Search results for: stagnation point

Authors: Aliouane Toufik, Hamdi Amine, Bouzid Djamel

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Aspheric optical components are an alternative to the use of conventional lenses in the implementation of imaging systems for the visible range. Spherical lenses are capable of producing aberrations. Therefore, they are not able to focus all the light into a single point. Instead, aspherical lenses correct aberrations and provide better resolution even with compact lenses incorporating a small number of lenses. Metrology of these components is very difficult especially when the resolution requirements increase and insufficient or complexity of conventional tools requires the development of specific approaches to characterization. This work is part of the problem existed because the objectives are the study and comparison of different methods used to measure surface rays hybrid aspherical lenses.

Keywords: manufacture of lenses, aspherical surface, precision molding, radius of curvature, roughness

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Authors: Leticia Lengler, Jefferson Oliveira, Vania Estivalete, Jordana Marques Kneipp, Lucia Regina Da Rosa Gama Madruga

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The way social entrepreneurs act and can positively impact on our society engages the interest of academics, companies and governments, who seek solutions to solve or alleviate issues related to the abuse of natural resources, as well as the increase of poverty (social aspects). Studies on social entrepreneurship have been characterized by diverse ramifications and their transdisciplinary character, permeating various disciplines and approaches. Different bibliometric studies were conducted within the theme of social entrepreneurship. In this context, because it is a topic in development and multifaceted, the aim of this article is to present the main interfaces of the studies on the Social Entrepreneur figure in relation to the social concern of sustainability, highlighting the relevant researches and their trends, as well as their relationship with the organizations. Aiming to achieve this purpose, the specific goals are: to identify the most cited authors and articles, to verify the authors and journals with the greatest number of publications and their approaches and to point out their affiliations, countries, and languages of publications. It is still a secondary objective to identify the emerging trends in relation to the social entrepreneur and his social concern stemming from the discussions on sustainability. This way, we analyzed articles from two international databases (Scopus and Web of Science), from 2004 to 2016. The main results were the increase in the number of publications, with most of them in English language, coming mainly from the United States institutions (such as Indiana University and Harvard University) and the United Kingdom (whose main institutions are University of London and Robert Gordon University). Although publications in Spanish and Portuguese are the least expressive in quantity, some tendencies point to publications that discuss the social entrepreneur in terms of gender (that relates to female entrepreneurship) and social class (that relates to the need of building communities that contemplate the Social entrepreneur at the base of the pyramid). It should be noted that the trends of the themes emerged from the analysis of the publication titles only in Portuguese, since this is the native language of the authors who carry out their studies mainly in Brazil. When considering articles in Portuguese (57 indicated by WOS and 9 by Scopus), a previous analysis of the titles was carried out to identify how researchers were approaching the theme social entrepreneur in a joint way to the social dimension of sustainability. However, the analysis of the titles themselves brought a limitation to our study, since it was felt a need to carry out a qualitative study, in which it could be possible to consider the abstracts of the available articles.

Keywords: base of pyramid, social dimension, social entrepreneur, sustainability

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Authors: Hee-Choul Kwon, Hyungjin Cho, Heeyong Kwon

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Image rotation is one of main pre-processing step in image processing or image pattern recognition. It is implemented with rotation matrix multiplication. However it requires lots of floating point arithmetic operations and trigonometric function calculations, so it takes long execution time. We propose a new high speed image rotation algorithm without two major time-consuming operations. We compare the proposed algorithm with the conventional rotation one with various size images. Experimental results show that the proposed algorithm is superior to the conventional rotation ones.

Keywords: high speed rotation operation, image processing, image rotation, pattern recognition, transformation matrix

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Authors: Ali Alshamrani

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This article aims to give a comprehensive and critical review of sukuk issuance in Saudi Arabia, and the extent to which the issuance of sukuk in Saudi Arabia is consistent with Shariah requirements. The article is divided into two sections. Accordingly, the first section of this article begins with an examination of sukuk in general, and includes the concept of sukuk, the basic principles of sukuk, common types of sukuk, and a critical analysis of the most important differences between sukuk and conventional bonds. The second section gives a critical analysis of how sukuk work in Saudi Arabia, offering the regulatory framework of the issuance of sukuk in the KSA, and the legal challenges from Shariah point of view, and provide recommendations to overcome these challenges.

Keywords: sukuk issuance, Shariah, Saudi Arabia, capital market authority

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Authors: Sanaa I. Abu Alasal, Madleen M. Esbeih, Eman R. Fayyad, Rami S. Gharaibeh, Mostafa Z. Ali, Ahmed A. Freewan, Monther M. Jamhawi

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This research proposes a novel reconstruction protocol for restoring missing surfaces and low-quality edges and shapes in photos of artifacts at historical sites. The protocol starts with the extraction of a cloud of points. This extraction process is based on four subordinate algorithms, which differ in the robustness and amount of resultant. Moreover, they use different -but complementary- accuracy to some related features and to the way they build a quality mesh. The performance of our proposed protocol is compared with other state-of-the-art algorithms and toolkits. The statistical analysis shows that our algorithm significantly outperforms its rivals in the resultant quality of its object files used to reconstruct the desired model.

Keywords: meshes, point clouds, surface reconstruction protocols, 3D reconstruction

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Authors: Yassine Meraihi, Dalila Acheli, Rabah Meraihi

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MANET for Mobile Ad hoc NETwork is a collection of wireless mobile nodes that communicates with each other without using any existing infrastructure, access point or centralized administration, due to the higher mobility and limited radio transmission range, routing is an important issue in ad hoc network, so in order to ensure reliable and efficient route between to communicating nodes quickly, an appropriate routing protocol is needed. In this paper, we present the performance analysis of two mobile ad hoc network routing protocols namely DSR and OLSR using NS2.34, the performance is determined on the basis of packet delivery ratio, throughput, average jitter and end to end delay with varying pause time.

Keywords: DSR, OLSR, quality of service, routing protocols, MANET

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Authors: Eun Mi Ryu, Ah Young An, Ji Yeon Kang, Yeong Soo Shin, Hee Sun Kim

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As the number of fire incidents has been increased, fire incidents significantly damage economy and human lives. Especially when high strength reinforced concrete is exposed to high temperature due to a fire, deterioration occurs such as loss in strength and elastic modulus, cracking, and spalling of the concrete. Therefore, it is important to understand risk of structural safety in building structures by studying structural behaviors and rehabilitation of fire damaged high strength concrete structures. This paper aims at investigating rehabilitation effect on fire damaged high strength concrete beams using experimental and analytical methods. In the experiments, flexural specimens with high strength concrete are exposed to high temperatures according to ISO 834 standard time temperature curve. After heated, the fire damaged reinforced concrete (RC) beams having different cover thicknesses and fire exposure time periods are rehabilitated by removing damaged part of cover thickness and filling polymeric mortar into the removed part. From four-point loading test, results show that maximum loads of the rehabilitated RC beams are 1.8~20.9% higher than those of the non-fire damaged RC beam. On the other hand, ductility ratios of the rehabilitated RC beams are decreased than that of the non-fire damaged RC beam. In addition, structural analyses are performed using ABAQUS 6.10-3 with same conditions as experiments to provide accurate predictions on structural and mechanical behaviors of rehabilitated RC beams. For the rehabilitated RC beam models, integrated temperature–structural analyses are performed in advance to obtain geometries of the fire damaged RC beams. After spalled and damaged parts are removed, rehabilitated part is added to the damaged model with material properties of polymeric mortar. Three dimensional continuum brick elements are used for both temperature and structural analyses. The same loading and boundary conditions as experiments are implemented to the rehabilitated beam models and nonlinear geometrical analyses are performed. Structural analytical results show good rehabilitation effects, when the result predicted from the rehabilitated models are compared to structural behaviors of the non-damaged RC beams. In this study, fire damaged high strength concrete beams are rehabilitated using polymeric mortar. From four point loading tests, it is found that such rehabilitation is able to make the structural performance of fire damaged beams similar to non-damaged RC beams. The predictions from the finite element models show good agreements with the experimental results and the modeling approaches can be used to investigate applicability of various rehabilitation methods for further study.

Keywords: fire, high strength concrete, rehabilitation, reinforced concrete beam

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Authors: N. Khursheed, M. Fatima, S. Jamal, A. Raza, S. Rattani, Q. Ahsan, A. Rasheed, M. Jawed

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Introduction: Antibiotics are among the commonly prescribed medicines to treat bacterial infections. Their misuse intensifies resistance, and overuse incurs heavy losses to the healthcare system in terms of increased treatment costs and enhanced disease burden. Studies show that 40% of empirically used antibiotics are irrationally utilized. The objective of this study was to evaluate prescribing pattern of antibiotics at six public sector tertiary care hospitals across Pakistan. Methods: A multicenter cross-sectional point prevalence survey (PPS) was conducted in selected wards of six public sector tertiary care hospitals in Pakistan as part of the Clinical Engagement program by Fleming Fund Country Grant Pakistan in collaboration with Indus Hospital & Health Network (IHHN) from February to March 2021, these included Jinnah Postgraduate Medical Center and Dr. Ruth K. M. Pfau Civil Hospital from Karachi, Sheikh Zayed Hospital Lahore, Nishtar Medical University Hospital Multan, Medical Teaching Institute Hayatabad Medical Complex Peshawar, and Provincial Headquarters Hospital Gilgit. WHO PPS methodology was used for data collection (Hospital, ward, and patient level data was collected). Data was entered into the open-source Kobo Collect application and was analyzed using SPSS (version 22.0). Findings: Medical records of 837 in-patients were surveyed, of which the prevalence of antibiotics use was 78.5%. The most commonly prescribed antimicrobial was Ceftriaxone (21.7%) which is categorized in the Watch group of WHO AWaRe Classification, followed by Metronidazole (17.3%), Cefoperazone/Sulbactam (8.4%), Co-Amoxiclav (6.3%) and Piperacillin/Tazobactam (5.9%). The antibiotics were prescribed largely for surgical prophylaxis (36.7%), followed by community-acquired infections (24.7%). One antibiotic was prescribed to 46.7%, two to 39.9%, and three or more to 12.5 %. Two of six (30%) hospitals had functional drug and therapeutic committees, three (50%) had infection prevention and control committees, and one facility had an antibiotic formulary. Conclusion: Findings demonstrate high consumption of broad-spectrum antimicrobials and emphasizes the importance of expanding the antimicrobial stewardship program. Mentoring clinical teams will help to rationalize antimicrobial use.

Keywords: antimicrobial resistance, antimicrobial stewardship, point prevalence survey, antibiotics

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Authors: Igor V. Savchenko, Dmitrii A. Samoshkin

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The active study of the properties of lanthanides has begun in the late 50s of the last century, when methods for their purification were developed and metals with a relatively low content of impurities were obtained. Nevertheless, up to date, many properties of the rare earth metals (REM) have not been experimentally investigated, or insufficiently studied. Currently, the thermal conductivity and thermal diffusivity of lanthanides have been studied most thoroughly in the low-temperature region and at moderate temperatures (near 293 K). In the high-temperature region, corresponding to the solid phase, data on the thermophysical characteristics of the REM are fragmentary and in some cases contradictory. Analysis of the literature showed that the data on the thermal conductivity and thermal diffusivity of light REM in the liquid state are few in number, little informative (only one point corresponds to the liquid state region), contradictory (the nature of the thermal conductivity change with temperature is not reproduced), as well as the results of measurements diverge significantly beyond the limits of the total errors. Thereby our experimental results allow to fill this gap and to clarify the existing information on the heat transfer coefficients of neodymium and samarium in a wide temperature range from the melting point up to 1770 K. The measurement of the thermal conductivity of investigated metallic melts was carried out by laser flash technique on an automated experimental setup LFA-427. Neodymium sample of brand NM-1 (99.21 wt % purity) and samarium sample of brand SmM-1 (99.94 wt % purity) were cut from metal ingots and then ones were annealed in a vacuum (1 mPa) at a temperature of 1400 K for 3 hours. Measuring cells of a special design from tantalum were used for experiments. Sealing of the cell with a sample inside it was carried out by argon-arc welding in the protective atmosphere of the glovebox. The glovebox was filled with argon with purity of 99.998 vol. %; argon was additionally cleaned up by continuous running through sponge titanium heated to 900–1000 K. The general systematic error in determining the thermal conductivity of investigated metallic melts was 2–5%. The approximation dependences and the reference tables of the thermal conductivity and thermal diffusivity coefficients were developed. New reliable experimental data on the transport properties of the REM and their changes in phase transitions can serve as a scientific basis for optimizing the industrial processes of production and use of these materials, as well as ones are of interest for the theory of thermophysical properties of substances, physics of metals, liquids and phase transformations.

Keywords: high temperatures, laser flash technique, liquid state, metallic melt, rare earth metals, thermal conductivity, thermal diffusivity

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Authors: M. Momoh, S. Abdullahi, A. U. Moreh

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Zinc oxide (ZnO) thin films were prepared on corning (7059) glass substrates at a thickness of 75.5 and 130.5 nm by RF sputtering technique. The deposition was carried out at room temperature after which the samples were annealed in open air at 150°C. The electrical and structural properties of these films were studied. The electrical properties of the films were monitored by four-point probe method while the structural properties were studied by X-ray diffraction (XRD). It was found that the electrical resistance of the films decreases with increase in the thickness of the films. The XRD analysis of the films showed that the films have a peak located at 34.31°-34.35° with hkl (002). Other parameters calculated include the stress (σ) and the grain size (D).

Keywords: electrical properties, film thickness, structural properties, zinc oxide

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Authors: Carolin Schulze

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Characterized by a positive interdependence of learners, cooperative learning (CL) is one possibility of successfully dealing with the increasing heterogeneity of students. Various positive effects of CL on the mental, physical and social health of students have already been documented. However, this structure is still rarely used in physical education (PE). Moreover, there is a lack of information about factors that determine the successful implementation of CL in PE. Therefore, the objective of the current study was to find out factors that determine the successful implementation of CL in PE using a digital questionnaire that was conducted from November to December 2022. In addition to socio-demographic data (age, gender, teaching experience, and education level), frequency of using CL, implementation strategies (theory-led, student-centred), and positive and negative effects of CL were measured. Furthermore, teachers were asked to rate the success of implementation on a 6-point rating scale (1-very successful to 6-not successful at all). For statistical analysis, multiple linear regression was performed, setting the success of implementation as the dependent variable. A total of 224 teachers (mean age=44.81±10.60 years; 58% male) took part in the current study. Overall, 39% of participants stated that they never use CL in their PE classes. Main reasons against the implementations of CL in PE were no time for preparation (74%) or for implementation (61%) and high heterogeneity of students (55%). When using CL, most of the reported difficulties are related to uncertainties about the correct procedure (54%) and the heterogeneous performance of students (54%). The most frequently mentioned positive effect was increased motivation of students (42%) followed by an improvement of psychological abilities (e.g. self-esteem, self-concept; 36%) and improved class cohesion (31%). Reported negative effects were unpredictability (29%), restlessness (24%), confusion (24%), and conflicts between students (17%). The successful use of CL is related to a theory-based preparation (e.g., heterogeneous formation of groups, use of rules and rituals) and a flexible implementation tailored to the needs and conditions of students (e.g., the possibility of individual work, omission of CL phases). Compared to teachers who solely implemented CL theory-led or student-adapted, teachers who switched from theory-led preparation to student-centred implementation of CL reported more successful implementation (t=5.312; p<.001). Neither frequency of using CL in PE nor the gender, age, the teaching experience, or the education level of the teacher showed a significant connection with the successful use of CL. Corresponding to the results of the current study, it is advisable that teachers gather enough knowledge about CL during their education and to point out the need to adapt the learning structure according to the diversity of their students. In order to analyse implementation strategies of teachers more deeply, qualitative methods and guided interviews with teachers are needed.

Keywords: diversity, educational technology, physical education, teaching styles

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Authors: Shai Sarussi

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Let S be an integral domain with field of fractions F and let A be an F-algebra. An S-subalgebra R of A is called S-nice if R∩F = S and the localization of R with respect to S \{0} is A. Denoting by W the set of all S-nice subalgebras of A, and defining a notion of open sets on W, one can view W as a T0-Alexandroff space. Thus, the algebraic structure of W can be viewed from the point of view of topology. It is shown that every nonempty open subset of W has a maximal element in it, which is also a maximal element of W. Moreover, a supremum of an irreducible subset of W always exists. As a notable connection with valuation theory, one considers the case in which S is a valuation domain and A is an algebraic field extension of F; if S is indecomposed in A, then W is an irreducible topological space, and W contains a greatest element.

Keywords: integral domains, Alexandroff topology, prime spectrum of a ring, valuation domains

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Authors: Hassan Eshkiki, Benjamin Mora

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The Neighbor Migrating Generator is a simple and efficient approach to finding the closest potential neighbor(s) with a different label for a given instance and so without the need to calibrate any kernel settings at all. This allows determining and explaining the most important features that will influence an AI model. It can be used to either migrate a specific sample to the class decision boundary of the original model within a close neighborhood of that sample or identify global features that can help localising neighbor classes. The proposed technique works by minimizing a loss function that is divided into two components which are independently weighted according to three parameters α, β, and ω, α being self-adjusting. Results show that this approach is superior to past techniques when detecting the smallest changes in the feature space and may also point out issues in models like over-fitting.

Keywords: explainable AI, EX AI, feature importance, counterfactual explanations

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Authors: Saif Alomari

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The paper aims at giving physical and mathematical descriptions of how the structural parameters of a resonant tunnelling diode (RTD) affect its output characteristics. Specifically, the value of the peak voltage, peak current, peak to valley current ratio (PVCR), and the difference between peak and valley voltages and currents ΔV and ΔI. A simulation-based approach using the Non-Equilibrium Green Function (NEGF) formalism based on the Silvaco ATLAS simulator is employed to conduct a series of designed experiments. These experiments show how the doping concentration in the emitter and collector layers, their thicknesses, and the width of the barriers and the quantum well influence the above-mentioned output characteristics. Each of these parameters was systematically changed while holding others fixed in each set of experiments. Factorial experiments are outside the scope of this work and will be investigated in future. The physics involved in the operation of the device is thoroughly explained and mathematical models based on curve fitting and underlaying physical principles are deduced. The models can be used to design devices with predictable output characteristics. These models were found absent in the literature that the author acanned. Results show that the doping concentration in each region has an effect on the value of the peak voltage. It is found that increasing the carrier concentration in the collector region shifts the peak to lower values, whereas increasing it in the emitter shifts the peak to higher values. In the collector’s case, the shift is either controlled by the built-in potential resulting from the concentration gradient or the conductivity enhancement in the collector. The shift to higher voltages is found to be also related to the location of the Fermi-level. The thicknesses of these layers play a role in the location of the peak as well. It was found that increasing the thickness of each region shifts the peak to higher values until a specific characteristic length, afterwards the peak becomes independent of the thickness. Finally, it is shown that the thickness of the barriers can be optimized for a particular well width to produce the highest PVCR or the highest ΔV and ΔI. The location of the peak voltage is important in optoelectronic applications of RTDs where the operating point of the device is usually the peak voltage point. Furthermore, the PVCR, ΔV, and ΔI are of great importance for building RTD-based oscillators as they affect the frequency response and output power of the oscillator.

Keywords: peak to valley ratio, peak voltage shift, resonant tunneling diodes, structural parameters

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Authors: Sabri Serkan Gulluoglu

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The study is aimed at examining the effects of internet marketing with IPTV on human beings. Internet marketing with IPTV is emerging as an integral part of business strategies in today’s technologically advanced world and the business activities all over the world are influences with the emergence of this modern marketing tool. As the population of the Internet and on-line users’ increases, new research issues have arisen concerning the demographics and psychographics of the on-line user and the opportunities for a product or service. In recent years, we have seen a tendency of various services converging to the ubiquitous Internet Protocol based networks. Besides traditional Internet applications such as web browsing, email, file transferring, and so forth, new applications have been developed to replace old communication networks. IPTV is one of the solutions. In the future, we expect a single network, the IP network, to provide services that have been carried by different networks today. For finding some important effects of a video based technology market web site on internet, we determine to apply a questionnaire on university students. Recently some researches shows that in Turkey the age of people 20 to 24 use internet when they buy some electronic devices such as cell phones, computers, etc. In questionnaire there are ten categorized questions to evaluate the effects of IPTV when shopping. There were selected 30 students who are filling the question form after watching an IPTV channel video for 10 minutes. This sample IPTV channel is “buy.com”, it look like an e-commerce site with an integrated IPTV channel on. The questionnaire for the survey is constructed by using the Likert scale that is a bipolar scaling method used to measure either positive or negative response to a statement (Likert, R) it is a common system that is used is the surveys. By following the Likert Scale “the respondents are asked to indicate their degree of agreement with the statement or any kind of subjective or objective evaluation of the statement. Traditionally a five-point scale is used under this methodology”. For this study also the five point scale system is used and the respondents were asked to express their opinions about the given statement by picking the answer from the given 5 options: “Strongly disagree, Disagree, Neither agree Nor disagree, Agree and Strongly agree”. These points were also rates from 1-5 (Strongly disagree, Disagree, Neither disagree Nor agree, Agree, Strongly agree). On the basis of the data gathered from the questionnaire some results are drawn in order to get the figures and graphical representation of the study results that can demonstrate the outcomes of the research clearly.

Keywords: IPTV, internet marketing, online, e-commerce, video based technology

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Authors: R. B. Mishra, Sudhakar Tripathi

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In this paper, the cable model of dendrites have been considered. The dendrites are cylindrical cables of various segments having variable length and reducing radius from start point at synapse and end points. For a particular event signal being received by a neuron in response only some dendrite are active at a particular instance. Initial current signals with different current flows in dendrite are assumed. Due to overlapping and coupling of active dendrite, they induce currents in the dendrite segments of each other at a particular instance. But how these currents are induced in the various segments of active dendrites due to coupling between these dendrites, It is not presented in the literature. Here the paper presents a model for induced currents in active dendrite segments due to mutual coupling at the starting instance of an activity in dendrite. The model is as discussed further.

Keywords: currents, dendrites, induction, simulation

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Authors: Pshtiwan Shafiq Ahmed

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The invasion of Iraq was a turning point in Iraq, destroying the economic infrastructure of several important strategic and historic cities, including Mosul, Anbar and Diyala, which will take decades to rebuild It left 18,805 people dead and 37,000 injured, destroying hundreds of villages and cities, displacing 2.3 million people, and increasing the number of orphans The increase in the number of windows and the destruction of society and the structure of the population so that the number of children, women and the elderly has increased. Religious clashes have increased and religious cleansing has begun, trying to eradicate Christianity, Yazidis and Kakais from the whole of Iraq, causing the largest number of Christians, Yazidis and Kakais to leave Iraq and many of them went missing.

Keywords: ISIS, population change, geographical change, Iraq

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Authors: Cleyton S. Stampa

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This paper addresses the perspectives of using low melting point metals (LMPMs) as phase change materials (PCMs) in latent thermal energy storage (LTES) units, through a numerical approach. This is a new class of PCMs that has been one of the most prospective alternatives to be considered in LTES, due to these materials present high thermal conductivity and elevated heat of fusion, per unit volume. The chosen type of LTES consists of several horizontal parallel slabs filled with PCM. The heat transfer fluid (HTF) circulates through the channel formed between each two consecutive slabs on a laminar regime through forced convection. The study deals with the LTES charging process (heat-storing) by using pure gallium as PCM, and it considers heat conduction in the solid phase during melting driven by natural convection in the melt. The transient heat transfer problem is analyzed in one arbitrary slab under the influence of the HTF. The mathematical model to simulate the isothermal phase change is based on a volume-averaged enthalpy method, which is successfully verified by comparing its predictions with experimental data from works available in the pertinent literature. Regarding the convective heat transfer problem in the HTF, it is assumed that the flow is thermally developing, whereas the velocity profile is already fully developed. The study aims to learn about the effect of the solid subcooling in the melting rate through comparisons with the melting process of the solid in which it starts to melt from its fusion temperature. In order to best understand this effect in a metallic compound, as it is the case of pure gallium, the study also evaluates under the same conditions established for the gallium, the melting process of commercial paraffin wax (organic compound) and of the calcium chloride hexahydrate (CaCl₂ 6H₂O-inorganic compound). In the present work, it is adopted the best options that have been established by several researchers in their parametric studies with respect to this type of LTES, which lead to high values of thermal efficiency. To do so, concerning with the geometric aspects, one considers a gap of the channel formed by two consecutive slabs, thickness and length of the slab. About the HTF, one considers the type of fluid, the mass flow rate, and inlet temperature.

Keywords: flat slab, heat storing, pure metal, solid subcooling

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Authors: Sara A. Ben Lashihar

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The heritage building information modelling (HBIM) of the historical masonry buildings has expanded lately to meet the urgent needs for conservation and structural analysis. The masonry structures are unique features for ancient building architectures worldwide that have special cultural, spiritual, and historical significance. However, there is a research gap regarding the reliability of the HBIM modeling process of these structures. The HBIM modeling process of the masonry structures faces significant challenges due to the inherent complexity and uniqueness of their structural systems. Most of these processes are based on tracing the point clouds and rarely follow documents, archival records, or direct observation. The results of these techniques are highly abstracted models where the accuracy does not exceed LOD 200. The masonry assemblages, especially curved elements such as arches, vaults, and domes, are generally modeled with standard BIM components or in-place models, and the brick textures are graphically input. Hence, future investigation is necessary to establish a methodology to generate automatically parametric masonry components. These components are developed algorithmically according to mathematical and geometric accuracy and the validity of the survey data. The main aim of this paper is to provide a comprehensive review of the state of the art of the existing researches and papers that have been conducted on the HBIM modeling of the masonry structural elements and the latest approaches to achieve parametric models that have both the visual fidelity and high geometric accuracy. The paper reviewed more than 800 articles, proceedings papers, and book chapters focused on "HBIM and Masonry" keywords from 2017 to 2021. The studies were downloaded from well-known, trusted bibliographic databases such as Web of Science, Scopus, Dimensions, and Lens. As a starting point, a scientometric analysis was carried out using VOSViewer software. This software extracts the main keywords in these studies to retrieve the relevant works. It also calculates the strength of the relationships between these keywords. Subsequently, an in-depth qualitative review followed the studies with the highest frequency of occurrence and the strongest links with the topic, according to the VOSViewer's results. The qualitative review focused on the latest approaches and the future suggestions proposed in these researches. The findings of this paper can serve as a valuable reference for researchers, and BIM specialists, to make more accurate and reliable HBIM models for historic masonry buildings.

Keywords: HBIM, masonry, structure, modeling, automatic, approach, parametric

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Authors: Arianna Vedaschi

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This paper addresses the relationship between freedom of expression, national security and radicalization. Is it still possible to talk about a balance between the first two elements? Or, due to the intrusion of the third, is it more appropriate to consider freedom of expression as “permanently disfigured” by securitarian concerns? In this study, both the legislative and the judicial level are taken into account and the comparative method is employed in order to provide the reader with a complete framework of relevant issues and a workable set of solutions. The analysis moves from the finding according to which the tension between free speech and national security has become a major issue in democratic countries, whose very essence is continuously endangered by the ever-changing and multi-faceted threat of international terrorism. In particular, a change in terrorist groups’ recruiting pattern, attracting more and more people by way of a cutting-edge communicative strategy, often employing sophisticated technology as a radicalization tool, has called on law-makers to modify their approach to dangerous speech. While traditional constitutional and criminal law used to punish speech only if it explicitly and directly incited the commission of a criminal action (“cause-effect” model), so-called glorification offences – punishing mere ideological support for terrorism, often on the web – are becoming commonplace in the comparative scenario. Although this is direct, and even somehow understandable, consequence of the impending terrorist menace, this research shows many problematic issues connected to such a preventive approach. First, from a predominantly theoretical point of view, this trend negatively impacts on the already blurred line between permissible and prohibited speech. Second, from a pragmatic point of view, such legislative tools are not always suitable to keep up with ongoing developments of both terrorist groups and their use of technology. In other words, there is a risk that such measures become outdated even before their application. Indeed, it seems hard to still talk about a proper balance: what was previously clearly perceived as a balancing of values (freedom of speech v. public security) has turned, in many cases, into a hierarchy with security at its apex. In light of these findings, this paper concludes that such a complex issue would perhaps be better dealt with through a combination of policies: not only criminalizing ‘terrorist speech,’ which should be relegated to a last resort tool, but acting at an even earlier stage, i.e., trying to prevent dangerous speech itself. This might be done by promoting social cohesion and the inclusion of minorities, so as to reduce the probability of people considering terrorist groups as a “viable option” to deal with the lack of identification within their social contexts.

Keywords: radicalization, free speech, international terrorism, national security

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Authors: Felicitas Pielsticker, Christoph Pielsticker, Ingo Witzke

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Many people know ‘Mathematics needs practice!’ statement or similar ones from their mathematics lessons. It seems important to practice when learning mathematics. At the same time, it also seems important to practice how to learn mathematics. This paper places neuroscientific-radiological findings on “practicing” while learning mathematics in a context of mathematics education. To accomplish this, we use a literature-based discussion of our case study on practice. We want to describe neuroscientific-radiological findings in the context of mathematics education and point out stimulating connections between both perspectives. From a connective perspective we expect incentives that lead discussions in future research in the field of mathematics education.

Keywords: functional magnetic resonance imaging, fMRI, education, mathematics learning, practicing

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Authors: Martina Marinelli, Samanta Vellante, Francesco Pilotti, Daniele Di Valerio, Gaetanino Paolone

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Any development in web marketing technology requires changes in information engineering to identify instruments and techniques suitable for the production of software applications for informative marketing. Moreover, for large web solutions, designing an interface that enables human interactions is a complex process that must bridge between informative marketing requirements and the developed solution. A user-friendly interface in web marketing applications is crucial for a successful business. The paper introduces mkInfo - a software platform that implements informative marketing. Informative marketing is a new interpretation of marketing which places the information at the center of every marketing action. The creative team includes software engineering researchers who have recently authored an article on automatic code generation. The authors have created the mkInfo software platform to generate informative marketing web applications. For each web application, it is possible to automatically implement an opt in page, a landing page, a sales page, and a thank you page: one only needs to insert the content. mkInfo implements an autoresponder to send mail according to a predetermined schedule. The mkInfo platform also includes e-commerce for a product or service. The stakeholder can access any opt-in page and get basic information about a product or service. If he wants to know more, he will need to provide an e-mail address to access a landing page that will generate an e-mail sequence. It will provide him with complete information about the product or the service. From this point on, the stakeholder becomes a user and is now able to purchase the product or related services through the mkInfo platform. This paper suggests a possible definition for Informative Marketing, illustrates its basic principles, and finally details the mkInfo platform that implements it. This paper also offers some Informative Marketing models, which are implemented in the mkInfo platform. Informative marketing can be applied to products or services. It is necessary to realize a web application for each product or service. The mkInfo platform enables the product or the service producer to send information concerning a specific product or service to all stakeholders. In conclusion, the technical contributions of this paper are: a different interpretation of marketing based on information; a modular architecture for web applications, particularly for one with standard features such as information storage, exchange, and delivery; multiple models to implement informative marketing; a software platform enabling the implementation of such models in a web application. Future research aims to enable stakeholders to provide information about a product or a service so that the information gathered about a product or a service includes both the producer’s and the stakeholders' point of view. The purpose is to create an all-inclusive management system of the knowledge regarding a specific product or service: a system that includes everything about the product or service and is able to address even unexpected questions.

Keywords: informative marketing, opt in page, software platform, web application

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Authors: Runlang Zhu, Weijun Gao, Yinqi Zhang, Gangwei Cai

Abstract:

In order to deal with issues such as the environmental problems and aging of the population, the Japanese government wanted to achieve goals like 'a city where everyone wants to live' and 'a city full of energy for everyone' by creating environmental, social, and economic values in the process of urban development. They began to promote the concept of 'Environmental Future City' in 2010, aiming to create cities and regions with excellent environments, sustainable economic development, and social systems. After taking a look at the history, concept, and development of environmental future cities, the paper will discuss the evaluation system of them, introduce representative cases, and point out what other cities can learn from their development process.

Keywords: environmental future city, city concept, CASBEE, environmental performance assessment

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Authors: Salim Belouettar, Kodjo Attipou

Abstract:

The thermal wrinkling behavior of thin membranes is investigated. The Fourier double scale series are used to deduce the macroscopic membrane wrinkling equations. The obtained equations account for the global and local wrinkling modes. Numerical examples are conducted to assess the validity of the approach developed. Compared to the finite element full model, the present model needs only few degrees of freedom to recover accurately the bifurcation curves and wrinkling paths. Different parameters such as membrane’s aspect ratio, wave number, pre-stressed membranes are discussed from a numerical point of view and the properties of the wrinkles (critical load, wavelength, size and location) are presented.

Keywords: wrinkling, thermal stresses, Fourier series, thin membranes

Procedia PDF Downloads 389

Authors: Mojtaba Hakimi-Moghaddam

Abstract:

Positive realness as the most important property of driving point impedance of passive electrical networks appears in the control systems stability theory in 1960’s. There are three important subsets of positive real (PR) systems are introduced by researchers, that is, loos-less positive real (LLPR) systems, weakly strictly positive real (WSPR) systems and strictly positive real (SPR) systems. In this paper, definitions, properties, lemmas, and theorems related to family of positive real systems are summarized. Properties in both frequency domain and state space representation of system are explained. Also, several illustrative examples are presented.

Keywords: real rational matrix transfer functions, positive realness property, strictly positive realness property, Hermitian form asymptotic property, pole-zero properties

Procedia PDF Downloads 273

Authors: J. L. Oliver, T. Agryzkov, L. Tortosa, J. F. Vicent, J. Santacruz

Abstract:

This paper aims to demonstrate how a system of indicators can be used in order to evaluate some heritage areas which can be understood as minor ones. We mean by that those urban areas with high heritage interest from an academical point of view, but never properly valued. The reasons for this situation may be diverse, either they are not old enough, or they may show the modest architecture, the fact is these areas have not been considered deserving of protection, as the historical ones. As a result of this reality, they usually show now a very degraded urban space, which in addition contribute to accelerate a process of deterioration. Using a technic well known in urban design, we propose here a system of indicators for patrimonial purposes, as a tool to identify and quantify the heritage value of these kinds of areas. As a case study, we apply this system in some part of the City of Quito (El Ecuador).

Keywords: heritage cities, indicators, spatial analysis, historic sites

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Authors: Ahmed W. Oda, Ahmed El-Desouky, Hassan Mahdy, Osama M. Moussa

Abstract:

Nanomaterials have many applications in the field of asphalt paving. Two locally produced nanomaterials were used in the asphalt binder modification. The nanomaterials used are Nanosilica (NS), and Nanoclay (NC). The virgin asphalt binder was characterized by the conventional tests. The bitumen was modified by 3%, 5% and 7% of NS and NC. The penetration index(PI), and the retaining penetration (RP) was calculated based on the results of the penetration and the softening point tests. The results show that the RP becomes 95.35% at 5%NS modified bitumen and reaches 97.56% when bitumen is modified with 3% NC. The results show significant improvement in the bitumen stiffness when modified by the two types of nanomaterials, either fresh or aged (stored).

Keywords: bitumen, modified bitumen, aged, stored, nanomaterials

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Authors: Ly Quyet Tien

Abstract:

The object of this paper is to study Vietnamese Les Rap as art to promote rights and gender in the twenty-first century. The author analyzed Vietnamese Les Rap from the point of view of a contemporary person who has witnessed the tumultuous destiny of the most suffering minority group in Vietnam’s LGBT community. He reviewed scholarly studies, and reputable newspapers on the topic and conducted face to face interviews for qualitative data. The study found that Vietnamese lesbians have composed and used rap as an effective tool to express their fight for visibility, identity, and sensibility. Research reveals that these songs did not only touch the heart of the LGBT community but also the larger public, marking the rising queer voice, contributing to a flourishing of LGBT culture, and revolutionizing the colors of Vietnamese hip hop music in the twenty-first century.

Keywords: culture, lesbian, rap, Vietnam

Procedia PDF Downloads 97

Authors: Ahmed Shaban Abdel Hay Gabr

Abstract:

Water hyacinth (W-H) has an adverse effect on Nile river in Egypt, it absorbs high quantities of water, it needs to serve these quantities especially at this time, so by burning W-H, it can be used in concrete mix to reduce the permeability of concrete and increase both the compressive and splitting strength. The effect of W-H on non-structural concrete properties was studied, but there is a lack of studies about the behavior of structural concrete containing W-H. Therefore, in the present study, the behavior of 15 RC beams with 100 x 150 mm cross section, 1250 mm span, different reinforcement ratios and different W-H ratios were studied by testing the beams under two-point bending test. The test results showed that Water Hyacinth is compatible with RC which yields promising results.

Keywords: beams, reinforcement ratio, reinforced concrete, water hyacinth

Procedia PDF Downloads 446

Authors: Joel Thomas, Alexa Squirini

Abstract:

The key argument of this research is that every element of systems interoperability is an enabler of regional disaster resilience, and arguably should become a focal point for standardized measurement of communities’ ability to work together. Few resilience research efforts have focused on the development and application of solutions that measurably improve communities’ ability to work together at a regional level, yet a majority of the most devastating and disruptive disasters are those that have had a regional impact. The key findings of the research include a unique theoretical, mathematical, and operational approach to tangibly and defensibly measure and assess systems interoperability required to support crisis information management activities performed by governments, the private sector, and humanitarian organizations. A most effective way for communities to measurably improve regional disaster resilience is through deliberately executed disaster preparedness activities. Developing interoperable crisis information management capabilities is a crosscutting preparedness activity that greatly affects a community’s readiness and ability to work together in times of crisis. Thus, improving communities’ human and technical posture to work together in advance of a crisis, with the ultimate goal of enabling information sharing to support coordination and the careful management of available resources, is a primary means by which communities may improve regional disaster resilience. This model describes how systems interoperability can be qualitatively and quantitatively assessed when characterized as five forms of capital: governance; standard operating procedures; technology; training and exercises; and usage. The unique measurement framework presented defines the relationships between systems interoperability, information sharing and safeguarding, operational coordination, community preparedness and regional disaster resilience, and offers a means by which to implement real-world solutions and measure progress over the course of a multi-year program. The model is being developed and piloted in partnership with the U.S. Department of Homeland Security (DHS) Science and Technology Directorate (S&T) and the North Atlantic Treaty Organization (NATO) Advanced Regional Civil Emergency Coordination Pilot (ARCECP) with twenty-three organizations in Bosnia and Herzegovina, Croatia, Macedonia, and Montenegro. The intended effect of the model implementation is to enable communities to answer two key questions: 'Have we measurably improved crisis information management capabilities as a result of this effort?' and, 'As a result, are we more resilient?'

Keywords: disaster, interoperability, measurement, resilience

Procedia PDF Downloads 142