LANDSAT image differencing as an automated land cover change detection technique

Image differencing was investigated as a technique for use with LANDSAT digital data to delineate areas of land cover change in an urban environment. LANDSAT data collected in April 1973 and April 1975 for Austin, Texas, were geometrically corrected and precisely registered to United States Geological Survey 7.5-minute quadrangle maps. At each pixel location reflectance values for the corresponding bands were subtracted to produce four difference images. Areas of major reflectance differences are isolated by thresholding each of the difference images. The resulting images are combined to obtain an image data set to total change. These areas of reflectance differences were found, in general, to correspond to areas of land cover change. Information on areas of land cover change was incorporated into a procedure to mask out all nonchange areas and perform an unsupervised classification only for data in the change areas. This procedure identified three broad categories: (1) areas of high reflectance (construction or extractive), (2) changes in agricultural areas, and (3) areas of confusion between agricultural and other areas

Noise Infusion as a Confidentiality Protection Measure for Graph-Based Statistics

We use the bipartite graph representation of longitudinally linked employer-employee data, and the associated projections onto the employer and employee nodes, respectively, to characterize the set of potential statistical summaries that the trusted custodian might produce. We consider noise infusion as the primary confidentiality protection method. We show that a relatively straightforward extension of the dynamic noise-infusion method used in the U.S. Census Bureau’s Quarterly Workforce Indicators can be adapted to provide the same confidentiality guarantees for the graph-based statistics: all inputs have been modified by a minimum percentage deviation (i.e., no actual respondent data are used) and, as the number of entities contributing to a particular statistic increases, the accuracy of that statistic approaches the unprotected value. Our method also ensures that the protected statistics will be identical in all releases based on the same inputs

A summary of NASA data relative to external-store separation characteristics

Aerodynamic characteristics of external stores in carriage position and their effect on separation characteristics under various delivery condition

Earnings Inequality and Mobility Trends in the United States: Nationally Representative Estimates from Longitudinally Linked Employer-Employee Data

Using earnings data from the U.S. Census Bureau, this paper analyzes the role of the employer in explaining the rise in earnings inequality in the United States. We first establish a consistent frame of analysis appropriate for administrative data used to study earnings inequality. We show that the trends in earnings inequality in the administrative data from the Longitudinal Employer-Household Dynamics Program are inconsistent with other data sources when we do not correct for the presence of misused SSNs. After this correction to the worker frame, we analyze how the earnings distribution has changed in the last decade. We present a decomposition of the year-to-year changes in the earnings distribution from 2004-2013. Even when simplifying these flows to movements between the bottom 20%, the middle 60% and the top 20% of the earnings distribution, about 20.5 million workers undergo a transition each year. Another 19.9 million move between employment and nonemployment. To understand the role of the firm in these transitions, we estimate a model for log earnings with additive fixed worker and firm effects using all jobs held by eligible workers from 2004-2013. We construct a composite log earnings firm component across all jobs for a worker in a given year and a non-firm component. We also construct a skill-type index. We show that, while the difference between working at a low- or middle-paying firm are relatively small, the gains from working at a top-paying firm are large. Specifically, the benefits of working for a high-paying firm are not only realized today, through higher earnings paid to the worker, but also persist through an increase in the probability of upward mobility. High-paying firms facilitate moving workers to the top of the earnings distribution and keeping them there

Total Error and Variability Measures with Integrated Disclosure Limitation for Quarterly Workforce Indicators and LEHD Origin Destination Employment Statistics in OnThe Map

We report results from the first comprehensive total quality evaluation of five major indicators in the U.S. Census Bureau\u27s Longitudinal Employer-Household Dynamics (LEHD) Program Quarterly Workforce Indicators (QWI): total employment, beginning-of-quarter employment, full-quarter employment, total payroll, and average monthly earnings of full-quarter employees. Beginning-of-quarter employment is also the main tabulation variable in the LEHD Origin-Destination Employment Statistics (LODES) workplace reports as displayed in OnTheMap (OTM). The evaluation is conducted by generating multiple threads of the edit and imputation models used in the LEHD Infrastructure File System. These threads conform to the Rubin (1987) multiple imputation model, with each thread or implicate being the output of formal probability models that address coverage, edit, and imputation errors. Design-based sampling variability and finite population corrections are also included in the evaluation. We derive special formulas for the Rubin total variability and its components that are consistent with the disclosure avoidance system used for QWI and LODES/OTM workplace reports. These formulas allow us to publish the complete set of detailed total quality measures for QWI and LODES. The analysis reveals that the five publication variables under study are estimated very accurately for tabulations involving at least 10 jobs. Tabulations involving three to nine jobs have quality in the range generally deemed acceptable. Tabulations involving zero, one or two jobs, which are generally suppressed in the QWI and synthesized in LODES, have substantial total variability but their publication in LODES allows the formation of larger custom aggregations, which will in general have the accuracy estimated for tabulations in the QWI based on a similar number of workers

Modeling Endogenous Mobility in Earnings Determination

We evaluate the bias from endogenous job mobility in fixed-effects estimates of worker- and firm-specific earnings heterogeneity using longitudinally linked employer-employee data from the LEHD infrastructure file system of the U.S. Census Bureau. First, we propose two new residual diagnostic tests of the assumption that mobility is exogenous to unmodeled determinants of earnings. Both tests reject exogenous mobility. We relax the exogenous mobility assumptions by modeling the evolution of the matched data as an evolving bipartite graph using a Bayesian latent class framework. Our results suggest that endogenous mobility biases estimated firm effects toward zero. To assess validity, we match our estimates of the wage components to out-of-sample estimates of revenue per worker. The corrected estimates attribute much more of the variation in revenue per worker to variation in match quality and worker quality than the uncorrected estimates

Modeling Endogenous Mobility in Wage Determination

We evaluate the bias from endogenous job mobility in fixed-effects estimates of worker- and firm-specific earnings heterogeneity using longitudinally linked employer-employee data from the LEHD infrastructure file system of the U.S. Census Bureau. First, we propose two new residual diagnostic tests of the assumption that mobility is exogenous to unmodeled determinants of earnings. Both tests reject exogenous mobility. We relax the exogenous mobility assumptions by modeling the evolution of the matched data as an evolving bipartite graph using a Bayesian latent class framework. Our results suggest that endogenous mobility biases estimated firm effects toward zero. To assess validity, we match our estimates of the wage components to out-of-sample estimates of revenue per worker. The corrected estimates attribute much more of the variation in revenue per worker to variation in match quality and worker quality than the uncorrected estimates

Therapist\u27s Perceptions of Walk and Talk Therapy: A Grounded Study

Our society has become less physically active (U.S. Department of Health and Human Services, 2010) and less connected to nature than ever before (Berger & Mcleod, 2006). Spending leisure time indoors, technological advancements, urban living, and car dependent communities have led to these changes (Dustin, Bricker, & Schwab, 2010; Hansen-Ketchum, Marck, & Reutter, 2009; Norman & Mills, 2004). As a result, physical health and mental health is deteriorating (Dustin et al., 2010; Maller, Townsend, Pryor, Brown & Leger, 2005). Physical activity and nature can each produce mental and physical health benefits; some approaches such as adventure-based counseling and wilderness therapy already incorporate these elements. A promising alternative approach using physical activity and nature has received attention in recent years. Walk and talk therapy has been described as an intervention that combines counseling, walking, and the outdoors (Doucette, 2004). Despite, a small number of therapists using the approach (Gontang, 2009), anecdotal research (Hays, 1994), and a description of the approach (Doucette, 2004), little is known about walk and talk therapy. In this qualitative study 11 therapists were interviewed about their experiences with walk and talk therapy. Main themes of the study suggested characteristics, a procedure, reasons walk and talk therapy evolved, limitations, outcomes, and a framework for practice for walk and talk therapy. Therapists believe walk and talk therapy is beneficial for clients as well as therapists. Implications for therapists, researchers, and counselor educators are provided

Therapist\u27s Perceptions of Walk and Talk Therapy: A Grounded Study

Our society has become less physically active (U.S. Department of Health and Human Services, 2010) and less connected to nature than ever before (Berger & Mcleod, 2006). Spending leisure time indoors, technological advancements, urban living, and car dependent communities have led to these changes (Dustin, Bricker, & Schwab, 2010; Hansen-Ketchum, Marck, & Reutter, 2009; Norman & Mills, 2004). As a result, physical health and mental health is deteriorating (Dustin et al., 2010; Maller, Townsend, Pryor, Brown & Leger, 2005). Physical activity and nature can each produce mental and physical health benefits; some approaches such as adventure-based counseling and wilderness therapy already incorporate these elements. A promising alternative approach using physical activity and nature has received attention in recent years. Walk and talk therapy has been described as an intervention that combines counseling, walking, and the outdoors (Doucette, 2004). Despite, a small number of therapists using the approach (Gontang, 2009), anecdotal research (Hays, 1994), and a description of the approach (Doucette, 2004), little is known about walk and talk therapy. In this qualitative study 11 therapists were interviewed about their experiences with walk and talk therapy. Main themes of the study suggested characteristics, a procedure, reasons walk and talk therapy evolved, limitations, outcomes, and a framework for practice for walk and talk therapy. Therapists believe walk and talk therapy is beneficial for clients as well as therapists. Implications for therapists, researchers, and counselor educators are provided