Leyla Ozsen | San Francisco State University (original) (raw)

Papers by Leyla Ozsen

Journal of Consumer Marketing, 2013

ABSTRACT Purpose ‐ The growing presence of foods that are labelled "locally/ecologically... more ABSTRACT Purpose ‐ The growing presence of foods that are labelled "locally/ecologically produced" leads to the question of how many consumers consider the impact of their food purchases. Do they value local/ecologically-produced food sufficiently to drive their purchasing behaviour, even if such foods are more costly? Can consumer segments be identified and, if so, what are their characteristics? This paper aims to focus on these questions. Design/methodology/approach ‐ In an exploratory study, the authors surveyed over 400 students from a public university in California asking them to select between apples based on a combination of price, origin and presence/absence of an ecological indicator. The authors collected information on their shopping attitudes, their affinity for international trade and demographic identifiers. Findings ‐ Evidence is found for three consumer segments: the deep green, the price conscious and switchers. The latter are the most prevalent category across demographic and attitudinal indicators, but with increased age, employment/shopping responsibilities, the preponderance of switchers diminishes and more deep green consumers appear. Deep green consumers tend to be both more information and variety seeking than the price conscious ones. Originality/value ‐ By identifying demographic and other characteristics that are likely to qualify consumers as belonging to a specific segment, marketers of local and ecologically produced foods can better target and influence appropriate consumers.

International Journal of Applied Decision Sciences, 2009

... Leyla Ozsen received her BSc in Operations Research and Industrial Engineering from Cornell U... more ... Leyla Ozsen received her BSc in Operations Research and Industrial Engineering from Cornell University, USA, in 1997, her MSc in Management Science and Engineering from Stanford University, USA, in 1999, and her ... zα standard normal deviate such that ( ) ≤ = Prob zzα α ...

The first capacitated location-inventory model we introduce in this dissertation assigns each ret... more The first capacitated location-inventory model we introduce in this dissertation assigns each retailer to a single distribution center. We formulate this model as a nonlinear integer program in which the objective function is neither concave nor convex. Feasible solutions for this ...

American Journal of Health-System Pharmacy, 2013

Transportation Science, Jan 1, 2009

Google, Inc. (search), Subscribe (Full Service), Register (Limited Service, Free), Login. Search:... more Google, Inc. (search), Subscribe (Full Service), Register (Limited Service, Free), Login. Search: The ACM Digital Library The Guide. ...

Naval Research Logistics, Jan 1, 2008

This study concerns the execution of open access appointment scheduling system at an urban outpat... more This study concerns the execution of open access appointment scheduling system at an urban outpatient clinic. The clinic underwent a change of its patient appointment scheduling policy from the traditional up-to-one- year fixed booking to the same-day appointment open access system. In this study, we developed a queueing network and a simulation model that help the decision making process of the clinic&#x27;s scheduling policy. From the analytical results and anecdotal evidence, we also discovered the important factors for successfully implementing of open access. Large outpatient healthcare clinics schedule thousands of patient appointments each year, and the effectiveness of processes used have direct and critical impacts on the efficiency of clinical resource use and patient satisfaction. It is not unusual in traditional scheduling systems for appointments to be made months in advance of the patient visit, even when the clinic supply and demand are balanced in the sense that the number of new appointments scheduled equals the number of visits completed each day. Furthermore, no-show patients, who fail to report at their scheduled time, may number as much as 42% of the total which introduces enormous volatility in clinic operations that squanders critical availability of physicians and other clinical staff.(1) Open Access Scheduling has been introduced in the past decade to address some of these challenges. Instead of booking well ahead, a substantial fraction of patients are asked to call in for appointments within a day or two of the time they wish to see their physician. If appointment slots are available the patient is scheduled immediately, thus avoiding the long delay of advanced booking and substantially reducing no-shows in many settings. Despite its apparent appeal, implementations of open access scheduling often fail or prove far less successful than anticipated because the system has not been optimized for the environment in the particular clinic tested. For example, indigent or aged patients may have much more difficulty with some forms of open access than more up- scale populations. Work patterns of physicians - especially when residents are included - may prevent or complicate the ability of open access scheduling to preserve continuity of care between the patient and his/her regular doctor. Also, a certain fraction of patients, such as those returning for follow-up visits, may require advance appointments like the traditional system; the number of slots reserved for such patients must be optimized for different settings. This paper details the development of modeling and analysis tools that are used to best configure an open access patient scheduling system for an outpatient clinic of a teaching hospital situated in Midwest urban area. In the spring of 2005, the clinic was experiencing an average of 23% of patients defaulting on scheduled appointments. A nearby outpatient clinic successfully implemented an open access scheduling system and saw both patient no-show rates and wait times decrease, prompting the clinic under study to consider open access. We were approached by the teaching clinic to help develop a tool for analyzing an open access setting for their clinic. Our approach consisted of developing a queueing network model to analyze clinic operation under steady state conditions. A simulation model evaluating an open access scheduling system parameters was developed in parallel to determine the impact of various factors on the delivery of care. The subsequent sections of this paper include a literature review, methodologies used in the study, an analysis of results and the current status of the clinic.

Health Care Management Science, 2007

Many outpatient clinics are experimenting with open access scheduling.

European Journal of Operational Research, 2009

We consider a two-stage supply chain with a production facility that replenishes a single product... more We consider a two-stage supply chain with a production facility that replenishes a single product at retailers. The objective is to locate distribution centers in the network such that the sum of facility location, pipeline inventory, and safety stock costs is minimized. We explicitly model the ...

Iie Transactions, 2007

Most existing network design and facility location models have focused on the trade-off between t... more Most existing network design and facility location models have focused on the trade-off between the fixed costs of locating facilities and variable transportation costs between facilities and customers. However, operational performance measures such as service levels and lead ...

Transportation Science, 2009

Naval Research Logistics, 2008

In this article, we introduce the capacitated warehouse location model with risk pooling (CLMRP),... more In this article, we introduce the capacitated warehouse location model with risk pooling (CLMRP), which captures the interdependence between capacity issues and the inventory management at the warehouses. The CLMRP models a logistics system in which a single plant ships one type of product to a set of retailers, each with an uncertain demand. Warehouses serve as the direct intermediary between the plant and the retailers for the shipment of the product and also retain safety stock to provide appropriate service levels to the retailers. The CLMRP minimizes the sum of the fixed facility location, transportation, and inventory carrying costs. The model simultaneously determines warehouse locations, shipment sizes from the plant to the warehouses, the working inventory, and safety stock levels at the warehouses and the assignment of retailers to the warehouses. The costs at each warehouse exhibit initially economies of scale and then an exponential increase due to the capacity limitations. We show that this problem can be formulated as a nonlinear integer program in which the objective function is neither concave nor convex. A Lagrangian relaxation solution algorithm is proposed. The Lagrangian subproblem is also a nonlinear integer program. An efficient algorithm is developed for the linear relaxation of this subproblem. The Lagrangian relaxation algorithm provides near-optimal solutions with reasonable computational requirements for large problem instances. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008