Is the assumption of normality or log-normality for continuous response data critical for benchmark dose estimation?

Energy Technology Data Exchange (ETDEWEB)

Shao, Kan, E-mail: Shao.Kan@epa.gov [ORISE Postdoctoral Fellow, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Gift, Jeffrey S. [National Center for Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Setzer, R. Woodrow [National Center for Computational Toxicology, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States)

2013-11-01

Continuous responses (e.g. body weight) are widely used in risk assessment for determining the benchmark dose (BMD) which is used to derive a U.S. EPA reference dose. One critical question that is not often addressed in dose–response assessments is whether to model the continuous data as normally or log-normally distributed. Additionally, if lognormality is assumed, and only summarized response data (i.e., mean ± standard deviation) are available as is usual in the peer-reviewed literature, the BMD can only be approximated. In this study, using the “hybrid” method and relative deviation approach, we first evaluate six representative continuous dose–response datasets reporting individual animal responses to investigate the impact on BMD/BMDL estimates of (1) the distribution assumption and (2) the use of summarized versus individual animal data when a log-normal distribution is assumed. We also conduct simulation studies evaluating model fits to various known distributions to investigate whether the distribution assumption has influence on BMD/BMDL estimates. Our results indicate that BMDs estimated using the hybrid method are more sensitive to the distribution assumption than counterpart BMDs estimated using the relative deviation approach. The choice of distribution assumption has limited impact on the BMD/BMDL estimates when the within dose-group variance is small, while the lognormality assumption is a better choice for relative deviation method when data are more skewed because of its appropriateness in describing the relationship between mean and standard deviation. Additionally, the results suggest that the use of summarized data versus individual response data to characterize log-normal distributions has minimal impact on BMD estimates. - Highlights: • We investigate to what extent the distribution assumption can affect BMD estimates. • Both real data analysis and simulation study are conducted. • BMDs estimated using hybrid method are more

Rill erosion in burned and salvage logged western montane forests: Effects of logging equipment type, traffic level, and slash treatment

Science.gov (United States)

Wagenbrenner, J. W.; Robichaud, P. R.; Brown, R. E.

2016-10-01

Following wildfires, forest managers often consider salvage logging burned trees to recover monetary value of timber, reduce fuel loads, or to meet other objectives. Relatively little is known about the cumulative hydrologic effects of wildfire and subsequent timber harvest using logging equipment. We used controlled rill experiments in logged and unlogged (control) forests burned at high severity in northern Montana, eastern Washington, and southern British Columbia to quantify rill overland flow and sediment production rates (fluxes) after ground-based salvage logging. We tested different types of logging equipment-feller-bunchers, tracked and wheeled skidders, and wheeled forwarders-as well as traffic levels and the addition of slash to skid trails as a best management practice. Rill experiments were done at each location in the first year after the fire and repeated in subsequent years. Logging was completed in the first or second post-fire year. We found that ground-based logging using heavy equipment compacted soil, reduced soil water repellency, and reduced vegetation cover. Vegetation recovery rates were slower in most logged areas than the controls. Runoff rates were higher in the skidder and forwarder plots than their respective controls in the Montana and Washington sites in the year that logging occurred, and the difference in runoff between the skidder and control plots at the British Columbia site was nearly significant (p = 0.089). Most of the significant increases in runoff in the logged plots persisted for subsequent years. The type of skidder, the addition of slash, and the amount of forwarder traffic did not significantly affect the runoff rates. Across the three sites, rill sediment fluxes were 5-1900% greater in logged plots than the controls in the year of logging, and the increases were significant for all logging treatments except the low use forwarder trails. There was no difference in the first-year sediment fluxes between the feller

Comparison of robustness to outliers between robust poisson models and log-binomial models when estimating relative risks for common binary outcomes: a simulation study.

Science.gov (United States)

Chen, Wansu; Shi, Jiaxiao; Qian, Lei; Azen, Stanley P

2014-06-26

To estimate relative risks or risk ratios for common binary outcomes, the most popular model-based methods are the robust (also known as modified) Poisson and the log-binomial regression. Of the two methods, it is believed that the log-binomial regression yields more efficient estimators because it is maximum likelihood based, while the robust Poisson model may be less affected by outliers. Evidence to support the robustness of robust Poisson models in comparison with log-binomial models is very limited. In this study a simulation was conducted to evaluate the performance of the two methods in several scenarios where outliers existed. The findings indicate that for data coming from a population where the relationship between the outcome and the covariate was in a simple form (e.g. log-linear), the two models yielded comparable biases and mean square errors. However, if the true relationship contained a higher order term, the robust Poisson models consistently outperformed the log-binomial models even when the level of contamination is low. The robust Poisson models are more robust (or less sensitive) to outliers compared to the log-binomial models when estimating relative risks or risk ratios for common binary outcomes. Users should be aware of the limitations when choosing appropriate models to estimate relative risks or risk ratios.

Local regularity analysis of strata heterogeneities from sonic logs

Directory of Open Access Journals (Sweden)

S. Gaci

2010-09-01

Full Text Available Borehole logs provide geological information about the rocks crossed by the wells. Several properties of rocks can be interpreted in terms of lithology, type and quantity of the fluid filling the pores and fractures.

Here, the logs are assumed to be nonhomogeneous Brownian motions (nhBms which are generalized fractional Brownian motions (fBms indexed by depth-dependent Hurst parameters H(z. Three techniques, the local wavelet approach (LWA, the average-local wavelet approach (ALWA, and Peltier Algorithm (PA, are suggested to estimate the Hurst functions (or the regularity profiles from the logs.

First, two synthetic sonic logs with different parameters, shaped by the successive random additions (SRA algorithm, are used to demonstrate the potential of the proposed methods. The obtained Hurst functions are close to the theoretical Hurst functions. Besides, the transitions between the modeled layers are marked by Hurst values discontinuities. It is also shown that PA leads to the best Hurst value estimations.

Second, we investigate the multifractional property of sonic logs data recorded at two scientific deep boreholes: the pilot hole VB and the ultra deep main hole HB, drilled for the German Continental Deep Drilling Program (KTB. All the regularity profiles independently obtained for the logs provide a clear correlation with lithology, and from each regularity profile, we derive a similar segmentation in terms of lithological units. The lithological discontinuities (strata' bounds and faults contacts are located at the local extrema of the Hurst functions. Moreover, the regularity profiles are compared with the KTB estimated porosity logs, showing a significant relation between the local extrema of the Hurst functions and the fluid-filled fractures. The Hurst function may then constitute a tool to characterize underground heterogeneities.

Toward an Automated Labeling of Event Log Attributes

DEFF Research Database (Denmark)

Abbad Andaloussi, Amine; Burattin, Andrea; Weber, Barbara

2018-01-01

information systems often do not comply with the required maturity level, since they lack the notion of process instance, also referred in process mining as “case id”. Without a proper identification of the case id attribute in log files, the outcome of process mining algorithms is unpredictable. This paper...... proposes a new approach that aims to overcome this challenge by automatically inferring the case id attribute from log files. The approach has been implemented as a ProM plugin and evaluated with several real-world event logs. The results demonstrate a high accuracy in inferring the case id attribute.......Process mining aims at exploring the data produced by executable business processes to mine the underlying control-flow and dataflow. Most of the process mining algorithms assume the existence of an event log with a certain maturity level. Unfortunately, the logs provided by process unaware...

Logging Concessions Enable Illegal Logging Crisis in the Peruvian Amazon

Science.gov (United States)

Finer, Matt; Jenkins, Clinton N.; Sky, Melissa A. Blue; Pine, Justin

2014-04-01

The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms.

Logging concessions enable illegal logging crisis in the Peruvian Amazon.

Science.gov (United States)

Finer, Matt; Jenkins, Clinton N; Sky, Melissa A Blue; Pine, Justin

2014-04-17

The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms.

[Evaluation of estimation of prevalence ratio using bayesian log-binomial regression model].

Science.gov (United States)

Gao, W L; Lin, H; Liu, X N; Ren, X W; Li, J S; Shen, X P; Zhu, S L

2017-03-10

To evaluate the estimation of prevalence ratio ( PR ) by using bayesian log-binomial regression model and its application, we estimated the PR of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea in their infants by using bayesian log-binomial regression model in Openbugs software. The results showed that caregivers' recognition of infant' s risk signs of diarrhea was associated significantly with a 13% increase of medical care-seeking. Meanwhile, we compared the differences in PR 's point estimation and its interval estimation of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea and convergence of three models (model 1: not adjusting for the covariates; model 2: adjusting for duration of caregivers' education, model 3: adjusting for distance between village and township and child month-age based on model 2) between bayesian log-binomial regression model and conventional log-binomial regression model. The results showed that all three bayesian log-binomial regression models were convergence and the estimated PRs were 1.130(95 %CI : 1.005-1.265), 1.128(95 %CI : 1.001-1.264) and 1.132(95 %CI : 1.004-1.267), respectively. Conventional log-binomial regression model 1 and model 2 were convergence and their PRs were 1.130(95 % CI : 1.055-1.206) and 1.126(95 % CI : 1.051-1.203), respectively, but the model 3 was misconvergence, so COPY method was used to estimate PR , which was 1.125 (95 %CI : 1.051-1.200). In addition, the point estimation and interval estimation of PRs from three bayesian log-binomial regression models differed slightly from those of PRs from conventional log-binomial regression model, but they had a good consistency in estimating PR . Therefore, bayesian log-binomial regression model can effectively estimate PR with less misconvergence and have more advantages in application compared with conventional log-binomial regression model.

Reducing Monte Carlo error in the Bayesian estimation of risk ratios using log-binomial regression models.

Science.gov (United States)

Salmerón, Diego; Cano, Juan A; Chirlaque, María D

2015-08-30

In cohort studies, binary outcomes are very often analyzed by logistic regression. However, it is well known that when the goal is to estimate a risk ratio, the logistic regression is inappropriate if the outcome is common. In these cases, a log-binomial regression model is preferable. On the other hand, the estimation of the regression coefficients of the log-binomial model is difficult owing to the constraints that must be imposed on these coefficients. Bayesian methods allow a straightforward approach for log-binomial regression models and produce smaller mean squared errors in the estimation of risk ratios than the frequentist methods, and the posterior inferences can be obtained using the software WinBUGS. However, Markov chain Monte Carlo methods implemented in WinBUGS can lead to large Monte Carlo errors in the approximations to the posterior inferences because they produce correlated simulations, and the accuracy of the approximations are inversely related to this correlation. To reduce correlation and to improve accuracy, we propose a reparameterization based on a Poisson model and a sampling algorithm coded in R. Copyright © 2015 John Wiley & Sons, Ltd.

SNG-logs at the Bagsvaerd Lake

International Nuclear Information System (INIS)

Korsbech, U.

1992-11-01

Spectral Natural Gamma-logs (SNG) were taken in old boreholes around Bagsvaerd Lake (Zealand). The purpose of this investigation was to clarify the geologic/lithologic conditions in this region and the potential risks of waste penetration into ground water. Relationship curves for thorium, uranium and potassium concentrations are given. Some special logs which can be useful for evaluating concentration variations or transition forms among various lithological layers are collected. Appendices contain technical information on the boreholes and discussion of differences between results of SNG-logging and the conventional gamma-logging. (EG)

Log-balanced combinatorial sequences

Directory of Open Access Journals (Sweden)

Tomislav Došlic

2005-01-01

Full Text Available We consider log-convex sequences that satisfy an additional constraint imposed on their rate of growth. We call such sequences log-balanced. It is shown that all such sequences satisfy a pair of double inequalities. Sufficient conditions for log-balancedness are given for the case when the sequence satisfies a two- (or more- term linear recurrence. It is shown that many combinatorially interesting sequences belong to this class, and, as a consequence, that the above-mentioned double inequalities are valid for all of them.

The Littoral Combat Ship: Is the US Navy Assuming Too Much Risk?

Science.gov (United States)

2006-06-16

whereas the General Dynamics design will focus on an all- aluminum trimaran hull. Additional study of the pros and cons based on these two designs and......also important to understand that not all risk is bad. The SWOT analysis, which looks at the strengths, weaknesses, opportunities, and threats

Empirical relationships between tree fall and landscape-level amounts of logging and fire.

Science.gov (United States)

Lindenmayer, David B; Blanchard, Wade; Blair, David; McBurney, Lachlan; Stein, John; Banks, Sam C

2018-01-01

Large old trees are critically important keystone structures in forest ecosystems globally. Populations of these trees are also in rapid decline in many forest ecosystems, making it important to quantify the factors that influence their dynamics at different spatial scales. Large old trees often occur in forest landscapes also subject to fire and logging. However, the effects on the risk of collapse of large old trees of the amount of logging and fire in the surrounding landscape are not well understood. Using an 18-year study in the Mountain Ash (Eucalyptus regnans) forests of the Central Highlands of Victoria, we quantify relationships between the probability of collapse of large old hollow-bearing trees at a site and the amount of logging and the amount of fire in the surrounding landscape. We found the probability of collapse increased with an increasing amount of logged forest in the surrounding landscape. It also increased with a greater amount of burned area in the surrounding landscape, particularly for trees in highly advanced stages of decay. The most likely explanation for elevated tree fall with an increasing amount of logged or burned areas in the surrounding landscape is change in wind movement patterns associated with cutblocks or burned areas. Previous studies show that large old hollow-bearing trees are already at high risk of collapse in our study area. New analyses presented here indicate that additional logging operations in the surrounding landscape will further elevate that risk. Current logging prescriptions require the protection of large old hollow-bearing trees on cutblocks. We suggest that efforts to reduce the probability of collapse of large old hollow-bearing trees on unlogged sites will demand careful landscape planning to limit the amount of timber harvesting in the surrounding landscape.

A semantic perspective on query log analysis

NARCIS (Netherlands)

Hofmann, K.; de Rijke, M.; Huurnink, B.; Meij, E.

2009-01-01

We present our views on the CLEF log file analysis task. We argue for a task definition that focuses on the semantic enrichment of query logs. In addition, we discuss how additional information about the context in which queries are being made could further our understanding of users’ information

California-Nevada uranium logging. Final report

International Nuclear Information System (INIS)

1981-04-01

The purpose of this project was to obtain geophysical logs of industry drill holes to assess the uranium resource potential of geologic formations of interest. The work was part of the US Department of Energy's National Uranium Resource Evaluation (NURE) Program. The principal objective of the logging program was to determine radioelement grade of formations through natural gamma ray detectors. Supplementary information was obtained from resistivity (R), self-potential (SP), point resistance (RE), and neutron density (NN) logs for formation interpretation. Additional data for log interpretation was obtained from caliper logs, casing schedules, and downhole temperature. This data was obtained from well operators when available, with new logs obtained where not formerly available. This report contains a summary of the project and data obtained to date

An innovative OSCE clinical log station: a quantitative study of its influence on Log use by medical students

Directory of Open Access Journals (Sweden)

Hudson Judith N

2012-11-01

Full Text Available Abstract Background A Clinical Log was introduced as part of a medical student learning portfolio, aiming to develop a habit of critical reflection while learning was taking place, and provide feedback to students and the institution on learning progress. It was designed as a longitudinal self-directed structured record of student learning events, with reflection on these for personal and professional development, and actions planned or taken for learning. As incentive was needed to encourage student engagement, an innovative Clinical Log station was introduced in the OSCE, an assessment format with established acceptance at the School. This study questions: How does an OSCE Clinical Log station influence Log use by students? Methods The Log station was introduced into the formative, and subsequent summative, OSCEs with careful attention to student and assessor training, marking rubrics and the standard setting procedure. The scoring process sought evidence of educational use of the log, and an ability to present and reflect on key learning issues in a concise and coherent manner. Results Analysis of the first cohort’s Log use over the four-year course (quantified as number of patient visits entered by all students revealed limited initial use. Usage was stimulated after introduction of the Log station early in third year, with some improvement during the subsequent year-long integrated community-based clerkship. Student reflection, quantified by the mean number of characters in the ‘reflection’ fields per entry, peaked just prior to the final OSCE (mid-Year 4. Following this, very few students continued to enter and reflect on clinical experience using the Log. Conclusion While the current study suggested that we can’t assume students will self-reflect unless such an activity is included in an assessment, ongoing work has focused on building learner and faculty confidence in the value of self-reflection as part of being a competent

Influence of deforestation, logging, and fire on malaria in the Brazilian Amazon.

Science.gov (United States)

Hahn, Micah B; Gangnon, Ronald E; Barcellos, Christovam; Asner, Gregory P; Patz, Jonathan A

2014-01-01

Malaria is a significant public health threat in the Brazilian Amazon. Previous research has shown that deforestation creates breeding sites for the main malaria vector in Brazil, Anopheles darlingi, but the influence of selective logging, forest fires, and road construction on malaria risk has not been assessed. To understand these impacts, we constructed a negative binomial model of malaria counts at the municipality level controlling for human population and social and environmental risk factors. Both paved and unpaved roadways and fire zones in a municipality increased malaria risk. Within the timber production states where 90% of deforestation has occurred, compared with areas without selective logging, municipalities where 0-7% of the remaining forests were selectively logged had the highest malaria risk (1.72, 95% CI 1.18-2.51), and areas with higher rates of selective logging had the lowest risk (0.39, 95% CI 0.23-0.67). We show that roads, forest fires, and selective logging are previously unrecognized risk factors for malaria in the Brazilian Amazon and highlight the need for regulation and monitoring of sub-canopy forest disturbance.

Engineering aspects of radiometric logging

International Nuclear Information System (INIS)

Huppert, P.

1982-01-01

Engineering problems encountered in the development of nuclear borehole logging techniques are discussed. Spectrometric techniques require electronic stability of the equipment. In addition the electronics must be capable of handling high count rates of randomly distributed pulses of fast rise time from the detector and the systems must be designed so that precise calibration is possible under field operating conditions. Components of a logging system are discussed in detail. They include the logging probe (electronics, detector, high voltage supply, preamplifier), electronic instrumentation for data collection and processing and auxiliary equipment

Influence of deforestation, logging, and fire on malaria in the Brazilian Amazon.

Directory of Open Access Journals (Sweden)

Micah B Hahn

Full Text Available Malaria is a significant public health threat in the Brazilian Amazon. Previous research has shown that deforestation creates breeding sites for the main malaria vector in Brazil, Anopheles darlingi, but the influence of selective logging, forest fires, and road construction on malaria risk has not been assessed. To understand these impacts, we constructed a negative binomial model of malaria counts at the municipality level controlling for human population and social and environmental risk factors. Both paved and unpaved roadways and fire zones in a municipality increased malaria risk. Within the timber production states where 90% of deforestation has occurred, compared with areas without selective logging, municipalities where 0-7% of the remaining forests were selectively logged had the highest malaria risk (1.72, 95% CI 1.18-2.51, and areas with higher rates of selective logging had the lowest risk (0.39, 95% CI 0.23-0.67. We show that roads, forest fires, and selective logging are previously unrecognized risk factors for malaria in the Brazilian Amazon and highlight the need for regulation and monitoring of sub-canopy forest disturbance.

Equilibrium initial data for moving puncture simulations: the stationary 1 + log slicing

International Nuclear Information System (INIS)

Baumgarte, T W; Matera, K; Etienne, Z B; Liu, Y T; Shapiro, S L; Taniguchi, K; Murchadha, N O

2009-01-01

We discuss a 'stationary 1 + log' slicing condition for the construction of solutions to Einstein's constraint equations. For stationary spacetimes, these initial data give a stationary foliation when evolved with 'moving puncture' gauge conditions that are often used in black hole evolutions. The resulting slicing is time independent and agrees with the slicing generated by being dragged along a timelike Killing vector of the spacetime. When these initial data are evolved with moving puncture gauge conditions, numerical errors arising from coordinate evolution should be minimized. While these properties appear very promising, suggesting that this slicing condition should be an attractive alternative to, for example, maximal slicing, we demonstrate in this paper that solutions can be constructed only for a small class of problems. For binary black hole initial data, in particular, it is often assumed that there exists an approximate helical Killing vector that generates the binary's orbit. We show that 1 + log slices that are stationary with respect to such a helical Killing vector cannot be asymptotically flat, unless the spacetime possesses an additional axial Killing vector.

Assessment of radiation safety in well logging

International Nuclear Information System (INIS)

Alles, A.; Pérez, Y.; Duménigo, C.

2015-01-01

Radiation safety assessments required by current regulations are a means to verify compliance with the requirements. Different methods have been used for this purpose. In the paper the results of applying the method of risk matrices, applied for the first time in the practice of well logging are exposed. For each initiating event frequency of occurrence, the severity of its consequences and the probability of failure of the barriers identified were evaluated. Starting from these assumptions, the risk associated is determined for each of the identified accident sequences, using for this the SEVRRA code 'Risk Assessment System', originally designed for use in radiotherapy. As an result sequences increased risk associated with the practice of well logging were identified, which is the starting point for the further implementation of a coherent program of dose optimization in practice. [es

Characterizing uncertainty when evaluating risk management metrics: risk assessment modeling of Listeria monocytogenes contamination in ready-to-eat deli meats.

Science.gov (United States)

Gallagher, Daniel; Ebel, Eric D; Gallagher, Owen; Labarre, David; Williams, Michael S; Golden, Neal J; Pouillot, Régis; Dearfield, Kerry L; Kause, Janell

2013-04-01

This report illustrates how the uncertainty about food safety metrics may influence the selection of a performance objective (PO). To accomplish this goal, we developed a model concerning Listeria monocytogenes in ready-to-eat (RTE) deli meats. This application used a second order Monte Carlo model that simulates L. monocytogenes concentrations through a series of steps: the food-processing establishment, transport, retail, the consumer's home and consumption. The model accounted for growth inhibitor use, retail cross contamination, and applied an FAO/WHO dose response model for evaluating the probability of illness. An appropriate level of protection (ALOP) risk metric was selected as the average risk of illness per serving across all consumed servings-per-annum and the model was used to solve for the corresponding performance objective (PO) risk metric as the maximum allowable L. monocytogenes concentration (cfu/g) at the processing establishment where regulatory monitoring would occur. Given uncertainty about model inputs, an uncertainty distribution of the PO was estimated. Additionally, we considered how RTE deli meats contaminated at levels above the PO would be handled by the industry using three alternative approaches. Points on the PO distribution represent the probability that - if the industry complies with a particular PO - the resulting risk-per-serving is less than or equal to the target ALOP. For example, assuming (1) a target ALOP of -6.41 log10 risk of illness per serving, (2) industry concentrations above the PO that are re-distributed throughout the remaining concentration distribution and (3) no dose response uncertainty, establishment PO's of -4.98 and -4.39 log10 cfu/g would be required for 90% and 75% confidence that the target ALOP is met, respectively. The PO concentrations from this example scenario are more stringent than the current typical monitoring level of an absence in 25 g (i.e., -1.40 log10 cfu/g) or a stricter criteria of absence

Calculating tissue shear modulus and pressure by 2D log-elastographic methods

International Nuclear Information System (INIS)

McLaughlin, Joyce R; Zhang, Ning; Manduca, Armando

2010-01-01

Shear modulus imaging, often called elastography, enables detection and characterization of tissue abnormalities. In this paper the data are two displacement components obtained from successive MR or ultrasound data sets acquired while the tissue is excited mechanically. A 2D plane strain elastic model is assumed to govern the 2D displacement, u. The shear modulus, μ, is unknown and whether or not the first Lamé parameter, λ, is known the pressure p = λ∇ . u which is present in the plane strain model cannot be measured and is unreliably computed from measured data and can be shown to be an order one quantity in the units kPa. So here we present a 2D log-elastographic inverse algorithm that (1) simultaneously reconstructs the shear modulus, μ, and p, which together satisfy a first-order partial differential equation system, with the goal of imaging μ; (2) controls potential exponential growth in the numerical error and (3) reliably reconstructs the quantity p in the inverse algorithm as compared to the same quantity computed with a forward algorithm. This work generalizes the log-elastographic algorithm in Lin et al (2009 Inverse Problems 25) which uses one displacement component, is derived assuming that the component satisfies the wave equation and is tested on synthetic data computed with the wave equation model. The 2D log-elastographic algorithm is tested on 2D synthetic data and 2D in vivo data from Mayo Clinic. We also exhibit examples to show that the 2D log-elastographic algorithm improves the quality of the recovered images as compared to the log-elastographic and direct inversion algorithms

Geophysical borehole logging

International Nuclear Information System (INIS)

McCann, D.; Barton, K.J.; Hearn, K.

1981-08-01

Most of the available literature on geophysical borehole logging refers to studies carried out in sedimentary rocks. It is only in recent years that any great interest has been shown in geophysical logging in boreholes in metamorphic and igneous rocks following the development of research programmes associated with geothermal energy and nuclear waste disposal. This report is concerned with the programme of geophysical logging carried out on the three deep boreholes at Altnabreac, Caithness, to examine the effectiveness of these methods in crystalline rock. Of particular importance is the assessment of the performance of the various geophysical sondes run in the boreholes in relation to the rock mass properties. The geophysical data can be used to provide additional in-situ information on the geological, hydrogeological and engineering properties of the rock mass. Fracturing and weathering in the rock mass have a considerable effect on both the design parameters for an engineering structure and the flow of water through the rock mass; hence, the relation between the geophysical properties and the degree of fracturing and weathering is examined in some detail. (author)

A legacy of low-impact logging does not elevate prevalence of potentially pathogenic protozoa in free-ranging gorillas and chimpanzees in the Republic of Congo: logging and parasitism in African apes.

Science.gov (United States)

Gillespie, Thomas R; Morgan, David; Deutsch, J Charlie; Kuhlenschmidt, Mark S; Salzer, Johanna S; Cameron, Kenneth; Reed, Trish; Sanz, Crickette

2009-12-01

Many studies have examined the long-term effects of selective logging on the abundance and diversity of free-ranging primates. Logging is known to reduce the abundance of some primate species through associated hunting and the loss of food trees for frugivores; however, the potential role of pathogens in such primate population declines is largely unexplored. Selective logging results in a suite of alterations in host ecology and forest structure that may alter pathogen dynamics in resident wildlife populations. In addition, environmental pollution with human fecal material may present a risk for wildlife infections with zoonotic protozoa, such as Cryptosporidium and Giardia. To better understand this interplay, we compared patterns of infection with these potentially pathogenic protozoa in sympatric western lowland gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in the undisturbed Goualougo Triangle of Nouabalé-Ndoki National Park and the adjacent previously logged Kabo Concession in northern Republic of Congo. No Cryptosporidium infections were detected in any of the apes examined and prevalence of infection with Giardia was low (3.73% overall) and did not differ between logged and undisturbed forest for chimpanzees or gorillas. These results provide a baseline for prevalence of these protozoa in forest-dwelling African apes and suggest that low-intensity logging may not result in long-term elevated prevalence of potentially pathogenic protozoa.

The pdk-100 enhances interpretation capabilities for pulsed neutron capture logs

International Nuclear Information System (INIS)

Randall, R.R.; Oliver, D.W.; Ferti, W.H.

1986-01-01

The PDK-100 is a new pulsed neutron logging system designed to measure Sigma (Σ), the macroscopic thermal neutron capture cross section. In addition to determining Σ, the system provides logging curves which are a measure of formation porosity and which furnish information concerning borehole conditions. This paper reviews the principles of operation of the PDK-100, and presents examples which illustrate the utility of the logging system. In addition, the progress of investigations into new parameters which can be derived with pulsed neutron logging data will be reported

LogScope

Science.gov (United States)

Havelund, Klaus; Smith, Margaret H.; Barringer, Howard; Groce, Alex

2012-01-01

LogScope is a software package for analyzing log files. The intended use is for offline post-processing of such logs, after the execution of the system under test. LogScope can, however, in principle, also be used to monitor systems online during their execution. Logs are checked against requirements formulated as monitors expressed in a rule-based specification language. This language has similarities to a state machine language, but is more expressive, for example, in its handling of data parameters. The specification language is user friendly, simple, and yet expressive enough for many practical scenarios. The LogScope software was initially developed to specifically assist in testing JPL s Mars Science Laboratory (MSL) flight software, but it is very generic in nature and can be applied to any application that produces some form of logging information (which almost any software does).

Nonblocking and orphan free message logging protocols

Science.gov (United States)

Alvisi, Lorenzo; Hoppe, Bruce; Marzullo, Keith

1992-12-01

Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. We show that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. We construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocol: our protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.

Dynamic Planar Convex Hull with Optimal Query Time and O(log n · log log n ) Update Time

DEFF Research Database (Denmark)

Brodal, Gerth Stølting; Jakob, Riko

2000-01-01

The dynamic maintenance of the convex hull of a set of points in the plane is one of the most important problems in computational geometry. We present a data structure supporting point insertions in amortized O(log n · log log log n) time, point deletions in amortized O(log n · log log n) time......, and various queries about the convex hull in optimal O(log n) worst-case time. The data structure requires O(n) space. Applications of the new dynamic convex hull data structure are improved deterministic algorithms for the k-level problem and the red-blue segment intersection problem where all red and all...

Generating log-normal mock catalog of galaxies in redshift space

Energy Technology Data Exchange (ETDEWEB)

Agrawal, Aniket; Makiya, Ryu; Saito, Shun; Komatsu, Eiichiro [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany); Chiang, Chi-Ting [C.N. Yang Institute for Theoretical Physics, Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Jeong, Donghui, E-mail: aniket@mpa-garching.mpg.de, E-mail: makiya@mpa-garching.mpg.de, E-mail: chi-ting.chiang@stonybrook.edu, E-mail: djeong@psu.edu, E-mail: ssaito@mpa-garching.mpg.de, E-mail: komatsu@mpa-garching.mpg.de [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)

2017-10-01

We present a public code to generate a mock galaxy catalog in redshift space assuming a log-normal probability density function (PDF) of galaxy and matter density fields. We draw galaxies by Poisson-sampling the log-normal field, and calculate the velocity field from the linearised continuity equation of matter fields, assuming zero vorticity. This procedure yields a PDF of the pairwise velocity fields that is qualitatively similar to that of N-body simulations. We check fidelity of the catalog, showing that the measured two-point correlation function and power spectrum in real space agree with the input precisely. We find that a linear bias relation in the power spectrum does not guarantee a linear bias relation in the density contrasts, leading to a cross-correlation coefficient of matter and galaxies deviating from unity on small scales. We also find that linearising the Jacobian of the real-to-redshift space mapping provides a poor model for the two-point statistics in redshift space. That is, non-linear redshift-space distortion is dominated by non-linearity in the Jacobian. The power spectrum in redshift space shows a damping on small scales that is qualitatively similar to that of the well-known Fingers-of-God (FoG) effect due to random velocities, except that the log-normal mock does not include random velocities. This damping is a consequence of non-linearity in the Jacobian, and thus attributing the damping of the power spectrum solely to FoG, as commonly done in the literature, is misleading.

Hardwood log grades and lumber grade yields for factory lumber logs

Science.gov (United States)

Leland F. Hanks; Glenn L. Gammon; Robert L. Brisbin; Everette D. Rast

1980-01-01

The USDA Forest Service Standard Grades for Hardwood Factory Lumber Logs are described, and lumber grade yields for 16 species and 2 species groups are presented by log grade and log diameter. The grades enable foresters, log buyers, and log sellers to select and grade those log suitable for conversion into standard factory grade lumber. By using the apropriate lumber...

Logging Concessions Enable Illegal Logging Crisis in the Peruvian Amazon

OpenAIRE

Finer, Matt; Jenkins, Clinton N.; Sky, Melissa A. Blue; Pine, Justin

2014-01-01

The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US?Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3%...

Latent log-linear models for handwritten digit classification.

Science.gov (United States)

Deselaers, Thomas; Gass, Tobias; Heigold, Georg; Ney, Hermann

2012-06-01

We present latent log-linear models, an extension of log-linear models incorporating latent variables, and we propose two applications thereof: log-linear mixture models and image deformation-aware log-linear models. The resulting models are fully discriminative, can be trained efficiently, and the model complexity can be controlled. Log-linear mixture models offer additional flexibility within the log-linear modeling framework. Unlike previous approaches, the image deformation-aware model directly considers image deformations and allows for a discriminative training of the deformation parameters. Both are trained using alternating optimization. For certain variants, convergence to a stationary point is guaranteed and, in practice, even variants without this guarantee converge and find models that perform well. We tune the methods on the USPS data set and evaluate on the MNIST data set, demonstrating the generalization capabilities of our proposed models. Our models, although using significantly fewer parameters, are able to obtain competitive results with models proposed in the literature.

http Log Analysis

DEFF Research Database (Denmark)

Bøving, Kristian Billeskov; Simonsen, Jesper

2004-01-01

This article documents how log analysis can inform qualitative studies concerning the usage of web-based information systems (WIS). No prior research has used http log files as data to study collaboration between multiple users in organisational settings. We investigate how to perform http log...... analysis; what http log analysis says about the nature of collaborative WIS use; and how results from http log analysis may support other data collection methods such as surveys, interviews, and observation. The analysis of log files initially lends itself to research designs, which serve to test...... hypotheses using a quantitative methodology. We show that http log analysis can also be valuable in qualitative research such as case studies. The results from http log analysis can be triangulated with other data sources and for example serve as a means of supporting the interpretation of interview data...

A cement channel-detection technique using the pulsed-neutron log

International Nuclear Information System (INIS)

Myers, G.D.

1991-01-01

A channel-detection technique has been developed using boron solutions and pulsed-neutron logging (PNL) tools. This technique relies on the extremely high-neutron-absorption cross section that boron exhibits relative to other common elements, including chlorine. The PNL tool is used to detect movement of a boron solution in a log-inject-log procedure. The technique has identified channels in such difficult applications as logging through two strings of pipe and in highly deviated wellbores. Logging procedures are simple and cement channels can be readily identified. The boron solutions are relatively inexpensive, safe to handle, and nonradioactive. Additional PNL information for reservoir performance evaluation is collected simultaneously during channel-detection logging. This paper describes the theory, development, field application, and limitations of this channel-detection logging technique

Comparing Multiple-Group Multinomial Log-Linear Models for Multidimensional Skill Distributions in the General Diagnostic Model. Research Report. ETS RR-08-35

Science.gov (United States)

Xu, Xueli; von Davier, Matthias

2008-01-01

The general diagnostic model (GDM) utilizes located latent classes for modeling a multidimensional proficiency variable. In this paper, the GDM is extended by employing a log-linear model for multiple populations that assumes constraints on parameters across multiple groups. This constrained model is compared to log-linear models that assume…

Log quality enhancement: A systematic assessment of logging company wellsite performance and log quality

International Nuclear Information System (INIS)

Farnan, R.A.; Mc Hattie, C.M.

1984-01-01

To improve the monitoring of logging company performance, computer programs were developed to assess information en masse from log quality check lists completed on wellsite by the service company engineer and Phillips representative. A study of all logging jobs performed by different service companies for Phillips in Oklahoma (panhandle excepted) during 1982 enabled several pertinent and beneficial interpretations to be made. Company A provided the best tool and crew service. Company B incurred an excessive amount of lost time related to tool failure, in particular the neutron-density tool combination. Company C, although used only three times, incurred no lost time. With a reasonable data base valid conclusions were made pertaining, for example, to repeated tool malfunctions. The actual logs were then assessed for quality

Effects of logging road removal on suspended sediment loads and turbidity

Science.gov (United States)

Randy D. Klein; Vicki Ozaki

2017-01-01

Poorly designed and unmaintained logging roads pose serious risks to aquatic ecosystems through sediment delivery from stream crossing failures and landslides. Redwood National Park (RNP) in northern coastal California has been implementing a restoration program for almost four decades, focused primarily on removing (decommissioning) abandoned logging roads on former...

Attitudes and Willingness to Assume Risk of Experimental Therapy to Eradicate Genital Herpes Simplex Virus Infection.

Science.gov (United States)

Oseso, Linda; Magaret, Amalia S; Jerome, Keith R; Fox, Julie; Wald, Anna

2016-09-01

Current treatment of genital herpes is focused on ameliorating signs and symptoms but is not curative. However, as potential herpes simplex virus (HSV) cure approaches are tested in the laboratory, we aimed to assess the interest in such studies by persons with genital herpes and the willingness to assume risks associated with experimental therapy. We constructed an anonymous online questionnaire that was posted on websites that provide information regarding genital herpes. The questions collected demographic and clinical information on adults who self-reported as having genital herpes, and assessed attitudes toward and willingness to participate in HSV cure clinical research. Seven hundred eleven participants provided sufficient responses to be included in the analysis. Sixty-six percent were women; the median age was 37 years, and the median time since genital HSV diagnosis was 4.7 years. The willingness to participate in trials increased from 59.0% in phase 1 to 68.5% in phase 2, and 81.2% in phase 3 trials, and 40% reported willingness to participate even in the absence of immediate, personal benefits. The most desirable outcome was the elimination of risk for transmission to sex partner or neonate. The mean perceived severity of receiving a diagnosis of genital HSV-2 was 4.2 on a scale of 1 to 5. Despite suppressive therapy available, persons with genital herpes are interested in participating in clinical research aimed at curing HSV, especially in more advanced stages of development.

Pulsed neutron generator for logging

International Nuclear Information System (INIS)

Thibideau, F.D.

1977-01-01

A pulsed neutron generator for uranium logging is described. This generator is one component of a prototype uranium logging probe which is being developed by SLA to detect, and assay, uranium by borehole logging. The logging method is based on the measurement of epithermal neutrons resulting from the prompt fissioning of uranium from a pulsed source of 17.6 MeV neutrons. An objective of the prototype probe was that its diameter not exceed 2.75 inches, which would allow its use in conventional rotary drill holes of 4.75-inch diameter. This restriction limited the generator to a maximum 2.375-inch diameter. The performance requirements for the neutron generator specified that it operate with a nominal output of 5 x 10 6 neutrons/pulse at up to 100 pulses/second for a one-hour period. The development of a neutron generator meeting the preliminary design goals was completed and two prototype models were delivered to SLA. These two generators have been used by SLA to log a number of boreholes in field evaluation of the probe. The results of the field evaluations have led to the recommendation of several changes to improve the probe's operation. Some of these changes will require additional development effort on the neutron generator. It is expected that this work will be performed during 1977. The design and operation of the first prototype neutron generators is described

One less trip : logging with less tripping, more protection

Energy Technology Data Exchange (ETDEWEB)

Byfield, M.

2005-12-15

New logging technology by Datalog Technology Inc. was described. Logging-while-tripping (LWT) technology uses a slim petrophysical sensor package that is moved to the targeted geological formation through a drill pipe, which reduces the exposure to vibration and shock involved in logging-while-drilling (LWD). The equipment features standard components in a patented configuration and comes in 2 segments: the receiver sub and the sensor package electronics. A receiver sub is inserted into the bottomhole assembly at the end of the drill string. Drilling progresses with the LWT sub in the bottomhole assembly until the borehole approaches the logging depth. The sensor package and electronics are then lowered into the drill string. If the well is horizontal, rig pumps push the package into the drill string until it lands in the LWT sub. Drill pipes are moved across the zone of interest and logs are recorded on downhole memory contained within the LWT package. As the logging operation progresses, a depth recorder at the surface records depth information along with the downhole recorders. When logging is completed, downhole tools are retrieved, and data downloaded from the LWT onboard memory is merged with the surface depth information to generate well logs. Retrieval via the drill string greatly reduces the risk of losing the logging gear, which contains radioactive material. Federal officials now routinely insist on extensive fishing operations to retrieve lost tools. If a well gets a gas kick while logging is in progress, the operator can still pump down mud or close the blowout preventer rams if necessary, and save time in determining where to perforate shallow gas wells. Compensated neutron logs, gamma rays, spectrum gamma rays, and induction have been tested with the LWT system. It was concluded that Petro-Canada has deployed the logs recently and has achieved results that compared satisfactorily with conventional logs. 2 figs.

Log N-log S in inconclusive

Science.gov (United States)

Klebesadel, R. W.; Fenimore, E. E.; Laros, J.

1983-01-01

The log N-log S data acquired by the Pioneer Venus Orbiter Gamma Burst Detector (PVO) are presented and compared to similar data from the Soviet KONUS experiment. Although the PVO data are consistent with and suggestive of a -3/2 power law distribution, the results are not adequate at this state of observations to differentiate between a -3/2 and a -1 power law slope.

Bayesian analysis of log Gaussian Cox processes for disease mapping

DEFF Research Database (Denmark)

Benes, Viktor; Bodlák, Karel; Møller, Jesper

We consider a data set of locations where people in Central Bohemia have been infected by tick-borne encephalitis, and where population census data and covariates concerning vegetation and altitude are available. The aims are to estimate the risk map of the disease and to study the dependence...... of the risk on the covariates. Instead of using the common area level approaches we consider a Bayesian analysis for a log Gaussian Cox point process with covariates. Posterior characteristics for a discretized version of the log Gaussian Cox process are computed using markov chain Monte Carlo methods...

Encyclopedia of well logging

International Nuclear Information System (INIS)

Desbrandes, R.

1985-01-01

The 16 chapters of this book aim to provide students, trainees and engineers with a manual covering all well-logging measurements ranging from drilling to productions, from oil to minerals going by way of geothermal energy. Each chapter is a summary but a bibliography is given at the end of each chapter. Well-logging during drilling, wireline logging equipment and techniques, petroleum logging, data processing of borehole data, interpretation of well-logging, sampling tools, completion and production logging, logging in relief wells to kill off uncontrolled blowouts, techniques for high temperature geothermal energy, small-scale mining and hydrology, logging with oil-base mud and finally recommended logging programs are all topics covered. There is one chapter on nuclear well-logging which is indexed separately. (UK)

Inherent Risk or Risky Decision? Coach's Failure to Use Safety Device an Assumed Risk

Science.gov (United States)

Dodds, Mark A.; Bochicchio, Kristi Schoepfer

2013-01-01

The court examined whether a coach's failure to implement a safety device during pitching practice enhanced the risk to the athlete or resulted in a suboptimal playing condition, in the context of the assumption of risk doctrine.

Risk perception, risk taking, accident involvement and the need for stimulation

NARCIS (Netherlands)

Heino, A.; van der Molen, H.H.; Wilde, G.J S

1996-01-01

In Wilde's risk homeostasis theory, it is assumed that people have a target risk which guides their behaviour. The prime purpose of this experimental on-road study was to establish the effect of the need for stimulation or sensation seeking on this target risk. in addition, the relationship between

Hog Producers' Risk Management Attitudes and Desire for Additional Risk Management Education

OpenAIRE

Patrick, George F.; Peiter, Amy J.; Knight, Thomas O.; Coble, Keith H.; Baquet, Alan E.

2007-01-01

Hog producers in Indiana and Nebraska were surveyed about sources of risk, effectiveness of risk management strategies, and prior participation in and desire for additional risk management education. Ownership of hogs by the producer, size of the operation, and age did have significant effects on ratings of both sources of risk and effectiveness of risk management strategies. Probit analysis found age, prior attendance, knowledge and prior use of the tool, level of integration, and concern ab...

Fuel and Additive Characterization for HCCI Combustion

International Nuclear Information System (INIS)

Aceves, S M; Flowers, D; Martinez-Frias, J; Espinosa-Loza, F; Pitz, W J; Dibble, R

2003-01-01

This paper shows a numerical evaluation of fuels and additives for HCCl combustion. First, a long list of candidate HCCl fuels is selected. For all the fuels in the list, operating conditions (compression ratio, equivalence ratio and intake temperature) are determined that result in optimum performance under typical operation for a heavy-duty engine. Fuels are also characterized by presenting Log(p)-Log(T) maps for multiple fuels under HCCl conditions. Log(p)-Log(T) maps illustrate important processes during HCCl engine operation, including compression, low temperature heat release and ignition. Log(p)-Log(T) diagrams can be used for visualizing these processes and can be used as a tool for detailed analysis of HCCl combustion. The paper also includes a ranking of many potential additives. Experiments and analyses have indicated that small amounts (a few parts per million) of secondary fuels (additives) may considerably affect HCCl combustion and may play a significant role in controlling HCCl combustion. Additives are ranked according to their capability to advance HCCl ignition. The best additives are listed and an explanation of their effect on HCCl combustion is included

Quantitative assessment of the microbial risk of leafy greens from farm to consumption: preliminary framework, data, and risk estimates.

Science.gov (United States)

Danyluk, Michelle D; Schaffner, Donald W

2011-05-01

This project was undertaken to relate what is known about the behavior of Escherichia coli O157:H7 under laboratory conditions and integrate this information to what is known regarding the 2006 E. coli O157:H7 spinach outbreak in the context of a quantitative microbial risk assessment. The risk model explicitly assumes that all contamination arises from exposure in the field. Extracted data, models, and user inputs were entered into an Excel spreadsheet, and the modeling software @RISK was used to perform Monte Carlo simulations. The model predicts that cut leafy greens that are temperature abused will support the growth of E. coli O157:H7, and populations of the organism may increase by as much a 1 log CFU/day under optimal temperature conditions. When the risk model used a starting level of -1 log CFU/g, with 0.1% of incoming servings contaminated, the predicted numbers of cells per serving were within the range of best available estimates of pathogen levels during the outbreak. The model predicts that levels in the field of -1 log CFU/g and 0.1% prevalence could have resulted in an outbreak approximately the size of the 2006 E. coli O157:H7 outbreak. This quantitative microbial risk assessment model represents a preliminary framework that identifies available data and provides initial risk estimates for pathogenic E. coli in leafy greens. Data gaps include retail storage times, correlations between storage time and temperature, determining the importance of E. coli O157:H7 in leafy greens lag time models, and validation of the importance of cross-contamination during the washing process.

Analysis of RIA standard curve by log-logistic and cubic log-logit models

International Nuclear Information System (INIS)

Yamada, Hideo; Kuroda, Akira; Yatabe, Tami; Inaba, Taeko; Chiba, Kazuo

1981-01-01

In order to improve goodness-of-fit in RIA standard analysis, programs for computing log-logistic and cubic log-logit were written in BASIC using personal computer P-6060 (Olivetti). Iterative least square method of Taylor series was applied for non-linear estimation of logistic and log-logistic. Hear ''log-logistic'' represents Y = (a - d)/(1 + (log(X)/c)sup(b)) + d As weights either 1, 1/var(Y) or 1/σ 2 were used in logistic or log-logistic and either Y 2 (1 - Y) 2 , Y 2 (1 - Y) 2 /var(Y), or Y 2 (1 - Y) 2 /σ 2 were used in quadratic or cubic log-logit. The term var(Y) represents squares of pure error and σ 2 represents estimated variance calculated using a following equation log(σ 2 + 1) = log(A) + J log(y). As indicators for goodness-of-fit, MSL/S sub(e)sup(2), CMD% and WRV (see text) were used. Better regression was obtained in case of alpha-fetoprotein by log-logistic than by logistic. Cortisol standard curve was much better fitted with cubic log-logit than quadratic log-logit. Predicted precision of AFP standard curve was below 5% in log-logistic in stead of 8% in logistic analysis. Predicted precision obtained using cubic log-logit was about five times lower than that with quadratic log-logit. Importance of selecting good models in RIA data processing was stressed in conjunction with intrinsic precision of radioimmunoassay system indicated by predicted precision. (author)

Bladder cancer mapping in Libya based on standardized morbidity ratio and log-normal model

Science.gov (United States)

Alhdiri, Maryam Ahmed; Samat, Nor Azah; Mohamed, Zulkifley

2017-05-01

Disease mapping contains a set of statistical techniques that detail maps of rates based on estimated mortality, morbidity, and prevalence. A traditional approach to measure the relative risk of the disease is called Standardized Morbidity Ratio (SMR). It is the ratio of an observed and expected number of accounts in an area, which has the greatest uncertainty if the disease is rare or if geographical area is small. Therefore, Bayesian models or statistical smoothing based on Log-normal model are introduced which might solve SMR problem. This study estimates the relative risk for bladder cancer incidence in Libya from 2006 to 2007 based on the SMR and log-normal model, which were fitted to data using WinBUGS software. This study starts with a brief review of these models, starting with the SMR method and followed by the log-normal model, which is then applied to bladder cancer incidence in Libya. All results are compared using maps and tables. The study concludes that the log-normal model gives better relative risk estimates compared to the classical method. The log-normal model has can overcome the SMR problem when there is no observed bladder cancer in an area.

Occupational Safety and Health Concerns in Logging: A Cross-Sectional Assessment in Virginia

Directory of Open Access Journals (Sweden)

Sunwook Kim

2017-11-01

Full Text Available Increased logging mechanization has helped improve logging safety and health, yet related safety risks and concerns are not well understood. A cross-sectional study was completed among Virginia loggers. Participants (n = 122 completed a self-administered questionnaire focusing on aspects of safety and health related to logging equipment. Respondents were at a high risk of workplace injuries, with reported career and 12-month injury prevalences of 51% and 14%, respectively. Further, nearly all (98% respondents reported experiencing musculoskeletal symptoms. Over half (57.4% of respondents reported symptoms related to diesel exhaust exposure in their career. Few (15.6%, however, perceived their jobs to be dangerous. Based on the opinions and suggestions of respondents, three priority areas were identified for interventions: struck-by/against hazards, situational awareness (SA during logging operations, and visibility hazards. To address these hazards, and to have a broader and more substantial positive impact on safety and health, we discuss the need for proactive approaches such as incorporating proximity technologies in a logging machine or personal equipment, and enhancing logging machine design to enhance safety, ergonomics, and SA.

Additional borehole geophysical logging at Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1994-07-01

This technical memorandum describes the borehole geophysical logging performed at selected coreholes at Waste Area Grouping 1 between March and November 1991 in support of the remedial investigation. The primary objectives of the borehole geophysical logging program were to (1) identify fractured bedrock zones and identify those fractured bedrock zones participating in active groundwater flow, (2) correlate the fractured intervals with the regional stratigraphy described, and (3) further characterize local bedrock geology and hydrogeology and gain insight about the bedrock aquifer flow system. A secondary objective was to provide stratigraphic correlations with existing logs for coreholes CH001 through CH005. Fractured bedrock zones and active or open fractures were identified in all coreholes logged. The fracture identification and analysis process was intended to distinguish between open or active fractures participating in active groundwater flow and closed or inactive fractures that are partially or completely filled (such as with calcite mineralization) and do not support groundwater circulation. Most of the fractures identified are bedding plane. Fracture occurrence varies with the different units of the Chickamauga Group; the greatest density of fractures and active fractures occurs in the upper 150 ft of stratum cored. Fractures actively contributing to groundwater flow were also identified, and direction of fluid movement within fractures was identified for those coreholes with flowmeter data

Neutron-neutron-resonance logging of boron in boreholes with the use of the PRKS-2 radiometer

International Nuclear Information System (INIS)

Vakhtin, B.S.; Ivanov, V.S.; Filippov, E.M.; Novoselov, A.V.

1973-01-01

The well rig of the PRKS-2 logging radiometer is supplemented with a probe device for neutron measurements permitting to vary the probe size from 20 to 45 cm. To decrease the natural gamma radiation effect an external lead shield 7-mm thick having 50-mm outer diameter is fixed on the instrument sleeve. The instrument is provided with a NaI detector and a set of foils of Cd, Ag, Rh, Tu, In, Ta, and a Pu-Be source of 1x10 6 n/sec strength. The optimal size of the probe is assumed as 25 cm. From the results of well measurements a better differentiation of neutron resonance logging was noticed in comparison with neutron gamma logging. Comparing the data obtained with those of kern analysis a calibration curve was derived of neutron resonance logging versus B for wells of 59 mm dia

National logging program for the National Uranium Resource Evaluation. Final report

International Nuclear Information System (INIS)

The Mineral Engineering Division (MED) of High Life Helicopters, Inc., operated from May, 1979, through August, 1981, as a subcontractor to the Department of Energy (DOE) to acquire downhole geophysical log information in support of the National Uranium Resource Evaluation program (NURE). MED acquired downhole geophysical log information in 26 1 0 x 2 0 NTMS quadrangles in Colorado, Montana, Nebraska, North Dakota, South Dakota, and Wyoming. MED obtained the log information by gaining permission to log oil and gas wells, water wells, and coal exploration holes. Actual geophysical logging was subcontracted to Century Geophysical Corporation. After logging of each well and completed, MED submitted the log information and other pertinent data to Bendix Field Engineering Corporation (BFEC) for evaluation. MED collected over 700,000 feet of geophysical logs. Additionally, MED conducted a search of log libraries for existing log data for twelve of the quadrangles included in the program. It should be noted that ERTEC, Inc. conducted geophysical logging and a log library search to five quadrangles in Wyoming. These areas were later assigned to MED. The location of all wells logged by MED and ERTEC and the location of other log data is shown on the enclosed maps. Detailed information that pertains to each well is provided following each map

Additive and polynomial representations

CERN Document Server

Krantz, David H; Suppes, Patrick

1971-01-01

Additive and Polynomial Representations deals with major representation theorems in which the qualitative structure is reflected as some polynomial function of one or more numerical functions defined on the basic entities. Examples are additive expressions of a single measure (such as the probability of disjoint events being the sum of their probabilities), and additive expressions of two measures (such as the logarithm of momentum being the sum of log mass and log velocity terms). The book describes the three basic procedures of fundamental measurement as the mathematical pivot, as the utiliz

Generalized localization for the double trigonometric Fourier series and the Walsh-Fourier series of functions in L log +L log + log +L

International Nuclear Information System (INIS)

Bloshanskaya, S K; Bloshanskii, I L; Roslova, T Y

1998-01-01

For an arbitrary open set Ω subset of I 2 =[0,1) 2 and an arbitrary function f element of L log + L log + log + L(I 2 ) such that f=0 on Ω the double Fourier series of f with respect to the trigonometric system Ψ=E and the Walsh-Paley system Ψ=W is shown to converge to zero (over rectangles) almost everywhere on Ω. Thus, it is proved that generalized localization almost everywhere holds on arbitrary open subsets of the square I 2 for the double trigonometric Fourier series and the Walsh-Fourier series of functions in the class L log + L log + log + L (in the case of summation over rectangles). It is also established that such localization breaks down on arbitrary sets that are not dense in I 2 , in the classes Φ Ψ (L)(I 2 ) for the orthonormal system Ψ=E and an arbitrary function such that Φ E (u)=o(u log + log + u) as u→∞ or for Φ W (u)=u( log + log + u) 1-ε , 0<ε<1

Logging technique for assaying for uranium in rocks

International Nuclear Information System (INIS)

Givens, W.W.

1973-01-01

A uranium exploration technique is described for determining the uranium content of a formation traversed by borehole. A delayed fission neutron assay log is obtained by irradiating the formation with repetitive bursts of fast neutrons and detecting delayed neutrons resulting from neutron fission of uranium at time intervals between the fast neutron bursts and after dissipation of the neutrons originating in the bursts. In addition, a response log is obtained by irradiating the formation with a source of fast neutrons whereby the neutrons from this source are moderated in the formation to lower energy levels and are subject to absorption. Secondary radiation attendant to these lower energy neutrons is recorded in order to obtain a log representative of the response of the formation to moderation and absorption of the neutrons. The two logs thus obtained are correlated in order to determine a corrected value of uranium content of the formation. (author)

Borehole logging

International Nuclear Information System (INIS)

Olsen, H.

1995-01-01

Numerous ground water investigations have been accomplished by means of borehole logging. Borehole logging can be applied to establish new water recovery wells, to control the existing water producing wells and source areas and to estimate ground water quality. (EG)

Why credit risk markets are predestined for exhibiting log-periodic power law structures

Science.gov (United States)

Wosnitza, Jan Henrik; Leker, Jens

2014-01-01

Recent research has established the existence of log-periodic power law (LPPL) patterns in financial institutions’ credit default swap (CDS) spreads. The main purpose of this paper is to clarify why credit risk markets are predestined for exhibiting LPPL structures. To this end, the credit risk prediction of two variants of logistic regression, i.e. polynomial logistic regression (PLR) and kernel logistic regression (KLR), are firstly compared to the standard logistic regression (SLR). In doing so, the question whether the performances of rating systems based on balance sheet ratios can be improved by nonlinear transformations of the explanatory variables is resolved. Building on the result that nonlinear balance sheet ratio transformations hardly improve the SLR’s predictive power in our case, we secondly compare the classification performance of a multivariate SLR to the discriminative powers of probabilities of default derived from three different capital market data, namely bonds, CDSs, and stocks. Benefiting from the prompt inclusion of relevant information, the capital market data in general and CDSs in particular increasingly outperform the SLR while approaching the time of the credit event. Due to the higher classification performances, it seems plausible for creditors to align their investment decisions with capital market-based default indicators, i.e., to imitate the aggregate opinion of the market participants. Since imitation is considered to be the source of LPPL structures in financial time series, it is highly plausible to scan CDS spread developments for LPPL patterns. By establishing LPPL patterns in governmental CDS spread trajectories of some European crisis countries, the LPPL’s application to credit risk markets is extended. This novel piece of evidence further strengthens the claim that credit risk markets are adequate breeding grounds for LPPL patterns.

LongLine: Visual Analytics System for Large-scale Audit Logs

Directory of Open Access Journals (Sweden)

Seunghoon Yoo

2018-03-01

Full Text Available Audit logs are different from other software logs in that they record the most primitive events (i.e., system calls in modern operating systems. Audit logs contain a detailed trace of an operating system, and thus have received great attention from security experts and system administrators. However, the complexity and size of audit logs, which increase in real time, have hindered analysts from understanding and analyzing them. In this paper, we present a novel visual analytics system, LongLine, which enables interactive visual analyses of large-scale audit logs. LongLine lowers the interpretation barrier of audit logs by employing human-understandable representations (e.g., file paths and commands instead of abstract indicators of operating systems (e.g., file descriptors as well as revealing the temporal patterns of the logs in a multi-scale fashion with meaningful granularity of time in mind (e.g., hourly, daily, and weekly. LongLine also streamlines comparative analysis between interesting subsets of logs, which is essential in detecting anomalous behaviors of systems. In addition, LongLine allows analysts to monitor the system state in a streaming fashion, keeping the latency between log creation and visualization less than one minute. Finally, we evaluate our system through a case study and a scenario analysis with security experts.

Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

International Nuclear Information System (INIS)

Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus; Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf

2015-01-01

The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [de

Importance of well logging measurements in the design of underground railway tunnels

International Nuclear Information System (INIS)

Kiss, E.Z.; Szlaboczky, P.

1981-01-01

The paper shows how logs can be used in the construction of underground railway tunnels in terciary sediments. Even standard well logging techniques (electric conductivity, gamma logging) can provide important additional information on the wells if conclusions concerning construction technology are gained from the logs. In the course of continuous research work the application of well logs renders an essential help if the measurements give in-situ information on absolute values of the well sections by revealing the various geological formations based on the distribution of characteristic parameters. Well logging increases the resolving power of the mechanical method of layer differentiation. Beside the usual geological interpretation of logs the zones of shifting rocks, hard and friable formations as well as intercalations leading to problems in construction technology can be pointed out. (author)

Using Structured Additive Regression Models to Estimate Risk Factors of Malaria: Analysis of 2010 Malawi Malaria Indicator Survey Data

Science.gov (United States)

Chirombo, James; Lowe, Rachel; Kazembe, Lawrence

2014-01-01

Background After years of implementing Roll Back Malaria (RBM) interventions, the changing landscape of malaria in terms of risk factors and spatial pattern has not been fully investigated. This paper uses the 2010 malaria indicator survey data to investigate if known malaria risk factors remain relevant after many years of interventions. Methods We adopted a structured additive logistic regression model that allowed for spatial correlation, to more realistically estimate malaria risk factors. Our model included child and household level covariates, as well as climatic and environmental factors. Continuous variables were modelled by assuming second order random walk priors, while spatial correlation was specified as a Markov random field prior, with fixed effects assigned diffuse priors. Inference was fully Bayesian resulting in an under five malaria risk map for Malawi. Results Malaria risk increased with increasing age of the child. With respect to socio-economic factors, the greater the household wealth, the lower the malaria prevalence. A general decline in malaria risk was observed as altitude increased. Minimum temperatures and average total rainfall in the three months preceding the survey did not show a strong association with disease risk. Conclusions The structured additive regression model offered a flexible extension to standard regression models by enabling simultaneous modelling of possible nonlinear effects of continuous covariates, spatial correlation and heterogeneity, while estimating usual fixed effects of categorical and continuous observed variables. Our results confirmed that malaria epidemiology is a complex interaction of biotic and abiotic factors, both at the individual, household and community level and that risk factors are still relevant many years after extensive implementation of RBM activities. PMID:24991915

A comparison between elemental logs and core data

International Nuclear Information System (INIS)

Kerr, S.A.; Grau, J.A.; Schweitzer, J.S.

1992-01-01

Neutron-induced gamma-ray spectroscopy, of prompt capture and delayed activation, together with natural gamma-ray measurements, provides a borehole elemental analysis to characterize rock matrix composition. This study involved extensive core and log data in two wells. One well was drilled with a barite-weighted oil-based mud through a shallow marine sand. The other was drilled with fresh water-based mud through a channel sand, mudstone sequence overlying limestone. The results illustrate the importance of a suitable core sampling strategy and the problems associated with matching core to log data. Possible inaccuracies from the modelling of Ca-, Fe- and S-bearing minerals have been determined. A method for correcting the total measured aluminium concentration for that due to the borehole mud has been successfully tested against aluminium concentrations measured in the cleaned core samples. Estimates of the overall accuracy and precision of the elemental logging concentrations are obtained by comparing the log results with those obtained from the laboratory core analysis. A comprehensive core elemental analysis can also provide useful insight into the way other logs, such as the photoelectric factor or formation thermal neutron macroscopic absorption cross section, are influenced by minor and trace elements. Differences between calculated values from elemental logs and measured macroscopic parameters provide additional data for a more detailed understanding of the rock properties. (Author)

Shear viscosity of the quark-gluon plasma in a weak magnetic field in perturbative QCD: Leading log

Science.gov (United States)

Li, Shiyong; Yee, Ho-Ung

2018-03-01

We compute the shear viscosity of two-flavor QCD plasma in an external magnetic field in perturbative QCD at leading log order, assuming that the magnetic field is weak or soft: e B ˜g4log (1 /g )T2. We work in the assumption that the magnetic field is homogeneous and static, and the electrodynamics is nondynamical in a formal limit e →0 while e B is kept fixed. We show that the shear viscosity takes a form η =η ¯(B ¯)T3/(g4log (1 /g )) with a dimensionless function η ¯(B ¯) in terms of a dimensionless variable B ¯=(e B )/(g4log (1 /g )T2). The variable B ¯ corresponds to the relative strength of the effect of cyclotron motions compared to the QCD collisions: B ¯˜lmfp/lcyclo. We provide a full numerical result for the scaled shear viscosity η ¯(B ¯).

The current situation and prospect of fundamental research about nuclear logging technology

International Nuclear Information System (INIS)

Zhang Feng; Wang Xinguang; Yuan Chao

2010-01-01

Nuclear logging technology is one of the important methods to evaluate complex hydrocarbon reservoir in the process of petroleum exploration and development. The fundamental research of nuclear logging is an important step of logging technology innovation. Through analyzing the current situation of the development of nuclear logging technology at home and abroad in recent years, the problems and gaps are pointed out in the field of fundamental research of nuclear logging at home, and the future development of new nuclear logging technologies is concisely analyzed. Therefore, the optimal design and processing are conducted from aspects of ray source, detector, data acquisition and processing method. In addition, the fundamental research of LWD and pulsed neutron logging technology is taken as the main breach. In the fundamental research of nuclear logging technology, innovative thinking should be expressed and the innovation should be achieved in every field of the development of nuclear logging technology. Meanwhile, the logging key lab should be taken as the platform and the latest achievement in the field of nuclear logging technology should be fully utilized. Thus, the level of independent R and D and technology innovation of logging tools will be raised and service for the exploration and development of petroleum and other mineral resources. (authors)

The application of geophysical logging at in-situ leaching uranium mine in China

International Nuclear Information System (INIS)

Liu Zeyao; Xu Shusheng; Li Zhongqiu

1999-01-01

The status of work, instrument and method employed for geophysical logging in different stages at in-situ leaching uranium mine are discussed and the development of software, electrical current logging and gamma ray logging are presented based on the requirement of in-situ leaching of uranium. In addition, new function and method with regard to home instrument are proposed for future work

Assume-Guarantee Abstraction Refinement Meets Hybrid Systems

Science.gov (United States)

Bogomolov, Sergiy; Frehse, Goran; Greitschus, Marius; Grosu, Radu; Pasareanu, Corina S.; Podelski, Andreas; Strump, Thomas

2014-01-01

Compositional verification techniques in the assume- guarantee style have been successfully applied to transition systems to efficiently reduce the search space by leveraging the compositional nature of the systems under consideration. We adapt these techniques to the domain of hybrid systems with affine dynamics. To build assumptions we introduce an abstraction based on location merging. We integrate the assume-guarantee style analysis with automatic abstraction refinement. We have implemented our approach in the symbolic hybrid model checker SpaceEx. The evaluation shows its practical potential. To the best of our knowledge, this is the first work combining assume-guarantee reasoning with automatic abstraction-refinement in the context of hybrid automata.

Study of the reservoirs of Jurassic and Cretaceous periods in the south-cast slope of Central Kara-Kum vault using combination of acoustic logging, neutron-gamma logging, gamma logging, and electrical logging

International Nuclear Information System (INIS)

Meredov, T.M.; Baranov, M.I.

1978-01-01

Considered is the possibility of application of the combination of neutron-gamma logging, gamma logging al partitioncoustic logging and electrical logging to lithologica of sections, discovery reservoir layers in carbonate and terrigeneous sections as well as quantitative estimation of the porosity coefficients values at prospecting areas in the south-east slope of Central Kara-Kum vault. Neutron-gamma logging mostly makes it possible to partition carbonate rocks into limestones, dolomites and their interstitial variaties and to indicate sand stone layers with different degree of carbonate content

The Meaning of Logs

NARCIS (Netherlands)

Etalle, Sandro; Massacci, Fabio; Yautsiukhin, Artsiom

2007-01-01

While logging events is becoming increasingly common in computing, in communication and in collaborative work, log systems need to satisfy increasingly challenging (if not conflicting) requirements.Despite the growing pervasiveness of log systems, to date there is no high-level framework which

The Meaning of Logs

NARCIS (Netherlands)

Etalle, Sandro; Massacci, Fabio; Yautsiukhin, Artsiom; Lambrinoudakis, Costas; Pernul, Günther; Tjoa, A Min

While logging events is becoming increasingly common in computing, in communication and in collaborative environments, log systems need to satisfy increasingly challenging (if not conflicting) requirements. In this paper we propose a high-level framework for modeling log systems, and reasoning about

Influence of borehole-eccentred tools on wireline and logging-while-drilling sonic logging measurements

KAUST Repository

Pardo, David

2013-02-13

We describe a numerical study to quantify the influence of tool-eccentricity on wireline (WL) and logging-while-drilling (LWD) sonic logging measurements. Simulations are performed with a height-polynomial-adaptive (hp) Fourier finite-element method that delivers highly accurate solutions of linear visco-elasto-acoustic problems in the frequency domain. The analysis focuses on WL instruments equipped with monopole or dipole sources and LWD instruments with monopole excitation. Analysis of the main propagation modes obtained from frequency dispersion curves indicates that the additional high-order modes arising as a result of borehole-eccentricity interfere with the main modes (i.e., Stoneley, pseudo-Rayleigh and flexural). This often modifies (decreases) the estimation of shear and compressional formation velocities, which should be corrected (increased) to account for borehole-eccentricity effects. Undesired interferences between different modes can occur at different frequencies depending upon the properties of the formation and fluid annulus size, which may difficult the estimation of the formation velocities. © 2013 European Association of Geoscientists & Engineers.

The effects of logging residue extraction for energy on ecosystem services and biodiversity: A synthesis.

Science.gov (United States)

Ranius, Thomas; Hämäläinen, Aino; Egnell, Gustaf; Olsson, Bengt; Eklöf, Karin; Stendahl, Johan; Rudolphi, Jörgen; Sténs, Anna; Felton, Adam

2018-03-01

We review the consequences for biodiversity and ecosystem services from the industrial-scale extraction of logging residues (tops, branches and stumps from harvested trees and small-diameter trees from thinnings) in managed forests. Logging residue extraction can replace fossil fuels, and thus contribute to climate change mitigation. The additional biomass and nutrients removed, and soils and other structures disturbed, have several potential environmental impacts. To evaluate potential impacts on ecosystem services and biodiversity we reviewed 279 scientific papers that compared logging residue extraction with non-extraction, the majority of which were conducted in Northern Europe and North America. The weight of available evidence indicates that logging residue extraction can have significant negative effects on biodiversity, especially for species naturally adapted to sun-exposed conditions and the large amounts of dead wood that are created by large-scaled forest disturbances. Slash extraction may also pose risks for future biomass production itself, due to the associated loss of nutrients. For water quality, reindeer herding, mammalian game species, berries, and natural heritage the results were complicated by primarily negative but some positive effects, while for recreation and pest control positive effects were more consistent. Further, there are initial negative effects on carbon storage, but these effects are transient and carbon stocks are mostly restored over decadal time perspectives. We summarize ways of decreasing some of the negative effects of logging residue extraction on specific ecosystem services, by changing the categories of residue extracted, and site or forest type targeted for extraction. However, we found that suggested pathways for minimizing adverse outcomes were often in conflict among the ecosystem services assessed. Compensatory measures for logging residue extraction may also be used (e.g. ash recycling, liming, fertilization

Ionising radiation risk disclosure: When should radiographers assume a duty to inform?

Science.gov (United States)

Younger, C W E; Douglas, C; Warren-Forward, H

2018-05-01

Autonomy is a fundamental patient right for ethical practice, and informed consent is the mechanism by which health care professionals ensure this right has been respected. The ethical notion of informed consent has evolved alongside legal developments. Under Australian law, a provider who fails to disclose risk may be found to be in breach of a duty of disclosure, potentially facing legal consequences if the patient experiences harm that is attributable to an undisclosed risk. These consequences may include the common law tort of negligence. Ionising radiation, in the form of a medical imaging examination, has the potential to cause harm. However, stochastic effects cannot be attributable to a specific ionising radiation event. What then is the role of the Australian medical imaging service provider in disclosing ionising radiation risk? The ethical and legal principles of informed consent, and the duty of information provision to the patient are investigated. These general principles are then applied to the specific and unusual case of ionising radiation, and what responsibilities apply to the medical imaging provider. Finally, the legal, professional and ethical duties of the radiographer to disclose information to their patients are investigated. Australian law is unclear as to whether a radiographer has a common law responsibility to disclose radiation risk. There is ambiguity as to whether stochastic ionising radiation risk could be considered a legal disclosure responsibility. While it is unlikely that not disclosing risk will have medicolegal consequences, doing so represents sound ethical practice. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

SDSS Log Viewer: visual exploratory analysis of large-volume SQL log data

Science.gov (United States)

Zhang, Jian; Chen, Chaomei; Vogeley, Michael S.; Pan, Danny; Thakar, Ani; Raddick, Jordan

2012-01-01

User-generated Structured Query Language (SQL) queries are a rich source of information for database analysts, information scientists, and the end users of databases. In this study a group of scientists in astronomy and computer and information scientists work together to analyze a large volume of SQL log data generated by users of the Sloan Digital Sky Survey (SDSS) data archive in order to better understand users' data seeking behavior. While statistical analysis of such logs is useful at aggregated levels, efficiently exploring specific patterns of queries is often a challenging task due to the typically large volume of the data, multivariate features, and data requirements specified in SQL queries. To enable and facilitate effective and efficient exploration of the SDSS log data, we designed an interactive visualization tool, called the SDSS Log Viewer, which integrates time series visualization, text visualization, and dynamic query techniques. We describe two analysis scenarios of visual exploration of SDSS log data, including understanding unusually high daily query traffic and modeling the types of data seeking behaviors of massive query generators. The two scenarios demonstrate that the SDSS Log Viewer provides a novel and potentially valuable approach to support these targeted tasks.

Static dictionaries on AC⁰ RAMs: query time (√log n/log log n) is necessary and sufficient

DEFF Research Database (Denmark)

Andersson, Arne; Miltersen, Peter Bro; Riis, Søren

1996-01-01

) on the time for answering membership queries in a set of size n when reasonable space is used for the data structure storing the set; the upper bound can be obtained using O(n) space, and the lower bound holds even if we allow space 2polylog n. Several variations of this result are also obtained. Among others......, we show a tradeoff between time and circuit depth under the unit-cost assumption: any RAM instruction set which permits a linear space, constant query time solution to the static dictionary problem must have an instruction of depth Ω(log w/log log to), where w is the word size of the machine (and log...

Monitoring Assumptions in Assume-Guarantee Contracts

Directory of Open Access Journals (Sweden)

Oleg Sokolsky

2016-05-01

Full Text Available Pre-deployment verification of software components with respect to behavioral specifications in the assume-guarantee form does not, in general, guarantee absence of errors at run time. This is because assumptions about the environment cannot be discharged until the environment is fixed. An intuitive approach is to complement pre-deployment verification of guarantees, up to the assumptions, with post-deployment monitoring of environment behavior to check that the assumptions are satisfied at run time. Such a monitor is typically implemented by instrumenting the application code of the component. An additional challenge for the monitoring step is that environment behaviors are typically obtained through an I/O library, which may alter the component's view of the input format. This transformation requires us to introduce a second pre-deployment verification step to ensure that alarms raised by the monitor would indeed correspond to violations of the environment assumptions. In this paper, we describe an approach for constructing monitors and verifying them against the component assumption. We also discuss limitations of instrumentation-based monitoring and potential ways to overcome it.

Log-Normality and Multifractal Analysis of Flame Surface Statistics

Science.gov (United States)

Saha, Abhishek; Chaudhuri, Swetaprovo; Law, Chung K.

2013-11-01

The turbulent flame surface is typically highly wrinkled and folded at a multitude of scales controlled by various flame properties. It is useful if the information contained in this complex geometry can be projected onto a simpler regular geometry for the use of spectral, wavelet or multifractal analyses. Here we investigate local flame surface statistics of turbulent flame expanding under constant pressure. First the statistics of local length ratio is experimentally obtained from high-speed Mie scattering images. For spherically expanding flame, length ratio on the measurement plane, at predefined equiangular sectors is defined as the ratio of the actual flame length to the length of a circular-arc of radius equal to the average radius of the flame. Assuming isotropic distribution of such flame segments we convolute suitable forms of the length-ratio probability distribution functions (pdfs) to arrive at corresponding area-ratio pdfs. Both the pdfs are found to be near log-normally distributed and shows self-similar behavior with increasing radius. Near log-normality and rather intermittent behavior of the flame-length ratio suggests similarity with dissipation rate quantities which stimulates multifractal analysis. Currently at Indian Institute of Science, India.

Processing well logging data, for example for verification and calibration of well logs

International Nuclear Information System (INIS)

Suau, J.; Boutemy, Y.

1981-01-01

A method is described of machine processing well logging data derived from borehole exploring devices which investigate earth formations traversed by boreholes. The method can be used for verifying and recalibrating logs, reconstructing missing logs and combining the data to form a statistical model of the traversed earth formations. (U.K.)

Risks associated with endotoxins in feed additives produced by fermentation.

Science.gov (United States)

Wallace, R John; Gropp, Jürgen; Dierick, Noël; Costa, Lucio G; Martelli, Giovanna; Brantom, Paul G; Bampidis, Vasileios; Renshaw, Derek W; Leng, Lubomir

2016-01-15

Increasingly, feed additives for livestock, such as amino acids and vitamins, are being produced by Gram-negative bacteria, particularly Escherichia coli. The potential therefore exists for animals, consumers and workers to be exposed to possibly harmful amounts of endotoxin from these products. The aim of this review was to assess the extent of the risk from endotoxins in feed additives and to calculate how such risk can be assessed from the properties of the additive. Livestock are frequently exposed to a relatively high content of endotoxin in the diet: no additional hazard to livestock would be anticipated if the endotoxin concentration of the feed additive falls in the same range as feedstuffs. Consumer exposure will be unaffected by the consumption of food derived from animals receiving endotoxin-containing feed, because the small concentrations of endotoxin absorbed do not accumulate in edible tissues. In contrast, workers processing a dusty additive may be exposed to hazardous amounts of endotoxin even if the endotoxin concentration of the product is low. A calculation method is proposed to compare the potential risk to the worker, based on the dusting potential, the endotoxin concentration and technical guidance of the European Food Safety Authority, with national exposure limits.

La logística integral como ventaja competitiva y sistema logístico

Directory of Open Access Journals (Sweden)

Mario Anselmo Martínez gallardo

2013-07-01

Full Text Available Esta investigación analiza la logística integral como una ventaja competitiva y el sistema logístico. Es opinión de los autores que la logística integral es esencial para el intercambio de mercancías, toda vez que reduce costos y hace más ágil la actividad comercial. La utilización de esta logística representa una ventaja competitiva con respecto de otras empresas por la optimización del capital y ahorro de tiempo.

The log S -log N distribution of gamma ray brust

International Nuclear Information System (INIS)

Yamagami, Takamasa; Nishimura, Jun; Fujii, Masami

1982-01-01

The relation between the size S and the frequency N of gamma ray burst has been studied. This relation may be determined from the celestial distribution of gamma ray burst sources. The present analysis gives that the log S - log N relation for any direction is determined by the celestial distribution of gamma ray burst sources. The observed bursts were analyzed. The celestial distribution of gamma ray burst sources was observed by the satellites of USSR. The results showed that the distribution seemed to be isotropic. However, the calculated log S - log N relation based on the isotropic distribution wasF in disagreement with the observed ones. As the result of analysis, it was found that the observed bursts missed low energy part because of the threshold of detectors. The levels of discrimination of detection were not clear. When a proper threshold level is set for each type of burst, and the size of bursts is determined, the above mentioned discrepancy will be deleted regardless of luminosity and the spatial distribution of bursts. (Kato, T.)

Digital mineral logging system

International Nuclear Information System (INIS)

West, J.B.

1980-01-01

A digital mineral logging system acquires data from a mineral logging tool passing through a borehole and transmits the data uphole to an electronic digital signal processor. A predetermined combination of sensors, including a deviometer, is located in a logging tool for the acquisition of the desired data as the logging tool is raised from the borehole. Sensor data in analog format is converted in the logging tool to a digital format and periodically batch transmitted to the surface at a predetermined sampling rate. An identification code is provided for each mineral logging tool, and the code is transmitted to the surface along with the sensor data. The self-identifying tool code is transmitted to the digital signal processor to identify the code against a stored list of the range of numbers assigned to that type of tool. The data is transmitted up the d-c power lines of the tool by a frequency shift key transmission technique. At the surface, a frequency shift key demodulation unit transmits the decoupled data to an asynchronous receiver interfaced to the electronic digital signal processor. During a recording phase, the signals from the logging tool are read by the electronic digital signal processor and stored for later processing. During a calculating phase, the stored data is processed by the digital signal processor and the results are outputted to a printer or plotter, or both

Hydrophysical logging: A new wellbore technology for hydrogeologic and contaminant characterization of aquifers

International Nuclear Information System (INIS)

Pedler, W.H.; Williams, L.L.; Head, C.L.

1992-01-01

In the continuing search for improved groundwater characterization technologies, a new wellbore fluid logging method has recently been developed to provide accurate and cost effective hydrogeologic and contaminant characterization of bedrock aquifers. This new technique, termed hydrophysical logging, provides critical information for contaminated site characterization and water supply studies and, in addition, offers advantages compared to existing industry standards for aquifer characterization. Hydrophysical logging is based on measuring induced electrical conductivity changes in the fluid column of a wellbore by employing advanced downhole water quality instrumentation specifically developed for the dynamic borehole environment. Hydrophysical logging contemporaneously identifies the locations of water bearing intervals, the interval-specific inflow rate during pumping, and in-situ hydrochemistry of the formation waters associated with each producing interval. In addition, by employing a discrete point downhole fluid sampler during hydrophysical logging, this technique provides evaluation of contaminant concentrations and migration of contaminants vertically within the borehole. Recently, hydrophysical logging was applied in a deep bedrock wellbore at an industrial site in New Hampshire contaminated with dense nonaqueous phase liquids (DNAPLs). The results of the hydrophysical logging, conducted as part of a hydrogeologic site investigation and feasibility study, facilitated investigation of the site by providing information which indicated that the contamination had not penetrated into deeper bedrock fractures at concentrations of concern. This information was used to focus the pending Remedial Action Plan and to provide a more cost-effective remedial design

Mapping soil particle-size fractions: A comparison of compositional kriging and log-ratio kriging

Science.gov (United States)

Wang, Zong; Shi, Wenjiao

2017-03-01

Soil particle-size fractions (psf) as basic physical variables need to be accurately predicted for regional hydrological, ecological, geological, agricultural and environmental studies frequently. Some methods had been proposed to interpolate the spatial distributions of soil psf, but the performance of compositional kriging and different log-ratio kriging methods is still unclear. Four log-ratio transformations, including additive log-ratio (alr), centered log-ratio (clr), isometric log-ratio (ilr), and symmetry log-ratio (slr), combined with ordinary kriging (log-ratio kriging: alr_OK, clr_OK, ilr_OK and slr_OK) were selected to be compared with compositional kriging (CK) for the spatial prediction of soil psf in Tianlaochi of Heihe River Basin, China. Root mean squared error (RMSE), Aitchison's distance (AD), standardized residual sum of squares (STRESS) and right ratio of the predicted soil texture types (RR) were chosen to evaluate the accuracy for different interpolators. The results showed that CK had a better accuracy than the four log-ratio kriging methods. The RMSE (sand, 9.27%; silt, 7.67%; clay, 4.17%), AD (0.45), STRESS (0.60) of CK were the lowest and the RR (58.65%) was the highest in the five interpolators. The clr_OK achieved relatively better performance than the other log-ratio kriging methods. In addition, CK presented reasonable and smooth transition on mapping soil psf according to the environmental factors. The study gives insights for mapping soil psf accurately by comparing different methods for compositional data interpolation. Further researches of methods combined with ancillary variables are needed to be implemented to improve the interpolation performance.

Financial Crisis: A New Measure for Risk of Pension Fund Portfolios.

Directory of Open Access Journals (Sweden)

Marinella Cadoni

Full Text Available It has been argued that pension funds should have limitations on their asset allocation, based on the risk profile of the different financial instruments available on the financial markets. This issue proves to be highly relevant at times of market crisis, when a regulation establishing limits to risk taking for pension funds could prevent defaults. In this paper we present a framework for evaluating the risk level of a single financial instrument or a portfolio. By assuming that the log asset returns can be described by a multifractional Brownian motion, we evaluate the risk using the time dependent Hurst parameter H(t which models volatility. To provide a measure of the risk, we model the Hurst parameter with a random variable with mixture of beta distribution. We prove the efficacy of the methodology by implementing it on different risk level financial instruments and portfolios.

Financial Crisis: A New Measure for Risk of Pension Fund Portfolios.

Science.gov (United States)

Cadoni, Marinella; Melis, Roberta; Trudda, Alessandro

2015-01-01

It has been argued that pension funds should have limitations on their asset allocation, based on the risk profile of the different financial instruments available on the financial markets. This issue proves to be highly relevant at times of market crisis, when a regulation establishing limits to risk taking for pension funds could prevent defaults. In this paper we present a framework for evaluating the risk level of a single financial instrument or a portfolio. By assuming that the log asset returns can be described by a multifractional Brownian motion, we evaluate the risk using the time dependent Hurst parameter H(t) which models volatility. To provide a measure of the risk, we model the Hurst parameter with a random variable with mixture of beta distribution. We prove the efficacy of the methodology by implementing it on different risk level financial instruments and portfolios.

Initiating events of accidents in the practice of oil well logging in Cuba

International Nuclear Information System (INIS)

Alles Leal, A.; Perez Reyes, Y.; Dumenigo Gonzalez, C.

2013-01-01

The oil well logging is an extremely important activity within the oil industry, but in turn, brings risks that occasionally result in damage to health, the environment and economic losses. In this context, risk analysis has become an important tool to control them through their prediction and the study of the factors that determine them, enabling substantiated decisions to, first, foresee accidents and, secondly, to minimize their consequences. This paper proposes the elaboration of a list of initiating events of accidents in the practice of oil well logging which is one of the most important aspects for further evaluation of radiation safety of this practice. For its determination the technique employed to identify risks was 'Failure Modes and Effects Analysis (FMEA)' by applying it to the different stages and processes of practice. (Author)

The human factors of implementing shift work in logging operations.

Science.gov (United States)

Mitchell, D L; Gallagher, T V; Thomas, R E

2008-10-01

A fairly recent development in the forest industry is the use of shift work in logging in the southeastern U.S. Logging company owners are implementing shift work as an opportunity to increase production and potentially reduce the cost of producing each unit of wood, without consideration of the potential impacts on the logging crew. There are many documented physiological and psychological impacts on workers from shift work in a variety of industries, although few address forestry workers in the U.S. Semi-structured interviews were performed to gather information about how logging company owners were implementing shift work in seven southeastern states. Data collected during the interviews included employee turnover, shift hours, shift scheduling, safety considerations, and production impacts. Various work schedules were employed. The majority of the schedules encompassed less than 24 hours per day. Permanent and rotating shift schedules were found. None of the logging company owners used more than two crews in a 24-hour period. Additional safety precautions were implemented as a result of working after dark. No in-woods worker accidents or injuries were reported by any of those interviewed. Results indicate that a variety of work schedules can be successfully implemented in the southeastern logging industry.

Estimation of the non records logs from existing logs using artificial neural networks

Directory of Open Access Journals (Sweden)

Mehdi Mohammad Salehi

2017-12-01

Full Text Available Finding the information of the hydrocarbon reservoirs from well logs is one of the main objectives of the engineers. But, missing the log records (due to many reasons such as broken instruments, unsuitable borehole and etc. is a major challenge to achieve it. Prediction of the density and resistivity logs (Rt, DT and LLS from the conventional wire-line logs in one of the Iranian southwest oil fields is the main purpose of this study. Multilayer neural network was applied to develop an intelligent predictive model for prediction of the logs. A total of 3000 data sets from 3 wells (A, B and C of the studied field were used. Among them, the data of A, B and C wells were used to constructing and testing the model, respectively. To evaluate the performance of the model, the mean square error (MSE and correlation coefficient (R2 in the test data were calculated. A comparison between the MSE of the proposed model and recently intelligent models shows that the proposed model is more accurate than others. Acceptable accuracy and using conventional well logging data are the highlight advantages of the proposed intelligent model.

The impact of mechanical log surface damage on chip size ...

African Journals Online (AJOL)

Mechanised harvesting operations are becoming more prevalent in South Africa with the realisation that motormanual and manual harvesting operations pose significant health and safety risks to workers. The damage inflicted by single-grip harvester feed rollers and delimbing knives on log surfaces during debranching ...

Computer method to detect and correct cycle skipping on sonic logs

International Nuclear Information System (INIS)

Muller, D.C.

1985-01-01

A simple but effective computer method has been developed to detect cycle skipping on sonic logs and to replace cycle skips with estimates of correct traveltimes. The method can be used to correct observed traveltime pairs from the transmitter to both receivers. The basis of the method is the linearity of a plot of theoretical traveltime from the transmitter to the first receiver versus theoretical traveltime from the transmitter to the second receiver. Theoretical traveltime pairs are calculated assuming that the sonic logging tool is centered in the borehole, that the borehole diameter is constant, that the borehole fluid velocity is constant, and that the formation is homogeneous. The plot is linear for the full range of possible formation-rock velocity. Plots of observed traveltime pairs from a sonic logging tool are also linear but have a large degree of scatter due to borehole rugosity, sharp boundaries exhibiting large velocity contrasts, and system measurement uncertainties. However, this scatter can be reduced to a level that is less than scatter due to cycle skipping, so that cycle skips may be detected and discarded or replaced with estimated values of traveltime. Advantages of the method are that it can be applied in real time, that it can be used with data collected by existing tools, that it only affects data that exhibit cycle skipping and leaves other data unchanged, and that a correction trace can be generated which shows where cycle skipping occurs and the amount of correction applied. The method has been successfully tested on sonic log data taken in two holes drilled at the Nevada Test Site, Nye County, Nevada

Displacement length and velocity of tagged logs in the tagliamento river

Directory of Open Access Journals (Sweden)

Diego Ravazzolo

2013-09-01

Full Text Available Large wood enhance the dynamics of geomorphic processes in river systems, increases the morphological complexity of the channel bed, and provides habitats for fish and invertebrates. On the other side, if transported during high-magnitude events, large wood pieces can increase flood risks in sensitive places such as bridges and narrow cross sections prone to outbank flows. However, the dynamics and mobility of logs in rivers is poorly understood, especially in wide gravel-bed rivers. Recent studies have employed fixed video cameras to assess logs velocity, but little evidence is still available about travel length during flood events of different magnitude. This study was conducted in a valley reach of the Tagliamento river, located in the North East of Italy. The Tagliamento river is approximately 800 m wide in the study area, and is characterized by relatively high natural conditions and complex fluvial dynamics. Log mobility have been studied from June 2010 to October 2011, a period characterized by a relatively high magnitude flood in November 2010. Log mobility and displacement during floods have been measured by implanting active radio transmitters (RFID in 113 logs and GPS track devices in 42 logs. The first devices allow to recover the log after flood events by using a portable antenna, and to derive the displacement length over the monitoring period, whereas the second devices allows to calculate instantaneous (1 sec and average log velocity of moving logs. Recovery rate of logs equipped with RFID and GPS was about 50% and 60%, respectively. A preliminary analysis of the data collected indicates that there is a positive relationship between displacement length and the peak of flood events, as well as a positive relationship between log velocity and the flood magnitude. Also, a critical flow rate over which logs stranded on active bars can be transported has been identified. The ability to predict wood mobility in gravel-bed rivers could

Geophysical well logging operations and log analysis in Geothermal Well Desert Peak No. B-23-1

Energy Technology Data Exchange (ETDEWEB)

Sethi, D.K.; Fertl, W.H.

1980-03-01

Geothermal Well Desert Peak No. B-23-1 was logged by Dresser Atlas during April/May 1979 to a total depth of 2939 m (9642 ft). A temperature of 209/sup 0/C (408/sup 0/F) was observed on the maximum thermometer run with one of the logging tools. Borehole tools rated to a maximum temperature of 204.4/sup 0/C (400/sup 0/F) were utilized for logging except for the Densilog tool, which was from the other set of borehole instruments, rated to a still higher temperature, i.e., 260/sup 0/C (500/sup 0/F). The quality of the logs recorded and the environmental effects on the log response have been considered. The log response in the unusual lithologies of igneous and metamorphic formations encountered in this well could be correlated with the drill cutting data. An empirical, statistical log interpretation approach has made it possible to obtain meaningful information on the rocks penetrated. Various crossplots/histograms of the corrected log data have been generated on the computer. These are found to provide good resolution between the lithological units in the rock sequence. The crossplotting techniques and the statistical approach were combined with the drill cutting descriptions in order to arrive at the lithological characteristics. The results of log analysis and recommendations for logging of future wells have been included.

Theoretical and Numerical Study of Seismoelectric Logs for Logging While Drilling (LWD

Directory of Open Access Journals (Sweden)

Sun Xiang-Yang

2017-01-01

Full Text Available When the acoustic field propagates in the porous medium, the electromagnetic wave can be induced by the seismoelectric effects which can be used in the logging. This paper studies the seismoelectric wave field and deduces the formulations of the acoustic and electromagnetic field of the liquid in the well, and gives the acoustic and electromagnetic boundary conditions between the driller collar and the log liquid, when the driller collar is added. We also do the numerical simulation of the seismoelectric wave field excited by monopole source, study the velocity dispersion characteristics of the acoustic and electromagnetic field, and investigate the detective depth of the seismoelectric logs. Through the simulation we know the seismoelectric logs can avoid the interference of drill collar wave. This paper also provides theoretical guidance for the design of receiving antenna.

Face logging in Copenhagen Limestone, Denmark

DEFF Research Database (Denmark)

Jakobsen, Lisa; Foged, Niels Nielsen; Erichsen, Lars

2015-01-01

tunnel in Copenhagen more than 2.5 km face logs were made in 467 locations at underground stations, shafts, caverns and along bored tunnels. Over 160 geotechnical boreholes, many with geophysical logging were executed prior to construction works. The bedrock consists of Paleogene "Copenhagen limestone......The requirement for excavation support can be assessed from face logging. Face logs can also improve our knowledge of lithological and structural conditions within bedrock and supplement information from boreholes and geophysical logs. During the construction of 8 km metro tunnel and 4 km heating....... The induration degrees recorded in face logs and boreholes are compared and correlated. Distinct geophysical log markers are used to divide the limestone into three units. These marker horizons are correlated between face logs and geotechnical boreholes. A 3D model of the strength variations recorded within...

Log4J

CERN Document Server

Perry, Steven

2009-01-01

Log4j has been around for a while now, and it seems like so many applications use it. I've used it in my applications for years now, and I'll bet you have too. But every time I need to do something with log4j I've never done before I find myself searching for examples of how to do whatever that is, and I don't usually have much luck. I believe the reason for this is that there is a not a great deal of useful information about log4j, either in print or on the Internet. The information is too simple to be of real-world use, too complicated to be distilled quickly (which is what most developers

Examination of some assumed severe reactor accidents at the Olkiluoto nuclear power plant

International Nuclear Information System (INIS)

Pekkarinen, E.; Rossi, J.

1989-02-01

Knowledge and analysis methods of severe accidents at nuclear power plants and of subsequent response of primary system and containment have been developed in last few years to the extent that realistic source tems of the specified accident sequences can be calculated for the Finnish nuclear power plants. The objective of this investigation was to calculate the source terms of off-site consequences brought about by some selected severe accident sequences initiated by the total loss of on-site and off-site AC power at the Olkiluoto nuclear power plant. The results describing the estimated off-site health risks are expressed as conditional assuming that the accident has taken place, because the probabilities of the occurence of the accident sequences considered have not been analysed in this study. The range and probabilities of occurence of health detriments are considered by calculating consequences in different weeather conditions and taking into account the annual frequency of each weather condition and statistical population distribution. The calculational results indicate that the reactor building provides and additional holdup and deposition of radioactive substance (except coble gases) released from the containment. Furthermore, the release fractions of the core inventory to the environment of volatile fission products such as iodine, cesium and tellurium remain under 0.03. No early health effects are predicted for the surrounding population in case the assumed short-tem countermeasures are performed effectively. Acute health effects are extremely improbable even without any active countermeasure. By reducing the long-term exposure from contaminated agricultural products, the collective dose from natural long-term background radiation, for instance in the sector of 30 degrees towards the southern Finland up to the distance of 300 kilometers, would be expected to increase with 2-20 percent depending on the release considered

Unsupervised signature extraction from forensic logs

NARCIS (Netherlands)

Thaler, S.M.; Menkovski, V.; Petkovic, M.; Altun, Y.; Das, K.; Mielikäinen, T.; Malerba, D.; Stefanowski, J.; Read, J.; Žitnik, M.; Ceci, M.

2017-01-01

Signature extraction is a key part of forensic log analysis. It involves recognizing patterns in log lines such that log lines that originated from the same line of code are grouped together. A log signature consists of immutable parts and mutable parts. The immutable parts define the signature, and

LOG2MARKUP: State module to transform a Stata text log into a markup document

DEFF Research Database (Denmark)

2016-01-01

log2markup extract parts of the text version from the Stata log command and transform the logfile into a markup based document with the same name, but with extension markup (or otherwise specified in option extension) instead of log. The author usually uses markdown for writing documents. However...

Additional investigations on the consequences of accidents

International Nuclear Information System (INIS)

Ehrhardt, J.; Bayer, A.; Burkart, K.

1982-01-01

As a first step to improve the accident consequence model of the German Risk Study within the Phase B, additional investigations on special problems and questions were performed. In detail attention is given to the following topics: emergency protective actions in the vicinity of the site; latent cancer fatalities - allocated to the population living during the nuclear accident and to persons born afterwards, within and beyond a distance of 540 km from the site, caused by radiation doses below the dose limits of the German radiation protection regulations estimated assuming a nonlinear dose response function; risk assessments of nuclear power plants with lower capacities; loss of life expectancy after accidental radiation exposure. All results are presented separately for the 8 release categories of the German Risk Study. (orig.) [de

Impact assessment of radionuclide dispersion due to stuck of sources used in well logging

International Nuclear Information System (INIS)

Amado, V. A.; Alvarez, D.E.; Lee Gonzáles, H.

2015-01-01

The well logging allows to characterize and to predict the hydrocarbon potential of an area. For this, tools that may contain one or more radioactive sources are used. Eventually, they may be stuck at a certain depth, without viable technical alternatives for recovery. In this case, it is necessary to implement actions that minimize the risk of release of radioactive material into the groundwater, because of the natural degradation of shielding or by the accidental destruction by the unexpected collision with another tool, in a possible future drilling. In this paper, a simplified assessment of the doses associated with the natural degradation and the breakdown of shielding radioactive sources is presented. For this purpose two main pathways of exposure; incorporation by ingestion of contaminated water from the aquifer and external irradiation because of the drilling mud that rise to the surface and distributed over it, are considered. Each of these pathways corresponds to a different scenario. In the first scenario, the evaluation was performed by applying the Dispersion of Radionuclides in Aquifers model that take in account pollutants dispersion in the aquifer unto extraction well water. This model solves the equation of solute transport in porous media in three dimensions, considering soil retention and radioactive decay. In the second scenario the contaminated mud rises from the well to the surface, due to actions taken to retrieve stuck sources or because of new drillings are assumed. The aim of this work is to present a simple and conservative method to estimate doses involved in the natural degradation of shielding or by accidental destruction of sources used in well logging. (authors) [es

An in-situ check of the epithermal neutron log calibration

International Nuclear Information System (INIS)

Burkhard, N.R.

1993-01-01

The epithermal neutron log is used to measure the water content of the formation. The large hole epithermal neutron sonde (ENS) utilized at the Nevada Test Site (NTS) has been calibrated in the Hydrogen Content Test Facility (HCTF). These calibrations are used to correct the measured neutron count rate for the effects of tool stand-off and density. For some time, the suspicion has existed that the water contents that are calculated from the ENS data are too large. Hole U2gj represented a unique opportunity to check the validity of the ENS calibration under realistic logging conditions; a portion of the hole had been cemented and redrilled and then logged. The cements have a known water content and can be used as an in-situ calibration check. The author found that the water contents from the log data after processing with the existing calibrations are consistent with these known cement water contents. In addition, the study indicates that the raw neutron data might be more appropriately smoothed by using a median smoother rather than the currently utilized mean smoother

An in-situ check of the epithermal neutron log calibration

International Nuclear Information System (INIS)

Burkhard, N.R.

1993-09-01

The epithermal neutron log is used to measure the water content of the formation. The large hole epithermal neutron sonde (ENS) that we utilize at the Nevada Test Site (NTS) has been calibrated in the Hydrogen Content Test Facility (HCTF). These calibrations are used to correct the measured neutron count rate for the effects of tool stand-off and density. For sometime, the suspicion has existed that the water contents that are calculated from the ENS data are too large. Hole U2gj represented a unique opportunity to check the validity of the ENS calibration under realistic logging conditions; a portion of the hole had been cemented and re drilled and then logged. The cements have a known water content and can be used as an in situ calibration check. I found that the water contents from the log data after processing with the existing calibrations are consistent with these known cement water contents. In addition, the study indicates that the raw neutron data might be more appropriately smoothed by using a median smoother rather than the currently utilized mean smoother

Effects of a primordial magnetic field with log-normal distribution on the cosmic microwave background

International Nuclear Information System (INIS)

Yamazaki, Dai G.; Ichiki, Kiyotomo; Takahashi, Keitaro

2011-01-01

We study the effect of primordial magnetic fields (PMFs) on the anisotropies of the cosmic microwave background (CMB). We assume the spectrum of PMFs is described by log-normal distribution which has a characteristic scale, rather than power-law spectrum. This scale is expected to reflect the generation mechanisms and our analysis is complementary to previous studies with power-law spectrum. We calculate power spectra of energy density and Lorentz force of the log-normal PMFs, and then calculate CMB temperature and polarization angular power spectra from scalar, vector, and tensor modes of perturbations generated from such PMFs. By comparing these spectra with WMAP7, QUaD, CBI, Boomerang, and ACBAR data sets, we find that the current CMB data set places the strongest constraint at k≅10 -2.5 Mpc -1 with the upper limit B < or approx. 3 nG.

Radiation protection in well logging: case studies in the Sudan

International Nuclear Information System (INIS)

Eltayeb, B. A.

2010-12-01

This study is performed to improve radiation protection level in well logging include tow case studies in Sudan (Lost or misplaced sources). General review of radiation and radiation protection basic concept is highlighted discussed. Also preview of well logging practice and source of radiation use in well logging, safety of radiation sources, storage and manage of not use sources (weak sources) and protection of worker and potential exposure for public and worker, investigations in cause of lost or misplaced sources in well. Assessment was made in well logging using checklist prepared in accordance with the International Atomic Energy Agency IAEA basic safety standard, International Committee for Radiological Protection ICRP and safety in transport of radiation sources. The checklist includes all requirement of radiation protection. It is found that all requirement was present except the delay of calibration of radiation detectors, the movement of radiation sources form storage to base of manipulated area need adequate care for shielding and safe transport and personal monitoring service must be provide in Sudan. Investigation was made in cause of lose of nine radiation source in well it is found that all those sources were loss in different depth in the well and with deferent location and there was no risk because there was no contamination of fluids which caused by damage of loss sources. Some recommendations were stated that, if implemented could improve the status of radiation protection in well logging. (Author)

Wood moisture monitoring during log house thermal insulation mounting

Directory of Open Access Journals (Sweden)

Pavla Kotásková

2011-01-01

Full Text Available The current designs of thermal insulation for buildings concentrate on the achievement of the required heat transmission coefficient. However, another factor that cannot be neglected is the assessment of the possible water vapour condensation inside the construction. The aim of the study was to find out whether the designed modification of the cladding structure of an existing log house will or will not lead to a risk of possible water vapour condensation in the walls after an additional thermal insulation mounting. The condensation could result in the increase in moisture of the walls and consequently the constructional timber, which would lead to the reduction of the timber construction strength, wood degradation by biotic factors – wood-destroying insects, mildew or wood-destroying fungi. The main task was to compare the theoretically established values of moisture of the constructional timber with the values measured inside the construction using a specific example of a thermal insulated log house. Three versions of thermal insulation were explored to find the solution of a log house reconstruction which would be the optimum for living purposes. Two versions deal with the cladding structure with the insulation from the interior, the third version deals with an external insulation.In a calculation model the results can be affected to a great degree by input values (boundary conditions. This especially concerns the factor of vapour barrier diffusion resistance, which is entered in accordance with the producer’s specifications; however, its real value can be lower as it depends on the perfectness and correctness of the technological procedure. That is why the study also includes thermal technical calculations of all designed insulation versions in the most unfavourable situation, which includes the degradation of the vapour barrier down to 10% efficiency, i.e. the reduction of the diffusion resistance factor to 10% of the original value

Certified and uncertified logging concessions compared in Gabon: changes in stand structure, tree species, and biomass.

Science.gov (United States)

Medjibe, V P; Putz, Francis E; Romero, Claudia

2013-03-01

Forest management certification is assumed to promote sustainable forest management, but there is little field-based evidence to support this claim. To help fill this gap, we compared a Forest Stewardship Council (FSC)-certified with an adjacent uncertified, conventionally logged concession (CL) in Gabon on the basis of logging damage, above-ground biomass (AGB), and tree species diversity and composition. Before logging, we marked, mapped, and measured all trees >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and tree damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m(3)/ha (0.39 trees/ha) and 11.4 m(3)/ha (0.76 trees/ha). For each tree felled, averages of 9.1 and 20.9 other trees were damaged in the FSC and CL plots, respectively; when expressed as the impacts per timber volume extracted, the values did not differ between the two treatments. Skid trails covered 2.9 % more of the CL surface, but skid trail length per unit timber volume extracted was not greater. Logging roads were wider in the CL than FSC site and disturbed 4.7 % more of the surface. Overall, logging caused declines in AGB of 7.1 and 13.4 % at the FSC and CL sites, respectively. Changes in tree species composition were small but greater for the CL site. Based on these findings and in light of the pseudoreplicated study design with less-than perfect counterfactual, we cautiously conclude that certification yields environmental benefits even after accounting for differences in logging intensities.

Radiometric well logging instruments

International Nuclear Information System (INIS)

Davydov, A.V.

1975-01-01

The technical properties of well instruments for radioactive logging used in the radiometric logging complexes PKS-1000-1 (''Sond-1'') and PRKS-2 (''Vitok-2'') are described. The main features of the electric circuit of the measuring channels are given

Hardwood log supply: a broader perspective

Science.gov (United States)

Iris Montague; Adri Andersch; Jan Wiedenbeck; Urs. Buehlmann

2015-01-01

At regional and state meetings we talk with others in our business about the problems we face: log exports, log quality, log markets, logger shortages, cash flow problems, the weather. These are familiar talking points and real and persistent problems. But what is the relative importance of these problems for log procurement in different regions of...

Is skin penetration a determining factor in skin sensitization potential and potency? Refuting the notion of a LogKow threshold for Skin Sensitization

Science.gov (United States)

Summary:Background. It is widely accepted that substances that cannot penetrate through the skin will not be sensitisers. Thresholds based on relevant physicochemical parameters such as a LogKow > 1 and a MW < 500, are assumed and widely accepted as self-evident truths. Objective...

Semi-automatic logarithmic converter of logs

International Nuclear Information System (INIS)

Gol'dman, Z.A.; Bondar's, V.V.

1974-01-01

Semi-automatic logarithmic converter of logging charts. An original semi-automatic converter was developed for use in converting BK resistance logging charts and the time interval, ΔT, of acoustic logs from a linear to a logarithmic scale with a specific ratio for subsequent combining of them with neutron-gamma logging charts in operative interpretation of logging materials by a normalization method. The converter can be used to increase productivity by giving curves different from those obtained in manual, pointwise processing. The equipment operates reliably and is simple in use. (author)

Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus [University Medical Center Hamburg-Eppendorf, Martini-Clinic Prostate Cancer Center, Hamburg (Germany); Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf [University Medical Center Hamburg-Eppendorf, Department of Radiation oncology, Hamburg (Germany)

2015-04-01

The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [German] Der Nutzen einer zusaetzlichen Hormonentzugstherapie (ADT, ''androgen deprivation therapy'') fuer Patienten mit Prostatakarzinom (PCa), welche mit einer Kombination aus HDR-Brachytherapie (HDR-BT) und perkutaner Bestrahlung (EBRT) behandelt werden, ist weiterhin ungeklaert. Fuer diese Studie wurden konsekutive, nach der D'Amico-Risikoklassifizierung in ''intermediate'' und ''high-risk'' eingeteilte Patienten ausgewaehlt, die zwischen Januar 1999 und Februar 2009 in unserem Institut eine kombinierte Therapie aus HDR-BT, EBRT ± ADT erhalten haben. Eine

Power to the logs!

CERN Multimedia

CERN. Geneva; MACMAHON, Joseph

2015-01-01

Are you tired of using grep, vi and emacs to read your logs? Do you feel like you’re missing the big picture? Does the word "statistics" put a smile on your face? Then it’s time to give power to the logs!

A method of estimating log weights.

Science.gov (United States)

Charles N. Mann; Hilton H. Lysons

1972-01-01

This paper presents a practical method of estimating the weights of logs before they are yarded. Knowledge of log weights is required to achieve optimum loading of modern yarding equipment. Truckloads of logs are weighed and measured to obtain a local density index (pounds per cubic foot) for a species of logs. The density index is then used to estimate the weights of...

Acoustic reflection log in transversely isotropic formations

Science.gov (United States)

Ronquillo Jarillo, G.; Markova, I.; Markov, M.

2018-01-01

We have calculated the waveforms of sonic reflection logging for a fluid-filled borehole located in a transversely isotropic rock. Calculations have been performed for an acoustic impulse source with the characteristic frequency of tens of kilohertz that is considerably less than the frequencies of acoustic borehole imaging tools. It is assumed that the borehole axis coincides with the axis of symmetry of the transversely isotropic rock. It was shown that the reflected wave was excited most efficiently at resonant frequencies. These frequencies are close to the frequencies of oscillations of a fluid column located in an absolutely rigid hollow cylinder. We have shown that the acoustic reverberation is controlled by the acoustic impedance of the rock Z = Vphρs for fixed parameters of the borehole fluid, where Vph is the velocity of horizontally propagating P-wave; ρs is the rock density. The methods of waveform processing to determine the parameters characterizing the reflected wave have been discussed.

The impact of assumed knowledge entry standards on undergraduate mathematics teaching in Australia

Science.gov (United States)

King, Deborah; Cattlin, Joann

2015-10-01

Over the last two decades, many Australian universities have relaxed their selection requirements for mathematics-dependent degrees, shifting from hard prerequisites to assumed knowledge standards which provide students with an indication of the prior learning that is expected. This has been regarded by some as a positive move, since students who may be returning to study, or who are changing career paths but do not have particular prerequisite study, now have more flexible pathways. However, there is mounting evidence to indicate that there are also significant negative impacts associated with assumed knowledge approaches, with large numbers of students enrolling in degrees without the stated assumed knowledge. For students, there are negative impacts on pass rates and retention rates and limitations to pathways within particular degrees. For institutions, the necessity to offer additional mathematics subjects at a lower level than normal and more support services for under-prepared students impacts on workloads and resources. In this paper, we discuss early research from the First Year in Maths project, which begins to shed light on the realities of a system that may in fact be too flexible.

Bird species and traits associated with logged and unlogged forest in Borneo.

Science.gov (United States)

Cleary, Daniel F R; Boyle, Timothy J B; Setyawati, Titiek; Anggraeni, Celina D; Van Loon, E Emiel; Menken, Steph B J

2007-06-01

The ecological consequences of logging have been and remain a focus of considerable debate. In this study, we assessed bird species composition within a logging concession in Central Kalimantan, Indonesian Borneo. Within the study area (approximately 196 km2) a total of 9747 individuals of 177 bird species were recorded. Our goal was to identify associations between species traits and environmental variables. This can help us to understand the causes of disturbance and predict whether species with given traits will persist under changing environmental conditions. Logging, slope position, and a number of habitat structure variables including canopy cover and liana abundance were significantly related to variation in bird composition. In addition to environmental variables, spatial variables also explained a significant amount of variation. However, environmental variables, particularly in relation to logging, were of greater importance in structuring variation in composition. Environmental change following logging appeared to have a pronounced effect on the feeding guild and size class structure but there was little evidence of an effect on restricted range or threatened species although certain threatened species were adversely affected. For example, species such as the terrestrial insectivore Argusianus argus and the hornbill Buceros rhinoceros, both of which are threatened, were rare or absent in recently logged forest. In contrast, undergrowth insectivores such as Orthotomus atrogularis and Trichastoma rostratum were abundant in recently logged forest and rare in unlogged forest. Logging appeared to have the strongest negative effect on hornbills, terrestrial insectivores, and canopy bark-gleaning insectivores while moderately affecting canopy foliage-gleaning insectivores and frugivores, raptors, and large species in general. In contrast, undergrowth insectivores responded positively to logging while most understory guilds showed little pronounced effect

Defining a Family of Cognitive Diagnosis Models Using Log-Linear Models with Latent Variables

Science.gov (United States)

Henson, Robert A.; Templin, Jonathan L.; Willse, John T.

2009-01-01

This paper uses log-linear models with latent variables (Hagenaars, in "Loglinear Models with Latent Variables," 1993) to define a family of cognitive diagnosis models. In doing so, the relationship between many common models is explicitly defined and discussed. In addition, because the log-linear model with latent variables is a general model for…

LOG-NORMAL DISTRIBUTION OF COSMIC VOIDS IN SIMULATIONS AND MOCKS

Energy Technology Data Exchange (ETDEWEB)

Russell, E.; Pycke, J.-R., E-mail: er111@nyu.edu, E-mail: jrp15@nyu.edu [Division of Science and Mathematics, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi (United Arab Emirates)

2017-01-20

Following up on previous studies, we complete here a full analysis of the void size distributions of the Cosmic Void Catalog based on three different simulation and mock catalogs: dark matter (DM), haloes, and galaxies. Based on this analysis, we attempt to answer two questions: Is a three-parameter log-normal distribution a good candidate to satisfy the void size distributions obtained from different types of environments? Is there a direct relation between the shape parameters of the void size distribution and the environmental effects? In an attempt to answer these questions, we find here that all void size distributions of these data samples satisfy the three-parameter log-normal distribution whether the environment is dominated by DM, haloes, or galaxies. In addition, the shape parameters of the three-parameter log-normal void size distribution seem highly affected by environment, particularly existing substructures. Therefore, we show two quantitative relations given by linear equations between the skewness and the maximum tree depth, and between the variance of the void size distribution and the maximum tree depth, directly from the simulated data. In addition to this, we find that the percentage of voids with nonzero central density in the data sets has a critical importance. If the number of voids with nonzero central density reaches ≥3.84% in a simulation/mock sample, then a second population is observed in the void size distributions. This second population emerges as a second peak in the log-normal void size distribution at larger radius.

32 CFR 700.846 - Status of logs.

Science.gov (United States)

2010-07-01

... Officers Afloat § 700.846 Status of logs. The deck log, the engineering log, the compass record, the bearing hooks, the engineer's bell book, and any records generated by automated data logging equipment...

Conventional intensive logging promotes loss of organic carbon from the mineral soil.

Science.gov (United States)

Dean, Christopher; Kirkpatrick, James B; Friedland, Andrew J

2017-01-01

There are few data, but diametrically opposed opinions, about the impacts of forest logging on soil organic carbon (SOC). Reviews and research articles conclude either that there is no effect, or show contradictory effects. Given that SOC is a substantial store of potential greenhouse gasses and forest logging and harvesting is routine, resolution is important. We review forest logging SOC studies and provide an overarching conceptual explanation for their findings. The literature can be separated into short-term empirical studies, longer-term empirical studies and long-term modelling. All modelling that includes major aboveground and belowground biomass pools shows a long-term (i.e. ≥300 years) decrease in SOC when a primary forest is logged and then subjected to harvesting cycles. The empirical longer-term studies indicate likewise. With successive harvests the net emission accumulates but is only statistically perceptible after centuries. Short-term SOC flux varies around zero. The long-term drop in SOC in the mineral soil is driven by the biomass drop from the primary forest level but takes time to adjust to the new temporal average biomass. We show agreement between secondary forest SOC stocks derived purely from biomass information and stocks derived from complex forest harvest modelling. Thus, conclusions that conventional harvests do not deplete SOC in the mineral soil have been a function of their short time frames. Forest managers, climate change modellers and environmental policymakers need to assume a long-term net transfer of SOC from the mineral soil to the atmosphere when primary forests are logged and then undergo harvest cycles. However, from a greenhouse accounting perspective, forest SOC is not the entire story. Forest wood products that ultimately reach landfill, and some portion of which produces some soil-like material there rather than in the forest, could possibly help attenuate the forest SOC emission by adding to a carbon pool in

Palm distributions for log Gaussian Cox processes

DEFF Research Database (Denmark)

Coeurjolly, Jean-Francois; Møller, Jesper; Waagepetersen, Rasmus Plenge

2017-01-01

This paper establishes a remarkable result regarding Palm distributions for a log Gaussian Cox process: the reduced Palm distribution for a log Gaussian Cox process is itself a log Gaussian Cox process that only differs from the original log Gaussian Cox process in the intensity function. This new...... result is used to study functional summaries for log Gaussian Cox processes....

Compound risk judgment in tasks with both idiosyncratic and systematic risk: The "Robust Beauty" of additive probability integration.

Science.gov (United States)

Sundh, Joakim; Juslin, Peter

2018-02-01

In this study, we explore how people integrate risks of assets in a simulated financial market into a judgment of the conjunctive risk that all assets decrease in value, both when assets are independent and when there is a systematic risk present affecting all assets. Simulations indicate that while mental calculation according to naïve application of probability theory is best when the assets are independent, additive or exemplar-based algorithms perform better when systematic risk is high. Considering that people tend to intuitively approach compound probability tasks using additive heuristics, we expected the participants to find it easiest to master tasks with high systematic risk - the most complex tasks from the standpoint of probability theory - while they should shift to probability theory or exemplar memory with independence between the assets. The results from 3 experiments confirm that participants shift between strategies depending on the task, starting off with the default of additive integration. In contrast to results in similar multiple cue judgment tasks, there is little evidence for use of exemplar memory. The additive heuristics also appear to be surprisingly context-sensitive, with limited generalization across formally very similar tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

Systematic logging utilizing a log sheet designed for drill core descriptions. An example in uranium exploration activities

International Nuclear Information System (INIS)

Sasao, Eiji; Tsuruta, Tadahiko; Iida, Yoshimasa

2000-01-01

We describe the log sheets used during uranium exploration activities for unconformity-related uranium deposits by JNC. The purpose of using the logging sheets is to standardize the objects which all geologists must observe and for data quality assurance. The log sheets are a three-part set describing basement lithology, sandstone lithology and geotechnics. We devised our own log sheets to describe both the sandstone and the underlying basement rock when we started exploration in Athabasca Basin, Canada. We modified the sheets to gain a better understanding of the geological features related to uranium mineralization, and made final improvements to satisfy required quality based on the criteria of descriptive objects and accuracy. Use of the log sheets resulted in effective performance of core logging and improvement in the display of data. (author)

Comparative analysis of nuclear magnetic resonance well logging and nuclear magnetic resonance mud logging

International Nuclear Information System (INIS)

Yuan Zugui

2008-01-01

The hydrogen atoms in oil and water are able to resonate and generate signals in the magnetic field, which is used by the NMR (nuclear magnetic resonance) technology in petroleum engineering to research and evaluate rock characteristics. NMR well logging was used to measure the physical property parameters of the strata in well bore, whereas NMR mud logging was used to analyze (while drilling) the physical property parameters of cores, cuttings and sidewall coring samples on surface (drilling site). Based on the comparative analysis of the porosity and permeability parameters obtained by NMR well logging and those from analysis of the cores, cuttings and sidewall coring samples by NMR mud logging in the same depth of 13 wells, these two methods are of certain difference, but their integral tendency is relatively good. (authors)

A mixed-methods analysis of logging injuries in Montana and Idaho.

Science.gov (United States)

Lagerstrom, Elise; Magzamen, Sheryl; Rosecrance, John

2017-12-01

Despite advances in mechanization, logging continues to be one of the most dangerous occupations in the United States. Logging in the Intermountain West region (Montana and Idaho) is especially hazardous due to steep terrain, extreme weather, and remote work locations. We implemented a mixed-methods approach combining analyses of workers' compensation claims and focus groups to identify factors associated with injuries and fatalities in the logging industry. Inexperienced workers (>6 months experience) accounted for over 25% of claims. Sprain/strain injuries were the most common, accounting for 36% of claims, while fatalities had the highest median claim cost ($274 411). Focus groups identified job tasks involving felling trees, skidding, and truck driving as having highest risk. Injury prevention efforts should focus on training related to safe work methods (especially for inexperienced workers), the development of a safety culture and safety leadership, as well as implementation of engineering controls. © 2017 Wiley Periodicals, Inc.

DOE-Grand Junction logging model data synopsis

International Nuclear Information System (INIS)

Mathews, M.A.; Koizumi, C.J.; Evans, H.B.

1978-05-01

This synopsis provides the available data concerning the logging models at the DoE-Grand Junction facility, to date (1976). Because gamma-ray logs are used in uranium exploration to estimate the grade (percent U 3 O 8 ) and the thickness of uranium ore zones in exploration drill holes, logging models are required to calibrate the gamma-ray logging equipment in order to obtain accuracy, uniformity, standardization, and repeatability during logging. This quality control is essential for accurate ore reserve calculations and for estimates of ore potential. The logging models at the DoE-Grand Junction facility are available for use by private industry in calibrating their gamma-ray logging equipment. 21 figures, 26 tables

SNG-logs at Skjern

DEFF Research Database (Denmark)

Korsbech, Uffe C C; Petersen, Jesper; Aage, Helle Karina

1998-01-01

Spectral Natural Gamma-ray logs have been run in two water supply borings at Skjern. The log data have been examined by a new technique - Noise Adjusted Singular Value Decomposition - in order to get a detailed and reliable picture of the distribution of uranium and thorium gamma-rays from heavy...

Influence of borehole-eccentred tools on wireline and logging-while-drilling sonic logging measurements

KAUST Repository

Pardo, David; Matuszyk, Paweł Jerzy; Torres-Verdí n, Carlos; Mora Cordova, Angel; Muga, Ignacio; Calo, Victor M.

2013-01-01

We describe a numerical study to quantify the influence of tool-eccentricity on wireline (WL) and logging-while-drilling (LWD) sonic logging measurements. Simulations are performed with a height-polynomial-adaptive (hp) Fourier finite-element method

Plant inspection tours with mobile data logging system

International Nuclear Information System (INIS)

Roesser, U.

2006-01-01

The MDE Mobile Data Logging System has been introduced in a number of German power plants for efficient logging, evaluation, and quality-assured documentation of data recorded on plant inspection tours by means of pocket PCs instead of slips of paper. It will be installed in other nuclear power plants in the near future. The MDE system is composed of the pocket PCs for logging data during plant inspection tours, the associated docking stations installed in the respective areas of application, one PC or, if necessary, several PCs with the appropriate user software, and the associated network links. To install the software in the power plant, lists of rooms and measurement stations as well as other positions on an inspection course are transmitted to the MDE system. When the system has been commissioned, inspection tours are planned in accordance with past experience and optimized in the computer. User experience is taken into account in program updates. New functions improve user comfort and ease of evaluation. Additions to the MDE software, and applications in other areas, are tentatively planned and will be implemented as the need arises. (orig.)

Audit and trace log management consolidation and analysis

CERN Document Server

Maier, Phillip Q

2006-01-01

As regulation and legislation evolve, the critical need for cost-effective and efficient IT audit and monitoring solutions will continue to grow. Audit and Trace Log Management: Consolidation and Analysis offers a comprehensive introduction and explanation of requirements and problem definition, and also delivers a multidimensional solution set with broad applicability across a wide range of organizations. Itprovidesa wealth of information in the form of processwalkthroughs. These include problem determination, requirements gathering,scope definition, risk assessment, compliance objectives,

Gas hydrate saturation from acoustic impedance and resistivity logs in the shenhu area, south china sea

Science.gov (United States)

Wang, X.; Wu, S.; Lee, M.; Guo, Y.; Yang, S.; Liang, J.

2011-01-01

During the China's first gas hydrate drilling expedition -1 (GMGS-1), gas hydrate was discovered in layers ranging from 10 to 25 m above the base of gas hydrate stability zone in the Shenhu area, South China Sea. Water chemistry, electrical resistivity logs, and acoustic impedance were used to estimate gas hydrate saturations. Gas hydrate saturations estimated from the chloride concentrations range from 0 to 43% of the pore space. The higher gas hydrate saturations were present in the depth from 152 to 177 m at site SH7 and from 190 to 225 m at site SH2, respectively. Gas hydrate saturations estimated from the resistivity using Archie equation have similar trends to those from chloride concentrations. To examine the variability of gas hydrate saturations away from the wells, acoustic impedances calculated from the 3 D seismic data using constrained sparse inversion method were used. Well logs acquired at site SH7 were incorporated into the inversion by establishing a relation between the water-filled porosity, calculated using gas hydrate saturations estimated from the resistivity logs, and the acoustic impedance, calculated from density and velocity logs. Gas hydrate saturations estimated from acoustic impedance of seismic data are ???10-23% of the pore space and are comparable to those estimated from the well logs. The uncertainties in estimated gas hydrate saturations from seismic acoustic impedances were mainly from uncertainties associated with inverted acoustic impedance, the empirical relation between the water-filled porosities and acoustic impedances, and assumed background resistivity. ?? 2011 Elsevier Ltd.

Nuclear well logging in hydrology

International Nuclear Information System (INIS)

1971-01-01

The optimum development of regional and local groundwater resources requires a quantitative evaluation of its aquifers and aquicludes, and of the physical and chemical properties relevant to the recharge to and withdrawal of water from them. If an understanding of the groundwater regime is to be obtained, geological observations at outcrop must be augmented by subsurface measurements of the strata and the waters they contain. Measurements of many hydrological and geological parameters can be made in situ by nuclear geophysical well-logging methods. Very simply, well logging consists of lowering a measuring probe into a well and making a continuous record of the variations of a particular parameter with depth. In most circumstances, repetition of the measurements under differing hydrodynamic conditions results in a better definition of the flow regime in the aquifer. Nuclear well-logging techniques have for some years been capable of solving a number of the sub-surface measurement problems faced by hydrogeologists. However, the present usage of these methods varies from country to country and the literature concerning applications is scattered in the professional journals of several disciplines. The objective of this report is to include in a single reference volume descriptions of the physical principles of nuclear logging methods, their applications to hydrogeological problems and their limitations on a level suitable for the practising hydrologists with a limited knowledge of nuclear physics. The Working Group responsible for compiling the report recommended that it should cover a broad spectrum of hydrogeological investigations and problems. For example, it saw no valid reason to distinguish for the purposes of the report between well-logging applications for water-supply purposes and for water-flooding studies in the petroleum industry. Neutron measurements made for soil-moisture determinations in the unsaturated zone have been specifically omitted, however, as

Effect of radon transport in groundwater upon gamma-ray borehole logs

International Nuclear Information System (INIS)

Nelson, P.H.; Rachiele, R.; Smith, A.

1980-09-01

Granitic rock at an experimental waste storage site at Stripa, Sweden, is unusually high in natural radioelements (40 ppM uranium) with higher concentrations occurring locally in thin chloritic zones and fractures. Groundwater seeping through fractures into open boreholes is consequently highly anomalous in its radon content, with activity as high as one microcurie per liter. When total count gamma-ray logs are run in boreholes where groundwater inflow is appreciable, the result is quite unusual: the radon daughter activity in the water adds considerably to the contribution from the rock, and in fact often dominates the log response. The total gamma activity increases where radon-charged groundwater enters a borehole, and remains at a high level as the water flows along the hole in response to the hydraulic gradient. As a consequence, the gamma log serves as a flow profile, locating zones of water entry (or loss) by an increase (or decrease) in the total gamma activity. A simple model has been developed for flow through a thin crack emanating radon at a rate E showing that the radon concentration of water entering a hole is E/Λh, where Λ is the radon decay rate and h the crack aperture, assuming that the flow rate and crack source area are such that an element of water resides within the source area for several radon half-lives or more. Concentration measurements can provide a measurement of the inflow rate. Data from the 127-mm holes in the time-scale drift behave in this fashion

A Universal Logging System for LHCb Online

International Nuclear Information System (INIS)

Nikolaidis, Fotis; Brarda, Loic; Garnier, Jean-Christophe; Neufeld, Niko

2011-01-01

A log is recording of system's activity, aimed to help system administrator to traceback an attack, find the causes of a malfunction and generally with troubleshooting. The fact that logs are the only information an administrator may have for an incident, makes logging system a crucial part of an IT infrastructure. In large scale infrastructures, such as LHCb Online, where quite a few GB of logs are produced daily, it is impossible for a human to review all of these logs. Moreover, a great percentage of them as just n oise . That makes clear that a more automated and sophisticated approach is needed. In this paper, we present a low-cost centralized logging system which allow us to do in-depth analysis of every log.

Model wells for nuclear well logging

International Nuclear Information System (INIS)

Tittle, C.W.

1989-01-01

Considerations needed in the design and construction of model wells for nuclear log calibration are covered, with special attention to neutron porosity logging and total γ-ray logging. Pulsed neutron decay-time and spectral γ-ray logging are discussed briefly. The American Petroleum Institute calibration facility for nuclear logs is a good starting point for similar or expanded facilities. A few of its shortcomings are mentioned; they are minor. The problem of fluid saturation is emphasized. Attention is given to models made of consolidated rock and those containing unconsolidated material such as Ottawa sand. Needed precautions are listed. A similarity method is presented for estimating the porosity index of formations that are not fully saturated. (author)

A mathematical foundation for controlling radiation health risks

International Nuclear Information System (INIS)

Kumazawa, S.

2000-01-01

Radiation protection is to attain an adequate control of radiation health risk compared with other risks. Our society in the 21 st century is predicted by some experts to seek the high priority of safety for expanding activity of human beings. The law of controlling risks will be a key subject to serve the safety of human beings and their environment. The main principles of the ICRP system of radiological system are strongly relating to the general law of various risk controls. The individual-based protection concept clearly gives us a mathematical model of controlling risks in general. This paper discusses the simplest formulation of controlling risks in the ICRP system, including other relating systems. First, the basic characteristics of occupational exposure as a risk control is presented by analyzing the data compiled over half a century. It shows the relation ship between dose control levels and individually controlled doses. The individual-based control also exerts some influence on the resultant collective dose. The study of occupational exposure concludes the simple mathematical expression of controlling doses under the ICRP system as shown by Kumazawa and Numakunai. Second, the typical characteristics of biological effects with repair or recovery of bio-systems are given by analyzing the data published. Those show the relationship between dose and biologically controlled or regulated response. The bio-system is undoubtedly relating to cybernetics that contains many functions of controlling risks. Consequently radiation effects might somewhat express the feature of biological risk controls. The shouldered survival of irradiated cells shows cybernetic characteristics that are assumed to be the mathematical foundation of controlling risks. The dose-response relationship shows another type of cybernetic characteristics, which could be reduced to the same basic form of controlling risks. The limited study of radiation effects definitely confirms the two

Logging slash from regeneration cuttings as a source of fuel; Paeaetehakkuualojen hakkuutaehde polttoainelaehteenae

Energy Technology Data Exchange (ETDEWEB)

Hakkila, P [Finnish Forest Research Inst., Vantaa (Finland); Asikainen, A [Joensuu Univ. (Finland); Korpilahti, A [Metsaeteho, Helsinki (Finland); Nurmi, J [Finnish Forest Research Inst., Kannus (Finland)

1997-12-31

Logging slash from regeneration areas is the major reserve of forest biomass for the production of renewable energy in Finland. Typically, about 52 m{sup 3} of unmerchantable stemwood and crown mass per hectare is left in a clear-cutting area of Scots pine, and 116 m{sup 3} per hectare in a clear-cutting area of Norway spruce. These figures correspond to 9,6 and 22,4 tons of oil equivalent per hectare. In addition to the abundant availability, logging slash is made attractive from the utilization point of view by moderate costs of recovery. This paper reviews the studies carried out by Project 114 of the national Bioenergy Research Program in 1995. The following aspects were included: The effect of the recovery of logging slash for fuel on the work techniques and productivity of one-grip harvesters in clear-cutting of Norway spruce; off-road transport of logging slash with a forwarder equipped with an enlarged load space; chipping of logging slash; and outside storage of fuel crushed from fresh logging slash. The participating research organizations are the Finnish Forest Research Institute, Metsaeteho and University of Joensuu

Logging slash from regeneration cuttings as a source of fuel; Paeaetehakkuualojen hakkuutaehde polttoainelaehteenae

Energy Technology Data Exchange (ETDEWEB)

Hakkila, P. [Finnish Forest Research Inst., Vantaa (Finland); Asikainen, A. [Joensuu Univ. (Finland); Korpilahti, A. [Metsaeteho, Helsinki (Finland); Nurmi, J. [Finnish Forest Research Inst., Kannus (Finland)

1996-12-31

Logging slash from regeneration areas is the major reserve of forest biomass for the production of renewable energy in Finland. Typically, about 52 m{sup 3} of unmerchantable stemwood and crown mass per hectare is left in a clear-cutting area of Scots pine, and 116 m{sup 3} per hectare in a clear-cutting area of Norway spruce. These figures correspond to 9,6 and 22,4 tons of oil equivalent per hectare. In addition to the abundant availability, logging slash is made attractive from the utilization point of view by moderate costs of recovery. This paper reviews the studies carried out by Project 114 of the national Bioenergy Research Program in 1995. The following aspects were included: The effect of the recovery of logging slash for fuel on the work techniques and productivity of one-grip harvesters in clear-cutting of Norway spruce; off-road transport of logging slash with a forwarder equipped with an enlarged load space; chipping of logging slash; and outside storage of fuel crushed from fresh logging slash. The participating research organizations are the Finnish Forest Research Institute, Metsaeteho and University of Joensuu

Logs of Paleoseismic Excavations Across the Central Range Fault, Trinidad

Science.gov (United States)

Crosby, Christopher J.; Prentice, Carol S.; Weber, John; Ragona, Daniel

2009-01-01

This publication makes available maps and trench logs associated with studies of the Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. Our studies were conducted in 2001 and 2002. We mapped geomorphic features indicative of active faulting along the right-lateral, Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. We excavated trenches at two sites, the Samlalsingh and Tabaquite sites. At the Samlalsingh site, sediments deposited after the most recent fault movement bury the fault, and the exact location of the fault was unknown until we exposed it in our excavations. At this site, we excavated a total of eleven trenches, six of which exposed the fault. The trenches exposed fluvial sediments deposited over a strath terrace developed on Miocene bedrock units. We cleaned the walls of the excavations, gridded the walls with either 1 m X 1 m or 1 m X 0.5 m nail and string grid, and logged the walls in detail at a scale of 1:20. Additionally, we described the different sedimentary units in the field, incorporating these descriptions into our trench logs. We mapped the locations of the trenches using a tape and compass. Our field logs were scanned, and unit contacts were traced in Adobe Illustrator. The final drafted logs of all the trenches are presented here, along with photographs showing important relations among faults and Holocene sedimentary deposits. Logs of south walls were reversed in Illustrator, so that all logs are drafted with the view direction to the north. We collected samples of various materials exposed in the trench walls, including charcoal samples for radiocarbon dating from both faulted and unfaulted deposits. The locations of all samples collected are shown on the logs. The ages of seventeen of the charcoal samples submitted for radiocarbon analysis at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, Ariz., are given in Table 1. Samples found in

Artificial intelligence approach to interwell log correlation

Energy Technology Data Exchange (ETDEWEB)

Lim, Jong-Se [Korea Maritime University, Pusan(Korea); Kang, Joo Myung [Seoul National University, Seoul(Korea); Kim, Jung Whan [Korea National Oil Corp., Anyang(Korea)

2000-04-30

This paper describes a new approach to automated interwell log correlation using artificial intelligence and principal component analysis. The approach to correlate wire line logging data is on the basis of a large set of subjective rules that are intended to represent human logical processes. The data processed are mainly the qualitative information such as the characteristics of the shapes extracted along log traces. The apparent geologic zones are identified by pattern recognition for the specific characteristics of log trace collected as a set of objects by object oriented programming. The correlation of zones between wells is made by rule-based inference program. The reliable correlation can be established from the first principal component logs derived from both the important information around well bore and the largest common part of variances of all available well log data. Correlation with field log data shows that this approach can make interwell log correlation more reliable and accurate. (author). 6 refs., 7 figs.

Results of investigations at the Zunil geothermal field, Guatemala: Well logging and brine geochemistry

Energy Technology Data Exchange (ETDEWEB)

Adams, A.; Dennis, B.; Van Eeckhout, E.; Goff, F.; Lawton, R.; Trujillo, P.E.; Counce, D.; Archuleta, J. (Los Alamos National Lab., NM (USA)); Medina, V. (Instituto Nacional de Electrificacion, Guatemala City (Guatemala). Unidad de Desarollo Geotermico)

1991-07-01

The well logging team from Los Alamos and its counterpart from Central America were tasked to investigate the condition of four producing geothermal wells in the Zunil Geothermal Field. The information obtained would be used to help evaluate the Zunil geothermal reservoir in terms of possible additional drilling and future power plant design. The field activities focused on downhole measurements in four production wells (ZCQ-3, ZCQ-4, ZCQ-5, and ZCQ-6). The teams took measurements of the wells in both static (shut-in) and flowing conditions, using the high-temperature well logging tools developed at Los Alamos National Laboratory. Two well logging missions were conducted in the Zunil field. In October 1988 measurements were made in well ZCQ-3, ZCQ-5, and ZCQ-6. In December 1989 the second field operation logged ZCQ-4 and repeated logs in ZCQ-3. Both field operations included not only well logging but the collecting of numerous fluid samples from both thermal and nonthermal waters. 18 refs., 22 figs., 7 tabs.

Processing of gamma-ray spectrometric logs

International Nuclear Information System (INIS)

Umiastowski, K.; Dumesnil, P.

1984-10-01

CEA (Commissariat a l'Energie Atomique) has developped a gamma-ray spectrometric tool, containing an analog-to-digital converter. This new tool permits to perform very precise uranium logs (natural gamma-ray spectrometry), neutron activation logs and litho-density logs (gamma-gamma spectrometric logs). Specific processing methods were developped to treate the particular problems of down-hole gamma-ray spectrometry. Extraction of the characteristic gamma-ray peak, even if they are superposed on the background radiation of very high intensity, is possible. This processing methode enables also to obtain geological informations contained in the continuous background of the spectrum. Computer programs are written in high level language for SIRIUS (VICTOR) and APOLLO computers. Exemples of uranium and neutron activation logs treatment are presented [fr

"The Dose Makes the Poison": Informing Consumers About the Scientific Risk Assessment of Food Additives.

Science.gov (United States)

Bearth, Angela; Cousin, Marie-Eve; Siegrist, Michael

2016-01-01

Intensive risk assessment is required before the approval of food additives. During this process, based on the toxicological principle of "the dose makes the poison,ˮ maximum usage doses are assessed. However, most consumers are not aware of these efforts to ensure the safety of food additives and are therefore sceptical, even though food additives bring certain benefits to consumers. This study investigated the effect of a short video, which explains the scientific risk assessment and regulation of food additives, on consumers' perceptions and acceptance of food additives. The primary goal of this study was to inform consumers and enable them to construct their own risk-benefit assessment and make informed decisions about food additives. The secondary goal was to investigate whether people have different perceptions of food additives of artificial (i.e., aspartame) or natural origin (i.e., steviolglycoside). To attain these research goals, an online experiment was conducted on 185 Swiss consumers. Participants were randomly assigned to either the experimental group, which was shown a video about the scientific risk assessment of food additives, or the control group, which was shown a video about a topic irrelevant to the study. After watching the video, the respondents knew significantly more, expressed more positive thoughts and feelings, had less risk perception, and more acceptance than prior to watching the video. Thus, it appears that informing consumers about complex food safety topics, such as the scientific risk assessment of food additives, is possible, and using a carefully developed information video is a successful strategy for informing consumers. © 2015 Society for Risk Analysis.

Nondestructive evaluation for sorting red maple logs

Science.gov (United States)

Xiping Wang; Robert J. Ross; David W. Green; Karl Englund; Michael Wolcott

2000-01-01

Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially...

Lung cancer risk from radon and smoking - additive or multiplicative effect?

International Nuclear Information System (INIS)

Tomasek, L.

2016-01-01

The aim of the work is to evaluate the risk of lung cancer when combined radon and smoking exposure. Methodologically the evaluation is based on case and control study nested in two cohort studies, including 11,000 miners and 12,000 residents exposed to high concentrations of radon in homes. Radon exposure in individuals is complemented by information on smoking gained personally from them or from their relatives. The study is based on 1,073 cases of lung cancer among miners and 372 cases in population study. Control subjects were randomly selected in each study based on gender, year of birth and age achieved. The combined effect of smoking and radon is evaluated using the so-called geometric mixed models, whose special case is an additive or multiplicative model. The resulting model of the risk is closer to additive interaction (parameter of mixed model 0.2). The consequences of the model in the study of population are illustrated by estimates of lifetime risk in a hypothetical population of smokers and nonsmokers. Compared to the multiplicative risk model, the lifetime risk significantly increased according to the best geometric mixed model, especially in the population of non-smokers. (author)

LHCb Online Log Analysis and Maintenance System

CERN Document Server

Garnier, J-C

2011-01-01

History has shown, many times computer logs are the only information an administrator may have for an incident, which could be caused either by a malfunction or an attack. Due to the huge amount of logs that are produced from large-scale IT infrastructures, such as LHCb Online, critical information may be overlooked or simply be drowned in a sea of other messages. This clearly demonstrates the need for an automatic system for long-term maintenance and real time analysis of the logs. We have constructed a low cost, fault tolerant centralized logging system which is able to do in-depth analysis and cross-correlation of every log. This system is capable of handling O(10000) different log sources and numerous formats, while trying to keep the overhead as low as possible. It provides log gathering and management, Offline analysis and online analysis. We call Offline analysis the procedure of analyzing old logs for critical information, while Online analysis refer to the procedure of early alerting and reacting. ...

Malaria in Africa: vector species' niche models and relative risk maps.

Directory of Open Access Journals (Sweden)

Alexander Moffett

2007-09-01

Full Text Available A central theoretical goal of epidemiology is the construction of spatial models of disease prevalence and risk, including maps for the potential spread of infectious disease. We provide three continent-wide maps representing the relative risk of malaria in Africa based on ecological niche models of vector species and risk analysis at a spatial resolution of 1 arc-minute (9 185 275 cells of approximately 4 sq km. Using a maximum entropy method we construct niche models for 10 malaria vector species based on species occurrence records since 1980, 19 climatic variables, altitude, and land cover data (in 14 classes. For seven vectors (Anopheles coustani, A. funestus, A. melas, A. merus, A. moucheti, A. nili, and A. paludis these are the first published niche models. We predict that Central Africa has poor habitat for both A. arabiensis and A. gambiae, and that A. quadriannulatus and A. arabiensis have restricted habitats in Southern Africa as claimed by field experts in criticism of previous models. The results of the niche models are incorporated into three relative risk models which assume different ecological interactions between vector species. The "additive" model assumes no interaction; the "minimax" model assumes maximum relative risk due to any vector in a cell; and the "competitive exclusion" model assumes the relative risk that arises from the most suitable vector for a cell. All models include variable anthrophilicity of vectors and spatial variation in human population density. Relative risk maps are produced from these models. All models predict that human population density is the critical factor determining malaria risk. Our method of constructing relative risk maps is equally general. We discuss the limits of the relative risk maps reported here, and the additional data that are required for their improvement. The protocol developed here can be used for any other vector-borne disease.

Modeling Precipitation Extremes using Log-Histospline

Science.gov (United States)

Huang, W. K.; Nychka, D. W.; Zhang, H.

2017-12-01

One of the commonly used approaches to modeling univariate extremes is the peaks-overthreshold (POT) method. The POT method models exceedances over a (sufficiently high/low) threshold as a generalized Pareto distribution (GPD). To apply this method, a threshold has to be chosen and the estimates might be sensitive to the chosen threshold. Here we propose an alternative, the "Log-Histospline", to explore modeling the tail behavior and the remainder of the density in one step using the full range of the data. Log-Histospline applies a smoothing spline model on a finely binned histogram of the log transformed data to estimate its log density. By construction, we are able to preserve the polynomial upper tail behavior, a feature commonly observed in geophysical observations. The Log-Histospline can be extended to the spatial setting by treating the marginal (log) density at each location as spatially indexed functional data, and perform a dimension reduction and spatial smoothing. We illustrate the proposed method by analyzing precipitation data from regional climate model output (North American Regional Climate Change and Assessment Program (NARCCAP)).

Advances in complex reservoir evaluation based on geophysical well logs

Energy Technology Data Exchange (ETDEWEB)

Fertl, W.H.; Sinha, A.K. (Western Atlas International, Inc., Houston, TX (USA)); McDougall, J.G. (Western Atlas Canada Ltd., Calgary, AB (Canada))

1988-09-01

The matrix of reservoirs having complex lithologies, cause different density, neutron, and acoustic responses. Therefore the lithologies and effective porosity of reservoirs can be determined by using various crossplot techniques on data collected from two of these logs. The Complex Reservoir Analysis program (CRA) computes lithology, porosity, water saturation and relative permeabilities in formations with interbedded limestone, dolomite, and anhydrite. Porosity options include crossplot and individual log response techniques. Corrections for light hydrocarbons were applied. In solving for porosity and mineral volumes, sand, limestone, dolomite, and anhydrite lines were defined on either density/neutron or neutron/acoustic crossplots. Four additional mineral lines were specified. Incorporation of Pe data from the Z-Densilog provided a significant advance in evaluating complex reservoirs via the Z-CRA analysis. The classic reservoir evaluation program CLASS, was used to perform both minerals and shaly evaluation based on density, neutron, resistivity, and natural gamma ray spectral measurements. Computations included total and effective porosities, fluid saturation distribution based on the Wasman-Smits model, productivity indices, and volume and distribution of clay minerals. Additional computed formation parameters included log-derived cation exchange capacity and hydrogen index of dry clay matrix to determine the type and amount of smectite, illite and chlorite/kaolinite present. Canadian field experiences was used to illustrate and support the techniques described. 11 refs., 11 figs., 6 tabs.

Selective logging in the Brazilian Amazon.

Science.gov (United States)

G. P. Asner; D. E. Knapp; E. N. Broadbent; P. J. C. Oliveira; M Keller; J. N. Silva

2005-01-01

Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square...

Linking log quality with product performance

Science.gov (United States)

D. W. Green; Robert Ross

1997-01-01

In the United States, log grading procedures use visual assessment of defects, in relation to the log scaling diameter, to estimate the yield of lumber that maybe expected from the log. This procedure was satisfactory when structural grades were based only on defect size and location. In recent years, however, structural products have increasingly been graded using a...

Logística del transporte

OpenAIRE

Robusté Antón, Francesc

2005-01-01

La logística se ha conformado como un proceso estratégico para organizar las actividades de producción y de distribución de las empresas. El concepto de sistema logístico ha incluido un amplio espectro de operaciones que condicionan la eficiencia y la competitividad empresarial en el actual contexto de globalización de la economía. En este sentido, este libro afronta y analiza los distintos aspectos que inciden en los procesos de planificación y gestión de los procesos logísticos relacionados...

The influence of felling season and log-soaking temperature on the wetting and phenol formaldehyde adhesive bonding characteristics of birch veneer

Science.gov (United States)

Anti Rohumaa; Christopher G. Hunt; Charles R. Frihart; Pekka Saranpää; Martin Ohlmeyer; Mark Hughes

2014-01-01

Most adhesive studies employing wood veneer as the substrate assume that it is a relatively uniform material if wood species and veneer thickness are constant. In the present study, veneers from rotary cut birch (Betula pendula Roth) were produced from logs harvested in spring, autumn and winter, and soaked at 20°C and 70°C prior to peeling. Firstly...

Application of the Bow Tie method for evaluation of safety in the procedure of logging wells

International Nuclear Information System (INIS)

Alfonso Pallares, C; Perez Reyes, Y.; Sarabia Molina, I.I.

2013-01-01

This work consists of an assessment of security in the practice of logging of oil wells, using the method of Bow Tie for being a simple method of evaluation of the risk, which makes it possible in a structured way to set priorities to manage risk

Research on Producing Green Dimension Directly From Hardwood Logs

Science.gov (United States)

Philip A. Araman

1995-01-01

Because of rising timber costs and an increasing demand for high-grade timber, suppliers of solid wood products need additional material options. We feel that European and Japanese processing concepts of producing green dimension and other clear material directly from logs could provide an answer. In this paper we present a brief overview of our research results on...

Treatment of log yard run-off by irrigation of grass and willows

International Nuclear Information System (INIS)

Jonsson, Maria; Dimitriou, Ioannis; Aronsson, Paer; Elowson, Torbjoern

2006-01-01

Log yard run-off is a potential environmental risk, among other things because it creates an oxygen deficiency in receiving watercourses. This study was conducted to investigate the purification efficiency of soil-plant systems with couchgrass (Elymus repens) and willows (Salix sp.) when intensively irrigated with run-off from an open sprinkling system at a Norway spruce (Picea abies) log yard. The purification efficiency was determined both at the field scale (couchgrass) and in 68-L lysimeters (couchgrass and willows). Groundwater in the field and drainage water from the lysimeters were analysed for Total Organic Carbon (TOC), distillable phenols, total P, and total N. Retention of TOC, phenols and P occurred but no difference between couchgrass and willows was observed. The system had better purification capacity at the field scale than in the lysimeters. -- By irrigating willow and couchgrass soil-plant systems with log yard run-off water, TOC, phenols, and phosphorus were reduced with 35% to 96% in the water

Data logging system upgrade for Indus accelerator

International Nuclear Information System (INIS)

Mishra, R.; Merh, B.N.; Agrawal, R.K.; Fatnani, P.; Navathe, C.P.; Pal, S.

2012-01-01

An accelerator has various subsystems like Magnet Power Supply, Beam Diagnostics and Vacuum etc. which are required to work in a stable manner to ensure required machine performance. Logging of system parameters at a faster rate plays a crucial role in analysing and understanding machine behaviour. Logging all the machine parameters consistently at the rate of typically more than 1 Hz has been the aim of a recent data logging system upgrade. Nearly ten thousand parameters are being logged at varying intervals of one second to one minute in Indus accelerator complex. The present logging scheme is augmented to log all these parameters at a rate equal to or more than 1 Hz. The database schema is designed according to the data type of the parameter. The data is distributed into historical table and intermediate table which comprises of recent data. Machine control applications read the parameter values from the control system and store them into the text files of finite time duration for each sub-system. The logging application of each sub-system passes these text files to database for bulk insertion. The detail design of database, logging scheme and its architecture is presented in the paper. (author)

Design of a transport calculation system for logging sondes simulation

International Nuclear Information System (INIS)

Marquez Damian, Jose Ignacio

2005-01-01

Analysis of available resources in earth crust is performed by different techniques, one of them is neutron logging. Design of sondes that are used to make such logging is supported by laboratory experiments as well as by numerical calculations.This work presents several calculation schemes, designed to simplify the task of whom has to planify such experiments or optimize parameters of this kind of sondes.These schemes use transport calculation codes, especially DaRT, TORT and MCNP, and cross section processing modules from SCALE system.Additionally a system for DaRT and TORT data postprocessing using OpenDX is presented.It allows scalar flux spatial distribution analysis, as wells as cross section condensation and reaction rates calculation

Continuous Tamper-proof Logging using TPM2.0

Science.gov (United States)

2014-06-16

process each log entry. Additional hardware support could mitigate this problem. Tradeoffs between performance and security guarantees Disk write...becomes weaker as the block size increases. This problem is mitigated in protocol B by allowing offline recovery from a power failure and detection of...M.K., Isozaki, H.: Flicker : An execution infrastructure for TCB minimization. ACM SIGOPS Operating Systems Review 42(4) (2008) 315–328 24. Parno, B

Improving risk assessment of color additives in medical device polymers.

Science.gov (United States)

Chandrasekar, Vaishnavi; Janes, Dustin W; Forrey, Christopher; Saylor, David M; Bajaj, Akhil; Duncan, Timothy V; Zheng, Jiwen; Riaz Ahmed, Kausar B; Casey, Brendan J

2018-01-01

Many polymeric medical device materials contain color additives which could lead to adverse health effects. The potential health risk of color additives may be assessed by comparing the amount of color additive released over time to levels deemed to be safe based on available toxicity data. We propose a conservative model for exposure that requires only the diffusion coefficient of the additive in the polymer matrix, D, to be specified. The model is applied here using a model polymer (poly(ether-block-amide), PEBAX 2533) and color additive (quinizarin blue) system. Sorption experiments performed in an aqueous dispersion of quinizarin blue (QB) into neat PEBAX yielded a diffusivity D = 4.8 × 10 -10 cm 2  s -1 , and solubility S = 0.32 wt %. On the basis of these measurements, we validated the model by comparing predictions to the leaching profile of QB from a PEBAX matrix into physiologically representative media. Toxicity data are not available to estimate a safe level of exposure to QB, as a result, we used a Threshold of Toxicological Concern (TTC) value for QB of 90 µg/adult/day. Because only 30% of the QB is released in the first day of leaching for our film thickness and calculated D, we demonstrate that a device may contain significantly more color additive than the TTC value without giving rise to a toxicological concern. The findings suggest that an initial screening-level risk assessment of color additives and other potentially toxic compounds found in device polymers can be improved. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 310-319, 2018. © 2017 Wiley Periodicals, Inc.

Intelligent approaches for the synthesis of petrophysical logs

International Nuclear Information System (INIS)

Rezaee, M Reza; Kadkhodaie-Ilkhchi, Ali; Alizadeh, Pooya Mohammad

2008-01-01

Log data are of prime importance in acquiring petrophysical data from hydrocarbon reservoirs. Reliable log analysis in a hydrocarbon reservoir requires a complete set of logs. For many reasons, such as incomplete logging in old wells, destruction of logs due to inappropriate data storage and measurement errors due to problems with logging apparatus or hole conditions, log suites are either incomplete or unreliable. In this study, fuzzy logic and artificial neural networks were used as intelligent tools to synthesize petrophysical logs including neutron, density, sonic and deep resistivity. The petrophysical data from two wells were used for constructing intelligent models in the Fahlian limestone reservoir, Southern Iran. A third well from the field was used to evaluate the reliability of the models. The results showed that fuzzy logic and artificial neural networks were successful in synthesizing wireline logs. The combination of the results obtained from fuzzy logic and neural networks in a simple averaging committee machine (CM) showed a significant improvement in the accuracy of the estimations. This committee machine performed better than fuzzy logic or the neural network model in the problem of estimating petrophysical properties from well logs

Log canonical thresholds of smooth Fano threefolds

International Nuclear Information System (INIS)

Cheltsov, Ivan A; Shramov, Konstantin A

2008-01-01

The complex singularity exponent is a local invariant of a holomorphic function determined by the integrability of fractional powers of the function. The log canonical thresholds of effective Q-divisors on normal algebraic varieties are algebraic counterparts of complex singularity exponents. For a Fano variety, these invariants have global analogues. In the former case, it is the so-called α-invariant of Tian; in the latter case, it is the global log canonical threshold of the Fano variety, which is the infimum of log canonical thresholds of all effective Q-divisors numerically equivalent to the anticanonical divisor. An appendix to this paper contains a proof that the global log canonical threshold of a smooth Fano variety coincides with its α-invariant of Tian. The purpose of the paper is to compute the global log canonical thresholds of smooth Fano threefolds (altogether, there are 105 deformation families of such threefolds). The global log canonical thresholds are computed for every smooth threefold in 64 deformation families, and the global log canonical thresholds are computed for a general threefold in 20 deformation families. Some bounds for the global log canonical thresholds are computed for 14 deformation families. Appendix A is due to J.-P. Demailly.

Limitations and developing directions of pulsed neutron logging

International Nuclear Information System (INIS)

Wu Wensheng; Xiao Lizhi

2007-01-01

The paper explains briefly the principle of pulsed neutron logging method, summarizes the system and uses of the method in petroleum logging. The paper points out the limitations of pulsed neutron logging such as low precise measurements, low logging speed, plenty of influence factors, low vertical resolution, bad adaptability, difficult logging interpretation and so on, and expounds its developing directions in hardware, software, method and principle. (authors)

A note on additive risk measures in rank-dependent utility

NARCIS (Netherlands)

Goovaerts, M.J.; Kaas, R.; Laeven, R.J.A.

2010-01-01

This note proves that risk measures obtained by applying the equivalent utility principle in rank-dependent utility are additive if and only if the utility function is linear or exponential and the probability weighting (distortion) function is the identity.

SU-F-T-233: Evaluation of Treatment Delivery Parameters Using High Resolution ELEKTA Log Files

Energy Technology Data Exchange (ETDEWEB)

Kabat, C; Defoor, D; Alexandrian, A; Papanikolaou, N; Stathakis, S [University of Texas HSC SA, San Antonio, TX (United States)

2016-06-15

Purpose: As modern linacs have become more technologically advanced with the implementation of IGRT and IMRT with HDMLCs, a requirement for more elaborate tracking techniques to monitor components’ integrity is paramount. ElektaLog files are generated every 40 milliseconds, which can be analyzed to track subtle changes and provide another aspect of quality assurance. This allows for constant monitoring of fraction consistency in addition to machine reliability. With this in mind, it was the aim of the study to evaluate if ElektaLog files can be utilized for linac consistency QA. Methods: ElektaLogs were reviewed for 16 IMRT patient plans with >16 fractions. Logs were analyzed by creating fluence maps from recorded values of MLC locations, jaw locations, and dose per unit time. Fluence maps were then utilized to calculate a 2D gamma index with a 2%–2mm criteria for each fraction. ElektaLogs were also used to analyze positional errors for MLC leaves and jaws, which were used to compute an overall error for the MLC banks, Y-jaws, and X-jaws by taking the root-meansquare value of the individual recorded errors during treatment. Additionally, beam on time was calculated using the number of ElektaLog file entries within the file. Results: The average 2D gamma for all 16 patient plans was found to be 98.0±2.0%. Recorded gamma index values showed an acceptable correlation between fractions. Average RMS values for MLC leaves and the jaws resulted in a leaf variation of roughly 0.3±0.08 mm and jaw variation of about 0.15±0.04 mm, both of which fall within clinical tolerances. Conclusion: The use of ElektaLog files for day-to-day evaluation of linac integrity and patient QA can be utilized to allow for reliable analysis of system accuracy and performance.

SU-F-T-233: Evaluation of Treatment Delivery Parameters Using High Resolution ELEKTA Log Files

International Nuclear Information System (INIS)

Kabat, C; Defoor, D; Alexandrian, A; Papanikolaou, N; Stathakis, S

2016-01-01

Purpose: As modern linacs have become more technologically advanced with the implementation of IGRT and IMRT with HDMLCs, a requirement for more elaborate tracking techniques to monitor components’ integrity is paramount. ElektaLog files are generated every 40 milliseconds, which can be analyzed to track subtle changes and provide another aspect of quality assurance. This allows for constant monitoring of fraction consistency in addition to machine reliability. With this in mind, it was the aim of the study to evaluate if ElektaLog files can be utilized for linac consistency QA. Methods: ElektaLogs were reviewed for 16 IMRT patient plans with >16 fractions. Logs were analyzed by creating fluence maps from recorded values of MLC locations, jaw locations, and dose per unit time. Fluence maps were then utilized to calculate a 2D gamma index with a 2%–2mm criteria for each fraction. ElektaLogs were also used to analyze positional errors for MLC leaves and jaws, which were used to compute an overall error for the MLC banks, Y-jaws, and X-jaws by taking the root-meansquare value of the individual recorded errors during treatment. Additionally, beam on time was calculated using the number of ElektaLog file entries within the file. Results: The average 2D gamma for all 16 patient plans was found to be 98.0±2.0%. Recorded gamma index values showed an acceptable correlation between fractions. Average RMS values for MLC leaves and the jaws resulted in a leaf variation of roughly 0.3±0.08 mm and jaw variation of about 0.15±0.04 mm, both of which fall within clinical tolerances. Conclusion: The use of ElektaLog files for day-to-day evaluation of linac integrity and patient QA can be utilized to allow for reliable analysis of system accuracy and performance.

Elephant logging and environment

International Nuclear Information System (INIS)

Tin-Aung-Hla

1995-01-01

The natural environment comprises non-biological elements such as air, water, light, heat and biological elements of animal and plant life; all interact with each other to create an ecosystem. Human activities like over-exploitation of forest results in deforestation and desertification. This consequently changes ecological balance. Topics on: (1) history of elephants utilization; (2) elephant logging; (3) classification of elephants; (4) dragging gear; (5) elephant power; (6) elephant logging and environment, are discussed

Well logging with natural gamma radiation

International Nuclear Information System (INIS)

Ellis, D.V.

1983-01-01

An invention is described for use in natural gamma radiation well logging in which measurements taken in a borehole are used in the search for valuable underground resources such as oil or gas. The invention comprises deriving a log of natural gamma radiation detected in selected energy windows for a selected borehole depth interval and converting it into a log of the selected subsurface materials, e.g. Th, U, K. This log is corrected for the effects of 1) either a gamma ray emitter in the borehole fluid, e.g. potassium salts and/or 2) a gamma ray attenuator in the borehole fluid, e.g. a strong attenuator such as barite and/or hematite. The Th, U, K log is particularly useful in the exploration of oil and gas resources since the Th, U, K concentrations are a good indication as to the presence, type and volume of shale and clay in the formations surrounding the borehole. (U.K.)

Financial feasibility of a log sort yard handling small-diameter logs: A preliminary study

Science.gov (United States)

Han-Sup Han; E. M. (Ted) Bilek; John (Rusty) Dramm; Dan Loeffler; Dave Calkin

2011-01-01

The value and use of the trees removed in fuel reduction thinning and restoration treatments could be enhanced if the wood were effectively evaluated and sorted for quality and highest value before delivery to the next manufacturing destination. This article summarizes a preliminary financial feasibility analysis of a log sort yard that would serve as a log market to...

Pembangkitan Data dari Distribusi Log-logistik

Directory of Open Access Journals (Sweden)

Aceng Komarudin Mutaqin

2014-11-01

Full Text Available Distribusi log-logistik merupakan salah satu distribusi yang dapat diaplikasikan untuk data mutu lingkungan. Makalah ini membahas pembangkitan data dari distribusi log-logistik mulai dari pembangunan algoritme sampai pembuatan program komputer pada perangkat lunak MATLAB. Metode pembangkitan datanya menggunakan metode inverse transform. Ada dua jenis data yang dibangkitkan, yaitu data lengkap dan data tersensor kiri. Dalam makalah ini diberikan contoh data yang dibangkitkan dari distribusi log-logistik.

Public risk perception of food additives and food scares. The case in Suzhou, China.

Science.gov (United States)

Wu, Linhai; Zhong, Yingqi; Shan, Lijie; Qin, Wei

2013-11-01

This study examined the factors affecting public risk perception of food additive safety and possible resulting food scares using a survey conducted in Suzhou, Jiangsu Province, China. The model was proposed based on literature relating to the role of risk perception and information perception of public purchase intention under food scares. Structural equation modeling (SEM) was used for data analysis. The results showed that attitude towards behavior, subjective norm and information perception exerted moderate to high effect on food scares, and the effects were also mediated by risk perceptions of additive safety. Significant covariance was observed between attitudes toward behavior, subjective norm and information perception. Establishing an effective mechanism of food safety risk communication, releasing information of government supervision on food safety in a timely manner, curbing misleading media reports on public food safety risk, and enhancing public knowledge of the food additives are key to the development and implementation of food safety risk management policies by the Chinese government. Copyright © 2013 Elsevier Ltd. All rights reserved.

Additional Treatments for High-Risk Obstetric Antiphospholipid Syndrome: a Comprehensive Review.

Science.gov (United States)

Ruffatti, Amelia; Hoxha, Ariela; Favaro, Maria; Tonello, Marta; Colpo, Anna; Cucchini, Umberto; Banzato, Alessandra; Pengo, Vittorio

2017-08-01

Most investigators currently advocate prophylactic-dose heparin plus low-dose aspirin as the preferred treatment of otherwise healthy women with obstetric antiphospholipid syndrome, whilst women with a history of vascular thrombosis alone or associated with pregnancy morbidity are usually treated with therapeutic heparin doses in association with low-dose aspirin in an attempt to prevent both thrombosis and pregnancy morbidity. However, the protocols outlined above fail in about 20 % of pregnant women with antiphospholipid syndrome. Identifying risk factors associated with pregnancy failure when conventional therapies are utilized is an important step in establishing guidelines to manage these high-risk patients. Some clinical and laboratory risk factors have been found to be related to maternal-foetal complications in pregnant women on conventional therapy. However, the most efficacious treatments to administer to high-risk antiphospholipid syndrome women in addition to conventional therapy in order to avoid pregnancy complications are as yet unestablished. This is a comprehensive review on this topic and an invitation to participate in a multicentre study in order to identify the best additional treatments to be used in this subset of antiphospholipid syndrome patients.

Risk management guide

International Nuclear Information System (INIS)

Briscoe, G.J.

1977-06-01

Risk management requires an assessment or a knowledge of risk. This, in turn, requires identification of hazards (sources of risk) and a determination of risk (evaluation of the hazard degree). The hazard identification and risk analysis techniques presented in this Guide are, in general, based on the MORT concept that accidents result from unwanted energy flow in the absence of adequate controls and/or barriers. This Guide presents an analytical tree designed to prevent oversight of specific energy sources in risk identification. Hazard identification by field personnel is also discussed. Quantitative risk analysis is discussed in the following section. A method for summary of the risks for each energy classification is given. This method uses a graphical log-normal projection so that low probability events, which are not adequately represented in the experience data, are included in the risk assessment. This permits a more acceptable risk assessment since catastrophes are not ignored, even though the actual risk is only approximated. In addition, a few examples of risk analysis of specific hazards are given. Rudimentary probability and fault tree theory are used in these examples. Total risk assessment and resource allocation and safety performance trend analysis are discussed

Web application for recording learners’ mouse trajectories and retrieving their study logs for data analysis

Directory of Open Access Journals (Sweden)

Yoshinori Miyazaki

2012-03-01

Full Text Available With the accelerated implementation of e-learning systems in educational institutions, it has become possible to record learners’ study logs in recent years. It must be admitted that little research has been conducted upon the analysis of the study logs that are obtained. In addition, there is no software that traces the mouse movements of learners during their learning processes, which the authors believe would enable teachers to better understand their students’ behaviors. The objective of this study is to develop a Web application that records students’ study logs, including their mouse trajectories, and to devise an IR tool that can summarize such diversified data. The results of an experiment are also scrutinized to provide an analysis of the relationship between learners’ activities and their study logs.

Pulsed neutron logging - a modern approach to petroleum exploration

International Nuclear Information System (INIS)

Navalkar, M.P.

1978-01-01

As hydrocarbons have strikingly different properties for neutrons as compared with rocks, neutronic methods are useful to prepare logs of bore holes drilled for petroleum exploration. The earlier neutron logs were based on steady neutron sources, but the superior logs, namely, neutron life time log and neutron induced spectral log are based on pulsed neutron sources. The methods of obtaining these logs, their limitations and the field equipment required are described briefly. As the two logs are complementary, a plea has been made to develop field equipment which can obtain two logs in a single run. (M.G.B.)

Experimental log hauling through a traditional caribou wintering area

Directory of Open Access Journals (Sweden)

Harold G. Cumming

1998-03-01

Full Text Available A 3-year field experiment (fall 1990-spring 1993 showed that woodland caribou (Rangifer tarandus caribou altered their dispersion when logs were hauled through their traditional wintering area. Unlike observations in control years 1 and 3, radio-collared caribou that had returned to the study area before the road was plowed on January 6 of the experimental year 2, moved away 8-60 km after logging activities began. Seasonal migration to Lake Nipigon islands usually peaked in April, but by February 22 of year 2, 4 of the 6 had returned. The islands provide summer refuge from predation, but not when the lake is frozen. Tracks in snow showed that some caribou remained but changed locations. They used areas near the road preferentially in year 1, early year 2, and year 3, but moved away 2-5 km after the road was plowed in year 2. In a nearby undisturbed control area, no such changes occurred. Caribou and moose partitioned habitat on a small scale; tracks showed gray wolf (Canis lupus remote from caribou but close to moose tracks. No predation on caribou was observed within the wintering area; 2 kills were found outside it. Due to the possibility of displacing caribou from winter refugia to places with higher predation risk, log hauling through important caribou winter habitat should be minimized.

Prospect theory: A parametric analysis of functional forms in Brazil

Directory of Open Access Journals (Sweden)

Robert Eugene Lobel

2017-10-01

Full Text Available This study aims to analyze risk preferences in Brazil based on prospect theory by estimating the risk aversion parameter of the expected utility theory (EUT for a select sample, in addition to the value and probability function parameter, assuming various functional forms, and a newly proposed value function, the modified log. This is the first such study in Brazil, and the parameter results are slightly different from studies in other countries, indicating that subjects are more risk averse and exhibit a smaller loss aversion. Probability distortion is the only common factor. As expected, the study finds that behavioral models are superior to EUT, and models based on prospect theory, the TK and Prelec weighting function, and the value power function show superior performance to others. Finally, the modified log function proposed in the study fits the data well, and can thus be used for future studies in Brazil.

Log-inject-log in sand consolidation

International Nuclear Information System (INIS)

Murphy, R.P.; Spurlock, J.W.

1977-01-01

A method is described for gathering information for the determination of the adequacy of placement of sand consolidating plastic for sand control in oil and gas wells. The method uses a high neutron cross-section tracer which becomes part of the plastic and uses pulsed neutron logging before and after injection of the plastic. Preferably, the method uses lithium, boron, indium, and/or cadmium tracers. Boron oxide is especially useful and can be dissolved in alcohol and mixed with the plastic ingredients

Comparison of additive (absolute) risk projection models and multiplicative (relative) risk projection models in estimating radiation-induced lifetime cancer risk

International Nuclear Information System (INIS)

Kai, Michiaki; Kusama, Tomoko

1990-01-01

Lifetime cancer risk estimates depend on risk projection models. While the increasing lengths of follow-up observation periods of atomic bomb survivors in Hiroshima and Nagasaki bring about changes in cancer risk estimates, the validity of the two risk projection models, the additive risk projection model (AR) and multiplicative risk projection model (MR), comes into question. This paper compares the lifetime risk or loss of life-expectancy between the two projection models on the basis of BEIR-III report or recently published RERF report. With Japanese cancer statistics the estimates of MR were greater than those of AR, but a reversal of these results was seen when the cancer hazard function for India was used. When we investigated the validity of the two projection models using epidemiological human data and animal data, the results suggested that MR was superior to AR with respect to temporal change, but there was little evidence to support its validity. (author)

Predicting logging residues: an interim equation for Appalachian oak sawtimber

Science.gov (United States)

A. Jeff Martin

1975-01-01

An equation, using dbh, dbh², bole length, and sawlog height to predict the cubic-foot volume of logging residue per tree, was developed from data collected on 36 mixed oaks in southwestern Virginia. The equation produced reliable results for small sawtimber trees, but additional research is needed for other species, sites, and utilization practices.

Profiling event logs to configure risk indicators for process delays

NARCIS (Netherlands)

Pika, A.; Aalst, van der W.M.P.; Fidge, C.J.; Hofstede, ter A.H.M.; Wynn, M.T.; Salinesi, C.; Norrie, M.C.; Pastor, O.

2013-01-01

Risk identification is one of the most challenging stages in the risk management process. Conventional risk management approaches provide little guidance and companies often rely on the knowledge of experts for risk identification. In this paper we demonstrate how risk indicators can be used to

A Lower Bound on the Differential Entropy of Log-Concave Random Vectors with Applications

Directory of Open Access Journals (Sweden)

Arnaud Marsiglietti

2018-03-01

Full Text Available We derive a lower bound on the differential entropy of a log-concave random variable X in terms of the p-th absolute moment of X. The new bound leads to a reverse entropy power inequality with an explicit constant, and to new bounds on the rate-distortion function and the channel capacity. Specifically, we study the rate-distortion function for log-concave sources and distortion measure d ( x , x ^ = | x − x ^ | r , with r ≥ 1 , and we establish that the difference between the rate-distortion function and the Shannon lower bound is at most log ( π e ≈ 1 . 5 bits, independently of r and the target distortion d. For mean-square error distortion, the difference is at most log ( π e 2 ≈ 1 bit, regardless of d. We also provide bounds on the capacity of memoryless additive noise channels when the noise is log-concave. We show that the difference between the capacity of such channels and the capacity of the Gaussian channel with the same noise power is at most log ( π e 2 ≈ 1 bit. Our results generalize to the case of a random vector X with possibly dependent coordinates. Our proof technique leverages tools from convex geometry.

29 CFR 1918.88 - Log operations.

Science.gov (United States)

2010-07-01

...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.88 Log operations. (a) Working in..., the employer shall ensure that employees remain clear of areas where logs being dumped could strike...

Logging utilization in Idaho: Current and past trends

Science.gov (United States)

Eric A. Simmons; Todd A. Morgan; Erik C. Berg; Stanley J. Zarnoch; Steven W. Hayes; Mike T. Thompson

2014-01-01

A study of commercial timber-harvesting activities in Idaho was conducted during 2008 and 2011 to characterize current tree utilization, logging operations, and changes from previous Idaho logging utilization studies. A two-stage simple random sampling design was used to select sites and felled trees for measurement within active logging sites. Thirty-three logging...

The need for reviewing log books in Birjand University of Medical Sciences clinical wards: Letter to Editor

Directory of Open Access Journals (Sweden)

Zoya Tahergorabi

2017-08-01

Furthermore, due to the pervasive use of electronic log books in recent years in medical universities across the country that are in line with developments and innovations in medical education, it is recommended that the log books at this university too, should be presented and evaluated electronically. Electronic log books with ongoing record of activities and clinical techniques based on educational objectives, in addition to learning consolidation, determine unavailable measures to achieve clinical objectives and, thus, cause regular monitoring and evaluation on the part of students.

Polymorphisms in VEGF-A are associated with COPD risk in the ...

Indian Academy of Sciences (India)

Both rs3025030 and rs3025033 are located on chromosome 6 in VEGF-A. We found one risk allele 'C' from rs3025030 and another 'G' from rs3025033 using the log-additive model (OR 1.40; 95% CI1.05–5.96; P = 0.022), (OR 1.38; 95% CI 1.03–1.84; P = 0.03). We also found another risk allele 'A' of rs9296092 in ...

New roles of LWD and wireline logging in scientific ocean drilling

Science.gov (United States)

Sanada, Y.; Kido, Y. N.; Moe, K.; Aoike, K.

2014-12-01

D/V Chikyu implemented by CDEX/JAMSTEC joined IODP from 2007. Various LWD (Logging While Drilling) and wireline logging have been carried out in many expeditions and for various purposes. Significant features of logging in Chikyu expeditions are many use of LWD than wireline logging, and riser dirlling. riser selected specific tools for each scientific target, and 3) carried out various borehole experiments. LWD has been more popular than wireline logging in Chikyu expeditions, because its advantages match theirs science targets. The advantages are followings. 1) LWD has more opportunities for measurement in unstable borehole, such as in the series of Nankai trough drilling expeditions. 2) LWD realtime data allows us to make realtime interpretation and operational decision. Realtime interpretation was required to set obsevartory at the properposition. 3) LWD before coring allows us to make a strategy of spot coring.We can design coring intervals for our interest and core length to improve core recovery.Riser drilling brings us merits for logging. One is hole stability (good hole condition) and the other is the use of large diameter tools. Controled drilling mud in riser drilling system prevent mud invasion to formation and mitigates collapse of borehole wall. They reduce the risk of tool stack and improve data quality. Large diameter of riser pipe enhances variation of tool seizes. A couple of new tools were used for new measurement and improvement of the data quality. For example, SonicScanner (trademark of Schulumberger) successfully measured compressional and share velocity in very low velocities at the soft sediment, where it has been difficult to measure them with conventional DSI tool (Exp319). The stress and pore pressure in the borehole were measured with the wireline logging tool, (Schlumberger MDT). The single probe tool enable to measure temporal formation fluid pressure. The double packer tool enable to fracture test by sealing and pumping in the

Assessment of the Log-Euclidean Metric Performance in Diffusion Tensor Image Segmentation

Directory of Open Access Journals (Sweden)

Mostafa Charmi

2010-06-01

Full Text Available Introduction: Appropriate definition of the distance measure between diffusion tensors has a deep impact on Diffusion Tensor Image (DTI segmentation results. The geodesic metric is the best distance measure since it yields high-quality segmentation results. However, the important problem with the geodesic metric is a high computational cost of the algorithms based on it. The main goal of this paper is to assess the possible substitution of the geodesic metric with the Log-Euclidean one to reduce the computational cost of a statistical surface evolution algorithm. Materials and Methods: We incorporated the Log-Euclidean metric in the statistical surface evolution algorithm framework. To achieve this goal, the statistics and gradients of diffusion tensor images were defined using the Log-Euclidean metric. Numerical implementation of the segmentation algorithm was performed in the MATLAB software using the finite difference techniques. Results: In the statistical surface evolution framework, the Log-Euclidean metric was able to discriminate the torus and helix patterns in synthesis datasets and rat spinal cords in biological phantom datasets from the background better than the Euclidean and J-divergence metrics. In addition, similar results were obtained with the geodesic metric. However, the main advantage of the Log-Euclidean metric over the geodesic metric was the dramatic reduction of computational cost of the segmentation algorithm, at least by 70 times. Discussion and Conclusion: The qualitative and quantitative results have shown that the Log-Euclidean metric is a good substitute for the geodesic metric when using a statistical surface evolution algorithm in DTIs segmentation.

Method and apparatus for logging inclined earth boreholes

International Nuclear Information System (INIS)

Youmans, A.H.

1981-01-01

An improved technique is provided for comparing the velocity of an elongated well logging instrument traversing an inclined earth borehole with the playout velocity of the well logging cable at the earth's surface to control both the cable hoist drum rotation and the rate of movement of the subsurface instrument and thus insure cable playout is in equilibrium with the logging instrument movement. Method and apparatus are described for detecting any reduction in movement of the logging instrument through the borehole and for reducing the velocity of the logging cable playout in response thereto by reducing drum rotation. Further, when the velocity of cable playout slows to a preselected value, a monitoring circuit generates control signals which actuate a means of power attached to or integral with the logging instrument which, upon initiation, apply a force to move the logging instrument upward or downward within the borehole

Log-concavity property for some well-known distributions

Directory of Open Access Journals (Sweden)

G. R. Mohtashami Borzadaran

2011-12-01

Full Text Available Interesting properties and propositions, in many branches of science such as economics have been obtained according to the property of cumulative distribution function of a random variable as a concave function. Caplin and Nalebuff (1988,1989, Bagnoli and Khanna (1989 and Bagnoli and Bergstrom (1989 , 1989, 2005 have discussed the log-concavity property of probability distributions and their applications, especially in economics. Log-concavity concerns twice differentiable real-valued function g whose domain is an interval on extended real line. g as a function is said to be log-concave on the interval (a,b if the function ln(g is a concave function on (a,b. Log-concavity of g on (a,b is equivalent to g'/g being monotone decreasing on (a,b or (ln(g" 6] have obtained log-concavity for distributions such as normal, logistic, extreme-value, exponential, Laplace, Weibull, power function, uniform, gamma, beta, Pareto, log-normal, Student's t, Cauchy and F distributions. We have discussed and introduced the continuous versions of the Pearson family, also found the log-concavity for this family in general cases, and then obtained the log-concavity property for each distribution that is a member of Pearson family. For the Burr family these cases have been calculated, even for each distribution that belongs to Burr family. Also, log-concavity results for distributions such as generalized gamma distributions, Feller-Pareto distributions, generalized Inverse Gaussian distributions and generalized Log-normal distributions have been obtained.

Seismic reflection data imaging and interpretation from Braniewo2014 experiment using additional wide-angle refraction and reflection and well-logs data

Science.gov (United States)

Trzeciak, Maciej; Majdański, Mariusz; Białas, Sebastian; Gaczyński, Edward; Maksym, Andrzej

2015-04-01

Braniewo2014 reflection and refraction experiment was realized in cooperation between Polish Oil and Gas Company (PGNiG) and the Institute of Geophysics (IGF), Polish Academy of Sciences, near the locality of Braniewo in northern Poland. PGNiG realized a 20-km-long reflection profile, using vibroseis and dynamite shooting; the aim of the reflection survey was to characterise Silurian shale gas reservoir. IGF deployed 59 seismic stations along this profile and registered additional full-spread wide-angle refraction and reflection data, with offsets up to 12 km; maximum offsets from the seismic reflection survey was 3 km. To improve the velocity information two velocity logs from near deep boreholes were used. The main goal of the joint reflection-refraction interpretation was to find relations between velocity field from reflection velocity analysis and refraction tomography, and to build a velocity model which would be consistent for both, reflection and refraction, datasets. In this paper we present imaging results and velocity models from Braniewo2014 experiment and the methodology we used.

Modeling turbulent/chemistry interactions using assumed pdf methods

Science.gov (United States)

Gaffney, R. L, Jr.; White, J. A.; Girimaji, S. S.; Drummond, J. P.

1992-01-01

Two assumed probability density functions (pdfs) are employed for computing the effect of temperature fluctuations on chemical reaction. The pdfs assumed for this purpose are the Gaussian and the beta densities of the first kind. The pdfs are first used in a parametric study to determine the influence of temperature fluctuations on the mean reaction-rate coefficients. Results indicate that temperature fluctuations significantly affect the magnitude of the mean reaction-rate coefficients of some reactions depending on the mean temperature and the intensity of the fluctuations. The pdfs are then tested on a high-speed turbulent reacting mixing layer. Results clearly show a decrease in the ignition delay time due to increases in the magnitude of most of the mean reaction rate coefficients.

La competitividad logística en Latinoamérica: índice logístico vs. propuesta metodológica

Directory of Open Access Journals (Sweden)

Marco Alberto Valenzo Jiménez

2016-02-01

Full Text Available Este artículo muestra la situación actual de la competitividad logística en los países latinoamericanos, tomando como base el informe denominado “Connecting to Compite” (Trade Logistics in the Global Economy, 2007 del Banco Mundial. Este informe muestra el ranking de las posiciones que tienen los países latinoamericanos en materia de logística y en el cual se analizan las variables —aduanas, infraestructura, embarques internacionales, competencia logística, trazabilidad y seguimiento, costos logísticos domésticos y tiempo de entrega— que contiene la metodología utilizada por el Banco Mundial. La plataforma de estudio de este artículo parte del índice de competitividad logística, que, mediante la aplicación de la metodología “Valenzo – Martínez” permite analizar la base de datos de una manera más profunda, y da como resultado una escala de competitividad logística que nos muestra el nivel general de la competitividad logística en Latinoamérica, así como también el nivel de competitividad por variable, para, de esta manera, permitir una fácil interpretación de los resultados.

Selective logging and its relation to deforestation

Science.gov (United States)

Gregory P. Asner; Michael Keller; Marco Lentini; Frank Merry; Souza Jr. Carlos

2009-01-01

Selective logging is a major contributor to the social, economic, and ecological dynamics of Brazilian Amazonia. Logging activities have expanded from low-volume floodplain harvests in past centuries to high-volume operations today that take about 25 million m3 of wood from the forest each year. The most common high-impact conventional and often illegal logging...

Clinicians were oblivious to incorrect logging of test dates and the associated risks in an online pathology application: a case study

Directory of Open Access Journals (Sweden)

Amber Appleton

2013-09-01

Full Text Available Background UK primary care physicians receive their laboratory test results electronically. This study reports a computerised physician order entry (CPOE system error in the pathology test request date that went unnoticed in family practices.Method We conducted a case study using a causation of risk theoretical framework; comprising interviews with clinicians and the manufacturer to explore the identification of and reaction to the error. The primary outcome was the evolution and  recognition of and response to the problem. The secondary outcome was to identify other issues with this system noted by users.Results The problem was defined as the incorrect logging of test dates ordered through a CPOE system. The system assigned the test request date to the results, hence a blood test taken after a therapeutic intervention (e.g. an increase in cholesterol-lowering therapy would appear in the computerised medical record as though it had been tested prior to the increase in treatment. This case demonstrates that: the manufacturers failed to understand family physician workflow; regulation of medical software did not prevent the error; and inherent user trust in technology exacerbated this problem. It took three months before users in two practices independently noted the date errors.Conclusion This case illustrates how users take software on trust and suppliers fail to make provision for risks associated with new software. Resulting errors led to inappropriate prescribing, follow-up, costs and risk. The evaluation of such devices should include utilising risk management processes (RMP to minimise and manage potential risk.

Mud Logging; Control geologico en perforaciones petroliferas (Mud Logging)

Energy Technology Data Exchange (ETDEWEB)

Pumarega Lafuente, J.C.

1994-12-31

Mud Logging is an important activity in the oil field and it is a key job in drilling operations, our duties are the acquisition, collection and interpretation of the geological and engineering data at the wellsite, also inform the client immediately of any significant changes in the well. (Author)

Well logging. Acquisition and applications; Diagraphies. Acquisition et applications

Energy Technology Data Exchange (ETDEWEB)

Serra, O.; Serra, L.

2001-07-01

This reference book on wire-line and LWD well logging covers all geophysical methods of underground survey in a synthetic, visual and dynamical way. It treats of: the physical principle of well logging measurements, the different types of existing probes, the factors that can influence the measurements, and the applications of these measurements. The following well-logging methods are reviewed: resistivity; electromagnetic wave propagation; magnetic susceptibility and magnetic field; spontaneous potential; nuclear logging: natural gamma radioactivity, density logging, photoelectric index, neutron emission probes, hydrogen index or neutron porosity, neutron induced gamma spectroscopy, neutron relaxation time, NMR; acoustic measurements: sonic logging, seismic profiles; texture, structure and stratigraphy data acquisition; borehole diameter measurement; temperature measurement; wire sampling methods; place and role of well-logging in petroleum exploration; well-logging programs. (J.S.)

Three-dimensional trend mapping using gamma-ray well logs: Simpson Group, south-central Kansas

International Nuclear Information System (INIS)

Doveton, J.H.; Davis, J.C.; Zhu Ke-an

1984-01-01

Gamma-ray logs are useful indicators of shale content as a function of depth. When several gamma-ray logs are drawn from an area, they may be interpreted in terms of shale variation in the 3 dimensions of geographic space and depth. (For several years, statistical moments of logs have been mapped as an expression of major trends of depth variation in lithologic development across an area. Moments have the additional valuable property that they also define unique polynomial trends as a function of depth. This property allows the interpolation of moments between well control to generate a 3-dimensional grid of shale referenced to any location and depth. The method was applied to the Simpson Group (Ordovician) of southcentral Kansas. Graphic results of the study outline the shapes of major sandstone and shale bodies in a series of cross sections.) The areal disposition of the initial transgressive sandstone is revealed on a basal slice map. The method is general and can be used in conjunction with other logs. As an example, use of either a neutron, density, or sonic log could be applied to 3-dimensional trend representations of porosity variation in reservoir units

Mariners Weather Log

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Mariners Weather Log (MWL) is a publication containing articles, news and information about marine weather events and phenomena, worldwide environmental impact...

Covariate selection for the semiparametric additive risk model

DEFF Research Database (Denmark)

Martinussen, Torben; Scheike, Thomas

2009-01-01

This paper considers covariate selection for the additive hazards model. This model is particularly simple to study theoretically and its practical implementation has several major advantages to the similar methodology for the proportional hazards model. One complication compared...... and study their large sample properties for the situation where the number of covariates p is smaller than the number of observations. We also show that the adaptive Lasso has the oracle property. In many practical situations, it is more relevant to tackle the situation with large p compared with the number...... of observations. We do this by studying the properties of the so-called Dantzig selector in the setting of the additive risk model. Specifically, we establish a bound on how close the solution is to a true sparse signal in the case where the number of covariates is large. In a simulation study, we also compare...

Pacific Rim log trade: determinants and trends.

Science.gov (United States)

Donald F. Flora; Andrea L. Anderson; Wendy J. McGinnls

1991-01-01

Pacific Rim trade in softwood logs amounts to about $3 billion annually, of which the U.S. share is about $2 billion. Log exporting is a significant part of the forest economy in the Pacific Northwest. The 10 major Pacific Rim log-trading client and competitor countries differ widely in their roles in trade and in their policies affecting the industry.

Log Analysis Using Splunk Hadoop Connect

Science.gov (United States)

2017-06-01

23 A. INPUT SELECTION ...Conversion Resource Consumption .............................................. 28 Figure 8. Distribution of Events in Years...running a logging service puts a performance tax on the system and may cause the degradation of performance. More thorough 8 logging will cause a

Log and tree sawing times for hardwood mills

Science.gov (United States)

Everette D. Rast

1974-01-01

Data on 6,850 logs and 1,181 trees were analyzed to predict sawing times. For both logs and trees, regression equations were derived that express (in minutes) sawing time per log or tree and per Mbf. For trees, merchantable height is expressed in number of logs as well as in feet. One of the major uses for the tables of average sawing times is as a bench mark against...

ANDRILL Borehole AND-1B: Well Log Analysis of Lithofacies and Glacimarine Cycles.

Science.gov (United States)

Jackolski, C. L.; Williams, T.; Powell, R. D.; Jarrard, R.; Morin, R. H.; Talarico, F. M.; Niessen, F.; Kuhn, G.

2008-12-01

During the 2006-2007 austral summer, the Antarctic geological drilling program ANDRILL recovered cores of sedimentary rock from a 1285-m-deep borehole below the McMurdo Ice Shelf. Well logging instruments were deployed to a depth of 1017 mbsf after core recovery. This study focuses on two intervals of the AND-1B borehole: upper HQ (238-343 mbsf; Pliocene) and NQ (698-1017 mbsf; upper Miocene), which were logged with natural gamma ray, induction resistivity and magnetic susceptibility tools. To understand how the well logs fit into a more complete physical properties data set, we performed factor and cluster analyses on a suite of well logs and core logs in the upper HQ and NQ intervals. In both intervals, factor analysis groups resistivity and core P-velocity into a factor that we interpret as being inversely proportional to porosity. It also groups natural gamma and potassium (from the XRF core scanner) into a factor that we interpret as a particle-size or lithology index. An additional factor in the NQ interval, influenced by clast number and magnetic susceptibility, distinguishes subglacial diamictites from other lithofacies. The factors in each interval (2 in HQ, 3 in NQ) are used as input to cluster analysis. The results are log data objectively organized into clusters, or electrofacies. We compare these electrofacies to the lithofacies, well logs and unconformity-bounded glacimarine cycles of AND-1B. Patterns in the glacimarine cycles are observed in the well logs and electrofacies. In the NQ glacimarine sediments, an electrofacies pattern is produced between subglacial diamictites at the bottom of each sequence and the glacial retreat facies above. Subglacial diamictites have higher values for the additional NQ factor, corresponding to clast number and magnetic susceptibility, than the muds and sands that form the retreat facies. Differences in the porosity factor are not observed in any electrofacies pattern in the NQ interval, but subtle patterns in the

Pulsed radiation decay logging

International Nuclear Information System (INIS)

Mills, W.R. Jr.

1983-01-01

There are provided new and improved well logging processes and systems wherein the detection of secondary radiation is accomplished during a plurality of time windows in a manner to accurately characterize the decay rate of the secondary radiation. The system comprises a well logging tool having a primary pulsed radiation source which emits repetitive time-spaced bursts of primary radiation and detector means for detecting secondary radiation resulting from the primary radiation and producing output signals in response to the detected radiation. A plurality of measuring channels are provided, each of which produces a count rate function representative of signals received from the detector means during successive time windows occurring between the primary radiation bursts. The logging system further comprises means responsive to the measuring channels for producing a plurality of functions representative of the ratios of the radiation count rates measured during adjacent pairs of the time windows. Comparator means function to compare the ratio functions and select at least one of the ratio functions to generate a signal representative of the decay rate of the secondary radiation

Mapping the lithotypes using the in-situ measurement of time domain induced polarization: El-log

DEFF Research Database (Denmark)

Auken, Esben; Fiandaca, Gianluca; Christiansen, Anders Vest

This study presents a novel application of the El-log-drilling technique for measurement while drilling of the DC, time domain IP and gamma log. In addition pore water samples can be taken at arbitrary levels. The technique itself is developed in Denmark and has been widely used in the field...... of ground water and environmental studies. The El-log drilling method yields detailed information on small changes in lithology, sediment chemistry and water quality and with data comparable to what can be obtained in the laboratory. . We collected the data at a landfill site located near Grindsted...... in the southern part of Denmark. The purpose of the study was 1) to obtain a direct correlation between the undisturbed geophysical logs and surface measurements, 2) correlation of IP parameters to lithology and grain size distribution and 3) to investigate any correlation with effluent and IP parameters. We...

A history of nuclear well logging in the oil industry

International Nuclear Information System (INIS)

Tittle, C.W.

1989-01-01

Spurred by an interest in logging through steel casing γ-ray logging began in the late 1930s followed soon by neutron logging for porosity. These were the first two nuclear well logs. Gamma-gamma density logging was developed during the 1950s. Pulsed neutron lifetime logging appeared in the 1960s; the slim tools came in the early 1970s. Developments since then have included dual detector devices of several types which offered improved measurements or interpretation, γ-ray spectrometry logging (natural and neutron-induced) which identifies certain chemical elements, induced radioactivity logging, and the photoelectric absorption log, which, combined with the density log in a single tool, is known as litho-density logging. A combination of several γ-ray spectrometers in one tool, designed to determine 10 formation elements, was recently introduced, and a new neutron porosity tool measuring epithermal neutron die-away time has been developed. Digital transmission of logging data was a step forward in about 1975. Also, log interpretation techniques have greatly expanded since the advent of digital computers, and the microcomputer has had a distinct impact. It is now practical and economical to do iterative analysis on a suite of logs to obtain an optimum overall interpretation. (author)

Review of the Czubek--Jonas gamma-log program

International Nuclear Information System (INIS)

Matthews, M.

1978-11-01

Several gamma-ray logs were computer processed using the Czubek--Jones and DOE's MDDAT gamma-log programs. Both of these programs convert counts per second from the gamma-ray logs to percent eU 3 O 8 . The results of these programs were compared to each other and to the core analysis (percent U 3 O 8 ) of the logged boreholes. The two gamma-log programs produced similar results. The core analysis did not compare favorably with the results of either gamma-log program. This unfavorable comparison is probably due to an incorrect assumption of secular equilibrium for the ore surrounding the boreholes. The Czubek--Jonas program requires a knowledge of the linear attenuation coefficient of the rocks surrounding a borehole. This limits the usefulness of the program because this coefficient is generally not known and varies for different gamma-ray energies. It is recommended that the MDDAT program continue to be used for estimating the grade (percent eU 3 O 8 ) from gamma-log data and not be replaced by the Czubek--Jonas program

Selective logging: do rates of forest turnover in stems, species composition and functional traits decrease with time since disturbance? - A 45 year perspective.

Science.gov (United States)

Osazuwa-Peters, Oyomoare L; Jiménez, Iván; Oberle, Brad; Chapman, Colin A; Zanne, Amy E

2015-12-01

Selective logging, the targeted harvesting of timber trees in a single cutting cycle, is globally rising in extent and intensity. Short-term impacts of selective logging on tropical forests have been widely investigated, but long-term effects on temporal dynamics of forest structure and composition are largely unknown. Understanding these long-term dynamics will help determine whether tropical forests are resilient to selective logging and inform choices between competing demands of anthropogenic use versus conservation of tropical forests. Forest dynamics can be studied within the framework of succession theory, which predicts that temporal turnover rates should decline with time since disturbance. Here, we investigated the temporal dynamics of a tropical forest in Kibale National Park, Uganda over 45 years following selective logging. We estimated turnover rates in stems, species composition, and functional traits (wood density and diameter at breast height), using observations from four censuses in 1989, 1999, 2006, and 2013, of stems ≥ 10 cm diameter within 17 unlogged and 9 logged 200 × 10 m vegetation plots. We used null models to account for interdependencies among turnover rates in stems, species composition, and functional traits. We tested predictions that turnover rates should be higher and decrease with increasing time since the selective logging event in logged forest, but should be less temporally variable in unlogged forest. Overall, we found higher turnover rates in logged forest for all three attributes, but turnover rates did not decline through time in logged forest and was not less temporally variable in unlogged forest. These results indicate that successional models that assume recovery to pre-disturbance conditions are inadequate for predicting the effects of selective logging on the dynamics of the tropical forest in Kibale. Selective logging resulted in persistently higher turnover rates, which may compromise the carbon storage capacity

Use of activity logs to improve online collaboration

Directory of Open Access Journals (Sweden)

César Coll Salvador

2018-02-01

Full Text Available This article presents a review of works that center their interest in eLearning platforms and the data mining of participants’ activity. The studies in this research area generate information, through the analysis of such logs and data, that is provided to the students in real time to help them to collaborate and learn through collaboration on the platform. There are studies from different areas of study such as Learning Analytics, Educational Data Mining, Group Awareness Tools or Interaction Analysis Tools. The review takes a double perspective: i to analyze the data extracted from activity logs, their processing, the information generated and the ways to communicate it; and ii to explorer the model and the instruments used to assess how the information provided impact on online collaborative processes and/or the learning. The conclusions emphasize that the models of collaborative learning that justifies the selection of the data extracted from the activity logs, the processing, the information generated and provided to the students and the way of communicating it, are not explicitly stated. In addition, important biases are detected because of not considering the multidimensional nature of the collaborative learning processes. Also, few studies analyze the relations between students' uses of the information provided and the quality of their collaborative processes and learning results. The very few studies that do analyze such relation do not go into depth on the changes in group dynamics caused by information.

CMLOG: A common message logging system

International Nuclear Information System (INIS)

Chen, J.; Akers, W.; Bickley, M.; Wu, D.; Watson, W. III

1997-01-01

The Common Message Logging (CMLOG) system is an object-oriented and distributed system that not only allows applications and systems to log data (messages) of any type into a centralized database but also lets applications view incoming messages in real-time or retrieve stored data from the database according to selection rules. It consists of a concurrent Unix server that handles incoming logging or searching messages, a Motif browser that can view incoming messages in real-time or display stored data in the database, a client daemon that buffers and sends logging messages to the server, and libraries that can be used by applications to send data to or retrieve data from the database via the server. This paper presents the design and implementation of the CMLOG system meanwhile it will also address the issue of integration of CMLOG into existing control systems. CMLOG into existing control systems

Nuclear log interpretation by first principle

International Nuclear Information System (INIS)

Oelgaard, P.L.

1988-07-01

A weakness connected to the present interpretation of nuclear borehole logs is that the interdependence of the various logs and physical effects of importance for the tools are not always taken into account in a correct way. Therefore a new approach to the interpretation of nuclear borehole logs is considered. It is based on the logs obtained with the natural gamma, the neutron porosity, the gamma density, and the pulsed neutron tools. For each of these tools a model, taking into account the important physical effects, is established. These models are incorporated into a computer programme which from the tool signals calculates, by use of iteration, a consistent set of the corresponding formation properties. In the paper the models developed for the four tools and the interpretation programme are briefly described. An example of the use of the interpretation programme is given and compared with a conventional interpretation. (author)

Well log characterization of natural gas-hydrates

Science.gov (United States)

Collett, Timothy S.; Lee, Myung W.

2012-01-01

In the last 25 years there have been significant advancements in the use of well-logging tools to acquire detailed information on the occurrence of gas hydrates in nature: whereas wireline electrical resistivity and acoustic logs were formerly used to identify gas-hydrate occurrences in wells drilled in Arctic permafrost environments, more advanced wireline and logging-while-drilling (LWD) tools are now routinely used to examine the petrophysical nature of gas-hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. Resistivity- and acoustic-logging tools are the most widely used for estimating the gas-hydrate content (i.e., reservoir saturations) in various sediment types and geologic settings. Recent integrated sediment coring and well-log studies have confirmed that electrical-resistivity and acoustic-velocity data can yield accurate gas-hydrate saturations in sediment grain-supported (isotropic) systems such as sand reservoirs, but more advanced log-analysis models are required to characterize gas hydrate in fractured (anisotropic) reservoir systems. New well-logging tools designed to make directionally oriented acoustic and propagation-resistivity log measurements provide the data needed to analyze the acoustic and electrical anisotropic properties of both highly interbedded and fracture-dominated gas-hydrate reservoirs. Advancements in nuclear magnetic resonance (NMR) logging and wireline formation testing (WFT) also allow for the characterization of gas hydrate at the pore scale. Integrated NMR and formation testing studies from northern Canada and Alaska have yielded valuable insight into how gas hydrates are physically distributed in sediments and the occurrence and nature of pore fluids(i.e., free water along with clay- and capillary-bound water) in gas-hydrate-bearing reservoirs. Information on the distribution of gas hydrate at the pore scale has provided invaluable insight on the mechanisms

A study on the development of risk perception concerning food additives

OpenAIRE

臼井, 宗一

2014-01-01

In order to study the development process of risk perception concerning food additives, a sur vey was conducted with female college students (sophomores) for sources of information that made them feel insecure about food additives. The main source of the information when they were in infancy and at elementar y school was found to be family (mostly mother); that was teachers when they were at middle school and high school, and that was ...

Evaluating and predicting overall process risk using event logs

NARCIS (Netherlands)

Pika, A.; Van Der Aalst, W.M.P.; Wynn, M.T.; Fidge, C.J.; Ter Hofstede, A.H.M.

2016-01-01

Companies standardise and automate their business processes in order to improve process efficiency and minimise operational risks. However, it is difficult to eliminate all process risks during the process design stage due to the fact that processes often run in complex and changeable environments

Advanced of X-ray fluorescence logging technique in China

International Nuclear Information System (INIS)

Zhou Sichun; Ge Liangquan; Lai Wanchang; Yang Qiang

2010-01-01

The paper discuses principle of X-ray fluorescence logging, and introduces advanced of X-ray fluorescence logging technique in China. By 2009, third generation XRF logging instrument has been developed in China, and good logging result has been obtained in Lala copper mine. (authors)

Additional components of risk assessment and their impact on the probability parameter

Directory of Open Access Journals (Sweden)

Piotr Saja

2017-04-01

Full Text Available The article raises the issue of risk assessment and its impact on the quality and safety of work. During the assessment of the turning lathe position additional components associated with the jobs personalization were taken into account. Paragraph 2 item 7 of the Regulation of the Minister of Laborr and Social Policy of 26 September 1997 on general safety regulations defines occupational risk as the likelihood of an adverse event. The authors drew attention to the reality of the accident, which sometimes depends on the predisposition of the employee. It turns out that a correct estimation of the probability of occurrence of the accident to be able to react in a timely way seems extremely important.. This parameter will be assessed more accurately if we take into account a number of additional components resulting from the characteristics of the employee. The results of the personalized assessment of risk may allow appropriate planning of corrective and preventive actions.

Nuisance or Not? Part 2 "Wood" New Additives Make a Difference?

Science.gov (United States)

Vilardi, J. R.

2017-12-01

Nuisance or Not? Part 2"Wood" New Additives Make a Difference? Julian Vilardi Wetumpka Middle School, Wetumpka, USA Last year fuel briquettes were created out of nuisance organisms. Several samples had results better or comparable to the controls. This project is a revision/ extension. Purpose: Find process and formula for a long lasting environmentally friendly biofuel that produces high energy with low byproducts and low cost. Hypotheses: If wisteria is processed to make a biofuel that contains 90% wisteria leaves and vines and 10% pine cones, then a high energy, low byproduct, biofuel will be created. Procedure: Collect, dry and chop material, compress mass, burn test, repeat for every organism. Kudzu was combined in a 70 % kudzu: 30 % wood additive with used cooking oil and pressed into logs. Logs were massed, burned and temperature was recorded and compared to controls. Results: Kudzu had the longest flame but produced smoke. Kudzu logs with recycled cooking oil had less smoke and burned for an hour plus. Conclusions: Wisteria did not compact or have great flammability. Pine cones did not flame well either. This hypothesis was unsupported. All kudzu samples when compacted and combined with any additive were the best biofuel. Kudzu logs with the mixture of wood additives burned the longest and was one of the hottest. The gas chromatograph/emissions tests showed the organic byproducts produced on burning the kudzu logs were less than the accepted range for air quality. These supported the hypothesis and met the purpose of this project. A low cost, environmentally friendly, efficient fuel source was created!

Rill erosion in burned and salvage logged western montane forests: Effects of logging equipment type, traffic level, and slash treatment

Science.gov (United States)

J. W. Wagenbrenner; P. R. Robichaud; R. E. Brown

2016-01-01

Following wildfires, forest managers often consider salvage logging burned trees to recover monetary value of timber, reduce fuel loads, or to meet other objectives. Relatively little is known about the cumulative hydrologic effects of wildfire and subsequent timber harvest using logging equipment. We used controlled rill experiments in logged and unlogged (control)...

Applicability estimation of flowmeter logging for detecting hydraulic pass

International Nuclear Information System (INIS)

Miyakawa, Kimio; Tanaka, Yasuji; Tanaka, Kazuhiro

1997-01-01

Estimation of the hydraulic pass governing hydrogeological structure contributes significantly to the siting HLW repository. Flowmeter logging can detect hydraulic passes by measuring vertical flow velocity of groundwater in the borehole. We reviewed application of this logging in situ. The hydraulic pass was detected with combination of ambient flow logging, with pumping and/or injecting induced flow logging. This application showed that the flowmeter logging detected hydraulic passes conveniently and accurately compared with other hydraulic tests. Hydraulic conductivity by using flowmeter logging was assessed above 10 -6 m/sec and within one order from comparison with injection packer tests. We suggest that appropriate application of the flowmeter logging for the siting is conducted before hydraulic tests because test sections and monitoring sections are decided rationally for procurement of quantitative hydraulic data. (author)

Efficient and Accurate Log-Levy Approximations of Levy-Driven LIBOR Models

DEFF Research Database (Denmark)

Papapantoleon, Antonis; Schoenmakers, John; Skovmand, David

2012-01-01

The LIBOR market model is very popular for pricing interest rate derivatives but is known to have several pitfalls. In addition, if the model is driven by a jump process, then the complexity of the drift term grows exponentially fast (as a function of the tenor length). We consider a Lévy-driven ...... ratchet caps show that the approximations perform very well. In addition, we also consider the log-Lévy approximation of annuities, which offers good approximations for high-volatility regimes....

Computation of distribution of minimum resolution for log-normal distribution of chromatographic peak heights.

Science.gov (United States)

Davis, Joe M

2011-10-28

General equations are derived for the distribution of minimum resolution between two chromatographic peaks, when peak heights in a multi-component chromatogram follow a continuous statistical distribution. The derivation draws on published theory by relating the area under the distribution of minimum resolution to the area under the distribution of the ratio of peak heights, which in turn is derived from the peak-height distribution. Two procedures are proposed for the equations' numerical solution. The procedures are applied to the log-normal distribution, which recently was reported to describe the distribution of component concentrations in three complex natural mixtures. For published statistical parameters of these mixtures, the distribution of minimum resolution is similar to that for the commonly assumed exponential distribution of peak heights used in statistical-overlap theory. However, these two distributions of minimum resolution can differ markedly, depending on the scale parameter of the log-normal distribution. Theory for the computation of the distribution of minimum resolution is extended to other cases of interest. With the log-normal distribution of peak heights as an example, the distribution of minimum resolution is computed when small peaks are lost due to noise or detection limits, and when the height of at least one peak is less than an upper limit. The distribution of minimum resolution shifts slightly to lower resolution values in the first case and to markedly larger resolution values in the second one. The theory and numerical procedure are confirmed by Monte Carlo simulation. Copyright © 2011 Elsevier B.V. All rights reserved.

The nuclear magnetic resonance well logging

International Nuclear Information System (INIS)

Zhang Yumin; Shen Huitang

2003-01-01

In this paper, the characteristic of the nuclear magnetic resonance logging is described at first. Then its development and its principle is presented. Compared with the nuclear magnetic resonance spectrometer, the magnet techniques is the first question that we must solve in the manufacture of the NMR well logging

Pulsed neutron uranium borehole logging with prompt fission neutrons

International Nuclear Information System (INIS)

Bivens, H.M.; Smith, G.W.; Jensen, D.H.

1976-01-01

The gross count natural gamma log normally used for uranium borehole logging is seriously affected by disequilibrium. Methods for the direct measurement of uranium, such as neutron logging, which are not affected by disequilibrium have been the object of considerable effort in recent years. This paper describes a logging system for uranium which uses a small accelerator to generate pulses of 14 MeV neutrons to detect and assay uranium by the measurement of prompt fission neutrons in the epithermal energy range. After an initial feasibility study, a prototype logging probe was built for field evaluation which began in January 1976. Physical and operational characteristics of the prototype probe, the neutron tube-transformer assembly, and the neutron tube are described. In logging operations, only the epithermal prompt fission neutrons detected between 250 microseconds to 2500 microseconds following the excitation neutron pulse are counted. Comparison of corrected neutron logs with the conventional gross count natural gamma logs and the chemical assays of cores from boreholes are shown. The results obtained with this neutron probe clearly demonstrate its advantages over the gross count natural gamma log, although at this time the accuracy of the neutron log assay is not satisfactory under some conditions. The necessary correction factors for various borehole and formation parameters are being determined and, when applied, should improve the assay accuracy

39 CFR 3060.40 - Calculation of the assumed Federal income tax.

Science.gov (United States)

2010-07-01

... Federal income tax. (a) The assumed Federal income tax on competitive products income shall be based on the Postal Service theoretical competitive products enterprise income statement for the relevant year... 39 Postal Service 1 2010-07-01 2010-07-01 false Calculation of the assumed Federal income tax...

Logging while drilling keeps horizontal well on small target

International Nuclear Information System (INIS)

Leake, J.; Shray, F.

1991-01-01

This paper reports that the logging-while-drilling (LWD) measurement to two resistivities of different characteristics had led to a new interpretation method for the analysis of horizontal wells. By logging deep and shallow resistivity in real-time, marker beds were identified to help maintain well bore trajectory. The resistivity measurements were split into vertical and horizontal components to provide additional information of formation evaluation. In 1945, Ark Fuel Co. discovered and began developing the Olla field on the crest of the La Salle arch in La Salle Parish, La. Oil production comes from the Wilcox formation from alluvial sand packages that range in thickness from 3 ft to 120 ft. Now operated by Oxy U.S.A. Inc., Olla field was chosen in 1990 for a horizontal well pilot project. It was hoped that a horizontal well could alleviate water coming in one of the field's more productive sand packages- the 40-ft Cruse sand

High mortality risk among individuals assumed to be TB-negative can be predicted using a simple test

DEFF Research Database (Denmark)

Rabna, Paulo; Andersen, Andreas; Wejse, Christian

2009-01-01

1007 aTBneg individuals who were enrolled from 2004 to 2006; 4983 age-matched controls were followed for comparison. Plasma suPAR levels were measured using the suPARnostic ELISA. Survival was analysed using Cox regression, ROC curves and Kaplan-Meier analysis. RESULTS: After 3 months of follow......-up, mortality was 21 per 100 person-year-observation (PYO) among aTBneg individuals and three per 100 PYO among the control population [mortality rate ratio (MRR) = 6.92 (95% CI 4.48-10.7)]. SuPAR values ranged between 0.9 and 45 ng/ml in aTBneg individuals. A log-linear relationship was found between su......PAR levels linear range, a 1 ng/ml increase was associated with a 46% increase in the mortality rate: MRR = 1.46 (95% CI 1.34-1.59). The area under the ROC curves was 0.88 for HIV-positive individuals and 0.79 for HIV-negative individuals. CONCLUSIONS: Our study showed...

Method and apparatus for neutron induced gamma ray logging for lithology identificaion

International Nuclear Information System (INIS)

Oliver, D.W.; Culver, R.B.

1979-01-01

A pulsed neutron generator in a well logging instrument is pulsed at a clock frequency of 20 KHz. Inelastic scatter gamma rays are detected during a first time interval coinciding with the neutron source being on and capture gamma rays are measured during a second interval subsequent to the end of each neutron burst. Only a single detected pulse, assuming detection occurs, is transmitted during each of the two detection intervals. Sync pulses are generated in the well logging instrument scaled down to a frequency of 200 Hz for transmission to the earth's surface. At the earth's surface, the scaled-down sync pulses are applied to a phase-locked loop system for regenerating the sync pulses to the same frequency as that of the clock frequency used to pulse the neutron source and to open the detection gates in the borehole instrument. The regenerated sync pulses are used in the surface instrumentation to route the pulses occurring in the inelastic interval into one section of a multichannel analyzer memory and the pulses occurring in the capture interval into another section of the multichannel analyzer. The use of memory address decoders, subtractors and ratio circuits enables both a carbon/oxygen ratio and a silicon/calcium ratio to be struck, substantially independent of the chlorine content of the borehole and formation

Neutron logging reliability techniques and apparatus

International Nuclear Information System (INIS)

Johnstone, C.W.

1978-01-01

This invention relates in general to neutron logging of earth formations, and in particular, to novel apparatus and procedures for determining the validity, or reliability, of data derived at least in part by logging neutron characteristics of earth formations and, if desired, for affording verifiably accurate indications of such data

Neutron logging reliability techniques and apparatus

International Nuclear Information System (INIS)

Johnstone, C.W.

1974-01-01

This invention relates in general to neutron logging of earth formations, and in particular, to novel apparatus and procedures for determining the validity, or reliability, of data derived at least in part by logging neutron characteristics of earth formations and, if desired, for affording verifiably accurate indications of such data. (author)

Towards an entropy-based analysis of log variability

DEFF Research Database (Denmark)

Back, Christoffer Olling; Debois, Søren; Slaats, Tijs

2017-01-01

the development of hybrid miners: given a (sub-)log, can we determine a priori whether the log is best suited for imperative or declarative mining? We propose using the concept of entropy, commonly used in information theory. We consider different measures for entropy that could be applied and show through...... experimentation on both synthetic and real-life logs that these entropy measures do indeed give insights into the complexity of the log and can act as an indicator of which mining paradigm should be used....

Towards an Entropy-based Analysis of Log Variability

DEFF Research Database (Denmark)

Back, Christoffer Olling; Debois, Søren; Slaats, Tijs

2018-01-01

the development of hybrid miners: given a log, can we determine a priori whether the log is best suited for imperative or declarative mining? We propose using the concept of entropy, commonly used in information theory. We consider different measures for entropy that could be applied and show through...... experimentation on both synthetic and real-life logs that these entropy measures do indeed give insights into the complexity of the log and can act as an indicator of which mining paradigm should be used....

Inversion of a lateral log using neural networks

International Nuclear Information System (INIS)

Garcia, G.; Whitman, W.W.

1992-01-01

In this paper a technique using neural networks is demonstrated for the inversion of a lateral log. The lateral log is simulated by a finite difference method which in turn is used as an input to a backpropagation neural network. An initial guess earth model is generated from the neural network, which is then input to a Marquardt inversion. The neural network reacts to gross and subtle data features in actual logs and produces a response inferred from the knowledge stored in the network during a training process. The neural network inversion of lateral logs is tested on synthetic and field data. Tests using field data resulted in a final earth model whose simulated lateral is in good agreement with the actual log data

Co-benefits of utilizing logging residues for bioenergy production: The case for East Texas, USA

International Nuclear Information System (INIS)

Gan, Jianbang; Smith, C.T.

2007-01-01

This study evaluated the co-benefits associated with the utilization of logging residues for electricity production in East Texas, USA. The benefits evaluated included the value of CO 2 emissions displaced due to substituting logging residues for coal in power generation, reductions in site preparation costs during forest regeneration, and creation of jobs and income in local communities. Based on the 2004 Forest Inventory Analysis data and a 70% biomass recovery rate, annual recoverable logging residues in East Texas were estimated at 1.3 Mt (dry). These residues, if used for electricity production, would displace about 2.44 Mt of CO 2 , valued at some 9M$ at the current CO 2 price traded at the Chicago Climate Exchange (accounting for about 2% of the stumpage value). Removing logging residues would also save $200-250 ha -1 in site preparation costs. In addition, input-output modeling revealed that logging residue procurement and electricity generation together would have a stronger ripple effect on employment than on output or value-added, with about 1340 new jobs created and 215M$ in value-added generated annually. These results offer new insights into the cost-competitiveness of forest biomass and bioenergy production. (author)

Ordinal Log-Linear Models for Contingency Tables

Directory of Open Access Journals (Sweden)

Brzezińska Justyna

2016-12-01

Full Text Available A log-linear analysis is a method providing a comprehensive scheme to describe the association for categorical variables in a contingency table. The log-linear model specifies how the expected counts depend on the levels of the categorical variables for these cells and provide detailed information on the associations. The aim of this paper is to present theoretical, as well as empirical, aspects of ordinal log-linear models used for contingency tables with ordinal variables. We introduce log-linear models for ordinal variables: linear-by-linear association, row effect model, column effect model and RC Goodman’s model. Algorithm, advantages and disadvantages will be discussed in the paper. An empirical analysis will be conducted with the use of R.

Assumed Probability Density Functions for Shallow and Deep Convection

Directory of Open Access Journals (Sweden)

Steven K Krueger

2010-10-01

Full Text Available The assumed joint probability density function (PDF between vertical velocity and conserved temperature and total water scalars has been suggested to be a relatively computationally inexpensive and unified subgrid-scale (SGS parameterization for boundary layer clouds and turbulent moments. This paper analyzes the performance of five families of PDFs using large-eddy simulations of deep convection, shallow convection, and a transition from stratocumulus to trade wind cumulus. Three of the PDF families are based on the double Gaussian form and the remaining two are the single Gaussian and a Double Delta Function (analogous to a mass flux model. The assumed PDF method is tested for grid sizes as small as 0.4 km to as large as 204.8 km. In addition, studies are performed for PDF sensitivity to errors in the input moments and for how well the PDFs diagnose some higher-order moments. In general, the double Gaussian PDFs more accurately represent SGS cloud structure and turbulence moments in the boundary layer compared to the single Gaussian and Double Delta Function PDFs for the range of grid sizes tested. This is especially true for small SGS cloud fractions. While the most complex PDF, Lewellen-Yoh, better represents shallow convective cloud properties (cloud fraction and liquid water mixing ratio compared to the less complex Analytic Double Gaussian 1 PDF, there appears to be no advantage in implementing Lewellen-Yoh for deep convection. However, the Analytic Double Gaussian 1 PDF better represents the liquid water flux, is less sensitive to errors in the input moments, and diagnoses higher order moments more accurately. Between the Lewellen-Yoh and Analytic Double Gaussian 1 PDFs, it appears that neither family is distinctly better at representing cloudy layers. However, due to the reduced computational cost and fairly robust results, it appears that the Analytic Double Gaussian 1 PDF could be an ideal family for SGS cloud and turbulence

Mechanics of log calibration

International Nuclear Information System (INIS)

Waller, W.C.; Cram, M.E.; Hall, J.E.

1975-01-01

For any measurement to have meaning, it must be related to generally accepted standard units by a valid and specified system of comparison. To calibrate well-logging tools, sensing systems are designed which produce consistent and repeatable indications over the range for which the tool was intended. The basics of calibration theory, procedures, and calibration record presentations are reviewed. Calibrations for induction, electrical, radioactivity, and sonic logging tools will be discussed. The authors' intent is to provide an understanding of the sources of errors, of the way errors are minimized in the calibration process, and of the significance of changes in recorded calibration data

Data Cleaning Methods for Client and Proxy Logs

NARCIS (Netherlands)

Weinreich, H.; Obendorf, H.; Herder, E.; Edmonds, A.; Hawkey, K.; Kellar, M.; Turnbull, D.

2006-01-01

In this paper we present our experiences with the cleaning of Web client and proxy usage logs, based on a long-term browsing study with 25 participants. A detailed clickstream log, recorded using a Web intermediary, was combined with a second log of user interface actions, which was captured by a

Financial and Economic Analysis of Reduced Impact Logging

Science.gov (United States)

Tom Holmes

2016-01-01

Concern regarding extensive damage to tropical forests resulting from logging increased dramatically after World War II when mechanized logging systems developed in industrialized countries were deployed in the tropics. As a consequence, tropical foresters began developing logging procedures that were more environmentally benign, and by the 1990s, these practices began...

Using Web Server Logs in Evaluating Instructional Web Sites.

Science.gov (United States)

Ingram, Albert L.

2000-01-01

Web server logs contain a great deal of information about who uses a Web site and how they use it. This article discusses the analysis of Web logs for instructional Web sites; reviews the data stored in most Web server logs; demonstrates what further information can be gleaned from the logs; and discusses analyzing that information for the…

Tucker Wireline Open Hole Wireline Logging; FINAL

International Nuclear Information System (INIS)

Milliken, M.

2002-01-01

The Tucker Wireline unit ran a suite of open hole logs right behind the RMOTC logging contractor for comparison purposes. The tools included Dual Laterolog, Phased Induction, BHC Sonic, and Density-Porosity

Monte Carlo Numerical Models for Nuclear Logging Applications

Directory of Open Access Journals (Sweden)

Fusheng Li

2012-06-01

Full Text Available Nuclear logging is one of most important logging services provided by many oil service companies. The main parameters of interest are formation porosity, bulk density, and natural radiation. Other services are also provided from using complex nuclear logging tools, such as formation lithology/mineralogy, etc. Some parameters can be measured by using neutron logging tools and some can only be measured by using a gamma ray tool. To understand the response of nuclear logging tools, the neutron transport/diffusion theory and photon diffusion theory are needed. Unfortunately, for most cases there are no analytical answers if complex tool geometry is involved. For many years, Monte Carlo numerical models have been used by nuclear scientists in the well logging industry to address these challenges. The models have been widely employed in the optimization of nuclear logging tool design, and the development of interpretation methods for nuclear logs. They have also been used to predict the response of nuclear logging systems for forward simulation problems. In this case, the system parameters including geometry, materials and nuclear sources, etc., are pre-defined and the transportation and interactions of nuclear particles (such as neutrons, photons and/or electrons in the regions of interest are simulated according to detailed nuclear physics theory and their nuclear cross-section data (probability of interacting. Then the deposited energies of particles entering the detectors are recorded and tallied and the tool responses to such a scenario are generated. A general-purpose code named Monte Carlo N– Particle (MCNP has been the industry-standard for some time. In this paper, we briefly introduce the fundamental principles of Monte Carlo numerical modeling and review the physics of MCNP. Some of the latest developments of Monte Carlo Models are also reviewed. A variety of examples are presented to illustrate the uses of Monte Carlo numerical models

Time-lapse cased hole reservoir evaluation based on the dual-detector neutron lifetime log: the CHES II approach

International Nuclear Information System (INIS)

DeVries, M.R.; Fertl, W.

1977-01-01

A newly developed cased hole analysis technique provides detailed information on (1) reservoir rock properties, such as porosity, shaliness, and formation permeability, (2) reservoir fluid saturation, (3) distinction of oil and gas pays, (4) state of reservoir depletion, such as cumulative hydrocarbon-feet at present time and cumulative hydrocarbon-feet already depleted (e.g., the sum of both values then giving the cumulative hydrocarbon-feet originally present), and (5) monitoring of hydrocarbon/water and gas/oil contacts behind pipe. The basic well log data required for this type of analysis include the Dual-Detector Neutron Lifetime Log, run in casing at any particular time in the life of a reservoir, and the initial open-hole resistivity log. In addition, porosity information from open-hole porosity log(s) or core data is necessary. Field examples from several areas are presented and discussed in the light of formation reservoir and hydrocarbon production characteristics

Controlled sliding of logs downhill by chute system integrated with portable winch and synthetic rope

Directory of Open Access Journals (Sweden)

Neşe Gülci

2016-01-01

Full Text Available Over 80% of wood extraction operations have been performed by conventional methods in Turkey. Conventional methods include skidding or sliding of logs mainly by man and animal power, which poses problems in terms of technical, economical, environmental, and ergonomic aspects. Skidding wood on plastic chutes has been implemented in limited numbers of logging applications in recent years, and provides important advantages such as reducing environmental damages and minimizing the value and volume loss of transported wood products. In this study, a chute system integrated with a mobile winch was developed for controlled sliding of large diameter logs downhill. In addition, synthetic ropes rather than steel cables were used to pull log products, resulting in a lower weight and more efficient extraction system. The system was tested on a sample wood production operation in Çınarpınar Forest Enterprise Chief of Kahramanmaraş Forest Enterprise Directorate. In the study, productivity analysis of chute system was performed and its ecological impacts were evaluated. During controlled sliding of logs downhill, the highest productivity (10.01 m3/hour was reached in the fourth chute system characterized as 36 m in length and 70% ground slope. One of the main factors that affected the productivity of chute system was the controlled sliding time of the logs. It was found that residual stand damage was very limited during controlled sliding operations.

Estimation of the fustal diameter on the central knotty cylinder in oak basal logs, Chile

Directory of Open Access Journals (Sweden)

Patricio Corvalán Vera

2018-01-01

Full Text Available In order to determine the diameter of the central knotted cylinder both alive and dead, a total of 60 trees belonging to the upper quartile of diametric classes in unmanaged renewal of N. obliqua from the Maule foothills were sampled. It is assumed that these are determined by the lowest living and dead branch present in tree height, respectively. We analyzed the relationships between the diameter of the central knotty cylinder, and the diameters at the lower end of logs 1.2, 2.4 and 3.6 m above the stump, the normal diameter and the insertion height of the first branch. From the analysis it is deduced that: i the diameter of the live and dead central knotted cylinder increases linearly with the normal diameter of the tree, ii that the diameter at the smaller end of the logs increases as it does and decreases as increases in height above the ground and iii that the fustal diameter on the dead central knotty cylinder increases linearly with the normal diameter and the insertion height of the lowest dead branch of the tree, allowing to determine the zone of occlusion of the knots of the tree.

PUMA Internet Task Logging Using the IDAC-1

Directory of Open Access Journals (Sweden)

K. N. Tarchanidis

2014-08-01

Full Text Available This project uses an IDAC-1 board to sample the joint angle position of the PUMA 76 1 robot and log the results on a computer. The robot is at the task location and the logging computer is located in a different one. The task the robot is performing is based on a Pseudo Stereo Vision System (PSVS. Internet is the transport media. The protocol used in this project is UDP/IP. The actual angle is taken straight from the PUMA controller. High-resolution potentiometers are connected on each robot joint and are buffered and sampled as potential difference on an A/D converter integrated on the IDAC-1. The logging computer through the Internet acting as client asks for the angle set, the IDAC-1 responds as server with the 10-bit resolution sampling of the joint position. The whole task is logged in a file on the logging computer. This application can give the ability to the Internet user to monitor and log the robot tasks anywhere in the Word Wide Web (www.

Neutron--neutron logging

International Nuclear Information System (INIS)

Allen, L.S.

1977-01-01

A borehole logging tool includes a steady-state source of fast neutrons, two epithermal neutron detectors, and two thermal neutron detectors. A count rate meter is connected to each neutron detector. A first ratio detector provides an indication of the porosity of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two epithermal neutron detectors. A second ratio detector provides an indication of both porosity and macroscopic absorption cross section of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two thermal neutron detectors. By comparing the signals of the two ratio detectors, oil bearing zones and salt water bearing zones within the formation being logged can be distinguished and the amount of oil saturation can be determined. 6 claims, 2 figures

Synthetic rope applications in Appalachian logging

Science.gov (United States)

Ben D. Spong; Jingxin Wang

2008-01-01

New ultra-high molecular weight polyethylene rope has shown good results as a replacement for wire rope in logging applications in the western United States. A single case study trial was performed in Appalachian forest conditions to assess the appropriateness of this technology for hardwood logging applications. The study focused on use of the rope in West Virginia...

A survey of animal-powered logging in Alabama

Science.gov (United States)

Christopher W. Toms; Mark R. Dubois; John C. Bliss; John H. Wilhoit; Robert B. Rummer

2001-01-01

In a state with a very large, highly mechanized timber harvesting industry, animal-powered logging still occupies a niche in Alabama as a small-scale harvesting alternative. This article summarizes the results from a study that examined the extent of animal logging in Alabama. We investigated this topic by asking who is logging with animals, where are they working,...

Sediment transport and soil disturbance after postfire logging.

Science.gov (United States)

James D. McIver

2003-01-01

Recently there has been considerable debate on the practice of postfire logging, in which burned forests are entered soon after fire to recover commercially valuable trees. Proponents of the practice argue that postfire logging is part of a 'restoration package' that can be used to control erosion (e.g., contour logging) and can help to mitigate costs of...

Use of pulsed neutron-neutron logging, thermal neutron-neutron logging, and gamma logging methods in classification for sand-clay sediments of Lower Cretaceous in Prikumsk oil-and-gas region according to filtration-capacitance characteristics

International Nuclear Information System (INIS)

Maksimenko, A.N.; Basin, Ya.N.; Novgorodov, V.A.

1974-01-01

To isolate reservoirs, the formation and deformation penetration zone parameters are used. They are estimated according to the false oil saturation factor and the time of the penetration zone deformation which are determined from the complex exploration of cased wells using the pulse neutron logging, thermal neutron-neutron logging and gamma logging techniques

Bowing-reactivity trends in EBR-II assuming zero-swelling ducts

International Nuclear Information System (INIS)

Meneghetti, D.

1994-01-01

Predicted trends of duct-bowing reactivities for the Experimental Breeder Reactor II (EBR-II) are correlated with predicted row-wise duct deflections assuming use of idealized zero-void-swelling subassembly ducts. These assume no irradiation induced swellings of ducts but include estimates of the effects of irradiation-creep relaxation of thermally induced bowing stresses. The results illustrate the manners in which at-power creeps may affect subsequent duct deflections at zero power and thereby the trends of the bowing component of a subsequent power reactivity decrement

Supply of Rubber Wood Log in Malaysia

OpenAIRE

Noraida, A. W.; Abdul-Rahim, A. S.

2014-01-01

Issue on shortage of raw material for wood processing solved by discovery of rubber wood log as one of the substitutes the natural log. This paper examines the supply of rubber wood log in Malaysia. We employ ARDL Bound Approach Test and time series data from 1980 to 2010 which represented the whole Malaysia are used to achieve the established objectives. The result shown, in the long run harvested area and wages have 1% and 10% significant level respectively. While in the short run, there wa...

Screening efficacy of a simplified logMAR chart

Directory of Open Access Journals (Sweden)

Naganathan Muthuramalingam

2016-04-01

Aim: This study evaluates the efficacy of a simplified logMAR chart, designed for VA testing over the conventional Snellen chart, in a school-based vision-screening programme. Methods: We designed a simplified logMAR chart by employing the principles of the Early Treatment Diabetic Retinopathy Study (ETDRS chart in terms of logarithmic letter size progression, inter-letter spacing, and inter-line spacing. Once the simplified logMAR chart was validated by students in the Elite school vision-screening programme, we set out to test the chart in 88 primary and middle schools in the Tiruporur block of Kancheepuram district in Tamil Nadu. One school teacher in each school was trained to screen a cross-sectional population of 10 354 primary and secondary school children (girls: 5488; boys: 4866 for VA deficits using a new, simplified logMAR algorithm. An experienced paediatric optometrist was recruited to validate the screening methods and technique used by the teachers to collect the data. Results: The optometrist screened a subset of 1300 school children from the total sample. The optometrist provided the professional insights needed to validate the clinical efficacy of the simplified logMAR algorithm and verified the reliability of the data collected by the teachers. The mean age of children sampled for validation was 8.6 years (range: 9–14 years. The sensitivity and the specificity of the simplified logMAR chart when compared to the standard logMAR chart were found to be 95% and 98%, respectively. Kappa value was 0.97. Sensitivity of the teachers’ screening was 66.63% (95% confidence interval [CI]: 52.73–77.02 and the specificity was 98.33% (95% CI: 97.49–98.95. Testing of VA was done under substandard illumination levels in 87% of the population. A total of 10 354 children were screened, 425 of whom were found to have some form of visual and/or ocular defect that was identified by the teacher or optometrist. Conclusion: The simplified logMAR testing algorithm

Environmental corrections of a dual-induction logging while drilling tool in vertical wells

Science.gov (United States)

Kang, Zhengming; Ke, Shizhen; Jiang, Ming; Yin, Chengfang; Li, Anzong; Li, Junjian

2018-04-01

With the development of Logging While Drilling (LWD) technology, dual-induction LWD logging is not only widely applied in deviated wells and horizontal wells, but it is used commonly in vertical wells. Accordingly, it is necessary to simulate the response of LWD tools in vertical wells for logging interpretation. In this paper, the investigation characteristics, the effects of the tool structure, skin effect and drilling environment of a dual-induction LWD tool are simulated by the three-dimensional (3D) finite element method (FEM). In order to closely simulate the actual situation, real structure of the tool is taking into account. The results demonstrate that the influence of the background value of the tool structure can be eliminated. The values of deducting the background of a tool structure and analytical solution have a quantitative agreement in homogeneous formations. The effect of measurement frequency could be effectively eliminated by chart of skin effect correction. In addition, the measurement environment, borehole size, mud resistivity, shoulder bed, layer thickness and invasion, have an effect on the true resistivity. To eliminate these effects, borehole correction charts, shoulder bed correction charts and tornado charts are computed based on real tool structure. Based on correction charts, well logging data can be corrected automatically by a suitable interpolation method, which is convenient and fast. Verified with actual logging data in vertical wells, this method could obtain the true resistivity of formation.

Anticardiolipin antibodies in proliferative diabetic retinopathy: An additional risk factor

International Nuclear Information System (INIS)

Shahin, Maha; ElDiasty, Amany M; Mabed, Mohamed

2009-01-01

To report the prevalence of anticardiolipin antibodies in patients with proliferative diabetic retinopathy (PDR) having high-risk criteria (HRC). Diabetic patients having PDR with HRC and diabetics free of retinopathy were compared for the presence of anticardiolipin antibodies. Among the 34 patients, 6 (17.7%) of diabetics having PDR with HRC were positive for anticardiolipin antibodies. There was no significant association of aCL antibodies with sex or type of diabetes. Using Pearson's correlation test, no significant associations of aCL antibodies with duration of diabetes or age of patients were found. All patients who were positive for anticardiolipin antibodies had PDR with HRC. The difference was statistically significant. Presence of anticardiolipin antibodies may represent an additional risk factor for PDR. (author)

Assuming a Pharmacy Organization Leadership Position: A Guide for Pharmacy Leaders.

Science.gov (United States)

Shay, Blake; Weber, Robert J

2015-11-01

Important and influential pharmacy organization leadership positions, such as president, board member, or committee chair, are volunteer positions and require a commitment of personal and professional time. These positions provide excellent opportunities for leadership development, personal promotion, and advancement of the profession. In deciding to assume a leadership position, interested individuals must consider the impact on their personal and professional commitments and relationships, career planning, employer support, current and future department projects, employee support, and personal readiness. This article reviews these factors and also provides an assessment tool that leaders can use to determine their readiness to assume leadership positions. By using an assessment tool, pharmacy leaders can better understand their ability to assume an important and influential leadership position while achieving job and personal goals.

Effects of reduced-impact logging on fish assemblages in central Amazonia.

Science.gov (United States)

Dias, Murilo S; Magnusson, William E; Zuanon, Jansen

2010-02-01

In Amazonia reduced-impact logging, which is meant to reduce environmental disturbance by controlling stem-fall directions and minimizing construction of access roads, has been applied to large areas containing thousands of streams. We investigated the effects of reduced-impact logging on environmental variables and the composition of fish in forest streams in a commercial logging concession in central Amazonia, Amazonas State, Brazil. To evaluate short-term effects, we sampled 11 streams before and after logging in one harvest area. We evaluated medium-term effects by comparing streams in 11 harvest areas logged 1-8 years before the study with control streams in adjacent areas. Each sampling unit was a 50-m stream section. The tetras Pyrrhulina brevis and Hemigrammus cf. pretoensis had higher abundances in plots logged > or =3 years before compared with plots logged fish composition did not differ two months before and immediately after reduced-impact logging. Temperature and pH varied before and after logging, but those differences were compatible with normal seasonal variation. In the medium term, temperature and cover of logs were lower in logged plots. Differences in ordination scores on the basis of relative fish abundance between streams in control and logged areas changed with time since logging, mainly because some common species increased in abundance after logging. There was no evidence of species loss from the logging concession, but differences in log cover and ordination scores derived from relative abundance of fish species persisted even after 8 years. For Amazonian streams, reduced-impact logging appears to be a viable alternative to clear-cut practices, which severely affect aquatic communities. Nevertheless, detailed studies are necessary to evaluated subtle long-term effects.

Expanded Occupational Safety and Health Administration 300 log as metric for bariatric patient-handling staff injuries.

Science.gov (United States)

Randall, Stephen B; Pories, Walter J; Pearson, Amy; Drake, Daniel J

2009-01-01

Mobilization of morbidly obese patients poses significant physical challenges to healthcare providers. The purpose of this study was to examine the staff injuries associated with the patient handling of the obese, to describe a process for identifying injuries associated with their mobilization, and to report on the need for safer bariatric patient handling. We performed our study at a 761-bed, level 1 trauma center affiliated with a U.S. medical school. The hospital's Occupational Safety and Health Administration (OSHA) 300 log was expanded to the "E-OSHA 300 log" to specifically identify injuries the staff attributed to bariatric patient handling. The 2007 E-OSHA 300 log was analyzed to identify and describe the frequency, severity, and nature of bariatric versus nonbariatric patient handling injuries. The analyses revealed that during 2007, although patients with a body mass index of > or =35 kg/m(2) constituted patient population, 29.8% of staff injuries related to patient handling were linked to working with a bariatric patient. Bariatric patient handling accounted for 27.9% of all lost workdays and 37.2% of all restricted workdays associated with patient handling. Registered nurses and nursing assistants accounted for 80% of the injuries related to bariatric patient handling. Turning and repositioning the patient in bed accounted for 31% of the injuries incurred. The E-OSHA 300 log narratives revealed that staff injuries associated with obese and nonobese patient handling were usually performed using biomechanics and not equipment. Manual mobilization of morbidly obese patients increases the risk of caregiver injury. A tracking indicator on the OSHA 300 logs for staff injury linked to a bariatric patient would provide the ability to compare obese and nonobese patient handling injuries. The E-OSHA 300 log provides a method to identify the frequency, severity, and nature of caregiver injury during mobilization of the obese. Understanding the heightened risk of

Logging methods and peeling of Aspen

Science.gov (United States)

T. Schantz-Hansen

1948-01-01

The logging of forest products is influenced by many factors, including the size of the trees, density of the stand, the soundness of the trees, size of the area logged, topography and soil, weather conditions, the degree of utilization, the skill of the logger and the equipment used, the distance from market, etc. Each of these factors influences not only the method...

Log Distribution, Persistence, and Geomorphic Function in Streams and Rivers, in the Northeastern U.S.

Science.gov (United States)

St Pierre, L.; Burchsted, D.; Warren, D.

2015-12-01

Large wood provides critical ecosystem services such as fish habitat, temperature regulation and bank stabilization. In the northeastern U.S., the distribution of large wood is documented; however, there is little understanding of the movement, longevity and geomorphic function. This research examines the hypothesis that tree species control the persistence and geomorphic function of instream wood in the Appalachian region of the northeastern U.S. To do this, we assessed size, location, and species of logs in New Hampshire rivers, including locations in the White Mountain National Forest (WMNF) where these data were collected ten years ago. We expanded the previous dataset to include assessment of geomorphic function, including creation of diversion channels, pool formation, and sediment storage, among others. We also added new sites in the WMNF and sites on a large rural river in southwestern NH to increase the range of geomorphic variables to now include: confined and unconfined channels; 1st to 4th order streams; low to high gradient; meandering, multithreaded, and straight channels; and land use such as historic logging, modern agriculture, and post-agricultural abandonment. At each study site, we located all large logs (>10cm diameter, > 1m length) and log jams (>3 accumulated logs that provide a geomorphic function) along 100m-700m reaches. We marked each identified log with a numbered tag and recorded species, diameter, length, orientation, GPS location, tag number, and photographs. We assessed function and accumulation, decay, stability, and source classes for each log. Along each reach we measured riparian forest composition and structure and channel width. Preliminary analysis suggests that tree species significantly affects the function of logs: yellow birch and American sycamore are highly represented. Additionally, geomorphic setting also plays a primary role, where unconfined reaches have large logs that provide important functions; those functions

Construction and validation of a Tamil logMAR chart.

Science.gov (United States)

Varadharajan, Srinivasa; Srinivasan, Krithica; Kumaresan, Brindha

2009-09-01

To design, construct and validate a new Tamil logMAR visual acuity chart based on current recommendations. Ten Tamil letters of equal legibility were identified experimentally and were used in the chart. Two charts, one internally illuminated and one externally illuminated, were constructed for testing at 4 m distance. The repeatability of the two charts was tested. For validation, the two charts were compared with a standard English logMAR chart (ETDRS). When compared to the ETDRS chart, a difference of 0.06 +/- 0.07 and 0.07 +/- 0.07 logMAR was found for the internally and externally illuminated charts respectively. Limits of agreement between the internally illuminated Tamil logMAR chart and ETDRS chart were found to be (-0.08, 0.19), and (-0.07, 0.20) for the externally illuminated chart. The test - retest results showed a difference of 0.02 +/- 0.04 and 0.02 +/- 0.06 logMAR for the internally and externally illuminated charts respectively. Limits of agreement for repeated measurements for the internally illuminated Tamil logMAR chart were found to be (-0.06, 0.10), and (-0.10, 0.14) for the externally illuminated chart. The newly constructed Tamil logMAR charts have good repeatability. The difference in visual acuity scores between the newly constructed Tamil logMAR chart and the standard English logMAR chart was within acceptable limits. This new chart can be used for measuring visual acuity in the literate Tamil population.

Dual detector neutron lifetime log: theory and practical applications

International Nuclear Information System (INIS)

Serpas, C.J.; Wichmann, P.A.; Fertl, W.H.; DeVries, M.R.; Rndall, R.R.

1977-01-01

The Neutron Lifetime Log instrumentation has continued to evolve and now is equipped with dual detectors for increased ease in gas detection and also a ratio response for a simultaneous porosity determination. A good deal of experimentation was involved to minimize both lithology and salinity effects on the porosity indication. This paper contains a discussion of the theory and concepts related to the application of the Dual Detector Neutron Lifetime Log (DNLL). It is important to note that with these advances the recording of thermal neutron capture cross section (Σ) remains consistent with the past measurements of earlier generations of instruments as the most accurate determination of this parameter. A number of field examples of the newly logged results are shown. These field cases include Dual Detector NLL's run thru the drill strings of highly deviated holes when difficulties were encountered in getting conventional open hole logs to bottom, logs thru open perforations and hot radioactive zones, comparisons of the large and small diameter instruments, logs with anomalous fluids in the annulus, logs thru multiple casing strings, and a number of other examples

Extracting the Textual and Temporal Structure of Supercomputing Logs

Energy Technology Data Exchange (ETDEWEB)

Jain, S; Singh, I; Chandra, A; Zhang, Z; Bronevetsky, G

2009-05-26

Supercomputers are prone to frequent faults that adversely affect their performance, reliability and functionality. System logs collected on these systems are a valuable resource of information about their operational status and health. However, their massive size, complexity, and lack of standard format makes it difficult to automatically extract information that can be used to improve system management. In this work we propose a novel method to succinctly represent the contents of supercomputing logs, by using textual clustering to automatically find the syntactic structures of log messages. This information is used to automatically classify messages into semantic groups via an online clustering algorithm. Further, we describe a methodology for using the temporal proximity between groups of log messages to identify correlated events in the system. We apply our proposed methods to two large, publicly available supercomputing logs and show that our technique features nearly perfect accuracy for online log-classification and extracts meaningful structural and temporal message patterns that can be used to improve the accuracy of other log analysis techniques.

Cased-hole log analysis and reservoir performance monitoring

CERN Document Server

Bateman, Richard M

2015-01-01

This book addresses vital issues, such as the evaluation of shale gas reservoirs and their production. Topics include the cased-hole logging environment, reservoir fluid properties; flow regimes; temperature, noise, cement bond, and pulsed neutron logging; and casing inspection. Production logging charts and tables are included in the appendices. The work serves as a comprehensive reference for production engineers with upstream E&P companies, well logging service company employees, university students, and petroleum industry training professionals. This book also: ·       Provides methods of conveying production logging tools along horizontal well segments as well as measurements of formation electrical resistivity through casing ·       Covers new information on fluid flow characteristics in inclined pipe and provides new and improved nuclear tool measurements in cased wells ·       Includes updates on cased-hole wireline formation testing  

Log-concave Probability Distributions: Theory and Statistical Testing

DEFF Research Database (Denmark)

An, Mark Yuing

1996-01-01

This paper studies the broad class of log-concave probability distributions that arise in economics of uncertainty and information. For univariate, continuous, and log-concave random variables we prove useful properties without imposing the differentiability of density functions. Discrete...... and multivariate distributions are also discussed. We propose simple non-parametric testing procedures for log-concavity. The test statistics are constructed to test one of the two implicati ons of log-concavity: increasing hazard rates and new-is-better-than-used (NBU) property. The test for increasing hazard...... rates are based on normalized spacing of the sample order statistics. The tests for NBU property fall into the category of Hoeffding's U-statistics...

Exploration of spatio-temporal patterns of students' movement in field trip by visualizing the log data

Science.gov (United States)

Cho, Nahye; Kang, Youngok

2018-05-01

A numerous log data in addition to user input data are being generated as mobile and web users continue to increase recently, and the studies in order to explore the patterns and meanings of various movement activities by making use of these log data are also rising rapidly. On the other hand, in the field of education, people have recognized the importance of field trip as the creative education is highlighted. Also, the examples which utilize the mobile devices in the field trip in accordance to the development of information technology are growing. In this study, we try to explore the patterns of student's activity by visualizing the log data generated from high school students' field trip with mobile device.

Stand structure, composition and illegal logging in selectively logged production forests of Myanmar: Comparison of two compartments subject to different cutting frequency

Directory of Open Access Journals (Sweden)

Tual Cin Khai

2016-07-01

Full Text Available Appropriate cutting cycles and annual allowable cuts are crucial to ensure sustainability of tropical selective logging, but there have been limited field data to verify long-term effects of different cutting cycles. This study reveals some evidence of forest degradation in selectively logged production forests of Myanmar, which are subject to inappropriate cutting frequency. We compared stand structure, commercial species composition, and incidence of illegal logging between two compartments with low (LCF; 1 time and high (HCF; 5 times cutting frequency over a recent 18 years. Prior to the latest cutting, LCF had 176 trees ha−1 with an inverted-J shape distribution of diameter at breast height (DBH, including a substantial amount of teak (Tectona grandis and other commercially important species in each DBH class. HCF prior to the latest cut had only 41 trees ha−1 without many commercially important species. At HCF, nearly half the standing trees of various species and size were illegally cut following legal operations; this was for charcoal making in nearby kilns. At LCF, two species, teak and Xylia xylocarpa, were cut illegally and sawn for timber on the spot. More extensive and systematic surveys are needed to generalize the findings of forest degradation and illegal logging. However, our study calls for urgent reconsideration of logging practices with high cutting frequency, which can greatly degrade forests with accompanying illegal logging, and for rehabilitating strongly degraded, bamboo-dominated forests. To reduce illegal logging, it would be important to pay more attention on a MSS regulation stating that logging roads should be destroyed after logging operations.

Western tight gas sands advanced logging workshop proceedings

Energy Technology Data Exchange (ETDEWEB)

Jennings, J B; Carroll, Jr, H B [eds.

1982-04-01

An advanced logging research program is one major aspect of the Western Tight Sands Program. Purpose of this workshop is to help BETC define critical logging needs for tight gas sands and to allow free interchange of ideas on all aspects of the current logging research program. Sixteen papers and abstracts are included together with discussions. Separate abstracts have been prepared for the 12 papers. (DLC)

Pulsed neutron porosity logging system

International Nuclear Information System (INIS)

Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

1978-01-01

An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations and, during the bursts, the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

Log Usage Analysis: What it Discloses about Use, Information Seeking and Trustworthiness

Directory of Open Access Journals (Sweden)

David Nicholas

2014-06-01

Full Text Available The Trust and Authority in Scholarly Communications in the Light of the Digital Transition research project1 was a study which investigated the behaviours and attitudes of academic researchers as producers and consumers of scholarly information resources in respect to how they determine authority and trustworthiness. The research questions for the study arose out of CIBER’s studies of the virtual scholar. This paper focuses on elements of this study, mainly an analysis of a scholarly publisher’s usage logs, which was undertaken at the start of the project in order to build an evidence base, which would help calibrate the main methodological tools used by the project: interviews and questionnaire. The specific purpose of the log study was to identify and assess the digital usage behaviours that potentially raise trustworthiness and authority questions. Results from the self-report part of the study were additionally used to explain the logs. The main findings were that: 1 logs provide a good indicator of use and information seeking behaviour, albeit in respect to just a part of the information seeking journey; 2 the ‘lite’ form of information seeking behaviour observed in the logs is a sign of users trying to make their mind up in the face of a tsunami of information as to what is relevant and to be trusted; 3 Google and Google Scholar are the discovery platforms of choice for academic researchers, which partly points to the fact that they are influenced in what they use and read by ease of access; 4 usage is not a suitable proxy for quality. The paper also provides contextual data from CIBER’s previous studies.

Fire Risk Scoping Study: Investigation of nuclear power plant fire risk, including previously unaddressed issues

International Nuclear Information System (INIS)

Lambright, J.A.; Nowlen, S.P.; Nicolette, V.F.; Bohn, M.P.

1989-01-01

An investigation of nuclear power plant fire risk issues raised as a result of the USNRC sponsored Fire Protection Research Program at Sandia National Laboratories has been performed. The specific objectives of this study were (1) to review and requantify fire risk scenarios from four fire probabilistic risk assessments (PRAs) in light of updated data bases made available as a result of USNRC sponsored Fire Protection Research Program and updated computer fire modeling capabilities, (2) to identify potentially significant fire risk issues that have not been previously addressed in a fire risk context and to quantify the potential impact of those identified fire risk issues where possible, and (3) to review current fire regulations and plant implementation practices for relevance to the identified unaddressed fire risk issues. In performance of the fire risk scenario requantifications several important insights were gained. It was found that utilization of a more extensive operational experience base resulted in both fire occurrence frequencies and fire duration times (i.e., time required for fire suppression) increasing significantly over those assumed in the original works. Additionally, some thermal damage threshold limits assumed in the original works were identified as being nonconservative based on more recent experimental data. Finally, application of the COMPBRN III fire growth model resulted in calculation of considerably longer fire damage times than those calculated in the original works using COMPBRN I. 14 refs., 2 figs., 16 tabs

How Afghanistan Can Assume Ownership for the Ongoing Conflict

National Research Council Canada - National Science Library

Horn, Sr, John M

2008-01-01

In view of United States global commitments and larger Global War on Terror (GWOT) strategy, the ultimate security goal in Afghanistan must be for the Afghans to assume ownership of the counterinsurgency struggle...

Specific features of well logging of boreholes drilled on electrical nonconducting solutions

International Nuclear Information System (INIS)

Ruchkin, A.F.; Fomenko, V.G.

1978-01-01

Methods for identification of permeable strata and determination of their porosity and oil-gas saturation using standard combination of geophysical investigations in the boreholes drilled with nonaqueous and inert drilling fluids are considered. Geophysical combination consists of the methods indications of which are independent on electrical conductivity of drilling fluids. They are all modifications of radioactivity logging (gamma logging, neutron logging, neutron-gamma logging, gamma-gamma logging, pulsed neutron logging, nuclear-magnetic logging), acoustic logging and thermal logging

The role of research and development work on the production costs of logging residue chips

International Nuclear Information System (INIS)

Nousiainen, I.

1998-01-01

Purchase of logging residue chips in the early 80s was mainly based on production chains in which the residues were collected with load-carrying tractors at the road-side storage, from which it was chipped or crushed directly into the trailer of a waiting lorry. Six new production chains were developed in the national Bioenergy Research Programme. Three of these are now commercial. Kotimaiset Energiat Pekka Lahti Ky has developed, on the basis of a traditional logging residue production chain, a high-efficiency EVOLUTION intermediate storage chipper, suitable for chipping of logging residues. Oy Logset Ab has developed a new type of lot-chipping chip-harvester, the LOGSET 536C. Nested containers have also been developed for the lot-chipping method. MOHA multi-purpose chipper, in which the chipping and lorry-transportation of chips have been integrated, has also been developed as a part of the research programme. In addition to these, a chipper-container lorry combination, transportation of complete logging residues, and whole- tree skidding have been developed in the project for production of logging residue chips. In the beginning of the 80s the production costs of logging residues at the place of utilization were about 52 FIM/MWh, and the average transportation distance 50 km. In 1992 the production costs, 64 FIM/MWh at the distance of 100 km, was significantly higher than the price of alternative fuels. The lowest production cost level, obtainable by the developed methods is 46 FIM/MWh

Water saturation in shaly sands: logging parameters from log-derived values

International Nuclear Information System (INIS)

Miyairi, M.; Itoh, T.; Okabe, F.

1976-01-01

The methods are presented for determining the relation of porosity to formation factor and that of true resistivity of formation to water saturation, which were investigated through the log interpretation of one of the oil and gas fields of northern Japan Sea. The values of the coefficients ''a'' and ''m'' in porosity-formation factor relation are derived from cross-plot of porosity and resistivity of formation corrected by clay content. The saturation exponent ''n'' is determined from cross-plot of porosity and resistivity index on the assumption that the product of porosity and irreducible water saturation is constant. The relation of porosity to irreducible water saturation is also investigated from core analysis. The new logging parameters determined from the methods, a = 1, m = 2, n = 1.4, improved the values of water saturation by 6 percent in average, and made it easy to distinguish the points which belong to the productive zone and ones belonging to the nonproductive zone

Nut Production in Bertholletia excelsa across a Logged Forest Mosaic: Implications for Multiple Forest Use

Science.gov (United States)

Rockwell, Cara A.; Guariguata, Manuel R.; Menton, Mary; Arroyo Quispe, Eriks; Quaedvlieg, Julia; Warren-Thomas, Eleanor; Fernandez Silva, Harol; Jurado Rojas, Edwin Eduardo; Kohagura Arrunátegui, José Andrés Hideki; Meza Vega, Luis Alberto; Revilla Vera, Olivia; Valera Tito, Jonatan Frank; Villarroel Panduro, Betxy Tabita; Yucra Salas, Juan José

2015-01-01

Although many examples of multiple-use forest management may be found in tropical smallholder systems, few studies provide empirical support for the integration of selective timber harvesting with non-timber forest product (NTFP) extraction. Brazil nut (Bertholletia excelsa, Lecythidaceae) is one of the world’s most economically-important NTFP species extracted almost entirely from natural forests across the Amazon Basin. An obligate out-crosser, Brazil nut flowers are pollinated by large-bodied bees, a process resulting in a hard round fruit that takes up to 14 months to mature. As many smallholders turn to the financial security provided by timber, Brazil nut fruits are increasingly being harvested in logged forests. We tested the influence of tree and stand-level covariates (distance to nearest cut stump and local logging intensity) on total nut production at the individual tree level in five recently logged Brazil nut concessions covering about 4000 ha of forest in Madre de Dios, Peru. Our field team accompanied Brazil nut harvesters during the traditional harvest period (January-April 2012 and January-April 2013) in order to collect data on fruit production. Three hundred and ninety-nine (approximately 80%) of the 499 trees included in this study were at least 100 m from the nearest cut stump, suggesting that concessionaires avoid logging near adult Brazil nut trees. Yet even for those trees on the edge of logging gaps, distance to nearest cut stump and local logging intensity did not have a statistically significant influence on Brazil nut production at the applied logging intensities (typically 1–2 timber trees removed per ha). In one concession where at least 4 trees ha-1 were removed, however, the logging intensity covariate resulted in a marginally significant (0.09) P value, highlighting a potential risk for a drop in nut production at higher intensities. While we do not suggest that logging activities should be completely avoided in Brazil nut rich

Nut Production in Bertholletia excelsa across a Logged Forest Mosaic: Implications for Multiple Forest Use.

Directory of Open Access Journals (Sweden)

Cara A Rockwell

Full Text Available Although many examples of multiple-use forest management may be found in tropical smallholder systems, few studies provide empirical support for the integration of selective timber harvesting with non-timber forest product (NTFP extraction. Brazil nut (Bertholletia excelsa, Lecythidaceae is one of the world's most economically-important NTFP species extracted almost entirely from natural forests across the Amazon Basin. An obligate out-crosser, Brazil nut flowers are pollinated by large-bodied bees, a process resulting in a hard round fruit that takes up to 14 months to mature. As many smallholders turn to the financial security provided by timber, Brazil nut fruits are increasingly being harvested in logged forests. We tested the influence of tree and stand-level covariates (distance to nearest cut stump and local logging intensity on total nut production at the individual tree level in five recently logged Brazil nut concessions covering about 4000 ha of forest in Madre de Dios, Peru. Our field team accompanied Brazil nut harvesters during the traditional harvest period (January-April 2012 and January-April 2013 in order to collect data on fruit production. Three hundred and ninety-nine (approximately 80% of the 499 trees included in this study were at least 100 m from the nearest cut stump, suggesting that concessionaires avoid logging near adult Brazil nut trees. Yet even for those trees on the edge of logging gaps, distance to nearest cut stump and local logging intensity did not have a statistically significant influence on Brazil nut production at the applied logging intensities (typically 1-2 timber trees removed per ha. In one concession where at least 4 trees ha-1 were removed, however, the logging intensity covariate resulted in a marginally significant (0.09 P value, highlighting a potential risk for a drop in nut production at higher intensities. While we do not suggest that logging activities should be completely avoided in Brazil

Use of pulsed neutron logging to evaluate perforation washing

International Nuclear Information System (INIS)

Dimon, C.A.

1986-01-01

This invention relates to the use of pulsed neutron logging techniques before and after perforation washing operations are performed to evaluate the degree of success of the perforation washing operations. Well logging operations of a type designed to respond to the difference between a formation immediately behind the well sheath and voids in the formation are performed both before and after the perforation washing operation. differences between the two resulting logs are then indicative of voids created by perforation washing. In a preferred embodiment, pulsed neutron logging is used as the logging technique, while a weighted brine having a high absorption cross section to pulsed neutrons is used as the perforation washing fluid

SU-F-T-469: A Clinically Observed Discrepancy Between Image-Based and Log- Based MLC Position

Energy Technology Data Exchange (ETDEWEB)

Neal, B; Ahmed, M; Siebers, J [University of Virginia Health System, Charlottesville, VA (United States)

2016-06-15

Purpose: To present a clinical case which challenges the base assumption of log-file based QA, by showing that the actual position of a MLC leaf can suddenly deviate from its programmed and logged position by >1 mm as observed with real-time imaging. Methods: An EPID-based exit-fluence dosimetry system designed to prevent gross delivery errors was used in cine mode to capture portal images during treatment. Visual monitoring identified an anomalous MLC leaf pair gap not otherwise detected by the automatic position verification. The position of the erred leaf was measured on EPID images and log files were analyzed for the treatment in question, the prior day’s treatment, and for daily MLC test patterns acquired on those treatment days. Additional standard test patterns were used to quantify the leaf position. Results: Whereas the log file reported no difference between planned and recorded positions, image-based measurements showed the leaf to be 1.3±0.1 mm medial from the planned position. This offset was confirmed with the test pattern irradiations. Conclusion: It has been clinically observed that log-file derived leaf positions can differ from their actual positions by >1 mm, and therefore cannot be considered to be the actual leaf positions. This cautions the use of log-based methods for MLC or patient quality assurance without independent confirmation of log integrity. Frequent verification of MLC positions through independent means is a necessary precondition to trusting log file records. Intra-treatment EPID imaging provides a method to capture departures from MLC planned positions. Work was supported in part by Varian Medical Systems.

Selective logging: do rates of forest turnover in stems, species composition and functional traits decrease with time since disturbance? – A 45 year perspective

Science.gov (United States)

Osazuwa-Peters, Oyomoare L.; Jiménez, Iván; Oberle, Brad; Chapman, Colin A.; Zanne, Amy E.

2015-01-01

Selective logging, the targeted harvesting of timber trees in a single cutting cycle, is globally rising in extent and intensity. Short-term impacts of selective logging on tropical forests have been widely investigated, but long-term effects on temporal dynamics of forest structure and composition are largely unknown. Understanding these long-term dynamics will help determine whether tropical forests are resilient to selective logging and inform choices between competing demands of anthropogenic use versus conservation of tropical forests. Forest dynamics can be studied within the framework of succession theory, which predicts that temporal turnover rates should decline with time since disturbance. Here, we investigated the temporal dynamics of a tropical forest in Kibale National Park, Uganda over 45 years following selective logging. We estimated turnover rates in stems, species composition, and functional traits (wood density and diameter at breast height), using observations from four censuses in 1989, 1999, 2006, and 2013, of stems ≥ 10 cm diameter within 17 unlogged and 9 logged 200 × 10 m vegetation plots. We used null models to account for interdependencies among turnover rates in stems, species composition, and functional traits. We tested predictions that turnover rates should be higher and decrease with increasing time since the selective logging event in logged forest, but should be less temporally variable in unlogged forest. Overall, we found higher turnover rates in logged forest for all three attributes, but turnover rates did not decline through time in logged forest and was not less temporally variable in unlogged forest. These results indicate that successional models that assume recovery to pre-disturbance conditions are inadequate for predicting the effects of selective logging on the dynamics of the tropical forest in Kibale. Selective logging resulted in persistently higher turnover rates, which may compromise the carbon storage capacity

Development of an Intelligent System to Synthesize Petrophysical Well Logs

Directory of Open Access Journals (Sweden)

Morteza Nouri Taleghani

2013-07-01

Full Text Available Porosity is one of the fundamental petrophysical properties that should be evaluated for hydrocarbon bearing reservoirs. It is a vital factor in precise understanding of reservoir quality in a hydrocarbon field. Log data are exceedingly crucial information in petroleum industries, for many of hydrocarbon parameters are obtained by virtue of petrophysical data. There are three main petrophysical logging tools for the determination of porosity, namely neutron, density, and sonic well logs. Porosity can be determined by the use of each of these tools; however, a precise analysis requires a complete set of these tools. Log sets are commonly either incomplete or unreliable for many reasons (i.e. incomplete logging, measurement errors, and loss of data owing to unsuitable data storage. To overcome this drawback, in this study several intelligent systems such as fuzzy logic (FL, neural network (NN, and support vector machine are used to predict synthesized petrophysical logs including neutron, density, and sonic. To accomplish this, the petrophysical well logs data were collected from a real reservoir in one of Iran southwest oil fields. The corresponding correlation was obtained through the comparison of synthesized log values with real log values. The results showed that all intelligent systems were capable of synthesizing petrophysical well logs, but SVM had better accuracy and could be used as the most reliable method compared to the other techniques.

Effects of salvage logging on fire risks after bark beetle outbreaks in Colorado lodgepole pine forests

Science.gov (United States)

Bryon J. Collins; Chuck C. Rhoades; Michael A. Battaglia; Robert M. Hubbard

2012-01-01

Most mature lodgepole pine (Pinus contorta var. latifolia Engelm. ex Wats.) forests in the central and southern Rocky Mountains originated after stand-replacing wildfires or logging (Brown 1975, Lotan and Perry 1983, Romme 1982). In recent years, mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks have created a widespread, synchronous disturbance (i.e.,...

Stress wave sorting of red maple logs for structural quality

Science.gov (United States)

Xiping Wang; Robert J. Ross; David W. Green; Brian Brashaw; Karl Englund; Michael Wolcott

2004-01-01

Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially...

Performance of sampling methods to estimate log characteristics for wildlife.

Science.gov (United States)

Lisa J. Bate; Torolf R. Torgersen; Michael J. Wisdom; Edward O. Garton

2004-01-01

Accurate estimation of the characteristics of log resources, or coarse woody debris (CWD), is critical to effective management of wildlife and other forest resources. Despite the importance of logs as wildlife habitat, methods for sampling logs have traditionally focused on silvicultural and fire applications. These applications have emphasized estimates of log volume...

Borehole logging in uranium exploration

International Nuclear Information System (INIS)

Kulkarni, N.H.

1992-01-01

The ultimate objective of exploration by drilling as far as Atomic Minerals Division is concerned is to locate the ore zone in the subsurface, draw samples and analyze them for their metal content. The presence of the ore zone is also indicated by gamma-ray logging of the borehole. A gamma-ray detector is lowered in the borehole and precise depth and grade of the ore zone is established. This helps the geologist in correlating the ore horizon with the surface outcrop or the ore zone intercepted in adjoining boreholes and in deciding about further drilling and location of boreholes. Most commonly, total gamma measurements are made although some units capable of measuring the gamma-ray spectrum are also in use. It is possible to know if the mineralization is due to uranium without waiting for the laboratory results. The present write up gives a brief account of the principles, equipment and methods of borehole gamma-ray logging including density and self-potential logging. (author). 8 refs., 5 figs

Secure Audit Logging with Tamper-Resistant Hardware

NARCIS (Netherlands)

Chong, C.N.; Peng, Z.; Peng, Z.; Hartel, Pieter H.; Gritzalis, D.; De Capitani di Vimercati, S.; Katsikas, S.K.; Samarati, P.

Secure perimeter schemes (e.g. DRM) and tracing traitor schemes (e.g. watermarking, audit logging) strive to mitigate the problems of content escaping the control of the rights holder. Secure audit logging records the user's actions on content and enables detection of some forms of tampering with

Palm distributions for log Gaussian Cox processes

DEFF Research Database (Denmark)

Coeurjolly, Jean-Francois; Møller, Jesper; Waagepetersen, Rasmus

This paper reviews useful results related to Palm distributions of spatial point processes and provides a new result regarding the characterization of Palm distributions for the class of log Gaussian Cox processes. This result is used to study functional summary statistics for a log Gaussian Cox...

Proposal of a method for evaluating tsunami risk using response-surface methodology

Science.gov (United States)

Fukutani, Y.

2017-12-01

Information on probabilistic tsunami inundation hazards is needed to define and evaluate tsunami risk. Several methods for calculating these hazards have been proposed (e.g. Løvholt et al. (2012), Thio (2012), Fukutani et al. (2014), Goda et al. (2015)). However, these methods are inefficient, and their calculation cost is high, since they require multiple tsunami numerical simulations, therefore lacking versatility. In this study, we proposed a simpler method for tsunami risk evaluation using response-surface methodology. Kotani et al. (2016) proposed an evaluation method for the probabilistic distribution of tsunami wave-height using a response-surface methodology. We expanded their study and developed a probabilistic distribution of tsunami inundation depth. We set the depth (x1) and the slip (x2) of an earthquake fault as explanatory variables and tsunami inundation depth (y) as an object variable. Subsequently, tsunami risk could be evaluated by conducting a Monte Carlo simulation, assuming that the generation probability of an earthquake follows a Poisson distribution, the probability distribution of tsunami inundation depth follows the distribution derived from a response-surface, and the damage probability of a target follows a log normal distribution. We applied the proposed method to a wood building located on the coast of Tokyo Bay. We implemented a regression analysis based on the results of 25 tsunami numerical calculations and developed a response-surface, which was defined as y=ax1+bx2+c (a:0.2615, b:3.1763, c=-1.1802). We assumed proper probabilistic distribution for earthquake generation, inundation height, and vulnerability. Based on these probabilistic distributions, we conducted Monte Carlo simulations of 1,000,000 years. We clarified that the expected damage probability of the studied wood building is 22.5%, assuming that an earthquake occurs. The proposed method is therefore a useful and simple way to evaluate tsunami risk using a response

Nuclear borehole logging for oil exploration

International Nuclear Information System (INIS)

Oelgaard, P.L.

1989-01-01

Reactor physics can be applied to the logging of boreholes for the exploration of oil and gas and the results obtained can be interpreted more correctly by use of reactor physics models, e.g. one-dimensional multi-group diffusion theory adapted for gamma quanta. The standard nuclear logging tools are: natural gamma, gamma density, neutron porosity and the pulsed-neutron tool. The models and interpretation procedures are discussed. 1 fig

Geophysical logging of the Harwell boreholes

International Nuclear Information System (INIS)

Brightman, M.A.

1983-08-01

A comprehensive geophysical borehole logging survey was carried out on each of three deep boreholes drilled at the Harwell research site. KOALA and PETRA computer programs were used to analyse and interpret the logs to obtain continuous quantitative estimates of the geological and hydrogeological properties of the sequences penetrated at the Harwell site. Quantitative estimates of the mineral composition and porosity of the cores samples were made. (UK)

An artificial intelligence approach to well log correlation

International Nuclear Information System (INIS)

Startzman, R.A.; Kuo, T.B.

1986-01-01

This paper shows how an expert computer system was developed to correlate two well logs in at least moderately difficult situations. A four step process was devised to process log trace information and apply a set of rules to identify zonal correlations. Some of the advantages and problems with the artificial intelligence approach are shown using field logs. The approach is useful and, if properly and systematically applied, it can result in good correlations

Anomalous self potential (sp) log signatures observed in a water ...

African Journals Online (AJOL)

Geophysical logging was done after drilling had been completed in a water well at Okwudor, South Eastern Nigeria. Three electric logs were run viz: Self Potential (SP), Resistivity N16″ and N64″ logs. An anomaly was observed in the SP log. The SP results from this well show some deviation from the standard norm.

Explorations in statistics: the log transformation.

Science.gov (United States)

Curran-Everett, Douglas

2018-06-01

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This thirteenth installment of Explorations in Statistics explores the log transformation, an established technique that rescales the actual observations from an experiment so that the assumptions of some statistical analysis are better met. A general assumption in statistics is that the variability of some response Y is homogeneous across groups or across some predictor variable X. If the variability-the standard deviation-varies in rough proportion to the mean value of Y, a log transformation can equalize the standard deviations. Moreover, if the actual observations from an experiment conform to a skewed distribution, then a log transformation can make the theoretical distribution of the sample mean more consistent with a normal distribution. This is important: the results of a one-sample t test are meaningful only if the theoretical distribution of the sample mean is roughly normal. If we log-transform our observations, then we want to confirm the transformation was useful. We can do this if we use the Box-Cox method, if we bootstrap the sample mean and the statistic t itself, and if we assess the residual plots from the statistical model of the actual and transformed sample observations.

Why, What, and How to Log? Lessons from LISTEN

Science.gov (United States)

Mostow, Jack; Beck, Joseph E.

2009-01-01

The ability to log tutorial interactions in comprehensive, longitudinal, fine-grained detail offers great potential for educational data mining--but what data is logged, and how, can facilitate or impede the realization of that potential. We propose guidelines gleaned over 15 years of logging, exploring, and analyzing millions of events from…

Biological legacies buffer local species extinction after logging.

Science.gov (United States)

Rudolphi, Jörgen; Jönsson, Mari T; Gustafsson, Lena; Bugmann, H

2014-02-01

Clearcutting has been identified as a main threat to forest biodiversity. In the last few decades, alternatives to clearcutting have gained much interest. Living and dead trees are often retained after harvest to serve as structural legacies to mitigate negative effects of forestry. However, this practice is widely employed without information from systematic before-after control-impact studies to assess the processes involved in species responses after clearcutting with retention. We performed a large-scale survey of the occurrence of logging-sensitive and red-listed bryophytes and lichens before and after clearcutting with the retention approach. A methodology was adopted that, for the first time in studies on retention approaches, enabled monitoring of location-specific substrates. We used uncut stands as controls to assess the variables affecting the survival of species after a major disturbance. In total, 12 bryophyte species and 27 lichen species were analysed. All were classified as sensitive to logging, and most species are also currently red-listed. We found that living and dead trees retained after final harvest acted as refugia in which logging-sensitive species were able to survive for 3 to 7 years after logging. Depending on type of retention and organism group, between 35% and 92% of the species occurrences persisted on retained structures. Most species observed outside retention trees or patches disappeared. Larger pre-harvest population sizes of bryophytes on dead wood increased the survival probability of the species and hence buffered the negative effects of logging. Synthesis and applications . Careful spatial planning of retention structures is required to fully embrace the habitats of logging-sensitive species. Bryophytes and lichens persisted to a higher degree in retention patches compared to solitary trees or in the clearcut area. Retaining groups of trees in logged areas will help to sustain populations of species over the clearcut phase

Managing risk in statistics - "Relative risk" | Durrheim | South African ...

African Journals Online (AJOL)

South African Family Practice. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 45, No 8 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Managing risk in statistics - "Relative risk". DN Durrheim ...

Real Time Face Quality Assessment for Face Log Generation

DEFF Research Database (Denmark)

Kamal, Nasrollahi; Moeslund, Thomas B.

2009-01-01

Summarizing a long surveillance video to just a few best quality face images of each subject, a face-log, is of great importance in surveillance systems. Face quality assessment is the back-bone for face log generation and improving the quality assessment makes the face logs more reliable....... Developing a real time face quality assessment system using the most important facial features and employing it for face logs generation are the concerns of this paper. Extensive tests using four databases are carried out to validate the usability of the system....

Tradeoffs and interdependence in the Alaska cant and log markets.

Science.gov (United States)

Donald Flora; Una Woller; Michael. Neergaard

1990-01-01

During the 1980s, log exports from Alaska have risen while cant (lumber) exports have declined. Eight explanations for the difference between cant and log market behavior are explored. It seems that declining demand for wood products in Japan and a surge of private-sector log harvests in Alaska are enough to account for the apparent substitution of logs for cants. It...

The time to ruin in some additive risk models with random premium rates

DEFF Research Database (Denmark)

Jacobsen, Martin

2012-01-01

to have a Laplace transform that is a rational function. The main results describe the joint Laplace transform of the time at ruin and the deficit at ruin. The method used consists in finding partial eigenfunctions for the generator of the joint process consisting of the Markov process and the accumulated...... of the present value of the Markov process. The intensity for a claim to occur is another nonnegative function of the value of the Markov process. The claim arrival times are the regeneration times for the Markov process. Two-sided claims are allowed, but the distribution of the positive claims is assumed......The risk processes considered in this paper are generated by an underlying Markov process with a regenerative structure and an independent sequence of independent and identically distributed claims. Between the arrivals of claims the process increases at a rate which is a nonnegative function...

49 CFR 568.7 - Requirements for manufacturers who assume legal responsibility for a vehicle.

Science.gov (United States)

2010-10-01

... MANUFACTURED IN TWO OR MORE STAGES § 568.7 Requirements for manufacturers who assume legal responsibility for a vehicle. (a) If an incomplete vehicle manufacturer assumes legal responsibility for all duties and... 49 CFR 567.5(f). (b) If an intermediate manufacturer of a vehicle assumes legal responsibility for...

Contrasting Patterns of Damage and Recovery in Logged Amazon Forests From Small Footprint LiDAR Data

Science.gov (United States)

Morton, D. C.; Keller, M.; Cook, B. D.; Hunter, Maria; Sales, Marcio; Spinelli, L.; Victoria, D.; Andersen, H.-E.; Saleska, S.

2012-01-01

Tropical forests ecosystems respond dynamically to climate variability and disturbances on time scales of minutes to millennia. To date, our knowledge of disturbance and recovery processes in tropical forests is derived almost exclusively from networks of forest inventory plots. These plots typically sample small areas (less than or equal to 1 ha) in conservation units that are protected from logging and fire. Amazon forests with frequent disturbances from human activity remain under-studied. Ongoing negotiations on REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus enhancing forest carbon stocks) have placed additional emphasis on identifying degraded forests and quantifying changing carbon stocks in both degraded and intact tropical forests. We evaluated patterns of forest disturbance and recovery at four -1000 ha sites in the Brazilian Amazon using small footprint LiDAR data and coincident field measurements. Large area coverage with airborne LiDAR data in 2011-2012 included logged and unmanaged areas in Cotriguacu (Mato Grosso), Fiona do Jamari (Rondonia), and Floresta Estadual do Antimary (Acre), and unmanaged forest within Reserva Ducke (Amazonas). Logging infrastructure (skid trails, log decks, and roads) was identified using LiDAR returns from understory vegetation and validated based on field data. At each logged site, canopy gaps from logging activity and LiDAR metrics of canopy heights were used to quantify differences in forest structure between logged and unlogged areas. Contrasting patterns of harvesting operations and canopy damages at the three logged sites reflect different levels of pre-harvest planning (i.e., informal logging compared to state or national logging concessions), harvest intensity, and site conditions. Finally, we used multi-temporal LiDAR data from two sites, Reserva Ducke (2009, 2012) and Antimary (2010, 2011), to evaluate gap phase dynamics in unmanaged forest areas. The rates and patterns of canopy gap

AML (Advanced Mud Logging: First Among Equals

Directory of Open Access Journals (Sweden)

T. Loermans

2017-09-01

Full Text Available During the past ten years an enormous development in mud logging technology has been made. Traditional mud logging was only qualitative in nature, and mudlogs could not be used for the petrophysical well evaluations which form the basis for all subsequent activities on wells and fields. AML however can provide quantitative information, logs with a reliability, trueness and precision like LWD and WLL. Hence for well evaluation programmes there are now three different logging methods available, each with its own pros and cons on specific aspects: AML, LWD and WLL. The largest improvements have been made in mud gas analysis and elemental analysis of cuttings. Mud gas analysis can yield hydrocarbon fluid composition for some components with a quality like PVT analysis, hence not only revolutionising the sampling programme so far done with only LWD/WLL, but also making it possible to geosteer on fluid properties. Elemental analysis of cuttings, e.g. with XRF, with an ability well beyond the capabilities of the spectroscopy measurements possible earlier with LWD/WLL tools, is opening up improved ways to evaluate formations, especially of course where the traditional methods are falling short of requirements, such as in unconventional reservoirs. An overview and specific examples of these AML logs is given, from which it may be concluded that AML now ought to be considered as “first among its equals”.

Rock mass characterization for Copenhagen Metro using face logs

DEFF Research Database (Denmark)

Hansen, Sanne Louise; Galsgaard, Jens; Foged, Niels Nielsen

2015-01-01

An extension of the existing Metro in central Copenhagen is currently under construction. We present a comparison of the different field logging techniques available from a large number of borehole logs and face logs carried out during the construction in cooperation with the constructor and client......, describing rock mass characteristics using detailed face logging with geological description and recording of induration and fracturing, giving a field RQD value during excavation, combined with televiewer logs, when available, has shown to be a valuable tool for rock mass characterization compared......’s representatives, which illustrate and approve the applied methods. The new ‘Cityringen’ Metro will consist of two 16 km single track tunnels, with 17 stations and 3 construction and ventilation shafts. The geological ground conditions are dominated by glacial and postglacial deposits overlying Paleocene Greensand...

Risk assessment for truck-transport assuming different concepts of the back-end of the fuel cycle

International Nuclear Information System (INIS)

Tully, A.; Sonnenschein, R.; Haeusler, S.

1983-01-01

The different concepts of the back-end of the fuel cycle existing in the Federal Republic of Germany require that various types of radioactive materials will be transported along different pathways, for various distances and at different frequencies, thus resulting in different risks to the public. In one part of the second phase of the R + D program Projekt Sicherheitsstudien Entsorgung (PSE), the risk during normal and accident conditions will be assessed for each of the concepts of the back-end of the fuel cycle. Within this part of the safety analysis, DORNIER SYSTEM will determine the risks resulting from the transport of radioactive materials by truck, using the probabilistic method of fault tree analysis. This part of the investigation will extend until the end of 1983. 4 references, 5 tables

Bacterial-based additives for the production of artificial snow: What are the risks to human health?

Energy Technology Data Exchange (ETDEWEB)

Lagriffoul, A. [Agence Francaise de Securite Sanitaire de l' Environnement et du Travail, 253, avenue du General Leclerc, 94701 Maisons-Alfort (France); Boudenne, J.L. [Universite de Provence, Laboratoire Chimie Provence, UMR6264, 3 Place Victor Hugo case 29 13331 Marseille CEDEX 3 (France); Absi, R. [Institut Polytechnique Saint-Louis, Ecole de Biologie Industrielle, Laboratoire EBInnov, 32 Boulevard du Port, 95094 Cergy-Pontoise (France); Ballet, J.J. [Laboratoire d' immunologie et immunopathologie, Centre hospitalo-universitaire de Caen, avenue de la cote de nacre 14000 Caen (France); Berjeaud, J.M. [Universite de Poitiers, Laboratoire de Chimie et Microbiologie de l' Eau, UMR6008, 40 avenue du recteur Pineau, 86022 Poitiers CEDEX (France); Chevalier, S. [Universite de Rouen, Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Securite Sanitaire, 55 rue St Germain, 27000 Evreux (France); Creppy, E.E. [Universite Bordeaux 2, UFR des Sciences Pharmaceutiques, Laboratoire de Toxicologie, 146, rue Leo-Saignat, 33076 Bordeaux CEDEX (France); Gilli, E. [Universite Paris 8, Departement de geographie, 2, rue de la Liberte, 93526 Saint Denis CEDEX (France); UMR Espace 6012, 98 bd Edouard Herriot, 06204, Nice, CEDEX 3 (France); Gadonna, J.P. [Institut Polytechnique Saint-Louis, Ecole de Biologie Industrielle, Laboratoire EBInnov, 32 Boulevard du Port, 95094 Cergy-Pontoise (France); Gadonna-Widehem, P. [Institut Polytechnique LaSalle Beauvais, departement STAI, rue P. Waguet BP 30313, 60026 Beauvais CEDEX (France); Morris, C.E. [INRA, Unite de Pathologie Vegetale UR407, F-84140 Montfavet (France); Zini, S., E-mail: sylvie.zini@afsset.fr [Agence Francaise de Securite Sanitaire de l' Environnement et du Travail, 253, avenue du General Leclerc, 94701 Maisons-Alfort (France)

2010-03-01

For around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow.

Bacterial-based additives for the production of artificial snow: what are the risks to human health?

Science.gov (United States)

Lagriffoul, A; Boudenne, J L; Absi, R; Ballet, J J; Berjeaud, J M; Chevalier, S; Creppy, E E; Gilli, E; Gadonna, J P; Gadonna-Widehem, P; Morris, C E; Zini, S

2010-03-01

For around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow.

Bacterial-based additives for the production of artificial snow: What are the risks to human health?

International Nuclear Information System (INIS)

Lagriffoul, A.; Boudenne, J.L.; Absi, R.; Ballet, J.J.; Berjeaud, J.M.; Chevalier, S.; Creppy, E.E.; Gilli, E.; Gadonna, J.P.; Gadonna-Widehem, P.; Morris, C.E.; Zini, S.

2010-01-01

For around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow.

Identification and Characterization of Trichoderma Species Damaging Shiitake Mushroom Bed-Logs Infested by Camptomyia Pest.

Science.gov (United States)

Kim, Jun Young; Kwon, Hyuk Woo; Yun, Yeo Hong; Kim, Seong Hwan

2016-05-28

The shiitake mushroom industry has suffered from Camptomyia (gall midges) pest, which feeds on the mycelium of shiitake mushroom during its cultivation. It has been postulated that fungal damage of shiitake bed-logs is associated with infestation by the insect pest, but this is not well understood. To understand the fungal damage associated with Camptomyia pest, various Trichoderma species were isolated, identified, and characterized. In addition to two previously known Trichoderma species, T. citrinoviride and T. deliquescens, two other Trichoderma species, T. harzianum and T. atroviride, were newly identified from the pestinfested bed-log samples obtained at three mushroom farms in Cheonan, Korea. Among these four species, T. harzianum was the most evident. The results of a chromogenic media-based assay for extracellular enzymes showed that these four species have the ability to produce amylase, carboxyl-methyl cellulase, avicelase, pectinase, and β-glucosidase, thus indicating that they can degrade wood components. A dual culture assay on PDA indicated that T. harzianum, T. atroviride, and T. citrinoviride were antagonistic against the mycelial growth of a shiitake strain (Lentinula edodes). Inoculation tests on shiitake bed-logs revealed that all four species were able to damage the wood of bed-logs. Our results provide evidence that the four green mold species are the causal agents involved in fungal damage of shiitake bed-logs infested by Camptomyia pest.

Analysis of log rate noise in Ontario's CANDU reactors

Energy Technology Data Exchange (ETDEWEB)

Hinds, H.W. [Dynamic Simulation and Analysis Corp., Deep River, Ontario (Canada); Banica, C.; Arguner, D. [Ontario Power Generation, Ajax, Ontario (Canada); Scharfenberg, R. [Bruce Power, Tiverton, Ontario (Canada)

2007-07-01

In the fall of 2003, the operators noticed that in the recently-refurbished Bruce A Shutdown System no. 1 (SDS1) the noise level in Log Rate signals were much larger than before. At the request of the Canadian Nuclear Safety Commission (CNSC), all Canadian CANDU reactors took action to characterize their Log Rate noise. Staff of the Inspection and Maintenance Services division of Ontario Power Generation (OPG) has collected high-speed high-accuracy noise data from nearly all 16 Ontario reactors, either as part of routine measurements before planned outages or as a dedicated noise recording. This paper gives the results of examining a suitable subset of this data, with respect to the characteristics and possible causes of Log Rate noise. The reactor and instrumentation design is different at each station: the locations of the moderator injection nozzles, the location of the ion chambers for each system, and the design of the Log Rate amplifiers. It was found that the Log noise (source of Log Rate noise) was much larger for those ion chambers in the path of the moderator injection nozzles, compared to those which were not in the path. This 'extra' Log noise would then be either attenuated or amplified depending on the transfer function (time constants) of the Log Rate amplifier. It was also observed that most of the Log and Log Rate noise is independent of any other signal measured. Although all CANDU reactors in Ontario have Log and Log Rate noise, the Bruce A SDS1 system has the largest amount of Log Rate noise, because (a) its SDS1 (and RRS) ion chambers are at the top of the reactor in the path of the moderator injection nozzles, and (b) its SDS1 Log Rate amplifiers have the smallest time constants. (author)

14 CFR 125.407 - Maintenance log: Airplanes.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintenance log: Airplanes. 125.407 Section... OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6... Maintenance log: Airplanes. (a) Each person who takes corrective action or defers action concerning a reported...

Management of construction cost contingency covering upside and downside risks

Directory of Open Access Journals (Sweden)

Ibrahim Adel Eldosouky

2014-12-01

Full Text Available Many contractors are of the opinion that adding contingency funds to the tender price of a project may lead to loss of the tender. This research is a trial to put an end to this incorrect opinion. A more mature attitude to risk would recognize that contingency exists to be spent in order to avoid or minimize threats and to exploit or maximize opportunities. This research proposes an approach for determination and monitoring of Cost Contingency Reserve (CCR for a project. Control of CCR is interfaced with Earned Value Management. Application to a real project is carried out. Post-mitigation simulations show that value of CCR is 2.88% of project cost but there is a potential saving due to opportunities. The project is monitored after eight months from its assumed start date with one assumed emergent risk. The final results are as follows: CCR is enough to cover project current and residual threats and the contractor has a considerable amount of money that will be transferred to his margin at project closure assuming the project will not be exposed to additional emergent risks. A contractor can balance project upside risks and its downsides to increase his chance to win tender of the project.

The application of radiation logs to groundwater hydrology

Energy Technology Data Exchange (ETDEWEB)

Scott Keys, W [United States Geological Survey, Denver, CO (United States)

1967-05-15

The drilling of exploratory holes to determine the availability of groundwater and to plan the most economical methods of water development is expensive. The only technique available at present for obtaining geological and hydrological information through the casing of pre-existing water wells and other boreholes is by radiation logging. Up to now these logging techniques have been little used in groundwater hydrology. This report describes inexpensive portable radiation logging equipment that is available or has been developed for groundwater studies in connection with a general research project on the application of borehole geophysics in groundwater hydrology. It is possible to obtain data on the following: the source, velocity, and chemical quality of groundwater; the location, extent, geometry, bulk density, porosity, permeability, and specific yield of aquifers and associated strata; and the position of casings, casing collars, leaks, perforations, and cement. The radiation logs employed include natural gamma, gamma-gamma, neutron-gamma. neutron epithermal-neutron. and radioactive tracer. The following radioisotopes are utilized: cobalt-60, plutonium-239, americium-241, and iodine-131. Typical radiation logs obtained by the various techniques are described and examples are given of practical applications of radiation logging to groundwater investigations. The applications cited are studies of perched water in basaltic rocks and associated sedimentary strata; the porosity, moisture content, and position of zones into which water was injected in volcanic tuff; the position of the interface between brine and fresh water in fine-grained carbonate rocks and associated fine clastic rocks; the interpretation of porosity from a neutron log; and the location by means of a radioactive tracer of the more permeable fracture zones in a well penetrating crystalline rock. (author)

Adiponectin provides additional information to conventional cardiovascular risk factors for assessing the risk of atherosclerosis in both genders.

Directory of Open Access Journals (Sweden)

Jin-Ha Yoon

Full Text Available BACKGROUND: This study evaluated the relation between adiponectin and atherosclerosis in both genders, and investigated whether adiponectin provides useful additional information for assessing the risk of atherosclerosis. METHODS: We measured serum adiponectin levels and other cardiovascular risk factors in 1033 subjects (454 men, 579 women from the Korean Genomic Rural Cohort study. Carotid intima-media-thickness (CIMT was used as measure of atherosclerosis. Odds ratios (ORs with 95% confidence intervals (95% CI were calculated using multiple logistic regression, and receiver operating characteristic curves (ROC, the category-free net reclassification improvement (NRI and integrated discrimination improvement (IDI were calculated. RESULTS: After adjustment for conventional cardiovascular risk factors, such as age, waist circumference, smoking history, low-density and high-density lipoprotein cholesterol, triglycerides, systolic blood pressure and insulin resistance, the ORs (95%CI of the third tertile adiponectin group were 0.42 (0.25-0.72 in men and 0.47 (0.29-0.75 in women. The area under the curve (AUC on the ROC analysis increased significantly by 0.025 in men and 0.022 in women when adiponectin was added to the logistic model of conventional cardiovascular risk factors (AUC in men: 0.655 to 0.680, p = 0.038; AUC in women: 0.654 to 0.676, p = 0.041. The NRI was 0.32 (95%CI: 0.13-0.50, p<0.001, and the IDI was 0.03 (95%CI: 0.01-0.04, p<0.001 for men. For women, the category-free NRI was 0.18 (95%CI: 0.02-0.34, p = 0.031 and the IDI was 0.003 (95%CI: -0.002-0.008, p = 0.189. CONCLUSION: Adiponectin and atherosclerosis were significantly related in both genders, and these relationships were independent of conventional cardiovascular risk factors. Furthermore, adiponectin provided additional information to conventional cardiovascular risk factors regarding the risk of atherosclerosis.

Borehole logging system

International Nuclear Information System (INIS)

Allen, L.S.

1988-01-01

A radioactive borehole logging tool employs an epithermal neutron detector having a neutron counter surrounded by an inner thermal neutron filter and an outer thermal neutron filter. Located between the inner and outer filters is a neutron moderating material for extending the lifetime of epithermal neutrons to enhance the counting rate of such epithermal neutrons by the neutron counter

Closed expressions for $\\int_{0}^{1} t^{-1} log^{n-1}t log^{p}(1 - t) dt$

CERN Document Server

Kölbig, Kurt Siegfried

1982-01-01

Closed expressions for the integral integral /sub 0//sup 1/ t/sup -1/ log/sup n-1/t log/sup p/(1-t)dt, whose general form is given elsewhere, are listed for n=1(1)9, p=1(1)9. A formula is derived which allows an easy evaluation of these expressions by formula manipulation on a computer. The majority of the above expressions are given in a microfiche supplement to the paper.

Multivariate log-skew-elliptical distributions with applications to precipitation data

KAUST Repository

Marchenko, Yulia V.

2009-07-13

We introduce a family of multivariate log-skew-elliptical distributions, extending the list of multivariate distributions with positive support. We investigate their probabilistic properties such as stochastic representations, marginal and conditional distributions, and existence of moments, as well as inferential properties. We demonstrate, for example, that as for the log-t distribution, the positive moments of the log-skew-t distribution do not exist. Our emphasis is on two special cases, the log-skew-normal and log-skew-t distributions, which we use to analyze US national (univariate) and regional (multivariate) monthly precipitation data. © 2009 John Wiley & Sons, Ltd.

Multivariate log-skew-elliptical distributions with applications to precipitation data

KAUST Repository

Marchenko, Yulia V.; Genton, Marc G.

2009-01-01

We introduce a family of multivariate log-skew-elliptical distributions, extending the list of multivariate distributions with positive support. We investigate their probabilistic properties such as stochastic representations, marginal and conditional distributions, and existence of moments, as well as inferential properties. We demonstrate, for example, that as for the log-t distribution, the positive moments of the log-skew-t distribution do not exist. Our emphasis is on two special cases, the log-skew-normal and log-skew-t distributions, which we use to analyze US national (univariate) and regional (multivariate) monthly precipitation data. © 2009 John Wiley & Sons, Ltd.

Toward effective ecological risk-management of refinery corrective action

International Nuclear Information System (INIS)

Metzger, B.H.; Rury, P.M.; Turton, D.; Archibald, B.; Clark, J.; Cura, J.

1995-01-01

Cleanup of complex industrial sites, such as refineries, requires risk-based decision tools to ensure that environmentally protective remediation is consistent with current and future land use. However, conventional ecological risk assessment approaches are not well suited for complex industrial sites. Site risk assessments focus on hypothetical chemical risk assuming diverse and undisturbed ecosystems, rather than industrial and disturbed area conditions. In addition, they offer little guidance as to how to make timely and effective risk management decisions. An innovative methodology is proposed to assist industry and regulatory risk managers with rapid EcoRisk reconnaissance and cost-effective remedial decision-making at complex industrial sites. Phase 1 comprises a three-step risk screening of areas of ecological concern at the site, which integrates habitat quality characteristics and potential chemical hazards. It yields an ordering of areas as follows: areas of no significant risk; areas of potentially significant risk; and areas of likely significant risk. A decision rule is then applied to determine appropriate risk management action, including: no action; additional study; and remedial or management action. In Phase 2, additional study is conducted for areas that exhibit potentially significant risk so as to facilitate risk management. This methodology is currently being applied at the 1,300 acre, former Exxon Bayway Refinery in New Jersey

Development of regional stump-to-mill logging cost estimators

Science.gov (United States)

Chris B. LeDoux; John E. Baumgras

1989-01-01

Planning logging operations requires estimating the logging costs for the sale or tract being harvested. Decisions need to be made on equipment selection and its application to terrain. In this paper a methodology is described that has been developed and implemented to solve the problem of accurately estimating logging costs by region. The methodology blends field time...

Teaching an Old Log New Tricks with Machine Learning.

Science.gov (United States)

Schnell, Krista; Puri, Colin; Mahler, Paul; Dukatz, Carl

2014-03-01

To most people, the log file would not be considered an exciting area in technology today. However, these relatively benign, slowly growing data sources can drive large business transformations when combined with modern-day analytics. Accenture Technology Labs has built a new framework that helps to expand existing vendor solutions to create new methods of gaining insights from these benevolent information springs. This framework provides a systematic and effective machine-learning mechanism to understand, analyze, and visualize heterogeneous log files. These techniques enable an automated approach to analyzing log content in real time, learning relevant behaviors, and creating actionable insights applicable in traditionally reactive situations. Using this approach, companies can now tap into a wealth of knowledge residing in log file data that is currently being collected but underutilized because of its overwhelming variety and volume. By using log files as an important data input into the larger enterprise data supply chain, businesses have the opportunity to enhance their current operational log management solution and generate entirely new business insights-no longer limited to the realm of reactive IT management, but extending from proactive product improvement to defense from attacks. As we will discuss, this solution has immediate relevance in the telecommunications and security industries. However, the most forward-looking companies can take it even further. How? By thinking beyond the log file and applying the same machine-learning framework to other log file use cases (including logistics, social media, and consumer behavior) and any other transactional data source.

Relating safety, productivity and company type for motor-manual logging operations in the Italian Alps.

Science.gov (United States)

Montorselli, Niccolò Brachetti; Lombardini, Carolina; Magagnotti, Natascia; Marchi, Enrico; Neri, Francesco; Picchi, Gianni; Spinelli, Raffaele

2010-11-01

The study compared the performance of four different logging crews with respect to productivity, organization and safety. To this purpose, the authors developed a data collection method capable of providing a quantitative analysis of risk-taking behavior. Four crews were tested under the same working conditions, representative of close-to-nature alpine forestry. Motor-manual working methods were applied, since these methods are still prevalent in the specific study area, despite the growing popularity of mechanical processors. Crews from public companies showed a significantly lower frequency of risk-taking behavior. The best safety performance was offered by the only (public) crew that had been administered formal safety training. The study seems to deny the common prejudice that safety practice is inversely proportional to productivity. Instead, productivity is increased by introducing more efficient working methods and equipment. The quantitative analysis of risk-taking behavior developed in this study can be applied to a number of industrial fields besides forestry. Characterizing risk-taking behavior for a given case may eventually lead to the development of custom-made training programmes, which may address problem areas while avoiding that the message is weakened by the inclusion of redundant information. In the specific case of logging crews in the central Alps, the study suggests that current training courses may be weak on ergonomics, and advocates a staged training programme, focusing first on accident reduction and then expanding to the prevention of chronic illness. 2010 Elsevier Ltd. All rights reserved.

Estimating option values of solar radiation management assuming that climate sensitivity is uncertain.

Science.gov (United States)

Arino, Yosuke; Akimoto, Keigo; Sano, Fuminori; Homma, Takashi; Oda, Junichiro; Tomoda, Toshimasa

2016-05-24

Although solar radiation management (SRM) might play a role as an emergency geoengineering measure, its potential risks remain uncertain, and hence there are ethical and governance issues in the face of SRM's actual deployment. By using an integrated assessment model, we first present one possible methodology for evaluating the value arising from retaining an SRM option given the uncertainty of climate sensitivity, and also examine sensitivities of the option value to SRM's side effects (damages). Reflecting the governance challenges on immediate SRM deployment, we assume scenarios in which SRM could only be deployed with a limited degree of cooling (0.5 °C) only after 2050, when climate sensitivity uncertainty is assumed to be resolved and only when the sensitivity is found to be high (T2x = 4 °C). We conduct a cost-effectiveness analysis with constraining temperature rise as the objective. The SRM option value is originated from its rapid cooling capability that would alleviate the mitigation requirement under climate sensitivity uncertainty and thereby reduce mitigation costs. According to our estimates, the option value during 1990-2049 for a +2.4 °C target (the lowest temperature target level for which there were feasible solutions in this model study) relative to preindustrial levels were in the range between $2.5 and $5.9 trillion, taking into account the maximum level of side effects shown in the existing literature. The result indicates that lower limits of the option values for temperature targets below +2.4 °C would be greater than $2.5 trillion.

Log ASCII Standard (LAS) Files for Geophysical Wireline Well Logs and Their Application to Geologic Cross Sections Through the Central Appalachian Basin

Science.gov (United States)

Crangle, Robert D.

2007-01-01

Introduction The U.S. Geological Survey (USGS) uses geophysical wireline well logs for a variety of purposes, including stratigraphic correlation (Hettinger, 2001, Ryder, 2002), petroleum reservoir analyses (Nelson and Bird, 2005), aquifer studies (Balch, 1988), and synthetic seismic profiles (Kulander and Ryder, 2005). Commonly, well logs are easier to visualize, manipulate, and interpret when available in a digital format. In recent geologic cross sections E-E' and D-D', constructed through the central Appalachian basin (Ryder, Swezey, and others, in press; Ryder, Crangle, and others, in press), gamma ray well log traces and lithologic logs were used to correlate key stratigraphic intervals (Fig. 1). The stratigraphy and structure of the cross sections are illustrated through the use of graphical software applications (e.g., Adobe Illustrator). The gamma ray traces were digitized in Neuralog (proprietary software) from paper well logs and converted to a Log ASCII Standard (LAS) format. Once converted, the LAS files were transformed to images through an LAS-reader application (e.g., GeoGraphix Prizm) and then overlain in positions adjacent to well locations, used for stratigraphic control, on each cross section. This report summarizes the procedures used to convert paper logs to a digital LAS format using a third-party software application, Neuralog. Included in this report are LAS files for sixteen wells used in geologic cross section E-E' (Table 1) and thirteen wells used in geologic cross section D-D' (Table 2).

Utilization and cost for animal logging operations

Science.gov (United States)

Suraj P. Shrestha; Bobby L. Lanford

2001-01-01

Forest harvesting with animals is a labor-intensive operation. Due to the development of efficient machines and high volume demands from the forest products industry, mechanization of logging developed very fast, leaving behind the traditional horse and mule logging. It is expensive to use machines on smaller woodlots, which require frequent moves if mechanically...

La logística y sus componentes

Directory of Open Access Journals (Sweden)

Deyanira Elizabeth Argumedo Sánchez

2014-05-01

Full Text Available Hoy en día el tema de la logística es un tema de suma importancia para las empresas ya que estas se han dado a la tarea de crear áreas especificas para su análisis se ha ido desarrollando a través del tiempo y en la actualidad se ha convertido en un aspecto de suma importancia para lograr que la empresa se posicione como del primer mundo. Antes se entendía como logística el tener el producto en el lugar indicado en el tiempo justo al menor costo posible pero ahora esas actividades han llegado a ser mejoradas que no solo se trata de eso ahora son todo un proceso. La logística determina y coordina en forma óptima el producto correcto, el cliente correcto, el tiempo y lugar correctos por lo tanto la logística no es una actividad funcional si no un modelo que permitirá reducir la incertidumbre de un futuro desconocido.

Efficient and accurate log-Lévy approximations to Lévy driven LIBOR models

DEFF Research Database (Denmark)

Papapantoleon, Antonis; Schoenmakers, John; Skovmand, David

2011-01-01

The LIBOR market model is very popular for pricing interest rate derivatives, but is known to have several pitfalls. In addition, if the model is driven by a jump process, then the complexity of the drift term is growing exponentially fast (as a function of the tenor length). In this work, we con...... ratchet caps show that the approximations perform very well. In addition, we also consider the log-L\\'evy approximation of annuities, which offers good approximations for high volatility regimes....

Numerical simulation of responses for cased-hole density logging

International Nuclear Information System (INIS)

Wu, Wensheng; Fu, Yaping; Niu, Wei

2013-01-01

Stabilizing or stimulating oil production in old oil fields requires density logging in cased holes where open-hole logging data are either missing or of bad quality. However, measured values from cased-hole density logging are more severely influenced by factors such as fluid, casing, cement sheath and the outer diameter of the open-hole well compared with those from open-hole logging. To correctly apply the cased-hole formation density logging data, one must eliminate these influences on the measured values and study the characteristics of how the cased-hole density logging instrument responds to these factors. In this paper, a Monte Carlo numerical simulation technique was used to calculate the responses of the far detector of a cased-hole density logging instrument to in-hole fluid, casing wall thickness, cement sheath density and the formation and thus to obtain influence rules and response coefficients. The obtained response of the detector is a function of in-hole liquid, casing wall thickness, the casing's outer diameter, cement sheath density, open-hole well diameter and formation density. The ratio of the counting rate of the detector in the calibration well to that in the measurement well was used to get a fairly simple detector response equation and the coefficients in the equation are easy to acquire. These provide a new way of calculating cased-hole density through forward modelling methods. (paper)

Impacts of extended working hours in logging

Science.gov (United States)

Dana Mitchell; Tom Gallagher

2008-01-01

Last year at the 2007 AIM in Minneapolis, MN, the authors presented the human factors impacts to consider when implementing extended working hours in the logging industry. In a continuation of this project, we have researched existing literature to identify possible actions that logging business owners can take to reduce the impact of extended working hours on their...

Grading sugar pine saw logs in trees.

Science.gov (United States)

John W. Henley

1972-01-01

Small limbs and small overgrown limbs cause problems when grading saw logs in sugar pine trees. Surface characteristics and lumber recovery information for 426 logs from 64 sugar pine trees were examined. Resulting modifications in the grading specification that allow a grader to ignore small limbs and small limb indicators do not appear to decrease the performance of...

Geophysical borehole logging in the unsaturated zone, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Schimschal, U.; Nelson, P.H.

1991-01-01

Borehole geophysical logging for site characterization in the volcanic rocks at the proposed nuclear waste repository at Yucca Mountain, Nevada, requires data collection under rather unusual conditions. Logging tools must operate in rugose, dry holes above the water table in the unsaturated zone. Not all logging tools will operate in this environment, therefore; careful consideration must be given to selection and calibration. A sample suite of logs is presented that demonstrates correlation of geological formations from borehole to borehole, the definition of zones of altered mineralogy, and the quantitative estimates of rock properties. The authors show the results of an exploratory calculation of porosity and water saturation based upon density and epithermal neutron logs. Comparison of the results with a few core samples is encouraging, particularly because the logs can provide continuous data in boreholes where core samples are not available

Analyzing Log Files using Data-Mining

Directory of Open Access Journals (Sweden)

Marius Mihut

2008-01-01

Full Text Available Information systems (i.e. servers, applications and communication devices create a large amount of monitoring data that are saved as log files. For analyzing them, a data-mining approach is helpful. This article presents the steps which are necessary for creating an ‘analyzing instrument’, based on an open source software called Waikato Environment for Knowledge Analysis (Weka [1]. For exemplification, a system log file created by a Windows-based operating system, is used as input file.

Log-Normal Turbulence Dissipation in Global Ocean Models

Science.gov (United States)

Pearson, Brodie; Fox-Kemper, Baylor

2018-03-01

Data from turbulent numerical simulations of the global ocean demonstrate that the dissipation of kinetic energy obeys a nearly log-normal distribution even at large horizontal scales O (10 km ) . As the horizontal scales of resolved turbulence are larger than the ocean is deep, the Kolmogorov-Yaglom theory for intermittency in 3D homogeneous, isotropic turbulence cannot apply; instead, the down-scale potential enstrophy cascade of quasigeostrophic turbulence should. Yet, energy dissipation obeys approximate log-normality—robustly across depths, seasons, regions, and subgrid schemes. The distribution parameters, skewness and kurtosis, show small systematic departures from log-normality with depth and subgrid friction schemes. Log-normality suggests that a few high-dissipation locations dominate the integrated energy and enstrophy budgets, which should be taken into account when making inferences from simplified models and inferring global energy budgets from sparse observations.

Fine mapping in the MHC region accounts for 18% additional genetic risk for celiac disease

NARCIS (Netherlands)

Gutierrez-Achury, Javier; Zhernakova, Alexandra; Pulit, Sara L.; Trynka, Gosia; Hunt, Karen A.; Romanos, Jihane; Raychaudhuri, Soumya; van Heel, David A.; Wijmenga, Cisca; de Balcker, Paul I. W.

Although dietary gluten is the trigger for celiac disease, risk is strongly influenced by genetic variation in the major histocompatibility complex (MHC) region. We fine mapped the MHC association signal to identify additional risk factors independent of the HLA-DQA1 and HLA-DQB1 alleles and

Two-stage recovery of amphibian assemblages following selective logging of tropical forests.

Science.gov (United States)

Adum, Gilbert Baase; Eichhorn, Markus Peter; Oduro, William; Ofori-Boateng, Caleb; Rödel, Mark-Oliver

2013-04-01

There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous forests in West Africa at varying times after timber extraction to assess post logging effects on amphibian assemblages. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. In 2009, we sampled amphibians in 3 forests (total of 48 study plots, each 2 ha) in southwestern Ghana. In each forest, we established plots in undisturbed forest, recently logged forest, and forest logged 10 and 20 years previously. Logging intensity was constant across sites with 3 trees/ha removed. Recently logged forests supported substantially more species than unlogged forests. This was due to an influx of disturbance-tolerant species after logging. Simultaneously Simpson's index decreased, with increased in dominance of a few species. As time since logging increased richness of disturbance-tolerant species decreased until 10 years after logging when their composition was indistinguishable from unlogged forests. Simpson's index increased with time since logging and was indistinguishable from unlogged forest 20 years after logging. Forest specialists decreased after logging and recovered slowly. However, after 20 years amphibian assemblages had returned to a state indistinguishable from that of undisturbed forest in both abundance and composition. These results demonstrate that even with low-intensity logging (≤3 trees/ha) a minimum 20-year rotation of logging is required for effective conservation of amphibian assemblages in moist semideciduous forests. Furthermore, remnant patches of intact forests retained in the landscape and the presence of permanent brooks may aid in the effective recovery of amphibian

Characterization of a complex near-surface structure using well logging and passive seismic measurements

Science.gov (United States)

Benjumea, Beatriz; Macau, Albert; Gabàs, Anna; Figueras, Sara

2016-04-01

We combine geophysical well logging and passive seismic measurements to characterize the near-surface geology of an area located in Hontomin, Burgos (Spain). This area has some near-surface challenges for a geophysical study. The irregular topography is characterized by limestone outcrops and unconsolidated sediments areas. Additionally, the near-surface geology includes an upper layer of pure limestones overlying marly limestones and marls (Upper Cretaceous). These materials lie on top of Low Cretaceous siliciclastic sediments (sandstones, clays, gravels). In any case, a layer with reduced velocity is expected. The geophysical data sets used in this study include sonic and gamma-ray logs at two boreholes and passive seismic measurements: three arrays and 224 seismic stations for applying the horizontal-to-vertical amplitude spectra ratio method (H/V). Well-logging data define two significant changes in the P-wave-velocity log within the Upper Cretaceous layer and one more at the Upper to Lower Cretaceous contact. This technique has also been used for refining the geological interpretation. The passive seismic measurements provide a map of sediment thickness with a maximum of around 40 m and shear-wave velocity profiles from the array technique. A comparison between seismic velocity coming from well logging and array measurements defines the resolution limits of the passive seismic techniques and helps it to be interpreted. This study shows how these low-cost techniques can provide useful information about near-surface complexity that could be used for designing a geophysical field survey or for seismic processing steps such as statics or imaging.

Perfil logístico de Colombia

OpenAIRE

Cardozo Maglioni, María Victoria; Lozano Suarez, María Goretty

2012-01-01

El presente documento ofrece un estudio del perfil logístico de Colombia con la finalidad de dar a conocer el estado de arte de las ciudades, puertos e infraestructura principal para facilitar la toma de decisiones de los empresarios. Para el desarrollo de este trabajo se determinaron a partir de un análisis competitivo del país; las principales ciudades y puertos; logrando establecer un inventario de maquinaria y equipo e infraestructura logística; enmarcados en retos ya establecidos en las ...

Borehole logging for uranium exploration

International Nuclear Information System (INIS)

1982-01-01

The present text has been prepared taking into account the requirements of both developing countries, which might be at an incipient stage of uranium exploration, and industrialized countries, where more advanced exploration and resource evaluation techniques are commonly in use. While it was felt necessary to include some discussion of exploration concepts and fundamental physical principles underlying various logging methods, it was not the intention of the consultants to provide a thorough, detailed explanation of the various techniques, or even to give a comprehensive listing thereof. However, a list of references has been included, and it is strongly recommended that the serious student of mineral logging consult this list for further guidance

Polymorphisms in the TNFA and IL6 genes represent risk factors for autoimmune thyroid disease.

Directory of Open Access Journals (Sweden)

Cecília Durães

Full Text Available Autoimmune thyroid disease (AITD comprises diseases including Hashimoto's thyroiditis and Graves' disease, both characterized by reactivity to autoantigens causing, respectively, inflammatory destruction and autoimmune stimulation of the thyroid-stimulating hormone receptor. AITD is the most common thyroid disease and the leading form of autoimmune disease in women. Cytokines are key regulators of the immune and inflammatory responses; therefore, genetic variants at cytokine-encoding genes are potential risk factors for AITD.Polymorphisms in the IL6-174 G/C (rs1800795, TNFA-308 G/A (rs1800629, IL1B-511 C/T (rs16944, and IFNGR1-56 T/C (rs2234711 genes were assessed in a case-control study comprising 420 Hashimoto's thyroiditis patients, 111 Graves' disease patients and 735 unrelated controls from Portugal. Genetic variants were discriminated by real-time PCR using TaqMan SNP genotyping assays.A significant association was found between the allele A in TNFA-308 G/A and Hashimoto's thyroiditis, both in the dominant (OR = 1.82, CI = 1.37-2.43, p-value = 4.4×10(-5 and log-additive (OR = 1.64, CI = 1.28-2.10, p-value = 8.2×10(-5 models. The allele C in IL6-174 G/C is also associated with Hashimoto's thyroiditis, however, only retained significance after multiple testing correction in the log-additive model (OR = 1.28, CI = 1.06-1.54, p-value = 8.9×10(-3. The group with Graves' disease also registered a higher frequency of the allele A in TNFA-308 G/A compared with controls both in the dominant (OR = 1.85, CI = 1.19-2.87, p-value = 7.0×10(-3 and log-additive (OR = 1.69, CI = 1.17-2.44, p-value = 6.6×10(-3 models. The risk for Hashimoto's thyroiditis and Graves' disease increases with the number of risk alleles (OR for two risk alleles is, respectively, 2.27 and 2.59.This study reports significant associations of genetic variants in TNFA and IL6 with the risk for AITD, highlighting the

Modelling tropical forests response to logging

Science.gov (United States)

Cazzolla Gatti, Roberto; Di Paola, Arianna; Valentini, Riccardo; Paparella, Francesco

2013-04-01

Tropical rainforests are among the most threatened ecosystems by large-scale fragmentation due to human activity such as heavy logging and agricultural clearance. Although, they provide crucial ecosystem goods and services, such as sequestering carbon from the atmosphere, protecting watersheds and conserving biodiversity. In several countries forest resource extraction has experienced a shift from clearcutting to selective logging to maintain a significant forest cover and understock of living biomass. However the knowledge on the short and long-term effects of removing selected species in tropical rainforest are scarce and need to be further investigated. One of the main effects of selective logging on forest dynamics seems to be the local disturbance which involve the invasion of open space by weed, vines and climbers at the expense of the late-successional state cenosis. We present a simple deterministic model that describes the dynamics of tropical rainforest subject to selective logging to understand how and why weeds displace native species. We argue that the selective removal of tallest tropical trees carries out gaps of light that allow weeds, vines and climbers to prevail on native species, inhibiting the possibility of recovery of the original vegetation. Our results show that different regime shifts may occur depending on the type of forest management adopted. This hypothesis is supported by a dataset of trees height and weed/vines cover that we collected from 9 plots located in Central and West Africa both in untouched and managed areas.

ADN* Density log estimation Using Rockcell*

International Nuclear Information System (INIS)

Okuku, C.; Iloghalu, Emeka. M.; Omotayo, O.

2003-01-01

This work is intended to inform on the possibilities of estimating good density data in zones associated with sliding in a reservoir with ADN* tool with or without ADOS in string in cases where repeat sections were not done, possibly due to hole stability or directional concerns. This procedure has been equally used to obtain a better density data in corkscrew holes. Density data (ROBB) was recomputed using neural network in RockCell* to estimate the density over zones of interest. RockCell* is a Schlumberger software that has neural network functionally which can be used to estimate missing logs using the combination of the responses of other log curves and intervals that are not affected by sliding. In this work, an interval was selected and within this interval twelve litho zones were defined using the unsupervised neural network. From this a training set was selected based on intervals of very good log responses outside the sliding zones. This training set was used to train and run the neural network for a specific lithostratigraphic interval. The results matched the known good density curve. Then after this, an estimation of the density curve was done using the supervised neural network. The output from this estimation matched very closely in the good portions of the log, thus providing some density measurements in the sliding zone. This methodology provides a scientific solution to missing data during the process of Formation evaluation

Aespoe Hard Rock Laboratory. BIPS logging in borehole KAS09

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Jaana; Gustafsson, Christer (Malaa Geoscience AB (Sweden))

2010-01-15

This report includes the data gained in BIPS logging performed at the Aespoe Hard Rock Laboratory. The logging operation presented here includes BIPS logging in the core drilled borehole KAS09. The objective for the BIPS logging was to observe the condition of KAS09 in order to restore the borehole in the hydrogeological monitoring programme.All measurements were conducted by Malaa Geoscience AB on October 9th 2009. The objective of the BIPS logging is to achieve information of the borehole including occurrence of rock types as well as determination of fracture distribution and orientation. This report describes the equipment used as well as the measurement procedures and data gained. For the BIPS survey, the result is presented as images. The basic conditions of the BIPS logging for geological mapping and orientation of structures are satisfying for borehole KAS09, although induced affects from the drilling on the borehole walls limit the visibility

Aespoe Hard Rock Laboratory. BIPS logging in borehole KAS09

International Nuclear Information System (INIS)

Gustafsson, Jaana; Gustafsson, Christer

2010-01-01

This report includes the data gained in BIPS logging performed at the Aespoe Hard Rock Laboratory. The logging operation presented here includes BIPS logging in the core drilled borehole KAS09. The objective for the BIPS logging was to observe the condition of KAS09 in order to restore the borehole in the hydrogeological monitoring programme.All measurements were conducted by Malaa Geoscience AB on October 9th 2009. The objective of the BIPS logging is to achieve information of the borehole including occurrence of rock types as well as determination of fracture distribution and orientation. This report describes the equipment used as well as the measurement procedures and data gained. For the BIPS survey, the result is presented as images. The basic conditions of the BIPS logging for geological mapping and orientation of structures are satisfying for borehole KAS09, although induced affects from the drilling on the borehole walls limit the visibility

The log-linear return approximation, bubbles, and predictability

DEFF Research Database (Denmark)

Engsted, Tom; Pedersen, Thomas Quistgaard; Tanggaard, Carsten

We study in detail the log-linear return approximation introduced by Campbell and Shiller (1988a). First, we derive an upper bound for the mean approximation error, given stationarity of the log dividendprice ratio. Next, we simulate various rational bubbles which have explosive conditional expec...

Geothermal well log interpretation midterm report

Energy Technology Data Exchange (ETDEWEB)

Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

1979-02-01

Reservoir types are defined according to fluid phase and temperature, lithology, geologic province, pore geometry, and salinity and fluid chemistry. Improvements are needed in lithology and porosity definition, fracture detection, and thermal evaluation for more accurate interpretation. Further efforts are directed toward improving diagnostic techniques for relating rock characteristics and log response, developing petrophysical models for geothermal systems, and developing thermal evaluation techniques. The Geothermal Well Log Interpretation study and report has concentrated only on hydrothermal geothermal reservoirs. Other geothermal reservoirs (hot dry rock, geopressured, etc.) are not considered.

Predicting the Rate of River Bank Erosion Caused by Large Wood Log

Science.gov (United States)

Zhang, N.; Rutherfurd, I.; Ghisalberti, M.

2016-12-01

When a single tree falls into a river channel, flow is deflected and accelerated between the tree roots and the bank face, increasing shear stress and scouring the bank. The scallop shaped erosion increases the diversity of the channel morphology, but also causes concern for adjacent landholders. Concern about increased bank erosion is one of the main reasons for large wood to still be removed from channels in SE Australia. Further, the hydraulic effect of many logs in the channel can reduce overall bank erosion rates. Although both phenomena have been described before, this research develops a hydraulic model that estimates their magnitude, and tests and calibrates this model with flume and field measurements, with logs with various configurations and sizes. Specifically, the model estimates the change in excess shear stress on the bank associated . The model addresses the effect of the log angle, distance from bank, and log size and flow condition by solving the mass continuity and energy conservation between the cross section at the approaching flow and contracted flow. Then, we evaluate our model against flume experiment preformed with semi-realistic log models to represent logs in different sizes and decay stages by comparing the measured and simulated velocity increase in the gap between the log and the bank. The log angle, distance from bank, and flow condition are systemically varied for each log model during the experiment. Final, the calibrated model is compared with the field data collected in anabranching channels of Murray River in SE Australia where there are abundant instream logs and regulated and consistent high flow for irrigation. Preliminary results suggest that a log can significantly increase the shear stress on the bank, especially when it positions perpendicular to the flow. The shear stress increases with the log angle in a rising curve (The log angle is the angle between log trunk and flow direction. 0o means log is parallel to flow with

Assessment of geophysical logs from borehole USW G-2, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Nelson, P.H.; Schimschal, U.

1993-01-01

Commercial logging contractors, Western Atlas, Schlumberger, and Edcon obtained borehole geophysical logs at the site of a potential high level nuclear waste repository at Yucca Mountain, Nevada. Drill hole USW-G2 was picked for this test of suitable logging tools and logging technology, both representing state-of-the-art technology by these commercial companies. Experience gained by analysis of existing core data and a variety of logs obtained earlier by Birdwell and Dresser Atlas served as a guide to a choice of logs to be obtained. Logs were obtained in water-filled borehole in zeolitized tuff (saturated zone) and in air-filled borehole largely in unaltered welded tuff (unsaturated zone)

Automated recognition of stratigraphic marker shales from geophysical logs in iron ore deposits

Science.gov (United States)

Silversides, Katherine; Melkumyan, Arman; Wyman, Derek; Hatherly, Peter

2015-04-01

The mining of stratiform ore deposits requires a means of determining the location of stratigraphic boundaries. A variety of geophysical logs may provide the required data but, in the case of banded iron formation hosted iron ore deposits in the Hamersley Ranges of Western Australia, only one geophysical log type (natural gamma) is collected for this purpose. The information from these logs is currently processed by slow manual interpretation. In this paper we present an alternative method of automatically identifying recurring stratigraphic markers in natural gamma logs from multiple drill holes. Our approach is demonstrated using natural gamma geophysical logs that contain features corresponding to the presence of stratigraphically important marker shales. The host stratigraphic sequence is highly consistent throughout the Hamersley and the marker shales can therefore be used to identify the stratigraphic location of the banded iron formation (BIF) or BIF hosted ore. The marker shales are identified using Gaussian Processes (GP) trained by either manual or active learning methods and the results are compared to the existing geological interpretation. The manual method involves the user selecting the signatures for improving the library, whereas the active learning method uses the measure of uncertainty provided by the GP to select specific examples for the user to consider for addition. The results demonstrate that both GP methods can identify a feature, but the active learning approach has several benefits over the manual method. These benefits include greater accuracy in the identified signatures, faster library building, and an objective approach for selecting signatures that includes the full range of signatures across a deposit in the library. When using the active learning method, it was found that the current manual interpretation could be replaced in 78.4% of the holes with an accuracy of 95.7%.

TENSOR DECOMPOSITIONS AND SPARSE LOG-LINEAR MODELS

Science.gov (United States)

Johndrow, James E.; Bhattacharya, Anirban; Dunson, David B.

2017-01-01

Contingency table analysis routinely relies on log-linear models, with latent structure analysis providing a common alternative. Latent structure models lead to a reduced rank tensor factorization of the probability mass function for multivariate categorical data, while log-linear models achieve dimensionality reduction through sparsity. Little is known about the relationship between these notions of dimensionality reduction in the two paradigms. We derive several results relating the support of a log-linear model to nonnegative ranks of the associated probability tensor. Motivated by these findings, we propose a new collapsed Tucker class of tensor decompositions, which bridge existing PARAFAC and Tucker decompositions, providing a more flexible framework for parsimoniously characterizing multivariate categorical data. Taking a Bayesian approach to inference, we illustrate empirical advantages of the new decompositions. PMID:29332971

Requirements-Driven Log Analysis Extended Abstract

Science.gov (United States)

Havelund, Klaus

2012-01-01

Imagine that you are tasked to help a project improve their testing effort. In a realistic scenario it will quickly become clear, that having an impact is diffcult. First of all, it will likely be a challenge to suggest an alternative approach which is significantly more automated and/or more effective than current practice. The reality is that an average software system has a complex input/output behavior. An automated testing approach will have to auto-generate test cases, each being a pair (i; o) consisting of a test input i and an oracle o. The test input i has to be somewhat meaningful, and the oracle o can be very complicated to compute. Second, even in case where some testing technology has been developed that might improve current practice, it is then likely difficult to completely change the current behavior of the testing team unless the technique is obviously superior and does everything already done by existing technology. So is there an easier way to incorporate formal methods-based approaches than the full edged test revolution? Fortunately the answer is affirmative. A relatively simple approach is to benefit from possibly already existing logging infrastructure, which after all is part of most systems put in production. A log is a sequence of events, generated by special log recording statements, most often manually inserted in the code by the programmers. An event can be considered as a data record: a mapping from field names to values. We can analyze such a log using formal methods, for example checking it against a formal specification. This separates running the system for analyzing its behavior. It is not meant as an alternative to testing since it does not address the important in- put generation problem. However, it offers a solution which testing teams might accept since it has low impact on the existing process. A single person might be assigned to perform such log analysis, compared to the entire testing team changing behavior.

The Log-Linear Return Approximation, Bubbles, and Predictability

DEFF Research Database (Denmark)

Engsted, Tom; Pedersen, Thomas Quistgaard; Tanggaard, Carsten

2012-01-01

We study in detail the log-linear return approximation introduced by Campbell and Shiller (1988a). First, we derive an upper bound for the mean approximation error, given stationarity of the log dividend-price ratio. Next, we simulate various rational bubbles which have explosive conditional expe...

Assessing the risks of Rn exposure: the influence of cigarette smoking

International Nuclear Information System (INIS)

Ginevan, M.E.; Mills, W.A.

1986-01-01

The principal hazard associated with exposure to Rn progeny is lung cancer. However, most lung cancer is caused by smoking, which raises a dual problem of deriving Rn-progeny cancer risk estimates from miner populations who, in large part, are smokers and applying these estimates to the general population whose lung cancer risk, in large part, is determined by smoking habits. We examine current risk estimates for Rn-progeny-induced lung cancer using a cohort life table methodology. Estimates of lifetime probability of dying of lung cancer, average loss in life expectancy due to premature lung cancer death, and loss in life expectancy per premature lung cancer death are calculated for the general population for 1969 and 1978, nonsmokers, and smokers. These calculations demonstrate that such risk estimates are affected by smoking, and by trends in smoking habits, in several ways. Major smoking-related factors in this interaction are the proportion of smokers in the mining population used to derive lung cancer risk estimates, the proportion of smokers in the ''general'' population, and the assumed interaction (additive or multiplicative) between lung cancer risk, Rn-progeny exposure, and smoking history. At this time the data are not sufficient to recommend one particular modeling approach. However, our evaluation demonstrates that broad statements about Rn-progeny lung cancer risk such as x cancers/10(6) person working level month, while informative, are incomplete without further specification. Any risk assessment must clearly state the population assumed to be at risk and the risk model assumed to be operating. Finally, the caveats appropriate to these assumptions should also be enunciated

Quantifying lead-time bias in risk factor studies of cancer through simulation.

Science.gov (United States)

Jansen, Rick J; Alexander, Bruce H; Anderson, Kristin E; Church, Timothy R

2013-11-01

Lead-time is inherent in early detection and creates bias in observational studies of screening efficacy, but its potential to bias effect estimates in risk factor studies is not always recognized. We describe a form of this bias that conventional analyses cannot address and develop a model to quantify it. Surveillance Epidemiology and End Results (SEER) data form the basis for estimates of age-specific preclinical incidence, and log-normal distributions describe the preclinical duration distribution. Simulations assume a joint null hypothesis of no effect of either the risk factor or screening on the preclinical incidence of cancer, and then quantify the bias as the risk-factor odds ratio (OR) from this null study. This bias can be used as a factor to adjust observed OR in the actual study. For this particular study design, as average preclinical duration increased, the bias in the total-physical activity OR monotonically increased from 1% to 22% above the null, but the smoking OR monotonically decreased from 1% above the null to 5% below the null. The finding of nontrivial bias in fixed risk-factor effect estimates demonstrates the importance of quantitatively evaluating it in susceptible studies. Copyright © 2013 Elsevier Inc. All rights reserved.

Operational Cybersecurity Risks and Their Effect on Adoption of Additive Manufacturing in the Naval Domain

Science.gov (United States)

2017-12-01

CYBERSECURITY RISKS AND THEIR EFFECT ON ADOPTION OF ADDITIVE MANUFACTURING IN THE NAVAL DOMAIN by Michael D. Grimshaw December 2017 Thesis...OF ADDITIVE MANUFACTURING IN THE NAVAL DOMAIN 5. FUNDING NUMBERS 6. AUTHOR(S) Michael D. Grimshaw 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Additive manufacturing (AM) has been proven to provide multiple benefits over traditional

Logging a roadside stand to protect scenic values

Science.gov (United States)

Philip M. McDonald; Raymond V. Whiteley

1972-01-01

A case study on the Challenge Experimental Forest, California, demonstrated that logging along roadsides need not despoil roadside stands. Nearly every tree was "viewed" before marking. Because of the "special-care" procedures followed, combined logging and slash-disposal cost was about twice that of a single-tree selection cut.

Direct push driven in situ color logging tool (CLT): technique, analysis routines, and application

Science.gov (United States)

Werban, U.; Hausmann, J.; Dietrich, P.; Vienken, T.

2014-12-01

Direct push technologies have recently seen a broad development providing several tools for in situ parameterization of unconsolidated sediments. One of these techniques is the measurement of soil colors - a proxy information that reveals to soil/sediment properties. We introduce the direct push driven color logging tool (CLT) for real-time and depth-resolved investigation of soil colors within the visible spectrum. Until now, no routines exist on how to handle high-resolved (mm-scale) soil color data. To develop such a routine, we transform raw data (CIEXYZ) into soil color surrogates of selected color spaces (CIExyY, CIEL*a*b*, CIEL*c*h*, sRGB) and denoise small-scale natural variability by Haar and Daublet4 wavelet transformation, gathering interpretable color logs over depth. However, interpreting color log data as a single application remains challenging. Additional information, such as site-specific knowledge of the geological setting, is required to correlate soil color data to specific layers properties. Hence, we exemplary provide results from a joint interpretation of in situ-obtained soil color data and 'state-of-the-art' direct push based profiling tool data and discuss the benefit of additional data. The developed routine is capable of transferring the provided information obtained as colorimetric data into interpretable color surrogates. Soil color data proved to correlate with small-scale lithological/chemical changes (e.g., grain size, oxidative and reductive conditions), especially when combined with additional direct push vertical high resolution data (e.g., cone penetration testing and soil sampling). Thus, the technique allows enhanced profiling by means of providing another reproducible high-resolution parameter for analysis subsurface conditions. This opens potential new areas of application and new outputs for such data in site investigation. It is our intention to improve color measurements by means method of application and data

SedMob: A mobile application for creating sedimentary logs in the field

Science.gov (United States)

Wolniewicz, Pawel

2014-05-01

SedMob is an open-source, mobile software package for creating sedimentary logs, targeted for use in tablets and smartphones. The user can create an unlimited number of logs, save data from each bed in the log as well as export and synchronize the data with a remote server. SedMob is designed as a mobile interface to SedLog: a free multiplatform package for drawing graphic logs that runs on PC computers. Data entered into SedMob are saved in the CSV file format, fully compatible with SedLog.

Gerencia logística y global

Directory of Open Access Journals (Sweden)

Pablo Cesar Ocampo Vélez

2009-04-01

Full Text Available La logística es una filosofía que se encarga de aplicar las buenas pá¡cticas en los macroprocesos, procesos, procedimientos, tareas y productos dentro de una organización, con el fin de satisfacer las necesidades del cliente, quien es la razón de ser de la empresa. Existen entes internacionales que velan porque las compañias en todo el mundo utilicen y difundan las diferentes disciplinas logísticas en toda la red de valor y tengan un mismo enfoque estratégico.El objetivo de este artículo es explicar la existencia de procesos y macroprocesos de clase mundial en la logística, gracias a los cuales hay una gran oportunidad de mejora para los empresarios colombianos, con el fin de reestructurar los procesos estratégicos, tácticos y operacionales de cada Unidad de Negocio, para que sean organizaciones más competitivas, que puedan enfrentar los tratados de libre comercio, brindando mayor sostenibilidad y óptimo nivel de servicio.

Standardized binomial models for risk or prevalence ratios and differences.

Science.gov (United States)

Richardson, David B; Kinlaw, Alan C; MacLehose, Richard F; Cole, Stephen R

2015-10-01

Epidemiologists often analyse binary outcomes in cohort and cross-sectional studies using multivariable logistic regression models, yielding estimates of adjusted odds ratios. It is widely known that the odds ratio closely approximates the risk or prevalence ratio when the outcome is rare, and it does not do so when the outcome is common. Consequently, investigators may decide to directly estimate the risk or prevalence ratio using a log binomial regression model. We describe the use of a marginal structural binomial regression model to estimate standardized risk or prevalence ratios and differences. We illustrate the proposed approach using data from a cohort study of coronary heart disease status in Evans County, Georgia, USA. The approach reduces problems with model convergence typical of log binomial regression by shifting all explanatory variables except the exposures of primary interest from the linear predictor of the outcome regression model to a model for the standardization weights. The approach also facilitates evaluation of departures from additivity in the joint effects of two exposures. Epidemiologists should consider reporting standardized risk or prevalence ratios and differences in cohort and cross-sectional studies. These are readily-obtained using the SAS, Stata and R statistical software packages. The proposed approach estimates the exposure effect in the total population. © The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Unification of acoustic drillhole logging data

International Nuclear Information System (INIS)

Oehman, I.; Palmen, J.; Heikkinen, E.

2009-04-01

Posiva Oy prepares for disposal of spent nuclear fuel in bedrock in Olkiluoto, Eurajoki. This is in accordance of the application filed in 1999, the Decision-in-Principle of the State Council in 2000, and ratification by the Parliament in 2001. The site characterization at Olkiluoto has included comprehensive geological, hydrological, geochemical and geophysical investigations airborne, on ground and in drillholes since 1988. One of key techniques in geophysical drillhole surveys has been acoustic full waveform logging, which has been implemented since 1994. Various tools have been used in acquisition of acoustic data and several processing techniques have been applied. The logging work and processing to P and S wave velocities has been previously carried out on single drillhole basis. Comparisons to actual values and levels have not been made, and the results have not been calibrated. Therefore results for different drillholes have not been comparable. Resolution of the P and S wave velocity has been rather coarse, and depth correlation to the core data has been on tentative level. As the investigation data has been accumulating, it has become possible to correlate the results to geological and laboratory control data and to calibrate the results of separate measurement campaigns and different drillholes together onto same reference level and resolution. The presented technique has been applied for drillhole OL-KR29 onwards and has set the processing standard, settings and reference levels for later surveys. This approach will further assist the application of the method for mapping and numerical description of lithology variation and possible effect of alteration and deformation on it. Further on, the P and S wave velocity data together with density can be used in computing of dynamic in situ rock mechanical parameters, and possibly in correlating rock strength laboratory data to P and S wave velocity logging data. The acoustic logging data from drillholes OL-KR1

On the generation of log-Levy distributions and extreme randomness

International Nuclear Information System (INIS)

Eliazar, Iddo; Klafter, Joseph

2011-01-01

The log-normal distribution is prevalent across the sciences, as it emerges from the combination of multiplicative processes and the central limit theorem (CLT). The CLT, beyond yielding the normal distribution, also yields the class of Levy distributions. The log-Levy distributions are the Levy counterparts of the log-normal distribution, they appear in the context of ultraslow diffusion processes, and they are categorized by Mandelbrot as belonging to the class of extreme randomness. In this paper, we present a natural stochastic growth model from which both the log-normal distribution and the log-Levy distributions emerge universally-the former in the case of deterministic underlying setting, and the latter in the case of stochastic underlying setting. In particular, we establish a stochastic growth model which universally generates Mandelbrot's extreme randomness. (paper)

Risk-sensitive mean-field games

KAUST Repository

Tembine, Hamidou

2014-04-01

In this paper, we study a class of risk-sensitive mean-field stochastic differential games. We show that under appropriate regularity conditions, the mean-field value of the stochastic differential game with exponentiated integral cost functional coincides with the value function satisfying a Hamilton -Jacobi- Bellman (HJB) equation with an additional quadratic term. We provide an explicit solution of the mean-field best response when the instantaneous cost functions are log-quadratic and the state dynamics are affine in the control. An equivalent mean-field risk-neutral problem is formulated and the corresponding mean-field equilibria are characterized in terms of backward-forward macroscopic McKean-Vlasov equations, Fokker-Planck-Kolmogorov equations, and HJB equations. We provide numerical examples on the mean field behavior to illustrate both linear and McKean-Vlasov dynamics. © 1963-2012 IEEE.

Risk-sensitive mean-field games

KAUST Repository

Tembine, Hamidou; Zhu, Quanyan; Başar, Tamer

2014-01-01

In this paper, we study a class of risk-sensitive mean-field stochastic differential games. We show that under appropriate regularity conditions, the mean-field value of the stochastic differential game with exponentiated integral cost functional coincides with the value function satisfying a Hamilton -Jacobi- Bellman (HJB) equation with an additional quadratic term. We provide an explicit solution of the mean-field best response when the instantaneous cost functions are log-quadratic and the state dynamics are affine in the control. An equivalent mean-field risk-neutral problem is formulated and the corresponding mean-field equilibria are characterized in terms of backward-forward macroscopic McKean-Vlasov equations, Fokker-Planck-Kolmogorov equations, and HJB equations. We provide numerical examples on the mean field behavior to illustrate both linear and McKean-Vlasov dynamics. © 1963-2012 IEEE.

A review of the additive health risk of cannabis and tobacco co-use.

Science.gov (United States)

Meier, Ellen; Hatsukami, Dorothy K

2016-09-01

Cannabis and tobacco are the most widely used substances, and are often used together. The present review examines the toxicant exposure associated with co-use (e.g., carbon monoxide, carcinogens), co-use via electronic nicotine delivery systems (ENDS), and problematic methodological issues present across co-use studies. An extensive literature search through PubMed was conducted and studies utilizing human subjects and in vitro methods were included. Keywords included tobacco, cigarette, e-cigarette, ENDS, smoking, or nicotine AND marijuana OR cannabis OR THC. Co-use may pose additive risk for toxicant exposure as certain co-users (e.g., blunt users) tend to have higher breath carbon monoxide levels and cannabis smoke can have higher levels of some carcinogens than tobacco smoke. Cannabis use via ENDS is low and occurs primarily among established tobacco or cannabis users, but its incidence may be increasing and expanding to tobacco/cannabis naïve individuals. There are several methodological issues across co-use research including varying definitions of co-use, sample sizes, lack of control for important covariates (e.g., time since last cigarette), and inconsistent measurement of outcome variables. There are some known additive risks for toxicant exposure as a result of co-use. Research utilizing consistent methodologies is needed to further establish the additive risk of co-use. Future research should also be aware of novel technologies (e.g., ENDS) as they likely alter some toxicant exposure when used alone and with cannabis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Log of Apollo 11.

Science.gov (United States)

National Aeronautics and Space Administration, Washington, DC.

The major events of the first manned moon landing mission, Apollo 11, are presented in chronological order from launch time until arrival of the astronauts aboard the U.S.S. Hornet. The log is descriptive, non-technical, and includes numerous color photographs of the astronauts on the moon. (PR)

The Spontaneous Ray Log: A New Aid for Constructing Pseudo-Synthetic Seismograms

Science.gov (United States)

Quadir, Adnan; Lewis, Charles; Rau, Ruey-Juin

2018-02-01

Conventional synthetic seismograms for hydrocarbon exploration combine the sonic and density logs, whereas pseudo-synthetic seismograms are constructed with a density log plus a resistivity, neutron, gamma ray, or rarely a spontaneous potential log. Herein, we introduce a new technique for constructing a pseudo-synthetic seismogram by combining the gamma ray (GR) and self-potential (SP) logs to produce the spontaneous ray (SR) log. Three wells, each of which consisted of more than 1000 m of carbonates, sandstones, and shales, were investigated; each well was divided into 12 Groups based on formation tops, and the Pearson product-moment correlation coefficient (PCC) was calculated for each "Group" from each of the GR, SP, and SR logs. The highest PCC-valued log curves for each Group were then combined to produce a single log whose values were cross-plotted against the reference well's sonic ITT values to determine a linear transform for producing a pseudo-sonic (PS) log and, ultimately, a pseudo-synthetic seismogram. The range for the Nash-Sutcliffe efficiency (NSE) acceptable value for the pseudo-sonic logs of three wells was 78-83%. This technique was tested on three wells, one of which was used as a blind test well, with satisfactory results. The PCC value between the composite PS (SR) log with low-density correction and the conventional sonic (CS) log was 86%. Because of the common occurrence of spontaneous potential and gamma ray logs in many of the hydrocarbon basins of the world, this inexpensive and straightforward technique could hold significant promise in areas that are in need of alternate ways to create pseudo-synthetic seismograms for seismic reflection interpretation.

Economic incentives exist to support measures to reduce illegal logging

Science.gov (United States)

J.A. Turner; J. Buongiorno; A. Katz; S. Zhu; R. Li

2008-01-01

Three studies of the global economic implications of eliminating illegal logging are summarized. Processors of illegally sourced wood would lose from the elimination of illegal logging through high prices for logs and decreased production of wood products. Associated with these changes could be losses in employment and income. Beyond these losses to the processing...

Interactive machine learning for postprocessing CT images of hardwood logs

Science.gov (United States)

Erol Sarigul; A. Lynn Abbott; Daniel L. Schmoldt

2003-01-01

This paper concerns the nondestructive evaluation of hardwood logs through the analysis of computed tomography (CT) images. Several studies have shown that the commercial value of resulting boards can be increased substantially if log sawing strategies are chosen using prior knowledge of internal log defects. Although CT imaging offers a potential means of obtaining...

A novel method for quantitative geosteering using azimuthal gamma-ray logging.

Science.gov (United States)

Yuan, Chao; Zhou, Cancan; Zhang, Feng; Hu, Song; Li, Chaoliu

2015-02-01

A novel method for quantitative geosteering by using azimuthal gamma-ray logging is proposed. Real-time up and bottom gamma-ray logs when a logging tool travels through a boundary surface with different relative dip angles are simulated with the Monte Carlo method. Study results show that response points of up and bottom gamma-ray logs when the logging tool moves towards a highly radioactive formation can be used to predict the relative dip angle, and then the distance from the drilling bit to the boundary surface is calculated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Increased risk of sadness and suicidality among victims of bullying experiencing additional threats to physical safety.

Science.gov (United States)

Pham, Tammy B; Adesman, Andrew

2017-11-23

Objective To examine, in a nationally-representative sample of high school students, to what extent one or more additional threats to physical safety exacerbates the risk of sadness and suicidality among victims of school and/or cyber-bullying. Methods National data from the 2015 Youth Risk Behavior Survey (YRBS) were analyzed for grades 9-12 (n = 15,624). Victimization groups were characterized by school-bullying and cyber-bullying, with and without additional threats to physical safety: fighting at school, being threatened/injured at school, and skipping school out of fear for one's safety. Outcomes included 2-week sadness and suicidality. Outcomes for victimization groups were compared to non-victims using logistic regression adjusting for sex, grade and race/ethnicity. Results Overall, 20.2% of students were school-bullied, and 15.5% were cyber-bullied in the past year. Compared to non-victims, victims of school-bullying and victims of cyber-bullying (VoCBs) who did not experience additional threats to physical safety were 2.76 and 3.83 times more likely to report 2-week sadness, and 3.39 and 3.27 times more likely to exhibit suicidality, respectively. Conversely, victims of bullying who experienced one or more additional threats to physical safety were successively more likely to report these adverse outcomes. Notably, victims of school-bullying and VoCBs with all three additional risk factors were 13.13 and 17.75 times more likely to exhibit suicidality, respectively. Conclusion Risk of depression symptoms and suicidality among victims of school-bullying and/or cyber-bullying is greatly increased among those who have experienced additional threats to physical safety: fighting at school, being threatened/injured at school and skipping school out of fear for their safety.

Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species.

Science.gov (United States)

Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P

2016-03-16

Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. © 2016 The Author(s).

Selective logging in tropical forests decreases the robustness of liana–tree interaction networks to the loss of host tree species

Science.gov (United States)

Magrach, Ainhoa; Senior, Rebecca A.; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F.; Santamaria, Luis; Edwards, David P.

2016-01-01

Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the ‘health’ and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana–tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of ‘extinction debt’. PMID:26936241

Linking downhole logging data and clay mineralogy analysis in the ICDP Lake Junín drilling Project, Peru

Science.gov (United States)

Pierdominici, S.; Schleicher, A.; Kueck, J.; Rodbell, D. T.; Abbott, M. B.

2017-12-01

The lake Junin drilling project, co-funded by the International Continental Drilling Program (ICDP), is located at 4000 m a.s.l. in the tropical Andes of Peru. Several boreholes were drilled with the goal to obtain both high-resolution paleoclimate records from lacustrine sediments and to reconstruct the history of the continental records covering the glacial-interglacial cycles. Lake Junín is characterized by a thick package of lacustrine sediments (> 125 m) deposited at a high rate (0.2 to 1.0 mm yr-1), and it is one of the few lakes in the tropical Andes that is hundreds of thousands of years old with a continuous sedimentation rate preserving a very long and continuous record of past ice age cycles. The boreholes reached a maximum depth of 110.08 m and continuous coring was performed at three sites with 11 boreholes. Additionally, an extensive geophysical downhole logging campaign was performed on five boreholes (1A, 1C, 1D, 2A and 3B) by the Operational Support Group of ICDP. Downhole logging measurements comprise total and spectrum gamma ray, magnetic susceptibility, borehole geometry, temperature, and sonic p-wave velocity. In order to fit the downhole logging depths to the composite profile depths, each borehole was depth-matched with the core data. Interpreting the downhole logging data permits to establish a complete lithological log, to characterize the in-situ physical properties of drilled lacustrine sediments, to determine sedimentary structures and to obtain evidences about palaeoclimatic conditions during up to 200 ka. Th and K values are used as a proxy for a first estimate and characterization of clay content in the sediments, which are present as montmorillonite, smectite, illite, and kaolinite in different amounts. Linking the clay minerals that occur in the core material with the downhole logging data allows assessing the geological history of the lake and the relationship to climate change processes. Additional laboratory analysis will be

Geophysical logging for mineral exploration and development

International Nuclear Information System (INIS)

Plouffe, R.D.

1981-01-01

It is possible to retrieve from small-diameter holes geophysical data for qualitative interpretation in exploration and quantitative interpretation in the development of orebodies. The primary objectives in the exploration stage are to identify where, within a hole, economic minerals are, and to help in lithological interpretations. Other aspects, which are more quantitative, are the interpretation of downhole logs for parameters which can be used in surface geophysical methods (i.e. density for gravity surveys, acoustic velocities for seismic surveys, and magnetic susceptibility for airborne and ground magnetic surveys). Recent advances in equipment design, portability and durability have made downhole logging in exploration more inexpensive and reliable. This new equipment is being used to generate very precise quantitative results. This is especially true on uranium development projects. The interpretation of gamma logs for eU 3 O 8 values has finally become precise enough that they have begun to replace chemical values in reserve calculations. Another part of development data is density and equilibrium information, which, with today's technology, is being derived from downhole probing. In the years to come, the trends for many metals are toward neutron activation techniques, or in-situ assaying, and the use of multiple logs for better lithological and physical rock property determinations. (auth)

Log-periodic dipole antenna with low cross-polarization

DEFF Research Database (Denmark)

Pivnenko, Sergey

2006-01-01

In this work, log-periodic antennas with improved cross-polarization level were studied. It was found that some modifications of the traditional design lead to an essential improvement of the co-to-cross polarization ratio up to 40 dB. An improved design of a log-periodic dipole antenna with low...

Mitigating Hillslope Erosion After Post-fire Salvage Logging Operations

Science.gov (United States)

Robichaud, P. R.; Bone, E. D.; Brown, R. E.

2017-12-01

In the past decades, wildfires around the world have continued to increase in size, severity, and cost. Major concerns after wildfires are the increased runoff and erosion due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. Salvage logging is often a post-fire forest management action to recoup the economic loss of the burned timber, yet concerns arise on the impacts of this activity on water quality. Recently, several studies have been conducted to determine the effect of salvage logging on hillslope erosion. Logging skid trails have been cited as being the cause of high erosion during and after salvage operations. We investigated the impacts of adding operational logging slash to skid trails to reduce hillslope erosion after salvage operations on the 2015 North Star Fire, Washington. We implemented well-designed rapid response approach to compare slash treatment effectiveness by monitoring sediment yield and runoff response from hillslopes with a concentrated flow (rill) experiment. Various runoff amounts are incrementally added to 4 m hillslope plots with and without slash treatments. Our initial results suggest that adding logging slash increased ground cover significantly which contributed to an order of magnitude decrease in hillslope erosion. Integrating erosion mitigation strategies into salvage logging operations should be commonplace when hillslope erosion is a concern.

Smartphone log data in a qualitative perspective

DEFF Research Database (Denmark)

Ørmen, Jacob; Thorhauge, Anne Mette

2015-01-01

into studies of smartphones in everyday life. Through an illustrative study, we explore a more nuanced perspective on what can be considered “log data” and how these types of data can be collected and analysed. A qualitative approach to log data analysis offers researchers new opportunities to situate......Log data from smartphones have primarily been used in large-scale research designs to draw statistical inferences from hundreds or even thousands of participants. In this article, we argue that more qualitatively oriented designs can also benefit greatly from integrating these rich data sources...... serve as cues to instigate discussion and reflection as well as act as resources for contextualizing and organizing related empirical material. In the discussion, the advantages of a qualitative perspective for research designs are assessed in relation to issues of validity. Further perspectives...

The incidence of injuries in young people: II. Log-linear multivariable models for risk factors in a collaborative study in Brazil, Chile, Cuba and Venezuela.

Science.gov (United States)

Bangdiwala, S I; Anzola-Pérez, E

1990-03-01

Injuries and accidents are acknowledged as leading causes of morbidity and mortality among children and adolescents in the developing countries of the world. The Pan American Health Organization sponsored a collaborative study in four selected countries in Latin America to study the extent of the problem as well as to examine the potential risk factors associated with selected non-fatal injuries in the countries. The study subjects were injured children and adolescents (0-19 years of age) presenting at the study hospitals in chosen urban centres, as well as injured that were surveyed in households in the catchment areas of the hospitals. Study methods and descriptive frequency results were presented earlier. In this paper, log-linear multivariate regression models are used to examine the potentiating effects within country of several measured variables on specific types of injuries. The significance of risk factors varied between countries; however, some general patterns emerged. Falls were more likely in younger children, and occurred at home. The main risk factor for home accidents was the age of the child. The education of the head of the household was an important risk factor for the type of injury suffered. The likelihood of traffic accident injury varied with time of day and day of the week, but also was more likely in higher educated households. The results found are consistent with those found in other studies in the developed world and suggest specific areas of concern for health planners to address.

Utilization and cost of log production from animal loging operations

Science.gov (United States)

Suraj P. Shrestha; Bobby L. Lanford; Robert B. Rummer; Mark Dubois

2006-01-01

Forest harvesting with animals is a labor-intensive operation. It is expensive to use machines on smaller woodlots, which require frequent moves if mechanically logged. So, small logging systems using animals may be more cost effective. In this study, work sampling was used for five animal logging operations in Alabama to measure productive and non-productive time...

Dimension yields from short logs of low-quality hardwood trees.

Science.gov (United States)

Howard N. Rosen; Harold A. Stewart; David J. Polak

1980-01-01

Charts are presented for determining yields of 4/4 dimension cuttings from short hardwood logs of aspen, soft maple, black cherry, yellow-poplar, and black walnut for several cutting grades and bolt sizes. Cost comparisons of short log and standard grade mixes show sizes. Cost comparisons of short log and standard grade mixes show the estimated least expensive...

Research on Test-bench for Sonic Logging Tool

Directory of Open Access Journals (Sweden)

Xianping Liu

2016-01-01

Full Text Available In this paper, the test-bench for sonic logging tool is proposed and designed to realize automatic calibration and testing of the sonic logging tool. The test-bench System consists of Host Computer, Embedded Controlling Board, and functional boards. The Host Computer serves as the Human Machine Interface (HMI and processes uploaded data. The software running on Host Computer is designed on VC++, which is developed based on multithreading, Dynamic Linkable Library (DLL and Multiple Document Interface (MDI techniques. The Embedded Controlling Board uses ARM7 as the microcontroller and communicates with Host Computer via Ethernet. The Embedded Controlling Board software is realized based on embedded uclinux operating system with a layered architecture. The functional boards are designed based on Field Programmable Gate Array (FPGA and provide test interfaces for the logging tool. The functional board software is divided into independent sub-modules that can repeatedly be used by various functional boards and then integrated those sub-modules in the top layer. With the layered architecture and modularized design, the software system is highly reliable and extensible. With the help of designed system, a test has been conducted quickly and successfully on the electronic receiving cabin of the sonic logging tool. It demonstrated that the system could greatly improve the production efficiency of the sonic logging tool.

Kaizen aplicado à logística

OpenAIRE

Santos, Ana Catarina Almeida

2011-01-01

O presente trabalho propõe alcançar um aumento de produtividade e consequente redução de custos e desperdícios ajudando o departamento logístico da Empresa Revigrés – Industria de Revestimentos de Grés, Lda, a tornar-se mais eficiente, através da aplicação da filosofia kaizen que propõe melhorias no desempenho por implementação de pequenas ações. O objetivo deste projeto é a melhoria do departamento logístico globalmente, para isso houve o recurso a pesquisas e levantamento ...

Some properties of the log-Laplace distribution

International Nuclear Information System (INIS)

Uppuluri, V.R.R.

1980-01-01

A random variable Y is said to have the Laplace distribution or the double exponential distribution whenever its probability density function is given by lambda exp(-lambda abs. value y), where -infinity 0. The random variable X = exp(Y) is said to have the log-Laplace distribution. With the problem of extrapolation to low doses in dose response curves as motivation, an axiomatic characterization of the log-Laplace distribution is obtained. 1 figure

Some properties of the log-Laplace distribution

International Nuclear Information System (INIS)

Uppuluri, V.R.R.

1980-08-01

A random variable γ is said to have the Laplace distribution or the double exponential distribution whenever its probability density function is given by lambda exp(-lambda absolute value (y)), where -infinity 0. The random variable X = exp(γ) is said to have the log-Laplace distribution. With the problem of extrapolation to low doses in dose response curves as a motivation, an axiomatic characterization of the log-Laplace distribution is obtained. 1 figure

Predictive models of forest logging residues of Triplochiton ...

African Journals Online (AJOL)

The model developed indicated that logarithmic functions performed better than other form of equation. The findings of this study revealed that there is significant logging residues left to waste in the forest after timber harvest and quantifying this logging residue in terms of biomass model can serve as management tools in ...

Estimating tree bole and log weights from green densities measured with the Bergstrom Xylodensimeter.

Science.gov (United States)

Dale R. Waddell; Michael B. Lambert; W.Y. Pong

1984-01-01

The performance of the Bergstrom xylodensimeter, designed to measure the green density of wood, was investigated and compared with a technique that derived green densities from wood disk samples. In addition, log and bole weights of old-growth Douglas-fir and western hemlock were calculated by various formulas and compared with lifted weights measured with a load cell...

Relative Importance and Additive Effects of Maternal and Infant Risk Factors on Childhood Asthma.

Science.gov (United States)

Wu, Pingsheng; Feldman, Amy S; Rosas-Salazar, Christian; James, Kristina; Escobar, Gabriel; Gebretsadik, Tebeb; Li, Sherian Xu; Carroll, Kecia N; Walsh, Eileen; Mitchel, Edward; Das, Suman; Kumar, Rajesh; Yu, Chang; Dupont, William D; Hartert, Tina V

2016-01-01

Environmental exposures that occur in utero and during early life may contribute to the development of childhood asthma through alteration of the human microbiome. The objectives of this study were to estimate the cumulative effect and relative importance of environmental exposures on the risk of childhood asthma. We conducted a population-based birth cohort study of mother-child dyads who were born between 1995 and 2003 and were continuously enrolled in the PRIMA (Prevention of RSV: Impact on Morbidity and Asthma) cohort. The individual and cumulative impact of maternal urinary tract infections (UTI) during pregnancy, maternal colonization with group B streptococcus (GBS), mode of delivery, infant antibiotic use, and older siblings at home, on the risk of childhood asthma were estimated using logistic regression. Dose-response effect on childhood asthma risk was assessed for continuous risk factors: number of maternal UTIs during pregnancy, courses of infant antibiotics, and number of older siblings at home. We further assessed and compared the relative importance of these exposures on the asthma risk. In a subgroup of children for whom maternal antibiotic use during pregnancy information was available, the effect of maternal antibiotic use on the risk of childhood asthma was estimated. Among 136,098 singleton birth infants, 13.29% developed asthma. In both univariate and adjusted analyses, maternal UTI during pregnancy (odds ratio [OR] 1.2, 95% confidence interval [CI] 1.18, 1.25; adjusted OR [AOR] 1.04, 95%CI 1.02, 1.07 for every additional UTI) and infant antibiotic use (OR 1.21, 95%CI 1.20, 1.22; AOR 1.16, 95%CI 1.15, 1.17 for every additional course) were associated with an increased risk of childhood asthma, while having older siblings at home (OR 0.92, 95%CI 0.91, 0.93; AOR 0.85, 95%CI 0.84, 0.87 for each additional sibling) was associated with a decreased risk of childhood asthma, in a dose-dependent manner. Compared with vaginal delivery, C

Relative Importance and Additive Effects of Maternal and Infant Risk Factors on Childhood Asthma.

Directory of Open Access Journals (Sweden)

Pingsheng Wu

Full Text Available Environmental exposures that occur in utero and during early life may contribute to the development of childhood asthma through alteration of the human microbiome. The objectives of this study were to estimate the cumulative effect and relative importance of environmental exposures on the risk of childhood asthma.We conducted a population-based birth cohort study of mother-child dyads who were born between 1995 and 2003 and were continuously enrolled in the PRIMA (Prevention of RSV: Impact on Morbidity and Asthma cohort. The individual and cumulative impact of maternal urinary tract infections (UTI during pregnancy, maternal colonization with group B streptococcus (GBS, mode of delivery, infant antibiotic use, and older siblings at home, on the risk of childhood asthma were estimated using logistic regression. Dose-response effect on childhood asthma risk was assessed for continuous risk factors: number of maternal UTIs during pregnancy, courses of infant antibiotics, and number of older siblings at home. We further assessed and compared the relative importance of these exposures on the asthma risk. In a subgroup of children for whom maternal antibiotic use during pregnancy information was available, the effect of maternal antibiotic use on the risk of childhood asthma was estimated.Among 136,098 singleton birth infants, 13.29% developed asthma. In both univariate and adjusted analyses, maternal UTI during pregnancy (odds ratio [OR] 1.2, 95% confidence interval [CI] 1.18, 1.25; adjusted OR [AOR] 1.04, 95%CI 1.02, 1.07 for every additional UTI and infant antibiotic use (OR 1.21, 95%CI 1.20, 1.22; AOR 1.16, 95%CI 1.15, 1.17 for every additional course were associated with an increased risk of childhood asthma, while having older siblings at home (OR 0.92, 95%CI 0.91, 0.93; AOR 0.85, 95%CI 0.84, 0.87 for each additional sibling was associated with a decreased risk of childhood asthma, in a dose-dependent manner. Compared with vaginal delivery, C

Applications of outcrop gamma-ray logging to field development and exploration

International Nuclear Information System (INIS)

Jordan, D.W.; Slatt, R.M.; Gillespie, R.H.; D'Agostino, A.E.; Scheihing, M.H.

1991-01-01

Gamma-ray logs of outcrops have been generated using two techniques. These techniques demonstrate the applicability of outcrop logging to better understand reservoir facies architecture and exploration type problems. The first logging technique employs the use of a standard logging truck and gamma-ray sonde. The truck is positioned near the top of the cliff face and the sonde is lowered to the bottom of the cliff. Gamma-ray counts are recorded as the sonde is raised at a constant rate. The second logging technique employs the use of a commercially available, hand-held, gamma-ray scintillometer. The tool measures total radiation at the outcrop. Equally-spaced measurements are made along the section and are displayed as a function of depth below a reference point. In this paper examples of gamma-ray logging experiments conducted on turbidities of the Jackfork Group (Pennsylvanian) in central and southern Arkansas are discussed, as are application of outcrop gamma-ray logging in the Long Beach Unit of Wilmington Oil Field, California, and Point Mugu (Santa Barbara Channel), California

A novel method for quantitative geosteering using azimuthal gamma-ray logging

International Nuclear Information System (INIS)

Yuan, Chao; Zhou, Cancan; Zhang, Feng; Hu, Song; Li, Chaoliu

2015-01-01

A novel method for quantitative geosteering by using azimuthal gamma-ray logging is proposed. Real-time up and bottom gamma-ray logs when a logging tool travels through a boundary surface with different relative dip angles are simulated with the Monte Carlo method. Study results show that response points of up and bottom gamma-ray logs when the logging tool moves towards a highly radioactive formation can be used to predict the relative dip angle, and then the distance from the drilling bit to the boundary surface is calculated. - Highlights: • A new method is proposed for geosteering by using azimuthal gamma-ray logging. • The new method can quantitatively determine the distance from the drilling bit to the boundary surface while the traditional geosteering method can only qualitatively guide the drilling bit in reservoirs. • The response points of real-time upper and lower gamma line when the logging tool meets high radioactive formation are used to predict the relative dip angles, and then the distance from the drilling bit to the boundary surface is calculated

VT Route Log Points 2017

Data.gov (United States)

Vermont Center for Geographic Information — This data layer is used with VTrans' Integrated Route Log System (IRA). It is also used to calibrate the linear referencing systems, including the End-to-End and...

Well-logging method using well-logging tools run through a drill stem test string for determining in-situ change in formation water saturation values

International Nuclear Information System (INIS)

Fertl, W.H.

1975-01-01

A logging tool (pulsed neutron or neutron-gamma ray) whose response indicates formation water saturation value, is run through an opening extending through a portion of a drill stem test string. A sample portion of the formation fluid in the zone of interest is removed and another logging run is made. The differences between the plots of the two logging runs indicate the formation potential productivity in the zone of interest

Jauch-Piron States and σ-Additivity

Science.gov (United States)

Bunce, L. J.; Hamhalter, Jan

We study σ-additivity of the physically plausible Jauch-Piron states on a von Neumann algebra M. Amongst other consequences we extend our earlier results [5] by showing that geometric conditions much weaker than pureness imply σ-additivity for a Jauch-Piron state and, further, that if M is properly infinite and the continuum hypothesis is assumed to be true then all Jauch-Piron factor states are σ-additive.

Cost of skid roads for arch logging in West Virginia

Science.gov (United States)

George R., Jr. Trimble; Carl R. Barr

1960-01-01

In the mountain hardwood country of the northern Appalachians, tree-length skidding with tractor and arch has proved to be economical logging. One essential part of this type of logging is that tree-length logs are winched to the skid roads: tractor and arch do not run around through the woods. Winching distance is commonly 200 to 300 feet; and occasionally an extra...

Environmental effects of postfire logging: literature review and annotated bibliography.

Science.gov (United States)

James D. McIver; Lynn Starr

2000-01-01

The scientific literature on logging after wildfire is reviewed, with a focus on environmental effects of logging and removal of large woody structure. Rehabilitation, the practice of planting or seeding after logging, is not reviewed here. Several publications are cited that can be described as “commentaries,” intended to help frame the public debate. We review 21...

Ultrafast CT scanning of an oak log for internal defects

Science.gov (United States)

Francis G. Wagner; Fred W. Taylor; Douglas S. Ladd; Charles W. McMillin; Fredrick L. Roder

1989-01-01

Detecting internal defects in sawlogs and veneer logs with computerized tomographic (CT) scanning is possible, but has been impractical due to the long scanning time required. This research investigated a new scanner able to acquire 34 cross-sectional log scans per second. This scanning rate translates to a linear log feed rate of 85 feet (25.91 m) per minute at one...

Additive composite ABCG2, SLC2A9 and SLC22A12 scores of high-risk alleles with alcohol use modulate gout risk.

Science.gov (United States)

Tu, Hung-Pin; Chung, Chia-Min; Min-Shan Ko, Albert; Lee, Su-Shin; Lai, Han-Ming; Lee, Chien-Hung; Huang, Chung-Ming; Liu, Chiu-Shong; Ko, Ying-Chin

2016-09-01

The aim of the present study was to evaluate the contribution of urate transporter genes and alcohol use to the risk of gout/tophi. Eight variants of ABCG2, SLC2A9, SLC22A12, SLC22A11 and SLC17A3 were genotyped in male individuals in a case-control study with 157 gout (33% tophi), 106 asymptomatic hyperuricaemia and 295 control subjects from Taiwan. The multilocus profiles of the genetic risk scores for urate gene variants were used to evaluate the risk of asymptomatic hyperuricaemia, gout and tophi. ABCG2 Q141K (T), SLC2A9 rs1014290 (A) and SLC22A12 rs475688 (C) under an additive model and alcohol use independently predicted the risk of gout (respective odds ratio for each factor=2.48, 2.03, 1.95 and 2.48). The additive composite Q141K, rs1014290 and rs475688 scores of high-risk alleles were associated with gout risk (Pgout and tophi risk (P for interaction=0.0452, 0.0033). The synergistic effect of genetic urate score 5-6 and alcohol use indicates that these combined factors correlate with gout and tophi occurrence.

A New Concept for Counter-Checking of Assumed CPM Pairs

Science.gov (United States)

Knapp, Wilfried; Nanson, John

2017-01-01

The inflation of “newly discovered” CPM pairs makes it necessary to develop an approach for a solid concept for counter-checking assumed CPM pairs with the target to identify false positives. Such a concept is presented in this report.

The analog CTS communication interface in nuclear logging

International Nuclear Information System (INIS)

Li Min

2000-01-01

The author introduced a micro-controller-based CTS communication interface in nuclear logging, which provided convenience for the overhaul and regulation of the logging tool in CTS communication system. The use of micro-controller simplified the hardware structure of the interface, made the soft structure more rational and the whole system more flexible to control

Perfil logístico del sector cemento en Colombia

OpenAIRE

Hernández Calderón, Miguel Ángel; Nieves de la Hoz, Celia Elena

2015-01-01

Este proyecto caracteriza la logística del sector cemento en Colombia al identificar y describir los principales actores, procesos y materiales involucrados en la cadena de suministros del sector. Este documento compila la información logística relevante para la producción de cemento en Colombia. Esta información se obtuvo sintetizando estudios y reportes acerca de las prácticas logísticas y las condiciones en las que éstas se desarrollan. Adicionalmente se realizaron visitas empresariales en...

Risk factors for an additional port in single-incision laparoscopic cholecystectomy in patients with cholecystitis.

Science.gov (United States)

Araki, Kenichiro; Shirabe, Ken; Watanabe, Akira; Kubo, Norio; Sasaki, Shigeru; Suzuki, Hideki; Asao, Takayuki; Kuwano, Hiroyuki

2017-01-01

Although single-incision laparoscopic cholecystectomy is now widely performed in patients with cholecystitis, some cases require an additional port to complete the procedure. In this study, we focused on risk factor of additional port in this surgery. We performed single-incision cholecystectomy in 75 patients with acute cholecystitis or after cholecystitis between 2010 and 2014 at Gunma University Hospital. Surgical indications followed the TG13 guidelines. Our standard procedure for single-incision cholecystectomy routinely uses two needlescopic devices. We used logistic regression analysis to identify the risk factors associated with use of an additional full-size port (5 or 10 mm). Surgical outcome was acceptable without biliary injury. Nine patients (12.0%) required an additional port, and one patient (1.3%) required conversion to open cholecystectomy because of severe adhesions around the cystic duct and common bile duct. In multivariate analysis, high C-reactive protein (CRP) values (>7.0 mg/dl) during cholecystitis attacks were significantly correlated with the need for an additional port (P = 0.009), with a sensitivity of 55.6%, specificity of 98.5%, and accuracy of 93.3%. This study indicated that the severe inflammation indicated by high CRP values during cholecystitis attacks predicts the need for an additional port. J. Med. Invest. 64: 245-249, August, 2017.

SU-E-T-392: Evaluation of Ion Chamber/film and Log File Based QA to Detect Delivery Errors

International Nuclear Information System (INIS)

Nelson, C; Mason, B; Kirsner, S; Ohrt, J

2015-01-01

Purpose: Ion chamber and film (ICAF) is a method used to verify patient dose prior to treatment. More recently, log file based QA has been shown as an alternative for measurement based QA. In this study, we delivered VMAT plans with and without errors to determine if ICAF and/or log file based QA was able to detect the errors. Methods: Using two VMAT patients, the original treatment plan plus 7 additional plans with delivery errors introduced were generated and delivered. The erroneous plans had gantry, collimator, MLC, gantry and collimator, collimator and MLC, MLC and gantry, and gantry, collimator, and MLC errors. The gantry and collimator errors were off by 4 0 for one of the two arcs. The MLC error introduced was one in which the opening aperture didn’t move throughout the delivery of the field. For each delivery, an ICAF measurement was made as well as a dose comparison based upon log files. Passing criteria to evaluate the plans were ion chamber less and 5% and film 90% of pixels pass the 3mm/3% gamma analysis(GA). For log file analysis 90% of voxels pass the 3mm/3% 3D GA and beam parameters match what was in the plan. Results: Two original plans were delivered and passed both ICAF and log file base QA. Both ICAF and log file QA met the dosimetry criteria on 4 of the 12 erroneous cases analyzed (2 cases were not analyzed). For the log file analysis, all 12 erroneous plans alerted a mismatch in delivery versus what was planned. The 8 plans that didn’t meet criteria all had MLC errors. Conclusion: Our study demonstrates that log file based pre-treatment QA was able to detect small errors that may not be detected using an ICAF and both methods of were able to detect larger delivery errors

Results of mine logging in Sn-W prospectina in Cinovec deposit

International Nuclear Information System (INIS)

Kudrna, R.; Masek, K.; Pavlik, I.; Rejl, L.

1984-01-01

The method is suggested of indicating cassiterite ore mineralization in the Cinovec deposit by combining the methods of selective gamma-gamma logging and magnetic susceptibility logging. The estimate of the tin content was based on selective gamma-gamma logging. (B.S.)

Log-layer mismatch and modeling of the fluctuating wall stress in wall-modeled large-eddy simulations

Science.gov (United States)

Yang, Xiang I. A.; Park, George Ilhwan; Moin, Parviz

2017-10-01

Log-layer mismatch refers to a chronic problem found in wall-modeled large-eddy simulation (WMLES) or detached-eddy simulation, where the modeled wall-shear stress deviates from the true one by approximately 15 % . Many efforts have been made to resolve this mismatch. The often-used fixes, which are generally ad hoc, include modifying subgrid-scale stress models, adding a stochastic forcing, and moving the LES-wall-model matching location away from the wall. An analysis motivated by the integral wall-model formalism suggests that log-layer mismatch is resolved by the built-in physics-based temporal filtering. In this work we investigate in detail the effects of local filtering on log-layer mismatch. We show that both local temporal filtering and local wall-parallel filtering resolve log-layer mismatch without moving the LES-wall-model matching location away from the wall. Additionally, we look into the momentum balance in the near-wall region to provide an alternative explanation of how LLM occurs, which does not necessarily rely on the numerical-error argument. While filtering resolves log-layer mismatch, the quality of the wall-shear stress fluctuations predicted by WMLES does not improve with our remedy. The wall-shear stress fluctuations are highly underpredicted due to the implied use of LES filtering. However, good agreement can be found when the WMLES data are compared to the direct numerical simulation data filtered at the corresponding WMLES resolutions.

Risk analysis of sulfites used as food additives in China.

Science.gov (United States)

Zhang, Jian Bo; Zhang, Hong; Wang, Hua Li; Zhang, Ji Yue; Luo, Peng Jie; Zhu, Lei; Wang, Zhu Tian

2014-02-01

This study was to analyze the risk of sulfites in food consumed by the Chinese people and assess the health protection capability of maximum-permitted level (MPL) of sulfites in GB 2760-2011. Sulfites as food additives are overused or abused in many food categories. When the MPL in GB 2760-2011 was used as sulfites content in food, the intake of sulfites in most surveyed populations was lower than the acceptable daily intake (ADI). Excess intake of sulfites was found in all the surveyed groups when a high percentile of sulfites in food was in taken. Moreover, children aged 1-6 years are at a high risk to intake excess sulfites. The primary cause for the excess intake of sulfites in Chinese people is the overuse and abuse of sulfites by the food industry. The current MPL of sulfites in GB 2760-2011 protects the health of most populations. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Weighted log-linear models for service delivery points in Ethiopia: a case of modern contraceptive users at health facilities.

Science.gov (United States)

Workie, Demeke Lakew; Zike, Dereje Tesfaye; Fenta, Haile Mekonnen; Mekonnen, Mulusew Admasu

2018-05-10

Ethiopia is among countries with low contraceptive usage prevalence rate and resulted in high total fertility rate and unwanted pregnancy which intern affects the maternal and child health status. This study aimed to investigate the major factors that affect the number of modern contraceptive users at service delivery point in Ethiopia. The Performance Monitoring and Accountability2020/Ethiopia data collected between March and April 2016 at round-4 from 461 eligible service delivery points were in this study. The weighted log-linear negative binomial model applied to analyze the service delivery point's data. Fifty percent of service delivery points in Ethiopia given service for 61 modern contraceptive users with the interquartile range of 0.62. The expected log number of modern contraceptive users at rural was 1.05 (95% Wald CI: - 1.42 to - 0.68) lower than the expected log number of modern contraceptive users at urban. In addition, the expected log count of modern contraceptive users at others facility type was 0.58 lower than the expected log count of modern contraceptive users at the health center. The numbers of nurses/midwives were affecting the number of modern contraceptive users. Since, the incidence rate of modern contraceptive users increased by one due to an additional nurse in the delivery point. Among different factors considered in this study, residence, region, facility type, the number of days per week family planning offered, the number of nurses/midwives and number of medical assistants were to be associated with the number of modern contraceptive users. Thus, the Government of Ethiopia would take immediate steps to address causes of the number of modern contraceptive users in Ethiopia.

Defect core detection in radiata pine logs

International Nuclear Information System (INIS)

Wallace, G.

1993-01-01

Internal defect cores in Pinus radiata logs arise primarily from the practice in New Zealand of pruning trees to increase the amount of clear wood. Realising the benefits of this practice when milling the logs is hampered by the lack of a practical method for detecting the defect cores. This report attempts to establish industry requirements for detections and examine techniques which may be suitable. Some trials of a novel technique are described. (author) 19 refs.; 11 figs

Accessibility versus accuracy in retrieving spatial memory: evidence for suboptimal assumed headings.

Science.gov (United States)

Yerramsetti, Ashok; Marchette, Steven A; Shelton, Amy L

2013-07-01

Orientation dependence in spatial memory has often been interpreted in terms of accessibility: Object locations are encoded relative to a reference orientation that affords the most accurate access to spatial memory. An open question, however, is whether people naturally use this "preferred" orientation whenever recalling the space. We tested this question by asking participants to locate buildings on a familiar campus from various imagined locations, without specifying the heading to be assumed. We then used these pointing judgments to infer the approximate heading participants assumed at each location. Surprisingly, each location showed a unique assumed heading that was consistent across participants and seemed to reflect episodic or visual properties of the space. This result suggests that although locations are encoded relative to a reference orientation, other factors may influence how people choose to access the stored information and whether they appeal to long-term spatial memory or other more sensory-based stores. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Generating porosity spectrum of carbonate reservoirs using ultrasonic imaging log

Science.gov (United States)

Zhang, Jie; Nie, Xin; Xiao, Suyun; Zhang, Chong; Zhang, Chaomo; Zhang, Zhansong

2018-03-01

Imaging logging tools can provide us the borehole wall image. The micro-resistivity imaging logging has been used to obtain borehole porosity spectrum. However, the resistivity imaging logging cannot cover the whole borehole wall. In this paper, we propose a method to calculate the porosity spectrum using ultrasonic imaging logging data. Based on the amplitude attenuation equation, we analyze the factors affecting the propagation of wave in drilling fluid and formation and based on the bulk-volume rock model, Wyllie equation and Raymer equation, we establish various conversion models between the reflection coefficient β and porosity ϕ. Then we use the ultrasonic imaging logging and conventional wireline logging data to calculate the near-borehole formation porosity distribution spectrum. The porosity spectrum result obtained from ultrasonic imaging data is compared with the one from the micro-resistivity imaging data, and they turn out to be similar, but with discrepancy, which is caused by the borehole coverage and data input difference. We separate the porosity types by performing threshold value segmentation and generate porosity-depth distribution curves by counting with equal depth spacing on the porosity image. The practice result is good and reveals the efficiency of our method.

Logística e Atualidade - Empregando TI em Novas Oportunidades

OpenAIRE

Araujo, Jefferson Borges; UNIABEU

2011-01-01

Este trabalho apresenta inicialmente um histórico sobre a logística, seus principais objetivos e funções. São apontadas as principais dificuldades no processo de Gestão de Logística e identificada a utilização agressiva de Tecnologia da Informação como forte candidata para otimização dos processos da área de logística. São apresentados os conceitos envolvidos na técnica de Mineração de Dados – Data Mining e sua aplicação no campo da logística. São apresentadas as diversas técnicas associadas ...

Midwest Logging Firm Perspectives: Harvesting on Increasingly Parcelized Forestlands

Directory of Open Access Journals (Sweden)

Shorna Allred

2011-01-01

Full Text Available Loggers play a critical role in the sustainable production of wood and paper products, and harvesting activities contribute to economic health and viability of many Upper Midwest communities in the United States. If the logging sector is unable to procure wood efficiently and economically from an increasingly parcelized land base, the competitive ability of the forest industry could be jeopardized. Little is known about the functions of the logging sector related to the forest resource land base on which they depend, and it is imperative to improve our understanding of this important part of the forest industry. The purpose of this study was to determine prospective attitudes about the future of the logging industry and how trends in forestland parcelization and harvesting mechanization are impacting the logging industry, especially as it relates to smaller tracts of land.

Tractor-logging costs and production in old-growth redwood forests

Science.gov (United States)

Kenneth N. Boe

1963-01-01

A cost accounting analysis of full-scale logging operations in old-growth redwood during 2 years revealed that it cost $12.24 per M bd. ft. (gross Scribner log scale) to get logs on trucks. Road development costs averaged another $5.19 per M bd. ft. Felling-bucking production was calculated by average tree d.b.h. Both skidding and loading outputs per hour were...

Analyzing Decision Logs to Understand Decision Making in Serious Crime Investigations.

Science.gov (United States)

Dando, Coral J; Ormerod, Thomas C

2017-12-01

Objective To study decision making by detectives when investigating serious crime through the examination of decision logs to explore hypothesis generation and evidence selection. Background Decision logs are used to record and justify decisions made during serious crime investigations. The complexity of investigative decision making is well documented, as are the errors associated with miscarriages of justice and inquests. The use of decision logs has not been the subject of an empirical investigation, yet they offer an important window into the nature of investigative decision making in dynamic, time-critical environments. Method A sample of decision logs from British police forces was analyzed qualitatively and quantitatively to explore hypothesis generation and evidence selection by police detectives. Results Analyses revealed diversity in documentation of decisions that did not correlate with case type and identified significant limitations of the decision log approach to supporting investigative decision making. Differences emerged between experienced and less experienced officers' decision log records in exploration of alternative hypotheses, generation of hypotheses, and sources of evidential inquiry opened over phase of investigation. Conclusion The practical use of decision logs is highly constrained by their format and context of use. Despite this, decision log records suggest that experienced detectives display strategic decision making to avoid confirmation and satisficing, which affect less experienced detectives. Application Potential applications of this research include both training in case documentation and the development of new decision log media that encourage detectives, irrespective of experience, to generate multiple hypotheses and optimize the timely selection of evidence to test them.

Nuclear cross section library for oil well logging analysis

International Nuclear Information System (INIS)

Kodeli, I.; Kitsos, S.; Aldama, D.L.; Zefran, B.

2003-01-01

As part of the IRTMBA (Improved Radiation Transport Modelling for Borehole Applications) Project of the EU Community's 5 th Programme a special purpose multigroup cross section library to be used in the deterministic (as well as Monte Carlo) oil well logging particle transport calculations was prepared. This library is expected to improve the prediction of the neutron and gamma spectra at the detector positions of the logging tool, and their use for the interpretation of the neutron logging measurements was studied. Preparation and testing of this library is described. (author)

Physical and measuring principles of nuclear well logging techniques

International Nuclear Information System (INIS)

Loetzsch, U.; Winkler, R.

1981-01-01

Proceeding from the general task of nuclear geophysics as a special discipline of applied geophyscis, the essential physical problems of nuclear well logging techniques are considered. Particularly, the quantitative relationship between measured values and interesting geologic parameters to be determined are discussed taking into account internal and external perturbation parameters. Resulting from this study, the technological requirements for radiation sources and their shielding, for detectors, electronic circuits in logging tools, signal transmission by cable and recording equipment are derived, and explained on the basis of examples of gamma-gamma and neutron-neutron logging. (author)

Practical borehole logging procedures for mineral exploration, with emphasis on uranium

International Nuclear Information System (INIS)

1986-01-01

Borehole logging is a basic tool in the exploration for and delineation of uranium deposits. This manual describes recommended procedures for carrying out borehole logging, concentrating on practical aspects of the operation of interest to those actually involved in day-to-day field work. The book begins with a discussion of boreholes and then deals with gamma ray logging as the main method of interest. Information is also provided on other techniques including resistance, spontaneous potential, density and neutron logging. Field procedures are described, and examples of logs and interpretations are given. The appendices provide information on calibration procedures and correction factors, a glossary of useful terms and some relevant basic data regarding drill holes and drilling

40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

Science.gov (United States)

2010-07-01

... cement bond and variable density log, and a temperature log after the casing is set and cemented. (ii..., gamma ray, and fracture finder logs before the casing is installed; and (B) A cement bond and variable density log, and a temperature log after the casing is set and cemented. (iii) The Director may allow the...

The fuel characteristics of logging residue and their response to storage; Puupolttoaineen laadunvalvonta

Energy Technology Data Exchange (ETDEWEB)

Nurmi, J [Finnish Forest Research Inst., Kannus (Finland). Kannus Research Station

1997-12-01

Logging residue is one of the major biomass reserves of Finland available for energy production. Some 29 million m{sup 3} of this residue material is left in the forest annually in conjunction with logging operations. The technically harvestable annual reserve is estimated to consist of 8.6 million m{sup 3} biomass needles included, or 5.6 million m{sup 3} needles excluded. The present technology is based on the mechanised harvesting of stemwood with single-grip harvesters, off- road transport of residue to road side with forwarders, chipping at the road side and truck transport of chips. The amount used at heating plants in 1995 was estimated to only 50 000 m{sup 3} solid or less than 1 % of the harvestable reserve. The aim of the Project 125 is to find out how the fuel characteristics and the elemental composition of logging residue change over time in different storage conditions. Based on the information from the first year experiments it can be concluded that the season of comminution is of importance. The enforced paper cover that was used to protect the residue from precipitation did not improve the fuel quality. In addition the release of elements from the needle was found to be very slow. (orig.)

CS model coil experimental log book

International Nuclear Information System (INIS)

Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi

2001-02-01

Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

Well logging instrumental and methodological research

International Nuclear Information System (INIS)

Andrassy, L.; Barath, I.; Dorko, R.

1983-01-01

This part of the Annual Report of the Roland Eoetvoes Geophysical Institute (ELGI) of Hungary for 1982, summarizes the well logging instrumental and methodological researches of ELGI. The theoretical neutron diffusion fluxes for black and brown coals of Hungarian mines were calculated. A coal probe was developed and tested in boreholes using computerized data processing and interpretation. An X-ray radiometric method was used for the determination of Cu and Fe contents of minerals. Researches in the field of magnetic susceptibility and induced polarization logging are also summarized. A rapid analyzer for bauxite mining and a photorecorder for petroleum industry were developed by ELGI. (D.Gy.)

Conversation Threads Hidden within Email Server Logs

Science.gov (United States)

Palus, Sebastian; Kazienko, Przemysław

Email server logs contain records of all email Exchange through this server. Often we would like to analyze those emails not separately but in conversation thread, especially when we need to analyze social network extracted from those email logs. Unfortunately each mail is in different record and those record are not tided to each other in any obvious way. In this paper method for discussion threads extraction was proposed together with experiments on two different data sets - Enron and WrUT..

Mean-variance model for portfolio optimization with background risk based on uncertainty theory

Science.gov (United States)

Zhai, Jia; Bai, Manying

2018-04-01

The aim of this paper is to develop a mean-variance model for portfolio optimization considering the background risk, liquidity and transaction cost based on uncertainty theory. In portfolio selection problem, returns of securities and assets liquidity are assumed as uncertain variables because of incidents or lacking of historical data, which are common in economic and social environment. We provide crisp forms of the model and a hybrid intelligent algorithm to solve it. Under a mean-variance framework, we analyze the portfolio frontier characteristic considering independently additive background risk. In addition, we discuss some effects of background risk and liquidity constraint on the portfolio selection. Finally, we demonstrate the proposed models by numerical simulations.

Risk Management and Insurance Decisions under Ambiguity

DEFF Research Database (Denmark)

Martínez-Correa, Jimmy

I study the impact of ambiguity on insurance decisions and the optimality of insurance contracts. My tractable approach allows me to study the interaction between risk and ambiguity attitudes. When insurance decisions are made independently of other assets, for a given increase in wealth, both risk...... portfolio theory that assumes Subjective Expected Utility theory; however, it provides hints to a possible solution of the under-diversification puzzle of households. I also identify conditions under which more risk or ambiguity aversion decreases the demand for coinsurance. Additionally, I show...... a counterexample to a classical result in insurance economics where an insurance contract with straight deductible is dominated by a coinsurance contract. Finally, I find that a modified Borch rule characterizes the optimal insurance contract with bilateral risk and ambiguity attitudes and heterogeneity in beliefs....

A revised design and implementation of the ATLAS Log Service package

Science.gov (United States)

Murillo Garcia, Raul; Lehamnn Miotto, Giovanna; ATLAS TDAQ Collaboration

2011-12-01

This paper presents a revised design and implementation of the Log Service for the ATLAS Trigger and Data Acquisition (TDAQ) framework at CERN. A previous version of this utility was rarely used for various reasons, herein explained. The lessons learned set the grounds and motivation for a new redesign. The Log Service consists of the Logger, the entity that collects logs and stores them in an Oracle database; a set of user utilities to access and maintain the database; and a Java based tool, known as the Log Manager, which provides a compact and intuitive interface for browsing the log messages based on a user defined search criteria. The outline of these software components are explained, including various optimization techniques deployed in order to handle the large volume of entries expected to be stored in the database. Finally, a performance study has been conducted to prove the validity and behavior of the Log Service.

A revised design and implementation of the ATLAS Log Service package

CERN Document Server

Murillo García, R; The ATLAS collaboration

2010-01-01

This paper presents a revised design and implementation of the Log Service for the ATLAS Trigger and Data Acquisition (TDAQ) framework at CERN. A previous version of this utility was rarely used for various reasons, herein explained. The lessons learned set the grounds and motivation for a new redesign. The Log Service consists of the Logger, the entity that collects logs and stores them in an Oracle database; a set of user utilities to access and maintain the database; and a Java based tool, known as the Log Manager, which provides a compact and intuitive interface for browsing the log messages based on a user defined search criteria. The outline of these software components are explained, including various optimization techniques deployed in order to handle the large volume of entries expected to be stored in the database. Finally, a performance study has been conducted to prove the validity and behavior of the Log Service.

New materials for fireplace logs

Science.gov (United States)

Kieselback, D. J.; Smock, A. W.

1971-01-01

Fibrous insulation and refractory concrete are used for logs as well as fireproof walls, incinerator bricks, planters, and roof shingles. Insulation is lighter and more shock resistant than fireclay. Lightweight slag bonded with refractory concrete serves as aggregrate.