Search results for "complexity"

Etude de certaines familles de variétés algébriques munies d'une action de groupe algébrique

2021

REMOTELY PILOTED AIRCRAFT SYSTEMS (RPAS) APPLICATION FOR STRUCTURE DESCRIPTION OF MEDITERRANEAN VERMETID REEFS

2016

Vermetid gastropods are coastal habitat engineers which build biogenic platforms typical of intertidal rocky shores of central and south -east of the Mediterranean. These bioconstructions create a secondary habitat which increases resource availability and space for organisms, locally transforming the environment and modifying coastal geomorphology. Biological characteristics and physical structure of these bioconstructions are commonly studied by field-based sampling. Nevertheless, a lot of time is required to collect data over large areas of reef, field conditions can impair data collection and direct reef image interpretation may be a challenge due to their intertidal position. In this s…

Managing complexity in global IT projects

2017

Projektien hallintaan kuuluu paljon erilaisia osa-alueita, joita projektipäällikön ja korkeamman tason henkilöstön tulee ottaa huomioon ennen projektin alkua ja sen aikana. Projektin kompleksisuus nousee kuitenkin erittäin korkealle ta-solle, kun kyseessä on kansainvälinen IT-projekti. Tämän kaltaisissa projek-teissa on useita osa-alueita, jotka voivat vaikuttaa kriittisesti niiden onnistumi-seen. Tämä tutkimus keskittyy havainnoimaan, mistä asioista kompleksisuus koostuu globaalien IT-projektien tapauksessa, miten se linkittyy kompleksi-suusteoriaan ja miten tätä kompleksisuutta kyetään hallitsemaan. Tekotapana tässä tutkimuksessa on kirjallisuuskatsaus. Kirjallisuus on kerätty kirjastoist…

La complejidad del conocimiento: retos para su eficaz creación y transferencia en la organización innovadora

2012

Una eficaz creación y transferencia de conocimiento es esencial para promover el aprendizaje organizativo y la innovación. Con este postulado como idea principal, este artículo explora sendos casos de proyectos de gestión del conocimiento en dos empresas españolas, profundizando en tres características problemáticas del conocimiento: dispersión, ambigüedad y perturbación. Los resultados recomiendan diseñar cuidadosamente el proyecto de gestión de conocimiento teniendo en cuenta: (i) el propósito de la estrategia de gestión de conocimiento, (ii) el equipo coordinador del proyecto y la distribución de responsabilidades, y (iii) los requerimientos y restricciones organizativos, incluyendo proc…

Earnings Premiums in Academia: Evidence from Personnel Data

2013

This study examines the existence of a gender earnings gap in the academic labour market with well-defined pay scales with panel data from the personnel records of a large university. We find that women earn approximately 10% less than men but that adjusting for different background characteristics and research performance decreases the gap to 2%. Our results suggest that the level of gender pay inequality is greater among older employees and lower for more productive employees. The results also imply that the gender gap is more pronounced in female-led departments than in male-led departments. peerReviewed

A New Feature Selection Methodology for K-mers Representation of DNA Sequences

2015

DNA sequence decomposition into k-mers and their frequency counting, defines a mapping of a sequence into a numerical space by a numerical feature vector of fixed length. This simple process allows to compare sequences in an alignment free way, using common similarities and distance functions on the numerical codomain of the mapping. The most common used decomposition uses all the substrings of a fixed length k making the codomain of exponential dimension. This obviously can affect the time complexity of the similarity computation, and in general of the machine learning algorithm used for the purpose of sequence analysis. Moreover, the presence of possible noisy features can also affect the…

Benefits and Drawbacks of A High Frequency Gan Zvzcps Converter

2017

This paper presents the benefits and drawbacks of replacing the traditional Si Mosfets transistors with enhancement mode GaN transistors in a Half-Bridge Zero Voltage and Zero Current Switching Power Switching (ZVZCPS) converter. This type of converters is usually used as Electronic Power Converters (EPC) for telecommunication satellites travelling-wave tube amplifiers (TWTAs). In this study, firstly the converter is theoretically analysed, obtaining its operation, losses and efficiency equations. From these equations, optimizations maps based on the main system parameters are obtained. These optimization maps are the key to quantify the potential benefits of GaN transistors in this type of…

Pathogenic Role of Complement in Antiphospholipid Syndrome and Therapeutic Implications

2018

Antiphospholipid syndrome (APS) is an acquired autoimmune disease characterized by thromboembolic events, pregnancy morbidity, and the presence of antiphospholipid (aPL) antibodies. There is sound evidence that aPL act as pathogenic autoantibodies being responsible for vascular clots and miscarriages. However, the exact mechanisms involved in the clinical manifestations of the syndrome are still a matter of investigation. In particular, while vascular thrombosis is apparently not associated with inflammation, the pathogenesis of miscarriages can be explained only in part by the aPL-mediated hypercoagulable state and additional non-thrombotic effects, including placental inflammation, have b…

Assessment of nonnegative matrix factorization algorithms for electroencephalography spectral analysis.

2020

AbstractBackgroundNonnegative matrix factorization (NMF) has been successfully used for electroencephalography (EEG) spectral analysis. Since NMF was proposed in the 1990s, many adaptive algorithms have been developed. However, the performance of their use in EEG data analysis has not been fully compared. Here, we provide a comparison of four NMF algorithms in terms of accuracy of estimation, stability (repeatability of the results) and time complexity of algorithms with simulated data. In the practical application of NMF algorithms, stability plays an important role, which was an emphasis in the comparison. A Hierarchical clustering algorithm was implemented to evaluate the stability of NM…

Continuous Improvement on Detailed Design Phase : A Process Perspective

2020

The construction project being studied is a government investment related to the relocation of a biomedical institute delivering research-based knowledge and contingency support in the fields of animal health, fish health and food safety. The project covers a total of 63,000 square meters distributed over 10 buildings with a very high degree of complexity. The design alone has required 1 million hours, which relates to a client cost of about 100 million Euro. The purpose of this paper is to study the applied methodology for managing the detailed design to identify lessons learned from the project. The theory underlying the study is inspired by lean design management and design theory linked…