An analysis of short haul air passenger demand, volume 2

Several demand models for short haul air travel are proposed and calibrated on pooled data. The models are designed to predict demand and analyze some of the motivating phenomena behind demand generation. In particular, an attempt is made to include the effects of competing modes and of alternate destinations. The results support three conclusions: (1) the auto mode is the air mode's major competitor; (2) trip time is an overriding factor in intermodal competition, with air fare at its present level appearing unimportant to the typical short haul air traveler; and (3) distance appears to underly several demand generating phenomena, and therefore, must be considered very carefully to any intercity demand model. It may be the cause of the wide range of fare elasticities reported by researchers over the past 15 years. A behavioral demand model is proposed and calibrated. It combines the travel generating effects of income and population, the effects of modal split, the sensitivity of travel to price and time, and the effect of alternative destinations satisfying the trip purpose

Tier- und Pflanzenbilder auf Munzen und Gemmen des klassischen Altertums

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Wild Bactrian Camel Conservation

The wild Bactrian camel (Camelus bactrianus ferus) is critically endangered throughout its range in China and Mongolia. Yet, wild camels remain poorly understood, with knowledge derived primarily from a few short studies and anecdotal information. We initiated a wild camel conservation project to determine the reasons for camel decline and to develop a program to address those problems. We are employing satellite telemetry to gather data on wild camel movement patterns, home ranges, habitat use, and sources of mortality. We are also collecting feces from camels and wolves to determine important forage plants and to begin to assess predation levels, respectively. In addition, steroid fecal analysis may help us evaluate wild camel reproductive physiology. Finally, we are directly observing wild camels to study their behavior. Thus far, we successfully collared two wild camels (one male, one female). We received one year’s data on the cow before her Doppler satellite collar failed and are receiving only sporadic data from the GPS satellite collar on the bull. Over one year, the cow covered a minimum distance of 4,527 km and her 100% minimum convex polygon (MCP) home range was 17,232 km2. Her kernel home range sizes covered 8,696 km2 for 95%, 4,031 km2 for 75%, 2,284 km2 for 55%, and 612 km2 for 25% kernels. We received only 20 GPS locations on our bull from October 10, 2003 to March 22, 2004. During that time, he travelled a minimum of 683 km and his 100% MCP home range extended over 9,191 km2. His kernel home ranges covered 7,255 km2 for the 95%, 3,741 km2 for the 75%, 1,346 km2 for the 50%, 585 km2 for the 25%, and 115 km2 for the 5% kernel. Over the past few autumns, mean group size was 10.07±1.82 wild camels/group. We are currently analyzing the behavioral data and plan to evaluate the fecal samples once we have sufficient samples. We hope to use the knowledge derived from our work to develop a proactive conservation program working in close cooperation with the Mongolian government and other scientists and conservationists

Absolute calibration of the LOPES antenna system

Radio emission in extensive air showers arises from an interaction with the geomagnetic field and is subject of theoretical studies. This radio emission has advantages for the detection of high energy cosmic rays compared to secondary particle or fluorescence measurement methods. Radio antennas like the LOPES30 antenna system are suited to investigate this emission process by detecting the radio pulses. The characteristic observable parameters like electric field strength and pulse length require a calibration which was done with a reference radio source resulting in an amplification factor representing the system behavior in the environment of the KASCADE-Grande experiment. Knowing the amplification factor and the gain of the LOPES antennas LOPES30 is calibrated absolutely for systematic analyses of the radio emission.Comment: 5 pages, Proceedings of International Workshop on Acoustic and Radio EeV Neutrino detection Activities: ARENA, May 17-19, 2005, DESY Zeuthe

Single-qubit unitary gates by graph scattering

We consider the effects of plane-wave states scattering off finite graphs, as an approach to implementing single-qubit unitary operations within the continuous-time quantum walk framework of universal quantum computation. Four semi-infinite tails are attached at arbitrary points of a given graph, representing the input and output registers of a single qubit. For a range of momentum eigenstates, we enumerate all of the graphs with up to $n=9$ vertices for which the scattering implements a single-qubit gate. As $n$ increases, the number of new unitary operations increases exponentially, and for $n>6$ the majority correspond to rotations about axes distributed roughly uniformly across the Bloch sphere. Rotations by both rational and irrational multiples of $\pi$ are found.Comment: 8 pages, 7 figure

De natuurlijke antibiotische eigenschappen van honing

De antibacteriële werking van honing berust vooral op inhibines (remmende stoffen), niet alleen waterstofperoxide (gevormd onder invloed van het enzym glucoseoxidase) maar ook niet-peroxide inhibines. Om wat voor groepen stoffen gaat het, zijn ze van plantaardige oorsprong of is er een bijdrage van de bijen, zijn er verschillen in antibacteriële werking tussen de stoffen en tussen verschillende honingsoorten, wat is de invloed van warmte, licht en opslag op de werkin

Air New England (1970-1974) : a case study of a commuter air carrier

October 1975On cover, series statement "R75-9" is the correct numbering; t.p. has "75-7" and has been corrected to "75-9" by handIncludes bibliographical referencesThis is a brief account of research by CAB staff. The success of Air New England from the beginning of its corporate life to the summer of 1974, when it was offered a certificate of public convenience and necessity by the CAB, can be attributed to a number of factors. The foremost was capable management. The management team at Air New England had previous experience operating commuter airlines in the New England area and was aware of the two major pitfalls that would undermine profitability, excess capacity and high corporate overhead, and was careful to avoid them. Further, the regulatory environment in which the commuters operated was such as to allow various competitive marketing strategies to be tried by management, such as modifying fare structures, flying different routings, and changing frequencies on routes. Additionally, the area chosen for initial market penetration, the Cape and Islands, was dense enough to support a number of airlines during the peak season, and allowed Air New England to minimize its start-up losses. Air New England's management was, of course, aware of the financial situation at Executive, its major established competitor. Air New England realized that if it was able to control its own costs, the financial difficulties that had existed at Executive during previous years would eventually lead to the disappearance of that particular competitor. (Of course, the possibility always existed that new commuters could also appear.) Thus, the emergence of Air New England as the dominant commuter air carrier in New England was a combination of management skills in all areas of airline operations combined with mismanagement on the part of their competitors. In the summer of 1974 Air New England's future was bright.Sponsored by the Department of Transportation

Course-based Science Research Promotes Learning in Diverse Students at Diverse Institutions

Course-based research experiences (CREs) are powerful strategies for spreading learning and improving persistence for all students, both science majors and nonscience majors. Here we address the crucial components of CREs (context, discovery, ownership, iteration, communication, presentation) found across a broad range of such courses at a variety of academic institutions. We also address how the design of a CRE should vary according to the background of student participants; no single CRE format is perfect. We provide a framework for implementing CREs across multiple institutional types and several disciplines throughout the typical four years of undergraduate work, designed to a variety of student backgrounds. Our experiences implementing CREs also provide guidance on overcoming barriers to their implementation

Low-energy electron scattering from methanol and ethanol

Measured and calculated differential cross sections for elastic (rotationally unresolved) electron scattering from two primary alcohols, methanol (CH3OH) and ethanol (C2H5OH), are reported. The measurements are obtained using the relative flow method with helium as the standard gas and a thin aperture as the collimating target gas source. The relative flow method is applied without the restriction imposed by the relative flow pressure conditions on helium and the unknown gas. The experimental data were taken at incident electron energies of 1, 2, 5, 10, 15, 20, 30, 50, and 100 eV and for scattering angles of 5°–130°. There are no previous reports of experimental electron scattering differential cross sections for CH3OH and C2H5OH in the literature. The calculated differential cross sections are obtained using two different implementations of the Schwinger multichannel method, one that takes all electrons into account and is adapted for parallel computers, and another that uses pseudopotentials and considers only the valence electrons. Comparison between theory and experiment shows that theory is able to describe low-energy electron scattering from these polyatomic targets quite well

Composite repetition-aware data structures

In highly repetitive strings, like collections of genomes from the same species, distinct measures of repetition all grow sublinearly in the length of the text, and indexes targeted to such strings typically depend only on one of these measures. We describe two data structures whose size depends on multiple measures of repetition at once, and that provide competitive tradeoffs between the time for counting and reporting all the exact occurrences of a pattern, and the space taken by the structure. The key component of our constructions is the run-length encoded BWT (RLBWT), which takes space proportional to the number of BWT runs: rather than augmenting RLBWT with suffix array samples, we combine it with data structures from LZ77 indexes, which take space proportional to the number of LZ77 factors, and with the compact directed acyclic word graph (CDAWG), which takes space proportional to the number of extensions of maximal repeats. The combination of CDAWG and RLBWT enables also a new representation of the suffix tree, whose size depends again on the number of extensions of maximal repeats, and that is powerful enough to support matching statistics and constant-space traversal.Comment: (the name of the third co-author was inadvertently omitted from previous version