7,148 research outputs found
Comparing Data Quality and Cost from Three Modes of On-Board Transit Passenger Surveys
This report presents the findings from a research project investigating the relative data quality and administration costs for three different modes of surveying bus passengers that produce results generalizable to the full passenger population. The three modes, all of which used survey methods distributed or administered onboard the transit vehicle, were: self-complete paper surveys, self-complete online surveys, and interviewer-assisted tablet-based surveys. Results from this study indicate several implications for practitioners choosing a survey mode. First, and most importantly, the analysis reinforces the point that there is no single, best survey mode. The choice of mode must depend on an agencyâs priorities for what questions most need to be answered, what population groups are most important to represent, and exactly how the agency chooses to define concepts like a âcompleteâ survey or a âusableâ address. Findings suggest several general recommendations for current survey practice: (1) online surveys administered via an invitation distributed on the transit vehicle are not a good option; (2) old-fashioned, low-tech paper survey may still be the best option for many bus passenger surveys; (3) changes in survey results that accompany changes in survey methods should be interpreted with caution; and (4) using a new survey method, especially one relying on more complex technologies, may create unexpected glitches
Vibrational Predissociation in Linear Hydrogen-Bonded Complexes
Dr. Shannon Lieb\u27s contribution to Volume 95 of the Proceedings of the Indiana Academy of Science
Detection of crop mark contrast for archaeological surveys
There are no author-identified significant results in this report
Trajectory generation for road vehicle obstacle avoidance using convex optimization
This paper presents a method for trajectory generation using convex optimization to find a feasible, obstacle-free path for a road vehicle. Consideration of vehicle rotation is shown to be necessary if the trajectory is to avoid obstacles specified in a fixed Earth axis system. The paper establishes that, despite the presence of significant non-linearities, it is possible to articulate the obstacle avoidance problem in a tractable convex form using multiple optimization passes. Finally, it is shown by simulation that an optimal trajectory that accounts for the vehicleâs changing velocity throughout the manoeuvre is superior to a previous analytical method that assumes constant speed
Capital structure and its determinants in the United Kingdom â a decompositional analysis
Prior research on capital structure by Rajan and Zingales (1995) suggests that the level of gearing in UK companies is positively related to size and tangibility, and negatively correlated with profitability and the level of growth opportunities. However, as argued by Harris and Raviv (1991), 'The interpretation of results must be tempered by an awareness of the difficulties involved in measuring both leverage and the explanatory variables of interest'. In this study the focus is on the difficulties of measuring gearing, and the sensitivity of Rajan and Zingales' results to variations in gearing measures are tested. Based on an analysis of the capital structure of 822 UK companies, Rajan and Zingales' results are found to be highly definitional-dependent. The determinants of gearing appear to vary significantly, depending upon which component of debt is being analysed. In particular, significant differences are found in the determinants of long- and short-term forms of debt. Given that trade credit and equivalent, on average, accounts for more than 62% of total debt, the results are particularly sensitive to whether such debt is included in the gearing measure. It is argued, therefore, that analysis of capital structure is incomplete without a detailed examination of all forms of corporate debt
HighâResolution ν1 Spectrum of Propyne: Application of a MicrocomputerâControlled InfraredâAcoustic Color Center Laser Spectrometer
Development of a microcomputerâcontrolled infraredâacoustic color center laserspectrometer capable of scanning in 100 cmâ1 sections over the wavelength range 2.2â3.3 Îźm with a resolution of 0.01 cmâ1 (300 MHz) is reported. Application of the spectrometer to investigation of the ν1spectrum of propyne is demonstrated
Real space first-principles derived semiempirical pseudopotentials applied to tunneling magnetoresistance
In this letter we present a real space density functional theory (DFT)
localized basis set semi-empirical pseudopotential (SEP) approach. The method
is applied to iron and magnesium oxide, where bulk SEP and local spin density
approximation (LSDA) band structure calculations are shown to agree within
approximately 0.1 eV. Subsequently we investigate the qualitative
transferability of bulk derived SEPs to Fe/MgO/Fe tunnel junctions. We find
that the SEP method is particularly well suited to address the tight binding
transferability problem because the transferability error at the interface can
be characterized not only in orbital space (via the interface local density of
states) but also in real space (via the system potential). To achieve a
quantitative parameterization, we introduce the notion of ghost semi-empirical
pseudopotentials extracted from the first-principles calculated Fe/MgO bonding
interface. Such interface corrections are shown to be particularly necessary
for barrier widths in the range of 1 nm, where interface states on opposite
sides of the barrier couple effectively and play a important role in the
transmission characteristics. In general the results underscore the need for
separate tight binding interface and bulk parameter sets when modeling
conduction through thin heterojunctions on the nanoscale.Comment: Submitted to Journal of Applied Physic
Molecular Dynamics in Hydrogenâbonded Interactions: A Preliminary Experimentally Determined Harmonic Stretching Force Field for HCNâââHF
Observation of the 2ν1 overtone band in the hydrogenâbonded complex HCNâââHF permits evaluation of the anharmonicity constant X 1 1=â116.9(1) cmâ 1 and determination of the anharmonicity corrected fundamental frequency Ď1. This information, and available data from previous rovibrational analyses in the common and perdeuterated isotopic species of HCNâââHF, offer an opportunity for calculation of an approximate stretching harmonic force field. With the assumptions f 1 2=f 2 4=0.0, the remaining force constants (in mdyn/Ă
) are evaluated as: f 1 1=8.600(20), f 2 2=6.228(9), f 3 3=19.115(40), f 4 4=0.2413(39), f 1 3=0.000(13), f 1 4=0.0343(2), f 2 3=â0.211(6), f 3 4=0.000(2). These compare to f 1 1=9.658(2) in the HF monomer and f 1 1=6.244(3) and f 3 3=18.707(16) in the HCN monomer. These results provide the information necessary to quantitatively assess the applicability of the Cummings and Wood approximation in this hydrogenâbonded complex and also give an estimate of D e j , the equilibrium distortion constant in the harmonic limit. Comparisons of these experimentally determined parameters with the predictions of a b i n i t i o molecular orbital calculations at several levels of approximation are presented
Predicting Purchase Intent Using Pragmatic and Hedonic Kansei Engineering Scales: A Case Study of Kitchen Equipment in China
A Chinese premium kitchen equipment manufacturer was interested in knowing what their consumers liked about their product, and how they could use this to strengthen their market position. They wanted a set of repeatable scales that could be used to both evaluate their own products for future development and to benchmark competitors for sales predictions. To be successful, kitchen equipment should function perfectly, be easy to use and have emotional attributes that appeal to consumers. Kansei Engineering methods have previously been used to support the development of scales to improve the emotional response to such products. However within the Kitchen Equipment industry, there is rarely the time or resource available to implement a full and comprehensive Kansei Engineering analysis within a new product development process. We used a simplified Kansei Engineering process with two notable differences. To develop a set of useful scales we used a mix of hedonic and pragmatic adjectives and we used Kano analysis as a means to systematically reduce the number of adjectives. A factor analysis found four Kansei factors and scales were developed to measure them. The major factor was a Hedonic Scale. The next three factors measured more pragmatic attributes and specifically were: User Interface Quality, Smoke Extraction Quality and Ease of Cleaning. The four factors contributed to 70% of the variance. These factors can be used by the company as repeatable measurement scales to both evaluate their own products for future development and to benchmark competitors for sales predictions
- âŚ