A Heuristic Approach to the Consecutive Ones Submatrix Problem

أعطيت مصفوفة (0،1)، تم اقتراح مسألة المصفوفة الجزئية ذات الواحدات المتعاقبة والتي تهدف إلى إيجاد تبديل للأعمدة التي تزيد من عدد الأعمدة التي تحتوي معًا على قالب واحد فقط من الواحدات المتعاقبة في كل صف. سيتم اقتراح اسلوب الاستدلال لحل المسألة. كما سيتم دراسة مسألة تقليل القوالب المتتالية ذات الصلة بمسألة المصفوفة الجزئية ذات الواحدات المتعاقبة. تم اقتراح اجراء جديد لتحسين طريقة إدراج العمود. يتم بعد ذلك تقييم مصفوفات العالم الحقيقي ومصفوفات متولدة عشوائيًا من مسألة غطاء المجموعة و تعرض النتائج الحسابية.Given a matrix, the Consecutive Ones Submatrix (C1S) problem which aims to find the permutation of columns that maximizes the number of columns having together only one block of consecutive ones in each row is considered here. A heuristic approach will be suggested to solve the problem. Also, the Consecutive Blocks Minimization (CBM) problem which is related to the consecutive ones submatrix will be considered. The new procedure is proposed to improve the column insertion approach. Then real world and random matrices from the set covering problem will be evaluated and computational results will be highlighted

Optimization Models for Inland Haulage Transportation of Containers

In container intermodal transportation, a significant portion of the total cost arises from the inland transportation of containers. There are many parties (shipping lines, haulage companies, customers) sharing this operation as well as many restrictions that increase the complexity of this problem and make it NP-hard. Shipping lines and haulage companies tend to apply efficient optimization techniques to manage this process in away to reduce the overall cost and to ensure that customers are satisfied. In this thesis, we focus on container inland transportation from the perspective of delivering 20ft and/or 40ft containers on a heterogenous fleet of trucks, between a single port and a list of customer locations and inland depots. We investigate three types of inland transportation problems: Homogenous Container Sizes, Heterogenous Container Sizes and Stripe and Discharge of Containers. Each of the above problems has its own complexity but all have been classified as NP-hard problems. For this reason we will study these problems separately and the main contributions are describing, modelling, solving and analysing of the: • Homogenous ContainerSizes: an efficient assignment Mixed Integer Linear Programming (MILP) model is formulated which solves large scale instances in a reasonable solution time and can be implemented on variants of the container drayage problem. • Heterogenous Container Sizes: a Mixed Integer Linear Programming (MILP) model for combining 20ft and 40ft, Stripe orders is designed, which solves more efficiently than its previous analog. For realistic instances, a decomposition and aggregation heuristic is designed and tested to be cost saving. • Strip and Discharge of Containers: a Genetic Algorithm (GA) approach is designed and tested for solving large scale problems within a quick computational time and the result shows that combining the Strip and Discharge types with the usage of inland empty depots is cost and fleet saving