Search results for: risk factor model

Authors: Lynne McCormack, Andrew Digges

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Since 2013, the Australian government has enforced mandatory detention of anyone arriving in Australia without a valid visa, including those subsequently identified as a refugee or seeking asylum. While consistent with the increased use of immigration detention internationally, Australia’s use of offshore processing facilities both during and subsequent to refugee status determination processing has until recently remained a unique feature of Australia’s program of deterrence. The commonplace detention of refugees and asylum seekers following displacement is a significant and independent source of trauma and a contributory factor in adverse psychological outcomes. Officially, these individuals have no prospect of resettlement in Australia, are barred from applying for substantive visas, and are frequently and indefinitely detained in closed facilities such as immigration detention centres, or alternative places of detention, including hotels. It is also important to note that the limited access to Australia’s immigration detention population made available to researchers often means that data available for secondary analysis may be incomplete or delayed in its release. Further, studies into the lived experience of refugees and asylum seekers are typically cross-sectional and convenience sampled, employing a variety of designs and research methodologies that limit comparability and focused on the immediacy of the individual’s experience. Consequently, how former detainees make sense of their experience, redefine their future trajectory upon release, and recover a sense of authenticity and purpose, is unknown. As such, the present study sought the positive and negative subjective interpretations of 6 participants in Australia regarding their lived experiences as refugees and asylum seekers within Australia’s immigration detention system and its impact on their future sense of self. It made use of interpretative phenomenological analysis (IPA), a qualitative research methodology that is interested in how individuals make sense of, and ascribe meaning to, their unique lived experiences of phenomena. Underpinned by phenomenology, hermeneutics, and critical realism, this idiographic study aimed to explore both positive and negative subjective interpretations of former refugees and asylum seekers held in detention in Australia. It sought to understand how they make sense of their experiences, how detention has impacted their overall journey as displaced persons, and how they have moved forward in the aftermath of protracted detention in Australia. Examining the unique lived experiences of previously detained refugees and asylum seekers may inform the future development of theoretical models of posttraumatic growth among this vulnerable population, thereby informing the delivery of future mental health and resettlement services.

Keywords: mandatory detention, refugee, asylum seeker, authenticity, Interpretative phenomenological analysis

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Authors: Abdul Rahman Hamdan

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The Fourth Industrial Revolution (4IR) has brought unprecedented technological advancements that have disrupted many industries worldwide. In keeping up with the technological advances and rapid disruption by the introduction of many technological advancements brought forth by the 4IR, the use of technology road mapping has emerged as one of the critical tools for organizations to leverage. Technology road mapping can be used by many companies to guide them to become more adaptable and anticipate future transformation and innovation, and avoid being redundant or irrelevant due to the rapid changes in technological advancement. This research paper provides a comprehensive analysis of technology road mapping within the context of the 4IR. The objectives of the paper are to provide companies with practical insights and a strategic framework of technology road mapping for them to navigate the fast-changing nature of the 4IR. This study also contributes to the understanding and practice of technology road mapping in the 4IR and, at the same time, provides organizations with the necessary tools and critical insight to navigate the 4IR transformation by leveraging technology road mapping. Based on the literature review and case studies, the study analyses key principles, methodologies, and best practices in technology road mapping and integrates them with the unique characteristics and challenges of the 4IR. The research paper gives the background of the fourth industrial revolution. It explores the disruptive potential of technologies in the 4IR and the critical need for technology road mapping that consists of strategic planning and foresight to remain competitive and relevant in the 4IR era. It also highlights the importance of technology road mapping as an organisation’s proactive approach to align the organisation’s objectives and resources to their technology and product development in meeting the fast-evolving technological 4IR landscape. The paper also includes the theoretical foundations of technology road mapping and examines various methodological approaches, and identifies external stakeholders in the process, such as external experts, stakeholders, collaborative platforms, and cross-functional teams to ensure an integrated and robust technological roadmap for the organisation. Moreover, this study presents a comprehensive framework for technology road mapping in the 4IR by incorporating key elements and processes such as technology assessment, competitive intelligence, risk analysis, and resource allocation. It provides a framework for implementing technology road mapping from strategic planning, goal setting, and technology scanning to road mapping visualisation, implementation planning, monitoring, and evaluation. In addition, the study also addresses the challenges and limitations related to technology roadmapping in 4IR, including the gap analysis. In conclusion of the study, the study will propose a set of practical recommendations for organizations that intend to leverage technology road mapping as a strategic tool in the 4IR in driving innovation and becoming competitive in the current and future ecosystem.

Keywords: technology management, technology road mapping, technology transfer, technology planning

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Authors: Marcin Michalak

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Due to the increasing efforts on saving our natural environment a change in the structure of energy resources can be observed - an increasing fraction of a renewable energy sources. In many countries traditional underground coal mining loses its significance but there are still countries, like Poland or Germany, in which the coal based technologies have the greatest fraction in a total energy production. This necessitates to make an effort to limit the costs and negative effects of underground coal mining. The longwall complex is as essential part of the underground coal mining. The safety and the effectiveness of the work is strongly dependent of the diagnostic state of powered roof supports. The building of a useful and reliable diagnostic system requires a lot of data. As the acquisition of a data of any possible operating conditions it is important to have a possibility to generate a demanded artificial working characteristics. In this paper a new approach of modelling a leg pressure in the single unit of powered roof support. The model is a result of the analysis of a typical working cycles.

Keywords: machine modelling, underground mining, coal mining, structure

Procedia PDF Downloads 339

Authors: P. Strakos, M. Jaros, T. Karasek, T. Kozubek, P. Vavra, T. Jonszta

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In medical imaging, segmentation of different areas of human body like bones, organs, tissues, etc. is an important issue. Image segmentation allows isolating the object of interest for further processing that can lead for example to 3D model reconstruction of whole organs. Difficulty of this procedure varies from trivial for bones to quite difficult for organs like liver. The liver is being considered as one of the most difficult human body organ to segment. It is mainly for its complexity, shape versatility and proximity of other organs and tissues. Due to this facts usually substantial user effort has to be applied to obtain satisfactory results of the image segmentation. Process of image segmentation then deteriorates from automatic or semi-automatic to fairly manual one. In this paper, overview of selected available software applications that can handle semi-automatic image segmentation with further 3D volume reconstruction of human liver is presented. The applications are being evaluated based on the segmentation results of several consecutive DICOM images covering the abdominal area of the human body.

Keywords: image segmentation, semi-automatic, software, 3D volumetric reconstruction

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Authors: Md Al Masum Bhuiyan, Maria C. Mariani, Osei K. Tweneboah

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In the present work, we develop a technique for estimating the volatility of financial time series by using stochastic differential equation. Taking the daily closing prices from developed and emergent stock markets as the basis, we argue that the incorporation of stochastic volatility into the time-varying parameter estimation significantly improves the forecasting performance via Maximum Likelihood Estimation. While using the technique, we see the long-memory behavior of data sets and one-step-ahead-predicted log-volatility with ±2 standard errors despite the variation of the observed noise from a Normal mixture distribution, because the financial data studied is not fully Gaussian. Also, the Ornstein-Uhlenbeck process followed in this work simulates well the financial time series, which aligns our estimation algorithm with large data sets due to the fact that this algorithm has good convergence properties.

Keywords: financial time series, maximum likelihood estimation, Ornstein-Uhlenbeck type models, stochastic volatility model

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Authors: Ali Pour Yazdanpanah, Farideh Foroozandeh Shahraki, Emma Regentova

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The reconstruction from sparse-view projections is one of important problems in computed tomography (CT) limited by the availability or feasibility of obtaining of a large number of projections. Traditionally, convex regularizers have been exploited to improve the reconstruction quality in sparse-view CT, and the convex constraint in those problems leads to an easy optimization process. However, convex regularizers often result in a biased approximation and inaccurate reconstruction in CT problems. Here, we present a nonconvex, Lipschitz continuous and non-smooth regularization model. The CT reconstruction is formulated as a nonconvex constrained L1 − L2 minimization problem and solved through a difference of convex algorithm and alternating direction of multiplier method which generates a better result than L0 or L1 regularizers in the CT reconstruction. We compare our method with previously reported high performance methods which use convex regularizers such as TV, wavelet, curvelet, and curvelet+TV (CTV) on the test phantom images. The results show that there are benefits in using the nonconvex regularizer in the sparse-view CT reconstruction.

Keywords: computed tomography, non-convex, sparse-view reconstruction, L1-L2 minimization, difference of convex functions

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Authors: Amel Hamma, Allesandro Pegoretti

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Kenaf fibres, with two aspect ratios, were melt compounded with two types of biopolymers named starch grafted polypropylene, and then blends compression molded to form plates of 1 mm thick. Results showed that processing induced variation of fibres length which is quantified by optical microscopy observations. Young modulus, stress at break and impact resistance values of starch-grafted-polypropylenes were remarkably improved by kenaf fibres for both matrixes and demonstrated best values when G906PJ were used as matrix. These results attest the good interfacial bonding between the matrix and fibres even in the absence of any interfacial modification. Vicat Softening Point and storage modules were also improved due to the reinforcing effect of fibres. Moreover, short-term tensile creep tests have proven that kenaf fibres remarkably improve the creep stability of composites. The creep behavior of the investigated materials was successfully modeled by the four parameters Burgers model.

Keywords: creep behaviour, kenaf fibres, mechanical properties, starch-grafted-polypropylene

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Authors: Khachen Kongpakwattana, Nathorn Chaiyakunapruk

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Background: Decision-analytic models for Alzheimer’s disease (AD) have been advanced to discrete-event simulation (DES), in which individual-level modelling of disease progression across continuous severity spectra and incorporation of key parameters such as treatment persistence into the model become feasible. This study aimed to apply the DES to perform a cost-effectiveness analysis of treatment for AD in Thailand. Methods: A dataset of Thai patients with AD, representing unique demographic and clinical characteristics, was bootstrapped to generate a baseline cohort of patients. Each patient was cloned and assigned to donepezil, galantamine, rivastigmine, memantine or no treatment. Throughout the simulation period, the model randomly assigned each patient to discrete events including hospital visits, treatment discontinuation and death. Correlated changes in cognitive and behavioral status over time were developed using patient-level data. Treatment effects were obtained from the most recent network meta-analysis. Treatment persistence, mortality and predictive equations for functional status, costs (Thai baht (THB) in 2017) and quality-adjusted life year (QALY) were derived from country-specific real-world data. The time horizon was 10 years, with a discount rate of 3% per annum. Cost-effectiveness was evaluated based on the willingness-to-pay (WTP) threshold of 160,000 THB/QALY gained (4,994 US$/QALY gained) in Thailand. Results: Under a societal perspective, only was the prescription of donepezil to AD patients with all disease-severity levels found to be cost-effective. Compared to untreated patients, although the patients receiving donepezil incurred a discounted additional costs of 2,161 THB, they experienced a discounted gain in QALY of 0.021, resulting in an incremental cost-effectiveness ratio (ICER) of 138,524 THB/QALY (4,062 US$/QALY). Besides, providing early treatment with donepezil to mild AD patients further reduced the ICER to 61,652 THB/QALY (1,808 US$/QALY). However, the dominance of donepezil appeared to wane when delayed treatment was given to a subgroup of moderate and severe AD patients [ICER: 284,388 THB/QALY (8,340 US$/QALY)]. Introduction of a treatment stopping rule when the Mini-Mental State Exam (MMSE) score goes below 10 to a mild AD cohort did not deteriorate the cost-effectiveness of donepezil at the current treatment persistence level. On the other hand, none of the AD medications was cost-effective when being considered under a healthcare perspective. Conclusions: The DES greatly enhances real-world representativeness of decision-analytic models for AD. Under a societal perspective, treatment with donepezil improves patient’s quality of life and is considered cost-effective when used to treat AD patients with all disease-severity levels in Thailand. The optimal treatment benefits are observed when donepezil is prescribed since the early course of AD. With healthcare budget constraints in Thailand, the implementation of donepezil coverage may be most likely possible when being considered starting with mild AD patients, along with the stopping rule introduced.

Keywords: Alzheimer's disease, cost-effectiveness analysis, discrete event simulation, health technology assessment

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Authors: Ruth Elvish, Alex Turner, Jen Wells

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Over recent years there has been an increasing interest in the topic of well-being at work, and staff support is an area of continued growth. The present qualitative study explored the impact of a staff well-being service that was specifically attached to a five-year multi-site research programme (the Neighbourhoods and Dementia Study, funded by the ESRC/NIHR). The well-being service was led by a clinical psychologist, who offered 1:1 sessions for staff and co-researchers with dementia. To our knowledge, this service was the first of its kind. Methodology: Interviews were undertaken with staff who had used the service and who opted to take part in the study (n=7). Thematic analysis was used as the method of analysis. Findings: Themes included: triggers, mechanisms of change, impact/outcomes, and unique aspects of a dedicated staff well-being service. Conclusions: The study highlights stressors that are pertinent amongst staff within academic settings, and shows the ways in which a dedicated staff well-being service can impact on both professional and personal lives. Positive change was seen in work performance, self-esteem, relationships, and coping. This exploratory study suggests that this well-being service model should be further trialled and evaluated.

Keywords: academic, service, staff, support, well-being

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Authors: Yuan Yue, Wen-Wei Wang

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The objective of this research is to comprehensively evaluate the impact of alkaline environments on the durability of Glass Fiber Reinforced Polymer (GFRP) reinforcements in concrete structures and further explore their potential value within the construction industry. Specifically, we investigate the effects of two widely used high-performance concrete (HPC) materials on the durability of GFRP bars when embedded within them under varying temperature conditions. A total of 279 GFRP bar specimens were manufactured for microcosmic and mechanical performance tests. Among them, 270 specimens were used to test the residual tensile strength after 120 days of immersion, while 9 specimens were utilized for microscopic testing to analyze degradation damage. SEM techniques were employed to examine the microstructure of GFRP and cover concrete. Unidirectional tensile strength experiments were conducted to determine the remaining tensile strength after corrosion. The experimental variables consisted of four types of concrete (engineering cementitious composite (ECC), ultra-high-performance concrete (UHPC), and two types of ordinary concrete with different compressive strengths) as well as three acceleration temperatures (20, 40, and 60℃). The experimental results demonstrate that high-performance concrete (HPC) offers superior protection for GFRP bars compared to ordinary concrete. Two types of HPC enhance durability through different mechanisms: one by reducing the pH of the concrete pore fluid and the other by decreasing permeability. For instance, ECC improves embedded GFRP's durability by lowering the pH of the pore fluid. After 120 days of immersion at 60°C under accelerated conditions, ECC (pH=11.5) retained 68.99% of its strength, while PC1 (pH=13.5) retained 54.88%. On the other hand, UHPC enhances FRP steel's durability by increasing porosity and compactness in its protective layer to reinforce FRP reinforcement's longevity. Due to fillers present in UHPC, it typically exhibits lower porosity, higher densities, and greater resistance to permeation compared to PC2 with similar pore fluid pH levels, resulting in varying degrees of durability for GFRP bars embedded in UHPC and PC2 after 120 days of immersion at a temperature of 60°C - with residual strengths being 66.32% and 60.89%, respectively. Furthermore, SEM analysis revealed no noticeable evidence indicating fiber deterioration in any examined specimens, thus suggesting that uneven stress distribution resulting from interface segregation and matrix damage emerges as a primary causative factor for tensile strength reduction in GFRP rather than fiber corrosion. Moreover, long-term prediction models were utilized to calculate residual strength values over time for reinforcement embedded in HPC under high temperature and high humidity conditions - demonstrating that approximately 75% of its initial strength was retained by reinforcement embedded in HPC after 100 years of service.

Keywords: GFRP bars, HPC, degeneration, durability, residual tensile strength.

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Authors: I. Bochev, A. Shterev, S. Kyurkchiev

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One of the factors associated with poor success rates in human in vitro fertilization (IVF) is the suboptimal culture conditions in which fertilization and early embryonic growth occur. Co-culture systems with helper cell lines appear to enhance the in vitro conditions and allow embryos to demonstrate improved in vitro development. The co-culture of human embryos with monolayers of autologous endometrial stromal cell (EnSCs) results in increased blastocyst development with a larger number of blastomeres, lower incidence of fragmentation and higher pregnancy rates in patients with recurrent implantation failure (RIF). The aim of the study was to examine the influence of autologous endometrial stromal cell (EnSC) co-culture on day 3 embryo quality by comparing the morphological status of the embryos from the same patients undergoing consecutive IVF/Intracytoplasmic sperm injection (ICSI) cycles without and with EnSC co-culture. This retrospective randomized study (2015-2017) includes 20 couples and a total of 46 IVF/ICSI cycles. Each patient couple included had at least two IVF/ICSI procedures – one with and one without autologous EnSC co-culture. Embryo quality was assessed at 68±1 hours in culture, according to Istanbul consensus criteria (2010). Day 3 embryos were classified into three groups: good – grade 1; fair – grade 2; poor – grade 3. Embryos from all cycles were divided into two groups (A – co-cultivated; B – not co-cultivated) and analyzed. Second, for each patient couple, embryos from matched IVF/ICSI cycles (with and without co-culture) were analyzed separately. When an analysis of co-cultivated day 3 embryos from all cycles was performed (n=137; group A), 43.1% of the embryos were graded as “good”, which was not significantly different from the respective embryo quality rate of 42.2% (p = NS) in group B (n=147) with non-co-cultivated embryos. The proportions of fair and poor quality embryos in group A and group B were similar as well – 11.7% vs 10.2% and 45.2% vs 47.6% (p=NS), respectively. Nevertheless, the separate embryo analysis by matched cycles for each couple revealed that in 65% of the cases the proportion of morphologically better embryos was increased in cycles with co-culture in comparison with those without co-culture. A decrease in this proportion after endometrial stromal cell co-cultivation was found in 30% of the cases, whereas no difference was observed in only one couple. The results demonstrated that there is no marked difference in the overall morphological quality between co-cultured and non-co-cultured embryos on day 3. However, in significantly greater percentage of couples the process of autologous EnSC co-culture could increase the proportion of morphologically improved day 3 embryos. By mimicking the in vivo relationship between embryo and maternal environment, co-culture in autologous EnSC system represents a perspective approach to improve the quality of embryos in cases with elevated risk for development of embryos with impaired morphology.

Keywords: autologous endometrial stromal cells, co-culture, day 3 embryo, morphological quality

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Authors: Min Han, Di Wu, Lin Yuan, Fei Liu

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Mechanical sensors have undergone a continuous evolution and have become an important part of many industries, ranging from manufacturing to process, chemicals, machinery, health-care, environmental monitoring, automotive, avionics, and household appliances. Concurrently, the microelectronics and microfabrication technology have provided us with the means of producing mechanical microsensors characterized by high sensitivity, small size, integrated electronics, on board calibration, and low cost. Here we report a new kind of mechanical sensors based on the quantum transport process of electrons in the closely spaced nanoparticle films covering a flexible polymer sheet. The nanoparticle films were fabricated by gas phase depositing of preformed metal nanoparticles with a controlled coverage on the electrodes. To amplify the conductance of the nanoparticle array, we fabricated silver interdigital electrodes on polyethylene terephthalate(PET) by mask evaporation deposition. The gaps of the electrodes ranged from 3 to 30μm. Metal nanoparticles were generated from a magnetron plasma gas aggregation cluster source and deposited on the interdigital electrodes. Closely spaced nanoparticle arrays with different coverage could be gained through real-time monitoring the conductance. In the film coulomb blockade and quantum, tunneling/hopping dominate the electronic conduction mechanism. The basic principle of the mechanical sensors relies on the mechanical deformation of the fabricated devices which are translated into electrical signals. Several kinds of sensing devices have been explored. As a strain sensor, the device showed a high sensitivity as well as a very wide dynamic range. A gauge factor as large as 100 or more was demonstrated, which can be at least one order of magnitude higher than that of the conventional metal foil gauges or even better than that of the semiconductor-based gauges with a workable maximum applied strain beyond 3%. And the strain sensors have a workable maximum applied strain larger than 3%. They provide the potential to be a new generation of strain sensors with performance superior to that of the currently existing strain sensors including metallic strain gauges and semiconductor strain gauges. When integrated into a pressure gauge, the devices demonstrated the ability to measure tiny pressure change as small as 20Pa near the atmospheric pressure. Quantitative vibration measurements were realized on a free-standing cantilever structure fabricated with closely-spaced nanoparticle array sensing element. What is more, the mechanical sensor elements can be easily scaled down, which is feasible for MEMS and NEMS applications.

Keywords: gas phase deposition, mechanical sensors, metallic nanoparticle arrays, quantum conductance

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Authors: Iris Vural Gursel, Jonathan Moncada, Ernst Worrell, Andrea Ramirez

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In order to achieve the transition from a fossil to bio-based economy, biomass needs to replace fossil resources in meeting the world’s energy and chemical needs. This calls for development of biorefinery systems allowing cost-efficient conversion of biomass to chemicals. In biorefinery systems, feedstock is converted to key intermediates called platforms which are converted to wide range of marketable products. The C6 sugars platform stands out due to its unique versatility as precursor for multiple valuable products. Among the different potential routes from C6 sugars to bio-based chemicals, 1,3-butadiene and ε-caprolactam appear to be of great interest. Butadiene is an important chemical for the production of synthetic rubbers, while caprolactam is used in production of nylon-6. In this study, ex-ante techno-economic performance of 1,3-butadiene and ε-caprolactam routes from C6 sugars were assessed. The aim is to provide insight from an early stage of development into the potential of these new technologies, and the bottlenecks and key cost-drivers. Two cases for each product line were analyzed to take into consideration the effect of possible changes on the overall performance of both butadiene and caprolactam production. Conceptual process design for the processes was developed using Aspen Plus based on currently available data from laboratory experiments. Then, operating and capital costs were estimated and an economic assessment was carried out using Net Present Value (NPV) as indicator. Finally, sensitivity analyses on processing capacity and prices was done to take into account possible variations. Results indicate that both processes perform similarly from an energy intensity point of view ranging between 34-50 MJ per kg of main product. However, in terms of processing yield (kg of product per kg of C6 sugar), caprolactam shows higher yield by a factor 1.6-3.6 compared to butadiene. For butadiene production, with the economic parameters used in this study, for both cases studied, a negative NPV (-642 and -647 M€) was attained indicating economic infeasibility. For the caprolactam production, one of the cases also showed economic infeasibility (-229 M€), but the case with the higher caprolactam yield resulted in a positive NPV (67 M€). Sensitivity analysis indicated that the economic performance of caprolactam production can be improved with the increase in capacity (higher C6 sugars intake) reflecting benefits of the economies of scale. Furthermore, humins valorization for heat and power production was considered and found to have a positive effect. Butadiene production was found sensitive to the price of feedstock C6 sugars and product butadiene. However, even at 100% variation of the two parameters, butadiene production remained economically infeasible. Overall, the caprolactam production line shows higher economic potential in comparison to that of butadiene. The results are useful in guiding experimental research and providing direction for further development of bio-based chemicals.

Keywords: bio-based chemicals, biorefinery, C6 sugars, economic analysis, process modelling

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Authors: Khaled Alshammari

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A facile approach to synthesizing highly active and stable Au/NiO catalysts for the hydrogenation of nitro-aromatics is reported. Preformed gold nanoparticles have been immobilized onto NiO using a colloidal method. In this article, the reduction of 4-nitrophenol with NaBH4 has been used as a model reaction to investigate the catalytic activity of synthesized Au/NiO catalysts. In addition, we report a systematic study of the reduction kinetics and the influence of specific reaction parameters such as (i) temperature, (ii) stirring rate, (iii) sodium borohydride concentration and (iv) substrate/metal molar ratio. The reaction has been performed at a substrate/metal molar ratio of 7.4, a ratio significantly higher than previously reported. The reusability of the catalyst has been examined, with little to no decrease in activity observed over 5 catalytic cycles. Systematic variation of Au loading reveals the successful synthesis of low-cost and efficient Au/NiO catalysts at very low Au content and using high substrate/metal molar ratios.

Keywords: nonochemistry, catalyst, nanoparticles supported, characterization of materials, colloidal nanoparticles

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Authors: B. G. Ayantunji, B. Musa, H. Mai-Unguwa, L. A. Sunmonu, A. S. Adewumi, L. Sa'ad, A. Kado

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For achieving reliable and efficient communication system, both terrestrial and satellite communication, surface refractivity is critical in planning and design of radio links. This study analyzed the impact of atmospheric parameters on Ultra High Frequency (UHF) signal strength over Gusau, North West, Nigeria. The analysis exploited meteorological data measured simultaneously with UHF signal strength for the month of June 2017 using a Davis Vantage Pro2 automatic weather station and UHF signal strength measuring devices respectively. The instruments were situated at the premise of Federal University, Gusau (6° 78' N, 12° 13' E). The refractivity values were computed using ITU-R model. The result shows that the refractivity value attained the highest value of 366.28 at 2200hr and a minimum value of 350.66 at 2100hr local time. The correlation between signal strength and refractivity is 0.350; Humidity is 0.532 and a negative correlation of -0.515 for temperature.

Keywords: refractivity, UHF (ultra high frequency) signal strength, free space, automatic weather station

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Authors: A. Mostafa

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This paper presents a numerical study on determination of ballistic limit velocity (V₅₀) of stainless steel 304 (SS 304) used in manufacturing security screens. The simulated ballistic impact tests were conducted on clamped sheets with different thicknesses using ABAQUS/Explicit nonlinear finite element (FE) package. The ballistic limit velocity was determined using three approaches, namely: numerical tests based on material properties, FE calculated residual velocities and FE calculated residual energies. Johnson-Cook plasticity and failure criterion were utilized to simulate the dynamic behaviour of the SS 304 under various strain rates, while the well-known Lambert-Jonas equation was used for the data regression for the residual velocity and energy model. Good agreement between the investigated numerical methods was achieved. Additionally, the dependence of the ballistic limit velocity on the sheet thickness was observed. The proposed approaches present viable and cost-effective assessment methods of the ballistic performance of SS 304, which will support the development of robust security screen systems.

Keywords: ballistic velocity, stainless steel, numerical approaches, security screen

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Authors: Wassim Katerji, Mercedes Farjas, Carmen Morillo

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Terrain-Based Analysis results in derived products from an input DEM and these products are needed to perform various analyses. To efficiently use these products in decision-making, their accuracies must be estimated systematically. This paper proposes a procedure to assess the accuracy of these derived products, by calculating the accuracy of the slope dataset and its significance, taking as an input the accuracy of the DEM. Based on the output of previously published research on modeling the relative accuracy of a DEM, specifically ASTER and SRTM DEMs with Lebanon coverage as the area of study, analysis have showed that ASTER has a low significance in the majority of the area where only 2% of the modeled terrain has 50% or more significance. On the other hand, SRTM showed a better significance, where 37% of the modeled terrain has 50% or more significance. Statistical analysis deduced that the accuracy of the slope dataset, calculated on a cell-by-cell basis, is highly correlated to the accuracy of the input DEM. However, this correlation becomes lower between the slope accuracy and the slope significance, whereas it becomes much higher between the modeled slope and the slope significance.

Keywords: terrain-based analysis, slope, accuracy assessment, Digital Elevation Model (DEM)

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Authors: Gangmin Li, Fan Yang

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Personalized recommendation is crucial for any recommendation system. One of the techniques for personalized recommendation is to identify the intention. Traditional user intention identification uses the user’s selection when facing multiple items. This modeling relies primarily on historical behaviour data resulting in challenges such as the cold start, unintended choice, and failure to capture intention when items are new. Motivated by recent advancements in Large Language Models (LLMs) like ChatGPT, we present an approach for user intention identification by embracing LLMs with Chain-of-Thought (CoT) prompting. We use the initial user profile as input to LLMs and design a collection of prompts to align the LLM's response through various recommendation tasks encompassing rating prediction, search and browse history, user clarification, etc. Our tests on real-world datasets demonstrate the improvements in recommendation by explicit user intention identification and, with that intention, merged into a user model.

Keywords: personalized recommendation, generative user modelling, user intention identification, large language models, chain-of-thought prompting

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Authors: Inês Ramalhete, Hugo Farias, Rui da Silva Pinto

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Adequate housing has been a widely discussed theme in academic circles related to low-cost housing, whereas its physical features are easy to deal with, overcrowding (related to social, cultural and economic aspects) is still ambiguous, particularly regarding the set of indicators that can accurately reflect and measure it. This paper develops research on low-cost housing models for developing countries and what is the best method to embed overcrowding as an important parameter for adaptability. A critical review of international overcrowding indicators and their application in two developing countries, Cape Verde and Angola, is presented. The several rationales and the constraints for an accurate assessment of overcrowding are considered, namely baseline data (statistics), which can induce misjudgments, as well as social and cultural factors (such as personal choices of residents). This paper proposes a way to tackle overcrowding through housing adaptability, considering factors such as physical flexibility, functional ambiguity, and incremental expansion schemes. Moreover, a case-study is presented to establish a framework for the theoretical application of the proposed approach.

Keywords: adaptive housing, low cost housing, overcrowding, housing model

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Authors: Jesus Salmeron, Carmen De Vega, Maria Soledad Vicente, Mireia Olabarria, Olaia Martinez

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Dysphagia or difficulty in swallowing affects mostly elder people: 56-78% of the institutionalized and 44% of the hospitalized. Liquid food thickening is a necessary measure in this situation because it reduces the risk of penetration-aspiration. Until now, and as proposed by the American Dietetic Association in 2002, possible consistencies have been categorized in three groups attending to their viscosity: nectar (50-350 mPa•s), honey (350-1750 mPa•s) and pudding (>1750 mPa•s). The adequate viscosity level should be identified for every patient, according to her/his impairment. Nevertheless, a systematic review on dysphagia diet performed recently indicated that there is no evidence to suggest that there is any transition of clinical relevance between the three levels proposed. It was also stated that other physical properties of the bolus (slipperiness, density or cohesiveness, among others) could influence swallowing in affected patients and could contribute to the amount of remaining residue. Texture parameters need to be evaluated as possible alternative to viscosity. The aim of this study was to evaluate the instrumental extrusion-compression test as a possible tool to characterize changes along time in water thickened with various products and in the three theoretical consistencies. Six commercial thickeners were used: NM® (NM), Multi-thick® (M), Nutilis Powder® (Nut), Resource® (R), Thick&Easy® (TE) and Vegenat® (V). All of them with a modified starch base. Only one of them, Nut, also had a 6,4% of gum (guar, tara and xanthan). They were prepared as indicated in the instructions of each product and dispensing the correspondent amount for nectar, honey and pudding consistencies in 300 mL of tap water at 18ºC-20ºC. The mixture was stirred for about 30 s. Once it was homogeneously spread, it was dispensed in 30 mL plastic glasses; always to the same height. Each of these glasses was used as a measuring point. Viscosity was measured using a rotational viscometer (ST-2001, Selecta, Barcelona). Extrusion-compression test was performed using a TA.XT2i texture analyzer (Stable Micro Systems, UK) with a 25 mm diameter cylindrical probe (SMSP/25). Penetration distance was set at 10 mm and a speed of 3 mm/s. Measurements were made at 1, 5, 10, 20, 30, 40, 50 and 60 minutes from the moment samples were mixed. From the force (g)–time (s) curves obtained in the instrumental assays, maximum force peak (F) was chosen a reference parameter. Viscosity (mPa•s) and F (g) showed to be highly correlated and had similar development along time, following time-dependent quadratic models. It was possible to predict viscosity using F as an independent variable, as they were linearly correlated. In conclusion, compression-extrusion test could be an alternative and a useful tool to assess physical characteristics of thickened liquids.

Keywords: compression-extrusion test, dysphagia, texture analyzer, thickener

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Authors: Maryam Shayan

Abstract:

Chemical Process Simulation (CPS) software has been generally utilized by chemical (process) designers to outline, test, advance, and coordinate process plants. It is relied upon that modern scientists to bring these same critical thinking advantages to the outline and operation of industrial ecosystems can utilize CPS. This paper gives modern environment researchers and experts with a prologue to CPS and a review of compound designing configuration standards. The paper highlights late research demonstrating that CPS can be utilized to model modern industrial ecosystems, and talks about the advantages of utilizing CPS to address a portion of the specialized difficulties confronting organizations partaking in an industrial ecosystem. CPS can be utilized to (i) quantitatively assess and analyze the potential ecological and monetary advantages of material and vitality linkages; (ii) unravel general plan, retrofit, or operational issues; (iii) help to distinguish complex and frequently irrational arrangements; and (iv) assess imagine a scenario in which situations. CPS ought to be a valuable expansion to the mechanical environment tool stash.

Keywords: chemical process simulation (CPS), process plants, industrial ecosystems, compound designing

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Authors: F. Rahimi Dehgolan, S. E. Khadem, S. Bab, M. Najafee

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Nowadays, using rotating systems like shafts and disks in industrial machines have been increased constantly. Dynamic stability is one of the most important factors in designing rotating systems. In this study, linear frequencies and stability of a coupled continuous flexible rotor-disk-blades system are studied. The Euler-Bernoulli beam theory is utilized to model the blade and shaft. The equations of motion are extracted using the extended Hamilton principle. The equations of motion have been simplified using the Coleman and complex transformations method. The natural frequencies of the linear part of the system are extracted, and the effects of various system parameters on the natural frequencies and decay rates (stability condition) are clarified. It can be seen that the centrifugal stiffening effect applied to the blades is the most important parameter for stability of the considered rotating system. This result highlights the importance of considering this stiffing effect in blades equation.

Keywords: rotating shaft, flexible blades, centrifugal stiffness, stability

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Authors: Muhammad Atif, M. Samsul Alam

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The purpose of this study is to investigate the effects of board room gender diversity on firm sustainable investment. We test the extent to which sustainable investment is affected by the presence of female directors on U.S. corporate boards. Using data of S&P 1500 indexed firms collected from Bloomberg covering the period 2004-2016, we estimate the baseline model to investigate the effects of board room gender diversity on firm sustainable investment. We find a positive relationship between board gender diversity and sustainable investment. We also find that boards with two or more women have a pronounced impact on sustainable investment, consistent with the critical mass theory. Female independent directors have a stronger impact on sustainable investment than female executive directors. Our findings are robust to different identification and estimation techniques. The study offers another perspective of the ongoing debate in the social responsibility literature about the accountability relationships between business and society.

Keywords: sustainable investment, gender diversity, environmental proctection, social responsibility

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Authors: Jarek Krajewski, Andre Wittenborn, Martin Sauerland

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This abstract describes a promising approach for estimating post-traumatic stress disorder (PTSD) based on prosodic speech characteristics. It illustrates the validity of this method by briefly discussing results from an Arabic refugee sample (N= 47, 32 m, 15 f). A well-established standardized self-report scale “Reaction of Adolescents to Traumatic Stress” (RATS) was used to determine the ground truth level of PTSD. The speech material was prompted by telling about autobiographical related sadness inducing experiences (sampling rate 16 kHz, 8 bit resolution). In order to investigate PTSD-induced speech changes, a self-developed set of 136 prosodic speech features was extracted from the .wav files. This set was adapted to capture traumatization related speech phenomena. An artificial neural network (ANN) machine learning model was applied to determine the PTSD level and reached a correlation of r = .37. These results indicate that our classifiers can achieve similar results to those seen in speech-based stress research.

Keywords: speech prosody, PTSD, machine learning, feature extraction

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Authors: Liam Martin, Martha Watson

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Patients with learning disabilities (LD) are at increased risk of physical and mental illness due to health inequality. To address this, NICE recommends that people from the age of 14 with a learning disability should have an annual LD health check. This consultation should include a holistic review of the patient’s physical, mental and social health needs with a view of creating an action plan to support the patient’s care. The expected standard set by the Quality and Outcomes Framework (QOF) is that each general practice should review at least 75% of their LD patients annually. During COVID-19, there have been barriers to primary care, including health anxiety, the shift to online general practice and the increase in GP workloads. A surgery in North London wanted to assess whether they were falling short of the expected standard for LD patient annual reviews in order to optimize care post Covid-19. A baseline audit was completed to assess how many LD patients were receiving their annual reviews over the period of 29th September 2020 to 29th September 2021. This information was accessed using EMIS Web Health Care System (EMIS). Patients included were aged 14 and over as per QOF standards. Doctors were not notified of this audit taking place. Following the results of this audit, the creation of learning disability clinics was recommended. These clinics were recommended to be on the ground floor and should be a dedicated time for LD reviews. A re-audit was performed via the same process 6 months later in March 2022. At the time of the baseline audit, there were 71 patients aged 14 and over that were on the LD register. 54% of these LD patients were found to have documentation of an annual LD review within the last 12 months. None of the LD patients between the ages of 14-18 years old had received their annual review. The results were discussed with the practice, and dedicated clinics were set up to review their LD patients. A second pass of the audit was completed 6 months later. This showed an improvement, with 84% of the LD patients registered at the surgery now having a documented annual review within the last 12 months. 78% of the patients between the ages of 14-18 years old had now been reviewed. The baseline audit revealed that the practice was not meeting the expected standard for LD patient’s annual health checks as outlined by QOF, with the most neglected patients being between the ages of 14-18. Identification and awareness of this vulnerable cohort is important to ensure measures can be put into place to support their physical, mental and social wellbeing. Other practices could consider an audit of their annual LD health checks to make sure they are practicing within QOF standards, and if there is a shortfall, they could consider implementing similar actions as used here; dedicated clinics for LD patient reviews.

Keywords: COVID-19, learning disability, learning disability health review, quality and outcomes framework

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Authors: N. Gigauri, A. Surmava, L. Intskirveli, V. Kukhalashvili, S. Mdivani

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The subject of our study is atmospheric air pollution with numerical modeling. In the presented article, as the object of research, there is chosen city Tbilisi, the capital of Georgia, with a population of one and a half million and a difficult terrain. The main source of pollution in Tbilisi is currently vehicles and construction dust. The concentrations of dust and PM (Particulate Matter) were determined in the air of Tbilisi and in its vicinity. There are estimated their monthly maximum, minimum, and average concentrations. Processes of dust propagation in the atmosphere of the city and its surrounding territory are modelled using a 3D regional model of atmospheric processes and an admixture transfer-diffusion equation. There were taken figures of distribution of the polluted cloud and dust concentrations in different areas of the city at different heights and at different time intervals with the background stationary westward and eastward wind. It is accepted that the difficult terrain and mountain-bar circulation affect the deformation of the cloud and its spread, there are determined time periods when the dust concentration in the city is greater than MAC (Maximum Allowable Concentration, MAC=0.5 mg/m³).

Keywords: air pollution, dust, numerical modeling, PM-particles

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Authors: Fadwa Alaskar, Fang-Chieh Chou, Carlos Flores, Xiao-Yun Lu, Alexandre M. Bayen

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This article proposes a perception model for enhancing the accuracy and stability of car-following control of a longitudinally automated truck. We applied a fusion-based tracking algorithm on measurements of a single preceding vehicle needed for car-following control. This algorithm fuses two types of data, radar and LiDAR data, to obtain more accurate and robust longitudinal perception of the subject vehicle in various weather conditions. The filter’s resulting signals are fed to the gap control algorithm at every tracking loop composed by a high-level gap control and lower acceleration tracking system. Several highway tests have been performed with two trucks. The tests show accurate and fast tracking of the target, which impacts on the gap control loop positively. The experiments also show the fulfilment of control design requirements, such as fast speed variations tracking and robust time gap following.

Keywords: object tracking, perception, sensor fusion, adaptive cruise control, cooperative adaptive cruise control

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Authors: Minna Theres James, Nirmal K Sebastian, Shoubhik Mandal, Pramita Mishra, R Ganesan, P S Anil Kumar

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We report the temperature-dependent evolution of Raman spectra of type-II Dirac semimetal (DSM) NiTe2 (001) in the form of bulk single crystal and a nanoflake (200 nm thick) for the first time. A physical model that can quantitatively explain the evolution of out of plane A1g and in-plane E1g Raman modes is used. The non-linear variation of peak positions of the Raman modes with temperature is explained by anharmonic three-phonon and four-phonon processes along with thermal expansion of the lattice. We also observe prominent effect of electron-phonon coupling from the variation of FWHM of the peaks with temperature, indicating the metallicity of the samples. Raman mode E1 1g corresponding to an in plane vibration disappears on decreasing the thickness from bulk to nanoflake.

Keywords: raman spectroscopy, type 2 dirac semimetal, nickel telluride, phonon-phonon coupling, electron phonon coupling, transition metal dichalcogonide

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Authors: Gemma Reynolds, Deborah Bailey Rodriguez, Maria Paula Valdivieso Rueda

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In recent years, the mental health of Higher Education (HE) students has been a growing concern. This has been further exacerbated by the stresses associated with the Covid-19 pandemic, placing students at even greater risk of developing mental health issues. Support available to students in HE tends to follow an established and traditional route. The demands for counselling services have grown, not only with the increase in student numbers but with the number of students seeking support for mental health issues. One way of improving well-being and mental health in HE students is through the use of brief interventions, such as expressive writing (EW). This intervention involves encouraging individuals to write continuously for at least 15-20 minutes for three to five sessions (often on consecutive days) about their deepest thoughts and feelings to explore significant personal experiences in a meaningful way. Given the brevity, simplicity and cost-effectiveness of EW, this intervention has considerable potential as an intervention for HE populations. The current study, therefore, employed a mixed-methods design to explore the effectiveness of EW in reducing anxiety, general stress, academic stress and depression in HE students while improving well-being. HE students at MDX were randomly assigned to one of three conditions: (1) The UniExp-EW group were required to write about their emotions and thoughts about any stressors they have faced that are directly relevant to their university experience (2) The NonUniExp-EW group were required to write about their emotions and thoughts about any stressors that are NOT directly relevant to their university experience, and (3) The Control group were required to write about how they spent their weekend, with no reference to thoughts or emotions, and without thinking about university. Participants were required to carry out the EW intervention for 15minutes per day for four consecutive days. Baseline mental health and wellbeing measures were taken before the intervention via a battery of standardised questionnaires. Following completion of the intervention on day four, participants were required to complete the questionnaires a second time and again one week later. Participants were also invited to attend focus groups to discuss their experience of the intervention. This will allow an in-depth investigation into students’ perceptions of EW as an effective intervention to determine whether they would choose to use this intervention in the future. The quantitative findings will be discussed at the conference as well as a discussion of the important implications of the findings. The study is fundamental because if EW is an effective intervention for improving mental health and well-being in HE students, its brevity and simplicity means it can be easily implemented and can be freely-available to students. Improving the mental health and well-being of HE students can have knock-on implications for improving academic skills and career development.

Keywords: mental health, wellbeing, higher education students, expressive writing

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Authors: Louis Nwachi

Abstract:

Urban planning systems in most countries still rely on expert-driven, top-down technocratic plan-making processes rather than a public and people-led process. This paper set out to evaluate the need for public participation in the plan-making process and to highlight the factors that affect public participation in the plan-making process. In doing this, it adopted a qualitative approach based on document review and interviews taken from real-world phenomena. A case study strategy using the Metropolitan Area of Abuja, the capital of Nigeria, as the study sample was used in carrying out the research. The research finds that participation is an important tool in the plan-making process and that public engagement in the process contributes to the identification of key urban issues that are unique to the specific local areas, thereby contributing to the establishment of priorities and, in turn, to the mobilization of resources to meet the identified needs. It also finds that the development of a participation model by city authorities encourages public engagement and helps to develop trust between those in authority and the different key stakeholder groups involved in the plan-making process.

Keywords: plan-making, participation, urban planning, city

Procedia PDF Downloads 72