Customer-oriented risk assessment in Network Utilities

For companies that distribute services such as telecommunications, water, energy, gas, etc., quality perceived by the customers has a strong impact on the fulfillment of financial goals, positively increasing the demand and negatively increasing the risk of customer churn (loss of customers). Failures by these companies may cause customer affection in a massive way, augmenting the intention to leave the company. Therefore, maintenance performance and specifically service reliability has a strong influence on financial goals. This paper proposes a methodology to evaluate the contribution of the maintenance department in economic terms, based on service unreliability by network failures. The developed methodology aims to provide an analysis of failures to facilitate decision making about maintenance (preventive/predictive and corrective) costs versus negative impacts in end-customer invoicing based on the probability of losing customers. Survival analysis of recurrent failures with the General Renewal Process distribution is used for this novel purpose with the intention to be applied as a standard procedure to calculate the expected maintenance financial impact, for a given period of time. Also, geographical areas of coverage are distinguished, enabling the comparison of different technical or management alternatives. Two case studies in a telecommunications services company are presented in order to illustrate the applicability of the methodology

Public Key Protocols over Twisted Dihedral Group Rings

Key management is a central problem in information security. The development of quantum computation could make the protocols we currently use unsecure. Because of that, new structures and hard problems are being proposed. In this work, we give a proposal for a key exchange in the context of NIST recommendations. Our protocol has a twisted group ring as setting, jointly with the so-called decomposition problem, and we provide a security and complexity analysis of the protocol. A computationally equivalent cryptosystem is also proposed

Viabilidad financiera y beneficios ambientales de sistemas de aprovechamiento de agua no convencionales en la zona urbana de Pereira

El presente trabajo se desarrolló con el propósito de identificar los potenciales beneficios ambientales, derivados de la implementación de sistemas de aprovechamiento de agua lluvia, en entornos urbanos. Así mismo, determinar la viabilidad económica referente a la implementación de estos sistemas en la ciudad de Pereira. En el transcurso de la investigación se identificaron los potenciales beneficios mediante la búsqueda documental de experiencias e investigaciones referentes al tema en diferentes partes de Colombia y el mundo. Se determinaron los valores de la inversión inicial relativos a la implementación de estos sistemas, además de evaluar la viabilidad de seis diferentes configuraciones por un periodo de tiempo de cincuenta años. Arrojando como resultado que la implementación de estos sistemas es viable para la ciudad de Pereira

A framework for effective management of condition based maintenance programs in the context of industrial development of E-Maintenance strategies

CBM (Condition Based Maintenance) solutions are increasingly present in industrial systems due to two main circumstances: rapid evolution, without precedents, in the capture and analysis of data and significant cost reduction of supporting technologies. CBM programs in industrial systems can become extremely complex, especially when considering the effective introduction of new capabilities provided by PHM (Prognostics and Health Management) and E-maintenance disciplines. In this scenario, any CBM solution involves the management of numerous technical aspects, that the maintenance manager needs to understand, in order to be implemented properly and effectively, according to the company’s strategy. This paper provides a comprehensive representation of the key components of a generic CBM solution, this is presented using a framework or supporting structure for an effective management of the CBM programs. The concept “symptom of failure”, its corresponding analysis techniques (introduced by ISO 13379-1 and linked with RCM/FMEA analysis), and other international standard for CBM open-software application development (for instance, ISO 13374 and OSA-CBM), are used in the paper for the development of the framework. An original template has been developed, adopting the formal structure of RCM analysis templates, to integrate the information of the PHM techniques used to capture the failure mode behaviour and to manage maintenance. Finally, a case study describes the framework using the referred template.Gobierno de Andalucía P11-TEP-7303 M

Cyclic Triindoles and Tetraindoles: Substituent and Symmetry Effects on their Structural and Electronic Characteristics

During the last decade heptacyclic 10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole (triindole) has been extensively studied as a new π-conjugated platform in the construction of self-assembling materials for optoelectronics. Specially remarkably is the record hole mobility values determined on triindole liquid crystals.1 In order to facilitate the design of new materials on a molecular basis and establish clear guidelines to fine tuning electronic parameters, we have recently synthesized new triindole and tetraindole-based systems.2-3 Our joint experimental and theoretical investigation shows that N-substitution, symmetry lowering of the platform, and insertion of π-spacers in extended dimers strongly impact on the fundamental electronic properties of triindoles.2 In addition, saddle-shaped tetraindoles are found to be an interesting 3D rigid scaffold to obtain electroactive molecules with increased dimensionality.3 We hope that this study can not only advance useful structure-property relationships of conjugated indole-based systems but also guide the design of new materials with potential applications in organic electronics.References 1. E.M. García-Frutos, U.K. Pandey, R. Termine, A. Omenat, J. Barberá, J.L. Serrano, A. Golemme, B. Gómez-Lor, Angew. Chem. Int. Ed. 2011, 50, 7399 2. a) C. Ruiz, J.T. López Navarrete, M.C.Ruiz Delgado, B. Gómez-Lor, Org. Lett. 2015, 17, 2258−2261. b) C. Ruiz, E.M. García-Frutos, D.A. da Silva Filho, J.T. López Navarrete, M.C. Ruiz Delgado, and B. Gómez-Lor, J. Phys. Chem. C 2014, 118, 5470−5477 3. C. Ruiz, A. Monge, E. Gutiérrez-Puebla, I. Alkorta, J. Elguero, J. T. López Navarrete, M.C. Ruiz Delgado and B. Gómez-Lor, submittedUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

On the Influence of Shade in Improving Thermal Comfort in Courtyards

This study analyzes the thermal performance of courtyards in traditional buildings in the city center of Córdoba (South of Spain), one of them displaying a shading component, to determine the influence of this precise element. The courtyards have been monitored simultaneously during a summer period when temperatures during the day reached over 45 °C. The obtained data was contrasted, and we confirmed that the shading element provided an improvement of the thermal performance of the courtyard which doubled the thermal leap between outdoor and inside the courtyard temperatures when the shading element was installed, in comparison to the courtyard without shade. Therefore, the tempering effect of courtyards can be significantly improved by means of using these simple elements

Desarrollo de la competencia lectora en secundaria

En México, los alumnos de telesecundaria obtienen los puntajes más bajos en competencia lectora. Este trabajo presenta los resultados de una investigación que tuvo como objetivo determinar la eficacia de un programa de comprensión lectora implementado en telesecundarias de una región marginada. El diseño fue experimental, con 16 grupos de octavo grado como grupo experimental y siete como control. Los resultados muestran que el grupo de control obtuvo los mismos puntajes antes y después de la intervención, mientras que el grupo experimental presentó una mejoría en la segunda evaluación, por lo que se considera que el programa fue eficaz.ITESO, A.C

Recommendations on seismic actions on bridges

The paper describes the main features of a technical Recommendation first draft on Seismic Actions on Bridges, promoted by the Spanish Ministry of Public Works (MOPT). Although much more research is needed to clarify the seismic behaviour of the vast class of problems present in port structures the current state of the art allows at least a classificaton of subjects and the establishment of minimum requirements to guide the design. Also the use of more refined methods for specially dangerous situations needs some general guidelines that contribute to mantein the design under reasonable safety margins. The Recommendations of the Spanish MOPT are a first try in those directions