Proposing an Interpretation Method for Clustering Algorithms

, M.Sc. Thesis Sharif University of Technology Khodaverdian, Masoud (Author) ; Jafari Siavoshani, Mahdi (Supervisor)

Abstract

The complexity of machine learning models has made it difficult for end-users and even experts in the field to understand the reasoning behind the decisions made by these models. As a result, the need for explanation and interpretation of machine learning models has been increasing. One subset of machine learning models is clustering models. Despite the extensive research conducted on interpreting supervised models, very few studies have been focused on interpreting clustering models. In this research, we aim to propose algorithms for interpreting a clustering model in a model-agnostic and post-hoc manner. In this study, various methods are presented for interpreting a clustering model. The...

A fuzzy vendor managed inventory of multi-item economic order quantity model under shortage: An ant colony optimization algorithm

, Article International Journal of Production Economics ; Vol. 155 , September , 2014 , pp. 259-271 Roozbeh Nia, A ; Hemmati Far, M ; Akhavan Niaki, S. T ; Sharif University of Technology

2014

Abstract

In this study, a multi-item economic order quantity model with shortage under vendor managed inventory policy in a single vendor single buyer supply chain is developed. This model explicitly includes warehouse capacity and delivery constraints, bounds order quantity, and limits the number of pallets. Not only the demands are considered imprecise, but also resources such as available storage and total order quantity of all items can be vaguely defined in different ways. An ant colony optimization is employed to find a near-optimum solution of the fuzzy nonlinear integer-programming problem with the objective of minimizing the total cost of the supply chain. Since no benchmark is available in...

A hybrid genetic and imperialist competitive algorithm for green vendor managed inventory of multi-item multi-constraint EOQ model under shortage

, Article Applied Soft Computing Journal ; Volume 30 , May , 2015 , Pages 353-364 ; 15684946 (ISSN) Roozbeh Nia, A ; Hemmati Far, M ; Akhavan Niaki, S. T ; Sharif University of Technology

Elsevier Ltd 2015

Abstract

The purpose of this paper is to develop a multi-item economic order quantity (EOQ) model with shortage for a single-buyer single-supplier supply chain under green vendor managed inventory (VMI) policy. This model explicitly includes the VMI contractual agreement between the vendor and the buyer such as warehouse capacity and delivery constraints, bounds for each order, and limits on the number of pallets. To create a kind of green supply chain, tax cost of green house gas (GHG) emissions and limitation on total emissions of all items are considered in the model. A hybrid genetic and imperialist competitive algorithm (HGA) is employed to find a near-optimum solution of a nonlinear...

An investigation of vendor-managed inventory application in supply chain: The EOQ model with shortage

, Article International Journal of Advanced Manufacturing Technology ; Volume 49, Issue 1-4 , July , 2010 , Pages 329-339 ; 02683768 (ISSN) Pasandideh, S. H. R ; Akhavan Niaki, S. T ; Roozbeh Nia, A ; Sharif University of Technology

2010

Abstract

Recent researches have shown the importance of improving the supply chain competitiveness by means of strategic alliances. This study considers the retailer-supplier partnership through a vendor-managed inventory (VMI) system and develops an analytical model to explore the effect of important supply chain parameters on the cost savings realized from collaborative initiatives. This model is developed for a two-level supply chain consisting of a single supplier and a single retailer and examines the inventory management practices before and after implementation of VMI. The results of analytical examination show that VMI implementation in economic order quantity model when shortage is...

Generation, Propagation and Domination in Graphs

, M.Sc. Thesis Sharif University of Technology Mohammad Ali Tajrishi, Mahshid (Author) ; Mahmoodian, Ebadollah (Supervisor) ; Tusserkani, Roozbeh (Supervisor)

Abstract

In this thesis, we discuss some basic concepts of graph theory and introduce some well-known graphs with a glimpse at the optimization concepts. We also have discussed the proof of theorems related with the domination sets and total domination sets. Indeed, let G = (V;E) be a graph with no isolated vertex. A subset of V , S is a domination set if every vertex in V n S is adjacent to at least one vertex in S. Also, a subset of V , S is a total domination set if every vertex in V is adjacent to at least one vertex in S. Generation and propagation codes that is introduced by R.Touserkani is one of the objects in this thesis, that we study and discuss. Also, for some classes of graphs, we...

Numerical Study of Unsteady Swirl Injector Spray

, M.Sc. Thesis Sharif University of Technology Khodaverdian, Roozbeh (Author) ; Morad, Mohammad Reza (Supervisor) ; Kebriaee, Azadeh (Co-Supervisor) ; Jahan Nama, Mohammad Reza (Co-Supervisor)

Abstract

Iin this thesis, evaporation of droplets of a spray from a pressure-swirl injector in a sub-atmospheric combustion chamber is studied. The liquid used in this sudy is a hypergolic oxidizer, Dinitrogen Tetroxide, also known as NTO. The significance of this thesis is its application during the cold startup of a satellite thruster when only oxidizer is injected into the combustion chamber. The most important phenomemon in this stage which is also the focal point for this study, is the ‘Flashing’. In this phenomenon a liquid having a temperature above the boiling point of its own species (for the surrounding gas pressure) is present in the solution field. This state is a non-equilibrium state....

Energy and environmental enhancement of power generation units by means of zero-flow coolant strategy

, Article International Journal of Energy Research ; Volume 45, Issue 7 , 2021 , Pages 10064-10085 ; 0363907X (ISSN) Samiezadeh, S ; Qasemian, A ; Sohani, A ; Rezaei, A ; Khodaverdian, R ; Soltani, R ; Li, L. K. B ; Doranehgard, M. H ; Sharif University of Technology

John Wiley and Sons Ltd 2021

Abstract

Warm-up period is considered as the most critical phase in the operation of any device that converts the energy of a fuel into heat, electricity, and other products, including power generation units since the system efficiency and environmental pollution levels are much worse than the normal operation in that phase. Considering this point, in this study, applying the zero-flow coolant strategy to reduce the warm-up period is suggested for power generation units and it is investigated in details. An internal combustion engine is selected as the case-study and implementation of the method to enhance the performance of that from both energy and environmental aspects are studied comprehensively....