Absolute stability analysis of attitude control systems for large boosters

Absolute stability analysis of attitude control systems for large launch vehicle

Westland/Hallmark: 2008 Beef Recall; A Case Study by The Food Industry Center

A Humane Society video, made secretly at the Westland/Hallmark plant in late 2007 and released in early 2008, led to the recall of 143 million pounds of beef. This case study illustrates the complexity of the food industry and the food recall process. Although ultimately, the incident had more to do with animal welfare than food safety — no sicknesses were tied to the recalled beef, it resulted in changes to the nation’s food safety procedures. The 2008 Westland/Hallmark beef recall, the largest beef recall in U.S. history, is a stepping-off point to examine the beef supply chain generally and the ground beef supply chain specifically.Agribusiness, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

An application of high authority/low authority control and positivity

Control Dynamics Company (CDy), in conjunction with NASA Marshall Space Flight Center (MSFC), has supported the U.S. Air Force Wright Aeronautical Laboratory (AFWAL) in conducting an investigation of the implementation of several DOD controls techniques. These techniques are to provide vibration suppression and precise attitude control for flexible space structures. AFWAL issued a contract to Control Dynamics to perform this work under the Active Control Technique Evaluation for Spacecraft (ACES) Program. The High Authority Control/Low Authority Control (HAC/LAC) and Positivity controls techniques, which were cultivated under the DARPA Active Control of Space Structures (ACOSS) Program, were applied to a structural model of the NASA/MSFC Ground Test Facility ACES configuration. The control systems design were accomplished and linear post-analyses of the closed-loop systems are provided. The control system designs take into account effects of sampling and delay in the control computer. Nonlinear simulation runs were used to verify the control system designs and implementations in the facility control computers. Finally, test results are given to verify operations of the control systems in the test facility

NASA/MSFC ground experiment for large space structure control verification

Marshall Space Flight Center has developed a facility in which closed loop control of Large Space Structures (LSS) can be demonstrated and verified. The main objective of the facility is to verify LSS control system techniques so that on orbit performance can be ensured. The facility consists of an LSS test article which is connected to a payload mounting system that provides control torque commands. It is attached to a base excitation system which will simulate disturbances most likely to occur for Orbiter and DOD payloads. A control computer will contain the calibration software, the reference system, the alignment procedures, the telemetry software, and the control algorithms. The total system will be suspended in such a fashion that LSS test article has the characteristics common to all LSS

THE 2003 SUPERMARKET PANEL ANNUAL REPORT

Executive Summary The Food Industry Center established the Supermarket Panel in 1998 as the basis for an ongoing study of the supermarket industry. Since 2000 the core of the Panel has been a random sample of stores drawn from the approximately 32,000 supermarkets in the U.S. that accept food stamps. The purpose of collecting data on supermarket operations and performance is to: Provide timely, useful information for the industry through benchmark reports and annual summaries, trends on key indices of technology adoption, competitive positions and performance. Be a ready source of data for research on current and emerging issues - to be able to track the changes in operation and its impacts on performance over time. This report presents findings from the 2003 Supermarket Panel, and provides an overview of findings from the past four years. The 2003 Panel includes 391 stores that are a representative cross-section of the supermarket industry. The Panel tries to follow the same stores over time. Of the 391 stores, 268 were in the Panel in 2002. Nine percent of the stores have been in the Panel all four years. At least one store from every state is in the Panel. New in 2003 The Panel was offered over the Internet. Forty-seven percent responded on-line. An index on variety offering was created. Questions about offering irradiated fresh ground beef are included (with a follow up study). Supply Chain Technology Practices The Supply Chain Score measures the extent to which stores have adopted computerized methods of communicating with suppliers, handling inventory management, ordering, invoicing, and analyzing consumer purchases. The average score has almost doubled in four years. Stores in groups (chains) with more than 750 stores and/or supercenter formats have adopted supply chain practices most intensively. Internet/Intranet is used by at least two-thirds of all stores; over ninety percent of stores in groups with more than 50 stores use this technology. Vendor managed inventory has been adopted by only 42 percent of stores in the biggest store groups with much lower rates of adoption in smaller store groups. A higher Supply Chain Score benefited significantly higher sales per labor hour. Service and Variety Scores About eighty percent of stores in all size groups offer bagging and custom meat cutting. Variety pays off in better performance for five out of eight measures. Variety helps to grow annual percentage sales. Supercenters/Top Stores/Unions Supercenters have significantly higher sales per labor hour and per transaction. They have lower sales growth. Fifty-three percent of supermarkets face supercenter competition. They have somewhat higher sales per square foot of selling area and higher annual sales growth than stores that do not face supercenter competition. Eleven percent of stores in the 2003 Panel qualified as "top stores." They had above the median levels for each of three performance measures: weekly sales per square foot, sales per labor hour, and annual percentage sales growth. Top stores are more likely to have a unionized labor force, be a price and variety leader, and be wholesaler supplied. One-third of 2003 Panel stores have unionized labor. These stores have more productive labor with significantly higher sales per labor hour. Statistically Significant Drivers of Performance Over Time The descriptive profile and analysis of the Panel provide useful insights on the structure of the supermarket industry and factors associated with strong performance. However, statistical regression analysis identifies whether a variable is significantly correlated with a performance measure holding all else constant. This section presents findings from a multivariate regression analysis of five key performance measures. These regression analyses are summarized on the table below. If a characteristic is listed on the table it was a significant correlate in at least three out of the past four years. For example, in the last row, the only variable that was consistently significant for increasing annual percentage sales growth is being in an area with higher household incomes. Having a warehouse format decreased sales growth and three other factors were significant in at least three years but alternated with positive and negative effects.Industrial Organization, Marketing,

2007 Supermarket Panel Report

Replaced with revised version of paper 12/16/10.Agribusiness, Industrial Organization,

THE SUPERMARKET INDUSTRY AT THE START OF THE 21st CENTURY: KEY FINDINGS FROM THE 2000 SUPERMARKET PANEL

The 2000 Supermarket Panel gathered data on store characteristics, management practices, and operating performance from a representative, nation-wide sample of supermarkets. The Panel is unique because the unit of analysis is the individual store, and the same stores will be surveyed over time. Linking information on management practices and store and market characteristics with measures for key performance measures provides useful information for both strategic and tactical decisions. Descriptive findings are presented for stores groups by ownership group size and format. Results from a multivariate analysis of relationships between store performance and key performance drivers also are presented.Agribusiness,

Inter-hemispheric linkages in climate change: Paleo-perspectives for future climate change

The Pole-Equator-Pole (PEP) projects of the PANASH (Paleoclimates of the Northern and Southern Hemisphere) programme have significantly advanced our understanding of past climate change on a global basis and helped to integrate paleo-science across regions and research disciplines. PANASH science allows us to constrain predictions for future climate change and to contribute to the management of consequent environmental changes. We identify three broad areas where PEP science makes key contributions. 1. The pattern of global changes. Knowing the exact timing of glacial advances (synchronous or otherwise) during the last glaciation is critical to understanding interhemispheric links in climate. Work in PEPI demonstrated that the tropical Andes in South America were deglaciated earlier than the Northern Hemisphere (NH) and that an extended warming began there ca. 21 000 cal years BP. The general pattern is consistent with Antarctica and has now been replicated from studies in Southern Hemisphere (SH) regions of the PEPII transect. That significant deglaciation of SH alpine systems and Antarctica led deglaciation of NH ice sheets may reflect either i) faster response times in alpine systems and Antarctica, ii) regional moisture patterns that influenced glacier mass balance, or iii) a SH temperature forcing that led changes in the NH. This highlights the limitations of current understanding and the need for further fundamental paleoclimate research. 2. Changes in modes of operation of oscillatory climate systems. Work across all the PEP transects has led to the recognition that the El Nino Southern Oscillation (ENSO) phenomenon has changed markedly through time. It now appears that ENSO operated during the last glacial termination and during the early Holocene, but that precipitation teleconnections even within the Pacific Basin were turned down, or off. In the modern ENSO phenomenon both inter-annual and seven year periodicities are present, with the inter-annual signal dominant. Paleo-data demonstrate that the relative importance of the two periodicities changes through time, with longer periodicities dominant in the early Holocene. 3. The recognition of climate modulation of oscillatory systems by climate events. We examine the relationship of ENSO to a SH climate event, the Antarctic cold reversal (ACR), in the New Zealand region. We demonstrate that the onset of the ACR was associated with the apparent switching on of an ENSO signal in New Zealand. We infer that this related to enhanced zonal SW winds with the amplification of the pressure fields allowing an existing but weak ENSO signal to manifest itself. Teleconnections of this nature would be difficult to predict for future abrupt change as boundary conditions cannot readily be specified. Paleo-data are critical to predicting the teleconnections of future changes

The Microsoft 2016 Conversational Speech Recognition System

We describe Microsoft's conversational speech recognition system, in which we combine recent developments in neural-network-based acoustic and language modeling to advance the state of the art on the Switchboard recognition task. Inspired by machine learning ensemble techniques, the system uses a range of convolutional and recurrent neural networks. I-vector modeling and lattice-free MMI training provide significant gains for all acoustic model architectures. Language model rescoring with multiple forward and backward running RNNLMs, and word posterior-based system combination provide a 20% boost. The best single system uses a ResNet architecture acoustic model with RNNLM rescoring, and achieves a word error rate of 6.9% on the NIST 2000 Switchboard task. The combined system has an error rate of 6.2%, representing an improvement over previously reported results on this benchmark task

Symptoms in pediatric asthmatics and air pollution: differences in effects by symptom severity, anti-inflammatory medication use and particulate averaging time.

Experimental research in humans and animals points to the importance of adverse respiratory effects from short-term particle exposures and to the importance of proinflammatory effects of air pollutants, particularly O(subscript)3. However, particle averaging time has not been subjected to direct scientific evaluation, and there is a lack of epidemiological research examining both this issue and whether modification of air pollutant effects occurs with differences in asthma severity and anti-inflammatory medication use. The present study examined the relationship of adverse asthma symptoms (bothersome or interfered with daily activities or sleep) to O(3) and particles (less than or equal to)10 micrometer (PM10) in a Southern California community in the air inversion zone (1200-2100 ft) with high O(3) and low PM (R = 0.3). A panel of 25 asthmatics 9-17 years of age were followed daily, August through October 1995 (n = 1,759 person-days excluding one subject without symptoms). Exposures included stationary outdoor hourly PM10 (highest 24-hr mean, 54 microgram/m(3), versus median of 1-hr maximums, 56 microgram/m(3) and O(3) (mean of 1-hr maximums, 90 ppb, 5 days (greater than or equal to)120 ppb). Longitudinal regression analyses utilized the generalized estimating equations (GEE) model controlling for autocorrelation, day of week, outdoor fungi, and weather. Asthma symptoms were significantly associated with both outdoor O(3) and PM(10) in single pollutant- and co-regressions, with 1-hr and 8-hr maximum PM(10) having larger effects than the 24-hr mean. Subgroup analyses showed effects of current day PM(10) maximums were strongest in 10 more frequently symptomatic (MS) children: the odds ratios (ORs) for adverse symptoms from 90th percentile increases were 2.24 [95% confidence interval (CI), 1.46-3.46] for 1-hr PM10 (47 microgram/m(3); 1.82 (CI, 1.18-2.81) for 8-hr PM10 (36 microgram/m(3); and 1.50 (CI, 0.80-2.80) for 24-hr PM10 (25 microgram/m(3). Subgroup analyses also showed the effect of current day O(subscript)3 was strongest in 14 less frequently symptomatic (LS) children: the ORs were 2.15 (CI, 1.04-4.44) for 1-hr O(3) (58 ppb) and 1.92 (CI, 0.97-3.80) for 8-hr O(3) (46 ppb). Effects of 24-hr PM10 were seen in both groups, particularly with 5-day moving averages (ORs were 1.95 for MS and 4. 03 for LS; p(less than or equal to)0.05). The largest effects were in 7 LS children not on anti-inflammatory medications [5-day, 8-hr PM10, 9.66 (CI, 2.80-33.21); current day, 1-hr O(3), 4.14 (CI, 1.71-11.85)]. Results suggest that examination of short-term particle excursions, medication use, and symptom severity in longitudinal studies of asthma yields sensitive measures of adverse respiratory effects of air pollution