A method that reveals the multi-level ultrametric tree hidden in p-spin glass like systems

In the study of disordered models like spin glasses the key object of interest is the rugged energy hypersurface defined in configuration space. The statistical mechanics calculation of the Gibbs-Boltzmann Partition Function gives the information necessary to understand the equilibrium behavior of the system as a function of the temperature but is not enough if we are interested in more general aspects of the hypersurface: it does not give us, for instance, the different degrees of ruggedness at different scales. In the context of the Replica Symmetry Breaking (RSB) approach we discuss here a rather simple extension that can provide a much more detailed picture. The attractiveness of the method relies in that it is conceptually transparent and the additional calculations are rather straightforward. We think that this approach reveals an ultrametric organisation with many levels in models like p-spin glasses when we include saddle points. In this first paper we present the detailed calculations for the spherical p-spin glass model where we discover that the corresponding decreasing Parisi function $q(x)$ codes this hidden ultrametric organisation

Time and foreign exchange markets

The definition of time is still an open question when one deals with high frequency time series. If time is simply the calendar time, prices can be modeled as continuous random processes and values resulting from transactions or given quotes are discrete samples of this underlying dynamics. On the contrary, if one takes the business time point of view, price dynamics is a discrete random process, and time is simply the ordering according which prices are quoted in the market. In this paper we suggest that the business time approach is perhaps a better way of modeling price dynamics than calendar time. This conclusion comes out from testing probability densities and conditional variances predicted by the two models against the experimental ones. The data set we use contains the DEM/USD exchange quotes provided to us by Olsen & Associates during a period of one year from January to December 1998. In this period 1,620,843 quotes entries in the EFX system were recorded

Assessing Team Member Effectiveness among higher education students using 180º perspective

[EN] Higher education institutions are increasingly aware of the advisability of training students in teamwork, as professional organisations require their employees to integrate in complex projects with other colleagues. Nevertheless, assessing the acquisition of teamwork skills by students is not an easy task. This research evaluates a project implemented with students on the Bachelor¿s degree in Business Administration in which the evolution of teamwork skills was tracked while they were doing a team-based assignment. For this purpose, the CATME-BARS scale was employed to evaluate the teamwork skills in peer-assessments during the semester. In addition, the SLPI was used for evaluating leadership. The teamwork dimensions that emerged as signifi- cant gave priority to social interdependence over the knowledge, skills, and abilities of the teammate. The student profile was revealed as a key factor. The free-rider problem was detected in the Erasmus students (exchange students). Belonging to more demanding groups and the self- perception of leadership had a positive effect on teamwork effectiveness. In our results, gender and job experience did not influence teamwork effectiveness. Some students underwent a process of personal maturation thanks to the reflection on this soft skill. The research carried out high- lights the importance of teamwork ability in university students.This work was supported by the Universitat Politecnica de Valencia under reference [PIME-B16]. Funding for open access charge: CRUE-Universitat Politecnica de Valencia.Baviera, T.; Baviera-Puig, A.; Escribá-Pérez, C. (2022). Assessing Team Member Effectiveness among higher education students using 180º perspective. International Journal of Management Education. 20(3):1-12. https://doi.org/10.1016/j.ijme.2022.10070211220

Optimal Strategies for Prudent Investors

We consider a stochastic model of investment on an asset of a stock market for a prudent investor. She decides to buy permanent goods with a fraction \a of the maximum amount of money owned in her life in order that her economic level never decreases. The optimal strategy is obtained by maximizing the exponential growth rate for a fixed \a. We derive analytical expressions for the typical exponential growth rate of the capital and its fluctuations by solving an one-dimensional random walk with drift.Comment: 14 pages, LaTeX, epsfig.sty, 7 eps figures, minor changes; accepted for International J. of Theoretical and Applied Financ

Leadership skill assessment: Student leadership practices inventory application in a Spanish Marketing Course

[EN] In this research, we analysed the data collected when assessing the "leadership ability" in our University in Bachelor's degree in Business Administration (BBA) as it is becoming a strategic skill in all organizations. The objective was to measure this generic skill in students and help them to develop it. For that, we used the Student Leadership Practices Inventory (SLPI) scale. This scale is based on Five Exemplary Leadership Practices: i) Model the way; ii) Inspire a shared vision; iii) Challenge the process; iv) Enable others to act; and v) Encourage the heart. Six items measure every practice or dimension. In total, there are thirty items. We analysed 132 students who assessed themselves according to this scale, obtaining a score for every item and dimension. To determine the profile of every student, the different variables considered were "Group", "Gender", "Erasmus students" and "Working or having worked". After collecting the data, we calculated the average, standard deviation and range for every item and dimension. We also conducted a cluster analysis and obtained two different segments. Based on the results, we can propose to each student a different development plan of this soft skill depending on the segment they belong. Therefore, we do not only get general conclusions from the whole group but we can also help our students to develop the "leadership ability" in a personalized way.We would like to thank our university for funding this project with reference PIME-B16.Baviera-Puig, A.; Escribá Pérez, C.; Baviera, T. (2021). Leadership skill assessment: Student leadership practices inventory application in a Spanish Marketing Course. IATED Academy. 6159-6165. https://doi.org/10.21125/inted.2021.12386159616