Passive Pedestrian Detection at Unsignalized Crossings

Author(s):  
Dana M. Beckwith ◽  
Katharine M. Hunter-Zaworski

The city of Portland, Oregon, is researching ways to provide safe unsignalized crossings for pedestrians. A concept that shows promise is known as passive pedestrian detection. Passive pedestrian detection is the detection of pedestrians in a stationary or moving state at the curbside of or in a pedestrian crossing by means other than those requiring physical response by the pedestrian. Research was conducted to find sensor technologies that can be used to passively detect pedestrians. Five technologies were found to be options for this type of detection: passive infrared, ultrasonic, microwave radar, video imaging, and piezometric. Of these five technologies, passive infrared, ultrasonic, and microwave radar were selected for testing. An unbiased selection of sensors was made by using a decision matrix in the form of the quality function deployment method, which also provides a record of sensor information for future research. Preliminary testing was conducted on the sensors to ensure that the detection of pedestrians was possible and to determine sensor operating characteristics. Sensors then went through secondary tests to ensure proper operation at an unsignalized crossing. The secondary test site was retrofitted with reflective pedestrian crossing signs, yellow beacons, Doppler radar, and passive infrared sensors chosen from the preliminary tests. Initial secondary tests have shown promising results for the Doppler radar and especially for the passive infrared sensors. Future applications of passive pedestrian detection in Portland will involve installation of sensors at signalized pedestrian crossings.

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3530
Author(s):  
Fukang Ma ◽  
Shuanlu Zhang ◽  
Zhenfeng Zhao ◽  
Yifang Wang

The hydraulic free-piston engine (HFPE) is a kind of hybrid-powered machine which combines the reciprocating piston-type internal combustion engine and the plunger pump as a whole. In recent years, the HFPE has been investigated by a number of research groups worldwide due to its potential advantages of high efficiency, energy savings, reduced emissions and multi-fuel operation. Therefore, our study aimed to assess the operating characteristics, core questions and research progress of HFPEs via a systematic review and meta-analysis. We included operational control, starting characteristics, misfire characteristics, in-cylinder working processes and operating stability. We conducted the literature search using electronic databases. The research on HFPEs has mainly concentrated on four kinds of free-piston engine, according to piston arrangement form: single piston, dual pistons, opposed pistons and four-cylinder complex configuration. HFPE research in China is mainly conducted in Zhejiang University, Tianjin University, Jilin University and the Beijing Institute of Technology. In addition, in China, research has mainly focused on the in-cylinder combustion process while a piston is free by considering in-cylinder combustion machinery and piston dynamics. Regarding future research, it is very important that we solve the instabilities brought about by chance fluctuations in the combustion process, which will involve the hydraulic system’s efficiency, the cyclical variation, the method of predicting instability and the recovery after instability.


2016 ◽  
Vol 8 (5) ◽  
pp. 81
Author(s):  
Farzana Elahi ◽  
Shamsad Ahmed ◽  
Mahbubul Haque ◽  
Nazreen Chowdhury

<p class="Default">In order to sustain in a competitive market like pharmaceutical in Bangladesh, it is important to get an insight into physicians’ preferences in prescribing the drugs. The aim of this work is to investigate and address the physician requirements through an integrated methodology of Analytic Hierarchy Process (AHP) and Quality Function Deployment (QFD). In this research, an expert panel has been interviewed to recognize the criteria affecting physicians’ decisions. The results from AHP derived through Expert Choice software demonstrate that from the viewpoint of physicians, out of the five criteria, quality of product offering is ranked highest in prescribing the drugs followed by the reputation of the company, relationship enjoyed with the company, etc. As for the technical aspects, derived from the relationship matrix of AHP and QFD, out of the sixteen, brand image is ranked first followed by the quality of raw and packaging materials, skilled production personnel etc. The contribution of this research is expected to enable the managers in the pharmaceutical companies to recognize the factors that influence physicians in prescribing drugs for the patients and help them find out challenging items with preeminent alternatives. Few suggestions for future research are also put forward. <strong></strong></p>


2021 ◽  
Author(s):  
Laura S. van Velzen ◽  
Yara J. Toenders ◽  
Aina Avila-Parcet ◽  
Richard Dinga ◽  
Jill A. Rabinowitz ◽  
...  

AbstractDespite numerous efforts to predict suicide risk in children, the ability to reliably identify youth that will engage in suicide thoughts or behaviors (STB) has remained remarkably unsuccessful. To further knowledge in this area, we apply a novel machine learning approach and examine whether children with STB could be differentiated from children without STB based on a combination of sociodemographic, physical health, social environmental, clinical psychiatric, cognitive, biological and genetic characteristics. The study sample included 5,885 unrelated children (50% female, 67% white) between 9 and 11 years old from the Adolescent Brain Cognitive Development (ABCD) study. Both parents and youth reported on children’s STB and based on these reports, we divided children into three subgroups: 1. children with current or past STB, 2. children with psychiatric disorder but no STB (clinical controls) and 3. healthy control children. We performed binomial penalized logistic regression analysis to distinguish between groups. The analyses were performed separately for child-reported STB and parent-reported STB. Results showed that we were able to distinguish the STB group from healthy controls and clinical controls (area under the receiver operating characteristics curve (AUROC) range: 0.79-0.81 and 0.70-0.78 respectively). However, we could not distinguish children with suicidal ideation from those who attempted suicide (AUROC range 0.49-0.59). Factors that differentiated the STB group from the clinical control group included family conflict, prodromal psychosis symptoms, impulsivity, depression severity and a history of mental health treatment. Future research is needed to determine if these variables prospectively predict subsequent suicidal behavior.


2020 ◽  
Vol 12 (14) ◽  
pp. 2279 ◽  
Author(s):  
Shekh Md Mahmudul Islam ◽  
Olga Borić-Lubecke ◽  
Yao Zheng ◽  
Victor M. Lubecke

Non-contact vital signs monitoring using microwave Doppler radar has shown great promise in healthcare applications. Recently, this unobtrusive form of physiological sensing has also been gaining attention for its potential for continuous identity authentication, which can reduce the vulnerability of traditional one-pass validation authentication systems. Physiological Doppler radar is an attractive approach for continuous identity authentication as it requires neither contact nor line-of-sight and does not give rise to privacy concerns associated with video imaging. This paper presents a review of recent advances in radar-based identity authentication systems. It includes an evaluation of the applicability of different research efforts in authentication using respiratory patterns and heart-based dynamics. It also identifies aspects of future research required to address remaining challenges in applying unobtrusive respiration-based or heart-based identity authentication to practical systems. With the advancement of machine learning and artificial intelligence, radar-based continuous authentication can grow to serve a wide range of valuable functions in society.


2007 ◽  
Vol 49 (3) ◽  
pp. 198-201 ◽  
Author(s):  
M. Kastek ◽  
H. Madura ◽  
M. Morawski ◽  
T. Piatkowski ◽  
E. Powiada ◽  
...  

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Eijaz Ahmed Khan ◽  
Mohammed Quaddus

PurposeIn urban streets of developing countries, informal e-rickshaw operation can contribute to the development of economically viable, citizen-oriented and environmentally friendly transport systems. Even though informal e-rickshaw operation is important, significant gaps are apparent in the literature in relation to e-rickshaw sustainability issues and policies, and the development of a methodology grounded in a robust theoretical base. The current paper aims to address these gaps by integrating stakeholder theory (ST) and resource dependency theory (RDT) as we consider the linkage between e-rickshaw operation and the sustainability concept.Design/methodology/approachWe apply fuzzy quality function deployment (QFD), integrated with the 0–1 non-linear optimisation technique, to identify optimal policies for the e-rickshaw informal sector on Khulna city's urban streets in Bangladesh.FindingsThe results suggest that optimal policies should be formalised to regularise e-rickshaw operation. Appropriate supervision and monitoring; infrastructural support for battery charging, parking, battery recycling and solar panel installation; and training and development should all be provided.Research limitations/implicationsThe theoretical and managerial implications of our results are discussed, with future research suggestions presented.Originality/valueTo the best of our knowledge, no previous study has used ST and RDT in e-rickshaw sector research. We recognised that the stakeholder settings for sustainability policies can well influence the behaviour of informal e-rickshaw operators while allotting the necessary resources to this sector. This move assists researchers and policymakers to understand the stakeholders and resource dependency sustainability requirements of this sector and the implementation of the required policies.


2019 ◽  
Vol 11 (17) ◽  
pp. 4741 ◽  
Author(s):  
Sheila Clark ◽  
Courtney Coughenour ◽  
Kelly Bumgarner ◽  
Hanns de la Fuente-Mella ◽  
Chantel Reynolds ◽  
...  

Walking is the most affordable, accessible, and environmentally friendly method of transportation. However, the risk of pedestrian injury or death from motor vehicle crashes is significant, particularly in sprawling metropolitan areas. The purpose of this study was to examine the effect of pedestrian crossing flags (PCFs) on driver yielding behaviors. Participants crossed a marked, midblock crosswalk on a multilane road in Las Vegas, Nevada, with and without PCFs, to determine if there were differences in driver yielding behaviors (n = 160 crossings). Trained observers recorded (1) the number of vehicles that passed in the nearest lane without yielding while the pedestrian waited at the curb and (2) the number of vehicles that passed through the crosswalk while the pedestrian was in the same half of the roadway. ANOVA revealed that drivers were significantly less likely to pass through the crosswalk with the pedestrian in the roadway when they were carrying a PCF (M = 0.20; M = 0.06); drivers were more likely to yield to the pedestrian waiting to enter the roadway when they were carrying a PCF (M = 1.38; M = 0.95). Pedestrian crossing flags are a low-tech, low-cost intervention that may improve pedestrian safety at marked mid-block crosswalks. Future research should examine driver fade-out effects and more advanced pedestrian safety alternatives.


Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2879 ◽  
Author(s):  
Nguyen Thi Phuoc Van ◽  
Liqiong Tang ◽  
Veysel Demir ◽  
Syed Faraz Hasan ◽  
Nguyen Duc Minh ◽  
...  

This paper presents a survey of recent developments using Doppler radar sensor in searching and locating an alive person under debris or behind a wall. Locating a human and detecting the vital signs such as breathing rate and heartbeat using a microwave sensor is a non-invasive technique. Recently, many hardware structures, signal processing approaches, and integrated systems have been introduced by researchers in this field. The purpose is to enhance the accuracy of vital signs’ detection and location detection and reduce energy consumption. This work concentrates on the representative research on sensing systems that can find alive people under rubble when an earthquake or other disasters occur. In this paper, various operating principles and system architectures for finding survivors using the microwave radar sensors are reviewed. A comparison between these systems is also discussed.


2009 ◽  
Vol 20 (05) ◽  
pp. 311-314 ◽  
Author(s):  
Julie A. Honaker ◽  
Thomas E. Boismier ◽  
Nathan P. Shepard ◽  
Neil T. Shepard

Background: A vestibulospinal test known as the Fukuda stepping test (FST) has been suggested to be a measure of asymmetrical labyrinthine function. However, an extensive review of the performance of this test to identify a peripheral vestibular lesion has not been reported. Purpose: The purpose of this study was to evaluate the sensitivity and specificity of the standard FST and a head shaking variation for identification of a peripheral vestibular system lesion. Research Design: In this retrospective review, we compared performance on the FST with and without a head shaking component to electronystagmography (ENG) caloric irrigation unilateral weakness results. Study Sample: We studied these factors in 736 chronic dizzy patients. Results: Receiving operating characteristics (ROC) analysis and area under the curve (AUC) indicated no significant benefit to performance from the head shaking variation compared to the standard FST in identifying labyrinthine weakness as classified by caloric unilateral weakness results. Conclusions: These findings suggest that the FST with and without head shake component is not a reliable screening tool for peripheral vestibular asymmetry in chronic dizzy patients; however, future research may hold promise for the FST as a tool for patients with acute unilateral disorders.


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