scholarly journals Integrated Optimization of Bus Line Fare and Operational Strategies Using Elastic Demand

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Chunyan Tang ◽  
Avishai (Avi) Ceder ◽  
Ying-En Ge
Keyword(s):  
Social Welfare ◽  
Optimization Approach ◽  
Elastic Demand ◽  
Operational Strategies ◽  
Service Levels ◽  
Passenger Demand ◽  
Trip Distance ◽  
Demand Variation ◽  
Additional Service

An optimization approach for designing a transit service system is proposed. Its objective would be the maximization of total social welfare, by providing a profitable fare structure and tailoring operational strategies to passenger demand. These operational strategies include full route operation (FRO), limited stop, short turn, and a mix of the latter two strategies. The demand function is formulated to reflect the attributes of these strategies, in-vehicle crowding, and fare effects on demand variation. The fare is either a flat fare or a differential fare structure; the latter is based on trip distance and achieved service levels. This proposed methodology is applied to a case study of Dalian, China. The optimal results indicate that an optimal combination of operational strategies integrated with a differential fare structure results in the highest potential for increasing total social welfare, if the value of parameter ε related to additional service fee is low. When this value increases up to more than a threshold, strategies with a flat fare show greater benefits. If this value increases beyond yet another threshold, the use of skipped stop strategies is not recommended.

Optimal Operational Strategies for Multiple Bus Lines Considering Passengers’ Preferences

2020 ◽  
Vol 2674 (5) ◽  
pp. 572-586
Author(s):  
Chunyan Tang ◽  
Avishai Ceder ◽  
Ying-En Ge ◽  
Na Wu
Keyword(s):  
Public Transit ◽  
Real Life ◽  
System Efficiency ◽  
Sample Problem ◽  
Transit System ◽  
Operational Strategies ◽  
Passenger Demand ◽  
Single Strategy ◽  
Operational Integration

A public transit system with multiple fixed bus lines faces non-uniform fluctuating passenger demand, both spatial and temporal. This non-uniformity warrants the use of public transit operational strategies to achieve efficiency. This study proposes a methodology for optimizing the operational integration of multiple bus lines to address the spatial non-uniformity of passenger demand by applying five operational strategies: full-route operation, short turn, limited stop, deadheading, and a mixture of either two or three of the latter three strategies. The operational strategies to be developed improve the efficiency of bus lines and accommodate the observed passenger demand in the most favorable manner, that is, through the consideration of passengers’ preferences with the objective of the minimum resulting cost. The methodology is first applied to a sample problem, and then to a real-life case study of multiple bus lines in Dalian, China. The results obtained demonstrate that the effectiveness of combined strategies is higher than that of any single strategy. In the real-life bus line case, a combination of strategies without considering deadheading trips saves four vehicles in comparison with the full-route operation scenario. The anticipated number of vehicles is further reduced by three by the introduction of the deadheading trip strategy, resulting in greater public transit system efficiency.

scholarly journals Introducing fairness in Norwegian air ambulance base location planning

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Caroline J. Jagtenberg ◽  
Maaike A. J. Vollebergh ◽  
Oddvar Uleberg ◽  
Jo Røislien
Keyword(s):  
Social Welfare ◽  
Social Welfare Function ◽  
Mathematical Optimization ◽  
Population Coverage ◽  
Air Ambulance ◽  
Service Levels ◽  
Remote Areas ◽  
The North ◽  
Time Threshold ◽  
Essential Question

Abstract Background A primary task of the Norwegian helicopter emergency medical services (HEMS) is to provide advanced medical care to the critical ill and injured outside of hospitals. Where HEMS bases are located, directly influences who in the population can be reached within a given response time threshold and who cannot. When studying the locations of bases, the focus is often on efficiency, that is, maximizing the total number of people that can be reached within a given set time. This approach is known to benefit people living in densely populated areas, such as cities, over people living in remote areas. The most efficient solution is thus typically not necessarily a fair one. This study aims to incorporate fairness in finding optimal air ambulance base locations. Methods We solve multiple advanced mathematical optimization models to determine optimal helicopter base locations, with different optimization criteria related to the level of aversion to inequality, including the utilitarian, Bernoulli-Nash and iso-elastic social welfare functions. This is the first study to use the latter social welfare function for HEMS. Results Focusing on efficiency, a utilitarian objective function focuses on covering the larger cities in Norway, leaving parts of Norway largely uncovered. Including fairness by rather using an iso-elastic social welfare function in the optimization avoids leaving whole areas uncovered and in particular increases service levels in the north of Norway. Conclusions Including fairness in determining optimal HEMS base locations has great impact on population coverage, in particular when the number of base locations is not enough to give full coverage of the country. As results differ depending on the mathematical objective, the work shows the importance of not only looking for optimal solutions, but also raising the essential question of ‘optimal with respect to what’.

scholarly journals Toward Decentralised Sanitary Sewage Collection Systems: A Multiobjective Approach for Cost-Effective and Resilient Designs

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1886
Author(s):  
Arezoo Zahediasl ◽  
Amin E. Bakhshipour ◽  
Ulrich Dittmer ◽  
Ali Haghighi
Keyword(s):  
Treatment Plant ◽  
Drainage System ◽  
Cost Effective ◽  
Optimization Approach ◽  
Hydraulic Design ◽  
Multiobjective Approach ◽  
Layout Generation ◽  
Plant Allocation ◽  
Problem Solving Process

In recent years, the concept of a centralized drainage system that connect an entire city to one single treatment plant is increasingly being questioned in terms of the costs, reliability, and environmental impacts. This study introduces an optimization approach based on decentralization in order to develop a cost-effective and sustainable sewage collection system. For this purpose, a new algorithm based on the growing spanning tree algorithm is developed for decentralized layout generation and treatment plant allocation. The trade-off between construction and operation costs, resilience, and the degree of centralization is a multiobjective problem that consists of two subproblems: the layout of the networks and the hydraulic design. The innovative characteristics of the proposed framework are that layout and hydraulic designs are solved simultaneously, three objectives are optimized together, and the entire problem solving process is self-adaptive. The model is then applied to a real case study. The results show that finding an optimum degree of centralization could reduce not only the network’s costs by 17.3%, but could also increase its structural resilience significantly compared to fully centralized networks.

scholarly journals Optimal Component Sizing for Peak Shaving in Battery Energy Storage System for Industrial Applications

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2048 ◽  
Author(s):  
Rodrigo Martins ◽  
Holger Hesse ◽  
Johanna Jungbauer ◽  
Thomas Vorbuchner ◽  
Petr Musilek
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Optimization Approach ◽  
Battery Energy Storage System ◽  
Peak Shaving ◽  
Battery Energy Storage ◽  
Battery Energy ◽  
Power Capability

Recent attention to industrial peak shaving applications sparked an increased interest in battery energy storage. Batteries provide a fast and high power capability, making them an ideal solution for this task. This work proposes a general framework for sizing of battery energy storage system (BESS) in peak shaving applications. A cost-optimal sizing of the battery and power electronics is derived using linear programming based on local demand and billing scheme. A case study conducted with real-world industrial profiles shows the applicability of the approach as well as the return on investment dependence on the load profile. At the same time, the power flow optimization reveals the best storage operation patterns considering a trade-off between energy purchase, peak-power tariff, and battery aging. This underlines the need for a general mathematical optimization approach to efficiently tackle the challenge of peak shaving using an energy storage system. The case study also compares the applicability of yearly and monthly billing schemes, where the highest load of the year/month is the base for the price per kW. The results demonstrate that batteries in peak shaving applications can shorten the payback period when used for large industrial loads. They also show the impacts of peak shaving variation on the return of investment and battery aging of the system.

scholarly journals Aboriginal Tourism as Sustainable Social-Environmental Enterprise (SSEE): A Tlingit Case Study from Southeast Alaska

2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Paphaphit Wanasuk ◽  
Thomas F Thornton
Keyword(s):  
Cultural Economic ◽  
Southeast Alaska ◽  
Operational Strategies ◽  
Cultural Sustainability ◽  
Operating Space ◽  
Social Environmental ◽  
Short Time ◽  
Safe Operating ◽  
Dominant Influence

The Tlingit Aboriginal tourism enterprise named Icy Strait Point in Hoonah, Southeast Alaska is used as a case study to develop the new concept of Sustainable Social-Environmental Enterprise (SSEE). SSEE is defined as an innovative enterprise that has dynamic operational strategies while still maintaining its corporate core values and integrating social, environmental, cultural, economic and political (SECEP) sustainabilities in its operations. The SSEE framework assesses enterprises according to five domains of sustainability: social, environmental, cultural, economic, and political. Applying this framework, we find that while social, economic, and cultural sustainability goals have been achieved in a relatively short time by the Aboriginal tourism enterprise in Hoonah, the political and environmental spheres of sustainability are constrained by the dominant influence of the multinational cruise ship industry over tourism development. Thus, for an emerging tourism enterprise to be sustainable, we suggest each of these livelihood dimensions needs to achieve "a safe operating space" that is adaptable over time and to changing social and environmental circumstances.

Identification of the Optimal Product Configuration and Parameters for Improving Manufacturability

1996 ◽  
Author(s):  
Deyi Xue
Keyword(s):  
Global Optimization ◽  
Optimization Methods ◽  
Product Configuration ◽  
Design System ◽  
Optimization Approach ◽  
Continuous Variables ◽  
Integer Variables ◽  
System A ◽  
Global Optimization Methods

Abstract A global optimization approach for identifying the optimal product configuration and parameters is proposed to improve manufacturability measures including feasibility, cost, and time of production. Different product configurations, including alternative design candidates and production processes, are represented by an AND/OR graph. Product parameters are described by variables including continuous variables, integer variables, Boolean variables, and discrete variables. Two global optimization methods, genetic algorithm and simulated annealing, are employed for identifying the optimal product configuration and parameters. The introduced approach serves as a key component in an integrated concurrent design system. A case study example is given to show how the proposed method is used for solving the engineering problems.

A Case Study of Mifos Implementation at Asomi

2010 ◽  
pp. 72-91 ◽  
Author(s):  
Puspadhar Das
Keyword(s):  
Open Source ◽  
The State ◽  
Point Of View ◽  
The Other ◽  
Loan Portfolio ◽  
Operational Strategies ◽  
Microfinance Institution

Mifos is an open source enterprise solution for microfinance. This chapter is a practitioner’s point of view on implementation of Mifos in an organization, based on the author’s experience in implementing Mifos at Asomi, a microfinance institution operating in the state of Assam, India. The factors to be considered in selection and implementation of Mifos are discussed. Various inputs, analyses and resources required for implementation are discussed. Any organization must have a concrete set of operational strategies that enables it to track its borrowers and loan portfolio effectively and on time in order to succeed. Wrong assumptions and choice of wrong technology may only aggravate MIS implementation. Development of technology has removed all the barriers to technologies and has enabled organizations to develop computerised systems streamlined to their operational needs and not the other way round. It is attempted to justify this by using the case of Mifos.

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