Iterative decoding combined with physical-layer network coding on impulsive noise channels

PhD ThesisThis thesis investigates the performance of a two-way wireless relay channel (TWRC) employing physical layer network coding (PNC) combined with binary and non-binary error-correcting codes on additive impulsive noise channels. This is a research topic that has received little attention in the research community, but promises to offer very interesting results as well as improved performance over other schemes. The binary channel coding schemes include convolutional codes, turbo codes and trellis bitinterleaved coded modulation with iterative decoding (BICM-ID). Convolutional codes and turbo codes defined in finite fields are also covered due to non-binary channel coding schemes, which is a sparse research area. The impulsive noise channel is based on the well-known Gaussian Mixture Model, which has a mixture constant denoted by α. The performance of PNC combined with the different coding schemes are evaluated with simulation results and verified through the derivation of union bounds for the theoretical bit-error rate (BER). The analyses of the binary iterative codes are presented in the form of extrinsic information transfer (ExIT) charts, which show the behaviour of the iterative decoding algorithms at the relay of a TWRC employing PNC and also the signal-to-noise ratios (SNRs) when the performance converges. It is observed that the non-binary coding schemes outperform the binary coding schemes at low SNRs and then converge at higher SNRs. The coding gain at low SNRs become more significant as the level of impulsiveness increases. It is also observed that the error floor due to the impulsive noise is consistently lower for non-binary codes. There is still great scope for further research into non-binary codes and PNC on different channels, but the results in this thesis have shown that these codes can achieve significant coding gains over binary codes for wireless networks employing PNC, particularly when the channels are harsh

Finite element modelling of cement augmentation and fixation for orthopaedic applications

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Estudio de caso del chat de grupo en WeChat entre estudiantes chinos de la Universidad Pompeu Fabra

Treball de fi de màster en Estudis del Discurs. Tutor: Pere Freixa i FontEstudiar en paísextranjero ya es un fenómeno muy habitual,pero cuando los individuosempiezansu vidaen el extranjero, adaptarse en una cultura extranjera es un proceso complicado.Para los estudiantes internacionales en países extranjeros,las aplicaciones de mensajería instantánea (IM) también pueden desempeñarun papel importante para mantener el contacto diario con susfamiliares y amigosen el país de origen, y con los amigoshechosen el país de acogida. Este estudio, se centraen los estudiantes chinos de la Universidad Pompeu Fabra de Barcelona, España. Con él se ha pretendidoobservar los diálogos realizado en el chat grupal en una aplicación de IMde China –WeChat,que ellos usan su vidahabitualmenteen el país extranjero.Con este trabajose pretendeobservar el proceso de adaptación transcultural, sobre todo en la fase inicial, con el fin delocalizar las temáticas, preocupaciones y situaciones relevantes que ocupan a los estudiantes chinos duranteesteprocesoy conocerlas estrategias de resolución de conflictos utilizadospor ellos. Se han utilizado tantometodologíascualitativascomocuantitativasse han utilizado. El corpus de la muestra analizada está formado por las conversaciones realizadas entre los miembros del grupo. Se han observado y analizado un total de 1277 entradas. Los resultados muestran que, en el proceso inicial de la , en el proceso inicial de la adaptación transcultural,los estudiantes no sólo presentan los sentimientos positivos por el descubrimiento de la nuevacultura,exótica para ellos, del país anfitrión, sino que también están afectados porlosinconvenientes que se pueden dar en su relacióncon la sociedad y la universidady que les pueden resultar negativos por la dificultad de comprender los procesos y encontrarse sin los recursos necesarios para resolver las situaciones. Además, en el caso de nuestra investigación el emoticón y unas calcomaníassimilares se utilizanfrecuentemente,que es reírse de mala gana,pero con lágrimas, para expresar un sentimiento complicado cuando se obliguea sufrir algo que no quiere, o para autocriticarse en unas ocasiones. La investigación nos permite confirmar que la observación de grupos de usuarios de aplicaciones sociales como WeChat permite monitorizar el proceso de adaptación transcultural en entornos académicos. Permite localizar las temáticas que preocupan a los estudiantes, dimensionar el grado de preocupación que provocan y los recursos que el grupo utiliza para resolver conflictos. Como recomendación final, se propone a las universidades que creen cuentas en las redes sociales, en plataformas como WhatsApp, WeChat. Puedenaprovechar lafunción de cuenta oficialde WeChat para la difusión de información necesaria para ayudar a los estudiantes chinos en evitar unos conflictos antes y después de llegara vivir y estudiaren España, con el fin de mejorar la competencia educativa internacional.Studying in a foreign country is already a very common phenomenon, but when individuals begin their life abroad, adapting to a foreign culture is a complicated process. For international students in foreign countries, instant messaging (IM) applications can also play an important role in maintaining daily contact with family and friends in the country of origin, and with friends made in the host country. This study focuses on Chinese students at the University Pompeu Fabra in Barcelona, Spain, pretending to observe the dialogues conducted in group chat on the application IM China – WeChat. With it we have been tried to observe the dialogues carried out in the group chat in an IM application from China - WeChat, which they use their life habitually in the foreign country. This work intends the process of transcultural adaptation, especially in the phase in order to locate the relevant issues, concerns and situations that Chinese students occupy during this process and to know the conflict resolution strategies used by them. This work intends to observe the process of transcultural adaptation, especially in the initial phase, in order to locate the relevant issues, concerns and situations that Chinese students occupy during this process and to know the conflict resolution strategies used by them. Both qualitative and quantitative methodologies have been used. The corpus of the analyzed sample is formed by the conversations made between the members of the group. A total of 1277 entries were observed and analyzed. The results show that, in the initial process of transcultural adaptation, students not only exhibit positive feelings about the discovery of the new culture, alien to them from the host country, but are also affected by the drawbacks in their relationship with society and the university and they can be negative because of the difficulty of understanding the processes and find themselves without the resources to resolve situations. In addition, in the case of our research, the emoticon :) and similar decals are frequently used, seems to laugh reluctantly, but with tears, to express a complicated feeling when it forces the car chat to suffer something that does not want, or self-criticize in some occasions. The research allows us to confirm that the observation of groups of users of social applications like WeChat allows monitoring the process of transcultural adaptation in academic environments. It locates the issues that concern the students, measure the degree of concern they cause and the resources that the group uses to resolve conflicts. As a final recommendation, it is proposed that universities create accounts on social networks, on platforms such as WhatsApp, WeChat. They can take advantage of the WeChat account official function to disseminate information needed to help Chinese students avoid conflicts before and after they live and study in Spain in order to improve international educational competence

Throughput maximization-based optimal power allocation for energy-harvesting cognitive radio networks with multiusers

Abstract An optimal power allocation (OPA) policy for orthogonal frequency division multiplexing (OFDM)-based cognitive radio networks (CRNs) using underlay spectrum access model is presented under multiple secondary users (SUs) with energy harvesting (EH). The proposed algorithm can allocate transmission power to each SU on each subcarrier with the objective of maximizing the average throughput of secondary network over a finite time interval. We consider both the interference power constraint limited by primary user (PU) and the minimum throughput constraint of each SU to improve the throughput of SUs while guaranteeing the communication quality of PU. To balance current throughput and expected future throughput, a dynamic programming (DP) problem is defined and solved by the backward induction method. Moreover, for each time slot, a convex immediate optimization is presented to obtain an optimal solution, which can be solved by the Lagrange dual method. Simulation results show that our policy can achieve better performance than some traditional policies and ensure good quality of service (QoS) of PU when SUs access the spectrum

The impact of musical expertise on anticipatory semantic processing during online speech comprehension: An electroencephalography study

Musical experience has been found to aid speech perception. This electroencephalography study further examined whether and how musical expertise affects high-level predictive semantic processing in speech comprehension. Musicians and non-musicians listened to semantically strongly/weakly constraining sentences, with each sentence being primed by a congruent/incongruent sentence-prosody. At the target nouns, a N400 reduction effect (strongly vs. weakly constraining) was observed in both groups, with the onset-latency of this effect being delayed for incongruent (vs. congruent) priming. At the transitive verbs preceding these target nouns, musicians' event-related-potential amplitude (in incongruent-priming) and beta-band oscillatory power (in congruent- and incongruent-priming) showed a semantic-constraint effect, and were correlated with the predictability of incoming nouns; non-musicians only demonstrated an event-related-potential semantic-constraint effect, which was correlated with the predictability of current verbs. These results indicate musical expertise enhances semantic prediction tendency in speech comprehension, and this effect might be not just an aftereffect of facilitated acoustic/phonological processing

Geochemical Characteristics of the Volcanic Rocks Associated with Boron-Rich Deposits from the Xiongba Basin, Qinghai–Tibet Plateau

The Qinghai–Tibet Plateau (QTP) hosts significant lacustrine sedimentary boron-rich deposits, with the Xiongba Basin being a prominent region housing two large sedimentary boron-rich deposits. These deposits are closely associated with extensive Neogene volcanic rocks. This study investigates the origin and boron sources of Miocene volcanic rocks in the Xiangqu River area, located within the Xiongba Basin. The volcanic rocks in the basin comprise ultrapotassic andesites, ultrapotassic trachyte, potassic trachyte, and potassic trachyandeiste. The trace element content and the active/inert elements ratios of the studied volcanic rocks have indicated that they were generated in a subduction environment and were influenced by enrichment fluids derived from deep-sea sediments or altered oceanic crust during their formation. Accordingly, the studied volcanic rocks exhibit significant boron enrichment. The eruption of magma and subsequent hydrothermal activity released boron, which became the primary source for the lacustrine sedimentary boron-rich deposits within the basin. The arc-like trace element features (e.g., Nb-Ta depletion relative to La and K) and high B concentrations in these rocks were inherited from the mantle source, which had been enriched by melt/fluid of the subducted sediments. A two-stage evolutionary model is proposed to explain the enrichment of B in subduction environments, as well as the subsequent melting of the B-enriched source during a post-collisional setting. These findings highlight the potential for boron and lithium mineralization in similar volcanic rock-bearing regions across the QTP. Future exploration efforts in such areas could provide valuable insights into the formation processes of lacustrine sedimentary boron-rich deposits and contribute to the understanding of boron and lithium resource potential

Petrogenesis of the Early Jurassic–Early Cretaceous Adakite-like Rocks in the Erguna Block, NE China: Implications for the Tectonic Evolution of the Mongol–Okhotsk Ocean

The petrogenesis and geodynamic setting of the Mesozoic magmatic rocks in the Erguna Block, NE China remains controversial, especially the relationship between magmatism and the subduction history of the Mongol–Okhotsk oceanic plate. Here we present data for the Early Jurassic–Early Cretaceous adakite-like magmatic rocks from Chaoman Farm in the northeastern part of the Erguna Block. Zircon U-Pb dating reveals that the syenogranites crystallized at around 190–180 Ma, while the monzonites, quartz diorite porphyries, and quartz monzonite porphyries were emplaced at around 147–143 Ma. The syenogranites, monzonites, quartz diorite porphyries, and quartz monzonite porphyries are adakite-like rocks. The syenogranites and quartz monzonite porphyries were produced by the partial melting of a thickened ancient mafic lower continental crust and a thickened juvenile lower crust, respectively. Meanwhile, the monzonites and quartz diorite porphyries were formed as a result of partial melting of the oceanic crust. In conclusion, the occurrence of these Early Jurassic magmatic rocks was closely linked to the process of southward subduction of the Mongol–Okhotsk oceanic plate. On the contrary, the Late Jurassic to early Early Cretaceous magmatism (147–143 Ma) occurred in an extensional environment, and was probably triggered by upwelling of the asthenosphere

Distribution and Source Apportionment of Heavy Metals in Soil around Dexing Copper Mine in Jiangxi Province, China

The soil heavy metal pollution around the mine threatens crop growth and human health. Intensively studies of the distribution characteristics and source of soil heavy metals around some typical mines are very crucial for environmental management and green development of mine. A total of eighty-nine soil samples, twenty-one sediment samples, five waste rock samples and two tailing sand samples were sampled to investigate copper (Cu), lead (Pb), zinc (Zn), arsenic (As), cadmium (Cd), chromium (Cr) and mercury (Hg) in soil, sediment, waste rocks and tailings sand around Dexing Copper Mine, Jiangxi Province, China. The concentrations of the seven heavy metals were determined using inductively coupled plasma mass spectrometry ICP-MS/atomic fluorescence spectroscopy (AFS). The Igeo values of soil heavy metal showed that 100% of Cu were at an unpolluted-to-moderately-polluted level (Igeo > 0), more than 50% of Cu were heavily polluted (Igeo > 3), 65.16%, and 22.47%, 7.86% and 7.87% of the soil samples for Cd, Hg, As and Zn were overly moderately polluted (Igeo > 1). A total of 13.48% and 11.24% of the soil samples for Pb and Cr, respectively, were moderately polluted (1 geo and RSVCAL, the soils around Dexing Copper Mine were polluted by heavy metals to some extent, with especially the Cu pollution of soil being the most serious. These heavy metal concentrations exceeding RSVCAL have threatened the safety of agricultural products. The results of soil profile analysis, principal component analysis (PCA) and cluster analysis (CA) indicated that the mining activities of Dexing copper mine should be the main source of Cu in the soil. High As concentration in soil obviously caused by the copper mine as well. In addition, Dexing Copper Mine should partly account for soil pollution by Zn, Pb, Cd, Hg and Cr around the mine