Sample sizes for point, double sampling

1992 ◽  
Vol 22 (7) ◽  
pp. 980-983 ◽  
Author(s):  
Richard G. Oderwald ◽  
Elizabeth Jones
Keyword(s):  
Basal Area ◽  
Double Sampling ◽  
Sample Sizes ◽  
Measuring Volume ◽  
Sample Points ◽  
Time Required ◽  
The Cost ◽  
Minimum Ratio

Formulas are derived for determining the total number of sample points and the number of volume points for a point, double sample with a ratio of means estimator to replace a point sample and achieve the same variance. A minimum ratio of the cost of measuring volume to the cost of measuring basal area at a point is determined for which the point, double sample will be less costly, in terms of time required to measure points, than the point sample.

Use of cold tolerant eucalyptus species as a partial replacement for southern mixed hardwoods

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 29-35 ◽  
Author(s):  
PETER W. HART ◽  
DALE E. NUTTER
Keyword(s):  
Potential Method ◽  
The United States ◽  
Partial Replacement ◽  
Growth Time ◽  
Eucalyptus Species ◽  
Cold Tolerant ◽  
Hardwood Pulp ◽  
Time Required ◽  
The Cost ◽  
Operational Data

During the last several years, the increasing cost and decreasing availability of mixed southern hardwoods have resulted in financial and production difficulties for southern U.S. mills that use a significant percentage of hardwood kraft pulp. Traditionally, in the United States, hardwoods are not plantation grown because of the growth time required to produce a quality tree suitable for pulping. One potential method of mitigating the cost and supply issues associated with the use of native hardwoods is to grow eucalyptus in plantations for the sole purpose of producing hardwood pulp. However, most of the eucalyptus species used in pulping elsewhere in the world are not capable of surviving in the southern U.S. climate. This study examines the potential of seven different cold-tolerant eucalyptus species to be used as replacements for, or supplements to, mixed southern hardwoods. The laboratory pulping and bleaching aspects of these seven species are discussed, along with pertinent mill operational data. Selected mill trial data also are reviewed.

scholarly journals A Short Path Quantum Algorithm for Exact Optimization

Quantum ◽  
2018 ◽  
Vol 2 ◽  
pp. 78 ◽  
Author(s):  
M. B. Hastings
Keyword(s):  
Hybrid Algorithm ◽  
Optimal Solution ◽  
Quantum Algorithm ◽  
Low Energy ◽  
Weighted Sum ◽  
Natural Hybrid ◽  
Sum Of Products ◽  
Time Required ◽  
The Cost ◽  
Exact Optimization

We give a quantum algorithm to exactly solve certain problems in combinatorial optimization, including weighted MAX-2-SAT as well as problems where the objective function is a weighted sum of products of Ising variables, all terms of the same degree D; this problem is called weighted MAX-ED-LIN2. We require that the optimal solution be unique for odd D and doubly degenerate for even D; however, we expect that the algorithm still works without this condition and we show how to reduce to the case without this assumption at the cost of an additional overhead. While the time required is still exponential, the algorithm provably outperforms Grover's algorithm assuming a mild condition on the number of low energy states of the target Hamiltonian. The detailed analysis of the runtime dependence on a tradeoff between the number of such states and algorithm speed: fewer such states allows a greater speedup. This leads to a natural hybrid algorithm that finds either an exact or approximate solution.

Rich-Media Interactive Simulations

2016 ◽  
pp. 261-283
Author(s):  
Suzanne Tsacoumis
Keyword(s):  
Real World ◽  
High Fidelity ◽  
Rich Media ◽  
Job Candidates ◽  
Real World Applications ◽  
Fidelity Measures ◽  
Time Required ◽  
The Cost ◽  
Interactive Simulations

High fidelity measures have proven to be powerful tools for measuring a broad range of competencies and their validity is well documented. However, their high-touch nature is often a deterrent to their use due to the cost and time required to develop and implement them. In addition, given the increased reliance on technology to screen and evaluate job candidates, organizations are continuing to search for more efficient ways to gather the information they need about one's capabilities. This chapter describes how innovative, interactive rich-media simulations that incorporate branching technology have been used in several real-world applications. The main focus is on describing the nature of these assessments and highlighting potential solutions to the unique measurement challenges associated with these types of assessments.

scholarly journals Estimating the Expected Value of Sample Information across Different Sample Sizes Using Moment Matching and Nonlinear Regression

2019 ◽  
Vol 39 (4) ◽  
pp. 347-359 ◽  
Author(s):  
Anna Heath ◽  
Ioanna Manolopoulou ◽  
Gianluca Baio
Keyword(s):  
Health Economic ◽  
Nonlinear Regression ◽  
Economic Model ◽  
Trial Design ◽  
Expected Value ◽  
Moment Matching ◽  
Sample Sizes ◽  
Sample Information ◽  
Health Economic Model ◽  
The Cost

Background. The expected value of sample information (EVSI) determines the economic value of any future study with a specific design aimed at reducing uncertainty about the parameters underlying a health economic model. This has potential as a tool for trial design; the cost and value of different designs could be compared to find the trial with the greatest net benefit. However, despite recent developments, EVSI analysis can be slow, especially when optimizing over a large number of different designs. Methods. This article develops a method to reduce the computation time required to calculate the EVSI across different sample sizes. Our method extends the moment-matching approach to EVSI estimation to optimize over different sample sizes for the underlying trial while retaining a similar computational cost to a single EVSI estimate. This extension calculates the posterior variance of the net monetary benefit across alternative sample sizes and then uses Bayesian nonlinear regression to estimate the EVSI across these sample sizes. Results. A health economic model developed to assess the cost-effectiveness of interventions for chronic pain demonstrates that this EVSI calculation method is fast and accurate for realistic models. This example also highlights how different trial designs can be compared using the EVSI. Conclusion. The proposed estimation method is fast and accurate when calculating the EVSI across different sample sizes. This will allow researchers to realize the potential of using the EVSI to determine an economically optimal trial design for reducing uncertainty in health economic models. Limitations. Our method involves rerunning the health economic model, which can be more computationally expensive than some recent alternatives, especially in complex models.

scholarly journals Run-Time and Compiler Support for Programming in Adaptive Parallel Environments

1997 ◽  
Vol 6 (2) ◽  
pp. 215-227 ◽  
Author(s):  
Guy Edjlali ◽  
Gagan Guyagrawal ◽  
Alan Sussman ◽  
Jim Humphries ◽  
Joel Saltz
Keyword(s):  
Parallel Programming ◽  
High Performance ◽  
Navier Stokes ◽  
Programming Environments ◽  
Data Parallel ◽  
Adaptive Environment ◽  
Run Time ◽  
Time Required ◽  
The Cost ◽  
Performance Results

For better utilization of computing resources, it is important to consider parallel programming environments in which the number of available processors varies at run-time. In this article, we discuss run-time support for data-parallel programming in such an adaptive environment. Executing programs in an adaptive environment requires redistributing data when the number of processors changes, and also requires determining new loop bounds and communication patterns for the new set of processors. We have developed a run-time library to provide this support. We discuss how the run-time library can be used by compilers of high-performance Fortran (HPF)-like languages to generate code for an adaptive environment. We present performance results for a Navier-Stokes solver and a multigrid template run on a network of workstations and an IBM SP-2. Our experiments show that if the number of processors is not varied frequently, the cost of data redistribution is not significant compared to the time required for the actual computation. Overall, our work establishes the feasibility of compiling HPF for a network of nondedicated workstations, which are likely to be an important resource for parallel programming in the future.

Hiding time of the hermit crab Calcinus californiensis: observations from different shell types

2015 ◽  
Vol 93 (7) ◽  
pp. 559-565 ◽  
Author(s):  
Carlos Enrique Chávez-Solís ◽  
Guillermina Alcaraz
Keyword(s):  
Water Column ◽  
Potential Risk ◽  
Hermit Crab ◽  
Hermit Crabs ◽  
Resource Value ◽  
Risk Of Predation ◽  
Potential Risks ◽  
Time Required ◽  
The Cost ◽  
Return To Activity

Hermit crabs respond to predators by hiding in their shells. However, retraction may cause the crab to lose hold of the rock and fall through the water column, and the crab may land with the shell aperture in a different orientation. When the shell is aperture down, hermit crabs return to activity by moving their bodies forward and placing their legs on the ground. In contrast, when the shell is aperture up, crabs need to perform a righting maneuver by extending part of their bodies out of the shell, which makes them more vulnerable to predation. The main goal of this study was to examine the hiding time of the hermit crab Calcinus californiensis Bouvier, 1898 in different shell species under these two different situations to better understand the conflict between the cost of staying in hiding and the risk of predation. The study was conducted in rocky tide pools using seven different shell types that reflect different predator protection and resource value to the crab (based on previous studies). We measured the time required to perform the righting maneuver as a measure of the potential risk incurred when returning to activity. The hiding time with the shell aperture down was not affected by shell species. The requirement to carry out a righting maneuver lengthened the hiding time, which varied in the different shell species according to the time required to recover the natural position. The potential risks associated with the righting time, the protection offered by the shells, and the resource value played an important role in the hiding time of the crabs using different shells. This study shows that hermit crabs are aware of the attributes of the shell and use this information to make decisions about how long to stay hidden after being threatened.

Interfacing Virtual Reality, CFD and the Internet

1997 ◽  
Author(s):  
David J. Freeman
Keyword(s):  
Fluid Dynamics ◽  
Virtual Reality ◽  
The Internet ◽  
Parallel Processor ◽  
Computing Power ◽  
Numerical Predictions ◽  
Computational Fluid Dynamics Cfd ◽  
Software And Hardware ◽  
Time Required ◽  
The Cost

Computational Fluid Dynamics (CFD) is a valuable tool for the process and petroleum industries. CFD reduces development timescales and costs by replacing expensive and lengthy laboratory investigation with numerical predictions of processes. However, there are several reasons why some companies are unwilling to use CFD. These include the cost of the software and hardware, the need for in-house CFD expertise and the time required to solve complex simulations. CHAM has developed a solution to these problems, in the form of a Virtual Reality Interface linked via the Internet to powerful parallel-processor computers. Virtual reality makes CFD accessible to non-CFD experts and allows the engineer to concentrate on the solution of his problem. Remote computing makes it possible to access from a PC the necessary computing power to solve the problem. Several examples will be shown, demonstrating the application and benefits of the PHOENICS-VR interface and the advantages of remote computing to the process and petroleum industries.

scholarly journals ON THE SQUATTING OF SHIPS IN SHALLOW AND RESTRICTED WATER

1986 ◽  
Vol 1 (20) ◽  
pp. 206
Author(s):  
A.M. Ferguson ◽  
R.C. McGregor
Keyword(s):  
Repair Cost ◽  
Reasonable Accuracy ◽  
Significant Cost ◽  
Continuous Increase ◽  
Earning Capacity ◽  
Port Authorities ◽  
Lateral Extent ◽  
Marine Technology ◽  
Time Required ◽  
The Cost

A major feature of the advances in marine technology is the increasing number, size and speed of ships and, consequently, an increased interest in hydrodynamic problems associated with water restricted in depth and/or lateral extent. The transport of dangerous cargoes and their impact on the benefits of resolving the areas of uncertainty. Experience of 1,104 vessels of different flags and trades during 1978, shows that grounding/stranding is the third most frequent cause of damage[1], An examination of the total expenditure of money and time required to repair the resulting damage shows this category to rank highly in both. Indeed, the total repair cost expended as a result of this cause rank top and account for more than l/5th of the total. Although the shipowner bears a large proportion of the cost of lost revenue, grounding represents a significant cost to underwriters, shipowners and port authorities. The continuous increase in size and draught of vessels in relation to water depth ensures that this situation will continue unless there is a radical development in instrumentation. To limit the risk of grounding it is extremely important to be able to predict which of a vessel's extremities will experience the greatest sinkage and ground. Where the underkeel clearance is low, reasonable accuracy is demanded in order to ensure safety and to avoid unduly reducing the earning capacity of the vessel by overcaution. This requires a sound knowledge of a vessel's tendency to 'squat'.

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