sequence of actuation of the end switches and hydraulic distributors during the stamping process is shown. In the article, two variants of engine operation were analyzed. Based on the results of the conducted research, it is necessary to focus on the second version of the 55 kW engine, the operation of which will provide the required characteristics of the hydraulic drive of the press, which in turn will allow for technological stamping operations. The simulation tools allow providing estimated information when selecting the necessary tools to ensure the optimal characteristics of hydraulic press drives. The article considered the variation of electric motors that differ from each other in nominal characteristics, with constant characteristics of the pump. For more accurate estimates of energy savings during the operation of the hydraulic drive, it is necessary to vary the characteristics of the pump in the simulation, and the best option is to form an experiment planning matrix when combining the characteristics of the electric motor and the hydraulic pump. This approach ultimately allows forming a function for which one can select a hydraulic drive from existing brands of electric motors and hydraulic pumps for presses of the corresponding range of nominal force.

About Determing the Microhardness of Composite Coatings

2021 ◽  
Vol 1037 ◽  
pp. 486-493
Author(s):  
Sergey Y. Zhachkin ◽  
Anatoly I. Zavrazhnov ◽  
Nikita A. Penkov ◽  
George V. Kudryavtsev ◽  
Paul V. Tsisarenko
Keyword(s):  
Composite Coating ◽  
Mechanical Treatment ◽  
Composite Coatings ◽  
Operational Parameters ◽  
Deposition Parameters ◽  
Cylinder Liners ◽  
High Degree ◽  
Applied Coating ◽  
Positive Effect ◽  
Selection Of

One of the fundamental tasks in restoring the operability of cylinder liners is the application of a composite coating with a predetermined microhardness value. The authors have developed a technology for applying composite coatings based on iron on cylindrical surfaces, which makes it possible to vary the physical, mechanical and operational parameters of the formed iron-containing coating due to the planned selection of the deposition parameters. This eliminates the need for mechanical treatment of the applied coating, which is the reason for the high degree of rejection parts that undergo the iron-on operation. Contact interaction of the working tool with the formed layer of the composite coating has a positive effect on the value of its roughness.

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