2,602 research outputs found

    Problem Based Learning In The AIS Course

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    This paper first introduces the reader to problem based learning and builds a case for implementing it in accounting. A problem suitable for introducing this approach in the AIS course is then presented. Two possible solutions to the problem are then presented using the MS Office Desktop. The first solution involves the use of dynamic data exchange (DDE) between Word and Excel and the second solution utilizes the reporting capabilities of Access. This is a very modest attempt at introducing this instructional approach in that it is introduced as part of a course rather than a redesign of a complete course or curriculum

    Validity of the Adiabatic Approximation

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    We analyze the validity of the adiabatic approximation, and in particular the reliability of what has been called the "standard criterion" for validity of this approximation. Recently, this criterion has been found to be insufficient. We will argue that the criterion is sufficient only when it agrees with the intuitive notion of slowness of evolution of the Hamiltonian. However, it can be insufficient in cases where the Hamiltonian varies rapidly but only by a small amount. We also emphasize the distinction between the adiabatic {\em theorem} and the adiabatic {\em approximation}, two quite different although closely related ideas.Comment: 4 pages, 1 figur

    Optimization of Airfield Parking and Fuel Asset Dispersal to Maximize Survivability and Mission Capability Level

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    While the US focus for the majority of the past two decades has been on combatting insurgency and promoting stability in Southwest Asia, strategic focus is beginning to shift toward concerns of conflict with a near-peer state. Such conflict brings with it the risk of ballistic missile attack on air bases. With 26 conflicts worldwide in the past 100 years including attacks on air bases, new doctrine and modeling capacity are needed to enable the Department of Defense to continue use of vulnerable bases during conflict involving ballistic missiles. Several models have been developed to date for Air Force strategic planning use, but these models have limited use on a tactical level or for civil engineer use. This thesis presents the development of a novel model capable of identifying base layout characteristics for aprons and fuel depots to maximize dispersal and minimize impact on sortie generation times during normal operations. This model is implemented using multi-objective genetic algorithms to identify solutions that provide optimal tradeoffs between competing objectives and is assessed using an application example. These capabilities are expected to assist military engineers in the layout of parking plans and fuel depots that ensure maximum resilience while providing minimal impact to the user while enabling continued sortie generation in a contested region

    Canada thistle regrowth control one year after herbicide application in winter wheat

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    Non-Peer ReviewedA field study was conducted to evaluate the effectiveness of several herbicides for long-term control of Canada thistle growing in winter wheat. Miscellaneous herbicides were applied at the five leaf stage of winter wheat in the presence of Canada thistle (30 plants per square meter). All herbicides gave effective control of Canada thistle top growth but did not increase yields compared to the weedy check. When Canada thistle control was evaluated one year after herbicide application, three of the nine treatments significantly reduced regrowth: 2,4-D amine at 840 g/ha, clopyralid + MCPA ester at 100 + 400 g/ha, and Clopyralid at 200 g/ha. These treatments reduced Canada thistle numbers by 58, 67, and 83 %, respectively. All herbicide treatments significantly reduced Canada thistle dry matter production one year after application as measured by shoot dry weight per square meter. Clopyralid at 100 g/ha in mixture with either 2,4-D or MCPA ester at 400 g/ha, and 2,4-D amine alone at 840 g/ha reduced dry weight of thistle shoots equally. Clopyralid at 200 g/ha was the most effective treatment tested; Canada thistle shoot dry weight per square meter was reduced by 93 % one year following treatment

    A new perturbative approach to the adiabatic approximation

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    A new and intuitive perturbative approach to time-dependent quantum mechanics problems is presented, which is useful in situations where the evolution of the Hamiltonian is slow. The state of a system which starts in an instantaneous eigenstate of the initial Hamiltonian is written as a power series which has a straightforward diagrammatic representation. Each term of the series corresponds to a sequence of "adiabatic" evolutions, during which the system remains in an instantaneous eigenstate of the Hamiltonian, punctuated by transitions from one state to another. The first term of this series is the standard adiabatic evolution, the next is the well-known first correction to it, and subsequent terms can be written down essentially by inspection. Although the final result is perhaps not terribly surprising, it seems to be not widely known, and the interpretation is new, as far as we know. Application of the method to the adiabatic approximation is given, and some discussion of the validity of this approximation is presented.Comment: 9 pages. Added references, discussion of previous results, expanded upon discussion of main result and application of i

    Observations on the coastal current of Arctic Alaska

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    This paper describes characteristics of the warm coastal current in the vicinity of the ice margin in the Chukchi and Beaufort seas. The warm current originates in Bering Strait and is traced around Pt. Barrow to longitude 152°W in the Beaufort Sea. In the Chukchi Sea it is concentrated near the surface, overlying dense relict bottom water trapped by the shallow depths. Eastward, as the bottom deepens, the warm water descends to mid-depth, eventually becoming warmest near bottom in depths of 30 to 50 m. Mechanisms for cooling and dilution of the warm water are discussed

    Sonic levitation apparatus

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    A sonic levitation apparatus is disclosed which includes a sonic transducer which generates acoustical energy responsive to the level of an electrical amplifier. A duct communicates with an acoustical chamber to deliver an oscillatory motion of air to a plenum section which contains a collimated hole structure having a plurality of parallel orifices. The collimated hole structure converts the motion of the air to a pulsed. Unidirectional stream providing enough force to levitate a material specimen. Particular application to the production of microballoons in low gravity environment is discussed
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