Tetrahedral lander

An apparatus and method is disclosed for decelerating and absorbing impact of a re-entry vehicle suitable for payloads that are relatively light as well as payloads weighing several tons or more. The apparatus includes four inflatable legs displaced equidistantly from each other around a capsule or housing which contains a payload. The legs are inflated at a designated altitude after entering earth's atmosphere to slow the descent of the re-entry vehicle. Connected between each of the four legs are drag inducing surfaces that deploy as the legs inflate. The drag inducing surfaces are triangularly shaped with one such surface being connected between each pair of legs for a total of six drag inducing surfaces. The legs have drag inducing outer surfaces which act to slow the descent of the re-entry vehicle

Training During SDM Implementation

Drucker (1988) suggests that new organizational structures result from the dynamic integration of corporate planning, systems analysis and design, and system development. This integration is not possible without a comprehensive system development methodology (SDM) that meets the organization\u27s needs. Today, a SDM can only be successful with a training program that prepares systems personnel to use automated tools within the life cycle phases and tasks of a system development methodology. This relationship between CASE and a SDM make methodology training for CASE users and development staff a key ingredient to a successful CASE implementation. McClure (1992) suggests the following formula for a successful CASE implementation: tools + trained people + methodology. In today\u27s information systems environment, a SDM comprises an overall strategy for computer-based information system development that includes a flexible framework to indicate the sequence of development along with the techniques used to accomplish each task. Automated tools aid the system development process may also be considered part of the methodolog

Historical survey of the progressivity of the U.S. income tax

While filing the 1988 tax returns, many taxpayers will see the full impact of the Tax Reform Act of 1986. Perhaps the most important changes made by this Act altered the progressivity of the federal income tax. . Given these very significant changes to the U.S. income tax and also given that the full impact of this tax law is effective on the seventy-fifth anniversary of the 1913 adoption of the income tax, it is worth the time to look back and contemplate how progressivity of the income tax structure has changed over time. This paper summarizes the historical findings

Adaptive Group Coordination and Role Differentiation

Many real world situations (potluck dinners, academic departments, sports teams, corporate divisions, committees, seminar classes, etc.) involve actors adjusting their contributions in order to achieve a mutually satisfactory group goal, a win-win result. However, the majority of human group research has involved situations where groups perform poorly because task constraints promote either individual maximization behavior or diffusion of responsibility, and even successful tasks generally involve the propagation of one correct solution through a group. Here we introduce a group task that requires complementary actions among participants in order to reach a shared goal. Without communication, group members submit numbers in an attempt to collectively sum to a randomly selected target number. After receiving group feedback, members adjust their submitted numbers until the target number is reached. For all groups, performance improves with task experience, and group reactivity decreases over rounds. Our empirical results provide evidence for adaptive coordination in human groups, and as the coordination costs increase with group size, large groups adapt through spontaneous role differentiation and self-consistency among members. We suggest several agent-based models with different rules for agent reactions, and we show that the empirical results are best fit by a flexible, adaptive agent strategy in which agents decrease their reactions when the group feedback changes. The task offers a simple experimental platform for studying the general problem of group coordination while maximizing group returns, and we distinguish the task from several games in behavioral game theory

Two Middle Holocene Marker Beds in Vertically Accreted Floodplain Deposits, Lower Fraser River, British Columbia

Drill cores obtained from the eastern Fraser Delta and adjoining Fraser River floodplain reveal two middle Holocene marker beds—a peat with an age of about 6000 14C yr BP and a tephra bed, identified as Mazama (6800 yr BP). These marker beds, in conjunction with 14C dates from the flood-plain sediments, indicate that the Fraser River floodplain aggraded in response to a rise in sea-level, between about 8000 and 2250 yr BP, and that aggradation kept pace with sea-level rise. The aggradational deposits form a sediment wedge consisting mainly of organic-rich silts and fine sands of overbank origin. The wedge extends at least 20 km into the lower Fraser River Valley. Preservation of the marker beds indicates considerable channel stability in the lower reaches of the Fraser River over about the last 7000 years.Des carottes recueillies dans la partie est du delta du Fraser et de la plaine d'inondation adjacente montrent deux lits repères datant du milieu de l'Holocène, un lit de tourbe datant d'à peu près 6000 BP et un lit de tephra, correspondant à l'éruption du mont Mazama (6800 BP). Ces lits repères, ainsi que les datations au radiocarbone obtenues dans les sédiments de crue, montrent que la plaine d'inondation du Fraser a progressé en réponse à une hausse du niveau marin survenue entre environ 8000 et 2250 BP et que l'aggradation suivait la hausse du niveau marin. L'accumulation de sédiments, de forme triangulaire, est composée principalement de limons riches en matière organique et de sables fins d'origine alluviale. Le triangle s'étend jusqu'à au moins 20 km dans la vallée inférieure du Fraser. La conservation des lits repères démontre la grande stabilité des biefs du Fraser inférieur depuis environ 7000 ans.Bohrkerne von dem ôstlichen Fraser-Delta und der angrenzenden Hochflutebene lassen zwei Betten aus dem mittleren Holozân erkennen, die als Anhalt dienen: ein Torfbett das auf etwa 6000 "1C Jahre v.u.Z. datiert wird und ein Tephra-Bett, das aus der Zeit des Ausbruchs des Mazamabergs stammt (6800 Jahre v.u.Z.). Die als Anhaltspunkt dienenden Betten weisen zusammen mit den von den Hochflutsedimenten gewonnenen 14C-Daten darauf hin, dass die Hochflut des Fraser-Flusses als Reaktion auf eine Anhebung des Meeresspiegels zwischen etwa 8000 und 2250 Jahren v.u.Z. zugenommen hat. und dass diese Zunahme der Hebung des Meeresspiegels entsprach. Die Akkumulationssedimente bilden einen Sedimentkeil, der vor allem aus organisch reichem Schlamm und feinem Sand alluvialer Herkunft besteht. Der Keil erstreckt sich mindestens 20 km in das TaI des unteren Fraser. Die Erhaltung der als Anhaltspunkte dienenden Betten beweist eine beachtliche Kanalstabilitât in den unteren Stillen des Fraser wâhrend ungefàhr 7000 Jahren

Light Assisted Collisional Loss in a 85/87^{85/87}Rb Ultracold Optical Trap

We have studied hetero- and homonuclear excited state/ground state collisions by loading both $^{85}$Rb and $^{87}$Rb into a far off resonant trap (FORT). Because of the relatively weak confinement of the FORT, we expect the hyperfine structure of the different isotopes to play a crucial role in the collision rates. This dependence on hyperfine structure allows us to measure collisions associated with long range interatomic potentials of different structure: such as long and short ranged; or such as purely attractive, purely repulsive, or mixed attractive and repulsive. We observe significantly different loss rates for different excited state potentials. Additionally, we observe that some collisional channels' loss rates are saturated at our operating intensities (~15 mW/cm$^{2}$). These losses are important limitations in loading dual isotope optical traps.Comment: about 8 pages, 5 figure

INDICATEURS FINANCIERS ET INDICATEURS NON FINANCIERS. IMPORTANCE DES INDICATEURS FINANCIERS, ET ORDRE DE PRESENTATION DES INDICATEURS : EFFETS SUR L'EVALUATION DE LA PERFORMANCE DES MANAGERS

International audienceDebate on the weight of financial vs. non financial indicators in performance measurement process is still going on. The purpose of this research is to examine, experimentally, factors that influence whether corporate managers exhibit bias toward financial versus nonfinancial corporate performance measures. First, we manipulated presentation order of financial and nonfinancial measures to test whether cognitive processing limits result in decision makers placing more weight on the first few items presented. Second, we manipulated the strength of the financial performance measures (the perceived relative importance based on rankings by an independent sample) to examine whether prior mixed results of financial measures bias among corporate managers can be explained by differences in the relative strength or importance of the particular set of financial and nonfinancial measures.Le débat sur l'importance des indicateurs non financiers et financiers dans le processus d'évaluation des performances est loin d'être clos. L'objectif de notre recherche est d'examiner, de façon expérimentale, les facteurs qui influencent le choix des évaluateurs en faveur des indicateurs financiers ou non financiers dans l'évaluation des performances d'une entreprise. Nous avons ainsi d'une part manipulé l'ordre de présentation des indicateurs financiers et non financiers dans le but de tester si les limitations cognitives conduisaient les évaluateurs à considérer seulement les premiers indicateurs qui leur étaient présentés. D'autre part, nous avons manipulé l'importance relative perçue des indicateurs financiers afin d'examiner si le biais en faveur des indicateurs financiers, souvent démontré, pouvait être expliqué par la nature même de ces indicateurs. L'importance relative perçue des indicateurs financiers se fondait sur les résultats d'une autre étude que nous avons conduite sur un échantillon indépendant

FOOD SAFETY INNOVATION IN THE UNITED STATES: EVIDENCE FROM THE MEAT INDUSTRY

Recent industry innovations improving the safety of the Nation's meat supply range from new pathogen tests, high-tech equipment, and supply chain management systems, to new surveillance networks. Despite these and other improvements, the market incentives that motivate private firms to invest in innovation seem to be fairly weak. Results from an ERS survey of U.S. meat and poultry slaughter and processing plants and two case studies of innovation in the U.S. beef industry reveal that the industry has developed a number of mechanisms to overcome that weakness and to stimulate investment in food safety innovation. Industry experience suggests that government policy can increase food safety innovation by reducing informational asymmetries and strengthening the ability of innovating firms to appropriate the benefits of their investments.Food safety, innovation, meat, asymmetric information, Beef Steam Pasteurization System, Bacterial Pathogen Sampling and Testing Program, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

Summarizing and Comparing Story Plans

Branching story games have gained popularity for creating unique playing experiences by adapting story content in response to user actions. Research in interactive narrative (IN) uses automated planning to generate story plans for a given story problem. However, a story planner can generate multiple story plan solutions, all of which equally-satisfy the story problem definition but contain different story content. These differences in story content are key to understanding the story branches in a story problem\u27s solution space, however we lack narrative-theoretic metrics to compare story plans. We address this gap by first defining a story plan summarization model to capture the important story semantics from a story plan. Secondly, we define a story plan comparison metric that compares story plans based on the summarization model. Using the Glaive narrative planner and a simple story problem, we demonstrate the usefulness of using the summarization model and distance metric to characterize the different story branches in a story problem\u27s solution space