We prove that a pushing-block puzzle called PUSHPUSH-k is PSPACE-complete for any fixed k ≥ 1. In this puzzle, a robot moves on a finite grid. Each grid position is either empty or occupied by a single obstacle block. While moving, the robot may push obstacle blocks in direction of its movement, subject to certain constraints. In particular, once an obstacle block starts moving, it continues to...

PRELIMINARY AND INCOMPLETE: PLEASE DO NOT CITE Big Push models suggest that local product demand can create multiple labor market equilibria: one featuring high wages, formalization, and high demand and one with low wages, informality, and low demand. I demonstrate that minimum wages may coordinate development at the high wage equilibrium. Using data from 1990s Indonesia, where minimum wages in...

Despite the consumers' increasing demand of technology-based innovations for making stores more appealing and the huge availability of advanced technologies, there is still a lack of research on the retailers' and employees' points of views towards the introduction of these systems. In fact, an efficient innovation should take care of both the final users/consumers' and the retailers/employees'...

Vol. 34 No. 5 • May 2009 • P&T® 243 (see the April issue of P&T, page 175). Ms. Levine sued and received a settlement from the clinic where the drug was administered. She also named Wyeth as a defendant, claiming that the drug’s label should have more clearly instructed clinicians against using an IV push injection. The label, which the FDA had approved, warned about inadvertent intra-arterial ...

We study the performance of a flexible manufacturing line producing multiple products under different material control strategies. Specifically, we compare the throughput versus average inventory characteristics when the line operates under pure pull and pure push strategies. Using simulation we show that the pure push strategy has a higher throughput for a given level of inventory than the pur...

Data broadcasting has emerged as an efficient way for the dissemination of information over asymmetric wireless environments where the needs of the various users of the data items are usually overlapping. In such environments, data broadcasting stands to be an efficient solution since the broadcast of a single information item is likely to satisfy a possibly large number of users. Communication...

Th e aim of this study is to assess the impact of a several factors on satisfaction with a visit to water-based natural attractions. After reviewing relevant studies, it was hypothesized that satisfaction is infl uenced by push motivations, pull motivations, on-site experience, perceived quality and perceived values of visit. As a method of data reduction, the factor analysis based on principal...