Search results for "BST"
showing 10 items of 10311 documents
New exact methods for the time-invariant berth allocation and quay crane assignment problem
2019
Abstract Efficient management of operations in seaport container terminals has become a critical issue, due to the increase in maritime traffic and the strong competition between ports. In this paper we focus on two seaside operational problems: the Berth Allocation Problem and the Quay Crane Assignment Problem, which are considered in an integrated way. For the continuous BACAP problem with time-invariant crane assignment we propose a new mixed integer linear model in which the vessels can be moored at any position on the quay, not requiring any quay discretization. The model is enhanced by adding several families of valid inequalities. The resulting model is able to solve instances with u…
Irregular packing problems: a review of mathematical models
2020
Abstract Irregular packing problems (also known as nesting problems) belong to the more general class of cutting and packing problems and consist of allocating a set of irregular and regular pieces to larger rectangular or irregular containers, while minimizing the waste of material or space. These problems combine the combinatorial hardness of cutting and packing problems with the computational difficulty of enforcing the geometric non-overlap and containment constraints. Unsurprisingly, nesting problems have been addressed, both in the scientific literature and in real-world applications, by means of heuristic and metaheuristic techniques. However, more recently a variety of mathematical …
System Dynamics in the Predictive Analytics of Container Freight Rates
2021
This study proposes a two-tier cross-validation and backtesting procedure, including expanding and rolling-window test metrics in predictive analytics of container freight rates by utilizing the system dynamics approach. The study utilized system dynamics to represent the nonlinear complex structure of container freight rates for predictive analytics and performed univariate and multivariate time-series analysis as benchmarks of the conventional approach. In particular, the China containerized freight index (CCFI) has been investigated through various parametric methodologies (both conventional time-series and system dynamics approaches). This study follows a strict validation process cons…
Application of queuing methodology to analyze congestion: A case study of the Manila International Container Terminal, Philippines
2016
The objective of this paper is to apply queuing methodology in order to analyze congestion at the Manila International Container Terminal (MICT) in the Port of Manila, the Philippines. The vessels calling at the MICT have to wait in a queue before receiving services at berths because of congestion. For vessel operators and cargo owners this situation creates waiting time costs and delays in delivery of goods to final customers. One option to decrease waiting time is to expand capacity by increasing the number of berths. Construction of a new berth is a time consuming and costly procedure, which needs to be considered carefully before being implemented. To determine whether the data collecte…
The periodic rural postman problem with irregular services on mixed graphs
2019
Abstract In this paper, we deal with an extension of the rural postman problem in which some links of a mixed graph must be traversed a given number of times over a time horizon. These links represent entities that must be serviced a specified number of times in some subsets of days (or periods) of the time horizon. The aim is to design a set of minimum-cost tours, one for each day/period of the time horizon, that satisfy the service requirements. We refer to this problem as the periodic rural postman problem with irregular services (PRPP–IS). Some practical applications of the problem can be found in road maintenance operations and road network surveillance, for example. In order to solve …
Competition and cooperation for intermodal container transhipment: A network optimization approach
2018
Abstract This study presents an analysis of cross-border competition and cooperation between ports in Bangladesh and India. Nepal and Bhutan are countries without access to seaports — two landlocked countries in South Asia, depending solely on the Indian port of Kolkata for their international seaborne trade. Alternatives do exist in the Bangladeshi ports of Chittagong and Mongla but these are not exploited, in spite of trade agreements that allow access to a third country's port, and/or crossing the land of a third, intermediate, country. We formulate a mixed integer linear programming optimization model to find the optimum economic benefit of port users (serving Bhutan, Nepal and Northeas…
The Theory of Forms Without Substance a Romanian Legal Transplant Theory Ahead of its Time
2020
Abstract Comparative law and legal history show us that law is dynamic, always in continuous development, change, or mutation. This dynamic dimension has become a central concern for the comparative law scholars. The circulation of legal models in the world (e.g. legal transplant, legal transfer, legal borrowing, legal migration) is an evergreen issue. This phenomenon has provoked numerous doctrinal disputes, which have been encapsulated in complex theories on its possibilities and impossibilities. In the present article, we will not explore the many modern theories regarding legal transplantation (or under other metaphors). Instead, we will go back in time, in the second half of the ninete…
Miscellaneous Graph Preliminaries
2020
Summary This article contains many auxiliary theorems which were missing in the Mizar Mathematical Library [2] to the best of the author’s knowledge. Most of them regard graph theory as formalized in the GLIB series (cf. [8]) and most of them are preliminaries needed in [7] or other forthcoming articles.
Spontaneous domain formation of phospholipase A2 at interfaces: fluorescence microscopy of the interaction of phospholipase A2 with mixed monolayers …
1992
Abstract Fluorescence microscopy has recently been proven to be an ideal tool to investigated the specific interaction of phospholipase A 2 with oriented substrate monolayers. Using a dual labeling technique, it could be shown that phospholipase A 2 can specifically attack and hydrolyze solid analogous l -α-DPPC domains. After a critical extent of monolayer hydrolysis the enzyme itself starts to aggregate forming regular shaped protein domains (Grainger et al. (1990) Biochim. Biophys. Acta 1023. 365–379). In order to confirm that the existence of hydrolysis products in the mononlayer is necessary for the observed aggregation of phospholipase A 2 , mixed monolayers of d - and l -α-DPPC, l -α…
The synthesis of fluorinated heteroaromatic compounds. Part 1. Five-membered rings with more than two heteroatoms. A review
2005
(2005). THE SYNTHESIS OF FLUORINATED HETEROAROMATIC COMPOUNDS. PART 1. FIVE-MEMBERED RINGS WITH MORE THAN TWO HETEROATOMS. A REVIEW. Organic Preparations and Procedures International: Vol. 37, No. 5, pp. 447-506.