scholarly journals Two-Dimensional Loading in Vehicle Routing Problem With Release and Due Dates

2021 ◽  
Author(s):  
Jaikishan Soman ◽  
Rahul J Patil
Keyword(s):  
Mathematical Formulation ◽  
Scatter Search ◽  
Release Dates ◽  
Two Dimensional ◽  
Due Dates ◽  
Routing Problem ◽  
Cost Structures ◽  
Large Size ◽  
Vehicle Loading ◽  
Strategic Oscillation

Abstract In this paper, we study a two-dimensional vehicle loading and routing problem, in which customer orders with deadlines become available for dispatch as per their release dates. The objective is to minimize the sum of transportation, inventory, and tardiness costs, while respecting various loading and routing constraints. This scenario allows us to study various tradeoffs that tend to arise due to temporal order aggregation across release dates. We thereby propose an integrated mathematical formulation to simultaneously model both the routing and loading requirements of the problem at hand. Specifically, as the problem is NP-hard, we propose a scatter search based heuristic approach to solve large-size instances. Further, its performance is enhanced using problem-specific procedures and strategic oscillation approaches. Additionally, the numerical experiments illustrate the influence of cost structures on both the optimal loading configurations along with the optimal routes. Importantly, our experiments also suggest that the proposed scatter search method can produce good quality solutions in less time.

scholarly journals A Universal Atomic Substitution Conversion Strategy Towards Synthesis of Large-Size Ultrathin Nonlayered Two-Dimensional Materials

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mei Zhao ◽  
Sijie Yang ◽  
Kenan Zhang ◽  
Lijie Zhang ◽  
Ping Chen ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
2D Materials ◽  
Direct Synthesis ◽  
Two Dimensional ◽  
Covalent Bonds ◽  
2D Layered Materials ◽  
Large Size ◽  
Two Dimensional Materials ◽  
Microfabrication Technique ◽  
Atomic Substitution

AbstractNonlayered two-dimensional (2D) materials have attracted increasing attention, due to novel physical properties, unique surface structure, and high compatibility with microfabrication technique. However, owing to the inherent strong covalent bonds, the direct synthesis of 2D planar structure from nonlayered materials, especially for the realization of large-size ultrathin 2D nonlayered materials, is still a huge challenge. Here, a general atomic substitution conversion strategy is proposed to synthesize large-size, ultrathin nonlayered 2D materials. Taking nonlayered CdS as a typical example, large-size ultrathin nonlayered CdS single-crystalline flakes are successfully achieved via a facile low-temperature chemical sulfurization method, where pre-grown layered CdI2 flakes are employed as the precursor via a simple hot plate assisted vertical vapor deposition method. The size and thickness of CdS flakes can be controlled by the CdI2 precursor. The growth mechanism is ascribed to the chemical substitution reaction from I to S atoms between CdI2 and CdS, which has been evidenced by experiments and theoretical calculations. The atomic substitution conversion strategy demonstrates that the existing 2D layered materials can serve as the precursor for difficult-to-synthesize nonlayered 2D materials, providing a bridge between layered and nonlayered materials, meanwhile realizing the fabrication of large-size ultrathin nonlayered 2D materials.

Multi-period Vehicle Routing Problem with Due dates

2015 ◽  
Vol 61 ◽  
pp. 122-134 ◽  
Author(s):  
Claudia Archetti ◽  
Ola Jabali ◽  
M. Grazia Speranza
Keyword(s):  
Vehicle Routing ◽  
Vehicle Routing Problem ◽  
Due Dates ◽  
Routing Problem

A Generalized Strategy for the Synthesis of Large-Size Ultrathin Two-Dimensional Metal Oxide Nanosheets

2017 ◽  
Vol 129 (30) ◽  
pp. 8892-8896 ◽  
Author(s):  
Hewei Zhao ◽  
Yujie Zhu ◽  
Fengshi Li ◽  
Rui Hao ◽  
Shaoxiong Wang ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Two Dimensional ◽  
Large Size

Modélisation hydrodynamique du lac Saint-Pierre, fleuve Saint-Laurent : l'influence de la végétation aquatique

1994 ◽  
Vol 21 (3) ◽  
pp. 471-489 ◽  
Author(s):  
Paul Boudreau ◽  
Michel Leclerc ◽  
Guy R. Fortin
Keyword(s):  
Finite Element ◽  
Aquatic Plants ◽  
Mathematical Formulation ◽  
Substantial Effect ◽  
Data Sets ◽  
Two Dimensional ◽  
Field Surveys ◽  
Dimensional Finite Element ◽  
Modelling Simulation ◽  
St Lawrence River

The macrophytes (aquatic plants) can have a substantial effect on the hydrodynamics of some watercourses. A mathematical formulation for the resistance effect of macrophytes on the current is inserted in a two-dimensional finite element hydrodynamic model. The method introduced herein allows to take into account the morphology, the density, and the growth curve of the different species of macrophytes present in the river. The Lake Saint-Pierre between Sorel and Trois-Rivières (Québec, Canada) in the St. Lawrence River is used to demonstrate the approach. The mathematical aspect of the model is first briefly presented. The field surveys of macrophytes and some other data sets used with the model are then analyzed. Finally, after the calibration–validation step, which insures the good behavior of the model, some results are presented to show the effect of the macrophytes on the flow structure. Key words: hydrodynamics, aquatic plants, St. Lawrence River, Lake Saint-Pierre, two-dimensional modelling, simulation, finite element method, Manning's coefficient.

scholarly journals New Instances for Maximum Weight Independent Set From a Vehicle Routing Application

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Yuanyuan Dong ◽  
Andrew V. Goldberg ◽  
Alexander Noe ◽  
Nikos Parotsidis ◽  
Mauricio G. C. Resende ◽  
...  
Keyword(s):  
Vehicle Routing ◽  
Real World ◽  
Vehicle Routing Problem ◽  
Independent Set ◽  
Maximum Weight ◽  
Routing Problem ◽  
Independent Set Problem ◽  
Maximum Weight Independent Set ◽  
Large Size

AbstractWe present a set of new instances of the maximum weight independent set problem. These instances are derived from a real-world vehicle routing problem and are challenging to solve in part because of their large size. We present instances with up to 881 thousand nodes and 383 million edges.

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