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Sample records for adjusted multinomial logistic

  1. Multinomial logistic regression ensembles.

    PubMed

    Lee, Kyewon; Ahn, Hongshik; Moon, Hojin; Kodell, Ralph L; Chen, James J

    2013-05-01

    This article proposes a method for multiclass classification problems using ensembles of multinomial logistic regression models. A multinomial logit model is used as a base classifier in ensembles from random partitions of predictors. The multinomial logit model can be applied to each mutually exclusive subset of the feature space without variable selection. By combining multiple models the proposed method can handle a huge database without a constraint needed for analyzing high-dimensional data, and the random partition can improve the prediction accuracy by reducing the correlation among base classifiers. The proposed method is implemented using R, and the performance including overall prediction accuracy, sensitivity, and specificity for each category is evaluated on two real data sets and simulation data sets. To investigate the quality of prediction in terms of sensitivity and specificity, the area under the receiver operating characteristic (ROC) curve (AUC) is also examined. The performance of the proposed model is compared to a single multinomial logit model and it shows a substantial improvement in overall prediction accuracy. The proposed method is also compared with other classification methods such as the random forest, support vector machines, and random multinomial logit model. PMID:23611203

  2. Multinomial logistic regression-based feature selection for hyperspectral data

    NASA Astrophysics Data System (ADS)

    Pal, Mahesh

    2012-02-01

    This paper evaluates the performance of three feature selection methods based on multinomial logistic regression, and compares the performance of the best multinomial logistic regression-based feature selection approach with the support vector machine based recurring feature elimination approach. Two hyperspectral datasets, one consisting of 65 features (DAIS data) and other with 185 features (AVIRIS data) were used. Result suggests that a total of between 15 and 10 features selected by using the multinomial logistic regression-based feature selection approach as proposed by Cawley and Talbot achieve a significant improvement in classification accuracy in comparison to the use of all the features of the DAIS and AVIRIS datasets. In addition to the improved performance, the Cawley and Talbot approach does not require any user-defined parameter, thus avoiding the requirement of a model selection stage. In comparison, the other two multinomial logistic regression-based feature selection approaches require one user-defined parameter and do not perform as well as the Cawley and Talbot approach in terms of (i) the number of features required to achieve classification accuracy comparable to that achieved using the full dataset, and (ii) the classification accuracy achieved by the selected features. The Cawley and Talbot approach was also found to be computationally more efficient than the SVM-RFE technique, though both use the same number of selected features to achieve an equal or even higher level of accuracy than that achieved with full hyperspectral datasets.

  3. Modeling urban growth with geographically weighted multinomial logistic regression

    NASA Astrophysics Data System (ADS)

    Luo, Jun; Kanala, Nagaraj Kapi

    2008-10-01

    Spatial heterogeneity is usually ignored in previous land use change studies. This paper presents a geographically weighted multinomial logistic regression model for investigating multiple land use conversion in the urban growth process. The proposed model makes estimation at each sample location and generates local coefficients of driving factors for land use conversion. A Gaussian function is used for determine the geographic weights guarantying that all other samples are involved in the calibration of the model for one location. A case study on Springfield metropolitan area is conducted. A set of independent variables are selected as driving factors. A traditional multinomial logistic regression model is set up and compared with the proposed model. Spatial variations of coefficients of independent variables are revealed by investigating the estimations at sample locations.

  4. Comparison of multinomial logistic regression and logistic regression: which is more efficient in allocating land use?

    NASA Astrophysics Data System (ADS)

    Lin, Yingzhi; Deng, Xiangzheng; Li, Xing; Ma, Enjun

    2014-12-01

    Spatially explicit simulation of land use change is the basis for estimating the effects of land use and cover change on energy fluxes, ecology and the environment. At the pixel level, logistic regression is one of the most common approaches used in spatially explicit land use allocation models to determine the relationship between land use and its causal factors in driving land use change, and thereby to evaluate land use suitability. However, these models have a drawback in that they do not determine/allocate land use based on the direct relationship between land use change and its driving factors. Consequently, a multinomial logistic regression method was introduced to address this flaw, and thereby, judge the suitability of a type of land use in any given pixel in a case study area of the Jiangxi Province, China. A comparison of the two regression methods indicated that the proportion of correctly allocated pixels using multinomial logistic regression was 92.98%, which was 8.47% higher than that obtained using logistic regression. Paired t-test results also showed that pixels were more clearly distinguished by multinomial logistic regression than by logistic regression. In conclusion, multinomial logistic regression is a more efficient and accurate method for the spatial allocation of land use changes. The application of this method in future land use change studies may improve the accuracy of predicting the effects of land use and cover change on energy fluxes, ecology, and environment.

  5. Robust Logistic and Probit Methods for Binary and Multinomial Regression

    PubMed Central

    Tabatabai, MA; Li, H; Eby, WM; Kengwoung-Keumo, JJ; Manne, U; Bae, S; Fouad, M; Singh, KP

    2015-01-01

    In this paper we introduce new robust estimators for the logistic and probit regressions for binary, multinomial, nominal and ordinal data and apply these models to estimate the parameters when outliers or inluential observations are present. Maximum likelihood estimates don't behave well when outliers or inluential observations are present. One remedy is to remove inluential observations from the data and then apply the maximum likelihood technique on the deleted data. Another approach is to employ a robust technique that can handle outliers and inluential observations without removing any observations from the data sets. The robustness of the method is tested using real and simulated data sets. PMID:26078914

  6. A note on the estimation of the multinomial logistic model with correlated responses in SAS.

    PubMed

    Kuss, Oliver; McLerran, Dale

    2007-09-01

    We show how multinomial logistic models with correlated responses can be estimated within SAS software. To achieve this, random effects and marginal models are introduced and the respective SAS code is given. An example data set on physicians' recommendations and preferences in traumatic brain injury rehabilitation is used for illustration. The main motivation for this work are two recent papers that recommend estimating multinomial logistic models with correlated responses by using a Poisson likelihood which is statistically correct but computationally inefficient. PMID:17686544

  7. Modeling Polytomous Item Responses Using Simultaneously Estimated Multinomial Logistic Regression Models

    ERIC Educational Resources Information Center

    Anderson, Carolyn J.; Verkuilen, Jay; Peyton, Buddy L.

    2010-01-01

    Survey items with multiple response categories and multiple-choice test questions are ubiquitous in psychological and educational research. We illustrate the use of log-multiplicative association (LMA) models that are extensions of the well-known multinomial logistic regression model for multiple dependent outcome variables to reanalyze a set of…

  8. A warning concerning the estimation of multinomial logistic models with correlated responses in SAS.

    PubMed

    de Rooij, Mark; Worku, Hailemichael M

    2012-08-01

    Kuss and McLerran in a paper in this journal provide SAS code for the estimation of multinomial logistic models for correlated data. Their motivation derived from two papers that recommended to estimate such models using a Poisson likelihood, which is according to Kuss and McLerran "statistically correct but computationally inefficient". Kuss and McLerran propose several estimating methods. Some of these are based on the fact that the multinomial model is a multivariate binary model. Subsequently a procedure proposed by Wright is exploited to fit the models. In this paper we will show that the new computation methods, based on the approach by Wright, are statistically incorrect because they do not take into account that for multinomial data a multivariate link function is needed. An alternative estimation strategy is proposed using the clustered bootstrap. PMID:22398107

  9. Predictive occurrence models for coastal wetland plant communities: Delineating hydrologic response surfaces with multinomial logistic regression

    NASA Astrophysics Data System (ADS)

    Snedden, Gregg A.; Steyer, Gregory D.

    2013-02-01

    Understanding plant community zonation along estuarine stress gradients is critical for effective conservation and restoration of coastal wetland ecosystems. We related the presence of plant community types to estuarine hydrology at 173 sites across coastal Louisiana. Percent relative cover by species was assessed at each site near the end of the growing season in 2008, and hourly water level and salinity were recorded at each site Oct 2007-Sep 2008. Nine plant community types were delineated with k-means clustering, and indicator species were identified for each of the community types with indicator species analysis. An inverse relation between salinity and species diversity was observed. Canonical correspondence analysis (CCA) effectively segregated the sites across ordination space by community type, and indicated that salinity and tidal amplitude were both important drivers of vegetation composition. Multinomial logistic regression (MLR) and Akaike's Information Criterion (AIC) were used to predict the probability of occurrence of the nine vegetation communities as a function of salinity and tidal amplitude, and probability surfaces obtained from the MLR model corroborated the CCA results. The weighted kappa statistic, calculated from the confusion matrix of predicted versus actual community types, was 0.7 and indicated good agreement between observed community types and model predictions. Our results suggest that models based on a few key hydrologic variables can be valuable tools for predicting vegetation community development when restoring and managing coastal wetlands.

  10. Knowledge and perception on tuberculosis transmission in Tanzania: Multinomial logistic regression analysis of secondary data.

    PubMed

    Ismail, Abbas; Josephat, Peter

    2014-01-01

    Tuberculosis (TB) is one of the most important public health problems in Tanzania and was declared as a national public health emergency in 2006. Community and individual knowledge and perceptions are critical factors in the control of the disease. The objective of this study was to analyze the knowledge and perception on the transmission of TB in Tanzania. Multinomial Logistic Regression analysis was considered in order to quantify the impact of knowledge and perception on TB. The data used was adopted as secondary data from larger national survey 2007-08 Tanzania HIV/AIDS and Malaria Indicator Survey. The findings across groups revealed that knowledge on TB transmission increased with an increase in age and level of education. People in rural areas had less knowledge regarding tuberculosis transmission compared to urban areas [OR = 0.7]. People with the access to radio [OR = 1.7] were more knowledgeable on tuberculosis transmission compared to those who did not have access to radio. People who did not have telephone [OR = 0.6] were less knowledgeable on tuberculosis route of transmission compared to those who had telephone. The findings showed that socio-demographic factors such as age, education, place of residence and owning telephone or radio varied systematically with knowledge on tuberculosis transmission. PMID:26867270

  11. Multinomial logistic regression analysis for differentiating 3 treatment outcome trajectory groups for headache-associated disability.

    PubMed

    Lewis, Kristin Nicole; Heckman, Bernadette Davantes; Himawan, Lina

    2011-08-01

    Growth mixture modeling (GMM) identified latent groups based on treatment outcome trajectories of headache disability measures in patients in headache subspecialty treatment clinics. Using a longitudinal design, 219 patients in headache subspecialty clinics in 4 large cities throughout Ohio provided data on their headache disability at pretreatment and 3 follow-up assessments. GMM identified 3 treatment outcome trajectory groups: (1) patients who initiated treatment with elevated disability levels and who reported statistically significant reductions in headache disability (high-disability improvers; 11%); (2) patients who initiated treatment with elevated disability but who reported no reductions in disability (high-disability nonimprovers; 34%); and (3) patients who initiated treatment with moderate disability and who reported statistically significant reductions in headache disability (moderate-disability improvers; 55%). Based on the final multinomial logistic regression model, a dichotomized treatment appointment attendance variable was a statistically significant predictor for differentiating high-disability improvers from high-disability nonimprovers. Three-fourths of patients who initiated treatment with elevated disability levels did not report reductions in disability after 5 months of treatment with new preventive pharmacotherapies. Preventive headache agents may be most efficacious for patients with moderate levels of disability and for patients with high disability levels who attend all treatment appointments. PMID:21420240

  12. Predictive occurrence models for coastal wetland plant communities: delineating hydrologic response surfaces with multinomial logistic regression

    USGS Publications Warehouse

    Snedden, Gregg A.; Steyer, Gregory D.

    2013-01-01

    Understanding plant community zonation along estuarine stress gradients is critical for effective conservation and restoration of coastal wetland ecosystems. We related the presence of plant community types to estuarine hydrology at 173 sites across coastal Louisiana. Percent relative cover by species was assessed at each site near the end of the growing season in 2008, and hourly water level and salinity were recorded at each site Oct 2007–Sep 2008. Nine plant community types were delineated with k-means clustering, and indicator species were identified for each of the community types with indicator species analysis. An inverse relation between salinity and species diversity was observed. Canonical correspondence analysis (CCA) effectively segregated the sites across ordination space by community type, and indicated that salinity and tidal amplitude were both important drivers of vegetation composition. Multinomial logistic regression (MLR) and Akaike's Information Criterion (AIC) were used to predict the probability of occurrence of the nine vegetation communities as a function of salinity and tidal amplitude, and probability surfaces obtained from the MLR model corroborated the CCA results. The weighted kappa statistic, calculated from the confusion matrix of predicted versus actual community types, was 0.7 and indicated good agreement between observed community types and model predictions. Our results suggest that models based on a few key hydrologic variables can be valuable tools for predicting vegetation community development when restoring and managing coastal wetlands.

  13. Evaluating risk factors for endemic human Salmonella Enteritidis infections with different phage types in Ontario, Canada using multinomial logistic regression and a case-case study approach

    PubMed Central

    2012-01-01

    Background Identifying risk factors for Salmonella Enteritidis (SE) infections in Ontario will assist public health authorities to design effective control and prevention programs to reduce the burden of SE infections. Our research objective was to identify risk factors for acquiring SE infections with various phage types (PT) in Ontario, Canada. We hypothesized that certain PTs (e.g., PT8 and PT13a) have specific risk factors for infection. Methods Our study included endemic SE cases with various PTs whose isolates were submitted to the Public Health Laboratory-Toronto from January 20th to August 12th, 2011. Cases were interviewed using a standardized questionnaire that included questions pertaining to demographics, travel history, clinical symptoms, contact with animals, and food exposures. A multinomial logistic regression method using the Generalized Linear Latent and Mixed Model procedure and a case-case study design were used to identify risk factors for acquiring SE infections with various PTs in Ontario, Canada. In the multinomial logistic regression model, the outcome variable had three categories representing human infections caused by SE PT8, PT13a, and all other SE PTs (i.e., non-PT8/non-PT13a) as a referent category to which the other two categories were compared. Results In the multivariable model, SE PT8 was positively associated with contact with dogs (OR=2.17, 95% CI 1.01-4.68) and negatively associated with pepper consumption (OR=0.35, 95% CI 0.13-0.94), after adjusting for age categories and gender, and using exposure periods and health regions as random effects to account for clustering. Conclusions Our study findings offer interesting hypotheses about the role of phage type-specific risk factors. Multinomial logistic regression analysis and the case-case study approach are novel methodologies to evaluate associations among SE infections with different PTs and various risk factors. PMID:23057531

  14. Trinculo: Bayesian and frequentist multinomial logistic regression for genome-wide association studies of multi-category phenotypes

    PubMed Central

    Jostins, Luke; McVean, Gilean

    2016-01-01

    Motivation: For many classes of disease the same genetic risk variants underly many related phenotypes or disease subtypes. Multinomial logistic regression provides an attractive framework to analyze multi-category phenotypes, and explore the genetic relationships between these phenotype categories. We introduce Trinculo, a program that implements a wide range of multinomial analyses in a single fast package that is designed to be easy to use by users of standard genome-wide association study software. Availability and implementation: An open source C implementation, with code and binaries for Linux and Mac OSX, is available for download at http://sourceforge.net/projects/trinculo Supplementary information: Supplementary data are available at Bioinformatics online. Contact: lj4@well.ox.ac.uk PMID:26873930

  15. Multinomial logistic regression modelling of obesity and overweight among primary school students in a rural area of Negeri Sembilan

    SciTech Connect

    Ghazali, Amirul Syafiq Mohd; Ali, Zalila; Noor, Norlida Mohd; Baharum, Adam

    2015-10-22

    Multinomial logistic regression is widely used to model the outcomes of a polytomous response variable, a categorical dependent variable with more than two categories. The model assumes that the conditional mean of the dependent categorical variables is the logistic function of an affine combination of predictor variables. Its procedure gives a number of logistic regression models that make specific comparisons of the response categories. When there are q categories of the response variable, the model consists of q-1 logit equations which are fitted simultaneously. The model is validated by variable selection procedures, tests of regression coefficients, a significant test of the overall model, goodness-of-fit measures, and validation of predicted probabilities using odds ratio. This study used the multinomial logistic regression model to investigate obesity and overweight among primary school students in a rural area on the basis of their demographic profiles, lifestyles and on the diet and food intake. The results indicated that obesity and overweight of students are related to gender, religion, sleep duration, time spent on electronic games, breakfast intake in a week, with whom meals are taken, protein intake, and also, the interaction between breakfast intake in a week with sleep duration, and the interaction between gender and protein intake.

  16. Multinomial logistic regression modelling of obesity and overweight among primary school students in a rural area of Negeri Sembilan

    NASA Astrophysics Data System (ADS)

    Ghazali, Amirul Syafiq Mohd; Ali, Zalila; Noor, Norlida Mohd; Baharum, Adam

    2015-10-01

    Multinomial logistic regression is widely used to model the outcomes of a polytomous response variable, a categorical dependent variable with more than two categories. The model assumes that the conditional mean of the dependent categorical variables is the logistic function of an affine combination of predictor variables. Its procedure gives a number of logistic regression models that make specific comparisons of the response categories. When there are q categories of the response variable, the model consists of q-1 logit equations which are fitted simultaneously. The model is validated by variable selection procedures, tests of regression coefficients, a significant test of the overall model, goodness-of-fit measures, and validation of predicted probabilities using odds ratio. This study used the multinomial logistic regression model to investigate obesity and overweight among primary school students in a rural area on the basis of their demographic profiles, lifestyles and on the diet and food intake. The results indicated that obesity and overweight of students are related to gender, religion, sleep duration, time spent on electronic games, breakfast intake in a week, with whom meals are taken, protein intake, and also, the interaction between breakfast intake in a week with sleep duration, and the interaction between gender and protein intake.

  17. Multinomial Logistic Regression & Bootstrapping for Bayesian Estimation of Vertical Facies Prediction in Heterogeneous Sandstone Reservoirs

    NASA Astrophysics Data System (ADS)

    Al-Mudhafar, W. J.

    2013-12-01

    Precisely prediction of rock facies leads to adequate reservoir characterization by improving the porosity-permeability relationships to estimate the properties in non-cored intervals. It also helps to accurately identify the spatial facies distribution to perform an accurate reservoir model for optimal future reservoir performance. In this paper, the facies estimation has been done through Multinomial logistic regression (MLR) with respect to the well logs and core data in a well in upper sandstone formation of South Rumaila oil field. The entire independent variables are gamma rays, formation density, water saturation, shale volume, log porosity, core porosity, and core permeability. Firstly, Robust Sequential Imputation Algorithm has been considered to impute the missing data. This algorithm starts from a complete subset of the dataset and estimates sequentially the missing values in an incomplete observation by minimizing the determinant of the covariance of the augmented data matrix. Then, the observation is added to the complete data matrix and the algorithm continues with the next observation with missing values. The MLR has been chosen to estimate the maximum likelihood and minimize the standard error for the nonlinear relationships between facies & core and log data. The MLR is used to predict the probabilities of the different possible facies given each independent variable by constructing a linear predictor function having a set of weights that are linearly combined with the independent variables by using a dot product. Beta distribution of facies has been considered as prior knowledge and the resulted predicted probability (posterior) has been estimated from MLR based on Baye's theorem that represents the relationship between predicted probability (posterior) with the conditional probability and the prior knowledge. To assess the statistical accuracy of the model, the bootstrap should be carried out to estimate extra-sample prediction error by randomly

  18. Modeling the dynamics of urban growth using multinomial logistic regression: a case study of Jiayu County, Hubei Province, China

    NASA Astrophysics Data System (ADS)

    Nong, Yu; Du, Qingyun; Wang, Kun; Miao, Lei; Zhang, Weiwei

    2008-10-01

    Urban growth modeling, one of the most important aspects of land use and land cover change study, has attracted substantial attention because it helps to comprehend the mechanisms of land use change thus helps relevant policies made. This study applied multinomial logistic regression to model urban growth in the Jiayu county of Hubei province, China to discover the relationship between urban growth and the driving forces of which biophysical and social-economic factors are selected as independent variables. This type of regression is similar to binary logistic regression, but it is more general because the dependent variable is not restricted to two categories, as those previous studies did. The multinomial one can simulate the process of multiple land use competition between urban land, bare land, cultivated land and orchard land. Taking the land use type of Urban as reference category, parameters could be estimated with odds ratio. A probability map is generated from the model to predict where urban growth will occur as a result of the computation.

  19. Changepoint Detection in Multinomial Logistic Regression with Application to Sky-Cloudiness Conditions in Canada

    NASA Astrophysics Data System (ADS)

    Lu, Q.; Wang, X. L.

    2009-04-01

    Detecting changepoints in a sequence of continuous random variables has been extensively explored in both statistics and climatology literature. There is little, however, for studying the case with multicategory random variables. For instance, the sky-cloudiness condition in Canada is reported in tenths of the sky dome and thus has 11 categories (from 0 for clear sky, to 10 tenths for overcast). This study develops an overall likelihood-ratio test statistic for detecting a sudden change in the parameters of the continuation-ratio logit random intercept model for a sequence of multinomial variables. A method of partitioning the overall test statistic is also proposed, which allows one to assess the significance of the effect of the detected change on individual categories. An application of this new technique to real sky cloudiness data is also presented.

  20. Multinomial Logistic Regression Predicted Probability Map To Visualize The Influence Of Socio-Economic Factors On Breast Cancer Occurrence in Southern Karnataka

    NASA Astrophysics Data System (ADS)

    Madhu, B.; Ashok, N. C.; Balasubramanian, S.

    2014-11-01

    Multinomial logistic regression analysis was used to develop statistical model that can predict the probability of breast cancer in Southern Karnataka using the breast cancer occurrence data during 2007-2011. Independent socio-economic variables describing the breast cancer occurrence like age, education, occupation, parity, type of family, health insurance coverage, residential locality and socioeconomic status of each case was obtained. The models were developed as follows: i) Spatial visualization of the Urban- rural distribution of breast cancer cases that were obtained from the Bharat Hospital and Institute of Oncology. ii) Socio-economic risk factors describing the breast cancer occurrences were complied for each case. These data were then analysed using multinomial logistic regression analysis in a SPSS statistical software and relations between the occurrence of breast cancer across the socio-economic status and the influence of other socio-economic variables were evaluated and multinomial logistic regression models were constructed. iii) the model that best predicted the occurrence of breast cancer were identified. This multivariate logistic regression model has been entered into a geographic information system and maps showing the predicted probability of breast cancer occurrence in Southern Karnataka was created. This study demonstrates that Multinomial logistic regression is a valuable tool for developing models that predict the probability of breast cancer Occurrence in Southern Karnataka.

  1. Comparative study of two sparse multinomial logistic regression models in decoding visual stimuli from brain activity of fMRI

    NASA Astrophysics Data System (ADS)

    Song, Sutao; Chen, Gongxiang; Zhan, Yu; Zhang, Jiacai; Yao, Li

    2014-03-01

    Recently, sparse algorithms, such as Sparse Multinomial Logistic Regression (SMLR), have been successfully applied in decoding visual information from functional magnetic resonance imaging (fMRI) data, where the contrast of visual stimuli was predicted by a classifier. The contrast classifier combined brain activities of voxels with sparse weights. For sparse algorithms, the goal is to learn a classifier whose weights distributed as sparse as possible by introducing some prior belief about the weights. There are two ways to introduce a sparse prior constraints for weights: the Automatic Relevance Determination (ARD-SMLR) and Laplace prior (LAP-SMLR). In this paper, we presented comparison results between the ARD-SMLR and LAP-SMLR models in computational time, classification accuracy and voxel selection. Results showed that, for fMRI data, no significant difference was found in classification accuracy between these two methods when voxels in V1 were chosen as input features (totally 1017 voxels). As for computation time, LAP-SMLR was superior to ARD-SMLR; the survived voxels for ARD-SMLR was less than LAP-SMLR. Using simulation data, we confirmed the classification performance for the two SMLR models was sensitive to the sparsity of the initial features, when the ratio of relevant features to the initial features was larger than 0.01, ARD-SMLR outperformed LAP-SMLR; otherwise, LAP-SMLR outperformed LAP-SMLR. Simulation data showed ARD-SMLR was more efficient in selecting relevant features.

  2. Multinomial logistic regression model to assess the levels in trans, trans-muconic acid and inferential-risk age group among benzene-exposed group.

    PubMed

    Mala, A; Ravichandran, B; Raghavan, S; Rajmohan, H R

    2010-08-01

    There are only a few studies performed on multinomial logistic regression on the benzene-exposed occupational group. A study was carried out to assess the relationship between the benzene concentration and trans-trans-muconic acid (t,t-MA), biomarkers in urine samples from petrol filling workers. A total of 117 workers involved in this occupation were selected for this current study. Generally, logistic regression analysis (LR) is a common statistical technique that could be used to predict the likelihood of categorical or binary or dichotomous outcome variables. The multinomial logistic regression equations were used to predict the relationship between benzene concentration and t,t-MA. The results showed a significant correlation between benzene and t,t-MA among the petrol fillers. Prediction equations were estimated by adopting the physical characteristic viz., age, experience in years and job categories of petrol filling station workers. Interestingly, there was no significant difference observed among experience in years. Petrol fillers and cashiers having a higher occupational risk were in the age group of ≤24 and between 25 and 34 years. Among the petrol fillers, the t,t-MA levels with exceeding ACGIH TWA-TLV level was showing to be more significant. This study demonstrated that multinomial logistic regression is an effective model for profiling the greatest risk of the benzene-exposed group caused by different explanatory variables. PMID:21120078

  3. Multinomial logistic regression model to assess the levels in trans, trans-muconic acid and inferential-risk age group among benzene-exposed group

    PubMed Central

    Mala, A.; Ravichandran, B.; Raghavan, S.; Rajmohan, H. R.

    2010-01-01

    There are only a few studies performed on multinomial logistic regression on the benzene-exposed occupational group. A study was carried out to assess the relationship between the benzene concentration and trans-trans-muconic acid (t,t-MA), biomarkers in urine samples from petrol filling workers. A total of 117 workers involved in this occupation were selected for this current study. Generally, logistic regression analysis (LR) is a common statistical technique that could be used to predict the likelihood of categorical or binary or dichotomous outcome variables. The multinomial logistic regression equations were used to predict the relationship between benzene concentration and t,t-MA. The results showed a significant correlation between benzene and t,t-MA among the petrol fillers. Prediction equations were estimated by adopting the physical characteristic viz., age, experience in years and job categories of petrol filling station workers. Interestingly, there was no significant difference observed among experience in years. Petrol fillers and cashiers having a higher occupational risk were in the age group of ≤24 and between 25 and 34 years. Among the petrol fillers, the t,t-MA levels with exceeding ACGIH TWA-TLV level was showing to be more significant. This study demonstrated that multinomial logistic regression is an effective model for profiling the greatest risk of the benzene-exposed group caused by different explanatory variables. PMID:21120078

  4. Modeling simultaneous exceedance of drinking-water standards of arsenic and nitrate in the Southern Ogallala aquifer using multinomial logistic regression

    NASA Astrophysics Data System (ADS)

    Venkataraman, Kartik; Uddameri, Venkatesh

    2012-08-01

    SummaryThe occurrence of elevated levels of arsenic and nitrate in aquifers impacted by agricultural activities is common and can result in adverse health effects in rural areas. Numerous wells located in the Ogallala aquifer in the Southern High Plains of Texas have tested positive for both arsenic and nitrate MCL exceedance. To model the simultaneous exceedance of both chemicals, two types of Logistic Regression (LR) models were developed by (a) treating arsenic and nitrate independently and combining the marginal probabilities of their exceedance, and (b) treating the two exceedances together by using a multinomial model. Influencing variables representative of both soil and aquifer properties and data for which was readily available were identified. The predictive capacities of the two models were evaluated using Received Operating Characteristics (ROCs) and spatial trends in predictions were studied. The LR model constructed from the marginal probabilities had lower overall accuracy (59% correct classifications) and was extremely conservative by over-predicting outcomes. In contrast, the multinomial model showed good overall accuracy (79% correct classifications), made the correct predictions 90% of the time when both arsenic and nitrate MCL exceedances were observed, and was a good fit for wells located in agricultural areas. The results of the multinomial model also confirm previous studies that attributed shallow subsurface arsenic to anthropogenic activities. Based on the insights provided by the model it is recommended that where agricultural areas are concerned, the occurrence of arsenic and nitrate are better evaluated together.

  5. The multivariate Dirichlet-multinomial distribution and its application in forensic genetics to adjust for subpopulation effects using the θ-correction.

    PubMed

    Tvedebrink, Torben; Eriksen, Poul Svante; Morling, Niels

    2015-11-01

    In this paper, we discuss the construction of a multivariate generalisation of the Dirichlet-multinomial distribution. An example from forensic genetics in the statistical analysis of DNA mixtures motivates the study of this multivariate extension. In forensic genetics, adjustment of the match probabilities due to remote ancestry in the population is often done using the so-called θ-correction. This correction increases the probability of observing multiple copies of rare alleles in a subpopulation and thereby reduces the weight of the evidence for rare genotypes. A recent publication by Cowell et al. (2015) showed elegantly how to use Bayesian networks for efficient computations of likelihood ratios in a forensic genetic context. However, their underlying population genetic model assumed independence of alleles, which is not realistic in real populations. We demonstrate how the so-called θ-correction can be incorporated in Bayesian networks to make efficient computations by modifying the Markov structure of Cowell et al. (2015). By numerical examples, we show how the θ-correction incorporated in the multivariate Dirichlet-multinomial distribution affects the weight of evidence. PMID:26344785

  6. [Case-control studies with multinomial responses: a proposal for analysis].

    PubMed

    Mafra, Ana Carolina Cintra Nunes; Nucci, Luciana Bertoldi; Cordeiro, Ricardo; Stephan, Celso

    2010-03-01

    This study reviews articles on case-control studies in which the cases were classified in two or more types. Application of multinomial models and their adequacy for case-control studies are discussed. Among the available multinomial adjustments, we argue that the polytomous logistic model is the most suitable for obtaining epidemiological measures of risk and association in case-control studies. By way of illustration, we present an application of this model in a population-based case-control study, comparing the results with those obtained in a binomial logistic model. The multinomial approach allows investigating, in a single analysis, the occurrence of associations between covariates and more or more subclasses of cases, thus providing the epidemiologically relevant possibility of identifying individualized risk and protective factors for each subclass. PMID:20464064

  7. Regularized logistic regression with adjusted adaptive elastic net for gene selection in high dimensional cancer classification.

    PubMed

    Algamal, Zakariya Yahya; Lee, Muhammad Hisyam

    2015-12-01

    Cancer classification and gene selection in high-dimensional data have been popular research topics in genetics and molecular biology. Recently, adaptive regularized logistic regression using the elastic net regularization, which is called the adaptive elastic net, has been successfully applied in high-dimensional cancer classification to tackle both estimating the gene coefficients and performing gene selection simultaneously. The adaptive elastic net originally used elastic net estimates as the initial weight, however, using this weight may not be preferable for certain reasons: First, the elastic net estimator is biased in selecting genes. Second, it does not perform well when the pairwise correlations between variables are not high. Adjusted adaptive regularized logistic regression (AAElastic) is proposed to address these issues and encourage grouping effects simultaneously. The real data results indicate that AAElastic is significantly consistent in selecting genes compared to the other three competitor regularization methods. Additionally, the classification performance of AAElastic is comparable to the adaptive elastic net and better than other regularization methods. Thus, we can conclude that AAElastic is a reliable adaptive regularized logistic regression method in the field of high-dimensional cancer classification. PMID:26520484

  8. Conditional pseudolikelihood methods for clustered ordinal, multinomial, or count outcomes with complex survey data.

    PubMed

    Brumback, Babette A; Cai, Zhuangyu; He, Zhulin; Zheng, Hao W; Dailey, Amy B

    2013-04-15

    In order to adjust individual-level covariate effects for confounding due to unmeasured neighborhood characteristics, we have recently developed conditional pseudolikelihood methods to estimate the parameters of a proportional odds model for clustered ordinal outcomes with complex survey data. The methods require sampling design joint probabilities for each within-neighborhood pair. In the present article, we develop a similar methodology for a baseline category logit model for clustered multinomial outcomes and for a loglinear model for clustered count outcomes. All of the estimators and asymptotic sampling distributions we present can be conveniently computed using standard logistic regression software for complex survey data, such as sas proc surveylogistic. We demonstrate validity of the methods theoretically and also empirically by using simulations. We apply the new method for clustered multinomial outcomes to data from the 2008 Florida Behavioral Risk Factor Surveillance System survey in order to investigate disparities in frequency of dental cleaning both unadjusted and adjusted for confounding by neighborhood. PMID:22976045

  9. On exchangeable multinomial distributions

    PubMed Central

    George, E. Olusegun; Cheon, Kyeongmi; Yuan, Yilian; Szabo, Aniko

    2016-01-01

    We derive an expression for the joint distribution of exchangeable multinomial random variables, which generalizes the multinomial distribution based on independent trials while retaining some of its important properties. Unlike de Finneti's representation theorem for a binary sequence, the exchangeable multinomial distribution derived here does not require that the finite set of random variables under consideration be a subset of an infinite sequence. Using expressions for higher moments and correlations, we show that the covariance matrix for exchangeable multinomial data has a different form from that usually assumed in the literature, and we analyse data from developmental toxicology studies. The proposed analyses have been implemented in R and are available on CRAN in the CorrBin package.

  10. Adjusting for unmeasured confounding due to either of two crossed factors with a logistic regression model.

    PubMed

    Li, Li; Brumback, Babette A; Weppelmann, Thomas A; Morris, J Glenn; Ali, Afsar

    2016-08-15

    Motivated by an investigation of the effect of surface water temperature on the presence of Vibrio cholerae in water samples collected from different fixed surface water monitoring sites in Haiti in different months, we investigated methods to adjust for unmeasured confounding due to either of the two crossed factors site and month. In the process, we extended previous methods that adjust for unmeasured confounding due to one nesting factor (such as site, which nests the water samples from different months) to the case of two crossed factors. First, we developed a conditional pseudolikelihood estimator that eliminates fixed effects for the levels of each of the crossed factors from the estimating equation. Using the theory of U-Statistics for independent but non-identically distributed vectors, we show that our estimator is consistent and asymptotically normal, but that its variance depends on the nuisance parameters and thus cannot be easily estimated. Consequently, we apply our estimator in conjunction with a permutation test, and we investigate use of the pigeonhole bootstrap and the jackknife for constructing confidence intervals. We also incorporate our estimator into a diagnostic test for a logistic mixed model with crossed random effects and no unmeasured confounding. For comparison, we investigate between-within models extended to two crossed factors. These generalized linear mixed models include covariate means for each level of each factor in order to adjust for the unmeasured confounding. We conduct simulation studies, and we apply the methods to the Haitian data. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26892025

  11. Multinomial pattern matching revisited

    NASA Astrophysics Data System (ADS)

    Horvath, Matthew S.; Rigling, Brian D.

    2015-05-01

    Multinomial pattern matching (MPM) is an automatic target recognition algorithm developed for specifically radar data at Sandia National Laboratories. The algorithm is in a family of algorithms that first quantizes pixel value into Nq bins based on pixel amplitude before training and classification. This quantization step reduces the sensitivity of algorithm performance to absolute intensity variation in the data, typical of radar data where signatures exhibit high variation for even small changes in aspect angle. Our previous work has focused on performance analysis of peaky template matching, a special case of MPM where binary quantization is used (Nq = 2). Unfortunately references on these algorithms are generally difficult to locate and here we revisit the MPM algorithm and illustrate the underlying statistical model and decision rules for two algorithm interpretations: the 1-of-K vector form and the scalar. MPM can also be used as a detector and specific attention is given to algorithm tuning where "peak pixels" are chosen based on their underlying empirical probabilities according to a reward minimization strategy aimed at reducing false alarms in the detection scenario and false positives in a classification capacity. The algorithms are demonstrated using Monte Carlo simulations on the AFRL civilian vehicle dataset for variety of choices of Nq.

  12. What's the Risk? A Simple Approach for Estimating Adjusted Risk Measures from Nonlinear Models Including Logistic Regression

    PubMed Central

    Kleinman, Lawrence C; Norton, Edward C

    2009-01-01

    Objective To develop and validate a general method (called regression risk analysis) to estimate adjusted risk measures from logistic and other nonlinear multiple regression models. We show how to estimate standard errors for these estimates. These measures could supplant various approximations (e.g., adjusted odds ratio [AOR]) that may diverge, especially when outcomes are common. Study Design Regression risk analysis estimates were compared with internal standards as well as with Mantel–Haenszel estimates, Poisson and log-binomial regressions, and a widely used (but flawed) equation to calculate adjusted risk ratios (ARR) from AOR. Data Collection Data sets produced using Monte Carlo simulations. Principal Findings Regression risk analysis accurately estimates ARR and differences directly from multiple regression models, even when confounders are continuous, distributions are skewed, outcomes are common, and effect size is large. It is statistically sound and intuitive, and has properties favoring it over other methods in many cases. Conclusions Regression risk analysis should be the new standard for presenting findings from multiple regression analysis of dichotomous outcomes for cross-sectional, cohort, and population-based case–control studies, particularly when outcomes are common or effect size is large. PMID:18793213

  13. Logistic Regression

    NASA Astrophysics Data System (ADS)

    Grégoire, G.

    2014-12-01

    The logistic regression originally is intended to explain the relationship between the probability of an event and a set of covariables. The model's coefficients can be interpreted via the odds and odds ratio, which are presented in introduction of the chapter. The observations are possibly got individually, then we speak of binary logistic regression. When they are grouped, the logistic regression is said binomial. In our presentation we mainly focus on the binary case. For statistical inference the main tool is the maximum likelihood methodology: we present the Wald, Rao and likelihoods ratio results and their use to compare nested models. The problems we intend to deal with are essentially the same as in multiple linear regression: testing global effect, individual effect, selection of variables to build a model, measure of the fitness of the model, prediction of new values… . The methods are demonstrated on data sets using R. Finally we briefly consider the binomial case and the situation where we are interested in several events, that is the polytomous (multinomial) logistic regression and the particular case of ordinal logistic regression.

  14. Estimation of incomplete multinomial data

    NASA Technical Reports Server (NTRS)

    Credeur, K. R.

    1980-01-01

    Program estimates cell probabilities for data observed to fall in one of two or more categories when exact category cannot be determined. Data are assumed to be randomly incomplete. Estimation minimizes risk of quadratic loss. Program should be useful in projects where multinomial data is analyzed, but where observations are sometimes incomplete. Program is in FORTRAN IV and Assembler for batch execution on CYBER 173.

  15. Fuzzy multinomial control chart and its application

    NASA Astrophysics Data System (ADS)

    Wibawati, Mashuri, Muhammad; Purhadi, Irhamah

    2016-03-01

    Control chart is a technique that has been used widely in industry and services. P chart is the simplest control chart. In this chart, item is classified into two categories as either conforming and non conforming. This chart based on binomial distribution. In practice, each item can classify in more than two categories such as very bad, bad, good and very good. Then to monitor the process we used multinomial p control chart. However, if the classification is an element of vagueness, the fuzzy multinomial control chart (FM) is more appropriately used. Control limit of FM chart obtained multinomial distribution and the degree of membership using fuzzy trianguler are 0, 0.25. 0.5 and 1. This chart will be applied to the data glass and will compare with multinomial p control chart.

  16. Multinomial and Compound Multinomial Error Models for Tests with Complex Item Scoring

    ERIC Educational Resources Information Center

    Lee, Won-Chan

    2007-01-01

    This article introduces a multinomial error model, which models an examinee's test scores obtained over repeated measurements of an assessment that consists of polytomously scored items. A compound multinomial error model is also introduced for situations in which items are stratified according to content categories and/or prespecified numbers of…

  17. Multinomial mixture model with heterogeneous classification probabilities

    USGS Publications Warehouse

    Holland, M.D.; Gray, B.R.

    2011-01-01

    Royle and Link (Ecology 86(9):2505-2512, 2005) proposed an analytical method that allowed estimation of multinomial distribution parameters and classification probabilities from categorical data measured with error. While useful, we demonstrate algebraically and by simulations that this method yields biased multinomial parameter estimates when the probabilities of correct category classifications vary among sampling units. We address this shortcoming by treating these probabilities as logit-normal random variables within a Bayesian framework. We use Markov chain Monte Carlo to compute Bayes estimates from a simulated sample from the posterior distribution. Based on simulations, this elaborated Royle-Link model yields nearly unbiased estimates of multinomial and correct classification probability estimates when classification probabilities are allowed to vary according to the normal distribution on the logit scale or according to the Beta distribution. The method is illustrated using categorical submersed aquatic vegetation data. ?? 2010 Springer Science+Business Media, LLC.

  18. The Finite and Moving Order Multinomial Universal Portfolio

    NASA Astrophysics Data System (ADS)

    Tan, Choon Peng; Theng Pang, Sook

    2013-04-01

    An upper bound for the ratio of wealths of the best constant -rebalanced portfolio to that of the multinomial universal portfolio is derived. The finite- order multinomial universal portfolios can reduce the implementation time and computer-memory requirements for computation. The improved performance of the finite-order portfolios on some selected local stock-price data sets is observed.

  19. Hierarchical Multinomial Processing Tree Models: A Latent-Class Approach

    ERIC Educational Resources Information Center

    Klauer, Karl Christoph

    2006-01-01

    Multinomial processing tree models are widely used in many areas of psychology. Their application relies on the assumption of parameter homogeneity, that is, on the assumption that participants do not differ in their parameter values. Tests for parameter homogeneity are proposed that can be routinely used as part of multinomial model analyses to…

  20. A spatial scan statistic for multinomial data

    PubMed Central

    Jung, Inkyung; Kulldorff, Martin; Richard, Otukei John

    2014-01-01

    As a geographical cluster detection analysis tool, the spatial scan statistic has been developed for different types of data such as Bernoulli, Poisson, ordinal, exponential and normal. Another interesting data type is multinomial. For example, one may want to find clusters where the disease-type distribution is statistically significantly different from the rest of the study region when there are different types of disease. In this paper, we propose a spatial scan statistic for such data, which is useful for geographical cluster detection analysis for categorical data without any intrinsic order information. The proposed method is applied to meningitis data consisting of five different disease categories to identify areas with distinct disease-type patterns in two counties in the U.K. The performance of the method is evaluated through a simulation study. PMID:20680984

  1. Modeling abundance using multinomial N-mixture models

    USGS Publications Warehouse

    Royle, Andy

    2016-01-01

    Multinomial N-mixture models are a generalization of the binomial N-mixture models described in Chapter 6 to allow for more complex and informative sampling protocols beyond simple counts. Many commonly used protocols such as multiple observer sampling, removal sampling, and capture-recapture produce a multivariate count frequency that has a multinomial distribution and for which multinomial N-mixture models can be developed. Such protocols typically result in more precise estimates than binomial mixture models because they provide direct information about parameters of the observation process. We demonstrate the analysis of these models in BUGS using several distinct formulations that afford great flexibility in the types of models that can be developed, and we demonstrate likelihood analysis using the unmarked package. Spatially stratified capture-recapture models are one class of models that fall into the multinomial N-mixture framework, and we discuss analysis of stratified versions of classical models such as model Mb, Mh and other classes of models that are only possible to describe within the multinomial N-mixture framework.

  2. Institutional Climate and Student Departure: A Multinomial Multilevel Modeling Approach

    ERIC Educational Resources Information Center

    Yi, Pyong-sik

    2008-01-01

    This study applied a multinomial HOLM technique to examine the extent to which the institutional climate for diversity influences the different types of college student withdrawal, such as stop out, drop out, and transfer. Based on a reformulation of Tinto's model along with the conceptualization of institutional climate for diversity by Hurtado…

  3. Pig Data and Bayesian Inference on Multinomial Probabilities

    ERIC Educational Resources Information Center

    Kern, John C.

    2006-01-01

    Bayesian inference on multinomial probabilities is conducted based on data collected from the game Pass the Pigs[R]. Prior information on these probabilities is readily available from the instruction manual, and is easily incorporated in a Dirichlet prior. Posterior analysis of the scoring probabilities quantifies the discrepancy between empirical…

  4. Hierarchical Multinomial Processing Tree Models: A Latent-Trait Approach

    ERIC Educational Resources Information Center

    Klauer, Karl Christoph

    2010-01-01

    Multinomial processing tree models are widely used in many areas of psychology. A hierarchical extension of the model class is proposed, using a multivariate normal distribution of person-level parameters with the mean and covariance matrix to be estimated from the data. The hierarchical model allows one to take variability between persons into…

  5. A Multinomial Model of Event-Based Prospective Memory

    ERIC Educational Resources Information Center

    Smith, Rebekah E.; Bayen, Ute J.

    2004-01-01

    Prospective memory is remembering to perform an action in the future. The authors introduce the 1st formal model of event-based prospective memory, namely, a multinomial model that includes 2 separate parameters related to prospective memory processes. The 1st measures preparatory attentional processes, and the 2nd measures retrospective memory…

  6. An Optimal Hierarchical Decision Model for a Regional Logistics Network with Environmental Impact Consideration

    PubMed Central

    Zhang, Dezhi; Li, Shuangyan

    2014-01-01

    This paper proposes a new model of simultaneous optimization of three-level logistics decisions, for logistics authorities, logistics operators, and logistics users, for regional logistics network with environmental impact consideration. The proposed model addresses the interaction among the three logistics players in a complete competitive logistics service market with CO2 emission charges. We also explicitly incorporate the impacts of the scale economics of the logistics park and the logistics users' demand elasticity into the model. The logistics authorities aim to maximize the total social welfare of the system, considering the demand of green logistics development by two different methods: optimal location of logistics nodes and charging a CO2 emission tax. Logistics operators are assumed to compete with logistics service fare and frequency, while logistics users minimize their own perceived logistics disutility given logistics operators' service fare and frequency. A heuristic algorithm based on the multinomial logit model is presented for the three-level decision model, and a numerical example is given to illustrate the above optimal model and its algorithm. The proposed model provides a useful tool for modeling competitive logistics services and evaluating logistics policies at the strategic level. PMID:24977209

  7. Analysis of multinomial models with unknown index using data augmentation

    USGS Publications Warehouse

    Royle, J. Andrew; Dorazio, R.M.; Link, W.A.

    2007-01-01

    Multinomial models with unknown index ('sample size') arise in many practical settings. In practice, Bayesian analysis of such models has proved difficult because the dimension of the parameter space is not fixed, being in some cases a function of the unknown index. We describe a data augmentation approach to the analysis of this class of models that provides for a generic and efficient Bayesian implementation. Under this approach, the data are augmented with all-zero detection histories. The resulting augmented dataset is modeled as a zero-inflated version of the complete-data model where an estimable zero-inflation parameter takes the place of the unknown multinomial index. Interestingly, data augmentation can be justified as being equivalent to imposing a discrete uniform prior on the multinomial index. We provide three examples involving estimating the size of an animal population, estimating the number of diabetes cases in a population using the Rasch model, and the motivating example of estimating the number of species in an animal community with latent probabilities of species occurrence and detection.

  8. Biomass Logistics

    SciTech Connect

    J. Richard Hess; Kevin L. Kenney; William A. Smith; Ian Bonner; David J. Muth

    2015-04-01

    Equipment manufacturers have made rapid improvements in biomass harvesting and handling equipment. These improvements have increased transportation and handling efficiencies due to higher biomass densities and reduced losses. Improvements in grinder efficiencies and capacity have reduced biomass grinding costs. Biomass collection efficiencies (the ratio of biomass collected to the amount available in the field) as high as 75% for crop residues and greater than 90% for perennial energy crops have also been demonstrated. However, as collection rates increase, the fraction of entrained soil in the biomass increases, and high biomass residue removal rates can violate agronomic sustainability limits. Advancements in quantifying multi-factor sustainability limits to increase removal rate as guided by sustainable residue removal plans, and mitigating soil contamination through targeted removal rates based on soil type and residue type/fraction is allowing the use of new high efficiency harvesting equipment and methods. As another consideration, single pass harvesting and other technologies that improve harvesting costs cause biomass storage moisture management challenges, which challenges are further perturbed by annual variability in biomass moisture content. Monitoring, sampling, simulation, and analysis provide basis for moisture, time, and quality relationships in storage, which has allowed the development of moisture tolerant storage systems and best management processes that combine moisture content and time to accommodate baled storage of wet material based upon “shelf-life.” The key to improving biomass supply logistics costs has been developing the associated agronomic sustainability and biomass quality technologies and processes that allow the implementation of equipment engineering solutions.

  9. A computer program for estimation from incomplete multinomial data

    NASA Technical Reports Server (NTRS)

    Credeur, K. R.

    1978-01-01

    Coding is given for maximum likelihood and Bayesian estimation of the vector p of multinomial cell probabilities from incomplete data. Also included is coding to calculate and approximate elements of the posterior mean and covariance matrices. The program is written in FORTRAN 4 language for the Control Data CYBER 170 series digital computer system with network operating system (NOS) 1.1. The program requires approximately 44000 octal locations of core storage. A typical case requires from 72 seconds to 92 seconds on CYBER 175 depending on the value of the prior parameter.

  10. Multinomial tau-leaping method for stochastic kinetic simulations.

    PubMed

    Pettigrew, Michel F; Resat, Haluk

    2007-02-28

    We introduce the multinomial tau-leaping (MtauL) method for general reaction networks with multichannel reactant dependencies. The MtauL method is an extension of the binomial tau-leaping method where efficiency is improved in several ways. First, tau-leaping steps are determined simply and efficiently using a priori information and Poisson distribution-based estimates of expectation values for reaction numbers over a tentative tau-leaping step. Second, networks are partitioned into closed groups of reactions and corresponding reactants in which no group reactant set is found in any other group. Third, product formation is factored into upper-bound estimation of the number of times a particular reaction occurs. Together, these features allow larger time steps where the numbers of reactions occurring simultaneously in a multichannel manner are estimated accurately using a multinomial distribution. Furthermore, we develop a simple procedure that places a specific upper bound on the total reaction number to ensure non-negativity of species populations over a single multiple-reaction step. Using two disparate test case problems involving cellular processes--epidermal growth factor receptor signaling and a lactose operon model--we show that the tau-leaping based methods such as the MtauL algorithm can significantly reduce the number of simulation steps thus increasing the numerical efficiency over the exact stochastic simulation algorithm by orders of magnitude. PMID:17343434

  11. Multinomial tau-leaping method for stochastic kinetic simulations

    NASA Astrophysics Data System (ADS)

    Pettigrew, Michel F.; Resat, Haluk

    2007-02-01

    We introduce the multinomial tau-leaping (MτL) method for general reaction networks with multichannel reactant dependencies. The MτL method is an extension of the binomial tau-leaping method where efficiency is improved in several ways. First, τ-leaping steps are determined simply and efficiently using a priori information and Poisson distribution-based estimates of expectation values for reaction numbers over a tentative τ-leaping step. Second, networks are partitioned into closed groups of reactions and corresponding reactants in which no group reactant set is found in any other group. Third, product formation is factored into upper-bound estimation of the number of times a particular reaction occurs. Together, these features allow larger time steps where the numbers of reactions occurring simultaneously in a multichannel manner are estimated accurately using a multinomial distribution. Furthermore, we develop a simple procedure that places a specific upper bound on the total reaction number to ensure non-negativity of species populations over a single multiple-reaction step. Using two disparate test case problems involving cellular processes—epidermal growth factor receptor signaling and a lactose operon model—we show that the τ-leaping based methods such as the MτL algorithm can significantly reduce the number of simulation steps thus increasing the numerical efficiency over the exact stochastic simulation algorithm by orders of magnitude.

  12. The outcome of tuberculosis treatment in subjects with chronic kidney disease in Brazil: a multinomial analysis*

    PubMed Central

    Reis-Santos, Barbara; Gomes, Teresa; Horta, Bernardo Lessa; Maciel, Ethel Leonor Noia

    2013-01-01

    OBJECTIVE: To analyze the association between clinical/epidemiological characteristics and outcomes of tuberculosis treatment in patients with concomitant tuberculosis and chronic kidney disease (CKD) in Brazil. METHODS: We used the Brazilian Ministry of Health National Case Registry Database to identify patients with tuberculosis and CKD, treated between 2007 and 2011. The tuberculosis treatment outcomes were compared with epidemiological and clinical characteristics of the subjects using a hierarchical multinomial logistic regression model, in which cure was the reference outcome. RESULTS: The prevalence of CKD among patients with tuberculosis was 0.4% (95% CI: 0.37-0.42%). The sample comprised 1,077 subjects. The outcomes were cure, in 58%; treatment abandonment, in 7%; death from tuberculosis, in 13%; and death from other causes, in 22%. The characteristics that differentiated the ORs for treatment abandonment or death were age; alcoholism; AIDS; previous noncompliance with treatment; transfer to another facility; suspected tuberculosis on chest X-ray; positive results in the first smear microscopy; and indications for/use of directly observed treatment, short-course strategy. CONCLUSIONS: Our data indicate the importance of sociodemographic characteristics for the diagnosis of tuberculosis in patients with CKD and underscore the need for tuberculosis control strategies targeting patients with chronic noncommunicable diseases, such as CKD. PMID:24310632

  13. NML computation algorithms for tree-structured multinomial Bayesian networks.

    PubMed

    Kontkanen, Petri; Wettig, Hannes; Myllymäki, Petri

    2007-01-01

    Typical problems in bioinformatics involve large discrete datasets. Therefore, in order to apply statistical methods in such domains, it is important to develop efficient algorithms suitable for discrete data. The minimum description length (MDL) principle is a theoretically well-founded, general framework for performing statistical inference. The mathematical formalization of MDL is based on the normalized maximum likelihood (NML) distribution, which has several desirable theoretical properties. In the case of discrete data, straightforward computation of the NML distribution requires exponential time with respect to the sample size, since the definition involves a sum over all the possible data samples of a fixed size. In this paper, we first review some existing algorithms for efficient NML computation in the case of multinomial and naive Bayes model families. Then we proceed by extending these algorithms to more complex, tree-structured Bayesian networks. PMID:18382603

  14. Pricing Asian options using moment matching on a multinomial lattice

    NASA Astrophysics Data System (ADS)

    Ogutu, Carolyne; Lundengârd, Karl; Silvestrov, Sergei; Weke, Patrick

    2014-12-01

    Pricing Asian options is often done using bi- or trinomial lattice methods. Here some results for generalizing these methods to lattices with more nodes are presented. We consider Asian option pricing on a lattice where the underlying asset follows Merton-Bates jump-diffusion model and describe the construction of a lattice using the moment matching technique which results in an equation system described by a rectangular Vandermonde matrix. The system is solved using the explicit expression for the inverse of the Vandermonde matrix and some restrictions on the jump sizes of the lattice and the distribution of moments are identified. The consequences of these restrictions for the suitability of the multinomial lattice methods are also discussed.

  15. Multinomial pattern matching for high range resolution radar profiles

    NASA Astrophysics Data System (ADS)

    Koudelka, Melissa L.; Richards, John A.; Koch, Mark W.

    2007-04-01

    Airborne ground moving-target indication (GMTI) radar can track moving vehicles at large standoff distances. Unfortunately, trajectories from multiple vehicles can become kinematically ambiguous, resulting in confusion between a target vehicle of interest and other vehicles. We propose the use of high range resolution (HRR) radar profiles and multinomial pattern matching (MPM) for target fingerprinting and track stitching to overcome kinematic ambiguities. Sandia's MPM algorithm is a robust template-based identification algorithm that has been applied successfully to various target recognition problems. MPM utilizes a quantile transformation to map target intensity samples to a small number of grayscale values, or quantiles. The algorithm relies on a statistical characterization of the multinomial distribution of the sample-by-sample intensity values for target profiles. The quantile transformation and statistical characterization procedures are extremely well suited to a robust representation of targets for HRR profiles: they are invariant to sensor calibration, robust to target signature variations, and lend themselves to efficient matching algorithms. In typical HRR tracking applications, target fingerprints must be initiated on the fly from a limited number of HRR profiles. Data may accumulate indefinitely as vehicles are tracked, and their templates must be continually updated without becoming unbounded in size or complexity. To address this need, an incrementally updated version of MPM has been developed. This implementation of MPM incorporates individual HRR profiles as they become available, and fuses data from multiple aspect angles for a given target to aid in track stitching. This paper provides a description of the incrementally updated version of MPM.

  16. GAM & RF for 3D mapping of multinomial peat properties.

    NASA Astrophysics Data System (ADS)

    Poggio, Laura; Gimona, Alessandro; Aalders, Inge; Morrice, Jane; Hough, Rupert

    2013-04-01

    Different statistical methods have been proposed for fitting the empirical quantitative function linking the soil information to the scorpan factors, while taking into account the spatial structure of the data . Regression kriging extends the methods of kriging and co-kriging and it has been further extended by the use of GAMs (Generalized Additive Models) with the estimation of uncertainty. When multinomial data are modelled, advanced non-parametric methods, such as CART (Classification and Regression Tree), can be used. CARTs have been used widely to estimate soil properties. Bagging trees and Random Forest (RF) approaches have among the best performances among CART methods. CARTs have been used in DSM applications, While RF have often been used in ecological modelling, fewer examples exist in DSM, such as soil erosion occurrence, soil types prediction and soil organic carbon content. In this paper we propose a methodology to map multinomial peat properties in 3D space with a combination of GAMs and RF. The methodology was applied to the humification (according to the VonPost classification) classes in a bog (18 km2) in the north-east of Scotland. A large survey campaign was carried out in 1955 and humification information were collected at 125 points. In order to integrate the information from the GAM in the RT, a series of binary GAMs were fitted using DEM-derived information as covariates. The binary GAMs were fitted assigning 1 if the class considered was present at the location, 0 if the class considered was absent. The probability predictions resulting from the binary GAMs, were included in the pool of covariates used for the RT together with other ancillary covariates. The model diagnostics had a fair to good agreement between measured and modelled values (K statistics). The probability predictions resulting from the binary GAMs proved to be important variables, increasing the agreement of the model. The obtained spatial distribution of values on the

  17. Using a multinomial tree model for detecting mixtures in perceptual detection

    PubMed Central

    Chechile, Richard A.

    2014-01-01

    In the area of memory research there have been two rival approaches for memory measurement—signal detection theory (SDT) and multinomial processing trees (MPT). Both approaches provide measures for the quality of the memory representation, and both approaches provide for corrections for response bias. In recent years there has been a strong case advanced for the MPT approach because of the finding of stochastic mixtures on both target-present and target-absent tests. In this paper a case is made that perceptual detection, like memory recognition, involves a mixture of processes that are readily represented as a MPT model. The Chechile (2004) 6P memory measurement model is modified in order to apply to the case of perceptual detection. This new MPT model is called the Perceptual Detection (PD) model. The properties of the PD model are developed, and the model is applied to some existing data of a radiologist examining CT scans. The PD model brings out novel features that were absent from a standard SDT analysis. Also the topic of optimal parameter estimation on an individual-observer basis is explored with Monte Carlo simulations. These simulations reveal that the mean of the Bayesian posterior distribution is a more accurate estimator than the corresponding maximum likelihood estimator (MLE). Monte Carlo simulations also indicate that model estimates based on only the data from an individual observer can be improved upon (in the sense of being more accurate) by an adjustment that takes into account the parameter estimate based on the data pooled across all the observers. The adjustment of the estimate for an individual is discussed as an analogous statistical effect to the improvement over the individual MLE demonstrated by the James–Stein shrinkage estimator in the case of the multiple-group normal model. PMID:25018741

  18. KSC ISS Logistics Support

    NASA Technical Reports Server (NTRS)

    Tellado, Joseph

    2014-01-01

    The presentation contains a status of KSC ISS Logistics Operations. It basically presents current top level ISS Logistics tasks being conducted at KSC, current International Partner activities, hardware processing flow focussing on late Stow operations, list of KSC Logistics POC's, and a backup list of Logistics launch site services. This presentation is being given at the annual International Space Station (ISS) Multi-lateral Logistics Maintenance Control Panel meeting to be held in Turin, Italy during the week of May 13-16. The presentatiuon content doesn't contain any potential lessons learned.

  19. Packaging for logistical support

    NASA Astrophysics Data System (ADS)

    Twede, Diana; Hughes, Harold

    Logistical packaging is conducted to furnish protection, utility, and communication for elements of a logistical system. Once the functional requirements of space logistical support packaging have been identified, decision-makers have a reasonable basis on which to compare package alternatives. Flexible packages may be found, for example, to provide adequate protection and superior utility to that of rigid packages requiring greater storage and postuse waste volumes.

  20. Multiple-Shrinkage Multinomial Probit Models with Applications to Simulating Geographies in Public Use Data

    PubMed Central

    Burgette, Lane F.; Reiter, Jerome P.

    2013-01-01

    Multinomial outcomes with many levels can be challenging to model. Information typically accrues slowly with increasing sample size, yet the parameter space expands rapidly with additional covariates. Shrinking all regression parameters towards zero, as often done in models of continuous or binary response variables, is unsatisfactory, since setting parameters equal to zero in multinomial models does not necessarily imply “no effect.” We propose an approach to modeling multinomial outcomes with many levels based on a Bayesian multinomial probit (MNP) model and a multiple shrinkage prior distribution for the regression parameters. The prior distribution encourages the MNP regression parameters to shrink toward a number of learned locations, thereby substantially reducing the dimension of the parameter space. Using simulated data, we compare the predictive performance of this model against two other recently-proposed methods for big multinomial models. The results suggest that the fully Bayesian, multiple shrinkage approach can outperform these other methods. We apply the multiple shrinkage MNP to simulating replacement values for areal identifiers, e.g., census tract indicators, in order to protect data confidentiality in public use datasets. PMID:24358073

  1. Multiple-Shrinkage Multinomial Probit Models with Applications to Simulating Geographies in Public Use Data.

    PubMed

    Burgette, Lane F; Reiter, Jerome P

    2013-06-01

    Multinomial outcomes with many levels can be challenging to model. Information typically accrues slowly with increasing sample size, yet the parameter space expands rapidly with additional covariates. Shrinking all regression parameters towards zero, as often done in models of continuous or binary response variables, is unsatisfactory, since setting parameters equal to zero in multinomial models does not necessarily imply "no effect." We propose an approach to modeling multinomial outcomes with many levels based on a Bayesian multinomial probit (MNP) model and a multiple shrinkage prior distribution for the regression parameters. The prior distribution encourages the MNP regression parameters to shrink toward a number of learned locations, thereby substantially reducing the dimension of the parameter space. Using simulated data, we compare the predictive performance of this model against two other recently-proposed methods for big multinomial models. The results suggest that the fully Bayesian, multiple shrinkage approach can outperform these other methods. We apply the multiple shrinkage MNP to simulating replacement values for areal identifiers, e.g., census tract indicators, in order to protect data confidentiality in public use datasets. PMID:24358073

  2. Significant Improvements to LOGIST.

    ERIC Educational Resources Information Center

    Wingersky, Marilyn S.

    The computer program LOGIST (Wingersky, Patrick, and Lord, 1988) estimates the item parameters and the examinee's abilities for Birnbaum's three-parameter logistic item response theory model using Newton's method for solving the joint maximum likelihood equations. In 1989, Martha Stocking discovered a problem with this procedure in that when the…

  3. A conditional predictive p-value to compare a multinomial with an overdispersed multinomial in the analysis of T-cell populations.

    PubMed

    Pei, Qinglin; Zuleger, Cindy L; Macklin, Michael D; Albertini, Mark R; Newton, Michael A

    2014-01-01

    Immunological experiments that record primary molecular sequences of T-cell receptors produce moderate to high-dimensional categorical data, some of which may be subject to extra-multinomial variation caused by technical constraints of cell-based assays. Motivated by such experiments in melanoma research, we develop a statistical procedure for testing the equality of two discrete populations, where one population delivers multinomial data and the other is subject to a specific form of overdispersion. The procedure computes a conditional-predictive p-value by splitting the data set into two, obtaining a predictive distribution for one piece given the other, and using the observed predictive ordinate to generate a p-value. The procedure has a simple interpretation, requires fewer modeling assumptions than would be required of a fully Bayesian analysis, and has reasonable operating characteristics as evidenced empirically and by asymptotic analysis. PMID:24096387

  4. Estimation from incomplete multinomial data. Ph.D. Thesis - Harvard Univ.

    NASA Technical Reports Server (NTRS)

    Credeur, K. R.

    1978-01-01

    The vector of multinomial cell probabilities was estimated from incomplete data, incomplete in that it contains partially classified observations. Each such partially classified observation was observed to fall in one of two or more selected categories but was not classified further into a single category. The data were assumed to be incomplete at random. The estimation criterion was minimization of risk for quadratic loss. The estimators were the classical maximum likelihood estimate, the Bayesian posterior mode, and the posterior mean. An approximation was developed for the posterior mean. The Dirichlet, the conjugate prior for the multinomial distribution, was assumed for the prior distribution.

  5. Green Logistics Management

    NASA Astrophysics Data System (ADS)

    Chang, Yoon S.; Oh, Chang H.

    Nowadays, environmental management becomes a critical business consideration for companies to survive from many regulations and tough business requirements. Most of world-leading companies are now aware that environment friendly technology and management are critical to the sustainable growth of the company. The environment market has seen continuous growth marking 532B in 2000, and 590B in 2004. This growth rate is expected to grow to 700B in 2010. It is not hard to see the environment-friendly efforts in almost all aspects of business operations. Such trends can be easily found in logistics area. Green logistics aims to make environmental friendly decisions throughout a product lifecycle. Therefore for the success of green logistics, it is critical to have real time tracking capability on the product throughout the product lifecycle and smart solution service architecture. In this chapter, we introduce an RFID based green logistics solution and service.

  6. A General Family of Limited Information Goodness-of-Fit Statistics for Multinomial Data

    ERIC Educational Resources Information Center

    Joe, Harry; Maydeu-Olivares, Alberto

    2010-01-01

    Maydeu-Olivares and Joe (J. Am. Stat. Assoc. 100:1009-1020, "2005"; Psychometrika 71:713-732, "2006") introduced classes of chi-square tests for (sparse) multidimensional multinomial data based on low-order marginal proportions. Our extension provides general conditions under which quadratic forms in linear functions of cell residuals are…

  7. Probabilistic evolution theory for ODE sets with second degree multinomial right hand side functions: Implementation

    NASA Astrophysics Data System (ADS)

    Gözükirmizi, Coşar; Demiralp, Metin

    2015-12-01

    This paper serves as a tutorial for the implementation of probabilistic evolution theory for the solution of initial value problem of ordinary differential equation sets with second degree multinomial right hand side functions. It also involves certain original ideas in technicality level and some novel observations.

  8. The Source of Adult Age Differences in Event-Based Prospective Memory: A Multinomial Modeling Approach

    ERIC Educational Resources Information Center

    Smith, Rebekah E.; Bayen, Ute J.

    2006-01-01

    Event-based prospective memory involves remembering to perform an action in response to a particular future event. Normal younger and older adults performed event-based prospective memory tasks in 2 experiments. The authors applied a formal multinomial processing tree model of prospective memory (Smith & Bayen, 2004) to disentangle age differences…

  9. Logistics planning for phased programs.

    NASA Technical Reports Server (NTRS)

    Cook, W. H.

    1973-01-01

    It is pointed out that the proper and early integration of logistics planning into the phased program planning process will drastically reduce these logistics costs. Phased project planning is a phased approach to the planning, approval, and conduct of major research and development activity. A progressive build-up of knowledge of all aspects of the program is provided. Elements of logistics are discussed together with aspects of integrated logistics support, logistics program planning, and logistics activities for phased programs. Continuing logistics support can only be assured if there is a comprehensive sequential listing of all logistics activities tied to the program schedule and a real-time inventory of assets.

  10. Practical Session: Logistic Regression

    NASA Astrophysics Data System (ADS)

    Clausel, M.; Grégoire, G.

    2014-12-01

    An exercise is proposed to illustrate the logistic regression. One investigates the different risk factors in the apparition of coronary heart disease. It has been proposed in Chapter 5 of the book of D.G. Kleinbaum and M. Klein, "Logistic Regression", Statistics for Biology and Health, Springer Science Business Media, LLC (2010) and also by D. Chessel and A.B. Dufour in Lyon 1 (see Sect. 6 of http://pbil.univ-lyon1.fr/R/pdf/tdr341.pdf). This example is based on data given in the file evans.txt coming from http://www.sph.emory.edu/dkleinb/logreg3.htm#data.

  11. Cumulative Socioeconomic Status Risk, Allostatic Load, and Adjustment: A Prospective Latent Profile Analysis With Contextual and Genetic Protective Factors

    PubMed Central

    Brody, Gene H.; Yu, Tianyi; Chen, Yi-fu; Kogan, Steven M.; Evans, Gary W.; Beach, Steven R. H.; Windle, Michael; Simons, Ronald L.; Gerrard, Meg; Gibbons, Frederick X.; Philibert, Robert A.

    2012-01-01

    The health disparities literature identified a common pattern among middle-aged African Americans that includes high rates of chronic disease along with low rates of psychiatric disorders despite exposure to high levels of cumulative SES risk. The current study was designed to test hypotheses about the developmental precursors to this pattern. Hypotheses were tested with a representative sample of 443 African American youths living in the rural South. Cumulative SES risk and protective processes were assessed at 11-13 years; psychological adjustment was assessed at ages 14-18 years; genotyping at the 5-HTTLPR was conducted at age 16 years; and allostatic load (AL) was assessed at age 19 years. A Latent Profile Analysis identified 5 profiles that evinced distinct patterns of SES risk, AL, and psychological adjustment, with 2 relatively large profiles designated as focal profiles: a physical health vulnerability profile characterized by high SES risk/high AL/low adjustment problems, and a resilient profile characterized by high SES risk/low AL/low adjustment problems. The physical health vulnerability profile mirrored the pattern found in the adult health disparities literature. Multinomial logistic regression analyses indicated that carrying an s allele at the 5-HTTLPR and receiving less peer support distinguished the physical health vulnerability profile from the resilient profile. Protective parenting and planful self-regulation distinguished both focal profiles from the other 3 profiles. The results suggest the public health importance of preventive interventions that enhance coping and reduce the effects of stress across childhood and adolescence. PMID:22709130

  12. A multinomial maximum likelihood program /MUNOML/. [in modeling sensory and decision phenomena

    NASA Technical Reports Server (NTRS)

    Curry, R. E.

    1975-01-01

    A multinomial maximum likelihood program (MUNOML) for signal detection and for behavior models is discussed. It is found to be useful in day to day operation since it provides maximum flexibility with minimum duplicated effort. It has excellent convergence qualities and rarely goes beyond 10 iterations. A library of subroutines is being collected for use with MUNOML, including subroutines for a successive categories model and for signal detectability models.

  13. Bayesian multinomial probit modeling of daily windows of susceptibility for maternal PM2.5 exposure and congenital heart defects

    EPA Science Inventory

    Past epidemiologic studies suggest maternal ambient air pollution exposure during critical periods of the pregnancy is associated with fetal development. We introduce a multinomial probit model that allows for the joint identification of susceptible daily periods during the pregn...

  14. Computing measures of explained variation for logistic regression models.

    PubMed

    Mittlböck, M; Schemper, M

    1999-01-01

    The proportion of explained variation (R2) is frequently used in the general linear model but in logistic regression no standard definition of R2 exists. We present a SAS macro which calculates two R2-measures based on Pearson and on deviance residuals for logistic regression. Also, adjusted versions for both measures are given, which should prevent the inflation of R2 in small samples. PMID:10195643

  15. Adjustment disorder

    MedlinePlus

    American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, Va: American Psychiatric Publishing. 2013. Powell AD. Grief, bereavement, and adjustment disorders. In: Stern TA, Rosenbaum ...

  16. The logistics of choice.

    PubMed

    Killeen, Peter R

    2015-07-01

    The generalized matching law (GML) is reconstructed as a logistic regression equation that privileges no particular value of the sensitivity parameter, a. That value will often approach 1 due to the feedback that drives switching that is intrinsic to most concurrent schedules. A model of that feedback reproduced some features of concurrent data. The GML is a law only in the strained sense that any equation that maps data is a law. The machine under the hood of matching is in all likelihood the very law that was displaced by the Matching Law. It is now time to return the Law of Effect to centrality in our science. PMID:25988932

  17. Steganalysis using logistic regression

    NASA Astrophysics Data System (ADS)

    Lubenko, Ivans; Ker, Andrew D.

    2011-02-01

    We advocate Logistic Regression (LR) as an alternative to the Support Vector Machine (SVM) classifiers commonly used in steganalysis. LR offers more information than traditional SVM methods - it estimates class probabilities as well as providing a simple classification - and can be adapted more easily and efficiently for multiclass problems. Like SVM, LR can be kernelised for nonlinear classification, and it shows comparable classification accuracy to SVM methods. This work is a case study, comparing accuracy and speed of SVM and LR classifiers in detection of LSB Matching and other related spatial-domain image steganography, through the state-of-art 686-dimensional SPAM feature set, in three image sets.

  18. General models for resource use or other compositional count data using the Dirichlet-multinomial distribution.

    PubMed

    De Valpine, Perry; Harmon-Threatt, Alexandra N

    2013-12-01

    Many ecological studies investigate how organisms use resources, such as habitats or foods, in relation to availability or other variables. Related statistical problems include analysis of proportions of species or genotypes in a community or population. These require statistical modeling of compositional count data: data on relative proportions of each category collected as counts. Common methods for analyzing compositional count data lack one or more important considerations. Some methods lack explicit accommodation of count data, dealing instead with proportions. Others do not handle between-sample heterogeneity for overdispersed data. Yet others do not allow general types of relationships between explanatory variables and resource use. All three components have been combined in a Bayesian framework, but for frequentist hypothesis tests and AIC model selection, maximum-likelihood estimation is needed. Here we propose the Dirichlet-multinomial distribution to accommodate overdispersed compositional count data. This approach can be used flexibly in combination with explanatory models, but the only correlations among compositional proportions that it can accommodate are the negative correlations due to the fact that proportions must sum to 1. Many existing models can be generalized to use the Dirichlet-multinomial distribution for residual variation, and the flexibility of the approach allows new hypotheses that have often not been considered in resource preference analysis, including that availability has no relation to use. We also highlight a new design for resource use studies, with multiple individual-use data sets from each of multiple sites, with different explanatory data for each site. We illustrate the approach with three examples. For two previously published habitat use data sets, we support the original conclusions and show that use is not unrelated to availability. For a data set of pollen collected by multiple bees from each of two sites, pollen use

  19. Adjustable microforceps.

    PubMed

    Bao, J Y

    1991-04-01

    The commonly used microforceps have a much greater opening distance and spring resistance than needed. A piece of plastic ring or rubber band can be used to adjust the opening distance and reduce most of the spring resistance, making the user feel more comfortable and less fatigued. PMID:2051437

  20. Landscape effects on diets of two canids in Northwestern Texas: A multinomial modeling approach

    USGS Publications Warehouse

    Lemons, P.R.; Sedinger, J.S.; Herzog, M.P.; Gipson, P.S.; Gilliland, R.L.

    2010-01-01

    Analyses of feces, stomach contents, and regurgitated pellets are common techniques for assessing diets of vertebrates and typically contain more than 1 food item per sampling unit. When analyzed, these individual food items have traditionally been treated as independent, which represents pseudoreplication. When food types are recorded as present or absent, these samples can be treated as multinomial vectors of food items, with each vector representing 1 realization of a possible diet. We suggest such data have a similar structure to capture histories for closed-capture, capturemarkrecapture data. To assess the effects of landscapes and presence of a potential competitor, we used closed-capture models implemented in program MARK into analyze diet data generated from feces of swift foxes (Vulpes velox) and coyotes (Canis latrans) in northwestern Texas. The best models of diet contained season and location for both swift foxes and coyotes, but year accounted for less variation, suggesting that landscape type is an important predictor of diets of both species. Models containing the effect of coyote reduction were not competitive (??QAICc 53.6685), consistent with the hypothesis that presence of coyotes did not influence diet of swift foxes. Our findings suggest that landscape type may have important influences on diets of both species. We believe that multinomial models represent an effective approach to assess hypotheses when diet studies have a data structure similar to ours. ?? 2010 American Society of Mammalogists.

  1. Uncovering a latent multinomial: Analysis of mark-recapture data with misidentification

    USGS Publications Warehouse

    Link, W.A.; Yoshizaki, J.; Bailey, L.L.; Pollock, K.H.

    2010-01-01

    Natural tags based on DNA fingerprints or natural features of animals are now becoming very widely used in wildlife population biology. However, classic capture-recapture models do not allow for misidentification of animals which is a potentially very serious problem with natural tags. Statistical analysis of misidentification processes is extremely difficult using traditional likelihood methods but is easily handled using Bayesian methods. We present a general framework for Bayesian analysis of categorical data arising from a latent multinomial distribution. Although our work is motivated by a specific model for misidentification in closed population capture-recapture analyses, with crucial assumptions which may not always be appropriate, the methods we develop extend naturally to a variety of other models with similar structure. Suppose that observed frequencies f are a known linear transformation f = A???x of a latent multinomial variable x with cell probability vector ?? = ??(??). Given that full conditional distributions [?? | x] can be sampled, implementation of Gibbs sampling requires only that we can sample from the full conditional distribution [x | f, ??], which is made possible by knowledge of the null space of A???. We illustrate the approach using two data sets with individual misidentification, one simulated, the other summarizing recapture data for salamanders based on natural marks. ?? 2009, The International Biometric Society.

  2. Uncovering a Latent Multinomial: Analysis of Mark-Recapture Data with Misidentification

    USGS Publications Warehouse

    Link, W.A.; Yoshizaki, J.; Bailey, L.L.; Pollock, K.H.

    2009-01-01

    Natural tags based on DNA fingerprints or natural features of animals are now becoming very widely used in wildlife population biology. However, classic capture-recapture models do not allow for misidentification of animals which is a potentially very serious problem with natural tags. Statistical analysis of misidentification processes is extremely difficult using traditional likelihood methods but is easily handled using Bayesian methods. We present a general framework for Bayesian analysis of categorical data arising from a latent multinomial distribution. Although our work is motivated by a specific model for misidentification in closed population capture-recapture analyses, with crucial assumptions which may not always be appropriate, the methods we develop extend naturally to a variety of other models with similar structure. Suppose that observed frequencies f are a known linear transformation f=A'x of a latent multinomial variable x with cell probability vector pi= pi(theta). Given that full conditional distributions [theta | x] can be sampled, implementation of Gibbs sampling requires only that we can sample from the full conditional distribution [x | f, theta], which is made possible by knowledge of the null space of A'. We illustrate the approach using two data sets with individual misidentification, one simulated, the other summarizing recapture data for salamanders based on natural marks.

  3. Space Shuttle operational logistics plan

    NASA Technical Reports Server (NTRS)

    Botts, J. W.

    1983-01-01

    The Kennedy Space Center plan for logistics to support Space Shuttle Operations and to establish the related policies, requirements, and responsibilities are described. The Directorate of Shuttle Management and Operations logistics responsibilities required by the Kennedy Organizational Manual, and the self-sufficiency contracting concept are implemented. The Space Shuttle Program Level 1 and Level 2 logistics policies and requirements applicable to KSC that are presented in HQ NASA and Johnson Space Center directives are also implemented.

  4. Jieke theory and logistic model

    SciTech Connect

    Cao, H.; Feng, G.

    1996-06-01

    What is a shell or a JIEKE (in Chinese) is introduced firstly, jieke is a sort of system boundary. From the concept of jieke theory, a new logistic model which takes account of the switch effect of the jieke is suggested. The model is analyzed and nonlinear mapping of the model is made. The results show the feature of the switch logistic model far differ from the original logistic model. {copyright} {ital 1996 American Institute of Physics.}

  5. Shaft adjuster

    DOEpatents

    Harry, Herbert H.

    1989-01-01

    Apparatus and method for the adjustment and alignment of shafts in high power devices. A plurality of adjacent rotatable angled cylinders are positioned between a base and the shaft to be aligned which when rotated introduce an axial offset. The apparatus is electrically conductive and constructed of a structurally rigid material. The angled cylinders allow the shaft such as the center conductor in a pulse line machine to be offset in any desired alignment position within the range of the apparatus.

  6. Technical issues: logistics. AAMC.

    PubMed

    Stillman, P L

    1993-06-01

    The author states that she became interested in standardized patients (SPs) around 20 years ago as a means of developing a more uniform and effective way to provide instruction and evaluation of basic clinical skills. She reflects upon in detail: (1) the logistics of using SPs in teaching; (2) how SPs are used in assessment; (3) what aspects of performance SPs can be trained to record and evaluate; (4) issues concerning checklists; (5) evaluation of interviewing skills; (6) evaluation of written communication skills; (7) importance of defining what is being tested; (8) various kinds and uses of inter-station exercises and problems of scoring them; (9) case development and the various sources for case material; (10) ways to generate scores; (11) selecting and training SPs; (12) role of the faculty and primary importance of bedside training with real patients; and (13) pros and cons of national versus single-school efforts to use SPs. She concludes by cautioning that further research must be done before SPs can be used for high-stakes certifying and licensing examinations. PMID:8507311

  7. Transfer Learning Based on Logistic Regression

    NASA Astrophysics Data System (ADS)

    Paul, A.; Rottensteiner, F.; Heipke, C.

    2015-08-01

    In this paper we address the problem of classification of remote sensing images in the framework of transfer learning with a focus on domain adaptation. The main novel contribution is a method for transductive transfer learning in remote sensing on the basis of logistic regression. Logistic regression is a discriminative probabilistic classifier of low computational complexity, which can deal with multiclass problems. This research area deals with methods that solve problems in which labelled training data sets are assumed to be available only for a source domain, while classification is needed in the target domain with different, yet related characteristics. Classification takes place with a model of weight coefficients for hyperplanes which separate features in the transformed feature space. In term of logistic regression, our domain adaptation method adjusts the model parameters by iterative labelling of the target test data set. These labelled data features are iteratively added to the current training set which, at the beginning, only contains source features and, simultaneously, a number of source features are deleted from the current training set. Experimental results based on a test series with synthetic and real data constitutes a first proof-of-concept of the proposed method.

  8. A note on Verhulst's logistic equation and related logistic maps

    NASA Astrophysics Data System (ADS)

    Ranferi Gutiérrez, M.; Reyes, M. A.; Rosu, H. C.

    2010-05-01

    We consider the Verhulst logistic equation and a couple of forms of the corresponding logistic maps. For the case of the logistic equation we show that using the general Riccati solution only changes the initial conditions of the equation. Next, we consider two forms of corresponding logistic maps reporting the following results. For the map xn + 1 = rxn(1 - xn) we propose a new way to write the solution for r = -2 which allows better precision of the iterative terms, while for the map xn + 1 - xn = rxn(1 - xn + 1) we show that it behaves identically to the logistic equation from the standpoint of the general Riccati solution, which is also provided herein for any value of the parameter r.

  9. Logistic Regression: Concept and Application

    ERIC Educational Resources Information Center

    Cokluk, Omay

    2010-01-01

    The main focus of logistic regression analysis is classification of individuals in different groups. The aim of the present study is to explain basic concepts and processes of binary logistic regression analysis intended to determine the combination of independent variables which best explain the membership in certain groups called dichotomous…

  10. A multinomial modeling analysis of the mnemonic benefits of bizarre imagery.

    PubMed

    Riefer, D M; Rouder, J N

    1992-11-01

    A series of experiments was conducted to explore the cognitive processes that mediate the bizarreness effect, that is, the finding that bizarre or unusual imagery is recalled better than common imagery. In all experiments, subjects were presented with noun pairs that were embedded within bizarre or common sentences in a mixed-list design. None of the experiments produced a bizarreness effect for cued recall; however, for two of the experiments, the bizarre noun pairs were remembered significantly better than the common pairs for free recall. To determine if these differences were due to the storage or retrieval of the items, a multinomial model for the analysis of imagery mediation in paired-associate learning was developed and applied to the data from the experiments. The model revealed that bizarre sentences benefited the retrieval of the noun pairs but not their storage within memory. The empirical and modeling results are discussed relative to previous findings and theories on the bizarreness effect. PMID:1435263

  11. Constancy adding space extension for ODE sets with second degree multinomial right hand side functions

    NASA Astrophysics Data System (ADS)

    Gözükirmizi, Coşar; Demiralp, Metin

    2014-10-01

    Constancy adding space extension is a technique to convert ODE of the form ẋ(t) = F0+F1x(t)+F2x(t)⊗2 to form ṡ = G1s+G2P-1s⊗2. There are arbitrary parameters in the representation. These parameters may be utilized in such a way that G1 becomes a multiple of identity matrix. Then, using a function transformation it is possible to obtain the form ds˜(u)/du = G2P-1s˜(u)⊗2. Therefore, a new universal representation for ODEs with second degree multinomial right hand side functions is proposed. There are remaining arbitrary parameters of the space extension and this paper also focuses on how to choose them.

  12. MPTinR: analysis of multinomial processing tree models in R.

    PubMed

    Singmann, Henrik; Kellen, David

    2013-06-01

    We introduce MPTinR, a software package developed for the analysis of multinomial processing tree (MPT) models. MPT models represent a prominent class of cognitive measurement models for categorical data with applications in a wide variety of fields. MPTinR is the first software for the analysis of MPT models in the statistical programming language R, providing a modeling framework that is more flexible than standalone software packages. MPTinR also introduces important features such as (1) the ability to calculate the Fisher information approximation measure of model complexity for MPT models, (2) the ability to fit models for categorical data outside the MPT model class, such as signal detection models, (3) a function for model selection across a set of nested and nonnested candidate models (using several model selection indices), and (4) multicore fitting. MPTinR is available from the Comprehensive R Archive Network at http://cran.r-project.org/web/packages/MPTinR/ . PMID:23344733

  13. A new method for multinomial inference using Dempster-Shafer theory

    SciTech Connect

    Lawrence, Earl Christopher; Vander Wiel, Scott; Liu, Chuanhai; Zhang, Jianchun

    2009-01-01

    A new method for multinomial inference is proposed by representing the cell probabilities as unordered segments on the unit interval and following Dempster-Shafer (DS) theory. The resulting DS posterior is then strengthened to improve symmetry and learning properties with the final posterior model being characterized by a Dirichlet distribution. In addition to computational simplicity, the new model has desirable invariance properties related to category permutations, refinements, and coarsenings. Furthemore, posterior inference on relative probabilities amongst certain cells depends only on data for the cells in question. Finally, the model is quite flexible with regard to parameterization and the range of testable assertions. Comparisons are made to existing methods and illustrated with two examples.

  14. On the Use of Factor-Analytic Multinomial Logit Item Response Models to Account for Individual Differences in Response Style

    ERIC Educational Resources Information Center

    Johnson, Timothy R.; Bolt, Daniel M.

    2010-01-01

    Multidimensional item response models are usually implemented to model the relationship between item responses and two or more traits of interest. We show how multidimensional multinomial logit item response models can also be used to account for individual differences in response style. This is done by specifying a factor-analytic model for…

  15. Monotonicity Properties of Dirichlet Integrals with Applications to the Multinomial Distribution and the Anova Test; A Draft.

    ERIC Educational Resources Information Center

    Olkin, Ingram

    Bounds for the tails of Dirichlet integrals are established by showing that each integral as a function of the limits is a Schur function. In particular, it is shown how these bounds apply to the simultaneous analysis of variance test and to the multinomial distribution. (Author)

  16. Fungible weights in logistic regression.

    PubMed

    Jones, Jeff A; Waller, Niels G

    2016-06-01

    In this article we develop methods for assessing parameter sensitivity in logistic regression models. To set the stage for this work, we first review Waller's (2008) equations for computing fungible weights in linear regression. Next, we describe 2 methods for computing fungible weights in logistic regression. To demonstrate the utility of these methods, we compute fungible logistic regression weights using data from the Centers for Disease Control and Prevention's (2010) Youth Risk Behavior Surveillance Survey, and we illustrate how these alternate weights can be used to evaluate parameter sensitivity. To make our work accessible to the research community, we provide R code (R Core Team, 2015) that will generate both kinds of fungible logistic regression weights. (PsycINFO Database Record PMID:26651981

  17. Tailored logistics: the next advantage.

    PubMed

    Fuller, J B; O'Conor, J; Rawlinson, R

    1993-01-01

    How many top executives have ever visited with managers who move materials from the factory to the store? How many still reduce the costs of logistics to the rent of warehouses and the fees charged by common carriers? To judge by hours of senior management attention, logistics problems do not rank high. But logistics have the potential to become the next governing element of strategy. Whether they know it or not, senior managers of every retail store and diversified manufacturing company compete in logistically distinct businesses. Customer needs vary, and companies can tailor their logistics systems to serve their customers better and more profitably. Companies do not create value for customers and sustainable advantage for themselves merely by offering varieties of goods. Rather, they offer goods in distinct ways. A particular can of Coca-Cola, for example, might be a can of Coca-Cola going to a vending machine, or a can of Coca-Cola that comes with billing services. There is a fortune buried in this distinction. The goal of logistics strategy is building distinct approaches to distinct groups of customers. The first step is organizing a cross-functional team to proceed through the following steps: segmenting customers according to purchase criteria, establishing different standards of service for different customer segments, tailoring logistics pipelines to support each segment, and creating economics of scale to determine which assets can be shared among various pipelines. The goal of establishing logistically distinct businesses is familiar: improved knowledge of customers and improved means of satisfying them. PMID:10126157

  18. NASA Space Rocket Logistics Challenges

    NASA Technical Reports Server (NTRS)

    Neeley, James R.; Jones, James V.; Watson, Michael D.; Bramon, Christopher J.; Inman, Sharon K.; Tuttle, Loraine

    2014-01-01

    The Space Launch System (SLS) is the new NASA heavy lift launch vehicle and is scheduled for its first mission in 2017. The goal of the first mission, which will be uncrewed, is to demonstrate the integrated system performance of the SLS rocket and spacecraft before a crewed flight in 2021. SLS has many of the same logistics challenges as any other large scale program. Common logistics concerns for SLS include integration of discreet programs geographically separated, multiple prime contractors with distinct and different goals, schedule pressures and funding constraints. However, SLS also faces unique challenges. The new program is a confluence of new hardware and heritage, with heritage hardware constituting seventy-five percent of the program. This unique approach to design makes logistics concerns such as commonality especially problematic. Additionally, a very low manifest rate of one flight every four years makes logistics comparatively expensive. That, along with the SLS architecture being developed using a block upgrade evolutionary approach, exacerbates long-range planning for supportability considerations. These common and unique logistics challenges must be clearly identified and tackled to allow SLS to have a successful program. This paper will address the common and unique challenges facing the SLS programs, along with the analysis and decisions the NASA Logistics engineers are making to mitigate the threats posed by each.

  19. Logistics Management: New trends in the Reverse Logistics

    NASA Astrophysics Data System (ADS)

    Antonyová, A.; Antony, P.; Soewito, B.

    2016-04-01

    Present level and quality of the environment are directly dependent on our access to natural resources, as well as their sustainability. In particular production activities and phenomena associated with it have a direct impact on the future of our planet. Recycling process, which in large enterprises often becomes an important and integral part of the production program, is usually in small and medium-sized enterprises problematic. We can specify a few factors, which have direct impact on the development and successful application of the effective reverse logistics system. Find the ways to economically acceptable model of reverse logistics, focusing on converting waste materials for renewable energy, is the task in progress.

  20. Lessons in logistics from Somalia.

    PubMed

    Kemball-Cook, D; Stephenson, R

    1984-03-01

    By February 1981 the refugee relief operation in Somalia was close to breakdown. The Governor of Somalia and the United Nations High Commission for Refugees (UNHCR) contracted the agency CARE to manage the logistics of the operation. By August 1981 over 99 % of food received at Mogadishu was reaching the camps. Here we describe this apparent success, and attempt to diagnose the contributing factors. Chief among these are dynamic leadership, 'systems' management, adaptability of personnel, the use of professional Indian food monitors in the camps, and the support given by the Government. The chief qualification on the success of the operation has been the continued dependency on expatriate expertise. General conclusions are offered relating to the management of logistics in relief operations. The most important conclusion is that there is a prime need for logistics to be centralized in a single organization at the start of major emergencies. We point to the current inadequacy in an international relief system which fails to ensure this, and suggest that a new or existing part of the United Nations family be given a 'brief for in-country logistics' to become a UN Emergency Logistics Office. PMID:20958559

  1. Classical and Bayesian estimation in the logistic regression model applied to diagnosis of child attention deficit hyperactivity disorder.

    PubMed

    Gordóvil-Merino, Amalia; Guàrdia-Olmos, Joan; Peró-Cebollero, Maribel; de la Fuente-Solanas, Emilia I

    2010-04-01

    The limitations inherent to classical estimation of the logistic regression models are known. The Bayesian approach in statistical analysis is an alternative to be considered, given that it makes it possible to introduce prior information about the phenomenon under study. The aim of the present work is to analyze binary and multinomial logistic regression simple models estimated by means of a Bayesian approach in comparison to classical estimation. To that effect, Child Attention Deficit Hyperactivity Disorder (ADHD) clinical data were analyzed. The sample included 286 participants of 6-12 years (78% boys, 22% girls) with ADHD positive diagnosis in 86.7% of the cases. The results show a reduction of standard errors associated to the coefficients obtained from the Bayesian analysis, thus bringing a greater stability to the coefficients. Complex models where parameter estimation may be easily compromised could benefit from this advantage. PMID:20524554

  2. Logistic Stick-Breaking Process

    PubMed Central

    Ren, Lu; Du, Lan; Carin, Lawrence; Dunson, David B.

    2013-01-01

    A logistic stick-breaking process (LSBP) is proposed for non-parametric clustering of general spatially- or temporally-dependent data, imposing the belief that proximate data are more likely to be clustered together. The sticks in the LSBP are realized via multiple logistic regression functions, with shrinkage priors employed to favor contiguous and spatially localized segments. The LSBP is also extended for the simultaneous processing of multiple data sets, yielding a hierarchical logistic stick-breaking process (H-LSBP). The model parameters (atoms) within the H-LSBP are shared across the multiple learning tasks. Efficient variational Bayesian inference is derived, and comparisons are made to related techniques in the literature. Experimental analysis is performed for audio waveforms and images, and it is demonstrated that for segmentation applications the LSBP yields generally homogeneous segments with sharp boundaries. PMID:25258593

  3. Source and destination memory in face-to-face interaction: A multinomial modeling approach.

    PubMed

    Fischer, Nele M; Schult, Janette C; Steffens, Melanie C

    2015-06-01

    Arguing that people are often in doubt concerning to whom they have presented what information, Gopie and MacLeod (2009) introduced a new memory component, destination memory: remembering the destination of output information (i.e., "Who did you tell this to?"). They investigated source (i.e., "Who told you that?") versus destination memory in computer-based imagined interactions. The present study investigated destination memory in real interaction situations. In 2 experiments with mixed-gender (N = 53) versus same-gender (N = 89) groups, source and destination memory were manipulated by creating a setup similar to speed dating. In dyads, participants completed phrase fragments with personal information, taking turns. At recognition, participants decided whether fragments were new or old and, if old, whether they were listened to or spoken and which depicted person was the source or the destination of the information. A multinomial model was used for analyses. Source memory significantly exceeded destination memory, whereas information itself was better remembered in the destination than in the source condition. These findings corroborate the trade-off hypothesis: Context is better remembered in input than in output events, but information itself is better remembered in output than in input events. We discuss the implications of these findings for real-world conversation situations. PMID:25893444

  4. Encoding, maintenance, and retrieval processes in the lag effect: a multinomial processing tree analysis.

    PubMed

    Küpper-Tetzel, Carolina E; Erdfelder, Edgar

    2012-01-01

    Short-term studies on repeated learning of verbatim material have typically revealed an overall benefit of long lags compared to short lags between repetitions. This has been referred to as the lag effect. On educationally relevant time scales, however, an inverted-U-shaped relation between lag and memory performance is often observed. Recently, Cepeda et al. (2009) showed that the optimal lag for relearning depends heavily on the time interval between the last learning session and the final memory test (i.e., the retention interval; RI). In order to explore the cognitive mechanisms underlying this result in more detail we independently manipulated both the lag and the RI in a 3×2 experimental design and analysed our data using a multinomial processing tree model for free-then-cued-recall data. Our results reveal that the lag effect trends are mainly driven by encoding and maintenance processes rather than by retrieval mechanisms. Our findings have important implications for theories of the lag effect. PMID:22171809

  5. Decomposing retrieval and integration in memory for actions: a multinomial modeling approach.

    PubMed

    Steffens, Melanie C; Jelenec, Petra; Mecklenbräuker, Silvia; Thompson, Erin Marie

    2006-03-01

    Typically, action phrases are recalled better if participants are asked to enact the phrases than if they are just asked to remember them. When investigating which processes constitute this enactment effect a difficulty is that observable effects in standard memory tests are ambiguous because such tests require several processes. In the present article, we introduce a multinomial model that decomposes observable memory performance into a retrieval parameter and a parameter concerning the item-specific processing and integration of an action phrase. These parameters are estimated from free recall and cued recall performance. The model fitted the data of two experiments designed to test it. Experiment 1 demonstrated the basic usefulness of the model by showing expected differences in the integration parameter in the absence of unexpected differences in the retrieval parameter. Experiment 2 extended the conditions under which the model is useful by showing expected differences in the retrieval parameter even in the presence of unexpected differences in the integration parameter. Together, these findings support our theoretical framework according to which enactment generally boosts integration of action phrases, but increases retrieval only for phrases with context cues. PMID:16627356

  6. Class-specific Gaussian-multinomial latent Dirichlet allocation for image annotation

    NASA Astrophysics Data System (ADS)

    Qian, Zhiming; Zhong, Ping; Wang, Runsheng

    2015-12-01

    Image annotation has been a challenging problem due to the well-known semantic gap between two heterogeneous information modalities, i.e., the visual modality referring to low-level visual features and the semantic modality referring to high-level human concepts. To bridge the semantic gap, we present an extension of latent Dirichlet allocation (LDA), denoted as class-specific Gaussian-multinomial latent Dirichlet allocation (csGM-LDA), in an effort to simulate the human's visual perception system. An analysis of previous supervised LDA models shows that the topics discovered by generative LDA models are driven by general image regularities rather than the semantic regularities for image annotation. To address this, csGM-LDA is introduced by using class supervision at the level of visual features for multimodal topic modeling. The csGM-LDA model combines the labeling strength of topic supervision with the flexibility of topic discovery, and the modeling problem can be effectively solved by a variational expectation-maximization (EM) algorithm. Moreover, as natural images usually generate an enormous size of high-dimensional data in annotation applications, an efficient descriptor based on Laplacian regularized uncorrelated tensor representation is proposed for explicitly exploiting the manifold structures in the high-order image space. Experimental results on two standard annotation datasets have shown the effectiveness of the proposed method by comparing with several state-of-the-art annotation methods.

  7. A general class of multinomial mixture models for anuran calling survey data

    USGS Publications Warehouse

    Royle, J. Andrew; Link, W.A.

    2005-01-01

    We propose a general framework for modeling anuran abundance using data collected from commonly used calling surveys. The data generated from calling surveys are indices of calling intensity (vocalization of males) that do not have a precise link to actual population size and are sensitive to factors that influence anuran behavior. We formulate a model for calling-index data in terms of the maximum potential calling index that could be observed at a site (the 'latent abundance class'), given its underlying breeding population, and we focus attention on estimating the distribution of this latent abundance class. A critical consideration in estimating the latent structure is imperfect detection, which causes the observed abundance index to be less than or equal to the latent abundance class. We specify a multinomial sampling model for the observed abundance index that is conditional on the latent abundance class. Estimation of the latent abundance class distribution is based on the marginal likelihood of the index data, having integrated over the latent class distribution. We apply the proposed modeling framework to data collected as part of the North American Amphibian Monitoring Program (NAAMP).

  8. Model-based Clustering of Categorical Time Series with Multinomial Logit Classification

    NASA Astrophysics Data System (ADS)

    Frühwirth-Schnatter, Sylvia; Pamminger, Christoph; Winter-Ebmer, Rudolf; Weber, Andrea

    2010-09-01

    A common problem in many areas of applied statistics is to identify groups of similar time series in a panel of time series. However, distance-based clustering methods cannot easily be extended to time series data, where an appropriate distance-measure is rather difficult to define, particularly for discrete-valued time series. Markov chain clustering, proposed by Pamminger and Frühwirth-Schnatter [6], is an approach for clustering discrete-valued time series obtained by observing a categorical variable with several states. This model-based clustering method is based on finite mixtures of first-order time-homogeneous Markov chain models. In order to further explain group membership we present an extension to the approach of Pamminger and Frühwirth-Schnatter [6] by formulating a probabilistic model for the latent group indicators within the Bayesian classification rule by using a multinomial logit model. The parameters are estimated for a fixed number of clusters within a Bayesian framework using an Markov chain Monte Carlo (MCMC) sampling scheme representing a (full) Gibbs-type sampler which involves only draws from standard distributions. Finally, an application to a panel of Austrian wage mobility data is presented which leads to an interesting segmentation of the Austrian labour market.

  9. Logistics background study: underground mining

    SciTech Connect

    Hanslovan, J. J.; Visovsky, R. G.

    1982-02-01

    Logistical functions that are normally associated with US underground coal mining are investigated and analyzed. These functions imply all activities and services that support the producing sections of the mine. The report provides a better understanding of how these functions impact coal production in terms of time, cost, and safety. Major underground logistics activities are analyzed and include: transportation and personnel, supplies and equipment; transportation of coal and rock; electrical distribution and communications systems; water handling; hydraulics; and ventilation systems. Recommended areas for future research are identified and prioritized.

  10. Continual Improvement in Shuttle Logistics

    NASA Technical Reports Server (NTRS)

    Flowers, Jean; Schafer, Loraine

    1995-01-01

    It has been said that Continual Improvement (CI) is difficult to apply to service oriented functions, especially in a government agency such as NASA. However, a constrained budget and increasing requirements are a way of life at NASA Kennedy Space Center (KSC), making it a natural environment for the application of CI tools and techniques. This paper describes how KSC, and specifically the Space Shuttle Logistics Project, a key contributor to KSC's mission, has embraced the CI management approach as a means of achieving its strategic goals and objectives. An overview of how the KSC Space Shuttle Logistics Project has structured its CI effort and examples of some of the initiatives are provided.

  11. A multinomial logit model-Bayesian network hybrid approach for driver injury severity analyses in rear-end crashes.

    PubMed

    Chen, Cong; Zhang, Guohui; Tarefder, Rafiqul; Ma, Jianming; Wei, Heng; Guan, Hongzhi

    2015-07-01

    Rear-end crash is one of the most common types of traffic crashes in the U.S. A good understanding of its characteristics and contributing factors is of practical importance. Previously, both multinomial Logit models and Bayesian network methods have been used in crash modeling and analysis, respectively, although each of them has its own application restrictions and limitations. In this study, a hybrid approach is developed to combine multinomial logit models and Bayesian network methods for comprehensively analyzing driver injury severities in rear-end crashes based on state-wide crash data collected in New Mexico from 2010 to 2011. A multinomial logit model is developed to investigate and identify significant contributing factors for rear-end crash driver injury severities classified into three categories: no injury, injury, and fatality. Then, the identified significant factors are utilized to establish a Bayesian network to explicitly formulate statistical associations between injury severity outcomes and explanatory attributes, including driver behavior, demographic features, vehicle factors, geometric and environmental characteristics, etc. The test results demonstrate that the proposed hybrid approach performs reasonably well. The Bayesian network reference analyses indicate that the factors including truck-involvement, inferior lighting conditions, windy weather conditions, the number of vehicles involved, etc. could significantly increase driver injury severities in rear-end crashes. The developed methodology and estimation results provide insights for developing effective countermeasures to reduce rear-end crash injury severities and improve traffic system safety performance. PMID:25888994

  12. A development of logistics management models for the Space Transportation System

    NASA Technical Reports Server (NTRS)

    Carrillo, M. J.; Jacobsen, S. E.; Abell, J. B.; Lippiatt, T. F.

    1983-01-01

    A new analytic queueing approach was described which relates stockage levels, repair level decisions, and the project network schedule of prelaunch operations directly to the probability distribution of the space transportation system launch delay. Finite source population and limited repair capability were additional factors included in this logistics management model developed specifically for STS maintenance requirements. Data presently available to support logistics decisions were based on a comparability study of heavy aircraft components. A two-phase program is recommended by which NASA would implement an integrated data collection system, assemble logistics data from previous STS flights, revise extant logistics planning and resource requirement parameters using Bayes-Lin techniques, and adjust for uncertainty surrounding logistics systems performance parameters. The implementation of these recommendations can be expected to deliver more cost-effective logistics support.

  13. Logistics support of space facilities

    NASA Technical Reports Server (NTRS)

    Lewis, William C.

    1988-01-01

    The logistic support of space facilities is described, with special attention given to the problem of sizing the inventory of ready spares kept at the space facility. Where possible, data from the Space Shuttle Orbiter is extrapolated to provide numerical estimates for space facilities. Attention is also given to repair effort estimation and long duration missions.

  14. NASA Space Rocket Logistics Challenges

    NASA Technical Reports Server (NTRS)

    Bramon, Chris; Neeley, James R.; Jones, James V.; Watson, Michael D.; Inman, Sharon K.; Tuttle, Loraine

    2014-01-01

    The Space Launch System (SLS) is the new NASA heavy lift launch vehicle in development and is scheduled for its first mission in 2017. SLS has many of the same logistics challenges as any other large scale program. However, SLS also faces unique challenges. This presentation will address the SLS challenges, along with the analysis and decisions to mitigate the threats posed by each.

  15. Multisource information fusion for logistics

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Petrov, Plamen; Noll, Warren

    2011-05-01

    Current Army logistical systems and databases contain massive amounts of data that need an effective method to extract actionable information. The databases do not contain root cause and case-based analysis needed to diagnose or predict breakdowns. A system is needed to find data from as many sources as possible, process it in an integrated fashion, and disseminate information products on the readiness of the fleet vehicles. 21st Century Systems, Inc. introduces the Agent- Enabled Logistics Enterprise Intelligence System (AELEIS) tool, designed to assist logistics analysts with assessing the availability and prognostics of assets in the logistics pipeline. AELEIS extracts data from multiple, heterogeneous data sets. This data is then aggregated and mined for data trends. Finally, data reasoning tools and prognostics tools evaluate the data for relevance and potential issues. Multiple types of data mining tools may be employed to extract the data and an information reasoning capability determines what tools are needed to apply them to extract information. This can be visualized as a push-pull system where data trends fire a reasoning engine to search for corroborating evidence and then integrate the data into actionable information. The architecture decides on what reasoning engine to use (i.e., it may start with a rule-based method, but, if needed, go to condition based reasoning, and even a model-based reasoning engine for certain types of equipment). Initial results show that AELEIS is able to indicate to the user of potential fault conditions and root-cause information mined from a database.

  16. Logistics, electronic commerce, and the environment

    NASA Astrophysics Data System (ADS)

    Sarkis, Joseph; Meade, Laura; Talluri, Srinivas

    2002-02-01

    Organizations realize that a strong supporting logistics or electronic logistics (e-logistics) function is important from both commercial and consumer perspectives. The implications of e-logistics models and practices cover the forward and reverse logistics functions of organizations. They also have direct and profound impact on the natural environment. This paper will focus on a discussion of forward and reverse e-logistics and their relationship to the natural environment. After discussion of the many pertinent issues in these areas, directions of practice and implications for study and research are then described.

  17. An ethnobiological study in Kala Chitta hills of Pothwar region, Pakistan: multinomial logit specification

    PubMed Central

    2014-01-01

    Background This paper constitutes an important ethnobiological survey in the context of utilizing biological resources by residents of Kala Chitta hills of Pothwar region, Pakistan. The fundamental aim of this research endeavour was to catalogue and analyse the indigenous knowledge of native community about plants and animals. The study is distinctive in the sense to explore both ethnobotanical and ethnozoological aspects of indigenous culture, and exhibits novelty, being based on empirical approach of Multinomial Logit Specifications (MLS) for examining ethnobotanical and ethnozoological uses of specific plants and animals. Methods To document the ethnobiological knowledge, the survey was conducted during 2011–12 by employing a semi-structured questionnaire and thus 54 informants were interviewed. Plant and animal specimens were collected, photographed and properly identified. Distribution of plants and animals were explored by descriptive and graphical examination. MLS were further incorporated to identify the probability of occurrence of diversified utilization of plants and animals in multipurpose domains. Results Traditional uses of 91 plant and 65 animal species were reported. Data analysis revealed more medicinal use of plants and animals than all other use categories. MLS findings are also in line with these proportional configurations. They reveal that medicinal and food consumption of underground and perennial plants was more as compared to aerial and annual categories of plants. Likewise, medicinal utilization of wild animals and domestic animals were more commonly observed as food items. However, invertebrates are more in the domain of medicinal and food utilization. Also carnivores are fairly common in the use of medicine while herbivores are in the category of food consumption. Conclusion This study empirically scans a good chunk of ethnobiological knowledge and depicts its strong connection with indigenous traditions. It is important to make local

  18. Comparing the Discrete and Continuous Logistic Models

    ERIC Educational Resources Information Center

    Gordon, Sheldon P.

    2008-01-01

    The solutions of the discrete logistic growth model based on a difference equation and the continuous logistic growth model based on a differential equation are compared and contrasted. The investigation is conducted using a dynamic interactive spreadsheet. (Contains 5 figures.)

  19. Research on 6R Military Logistics Network

    NASA Astrophysics Data System (ADS)

    Jie, Wan; Wen, Wang

    The building of military logistics network is an important issue for the construction of new forces. This paper has thrown out a concept model of 6R military logistics network model based on JIT. Then we conceive of axis spoke y logistics centers network, flexible 6R organizational network, lean 6R military information network based grid. And then the strategy and proposal for the construction of the three sub networks of 6Rmilitary logistics network are given.

  20. Mini pressurized logistics module (MPLM)

    NASA Astrophysics Data System (ADS)

    Vallerani, E.; Brondolo, D.; Basile, L.

    1996-06-01

    The MPLM Program was initiated through a Memorandum of Understanding (MOU) between the United States' National Aeronautics and Space Administration (NASA) and Italy's ASI, the Italian Space Agency, that was signed on 6 December 1991. The MPLM is a pressurized logistics module that will be used to transport supplies and materials (up to 20,000 lb), including user experiments, between Earth and International Space Station Alpha (ISSA) using the Shuttle, to support active and passive storage, and to provide a habitable environment for two people when docked to the Station. The Italian Space Agency has selected Alenia Spazio to develop MPLM modules that have always been considered a key element for the new International Space Station taking benefit from its design flexibility and consequent possible cost saving based on the maximum utilization of the Shuttle launch capability for any mission. In the frame of the very recent agreement between the U.S. and Russia for cooperation in space, that foresees the utilization of MIR 1 hardware, the Italian MPLM will remain an important element of the logistics system, being the only pressurized module designed for re-entry. Within the new scenario of anticipated Shuttle flights to MIR 1 during Space Station phase 1, MPLM remains a candidate for one or more missions to provide MIR 1 resupply capabilities and advanced ISSA hardware/procedures verification. Based on the concept of Flexible Carriers, Alenia Spazio is providing NASA with three MPLM flight units that can be configured according to the requirements of the Human-Tended Capability (HTC) and Permanent Human Capability (PHC) of the Space Station. Configurability will allow transportation of passive cargo only, or a combination of passive and cold cargo accommodated in R/F racks. Having developed and qualified the baseline configuration with respect to the worst enveloping condition, each unit could be easily configured to the passive or active version depending upon the

  1. Logistics Handbook, 1976. Colorado Outward Bound School.

    ERIC Educational Resources Information Center

    Colorado Outward Bound School, Denver.

    Logistics, a support mission, is vital to the successful operation of the Colorado Outward Bound School (COBS) courses. Logistics is responsible for purchasing, maintaining, transporting, and replenishing a wide variety of items, i.e., food, mountaineering and camping equipment, medical and other supplies, and vehicles. The Logistics coordinator…

  2. Network-Constrained Group Lasso for High-Dimensional Multinomial Classification with Application to Cancer Subtype Prediction

    PubMed Central

    Tian, Xinyu; Wang, Xuefeng; Chen, Jun

    2014-01-01

    Classic multinomial logit model, commonly used in multiclass regression problem, is restricted to few predictors and does not take into account the relationship among variables. It has limited use for genomic data, where the number of genomic features far exceeds the sample size. Genomic features such as gene expressions are usually related by an underlying biological network. Efficient use of the network information is important to improve classification performance as well as the biological interpretability. We proposed a multinomial logit model that is capable of addressing both the high dimensionality of predictors and the underlying network information. Group lasso was used to induce model sparsity, and a network-constraint was imposed to induce the smoothness of the coefficients with respect to the underlying network structure. To deal with the non-smoothness of the objective function in optimization, we developed a proximal gradient algorithm for efficient computation. The proposed model was compared to models with no prior structure information in both simulations and a problem of cancer subtype prediction with real TCGA (the cancer genome atlas) gene expression data. The network-constrained mode outperformed the traditional ones in both cases. PMID:25635165

  3. Country logistics performance and disaster impact.

    PubMed

    Vaillancourt, Alain; Haavisto, Ira

    2016-04-01

    The aim of this paper is to deepen the understanding of the relationship between country logistics performance and disaster impact. The relationship is analysed through correlation analysis and regression models for 117 countries for the years 2007 to 2012 with disaster impact variables from the International Disaster Database (EM-DAT) and logistics performance indicators from the World Bank. The results show a significant relationship between country logistics performance and disaster impact overall and for five out of six specific logistic performance indicators. These specific indicators were further used to explore the relationship between country logistic performance and disaster impact for three specific disaster types (epidemic, flood and storm). The findings enhance the understanding of the role of logistics in a humanitarian context with empirical evidence of the importance of country logistics performance in disaster response operations. PMID:26282578

  4. Logistic equation of arbitrary order

    NASA Astrophysics Data System (ADS)

    Grabowski, Franciszek

    2010-08-01

    The paper is concerned with the new logistic equation of arbitrary order which describes the performance of complex executive systems X vs. number of tasks N, operating at limited resources K, at non-extensive, heterogeneous self-organization processes characterized by parameter f. In contrast to the classical logistic equation which exclusively relates to the special case of sub-extensive homogeneous self-organization processes at f=1, the proposed model concerns both homogeneous and heterogeneous processes in sub-extensive and super-extensive areas. The parameter of arbitrary order f, where -∞

  5. ADJUSTABLE DOUBLE PULSE GENERATOR

    DOEpatents

    Gratian, J.W.; Gratian, A.C.

    1961-08-01

    >A modulator pulse source having adjustable pulse width and adjustable pulse spacing is described. The generator consists of a cross coupled multivibrator having adjustable time constant circuitry in each leg, an adjustable differentiating circuit in the output of each leg, a mixing and rectifying circuit for combining the differentiated pulses and generating in its output a resultant sequence of negative pulses, and a final amplifying circuit for inverting and square-topping the pulses. (AEC)

  6. Adjustable sutures in children.

    PubMed

    Engel, J Mark; Guyton, David L; Hunter, David G

    2014-06-01

    Although adjustable sutures are considered a standard technique in adult strabismus surgery, most surgeons are hesitant to attempt the technique in children, who are believed to be unlikely to cooperate for postoperative assessment and adjustment. Interest in using adjustable sutures in pediatric patients has increased with the development of surgical techniques specific to infants and children. This workshop briefly reviews the literature supporting the use of adjustable sutures in children and presents the approaches currently used by three experienced strabismus surgeons. PMID:24924284

  7. Optimal distributions for multiplex logistic networks.

    PubMed

    Solá Conde, Luis E; Used, Javier; Romance, Miguel

    2016-06-01

    This paper presents some mathematical models for distribution of goods in logistic networks based on spectral analysis of complex networks. Given a steady distribution of a finished product, some numerical algorithms are presented for computing the weights in a multiplex logistic network that reach the equilibrium dynamics with high convergence rate. As an application, the logistic networks of Germany and Spain are analyzed in terms of their convergence rates. PMID:27368801

  8. Integrated Computer System of Management in Logistics

    NASA Astrophysics Data System (ADS)

    Chwesiuk, Krzysztof

    2011-06-01

    This paper aims at presenting a concept of an integrated computer system of management in logistics, particularly in supply and distribution chains. Consequently, the paper includes the basic idea of the concept of computer-based management in logistics and components of the system, such as CAM and CIM systems in production processes, and management systems for storage, materials flow, and for managing transport, forwarding and logistics companies. The platform which integrates computer-aided management systems is that of electronic data interchange.

  9. Optimal distributions for multiplex logistic networks

    NASA Astrophysics Data System (ADS)

    Solá Conde, Luis E.; Used, Javier; Romance, Miguel

    2016-06-01

    This paper presents some mathematical models for distribution of goods in logistic networks based on spectral analysis of complex networks. Given a steady distribution of a finished product, some numerical algorithms are presented for computing the weights in a multiplex logistic network that reach the equilibrium dynamics with high convergence rate. As an application, the logistic networks of Germany and Spain are analyzed in terms of their convergence rates.

  10. Logistics Reduction Technologies for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L., Jr.; Ewert, Michael K.; Fink, Patrick W.

    2014-01-01

    Human exploration missions under study are limited by the launch mass capacity of existing and planned launch vehicles. The logistical mass of crew items is typically considered separate from the vehicle structure, habitat outfitting, and life support systems. Although mass is typically the focus of exploration missions, due to its strong impact on launch vehicle and habitable volume for the crew, logistics volume also needs to be considered. NASA's Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project is developing six logistics technologies guided by a systems engineering cradle-to-grave approach to enable after-use crew items to augment vehicle systems. Specifically, AES LRR is investigating the direct reduction of clothing mass, the repurposing of logistical packaging, the use of autonomous logistics management technologies, the processing of spent crew items to benefit radiation shielding and water recovery, and the conversion of trash to propulsion gases. Reduction of mass has a corresponding and significant impact to logistical volume. The reduction of logistical volume can reduce the overall pressurized vehicle mass directly, or indirectly benefit the mission by allowing for an increase in habitable volume during the mission. The systematic implementation of these types of technologies will increase launch mass efficiency by enabling items to be used for secondary purposes and improve the habitability of the vehicle as mission durations increase. Early studies have shown that the use of advanced logistics technologies can save approximately 20 m(sup 3) of volume during transit alone for a six-person Mars conjunction class mission.

  11. Analysis of Jingdong Mall Logistics Distribution Model

    NASA Astrophysics Data System (ADS)

    Shao, Kang; Cheng, Feng

    In recent years, the development of electronic commerce in our country to speed up the pace. The role of logistics has been highlighted, more and more electronic commerce enterprise are beginning to realize the importance of logistics in the success or failure of the enterprise. In this paper, the author take Jingdong Mall for example, performing a SWOT analysis of their current situation of self-built logistics system, find out the problems existing in the current Jingdong Mall logistics distribution and give appropriate recommendations.

  12. FUTURE LOGISTICS AND OPERATIONAL ADAPTABILITY

    SciTech Connect

    Houck, Roger P.

    2009-10-01

    While we cannot predict the future, we can ascertain trends and examine them through the use of alternative futures methodologies and tools. From a logistics perspective, we know that many different futures are possible, all of which are obviously dependent on decisions we make in the present. As professional logisticians we are obligated to provide the field - our Soldiers - with our best professional opinion of what will result in success on the battlefield. Our view of the future should take history and contemporary conflict into account, but it must also consider that continuity with the past cannot be taken for granted. If we are too focused on past and current experience, then our vision of the future will be limited indeed. On the one hand, the future must be explained in language that does not defy common sense. On the other hand, the pace of change is such that we must conduct qualitative and quantitative trend analyses, forecasting, and explorative scenario development in ways that allow for significant breaks - or "shocks" - that may "change the game". We will need capabilities and solutions that are constantly evolving - and improving - to match the operational tempo of a radically changing threat environment. For those who provide quartermaster services, this article will briefly examine what this means from the perspective of creating what might be termed a preferred future.

  13. Biomass supply logistics and infrastructure.

    PubMed

    Sokhansanj, Shahabaddine; Hess, J Richard

    2009-01-01

    Feedstock supply system encompasses numerous unit operations necessary to move lignocellulosic feedstock from the place where it is produced (in the field or on the stump) to the start of the conversion process (reactor throat) of the biorefinery. These unit operations, which include collection, storage, preprocessing, handling, and transportation, represent one of the largest technical and logistics challenges to the emerging lignocellulosic biorefining industry. This chapter briefly reviews the methods of estimating the quantities of biomass, followed by harvesting and collection processes based on current practices on handling wet and dry forage materials. Storage and queuing are used to deal with seasonal harvest times, variable yields, and delivery schedules. Preprocessing can be as simple as grinding and formatting the biomass for increased bulk density or improved conversion efficiency, or it can be as complex as improving feedstock quality through fractionation, tissue separation, drying, blending, and densification. Handling and transportation consists of using a variety of transport equipment (truck, train, ship) for moving the biomass from one point to another. The chapter also provides typical cost figures for harvest and processing of biomass. PMID:19768612

  14. Biomass Supply Logistics and Infrastructure

    SciTech Connect

    Sokhansanj, Shahabaddine

    2009-04-01

    Feedstock supply system encompasses numerous unit operations necessary to move lignocellulosic feedstock from the place where it is produced (in the field or on the stump) to the start of the conversion process (reactor throat) of the Biorefinery. These unit operations, which include collection, storage, preprocessing, handling, and transportation, represent one of the largest technical and logistics challenges to the emerging lignocellulosic biorefining industry. This chapter briefly reviews methods of estimating the quantities of biomass followed by harvesting and collection processes based on current practices on handling wet and dry forage materials. Storage and queuing are used to deal with seasonal harvest times, variable yields, and delivery schedules. Preprocessing can be as simple as grinding and formatting the biomass for increased bulk density or improved conversion efficiency, or it can be as complex as improving feedstock quality through fractionation, tissue separation, drying, blending, and densification. Handling and Transportation consists of using a variety of transport equipment (truck, train, ship) for moving the biomass from one point to another. The chapter also provides typical cost figures for harvest and processing of biomass.

  15. Biomass Supply Logistics and Infrastructure

    NASA Astrophysics Data System (ADS)

    Sokhansanj, Shahabaddine; Hess, J. Richard

    Feedstock supply system encompasses numerous unit operations necessary to move lignocellulosic feedstock from the place where it is produced (in the field or on the stump) to the start of the conversion process (reactor throat) of the biorefinery. These unit operations, which include collection, storage, preprocessing, handling, and transportation, represent one of the largest technical and logistics challenges to the emerging lignocellulosic biorefining industry. This chapter briefly reviews the methods of estimating the quantities of biomass, followed by harvesting and collection processes based on current practices on handling wet and dry forage materials. Storage and queuing are used to deal with seasonal harvest times, variable yields, and delivery schedules. Preprocessing can be as simple as grinding and formatting the biomass for increased bulk density or improved conversion efficiency, or it can be as complex as improving feedstock quality through fractionation, tissue separation, drying, blending, and densification. Handling and transportation consists of using a variety of transport equipment (truck, train, ship) for moving the biomass from one point to another. The chapter also provides typical cost figures for harvest and processing of biomass.

  16. Insights into the latent multinomial model through mark-resight data on female grizzly bears with cubs-of-the-year

    USGS Publications Warehouse

    Higgs, Megan D.; Link, William; White, Gary C.; Haroldson, Mark A.; Bjornlie, Daniel D

    2013-01-01

    Mark-resight designs for estimation of population abundance are common and attractive to researchers. However, inference from such designs is very limited when faced with sparse data, either from a low number of marked animals, a low probability of detection, or both. In the Greater Yellowstone Ecosystem, yearly mark-resight data are collected for female grizzly bears with cubs-of-the-year (FCOY), and inference suffers from both limitations. To overcome difficulties due to sparseness, we assume homogeneity in sighting probabilities over 16 years of bi-annual aerial surveys. We model counts of marked and unmarked animals as multinomial random variables, using the capture frequencies of marked animals for inference about the latent multinomial frequencies for unmarked animals. We discuss undesirable behavior of the commonly used discrete uniform prior distribution on the population size parameter and provide OpenBUGS code for fitting such models. The application provides valuable insights into subtleties of implementing Bayesian inference for latent multinomial models. We tie the discussion to our application, though the insights are broadly useful for applications of the latent multinomial model.

  17. Visualizing the Logistic Map with a Microcontroller

    ERIC Educational Resources Information Center

    Serna, Juan D.; Joshi, Amitabh

    2012-01-01

    The logistic map is one of the simplest nonlinear dynamical systems that clearly exhibits the route to chaos. In this paper, we explore the evolution of the logistic map using an open-source microcontroller connected to an array of light-emitting diodes (LEDs). We divide the one-dimensional domain interval [0,1] into ten equal parts, an associate…

  18. Standards for Standardized Logistic Regression Coefficients

    ERIC Educational Resources Information Center

    Menard, Scott

    2011-01-01

    Standardized coefficients in logistic regression analysis have the same utility as standardized coefficients in linear regression analysis. Although there has been no consensus on the best way to construct standardized logistic regression coefficients, there is now sufficient evidence to suggest a single best approach to the construction of a…

  19. Exploration Mission Benefits From Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.; Ewert, Michael K.; Schlesinger, Thilini

    2016-01-01

    Technologies that reduce logistical mass, volume, and the crew time dedicated to logistics management become more important as exploration missions extend further from the Earth. Even modest reductions in logistical mass can have a significant impact because it also reduces the packaging burden. NASA's Advanced Exploration Systems' Logistics Reduction Project is developing technologies that can directly reduce the mass and volume of crew clothing and metabolic waste collection. Also, cargo bags have been developed that can be reconfigured for crew outfitting, and trash processing technologies are under development to increase habitable volume and improve protection against solar storm events. Additionally, Mars class missions are sufficiently distant that even logistics management without resupply can be problematic due to the communication time delay with Earth. Although exploration vehicles are launched with all consumables and logistics in a defined configuration, the configuration continually changes as the mission progresses. Traditionally significant ground and crew time has been required to understand the evolving configuration and to help locate misplaced items. For key mission events and unplanned contingencies, the crew will not be able to rely on the ground for logistics localization assistance. NASA has been developing a radio-frequency-identification autonomous logistics management system to reduce crew time for general inventory and enable greater crew self-response to unplanned events when a wide range of items may need to be located in a very short time period. This paper provides a status of the technologies being developed and their mission benefits for exploration missions.

  20. On some generalized discrete logistic maps

    PubMed Central

    Radwan, Ahmed G.

    2012-01-01

    Recently, conventional logistic maps have been used in different vital applications like modeling and security. However, unfortunately the conventional logistic maps can tolerate only one changeable parameter. In this paper, three different generalized logistic maps are introduced with arbitrary powers which can be reduced to the conventional logistic map. The added parameter (arbitrary power) increases the degree of freedom of each map and gives us a versatile response that can fit many applications. Therefore, the conventional logistic map is considered only a special case from each proposed map. This new parameter increases the flexibility of the system, and illustrates the performance of the conventional system within any required neighborhood. Many cases will be illustrated showing the effect of the arbitrary power and the equation parameter on the number of equilibrium points, their locations, stability conditions, and bifurcation diagrams up to the chaotic behavior. PMID:25685414

  1. Comparison of logistic equations for population growth.

    PubMed

    Jensen, A L

    1975-12-01

    Two different forms of the logistic equation for population growth appear in the ecological literature. In the form of the logistic equation that appears in recent ecology textbooks the parameters are the instantaneous rate of natural increase per individual and the carrying capacity of the environment. In the form of the logistic equation that appears in some older literature the parameters are the instantaneous birth rate per individual and the carrying capacity. The decision whether to use one form or the other depends on which form of the equation is biologically more realistic. In this study the form of the logistic equation in which the instantaneous birth rate per individual is a parameter is shown to be more realistic in terms of the birth and death processes of population growth. Application of the logistic equation to calculate yield from an exploited fish population also shows that the parameters must be the instantaneous birth rate per individual and the carrying capacity. PMID:1203427

  2. Improvement in fresh fruit and vegetable logistics quality: berry logistics field studies.

    PubMed

    do Nascimento Nunes, M Cecilia; Nicometo, Mike; Emond, Jean Pierre; Melis, Ricardo Badia; Uysal, Ismail

    2014-06-13

    Shelf life of fresh fruits and vegetables is greatly influenced by environmental conditions. Increasing temperature usually results in accelerated loss of quality and shelf-life reduction, which is not physically visible until too late in the supply chain to adjust logistics to match shelf life. A blackberry study showed that temperatures inside pallets varied significantly and 57% of the berries arriving at the packinghouse did not have enough remaining shelf life for the longest supply routes. Yet, the advanced shelf-life loss was not physically visible. Some of those pallets would be sent on longer supply routes than necessary, creating avoidable waste. Other studies showed that variable pre-cooling at the centre of pallets resulted in physically invisible uneven shelf life. We have shown that using simple temperature measurements much waste can be avoided using 'first expiring first out'. Results from our studies showed that shelf-life prediction should not be based on a single quality factor as, depending on the temperature history, the quality attribute that limits shelf life may vary. Finally, methods to use air temperature to predict product temperature for highest shelf-life prediction accuracy in the absence of individual sensors for each monitored product have been developed. Our results show a significant reduction of up to 98% in the root-mean-square-error difference between the product temperature and air temperature when advanced estimation methods are used. PMID:24797135

  3. Exploration Mission Benefits From Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.; Schlesinger, Thilini; Ewert, Michael K.

    2016-01-01

    Technologies that reduce logistical mass, volume, and the crew time dedicated to logistics management become more important as exploration missions extend further from the Earth. Even modest reductions in logical mass can have a significant impact because it also reduces the packing burden. NASA's Advanced Exploration Systems' Logistics Reduction Project is developing technologies that can directly reduce the mass and volume of crew clothing and metabolic waste collection. Also, cargo bags have been developed that can be reconfigured for crew outfitting and trash processing technologies to increase habitable volume and improve protection against solar storm events are under development. Additionally, Mars class missions are sufficiently distant that even logistics management without resupply can be problematic due to the communication time delay with Earth. Although exploration vehicles are launched with all consumables and logistics in a defined configuration, the configuration continually changes as the mission progresses. Traditionally significant ground and crew time has been required to understand the evolving configuration and locate misplaced items. For key mission events and unplanned contingencies, the crew will not be able to rely on the ground for logistics localization assistance. NASA has been developing a radio frequency identification autonomous logistics management system to reduce crew time for general inventory and enable greater crew self-response to unplanned events when a wide range of items may need to be located in a very short time period. This paper provides a status of the technologies being developed and there mission benefits for exploration missions.

  4. Logistics Modeling for Lunar Exploration Systems

    NASA Technical Reports Server (NTRS)

    Andraschko, Mark R.; Merrill, R. Gabe; Earle, Kevin D.

    2008-01-01

    The extensive logistics required to support extended crewed operations in space make effective modeling of logistics requirements and deployment critical to predicting the behavior of human lunar exploration systems. This paper discusses the software that has been developed as part of the Campaign Manifest Analysis Tool in support of strategic analysis activities under the Constellation Architecture Team - Lunar. The described logistics module enables definition of logistics requirements across multiple surface locations and allows for the transfer of logistics between those locations. A key feature of the module is the loading algorithm that is used to efficiently load logistics by type into carriers and then onto landers. Attention is given to the capabilities and limitations of this loading algorithm, particularly with regard to surface transfers. These capabilities are described within the context of the object-oriented software implementation, with details provided on the applicability of using this approach to model other human exploration scenarios. Some challenges of incorporating probabilistics into this type of logistics analysis model are discussed at a high level.

  5. ISS Logistics Hardware Disposition and Metrics Validation

    NASA Technical Reports Server (NTRS)

    Rogers, Toneka R.

    2010-01-01

    I was assigned to the Logistics Division of the International Space Station (ISS)/Spacecraft Processing Directorate. The Division consists of eight NASA engineers and specialists that oversee the logistics portion of the Checkout, Assembly, and Payload Processing Services (CAPPS) contract. Boeing, their sub-contractors and the Boeing Prime contract out of Johnson Space Center, provide the Integrated Logistics Support for the ISS activities at Kennedy Space Center. Essentially they ensure that spares are available to support flight hardware processing and the associated ground support equipment (GSE). Boeing maintains a Depot for electrical, mechanical and structural modifications and/or repair capability as required. My assigned task was to learn project management techniques utilized by NASA and its' contractors to provide an efficient and effective logistics support infrastructure to the ISS program. Within the Space Station Processing Facility (SSPF) I was exposed to Logistics support components, such as, the NASA Spacecraft Services Depot (NSSD) capabilities, Mission Processing tools, techniques and Warehouse support issues, required for integrating Space Station elements at the Kennedy Space Center. I also supported the identification of near-term ISS Hardware and Ground Support Equipment (GSE) candidates for excessing/disposition prior to October 2010; and the validation of several Logistics Metrics used by the contractor to measure logistics support effectiveness.

  6. Adjusting the Chain Gear

    NASA Astrophysics Data System (ADS)

    Koloc, Z.; Korf, J.; Kavan, P.

    The adjustment (modification) deals with gear chains intermediating (transmitting) motion transfer between the sprocket wheels on parallel shafts. The purpose of the adjustments of chain gear is to remove the unwanted effects by using the chain guide on the links (sliding guide rail) ensuring a smooth fit of the chain rollers into the wheel tooth gap.

  7. Adjustment to Recruit Training.

    ERIC Educational Resources Information Center

    Anderson, Betty S.

    The thesis examines problems of adjustment encountered by new recruits entering the military services. Factors affecting adjustment are discussed: the recruit training staff and environment, recruit background characteristics, the military's image, the changing values and motivations of today's youth, and the recruiting process. Sources of…

  8. Front-End Analysis Cornerstone of Logistics

    NASA Technical Reports Server (NTRS)

    Nager, Paul J.

    2000-01-01

    The presentation provides an overview of Front-End Logistics Support Analysis (FELSA), when it should be performed, benefits of performing FELSA and why it should be performed, how it is conducted, and examples.

  9. Satellite rainfall retrieval by logistic regression

    NASA Technical Reports Server (NTRS)

    Chiu, Long S.

    1986-01-01

    The potential use of logistic regression in rainfall estimation from satellite measurements is investigated. Satellite measurements provide covariate information in terms of radiances from different remote sensors.The logistic regression technique can effectively accommodate many covariates and test their significance in the estimation. The outcome from the logistical model is the probability that the rainrate of a satellite pixel is above a certain threshold. By varying the thresholds, a rainrate histogram can be obtained, from which the mean and the variant can be estimated. A logistical model is developed and applied to rainfall data collected during GATE, using as covariates the fractional rain area and a radiance measurement which is deduced from a microwave temperature-rainrate relation. It is demonstrated that the fractional rain area is an important covariate in the model, consistent with the use of the so-called Area Time Integral in estimating total rain volume in other studies. To calibrate the logistical model, simulated rain fields generated by rainfield models with prescribed parameters are needed. A stringent test of the logistical model is its ability to recover the prescribed parameters of simulated rain fields. A rain field simulation model which preserves the fractional rain area and lognormality of rainrates as found in GATE is developed. A stochastic regression model of branching and immigration whose solutions are lognormally distributed in some asymptotic limits has also been developed.

  10. Logistics Reduction Technologies for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L., Jr.; Ewert, Michael K.; Fink, Patrick W.

    2014-01-01

    Human exploration missions under study are very limited by the launch mass capacity of existing and planned vehicles. The logistical mass of crew items is typically considered separate from the vehicle structure, habitat outfitting, and life support systems. Consequently, crew item logistical mass is typically competing with vehicle systems for mass allocation. NASA's Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project is developing five logistics technologies guided by a systems engineering cradle-to-grave approach to enable used crew items to augment vehicle systems. Specifically, AES LRR is investigating the direct reduction of clothing mass, the repurposing of logistical packaging, the use of autonomous logistics management technologies, the processing of spent crew items to benefit radiation shielding and water recovery, and the conversion of trash to propulsion gases. The systematic implementation of these types of technologies will increase launch mass efficiency by enabling items to be used for secondary purposes and improve the habitability of the vehicle as the mission duration increases. This paper provides a description and the challenges of the five technologies under development and the estimated overall mission benefits of each technology.

  11. SLIT ADJUSTMENT CLAMP

    DOEpatents

    McKenzie, K.R.

    1959-07-01

    An electrode support which permits accurate alignment and adjustment of the electrode in a plurality of planes and about a plurality of axes in a calutron is described. The support will align the slits in the electrode with the slits of an ionizing chamber so as to provide for the egress of ions. The support comprises an insulator, a leveling plate carried by the insulator and having diametrically opposed attaching screws screwed to the plate and the insulator and diametrically opposed adjusting screws for bearing against the insulator, and an electrode associated with the plate for adjustment therewith.

  12. CMS Frailty Adjustment Model

    PubMed Central

    Kautter, John; Pope, Gregory C.

    2004-01-01

    The authors document the development of the CMS frailty adjustment model, a Medicare payment approach that adjusts payments to a Medicare managed care organization (MCO) according to the functional impairment of its community-residing enrollees. Beginning in 2004, this approach is being applied to certain organizations, such as Program of All-Inclusive Care for the Elderly (PACE), that specialize in providing care to the community-residing frail elderly. In the future, frailty adjustment could be extended to more Medicare managed care organizations. PMID:25372243

  13. Weighted pseudometric discriminatory power improvement using a Bayesian logistic regression model based on a variational method.

    PubMed

    Ksantini, Riadh; Ziou, Djemel; Colin, Bernard; Dubeau, François

    2008-02-01

    In this paper, we investigate the effectiveness of a Bayesian logistic regression model to compute the weights of a pseudo-metric, in order to improve its discriminatory capacity and thereby increase image retrieval accuracy. In the proposed Bayesian model, the prior knowledge of the observations is incorporated and the posterior distribution is approximated by a tractable Gaussian form using variational transformation and Jensen's inequality, which allow a fast and straightforward computation of the weights. The pseudo-metric makes use of the compressed and quantized versions of wavelet decomposed feature vectors, and in our previous work, the weights were adjusted by classical logistic regression model. A comparative evaluation of the Bayesian and classical logistic regression models is performed for content-based image retrieval as well as for other classification tasks, in a decontextualized evaluation framework. In this same framework, we compare the Bayesian logistic regression model to some relevant state-of-the-art classification algorithms. Experimental results show that the Bayesian logistic regression model outperforms these linear classification algorithms, and is a significantly better tool than the classical logistic regression model to compute the pseudo-metric weights and improve retrieval and classification performance. Finally, we perform a comparison with results obtained by other retrieval methods. PMID:18084057

  14. FACTORS ASSOCIATED WITH THE LIKELIHOOD OF FURTHER MOVEMENT AMONG MOBILE FEMALE SEX WORKERS IN INDIA: A MULTINOMIAL LOGIT APPROACH.

    PubMed

    Suryawanshi, Dipak; Sharma, Varun; Saggurti, Niranjan; Bharat, Shalini

    2016-08-01

    Female sex workers (FSWs) are vulnerable to HIV infection. Their socioeconomic and behavioural vulnerabilities are crucial push factors for movement for sex work. This paper assesses the factors associated with the likelihood of movement of sex workers from their current place of work. Data were derived from a cross-sectional survey conducted among 5498 mobile FSWs in 22 districts of high in-migration across four states in southern India. A multinomial logit model was constructed to predict the likelihood of FSWs moving from their current place of work. Ten per cent of the sampled mobile FSWs were planning to move from their current place of sex work. Educational attainment, marital status, income at current place of work, debt, sexual coercion, experience of violence and having tested for HIV and collected the results were found to be significant predictors of the likelihood of movement from the current place of work. Consistent condom use with different clients was significantly low among those planning to move. Likewise, the likelihood of movement was significantly higher among those who had any STI symptom in the last six months and those who had a high self-perceived risk of HIV. The findings highlight the need to address factors associated with movement among mobile FSWs as part of HIV prevention and access to care interventions. PMID:26257210

  15. Why do patients prefer hospital emergency visits? A nested multinomial logit analysis for patient-initiated contacts.

    PubMed

    Puig-Junoy, J; Saez, M; Martínez-García, E

    1998-09-01

    This paper analyzes the nature of health care provider choice in the case of patient-initiated contacts, with special reference to a National Health Service setting, where monetary prices are zero and general practitioners act as gatekeepers to publicly financed specialized care. We focus our attention on the factors that may explain the continuously increasing use of hospital emergency visits as opposed to other provider alternatives. An extended version of a discrete choice model of demand for patient-initiated contacts is presented, allowing for individual and town residence size differences in perceived quality (preferences) between alternative providers and including travel and waiting time as non-monetary costs. Results of a nested multinomial logit model of provider choice are presented. Individual choice between alternatives considers, in a repeated nested structure, self-care, primary care, hospital and clinic emergency services. Welfare implications and income effects are analyzed by computing compensating variations, and by simulating the effects of user fees by levels of income. Results indicate that compensating variation per visit is higher than the direct marginal cost of emergency visits, and consequently, emergency visits do not appear as an inefficient alternative even for non-urgent conditions. PMID:10916583

  16. Multinomial tree models for assessing the status of the reference in studies of the accuracy of tools for binary classification

    PubMed Central

    Botella, Juan; Huang, Huiling; Suero, Manuel

    2013-01-01

    Studies that evaluate the accuracy of binary classification tools are needed. Such studies provide 2 × 2 cross-classifications of test outcomes and the categories according to an unquestionable reference (or gold standard). However, sometimes a suboptimal reliability reference is employed. Several methods have been proposed to deal with studies where the observations are cross-classified with an imperfect reference. These methods require that the status of the reference, as a gold standard or as an imperfect reference, is known. In this paper a procedure for determining whether it is appropriate to maintain the assumption that the reference is a gold standard or an imperfect reference, is proposed. This procedure fits two nested multinomial tree models, and assesses and compares their absolute and incremental fit. Its implementation requires the availability of the results of several independent studies. These should be carried out using similar designs to provide frequencies of cross-classification between a test and the reference under investigation. The procedure is applied in two examples with real data. PMID:24106484

  17. Adolescent suicide attempts and adult adjustment

    PubMed Central

    Brière, Frédéric N.; Rohde, Paul; Seeley, John R.; Klein, Daniel; Lewinsohn, Peter M.

    2014-01-01

    Background Adolescent suicide attempts are disproportionally prevalent and frequently of low severity, raising questions regarding their long-term prognostic implications. In this study, we examined whether adolescent attempts were associated with impairments related to suicidality, psychopathology, and psychosocial functioning in adulthood (objective 1) and whether these impairments were better accounted for by concurrent adolescent confounders (objective 2). Method 816 adolescents were assessed using interviews and questionnaires at four time points from adolescence to adulthood. We examined whether lifetime suicide attempts in adolescence (by T2, mean age 17) predicted adult outcomes (by T4, mean age 30) using linear and logistic regressions in unadjusted models (objective 1) and adjusting for sociodemographic background, adolescent psychopathology, and family risk factors (objective 2). Results In unadjusted analyses, adolescent suicide attempts predicted poorer adjustment on all outcomes, except those related to social role status. After adjustment, adolescent attempts remained predictive of axis I and II psychopathology (anxiety disorder, antisocial and borderline personality disorder symptoms), global and social adjustment, risky sex, and psychiatric treatment utilization. However, adolescent attempts no longer predicted most adult outcomes, notably suicide attempts and major depressive disorder. Secondary analyses indicated that associations did not differ by sex and attempt characteristics (intent, lethality, recurrence). Conclusions Adolescent suicide attempters are at high risk of protracted and wide-ranging impairments, regardless of the characteristics of their attempt. Although attempts specifically predict (and possibly influence) several outcomes, results suggest that most impairments reflect the confounding contributions of other individual and family problems or vulnerabilites in adolescent attempters. PMID:25421360

  18. Remotely Adjustable Hydraulic Pump

    NASA Technical Reports Server (NTRS)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  19. Weighted triangulation adjustment

    USGS Publications Warehouse

    Anderson, Walter L.

    1969-01-01

    The variation of coordinates method is employed to perform a weighted least squares adjustment of horizontal survey networks. Geodetic coordinates are required for each fixed and adjustable station. A preliminary inverse geodetic position computation is made for each observed line. Weights associated with each observed equation for direction, azimuth, and distance are applied in the formation of the normal equations in-the least squares adjustment. The number of normal equations that may be solved is twice the number of new stations and less than 150. When the normal equations are solved, shifts are produced at adjustable stations. Previously computed correction factors are applied to the shifts and a most probable geodetic position is found for each adjustable station. Pinal azimuths and distances are computed. These may be written onto magnetic tape for subsequent computation of state plane or grid coordinates. Input consists of punch cards containing project identification, program options, and position and observation information. Results listed include preliminary and final positions, residuals, observation equations, solution of the normal equations showing magnitudes of shifts, and a plot of each adjusted and fixed station. During processing, data sets containing irrecoverable errors are rejected and the type of error is listed. The computer resumes processing of additional data sets.. Other conditions cause warning-errors to be issued, and processing continues with the current data set.

  20. NASA Space Exploration Logistics Workshop Proceedings

    NASA Technical Reports Server (NTRS)

    deWeek, Oliver; Evans, William A.; Parrish, Joe; James, Sarah

    2006-01-01

    As NASA has embarked on a new Vision for Space Exploration, there is new energy and focus around the area of manned space exploration. These activities encompass the design of new vehicles such as the Crew Exploration Vehicle (CEV) and Crew Launch Vehicle (CLV) and the identification of commercial opportunities for space transportation services, as well as continued operations of the Space Shuttle and the International Space Station. Reaching the Moon and eventually Mars with a mix of both robotic and human explorers for short term missions is a formidable challenge in itself. How to achieve this in a safe, efficient and long-term sustainable way is yet another question. The challenge is not only one of vehicle design, launch, and operations but also one of space logistics. Oftentimes, logistical issues are not given enough consideration upfront, in relation to the large share of operating budgets they consume. In this context, a group of 54 experts in space logistics met for a two-day workshop to discuss the following key questions: 1. What is the current state-of the art in space logistics, in terms of architectures, concepts, technologies as well as enabling processes? 2. What are the main challenges for space logistics for future human exploration of the Moon and Mars, at the intersection of engineering and space operations? 3. What lessons can be drawn from past successes and failures in human space flight logistics? 4. What lessons and connections do we see from terrestrial analogies as well as activities in other areas, such as U.S. military logistics? 5. What key advances are required to enable long-term success in the context of a future interplanetary supply chain? These proceedings summarize the outcomes of the workshop, reference particular presentations, panels and breakout sessions, and record specific observations that should help guide future efforts.

  1. Definition of main pollen season using a logistic model.

    PubMed

    Ribeiro, Helena; Cunha, Mário; Abreu, Ilda

    2007-01-01

    This paper proposes a method to unify the definition of the main pollen season based on statistical analysis. For this, an aerobiological study was carried out in Porto region (Portugal), from 2003-2005 using a 7-day Hirst-type volumetric spore trap. To define the main pollen season, a non-linear logistic regression model was fitted to the values of the accumulated sum of the daily airborne pollen concentration from several allergological species. An important feature of this method is that the main pollen season will be characterized by the model parameters calculated. These parameters are identifiable aspects of the flowering phenology, and determine not only the beginning and end of the main pollen season, but are also influenced by the meteorological conditions. The results obtained with the proposed methodology were also compared with two of the most used percentage methods. The logistic model fitted well with the sum of accumulated pollen. The explained variance was always higher than 97%, and the exponential part of the predicted curve was well adjusted to the time when higher atmospheric pollen concentration was sampled. The comparison between the different methods tested showed large divergence in the duration and end dates of the main pollen season of the studied species. PMID:18247462

  2. ISS Update: Logistics Reduction and Repurposing (Part 2)

    NASA Video Gallery

    Public Affairs Officer Brandi Dean interviews Sarah Shull, Deputy Project Manager Logistics Reduction and Repurposing. Shull, who is with the Advanced Exploration Systems, discusses the Logistics t...

  3. ISS Update: Logistics Reduction and Repurposing (Part 1)

    NASA Video Gallery

    Public Affairs Officer Brandi Dean interviews Sarah Shull, Deputy Project Manager Logistics Reduction and Repurposing. Shull, who is with the Advanced Exploration Systems, discusses the Logistics t...

  4. Logistics Lessons Learned in NASA Space Flight

    NASA Technical Reports Server (NTRS)

    Evans, William A.; DeWeck, Olivier; Laufer, Deanna; Shull, Sarah

    2006-01-01

    The Vision for Space Exploration sets out a number of goals, involving both strategic and tactical objectives. These include returning the Space Shuttle to flight, completing the International Space Station, and conducting human expeditions to the Moon by 2020. Each of these goals has profound logistics implications. In the consideration of these objectives,a need for a study on NASA logistics lessons learned was recognized. The study endeavors to identify both needs for space exploration and challenges in the development of past logistics architectures, as well as in the design of space systems. This study may also be appropriately applied as guidance in the development of an integrated logistics architecture for future human missions to the Moon and Mars. This report first summarizes current logistics practices for the Space Shuttle Program (SSP) and the International Space Station (ISS) and examines the practices of manifesting, stowage, inventory tracking, waste disposal, and return logistics. The key findings of this examination are that while the current practices do have many positive aspects, there are also several shortcomings. These shortcomings include a high-level of excess complexity, redundancy of information/lack of a common database, and a large human-in-the-loop component. Later sections of this report describe the methodology and results of our work to systematically gather logistics lessons learned from past and current human spaceflight programs as well as validating these lessons through a survey of the opinions of current space logisticians. To consider the perspectives on logistics lessons, we searched several sources within NASA, including organizations with direct and indirect connections with the system flow in mission planning. We utilized crew debriefs, the John Commonsense lessons repository for the JSC Mission Operations Directorate, and the Skylab Lessons Learned. Additionally, we searched the public version of the Lessons Learned

  5. Reverse logistics in the construction industry.

    PubMed

    Hosseini, M Reza; Rameezdeen, Raufdeen; Chileshe, Nicholas; Lehmann, Steffen

    2015-06-01

    Reverse logistics in construction refers to the movement of products and materials from salvaged buildings to a new construction site. While there is a plethora of studies looking at various aspects of the reverse logistics chain, there is no systematic review of literature on this important subject as applied to the construction industry. Therefore, the objective of this study is to integrate the fragmented body of knowledge on reverse logistics in construction, with the aim of promoting the concept among industry stakeholders and the wider construction community. Through a qualitative meta-analysis, the study synthesises the findings of previous studies and presents some actions needed by industry stakeholders to promote this concept within the real-life context. First, the trend of research and terminology related with reverse logistics is introduced. Second, it unearths the main advantages and barriers of reverse logistics in construction while providing some suggestions to harness the advantages and mitigate these barriers. Finally, it provides a future research direction based on the review. PMID:26018543

  6. Humanitarian response: improving logistics to save lives.

    PubMed

    McCoy, Jessica

    2008-01-01

    Each year, millions of people worldwide are affected by disasters, underscoring the importance of effective relief efforts. Many highly visible disaster responses have been inefficient and ineffective. Humanitarian agencies typically play a key role in disaster response (eg, procuring and distributing relief items to an affected population, assisting with evacuation, providing healthcare, assisting in the development of long-term shelter), and thus their efficiency is critical for a successful disaster response. The field of disaster and emergency response modeling is well established, but the application of such techniques to humanitarian logistics is relatively recent. This article surveys models of humanitarian response logistics and identifies promising opportunities for future work. Existing models analyze a variety of preparation and response decisions (eg, warehouse location and the distribution of relief supplies), consider both natural and manmade disasters, and typically seek to minimize cost or unmet demand. Opportunities to enhance the logistics of humanitarian response include the adaptation of models developed for general disaster response; the use of existing models, techniques, and insights from the literature on commercial supply chain management; the development of working partnerships between humanitarian aid organizations and private companies with expertise in logistics; and the consideration of behavioral factors relevant to a response. Implementable, realistic models that support the logistics of humanitarian relief can improve the preparation for and the response to disasters, which in turn can save lives. PMID:19069032

  7. Partial covariate adjusted regression

    PubMed Central

    Şentürk, Damla; Nguyen, Danh V.

    2008-01-01

    Covariate adjusted regression (CAR) is a recently proposed adjustment method for regression analysis where both the response and predictors are not directly observed (Şentürk and Müller, 2005). The available data has been distorted by unknown functions of an observable confounding covariate. CAR provides consistent estimators for the coefficients of the regression between the variables of interest, adjusted for the confounder. We develop a broader class of partial covariate adjusted regression (PCAR) models to accommodate both distorted and undistorted (adjusted/unadjusted) predictors. The PCAR model allows for unadjusted predictors, such as age, gender and demographic variables, which are common in the analysis of biomedical and epidemiological data. The available estimation and inference procedures for CAR are shown to be invalid for the proposed PCAR model. We propose new estimators and develop new inference tools for the more general PCAR setting. In particular, we establish the asymptotic normality of the proposed estimators and propose consistent estimators of their asymptotic variances. Finite sample properties of the proposed estimators are investigated using simulation studies and the method is also illustrated with a Pima Indians diabetes data set. PMID:20126296

  8. Bayesian multinomial probit modeling of daily windows of susceptibility for maternal PM2.5 exposure and congenital heart defects.

    PubMed

    Warren, Joshua L; Stingone, Jeanette A; Herring, Amy H; Luben, Thomas J; Fuentes, Montserrat; Aylsworth, Arthur S; Langlois, Peter H; Botto, Lorenzo D; Correa, Adolfo; Olshan, Andrew F

    2016-07-20

    Epidemiologic studies suggest that maternal ambient air pollution exposure during critical periods of pregnancy is associated with adverse effects on fetal development. In this work, we introduce new methodology for identifying critical periods of development during post-conception gestational weeks 2-8 where elevated exposure to particulate matter less than 2.5 µm (PM2.5 ) adversely impacts development of the heart. Past studies have focused on highly aggregated temporal levels of exposure during the pregnancy and have failed to account for anatomical similarities between the considered congenital heart defects. We introduce a multinomial probit model in the Bayesian setting that allows for joint identification of susceptible daily periods during pregnancy for 12 types of congenital heart defects with respect to maternal PM2.5 exposure. We apply the model to a dataset of mothers from the National Birth Defect Prevention Study where daily PM2.5 exposures from post-conception gestational weeks 2-8 are assigned using predictions from the downscaler pollution model. This approach is compared with two aggregated exposure models that define exposure as the average value over post-conception gestational weeks 2-8 and the average over individual weeks, respectively. Results suggest an association between increased PM2.5 exposure on post-conception gestational day 53 with the development of pulmonary valve stenosis and exposures during days 50 and 51 with tetralogy of Fallot. Significant associations are masked when using the aggregated exposure models. Simulation study results suggest that the findings are robust to multiple sources of error. The general form of the model allows for different exposures and health outcomes to be considered in future applications. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26853919

  9. Using Cultural Algorithms to Improve Intelligent Logistics

    NASA Astrophysics Data System (ADS)

    Ochoa, Alberto; García, Yazmani; Yañez, Javier; Teymanoglu, Yaddik

    Today the issue of logistics is a very important within companies to the extent that some have departments devoted exclusively to it. This has evolved over time and today is a fundamental aspect in the fight business seeking to consolidate or remain leaders in their field. With the above we know that logistics can be divided into different classes, however, in this regard, our study is based on the timely distribution to the customer with a lower cost, higher sales and better utilization of space resulting in excellent service. Finally, prepare a comparative analysis of the results with respect to another method of optimization solution space.

  10. Asymptotic behavior of degenerate logistic equations

    NASA Astrophysics Data System (ADS)

    Arrieta, José M.; Pardo, Rosa; Rodríguez-Bernal, Aníbal

    2015-12-01

    We analyze the asymptotic behavior of positive solutions of parabolic equations with a class of degenerate logistic nonlinearities of the type λu - n (x)uρ. An important characteristic of this work is that the region where the logistic term n (ṡ) vanishes, that is K0 = { x : n (x) = 0 }, may be non-smooth. We analyze conditions on λ, ρ, n (ṡ) and K0 guaranteeing that the solution starting at a positive initial condition remains bounded or blows up as time goes to infinity. The asymptotic behavior may not be the same in different parts of K0.

  11. Rural to Urban Adjustment

    ERIC Educational Resources Information Center

    Abramson, Jane A.

    Personal interviews with 100 former farm operators living in Saskatoon, Saskatchewan, were conducted in an attempt to understand the nature of the adjustment process caused by migration from rural to urban surroundings. Requirements for inclusion in the study were that respondents had owned or operated a farm for at least 3 years, had left their…

  12. Self adjusting inclinometer

    DOEpatents

    Hunter, Steven L.

    2002-01-01

    An inclinometer utilizing synchronous demodulation for high resolution and electronic offset adjustment provides a wide dynamic range without any moving components. A device encompassing a tiltmeter and accompanying electronic circuitry provides quasi-leveled tilt sensors that detect highly resolved tilt change without signal saturation.

  13. Self Adjusting Sunglasses

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Corning Glass Works' Serengeti Driver sunglasses are unique in that their lenses self-adjust and filter light while suppressing glare. They eliminate more than 99% of the ultraviolet rays in sunlight. The frames are based on the NASA Anthropometric Source Book.

  14. Applying waste logistics modeling to regional planning

    SciTech Connect

    Holter, G.M.; Khawaja, A.; Shaver, S.R.; Peterson, K.L.

    1995-05-01

    Waste logistics modeling is a powerful analytical technique that can be used for effective planning of future solid waste storage, treatment, and disposal activities. Proper waste management is essential for preventing unacceptable environmental degradation from ongoing operations, and is also a critical part of any environmental remediation activity. Logistics modeling allows for analysis of alternate scenarios for future waste flowrates and routings, facility schedules, and processing or handling capacities. Such analyses provide an increased understanding of the critical needs for waste storage, treatment, transport, and disposal while there is still adequate lead time to plan accordingly. They also provide a basis for determining the sensitivity of these critical needs to the various system parameters. This paper discusses the application of waste logistics modeling concepts to regional planning. In addition to ongoing efforts to aid in planning for a large industrial complex, the Pacific Northwest Laboratory (PNL) is currently involved in implementing waste logistics modeling as part of the planning process for material recovery and recycling within a multi-city region in the western US.

  15. A Logistic Regression Model for Personnel Selection.

    ERIC Educational Resources Information Center

    Raju, Nambury S.; And Others

    1991-01-01

    A two-parameter logistic regression model for personnel selection is proposed. The model was tested with a database of 84,808 military enlistees. The probability of job success was related directly to trait levels, addressing such topics as selection, validity generalization, employee classification, selection bias, and utility-based fair…

  16. Biomass round bales infield aggregation logistic scenarios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass bales often need to be aggregated (collected into groups and transported) to a field-edge stack for temporary storage for feedlots or processing facilities. Aggregating the bales with the least total distance involved is a goal of producers and bale handlers. Several logistics scenarios for ...

  17. Predicting Social Trust with Binary Logistic Regression

    ERIC Educational Resources Information Center

    Adwere-Boamah, Joseph; Hufstedler, Shirley

    2015-01-01

    This study used binary logistic regression to predict social trust with five demographic variables from a national sample of adult individuals who participated in The General Social Survey (GSS) in 2012. The five predictor variables were respondents' highest degree earned, race, sex, general happiness and the importance of personally assisting…

  18. Linear Logistic Test Modeling with R

    ERIC Educational Resources Information Center

    Baghaei, Purya; Kubinger, Klaus D.

    2015-01-01

    The present paper gives a general introduction to the linear logistic test model (Fischer, 1973), an extension of the Rasch model with linear constraints on item parameters, along with eRm (an R package to estimate different types of Rasch models; Mair, Hatzinger, & Mair, 2014) functions to estimate the model and interpret its parameters. The…

  19. LOGISTICS OF ECOLOGICAL SAMPLING ON LARGE RIVERS

    EPA Science Inventory

    The objectives of this document are to provide an overview of the logistical problems associated with the ecological sampling of boatable rivers and to suggest solutions to those problems. It is intended to be used as a resource for individuals preparing to collect biological dat...

  20. Mission Benefits Analysis of Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K.; Broyan, James L.

    2012-01-01

    Future space exploration missions will need to use less logistical supplies if humans are to live for longer periods away from our home planet. Anything that can be done to reduce initial mass and volume of supplies or reuse or recycle items that have been launched will be very valuable. Reuse and recycling also reduce the trash burden and associated nuisances, such as smell, but require good systems engineering and operations integration to reap the greatest benefits. A systems analysis was conducted to quantify the mass and volume savings of four different technologies currently under development by NASA fs Advanced Exploration Systems (AES) Logistics Reduction and Repurposing project. Advanced clothing systems lead to savings by direct mass reduction and increased wear duration. Reuse of logistical items, such as packaging, for a second purpose allows fewer items to be launched. A device known as a heat melt compactor drastically reduces the volume of trash, recovers water and produces a stable tile that can be used instead of launching additional radiation protection. The fourth technology, called trash ]to ]supply ]gas, can benefit a mission by supplying fuel such as methane to the propulsion system. This systems engineering work will help improve logistics planning and overall mission architectures by determining the most effective use, and reuse, of all resources.

  1. Mission Benefits Analysis of Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K.; Broyan, James Lee, Jr.

    2013-01-01

    Future space exploration missions will need to use less logistical supplies if humans are to live for longer periods away from our home planet. Anything that can be done to reduce initial mass and volume of supplies or reuse or recycle items that have been launched will be very valuable. Reuse and recycling also reduce the trash burden and associated nuisances, such as smell, but require good systems engineering and operations integration to reap the greatest benefits. A systems analysis was conducted to quantify the mass and volume savings of four different technologies currently under development by NASA s Advanced Exploration Systems (AES) Logistics Reduction and Repurposing project. Advanced clothing systems lead to savings by direct mass reduction and increased wear duration. Reuse of logistical items, such as packaging, for a second purpose allows fewer items to be launched. A device known as a heat melt compactor drastically reduces the volume of trash, recovers water and produces a stable tile that can be used instead of launching additional radiation protection. The fourth technology, called trash-to-gas, can benefit a mission by supplying fuel such as methane to the propulsion system. This systems engineering work will help improve logistics planning and overall mission architectures by determining the most effective use, and reuse, of all resources.

  2. Multinomial Diffusion Equation

    SciTech Connect

    Balter, Ariel I.; Tartakovsky, Alexandre M.

    2011-06-01

    We have developed a novel stochastic, space/time discrete representation of particle diffusion (e.g. Brownian motion) based on discrete probability distributions. We show that in the limit of both very small time step and large concentration, our description is equivalent to the space/time continuous stochastic diffusion equation. Being discrete in both time and space, our model can be used as an extremely accurate, efficient, and stable stochastic finite-difference diffusion algorithm when concentrations are so small that computationally expensive particle-based methods are usually needed. Through numerical simulations, we show that our method can generate realizations that capture the statistical properties of particle simulations. While our method converges converges to both the correct ensemble mean and ensemble variance very quickly with decreasing time step, but for small concentration, the stochastic diffusion PDE does not, even for very small time steps.

  3. Multinomial diffusion equation

    NASA Astrophysics Data System (ADS)

    Balter, Ariel; Tartakovsky, Alexandre M.

    2011-06-01

    We describe a new, microscopic model for diffusion that captures diffusion induced fluctuations at scales where the concept of concentration gives way to discrete particles. We show that in the limit as the number of particles N→∞, our model is equivalent to the classical stochastic diffusion equation (SDE). We test our new model and the SDE against Langevin dynamics in numerical simulations, and show that our model successfully reproduces the correct ensemble statistics, while the classical model fails.

  4. Multinomial diffusion equation

    SciTech Connect

    Balter, Ariel I.; Tartakovsky, Alexandre M.

    2011-06-24

    We describe a new, microscopic model for diffusion that captures diffusion induced uctuations at scales where the concept of concentration gives way to discrete par- ticles. We show that in the limit as the number of particles N ! 1, our model is equivalent to the classical stochastic diffusion equation (SDE). We test our new model and the SDE against Langevin dynamics in numerical simulations, and show that our model successfully reproduces the correct ensemble statistics, while the classical model fails.

  5. Precision adjustable stage

    DOEpatents

    Cutburth, Ronald W.; Silva, Leonard L.

    1988-01-01

    An improved mounting stage of the type used for the detection of laser beams is disclosed. A stage center block is mounted on each of two opposite sides by a pair of spaced ball bearing tracks which provide stability as well as simplicity. The use of the spaced ball bearing pairs in conjunction with an adjustment screw which also provides support eliminates extraneous stabilization components and permits maximization of the area of the center block laser transmission hole.

  6. Adjustable Autonomy Testbed

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Schrenkenghost, Debra K.

    2001-01-01

    The Adjustable Autonomy Testbed (AAT) is a simulation-based testbed located in the Intelligent Systems Laboratory in the Automation, Robotics and Simulation Division at NASA Johnson Space Center. The purpose of the testbed is to support evaluation and validation of prototypes of adjustable autonomous agent software for control and fault management for complex systems. The AA T project has developed prototype adjustable autonomous agent software and human interfaces for cooperative fault management. This software builds on current autonomous agent technology by altering the architecture, components and interfaces for effective teamwork between autonomous systems and human experts. Autonomous agents include a planner, flexible executive, low level control and deductive model-based fault isolation. Adjustable autonomy is intended to increase the flexibility and effectiveness of fault management with an autonomous system. The test domain for this work is control of advanced life support systems for habitats for planetary exploration. The CONFIG hybrid discrete event simulation environment provides flexible and dynamically reconfigurable models of the behavior of components and fluids in the life support systems. Both discrete event and continuous (discrete time) simulation are supported, and flows and pressures are computed globally. This provides fast dynamic simulations of interacting hardware systems in closed loops that can be reconfigured during operations scenarios, producing complex cascading effects of operations and failures. Current object-oriented model libraries support modeling of fluid systems, and models have been developed of physico-chemical and biological subsystems for processing advanced life support gases. In FY01, water recovery system models will be developed.

  7. Integrated tracking of components by engineering and logistics utilizing logistics asset tracking system

    NASA Technical Reports Server (NTRS)

    Renfroe, Michael B.; Mcdonald, Edward J.; Bradshaw, Kimberly

    1988-01-01

    The Logistics Asset Tracking System (LATS) devised by NASA contains data on Space Shuttle LRUs that are daily updated to reflect such LRU status changes as repair due to failure or modification due to changing engineering requirements. The implementation of LATS has substantially increased personnel responsiveness, preventing costly delays in Space Shuttle processing and obviating hardware cannibalization. An evaluation is presented of LATS achievements in the direction of an integrated logistical support posture.

  8. Imbalanced Learning Based on Logistic Discrimination

    PubMed Central

    Guo, Huaping; Zhi, Weimei; Liu, Hongbing; Xu, Mingliang

    2016-01-01

    In recent years, imbalanced learning problem has attracted more and more attentions from both academia and industry, and the problem is concerned with the performance of learning algorithms in the presence of data with severe class distribution skews. In this paper, we apply the well-known statistical model logistic discrimination to this problem and propose a novel method to improve its performance. To fully consider the class imbalance, we design a new cost function which takes into account the accuracies of both positive class and negative class as well as the precision of positive class. Unlike traditional logistic discrimination, the proposed method learns its parameters by maximizing the proposed cost function. Experimental results show that, compared with other state-of-the-art methods, the proposed one shows significantly better performance on measures of recall, g-mean, f-measure, AUC, and accuracy. PMID:26880877

  9. Technological Support for Logistics Transportation Systems

    NASA Astrophysics Data System (ADS)

    Bujak, Andrzej; Śliwa, Zdzisław; Gębczyńska, Alicja

    The modern world is changing introducing robots, remotely controlled vehicles and other crewless means of transportation to reduce people's mistakes, as the main cause of incidents and crashes during traffic. New technologies are supporting operators and drivers, and according to some studies they can even replace them. Such programs as: AHS, UAH, IVBSS or MTVR are under development to improve traffic flow and its safety, to reduce traffic hazards and crashes. It is necessary to analyze such concepts and implement them boldly, including Polish logistics' companies, new programs, highways' system etc., as they will be applied in the future, so it is necessary to prepare logistics infrastructure ahead of time in order to capitalize on these improvements. The problem is quite urgent as transportation in the country must not be outdated to meet clients' expectations and to keep pace with competing foreign companies.

  10. Exact solution to fractional logistic equation

    NASA Astrophysics Data System (ADS)

    West, Bruce J.

    2015-07-01

    The logistic equation is one of the most familiar nonlinear differential equations in the biological and social sciences. Herein we provide an exact solution to an extension of this equation to incorporate memory through the use of fractional derivatives in time. The solution to the fractional logistic equation (FLE) is obtained using the Carleman embedding technique that allows the nonlinear equation to be replaced by an infinite-order set of linear equations, which we then solve exactly. The formal series expansion for the initial value solution of the FLE is shown to be expressed in terms of a series of weighted Mittag-Leffler functions that reduces to the well known analytic solution in the limit where the fractional index for the derivative approaches unity. The numerical integration to the FLE provides an excellent fit to the analytic solution. We propose this approach as a general technique for solving a class of nonlinear fractional differential equations.

  11. To adjust or not to adjust for baseline when analyzing repeated binary responses? The case of complete data when treatment comparison at study end is of interest.

    PubMed

    Jiang, Honghua; Kulkarni, Pandurang M; Mallinckrodt, Craig H; Shurzinske, Linda; Molenberghs, Geert; Lipkovich, Ilya

    2015-01-01

    The benefits of adjusting for baseline covariates are not as straightforward with repeated binary responses as with continuous response variables. Therefore, in this study, we compared different methods for analyzing repeated binary data through simulations when the outcome at the study endpoint is of interest. Methods compared included chi-square, Fisher's exact test, covariate adjusted/unadjusted logistic regression (Adj.logit/Unadj.logit), covariate adjusted/unadjusted generalized estimating equations (Adj.GEE/Unadj.GEE), covariate adjusted/unadjusted generalized linear mixed model (Adj.GLMM/Unadj.GLMM). All these methods preserved the type I error close to the nominal level. Covariate adjusted methods improved power compared with the unadjusted methods because of the increased treatment effect estimates, especially when the correlation between the baseline and outcome was strong, even though there was an apparent increase in standard errors. Results of the Chi-squared test were identical to those for the unadjusted logistic regression. Fisher's exact test was the most conservative test regarding the type I error rate and also with the lowest power. Without missing data, there was no gain in using a repeated measures approach over a simple logistic regression at the final time point. Analysis of results from five phase III diabetes trials of the same compound was consistent with the simulation findings. Therefore, covariate adjusted analysis is recommended for repeated binary data when the study endpoint is of interest. PMID:25866149

  12. Model selection for logistic regression models

    NASA Astrophysics Data System (ADS)

    Duller, Christine

    2012-09-01

    Model selection for logistic regression models decides which of some given potential regressors have an effect and hence should be included in the final model. The second interesting question is whether a certain factor is heterogeneous among some subsets, i.e. whether the model should include a random intercept or not. In this paper these questions will be answered with classical as well as with Bayesian methods. The application show some results of recent research projects in medicine and business administration.

  13. Moment closure and the stochastic logistic model.

    PubMed

    Nåsell, Ingemar

    2003-03-01

    The quasi-stationary distribution of the stochastic logistic model is studied in the parameter region where its body is approximately normal. Improved asymptotic approximations of its first three cumulants are derived. It is shown that the same results can be derived with the aid of the moment closure method. This indicates that the moment closure method leads to expressions for the cumulants that are asymptotic approximations of the cumulants of the quasi-stationary distribution. PMID:12615498

  14. Space Station - An integrated approach to operational logistics support

    NASA Technical Reports Server (NTRS)

    Hosmer, G. J.

    1986-01-01

    Development of an efficient and cost effective operational logistics system for the Space Station will require logistics planning early in the program's design and development phase. This paper will focus on Integrated Logistics Support (ILS) Program techniques and their application to the Space Station program design, production and deployment phases to assure the development of an effective and cost efficient operational logistics system. The paper will provide the methodology and time-phased programmatic steps required to establish a Space Station ILS Program that will provide an operational logistics system based on planned Space Station program logistics support.

  15. Continuously adjustable Pulfrich spectacles

    NASA Astrophysics Data System (ADS)

    Jacobs, Ken; Karpf, Ron

    2011-03-01

    A number of Pulfrich 3-D movies and TV shows have been produced, but the standard implementation has inherent drawbacks. The movie and TV industries have correctly concluded that the standard Pulfrich 3-D implementation is not a useful 3-D technique. Continuously Adjustable Pulfrich Spectacles (CAPS) is a new implementation of the Pulfrich effect that allows any scene containing movement in a standard 2-D movie, which are most scenes, to be optionally viewed in 3-D using inexpensive viewing specs. Recent scientific results in the fields of human perception, optoelectronics, video compression and video format conversion are translated into a new implementation of Pulfrich 3- D. CAPS uses these results to continuously adjust to the movie so that the viewing spectacles always conform to the optical density that optimizes the Pulfrich stereoscopic illusion. CAPS instantly provides 3-D immersion to any moving scene in any 2-D movie. Without the glasses, the movie will appear as a normal 2-D image. CAPS work on any viewing device, and with any distribution medium. CAPS is appropriate for viewing Internet streamed movies in 3-D.

  16. Subsea adjustable choke valves

    SciTech Connect

    Cyvas, M.K. )

    1989-08-01

    With emphasis on deepwater wells and marginal offshore fields growing, the search for reliable subsea production systems has become a high priority. A reliable subsea adjustable choke is essential to the realization of such a system, and recent advances are producing the degree of reliability required. Technological developments have been primarily in (1) trim material (including polycrystalline diamond), (2) trim configuration, (3) computer programs for trim sizing, (4) component materials, and (5) diver/remote-operated-vehicle (ROV) interfaces. These five facets are overviewed and progress to date is reported. A 15- to 20-year service life for adjustable subsea chokes is now a reality. Another factor vital to efficient use of these technological developments is to involve the choke manufacturer and ROV/diver personnel in initial system conceptualization. In this manner, maximum benefit can be derived from the latest technology. Major areas of development still required and under way are listed, and the paper closes with a tabulation of successful subsea choke installations in recent years.

  17. Micro-Logistics Analysis for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    Cirillo, William; Stromgren, Chel; Galan, Ricardo

    2008-01-01

    Traditionally, logistics analysis for space missions has focused on the delivery of elements and goods to a destination. This type of logistics analysis can be referred to as "macro-logistics". While the delivery of goods is a critical component of mission analysis, it captures only a portion of the constraints that logistics planning may impose on a mission scenario. The other component of logistics analysis concerns the local handling of goods at the destination, including storage, usage, and disposal. This type of logistics analysis, referred to as "micro-logistics", may also be a primary driver in the viability of a human lunar exploration scenario. With the rigorous constraints that will be placed upon a human lunar outpost, it is necessary to accurately evaluate micro-logistics operations in order to develop exploration scenarios that will result in an acceptable level of system performance.

  18. Risk adjusting capitation: applications in employed and disabled populations.

    PubMed

    Madden, C W; Mackay, B P; Skillman, S M; Ciol, M; Diehr, P K

    2000-02-01

    Risk adjustment may be a sensible strategy to reduce selection bias because it links managed care payment directly to the costs of providing services. In this paper we compare risk adjustment models in two populations (public employees and their dependents, and publicly-insured low income individuals with disabilities) in Washington State using two statistical approaches and three health status measures. We conclude that a two-part logistic/GLM statistical model performs better in populations with large numbers of individuals who do not use health services. This model was successfully implemented in the employed population, but the managed care program for the publicly insured population was terminated before risk adjustment could be applied. The choice of the most appropriate health status measure depends on purchasers' principles and desired outcomes. PMID:10780278

  19. The Application used RFID in Third Party Logistics*

    NASA Astrophysics Data System (ADS)

    Mingxiu, Zheng; Chunchang, Fu; Minggen, Yang

    RFID is a non-contact automatic identification technology, which will be the future information storage extraction and processing technology. In recent years the mainstream of the large-scale development has manifested the situation. RFID is the key technology of tripartite logistics information and automation. RFID-based logistics system can enlarge the logistics operation capacity, and improve labor productivity to reduce logistics operations mistakes.

  20. Research and design of logistical information system based on SOA

    NASA Astrophysics Data System (ADS)

    Zhang, Bo

    2013-03-01

    Through the study on the existing logistics information systems and SOA technology, based on the current situation of enterprise logistics management and business features, this paper puts forward a SOA-based logistics system design program. This program is made in the WCF framework, with the combination of SOA and the actual characteristics of logistics enterprises, is simple to realize, easy to operate, and has strong expansion characteristic, therefore has high practical value.

  1. 77 FR 40387 - Price Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-09

    ... Price Adjustment AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: The Commission is noticing a recently filed Postal Service request to adjust prices for several market dominant products... announcing its intent to adjust prices for several market dominant products within First-Class Mail...

  2. Comparison of a Bayesian Network with a Logistic Regression Model to Forecast IgA Nephropathy

    PubMed Central

    Ducher, Michel; Kalbacher, Emilie; Combarnous, François; Finaz de Vilaine, Jérome; McGregor, Brigitte; Fouque, Denis; Fauvel, Jean Pierre

    2013-01-01

    Models are increasingly used in clinical practice to improve the accuracy of diagnosis. The aim of our work was to compare a Bayesian network to logistic regression to forecast IgA nephropathy (IgAN) from simple clinical and biological criteria. Retrospectively, we pooled the results of all biopsies (n = 155) performed by nephrologists in a specialist clinical facility between 2002 and 2009. Two groups were constituted at random. The first subgroup was used to determine the parameters of the models adjusted to data by logistic regression or Bayesian network, and the second was used to compare the performances of the models using receiver operating characteristics (ROC) curves. IgAN was found (on pathology) in 44 patients. Areas under the ROC curves provided by both methods were highly significant but not different from each other. Based on the highest Youden indices, sensitivity reached (100% versus 67%) and specificity (73% versus 95%) using the Bayesian network and logistic regression, respectively. A Bayesian network is at least as efficient as logistic regression to estimate the probability of a patient suffering IgAN, using simple clinical and biological data obtained during consultation. PMID:24328031

  3. 77 FR 46653 - Defense Logistics Agency Privacy Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... of the Secretary 32 CFR Part 323 RIN 0790-AI86 Defense Logistics Agency Privacy Program AGENCY: Defense Logistics Agency, DoD. ACTION: Proposed rule with request for comments. SUMMARY: The Defense Logistics Agency (DLA) is proposing to amend the DLA Privacy Program Regulation. The DLA Privacy...

  4. Using Dominance Analysis to Determine Predictor Importance in Logistic Regression

    ERIC Educational Resources Information Center

    Azen, Razia; Traxel, Nicole

    2009-01-01

    This article proposes an extension of dominance analysis that allows researchers to determine the relative importance of predictors in logistic regression models. Criteria for choosing logistic regression R[superscript 2] analogues were determined and measures were selected that can be used to perform dominance analysis in logistic regression. A…

  5. The dynamics of coupled logistic social groups

    NASA Astrophysics Data System (ADS)

    McCartney, Mark; Glass, David H.

    2015-06-01

    A society made up of a network of social groups is investigated. Each group is partitioned into two mutually exclusive subsets with the movement of members between the two subsets being modelled via a logistic-like equation. We consider various ways in which the groups in the network may influence each other, via both group size and the utility groups place on the possible subsets. Scenarios where social groups act as 'agenda setters' for the rest of the society are considered. A number of analytic and numerical results are presented.

  6. Judging hospitals by severity-adjusted mortality rates: the influence of the severity-adjustment method.

    PubMed Central

    Iezzoni, L I; Ash, A S; Shwartz, M; Daley, J; Hughes, J S; Mackiernan, Y D

    1996-01-01

    OBJECTIVES: This research examined whether judgments about a hospital's risk-adjusted mortality performance are affected by the severity-adjustment method. METHODS: Data came from 100 acute care hospitals nationwide and 11880 adults admitted in 1991 for acute myocardial infarction. Ten severity measures were used in separate multivariable logistic models predicting in-hospital death. Observed-to-expected death rates and z scores were calculated with each severity measure for each hospital. RESULTS: Unadjusted mortality rates for the 100 hospitals ranged from 4.8% to 26.4%. For 32 hospitals, observed mortality rates differed significantly from expected rates for 1 or more, but not for all 10, severity measures. Agreement between pairs of severity measures on whether hospitals were flagged as statistical mortality outliers ranged from fair to good. Severity measures based on medical records frequently disagreed with measures based on discharge abstracts. CONCLUSIONS: Although the 10 severity measures agreed about relative hospital performance more often than would be expected by chance, assessments of individual hospital mortality rates varied by different severity-adjustment methods. PMID:8876505

  7. Supporting Regularized Logistic Regression Privately and Efficiently.

    PubMed

    Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei

    2016-01-01

    As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc. PMID:27271738

  8. Reducing food losses by intelligent food logistics

    PubMed Central

    Jedermann, Reiner; Nicometo, Mike; Uysal, Ismail; Lang, Walter

    2014-01-01

    The need to feed an ever-increasing world population makes it obligatory to reduce the millions of tons of avoidable perishable waste along the food supply chain. A considerable share of these losses is caused by non-optimal cold chain processes and management. This Theme Issue focuses on technologies, models and applications to monitor changes in the product shelf life, defined as the time remaining until the quality of a food product drops below an acceptance limit, and to plan successive chain processes and logistics accordingly to uncover and prevent invisible or latent losses in product quality, especially following the first-expired-first-out strategy for optimized matching between the remaining shelf life and the expected transport duration. This introductory article summarizes the key findings of this Theme Issue, which brings together research study results from around the world to promote intelligent food logistics. The articles include three case studies on the cold chain for berries, bananas and meat and an overview of different post-harvest treatments. Further contributions focus on the required technical solutions, such as the wireless sensor and communication system for remote quality supervision, gas sensors to detect ethylene as an indicator of unwanted ripening and volatile components to indicate mould infections. The final section of this introduction discusses how improvements in food quality can be targeted by strategic changes in the food chain. PMID:24797131

  9. Electronically-implemented coupled logistic maps

    NASA Astrophysics Data System (ADS)

    L'Her, Alexandre; Amil, Pablo; Rubido, Nicolás; Marti, Arturo C.; Cabeza, Cecilia

    2016-03-01

    The logistic map is a paradigmatic dynamical system originally conceived to model the discrete-time demographic growth of a population, which shockingly, shows that discrete chaos can emerge from trivial low-dimensional non-linear dynamics. In this work, we design and characterize a simple, low-cost, easy-to-handle, electronic implementation of the logistic map. In particular, our implementation allows for straightforward circuit-modifications to behave as different one-dimensional discrete-time systems. Also, we design a coupling block in order to address the behavior of two coupled maps, although, our design is unrestricted to the discrete-time system implementation and it can be generalized to handle coupling between many dynamical systems, as in a complex system. Our findings show that the isolated and coupled maps' behavior has a remarkable agreement between the experiments and the simulations, even when fine-tuning the parameters with a resolution of ~10-3. We support these conclusions by comparing the Lyapunov exponents, periodicity of the orbits, and phase portraits of the numerical and experimental data for a wide range of coupling strengths and map's parameters.

  10. Reducing food losses by intelligent food logistics.

    PubMed

    Jedermann, Reiner; Nicometo, Mike; Uysal, Ismail; Lang, Walter

    2014-06-13

    The need to feed an ever-increasing world population makes it obligatory to reduce the millions of tons of avoidable perishable waste along the food supply chain. A considerable share of these losses is caused by non-optimal cold chain processes and management. This Theme Issue focuses on technologies, models and applications to monitor changes in the product shelf life, defined as the time remaining until the quality of a food product drops below an acceptance limit, and to plan successive chain processes and logistics accordingly to uncover and prevent invisible or latent losses in product quality, especially following the first-expired-first-out strategy for optimized matching between the remaining shelf life and the expected transport duration. This introductory article summarizes the key findings of this Theme Issue, which brings together research study results from around the world to promote intelligent food logistics. The articles include three case studies on the cold chain for berries, bananas and meat and an overview of different post-harvest treatments. Further contributions focus on the required technical solutions, such as the wireless sensor and communication system for remote quality supervision, gas sensors to detect ethylene as an indicator of unwanted ripening and volatile components to indicate mould infections. The final section of this introduction discusses how improvements in food quality can be targeted by strategic changes in the food chain. PMID:24797131

  11. Supporting Regularized Logistic Regression Privately and Efficiently

    PubMed Central

    Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei

    2016-01-01

    As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc. PMID:27271738

  12. Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 2: OSSA integrated logistics support strategy

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    The purpose is to outline an Office of Space Science and Applications (OSSA) integrated logistics support strategy that will ensure effective logistics support of OSSA payloads at an affordable life-cycle cost. Program objectives, organizational relationships, and implementation of the logistics strategy are discussed.

  13. Complex Logistics Strategy for Industrial Companies in Slovakia

    NASA Astrophysics Data System (ADS)

    Horňáková, Natália; Hudák, Ján; Vidová, Helena

    2014-12-01

    Presented paper is a part of the dissertation thesis titled as "A proposal to develop Complex Logistics Strategy for industrial companies. The result of the thesis will be a methodology for developing a Complex Logistics Strategy for industrial companies in Slovakia. The main aim of the paper is to present some trends and strategies in Logistics and clarify the need of resolving the issue of Logistics Strategy based on the theoretical knowledge, case studies and analysis of current state of Logistics Strategies in industrial companies in Slovakia and other European countries.

  14. Flexible use and technique extension of logistics management

    NASA Astrophysics Data System (ADS)

    Xiong, Furong

    2011-10-01

    As we all know, the origin of modern logistics was in the United States, developed in Japan, became mature in Europe, and expanded in China. This is a historical development of the modern logistics recognized track. Due to China's economic and technological development, and with the construction of Shanghai International Shipping Center and Shanghai Yangshan International Deepwater development, China's modern logistics industry will attain a leap-forward development of a strong pace, and will also catch up with developed countries in the Western modern logistics level. In this paper, the author explores the flexibility of China's modern logistics management techniques to extend the use, and has certain practical and guidance significances.

  15. Space Shuttle Orbiter logistics - Managing in a dynamic environment

    NASA Technical Reports Server (NTRS)

    Renfroe, Michael B.; Bradshaw, Kimberly

    1990-01-01

    The importance and methods of monitoring logistics vital signs, logistics data sources and acquisition, and converting data into useful management information are presented. With the launch and landing site for the Shuttle Orbiter project at the Kennedy Space Center now totally responsible for its own supportability posture, it is imperative that logistics resource requirements and management be continually monitored and reassessed. Detailed graphs and data concerning various aspects of logistics activities including objectives, inventory operating levels, customer environment, and data sources are provided. Finally, some lessons learned from the Shuttle Orbiter project and logistics options which should be considered by other space programs are discussed.

  16. Logistics of Guinea Worm Disease Eradication in South Sudan

    PubMed Central

    Jones, Alexander H.; Becknell, Steven; Withers, P. Craig; Ruiz-Tiben, Ernesto; Hopkins, Donald R.; Stobbelaar, David; Makoy, Samuel Yibi

    2014-01-01

    From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical–logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities. Lessons learned from logistical design and management can resonate across similar complex surveillance and public health intervention delivery programs, such as mass drug administration for the control of neglected tropical diseases and other disease eradication programs. Logistical challenges in various public health scenarios and the pivotal contribution of logistics to Guinea worm case reductions in South Sudan underscore the need for additional inquiry into the role of logistics in public health programming in low-income countries. PMID:24445199

  17. Analysis of Logistics in Support of a Human Lunar Outpost

    NASA Technical Reports Server (NTRS)

    Cirillo, William; Earle, Kevin; Goodliff, Kandyce; Reeves, j. D.; Andrashko, Mark; Merrill, R. Gabe; Stromgren, Chel

    2008-01-01

    Strategic level analysis of the integrated behavior of lunar transportation system and lunar surface system architecture options is performed to inform NASA Constellation Program senior management on the benefit, viability, affordability, and robustness of system design choices. This paper presents an overview of the approach used to perform the campaign (strategic) analysis, with an emphasis on the logistics modeling and the impacts of logistics resupply on campaign behavior. An overview of deterministic and probabilistic analysis approaches is provided, with a discussion of the importance of each approach to understanding the integrated system behavior. The logistics required to support lunar surface habitation are analyzed from both 'macro-logistics' and 'micro-logistics' perspectives, where macro-logistics focuses on the delivery of goods to a destination and micro-logistics focuses on local handling of re-supply goods at a destination. An example campaign is provided to tie the theories of campaign analysis to results generation capabilities.

  18. Delay Adjusted Incidence Infographic

    Cancer.gov

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  19. 48 CFR 5416.203 - Fixed-price contracts with economic price adjustment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Fixed-price contracts with economic price adjustment. 5416.203 Section 5416.203 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE TYPES OF CONTRACTS Fixed Price Contracts 5416.203...

  20. 48 CFR 5416.203 - Fixed-price contracts with economic price adjustment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 7 2014-10-01 2014-10-01 false Fixed-price contracts with economic price adjustment. 5416.203 Section 5416.203 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE TYPES OF CONTRACTS Fixed Price Contracts 5416.203...

  1. 48 CFR 5416.203 - Fixed-price contracts with economic price adjustment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 7 2012-10-01 2012-10-01 false Fixed-price contracts with economic price adjustment. 5416.203 Section 5416.203 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE TYPES OF CONTRACTS Fixed Price Contracts 5416.203...

  2. 48 CFR 5416.203 - Fixed-price contracts with economic price adjustment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fixed-price contracts with economic price adjustment. 5416.203 Section 5416.203 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE TYPES OF CONTRACTS Fixed Price Contracts 5416.203...

  3. Stochastic dynamics and logistic population growth.

    PubMed

    Méndez, Vicenç; Assaf, Michael; Campos, Daniel; Horsthemke, Werner

    2015-06-01

    The Verhulst model is probably the best known macroscopic rate equation in population ecology. It depends on two parameters, the intrinsic growth rate and the carrying capacity. These parameters can be estimated for different populations and are related to the reproductive fitness and the competition for limited resources, respectively. We investigate analytically and numerically the simplest possible microscopic scenarios that give rise to the logistic equation in the deterministic mean-field limit. We provide a definition of the two parameters of the Verhulst equation in terms of microscopic parameters. In addition, we derive the conditions for extinction or persistence of the population by employing either the momentum-space spectral theory or the real-space Wentzel-Kramers-Brillouin approximation to determine the probability distribution function and the mean time to extinction of the population. Our analytical results agree well with numerical simulations. PMID:26172687

  4. Green Packaging Management of Logistics Enterprises

    NASA Astrophysics Data System (ADS)

    Zhang, Guirong; Zhao, Zongjian

    From the connotation of green logistics management, we discuss the principles of green packaging, and from the two levels of government and enterprises, we put forward a specific management strategy. The management of green packaging can be directly and indirectly promoted by laws, regulations, taxation, institutional and other measures. The government can also promote new investment to the development of green packaging materials, and establish specialized institutions to identify new packaging materials, standardization of packaging must also be accomplished through the power of the government. Business units of large scale through the packaging and container-based to reduce the use of packaging materials, develop and use green packaging materials and easy recycling packaging materials for proper packaging.

  5. Space station synergetic RAM-logistics analysis

    NASA Technical Reports Server (NTRS)

    Dejulio, Edmund T.; Leet, Joel H.

    1988-01-01

    NASA's Space Station Maintenance Planning and Analysis (MP&A) Study is a step in the overall Space Station Program to define optimum approaches for on-orbit maintenance planning and logistics support. The approach used in the MP&A study and the analysis process used are presented. Emphasis is on maintenance activities and processes that can be accomplished on orbit within the known design and support constraints of the Space Station. From these analyses, recommendations for maintainability/maintenance requirements are established. The ultimate goal of the study is to reduce on-orbit maintenance requirements to a practical and safe minimum, thereby conserving crew time for productive endeavors. The reliability, availability, and maintainability (RAM) and operations performance evaluation models used were assembled and developed as part of the MP&A study and are described. A representative space station system design is presented to illustrate the analysis process.

  6. Stochastic dynamics and logistic population growth

    NASA Astrophysics Data System (ADS)

    Méndez, Vicenç; Assaf, Michael; Campos, Daniel; Horsthemke, Werner

    2015-06-01

    The Verhulst model is probably the best known macroscopic rate equation in population ecology. It depends on two parameters, the intrinsic growth rate and the carrying capacity. These parameters can be estimated for different populations and are related to the reproductive fitness and the competition for limited resources, respectively. We investigate analytically and numerically the simplest possible microscopic scenarios that give rise to the logistic equation in the deterministic mean-field limit. We provide a definition of the two parameters of the Verhulst equation in terms of microscopic parameters. In addition, we derive the conditions for extinction or persistence of the population by employing either the momentum-space spectral theory or the real-space Wentzel-Kramers-Brillouin approximation to determine the probability distribution function and the mean time to extinction of the population. Our analytical results agree well with numerical simulations.

  7. Development of a comprehensive logistics and warfighting simulation system.

    SciTech Connect

    Hummel, J. R.

    1998-08-12

    An efficient logistics system is critical to the success of military operations. Recently, the Department of Defense (DoD) has begun to move from a ''just in case'' logistics system that relies on large stores of inventoried materials toward a ''just in time'' system based on obtaining and delivering supplies when and where they are needed. For this new logistics concept to operate smoothly and responsively and be highly robust, one must understand the interrelationships between warfighting and logistics, such as the impact of losses of logistics links/nodes and the changing pace of warfighting operations. Two DoD programs, the Distributed Intelligent Agents for Logistics (DIAL) and the Warfighting Logistics Technology and Assessment Environment (WLTAE), are focusing on different aspects of this problem. These programs are being integrated to develop a Comprehensive Logistics and Warfighting System (CLAWS) that can be used to address a variety of different logistics applications in the military arena. In this paper, we describe how CLAWS will be developed, including the development of a generalized Federation Object Model that could be used in a variety of logistics and military operations applications.

  8. 78 FR 73872 - Agency Information Collection Activities: Proposed Collection; Comment Request; Logistics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ...; Comment Request; Logistics Capability Assistance Tool (LCAT) AGENCY: Federal Emergency Management Agency... accordance with the Paperwork Reduction Act of 1995, this notice seeks comments concerning the Logistics... Repass, Program Analyst, Logistics Management Directorate, Logistics Plans & Exercises Division,...

  9. 78 FR 37814 - Tesoro Corporation and Tesoro Logistics Operations LLC; Analysis of Proposed Agreement Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ... Tesoro Corporation and Tesoro Logistics Operations LLC; Analysis of Proposed Agreement Containing Consent... Tesoro Logistics Operations LLC (``Respondents''). On December 6, 2012, Respondents executed related.... Tesoro Logistics Operations LLC Tesoro Logistics Operations LLC, a limited liability company, is a...

  10. 76 FR 28757 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION: Notice of Availability (NOA) of Revised Defense Logistics Agency Regulation. SUMMARY: The Defense...

  11. 78 FR 62712 - Rate Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... Rate Adjustment AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: The Commission is noticing a recent Postal Service filing seeking postal rate adjustments based on exigent circumstances... On September 26, 2013, the Postal Service filed an exigent rate request with the Commission...

  12. Adjustable holder for transducer mounting

    NASA Technical Reports Server (NTRS)

    Deotsch, R. C.

    1980-01-01

    Positioning of acoustic sensor, strain gage, or similar transducer is facilitated by adjustable holder. Developed for installation on Space Shuttle, it includes springs for maintaining uniform load on transducer with adjustable threaded cap for precisely controlling position of sensor with respect to surrounding structure.

  13. Spousal Adjustment to Myocardial Infarction.

    ERIC Educational Resources Information Center

    Ziglar, Elisa J.

    This paper reviews the literature on the stresses and coping strategies of spouses of patients with myocardial infarction (MI). It attempts to identify specific problem areas of adjustment for the spouse and to explore the effects of spousal adjustment on patient recovery. Chapter one provides an overview of the importance in examining the…

  14. Mood Adjustment via Mass Communication.

    ERIC Educational Resources Information Center

    Knobloch, Silvia

    2003-01-01

    Proposes and experimentally tests mood adjustment approach, complementing mood management theory. Discusses how results regarding self-exposure across time show that patterns of popular music listening among a group of undergraduate students differ with initial mood and anticipation, lending support to mood adjustment hypotheses. Describes how…

  15. Space Station logistics policy - Risk management from the top down

    NASA Technical Reports Server (NTRS)

    Paules, Granville; Graham, James L., Jr.

    1990-01-01

    Considerations are presented in the area of risk management specifically relating to logistics and system supportability. These considerations form a basis for confident application of concurrent engineering principles to a development program, aiming at simultaneous consideration of support and logistics requirements within the engineering process as the system concept and designs develop. It is shown that, by applying such a process, the chances of minimizing program logistics and supportability risk in the long term can be improved. The problem of analyzing and minimizing integrated logistics risk for the Space Station Freedom Program is discussed.

  16. Use of Ubiquitous Technologies in Military Logistic System in Iran

    NASA Astrophysics Data System (ADS)

    Jafari, P.; Sadeghi-Niaraki, A.

    2013-09-01

    This study is about integration and evaluation of RFID and ubiquitous technologies in military logistic system management. Firstly, supply chain management and the necessity of a revolution in logistic systems especially in military area, are explained. Secondly RFID and ubiquitous technologies and the advantages of their use in supply chain management are introduced. Lastly a system based on these technologies for controlling and increasing the speed and accuracy in military logistic system in Iran with its unique properties, is presented. The system is based on full control of military logistics (supplies) from the time of deployment to replenishment using sensor network, ubiquitous and RFID technologies.

  17. Logistics Reduction and Repurposing Beyond Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.; Ewert, Michael K.

    2011-01-01

    All human space missions, regardless of destination, require significant logistical mass and volume that is strongly proportional to mission duration. Anything that can be done to reduce initial mass and volume of supplies or reuse items that have been launched will be very valuable. Often, the logistical items require disposal and represent a trash burden. Utilizing systems engineering to analyze logistics from cradle-to-grave and then to potential reuse, can minimize logistics contributions to total mission architecture mass. In NASA's Advanced Exploration Systems Logistics Reduction and Repurposing Project , various tasks will reduce the intrinsic mass of logistical packaging, enable reuse and repurposing of logistical packaging and carriers for other habitation, life support, crew health, and propulsion functions, and reduce or eliminate the nuisances aspects of trash at the same time. Repurposing reduces the trash burden and eliminates the need for hardware whose function can be provided by use of spent logistic items. However, these reuse functions need to be identified and built into future logical systems to enable them to effectively have a secondary function. These technologies and innovations will help future logistic systems to support multiple exploration missions much more efficiently.

  18. Effect of randomness in logistic maps

    NASA Astrophysics Data System (ADS)

    Khaleque, Abdul; Sen, Parongama

    2015-01-01

    We study a random logistic map xt+1 = atxt[1 - xt] where at are bounded (q1 ≤ at ≤ q2), random variables independently drawn from a distribution. xt does not show any regular behavior in time. We find that xt shows fully ergodic behavior when the maximum allowed value of at is 4. However , averaged over different realizations reaches a fixed point. For 1 ≤ at ≤ 4, the system shows nonchaotic behavior and the Lyapunov exponent is strongly dependent on the asymmetry of the distribution from which at is drawn. Chaotic behavior is seen to occur beyond a threshold value of q1(q2) when q2(q1) is varied. The most striking result is that the random map is chaotic even when q2 is less than the threshold value 3.5699⋯ at which chaos occurs in the nonrandom map. We also employ a different method in which a different set of random variables are used for the evolution of two initially identical x values, here the chaotic regime exists for all q1 ≠ q2 values.

  19. Nowcasting sunshine number using logistic modeling

    NASA Astrophysics Data System (ADS)

    Brabec, Marek; Badescu, Viorel; Paulescu, Marius

    2013-04-01

    In this paper, we present a formalized approach to statistical modeling of the sunshine number, binary indicator of whether the Sun is covered by clouds introduced previously by Badescu (Theor Appl Climatol 72:127-136, 2002). Our statistical approach is based on Markov chain and logistic regression and yields fully specified probability models that are relatively easily identified (and their unknown parameters estimated) from a set of empirical data (observed sunshine number and sunshine stability number series). We discuss general structure of the model and its advantages, demonstrate its performance on real data and compare its results to classical ARIMA approach as to a competitor. Since the model parameters have clear interpretation, we also illustrate how, e.g., their inter-seasonal stability can be tested. We conclude with an outlook to future developments oriented to construction of models allowing for practically desirable smooth transition between data observed with different frequencies and with a short discussion of technical problems that such a goal brings.

  20. Source Recertification, Refurbishment, and Transfer Logistics

    SciTech Connect

    Gastelum, Zoe N.; Duckworth, Leesa L.; Greenfield, Bryce A.; Doll, Stephanie R.

    2013-09-01

    The 2012 Gap Analysis of Department of Energy Radiological Sealed Sources, Standards, and Materials for Safeguards Technology Development [1] report, and the subsequent Reconciliation of Source Needs and Surpluses across the U.S. Department of Energy National Laboratory Complex [2] report, resulted in the identification of 33 requests for nuclear or radiological sealed sources for which there was potentially available, suitable material from within the U.S. Department of Energy (DOE) complex to fill the source need. Available, suitable material was defined by DOE laboratories as material slated for excess, or that required recertification or refurbishment before being used for safeguards technology development. This report begins by outlining the logistical considerations required for the shipment of nuclear and radiological materials between DOE laboratories. Then, because of the limited need for transfer of matching sources, the report also offers considerations for an alternative approach – the shipment of safeguards equipment between DOE laboratories or technology testing centers. Finally, this report addresses repackaging needs for the two source requests for which there was available, suitable material within the DOE complex.

  1. Final adjustments in payload bay prior to door closure

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Final adjustments in payload bay prior to door closure KSC-01PD-1732 KENNEDY SPACE CENTER, Fla. - A worker makes a final adjustment in the payload bay of Space Shuttle Endeavour before door closure. Inside the bay is the Multi-Purpose Logistics Module Raffaello (foreground), carrying supplies, equipment and experiments for the International Space Station. Sharing the payload bay are several carriers with varying experiment packages, such as Starshine-2, a Get-Away Special. Endeavour is scheduled to launch Nov. 29 on this first Utilization Flight to the International Space Station. Endeavour will also carry the replacement Expedition 4 crew to the Station and return to Earth with the Expedition 3 crew.

  2. Controlling Type I Error Rates in Assessing DIF for Logistic Regression Method Combined with SIBTEST Regression Correction Procedure and DIF-Free-Then-DIF Strategy

    ERIC Educational Resources Information Center

    Shih, Ching-Lin; Liu, Tien-Hsiang; Wang, Wen-Chung

    2014-01-01

    The simultaneous item bias test (SIBTEST) method regression procedure and the differential item functioning (DIF)-free-then-DIF strategy are applied to the logistic regression (LR) method simultaneously in this study. These procedures are used to adjust the effects of matching true score on observed score and to better control the Type I error…

  3. Logistics engineering education from the point of view environment

    NASA Astrophysics Data System (ADS)

    Bányai, Ágota

    2010-05-01

    A new field of MSc programme offered by the Faculty of Mechanical Engineering and Informatics of the University of Miskolc is represented by the programme in logistics engineering. The Faculty has always laid great emphasis on assigning processes connected with environment protection and globalisation issues the appropriate weight in its programmes. This is based on the fact that the Faculty has initiated and been involved in a great number of research and development projects with a substantial emphasis on the fundamental principles of sustainable development. The objective of the programme of logistics engineering is to train engineers who, in possession of the science, engineering, economic, informatics and industrial, transportation technological knowledge related to the professional field of logistics, are able to analyse, design, organise, and control logistics processes and systems (freight transportation, materials handling, storage, commissioning, loading, purchasing, distribution and waste management) as well as to design and develop machinery and equipment as the elements of logistic systems and also to be involved in their manufacture and quality control and are able to control their operation. The programme prepares its students for performing the logistics management tasks in a company, for creative participation in solving research and development problems in logistics and for pursuing logistics studies in doctoral programmes. There are several laboratories available for practice-oriented training. The 'Integrated Logistics Laboratory' consists of various fixed and mobile, real industrial, i.e. not model-level equipment, the integration of which in one system facilitates not only the presentation, examination and development of the individual self-standing facilities, but the study of their interaction as well in terms of mechatronics, engineering, control engineering, informatics, identification technology and logistics. The state

  4. Pattern formation, logistics, and maximum path probability

    NASA Astrophysics Data System (ADS)

    Kirkaldy, J. S.

    1985-05-01

    The concept of pattern formation, which to current researchers is a synonym for self-organization, carries the connotation of deductive logic together with the process of spontaneous inference. Defining a pattern as an equivalence relation on a set of thermodynamic objects, we establish that a large class of irreversible pattern-forming systems, evolving along idealized quasisteady paths, approaches the stable steady state as a mapping upon the formal deductive imperatives of a propositional function calculus. In the preamble the classical reversible thermodynamics of composite systems is analyzed as an externally manipulated system of space partitioning and classification based on ideal enclosures and diaphragms. The diaphragms have discrete classification capabilities which are designated in relation to conserved quantities by descriptors such as impervious, diathermal, and adiabatic. Differentiability in the continuum thermodynamic calculus is invoked as equivalent to analyticity and consistency in the underlying class or sentential calculus. The seat of inference, however, rests with the thermodynamicist. In the transition to an irreversible pattern-forming system the defined nature of the composite reservoirs remains, but a given diaphragm is replaced by a pattern-forming system which by its nature is a spontaneously evolving volume partitioner and classifier of invariants. The seat of volition or inference for the classification system is thus transferred from the experimenter or theoretician to the diaphragm, and with it the full deductive facility. The equivalence relations or partitions associated with the emerging patterns may thus be associated with theorems of the natural pattern-forming calculus. The entropy function, together with its derivatives, is the vehicle which relates the logistics of reservoirs and diaphragms to the analog logistics of the continuum. Maximum path probability or second-order differentiability of the entropy in isolation are

  5. Logistic Regression: Going beyond Point-and-Click.

    ERIC Educational Resources Information Center

    King, Jason E.

    A review of the literature reveals that important statistical algorithms and indices pertaining to logistic regression are being underused. This paper describes logistic regression in comparison with discriminant analysis and linear regression, and suggests that some techniques only accessible through computer syntax should be consulted in…

  6. Bayesian Estimation of the Logistic Positive Exponent IRT Model

    ERIC Educational Resources Information Center

    Bolfarine, Heleno; Bazan, Jorge Luis

    2010-01-01

    A Bayesian inference approach using Markov Chain Monte Carlo (MCMC) is developed for the logistic positive exponent (LPE) model proposed by Samejima and for a new skewed Logistic Item Response Theory (IRT) model, named Reflection LPE model. Both models lead to asymmetric item characteristic curves (ICC) and can be appropriate because a symmetric…

  7. A Model for Logistics Systems Engineering Management Education in Europe.

    ERIC Educational Resources Information Center

    Naim, M.; Lalwani, C.; Fortuin, L.; Schmidt, T.; Taylor, J.; Aronsson, H.

    2000-01-01

    Presents the need for a systems and process perspective of logistics, and develops a template for a logistics education course. The template addresses functional, process, and supply chain needs and was developed by a number of university partners with core skills in different traditional disciplines. (Contains 31 references.) (Author/WRM)

  8. Preliminary analysis of an integrated logistics system for OSSA payloads

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    The results of studies of the Office of Space Science and Applications' (OSSA) need for an integrated logistics system to support OSSA payloads, whether attached to the Space Station or free-flying are detailed. An executive summary, the integrated logistics support strategy, preparation of planning documents and a supportability analysis of the 1.8 meter centrifuge are discussed.

  9. The Impact of Logistical Resources on Prereferral Team Acceptability

    ERIC Educational Resources Information Center

    Yetter, Georgette; Doll, Beth

    2007-01-01

    This study investigated the impact of logistical resources on the acceptability of student assistance team consultation to school staff. Elementary and middle school staff (N=113) completed a measure of the acceptability of prereferral intervention team procedures while also rating the importance of five logistical supports for effective team…

  10. Logistics Reduction and Repurposing Beyond Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K.; Broyan, James L., Jr.

    2012-01-01

    All human space missions, regardless of destination, require significant logistical mass and volume that is strongly proportional to mission duration. Anything that can be done to reduce initial mass and volume of supplies or reuse items that have been launched will be very valuable. Often, the logistical items require disposal and represent a trash burden. Logistics contributions to total mission architecture mass can be minimized by considering potential reuse using systems engineering analysis. In NASA's Advanced Exploration Systems "Logistics Reduction and Repurposing Project," various tasks will reduce the intrinsic mass of logistical packaging, enable reuse and repurposing of logistical packaging and carriers for other habitation, life support, crew health, and propulsion functions, and reduce or eliminate the nuisance aspects of trash at the same time. Repurposing reduces the trash burden and eliminates the need for hardware whose function can be provided by use of spent logistical items. However, these reuse functions need to be identified and built into future logical systems to enable them to effectively have a secondary function. These technologies and innovations will help future logistics systems to support multiple exploration missions much more efficiently.

  11. Adjustable Induction-Heating Coil

    NASA Technical Reports Server (NTRS)

    Ellis, Rod; Bartolotta, Paul

    1990-01-01

    Improved design for induction-heating work coil facilitates optimization of heating in different metal specimens. Three segments adjusted independently to obtain desired distribution of temperature. Reduces time needed to achieve required temperature profiles.

  12. Defense waste transportation: cost and logistics studies

    SciTech Connect

    Andrews, W.B.; Cole, B.M.; Engel, R.L.; Oylear, J.M.

    1982-08-01

    Transportation of nuclear wastes from defense programs is expected to significantly increase in the 1980s and 1990s as permanent waste disposal facilities come into operation. This report uses models of the defense waste transportation system to quantify potential transportation requirements for treated and untreated contact-handled transuranic (CH-TRU) wastes and high-level defense wastes (HLDW). Alternative waste management strategies in repository siting, waste retrieval and treatment, treatment facility siting, waste packaging and transportation system configurations were examined to determine their effect on transportation cost and hardware requirements. All cost estimates used 1980 costs. No adjustments were made for future changes in these costs relative to inflation. All costs are reported in 1980 dollars. If a single repository is used for defense wastes, transportation costs for CH-TRU waste currently in surface storage and similar wastes expected to be generated by the year 2000 were estimated to be 109 million dollars. Recovery and transport of the larger buried volumes of CH-TRU waste will increase CH-TRU waste transportation costs by a factor of 70. Emphasis of truck transportation and siting of multiple repositories would reduce CH-TRU transportation costs. Transportation of HLDW to repositories for 25 years beginning in 1997 is estimated to cost $229 M in 1980 costs and dollars. HLDW transportation costs could either increase or decrease with the selection of a final canister configuration. HLDW transportation costs are reduced when multiple repositories exist and emphasis is placed on truck transport.

  13. 7 CFR 251.7 - Formula adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Formula adjustments. 251.7 Section 251.7 Agriculture... GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION THE EMERGENCY FOOD ASSISTANCE PROGRAM § 251.7 Formula adjustments. Formula adjustments. (a) Commodity adjustments. The Department will make annual adjustments...

  14. 12 CFR 1209.80 - Inflation adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 10 2014-01-01 2014-01-01 false Inflation adjustments. 1209.80 Section 1209.80... PROCEDURE Civil Money Penalty Inflation Adjustments § 1209.80 Inflation adjustments. The maximum amount of... thereafter adjusted in accordance with the Inflation Adjustment Act, on a recurring four-year cycle, is...

  15. 12 CFR 1209.80 - Inflation adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 9 2012-01-01 2012-01-01 false Inflation adjustments. 1209.80 Section 1209.80... PROCEDURE Civil Money Penalty Inflation Adjustments § 1209.80 Inflation adjustments. The maximum amount of... thereafter adjusted in accordance with the Inflation Adjustment Act, on a recurring four-year cycle, is...

  16. 12 CFR 1209.80 - Inflation adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 9 2013-01-01 2013-01-01 false Inflation adjustments. 1209.80 Section 1209.80... PROCEDURE Civil Money Penalty Inflation Adjustments § 1209.80 Inflation adjustments. The maximum amount of... thereafter adjusted in accordance with the Inflation Adjustment Act, on a recurring four-year cycle, is...

  17. The Effect of Stochastic Perturbation of Fuel Distribution on the Criticality of a One Speed Reactor and the Development of Multi-Material Multinomial Line Statistics

    NASA Technical Reports Server (NTRS)

    Jahshan, S. N.; Singleterry, R. C.

    2001-01-01

    The effect of random fuel redistribution on the eigenvalue of a one-speed reactor is investigated. An ensemble of such reactors that are identical to a homogeneous reference critical reactor except for the fissile isotope density distribution is constructed such that it meets a set of well-posed redistribution requirements. The average eigenvalue, , is evaluated when the total fissile loading per ensemble element, or realization, is conserved. The perturbation is proven to increase the reactor criticality on average when it is uniformly distributed. The various causes of the change in reactivity, and their relative effects are identified and ranked. From this, a path towards identifying the causes. and relative effects of reactivity fluctuations for the energy dependent problem is pointed to. The perturbation method of using multinomial distributions for representing the perturbed reactor is developed. This method has some advantages that can be of use in other stochastic problems. Finally, some of the features of this perturbation problem are related to other techniques that have been used for addressing similar problems.

  18. Estimating wetland vegetation abundance from Landsat-8 operational land imager imagery: a comparison between linear spectral mixture analysis and multinomial logit modeling methods

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Gong, Zhaoning; Zhao, Wenji; Pu, Ruiliang; Liu, Ke

    2016-01-01

    Mapping vegetation abundance by using remote sensing data is an efficient means for detecting changes of an eco-environment. With Landsat-8 operational land imager (OLI) imagery acquired on July 31, 2013, both linear spectral mixture analysis (LSMA) and multinomial logit model (MNLM) methods were applied to estimate and assess the vegetation abundance in the Wild Duck Lake Wetland in Beijing, China. To improve mapping vegetation abundance and increase the number of endmembers in spectral mixture analysis, normalized difference vegetation index was extracted from OLI imagery along with the seven reflective bands of OLI data for estimating the vegetation abundance. Five endmembers were selected, which include terrestrial plants, aquatic plants, bare soil, high albedo, and low albedo. The vegetation abundance mapping results from Landsat OLI data were finally evaluated by utilizing a WorldView-2 multispectral imagery. Similar spatial patterns of vegetation abundance produced by both fully constrained LSMA algorithm and MNLM methods were observed: higher vegetation abundance levels were distributed in agricultural and riparian areas while lower levels in urban/built-up areas. The experimental results also indicate that the MNLM model outperformed the LSMA algorithm with smaller root mean square error (0.0152 versus 0.0252) and higher coefficient of determination (0.7856 versus 0.7214) as the MNLM model could handle the nonlinear reflection phenomenon better than the LSMA with mixed pixels.

  19. Using informative Multinomial-Dirichlet prior in a t-mixture with reversible jump estimation of nucleosome positions for genome-wide profiling.

    PubMed

    Samb, Rawane; Khadraoui, Khader; Belleau, Pascal; Deschênes, Astrid; Lakhal-Chaieb, Lajmi; Droit, Arnaud

    2015-12-01

    Genome-wide mapping of nucleosomes has revealed a great deal about the relationships between chromatin structure and control of gene expression. Recent next generation CHIP-chip and CHIP-Seq technologies have accelerated our understanding of basic principles of chromatin organization. These technologies have taught us that nucleosomes play a crucial role in gene regulation by allowing physical access to transcription factors. Recent methods and experimental advancements allow the determination of nucleosome positions for a given genome area. However, most of these methods estimate the number of nucleosomes either by an EM algorithm using a BIC criterion or an effective heuristic strategy. Here, we introduce a Bayesian method for identifying nucleosome positions. The proposed model is based on a Multinomial-Dirichlet classification and a hierarchical mixture distributions. The number and the positions of nucleosomes are estimated using a reversible jump Markov chain Monte Carlo simulation technique. We compare the performance of our method on simulated data and MNase-Seq data from Saccharomyces cerevisiae against PING and NOrMAL methods. PMID:26656614

  20. The role of orthographic and phonological codes in the word and the pseudoword superiority effect: an analysis by means of multinomial processing tree models.

    PubMed

    Maris, Eric

    2002-12-01

    Central to the current accounts of the word and the pseudoword superiority effect (WSE and PWSE, respectively) is the concept of a unitized code that is less susceptible to masking than single-letter codes. Current explanations of the WSE and PWSE assume that this unitized code is orthographic, explaining these phenomena by the assumption of dual read-out from unitized and single-letter codes. In this article, orthographic dual read-out models are compared with a phonological dual read-out model (which is based on the assumption that the 1st unitized code is phonological). From this phonological code, an orthographic code is derived, through either lexical access or assembly. Comparison of the orthographic and phonological dual read-out models was performed by formulating both models as multinomial processing tree models. From an application of these models to the data of 2 letter identification experiments, it was clear that the orthographic dual read-out models are insufficient as an explanation of the PWSE, whereas the phonological dual read-out model is sufficient. PMID:12542135

  1. Logistics engineering education from the point of view environment

    NASA Astrophysics Data System (ADS)

    Bányai, Ágota

    2010-05-01

    A new field of MSc programme offered by the Faculty of Mechanical Engineering and Informatics of the University of Miskolc is represented by the programme in logistics engineering. The Faculty has always laid great emphasis on assigning processes connected with environment protection and globalisation issues the appropriate weight in its programmes. This is based on the fact that the Faculty has initiated and been involved in a great number of research and development projects with a substantial emphasis on the fundamental principles of sustainable development. The objective of the programme of logistics engineering is to train engineers who, in possession of the science, engineering, economic, informatics and industrial, transportation technological knowledge related to the professional field of logistics, are able to analyse, design, organise, and control logistics processes and systems (freight transportation, materials handling, storage, commissioning, loading, purchasing, distribution and waste management) as well as to design and develop machinery and equipment as the elements of logistic systems and also to be involved in their manufacture and quality control and are able to control their operation. The programme prepares its students for performing the logistics management tasks in a company, for creative participation in solving research and development problems in logistics and for pursuing logistics studies in doctoral programmes. There are several laboratories available for practice-oriented training. The 'Integrated Logistics Laboratory' consists of various fixed and mobile, real industrial, i.e. not model-level equipment, the integration of which in one system facilitates not only the presentation, examination and development of the individual self-standing facilities, but the study of their interaction as well in terms of mechatronics, engineering, control engineering, informatics, identification technology and logistics. The state

  2. A fast, streaming SIMD Extensions 2, logistic squashing function.

    PubMed

    Milner, J J; Grandison, A J

    2008-12-01

    Schraudolph proposed an excellent exponential approximation providing increased performance particularly suited to the logistic squashing function used within many neural networking applications. This note applies Intel's streaming SIMD Extensions 2 (SSE2), where SIMD is single instruction multiple data, of the Pentium IV class processor to Schraudolph's technique, further increasing the performance of the logistic squashing function. It was found that the calculation of the new 32-bit SSE2 logistic squashing function described here was up to 38 times faster than the conventional exponential function and up to 16 times faster than a Schraudolph-style 32-bit method on an Intel Pentium D 3.6 GHz CPU. PMID:18624654

  3. Time-delayed coupled logistic capacity model in population dynamics

    NASA Astrophysics Data System (ADS)

    Cáceres, Manuel O.

    2014-08-01

    This study proposes a delay-coupled system based on the logistic equation that models the interaction of a population with its varying environment. The integro-diferential equations of the model are presented in terms of a distributed time-delayed coupled logistic-capacity equation. The model eliminates the need for a prior knowledge of the maximum saturation environmental carrying capacity value. Therefore the dynamics toward the final attractor in a distributed time-delayed coupled logistic-capacity model is studied. Exact results are presented, and analytical conclusions have been done in terms of the two parameters of the model.

  4. Chaos-based secure communication system using logistic map

    NASA Astrophysics Data System (ADS)

    Singh, Narendra; Sinha, Aloka

    2010-03-01

    We propose a new opto-electronic secure communication system using logistic map and pulse position modulation. A modified version of the electronic circuit of the logistic map is used to generate the chaotic signal. Pulse position modulation scheme together with the logistic map has been used to encrypt the signal. Optical fiber has been used to demonstrate the proposed scheme. Eye pattern has been used to verify the noise-like nature of the encrypted signal. Opto-electronic implementation of the technique has been carried out. Experimental results are presented to verify the validity of the proposed technique.

  5. Final RQ adjustments rule issued

    SciTech Connect

    Bergeson, L.L.

    1995-08-01

    On June 12, 1995, the US Environmental Protection Agency (EPA) issued its long awaited final rule adjusting certain reportable quantities (RQs) for hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The rule: revises the table of hazardous substances to add 47 individual Clean Air Act (CAA) hazardous air pollutants (HAPs); adjustments their statutory one-pound RQs; adds five other CAA HAPs that are categories of substances and assigns no RQ to the categories; and adjusts RQs for 11 Resource Conservation and Recovery Act (RCRA) listed hazardous wastes. EPA made conforming changes to the Clean Water Act table of hazardous substances and the Emergency Planning and Community Right-to-Know Act (EPCRA) table of extremely hazardous substances. The rule became effective July 12, 1995.

  6. MCCB warm adjustment testing concept

    NASA Astrophysics Data System (ADS)

    Erdei, Z.; Horgos, M.; Grib, A.; Preradović, D. M.; Rodic, V.

    2016-08-01

    This paper presents an experimental investigation in to operating of thermal protection device behavior from an MCCB (Molded Case Circuit Breaker). One of the main functions of the circuit breaker is to assure protection for the circuits where mounted in for possible overloads of the circuit. The tripping mechanism for the overload protection is based on a bimetal movement during a specific time frame. This movement needs to be controlled and as a solution to control this movement we choose the warm adjustment concept. This concept is meant to improve process capability control and final output. The warm adjustment device design will create a unique adjustment of the bimetal position for each individual breaker, determined when the testing current will flow thru a phase which needs to trip in a certain amount of time. This time is predetermined due to scientific calculation for all standard types of amperages and complies with the IEC 60497 standard requirements.

  7. Adjustable spacer with rotational lock

    SciTech Connect

    Bowyer, M.L.

    1984-02-28

    A spacing apparatus for tubing conduit in a subterranean well, normally for use with an electric component with a longitudinally extending external electrical cable, permits irrotational adjustment of the length of the tubing conduit. The spacing apparatus comprises telescoping members which are keyed to prevent rotation therebetween. A threaded member, longitudinally fixed relative to one longitudinal member, normally engages threads extending substantially along the entire length of the other telescoping member. Movement of a retaining sleeve permits disengagement of the threaded segments which ratchet along the threads during telescoping movement. The length of the conduit can thus be irrotationally adjusted to remove slack from the electrical cable.

  8. Convective adjustment in baroclinic atmospheres

    NASA Technical Reports Server (NTRS)

    Emanuel, Kerry A.

    1986-01-01

    Local convection in planetary atmospheres is generally considered to result from the action of gravity on small regions of anomalous density. That in rotating baroclinic fluids the total potential energy for small scale convection contains a centrifugal as well as a gravitational contribution is shown. Convective adjustment in such an atmosphere results in the establishment of near adiabatic lapse rates of temperature along suitably defined surfaces of constant angular momentum, rather than in the vertical. This leads in general to sub-adiabatic vertical lapse rates. That such an adjustment actually occurs in the earth's atmosphere is shown by example and the magnitude of the effect for several other planetary atmospheres is estimated.

  9. 76 FR 54468 - Petra Pet, Inc. (a/k/a Petrapport) v. Panda Logistics Limited; Panda Logistics Co., Ltd. (f/k/a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Petra Pet, Inc. (a/k/a Petrapport) v. Panda Logistics Limited; Panda Logistics Co., Ltd. (f/k/a panda... Petra Pet, Inc. (a/k/a Petrapport), hereinafter ``Complainant,'' against Respondents Panda Logistics Limited, Panda Logistics Co., Ltd. (f/k/a Panda Int'l Transportation Co., Ltd), and RDM Solutions...

  10. 75 FR 33379 - Railroad Cost Recovery Procedures-Productivity Adjustment; Quarterly Rail Cost Adjustment Factor

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... Surface Transportation Board Railroad Cost Recovery Procedures--Productivity Adjustment; Quarterly Rail... Railroads that the Board restate the previously published productivity adjustment for the 2003-2007 averaging period (2007 productivity adjustment) so that it tracks the 2007 productivity adjustment...

  11. Expendable launch vehicles in Space Station Freedom logistics resupply operations

    NASA Technical Reports Server (NTRS)

    Newman, J. Steven; Courtney, Roy L.; Brunt, Peter

    1990-01-01

    The projected Space Station Freedom (SSF) annual logistics resupply requirements were predicted to exceed the 1988 baseline Shuttle resupply system capability. This paper examines the implications of employing a 'mixed fleet' of Shuttles and ELVs to provide postassembly, steady-state logistics resupply. The study concluded that ELVs supported by the OMV could provide the additional required resupply capability with one to three launches per annum. However, the study determined that such a capability would require significant programmatic commitments, including baseline SSF OMV accommodations, on-orbit OMV monoprop replenishment capability, and substantial economics investments. The study also found the need for a half-size pressurized logistics module for the increase in the efficiency of logistics manifesting on the Shuttle as well as ELVs.

  12. Sparse logistic regression with Lp penalty for biomarker identification.

    PubMed

    Liu, Zhenqiu; Jiang, Feng; Tian, Guoliang; Wang, Suna; Sato, Fumiaki; Meltzer, Stephen J; Tan, Ming

    2007-01-01

    In this paper, we propose a novel method for sparse logistic regression with non-convex regularization Lp (p <1). Based on smooth approximation, we develop several fast algorithms for learning the classifier that is applicable to high dimensional dataset such as gene expression. To the best of our knowledge, these are the first algorithms to perform sparse logistic regression with an Lp and elastic net (Le) penalty. The regularization parameters are decided through maximizing the area under the ROC curve (AUC) of the test data. Experimental results on methylation and microarray data attest the accuracy, sparsity, and efficiency of the proposed algorithms. Biomarkers identified with our methods are compared with that in the literature. Our computational results show that Lp Logistic regression (p <1) outperforms the L1 logistic regression and SCAD SVM. Software is available upon request from the first author. PMID:17402921

  13. MODELING SNAKE MICROHABITAT FROM RADIOTELEMETRY STUDIES USING POLYTOMOUS LOGISTIC REGRESSION

    EPA Science Inventory

    Multivariate analysis of snake microhabitat has historically used techniques that were derived under assumptions of normality and common covariance structure (e.g., discriminant function analysis, MANOVA). In this study, polytomous logistic regression (PLR which does not require ...

  14. Research challenges in municipal solid waste logistics management.

    PubMed

    Bing, Xiaoyun; Bloemhof, Jacqueline M; Ramos, Tania Rodrigues Pereira; Barbosa-Povoa, Ana Paula; Wong, Chee Yew; van der Vorst, Jack G A J

    2016-02-01

    During the last two decades, EU legislation has put increasing pressure on member countries to achieve specified recycling targets for municipal household waste. These targets can be obtained in various ways choosing collection methods, separation methods, decentral or central logistic systems, etc. This paper compares municipal solid waste (MSW) management practices in various EU countries to identify the characteristics and key issues from a waste management and reverse logistics point of view. Further, we investigate literature on modelling municipal solid waste logistics in general. Comparing issues addressed in literature with the identified issues in practice result in a research agenda for modelling municipal solid waste logistics in Europe. We conclude that waste recycling is a multi-disciplinary problem that needs to be considered at different decision levels simultaneously. A holistic view and taking into account the characteristics of different waste types are necessary when modelling a reverse supply chain for MSW recycling. PMID:26704064

  15. Multi-Purpose Logistics Module (MPLM) Cargo Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Zampiceni, John J.; Harper, Lon T.

    2002-01-01

    This paper describes the New Shuttle Orbiter's Multi- Purpose Logistics Modulo (MPLM) Cargo Heat Exchanger (HX) and associated MPLM cooling system. This paper presents Heat Exchanger (HX) design and performance characteristics of the system.

  16. Large unbalanced credit scoring using Lasso-logistic regression ensemble.

    PubMed

    Wang, Hong; Xu, Qingsong; Zhou, Lifeng

    2015-01-01

    Recently, various ensemble learning methods with different base classifiers have been proposed for credit scoring problems. However, for various reasons, there has been little research using logistic regression as the base classifier. In this paper, given large unbalanced data, we consider the plausibility of ensemble learning using regularized logistic regression as the base classifier to deal with credit scoring problems. In this research, the data is first balanced and diversified by clustering and bagging algorithms. Then we apply a Lasso-logistic regression learning ensemble to evaluate the credit risks. We show that the proposed algorithm outperforms popular credit scoring models such as decision tree, Lasso-logistic regression and random forests in terms of AUC and F-measure. We also provide two importance measures for the proposed model to identify important variables in the data. PMID:25706988

  17. NASA Advanced Explorations Systems: Concepts for Logistics to Living

    NASA Technical Reports Server (NTRS)

    Shull, Sarah A.; Howe, A. Scott; Flynn, Michael T.; Howard, Robert

    2012-01-01

    The NASA Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) project strives to enable a largely mission-independent cradle-to-grave-to-cradle approach to minimize logistics contributions to total mission architecture mass. The goals are to engineer logistics materials, common crew consumables, and container configurations to meet the following five basic goals: 1. Minimize intrinsic logistics mass and improve ground logistics flexibility. 2. Allow logistics components to be directly repurposed for on-orbit non-logistics functions (e.g., crew cabin outfitting) thereby indirectly reducing mass/volume. 3. Compact and process logistics that have not been directly repurposed to generate useful on-orbit components and/or compounds (e.g., radiation shielding, propellant, other usable chemical constituents). 4. Enable long-term stable storage and disposal of logistics end products that cannot be reused or repurposed (e.g., compaction for volume reduction, odor control, and maintenance of crew cabin hygienic conditions). 5. Allow vehicles in different mission phases to share logistics resources. This paper addresses the work being done to meet the second goal, the direct repurposing of logistics components to meet other on-orbit needs, through a strategy termed Logistics to Living (L2L). L2L has several areas but can be defined as repurposing or converting logistical items (bags, containers, foam, components, etc.) into useful crew items or life support augmentation on-orbit after they have provided their primary logistics function. The intent is that by repurposing items, dedicated crew items do not have to be launched and overall launch mass is decreased. For non-LEO missions, the vehicle interior volume will be relatively fixed so L2L will enable this volume to be used more effectively through reuse and rearrangement of logistical components. Past work in the area of L2L has already conceptually developed several potential technologies [Howe

  18. Reducing Mission Logistics with Multipurpose Cargo Transfer Bags

    NASA Technical Reports Server (NTRS)

    Baccus, Shelley; Broyan, James Lee, Jr.; Borrego, Melissa

    2016-01-01

    The Logistics Reduction (LR) project within Advanced Exploration Systems (AES) is tasked with reducing logistical mass and repurposing logistical items. Multipurpose Cargo Transfer Bags (MCTB) have been designed such that they can serve the same purpose as a Cargo Transfer Bag (CTB), the common logistics carrying bag for the International Space Station (ISS). After use as a cargo carrier, a regular CTB becomes trash, whereas the MCTB can be unfolded into a flat panel for reuse. Concepts and potential benefits for various MCTB applications will be discussed including partitions, crew quarters, solar radiation storm shelters, acoustic blankets, and forward osmosis water processing. Acoustic MCTBs are currently in use on ISS to reduce the noise generated by the T2 treadmill, which reaches the hazard limit at high speeds. The development of the AMCTB included identification of keep-out zones, acoustic properties, deployment considerations, and structural testing. Features developed for these considerations are applicable to MCTBs for all crew outfitting applications.

  19. A note on 'A generalized two-sex logistic model'.

    PubMed

    Maxin, D; Sega, L

    2015-01-01

    We re-visit the recently published paper on a generalization of the two-sex logistic model by Maxin and Sega [A generalized two-sex logistic model, J. Biol. Dyn. 7(1) (2013), pp. 302-318]. We show that the logistic assumption of a non-increasing birth rate can be replaced by a more general assumption of a non-increasing ratio between the female/male birth and mortality rate. In this note we indicate the changes necessary in the proofs of the theorems in [D. Maxin and L. Sega, A generalized two-sex logistic model, J. Biol. Dyn. 7(1) (2013), pp. 302--318] and discuss several situations where this new assumption is useful. PMID:25653171

  20. Multipurpose Cargo Transfer Bags fro Reducing Exploration Mission Logistics

    NASA Technical Reports Server (NTRS)

    Baccus, Shelley; Broyan, James Lee, Jr.; Borrego, Melissa

    2016-01-01

    The Logistics Reduction (LR) project within the Advanced Exploration Systems (AES) division is tasked with reducing logistical mass and repurposing logistical items. Multipurpose Cargo Transfer Bags (MCTB) have been designed such that they can serve the same purpose as a Cargo Transfer Bag (CTB), the common logistics carrying bag for the International Space Station (ISS). After use as a cargo carrier, a regular CTB becomes trash, whereas the MCTB can be unfolded into a flat panel for reuse. Concepts and potential benefits for various MCTB applications will be discussed including partitions, crew quarters, solar radiation storm shelters, acoustic blankets, and forward osmosis water processing. Acoustic MCTBs are currently in use on ISS to reduce the noise generated by the T2 treadmill, which reaches the hazard limit at high speeds. The development of the AMCTB included identification of keep out zones, acoustic properties, deployment considerations, and structural testing. Features developed for these considerations are applicable to MCTBs for all crew outfitting applications.

  1. Virus evolutionary genetic algorithm for task collaboration of logistics distribution

    NASA Astrophysics Data System (ADS)

    Ning, Fanghua; Chen, Zichen; Xiong, Li

    2005-12-01

    In order to achieve JIT (Just-In-Time) level and clients' maximum satisfaction in logistics collaboration, a Virus Evolutionary Genetic Algorithm (VEGA) was put forward under double constraints of logistics resource and operation sequence. Based on mathematic description of a multiple objective function, the algorithm was designed to schedule logistics tasks with different due dates and allocate them to network members. By introducing a penalty item, make span and customers' satisfaction were expressed in fitness function. And a dynamic adaptive probability of infection was used to improve performance of local search. Compared to standard Genetic Algorithm (GA), experimental result illustrates the performance superiority of VEGA. So the VEGA can provide a powerful decision-making technique for optimizing resource configuration in logistics network.

  2. Large Unbalanced Credit Scoring Using Lasso-Logistic Regression Ensemble

    PubMed Central

    Wang, Hong; Xu, Qingsong; Zhou, Lifeng

    2015-01-01

    Recently, various ensemble learning methods with different base classifiers have been proposed for credit scoring problems. However, for various reasons, there has been little research using logistic regression as the base classifier. In this paper, given large unbalanced data, we consider the plausibility of ensemble learning using regularized logistic regression as the base classifier to deal with credit scoring problems. In this research, the data is first balanced and diversified by clustering and bagging algorithms. Then we apply a Lasso-logistic regression learning ensemble to evaluate the credit risks. We show that the proposed algorithm outperforms popular credit scoring models such as decision tree, Lasso-logistic regression and random forests in terms of AUC and F-measure. We also provide two importance measures for the proposed model to identify important variables in the data. PMID:25706988

  3. Oshkosh Logistic Management and Public Relations Responsibilities at NASA Langley

    NASA Technical Reports Server (NTRS)

    Beck, Danielle

    1995-01-01

    The central focus of my study for the summer of 1995 was to provide logistical support to Margaret Hunt, the logistics manager of the OSHKOSH airshow. In this capacity responsibilities included making arrangements for participants from NASA centers and SBIR companies for their stay in Wisconsin, while visiting the airshow, and managing staff for exhibits and the aerospace theater. A secondary purpose was to serve in other public service capacities by writing news releases, fact sheets, announcements, and articles for the Researcher News.

  4. Airship logistics: The LTA vehicle; a total cargo system

    NASA Technical Reports Server (NTRS)

    Hackney, L. R. M.

    1975-01-01

    Design considerations for logistics are dealt with as they pertain to the large rigid LTA vehicle as either a commercial or military cargo carrier. Pertinent factors discussed are: (1) the basic mission; (2) types of payload; (3) the payload space in regards to configuration and sizing, its capacity, and its loadability. A logistic capability comparison of selected cargo airships versus jumbo jets is also made.

  5. Contractivity for nonautonomous logistic equation with piecewise constant delays

    NASA Astrophysics Data System (ADS)

    Nakata, Yukihiko; Kuroda, Masataka; Muroya, Yoshiaki

    2009-05-01

    In this paper, we extend the result in [Y. Muroya, Persistence, contractivity and global stability in logistic equations with piecewise constant delays, J. Math. Anal. Appl. 270 (2002) 602-635] to nonautonomous logistic equations with piecewise constant arguments and establish two sufficient conditions for contractivity-like property, from which the global asymptotic stability of the solutions of this equation is derived, even if the effect of delays dominates over the instantaneous feedback. We offer two examples to illustrate our results.

  6. Information logistics: A production-line approach to information services

    NASA Technical Reports Server (NTRS)

    Adams, Dennis; Lee, Chee-Seng

    1991-01-01

    Logistics can be defined as the process of strategically managing the acquisition, movement, and storage of materials, parts, and finished inventory (and the related information flow) through the organization and its marketing channels in a cost effective manner. It is concerned with delivering the right product to the right customer in the right place at the right time. The logistics function is composed of inventory management, facilities management, communications unitization, transportation, materials management, and production scheduling. The relationship between logistics and information systems is clear. Systems such as Electronic Data Interchange (EDI), Point of Sale (POS) systems, and Just in Time (JIT) inventory management systems are important elements in the management of product development and delivery. With improved access to market demand figures, logisticians can decrease inventory sizes and better service customer demand. However, without accurate, timely information, little, if any, of this would be feasible in today's global markets. Information systems specialists can learn from logisticians. In a manner similar to logistics management, information logistics is concerned with the delivery of the right data, to the ring customer, at the right time. As such, information systems are integral components of the information logistics system charged with providing customers with accurate, timely, cost-effective, and useful information. Information logistics is a management style and is composed of elements similar to those associated with the traditional logistics activity: inventory management (data resource management), facilities management (distributed, centralized and decentralized information systems), communications (participative design and joint application development methodologies), unitization (input/output system design, i.e., packaging or formatting of the information), transportations (voice, data, image, and video communication systems

  7. Modeling age-specific cancer incidences using logistic growth equations: implications for data collection.

    PubMed

    Shen, Xing-Rong; Feng, Rui; Chai, Jing; Cheng, Jing; Wang, De-Bin

    2014-01-01

    Large scale secular registry or surveillance systems have been accumulating vast data that allow mathematical modeling of cancer incidence and mortality rates. Most contemporary models in this regard use time series and APC (age-period-cohort) methods and focus primarily on predicting or analyzing cancer epidemiology with little attention being paid to implications for designing cancer registry, surveillance or evaluation initiatives. This research models age-specific cancer incidence rates using logistic growth equations and explores their performance under different scenarios of data completeness in the hope of deriving clues for reshaping relevant data collection. The study used China Cancer Registry Report 2012 as the data source. It employed 3-parameter logistic growth equations and modeled the age-specific incidence rates of all and the top 10 cancers presented in the registry report. The study performed 3 types of modeling, namely full age-span by fitting, multiple 5-year- segment fitting and single-segment fitting. Measurement of model performance adopted adjusted goodness of fit that combines sum of squred residuals and relative errors. Both model simulation and performance evalation utilized self-developed algorithms programed using C# languade and MS Visual Studio 2008. For models built upon full age-span data, predicted age-specific cancer incidence rates fitted very well with observed values for most (except cervical and breast) cancers with estimated goodness of fit (Rs) being over 0.96. When a given cancer is concerned, the R valuae of the logistic growth model derived using observed data from urban residents was greater than or at least equal to that of the same model built on data from rural people. For models based on multiple-5-year-segment data, the Rs remained fairly high (over 0.89) until 3-fourths of the data segments were excluded. For models using a fixed length single-segment of observed data, the older the age covered by the corresponding

  8. Analysis of efficiency of waste reverse logistics for recycling.

    PubMed

    Veiga, Marcelo M

    2013-10-01

    Brazil is an agricultural country with the highest pesticide consumption in the world. Historically, pesticide packaging has not been disposed of properly. A federal law requires the chemical industry to provide proper waste management for pesticide-related products. A reverse logistics program was implemented, which has been hailed a great success. This program was designed to target large rural communities, where economy of scale can take place. Over the last 10 years, the recovery rate has been very poor in most small rural communities. The objective of this study was to analyze the case of this compulsory reverse logistics program for pesticide packaging under the recent Brazilian Waste Management Policy, which enforces recycling as the main waste management solution. This results of this exploratory research indicate that despite its aggregate success, the reverse logistics program is not efficient for small rural communities. It is not possible to use the same logistic strategy for small and large communities. The results also indicate that recycling might not be the optimal solution, especially in developing countries with unsatisfactory recycling infrastructure and large transportation costs. Postponement and speculation strategies could be applied for improving reverse logistics performance. In most compulsory reverse logistics programs, there is no economical solution. Companies should comply with the law by ranking cost-effective alternatives. PMID:23997069

  9. Visual adjustments to temporal blur

    NASA Astrophysics Data System (ADS)

    Bilson, Aaron C.; Mizokami, Yoko; Webster, Michael A.

    2005-10-01

    After observers have adapted to an edge that is spatially blurred or sharpened, a focused edge appears too sharp or blurred, respectively. These adjustments to blur may play an important role in calibrating spatial sensitivity. We examined whether similar adjustments influence the perception of temporal edges, by measuring the appearance of a step change in the luminance of a uniform field after adapting to blurred or sharpened transitions. Stimuli were square-wave alternations (at 1 to 8 Hz) filtered by changing the slope of the amplitude spectrum. A two-alternative-forced-choice task was used to adjust the slope until it appeared as a step change, or until it matched the perceived transitions in a reference stimulus. Observers could accurately set the waveform to a square wave, but only at the slower alternation rates. However, these settings were strongly biased by prior adaptation to filtered stimuli, or when the stimuli were viewed within temporally filtered surrounds. Control experiments suggest that the latter induction effects result directly from the temporal blur and are not simply a consequence of brightness induction in the fields. These results suggest that adaptation and induction adjust visual coding so that images are focused not only in space but also in time.

  10. Self-Adjusting Fluency Therapy.

    ERIC Educational Resources Information Center

    Schneider, Phillip

    1998-01-01

    Presents a rationale and methodology for a self-adjusting "fluency sensitive" approach to working with children who exhibit overt speech-fluency interruptions and a minimal amount of avoidance behavior. The approach emphasizes repeated experiences of volitional increases and decreases in loudness and pauses. Case examples demonstrate how several…

  11. Adjustable Walker for the Handicapped

    NASA Technical Reports Server (NTRS)

    Kitts, R. G.

    1984-01-01

    Front legs adjust at touch of lever for use on stairs or ramps. Spring loaded legs extend when lever is depressed by user. Legs lock in position when lever is released. Lever mounted on either side of walker or on both sides, so legs operated independently.

  12. Adjustable Optical-Fiber Attenuator

    NASA Technical Reports Server (NTRS)

    Buzzetti, Mike F.

    1994-01-01

    Adjustable fiber-optic attenuator utilizes bending loss to reduce strength of light transmitted along it. Attenuator functions without introducing measurable back-reflection or insertion loss. Relatively insensitive to vibration and changes in temperature. Potential applications include cable television, telephone networks, other signal-distribution networks, and laboratory instrumentation.

  13. Adjustable-Angle Drill Block

    NASA Technical Reports Server (NTRS)

    Gallimore, F. H.

    1986-01-01

    Adjustable angular drill block accurately transfers hole patterns from mating surfaces not normal to each other. Block applicable to transfer of nonperpendicular holes in mating contoured assemblies in aircraft industry. Also useful in general manufacturing to transfer mating installation holes to irregular and angular surfaces.

  14. Economic Pressures and Family Adjustment.

    ERIC Educational Resources Information Center

    Haccoun, Dorothy Markiewicz; Ledingham, Jane E.

    The relationships between economic stress on the family and child and parental adjustment were examined for a sample of 199 girls and boys in grades one, four, and seven. These associations were examined separately for families in which both parents were present and in which mothers only were at home. Economic stress was associated with boys'…

  15. Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 3: OSSA integrated logistics support planning document

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    Guidance in preparing and updating an integrated logistics support plan (ILSP) is given. Clear, concise, and detailed instructions are provided on the preparation and content of an ILSP in order to ensure a quality document that reflects total program requirements.

  16. Incremental value of hormonal therapy for deep vein thrombosis prediction: an adjusted Wells score for women.

    PubMed

    de Barros, Márcio Vinícius Lins; Arancibia, Ana Elisa Loyola; Costa, Ana Paula; Bueno, Fernando Brito; Martins, Marcela Aparecida Corrêa; Magalhães, Maria Cláudia; Silva, José Luiz Padilha; de Bastos, Marcos

    2016-04-01

    Deep venous thrombosis (DVT) management includes prediction rule evaluation to define standard pretest DVT probabilities in symptomatic patients. The aim of this study was to evaluate the incremental usefulness of hormonal therapy to the Wells prediction rules for DVT in women. We studied women undertaking compressive ultrasound scanning for suspected DVT. We adjusted the Wells score for DVT, taking into account the β-coefficients of the logistic regression model. Data discrimination was evaluated by the receiver operating characteristic (ROC) curve. The adjusted score calibration was assessed graphically and by the Hosmer-Lemeshow test. Reclassification tables and the net reclassification index were used for the adjusted score comparison with the Wells score for DVT. We observed 461 women including 103 DVT events. The mean age was 56 years (±21 years). The adjusted logistic regression model included hormonal therapy and six Wells prediction rules for DVT. The adjusted score weights ranged from -4 to 4. Hosmer-Lemeshow test showed a nonsignificant P value (0.69) and the calibration graph showed no differences between the expected and the observed values. The area under the ROC curve was 0.92 [95% confidence interval (CI) 0.90-0.95] for the adjusted model and 0.87 (95% CI 0.84-0.91) for the Wells score for DVT (Delong test, P value < 0.01). Net reclassification index for the adjusted score was 0.22 (95% CI 0.11-0.33, P value < 0.01). Our results suggest an incremental usefulness of hormonal therapy as an independent DVT prediction rule in women compared with the Wells score for DVT. The adjusted score must be evaluated in different populations before clinical use. PMID:26757018

  17. Social and Demographic Factors Associated with Morbidities in Young Children in Egypt: A Bayesian Geo-Additive Semi-Parametric Multinomial Model

    PubMed Central

    Khatab, Khaled; Adegboye, Oyelola; Mohammed, Taofeeq Ibn

    2016-01-01

    Background Globally, the burden of mortality in children, especially in poor developing countries, is alarming and has precipitated concern and calls for concerted efforts in combating such health problems. Examples of diseases that contribute to this burden of mortality include diarrhoea, cough, fever, and the overlap between these illnesses, causing childhood morbidity and mortality. Methods To gain insight into these health issues, we employed the 2008 Demographic and Health Survey Data of Egypt, which recorded details from 10,872 children under five. This data focused on the demographic and socio-economic characteristics of household members. We applied a Bayesian multinomial model to assess the area-specific spatial effects and risk factors of co-morbidity of fever, diarrhoea and cough for children under the age of five. Results The results showed that children under 20 months of age were more likely to have the three diseases (OR: 6.8; 95% CI: 4.6–10.2) than children between 20 and 40 months (OR: 2.14; 95% CI: 1.38–3.3). In multivariate Bayesian geo-additive models, the children of mothers who were over 20 years of age were more likely to have only cough (OR: 1.2; 95% CI: 0.9–1.5) and only fever (OR: 1.2; 95% CI: 0.91–1.51) compared with their counterparts. Spatial results showed that the North-eastern region of Egypt has a higher incidence than most of other regions. Conclusions This study showed geographic patterns of Egyptian governorates in the combined prevalence of morbidity among Egyptian children. It is obvious that the Nile Delta, Upper Egypt, and south-eastern Egypt have high rates of diseases and are more affected. Therefore, more attention is needed in these areas. PMID:27442018

  18. Modeling data for pancreatitis in presence of a duodenal diverticula using logistic regression

    NASA Astrophysics Data System (ADS)

    Dineva, S.; Prodanova, K.; Mlachkova, D.

    2013-12-01

    The presence of a periampullary duodenal diverticulum (PDD) is often observed during upper digestive tract barium meal studies and endoscopic retrograde cholangiopancreatography (ERCP). A few papers reported that the diverticulum had something to do with the incidence of pancreatitis. The aim of this study is to investigate if the presence of duodenal diverticula predisposes to the development of a pancreatic disease. A total 3966 patients who had undergone ERCP were studied retrospectively. They were divided into 2 groups-with and without PDD. Patients with a duodenal diverticula had a higher rate of acute pancreatitis. The duodenal diverticula is a risk factor for acute idiopathic pancreatitis. A multiple logistic regression to obtain adjusted estimate of odds and to identify if a PDD is a predictor of acute or chronic pancreatitis was performed. The software package STATISTICA 10.0 was used for analyzing the real data.

  19. Small molecule compound logistics outsourcing--going beyond the "thought experiment".

    PubMed

    Ramsay, Devon L; Kwasnoski, Joseph D; Caldwell, Gary W

    2012-01-01

    Increasing pressure on the pharmaceutical industry to reduce cost and focus internal resources on "high value" activities is driving a trend to outsource traditionally "in-house" drug discovery activities. Compound collections are typically viewed as drug discovery's "crown jewels"; however, in late 2007, Johnson & Johnson Pharmaceutical Research & Development (J PRD) took a bold step to move their entire North American compound inventory and processing capability to an external third party vendor. The authors discuss the combination model implemented, that of local compound logistics site support with an outsourced centralized processing center. Some of the lessons learned over the past five years were predictable while others were unexpected. The substantial cost savings, improved local service response and flexible platform to adjust to changing business needs resulted. Continued sustainable success relies heavily upon maintaining internal headcount dedicated to vendor management, an open collaboration approach and a solid information technology infrastructure with complete transparency and visibility. PMID:22571792

  20. Unified heuristics to solve routing problem of reverse logistics in sustainable supply chain

    NASA Astrophysics Data System (ADS)

    Anbuudayasankar, S. P.; Ganesh, K.; Lenny Koh, S. C.; Mohandas, K.

    2010-03-01

    A reverse logistics problem, motivated by many real-life applications, is examined where bottles/cans in which products are delivered from a processing depot to customers in one period are available for return to the depot in the following period. The picked-up bottles/cans need to be adjusted in the place of delivery load. This problem is termed as simultaneous delivery and pick-up problem with constrained capacity (SDPC). We develop three unified heuristics based on extended branch and bound heuristic, genetic algorithm and simulated annealing to solve SDPC. These heuristics are also designed to solve standard travelling salesman problem (TSP) and TSP with simultaneous delivery and pick-up (TSDP). We tested the heuristics on standard, derived and randomly generated datasets of TSP, TSDP and SDPC and obtained satisfying results with high convergence in reasonable time.

  1. 12 CFR 19.240 - Inflation adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount... Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note) as follows: ER10NO08.001 (b)...

  2. 12 CFR 19.240 - Inflation adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount... Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note) as follows: ER10NO08.001 (b)...

  3. 12 CFR 19.240 - Inflation adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount... Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note) as follows: ER10NO08.001 (b)...

  4. Cultural Adjustment and the Puerto Rican.

    ERIC Educational Resources Information Center

    Prewitt-Diaz, Joseph O.

    This review of the literature on cultural adjustment is divided into four sections: the nature of cultural adjustment; acculturation as a model of cultural adjustment; psychological responses to acculturation; and a model of cultural adjustment developed by the author as a result of his immigration from Puerto Rico to the United States mainland.…

  5. Adjusting to University: The Hong Kong Experience

    ERIC Educational Resources Information Center

    Yau, Hon Keung; Sun, Hongyi; Cheng, Alison Lai Fong

    2012-01-01

    Students' adjustment to the university environment is an important factor in predicting university outcomes and is crucial to their future achievements. University support to students' transition to university life can be divided into three dimensions: academic adjustment, social adjustment and psychological adjustment. However, these…

  6. AIAA/SOLE Space Logistics Symposium, 4th, Cocoa Beach, FL, Nov. 4-6, 1991, Technical Papers

    SciTech Connect

    Not Available

    1991-01-01

    Various papers on space logistics are presented. The general topics addressed include: commercial space systems operations and logistics; operations and logistics technology development; space operations and logistics CE, TQM, and LCC; ground systems infrastructure development supporting space operations; logistics support of orbital operations; logistics software, data, and documentation; ground operations supporting space operations; automation, robotics, and manned systems operations and logistics; Space Station operations and logistics; launch operations and processing support for space programs, space transportation operations and logistics, Space Exploration Initiative support.

  7. Asymptotically Unbiased Estimation of Exposure Odds Ratios in Complete Records Logistic Regression

    PubMed Central

    Bartlett, Jonathan W.; Harel, Ofer; Carpenter, James R.

    2015-01-01

    Missing data are a commonly occurring threat to the validity and efficiency of epidemiologic studies. Perhaps the most common approach to handling missing data is to simply drop those records with 1 or more missing values, in so-called “complete records” or “complete case” analysis. In this paper, we bring together earlier-derived yet perhaps now somewhat neglected results which show that a logistic regression complete records analysis can provide asymptotically unbiased estimates of the association of an exposure of interest with an outcome, adjusted for a number of confounders, under a surprisingly wide range of missing-data assumptions. We give detailed guidance describing how the observed data can be used to judge the plausibility of these assumptions. The results mean that in large epidemiologic studies which are affected by missing data and analyzed by logistic regression, exposure associations may be estimated without bias in a number of settings where researchers might otherwise assume that bias would occur. PMID:26429998

  8. Sub-resolution assist feature (SRAF) printing prediction using logistic regression

    NASA Astrophysics Data System (ADS)

    Tan, Chin Boon; Koh, Kar Kit; Zhang, Dongqing; Foong, Yee Mei

    2015-03-01

    In optical proximity correction (OPC), the sub-resolution assist feature (SRAF) has been used to enhance the process window of main structures. However, the printing of SRAF on wafer is undesirable as this may adversely degrade the overall process yield if it is transferred into the final pattern. A reasonably accurate prediction model is needed during OPC to ensure that the SRAF placement and size have no risk of SRAF printing. Current common practice in OPC is either using the main OPC model or model threshold adjustment (MTA) solution to predict the SRAF printing. This paper studies the feasibility of SRAF printing prediction using logistic regression (LR). Logistic regression is a probabilistic classification model that gives discrete binary outputs after receiving sufficient input variables from SRAF printing conditions. In the application of SRAF printing prediction, the binary outputs can be treated as 1 for SRAFPrinting and 0 for No-SRAF-Printing. The experimental work was performed using a 20nm line/space process layer. The results demonstrate that the accuracy of SRAF printing prediction using LR approach outperforms MTA solution. Overall error rate of as low as calibration 2% and verification 5% was achieved by LR approach compared to calibration 6% and verification 15% for MTA solution. In addition, the performance of LR approach was found to be relatively independent and consistent across different resist image planes compared to MTA solution.

  9. Mining machine with adjustable jib

    SciTech Connect

    Hart, D.

    1987-05-26

    A mining machine is described having a pair of crawler tracks, a means for individually driving each of the crawler tracks, a frame mounted on the crawler tracks, an elongated jib carrying a sprocket at each end, an endless cutting chain supported on the sprockets, cutters and loading flights mounted on the endless cutting chain, and means on the frame supporting the elongated jib. The means support the elongated jib consisting of a bridge on the frame, at least one scissors linkage pivotally mounted on the bridge, and arm having a first end attached to the scissors linkage, a front plate mounted on the second end of the arm and means adjustably mounting the elongated jib on the front plate. The means adjustably mount the elongated jib on the front plate including a first means for rotating the elongated jib between a vertical position and a horizontal position.

  10. Coverage-adjusted entropy estimation.

    PubMed

    Vu, Vincent Q; Yu, Bin; Kass, Robert E

    2007-09-20

    Data on 'neural coding' have frequently been analyzed using information-theoretic measures. These formulations involve the fundamental and generally difficult statistical problem of estimating entropy. We review briefly several methods that have been advanced to estimate entropy and highlight a method, the coverage-adjusted entropy estimator (CAE), due to Chao and Shen that appeared recently in the environmental statistics literature. This method begins with the elementary Horvitz-Thompson estimator, developed for sampling from a finite population, and adjusts for the potential new species that have not yet been observed in the sample-these become the new patterns or 'words' in a spike train that have not yet been observed. The adjustment is due to I. J. Good, and is called the Good-Turing coverage estimate. We provide a new empirical regularization derivation of the coverage-adjusted probability estimator, which shrinks the maximum likelihood estimate. We prove that the CAE is consistent and first-order optimal, with rate O(P)(1/log n), in the class of distributions with finite entropy variance and that, within the class of distributions with finite qth moment of the log-likelihood, the Good-Turing coverage estimate and the total probability of unobserved words converge at rate O(P)(1/(log n)(q)). We then provide a simulation study of the estimator with standard distributions and examples from neuronal data, where observations are dependent. The results show that, with a minor modification, the CAE performs much better than the MLE and is better than the best upper bound estimator, due to Paninski, when the number of possible words m is unknown or infinite. PMID:17567838

  11. Reverse bifurcation and fractal of the compound logistic map

    NASA Astrophysics Data System (ADS)

    Wang, Xingyuan; Liang, Qingyong

    2008-07-01

    The nature of the fixed points of the compound logistic map is researched and the boundary equation of the first bifurcation of the map in the parameter space is given out. Using the quantitative criterion and rule of chaotic system, the paper reveal the general features of the compound logistic map transforming from regularity to chaos, the following conclusions are shown: (1) chaotic patterns of the map may emerge out of double-periodic bifurcation and (2) the chaotic crisis phenomena and the reverse bifurcation are found. At the same time, we analyze the orbit of critical point of the compound logistic map and put forward the definition of Mandelbrot-Julia set of compound logistic map. We generalize the Welstead and Cromer's periodic scanning technology and using this technology construct a series of Mandelbrot-Julia sets of compound logistic map. We investigate the symmetry of Mandelbrot-Julia set and study the topological inflexibility of distributing of period region in the Mandelbrot set, and finds that Mandelbrot set contain abundant information of structure of Julia sets by founding the whole portray of Julia sets based on Mandelbrot set qualitatively.

  12. Dual Use of Packaging on the Moon: Logistics-2-Living

    NASA Technical Reports Server (NTRS)

    Howe, A. Scott; Howard, Robert

    2010-01-01

    This paper describes a modular packaging system for logistics that can be reconfigured into internal outfitting for a lunar outpost, including desks, chairs, partitions, cabinets, and radiation shielding. Logistics include clothes, equipment, food, and other consumables needed to sustain the crew for the duration of the mission. A significant mass penalty is required for the packaging and handling of logistics for re-supply of short to long-term space missions that must be brought out of the gravity well on a launch vehicle. Once the supplies have been exhausted, the packaging material is typically of no further use and is discarded. If a scheme can be developed that reuses the logistics packaging, the mass penalty can be reduced. In this research, a modular packaging system has been devised as a kit-of-parts that can be used for both handling logistics supplies, and then reconfigured into desks, chairs, partitions, cabinets, and radiation shielding. The system is derived from a standard International Space Station (ISS)-type Cargo Transfer Bag (CTB), using soft, unfoldable box-like containers with stiff metal inserts. The empty hydrogen-impregnated CTBs can be used as-is for cabinets, opened up for use as partitions, or draped over the habitat as layers of radiation shielding. Stiff metal inserts can be reconfigured into desks and other useful outfitting.

  13. Application of logistic analysis to the history of physics.

    SciTech Connect

    LePoire, D. J.; Environmental Assessment

    2005-05-01

    Recently, two analyses have tried to put technological progress in a larger context. One interpretation hypothesizes that technological progress is likely to continue at increasingly higher rates of change. Another interpretation, which includes data from the beginning of the universe to the present, suggests that the universe is approaching a transition point in a logistic development of complexity. This logistic development is similar to the way ideas or products diffuse in a population, i.e., the rate of discovery in a field of knowledge is proportional to the amount discovered and the amount to be discovered. To test a part of this hypothesis, a leading indicator field (fundamental physics) was identified and the events in the history of this field were analyzed. Twelve subfields were identified and grouped into six stages. Each stage seemed to demonstrate a logistic-like development. By analyzing both the median time of development and the characteristic time of development of these stages, the overall development of this one field was found to suggest logistic development. These data seem to indicate that development in fundamental physics is slowing down, with at least one subfield beyond string physics yet to be developed. The data tend to support the hypothesis that a knowledge field can develop logistically.

  14. Cradle-to-Grave Logistic Technologies for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L.; Ewert, Michael K.; Shull, Sarah

    2013-01-01

    Human exploration missions under study are very limited by the launch mass capacity of exiting and planned vehicles. The logistical mass of crew items is typically considered separate from the vehicle structure, habitat outfitting, and life support systems. Consequently, crew item logistical mass is typically competing with vehicle systems for mass allocation. NASA is Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project is developing four logistics technologies guided by a systems engineering cradle-to-grave approach to enable used crew items to augment vehicle systems. Specifically, AES LRR is investigating the direct reduction of clothing mass, the repurposing of logistical packaging, the processing of spent crew items to benefit radiation shielding and water recovery, and the conversion of trash to propulsion supply gases. The systematic implementation of these types of technologies will increase launch mass efficiency by enabling items to be used for secondary purposes and improve the habitability of the vehicle as the mission duration increases. This paper provides a description, benefits, and challenges of the four technologies under development and a status of progress at the mid ]point of the three year AES project.

  15. Logistics support economy and efficiency through consolidation and automation

    NASA Technical Reports Server (NTRS)

    Savage, G. R.; Fontana, C. J.; Custer, J. D.

    1985-01-01

    An integrated logistics support system, which would provide routine access to space and be cost-competitive as an operational space transportation system, was planned and implemented to support the NSTS program launch-on-time goal of 95 percent. A decision was made to centralize the Shuttle logistics functions in a modern facility that would provide office and training space and an efficient warehouse area. In this warehouse, the emphasis is on automation of the storage and retrieval function, while utilizing state-of-the-art warehousing and inventory management technology. This consolidation, together with the automation capabilities being provided, will allow for more effective utilization of personnel and improved responsiveness. In addition, this facility will be the prime support for the fully integrated logistics support of the operations era NSTS and reduce the program's management, procurement, transportation, and supply costs in the operations era.

  16. A Formal Approach for Milk-Run Transport Logistics

    NASA Astrophysics Data System (ADS)

    Satoh, Ichiro

    A formal approach for specifying and reasoning about earth-friendly logistics management systems is presented. To reduce fossil fuel consumption and carbon dioxide emissions resulting from transport, we must enhance the transport efficiency of trucks, which play an essential role as carriers in modern logistics services. This paper addresses the milk-run approach. It is one of the most effective and popular solutions to this problem, but it makes it be complicated to implement in a logistics management system. We propose a language for specifying the routes of trucks and an order relation between the requirements of routes and the possible routes of trucks. The former is formulated as process calculus and the latter selects suitable trucks according to their routes.

  17. Estimating the exceedance probability of rain rate by logistic regression

    NASA Technical Reports Server (NTRS)

    Chiu, Long S.; Kedem, Benjamin

    1990-01-01

    Recent studies have shown that the fraction of an area with rain intensity above a fixed threshold is highly correlated with the area-averaged rain rate. To estimate the fractional rainy area, a logistic regression model, which estimates the conditional probability that rain rate over an area exceeds a fixed threshold given the values of related covariates, is developed. The problem of dependency in the data in the estimation procedure is bypassed by the method of partial likelihood. Analyses of simulated scanning multichannel microwave radiometer and observed electrically scanning microwave radiometer data during the Global Atlantic Tropical Experiment period show that the use of logistic regression in pixel classification is superior to multiple regression in predicting whether rain rate at each pixel exceeds a given threshold, even in the presence of noisy data. The potential of the logistic regression technique in satellite rain rate estimation is discussed.

  18. Health care logistics: who has the ball during disaster?

    PubMed Central

    VanVactor, Jerry D.

    2011-01-01

    In contemporary organizations, a wide gamut of options is available for sustaining and supporting health care operations. When disaster strikes, despite having tenable plans for routine replenishment and operations, many organizations find themselves ill-prepared, ill-equipped, and without effective mechanisms in place to sustain operations during the immediate aftermath of a crisis. Health care operations can be abruptly halted due to the non-availability of supply. The purpose of this work is to add to a necessary, growing body of works related specifically to health care logistics preparedness and disaster mitigation. Logistics management is a specialized genre of expertise within the health care industry and is largely contributive to the success or failure of health care organizations. Logistics management requires extensive collaboration among multiple stakeholders—internal and external to an organization. Effective processes and procedures can be largely contributive to the success or failure of organizational operations. This article contributes to the closure of an obvious gap in professional and academic literature related to disaster health care logistics management and provides timely insight into a potential problem for leaders industry-wide. One critical aspect of disaster planning is regard for competent logistics management and the effective provision of necessary items when they are needed most. In many communities, there seems to be little evidence available regarding health care logistics involvement in disaster planning; at times, evidence of planning efforts perceptibly end at intra-organizational doors within facilities. Strategic planners are being continually reminded that health care organizations serve a principal role in emergency preparedness planning and must be prepared to fulfill the associated possibilities without notification. The concern is that not enough attention is being paid to repeated lessons being observed in disasters

  19. Logistics Reduction and Repurposing Technology for Long Duration Space Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L.; Chu, Andrew; Ewert, Michael K.

    2014-01-01

    One of NASA's Advanced Exploration Systems (AES) projects is the Logistics Reduction and Repurposing (LRR) project, which has the goal of reducing logistics resupply items through direct and indirect means. Various technologies under development in the project will reduce the launch mass of consumables and their packaging, enable reuse and repurposing of items and make logistics tracking more efficient. Repurposing also reduces the trash burden onboard spacecraft and indirectly reduces launch mass by replacing some items on the manifest. Examples include reuse of trash as radiation shielding or propellant. This paper provides the status of the LRR technologies in their third year of development under AES. Advanced clothing systems (ACS) are being developed to enable clothing to be worn longer, directly reducing launch mass. ACS has completed a ground exercise clothing study in preparation for an International Space Station (ISS) technology demonstration in 2014. Development of launch packaging containers and other items that can be repurposed on-orbit as part of habitation outfitting has resulted in a logistics-to-living (L2L) concept. L2L has fabricated and evaluated several multi-purpose cargo transfer bags (MCTBs) for potential reuse on orbit. Autonomous logistics management (ALM) is using radio frequency identification (RFID) to track items and thus reduce crew requirements for logistics functions. An RFID dense reader prototype is under construction and plans for integrated testing are being made. Development of a heat melt compactor (HMC) second generation unit for processing trash into compact and stable tiles is nearing completion. The HMC prototype compaction chamber has been completed and system development testing is underway. Research has been conducted on the conversion of trash-to-gas (TtG) for high levels of volume reduction and for use in propulsion systems. A steam reformation system was selected for further system definition of the TtG technology

  20. Adjustable link for kinematic mounting systems

    DOEpatents

    Hale, L.C.

    1997-07-01

    An adjustable link for kinematic mounting systems is disclosed. The adjustable link is a low-cost, passive device that provides backlash-free adjustment along its single constraint direction and flexural freedom in all other directions. The adjustable link comprises two spheres, two sockets in which the spheres are adjustable retain, and a connection link threadly connected at each end to the spheres, to provide a single direction of restraint and to adjust the length or distance between the sockets. Six such adjustable links provide for six degrees of freedom for mounting an instrument on a support. The adjustable link has applications in any machine or instrument requiring precision adjustment in six degrees of freedom, isolation from deformations of the supporting platform, and/or additional structural damping. The damping is accomplished by using a hollow connection link that contains an inner rod and a viscoelastic separation layer between the two. 3 figs.

  1. Adjustable link for kinematic mounting systems

    DOEpatents

    Hale, Layton C.

    1997-01-01

    An adjustable link for kinematic mounting systems. The adjustable link is a low-cost, passive device that provides backlash-free adjustment along its single constraint direction and flexural freedom in all other directions. The adjustable link comprises two spheres, two sockets in which the spheres are adjustable retain, and a connection link threadly connected at each end to the spheres, to provide a single direction of restraint and to adjust the length or distance between the sockets. Six such adjustable links provide for six degrees of freedom for mounting an instrument on a support. The adjustable link has applications in any machine or instrument requiring precision adjustment in six degrees of freedom, isolation from deformations of the supporting platform, and/or additional structural damping. The damping is accomplished by using a hollow connection link that contains an inner rod and a viscoelastic separation layer between the two.

  2. Logistics: An integral part of cost efficient space operations

    NASA Technical Reports Server (NTRS)

    Montgomery, Ann D.

    1996-01-01

    The logistics of space programs and its history within NASA are discussed, with emphasis on manned space flight and the Space Shuttle program. The lessons learned and the experience gained during these programs are reported on. Key elements of logistics are highlighted, and the problems and issues that can be expected to arise in relation to the support of long-term space operations and future space programs, are discussed. Such missions include the International Space Station program and the reusable launch vehicle. Possible solutions to the problems identified are outlined.

  3. On an approximate method for the delay logistic equation

    NASA Astrophysics Data System (ADS)

    Röst, Gergely

    2011-09-01

    This note concerns with the asymptotic properties of solutions of the delay logistic equation. In particular, we point out some false statements in the recent paper Khan et al. [Khan H, Liao SJ, Mohapatra RN, Vajravelu K. An analytical solution for a nonlinear time-delay model in biology. Commun Nonlinear Sci Numer Simulat 2009;14:3141-3148]. Moreover, we show that the author's method is not able to reveal the basic and important features of the dynamics of the delay logistic equation, and gives misleading results.

  4. Analysis of sparse data in logistic regression in medical research: A newer approach

    PubMed Central

    Devika, S; Jeyaseelan, L; Sebastian, G

    2016-01-01

    Background and Objective: In the analysis of dichotomous type response variable, logistic regression is usually used. However, the performance of logistic regression in the presence of sparse data is questionable. In such a situation, a common problem is the presence of high odds ratios (ORs) with very wide 95% confidence interval (CI) (OR: >999.999, 95% CI: <0.001, >999.999). In this paper, we addressed this issue by using penalized logistic regression (PLR) method. Materials and Methods: Data from case-control study on hyponatremia and hiccups conducted in Christian Medical College, Vellore, Tamil Nadu, India was used. The outcome variable was the presence/absence of hiccups and the main exposure variable was the status of hyponatremia. Simulation dataset was created with different sample sizes and with a different number of covariates. Results: A total of 23 cases and 50 controls were used for the analysis of ordinary and PLR methods. The main exposure variable hyponatremia was present in nine (39.13%) of the cases and in four (8.0%) of the controls. Of the 23 hiccup cases, all were males and among the controls, 46 (92.0%) were males. Thus, the complete separation between gender and the disease group led into an infinite OR with 95% CI (OR: >999.999, 95% CI: <0.001, >999.999) whereas there was a finite and consistent regression coefficient for gender (OR: 5.35; 95% CI: 0.42, 816.48) using PLR. After adjusting for all the confounding variables, hyponatremia entailed 7.9 (95% CI: 2.06, 38.86) times higher risk for the development of hiccups as was found using PLR whereas there was an overestimation of risk OR: 10.76 (95% CI: 2.17, 53.41) using the conventional method. Simulation experiment shows that the estimated coverage probability of this method is near the nominal level of 95% even for small sample sizes and for a large number of covariates. Conclusions: PLR is almost equal to the ordinary logistic regression when the sample size is large and is superior in

  5. Correlates of household seismic hazard adjustment adoption.

    PubMed

    Lindell, M K; Whitney, D J

    2000-02-01

    This study examined the relationships of self-reported adoption of 12 seismic hazard adjustments (pre-impact actions to reduce danger to persons and property) with respondents' demographic characteristics, perceived risk, perceived hazard knowledge, perceived protection responsibility, and perceived attributes of the hazard adjustments. Consistent with theoretical predictions, perceived attributes of the hazard adjustments differentiated among the adjustments and had stronger correlations with adoption than any of the other predictors. These results identify the adjustments and attributes that emergency managers should address to have the greatest impact on improving household adjustment to earthquake hazard. PMID:10795335

  6. Adjustable extender for instrument module

    DOEpatents

    Sevec, J.B.; Stein, A.D.

    1975-11-01

    A blank extender module used to mount an instrument module in front of its console for repair or test purposes has been equipped with a rotatable mount and means for locking the mount at various angles of rotation for easy accessibility. The rotatable mount includes a horizontal conduit supported by bearings within the blank module. The conduit is spring-biased in a retracted position within the blank module and in this position a small gear mounted on the conduit periphery is locked by a fixed pawl. The conduit and instrument mount can be pulled into an extended position with the gear clearing the pawl to permit rotation and adjustment of the instrument.

  7. 77 FR 5788 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application Take notice that on January 27, 2012, PetroLogistics Natural Gas Storage, LLC (PetroLogistics), 4470 Bluebonnet... previously filed application in Docket No. CP11-50-000. Specifically, PetroLogistics request to amend...

  8. 76 FR 544 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-05

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application December 28, 2010. Take notice that on December 14, 2010, PetroLogistics Natural Gas Storage, LLC (PetroLogistics... parallel PetroLogistics' existing header; (3) constructing two new compressor units, totaling...

  9. 77 FR 20618 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-05

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application Take notice that on March 22, 2012, PetroLogistics Natural Gas Storage, LLC (PetroLogistics), 4470 Bluebonnet Blvd..., and CP07-429-000, as amended in Docket No. CP10-66-000. Specifically, PetroLogistics request to...

  10. 75 FR 43944 - Membership of the Defense Logistics Agency (DLA) Senior Executive Service (SES) Performance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... Defense Logistics Agency Membership of the Defense Logistics Agency (DLA) Senior Executive Service (SES... 16, 2010. ADDRESSES: Defense Logistics Agency, 8725 John J. Kingman Road, Suite 2533, Fort Belvoir... Resources (J-14), Defense Logistics Agency, (703) 767-6447. SUPPLEMENTARY INFORMATION: In accordance with...

  11. 75 FR 49917 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application August 3, 2010. Take notice that on July 21, 2010, PetroLogistics Natural Gas Storage, LLC (PetroLogistics), 4470..., measuring, and appurtenant facilities in order to connect the cavern to PetroLogistics' existing...

  12. On the Usefulness of a Multilevel Logistic Regression Approach to Person-Fit Analysis

    ERIC Educational Resources Information Center

    Conijn, Judith M.; Emons, Wilco H. M.; van Assen, Marcel A. L. M.; Sijtsma, Klaas

    2011-01-01

    The logistic person response function (PRF) models the probability of a correct response as a function of the item locations. Reise (2000) proposed to use the slope parameter of the logistic PRF as a person-fit measure. He reformulated the logistic PRF model as a multilevel logistic regression model and estimated the PRF parameters from this…

  13. 76 FR 53119 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-25

    ... of Availability (NOA) in the Federal Register (76 FR 28757) announcing the revised Defense Logistics... Office of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense....

  14. 77 FR 22576 - Possible Revocation of Ocean Transportation Intermediary License No. 021899-Trans World Logistics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Possible Revocation of Ocean Transportation Intermediary License No. 021899--Trans World Logistics Corporation; Order To Show Cause Trans World Logistics Corporation (Trans World Logistics) is an Indiana... Licensing (BCL) indicate that Trans World Logistics maintains its principal offices at 702 Penny...

  15. 77 FR 52713 - PetroLogistics Natural Gas Storage, LLC; Notice of Request Under Blanket Authorization

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Request Under Blanket Authorization Take notice that on August 17, 2012, PetroLogistics Natural Gas Storage, LLC (PetroLogistics... Iberville Parish, Louisiana, under PetroLogistics' blanket certificate issued in Docket No. CP07-427-000,...

  16. Segment of Challenger's right wing unloaded at KSC Logistics Facility

    NASA Technical Reports Server (NTRS)

    1986-01-01

    a 9'7' x 16' segment of Challenger's right wing is unloaded at the Logistics Facility after being off-loaded from the rescue and salvage ship USS Opportune. It was located and recovered by Navy divers from the Opportune about 12 nautical miles northeast of Cape Canaveral in 70 feet of water.

  17. Re-Purposing Google Maps Visualisation for Teaching Logistics Systems

    ERIC Educational Resources Information Center

    Cheong, France; Cheong, Christopher; Jie, Ferry

    2012-01-01

    Routing is the process of selecting appropriate paths and ordering waypoints in a network. It plays an important part in logistics and supply chain management as choosing the optimal route can minimise distribution costs. Routing optimisation, however, is a difficult problem to solve and computer software is often used to determine the best route.…

  18. Logistics modeling of future solid waste storage, treatment, and disposal

    SciTech Connect

    Holter, G.M.; Stiles, D.L.; Shaver, S.R.; Armacost, L.L.

    1993-11-01

    Logistics modeling is a powerful analytical technique for effective planning of waste storage, treatment, and disposal activities. Logistics modeling facilitates analyses of alternate scenarios for future waste flows, facility schedules, and processing or handling capacities. These analyses provide an increased understanding of the specific needs for waste storage, treatment, and disposal while adequate time remains to plan accordingly. They also help to determine the sensitivity of these needs to various system parameters. This paper discusses a logistics modeling system developed by the Pacific Northwest Laboratory (PNL) to aid in solid waste planning for a large industrial complex managing many different types and classifications of waste. The basic needs for such a system are outlined, and the approach adopted in developing the system is described. A key component of this approach is the development of a conceptual model that provides a flexible framework for modeling the waste management system and addressing the range of logistics and economic issues involved. Developing an adequate description of the waste management system being analyzed is discussed. Examples are then provided of the types of analyses that have been conducted. The potential application of this modeling system to different settings is also examined.

  19. The imperative for stronger vaccine supply and logistics systems.

    PubMed

    Zaffran, Michel; Vandelaer, Jos; Kristensen, Debra; Melgaard, Bjørn; Yadav, Prashant; Antwi-Agyei, K O; Lasher, Heidi

    2013-04-18

    With the introduction of new vaccines, developing countries are facing serious challenges in their vaccine supply and logistics systems. Storage capacity bottlenecks occur at national, regional, and district levels and system inefficiencies threaten vaccine access, availability, and quality. As countries adopt newer and more expensive vaccines and attempt to reach people at different ages and in new settings, their logistics systems must be strengthened and optimized. As a first step, national governments, donors, and international agencies have crafted a global vision for 2020 vaccine supply and logistics systems with detailed plans of action to achieve five priority objectives. Vaccine products and packaging are designed to meet the needs of developing countries. Immunization supply systems support efficient and effective vaccine delivery. The environmental impact of energy, materials, and processes used in immunization systems is minimized. Immunization information systems enable better and more timely decision-making. Competent and motivated personnel are empowered to handle immunization supply chain issues. Over the next decade, vaccine supply and logistics systems in nearly all developing countries will require significant investments of time and resources from global and national partners, donors, and governments. These investments are critical if we are to reach more people with current and newer vaccines. PMID:23598495

  20. "Contested Rights": The Pedagogy and Logistics of Hosting Constitution Day

    ERIC Educational Resources Information Center

    Miracle, Amanda; Smith, Michael; Anderson, Kevin; Catlett, Rob

    2016-01-01

    To seriously consider one's rights under the US Constitution, one must grapple with the realization that many rights are not absolute. Instead, they are contested. But how to introduce younger students to such a complex concept, given short attention spans? In this article, we discuss the opportunities, pitfalls, and planning logistics of the 2013…

  1. Deciphering an Image Cipher Based on Mixed Transformed Logistic Maps

    NASA Astrophysics Data System (ADS)

    Liu, Yuansheng; Fan, Hua; Xie, Eric Yong; Cheng, Ge; Li, Chengqing

    2015-12-01

    Since John von Neumann suggested utilizing Logistic map as a random number generator in 1947, a great number of encryption schemes based on Logistic map and/or its variants have been proposed. This paper re-evaluates the security of an image cipher based on transformed logistic maps and proves that the image cipher can be deciphered efficiently under two different conditions: (1) two pairs of known plain-images and the corresponding cipher-images with computational complexity of O(218 + L); (2) two pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(L), where L is the number of pixels in the plain-image. In contrast, the required condition in the previous deciphering method is 87 pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(27 + L). In addition, three other security flaws existing in most Logistic-map-based ciphers are also reported.

  2. Modeling logistic performance in quantitative microbial risk assessment.

    PubMed

    Rijgersberg, Hajo; Tromp, Seth; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2010-01-01

    In quantitative microbial risk assessment (QMRA), food safety in the food chain is modeled and simulated. In general, prevalences, concentrations, and numbers of microorganisms in media are investigated in the different steps from farm to fork. The underlying rates and conditions (such as storage times, temperatures, gas conditions, and their distributions) are determined. However, the logistic chain with its queues (storages, shelves) and mechanisms for ordering products is usually not taken into account. As a consequence, storage times-mutually dependent in successive steps in the chain-cannot be described adequately. This may have a great impact on the tails of risk distributions. Because food safety risks are generally very small, it is crucial to model the tails of (underlying) distributions as accurately as possible. Logistic performance can be modeled by describing the underlying planning and scheduling mechanisms in discrete-event modeling. This is common practice in operations research, specifically in supply chain management. In this article, we present the application of discrete-event modeling in the context of a QMRA for Listeria monocytogenes in fresh-cut iceberg lettuce. We show the potential value of discrete-event modeling in QMRA by calculating logistic interventions (modifications in the logistic chain) and determining their significance with respect to food safety. PMID:20055976

  3. Vehicle scheduling schemes for commercial and emergency logistics integration.

    PubMed

    Li, Xiaohui; Tan, Qingmei

    2013-01-01

    In modern logistics operations, large-scale logistics companies, besides active participation in profit-seeking commercial business, also play an essential role during an emergency relief process by dispatching urgently-required materials to disaster-affected areas. Therefore, an issue has been widely addressed by logistics practitioners and caught researchers' more attention as to how the logistics companies achieve maximum commercial profit on condition that emergency tasks are effectively and performed satisfactorily. In this paper, two vehicle scheduling models are proposed to solve the problem. One is a prediction-related scheme, which predicts the amounts of disaster-relief materials and commercial business and then accepts the business that will generate maximum profits; the other is a priority-directed scheme, which, firstly groups commercial and emergency business according to priority grades and then schedules both types of business jointly and simultaneously by arriving at the maximum priority in total. Moreover, computer-based simulations are carried out to evaluate the performance of these two models by comparing them with two traditional disaster-relief tactics in China. The results testify the feasibility and effectiveness of the proposed models. PMID:24391724

  4. Vehicle Scheduling Schemes for Commercial and Emergency Logistics Integration

    PubMed Central

    Li, Xiaohui; Tan, Qingmei

    2013-01-01

    In modern logistics operations, large-scale logistics companies, besides active participation in profit-seeking commercial business, also play an essential role during an emergency relief process by dispatching urgently-required materials to disaster-affected areas. Therefore, an issue has been widely addressed by logistics practitioners and caught researchers' more attention as to how the logistics companies achieve maximum commercial profit on condition that emergency tasks are effectively and performed satisfactorily. In this paper, two vehicle scheduling models are proposed to solve the problem. One is a prediction-related scheme, which predicts the amounts of disaster-relief materials and commercial business and then accepts the business that will generate maximum profits; the other is a priority-directed scheme, which, firstly groups commercial and emergency business according to priority grades and then schedules both types of business jointly and simultaneously by arriving at the maximum priority in total. Moreover, computer-based simulations are carried out to evaluate the performance of these two models by comparing them with two traditional disaster-relief tactics in China. The results testify the feasibility and effectiveness of the proposed models. PMID:24391724

  5. Stability analysis of a stochastic logistic model with infinite delay

    NASA Astrophysics Data System (ADS)

    Liu, Meng; Fan, Dejun; Wang, Ke

    2013-09-01

    This report is concerned with a stochastic logistic equation with infinite delay. We establish the sufficient conditions for global asymptotical stability of the zero solution and the positive equilibrium. Some classical results are improved and extended. Several numerical simulations are introduced to illustrate the main results.

  6. Dynamics of strongly coupled spatially distributed logistic equations with delay

    NASA Astrophysics Data System (ADS)

    Kashchenko, I. S.; Kashchenko, S. A.

    2015-04-01

    The dynamics of a system of two logistic delay equations with spatially distributed coupling is studied. The coupling coefficient is assumed to be sufficiently large. Special nonlinear systems of parabolic equations are constructed such that the behavior of their solutions is determined in the first approximation by the dynamical properties of the original system.

  7. Flower Power: Sunflowers as a Model for Logistic Growth

    ERIC Educational Resources Information Center

    Fernandez, Eileen; Geist, Kristi A.

    2011-01-01

    Logistic growth displays an interesting pattern: It starts fast, exhibiting the rapid growth characteristic of exponential models. As time passes, it slows in response to constraints such as limited resources or reallocation of energy. The growth continues to slow until it reaches a limit, called capacity. When the growth describes a population,…

  8. Sourcing for Parameter Estimation and Study of Logistic Differential Equation

    ERIC Educational Resources Information Center

    Winkel, Brian J.

    2012-01-01

    This article offers modelling opportunities in which the phenomena of the spread of disease, perception of changing mass, growth of technology, and dissemination of information can be described by one differential equation--the logistic differential equation. It presents two simulation activities for students to generate real data, as well as…

  9. Detecting Differential Item Functioning Using Logistic Regression Procedures.

    ERIC Educational Resources Information Center

    Swaminathan, Hariharan; Rogers, H. Jane

    1990-01-01

    A logistic regression model for characterizing differential item functioning (DIF) between two groups is presented. A distinction is drawn between uniform and nonuniform DIF in terms of model parameters. A statistic for testing the hypotheses of no DIF is developed, and simulation studies compare it with the Mantel-Haenszel procedure. (Author/TJH)

  10. Charter Starters Leadership Training Workbook 1: Start-Up Logistics.

    ERIC Educational Resources Information Center

    Ley, Joyce

    This workbook is the first in a series devoted to all areas of charter-school development. It addresses the logistics of starting a school, such as drafting a charter, creating a vision and mission, accessing expert information, navigating the application process, acquiring a facility, establishing a legal entity, and contracting for services. The…

  11. 77 FR 39662 - Hazardous Materials; Reverse Logistics (RRR)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... final rule issued under docket HM-215K (76 FR 3308, January 19, 2011), PHMSA began phasing out the ORM-D... Federal Register published on April 11, 2000 (65 FR 19477) or you may visit http://www.dot.gov/privacy... an NPRM that will propose to simplify the regulations for reverse logistics shipments and...

  12. Hierarchical Logistic Regression: Accounting for Multilevel Data in DIF Detection

    ERIC Educational Resources Information Center

    French, Brian F.; Finch, W. Holmes

    2010-01-01

    The purpose of this study was to examine the performance of differential item functioning (DIF) assessment in the presence of a multilevel structure that often underlies data from large-scale testing programs. Analyses were conducted using logistic regression (LR), a popular, flexible, and effective tool for DIF detection. Data were simulated…

  13. Co-integration Model of Logistics Infrastructure Investment and Regional Economic Growth in Central China

    NASA Astrophysics Data System (ADS)

    Hu, Kai; Gan, Xiao-qing; Gao, Kuo

    The speed of logistics infrastructures investment in Central China is still lower than other regions since the rise of the central region strategy was put forward. And the ration of freight turnover was also being down. The analysis with the relations among the central region of the logistics investment, logistics value-added and GDP, found that three variables exists co-integration relation. And found that the investment in logistics infrastructure was the Granger reason of the GDP, the investment in logistics infrastructure and logistics value-added was the Granger reason for each other. According to the analysis, some countermeasures be put forward as following: accelerate the speed of logistics investment, optimize logistics environment, promote the logistics capability, reduce logistics cost, and so on.

  14. Adjusting the Contour of Reflector Panels

    NASA Technical Reports Server (NTRS)

    Palmer, W. B.; Giebler, M. M.

    1984-01-01

    Postfabrication adjustment of contour of panels for reflector, such as parabolic reflector for radio antennas, possible with simple mechanism consisting of threaded stud, two nuts, and flexure. Contours adjusted manually.

  15. 48 CFR 1450.103 - Contract adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract adjustments. 1450.103 Section 1450.103 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT... Contract adjustments....

  16. Cognitive modeling to predict video interpretability

    NASA Astrophysics Data System (ADS)

    Young, Darrell L.; Bakir, Tariq

    2011-06-01

    Processing framework for cognitive modeling to predict video interpretability is discussed. Architecture consists of spatiotemporal video preprocessing, metric computation, metric normalization, pooling of like metric groups with masking adjustments, multinomial logistic pooling of Minkowski pooled groups of similar quality metrics, and estimation of confidence interval of final result.

  17. 76 FR 4395 - Postal Service Price Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ... Postal Service Price Adjustment AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: The Commission is noticing a recently-filed Postal Service request to establish price adjustments for all market... with the Commission announcing price adjustments, effective April 17, 2011, affecting all...

  18. 12 CFR 1780.80 - Inflation adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Inflation adjustments. 1780.80 Section 1780.80... DEVELOPMENT RULES OF PRACTICE AND PROCEDURE RULES OF PRACTICE AND PROCEDURE Civil Money Penalty Inflation Adjustments § 1780.80 Inflation adjustments. The maximum amount of each civil money penalty within...

  19. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION § 36.2..., Section 36.2—Civil Monetary Penalty Inflation Adjustments Statute Description New maximum (and minimum,...

  20. 19 CFR 201.205 - Salary adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Salary adjustments. 201.205 Section 201.205 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Debt Collection § 201.205 Salary adjustments. Any negative adjustment to pay arising out of an employee's...

  1. 19 CFR 201.205 - Salary adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Salary adjustments. 201.205 Section 201.205 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Debt Collection § 201.205 Salary adjustments. Any negative adjustment to pay arising out of an employee's...

  2. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION § 36.2..., Section 36.2—Civil Monetary Penalty Inflation Adjustments Statute Description New maximum (and minimum,...

  3. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION § 36.2..., Section 36.2—Civil Monetary Penalty Inflation Adjustments Statute Description New maximum (and minimum,...

  4. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION § 36.2..., Section 36.2—Civil Monetary Penalty Inflation Adjustments Statute Description New maximum (and minimum,...

  5. 34 CFR 36.2 - Penalty adjustment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false Penalty adjustment. 36.2 Section 36.2 Education Office of the Secretary, Department of Education ADJUSTMENT OF CIVIL MONETARY PENALTIES FOR INFLATION § 36.2..., Section 36.2—Civil Monetary Penalty Inflation Adjustments Statute Description New maximum (and minimum,...

  6. 12 CFR 1780.80 - Inflation adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Inflation adjustments. 1780.80 Section 1780.80... DEVELOPMENT RULES OF PRACTICE AND PROCEDURE RULES OF PRACTICE AND PROCEDURE Civil Money Penalty Inflation Adjustments § 1780.80 Inflation adjustments. The maximum amount of each civil money penalty within...

  7. Adjustment to College in Students with ADHD

    ERIC Educational Resources Information Center

    Rabiner, David L.; Anastopoulos, Arthur D.; Costello, Jane; Hoyle, Rick H.; Swartzwelder, H. Scott

    2008-01-01

    Objective: To examine college adjustment in students reporting an ADHD diagnosis and the effect of medication treatment on students' adjustment. Method: 1,648 first-semester freshmen attending a public and a private university completed a Web-based survey to examine their adjustment to college. Results: Compared with 200 randomly selected control…

  8. Dimensions of Adjustment among College Women.

    ERIC Educational Resources Information Center

    Tomlinson-Clarke, Saundra

    1998-01-01

    Examines academic, social, and personal-emotional adjustment, as well as institutional attachment for women (N=198) attending a predominantly white coeducational research university. Significant main effects were found on academic achievement for year in college. Students differed on personal-emotional adjustment by race. Academic adjustment and…

  9. LOGISTIC FUNCTION PROFILE FIT: A least-squares program for fitting interface profiles to an extended logistic function

    SciTech Connect

    Kirchhoff, William H.

    2012-09-15

    The extended logistic function provides a physically reasonable description of interfaces such as depth profiles or line scans of surface topological or compositional features. It describes these interfaces with the minimum number of parameters, namely, position, width, and asymmetry. Logistic Function Profile Fit (LFPF) is a robust, least-squares fitting program in which the nonlinear extended logistic function is linearized by a Taylor series expansion (equivalent to a Newton-Raphson approach) with no apparent introduction of bias in the analysis. The program provides reliable confidence limits for the parameters when systematic errors are minimal and provides a display of the residuals from the fit for the detection of systematic errors. The program will aid researchers in applying ASTM E1636-10, 'Standard practice for analytically describing sputter-depth-profile and linescan-profile data by an extended logistic function,' and may also prove useful in applying ISO 18516: 2006, 'Surface chemical analysis-Auger electron spectroscopy and x-ray photoelectron spectroscopy-determination of lateral resolution.' Examples are given of LFPF fits to a secondary ion mass spectrometry depth profile, an Auger surface line scan, and synthetic data generated to exhibit known systematic errors for examining the significance of such errors to the extrapolation of partial profiles.

  10. COOPERATION MAINTAINED BY FITNESS ADJUSTMENT

    PubMed Central

    TAYLOR, CHRISTINE; CHEN, JANET; IWASA, YOH

    2008-01-01

    Questions Whether or not cooperation can be enhanced if players with a performance higher than the mean are forced to pay an additional cost in each generation? Mathematical Methods Analysis of replicator dynamics with mutation. The ESS distribution of cooperation level is obtained. Key Assumptions Players engage in cooperative dilemma game, and at the end of each generation, those with higher performance than the mean are forced to pay additional cost. Conclusions Without mutation, the entire population eventually conforms to a single cooperation level determined by the initial composition of the population. With mutation, there is an equilibrium distribution of cooperation level, which has a peak at an intermediate level of cooperation. Whether it is institutionalized such as tax or just a social custom, fitness adjustment based ultimately on people’s emtion of “envy” is able to maintain cooperation. PMID:19079742

  11. The Soufriere Hills Volcano, Montserrat, is "log logistic"

    NASA Astrophysics Data System (ADS)

    Connor, C.; Sparks, S.; Mason, R.; Bonadonna, C.; Young, S.; Lejeune, A.

    2002-12-01

    The Soufriere Hills Volcano, Montserrat, experienced a remarkable episode of activity in September-October, 1997. During this period, 75 vulcanian explosions generated plumes that commonly rose between 5 to 15 km a.s.l. accompanied by pyroclastic flows. Repose intervals between vulcanian explosions varied from 2.77 to 33.7 hrs, with a median repose interval of 9.0 hr and mean of 9.6 hr. During the eruption, this narrow range of repose intervals was used in a practical way to provide qualitative forecasts of volcanic hazard. We analyzed repose intervals for these 75 vulcanian explosions and discovered they fit a log logistic distribution with > 99% confidence. This comparatively simple, two parameter model accounts for departures from a classical material failure model (Weibull distribution) at long repose intervals, and serves as the basis for improved hazard forecasts. The crucial differences between Weibull, and log logistic probability models for volcano repose interval are illustrated by comparing their hazard functions. For Weibull distributions the hazard increases indefinitely: the volcano must erupt explosively eventually and as time increases the probability of an eruption in the next time interval becomes much greater. In contrast the log logistic hazard function goes through a simple maximum. We note that largest magnitude eruptions in the time series, deduced from column height estimates and seismic explosion amplitudes, correlate with the peak in the log logistic hazard function. The excellent model fit is explained in terms of two competing processes operating in the upper conduit on different time scales. Gas bubble pressure increases with time due to exsolution and due to rheological stiffening of magma of magma following an abrupt decompression caused by a previous explosion. Once bubble gas pressure exceeds the tensile strength of the magma an explosion occurs - a material failure model that should follow a Weibull distribution. However, this

  12. Ariane Transfer Vehicle - Logistic support to Space Station Freedom

    NASA Astrophysics Data System (ADS)

    Cougnet, C.; Ricaud, C.; Deutscher, N.

    The attractiveness of the Ariane 5 and Ariane transfer vehicle (ATV) is described: it avoids the one-sidedness of the National STS, it increases the lift capacity to meet the demands of the Space Station, and it offers a system independent of, but consistent with, the STS in providing backup contingency capability. The Ariane 5/ATV system is able to launch and transfer any cargo module to the Space Station Freedom (SSF) and dispose of it at the end of the mission. Consideration is given to Space Station and SSF logistic support, and ATV operations and design. Diagrams are provided to illustrate the ATV's requirements and capability; an ATV mission toward the SSF; ATV design and components; the ATV's attitude, layout, and the architecture of the main propulsion system and avionic; and the ATV's performance. It is demonstrated that the Ariane 5/ATV system would be an adequate complement to the NSTS for logistic support of the SSF.

  13. In-space propellant logistics. Volume 4: Project planning data

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The prephase A conceptual project planning data as it pertains to the development of the selected logistics module configuration transported into earth orbit by the space shuttle orbiter. The data represents the test, implementation, and supporting research and technology requirements for attaining the propellant transfer operational capability for early 1985. The plan is based on a propellant module designed to support the space-based tug with cryogenic oxygen-hydrogen propellants. A logical sequence of activities that is required to define, design, develop, fabricate, test, launch, and flight test the propellant logistics module is described. Included are the facility and ground support equipment requirements. The schedule of activities are based on the evolution and relationship between the R and T, the development issues, and the resultant test program.

  14. Interacting Bose gas, the logistic law, and complex networks

    NASA Astrophysics Data System (ADS)

    Sowa, A.

    2015-01-01

    We discuss a mathematical link between the Quantum Statistical Mechanics and the logistic growth and decay processes. It is based on an observation that a certain nonlinear operator evolution equation, which we refer to as the Logistic Operator Equation (LOE), provides an extension of the standard model of noninteracting bosons. We discuss formal solutions (asymptotic formulas) for a special calibration of the LOE, which sets it in the number-theoretic framework. This trick, in the tradition of Julia and Bost-Connes, makes it possible for us to tap into the vast resources of classical mathematics and, in particular, to construct explicit solutions of the LOE via the Dirichlet series. The LOE is applicable to a range of modeling and simulation tasks, from characterization of interacting boson systems to simulation of some complex man-made networks. The theoretical results enable numerical simulations, which, in turn, shed light at the unique complexities of the rich and multifaceted models resulting from the LOE.

  15. Antibiotic lock therapy: review of technique and logistical challenges

    PubMed Central

    Justo, Julie Ann; Bookstaver, P Brandon

    2014-01-01

    Antibiotic lock therapy (ALT) for the prevention and treatment of catheter-related bloodstream infections is a simple strategy in theory, yet its real-world application may be delayed or avoided due to technical questions and/or logistical challenges. This review focuses on these latter aspects of ALT, including preparation information for a variety of antibiotic lock solutions (ie, aminoglycosides, beta-lactams, fluoroquinolones, folate antagonists, glycopeptides, glycylcyclines, lipopeptides, oxazolidinones, polymyxins, and tetracyclines) and common clinical issues surrounding ALT administration. Detailed data regarding concentrations, additives, stability/compatibility, and dwell times are summarized. Logistical challenges such as lock preparation procedures, use of additives (eg, heparin, citrate, or ethylenediaminetetraacetic acid), timing of initiation and therapy duration, optimal dwell time and catheter accessibility, and risks of ALT are also described. Development of local protocols is recommended in order to avoid these potential barriers and encourage utilization of ALT where appropriate. PMID:25548523

  16. Applying simulation and logistics modeling to tansportation issues

    SciTech Connect

    Funkhouser, B.R.; Ballweg, E.L.; Mackoy, R.D.

    1995-08-15

    This paper describes an application where transportation logistics and simulation tools are integrated to create a modeling environment for transportation planning. The Transportation Planning Model (TPM) is a tool developed for the Department of Energy (DOE) to aid in the long-term planning of their transportation resources. The focus of the tool is to aid DOE and Sandia National Laboratory analysts in the planning of future fleet sizes, driver and support personnel sizes, base site locations, and resource balancing among the base sites. The design approach is to develop a rapid modeling environment which integrates graphical user interfaces, logistics optimizing tools, and simulation modeling. Using the TPM an analyst can easily set up a shipment scenario and perform multiple ``What If`` evaluations. The TPM has been developed on personal computers using commercial off-the-shelf software tools under the WINDOW{reg_sign} operating environment.

  17. In-space propellant logistics. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The study addresses the systems and operational problems associated with the transport, transfer, and storage of cryogenic propellants in low earth orbits. The safety problems connected with in-space propellant logistics operations are also considered.Correlation between the two projects was maintained by including safety considerations, resulting from the system safety analysis, in the trade studies and evaluations of alternate operating concepts in the systems operations analysis.

  18. Security controls in the Stockpoint Logistics Integrated Communications Environment (SPLICE)

    NASA Astrophysics Data System (ADS)

    Arseneault, D. S.

    1985-03-01

    This thesis examines security controls specified and implemented in the Stock Point Logistics Integrated Communications Environment (SPLICE) project. Controls provided by the Defense Data Network and the Tandem operating system are reviewed. Alternatives from current literature in areas of authentication, encryption, and dial-port protection are reviewed for the purpose of suggesting enhancements. Issues discussed apply to most interactive/decentralized systems in operation today and include administrative as well as technical recommendations.

  19. Logistics Operations Management Center: Maintenance Support Baseline (LOMC-MSB)

    NASA Technical Reports Server (NTRS)

    Kurrus, R.; Stump, F.

    1995-01-01

    The Logistics Operations Management Center Maintenance Support Baseline is defined. A historical record of systems, applied to and deleted from, designs in support of future management and/or technical analysis is provided. All Flight elements, Ground Support Equipment, Facility Systems and Equipment and Test Support Equipment for which LOMC has responsibilities at Kennedy Space Center and other locations are listed. International Space Station Alpha Program documentation is supplemented. The responsibility of the Space Station Launch Site Support Office is established.

  20. Estimating Logistics Support of Reusable Launch Vehicles During Conceptual Design

    NASA Technical Reports Server (NTRS)

    Morris, W. D.; White, N. H.; Davies, W. T.; Ebeling, C. E.

    1997-01-01

    Methods exist to define the logistics support requirements for new aircraft concepts but are not directly applicable to new launch vehicle concepts. In order to define the support requirements and to discriminate among new technologies and processing choices for these systems, NASA Langley Research Center (LaRC) is developing new analysis methods. This paper describes several methods under development, gives their current status, and discusses the benefits and limitations associated with their use.

  1. [Outliers and robust logistic regression in Health Sciences].

    PubMed

    Cutanda Henríquez, Francisco

    2008-01-01

    Logistic regression methods have many applications in Health Sciences. There is a vast literature about procedures to be followed and the way to find the estimators for the parameters from the observed values, and these methods are implemented to all the usual statistical packages. These estimators are of the 'maximum likelihood' kind, i.e., they are the ones that make the observed values the most probable among all the models that could have been used. The good properties of the maximum likelihood estimators are widely demonstrated. However, there are some practical circumstances that may cause the presence of 'outliers', i.e., observed values not corresponding to the logistic model we are assuming as a hypothesis. Occasionally, these anomalous observations can have a strong effect on the fit, and lead the study to the wrong conclusion. The causes of these outliers depend on the particular study, but it is possible to point out classification errors, observations (subjects) with special features which have not been taken into account, uncertainty in the measurement of some parameters, etc. The problem with maximum likelihood estimators is that they are not 'robust', i.e., their sensitivity to outliers could be arbitrarily large, and a minority of outliers could lead to a wrong logistic model. In this work, we will show two cases illustrating possible consequences, and we will discuss the application of robust methods. PMID:19180273

  2. Lunar Surface Architecture Utilization and Logistics Support Assessment

    NASA Astrophysics Data System (ADS)

    Bienhoff, Dallas; Findiesen, William; Bayer, Martin; Born, Andrew; McCormick, David

    2008-01-01

    Crew and equipment utilization and logistics support needs for the point of departure lunar outpost as presented by the NASA Lunar Architecture Team (LAT) and alternative surface architectures were assessed for the first ten years of operation. The lunar surface architectures were evaluated and manifests created for each mission. Distances between Lunar Surface Access Module (LSAM) landing sites and emplacement locations were estimated. Physical characteristics were assigned to each surface element and operational characteristics were assigned to each surface mobility element. Stochastic analysis was conducted to assess probable times to deploy surface elements, conduct exploration excursions, and perform defined crew activities. Crew time is divided into Outpost-related, exploration and science, overhead, and personal activities. Outpost-related time includes element deployment, EVA maintenance, IVA maintenance, and logistics resupply. Exploration and science activities include mapping, geological surveys, science experiment deployment, sample analysis and categorizing, and physiological and biological tests in the lunar environment. Personal activities include sleeping, eating, hygiene, exercising, and time off. Overhead activities include precursor or close-out tasks that must be accomplished but don't fit into the other three categories such as: suit donning and doffing, airlock cycle time, suit cleaning, suit maintenance, post-landing safing actions, and pre-departure preparations. Equipment usage time, spares, maintenance actions, and Outpost consumables are also estimated to provide input into logistics support planning. Results are normalized relative to the NASA LAT point of departure lunar surface architecture.

  3. Automatic Ammunition Identification Technology Project. Ammunition Logistics Program

    SciTech Connect

    Weil, B.

    1993-03-01

    The Automatic Ammunition Identification Technology (AAIT) Project is an activity of the Robotics & Process Systems Division at the Oak Ridge National Laboratory (ORNL) for the US Army`s Project Manager-Ammunition Logistics (PM-AMMOLOG) at the Picatinny Arsenal in Picatinny, New Jersey. The project objective is to evaluate new two-dimensional bar code symbologies for potential use in ammunition logistics systems and automated reloading equipment. These new symbologies are a significant improvement over typical linear bar codes since machine-readable alphanumeric messages up to 2000 characters long are achievable. These compressed data symbologies are expected to significantly improve logistics and inventory management tasks and permit automated feeding and handling of ammunition to weapon systems. The results will be increased throughout capability, better inventory control, reduction of human error, lower operation and support costs, and a more timely re-supply of various weapon systems. This paper will describe the capabilities of existing compressed data symbologies and the symbol testing activities being conducted at ORNL for the AAIT Project.

  4. Classifying machinery condition using oil samples and binary logistic regression

    NASA Astrophysics Data System (ADS)

    Phillips, J.; Cripps, E.; Lau, John W.; Hodkiewicz, M. R.

    2015-08-01

    The era of big data has resulted in an explosion of condition monitoring information. The result is an increasing motivation to automate the costly and time consuming human elements involved in the classification of machine health. When working with industry it is important to build an understanding and hence some trust in the classification scheme for those who use the analysis to initiate maintenance tasks. Typically "black box" approaches such as artificial neural networks (ANN) and support vector machines (SVM) can be difficult to provide ease of interpretability. In contrast, this paper argues that logistic regression offers easy interpretability to industry experts, providing insight to the drivers of the human classification process and to the ramifications of potential misclassification. Of course, accuracy is of foremost importance in any automated classification scheme, so we also provide a comparative study based on predictive performance of logistic regression, ANN and SVM. A real world oil analysis data set from engines on mining trucks is presented and using cross-validation we demonstrate that logistic regression out-performs the ANN and SVM approaches in terms of prediction for healthy/not healthy engines.

  5. Evaluating sediment chemistry and toxicity data using logistic regression modeling

    USGS Publications Warehouse

    Field, L.J.; MacDonald, D.D.; Norton, S.B.; Severn, C.G.; Ingersoll, C.G.

    1999-01-01

    This paper describes the use of logistic-regression modeling for evaluating matching sediment chemistry and toxicity data. Contaminant- specific logistic models were used to estimate the percentage of samples expected to be toxic at a given concentration. These models enable users to select the probability of effects of concern corresponding to their specific assessment or management objective or to estimate the probability of observing specific biological effects at any contaminant concentration. The models were developed using a large database (n = 2,524) of matching saltwater sediment chemistry and toxicity data for field-collected samples compiled from a number of different sources and geographic areas. The models for seven chemicals selected as examples showed a wide range in goodness of fit, reflecting high variability in toxicity at low concentrations and limited data on toxicity at higher concentrations for some chemicals. The models for individual test endpoints (e.g., amphipod mortality) provided a better fit to the data than the models based on all endpoints combined. A comparison of the relative sensitivity of two amphipod species to specific contaminants illustrated an important application of the logistic model approach.

  6. Emergency management logistics must become emergency supply chain management.

    PubMed

    Young, Richard R; Peterson, Matthew R

    2014-01-01

    Much has been written about how emergency management (EM) needs to look to the future regarding issues of resource management (monetary, human, and material). Constraints on budgets are ongoing and the staffing of emergency response activities is often difficult because volunteers have little to no training. The management of material resources has also been a challenge because 1) the categories of material vary by the type of emergency, 2) the necessary quantities of material are often not located near the ultimate point of need, and 3) the transportation assets are rarely available in the form and quantity required to allow timely and effective response. The logistics and resource management functions of EM (what we refer to as EM logistics) have been largely reactive, with little to no pre-event planning for potential demand. We applied the Supply Chain Operational Reference (SCOR) model to EM logistics in an effort to transform it to an integrated and scalable system of physical, information, and financial flows into which are woven the functions of sourcing, making, delivering, and returning, with an overarching planning function that transcends the organizational boundaries of participants. The result is emergency supply chain management, which embraces many more participants who share in a larger quantity of more useful information about the resources that need to be deployed when responding to and recovering from emergency events. PMID:24828913

  7. Logistics Process Analysis ToolProcess Analysis Tool

    2008-03-31

    LPAT is the resulting integrated system between ANL-developed Enhanced Logistics Intra Theater Support Tool (ELIST) sponsored by SDDC-TEA and the Fort Future Virtual Installation Tool (sponsored by CERL). The Fort Future Simulation Engine was an application written in the ANL Repast Simphony framework and used as the basis for the process Anlysis Tool (PAT) which evolved into a stand=-along tool for detailed process analysis at a location. Combined with ELIST, an inter-installation logistics component wasmore » added to enable users to define large logistical agent-based models without having to program. PAT is the evolution of an ANL-developed software system called Fort Future Virtual Installation Tool (sponsored by CERL). The Fort Future Simulation Engine was an application written in the ANL Repast Simphony framework and used as the basis for the Process Analysis Tool(PAT) which evolved into a stand-alone tool for detailed process analysis at a location (sponsored by the SDDC-TEA).« less

  8. Exploration adjustment by ant colonies

    PubMed Central

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  9. Exploration adjustment by ant colonies.

    PubMed

    Doran, Carolina; Stumpe, Martin C; Sendova-Franks, Ana; Franks, Nigel R

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  10. Demand Analysis of Logistics Information Matching Platform: A Survey from Highway Freight Market in Zhejiang Province

    NASA Astrophysics Data System (ADS)

    Chen, Daqiang; Shen, Xiahong; Tong, Bing; Zhu, Xiaoxiao; Feng, Tao

    With the increasing competition in logistics industry and promotion of lower logistics costs requirements, the construction of logistics information matching platform for highway transportation plays an important role, and the accuracy of platform design is the key to successful operation or not. Based on survey results of logistics service providers, customers and regulation authorities to access to information and in-depth information demand analysis of logistics information matching platform for highway transportation in Zhejiang province, a survey analysis for framework of logistics information matching platform for highway transportation is provided.

  11. The Application of the Ten Group Classification System (TGCS) in Caesarean Delivery Case Mix Adjustment. A Multicenter Prospective Study

    PubMed Central

    Maso, Gianpaolo; Alberico, Salvatore; Monasta, Lorenzo; Ronfani, Luca; Montico, Marcella; Businelli, Caterina; Soini, Valentina; Piccoli, Monica; Gigli, Carmine; Domini, Daniele; Fiscella, Claudio; Casarsa, Sara; Zompicchiatti, Carlo; De Agostinis, Michela; D'Atri, Attilio; Mugittu, Raffaela; La Valle, Santo; Di Leonardo, Cristina; Adamo, Valter; Smiroldo, Silvia; Frate, Giovanni Del; Olivuzzi, Monica; Giove, Silvio; Parente, Maria; Bassini, Daniele; Melazzini, Simona; Guaschino, Secondo; De Seta, Francesco; Demarini, Sergio; Travan, Laura; Marchesoni, Diego; Rossi, Alberto; Simon, Giorgio; Zicari, Sandro; Tamburlini, Giorgio

    2013-01-01

    Background Caesarean delivery (CD) rates are commonly used as an indicator of quality in obstetric care and risk adjustment evaluation is recommended to assess inter-institutional variations. The aim of this study was to evaluate whether the Ten Group classification system (TGCS) can be used in case-mix adjustment. Methods Standardized data on 15,255 deliveries from 11 different regional centers were prospectively collected. Crude Risk Ratios of CDs were calculated for each center. Two multiple logistic regression models were herein considered by using: Model 1- maternal (age, Body Mass Index), obstetric variables (gestational age, fetal presentation, single or multiple, previous scar, parity, neonatal birth weight) and presence of risk factors; Model 2- TGCS either with or without maternal characteristics and presence of risk factors. Receiver Operating Characteristic (ROC) curves of the multivariate logistic regression analyses were used to assess the diagnostic accuracy of each model. The null hypothesis that Areas under ROC Curve (AUC) were not different from each other was verified with a Chi Square test and post hoc pairwise comparisons by using a Bonferroni correction. Results Crude evaluation of CD rates showed all centers had significantly higher Risk Ratios than the referent. Both multiple logistic regression models reduced these variations. However the two methods ranked institutions differently: model 1 and model 2 (adjusted for TGCS) identified respectively nine and eight centers with significantly higher CD rates than the referent with slightly different AUCs (0.8758 and 0.8929 respectively). In the adjusted model for TGCS and maternal characteristics/presence of risk factors, three centers had CD rates similar to the referent with the best AUC (0.9024). Conclusions The TGCS might be considered as a reliable variable to adjust CD rates. The addition of maternal characteristics and risk factors to TGCS substantially increase the predictive

  12. Transition and protective agency of early childhood learning behaviors as portents of later school attendance and adjustment.

    PubMed

    McDermott, Paul A; Rikoon, Samuel H; Fantuzzo, John W

    2016-02-01

    This article reports on the study of differential change trajectories for early childhood learning behaviors as they relate to future classroom adjustment and school attendance. A large sample (N=2152) of Head Start children was followed through prekindergarten, kindergarten, and 1st grade. Classroom learning behaviors were assessed twice each year by teachers who observed gradual declines in Competence Motivation and Attentional Persistence as children transitioned through schooling. Cross-classified multilevel growth models revealed distinct transitional pathways for future adjustment versus maladjustment and sporadic versus chronic absenteeism. Generalized multilevel logistic modeling and receiver operating characteristic curve analyses showed that teachers' earliest assessments were substantially predictive of eventual good classroom adjustment and school attendance, with increasing accuracy for prediction of future sociobehavioral adjustment as time progressed. PMID:26790703

  13. A technique for determining viable military logistics support alternatives

    NASA Astrophysics Data System (ADS)

    Hester, Jesse Stuart

    A look at today's US military will see them operating much beyond the scope of protecting and defending the United States. These operations now consist of, but are not limited to humanitarian aid, disaster relief, peace keeping, and conflict resolution. This broad spectrum of operational environments has necessitated a transformation of the individual military services to a hybrid force that is attempting to leverage the inherent and emerging capabilities and strengths of all those under the umbrella of the Department of Defense (DOD), this concept has been coined Joint Operations. Supporting Joint Operations requires a new approach to determining a viable military logistics support system. The logistics architecture for these operations has to accommodate scale, time, varied mission objectives, and imperfect information. Compounding the problem is the human in the loop (HITL) decision maker (DM) who is a necessary component for quickly assessing and planning logistics support activities. Past outcomes are not necessarily good indicators of future results, but they can provide a reasonable starting point for planning and prediction of specific needs for future requirements. Adequately forecasting the necessary logistical support structure and commodities needed for any resource intensive environment has progressed well beyond stable demand assumptions to one in which dynamic and nonlinear environments can be captured with some degree of fidelity and accuracy. While these advances are important, a holistic approach that allows exploration of the operational environment or design space does not exist to guide the military logistician in a methodical way to support military forecasting activities. To bridge this capability gap, a method called Adaptive Technique for Logistics Architecture Solutions (ATLAS) has been developed. This method provides a process that facilitates the use of techniques and tools that filter and provide relevant information to the DM. By doing

  14. Determination of riverbank erosion probability using Locally Weighted Logistic Regression

    NASA Astrophysics Data System (ADS)

    Ioannidou, Elena; Flori, Aikaterini; Varouchakis, Emmanouil A.; Giannakis, Georgios; Vozinaki, Anthi Eirini K.; Karatzas, George P.; Nikolaidis, Nikolaos

    2015-04-01

    Riverbank erosion is a natural geomorphologic process that affects the fluvial environment. The most important issue concerning riverbank erosion is the identification of the vulnerable locations. An alternative to the usual hydrodynamic models to predict vulnerable locations is to quantify the probability of erosion occurrence. This can be achieved by identifying the underlying relations between riverbank erosion and the geomorphological or hydrological variables that prevent or stimulate erosion. Thus, riverbank erosion can be determined by a regression model using independent variables that are considered to affect the erosion process. The impact of such variables may vary spatially, therefore, a non-stationary regression model is preferred instead of a stationary equivalent. Locally Weighted Regression (LWR) is proposed as a suitable choice. This method can be extended to predict the binary presence or absence of erosion based on a series of independent local variables by using the logistic regression model. It is referred to as Locally Weighted Logistic Regression (LWLR). Logistic regression is a type of regression analysis used for predicting the outcome of a categorical dependent variable (e.g. binary response) based on one or more predictor variables. The method can be combined with LWR to assign weights to local independent variables of the dependent one. LWR allows model parameters to vary over space in order to reflect spatial heterogeneity. The probabilities of the possible outcomes are modelled as a function of the independent variables using a logistic function. Logistic regression measures the relationship between a categorical dependent variable and, usually, one or several continuous independent variables by converting the dependent variable to probability scores. Then, a logistic regression is formed, which predicts success or failure of a given binary variable (e.g. erosion presence or absence) for any value of the independent variables. The

  15. Ergonomic evaluation of the Apple Adjustable Keyboard

    SciTech Connect

    Tittiranonda, P.; Burastero, S.; Shih, M.; Rempel, D.

    1994-05-01

    This study presents an evaluation of the Apple Adjustable Keyboard based on subjective preference and observed joint angles during typing. Thirty five keyboard users were asked to use the Apple adjustable keyboard for 7--14 days and rate the various characteristics of the keyboard. Our findings suggest that the most preferred opening angles range from 11--20{degree}. The mean ulnar deviation on the Apple Adjustable keyboard is 11{degree}, compared to 16{degree} on the standard keyboard. The mean extension was decreased from 24{degree} to 16{degree} when using the adjustable keyboard. When asked to subjectively rate the adjustable keyboard in comparison to the standard, the average subject felt that the Apple Adjustable Keyboard was more comfortable and easier to use than the standard flat keyboard.

  16. Efficient Adjustable Reflectivity Smart Window

    SciTech Connect

    D. Morgan Tench

    2005-12-01

    This project addressed the key technical issues for development of an efficient smart window based on reversible electrochemical transfer of silver between a mirror electrode and a localized counter electrode. Effort to provide uniform switching over large areas focused on use of a resistive transparent electrode innerlayer to increase the interelectrode resistance. An effective edge seal was developed in collaboration with adhesive suppliers and an electrochromic device manufacturer. Work to provide a manufacturable counter electrode focused on fabricating a dot matrix electrode without photolithography by electrodeposition of Pt nuclei on inherent active sites on a transparent oxide conductor. An alternative counter electrode based on a conducting polymer and an ionic liquid electrolyte was also investigated. Work in all of these areas was successful. Sputtered large-bandgap oxide innerlayers sandwiched between conductive indium tin oxide (ITO) layers were shown to provide sufficient cross-layer resistance (>300 ohm/cm{sup 2}) without significantly affecting the electrochemical properties of the ITO overlayer. Two edge seal epoxies, one procured from an epoxy manufacturer and one provided by an electrochromic device manufacturer in finished seals, were shown to be effective barriers against oxygen intrusion up to 80 C. The optimum density of nuclei for the dot matrix counter electrode was attained without use of photolithography by electrodeposition from a commercial alkaline platinum plating bath. Silver loss issues for cells with dot matrix electrodes were successfully addressed by purifying the electrolyte and adjusting the cell cycling parameters. More than 30K cycles were demonstrated for a REM cell (30-cm square) with a dot matrix counter electrode. Larger cells (30-cm square) were successfully fabricated but could not be cycled since the nucleation layers (provided by an outside supplier) were defective so that mirror deposits could not be produced.

  17. Three-dimensional adjustment of trilateration data

    NASA Technical Reports Server (NTRS)

    Sung, L.-Y.; Jackson, D. D.

    1985-01-01

    The three-dimensional locations of the monuments in the USGS Hollister trilateration network were adjusted to fit line length observations observed in 1977, using a Bayesian approach, and incorporating prior elevation estimates as data in the adjustment procedure. No significant discrepancies in the measured line lengths were found, but significant elevation adjustments (up to 1.85 m) were needed to fit the length data.

  18. Asian immigrant settlement and adjustment in Australia.

    PubMed

    Khoo, S; Kee, P; Dang, T; Shu, J

    1994-01-01

    "This article provides a broad assessment of the settlement and adjustment of people born in the many countries of Asia who are resident in Australia, based on recently available data from the 1991 Census of Population and Housing. It examines some indicators of economic adjustment such as performance in the labor market, and some indicators of social adjustment, such as acquisition of English language proficiency." PMID:12289777

  19. Rate adjusters for Medicare under capitation

    PubMed Central

    Newhouse, Joseph P.

    1986-01-01

    This article addresses three issues related to capitation. First, the average adjusted per capita cost (AAPCC) fluctuates with the mix of risks in the fee-for-service system. More sensitive adjusters in the AAPCC are needed. Second, the AAPCC, as now estimated, exhibits large geographic variance; so-called shrinkage estimators may help. Third, the AAPCC requires new adjusters to yield more homogeneous risk classes. Otherwise, the portion of the Medicare population under capitation may experience access problems at alternative delivery systems: Until such adjusters are developed, it seems better to rely upon a blend of capitation and fee-for-service than the present AAPCC. PMID:10311926

  20. Techniques and applications of adjustable sutures.

    PubMed

    Fells, P

    1987-02-01

    The 'rediscovery' of adjustable sutures some 10 years ago has given the ophthalmic surgeon much more confidence in his ability to correct strabismus. Three methods of use are described: during surgery under general anaesthesia with adjustment during the operation using the 'springback' test to centralise the eye; during surgery under general anaesthesia and subsequent adjustment under local anaesthesia using the patient's subjective responses to obtain optimal positioning; and performance of the operation and adjustment under topical local anaesthesia in one procedure. Full details are given of each technique and the indications for their application to particular problems are discussed. PMID:3297111

  1. 76 FR 58263 - Kenai Pipe Line Company; Tesoro Alaska Company; Tesoro Logistics Operations, LLC; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Kenai Pipe Line Company; Tesoro Alaska Company; Tesoro Logistics Operations... Company (Tesoro Alaska), and Tesoro Logistics, LLC (TLO) (collectively, Tesoro) filed a Request...

  2. Research on the Environmental Performance Evaluation of Electronic Waste Reverse Logistics Enterprise

    NASA Astrophysics Data System (ADS)

    Yang, Yu-Xiang; Chen, Fei-Yang; Tong, Tong

    According to the characteristic of e-waste reverse logistics, environmental performance evaluation system of electronic waste reverse logistics enterprise is proposed. We use fuzzy analytic hierarchy process method to evaluate the system. In addition, this paper analyzes the enterprise X, as an example, to discuss the evaluation method. It's important to point out attributes and indexes which should be strengthen during the process of ewaste reverse logistics and provide guidance suggestions to domestic e-waste reverse logistics enterprises.

  3. Ratios as a size adjustment in morphometrics.

    PubMed

    Albrecht, G H; Gelvin, B R; Hartman, S E

    1993-08-01

    Simple ratios in which a measurement variable is divided by a size variable are commonly used but known to be inadequate for eliminating size correlations from morphometric data. Deficiencies in the simple ratio can be alleviated by incorporating regression coefficients describing the bivariate relationship between the measurement and size variables. Recommendations have included: 1) subtracting the regression intercept to force the bivariate relationship through the origin (intercept-adjusted ratios); 2) exponentiating either the measurement or the size variable using an allometry coefficient to achieve linearity (allometrically adjusted ratios); or 3) both subtracting the intercept and exponentiating (fully adjusted ratios). These three strategies for deriving size-adjusted ratios imply different data models for describing the bivariate relationship between the measurement and size variables (i.e., the linear, simple allometric, and full allometric models, respectively). Algebraic rearrangement of the equation associated with each data model leads to a correctly formulated adjusted ratio whose expected value is constant (i.e., size correlation is eliminated). Alternatively, simple algebra can be used to derive an expected value function for assessing whether any proposed ratio formula is effective in eliminating size correlations. Some published ratio adjustments were incorrectly formulated as indicated by expected values that remain a function of size after ratio transformation. Regression coefficients incorporated into adjusted ratios must be estimated using least-squares regression of the measurement variable on the size variable. Use of parameters estimated by any other regression technique (e.g., major axis or reduced major axis) results in residual correlations between size and the adjusted measurement variable. Correctly formulated adjusted ratios, whose parameters are estimated by least-squares methods, do control for size correlations. The size-adjusted

  4. Logistical Consideration in Computer-Based Screening of Astronaut Applicants

    NASA Technical Reports Server (NTRS)

    Galarza, Laura

    2000-01-01

    This presentation reviews the logistical, ergonomic, and psychometric issues and data related to the development and operational use of a computer-based system for the psychological screening of astronaut applicants. The Behavioral Health and Performance Group (BHPG) at the Johnson Space Center upgraded its astronaut psychological screening and selection procedures for the 1999 astronaut applicants and subsequent astronaut selection cycles. The questionnaires, tests, and inventories were upgraded from a paper-and-pencil system to a computer-based system. Members of the BHPG and a computer programmer designed and developed needed interfaces (screens, buttons, etc.) and programs for the astronaut psychological assessment system. This intranet-based system included the user-friendly computer-based administration of tests, test scoring, generation of reports, the integration of test administration and test output to a single system, and a complete database for past, present, and future selection data. Upon completion of the system development phase, four beta and usability tests were conducted with the newly developed system. The first three tests included 1 to 3 participants each. The final system test was conducted with 23 participants tested simultaneously. Usability and ergonomic data were collected from the system (beta) test participants and from 1999 astronaut applicants who volunteered the information in exchange for anonymity. Beta and usability test data were analyzed to examine operational, ergonomic, programming, test administration and scoring issues related to computer-based testing. Results showed a preference for computer-based testing over paper-and -pencil procedures. The data also reflected specific ergonomic, usability, psychometric, and logistical concerns that should be taken into account in future selection cycles. Conclusion. Psychological, psychometric, human and logistical factors must be examined and considered carefully when developing and

  5. Prediction of siRNA potency using sparse logistic regression.

    PubMed

    Hu, Wei; Hu, John

    2014-06-01

    RNA interference (RNAi) can modulate gene expression at post-transcriptional as well as transcriptional levels. Short interfering RNA (siRNA) serves as a trigger for the RNAi gene inhibition mechanism, and therefore is a crucial intermediate step in RNAi. There have been extensive studies to identify the sequence characteristics of potent siRNAs. One such study built a linear model using LASSO (Least Absolute Shrinkage and Selection Operator) to measure the contribution of each siRNA sequence feature. This model is simple and interpretable, but it requires a large number of nonzero weights. We have introduced a novel technique, sparse logistic regression, to build a linear model using single-position specific nucleotide compositions which has the same prediction accuracy of the linear model based on LASSO. The weights in our new model share the same general trend as those in the previous model, but have only 25 nonzero weights out of a total 84 weights, a 54% reduction compared to the previous model. Contrary to the linear model based on LASSO, our model suggests that only a few positions are influential on the efficacy of the siRNA, which are the 5' and 3' ends and the seed region of siRNA sequences. We also employed sparse logistic regression to build a linear model using dual-position specific nucleotide compositions, a task LASSO is not able to accomplish well due to its high dimensional nature. Our results demonstrate the superiority of sparse logistic regression as a technique for both feature selection and regression over LASSO in the context of siRNA design. PMID:21091052

  6. The Impact of Flight Hardware Scavenging on Space Logistics

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.

    2011-01-01

    For a given fixed launch vehicle capacity the logistics payload delivered to the moon may be only roughly 20 percent of the payload delivered to the International Space Station (ISS). This is compounded by the much lower flight frequency to the moon and thus low availability of spares for maintenance. This implies that lunar hardware is much more scarce and more costly per kilogram than ISS and thus there is much more incentive to preserve hardware. The Constellation Lunar Surface System (LSS) program is considering ways of utilizing hardware scavenged from vehicles including the Altair lunar lander. In general, the hardware will have only had a matter of hours of operation yet there may be years of operational life remaining. By scavenging this hardware the program, in effect, is treating vehicle hardware as part of the payload. Flight hardware may provide logistics spares for system maintenance and reduce the overall logistics footprint. This hardware has a wide array of potential applications including expanding the power infrastructure, and exploiting in-situ resources. Scavenging can also be seen as a way of recovering the value of, literally, billions of dollars worth of hardware that would normally be discarded. Scavenging flight hardware adds operational complexity and steps must be taken to augment the crew s capability with robotics, capabilities embedded in flight hardware itself, and external processes. New embedded technologies are needed to make hardware more serviceable and scavengable. Process technologies are needed to extract hardware, evaluate hardware, reconfigure or repair hardware, and reintegrate it into new applications. This paper also illustrates how scavenging can be used to drive down the cost of the overall program by exploiting the intrinsic value of otherwise discarded flight hardware.

  7. Using and Interpreting Logistic Regression: A Guide for Teachers and Students.

    ERIC Educational Resources Information Center

    Lottes, Ilsa L.; And Others

    1996-01-01

    Defines and illustrates basic concepts of dichotomous logistic regression (DLR) and presents strategies for teaching these concepts. Strategies include using analogies between ordinary least squares regression and logistic regression; illustrating concepts with contingency tables; and linking logistic regression concepts to interpretation of…

  8. And Who Will Teach Them? An Investigation of the Logistics PhD Market

    ERIC Educational Resources Information Center

    Golicic, Susan L.; Bobbitt, L. Michelle; Frankel, Robert; Clinton, Steven R.

    2004-01-01

    At a time when there is high demand for logistics/supply chain education at the undergraduate and master's levels, there is short supply of logistics PhDs to take faculty positions. In this research, the authors used both primary and secondary research to confirm the gap between supply and demand of logistics/supply-chain scholars. Their study…

  9. Exploring the Lived Experiences of Program Managers Regarding an Automated Logistics Environment

    ERIC Educational Resources Information Center

    Allen, Ronald Timothy

    2014-01-01

    Automated Logistics Environment (ALE) is a new term used by Navy and aerospace industry executives to describe the aggregate of logistics-related information systems that support modern aircraft weapon systems. The development of logistics information systems is not always well coordinated among programs, often resulting in solutions that cannot…

  10. Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    The purpose is to describe the logistics study background and approach to providing estimates of of logistics support requirements for Office of Space Science and Applications' payloads in the Space Station era. A concise summary is given of the study results. Future logistics support analysis tasks are identified.

  11. 77 FR 62469 - Defense Logistics Agency Freedom of Information Act Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ... beginning to process a new or pending request from the requester (see OMB Fee Guidelines, 52 FR at 10012... of the Secretary 32 CFR Part 300 Defense Logistics Agency 32 CFR Part 1285 RIN 0790-AI87 Defense Logistics Agency Freedom of Information Act Program AGENCY: Defense Logistics Agency, DoD. ACTION:...

  12. 76 FR 28226 - Ndahendekire Barbara v. African Shipping; Njoroge Muhia; Alco Logistics, Llc; Brenda Alexander...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... Ndahendekire Barbara v. African Shipping; Njoroge Muhia; Alco Logistics, Llc; Brenda Alexander; and AIR 7 Seas... ``Complainant,'' against African Shipping; Njoroge Muhia, ALCO Logistics, LLC; Brenda Alexander; and Air 7 Seas Transport Logistics, Inc.; hereinafter ``Respondents''. Complainant asserts that she is acting agent...

  13. 76 FR 72391 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... (DLA) published a Notice of Availability (NOA) in the Federal Register (76 FR 28757) announcing the... of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION:...

  14. 77 FR 55817 - Delek Crude Logistics, LLC; Notice of Petition for Waiver

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... Energy Regulatory Commission Delek Crude Logistics, LLC; Notice of Petition for Waiver Take notice that on June 11, 2012, Delek Crude Logistics, LLC (``Delek Crude'') respectfully requests that the Federal... Commission's regulations with respect to the East Texas Crude Logistics crude oil pipeline system. Any...

  15. NASA Shuttle Logistics Depot (NSLD) - The application of ATE

    NASA Technical Reports Server (NTRS)

    Simpkins, Lorenz G.; Jenkins, Henry C.; Mauceri, A. Jack

    1990-01-01

    The concept of the NASA Shuttle Logistics Depot (NSLD) developed for the Space Shuttle Orbiter Program is described. The function of the NSLD at Cape Canaveral is to perform the acceptance and diagnostic testing of the Shuttle's space-rated line-replaceable units and shop-replaceable units (SRUs). The NSLD includes a comprehensive electronic automatic test station, program development stations, and assorted manufacturing support equipment (including thermal and vibration test equipment, special test equipment, and a card SRU test system). The depot activities also include the establishment of the functions for manufacturing of mechanical parts, soldering, welding, painting, clean room operation, procurement, and subcontract management.

  16. Logistic ex Vivo Lung Perfusion for Hyperimmunized Patients.

    PubMed

    De Wolf, Julien; Puyo, Philippe; Bonnette, Pierre; Roux, Antoine; Le Guen, Morgan; Parquin, François; Chapelier, Alain; Sage, Edouard

    2016-09-01

    Hyperimmunized patients have restricted access to lung transplantation because of the low rate of donor lung availability. Sensitization to human leukocyte antigen is associated with acute rejection, allograft dysfunction, and decreased survival. Prospective crossmatching could allow matching a lung graft with the recipient; however, such a strategy would increase graft ischemia, with a worse impact on the long-term results of lung transplantation. We used logistic ex vivo lung perfusion for 3 patients at the Foch Hospital while waiting for a negative result of the prospective crossmatching and then moved forward to lung transplantation. All patients are alive 3 years after bilateral lung transplantation. PMID:27549543

  17. Benefits of VTOL aircraft in offshore petroleum logistics support

    NASA Technical Reports Server (NTRS)

    Wilcox, D. E.; Shovlin, M. D.

    1975-01-01

    The mission suitability and potential economic benefits of advanced VTOL aircraft were investigated for logistics support of petroleum operations in the North Sea and the Gulf of Mexico. Concepts such as the tilt rotor and lift/cruise fan are promising for future operations beyond 150 miles offshore, where their high cruise efficiency provides savings in trip time, fuel consumption, and capital investment. Depending upon mission requirements, the aircraft operating costs are reduced by as much as 20 percent to 50 percent from those of current helicopters.

  18. Stochastic growth logistic model with aftereffect for batch fermentation process

    NASA Astrophysics Data System (ADS)

    Rosli, Norhayati; Ayoubi, Tawfiqullah; Bahar, Arifah; Rahman, Haliza Abdul; Salleh, Madihah Md

    2014-06-01

    In this paper, the stochastic growth logistic model with aftereffect for the cell growth of C. acetobutylicum P262 and Luedeking-Piret equations for solvent production in batch fermentation system is introduced. The parameters values of the mathematical models are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic models numerically. The effciency of mathematical models is measured by comparing the simulated result and the experimental data of the microbial growth and solvent production in batch system. Low values of Root Mean-Square Error (RMSE) of stochastic models with aftereffect indicate good fits.

  19. Scheduling algorithm for mission planning and logistics evaluation users' guide

    NASA Technical Reports Server (NTRS)

    Chang, H.; Williams, J. M.

    1976-01-01

    The scheduling algorithm for mission planning and logistics evaluation (SAMPLE) program is a mission planning tool composed of three subsystems; the mission payloads subsystem (MPLS), which generates a list of feasible combinations from a payload model for a given calendar year; GREEDY, which is a heuristic model used to find the best traffic model; and the operations simulation and resources scheduling subsystem (OSARS), which determines traffic model feasibility for available resources. The SAMPLE provides the user with options to allow the execution of MPLS, GREEDY, GREEDY-OSARS, or MPLS-GREEDY-OSARS.

  20. Stochastic growth logistic model with aftereffect for batch fermentation process

    SciTech Connect

    Rosli, Norhayati; Ayoubi, Tawfiqullah; Bahar, Arifah; Rahman, Haliza Abdul; Salleh, Madihah Md

    2014-06-19

    In this paper, the stochastic growth logistic model with aftereffect for the cell growth of C. acetobutylicum P262 and Luedeking-Piret equations for solvent production in batch fermentation system is introduced. The parameters values of the mathematical models are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic models numerically. The effciency of mathematical models is measured by comparing the simulated result and the experimental data of the microbial growth and solvent production in batch system. Low values of Root Mean-Square Error (RMSE) of stochastic models with aftereffect indicate good fits.

  1. Programmable Thermostat Module Upgrade for the Multipurpose Logistics Module

    NASA Technical Reports Server (NTRS)

    Clark, D. W.; Glasgow, S. d.; Reagan, S. E.; Presson, K. H.; Howard, D. E.; Smith, D. A.

    2007-01-01

    The STS-121/ULF 1.1 mission was the maiden flight of the programmable thermostat module (PTM) system used to control the 28 V shell heaters on the multi-purpose logistics module (MPLM). These PTMs, in conjunction with a data recorder module (DRM), provide continuous closed loop temperature control and data recording of MPLM on-orbit heater operations. This Technical Memorandum discusses the hardware design, development, test, and verification (DDT&V) activities performed at the Marshall Space Flight Center as well as the operational implementation and mission performance.

  2. Ranked Tag Recommendation Systems Based on Logistic Regression

    NASA Astrophysics Data System (ADS)

    Quevedo, J. R.; Montañés, E.; Ranilla, J.; Díaz, I.

    This work proposes an approach to tag recommendation based on a logistic regression based system. The goal of the method is to support users of current social network systems by providing a rank of new meaningful tags for a resource. This system provides a ranked tag set and it feeds on different posts depending on the resource for which the user requests the recommendation. The performance of this approach is tested according to several evaluation measures, one of them proposed in this paper (F_1^+). The experiments show that this learning system outperforms certain benchmark recommenders.

  3. C*-algebras associated with reversible extensions of logistic maps

    NASA Astrophysics Data System (ADS)

    Kwaśniewski, Bartosz K.

    2012-10-01

    The construction of reversible extensions of dynamical systems presented in a previous paper by the author and A.V. Lebedev is enhanced, so that it applies to arbitrary mappings (not necessarily with open range). It is based on calculating the maximal ideal space of C*-algebras that extends endomorphisms to partial automorphisms via partial isometric representations, and involves a new set of 'parameters' (the role of parameters is played by chosen sets or ideals). As model examples, we give a thorough description of reversible extensions of logistic maps and a classification of systems associated with compression of unitaries generating homeomorphisms of the circle. Bibliography: 34 titles.

  4. SpaceNet: Modeling and Simulating Space Logistics

    NASA Technical Reports Server (NTRS)

    Lee, Gene; Jordan, Elizabeth; Shishko, Robert; de Weck, Olivier; Armar, Nii; Siddiqi, Afreen

    2008-01-01

    This paper summarizes the current state of the art in interplanetary supply chain modeling and discusses SpaceNet as one particular method and tool to address space logistics modeling and simulation challenges. Fundamental upgrades to the interplanetary supply chain framework such as process groups, nested elements, and cargo sharing, enabled SpaceNet to model an integrated set of missions as a campaign. The capabilities and uses of SpaceNet are demonstrated by a step-by-step modeling and simulation of a lunar campaign.

  5. C*-algebras associated with reversible extensions of logistic maps

    SciTech Connect

    Kwasniewski, Bartosz K

    2012-10-31

    The construction of reversible extensions of dynamical systems presented in a previous paper by the author and A.V. Lebedev is enhanced, so that it applies to arbitrary mappings (not necessarily with open range). It is based on calculating the maximal ideal space of C*-algebras that extends endomorphisms to partial automorphisms via partial isometric representations, and involves a new set of 'parameters' (the role of parameters is played by chosen sets or ideals). As model examples, we give a thorough description of reversible extensions of logistic maps and a classification of systems associated with compression of unitaries generating homeomorphisms of the circle. Bibliography: 34 titles.

  6. 15 CFR 6.5 - Effective date of adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INFLATION ADJUSTMENTS § 6.5 Effective date of adjustments. The adjustments made by § 6.4 of this part, of... December 11, 2008, and before the effective date of any future inflation adjustment thereto made...

  7. 15 CFR 6.5 - Effective date of adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... INFLATION ADJUSTMENTS § 6.5 Effective date of adjustments. The adjustments made by § 6.4 of this part, of... December 7, 2012, and before the effective date of any future inflation adjustment thereto made...

  8. 15 CFR 6.5 - Effective date of adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... INFLATION ADJUSTMENTS § 6.5 Effective date of adjustments. The adjustments made by § 6.4 of this part, of... December 11, 2008, and before the effective date of any future inflation adjustment thereto made...

  9. 15 CFR 6.5 - Effective date of adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INFLATION ADJUSTMENTS § 6.5 Effective date of adjustments. The adjustments made by § 6.4 of this part, of... December 11, 2008, and before the effective date of any future inflation adjustment thereto made...

  10. 15 CFR 6.5 - Effective date of adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... INFLATION ADJUSTMENTS § 6.5 Effective date of adjustments. The adjustments made by § 6.4 of this part, of... December 7, 2012, and before the effective date of any future inflation adjustment thereto made...

  11. 7 CFR 718.110 - Adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Adjustments. 718.110 Section 718.110 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE FARM... Determination of Acreage and Compliance § 718.110 Adjustments. (a) The farm operator or other...

  12. 7 CFR 718.110 - Adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Adjustments. 718.110 Section 718.110 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE FARM... Determination of Acreage and Compliance § 718.110 Adjustments. (a) The farm operator or other...

  13. 7 CFR 718.110 - Adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Adjustments. 718.110 Section 718.110 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE FARM... Determination of Acreage and Compliance § 718.110 Adjustments. (a) The farm operator or other...

  14. 45 CFR 84.44 - Academic adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Academic adjustments. 84.44 Section 84.44 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 84.44 Academic adjustments. (a)...

  15. 22 CFR 142.44 - Academic adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Academic adjustments. 142.44 Section 142.44 Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 142.44 Academic adjustments. (a) Academic requirements. A...

  16. Family Adjustment Measure: Scale Construction and Validation

    ERIC Educational Resources Information Center

    Daire, Andrew P.; Dominguez, Vanessa N.; Carlson, Ryan G.; Case-Pease, Jenene

    2014-01-01

    We administered the Family Adjustment Measure to 368 parents of children with special needs to identify positive adjustment. We randomly split the sample to conduct exploratory factor analysis ("n" = 194) and confirmatory factor analysis ("n" = 174). Results indicated four possible subscales and that explain 51% of the variance.

  17. Marital Adjustment among Housestaff and New Attorneys.

    ERIC Educational Resources Information Center

    Spendlove, David C.; And Others

    1990-01-01

    This study, involving 116 housestaff physicians, 106 new attorneys, and the spouses of both groups, identified the factors that significantly affected their marital adjustments. No differences were found. The most important factor associated with adjustment was perceived level of emotional support from one's spouse. (Author/MLW)

  18. 15 CFR 6.6 - Subsequent adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Subsequent adjustments. 6.6 Section 6.6 Commerce and Foreign Trade Office of the Secretary of Commerce CIVIL MONETARY PENALTY INFLATION... once every four years after October 23, 1996, make the inflation adjustment, described in Section...

  19. Religiousity, Spirituality and Adolescents' Self-Adjustment

    ERIC Educational Resources Information Center

    Japar, Muhammad; Purwati

    2014-01-01

    Religiuosity, spirituality, and adolescents' self-adjustment. The objective of this study is to test the correlation among religiosity, spirituality and adolescents' self-adjustment. A quantitative approach was employed in this study. Data were collected from 476 junior high schools students of 13 State Junior High Schools and one Junior High…

  20. Adjustable Optical Mount Is More Rigid

    NASA Technical Reports Server (NTRS)

    Asbury, Bill G.; Coombs, David S.; Jones, Irby W.; Moore, Alvah S., Jr.

    1994-01-01

    Improved mount for lens or mirror in laser offers rigidity similar to that of nonadjustable optical mount. In comparison with older adjustable optical mounts, this one less susceptible to movements and distortions caused by vibrations and by thermal expansions and contractions. Mount contains neither adjustment rods (which grow or shrink as temperature varies) nor springs (which transmit vibrations to mounted optic).

  1. 24 CFR 9.155 - Housing adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Housing adjustments. 9.155 Section 9.155 Housing and Urban Development Office of the Secretary, Department of Housing and Urban... THE DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.155 Housing adjustments. (a) The agency...

  2. 15 CFR 6.6 - Subsequent adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Subsequent adjustments. 6.6 Section 6.6 Commerce and Foreign Trade Office of the Secretary of Commerce CIVIL MONETARY PENALTY INFLATION... once every four years after October 23, 1996, make the inflation adjustment, described in Section...

  3. 15 CFR 6.6 - Subsequent adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Subsequent adjustments. 6.6 Section 6.6 Commerce and Foreign Trade Office of the Secretary of Commerce CIVIL MONETARY PENALTY INFLATION... once every four years after October 23, 1996, make the inflation adjustment, described in Section...

  4. 15 CFR 6.6 - Subsequent adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Subsequent adjustments. 6.6 Section 6.6 Commerce and Foreign Trade Office of the Secretary of Commerce CIVIL MONETARY PENALTY INFLATION... once every four years after October 23, 1996, make the inflation adjustment, described in Section...

  5. 15 CFR 6.6 - Subsequent adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Subsequent adjustments. 6.6 Section 6.6 Commerce and Foreign Trade Office of the Secretary of Commerce CIVIL MONETARY PENALTY INFLATION... once every four years after October 23, 1996, make the inflation adjustment, described in Section...

  6. 14 CFR 254.6 - Periodic adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Periodic adjustments. 254.6 Section 254.6 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS DOMESTIC BAGGAGE LIABILITY § 254.6 Periodic adjustments. The Department of Transportation...

  7. Affect and Status Dimensions of Marital Adjustment

    ERIC Educational Resources Information Center

    Fineberg, Beth L.; Joseph Lowman

    1975-01-01

    The interactions of 10 maritally adjusted and 10 maladjusted couples were compared using a coding system based on the Leary circumplex. Major findings are (1) adjusted couples communicated more affection and submission than did maladjusted ones, (2) all couples were more likely to show complementary sequencing patterns with some interesting…

  8. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  9. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  10. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  11. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  12. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  13. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  14. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  15. 49 CFR 630.11 - Data adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Data adjustments. 630.11 Section 630.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.11 Data adjustments. Errors in the data used...

  16. 24 CFR 902.24 - Database adjustment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Database adjustment. 902.24 Section 902.24 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED... PUBLIC HOUSING ASSESSMENT SYSTEM Physical Condition Indicator § 902.24 Database adjustment....

  17. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment... continue to take place based on existing contract/marketing criteria principles....

  18. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment... continue to take place based on existing contract/marketing criteria principles....

  19. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment... continue to take place based on existing contract/marketing criteria principles....

  20. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment... continue to take place based on existing contract/marketing criteria principles....

  1. 10 CFR 905.34 - Adjustment provisions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment... continue to take place based on existing contract/marketing criteria principles....

  2. Ergonomically Adjustable School Furniture for Male Students

    ERIC Educational Resources Information Center

    Al-Saleh, Khalid S.; Ramadan, Mohamed Z.; Al-Ashaikh, Riyad A.

    2013-01-01

    The need for adjustability in school furniture, in order to accommodate the variation in anthropometric measures of different genders, cultures and ages is becoming increasingly important. Four chair-table combinations, different in dimensions, with adjustable chair seating heights and table heights were designed, manufactured and distributed to…

  3. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... for a contract that otherwise would be approved by RUS. See 7 CFR part 1753. ... 7 Agriculture 11 2011-01-01 2011-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in...

  4. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... for a contract that otherwise would be approved by RUS. See 7 CFR part 1753. ... 7 Agriculture 11 2013-01-01 2013-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in...

  5. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... for a contract that otherwise would be approved by RUS. See 7 CFR part 1753. ... 7 Agriculture 11 2014-01-01 2014-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in...

  6. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... for a contract that otherwise would be approved by RUS. See 7 CFR part 1753. ... 7 Agriculture 11 2012-01-01 2012-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in...

  7. 7 CFR 1744.64 - Budget adjustment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... for a contract that otherwise would be approved by RUS. See 7 CFR part 1753. ... 7 Agriculture 11 2010-01-01 2010-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in...

  8. 7 CFR 15b.32 - Academic adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Academic adjustments. 15b.32 Section 15b.32 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 15b.32 Academic adjustments. (a) Academic requirements. A recipient...

  9. A Digital Game for International Students' Adjustment

    ERIC Educational Resources Information Center

    Bisadi, Maryam; Chua, Alton Y. K; Keong, Lee Chu

    2013-01-01

    Although digital games have been developed for various subject areas, little attention has been focused on using digital games to address international students' adjustment issues. For this reason, this paper endeavors to explore the use of a digital game in facilitating international students acquire adjustment-related information. Specifically,…

  10. Marital Adjustment Correlates in Young Couples.

    ERIC Educational Resources Information Center

    Haskell, Samuel D.

    The Locke-Wallace Marital Adjustment Scale was administered to 35 Caucasian, Protestant couples who were married an average of nine years, largely middle class, and lived in Knoxville, Tennessee. Significant correlates of marital adjustment were organized into groups of similar variables. Correlate groups that were the same for the husband and…

  11. 24 CFR 886.112 - Rent adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Adjustment Factor most recently published by HUD in the Federal Register in accordance with 24 CFR part 888... unassisted housing in the area to ensure that adjustments in the Contract Rents shall not result in material differences between the rents charged for assisted and comparable unassisted units. Contract Rents may...

  12. 24 CFR 886.112 - Rent adjustments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Adjustment Factor most recently published by HUD in the Federal Register in accordance with 24 CFR part 888... unassisted housing in the area to ensure that adjustments in the Contract Rents shall not result in material differences between the rents charged for assisted and comparable unassisted units. Contract Rents may...

  13. 24 CFR 886.112 - Rent adjustments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Adjustment Factor most recently published by HUD in the Federal Register in accordance with 24 CFR part 888... unassisted housing in the area to ensure that adjustments in the Contract Rents shall not result in material differences between the rents charged for assisted and comparable unassisted units. Contract Rents may...

  14. 24 CFR 886.112 - Rent adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Adjustment Factor most recently published by HUD in the Federal Register in accordance with 24 CFR part 888... unassisted housing in the area to ensure that adjustments in the Contract Rents shall not result in material differences between the rents charged for assisted and comparable unassisted units. Contract Rents may...

  15. 24 CFR 886.112 - Rent adjustments.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Adjustment Factor most recently published by HUD in the Federal Register in accordance with 24 CFR part 888... unassisted housing in the area to ensure that adjustments in the Contract Rents shall not result in material differences between the rents charged for assisted and comparable unassisted units. Contract Rents may...

  16. 24 CFR 9.155 - Housing adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Housing adjustments. 9.155 Section 9.155 Housing and Urban Development Office of the Secretary, Department of Housing and Urban... THE DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.155 Housing adjustments. (a) The agency...

  17. 34 CFR 104.44 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Academic adjustments. 104.44 Section 104.44 Education... Postsecondary Education § 104.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure...

  18. 45 CFR 84.44 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Academic adjustments. 84.44 Section 84.44 Public... Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure that such requirements do not...

  19. 45 CFR 605.44 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Academic adjustments. 605.44 Section 605.44 Public... Postsecondary Education § 605.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure...

  20. 7 CFR 15b.32 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Academic adjustments. 15b.32 Section 15b.32... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 15b.32 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to...

  1. 34 CFR 104.44 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Academic adjustments. 104.44 Section 104.44 Education... Postsecondary Education § 104.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure...

  2. 7 CFR 15b.32 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Academic adjustments. 15b.32 Section 15b.32... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 15b.32 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to...

  3. 45 CFR 605.44 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Academic adjustments. 605.44 Section 605.44 Public... Postsecondary Education § 605.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure...

  4. 22 CFR 142.44 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Academic adjustments. 142.44 Section 142.44... OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 142.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make...

  5. 38 CFR 18.444 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Academic adjustments. 18....444 Academic adjustments. (a) Academic requirements. A recipient shall make necessary modifications to its academic requirements to ensure that these requirements do not discriminate or have the effect...

  6. 45 CFR 1170.44 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Academic adjustments. 1170.44 Section 1170.44... ASSISTED PROGRAMS OR ACTIVITIES Postsecondary Education § 1170.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its...

  7. 15 CFR 8b.22 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Academic adjustments. 8b.22 Section 8b... Secondary Education § 8b.22 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure...

  8. 15 CFR 8b.22 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Academic adjustments. 8b.22 Section 8b... Secondary Education § 8b.22 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure...

  9. 22 CFR 217.44 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Academic adjustments. 217.44 Section 217.44... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 217.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make...

  10. 22 CFR 142.44 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Academic adjustments. 142.44 Section 142.44... OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 142.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make...

  11. 45 CFR 1170.44 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Academic adjustments. 1170.44 Section 1170.44... ASSISTED PROGRAMS OR ACTIVITIES Postsecondary Education § 1170.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its...

  12. 38 CFR 18.444 - Academic adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Academic adjustments. 18....444 Academic adjustments. (a) Academic requirements. A recipient shall make necessary modifications to its academic requirements to ensure that these requirements do not discriminate or have the effect...

  13. 45 CFR 84.44 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Academic adjustments. 84.44 Section 84.44 Public... Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make such modifications to its academic requirements as are necessary to ensure that such requirements do not...

  14. 22 CFR 217.44 - Academic adjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Academic adjustments. 217.44 Section 217.44... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Postsecondary Education § 217.44 Academic adjustments. (a) Academic requirements. A recipient to which this subpart applies shall make...

  15. Do subfertile women adjust their habits when trying to conceive?

    PubMed Central

    Joelsson, Lana Salih; Berglund, Anna; Wånggren, Kjell; Lood, Mikael; Rosenblad, Andreas; Tydén, Tanja

    2016-01-01

    Aim The aim of this study was to investigate lifestyle habits and lifestyle adjustments among subfertile women trying to conceive. Materials and methods Women (n = 747) were recruited consecutively at their first visit to fertility clinics in mid-Sweden. Participants completed a questionnaire. Data were analyzed using logistic regression, t tests, and chi-square tests. Results The response rate was 62% (n = 466). Mean duration of infertility was 1.9 years. During this time 13.2% used tobacco daily, 13.6% drank more than three cups of coffee per day, and 11.6% consumed more than two glasses of alcohol weekly. In this sample, 23.9% of the women were overweight (body mass index, BMI 25–29.9 kg/m2), and 12.5% were obese (BMI ≥30 kg/m2). Obese women exercised more and changed to healthy diets more frequently than normal-weight women (odds ratio 7.43; 95% confidence interval 3.7–14.9). Six out of ten women (n = 266) took folic acid when they started trying to conceive, but 11% stopped taking folic acid after some time. Taking folic acid was associated with a higher level of education (p < 0.001). Conclusions Among subfertile women, one-third were overweight or obese, and some had other lifestyle factors with known adverse effects on fertility such as use of tobacco. Overweight and obese women adjusted their habits but did not reduce their body mass index. Women of fertile age would benefit from preconception counseling, and the treatment of infertility should routinely offer interventions for lifestyle changes. PMID:27216564

  16. Adjusting for confounding by neighborhood using complex survey data.

    PubMed

    Brumback, Babette A; He, Zhulin

    2011-04-30

    Recently, we examined methods of adjusting for confounding by neighborhood of an individual exposure effect on a binary outcome, using complex survey data; the methods were found to fail when the neighborhood sample sizes are small and the selection bias is strongly informative. More recently, other authors have adapted an older method from the genetics literature for application to complex survey data; their adaptation achieves a consistent estimator under a broad range of circumstances. The method is based on weighted pseudolikelihoods, in which the contribution from each neighborhood involves all pairs of cases and controls in the neighborhood. The pairs are treated as if they were independent, a pairwise pseudo-conditional likelihood is thus derived, and then the corresponding score equation is weighted with inverse-probabilities of sampling each case-control pair. We have greatly simplified the implementation by translating the pairwise pseudo-conditional likelihood into an equivalent ordinary weighted log-likelihood formulation. We show how to program the method using standard software for ordinary logistic regression with complex survey data (e.g. SAS PROC SURVEYLOGISTIC). We also show that the methodology applies to a broader set of sampling scenarios than the ones considered by the previous authors. We demonstrate the validity of our simplified implementation by applying it to a simulation for which previous methods failed; the new method performs beautifully. We also apply the new method to an analysis of 2009 National Health Interview Survey (NHIS) public-use data, to estimate the effect of education on health insurance coverage, adjusting for confounding by neighborhood. PMID:21287588

  17. Generalized Fiducial Inference for Binary Logistic Item Response Models.

    PubMed

    Liu, Yang; Hannig, Jan

    2016-06-01

    Generalized fiducial inference (GFI) has been proposed as an alternative to likelihood-based and Bayesian inference in mainstream statistics. Confidence intervals (CIs) can be constructed from a fiducial distribution on the parameter space in a fashion similar to those used with a Bayesian posterior distribution. However, no prior distribution needs to be specified, which renders GFI more suitable when no a priori information about model parameters is available. In the current paper, we apply GFI to a family of binary logistic item response theory models, which includes the two-parameter logistic (2PL), bifactor and exploratory item factor models as special cases. Asymptotic properties of the resulting fiducial distribution are discussed. Random draws from the fiducial distribution can be obtained by the proposed Markov chain Monte Carlo sampling algorithm. We investigate the finite-sample performance of our fiducial percentile CI and two commonly used Wald-type CIs associated with maximum likelihood (ML) estimation via Monte Carlo simulation. The use of GFI in high-dimensional exploratory item factor analysis was illustrated by the analysis of a set of the Eysenck Personality Questionnaire data. PMID:26769340

  18. Landslide Hazard Mapping in Rwanda Using Logistic Regression

    NASA Astrophysics Data System (ADS)

    Piller, A.; Anderson, E.; Ballard, H.

    2015-12-01

    Landslides in the United States cause more than $1 billion in damages and 50 deaths per year (USGS 2014). Globally, figures are much more grave, yet monitoring, mapping and forecasting of these hazards are less than adequate. Seventy-five percent of the population of Rwanda earns a living from farming, mostly subsistence. Loss of farmland, housing, or life, to landslides is a very real hazard. Landslides in Rwanda have an impact at the economic, social, and environmental level. In a developing nation that faces challenges in tracking, cataloging, and predicting the numerous landslides that occur each year, satellite imagery and spatial analysis allow for remote study. We have focused on the development of a landslide inventory and a statistical methodology for assessing landslide hazards. Using logistic regression on approximately 30 test variables (i.e. slope, soil type, land cover, etc.) and a sample of over 200 landslides, we determine which variables are statistically most relevant to landslide occurrence in Rwanda. A preliminary predictive hazard map for Rwanda has been produced, using the variables selected from the logistic regression analysis.

  19. Fuel cell technology for prototype logistic fuel cell mobile systems

    SciTech Connect

    Sederquist, R.A.; Garow, J.

    1995-08-01

    Under the aegis of the Advanced Research Project Agency`s family of programs to develop advanced technology for dual use applications, International Fuel Cells Corporation (IFC) is conducting a 39 month program to develop an innovative system concept for DoD Mobile Electric Power (MEP) applications. The concept is to integrate two technologies, the phosphoric acid fuel cell (PAFC) with an auto-thermal reformer (ATR), into an efficient fuel cell power plant of nominally 100-kilowatt rating which operates on logistic fuels (JP-8). The ATR fuel processor is the key to meeting requirements for MEP (including weight, volume, reliability, maintainability, efficiency, and especially operation on logistic fuels); most of the effort is devoted to ATR development. An integrated demonstration test unit culminates the program and displays the benefits of the fuel cell system, relative to the standard 100-kilowatt MEP diesel engine generator set. A successful test provides the basis for proceeding toward deployment. This paper describes the results of the first twelve months of activity during which specific program aims have remained firm.

  20. Multipurpose Logistics Module, Leonardo, Rests in Discovery's Payload Bay

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This in-orbit close up shows the Italian Space Agency-built multipurpose Logistics Module (MPLM), Leonardo, the primary cargo of the STS-102 mission, resting in the payload bay of the Space Shuttle Orbiter Discovery. The Leonardo MPLM is the first of three such pressurized modules that will serve as the International Space Station's (ISS') moving vans, carrying laboratory racks filled with equipment, experiments, and supplies to and from the Station aboard the Space Shuttle. The cylindrical module is approximately 21-feet long and 15- feet in diameter, weighing almost 4.5 tons. It can carry up to 10 tons of cargo in 16 standard Space Station equipment racks. Of the 16 racks the module can carry, 5 can be furnished with power, data, and fluid to support refrigerators or freezers. In order to function as an attached station module as well as a cargo transport, the logistics module also includes components that provide life support, fire detection and suppression, electrical distribution, and computer functions. The eighth station assembly flight and NASA's 103rd overall flight, STS-102 launched March 8, 2001 for an almost 13 day mission.