book/book chapter

Urban Spatial Structure

Publication Date

March 1, 1997

Associated Project

Author(s)

Richard Arnott, Kenneth Small

Abstract

An interview with Chicago’s current mayor, Richard M. Daley:

‘New York is too big this way,’ the mayor says, raising a thick hand over his head. Stretching both arms out at his sides, he adds, ‘Los Angeles is too big this way. All the other cities are too small. We’re just right.’ (Bailey and Coleman, 1996, p. 6)

Mayor Daley is catering to a widespread fascination with the roles that urban size and structure play in people’s lives. Academic as well as other observers have long sought explanations for urban development patterns and criteria by which to judge their desirability. Furthermore, as we shall see, understanding the organization of cities yields insights about economy-wide growth processes and sheds light on economic concepts of long standing interest: returns to scale, monopolistic competition, vertical integration, technological innovation, innovation diffusion, and international specialization. Cities also are prime illustrations of some newer academic interests such as complex structural evolution and self-organization.

working paper

Urban Transportation Deregulation in Arizona

Publication Date

December 1, 1983

Author(s)

Roger Teal, Mary Berglund, Terry Nemer

Abstract

On July 1, 1983 privately provided common carriage urban transportation was completely deregulated in Arizona. Deregulation did not directly affect subsidized public transit, but in all other respects the former regulatory framework was abolished. This paper reports on the impacts of deregulation in the first year following its advent. All urban transportation industries are included in the analysis, although the primary impacts occurred to the taxi, airport limousine, and DRT contract industries. The study focused on entry, exit, prices, service innovation, market growth (or decline), and productivity and profitability of the various industries. An adaptation of the industrial organization methodology was used to focus attention on the key economic factors influencing the outcome of the above issues of concern. Results of the first year of deregulation generally conformed to those which were hypothesized. There was no significant impact on the overall urban transportation system or on the modal preferences of travellers. No unsubsidized competitors to public transit appeared in the form of jitneys or commuter buses. The major effects were felt within the taxicab and airport limousine industries, where significant new entry occurred. Prices in the taxi market increased substantially, resulting in a reduction in demand. Productivity and profitability declined in both the taxi and airport limousine industries. Any major benefits to consumers were elmininated when the Phoenix airport authorities prohibited passenger soliciting inside the terminals, which had led to lower ground transportation prices. Prices to consumers are now almost uniformly higher than before deregulation. The prime beneficiaries of deregulation are entrepreneurs who previously were denied entry to the common carriage market, and public agencies who contract for local transit service and have seen contract rates drop because of increased competition.

Suggested Citation
Roger F. Teal, Mary Berglund and Terry Nemer (1983) Urban Transportation Deregulation in Arizona. Working Paper UCI-ITS-WP-83-5. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/2dj2v783.

conference paper

WIP: Practical Removal Attacks on LiDAR-based Object Detection in Autonomous Driving

ISOC Symposium on Vehicle Security and Privacy (VehicleSec)

Publication Date

January 1, 2023

Author(s)

Takami Sato, Yuki Hayakawa, Ryo Suzuki, Yohsuke Shiiki, Kentaro Yoshioka, Qi Alfred Chen

Abstract

LiDAR (Light Detection And Ranging) is an indispensable sensor for precise long- and wide-range 3D sensing, which directly benefited the recent rapid deployment of autonomous driving (AD). Meanwhile, such a safety-critical application strongly motivates its security research. A recent line of research demonstrates that one can manipulate the LiDAR point cloud and fool object detection by firing malicious lasers against LiDAR. However, these efforts evaluate only a specific LiDAR (VLP-16) and do not consider the state-of-the-art defense mechanisms in the recent LiDARs, so-called next-generation LiDARs. In this WIP work, we report our recent progress in the security analysis of the next-generation LiDARs. We identify a new type of LiDAR spoofing attack applicable to a much more general and recent set of LiDARs. We find that our attack can remove >72% of points in a 10×10 m2 area and can remove real vehicles in the physical world. We also discuss our future plans.

Suggested Citation
Takami Sato, Yuki Hayakawa, Ryo Suzuki, Yohsuke Shiiki, Kentaro Yoshioka and Qi Alfred Chen (2023) “WIP: Practical Removal Attacks on LiDAR-based Object Detection in Autonomous Driving”, in ISOC Symposium on Vehicle Security and Privacy (VehicleSec). Available at: https://par.nsf.gov/biblio/10427123-wip-practical-removal-attacks-lidar-based-object-detection-autonomous-driving (Accessed: September 13, 2024).

conference paper

Energy management as a service over fog computing platform

Proceedings of the ACM/IEEE sixth international conference on cyber-physical systems - ICCPS '15

Publication Date

January 1, 2015

Author(s)

Korosh Vatanparvar, Mohammad Al Faruque
Suggested Citation
Korosh Vatanparvar and Mohammad Abdullah Al Faruque (2015) “Energy management as a service over fog computing platform”, in Proceedings of the ACM/IEEE sixth international conference on cyber-physical systems - ICCPS '15. ACM Press, pp. 248–249. Available at: 10.1145/2735960.2735986.

published journal article

Association of Postpartum Temperature Exposure and Postpartum Depression

ISEE Conference Abstracts

Publication Date

August 15, 2024

Author(s)

Yi Sun, Kathryne S. Headon, Wajeeha Umer, Anqi Jiao, Jeff M. Slezak, Chantal C. Avila, Vicki Y. Chiu, David A. Sacks, John Molitor, Tarik Benmarhnia, Jiu Chiuan Chen, Darios Getahun, Jun Wu

Abstract

BACKGROUND AND AIM[|]Women are more prone to mental health problems at postpartum because of biological, emotional, and social changes during this period. Evidence regarding the effect of temperature on postpartum depression (PPD) is extremely limited. We aimed to examine the associations between postpartum temperature exposure and PPD.[¤]METHOD[|]We conducted a retrospective cohort study using data from Kaiser Permanente Southern California electronic health records from 01/01/2008 through 12/31/2018. PPD was first assessed using the Edinburgh Postnatal Depression Scale (score≥10) during the first year of the postpartum period, and further identified by using both diagnostic codes and prescription medications. Historical daily ambient temperatures were obtained from the 4-km resolution gridMET dataset, and linked to participants’ residential addresses at delivery. Postpartum temperature exposures were measured by calculating various temperatures metrics during the period from delivery to PPD diagnosis date. A time-to-event approach with a discrete-time logistic regression was applied to estimate the association between temperature and time to PPD. Effect modification by maternal characteristics and other environmental factors was examined.[¤]RESULTS[|]There were 46,114 (10.73%) PPD cases among 429,839 pregnancies. Increased PPD risks were positively associated with exposure to higher mean temperature (adjusted odds ratio [aOR] per interquartile range increment: 1.07, 95% confidence interval [CI]: 1.05-1.09) and diurnal temperature range (aOR=1.08, 95%CI: 1.06-1.10); the associations were stronger for maximum temperature compared to minimum temperature. African American, Asian, or Hispanic mothers, and mothers ≥25 years of age were more susceptible to temperature-related PPD risk compared to their counterparts. We also observed higher effect of temperature on PPD among mothers exposed to higher air pollution levels or with lower air conditioning penetration rates.[¤]CONCLUSIONS[|]Maternal exposure to higher temperature and diurnal temperature variation during the postpartum period was associated with an increased risk of PPD. Effect modification by maternal age, race/ethnicity, air pollution and air conditioning penetration was identified.[¤]

Suggested Citation
Yi Sun, Kathryne S. Headon, Wajeeha Umer, Anqi Jiao, Jeff M. Slezak, Chantal C. Avila, Vicki Y. Chiu, David A. Sacks, John Molitor, Tarik Benmarhnia, Jiu Chiuan Chen, Darios Getahun and Jun Wu (2024) “Association of Postpartum Temperature Exposure and Postpartum Depression”, ISEE Conference Abstracts, 2024(1). Available at: 10.1289/isee.2024.0299.

other

Custom Python scripts

published journal article

How do compact, accessible, and walkable communities promote gender equality in spatial behavior?

Journal of Transport Geography

Publication Date

April 1, 2018

Author(s)

A.W.-T. Lo, Doug Houston

Abstract

Directing growth towards denser communities with mixed-use, accessible, and walkable neighborhood design has become an important strategy for promoting sustainability, but few studies have examined whether compact development strategies could help reduce within-household gender disparities in spatial behavior by increasing accessibility. We analyze spatial behavior of heterosexual married couples in Southern California based on the 2012 California Household Travel Survey and find that households living in areas with greater regional accessibility and neighborhood walkability have smaller, more centered, and more compact activity spaces overall compared to households in less compact areas, and that married pairs living in more accessible areas have greater equality in the size and centeredness of their activity spaces. We account for residential selection bias in our multivariate analysis and find that a ten unit increase in near-residence Walk Score was associated with a 12–18

Suggested Citation
A.W.-T. Lo and D. Houston (2018) “How do compact, accessible, and walkable communities promote gender equality in spatial behavior?”, Journal of Transport Geography, 68, pp. 42–54. Available at: 10.1016/j.jtrangeo.2018.02.009.

published journal article

Profile of a carless population

Transportation research record

Publication Date

January 1, 1976

Author(s)

R. E. Paaswell, Will Recker, V. Milione

Abstract

A survey was carried out in which 401 respondents in Buffalo, New York, were queried on car accessibility, activity choice, travel mode choice, and attitude toward travel modes and activities. The purpose of the survey was to examine the differences in travel behavior between those who had access to and use of a car and those who did not. Of the households without cars, only 21 percent never had access to a car. The carless sample showed a profile that was predominately low income, female, elderly, and unemployed. The largest segment of those identified as carless lived in the most densely populated portions of the city. Discriminating among modal-use patterns and activities of the various respondent groups was possible. The carless shopped for groceries more often (by walking) and participated in other neighborhood-centered activities more often than did those with cars. Paid social activities was engaged in much less frequently by the carless group. Walking was an important mode for the carless, but the bus was used by most of them, at least occasionally, for all but grocery trips.¡p /¿

Suggested Citation
R. E. Paaswell, W. W. Recker and V. Milione (1976) “Profile of a carless population”, Transportation research record, 578, pp. 16–28. Available at: http://dx.doi.org/.

published journal article

State innovations in affordable housing policy: Lessons from California and New Jersey

Housing Policy Debate

Publication Date

January 1, 2008

Author(s)

Victoria Basolo, Corianne P. Scally

Abstract

Decades of diminishing federal leadership and support for affordable housing policy have opened up a gap in public response to housing needs. Filling this gap is critical if the long-held goal of decent (and affordable) housing for every American is to be honored and communities are to thrive. This article investigates state governments in an era of federal retreat by examining the factors associated with innovations in housing policy in California and New Jersey, two reputed leaders in state housing policy. We collected data through interviews with key informants, as well as from meetings, reports, public documents, agency records, and other secondary sources. Our analysis indicates that state innovations in housing policy are influenced by bureaucratic (internal) factors, such as funding and agency structure, and by environmental (external) factors, such as local autonomy and interest group activity. We conclude with the policy and research implications of our findings.

Suggested Citation
Victoria Basolo and Corianne P. Scally (2008) “State innovations in affordable housing policy: Lessons from California and New Jersey”, Housing Policy Debate, 19(4), pp. 741–774. Available at: 10.1080/10511482.2008.9521654.