A SEQUENTIAL SAMPLING TECHNIQUE FOR SPRUCE BUDWORM EGG SURVEYS

1954 ◽  
Vol 32 (4) ◽  
pp. 302-313 ◽  
Author(s):  
R. F. Morris
Keyword(s):  
New Brunswick ◽  
Field Test ◽  
Sequential Sampling ◽  
Sampling Technique ◽  
Spruce Budworm ◽  
Test Field ◽  
Operating Characteristics ◽  
Fixed Sample ◽  
Sampling Points ◽  
Average Sample

The object in extensive spruce budworm egg surveys is to classify the infestation as light, moderate, or severe, at a large number of sampling points. The sequential plan, having no fixed sample size, was tested in 1953. It proved very useful, particularly in eliminating superfluous sampling at points where the infestation was definitely light or definitely severe. Curves showing operating characteristics and average sample numbers in relation to population mean permitted an appraisal of the plan in advance of the field test. Field parties were provided with simple tabulations prepared from the acceptance and rejection lines. With an expenditure of 1300 man-days, more than 1000 points were classified in northern New Brunswick.

Evaluation of bag sequential sampling technique for ambient air analysis. Comments

1979 ◽  
Vol 13 (5) ◽  
pp. 609-610
Author(s):  
Allen Hoffman ◽  
Roger Sperling ◽  
John Polasek ◽  
Jerry Bullin
Keyword(s):  
Sequential Sampling ◽  
Sampling Technique ◽  
Ambient Air ◽  
Air Analysis

Estimating the area under a receiver operating characteristic curve using partially ordered sets

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ehsan Zamanzade ◽  
Xinlei Wang
Keyword(s):  
Roc Curve ◽  
Characteristic Curve ◽  
Partially Ordered Sets ◽  
Sampling Technique ◽  
Real Data ◽  
Cost Effective ◽  
Ordered Sets ◽  
Operating Characteristics ◽  
Partially Ordered ◽  
Receiver Operating

AbstractRanked set sampling (RSS), known as a cost-effective sampling technique, requires that the ranker gives a complete ranking of the units in each set. Frey (2012) proposed a modification of RSS based on partially ordered sets, referred to as RSS-t in this paper, to allow the ranker to declare ties as much as he/she wishes. We consider the problem of estimating the area under a receiver operating characteristics (ROC) curve using RSS-t samples. The area under the ROC curve (AUC) is commonly used as a measure for the effectiveness of diagnostic markers. We develop six nonparametric estimators of the AUC with/without utilizing tie information based on different approaches. We then compare the estimators using a Monte Carlo simulation and an empirical study with real data from the National Health and Nutrition Examination Survey. The results show that utilizing tie information increases the efficiency of estimating the AUC. Suggestions about when to choose which estimator are also made available to practitioners.

The influence of hardwood content on balsam fir defoliation by spruce budworm

1996 ◽  
Vol 26 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Qiong Su ◽  
Ted D. Needham ◽  
David A. MacLean
Keyword(s):  
New Brunswick ◽  
Natural Enemies ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Generalized Model ◽  
Stand Management ◽  
Working Hypothesis ◽  
Model Combining

Changing stand composition by increasing hardwood content has been suggested as a long-term method for reducing susceptibility and vulnerability of balsam fir (Abiesbalsamea (L.) Mill.) to spruce budworm (Choristoneurafumiferana (Clem.)). Twenty-five mixed balsam fir–hardwood stands were selected in northern New Brunswick, with five stands in each 20% hardwood class (0–20, 21–40%, etc.). Defoliation each year from 1989 to 1993 was significantly (p < 0.0001) related to hardwood content, with r2 ranging from 0.57 to 0.81. As hardwood content increased, defoliation of balsam fir decreased. From 1989 to 1992, the years of moderate to severe defoliation, balsam fir stands with <40% hardwoods sustained 58–71% defoliation, on average, versus 12–15% defoliation in stands with >80% hardwood. A generalized model combining hardwood content and the estimated defoliation in pure softwood stands in a given year explained 77% of the variation in defoliation over stands and years. This study indicated that mixed balsam fir–hardwood stand management, with hardwood content >40%, could substantially reduce losses during spruce budworm outbreaks. Further research is warranted to elucidate the mechanism involved, but our working hypothesis is that greater hardwood content increased the diversity or populations of natural enemies such as birds and parasitoids.

AI Assisted High Fidelity Multi-Physics Digital Twin of Industrial Gas Turbines

2021 ◽  
Author(s):  
Senthil Krishnababu ◽  
Omar Valero ◽  
Roger Wells
Keyword(s):  
Gas Turbine ◽  
Data Storage ◽  
Gas Turbines ◽  
Building Blocks ◽  
Data Driven ◽  
High Fidelity ◽  
Test Field ◽  
Operating Characteristics ◽  
Digital Twin ◽  
The Impact

Abstract Data driven technologies are revolutionising the engineering sector by providing new ways of performing day to day tasks through the life cycle of a product as it progresses through manufacture, to build, qualification test, field operation and maintenance. Significant increase in data transfer speeds combined with cost effective data storage, and ever-increasing computational power provide the building blocks that enable companies to adopt data driven technologies such as data analytics, IOT and machine learning. Improved business operational efficiency and more responsive customer support provide the incentives for business investment. Digital twins, that leverages these technologies in their various forms to converge physics and data driven models, are therefore being widely adopted. A high-fidelity multi-physics digital twin, HFDT, that digitally replicates a gas turbine as it is built based on part and build data using advanced component and assembly models is introduced. The HFDT, among other benefits enables data driven assessments to be carried out during manufacture and assembly for each turbine allowing these processes to be optimised and the impact of variability or process change to be readily evaluated. On delivery of the turbine and its associated HFDT to the service support team the HFDT supports the evaluation of in-service performance deteriorations, the impact of field interventions and repair and the changes in operating characteristics resulting from overhaul and turbine upgrade. Thus, creating a cradle to grave physics and data driven twin of the gas turbine asset. In this paper, one branch of HFDT using a power turbine module is firstly presented. This involves simultaneous modelling of gas path and solid using high fidelity CFD and FEA which converts the cold geometry to hot running conditions to assess the impact of various manufacturing and build variabilities. It is shown this process can be executed within reasonable time frames enabling creation of HFDT for each turbine during manufacture and assembly and for this to be transferred to the service team for deployment during field operations. Following this, it is shown how data driven technologies are used in conjunction with the HFDT to improve predictions of engine performance from early build information. The example shown, shows how a higher degree of confidence is achieved through the development of an artificial neural network of the compressor tip gap feature and its effect on overall compressor efficiency.

Verification of reference ranges by using a Monte Carlo sampling technique

1994 ◽  
Vol 40 (12) ◽  
pp. 2216-2222 ◽  
Author(s):  
E W Holmes ◽  
S E Kahn ◽  
P A Molnar ◽  
E W Bermes
Keyword(s):  
Monte Carlo ◽  
Sampling Technique ◽  
Monte Carlo Sampling ◽  
Monte Carlo Technique ◽  
Reference Ranges ◽  
Operating Characteristics ◽  
Significance Tests ◽  
Software Program

Abstract We have investigated the application of Monte Carlo significance tests to the verification of reference ranges in the context of the transfer of an established range from one laboratory to another. Here we present an introduction to the Monte Carlo technique, outline a procedure for performing these tests using a commercially available software program, and demonstrate some of the operating characteristics of the tests when they are used to compare samples of different sizes and variances.

Spruce budworm and management effects on forest and wood product carbon for an intensively managed forest

2010 ◽  
Vol 40 (9) ◽  
pp. 1736-1750 ◽  
Author(s):  
Chris R. Hennigar ◽  
David A. MacLean
Keyword(s):  
New Brunswick ◽  
Management Strategies ◽  
Spruce Budworm ◽  
Wood Product ◽  
Managed Forest ◽  
Insecticide Application ◽  
C Storage ◽  
Biological Insecticide ◽  
Intensively Managed ◽  
Forest C

An integrated forest management optimization model was developed to calculate potential spruce budworm ( Choristoneura fumiferana Clemens) effects on forest and wood product carbon (C) from 2007 to 2057 and to evaluate potential C sequestration benefits of alternative management strategies (salvage, biological insecticide application). The model was tested using simulated spruce budworm outbreaks on a 210 000 ha intensively managed forest in northwestern New Brunswick, Canada. Under a severe spruce budworm outbreak scenario from 2007 to 2020, harvest volume and forest and wood product C storage in 2027 were projected to be reduced by 1.34 Mm3, 1.48 Mt, and 0.26 Mt, respectively, compared with the levels under no defoliation. Under the same severe outbreak scenario, implementation of salvage and harvest replanning plus a biological insecticide applied aerially to 40% of susceptible forest area, reduced harvest, forest C, and wood product C impacts by 73%, 41%, and 56%, respectively. Extrapolation of these results to all of New Brunswick suggests that a future severe spruce budworm outbreak could effectively increase total provincial annual C emissions (all sources) by up to 40%, on average, over the next 20 years. This modeling approach can be used to identify to what extent insecticide application, as a forest-C-offset project, could result in additional C storage than without forest and pest management.

The Interaction of the Spruce Budworm, Choristoneura fumiferana (Clem.), and the Parasite Glypta fumiferanae (Vier.)

1960 ◽  
Vol 92 (11) ◽  
pp. 839-850 ◽  
Author(s):  
C. A. Miller
Keyword(s):  
New Brunswick ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Actual Number ◽  
Emergence Period ◽  
Realistic Estimate ◽  
Host Generation

This is the second of a series of papers (Miller, 1959) describing the interaction of primary parasites and the spruce budworm, Choristoneura fumiferana (Clem.), based on data collected during an outbreak of the budworm in northern New Brunswick during the period 1947–1958. The first paper showed that the interaction between the spruce budworm and Apanteles fumiferanae Vier. is adequately described by the general mathematicai model developed by Watt (1959). The data on the parasite Glypta fumiferanae (Vier.) to be presented in this paper are also analysed by means of Watt's model and consequently the method is essentially the same. There is, however, one important difference. In the case of A. fumiferanae, the estimated number of adult parasites was only an index based on the potential number emerging from the previous host generation. The observed density of G. fumiferanae is a more realistic estimate. It is based on the actual number of cocoons found on the foliage during the adult emergence period.

Evidence of DDT Resistance in Populations of Spruce Budworm, Choristoneura fumiferana (Clem.), From DDT-sprayed Areas of New Brunswick

1965 ◽  
Vol 97 (12) ◽  
pp. 1281-1293 ◽  
Author(s):  
A. P. Randall
Keyword(s):  
New Brunswick ◽  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Data Interpretation ◽  
Fuel Oil ◽  
Susceptible Population ◽  
Mortality Curve ◽  
Progressive Development ◽  
Ddt Resistance

AbstractA series of laboratory toxicological experiments using various concentrations of oil formulated DDT solutions (AR-50/fuel oil (2:7 V/V)) was carried out on 5th and 6th instar spruce budworm larvae collected in the field from DDT-sprayed and untreated areas of New Brunswick, Canada, and Maine, U.S.A.Results obtained in 1959, 1961, and 1962 with larvae collected from isolated, unsprayed areas in New Brunswick showed a consistent, straight log-dosage probit mortality curve. Larvae collected in 1962 and 1963 from infestation centres previously subjected to three, four, and five applications of non-consecutive large-scale aerial sprays of DDT showed a significant departure from the straight log-dosage probit curve previously obtained. The departure occurs as a change in the shape of the curve as well as a shift to the higher concentration range of DDT. The magnitude of change appears to be correlated with the number of sprays to which the population was exposed. Results obtained in 1962 and 1963, from untreated control and inter-spray areas, bounded by DDT-sprayed forest lands, showed a small but significant departure from the normal straight probit line of a susceptible population. These changes are indicative of a progressive development of DDT resistance in wild populations of spruce budworm.Studies on the effect of the tolerance of spruce budworm larvae within instar classes to the action of DDT showed that the early phase of instar development immediately after moulting is more susceptible to the action of DDT, whereas the latter phase of instar development immediately prior to moulting is more tolerant to topical application of DDT than the average for the instar. This effect is evident in both susceptible and resistant populations.The data interpretation assumes that a deviation from the straight line probit dosage – mortality curve is indicative of a difference in the DDT-susceptibility factor of the budworm population and that in the course of the tests, the amount of toxicant causing mortality was not proportional to the dosage.

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