Optimization of a plasma etching machine for failure analysis of semiconductors

Microwave Induced Plasma (MIP) is an advanced decapsulation tool developed by Jiaco Instruments. The goal of this thesis is to optimise the current MIP system. There are two directions: 1. Improve the etching rate. 2. Find selectivity between different materials (Si, SiO2, SiN). The experiments are divided into two parts in total, improved...

Heuristics for a facility location problem with a quadratic objective function

Facility location problems are an important set of problems within the field of optimisation. These problems consider which facilities to open out of a set of possible facilities and how to assign users to the open facilities. Most of the facility location problems studied have a linear objective. In this thesis, we consider a facility location...

Influence of pore connectivity on the spalling behaviour of mortars

Experimental research into the spalling behaviour of mortars and if it is possible to predict the spalling resistance. Research is divided into spalling experiments with varying parameters and experiments to analyse and characterize the pore structure. By combining both results, a first step is taken into a formula that is able to predict the...

Robust Tail Assignment: Incorporating Delay Predictions into a Tail Assignment Model to Decrease Flight Operation Costs

In this thesis a novel model is proposed to solve the Robust Tail Assignment problem. The Robust Tail Assignment problem aims to assign aircraft to flights, while minimize expected costs of operating a flight schedule, including expected delay costs. This problem is difficult, because delays can propagate between successive flights in the...

IAF Assignment Optimization for Amsterdam Airport Schiphol

During the COVID-19 pandemic people living close to the airport got accustomed to less flights, and therefore less noise disturbance. Now the amount of traffic is increasing again and so is the noise disturbance. For this research specifically the optimizing task of distributing of arriving aircraft over the IAF is addressed, as often the...

Freeze-thaw resistance and air-void analysis of concrete with recycled glass-pozzolan using X-ray micro-tomography

Recent studies have shown promising potential for using Glass Pozzolan (GP) as an alternative supplementary cementitious material (SCM) due to the scarcity of fly ash and slag in the United States. However, comprehensive studies on the freeze-thaw (FT) resistance and air void system of mixtures containing GP are lacking. Therefore, this study...

An Optimization Model to Upgrade the Charging Network of Electric Vehicles

The current city charging network for electric vehicle (EV) is mainly composed of low-speed charging points. When the number of EVs increase dramatically in the future, the current charging network needs to be upgraded with more charging stations and fast-charging (FC) facilities. We build a mixed-integer programming (MIP) model to propose an...

Pore Structure Characterization of Sodium Hydroxide Activated Slag Using Mercury Intrusion Porosimetry, Nitrogen Adsorption, and Image Analysis

The pore structure of alkali-activated slag has a significant influence on its performance. However, the literature shows insufficient studies regarding the suitability of different techniques for characterizing the pore structure and the influences of Na2O and curing age on pore structure development. In pursuit of a better understanding, the...

Resolving infeasibilities in the PESP model of the Dutch railway timetabling problem

Many times the railway timetabling problem is infeasible. This means a set of constraints can not be satisfied at the same time. It is hard to solve this by hand. This thesis proposed two algorithm to resolve the infeasibilities and to come up with a timetable. It serves as an extention to the CADANS solver.

Tight MIP formulations of the power-based unit commitment problem

This paper provides the convex hull description for the basic operation of slow- and quick-start units in power-based unit commitment (UC) problems. The basic operating constraints that are modeled for both types of units are (1) generation limits and (2) minimum up and down times. Apart from this, the startup and shutdown processes are also...

MIP Plasma Decapsulation of Copper-wired Semiconductor Devices for Failure Analysis

The majority of Integrated Circuit (IC) devices are encapsulated in wire-bonded plastic IC packages. Epoxy molding compound is used as the encapsulation material and gold was used as the bonding wire material. However, the increase of gold material price from 400 USD/ounce in year 2005 to 1400 USD/ounce in year 2013 results in a major cost issue...

Mechanical, electrical and microstructural properties of cement-based materials in conditions of stray current flow

This investigation presents a comparative study on mechanical properties, electrical resistivity and microstructure of mortar under DC current, compared to mortar in rest (no current) conditions. Monitoring was performed from 24h after casting until 84 days of cement hydration. A current density level of 10 mA/m2 was chosen as a simulation...

Microstructure Analysis of Heated Portland Cement Paste

When a concrete structure is exposed to high temperature, the mechanical damage and chemical transformation take place simultaneously, which will change the microstructure of material. On the other hand, the mechanical properties and transport properties depend on the development of microstructure of cement paste. In order to study the...