Survey on Data-Centric based Routing Protocols for Wireless Sensor Networks

The great concern for energy that grew with the technological advances in the field of networks and especially in sensor network has triggered various approaches and protocols that relate to sensor networks. In this context, the routing protocols were of great interest. The aim of the present paper is to discuss routing protocols for sensor networks. This paper will focus mainly on the discussion of the data-centric approach (COUGAR, rumor, SPIN, flooding and Gossiping), while shedding light on the other approaches occasionally. The functions of the nodes will be discussed as well. The methodology selected for this paper is based on a close description and discussion of the protocol. As a conclusion, open research questions and limitations are proposed to the reader at the end of this paper

SparkIR: a Scalable Distributed Information Retrieval Engine over Spark

Search engines have to deal with a huge amount of data (e.g., billions of documents in the case of the Web) and find scalable and efficient ways to produce effective search results. In this thesis, we propose to use Spark framework, an in memory distributed big data processing framework, and leverage its powerful capabilities of handling large amount of data to build an efficient and scalable experimental search engine over textual documents. The proposed system, SparkIR, can serve as a research framework for conducting information retrieval (IR) experiments. SparkIR supports two indexing schemes, document-based partitioning and term-based partitioning, to adopt document-at-a-time (DAAT) and term-at-a-time (TAAT) query evaluation methods. Moreover, it offers static and dynamic pruning to improve the retrieval efficiency. For static pruning, it employs champion list and tiering, while for dynamic pruning, it uses MaxScore top k retrieval. We evaluated the performance of SparkIR using ClueWeb12-B13 collection that contains about 50M English Web pages. Experiments over different subsets of the collection and compared the Elasticsearch baseline show that SparkIR exhibits reasonable efficiency and scalability performance overall for both indexing and retrieval. Implemented as an open-source library over Spark, users of SparkIR can also benefit from other Spark libraries (e.g., MLlib and GraphX), which, therefore, eliminates the need of usin

Social vulnerability to tropical cyclones: A case study in Muscat Governorate, Oman

Social vulnerability (SV) assessment reveals the hidden weaknesses in the human system that make populations susceptible to loss following exposure to external stress. In this study, SV to natural hazards, such as tropical cyclones, are studied and assessed at the local level for coastal cities in Oman. Vulnerability is determined using the underlying social characteristics specific to people in Oman that put them at risk from cyclones. Oman is a developing country exposed to frequent tropical cyclones that create devastating impacts on its coastal cities, yet disaster risk reduction is undeveloped, with limited understanding of the spatial and temporal distribution of risk and vulnerability, and limited investment in resources and skills in this field. In particular, Oman lacks a natural hazard risk assessment system, hence the response to cyclone events is still reactive and not scientifically based. Some unpublished biophysical vulnerability studies exist that focus mainly on the coastal vulnerability to tsunami in Oman, but there have been no prior studies of SV to natural hazards. In this research, an SV model is adopted and applied at the local level (smallest administration boundary) for four coastal cities in the Muscat capital region. Drawing on a conceptual framework of social vulnerability, based on the work of Susan Cutter, the study identified appropriate SV variables reported by the 2010 census. From a preliminary list of 38 potential variables, 24 variables in 9 social dimensions were selected following exclusion of variables due to multicollinearity and singularity. These variables were then used in a principal component analysis (PCA) to further reduce the number of factors to a few meaningful components/factors/indicators. This process produced three indicators, each consisting of a cluster of variables that make up a construct representative of a vulnerable social group. The subsequent aggregation of these variables created a social vulnerability index (SVI) used in GIS to map the spatial distribution of SV to cyclones across Muscat region. This analysis was then repeated for the 1993 and 2003 censuses, which along with the 2010 analysis, allowed an exploration of the temporal variation of SV over two decades. The results show that for Muscat’s coastal cities, in addition to their exposure to physical hazards, there are clusters of municipal blocks with high SV to cyclones, and others with very low social vulnerability. The level of SV also increases over time. In 1993 there were only three municipal blocks with high SV to cyclones, but by 2010 there were 20 high SV municipal blocks, and a decline in low vulnerability areas. This increase in SV is attributed mainly to an increase in population (particularly rural to urban migration for employment), and an increase in the number of non-Omanis arriving for work, especially those in low wage categories. The study thus demonstrates the need to consider the dynamic nature of SV in natural hazard risk assessment and management. The results can be useful in practice, with the spatial SV maps supporting decision makers in planning and resource allocation before and during an emergency event. The Muscat case study can also be replicated elsewhere in Oman, based on the common nationally available small area data

Thermal performance of traditional and contemporary mosque buildings in the Sultanate of Oman

The objectives of enhancing building energy efficiency and ensuring human thermal comfort are often challenging to achieve concurrently. Oman’s climate is hot and dry, and its buildings have high cooling demands. This research aims to investigate the thermal performance of buildings in Oman and improve it without compromising human thermal comfort. Mosque buildings are an interesting case for this research, as daily prayers are conducted intermittently throughout every day. An enhancement in the energy efficiency of mosque buildings would contribute to environmental sustainability through the reduction of energy consumption. This research project aims to investigate two types of mosques: traditional mosque buildings that are 500 years old or older, and contemporary mosque buildings that have been built recently within the last 40 years. There are two primary research methodologies followed in this study: Computer Simulations, and Field Measurements. The computer simulation methodology utilises energy modelling using EDSL TAS computer simulation software. The field measurements methodology is conducted using thermal measurement instruments including temperature and humidity dataloggers. Findings from both the computer simulation and the field measurements were compared for analysis and discussion. The analysis compared between the traditional and contemporary mosque buildings. The objective was to identify solutions for improving building thermal performance and occupants’ thermal comfort. The findings show that traditional buildings, which are naturally ventilated, perform better than contemporary buildings. During the winter, findings from both the field measurements and computer simulations concur that all mosques are within the thermal comfort zone as per the Muscat bioclimatic chart. During the summer, the case studies exceeded the maximum thermal comfort zone temperature despite their high energy consumption. This indicated room for improvement in both the energy efficiency and thermal comfort of the case studies. After a thorough review of the academic literature, field measurements, and computer simulations, a total of fourteen suggested improvements were presented in Chapter 8 (Suggested Improvements Chapter). The initial set of nine improvements were made to enhance the building elements’ conductivity, glazing area, and material composition of walls and roof in the six mosques. The subsequent five improvements were suggested to improve the internal conditions of the buildings and to incorporate passive cooling techniques, such as adjusting the cooling thermostat setpoint, reducing infiltration rate, introducing higher efficiency lighting, introducing a Khalwah (an underground chamber), and increasing vegetation around the buildings. The proposed improvements aim to optimise thermal performance and create more comfortable environments within the mosque buildings. These suggested improvements were carefully combined into three distinct combinations, each of which represented the most effective enhancements tailored to the specific needs of individual mosques targeting three key parameters: Resultant Temperature (RT), Cooling Load (CL), and Predicted Mean Vote (PMV). The first combination was designed to enhance the Resultant Temperature (RT) parameter, leading to a 24% improvement compared to the baseline model. For the second combination, the most effective improvements were combined to address the Cooling Load (CL) parameter, yielding a 58% reduction in cooling load compared to the baseline model. Lastly, the third combination focused on optimising the Predicted Mean Vote (PMV) parameter, resulting in a reduction of up to 15% in annual discomfort hours. These suggested improvements have the potential to offer significant benefits for clients, architects, builders, and stakeholders in the region to provide a pathway to achieve both energy efficiency and thermal comfort in building designs

Quantum physics cannot be captured by classical linear hidden variable theories even in the absence of entanglement

Recent experimental tests of Bell inequalities confirm that entangled quantum systems cannot be described by local classical theories but still do not answer the question whether or not quantum systems could in principle be modelled by linear hidden variable theories. In this paper, we study the quantum trajectories of a single qubit that experiences a sequence of repeated generalised measurements. It is shown that this system, which constitutes a Hidden Quantum Markov Model, is more likely to produce complex time correlations than any classical Hidden Markov Model with two output symbols. From this, we conclude that quantum physics cannot be replaced by linear hidden variable theories. Indeed, it has already been recognised that not only entanglement but also non-classical time correlations of quantum systems with quantum feedback are a valuable resource for quantum technology applications.Comment: 11 pages, 4 figure

Thermal performance of traditional and contemporary mosque buildings in the Sultanate of Oman

The objectives of enhancing building energy efficiency and ensuring human thermal comfort are often challenging to achieve concurrently. Oman’s climate is hot and dry, and its buildings have high cooling demands. This research aims to investigate the thermal performance of buildings in Oman and improve it without compromising human thermal comfort. Mosque buildings are an interesting case for this research, as daily prayers are conducted intermittently throughout every day. An enhancement in the energy efficiency of mosque buildings would contribute to environmental sustainability through the reduction of energy consumption. This research project aims to investigate two types of mosques: traditional mosque buildings that are 500 years old or older, and contemporary mosque buildings that have been built recently within the last 40 years. There are two primary research methodologies followed in this study: Computer Simulations, and Field Measurements. The computer simulation methodology utilises energy modelling using EDSL TAS computer simulation software. The field measurements methodology is conducted using thermal measurement instruments including temperature and humidity dataloggers. Findings from both the computer simulation and the field measurements were compared for analysis and discussion. The analysis compared between the traditional and contemporary mosque buildings. The objective was to identify solutions for improving building thermal performance and occupants’ thermal comfort. The findings show that traditional buildings, which are naturally ventilated, perform better than contemporary buildings. During the winter, findings from both the field measurements and computer simulations concur that all mosques are within the thermal comfort zone as per the Muscat bioclimatic chart. During the summer, the case studies exceeded the maximum thermal comfort zone temperature despite their high energy consumption. This indicated room for improvement in both the energy efficiency and thermal comfort of the case studies. After a thorough review of the academic literature, field measurements, and computer simulations, a total of fourteen suggested improvements were presented in Chapter 8 (Suggested Improvements Chapter). The initial set of nine improvements were made to enhance the building elements’ conductivity, glazing area, and material composition of walls and roof in the six mosques. The subsequent five improvements were suggested to improve the internal conditions of the buildings and to incorporate passive cooling techniques, such as adjusting the cooling thermostat setpoint, reducing infiltration rate, introducing higher efficiency lighting, introducing a Khalwah (an underground chamber), and increasing vegetation around the buildings. The proposed improvements aim to optimise thermal performance and create more comfortable environments within the mosque buildings. These suggested improvements were carefully combined into three distinct combinations, each of which represented the most effective enhancements tailored to the specific needs of individual mosques targeting three key parameters: Resultant Temperature (RT), Cooling Load (CL), and Predicted Mean Vote (PMV). The first combination was designed to enhance the Resultant Temperature (RT) parameter, leading to a 24% improvement compared to the baseline model. For the second combination, the most effective improvements were combined to address the Cooling Load (CL) parameter, yielding a 58% reduction in cooling load compared to the baseline model. Lastly, the third combination focused on optimising the Predicted Mean Vote (PMV) parameter, resulting in a reduction of up to 15% in annual discomfort hours. These suggested improvements have the potential to offer significant benefits for clients, architects, builders, and stakeholders in the region to provide a pathway to achieve both energy efficiency and thermal comfort in building designs

Quantum jump metrology in a two-cavity network

Quantum metrology enhances measurement precision by utilising the properties of quantum physics. In interferometry, this is typically achieved by evolving highly-entangled quantum states before performing single-shot measurements to reveal information about an unknown parameter. While this is often the optimum approach, implementation with all but the smallest states is still extremely challenging. An alternative approach is quantum jump metrology [L. A. Clark {\em et al.}, Phys. Rev. A {\bf 99}, 022102 (2019)] which deduces information by continuously monitoring an open quantum system, while inducing phase-dependent temporal correlations with the help of quantum feedback. Taking this approach here, we analyse measurements of a relative phase in an optical network of two cavities with quantum feedback in the form of laser pulses. It is shown that the proposed approach can exceed the standard quantum limit without the need for complex quantum states while being scalable and more practical than previous related schemes.Comment: 13 pages, 6 figures, substantially revised version, new titl

Motivation of Omani schoolteachers

Oman’s school system is of relatively recent origin, having been developed from the 1970’s and much is expected of Omani schoolteachers. The research reported in this thesis was a comprehensive attempt to explore Omani schoolteachers’ understanding of the term motivation. A mixed methods approach was used, with a large-scale questionnaire survey of 3065 teachers producing a 69% response rate (2112) and yielding results that were subject to further exploration by means of 7 teacher focus-groups (with 53 teachers participating), 21 interviews with individual teachers, and 3 focus-groups with 21 headteachers. The key finding from the research was that the overwhelming majority of Omani schoolteachers participating in the research regard themselves as motivated with the most important motivating factors for them being working with pupils and being productive in society. However, both Omani teachers and headteachers would appreciate a reduction in administration and greater participation in decision-making. Analysis of my findings distinguished four groups of factors that might provide better understanding of motivation of Omani schoolteachers. These four divisions are (1) the main factors that appeared to attract Omanis to teaching profession, (2) the main factors that appeared to contribute to confirm or extend the initial motivation to enter the teaching profession, (3) two factors that appeared to increase the level of motivation of Omani schoolteachers, and (4) the main factors that appeared to contribute in maintaining the level of motivation of Omani schoolteachers, which I term guarantors. The findings from this research should help teacher educators and policy makers in Oman better understand teacher motivation. The research concludes some practical recommendations that might help maintain or enhance teacher motivation and some recommendations for follow-up research. Finally, I hope the research has contributed a little to the ongoing international debate around teacher motivation, from an Omani perspective

Predictors of Hypersensitivity Reactions to Platinum-Based Chemotherapy in a Tertiary Hospital in Oman: A case-control study

Objectives: Platinum-based compounds (PBC) play an important role in cancer therapy. However, one of the drawbacks of PBC is the occasional occurrence of hypersensitivity reactions (HSR) which can lead to serious consequences. The aim of the study is to estimate the prevalence and evaluate risk factors of HSR to PBC in cancer patients. Methods: A case-control study of patients who received any PBC for the management of non-haematological cancers from 2013 to 2020 at Sultan Qaboos University Hospital, Oman. Data regarding demographic features and diseases and treatment details were collected from the hospital’s electronic patients record. We quantitatively described the data, and Student’s t-test and Wilcoxon Man-Whittney tests were used to detect significant differences. Results: A total of 38 cases and 148 matched controls were studied. The prevalence of HSR to PBC in our cohort was 4.7% (95% confidence interval: 3.33%-6.37%), more with carboplatin compared to cisplatin and oxaliplatin. In our study, female gender (p=0.032), concomitant taxanes (p=0.002) and concurrent radiation (p<0.001) were significant predictors of HSR to PBC. The majority of reactions were of mild to moderate severity and the rechallenge rate after HSR development was 13%. Conclusion: HSR to PBC impact therapy decisions and understanding the risk factors are important to improve treatment outcomes in cancer patients. Keywords: Hypersensitivity; Platinum; Anti-neoplastic; Oncology; Oman