ESTIMATING SHOPPING DESTINATION CHOICE MODELS FROM TRAVEL DIARY DATA*     

Eric J. Miller  Morton E. O'Kelly 《The Professional geographer》1983,35(4):440-449

This paper examines the issue of modeling dynamic aspects of shopping trip-making behavior using time series data and presents the results of an empirical analysis based on a two-week travel diary survey of households in Hamilton, Ontario. It is concluded that logit models incorporating time dependent variables perform significantly better in terms of both calibrated goodness-of-fit and predictive capabilities than do models which assume no time dependency between choices.  相似文献   

Analyzing hydrologic uncertainty and its impact upon decision making in water resources     

Eric F. Wood 《Advances in water resources》1978,1(5):299-305

Bayesian Inference and Decision Theory tools are applied to the problem of synthetic hydrology when model and parameter uncertainty exist. Issues such as optimal parameter estimation, use of synthetic generation in design problems, and the effects of parameter uncertainty on statistical estimation are discussed and applied to the problem of reservoir slorage-yield analysis.  相似文献   

Measurement of physical librations using laser retroreflectors     

J. Derral Mulholland  Eric C. Silverberg 《Earth, Moon, and Planets》1972,4(1-2):155-159

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Systems for Hazards Identification in High Mountain Areas： An Example from the Kullu District, Western Himalaya   总被引：2，自引：1，他引：1  

JamesS.Gardner EricSaczuk 《山地科学学报》2004,1(2):115-127

Methods and techniques for the identification, monitoring and management of natural hazards in high mountain areas are enumerated and described. A case study from the western Himalayan Kullu District in Himachal Pradesh, India is used to illustrate some of the methods. Research on the general topic has been conducted over three decades and that in the Kullu District has been carried out since 1994. Early methods of hazards identification in high mountain areas involved intensive and lengthy fieldwork and mapping with primary reliance on interpretation of landforms, sediments and vegetation thought to be indicative of slope fail ures, rock falls, debris flows, floods and accelerated soil surface erosion. Augmented by the use of airphotos and ad hoc observations of specific events over time, these methods resulted in the gradual accumulation of information on hazardous sites and the beginnings of a chronology of occurrences in an area. The use of historical methods applied to written and photographic material, often held in archives and libraries, further improved the resolution of hazards information. In the past two decades, both the need for, and the ability to, accurately identify potential hazards have increased. The need for accurate information and monitoring comes about as a result of rapid growth in population, settlements, transportation infrastructure and intensified land uses and, therefore, risk and vulnerability in mountain areas. Ability has improved as the traditional methods of gathering and manipulating data have been supplemented by the use of remotesensing, automated terrain modeling, global positioning systems and geographical information systems. This paper focuses on the development and application of the latter methods and techniques to characterize and monitor hazards in high mountain areas.  相似文献   

The properties of spiral galaxies: confronting hierarchical galaxy formation models with observations     

Eric F. Bell  Carlton M. Baugh  Shaun Cole  Carlos S. Frenk  Cedric G. Lacey 《Monthly notices of the Royal Astronomical Society》2003,343(2):367-384

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FRAGMENTAL BRECCIAS AND THE COLLISIONAL EVOLUTION OF ORDINARY CHONDRITE PARENT BODIES     

Alan E. Rubin  Angeline Rehfeldt  Eric Peterson  Klaus Keil  Eugene Jarosewich 《Meteoritics & planetary science》1983,18(3):179-196

Our survey of type 4–6 ordinary chondrites indicates that gas-poor, melt-rock and/or exotic clast-bearing fragmental breccias constitute 5%, 22% and 23%, respectively, of H, L and LL chondrites. These abundances contrast with the percentages of solar-gas-rich regolith breccias among ordinary chondrites: H (14%), L (3%) and LL (8%) (Crabb and Schultz, 1981). Petrologic study of several melt-rock-clast-bearing fragmental breccias indicates that some acquired their clasts prior to breccia metamorphism and others acquired them after metamorphism of host material. In general, the melt-rock clasts in gas-poor H chondrite fragmental breccias were acquired after breccia metamorphism and were probably formed by impacts into boulders or exposed outcrops of H4-6 material in the H chondrite parent body regolith. In contrast, most of the melt-rock clasts in gas-poor L and LL fragmental breccias were acquired prior to breccia metamorphism. The low abundance of regolith breccias among L chondrites and evidence that at least two-thirds of the L chondrites suffered a major shock event 0.5 Gyr ago, suggest that the L parent body may have been disrupted by a major collision at that time and that the remaining parent body fragments were too small to develop substantial regoliths (e.g., Heymann, 1967; Crabb and Schultz, 1981). Such a disruption would have exposed a large amount of L chondrite bedrock, some of which would consist of fragmental breccias that acquired melt-rock clasts very early in solar system history, prior to metamorphism. The exposed bedrock would serve as a potential target for sporadic meteoroid impacts to produce a few fragmental breccias with unmetamorphosed melt-rock clasts. The high proportion of genomict brecciated LL chondrites reflects a complex collisional history, probably including several episodes of parent body disruption and gravitational reassembly. Differences in the abundances of different kinds of breccias among the ordinary chondrite groups are probably due to the stochastic nature of major asteroidal collisions.  相似文献   

IGU commission on the coastal environment     

Eric C. F. Bird 《GeoJournal》1983,7(4):377-377

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PLAGIOCLASE TWIN LAWS IN LUNAR HIGHLAND ROCKS; POSSIBLE PETROGENETIC SIGNIFICANCE     

Eric Dowty  Klaus Keil  Martin Prinz 《Meteoritics & planetary science》1974,9(3):183-197

Plagioclases in different types of lunar highland rocks (all highly feldspathic) are twinned according to different laws and in different styles. Carlsbad and Carlsbad-albite twins, presumed to be growth twins, occur mainly in rocks which show igneous texture, and which have not been severely brecciated. These two twin laws appear to be absent from cataclastic rocks, including cataclastic anorthosite, possibly because the original twins were preferentially broken up in cataclasis (the composition plane being a plane of weakness). Pericline and lamellar albite twins, presumed to be deformation twins (except for some albite growth twins) occur in all types of rocks, and obvious deformation features, such as bending of lamellae, are well shown in many cataclastic rocks. Surprisingly, some Carlsbad and Carlsbad-albite twins are found in rocks with granoblastic texture, which presumably recrystallized in the solid state. This contrasts with previous observations on terrestrial metamorphic rocks, in which such growth twins are scarce or absent. The difference may be due to a higher rate of temperature change in the shock-heated lunar rocks. Further study of plagioclase twin laws in lunar rocks may assist in deciphering the complicated history of the highlands.  相似文献   

Co-Phase Analysis of Atmospheric Wave Data     

Hernan A. Montes  Eric S. Posmentier 《Geophysical Journal International》1971,26(1-4):271-278

Summary Co-phase is a statistic designed for the detection and parameter estimation of signals by detector arrays. Ionospheric motions detected by an array of four phase-path sounders following a large earthquake are found by the co-phase technique to have a phase velocity equal to that of seismic Rayleigh waves of the same period, and to arrive from the direction of the epicentre. The calculation of co-phase for an 80-min sample of data from an 8-element array of microbarographs detects the presence of a signal from a high energy event despite a signal-to-noise ratio of less than unity. Co-phase analysis of acoustic signals generated by the Saturn-Apollo rocket launches indicates that these signals originate at ionospheric heights and propagate in a waveguide between a soundspeed maximum and a steep density gradient in the mesosphere.  相似文献   

Hα flare spectra     

Stephen A. Schoolman  Eric D. Ganz 《Solar physics》1981,70(2):363-374

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