Physical-Layer Transmission Cooperative Strategies for Heterogeneous Networks

The deployment of small cells within the boundaries of a macro-cell is considered to be an effective solution to cope with the current trend of higher data rates and improved system capacity. In the current heterogeneous configuration with the mass deployment of small cells, it is preferred that these two cell types coexist over the same spectrum, because acquiring additional spectrum licenses for small cells is difficult and expensive. However, the coexistence leads to cross-tier/inter-system interference. In this context, this contribution investigates interference alignment (IA) methods in order to mitigate the interference of macro-cell base station towards the small cell user terminals. More specifically, we design a diversity-oriented interference alignment scheme with space-frequency block codes (SFBC). The main motivation for joint interference alignment with SFBC is to allow the coexistence of two systems under minor inter-system information exchange. The small cells just need to know what space-frequency block code is used by the macro-cell system and no inter-system channels need to be exchanged, contrarily to other schemes recently proposed. Numerical results show that the proposed method achieves a performance close to the case where full-cooperation between the tiers is allowed

Joint space-frequency block codes and signal alignment for heterogeneous networks

In this paper, we propose a new diversity-oriented space-frequency block codes (SFBC) and signal alignment (SA) enabled physical network coding (PNC) method for the uplink of heterogeneous networks. The proposed joint Dual-SFBC with SA-PNC design substantially reduces interference and enables connecting a larger number of users when compared with methods adopting interference alignment (IA) or PNC. The main motivation behind the dual SFBC and SA-PNC design is that it allows the efficient coexistence of macro and small cells without any inter-system channel information requirements. Numerical results also verify that the proposed method outperforms the existing SA-PNC static method without any additional information exchange requirement between the two systems while achieving the main benefits of IA and SA-PNC coordinated methods recently proposed.publishe

Joint IA and SFBC Macrocells and Small-Cells Coexistence under Minor Information Exchange

Thedeployment of small-cells within the boundaries of a macrocell is considered to be an effective solution to cope with the current trend of higher data rates and improved system capacity. In the current heterogeneous configuration with the mass deployment of small-cells, it is preferred that these two cell types will coexist over the same spectrum, because acquiring additional spectrum licenses for small-cells is difficult and expensive. However, the coexistence leads to cross-tier/intersystem interference. In this context, this contribution investigates interference alignment (IA) methods in order to mitigate the interference of macrocell base station towards the small-cell user terminals.More specifically, we design a diversity-oriented interference alignment scheme with space-frequency block codes (SFBCs).The main motivation for joint interference alignment with SFBC is to allow the coexistence of two systems under minor intersysteminformation exchange.The small-cells just need to know what space-frequency block code is used by the macrocell system and no intersystem channels need to be exchanged, contrarily to other schemes recently proposed. Numerical results show that the proposed method achieves a performance close to the case where full cooperation between the tiers is allowed

Electric Supply Substation Simulation using ETAP Software

Electric supply substations are vital component of electrical power system that delivers electrical power from generating stations to consumers. Electric supply substation generally deals with high voltage and current ratings, proper analysis and protection is essential for safety of operating staff lives and electrical equipment installed in the vicinity. Malfunctioning of electric supply substation has two drastic effects; one is cost for the replacement of equipment and second is the cost of entire down-time. Analysis and protection of electric supply substation using “Electrical Transient Analyzer Program (ETAP)” is presented in this paper. A 132kV electric supply substation was simulated; fault analysis, load flow study and protection scheme was designed that can enhance the performance of Pakistan’s electrical power system

Migrasjonsundervisning

Som en del av trafikklærerutdanningen ved høgskolen i Nord-Trøndelag er det krav om innlevering av kandidatoppgave i siste semester. Denne skal ha et tema som er aktuelt for det som er blitt jobbet med under trafikklærerutdanningen. Gjennom denne besvarelsen ønsker vi å legge frem funnene vi har gjort i forbindelse med undersøkelsene rundt migrasjonsundervisningen. Vi ønsker å takke våre veiledere Olav Krogstad, Svein Loeng, Roger Hanssen og Kåre Robertsen som har inspirert oss og gitt gode råd i utarbeidelsen av denne besvarelsen. Vi vil også takke voksenopplæringssenteret i Stjørdal ved Ole Walnum for hjelp med å finne kandidater til undersøkelsen. For å gjennomføre prosjektet var vi avhengig av at studenter ved voksenopplæringen og faglærere ved HiNT TLU ville stille opp i aksjonen. Vi ønsker å takke for deres deltakelse og entusiasmen de viste i undersøkelsen. Vi setter pris på den humoren og lærevilje samtlige av intervjuobjektene våre viste, og vil takke dem for det. Vi vil også takke badstuminister Odd-Erik Hansen for gode råd i forbindelse med utarbeiding av oppgaven. Vi ønsker å takke hverandre i gruppa for at vi har holdt ut med hverandre i disse hektiske månedene og vi takker våre familier for tålmodighet, mat og støtte. I starten av prosjektet ble vi enige om at vi skulle ta tak i intervjuobjekter fra Sunndalsøra internasjonale skole, hvor Olav Krogstad har startet pilotprosjektet sitt med migrasjonsundervisning. Planen var å intervjue ansvarlige og elever ved Sunndal internasjonale skole som har gjennomført tilrettelagt opplæring, men dette lot seg ikke gjennomføre på grunn av sykdom fra deres side. Vi fikk ikke frem den ønskede effekten av tilrettelagt opplæring fordi elevene vi intervjuet ikke hadde fulgt løpet med tilrettelagt opplæring som de på Sunndalsøra. Vi mistet godt over en måned til utsettelser av intervjuene og dette medførte også at vi måtte finne andre intervjuobjekter fra Voksenopplæringen Stjørdal. Vi måtte tilpasse spørsmålene til disse. Vi ønsker rette vedkommende god bedring.

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Técnicas cooperativas de eliminação de interferência ao nível da camada física para sistemas heterogéneos sem fios

Doutoramento em Telecomunicações Departamento de ElectrónicaO tráfego móvel com origem em redes celulares está a aumentar exponencialmente, principalmente devido ao uso de serviços de dados como o vídeo. Uma forma efetiva de lidar com essas exigências é reduzir o tamanho da célula, implementando células pequenas (SCs), ao longo da área de cobertura do atual sistema macro-celular. A implementação de SCs melhora a cobertura de forma significativa. No entanto, como as licenças de espectro adicionais são difíceis e caras de adquirir, espera-se que a macro e as pequenas células possam coexistir sob o mesmo espectro. A coexistência dos dois sistemas resulta em interferências entre eles. Neste contexto, esta tese foca-se no projeto de várias técnicas de mitigação de interferência em redes heterogéneas (HetNets) sob requisitos de coordenação limitados. A primeira parte da tese foca-se no projeto de várias técnicas baseadas no alinhamento de interferência (IA) para o sentido descendente do sistema heterogéneo. Mais especificamente, são propostos esquemas baseados no alinhamento de interferência com diferentes níveis de coordenação intersistema e a restrição de que o desempenho do sistema macro-célula é mantido próximo do caso em que o sistema SCs é desligado. A segunda parte da tese centra-se no projeto conjunto de técnicas baseadas no IA e códigos por bloco no espaço -frequência (SFBCs) para o sentido descendente. Mais especificamente, é apresentado o projeto do esquema de IA com SFBCs orientado para se obter diversidade. A principal motivação para o projeto conjunto do IA com SFBCs, é permitir a coexistência dos dois sistemas, considerando uma pequena troca de informação entre sistemas. As células pequenas apenas precisam de saber que o SFBC é usado pelo sistema macro-celular, não sendo necessária a troca de nenhum canal inter-sistema, contrariamente aos outros esquemas propostos na primeira parte da tese. A parte final da tese apresenta a aplicação do alinhamento de sinal (SA) e codificação de rede física (PNC) para a ligação ascendente do sistema heterogéneo. A principal motivação por detrás do projeto conjunto SA-PNC é aproveitar o alinhamento do sinal e codificação de rede física, para utilizar a interferência como um sinal útil, permitindo que mais utilizadores possam estar ativos simultaneamente. Os resultados numéricos mostram claramente que os métodos propostos fornecem um desempenho próximo do ótimo, com o mínimo de troca de informação entre sistemas.Mobile tra c in cellular based networks is increasing exponentially, mainly due to the use of data intensive services like video. One e ective way to cope with these demands is to reduce the cell-size by deploying small-cells (SCs) along the coverage area of the current macro-cell system. The deployment of SCs signi cantly improves the coverage. Nevertheless, as additional spectrum licenses are di cult and expensive to acquire, it is expected that the macro and small-cells will coexist under the same spectrum. The coexistence of the two systems results in co-tier/intra-system and crosstier/ inter-system interference. In this context, this thesis focuses on the design of several interference mitigation techniques in order to cancel the interference in heterogeneous networks (HetNets) under limited coordination requirements. The rst part of the thesis focuses on the design of several interference alignment (IA) based techniques for the downlink of HetNets. More specifically, we design IA based schemes under di erent levels of inter-system coordination and the constraint that the performance of macro-cell system is kept close to the case where SC system is switched-o . The second part of the thesis focuses on the joint design of IA and spacefrequency block codes (SFBCs) for the downlink of HetNet. More specifically, the design of diversity-oriented IA scheme with SFBCs is presented. The main motivation for joint IA with SFBCs is to allow the coexistence of two systems under minor inter-system information exchange. The SCs just need to know what SFBC is used by the macro-cell system and no inter-system channels need to be exchanged, contrarily to other schemes proposed in the rst part of the thesis. The nal part of the thesis presents the application of joint signal alignment (SA) and physical network coding (PNC) for the uplink of HetNets. The main motivation behind the joint design of SA-PNC is to take advantage of SA and PNC to utilize the interference as a useful signal that allows the network to achieve high degree of freedom (DoF) by serving more users. The numerical results clearly show that the proposed methods provide close to optimal performance with minor overheads

Application of coupling machine learning techniques and linear Bias scaling for optimizing 10-daily flow simulations, Swat River Basin

Accurate hydrological simulations comply with the water (sixth) Sustainable Development Goals (SDGs). The study investigates the utility of ANN and SVR, as well as the post-simulation bias treatment of these simulations at Swat River basin, Pakistan. For this, climate variables were lag adjusted for the first time, then cross-correlated with the flow to identify the most associative delay time. In sensitivity analysis, seven combinations were selected as input with suitable hyperparameters. For SVR, grid search cross-validation determined the optimal set of hyper-parameters, while for ANN, neurons and hidden layers were optimized by trial and error. We ran model by using optimized hyperparameter configurations and input combinations. In comparison to SVRs (Root mean square error (RMSE) 34.2; mean absolute error (MAE) 3.0; CC 0.91) values, respectively, ANN fits the observations better than SVR with (RMSE 11.9; MAE 1.14; CC 0.99). Linear bias-corrected simulations greatly improved ANN performance (RMSE 3.98; MAE 0.625; CC 0.99), while the improvement was slight in the case of SVR (RMSE 35; MAE 0.58; CC 0.92). On seasonal scale, bias-corrected simulations remedy low- and high-flow seasonal discrepancies. Flow duration analysis results reveal deviation at low- and high-flow conditions by models, which were then reconciled by applying bias corrections. HIGHLIGHTS The study represents a couple of AI prognostic models with bias scaling on the Swat Basin case study.; ANN performs best with higher input parameters, while SVR performs robustly with lower input parameters.; Bias scaling of SVR (SVR-BC) improves in depicting peaks.; Bias correction of ANN yields better flow series having minimum errors than other models.