Algorithms for scheduling parallel batch processing machines with non-identical job ready times

This research is motivated by a practical application observed at a printed circuit board (PCB) manufacturing facility. After assembly, the PCBs (or jobs) are tested in environmental stress screening (ESS) chambers (or batch processing machines) to detect early failures. Several PCBs can be simultaneously tested as long as the total size of all the PCBs in the batch does not violate the chamber capacity. PCBs from different production lines arrive dynamically to a queue in front of a set of identical ESS chambers, where they are grouped into batches for testing. Each line delivers PCBs that vary in size and require different testing (or processing) times. Once a batch is formed, its processing time is the longest processing time among the PCBs in the batch, and its ready time is given by the PCB arriving last to the batch. ESS chambers are expensive and a bottleneck. Consequently, its makespan has to be minimized. ^ A mixed-integer formulation is proposed for the problem under study and compared to a formulation recently published. The proposed formulation is better in terms of the number of decision variables, linear constraints and run time. A procedure to compute the lower bound is proposed. For sparse problems (i.e. when job ready times are dispersed widely), the lower bounds are close to optimum. ^ The problem under study is NP-hard. Consequently, five heuristics, two metaheuristics (i.e. simulated annealing (SA) and greedy randomized adaptive search procedure (GRASP)), and a decomposition approach (i.e. column generation) are proposed—especially to solve problem instances which require prohibitively long run times when a commercial solver is used. Extensive experimental study was conducted to evaluate the different solution approaches based on the solution quality and run time. ^ The decomposition approach improved the lower bounds (or linear relaxation solution) of the mixed-integer formulation. At least one of the proposed heuristic outperforms the Modified Delay heuristic from the literature. For sparse problems, almost all the heuristics report a solution close to optimum. GRASP outperforms SA at a higher computational cost. The proposed approaches are viable to implement as the run time is very short. ^

Examining the Impact of Service Times on Overall Guest Satisfaction Perception in the Casual Dining Environment

A mystery shopper study was used to examine the influence of service times on customer satisfaction. The impact of management emphasis on service quality was also examined. In the restaurants studied, service time influenced customer satisfaction. Management attention to service time improved performance in direct relationship to the level of emphasis.

Timeshare Owner Preferences - An Analysis of Program and Service Relationships during Recessionary Times

Since the 1970s various industry studies have indicated that the vacation ownership industry has enjoyed unprecedented growth in unit sales, resort growth, and the number of owners (American Resort Devleopment Association [ARDA], 2007; ARDA, 2009a; ARDA, 2009b). However, due to the recent economic downturn these growth metrics are no longer obtainable. This external impact has caused developers to retrench and therefore reflect upon their existing product and service offerings, financial metrics, and consumer markets (ARDA, 2010a; ARDA 2010b). The crux of these findings indicates that the industry has shifted to maintaining and enhancing product and service offerings as a reaction to changing economic conditions. The findings reported in the body of this manuscript represent product and service preferences as collected from a random data pull of their existing ownership base. The study also revealed current preferences of timeshare owners with relation to services provided and products/amenities offered. Management implications and limitations of the current study are discussed.

Maintaining your loyal customers during hard times: An observation from the gaming industry

The Las Vegas gaming arena was one of the most severely affected consumeroriented industries to be impacted by the recent economic recession. The purpose of this study was to investigate the impact of relational benefits on customers’ behavioral loyalty in the Las Vegas gaming industry. This study particularly took a comparative approach and examined the relational impact during the economic recession and after the economic recession. Secondary data was obtained and regression analysis was performed to test the study hypothesis. The findings of this study revealed the economic recession impact on the Las Vegas gaming industry, as well as valuable insights for effective utilization of relational benefits to increase customer loyalty.

The Urban Insurrection against Batista: The Life and Times of José Antonio Echeverria, A Symposium

This flyer promotes the event "The Urban Insurrection against Batista: The Life and Times of José Antonio Echeverria, A Symposium".

Drying Times: Integrating Citizen Science to Examine Survival of Florida Largemouth Bass in a Coastal Refuge Habitat

In aquatic systems refuge habitats increase resistance to drying events and are necessary for maintaining populations in disturbed environments. However, reduced water availability and altered flow regimes threaten the existence and function of these habitats. To test refuge function I conducted a capture-mark-recapture (CMR) study, integrating citizen science angler sampling into fisheries-independent methods. The objectives of this study were twofold: 1) To determine the contribution of citizen science anglers to improving CMR research, and 2.) to quantify apparent survival of Florida Largemouth Bass, Micropterus salmoides floridanus, in a coastal refuge habitat across multiple years of drying severity. The inclusion of angler sampling was determined to be an effective and feasible method for increasing capture probability. Apparent survival of Florida Bass varied among hydrologic periods with lowest survival when marshes functionally dried (< 10 cm). Overall mortality from drying events increased with the duration of marsh drying upstream.

Ten Year Study on Water Flushing Times and Water Quality in Southern Taylor Slough, Everglades National Park, FL

The purpose of this research was to investigate the effects of wetland restoration on the water balance, flushing time, and water chemistry of southern Taylor Slough, a major water way in Everglades National Park. Water balance and flushing time equations were calculated on a monthly time step from 2001 – 2011. Water chemistry of major ions and nutrients were analyzed and correlated with water flushing times. Results showed that evapotranspiration followed by water volume had the greatest influence on flushing time. The flushing times varied between 3 and 78 days, with longer times observed between October and December, and the shorter times between March and May. Ion concentrations at the coastal areas decreased with increased flushing times. Increased surface water inflow that resulted from restoration projects and water management changes were productive in the rainy season and should result in increased flushing times and decreased ion concentrations in Taylor Slough.

Exploring Armenian keyboard music : roots to modern times

The extended program notes include historical facts of the composers and characteristics of the pieces being performed. The thesis also includes information about Armenian composers starting from 18th to the 20th century, composition's historical background, brief biographies of the composers as well as analysis of form and structure. The graduate piano recital comprised the following compositions: Sayat Nova - R. Andriasian Yes Mi Kharib Blbuli Pes; Komitas - R. Andriasian Garun a, Shoker Jan, Dzirani Dzar, Gakavik; A. Khachaturyan Poem; A. Babadjanyan Elegy in Commemoration of A. Khachaturyan; E. Bagdasarian Humoresque, Prelude in D Minor, Prelude in B Minor; A. Babadjanyan Improvisation and Traditional from six Pictures; A. Babadjanyan Prelude and Vagarshapat Dance; A. Arutyunian Dance of Sasoon; A. Arutyunian - A. Babadjanyan Armenian Rhapsody for Two Pianos.