Operations Research, Systems Engineering and Industrial Engineering Commons^™

Knot Optimization For Univariate Cubic L^1 Spline Fits With Application In Change Point Detection, Manfei Xie

Graduate Research Theses & Dissertations

Cubic $L^1$ spline fits, as a type of $L^1$ approximating splines, have shown superior performance in shape preservation of geometric data with great changes. To better construct a cubic $L^1$ spline fit, the number and the location of the spline knots should be optimized rather than predetermined. This research investigates knot optimization methods for univariate cubic $L^1$ spline fits. When the number of knots is given, we design an optimization-based method to determine the best location of the knots. When the number and the location are unknown, we propose a heuristic method to find proper knot number and location. Numerical …

Sky Surveys Scheduling Using Reinforcement Learning, Andres Felipe Alba Hernandez

Graduate Research Theses & Dissertations

Modern cosmic sky surveys (e.g., CMB S4, DES, LSST) collect a complex diversity of astronomical objects. Each of class of objects presents different requirements for observation time and sensitivity. For determining the best sequence of exposures for mapping the sky systematically, conventional scheduling methods do not optimize the use of survey time and resources. Dynamic sky survey scheduling is an NP-hard problem that has been therefore treated primarily with heuristic methods. We present an alternative scheduling method based on reinforcement learning (RL) that aims to optimize the use of telescope resources for scheduling sky surveys.

We present an exploration of …

Minimizing Total Number Of Tardy Jobs In Parallel Batch Processing Machines Using Column Generation And Simulated Annealing, Sameer Neupane

Graduate Research Theses & Dissertations

This research considers a scheduling problem where jobs need to be grouped into batches and the batches need to be scheduled on parallel batch processing machines with an objective to minimize the total number of tardy jobs. The jobs are assigned to batches in such a way that machine capacity is not violated. This research considers jobs with unequal ready times, unequal processing times and unequal sizes. The machines are identical in processing capabilities; however, their capacities are different. This research aims to develop effective solution approaches to solve the problem under study. A Mixed Integer Linear Programming (MILP) model …

A Lagrangian-Based Heuristic To Consolidate Perishable Products, Samir Babu Bhetwal

Graduate Research Theses & Dissertations

A consolidation center with multiple suppliers and multiple destinations for a perishable product is considered in this research. Perishable products deteriorate with time and this research includes a deterioration cost to measure this behavior. The model considers a variety of suppliers ranging from small to mid-sized. Due to dependencies of inventory and shipment release decisions, an integrated approach of making the operational decisions is necessary. This coordinated approach considers deterioration cost, inventory cost, and transportation cost.

Tradeoff decisions between different supply chain costs are not straightforward as the problem contains constraints like inventory capacity and transportation constraints from suppliers to …

Computational Methods For Bicubic L1 Splines, Priyesh Koyu Rai

Graduate Research Theses & Dissertations

The past two decades have seen the development of L1 splines for interpolation and approximation of geometric data. L1 splines have been shown to preserve shapes better than the conventional L2 splines, especially for data with abrupt changes in the magnitude of spacing. Efficient computation plays an important role in the practical application of L1 splines. This thesis creates new computational methods for constructing bicubic L1 interpolating splines and bicubic L1 spline fits. The bicubic splines in this study are piecewise bicubic polynomials defined on a rectangular grid generated by the tensor product of nodes. We developed a hybrid computational …

Validation Of A Low-Cost Sensor For Development Of Wearable And Handheld Spectrometers, Justin Leslie Cathey

Graduate Research Theses & Dissertations

This study examined the possibility of creating a quantitative radiometric spectrometer from a low-cost relative radiometric spectrometer sensor through the use of statistical analysis and development of a correction factor (p > 0.05). Radiometric spectrometers are able to measure and fully characterize the radiometric and photometric characteristics of light, while relative spectrometers are not able to fully, quantitatively characterize the radiometric response from a light source, thus they are less expensive. The spectrometer created in this research is able to measure and produce comparative lighting parameters as well as an actual radiometer spectrometer.

The photoreceptors cells within the human eye allow …