Making Automatic Passenger Counts Mainstream

2005 ◽  
Vol 1927 (1) ◽  
pp. 206-216 ◽  
Author(s):  
Peter G. Furth ◽  
James G. Strathman ◽  
Brendon Hemily
Keyword(s):  
Case Studies ◽  
Data Structures ◽  
Data Stream ◽  
Peak Load ◽  
Data Accuracy ◽  
Load Measurement ◽  
Automatic Passenger Counters ◽  
Transit Agencies

Although automatic passenger counters (APCs) have been used for many years, significant obstacles have hindered their becoming a mainstream source of data for monitoring ridership and peak load, estimating passenger miles, and other measures of passenger use important for transit management. The key to APC usefulness is the automatic, routine conversion of the APC data stream into a database of accurate counts. On the basis of case studies of transit agencies, five issues important to achieving this goal are analyzed: data structures, data accuracy, accuracy need and sampling requirements, controlling drift, and balancing algorithms. Balancing algorithms deal with routes with loop ends, negative loads, and rounding. Sampling and accuracy requirements related to passenger miles estimates for National Transit Database (NTD) reporting are also analyzed. The analysis shows that, for most agencies, NTD precision requirements can be met with a small level of fleet penetration, provided that measurement, screening, parsing, and balancing methods keep bias in load measurement below 8%.

Lock-free Data Structures for Data Stream Processing

2019 ◽  
Vol 19 (3) ◽  
pp. 209-218
Author(s):  
Alexander Baumstark ◽  
Constantin Pohl
Keyword(s):  
Data Structures ◽  
Data Stream ◽  
Stream Processing ◽  
Data Stream Processing ◽  
Free Data

scholarly journals Fork of Energy Hybrid for Small Island: Case Studies North Maluku

2017 ◽  
Author(s):  
Rishal Asri
Keyword(s):  
Diesel Engine ◽  
Solar Energy ◽  
Case Studies ◽  
Fossil Fuel ◽  
Peak Load ◽  
Small Island ◽  
Electrical System ◽  
Provincial Capital ◽  
Total Capacity

North Maluku province has an area of 145.8 thousand km2 with the Provincial Capital in Sofifi. North Maluku electrical system is divided into 7 system that is Ternate Tobelo, Tidore, Bacan, Sanana and Daruba, and plus 21 smaller generating units spread out. The source of electricity North Maluku province is dominated (99%) from fossil fuel by using diesel engine, and small portion from solar energy (1%). Total capacity of the electricity is 200MW, with peak load 186 MW.Keywords: Electrcity, North MalukuSeminar

scholarly journals Energy Hybrid for Small Island: Case Studies North Maluku

2017 ◽  
Author(s):  
Rishal Asri
Keyword(s):  
Diesel Engine ◽  
Solar Energy ◽  
Case Studies ◽  
Fossil Fuel ◽  
Peak Load ◽  
Small Island ◽  
Electrical System ◽  
Provincial Capital ◽  
Total Capacity

North Maluku province has an area of 145.8 thousand km2 with the Provincial Capital in Sofifi. North Maluku electrical system is divided into 7 system that is Ternate Tobelo, Tidore, Bacan, Sanana and Daruba, and plus 21 smaller generating units spread out. The source of electricity North Maluku province is dominated (99%) from fossil fuel by using diesel engine, and small portion from solar energy (1%). Total capacity of the electricity is 200MW, with peak load 186 MW.Keywords: Electrcity, North Maluku

Evaluating Interface Standards for the Public Transit Industry

1998 ◽  
Vol 1618 (1) ◽  
pp. 172-179 ◽  
Author(s):  
Mark Hickman ◽  
Sam Tabibnia ◽  
Theodore Day
Keyword(s):  
Case Studies ◽  
San Francisco ◽  
Public Transit ◽  
Systems Integration ◽  
Learning By Doing ◽  
Systems Architecture ◽  
The Public ◽  
Advantages And Disadvantages ◽  
Bay Area ◽  
Transit Agencies

The rationale behind the current research and development of interface standards for the public transit industry is explored. Recent efforts to define an information systems architecture for public transit have not sufficiently discussed the underlying need for information system standards and what impacts these standards might have on the transit industry as well as on vendors. Both advantages and disadvantages to the development of these standards are identified. For public transit agencies, there appears to be a well-reasoned yet unsupported belief that interface standards will be beneficial for systems integration. To explore the impacts for vendors, a survey was developed and fielded to learn about the characteristics of products and vendor attitudes toward interface standards. The results, though not conclusive, suggest that vendors are willing to consider standards; however, needed product customization and more comprehensive systems are important factors weighing against open interface standards. Also reported are three case studies of recent technology applications in the San Francisco Bay Area in which experiences with technical system design and systems integration are described. These case studies strongly suggest that key factors such as market timing, vendor-agency communication, and “learning by doing” affect the development of interface requirements and standards for the transit industry.

Dynamic authenticated data structures with access control for outsourcing data stream

2017 ◽  
Vol 11 (5) ◽  
pp. 235-242 ◽  
Author(s):  
Yi Sun ◽  
Xingyuan Chen ◽  
Xuehui Du ◽  
Jian Xu
Keyword(s):  
Access Control ◽  
Data Structures ◽  
Data Stream ◽  
Authenticated Data Structures

scholarly journals Bounded Model Checking for Hyperproperties

2021 ◽  
pp. 94-112
Author(s):  
Tzu-Han Hsu ◽  
César Sánchez ◽  
Borzoo Bonakdarpour
Keyword(s):  
Model Checking ◽  
Path Planning ◽  
Case Studies ◽  
Data Structures ◽  
Mutation Testing ◽  
Bounded Model Checking ◽  
Sat Solving ◽  
Concurrent Data Structures ◽  
Simultaneous Quantification

AbstractThis paper introduces a bounded model checking (BMC) algorithm for hyperproperties expressed in HyperLTL, which — to the best of our knowledge — is the first such algorithm. Just as the classic BMC technique for LTL primarily aims at finding bugs, our approach also targets identifying counterexamples. BMC for LTL is reduced to SAT solving, because LTL describes a property via inspecting individual traces. Our BMC approach naturally reduces to QBF solving, as HyperLTL allows explicit and simultaneous quantification over multiple traces. We report on successful and efficient model checking, implemented in our tool called , of a rich set of experiments on a variety of case studies, including security, concurrent data structures, path planning for robots, and mutation testing.

scholarly journals Extending Non-Termination Proof Techniques to Asynchronously Communicating Concurrent Programs

10.29007/c7v2 ◽  
2018 ◽  
Author(s):  
Matthias Kuntz ◽  
Stefan Leue ◽  
Christoph Scheben
Keyword(s):  
Case Studies ◽  
Data Structures ◽  
Theorem Proving ◽  
Asynchronous Communication ◽  
Control Flow ◽  
Concurrent Programs ◽  
Prototype Tool ◽  
Proof Techniques ◽  
High Level ◽  
Termination Proofs

Currently, there are no approaches known that allow for non-termination proofs of concurrent programs which account for asynchronous communication via FIFO message queues. Those programs may be written in high-level languages such as Java or Promela. We present a first approach to prove non-termination for such programs. In addition to integers, the programs that we consider may contain queues as data structures. We present a representation of queues and the operations on them in the domain of integers, and generate invariants that help us prove non-termination of selected control flow loops using a theorem proving approach. We illustrate this approach by applying a prototype tool implementation to a number of case studies.

scholarly journals Third-Rail Insulator Failure Causes and Mitigating Practices: A Comparative Study of Multiple Case Studies in the U.S.

2020 ◽  
Vol 6 (4) ◽  
pp. 205-217
Author(s):  
Behzad Rouhanizadeh ◽  
Sharareh Kermanshachi
Keyword(s):  
Case Studies ◽  
Decision Makers ◽  
Transit System ◽  
Transit Systems ◽  
Rail Systems ◽  
Multiple Case ◽  
Multiple Case Studies ◽  
Transit Agencies ◽  
Appropriate Practices ◽  
Best Fit

AbstractRail transit systems are one of the most important and popular types of transit systems used daily in metropolitan areas all around the world. The third rail is one of the providers of traction power in electrified rail systems, but it faces several issues, such as insulator failures. The purpose of this study is to investigate the causes of insulator failures, which have not been comprehensively studied and presented in the literature. To accomplish this objective, eight transit systems with third rails were selected to (1) investigate the characteristics of third-rail systems, (2) determine the causes of insulator failures, (3) analyze the costs associated with insulator failures, and (4) determine mitigating practices to reduce the number and cost of insulator failures. After a thorough literature review, details of eight case studies were collected from different transit agencies, and their subject matter experts were asked to complete a survey and provide input. The results revealed that a build-up of dirt was the major cause of the 17 identified causes of insulator failures; carbon dust and dirt were identified as the most present particles in third-rail systems. It was noted that transit agencies often implement multiple mitigating practices such as cleaning the insulator, performing visual inspections, and conducting regular maintenance to reduce the number and cost of insulator failures. The findings of this study will help decision-makers for transit systems make timely decisions to prevent third-rail insulator failures and adopt appropriate practices that best fit their transit system.

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