A New Perspective on the Average Mixing Matrix

We consider the continuous-time quantum walk defined on the adjacency matrix of a graph. At each instant, the walk defines a mixing matrix which is doubly-stochastic. The average of the mixing matrices contains relevant information about the quantum walk and about the graph. We show that it is the matrix of transformation of the orthogonal projection onto the commutant algebra of the adjacency matrix, restricted to diagonal matrices. Using this formulation of the average mixing matrix, we find connections between its rank and automorphisms of the graph.Comment: 14 page

Bolt Detection Signal Analysis Method Based on ICEEMD

The construction quality of the bolt is directly related to the safety of the project, and as such, it must be tested. In this paper, the improved complete ensemble empirical mode decomposition (ICEEMD) method is introduced to the bolt detection signal analysis. The ICEEMD is used in order to decompose the anchor detection signal according to the approximate entropy of each intrinsic mode function (IMF). The noise of the IMFs is eliminated by the wavelet soft threshold de-noising technique. Based on the approximate entropy, and the wavelet de-noising principle, the ICEEMD-De anchor signal analysis method is proposed. From the analysis of the vibration analog signal, as well as the bolt detection signal, the result shows that the ICEEMD-De method is capable of correctly separating the different IMFs under noisy conditions, and also that the IMF can effectively identify the reflection signal of the end of the bolt

Residential On-Site Carsharing and Off-Street Parking Policy in the San Francisco Bay Area, Research Report 11-28

In light of rising motorization, transportation planners have increasingly supported alternatives to the indiscriminate use of the car. Off-street parking policy and carsharing have emerged as credible alternatives for discouraging car ownership. This report explores an initiative that could connect these policy fields and build on their synergy: the provision of on-site carsharing service in residential developments. It evaluates the performance of on-site carsharing programs in the San Francisco Bay Area by interviewing developers, planners, and carsharing service providers. Interviews were conducted in four Bay Area cities that support the provision of carsharing as an alternative to the private automobile. Based on these interviews, this report identifies the principal factors contributing to the success or failure of on-site carsharing: the unbundling status of off-street parking in residential developments; ties to off-street parking standards; financial constraints; and the level of coordination among stakeholders. The interviews revealed that on-site carsharing has been accepted by developers, planners, and service providers, particularly in densely-populated, transit-rich communities. Nevertheless, there appears to be a gap between on-site carsharing programs and off-street parking standards, and between carsharing programs and carsharing business operations. The authors recommend that a few models for establishing carsharing policy be tested: a model designed to serve high-density cities with traditional carsharing; and another designed to serve moderately-dense communities, with new carsharing options (e.g., peer-to-peer). In the case of the latter, trip reduction can be achieved through the promotion of alternative modes along major corridors

Amenity or Necessity? Street Standards as Parking Policy, Research Report 11-23

This paper explores the rationales underlying the use of minimum street width requirements to mandate street parking. A survey of 97 cities reveals that this mandate is not a technical necessity based on safety concerns or an amenity reflecting market demand, two common beliefs held by decision-makers. Many residents are likely unwilling to pay for street parking if it is unbundled from housing. The hidden parking policies should be made transparent and subject to public oversight, the double standard between private and public streets should be eliminated, and parking on residential streets should be optional

The Intersection of Urban Form and Mileage Fees: Findings from the Oregon Road User Fee Pilot Program, Research Report 10-04

This report analyzes data from the 2006-2007 Oregon Road User Fee Pilot program to assess if and how urban form variables correlate with travel behavior changes that participants made in response to the mileage-based fee program. It finds that charging a noticeably higher fee for driving in congested conditions can successfully motivate households to reduce their VMT in those times and places where congestion is most a problem. Households in both traditional (mixed use, dense, transit-accessible) and suburban (single-use, low density) neighborhoods will likely reduce their peak-hour and overall travel under a charging scheme that charges a high-rate for peak-hour travel, though households in the traditional neighborhoods will do so more. It also finds that a mileage fee program that charges a high rate during the peak hour is likely to strengthen the underlying influence of urban form on travel behavior. In other words, land use probably will matter more to transportation planning if the nation shifts to a new paradigm of mileage-based financing and pricing system. For transportation policy-makers, this raises another layer of consideration when designing the optimal rate structure to achieve policy goals—either reduced VMT and congestion or sustained funding sources. For urban planners, this offers a wonderful opportunity to move towards a sustainable built environment through revised and compatible land use regulation under the context of a mileage-based fee. The research also reveals that program design could significantly affect a household’s response to a mileage-based fee program. Particularly in Portland, the establishment of an endowment account for participants actually increased household VMT when a flat-rate fee was charged, the opposite to policy-makers’ expectation. One possible explanation is that paying the mileage-based fees once a month, instead of paying the gas tax at each visit to the pump, may have encouraged households to drive more due to the reduced gas price at the pump

Analysis on Customer Satisfaction from the Perspective of Cross-border Network Retail Platform AliExpress

On the basis of reviewing the research on customer satisfaction of domestic and foreign scholars, this paper takes the AliExpress platform as an example, expounds the connotation of customer satisfaction from the perspective of cross-border network retail platform, and focuses on the AliExpress DSR service score, namely, product description, customer service and cross-border logistics to analyze customer satisfaction. It is designed to enable merchants to provide superior customer service, increase customer satisfaction, attract and retain customers

Do parking standards matter? Evaluating the London parking reform with a matched-pair approach

Minimum parking standards, which require developers to build a certain amount of off-street parking spaces, are increasingly criticized for leading to excess parking supply and automobile travel in recent years. However, due to the difficulty in identifying the policy effect, few empirical studies have directly and accurately estimated the effects of parking standards on parking supply. The present study examines a parking reform in London, UK, where minimum parking standards for residential developments were replaced with maximum standards in the early 2000s. Using planning application records, we match neighboring pre-reform and post-reform developments to estimate the effect of the parking standard switch and further identify the “binding” and “capping” effects of minimum and maximum parking standards. It is found that the parking reform in London has led to a reduction of approximately 0.76 parking spaces per unit in residential development applications, or 49% of the pre-reform level. Minimum parking standards seem to have a larger impact than maximum ones on parking supply that fell more upon inner city developments, while maximum parking standards have more influenced suburban neighborhoods. Market forces have played a major role in the decline of parking supply. The findings provide strong evidence for the market distortion effect of minimum parking standards

Will mandatory inclusionary housing create mixed-income communities? Evidence from London, UK

Mandatory inclusionary housing, which requires market-rate housing developments to include a proportion of affordable housing units, has the potential to deliver affordable housing in more affluent neighborhoods and create mixed-income communities. This study evaluates this potential effect in London, United Kingdom, where mandatory inclusionary housing has been implemented in all local authorities since the early 2000s. Comparing the spatial concentration and average neighborhood characteristics of affordable housing delivered under inclusionary housing and those created via conventional means (i.e., in the public or nonprofit sector), we find that a higher percentage of inclusionary affordable units are concentrated in a small number of neighborhoods, and both types of affordable units are more likely to be placed in disadvantaged neighborhoods than market-rate units are. We explore the ways in which local implementation of inclusionary housing could have allowed developers to shift some of the inclusionary affordable housing toward disadvantaged neighborhoods