Search

Purpose – Telephone response system is the frontline of hospital operations. The purpose of this paper is to analyze a representative telephone response system of Veterans Affairs (VA) hospitals, address the existing inefficiency issues such as long call waiting time, and improve system resilience to changes. Design/methodology/approach – Resource sharing schemes are proposed to improve the system performance in answering calls related to appointment booking and medication renewal. Discrete event simulation is adopted to model the current system and the resource sharing schemes. Findings – The resource sharing schemes dramatically improve system performance reflected by the decrease of call waiting time and queue, as well as the extreme high utilization of agents in a key unit. Compared with the less desired alternative of hiring additional employees to mitigate the performance issues, the resource sharing schemes perform at par or even better. Sharing more resource during the peak hours can further balance the agent workload. Practical implications – The resource sharing schemes could alleviate staffing shortage, long waiting time, and high-abandonment rate in the bottle-beck unit of the system, and lead to better utilization of scarce resources on the hospital floor. The concept reflects localized centralization efforts in traditionally highly decentralized telephone operations in hospital systems. Originality/value – This research provides a structured approach to analyze the operations of a VA telephone response system. The developed simulation model is validated, and this provides a valuable tool for management to analyze the complicated telephone operations of the telephone systems of other VA and non-VA hospitals. Resource sharing constitutes a cost-effective solution for improving system performance and resilience.

This study focuses on experimental design-based approach for process optimisation of a custom-made digital light processing 3D printer. Output measures are developed taking precision and accuracy into consideration. Initial runs were conducted to identify the prominent factors which might play role on output measures. The results indicate that the layer thickness plays a significant role for the two of the developed output measures, photopolymerisation time for one measure, and sequence time for two measures as the interaction-effects also play a role to some. A composite figure that considers all three output measures simultaneously is also developed and a stepwise regression analysis is conducted to identify significant factors. The regression model has moderate R2 value (68.12%), also indicating that layer thickness and photopolymerisation period play a role. The recommended levels for layer thickness is found to be 0.2 millimetres and photopolymerisation period as 12 seconds based on the composite figure.

The convex recoloring (CR) problem is to recolor the nodes of a colored graph at minimum number of color changes such that each color induces a connected subgraph. We adjust to the convex recoloring problem the column generation framework developed by Johnson et al. (Math Program 62:133–151, 1993). For the convex recoloring problem on a tree, the subproblem to generate columns can be solved in polynomial time by a dynamic programming algorithm. The column generation framework solves the convex recoloring problem on a tree with a large number of colors extremely fast.

In this study, a mixed integer linear programming (MILP) model is developed for rescheduling elective patients upon the arrival of emergency patients by considering two types of clinical units, namely operating rooms and post-anesthesia care units (PACUs). The model considers the overtime cost of the operating rooms and/or the PACUs, the cost of postponing or preponing elective surgeries, and the cost of turning down the emergency patients. The results indicate that a mainstream commercial solver can efficiently find an optimal solution in a particular scenario with light elective surgery load, but becomes very inefficient in searching optimal solutions in all other scenarios. As such, a genetic algorithm is developed to efficiently obtain the approximately optimal solutions in those scenarios that are difficult for the commercial solver. In the genetic algorithm, a novel chromosome structure is proposed and applied to represent the feasible solutions to the MILP model. It is shown that for the scenarios with heavy load of elective surgeries, the genetic algorithm can find approximate optimal solutions significantly faster than the commercial solver. In practice, the two solution methodologies should be used jointly to provide hospitals a solid tool for making sound and timely decisions in admitting emergency patients and rescheduling elective patients.

A genetic algorithm (GA) based approach for reliability placement of phasor measurement units (PMUs) in smart grid is proposed. The algorithm combines two conflicting objectives which are maximization of the reliability of observability and minimization of the number of PMU placements for ensuring full system observability. The multi-objective problem is formulated as a nonlinear optimization problem and genetic algorithm approach is employed for solving the large scale bus systems. The optimization model is solved for IEEE 14, and 30 standard bus systems. The effectiveness of the proposed approach has been demonstrated by comparing results with exact algorithms for smaller problem sizes. The system reliability of observability is improved compared to traditional optimal PMU placement. The proposed approach achieves significant cost savings compared to available reliability based models in literature.

The applications of radio frequency identification (RFID) technology carry a tremendous potential for pharmaceutical industry. There is a pressing need to analyze the performance of RFID tags attached to various pharmaceutical dosage forms.The readability of RFID-tagged pharmaceutical products is, for the first time, systematically investigated by experiments. Factors considered include dosage forms, ion concentration in solution, angle of rotation, and distance between the RFID tag and the interrogator.Compared with empty container, the filling of any representative dosage forms causes deteriorated readability for the tag attached to container. Analysis of variance reveals that the effects of dosage forms, angle of rotation, and their interaction are statistically significant. In addition, an increase in distance (equivalent to higher RF attenuation level) and higher ion concentration in solution beyond a certain level have detrimental effect on tag readability.The analysis shows that the RFID tag readability is strongly dependent on the factors that are experimented with. The level of the factors for optimum RFID system performance should be adjusted based on the particular application.