Robust Fingerprint Construction Based on Multiple Path Loss Model (M-PLM) for Indoor Localization

A robust radio map is essential in implementing a fingerprint-based indoor positioning system(IPS).However,the offline site survey to manually construct the radio map is time-consuming and labour-intensive.Various interpolation techniques have been proposed to infer the virtual fingerprints to reduce the time and effort required for offline site surveys.This paper presents a novel fingerprint interpolator using a multi-path loss model(MPLM)to create the virtual fingerprints from the collected sample data based on different signal paths from different access points(APs).Based on the historical signal data,the poor signal paths are identified using their standard deviations.The proposed method reduces the positioning errors by smoothing out the wireless signal fluctuations and stabilizing the signals for those poor signal paths.By consideringmultipath signal propagations from different APs,the inherent noise from these signal paths can be alleviated.Firstly,locations of the signal data with standard deviations higher than the threshold are identified.The new fingerprints are then generated at these locations based on the proposed M-PLM interpolation function to replace the old fingerprints.The proposed technique interpolates virtual fingerprints based on good signal paths with more stable signals to improve the positioning performance.Experimental results show that the proposed scheme enhances the positioning accuracy by up to 44%compared to the conventional interpolation techniques such as the Inverse DistanceWeighting,Kriging,and single Path LossModel.As a result,we can overcome the site survey problems for IPS by building an accurate radio map with more reliable signals to improve indoor positioning performance.

Measurement and correlation of physical properties of aqueous solutions of tetrabutylammonium hydroxide, piperazine and their aqueous blends

The density,viscosity and refractive index of aqueous solutions of tetrabutylammonium hydroxide(TBAOH),piperazine(PZ) and their aqueous blends are determined at several temperatures(303.15 to 333.15 K).All these measured physicochemical properties decreases with an increase in temperature.The density data is used to calculate the coefficient of thermal expansion and excess molar volume of all aqueous binary and ternary solutions.The coefficient of thermal expansion increases with increase in temperatures and concentrations.The negativity of excess molar volume for all the aqueous solution decreased with increase in temperature.Each physical property is correlated with temperature by least square method and the corresponding coefficients for each property are presented.The prediction values from correlations for the physical properties are in good agreement with the experimental values.

A Novel Energy Lifting Approach Using J-Function and Flow Zone Indicator for Oil Fields

The X field is located in the southwestern part of block NX89 of Kentan Basin in Libya.This field is produced from Hailan multilayer consolidated sandstone with moderate rock property and a relatively low energy supplying.The reserve of subsurface energy sources is declining with years.Therefore,techniques were combined to achieve the energy optimization and increase hydrocarbon recovery.In order to understand the subsurface formation of the reservoir and facilitate oil production,global hydraulic element technique was used to quantify the reservoir rock types.In addition,stratigraphic modified Lorenz plot was used for reservoir layering.Reservoir heterogeneity was identified using stratigraphic modified Lorenz plot and Dykstra-Parsons coefficient.Leverett J-functionwas used to average the 13 capillary pressure curves into four main curves to represent the whole reservoir based on flow zone indicator values.Capillary pressure was calculated and plotted with normalized water saturation;a single average curve was defined to represent the rest of the curves.Water saturation was calculated using single and multiple J-functions and compared with the available logs.With multiple J-functions,the matching results were good for both high and low-quality layers,whereas using a single J-function,the match was poor,especially for low FZI layers such as H4c and H6a.Four rock types were identified for this reservoir ranging from medium to good reservoir quality and six different layers were obtained.The reservoir was heterogeneous with a Lorenz coefficient value of approximately 0.72 and a Dykstra-Parsons value of 0.70.All approaches used in this paper were validated and showed improved hydrocarbon recovery factor.

Space-Time Cluster Analysis of Accidental Oil Spills in Rivers State, Nigeria, 2011–2019

Oil spills cause environmental pollution with a serious threat to local communities and sustainable development.Accidental oil spills can be modelled as a stochastic process where each oil spill event is described by its spatial locations and incidence-time and hence allow for space-time cluster analysis.Spacetime cluster analysis can detect space-time pattern distribution of oil spills which can be useful for implementing preventive measures and evidence-based decision making.This study aims to detect the space-time clusters of accidental oil spills in Rivers state,Nigeria through the Space-time Scan Statistic.The Space-time Scan Statistic was applied under the permutation model to the oil spill data(each for sabotage and operational oil spills)collected at Local Government Area(LGA)-level during the period from 2011 to 2019.The results show that the sabotage oil spill clusters have covered most of the LGAs in the southern part of the state at the start of the study period and then in 2018–2019,it moved to the west covering a single LGA.The operational oil spill clusters covered two neighboring LGAs in the south.In addition,the temporal cluster of sabotage oil spills was seen in 2019 and operational oil spills in 2011–2012.The sabotage oil spills show an increasing trend with the maximum in 2019 while the operational oil spills show a decreasing trend with the minimum in 2019.These findings assist in more effective decision-making for combating the environmental problems and controlling the future spill incidence in the cluster-regions.

Assessing the dynamics and impact of COVID-19 vaccination on disease spread:A data-driven approach

The COVID-19 pandemic has significantly impacted global health,social,and economic situations since its emergence in December 2019.The primary focus of this study is to propose a distinct vaccination policy and assess its impact on controlling COVID-19 transmission in Malaysia using a Bayesian data-driven approach,concentrating on the year 2021.We employ a compartmental Susceptible-Exposed-Infected-Recovered-Vaccinated(SEIRV)model,incorporating a time-varying transmission rate and a data-driven method for its estimation through an Exploratory Data Analysis(EDA)approach.While no vaccine guarantees total immunity against the disease,and vaccine immunity wanes over time,it is critical to include and accurately estimate vaccine efficacy,as well as a constant vaccine immunity decay or wane factor,to better simulate the dynamics of vaccine-induced protection over time.Based on the distribution and effectiveness of vaccines,we integrated a data-driven estimation of vaccine efficacy,calculated at 75%for Malaysia,underscoring the model's realism and relevance to the specific context of the country.The Bayesian inference framework is used to assimilate various data sources and account for underlying uncertainties in model parameters.The model is fitted to real-world data from Malaysia to analyze disease spread trends and evaluate the effectiveness of our proposed vaccination policy.Our findings reveal that this distinct vaccination policy,which emphasizes an accelerated vaccination rate during the initial stages of the program,is highly effective in mitigating the spread of COVID-19 and substantially reducing the pandemic peak and new infections.The study found that vaccinating 57–66%of the population(as opposed to 76%in the real data)with a better vaccination policy such as proposed here is able to significantly reduce the number of new infections and ultimately reduce the costs associated with new infections.The study contributes to the development of a robust and informative representation of COVID-19 transmission and vaccination,offering valuable insights for policymakers on the potential benefits and limitations of different vaccination policies,particularly highlighting the importance of a well-planned and efficient vaccination rollout strategy.While the methodology used in this study is specifically applied to national data from Malaysia,its successful application to local regions within Malaysia,such as Selangor and Johor,indicates its adaptability and potential for broader application.This demonstrates the model's adaptability for policy assessment and improvement across various demographic and epidemiological landscapes,implying its usefulness for similar datasets from various geographical regions.

An experimental study of elastic properties of dragonfly-like flapping wings for use in biomimetic micro air vehicles(BMAVs)

This article studies the elastic properties of several biomimetic micro air vehicle（BMAV）wings that are based on a dragonfly wing.BMAVs are a new class of unmanned micro-sized air vehicles that mimic the flapping wing motion of flying biological organisms（e.g.,insects,birds,and bats）.Three structurally identical wings were fabricated using different materials：acrylonitrile butadiene styrene（ABS）,polylactic acid（PLA）,and acrylic.Simplified wing frame structures were fabricated from these materials and then a nanocomposite film was adhered to them which mimics the membrane of an actual dragonfly.These wings were then attached to an electromagnetic actuator and passively flapped at frequencies of 10-250 Hz.A three-dimensional high frame rate imaging system was used to capture the flapping motions of these wings at a resolution of 320 pixels x 240 pixels and 35000 frames per second.The maximum bending angle,maximum wing tip deflection,maximum wing tip twist angle,and wing tip twist speed of each wing were measured and compared to each other and the actual dragonfly wing.The results show that the ABS wing has considerable flexibility in the chordwise direction,whereas the PLA and acrylic wings show better conformity to an actual dragonfly wing in the spanwise direction.Past studies have shown that the aerodynamic performance of a BMAV flapping wing is enhanced if its chordwise flexibility is increased and its spanwise flexibility is reduced.Therefore,the ABS wing（fabricated using a 3D printer） shows the most promising results for future applications.

Enhancement and validation of building integrated PV system:3D modelling,techno-economics and environmental assessment

The incorporation of photovoltaic elements in buildings have been gaining more mileage in recent times.Building integrated photovoltaic(BIPV)technologies are on the rise in terms of efficiency and longevity,with a compound annual growth rate(CAGR)of 15.7%since 2018.The costs of production and raw materials of BIPV have reached a level that is economically beneficial for building developers to adopt the technology.However,the lack of infras-tructure as compared to traditional means of energy production has impeded the maturing of such technologies.The issue of conversion efficiency and module degradation have been addressed but not completely resolved by the scientific community.Although attractive governmental incentives such as net energy metering(NEM)and better returns of investments are shifting the tide as of late,what remains to be seen is the mass adoption of BIPV technology in residential and commercial infrastructure.This work aims to develop an optimal layout for photo-voltaic panels in the university building precise 3D modelling and solar energy resource assessment.The method adopted is based on energy production capability of a 3D modelled BIPV system which will be carried out in three stages.They are i)Assessment of geographical location and meteorological data,ii)Development of 3D model and orientation analytics and(iii)Development of optimal PV layout.Three systems were considered for this study,which is the roof and two systems on the Southern Façade.The proposed rooftop BIPV design is expected to provide 49.27%of the building’s energy consumption while reducing CO_(2)emissions by 20155.32 tonnes throughout the lifespan of the system’s deployment.This paper serves as a pioneering study on the feasibility of a BIPV system through the incorporation of building geometry for computations on incident solar irradiation.Through the reduction of electricity imported from the grid,the adoption of the BIPV system also serves as an incremental step towards achieving Net Zero Energy Building(NZEB)status for HWUM.

Graphene Oxide Functionalized Optical Planar Waveguide for Water Content Measurement in Alcohol

An abrupt change in optical transmission characteristic of a graphene oxide(GO)coated optical planar waveguide was observed.This observation was based on the peculiar characteristics of the graphene oxide film,namely its high transverse-electric polarized light propagation loss,highly selective permeability of water,and change in optical propagation characteristic in the presence of water.The as-fabricated GO-coated optical waveguide showed a large polarization dependent loss of~32 dB in the C-band optical fiber communication window(1550 nm).The response of the proposed sensor was first tested by using water.When a drop of water was applied onto the GO coating,the large polarization dependent loss was fully suppressed almost instantaneously.This effect was reversible as the polarization dependent loss was restored after complete water evaporation from the GO coating.All-optical measurement of water content in alcohol was then demonstrated by using the GO-coated optical waveguide.By analyzing the drying profile of the water-alcohol mixture,water content in the range of 0.2 volume%-100 volume%could be measured.These measurements were carried out by using solution volume of 1.0μL only.The all-optical sensing nature of the proposed sensor has potential applications in in-situ monitoring of water content in alcohol.

Optimization of enhanced weathering networks with alternative transportation modes

Enhanced weathering of alkaline rocks and minerals is a negative emissions technology (NET) that is potentiallyscalable to deliver gigaton-level carbon dioxide removal (CDR) for climate change mitigation. This techniquerelies on the acceleration of naturally occurring weathering reactions with water and carbon dioxide by reducingthese substances into a fine powder with high specific surface area. The ex situ enhanced weathering processchain consists of the acquisition of suitable natural or synthetic materials, grinding to a fine particle size,transportation, and application on suitable sites. Future enhanced weathering systems can be envisioned assupply chain-like networks which have to be optimized to deliver maximum CDR given physical constraints.There is a notable research gap in the literature on decision support for such systems. To address this gap, amixed integer linear programming (MILP) model is developed in this work to optimize enhanced weatheringnetworks for CDR. The model also incorporates the availability of multiple transportation options and constraintson network topology. Two test cases are used to demonstrate the model capability to determine optimal andnear-optimal networks. The top ten solutions in these two scenarios yield total CDR levels of 3.4316–3.4363 Mtand 15.27017–15.27960 Mt.