An Examination of the Effects of Self-Regulatory Focus on the Perception of the Media Richness: The Case of E-Mail

Citation

Armengol, Xavier; Fernandez, V.; Simo, P.; Sallan, J. M. (2015). An Examination of the Effects of Self-Regulatory Focus on the Perception of the Media Richness: The Case of E-Mail. International Journal of Business Communication
http://dx.doi.org/10.1177/2329488415572780

Abstract

Communication is a key element in organizations’ business success. The media richness theory and the channel expansion theory are two of the most influential theories regarding the selection and use of communication media in organizations; however, literature has focused little on the effects of self-regulation by managers and employees in these theories. To analyze these topics, this study develops an empirical investigation by gathering data from 600 managers and employees using a questionnaire. The results suggest that the perception of media richness is positively affected when the individual shows a promotion focus or strategy.

Correlation does not mean causation

A variety of images showing that correlation does not imply causation.

A plot showing the relationship between the number of Nobel prizes earned in each country, and chocolate consumption. Both data are adjusted by the population of each country (an indirect source of this graph here).

Phenomena like the shown in the image above usually come from the fact that both variables involved correlate highly with a third (not shown) variable. Many times this third variable is population (source: xkcd)

The fact that a linear association might be easily confounded with a causal relationship may be the reason of the mith that storks deliver babies. This article shows the strong correlation between stork population and human birth rate.

Conclusion, keep in mind that correlation does not mean causation. Although an unexpected correlation may lead to a serendipious discovering (source: xkcd)...

50 shades of grey

The readers of the novel series on unconventional desires may enjoy this little picture showing (literally) 50 shades of grey:

The picture is easily generated using the following R code:

shades <- seq(0, 1, length.out =50)
m.shades <- matrix(rep(shades, 50), 50, 50)
shades.of.grey <- grey(shades)
png("shades.png")
image(m.shades, col=shades.of.grey)
dev.off()

Estudio de un plan de operaciones para una nueva modalidad de handling en la terminal T1 del aeropuerto BCN-El Prat

Student

Àlvar Jaime Hileno

Supervisors

Oriol Lordan / Jose M Sallan

Defense date 

30th June, 2014

Abstract

Carrying the luggage to the airport on your way back home can be an exhausting and stressing task, and some customers of luxury hotels may be interested in a service in which their luggage is dropped directly in the hotel.

This project assesses the operational, legal and financial viability of a business consisting in facilitating the check in directly in the hotel, and carrying customer's luggage directly to the airport handling services in the context of the El-Prat Barcelona (BCN) airport. 

Estudio de implantación de un Pace-Maker en una línea de montaje de una empresa del sector de la automoción

Student

Mireia Magallón Gracia

Supervisors

Jose M Sallan

Defense date 

12th February, 2015

Abstract

English title: Study of the implementation of a pacemaker in an assembly line in the automotive industry

One of the tools that can be used in the context of lean manufacturing is a pacemaker. In this project several alternatives to implement a pacemaker in an assembly line are assessed. Then, the guidelines for implementing the selected alternative are detailed, and the implementation process is planned through the PMBOK standards in project management.

A list of linear programming solvers

Here is a list of software available to solve linear programming (LP) models, focused on free software with an R implementation. Most of this software is also able to solve integer linear programming (ILP) and mixed integer linear programming (MILP) models. The list is intended to be extended and more extensively annotated in the future. Don't hesitate to comment below if you see how this list can be extended or enhanced.

lp_solve

lp_solve is a MILP solver, that runs in a large variety of languages. Models can be passed via input files, an API (application programming interface) or an IDE (integrated development environment). It is also embedded into R via the lp_solve and lp_solveAPI packages. The reference guide is quite exhaustive, and a good place to start using this software.

lp_solve reference guide
lp_solve FAQ (MIT)
R package lp_solve
R package lp_solveAPI

GLPK

GLPK stands for GNU Linear Programming Kit. It is a set of callable libraries written in C intended to solve large scale LP, ILP and MILP models. It is developed by Andrei Makhorin, of the Moscow Aviation Institute. GLPK contains an standalone solver, glpsol, that can be called from the command line. It can read models written in a variety of languages, among them CPLEX, convenient for relatively small problems and GNU MathProg, a standard based on the AMPL format adequate to write large models with regular structure.

GLPK can be used in R via the Rglpk package. For windows users is available GUSEK, an IDE running the GLPK libraries.

GLPK homepage
R package Rglpk
GUSEK IDE

SYMPHONY

Symphony is an open-source solver of MILP problems written in C. It is an initiative of the COIN-OR project. It can read problems written in MPS and MathProg formats. It is also implemented in R through the Rsymphony package.

SYMPHONY homepage
SYMPHONY user's manual
R package Rsymphony

linprog

A library for solving linear programming models, quite popular in MATLAB. There is also a R package available. This library does not solve ILP/MILP models.

linprog in MATLAB
linprog R package