scholarly journals Collaborative Fleet Deployment and Routing for Sustainable Transport

2019 ◽  
Vol 11 (20) ◽  
pp. 5666 ◽  
Author(s):  
Ypsilantis ◽  
Zuidwijk
Keyword(s):  
High Capacity ◽  
Container Terminals ◽  
Sustainable Transport ◽  
Service Levels ◽  
Fleet Size ◽  
Transport Services ◽  
Trade Offs ◽  
Time Requirements ◽  
Important Design ◽  
Fleet Size And Mix

Efficient multi-modal transportation in the hinterland of seaport terminals dependson consolidation of container volumes in support of frequent services of high capacity means oftransport, such that sustainable multi-modal transport can compete with uni-modal road transportin cost and time. The tactical design of barge scheduled transport services involves fleet selectionand routing through the inland waterway network. The resulting network service design shouldmeet expected demand and service time requirements set by the shippers. We develop a tightMILP formulation for the Fleet Size and Mix Vehicle Routing (FSMVRP) especially adapted for thePort-Hinterland multi-modal barge network design. Also, an analytical model is developed to helpunderstand important design trade-offs made. We consider the case of horizontal cooperation of dryport container terminals that share capacity. Our results show that in case of cooperation, both costsavings and service levels are improved, and allow for sustainable multi-modal transport to becompetitive with uni-modal truck transport.

The structure and application of an automated system for monitoring passenger traffic

2021 ◽  
Vol 14 (3) ◽  
pp. 4-11
Author(s):  
Evgeniy Anikeev
Keyword(s):  
Data Collection ◽  
General Structure ◽  
Automated System ◽  
Passenger Transport ◽  
Service Levels ◽  
Passenger Traffic ◽  
Advantages And Disadvantages ◽  
Transport Services ◽  
Transport Control

Various methods of collecting data on passenger traffic, their advantages and disadvantages are considered. It is shown that in order to improve the quality of transport services, it is necessary to regularly collect and refine data on passenger traffic. The goals and methods of obtaining information about passenger traffic in the system of municipal passenger transport are indicated. All currently existing methods are divided into three categories: data collection using technical means, data collection with the help of censors and volunteers, and interpretation of fare payments. All the methods presented in the article were compared in terms of labor intensity, costs and accuracy of the results obtained. The advantages and disadvantages of each method are considered. The general structure of an automated system for collecting data on passenger traffic is presented. The necessity of creating a centralized system for collecting and processing data associated with all passenger transport control systems has been substantiated. The tasks solved by this system at all levels of transport services for passengers are shown. Each of the tasks is assigned to one of three service levels: pre-transport, transport and post-transport. It is shown that only solving problems at all levels can ensure high-quality operation of the municipal passenger transport system.

High Yield Assembly of Compliant MEMS Snap Fasteners

2008 ◽  
Author(s):  
Rakesh Murthy ◽  
Aditya N. Das ◽  
Dan O. Popa
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Deformation Energy ◽  
High Yield ◽  
3 Dimensional ◽  
Lab Experiments ◽  
Trade Offs ◽  
Robotic Cells ◽  
And Performance ◽  
Important Design

Heterogeneous assembly at the microscale has recently emerged as a viable pathway to constructing 3-dimensional microrobots and other miniaturized devices. In contrast to self-assembly, this method is directed and deterministic, and is based on serial or parallel microassembly. Whereas at the meso and macro scales, automation is often undertaken after, and often benchmarked against manual assembly, we demonstrate that deterministic automation at the MEMS scale can be completed with higher yields through the use of engineered compliance and precision robotic cells. Snap fasteners have long been used as a way to exploit the inherent stability of local minima of the deformation energy caused by interference during part mating. In this paper we assume that the building blocks are 2 1/2 -dimensional, as is the case with lithographically microfabricated MEMS parts. The assembly of the snap fasteners is done using μ3, a multi-robot microassembly station with unique characteristics located at our ARRI’s Texas Microfactory lab. Experiments are performed to demonstrate that fast and reliable assemblies can be expected if the microparts and the robotic cell satisfy a so-called “High Yield Assembly Condition” (H.Y.A.C.). Important design trade-offs for assembly and performance of microsnap fasteners are discussed and experimentally evaluated.

Design Trade-Offs Under Power Asymmetry: COPs and Flexibility Clauses

2021 ◽  
pp. 1-25
Author(s):  
Jean-Frédéric Morin ◽  
Benjamin Tremblay-Auger ◽  
Claire Peacock
Keyword(s):  
Design Feature ◽  
Original Data ◽  
Environmental Agreements ◽  
Data Set ◽  
Power Asymmetry ◽  
Trade Offs ◽  
Environmental Agreement ◽  
The Creation ◽  
Insurance Mechanism ◽  
Important Design

Abstract Negotiating parties to an environmental agreement can manage uncertainty by including flexibility clauses, such as escape and withdrawal clauses. This article investigates a type of uncertainty so far overlooked by the literature: the uncertainty generated by the creation of a Conference of the Parties (COP) in a context of sharp power asymmetry. When negotiating an agreement, it is difficult for powerful states to make a credible commitment to weaker states, whereby they will not abuse their power to influence future COP decision-making. Flexibility clauses provide a solution to this credibility issue. They act as an insurance mechanism in case a powerful state hijacks the COP. Thus we expect that the creation of a collective body interacts with the degree of power asymmetry to make flexibility clauses more likely in environmental agreements. To test this argument, we draw on an original data set of several specific clauses in 2,090 environmental agreements, signed between 1945 and 2018. The results support our hypothesis and suggest that flexibility clauses are an important design feature of adaptive environmental agreements.

scholarly journals Forward Link Optimization for the Design of VHTS Satellite Networks

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 473 ◽  
Author(s):  
Flor G. Ortiz-Gomez ◽  
Ramón Martínez ◽  
Miguel A. Salas-Natera ◽  
Andrés Cornejo ◽  
Salvador Landeros-Ayala
Keyword(s):  
Cost Model ◽  
High Capacity ◽  
Optimal Solution ◽  
Satellite Networks ◽  
Forward Link ◽  
User Terminal ◽  
Trade Offs ◽  
Service Areas ◽  
Optimum Solution ◽  
The Cost

The concept of geostationary VHTS (Very High Throughput Satellites) is based on multibeam coverage with intensive frequency and polarization reuse, in addition to the use of larger bandwidths in the feeder links, in order to provide high capacity satellite links at a reduced cost per Gbps in orbit. The dimensioning and design of satellite networks based on VHTS imposes the analysis of multiple trade-offs to achieve an optimal solution in terms of cost, capacity, and the figure of merit of the user terminal. In this paper, we propose a new method for sizing VHTS satellite networks based on an analytical expression of the forward link CINR (Carrier-to-Interference-plus-Noise Ratio) that is used to evaluate the trade-off of different combinations of system parameters. The proposed method considers both technical and commercial requirements as inputs, including the constraints to achieve the optimum solution in terms of the user G/T, the number of beams, and the system cost. The cost model includes both satellite and ground segments. Exemplary results are presented with feeder links using Q/V bands, DVB-S2X and transmission methods based on CCM and VCM (Constant and Variable Coding and Modulation, respectively) in two scenarios with different service areas.

scholarly journals Anatomy of an Informal Transit City: Mobility Analysis of the Metropolitan Area of Lima

Urban Science ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 67 ◽  
Author(s):  
Franco Jauregui-Fung ◽  
Jeffrey Kenworthy ◽  
Samar Almaaroufi ◽  
Natalia Pulido-Castro ◽  
Sara Pereira ◽  
...  
Keyword(s):  
Urban Form ◽  
Government Regulation ◽  
High Capacity ◽  
System Quality ◽  
Sustainable Transport ◽  
Mobility Analysis ◽  
Transit System ◽  
Public And Private ◽  
Informal Transit ◽  
German Cities

Lima, as the capital of Peru, has become its first megacity with more than 10 million people in an area that extends over 80 km in a North-South direction. As a city of this size, it faces complex mobility issues with a strong reliance on informal transport modes (buses, minibuses, and paratransit vehicles) due to the deterioration of its transit system quality during the 20th century. This paper examines the current urban situation in Lima through an analysis of the city’s structure, with an emphasis on its transport history and the resulting types of walking, transit, and car-oriented fabrics that can be identified. The mobility analysis was made through data collection, including daily trips by public and private modes, annual passenger kilometers and vehicle kilometers of travel, length of exclusive lanes for public transport and freeways, car and paratransit modes ownership, transport emissions, and safety. These data are used to position Lima in a comparative global context showing its relative strengths and weaknesses in urban form and mobility and providing suggestions for a more sustainable transport and land use system. It is asserted that Lima is an informal transit-oriented city, as distinct from recognized transit metropolises (e.g., Tokyo or German cities such as Berlin or Munich), which often involve private companies, operating under an umbrella of strong government regulation, fare setting, and high service standards. Lima is shown to have some important qualities such as a high density, comparatively low car ownership and freeway provision and still healthy levels of transit and non-motorized mode use despite non-ideal conditions for either. These qualities, if combined with effective governance structures, government commitment to higher quality formal transit systems, which better integrate the important informal transit sector, cessation of high capacity road building, greater protection and encouragement for non-motorized modes and some effective controls over growing car and motorcycle ownership, would see Lima develop a more sustainable transport system.

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