Solution of Two-Echelon Facility Location Problems by Approximation Methods

2017 ◽  
Vol 2610 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Mahyar Jahangiriesmaili ◽  
Sina Bahrami ◽  
Matthew J. Roorda
Keyword(s):  
Urban Areas ◽  
Transportation Cost ◽  
Cost Effective ◽  
Optimal Number ◽  
Approximation Techniques ◽  
Delivery Costs ◽  
Last Mile ◽  
Selection Of ◽  
Center Potential

The two-echelon delivery structure is a strategy that can be implemented in urban areas to lower delivery costs by reducing the movement of heavy goods vehicles. In a two-echelon delivery structure, large trucks deliver shipments from a consolidation center to several terminals, where packages are transferred to smaller trucks for last-mile deliveries. This paper formulates a model that solves the two-echelon delivery structure by the use of approximation techniques. Several potential terminal locations and demand areas were identified, and the optimal number and locations of the terminals were examined, as the model evaluated the most cost-effective routes between the consolidation center, potential terminals, and demand areas. Downtown Toronto, Ontario, Canada, was chosen as the case study area to assess the model, and a cost analysis of the number and locations of the terminals was performed. The experiments showed that the number and the locations of the terminals were greatly influenced by the opening cost of the terminals and the transportation cost of the delivery trucks. It was also discovered that the likelihood of selection of terminals that were positioned near both the consolidation center and the center of the service area was higher than the likelihood of selection of terminals at any other location.

Selecting Sanitation Solutions for Peri-urban Areas: A Case Study of Can Tho, Vietnam

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
Naomi Carrard ◽  
Juliet Willetts ◽  
Cynthia Mitchell ◽  
Mick Paddon ◽  
Monique Retamal
Keyword(s):  
Urban Areas ◽  
Cost Effective ◽  
Asset Replacement ◽  
Fit For Purpose ◽  
Infrastructure Investments ◽  
Sanitation Systems ◽  
Can Tho City ◽  
Sustainable Futures ◽  
Sanitation Infrastructure ◽  
Selection Of

In peri-urban areas where infrastructure investments have not yet been made, there is a need to determine the most context-appropriate, fit for purpose and sustainable sanitation solutions. Decision makers must identify the optimal system scale (on the spectrum from centralized to community to cluster scale) and assess the long-term costs and socio-economic/environmental impacts associated with different options. Addressing both cost-effectiveness and sustainability are essential to ensure that institutions and communities are able to continue to bear the costs and management burden of infrastructure operation, maintenance and asset replacement. This paper describes an approach to sanitation planning currently being undertaken as a research study in Can Tho City in southern Vietnam, by the Institute for Sustainable Futures and Can Tho University in collaboration with Can Tho Water Supply and Sewerage Company. The aim of the study is to facilitate selection of the most context-appropriate, fit for purpose, cost effective and sustainable sanitation infrastructure solution. As such, the study compares a range of sanitation alternatives including centralized, decentralized (at household or cluster scale) and resource recovery options. This paper provides an overview of the study and considers aspects of the Can Tho and Vietnamese regulatory, development and institutional context that present drivers and challenges for comparison of options and selection of fit for purpose sanitation systems.

Uncertainty in 2-D hydraulic modeling: a case study of an experiment in transcritical flowThis article is one of a selection of papers published in this Special Issue on Hydrotechnical Engineering.

2010 ◽  
Vol 37 (7) ◽  
pp. 1014-1023 ◽  
Author(s):  
L. Lewicki ◽  
A. Paquier ◽  
K. El kadi Abderrezzak ◽  
N. Rivière
Keyword(s):  
Urban Areas ◽  
Hydraulic Modeling ◽  
Special Issue ◽  
Numerical Predictions ◽  
Space Step ◽  
Dam Break Flow ◽  
Flow Propagation ◽  
Averaged Model ◽  
Selection Of

Change in flow regime from subcritical to supercritical flow or opposite can be met during a dam break flow propagation but also during floods in urban areas, particularly near crossroads. Detailed laboratory measurements of flow discharge distribution and flow depths are carried out for transcritical dividing flows in a 90° sharp-edged, rectangular junction formed by horizontal open-channels of equal width. These measurements are used to assess the uncertainty of numerical predictions obtained using a two-dimensional (2-D) depth-averaged model. A sensitivity analysis to four parameters, i.e., space step, friction coefficient, diffusion coefficient, and downstream boundary condition, is carried out. For the water depths in the vicinity of the intersection, uncertainty linked to the calibration of the four aforementioned parameters can be higher than 50% because of the difficulty in representing the location and amplitude of the hydraulic jumps while, for the flow ratio between the downstream branches, uncertainty is limited to 10%.

scholarly journals Development of a Sanitation Safety Plan for improving the sanitation system in peri-urban areas of Iringa, Tanzania

2017 ◽  
Vol 7 (2) ◽  
pp. 340-348 ◽  
Author(s):  
M. Domini ◽  
G. Langergraber ◽  
L. Rondi ◽  
S. Sorlini ◽  
S. Maswaga
Keyword(s):  
Urban Areas ◽  
Cost Effective ◽  
Control Measures ◽  
Effective Control ◽  
Safety Plan ◽  
First Results ◽  
Assessment Matrix ◽  
Planning Methodology ◽  
The Given

The Sanitation Safety Planning methodology is implemented within a cooperation project in Iringa, Tanzania. The study presents the methodology and its adaptation and use for the given context, in order to assess risks and to support stakeholders in improving the current sanitation system and validate the design of an improved one. First results of the application of the methodology, obtained in one of the four peri-urban wards of Iringa, demonstrated its efficacy and utility in prioritising risks and identifying cost-effective control measures. Risks were assessed by the use of a semi-quantitative approach, and a simplified risk assessment matrix was developed for the case study. A sensitivity analysis was carried out in order to evaluate criteria for prioritising control measures to be selected for the development of an achievable improvement plan.

scholarly journals Process Plant Upgradation Using Reliability, Availability, and Maintainability (RAM) Criteria

2022 ◽  
Vol 2022 ◽  
pp. 1-17
Author(s):  
Dongqiao Bai ◽  
Qi Yang ◽  
Jian Zhang ◽  
Shouzhi Li
Keyword(s):  
Modular Design ◽  
Cost Effective ◽  
Market Survey ◽  
Effective Solution ◽  
Process Plant ◽  
Process Plants ◽  
Reliability And Availability ◽  
Expected Outcomes ◽  
Selection Of

The objective of this study is to propose a solution for process plant upgradation becoming extinct due to obsoleteness of spares. The study will help in reliability, availability, and maintainability (RAM) based upgradation of control system of process plants in developing countries. Available options for plant upgradation are compact control, modular, and semiautomatic. RAM based upgradation provides solution which is high in reliability and availability (usually all parts are replaced with upgraded and compatible technology) and is easy to maintain throughout the service life of process plant. Case study for stacker and reclaimer of cement plant upgradation is considered to both implement and evaluate the idea. Upgradation methodology is finalized by expert’s feedback regarding selection of hardware with respect to availability, market survey to validate the opinion, and economical availability viability of selected hardware. Pre- and postupgradation scenarios are analyzed to validate the implementation of study and conclude the expected outcomes. The process plant upgradation yielded a cost-effective solution to the problem with automation increasing by 17%, plant maintainability increasing by 80%, and downtime of plant decreasing by 17%. Among all available options, modular design Op1 is considered the best choice that can satisfy RAM criteria.

scholarly journals Picture fuzzy WASPAS method for selecting last-mile delivery mode: a case study of Belgrade

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Vladimir Simić ◽  
Dragan Lazarević ◽  
Momčilo Dobrodolac
Keyword(s):  
Urban Areas ◽  
High Reliability ◽  
Real Life ◽  
Delivery Mode ◽  
Uncertain Information ◽  
Logistics Industry ◽  
Last Mile ◽  
Picture Fuzzy Set ◽  
Last Mile Delivery

Abstract Background Last-mile delivery (LMD) is becoming more and more demanding due to an increasing number of users and traffic problems in cities. Besides, medical crises (like the COVID-19 outbreak) and air pollution represent additional motives for the transition from traditional to socially and environmentally sustainable LMD mode. An emerging problem for companies in the postal and logistics industry is how to determine the best LMD mode in a multi-criteria setting under uncertainty. Method For the first time, an extension of the Weighted Aggregated Sum Product ASsessment (WASPAS) method under the picture fuzzy environment is presented to solve the LMD mode selection problem. The introduced picture fuzzy set (PFS) based multi-criteria decision-making (MCDM) method can be highly beneficial to managers who are in charge of LMD since it can take into account the neutral/refusal information and efficiently deal with high levels of imprecise, vague, and uncertain information. The comparative analysis with the existing state-of-the-art PFS-based MCDM methods approved the high reliability of the proposed picture fuzzy WASPAS method. Its high robustness and consistency are also confirmed. The presented method can be used to improve LMD in urban areas worldwide. Besides, it can be applied to solve other emerging MCDM problems in an uncertain environment. Findings A real-life case study of Belgrade is presented to fully illustrate the potentials and applicability of the picture fuzzy WASPAS method. The results show that postomates are the best mode for LMD in Belgrade, followed by cargo bicycles, drones, traditional delivery, autonomous vehicles, and tube transport.

Vehicle Routing with Stochastic Supply of Crowd Vehicles and Time Windows

2021 ◽  
Author(s):  
Fabian Torres ◽  
Michel Gendreau ◽  
Walter Rei
Keyword(s):  
Urban Areas ◽  
Time Window ◽  
Time Windows ◽  
Cost Effective ◽  
Branch And Price ◽  
Irrational Behavior ◽  
Last Mile ◽  
Stochastic Solution ◽  
The Cost ◽  
Price Algorithm

The growth of e-commerce has increased demand for last-mile deliveries, increasing the level of congestion in the existing transportation infrastructure in urban areas. Crowdsourcing deliveries can provide the additional capacity needed to meet the growing demand in a cost-effective way. We introduce a setting where a crowd-shipping platform sells heterogeneous products of different sizes from a central depot. Items sold vary from groceries to electronics. Some items must be delivered within a time window, whereas others need a customer signature. Furthermore, customer presence is not guaranteed, and some deliveries may need to be returned to the depot. Delivery requests are fulfilled by a fleet of professional drivers and a pool of crowd drivers. We present a crowd-shipping platform that standardizes crowd drivers’ capacities and compensates them to return undelivered packages back to the depot. We formulate a two-stage stochastic model, and we propose a branch and price algorithm to solve the problem exactly and a column generation heuristic to solve larger problems quickly. We further develop an analytical method to calculate upper bounds on the supply of vehicles and an innovative cohesive pricing problem to generate columns for the pool of crowd drivers. Computational experiments are carried out on modified Solomon instances with a pool of 100 crowd vehicles. The branch and price algorithm is able to solve instances of up to 100 customers. We show that the value of the stochastic solution can be as high as 18% when compared with the solution obtained from a deterministic simplification of the model. Significant cost reductions of up to 28% are achieved by implementing crowd drivers with low compensations or higher capacities. Finally, we evaluate what happens when crowd drivers are given the autonomy to select routes based on rational and irrational behavior. There is no cost increase when crowd drivers are rational and select routes that have a higher compensation first. However, when crowd drivers are irrational and select routes randomly, the cost can increase up to 4.2% for some instances.

Traffic Flow Control in Congested Motorway Networks Using Buffers

1998 ◽  
Vol 1612 (1) ◽  
pp. 34-41
Author(s):  
Patrick T. W. Broeren ◽  
Dirk Westland
Keyword(s):  
The Netherlands ◽  
Flow Control ◽  
Traffic Flow ◽  
Urban Areas ◽  
Cost Effective ◽  
Normal Pattern ◽  
Total Delay ◽  
Design Elements ◽  
Motorway Networks

Around large urban areas, daily recurrent congestion in the form of queueing at bottlenecks is nowadays a normal pattern. Apart from the congestion that directly follows from the capacity deficit at bottlenecks, more and more motorways are affected by a secondary congestion problem due to blocking of motorway exits and entries by long queues that build up upstream of bottlenecks, causing delay to travelers who are not going through the bottleneck. A solution to avoid congestion-induced blockage is the construction of so-called buffer facilities. These are local widenings of the motorway by adding one or more lanes just before a bottleneck. Buffers can shorten queues by an amount that is more than proportional to the number of added lanes. In this way congestion-induced blockage can be avoided and total delay is reduced significantly. Buffers are a cost-effective way to fight motorway congestion. The principles and functioning of buffer facilities are explained. Design elements and criteria as well as calculation of buffer dimensions are considered. Attention is given to the control of traffic flow at the entrance and exit of buffers. This is demonstrated with a case study from the Netherlands.

scholarly journals Conception and Development of a Last Mile Vehicle for Urban Areas

2021 ◽  
pp. 167-177
Author(s):  
Andreas Höfer ◽  
Erhard Esl ◽  
Daniel Türk ◽  
Veronika Hüttinger
Keyword(s):  
Urban Areas ◽  
Cost Effective ◽  
Drive Train ◽  
Maximum Speed ◽  
Vehicle Concept ◽  
Legal Regulations ◽  
Last Mile ◽  
Speed Up ◽  
Continuous Power ◽  
On Time Delivery

AbstractIn megacities, increasing globalization effects are leading to rapidly increasing prosperity and augmented purchasing power, and thus to a growing need for punctual, cost-effective, and environmentally friendly delivery of goods. A smart, small electric vehicle concept is presented that targets on meeting the requirements for the delivery of goods in urban areas and that is designed especially for the delivery on the last mile. This last mile vehicle (LMV) for cargo transportation is attached to a truck. Whenever it is needed, for example to deliver goods into narrow streets, in pedestrian areas or in case of traffic jams, it can be unfolded and unloaded from the truck and hereby guarantees a flexible and punctual delivery of goods. This flexible on-time delivery is possible because the last mile vehicle is designed, so that the legal regulations of the non-motorized vehicle lane, that is everywhere to be found in Asia, are met. The vehicle is designed with three wheels, a range of 40-60 km and an electric drive train with a continuous power of 2 × 250 W that enables a maximum speed up to 40 km/h of the vehicle. The drive train consists of a battery pack that can be charged electrically from the truck, two inverters, and two electric wheel hub motors. The LMV has been designed and constructed as a prototype and has been tested on non-public roads to prove the vehicle concept. For Europe, it can be classified as an L2e vehicle and with slight modifications; it can be applied on European roads as well.

scholarly journals EFFECT OF APAMARGA KSARTAIL UTTARBASTI AND PHALAGHRITA IN BILATERAL TUBAL BLOCKAGE- A CASE STUDY

2021 ◽  
pp. 77-81
Author(s):  
Komal Gurjar ◽  
Poonam Choudhary ◽  
K.Bharathi ◽  
B.Pushpalatha
Keyword(s):  
Local Therapy ◽  
Cost Effective ◽  
Significant Treatment ◽  
Tubal Blockage ◽  
Ayurvedic Treatment ◽  
Present Case Study ◽  
Criteria For Selection ◽  
Selection Of

The present case study was carried out to evaluate the role of Uttar basti with in tubal blockage, in order to establish it as a safer and cost effective Ayurvedic treatment modality. The criteria for selection of tubal blockage diagnosed in diagnostic laproscopy. Uttar basti was administered, after cessation of menstruation, to the screened patient through hematological, urinary and serological (HIV, VDRL, HBsAG) investigations. The result suggests that Uttar basti is a highly significant treatment for tubal blockage. Uttar basti is ideal local therapy is to be adopted in tubal block. Apamarga ksar tail is very good Vata kaphashamak guna and Lekhan properties, Taila is having the property to reach minute channels in body. Phala ghruta is best for all Yonirogas, also to reduce Dhaha which is due to Kshar tail.

Consumer perception and readership pattern of toi readers – a case study

2018 ◽  
Vol 9 (1) ◽  
pp. 39-46
Author(s):  
Ishita Adhikari ◽  
Rashi Sangal
Keyword(s):  
Consumer Behaviour ◽  
Print Media ◽  
Developing Economies ◽  
Cost Effective ◽  
Media Industry ◽  
High Effect ◽  
Social Media Platforms ◽  
Buying Behaviour ◽  
Selection Of

India is one of the fastest developing countries today. The increased newspaper readership is the result of its growing literacy and access to news on multiple technology and social media platforms. The research is based on overall consumer behaviour towards selection of newspaper with special reference with, India’s leading newspaper brand. Study of consumer behaviour helps the organisations in improvisation of various strategies by understanding customer psyche while evaluating the various alternatives and selecting the best suited one from all available. It also emphasises on factors influencing buying decision and help the firm figure out the consumer’s needs and accordingly provide customised products as desired by them. The current study demonstrates how individuals make decision regarding the preferences towards the selection of a leading newspaper brand. Further, the research provided information which is useful in taking various marketing decision and helped to reduce the risk of consumer shift to various other brands prevailing in the market. The study was conducted through a survey of respondent’s residing in NCR, Delhi. The research concluded that promotional schemes offered by Times of India had a positive correlation with the buying behaviour of the subscribers. However there is a need to strengthen the awareness of the promotional schemes on regular basis and establishing a strong emotional connect with the readers. I Print media is one of the most powerful and cost effective medium to transfer information and knowledge. The print media industry in India is over century old. Additionally it is a settled industry. This industry basically involves in publishing daily papers and magazines. India has the second biggest population and one of the fastest developing economies on the planet. Along these the expanding level of income of people, groups and the strong rivalry in this industry help print media in its development. As per Arc Gate (2010), Indian Magazine Market Overview, “sensational impacts of internet and globalization in current situation are playing high effect on media industry. Individuals presently consuming news and data from web through computers or mobiles, the fame of print media is not decreasing. To avoid a decline of market share in comparison with other media instruments, the producer should be able to produce high quality printed content and magazines”.

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