Tabu search for ship routing and scheduling

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 20/12/2006.This thesis examines exact and heuristic approaches to solve the Ship Routing and Scheduling Problem (SRSP). The method was developed to address the problem of loading cargos for many customers using heterogeneous vessels. Constraints relate to delivery time windows imposed by customers, the time horizon by which all deliveries must be made and vessel capacities. The objective is to minimise the overall operation cost, where all customers are satisfied. Two types of routing and scheduling are considered, one called single-cargo problem, where only one cargo can be loaded into a ship, and the second type called multi-cargo problem, where multiple products can be carried on a ship to be delivered to different customers. The exact approach comprises two stages. In the first stage, a number of candidate feasible schedules is generated for each ship in the fleet. The second stage is to model the problem as a set partitioning problem (SPP) where the columns are the candidate feasible schedules obtained in the first stage. The heuristic approach uses Tabu Search (TS). Most of the TS operations, such as insert and swap moves, tenure, tabu list, intensification, and diversification are used. The results of a computational investigation are presented. Solution quality and execution time are explored with respect to problem size and parameters controlling the tabu search such as tenure and neighbourhood size. The results showed that the average of the solution gap between TS solution and SPP solution is up to 28% (for small problems) and up to 18% for large problems. However, obtaining an optimal solution requires a large amount of computer time to produce the solution compared to obtaining approximate solutions using the TS approach. The use of Tabu Search for SRSP is novel and the results indicate that it is viable approach for large problems

Cloud Computing: The Future of IT Industry

As a result of the research processing in the computing field, a new computing model appeared based on the development of many computing models such as parallel computing, distributed computing, and grid computing. Many normal distributed computers collaborate of achieve a function like a super computer. The computation will be assigned to this super computer rather than local computer or remote server. This is the basic concept of cloud computing. However, there is a new implementation of cloud computing was introduced based on using the internet millions of computers connected to a super cloud. Cloud computing has several advantages such as; user does not need to worry about how the cloud runs, viruses, maintenance, etc. We would expect that cloud computing is going to reshape the IT industry. In this paper we discuss cloud computing from different angles such as concept, characteristics and classifications of cloud computing

Integrating Balanced Scorecard and Simulation Modelling to Improve Emergency Department Performance in Irish Hospitals

In the healthcare sector, there is a requirement for innovative solutions in managing the high levels of complexity and uncertainty within Emergency Departments (EDs). Simulation modeling is currently seen as a competent means of analyzing EDs, which allows changes effects to be understood and predicted more easily. The Balanced Scorecard (BSC), well-known performance management concept, has become a steering method in approaching new improvement cycles. This paper presents a methodology that integrates BSC and simulation modeling to improve the performance of ED in a University Hospital in North Dublin. BSC design began with understanding patient\u27s needs, ED activities, as well as training and development programs. Then a detailed simulation model was developed and integrated with the BSC to provide a comprehensive decision support system. This integrated model can be used for evaluation of various decisions in emergency area. The developed integrated model is also a tool for improvement

Chitosan as an eco-friendly heterogeneous catalyst for Michael type addition reactions. A simple and efficient route to pyridones and phthalazines

Depending on their nature, nitrile activated methylene compounds add readily to β-enaminones in presence of chitosan to yield dienamides, pyridones or pyridine thiones. The dienamides, formed in this manner, can be readily converted to pyridones by stirring in refluxing acetic acid. Reaction of pyridazinones with a mixture containing benzaldehyde, malononitrile and chitosan affords phthalazines that are also produced by reaction of pyridazinone with benzylidene-malononitrile

Developing New Technology-Related Bachelor Programs in The Middle East

The purpose of this paper is to summarize the development of five recently launched bachelor programs at the University College of Applied Sciences in Gaza, Palestine. These programs are Technology Education, Business with Technology, Geographic Information Systems, Development Planning, and Building Technology. These programs are non-traditional academic programs where traditional curricula are hybrid with a varying degree of engineering and IT-related technology courses. These programs have been accredited by the local accreditation board and a few hundred students are currently enrolled in these programs, with the first batch of these students have already graduated in the summer of 2010-2011. The paper sheds some details on the curriculum of these programs. Though these engineering and technology-related academic programs were developed with both local and regional interests, universities worldwide could benefit from this experience

Submerged vanes turbulence : experimental analysis

Experimental study was conducted to analyze the physical flow turbulence and sediment distribution with submerged vane. The objectives behind the investigation were verified and compare results with the Odgaard theory, also; achieved to measure vertical pressures acting on both sides of submerged vane, calculate lift and drag forces, lift and drag coefficients experimentally, that the theory of Odgaard was fails to predict satisfactorily. Other motivation of the study was investigates experimentally the hydrodynamic characterization of submerged vanes as; velocities fields, circulation, vorticity, bed topography, pressures, drag and lift forces with its coefficients, study physical fluid turbulence of submerged vanes as; Reynolds normal and shear stresses, turbulent kinetic energy and rate of dissipation, turbulence intensities, Kolmogorov scales, kinetic energy spectrum, turbulent velocities fields, fluctuating velocities and finally Reynolds stresses histograms. Tests were conducted with clear water was transported throughout the re-circulated rectangular channel with cross-section 7.5 m long, 2.52 m wide channel with a bed consisting of 50 cm thick layer of sand with a median diameter of 1.6-mm and a geometric standard deviation of 1.36. Velocities were measured with a 7 Acoustic Doppler Velocimeter ADV, which were calibrated and checked periodically, depths and water surface elevations were measured with a gauge that could be read with an error of less than 0.3 mm. The current meter, gauges were mounted on a movable instrument sliding carriage, which rode on rails a top of the channel walls, on a traversing mechanism, which enabled them to be positioned at any desired location in the channel. Positioning and data sampling were controlled from a computer program. The water surface elevations were used to determine water surface slope S and Darcy-Weisbach friction factor f=8gRS/u_o^2, where uo = undisturbed (pre-vane) cross-sectional-averaged velocity. In all tests, uo=0.2867 m/s, and the discharge Q=116,62 l/s =0.11662 m^3/s. The vanes were made of 14 mm-thick PVC sheet, they were rectangular in shape, with height H = 7 cm = 0.4337d, and length L = 25 cm = 3.571H. In all tests, the vanes were placed at an angle of attack of 20 degrees with the channel centerline. Water depth was 0.1614 m, pre-vane water surface slope, friction factor and geometric standard deviation, sg, were 1.6×10^(-3), 0.045 and 1.36 respectively. The Vectrinos were been calibrated to work at 25Hz and for each position taken data for 4 minutes, a sample volume that is located approximately 4.3 mm of the device. For each position there are seven Vectrinos 10 cm distance from one to other taking data, so data recorded 7 points at the same time. Data recorded were taking on about 24.080 points on whole the sectional cross channel, with the aim to measure the velocities once the channel-bed has reached to the permanent regime or steady state (equilibrium), during the measurements of velocities, we has taken the bed topography (bathymetry) of the channel-bed by using ADV. In the current dissertation, we installed 30 piezometers in each side of Vane. Once obtained the experimental pressures measured at the laboratory on both sides of vane, the pressure difference between vane sides (¿P), and the perpendicular resultant force (FR¿) acting on the vane, first calculated the resultant force between drag and lift components (FR), then we used this force to calculate drag force FD and lift force FL, also calculated Drag coefficient CD, and finally we calculated the Lift coefficient CL. Results, includes submerged vanes turbulence statistics as; Probability distribution of the velocity field, Reynolds stresses, Turbulence intensity, Kinetic and Dissipation energy, and finally, Kolmogorov turbulence scales. Other results contain energy spectrum, turbulent velocities fields, fluctuating velocities and Reynolds stresses histograms.El estudio experimental se ha llevado a cabo para analizar el funcionamiento, la turbulencia del flujo y el transporte de sedimentos con paneles sumergidos. Los objetivos tras la investigación fueron verificados y comparados con los resultados de la teoría de Odgaard, también; se han medido las presiones verticales que actúan sobre ambos lados de los paneles sumergidos, se han calculado las fuerzas de drag y lift y, sus coeficientes experimentalmente, ya que la teoría de Odgaard no pudo predecirlas satisfactoriamente. Otra motivación del estudio, fue investigar experimentalmente la caracterización hidrodinámica de los paneles sumergidos como; distribución de velocidades, circulación, vorticidad, topografía del fondo, presiones, fuerzas de drag y lift y sus coeficientes, tensiones de Reynolds, energía cinética turbulenta y disipación turbulenta, intensidades de turbulencia, escalas de Kolmogorov, espectro de energía cinética, campos de velocidades turbulentas, velocidades fluctuantes y finalmente, histogramas de las tensiones de Reynolds. Se realizaron pruebas en aguas claras, a lo largo de un canal rectangular con una sección de 7.5 m de largo, 2.52 m de ancho y un espesor de 50 cm de arena de 1.6 mm de diámetro medio y una desviación geométrica de 1.36. Las velocidades fueron medidas con 7 Acoustic Doppler velocímeter ADV, las que fueron calibradas y revisadas periódicamente, las profundidades y las alturas de superficie de agua fueron medidas con un limnímetro que puede leerse con un error de menos de 0.3 mm. Los paneles fueron construidos con placas de PVC de 14 mm de espesor, de forma rectangular, con altura H = 7 cm = 0.4337d y longitud L = 25 cm = 3.571H. En todos los ensayos, los paneles se colocaron con un ángulo de ataque al flujo de 20 grados con la línea central del canal. El calado del agua es de 0.1614 m, la pendiente superficie, el factor de fricción y la desviación geométrica, fueron, 0.045 y 1.36 respectivamente. Los Vectrinos se han calibrado para trabajar a 25Hz y con un volumen de control de 4.3 mm, para cada posición se tomaron datos durante 4 minutos. Para cada posición hay siete Vectrinos con una distancia de 10 cm entre ellos, registrando por lo tanto 7 puntos al mismo tiempo. Los datos registrados fueron alrededor de 24,080 puntos en toda la sección del canal, con el objetivo de medir las velocidades una vez los sedimentos en el canal han alcanzado el régimen permanente o estacionario (equilibrio), durante las mediciones de las velocidades, se ha medido la topografía del fondo (batimetría) mediante el uso de los sensores ADV. La tesis actual, ha desarrollado un sistema para medir la presión vertical que actúa sobre ambas caras del panel, se instalaron 30 piezómetros de plástico en cada lado del panel. Una vez obtenida la presión experimental medida en el laboratorio a ambos lados del panel, se halla la diferencia de presión entre los dos lados, y la fuerza perpendicular resultante actuando sobre el panel, primero se calculó la fuerza resultante entre los dos componentes de drag y lift, para utilizarla después en el cálculo de la fuerza del drag FD y lift FL, así como el coeficiente de arrastre CD, y finalmente se calculó el coeficiente de lift CL. Los resultados de turbulencia incluyen; Distribución de probabilidad de la distribución de velocidades, tensiones de Reynolds, intensidad turbulenta, energía cinética y disipación. Finalmente, escalas de turbulencia de Kolmogorov. Otros resultados contienen el espectro de energía, campos de velocidades turbulentas, velocidades fluctuantes y los histogramas de las tensiones de Reynolds

Tabu search for ship routing and scheduling

This thesis examines exact and heuristic approaches to solve the Ship Routing and Scheduling Problem (SRSP). The method was developed to address the problem of loading cargos for many customers using heterogeneous vessels. Constraints relate to delivery time windows imposed by customers, the time horizon by which all deliveries must be made and vessel capacities. The objective is to minimise the overall operation cost, where all customers are satisfied. Two types of routing and scheduling are considered, one called single-cargo problem, where only one cargo can be loaded into a ship, and the second type called multi-cargo problem, where multiple products can be carried on a ship to be delivered to different customers. The exact approach comprises two stages. In the first stage, a number of candidate feasible schedules is generated for each ship in the fleet. The second stage is to model the problem as a set partitioning problem (SPP) where the columns are the candidate feasible schedules obtained in the first stage. The heuristic approach uses Tabu Search (TS). Most of the TS operations, such as insert and swap moves, tenure, tabu list, intensification, and diversification are used. The results of a computational investigation are presented. Solution quality and execution time are explored with respect to problem size and parameters controlling the tabu search such as tenure and neighbourhood size. The results showed that the average of the solution gap between TS solution and SPP solution is up to 28% (for small problems) and up to 18% for large problems. However, obtaining an optimal solution requires a large amount of computer time to produce the solution compared to obtaining approximate solutions using the TS approach. The use of Tabu Search for SRSP is novel and the results indicate that it is viable approach for large problems.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Optimization-Based Evolutionary Data Mining Techniques for Structural Health Monitoring

In recent years, data mining technology has been employed to solve various Structural Health Monitoring (SHM) problems as a comprehensive strategy because of its computational capability. Optimization is one the most important functions in Data mining. In an engineering optimization problem, it is not easy to find an exact solution. In this regard, evolutionary techniques have been applied as a part of procedure of achieving the exact solution. Therefore, various metaheuristic algorithms have been developed to solve a variety of engineering optimization problems in SHM. This study presents the most applicable as well as effective evolutionary techniques used in structural damage identification. To this end, a brief overview of metaheuristic techniques is discussed in this paper. Then the most applicable optimization-based algorithms in structural damage identification are presented, i.e. Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Imperialist Competitive Algorithm (ICA) and Ant Colony Optimization (ACO). Some related examples are also detailed in order to indicate the efficiency of these algorithms

StEduCov: An Explored and Benchmarked Dataset on Stance Detection in Tweets towards Online Education during COVID-19 Pandemic

In this paper, we present StEduCov, an annotated dataset for the analysis of stances toward online education during the COVID-19 pandemic. StEduCov consists of 16,572 tweets gathered over 15 months, from March 2020 to May 2021, using the Twitter API. The tweets were manually annotated into the classes agree, disagreeor neutral. We performed benchmarking on the dataset using state-of-the-art and traditional machine learning models. Specifically, we trained deep learning models-bidirectional encoder representations from transformers, long short-term memory, convolutional neural networks, attention-based biLSTM and Naive Bayes SVM-in addition to naive Bayes, logistic regression, support vector machines, decision trees, K-nearest neighbor and random forest. The average accuracy in the 10-fold cross-validation of these models ranged from 75% to (Formula presented.) % and from (Formula presented.) % to 68% for binary and multi-class stance classifications, respectively. Performances were affected by high vocabulary overlaps between classes and unreliable transfer learning using deep models pre-trained on general texts in relation to specific domains such as COVID-19 and distance education. 2022 by the authors.Scopu