The present study investigated the way people acquire and control skilled performance in the context of typewriting. Typing skill was degraded by changing the location of a key (target key) while retaining the locations of other keys to disable an association between the letter and the key. We conducted 4 experiments: Experiment 1 demonstrated that disabling a letter-key association affected no...

We analyze the polytope associated with a combinatorial problem that combines the Steiner tree problem and the uncapacitated facility location problem. The problem, called connected facility location problem, is motivated by a real-world application in the design of a telecommunication network, and concerns with deciding the facilities to open, the assignment of customers to open facilities, an...

In this paper we present a randomized constant factor approximation algorithm for the problem of computing the optimal cost of the metric Minimum Facility Location problem, in the case of uniform costs and uniform demands, and in which every point can open a facility. By exploiting the fact that we are approximating the optimal cost without computing an actual solution, we give the first algori...

A Simple logarithmic approximation This problem can be formulated as a set cover problem. Given an instance (D,F, f, d) of the facility location problem, it can be transformed into an instance of a set cover problem (X,S, cost) by • setting X = D, and • setting S = {(i, A) : i ∈ F,A ⊆ D}. (i, A) covers elements of the set A. The cost of the set (i, A) is fi + ∑ j∈A dij . We can then use the sta...

Understanding the dynamics of evolving social or infrastructure networks is a challenge in applied areas such as epidemiology, viral marketing, or urban planning. During the past decade, data has been collected on such networks but has yet to be fully analyzed. We propose to use information on the dynamics of the data to find stable partitions of the network into groups. For that purpose, we in...

In the maximum facility location problem, we are given a set of clients C and facilities F . Assigning a client u to a facility v incurs a cost w uv and each facility has an associated interval I v on the real line. Our goal is to assign as many clients to open facilities in order to maximise the cost of assignment, subject to the constraint that open facilities cannot have their respective int...

Facility location decisions are a critical element in strategic planning for a wide range of private and public ®rms. The rami®cations of siting facilities are broadly based and long-lasting, impacting numerous operational and logistical decisions. High costs associated with property acquisition and facility construction make facility location or relocation projects long-term investments. To ma...

We present a deterministic kinetic data structure for the facility location problem that maintains a subset of the moving points as facilities such that, at any point of time, the accumulated cost for the whole point set is at most a constant factor larger than the current optimal cost. At any point of time, the cost that arise for a point depends on the status and the position of the point. In...

High-quality obstetric delivery in a health facility reduces maternal and perinatal morbidity and mortality. This systematic review synthesizes qualitative evidence related to the facilitators and barriers to delivering at health facilities in low- and middle-income countries. We aim to provide a useful framework for better understanding how various factors influence the decision-making process...