We report on experiments comparing different focal plane array (FPA) tracking algorithms for emulated laser communications links between an aircraft and spacecraft. The links include look-angle-dependent phase distur-bances caused by... more
We report on experiments comparing different focal plane array (FPA) tracking algorithms for emulated laser communications links between an aircraft and spacecraft. The links include look-angle-dependent phase distur-bances caused by boundary-layer turbulence replicated using a deformable mirror. Impairments from platform jitter, atmospheric scintillation, and propagation delay are also included. We study a hyper-hemispherical dome geometry that provides a large field-of-regard, but generates boundary-layer turbulence. Results from experiments comparing peak and centroid FPA tracking algorithms in various environments show that power delivered to the optical fiber varies with algorithm and look-angle. An improvement in steady-state fiber-coupled power of up to 1.0 dB can be achieved through appropriate choice of algorithm. In a real system, this advantage could be realized by implementing a tracking processor that dynamically changes its tracking algorithm depending on look angle an...
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Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of... more
Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
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In addition to the primary high rate communications signal, optical communications systems can include lower power beacon signals to aid in the pointing alignment between the transmitter and receiver. The beacon can be a simple always-on... more
In addition to the primary high rate communications signal, optical communications systems can include lower power beacon signals to aid in the pointing alignment between the transmitter and receiver. The beacon can be a simple always-on signal at a separate wavelength that the receiver can use for spatial tracking. The beacon signal may also be modulated at a low frequency for the purpose of discrimination between potentially multiple optical transmitting terminals. Applying data modulation to the beacon signal to form a low rate communications signal is also possible. The practical application of applying data modulation to a beacon signal along with associated system trades are discussed.
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This article examines the sequencing and timing of firms’ strategic responses after significant industry disruption. We show that it is not the single strategic choice or response per se, but the sequencing and patterns of consecutive... more
This article examines the sequencing and timing of firms’ strategic responses after significant industry disruption. We show that it is not the single strategic choice or response per se, but the sequencing and patterns of consecutive strategic responses that drive a firm’s adaptation and survival in the aftermath of a shift in the industry. We find that firms’ renewal efforts involved differential adaptability in finding balance at the juxtaposition of responding to demand-side pressures and choosing a path of new capability acquisition efficiently. Our study underscores the importance of taking a sequencing approach to studying strategic responses to industry disruption.
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Venkataraman’s essay in this volume argues that the “fourth” force of control of the modern corporation, the entrepreneurial discovery process, can limit the ability of firms to exploit stakeholders. In this essay I explicitly examine the... more
Venkataraman’s essay in this volume argues that the “fourth” force of control of the modern corporation, the entrepreneurial discovery process, can limit the ability of firms to exploit stakeholders. In this essay I explicitly examine the role of time in the entrepreneurial discovery process. First, the role of time in the individual stakeholder’s decisions is examined. Second, at an organizational level, I examine some historical evidence in order to empirically consider how swiftly the discovery process may work. Implications for both theory and empirical testing are discussed.
This is the story of a search for a quest - not the quest itself, but the search for what purports to be the only tangible object of the quest, «the fountain of prosperity». The story is as much mystery and fantasy as it is economics or... more
This is the story of a search for a quest - not the quest itself, but the search for what purports to be the only tangible object of the quest, «the fountain of prosperity». The story is as much mystery and fantasy as it is economics or history, or even sculpture for that matter. Like the quest itself, the search
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Piracy ofcopyrighted digital contents, suchas movies andmusicisrampantincyberspace. A piece ofdigital material may be repeatedly copiedand proliferated throughout theInternet withease. We examined bothsoftware andhardware vulnerabilities... more
Piracy ofcopyrighted digital contents, suchas movies andmusicisrampantincyberspace. A piece ofdigital material may be repeatedly copiedand proliferated throughout theInternet withease. We examined bothsoftware andhardware vulnerabilities inexisting digital copy-protection methods. Asaresult, wepropose anon-copyable disk(NCdisk) thatmakesitsignificantly harderfordigital contents tobe copied. Anydigital content written ontotheNCdiskcanonly bereadthrough apredefined setofoutputs oftheNCdisk, and theoriginal plaintext digital formmayneverbereadoutofthe NCdisk. We addaminimal setofcomponents basedonthe Secret-Protection (SP)architecture totheexisting disk's SoC chipset toattribute thediskwiththenon-copyable property. We further present thesecurity protocol tobeusedalong with theNCdisktoprovide acopy-protected digital moviedownload scenario.
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... Hofer (1980) conducted case analyses on twelve poorly performing firms and identified three successful operating turnaround strategies: cost reduction, asset reduction, and revenue-generation. ... Hofer, CW (1980).... more
... Hofer (1980) conducted case analyses on twelve poorly performing firms and identified three successful operating turnaround strategies: cost reduction, asset reduction, and revenue-generation. ... Hofer, CW (1980). "Turnaround Strategies," Journal of Business Strategy ...
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Abstract Thesis (SM)--Massachusetts Institute of Technology, System Design & Management Program, 2004.. Includes bibliographical references (p. 87-88).. Change is an absolutely essential component of product development. However, some... more
Abstract Thesis (SM)--Massachusetts Institute of Technology, System Design & Management Program, 2004.. Includes bibliographical references (p. 87-88).. Change is an absolutely essential component of product development. However, some changes are too difficult to ...
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Page 1. mir vol. 43, 2003/3, pp. 267-290 # mir MonoQ6nt6nt IntOi lèúliOIKn K6VI6W İ Gabler Verlag 2003 Steven C. Michael Determinants of the Rate of Franchising Among Nations1 Abstract ■ Prior research has examined why franchisors expand... more
Page 1. mir vol. 43, 2003/3, pp. 267-290 # mir MonoQ6nt6nt IntOi lèúliOIKn K6VI6W İ Gabler Verlag 2003 Steven C. Michael Determinants of the Rate of Franchising Among Nations1 Abstract ■ Prior research has examined why franchisors expand abroad, but no paper has ...
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The preliminary results of a novel approach to low-temperature annealing of previously irradiated indium phosphide and gallium arsenide solar cells are reported. The technique is based on forward-biased current annealing. The two types of... more
The preliminary results of a novel approach to low-temperature annealing of previously irradiated indium phosphide and gallium arsenide solar cells are reported. The technique is based on forward-biased current annealing. The two types of III-V semiconductor solar cells were irradiated with 1 MeV electrons to a fluence level of (1-10)*10/sup 14/ electrons/cm/sup 2/. Several annealing attempts were made, varying all conditions. Optimum annealing was achieved when cells were injected with minority currents at a constant 90 degrees C. The current density for each type of cell was also determined. Significant recovery of degraded parameters was achieved in both cases. However, the InP cell recovery notably exceeded the recovery in GaAs cells. The recovery is thought to be caused by current stimulated reordering of the radiator-induced displacement damage. Both types of cell were then subjected to several cycles of irradiation and annealing. The results were also very promising. The significant recovery of degraded cell parameters at low temperature might play a major role in considerably extending the end of life of future spacecraft power supplies.<<ETX>>
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ABSTRACT
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An agency relationship exists whenever one party (the principal) delegates authority to another (the agent). Because agents are assumed to be self-interested and to possess goals that diverge from the principal's goals, the principal... more
An agency relationship exists whenever one party (the principal) delegates authority to another (the agent). Because agents are assumed to be self-interested and to possess goals that diverge from the principal's goals, the principal must expend resources (called agency costs) to insure that agents act in her interest (Jensen & Meckling, 1976). In chains, the firm can choose as outlet managers either employees who are paid a salary (and perhaps a bonus) or franchisees who are granted the right to their outlet's profits after royalties and other expenses. In both cases, an agency problem is created because the firm delegates local decision-making to outlet managers whose interests are not perfectly aligned with that of the franchisor's (Rubin, 1978).
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ABSTRACT Strategic group theory has two distinct aspects. The first is a resemblance among firms grounded in a common pattern of investment; the second is a mutual dependence among firms in the strategic group. Each aspect is analyzed to... more
ABSTRACT Strategic group theory has two distinct aspects. The first is a resemblance among firms grounded in a common pattern of investment; the second is a mutual dependence among firms in the strategic group. Each aspect is analyzed to develop implications for research generally and multi-level research particularly.
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We study the effect of atmospheric fading on the pointing and tracking system of the Mars lasercom terminal. We show system performance with varying atmospheric turbulence. Algorithms to mitigate errors caused by fading are demonstrated.
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This paper examines the sequencing of growth strategies pursued by rival firms in a postderegulated environment. The results indicate heterogeneity in the scale and scope-related choices made by fi...
Optical communications provides an attractive means of achieving wideband data transfer over long distances. We review perceived challenges and enabling technology developments that promise to facilitate a new era of free-space laser... more
Optical communications provides an attractive means of achieving wideband data transfer over long distances. We review perceived challenges and enabling technology developments that promise to facilitate a new era of free-space laser communications. OCIS codes: (060.2605) Free-space optical comm.; (060.4510) Optical comm..; (010.1300) Atmospheric propagation