1,851 research outputs found

    Pensions in the laboratory: the role of commitment and reputation for deferred compensation in multi-period labor contracts

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    This paper examines the relationship between firms‘ wage offers and workers‘ supply of effort in a multi-period environment. If firms are able to commit to a schedule of wage payments, in equilibrium they will offer deferred compensation: first-period productivity is positive and wages are zero, while last-period productivity is zero and wages are positive. Workers respond to deferred compensation by supplying sufficient effort to avoid dismissal. In the absence of commitment, firms pay zero wages and workers supply low effort. The experiment produces strong evidence of these predictions. With commitment, we frequently observe deferred compensation and relatively high worker effort. In the absence of commitment, we observe no deferred compensation, much lower wages, and little worker effort. A third treatment where commitment is not possible, but firms are able to build a reputation, produces an intermediate result. Finally, we also find some evidence of gift exchange, in particular in the absence of commitment when deferred compensation does not work

    Deferred compensation and gift exchange: an experimental investigation into multi-period labor markets

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    This paper examines the relationship between firms’ wage offers and workers’ supply of effort using a three-period experiment. In equilibrium, firms will offer deferred compensation: first period productivity is positive and wages are zero, while third period productivity is zero and wages are positive. The experiment produces strong evidence that deferred compensation increases worker effort; in about 70 percent of cases subjects supplied the optimal effort given the wage offer, and there was a strong effort response to future-period wages. We also find some evidence of gift exchange; worker players increased the effort levels in response to above equilibrium wage offers by a human, but not in response to similar offers by a computer. Finally, we find that firm players who are initially hesitant to defer compensation learn over time that it is beneficial to do so

    Definition of ground test for verification of large space structure control

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    Directions regarding the analytical models were received. A counter balance arm with weights was added at the top of the ASTROMAST to offset the arm with the gimbals. In addition to this model, three more models were requested from MSFC: structure as in the revised model with the addition of lumped masses at bays 46 and 91 of the ASTROMAST; cantilevered cruciform structure with lumped masses at bays 46 and 91, and an all up cruciform structure with lumped masses at bays 46 and 91. Figures for each model and their corresponding natural frequencies and general mode shapes associated with these frequencies are included. The drawbar in use in the cruciform models must be incorporated into the antenna and ASTROMAST models. The total tensile load carrying capability of the ASTROMAST is approximately 840 pounds

    NASA-VCOSS dynamic test facility

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    The Large Space Structure Ground Test Facility under development at the NASA Marshall Space Flight Center in Huntsville, Alabama is described. The Ground Test Facility was established initially to test experimentally the control system to be used on the Solar Array flight Experiment. The structural dynamics of the selected test article were investigated, including the fidelity of the associated mathematical model. The facility must permit the investigation of structural dynamics phenomena and be able to evaluate candidate attitude control and vibration suppression techniques

    The Years were Good

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    This life and those years are shared with you in the pages of this book by a man who would be remarkable at any time in history and is doubly remarkable in today\u27s...world. Reading what he has to say of himself, of his career, of his work, of his philosophy, is to find yourself thinking of the quiet sages of another era. Seltzer was editor of The Cleveland Press from 1928-1966. Original publication date 1956.https://engagedscholarship.csuohio.edu/clevmembks/1052/thumbnail.jp

    NASA/MSFC ground experiment for large space structure control verification

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    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

    Development of high-emittance scales on thoriated nickel-chromium-aluminum-base alloys

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    The surface regions of a DSNiCrAl alloy have been doped, by a pack diffusion process, with small amounts of Mn, Fe, or Co, and the effect of these dopants on the total normal emissivity of the scales produced by subsequent high temperature oxidation has been measured. While all three elements lead to a modest increase in emissivity, (up to 23% greater than the undoped alloy) only the change caused by manganese is thermally stable. However, this increased emissivity is within 85 percent of that of TDNiCr oxidized to form a chromia scale. The maganese-doped alloy is some 50 percent weaker than undoped DSNiCrAl after the doping treatment, and approximately 30 percent weaker after oxidation

    Cost effective development of a national test bed

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    For several years, the Marshall Space Flight Center has pursued the coordinated development of a Large Space Structures (LSS) National Test Bed for the investigation of numerous technical issues involved in the use of LSS in space. The origins of this development, the current status of the various test facilities and the plans laid down for the next five years' activities are described. Particular emphasis on the control and structural interaction issues has been paid so far; however, immediately emerging are user applications (such as the proposed pinhole occulter facility). In the immediate future, such emerging technologies as smart robots and multibody interactions will be studied. These areas are covered

    Design of a digital controller for spinning flexible spacecraft

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    An approach to digital control system design is applied to the analysis and design of a practical onboard digital attitude control system for a class of spinning vehicles characterized by a rigid body and two connected flexible appendages. The approach used is to design a continuous-data control system that will provide a satisfactory system response. Then, using the digital redesign method, a digital controller with onboard digital computer is designed to provide a digital control system whose states are similar to those of the continuous system at sampling instants. The simplicity of application of this approach is indicated by example. The example, using spinning Skylab parameters, is used to substantiate the conclusions

    An application of high authority/low authority control and positivity

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    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
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