Search results for: backward facing step

Authors: Bohuslava Juhasova, Martin Juhas, Renata Masarova, Zuzana Sutova

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The article deals with the tool in Matlab GUI form that is designed to analyse a mechatronic system sensitivity and tolerance. In the analysed mechatronic system, a torque is transferred from the drive to the load through a coupling containing flexible elements. Different methods of control system design are used. The classic form of the feedback control is proposed using Naslin method, modulus optimum criterion and inverse dynamics method. The cascade form of the control is proposed based on combination of modulus optimum criterion and symmetric optimum criterion. The sensitivity is analysed on the basis of absolute and relative sensitivity of system function to the change of chosen parameter value of the mechatronic system, as well as the control subsystem. The tolerance is analysed in the form of determining the range of allowed relative changes of selected system parameters in the field of system stability. The tool allows to analyse an influence of torsion stiffness, torsion damping, inertia moments of the motor and the load and controller(s) parameters. The sensitivity and tolerance are monitored in terms of the impact of parameter change on the response in the form of system step response and system frequency-response logarithmic characteristics. The Symbolic Math Toolbox for expression of the final shape of analysed system functions was used. The sensitivity and tolerance are graphically represented as 2D graph of sensitivity or tolerance of the system function and 3D/2D static/interactive graph of step/frequency response.

Keywords: mechatronic systems, Matlab GUI, sensitivity, tolerance

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Authors: Hari Singh, Abhishek Kamboj, Sudhir Kumar

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This investigation proposes a grey-based Taguchi method to solve the multi-response problems. The grey-based Taguchi method is based on the Taguchi’s design of experimental method, and adopts Grey Relational Analysis (GRA) to transfer multi-response problems into single-response problems. In this investigation, an attempt has been made to optimize the drilling process parameters considering weighted output response characteristics using grey relational analysis. The output response characteristics considered are surface roughness, burr height and hole diameter error under the experimental conditions of cutting speed, feed rate, step angle, and cutting environment. The drilling experiments were conducted using L27 orthogonal array. A combination of orthogonal array, design of experiments and grey relational analysis was used to ascertain best possible drilling process parameters that give minimum surface roughness, burr height and hole diameter error. The results reveal that combination of Taguchi design of experiment and grey relational analysis improves surface quality of drilled hole.

Keywords: metal matrix composite, drilling, optimization, step drill, surface roughness, burr height, hole diameter error

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Authors: Lu-Yin Lin

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The morphology of electroactive material is highly related to energy storage ability. Structure-directing agent (SDA) can design electroactive materials with favorable surface properties. Zeolitic imidazolate framework 67 (ZIF67) is one of the potential electroactive materials for energy storage devices. The SDA concept is less applied to designing ZIF67 derivatives in previous studies. An in-situ technique with ammonium fluoride (NH₄F) as SDA is proposed to produce a ZIF67 derivative with highly improved energy storage ability. Attracted by the effective in-situ technique, the NH₄F, ammonium bifluoride (NH₄HF₂), and ammonium tetrafluoroborate (NH₄BF₄) are first used as SDA to synthesize ZIF67 derivatives in one-step solution process as electroactive material of energy storage devices. The mechanisms of forming ZIF67 derivatives synthesized with different SDAs are discussed to explain the SDA effects on physical and electrochemical properties. The largest specific capacitance (CF) of 1527.0 Fg-¹ and the capacity of 296.9 mAhg-¹ are obtained for the ZIF67 derivative prepared using NH₄BF₄ as SDA. The energy storage device composed of the optimal ZIF67 derivative and carbon electrodes presents a maximum energy density of 15.1 Whkg-¹ at the power density of 857 Wkg-¹. The CF retention of 90% and Coulombic efficiency larger than 98% are also obtained after 5000 cycles.

Keywords: ammonium bifluoride, ammonium tetrafluoroborate, energy storage device, one-step solution process, structure-directing agent, zeolitic imidazolate framework 67

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Authors: A. Giani

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The current pedagogical culture recognizes an educational scope within the sports practices. It is widely accepted, in the pedagogical culture, that thanks to the acquisition and development of motor skills, it is also possible to exercise abilities that concern the way of facing and managing the difficulties of everyday life. Sport is a peculiar educational environment: the children have the opportunity to discover the possibilities of their body, to correlate with their peers, and to learn how to manage the rules and the relationship with authorities, such as coaches. Educational aspects of the sport concern both non-formal and formal educational environments. Coaches play a critical role in an agonistic sphere: exactly like the competencies developed by the children, coaches have to work on their skills to properly set up the educational scene. Facing these new educational tasks - which are not new per se, but new because they are brought back to awareness - a few questions arise: does the coach have adequate preparation? Is the training of the coach in this specific area appropriate? This contribution aims to explore the issue in depth by focusing on the reality of the Football School. Starting from a possible sense of pedagogical inadequacy detected during a series of meetings with several football clubs in Piedmont (Italy), there have been highlighted some important educational needs within the professional training of sports coaches. It is indeed necessary for the coach to know the processes underlying the educational relationship in order to better understand the centrality of the assessment during the educational intervention and to be able to manage the asymmetry in the coach-athlete relationship. In order to provide a response to these pedagogical needs, a formative plan has been designed to allow both an in-depth study of educational issues and a correct self-evaluation of certain pedagogical skills’ control levels, led by the coach. This plan has been based on particular practices, the Educational Practices of Pre-test (EPP), a specific version of community practices designed for the extracurricular activities. The above-mentioned practices realized through the use of texts meant as pre-tests, promoted a reflection within the group of coaches: they set up real and plausible sports experiences - in particular football, triggering a reflection about the relationship’s object, spaces, and methods. The characteristic aspect of pre-tests is that it is impossible to anticipate the reflection as it is necessarily connected to the personal experience and sensitivity, requiring a strong interest and involvement by participants: situations must be considered by the coaches as possible settings in which they could be found on the field.

Keywords: relational needs, values, responsibility, self-evaluation

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Authors: Peien Ma

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Bilingual effect/advantage theorized the positive effect of being bilingual on general cognitive abilities, but it was unknown which factors tend to modulate these bilingualism effects on working memory capacity. This study imposed empirical field research on a group of low-SES emerging bilinguals, Miao people, in the hill tribes of rural China to investigate whether bilingualism affected their verbal working memory performance. 20 Miao-Chinese bilinguals (13 girls and 7 boys with a mean age of 11.45, SD=1.67) and 20 Chinese monolingual peers (13 girls and 7 boys with a mean age of 11.6, SD=0.68) were recruited. These bilingual and monolingual juveniles, matched on age, sex, socioeconomic status, and educational status, completed a language background questionnaire and a standard forward and backward digit span test adapted from Wechsler Adult Intelligence Scale-Revised (WAIS-R). The results showed that bilinguals earned a significantly higher overall mean score of the task, suggesting the superiority of working memory ability over the monolinguals. And bilingual cognitive benefits were independent of proficiency levels in learners’ two languages. The results suggested that bilingualism enhances working memory in sequential bilinguals from low SES backgrounds and shed light on our understanding of the bilingual advantage from a psychological and social perspective.

Keywords: bilingual effects, heritage language, Miao/Hmong language Mandarin, working memory

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Authors: Sri Poedjiastoeti

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One of the traits of living beings is eating. As the living beings, people must provide their life by taking material. They must assimilate for themselves with substances. They grow and develop themselves by changing what they eat and digest into their own substance. This happened in the so-called eating. This article aims to analyze distinction between human beings and other infrahumans when facing and eating food. It uses the analytical description with metaphysical anthropology approach. As a result, to give the expression that eating is not simply to put food in mouth, chew and swallow it. Eating constitutes a sacred ceremonial if it is done in accordance with human dignity. They face food with distance and moderation as well as civilize or make their behaviour better for it. Accordingly, they are being to be human.

Keywords: human beings, behaviour, eating, dignity

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Authors: Neimenuo Kengurusie

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Human trafficking is considered a form of slavery in modern day era and a gross violation of human rights and one of the most organized crimes of the day transcending cultures, geography and time. Human trafficking is a highly complex phenomenon involving many actors like victims, survivors, their families, communities and third parties that recruit, transport and exploit the trafficked victims. It takes different forms such as child trafficking, trafficking for labour, trafficking for sexual exploitation, trafficking for organ transplantation etc. and affects virtually every corner of the world. This research draws on a variety of sources, including books, articles, journals, newspaper reports, human rights reports, online materials and interviews. In India, particularly the North East region, the issue of human trafficking has become a concern regionally, nationally and internationally. The focus of this paper is on the North Eastern part of India as it is a socially and economically backward region of the country which makes women and children susceptible to trafficking. Women and children from these regions are trafficked within and outside the state. Therefore, the paper seeks to explore the issue of human trafficking, especially trafficking of women and children in North East India, which receives insufficient attention in literature. The paper seeks to analyze and understand the trend and patterns of trafficking and the mechanisms that reinforces the process and perpetuates the phenomenon of trafficking considering the nature and scope of the problem. The paper also analyzes the anti-trafficking laws initiated by India and the North East states in particular for combating human trafficking in North East India.

Keywords: children, human trafficking, North East India, women

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Authors: Chih-Hung Chen, Yih-Shyang Cheng, Yu-Hsin Tu

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Holographic optical elements (HOEs) have recently been one of the most suitable components in optoelectronic technology owing to the requirement of the product system with compact size. Computer-generated holography (CGH) is a well-known technology for HOEs production. In some cases, a well-designed diffractive optical element with multifunctional components is also an important issue and needed for an advanced optoelectronic system. Spatial light modulator (SLM) is one of the key components that has great capability to display CGH pattern and is widely used in various applications, such as an image projection system. As mentioned to multifunctional components, such as phase and amplitude modulation of light, high-resolution hologram with multiple-exposure procedure is also one of the suitable candidates. However, holographic recording under multiple exposures, the diffraction efficiency of the final hologram is inevitably lower than that with single exposure process. In this study, a two-step holographic recording method, including the master hologram fabrication and the replicated hologram production, will be designed. Since there exist a reduction factor M² of diffraction efficiency in multiple-exposure holograms (M multiple exposures), so it seems that single exposure would be more efficient for holograms replication. In the second step of holographic replication, a stable optical system with one-shot copying is introduced. For commercial application, one may utilize this concept of holographic copying to obtain duplications of HOEs with higher optical performance.

Keywords: holographic replication, holography, one-shot copying, optical element

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Authors: Fuqiang Wang, Jun Liu, Liyan Cai

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This paper investigates the coordination of the conflicting two-stage low carbon supply chain consisting of upstream and downstream manufacturers. The conflict means that the upstream manufacturer takes action for carbon emissions reduction under carbon trading mechanism while the downstream manufacturer’s production cost rises. It assumes for the Stackelberg game that the upstream manufacturer plays as a leader and the downstream manufacturer does as a follower. Four kinds of the situation of decentralized decision making, centralized decision-making, the production cost sharing contract and the carbon emissions reduction revenue sharing contract under decentralized decision making are considered. The backward induction approach is adopted to solve the game. The results show that the more intense the conflict is, the lower the efficiency of carbon emissions reduction and the higher the retail price is. The optimal investment of the decentralized supply chain under the two contracts is unchanged and still lower than that of the centralized supply chain. Both the production cost sharing contract and the carbon emissions reduction revenue sharing contract cannot coordinate the supply chain, because that the sharing cost or carbon emissions reduction sharing revenue will transfer through the wholesale price mechanism. As a result, it requires more complicated contract forms to coordinate such a supply chain.

Keywords: cap-and-trade mechanism, carbon emissions reduction, conflict, supply chain coordination

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Authors: Siti Nur Syazni Mohd Zuki, Tan Ling Ling, Nina Suhaity Azmi, Chong Kwok Feng, Lee Yook Heng

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Nitrite (NO2-) ion is used prevalently as a preservative in processed meat. Elevated levels of nitrite also found in edible bird’s nests (EBNs). Consumption of NO2- ion at levels above the health-based risk may cause cancer in humans. Spectrophotometric Griess test is the simplest established standard method for NO2- ion detection, however, it requires careful control of pH of each reaction step and susceptible to strong oxidants and dyeing interferences. Other traditional methods rely on the use of laboratory-scale instruments such as GC-MS, HPLC and ion chromatography, which cannot give real-time response. Therefore, it is of significant need for devices capable of measuring nitrite concentration in-situ, rapidly and without reagents, sample pretreatment or extraction step. Herein, we constructed a microspheres-based microbial optode for visual quantitation of NO2- ion. Raoutella planticola, the bacterium expressing NAD(P)H nitrite reductase (NiR) enzyme has been successfully extracted by microbial technique from EBN collected from local birdhouse. The whole cells and the lipophilic Nile Blue chromoionophore were physically absorbed on the photocurable poly(n-butyl acrylate-N-acryloxysuccinimide) [poly (nBA-NAS)] microspheres, whilst the reduced coenzyme NAD(P)H was covalently immobilized on the succinimide-functionalized acrylic microspheres to produce a reagentless biosensing system. Upon the NiR enzyme catalyzes the oxidation of NAD(P)H to NAD(P)+, NO2- ion is reduced to ammonium hydroxide, and that a colour change from blue to pink of the immobilized Nile Blue chromoionophore is perceived as a result of deprotonation reaction increasing the local pH in the microspheres membrane. The microspheres-based optosensor was optimized with a reflectance spectrophotometer at 639 nm and pH 8. The resulting microbial bio-optode membrane could quantify NO2- ion at 0.1 ppm and had a linear response up to 400 ppm. Due to the large surface area to mass ratio of the acrylic microspheres, it allows efficient solid state diffusional mass transfer of the substrate to the bio-recognition phase, and achieve the steady state response as fast as 5 min. The proposed optical microbial biosensor requires no sample pre-treatment step and possesses high stability as the whole cell biocatalyst provides protection to the enzymes from interfering substances, hence it is suitable for measurements in contaminated samples.

Keywords: acrylic microspheres, microbial bio-optode, nitrite ion, reflectometric

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Authors: Eumsin Payan

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The article desires the Association of Southeast Asian Nations (ASEAN) to take interest in the policies and give importance to India over other powerful countries in the World, including powerful countries in Asia, comprising of: People’s Republic of China (PRC), Russia, and India countries with the ability to drive the Asian continent, specifically, the ASEAN Economic Community (AEC). (Japan was incapable of stepping up to become the leader of ASEAN due to the fact that Japan has created “wounds” from military history with too many countries in Asia, including wounds from the Greater East Asia War, combining with economic problems Japan is currently facing and also several natural disasters, therefore Japan is not considered a good option of our era.) China appears to be an option that stands out, which could be seen through countless published articles in the general public. However, this article desires to propose India as an option to develop and drive the relationship between ASEAN countries in the future development of Computer Science Technology and allow India to be the leader in driving the Asian Economy in place of China and the United States. As for Russia, its location is distant and apart from South East Asia. Moreover, Russia does not give as much importance to ASEAN. In this light, the author perceives that India already has the “Look East” policy. Therefore, it would be simple for ASEAN to look back at India by simply starting cooperation through policies related to collaboration in the areas of computer science. In effect, this will continuously adjust and improve the relationship towards cooperation in the areas of economics, society, and culture. Referring to the above, the author suggests a word that could be used to call the relationship between India and ASEAN, INSEAN or IN-SEAN. Hereinafter, the author hopes that Thailand, in the position of one in the five founders of ASEAN, could become the leader or be the entity that pushes forward the ASEAN policies that will increase the importance of looking towards India. India is an emerging giant that has the ability to step up in Asia. With the proficient use of English, India is able to pass on the knowledge and drive the ASEAN’s Economic relationship better than China or Russia, as faced with higher language barriers. Moreover, India has cultivated democratic civilization from the colonization of the British Empire, similar to other nations of Southeast Asia, which are familiar with various heritage cultures that the British has brought them. The most important aspect in the author’s perspective is the fact that India is not aggressive and that they have courtesy. Through developing policies of the East through the “Look East” policy, it enabled India to establish a more smooth relationship with Asian countries comparing to China. China has imposed harsh policies towards democracy to the land above the South China Sea, which directly affect the ASEAN countries. From the above reasons, India, therefore, is an appropriate option in the establishment of a closer relationship with ASEAN, as the author has proposed relationship as INSEAN or IN-SEAN.

Keywords: IN-SEAN, INSEAN, look west policy, look east policy, ASEAN, India

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Authors: Hoda Mahgoub, Abeer Hanafy

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Linagliptin (LNG) belongs to dipeptidyl-peptidase-4 (DPP-4) inhibitor class. DPP-4 inhibitors represent a new therapeutic approach for the treatment of type 2 diabetes in adults. The aim of this work was to develop and validate an accurate and reproducible HPLC method for the determination of LNG with high sensitivity in rat plasma. The method involved separation of both LNG and pindolol (internal standard) at ambient temperature on a Zorbax Eclipse XDB C18 column and a mobile phase composed of 75% methanol: 25% formic acid 0.1% pH 4.1 at a flow rate of 1.0 mL.min-1. UV detection was performed at 254nm. The method was validated in compliance with ICH guidelines and found to be linear in the range of 5–1000ng.mL-1. The limit of quantification (LOQ) was found to be 5ng.mL-1 based on 100µL of plasma. The variations for intra- and inter-assay precision were less than 10%, and the accuracy values were ranged between 93.3% and 102.5%. The extraction recovery (R%) was more than 83%. The method involved a single extraction step of a very small plasma volume (100µL). The assay was successfully applied to an in-vivo pharmacokinetic study of LNG in rats that were administered a single oral dose of 10mg.kg-1 LNG. The maximum concentration (Cmax) was found to be 927.5 ± 23.9ng.mL-1. The area under the plasma concentration-time curve (AUC0-72) was 18285.02 ± 605.76h.ng.mL-1. In conclusion, the good accuracy and low LOQ of the bioanalytical HPLC method were suitable for monitoring the full pharmacokinetic profile of LNG in rats. The main advantages of the method were the sensitivity, small sample volume, single-step extraction procedure and the short time of analysis.

Keywords: HPLC, linagliptin, pharmacokinetic study, rat plasma

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Authors: Marian Sagat, Mariana Remesikova

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In civil engineering, there is a problem how to industrially produce tensile membrane structures that are non-developable surfaces. Nondevelopable surfaces can only be developed with a certain error and we want to minimize this error. To that goal, the non-developable surfaces are cut into plates along to the geodesic curves. We propose a numerical algorithm for finding approximations of open geodesics on meshes and surfaces based on geodesic curvature flow. For practical reasons, it is important to automatize the choice of the time step. We propose a method for automatic setting of the time step based on the diagonal dominance criterion for the matrix of the linear system obtained by discretization of our partial differential equation model. Practical experiments show reliability of this method. Because approximation of the model is made by numerical method based on classic derivatives, it is necessary to solve obstacles which occur for meshes with sharp corners. We solve this problem for big family of meshes with sharp corners via special rotations which can be seen as partial unfolding of the mesh. In practical applications, it is required that the approximation of geodesic has its vertices only on the edges of the mesh. This problem is solved by a specially designed pointing tracking algorithm. We also partially solve the problem of finding geodesics on meshes with holes. We implemented the whole algorithm in Rhinoceros (commercial 3D computer graphics and computer-aided design software ). It is done by using C# language as C# assembly library for Grasshopper, which is plugin in Rhinoceros.

Keywords: geodesic, geodesic curvature flow, mesh, Rhinoceros software

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Authors: Haiqiang Song, Huiqing Liu

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The Doseo basin in Chad, Central Africa is one of the most important oil and gas blocks in the world. However, the low degree of oil and gas exploration and the lack of relevant geological data restrict the understanding and resource evaluation of the basin. To further develop the Doseo basin efficiently, it is urgent to deeply analyze the source rock characteristics and hydrocarbon generation potential of the Doseo basin. Based on seismic and drilling data in recent years, this paper systematically evaluates the geochemical characteristics of source rocks and their generated oils in Doseo Basin, explores the development, distribution, and evolution characteristics of source rocks, and evaluates the exploration potential of Doseo Basin according to the hydrocarbon enrichment law. The results show that the Lower Cretaceous Baliemian and Apudian source rocks in Doseo Basin are well developed, with high organic matter abundance (average TOC≥3%) and good organic matter types (type I~II), which are the main development layers of source rocks, but the organic matter maturity is generally low (Ro of the drilled source rocks is mainly between 0.4%~0.8%). The planar structure also shows that the main hydrocarbon accumulation mode in Doseo sag is the forward tectonic reservoirs such as near source anticlines and faulted noses. Finally, it is estimated that the accumulative resources of the main source rocks in the Doseo Basin are about 4.33× 108T in Apudite and Balim terrace layers. The results of this study will help guide the next step of oil and gas exploration, which is expected to drive the next step of oil and gas development.

Keywords: Doseo basin, lower cretaceous, source rock characteristics, developmental characteristics, hydrocarbon generation potential

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Authors: Camille Perréard, Yoann Ladner, Fanny D'Orlyé, Stéphanie Descroix, Vélan Taniga, Anne Varenne, Cédric Guyon, Michael. Tatoulian, Frédéric Kanoufi, Cyrine Slim, Sophie Griveau, Fethi Bedioui

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The development of micro total analysis systems is of major interest for contaminant and biomarker analysis. As a lab-on-chip integrates all steps of an analysis procedure in a single device, analysis can be performed in an automated format with reduced time and cost, while maintaining performances comparable to those of conventional chromatographic systems. Moreover, these miniaturized systems are either compatible with field work or glovebox manipulations. This work is aimed at developing an analytical microsystem for trace and ultra trace quantitation in complex matrices. The strategy consists in the integration of a sample pretreatment step within the lab-on-chip by a confinement zone where selective ligands are immobilized for target extraction and preconcentration. Aptamers were chosen as selective ligands, because of their high affinity for all types of targets (from small ions to viruses and cells) and their ease of synthesis and functionalization. This integrated target extraction and concentration step will be followed in the microdevice by an electrokinetic separation step and an on-line detection. Polymers consisting of cyclic olefin copolymer (COC) or fluoropolymer (Dyneon THV) were selected as they are easy to mold, transparent in UV-visible and have high resistance towards solvents and extreme pH conditions. However, because of their low chemical reactivity, surface treatments are necessary. For the design of this miniaturized diagnostics, we aimed at modifying the microfluidic system at two scales : (1) on the entire surface of the microsystem to control the surface hydrophobicity (so as to avoid any sample wall adsorption) and the fluid flows during electrokinetic separation, or (2) locally so as to immobilize selective ligands (aptamers) on restricted areas for target extraction and preconcentration. We developed different novel strategies for the surface functionalization of COC and Dyneon, based on plasma, chemical and /or electrochemical approaches. In a first approach, a plasma-induced immobilization of brominated derivatives was performed on the entire surface. Further substitution of the bromine by an azide functional group led to covalent immobilization of ligands through “click” chemistry reaction between azides and terminal alkynes. COC and Dyneon materials were characterized at each step of the surface functionalization procedure by various complementary techniques to evaluate the quality and homogeneity of the functionalization (contact angle, XPS, ATR). With the objective of local (micrometric scale) aptamer immobilization, we developed an original electrochemical strategy on engraved Dyneon THV microchannel. Through local electrochemical carbonization followed by adsorption of azide-bearing diazonium moieties and covalent linkage of alkyne-bearing aptamers through click chemistry reaction, typical dimensions of immobilization zones reached the 50 µm range. Other functionalization strategies, such as sol-gel encapsulation of aptamers, are currently investigated and may also be suitable for the development of the analytical microdevice. The development of these functionalization strategies is the first crucial step in the design of the entire microdevice. These strategies allow the grafting of a large number of molecules for the development of new analytical tools in various domains like environment or healthcare.

Keywords: alkyne-azide click chemistry (CuAAC), electrochemical modification, microsystem, plasma bromination, surface functionalization, thermoplastic polymers

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Authors: Kanika Gupta, Ashok Kumar

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Biofilms are dense, highly hydrated cell clusters that are irreversibly attached to a substratum, to an interface or to each other, and are embedded in a self-produced gelatinous matrix composed of extracellular polymeric substances. Research in biofilm field has become very significant, as biofilm has shown high mechanical resilience and resistance to antibiotic treatment and constituted as a significant problem in both healthcare and other industry related to microorganisms. The massive information both stated and hidden in the biofilm literature are growing exponentially therefore it is not possible for researchers and practitioners to automatically extract and relate information from different written resources. So, the current work proposes and discusses the use of text mining techniques for the extraction of information from biofilm literature corpora containing 34306 documents. It is very difficult and expensive to obtain annotated material for biomedical literature as the literature is unstructured i.e. free-text. Therefore, we considered unsupervised approach, where no annotated training is necessary and using this approach we developed a system that will classify the text on the basis of growth and development, drug effects, radiation effects, classification and physiology of biofilms. For this, a two-step structure was used where the first step is to extract keywords from the biofilm literature using a metathesaurus and standard natural language processing tools like Rapid Miner_v5.3 and the second step is to discover relations between the genes extracted from the whole set of biofilm literature using pubmed.mineR_v1.0.11. We used unsupervised approach, which is the machine learning task of inferring a function to describe hidden structure from 'unlabeled' data, in the above-extracted datasets to develop classifiers using WinPython-64 bit_v3.5.4.0Qt5 and R studio_v0.99.467 packages which will automatically classify the text by using the mentioned sets. The developed classifiers were tested on a large data set of biofilm literature which showed that the unsupervised approach proposed is promising as well as suited for a semi-automatic labeling of the extracted relations. The entire information was stored in the relational database which was hosted locally on the server. The generated biofilm vocabulary and genes relations will be significant for researchers dealing with biofilm research, making their search easy and efficient as the keywords and genes could be directly mapped with the documents used for database development.

Keywords: biofilms literature, classifiers development, text mining, unsupervised learning approach, unstructured data, relational database

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Authors: Otana A. Jakpor

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Air pollution is without a doubt one of the gravest environmental threats the world is facing today in terms of its sheer toll on human lives. Each year an estimated 70,000 Americans lose their lives to air pollution -- a number equal to deaths from both breast and prostate cancer combined. Since Americans spend nearly 90% of their time indoors, more research is needed on indoor air pollution and common exposures such as candles. Paraffin wax is a by-product of petroleum, and similarities have been observed between fine particulate emissions from paraffin candles and diesel exhaust. The purpose of this study is to determine whether or not paraffin candles are a major potential source of indoor air pollution. Furthermore, this study aims to determine whether or not soy candles are a safer, cleaner alternative to paraffin candles.

Keywords: soy candle, soy, paraffin candle, paraffin

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Authors: Ömer Faruk Ada, Türker Baş, M. Yaman Öztek

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In this study, we aim to investigate the skills to be owned by procurement professionals in order to fulfill their developing and changing role completely. Market conditions, competitive pressure, and high financial costs make it more important than ever for organizations to be able to use resources more efficiently. Research shows that procurement expenses consist more than 50 % of the operating expenses. With increasing profit impact of procurement, reviewing the position of the procurement function within the organization has become inevitable. This study is significant as it indicates the necessary skills that procurement professionals must have to keep in step with the transformation of procurement units from transaction oriented to value chain oriented. In this study, the transformation of procurement is investigated from the perspective of procurement professionals and we aim to answer following research questions: • How do procurement professionals perceive their role within the organization? • How has their role changed and what challenges have they had to face? • What portfolio of skills do they believe will enable them to fulfill their role effectively? Literature review consists of the first part of the study by investigating the changing role of procurement from different perspectives. In the second part, we present the results of the in-depth interviews with 15 procurement professionals and we used descriptive analysis as a methodology. In the light of these results, we classified procurement skills under operational, tactical and strategic levels and Procurement Skills Framework has been developed. This study shows the differences in the perception of purchasing by professionals and the organizations. The differences in the perception are considered as an important barrier beyond the procurement transformation. Although having the necessary skills has a significant effect for procurement professionals to fulfill their role completely and keep in step with the transformation of the procurement function, It is not the only factor and the degree of high-level management and organizational support has also a direct impact during this transformation.

Keywords: procuement skills, procurement transformation, strategic procurement, value chain

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Authors: Damiano Omari, Topirian Kerempe, Dibo Sama, Walter Wafula, Sharon Chepkoech, Chrispine Juma, Gilbert Kirui, Simon Mburu, Susan Keino

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The One Health concept was officially adopted by the international organizations and scholarly bodies in 1984. It aims at combining human, animal and environmental components to address global health challenges. Using collaborative efforts optimal health to people, animals, and the environment can be achieved. One health approach plays a significant approach role in prevention and control of zoonosis diseases. It has also been noted that 75% of new emerging human infectious diseases are zoonotic. In Kenya, one health has been embraced and strongly advocated for by One Health East and Central Africa (OHCEA). It was inaugurated on 17th of October 2010 at a historic meeting facilitated by USAID with participants from 7 public health schools, seven faculties of veterinary medicine in Eastern Africa and 2 American universities (Tufts and University of Minnesota) in addition to respond project staff. The study was conducted in Loitoktok Sub County, specifically in the Amboseli Ecosystem. The Amboseli ecosystem covers an area of 5,700 square kilometers and stretches between Mt. Kilimanjaro, Chyulu Hills, Tsavo West National park and the Kenya/Tanzania border. The area is arid to semi-arid and is more suitable for pastoralism with a high potential for conservation of wildlife and tourism enterprises. The ecosystem consists of the Amboseli National Park, which is surrounded by six group ranches which include Kimana, Olgulului, Selengei, Mbirikani, Kuku and Rombo in Loitoktok District. The Manyatta of study was Osiram Cultural Manyatta in Mbirikani group ranch. Apart from visiting the Manyatta, we also visited the sub-county hospital, slaughter slab, forest service, Kimana market, and the Amboseli National Park. The aim of the study was to identify the one health issues facing the community. This was done by a conducting a community needs assessment and prioritization. Different methods were used in data collection for the qualitative and numerical data. They include among others; key informant interviews and focus group discussions. We also guided the community members in drawing their Resource Map this helped identify the major resources in their land and also help them identify some of the issues they were facing. Matrix piling, root cause analysis, and force field analysis tools were used to establish the one health related priority issues facing community members. Skits were also used to present to the community interventions to the major one health issues. Some of the prioritized needs among the community were water scarcity and inadequate markets for their beadwork. The group intervened on the various needs of the Manyatta. For water scarcity, we educated the community on water harvesting methods using gutters as well as proper storage by the use of tanks and earth dams. The community was also encouraged to recycle and conserve water. To improve markets; we educated the community to upload their products online, a page was opened for them and uploading the photos was demonstrated to them. They were also encouraged to be innovative to attract more clients.

Keywords: Amboseli ecosystem, community interventions, community needs assessment and prioritization, one health issues

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Authors: Elodie Niemiec, Philippe Champagne, Jean-Francois Blach, Philippe Moreau, Anthony Thuault, Arnaud Tricoteaux

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Hygiene of equipment in contact with users is an important issue in the railroad industry. The numerous cleanings to eliminate bacteria and dirt cost a lot. Besides, mechanical solicitations on contact parts are observed daily. It should be interesting to elaborate on a self-cleaning and antibacterial coating with sufficient adhesion and good resistance against mechanical and chemical solicitations. Thus, a Hauts-de-France and Maubeuge Val-de-Sambre conurbation authority co-financed Ph.D. thesis has been set up since October 2017 based on anterior studies carried by the Laboratory of Ceramic Materials and Processing. To accomplish this task, a soft chemical route has been implemented to bring a lotus effect on metallic substrates. It involves nanometric liquid zinc oxide synthesis under 100°C. The originality here consists in a variation of surface texturing by modification of the synthesis time of the species in solution. This helps to adjust wettability. Nanostructured zinc oxide has been chosen because of the inherent photocatalytic effect, which can activate organic substance degradation. Two methods of heating have been compared: conventional and microwave assistance. Tested subtracts are made of stainless steel to conform to transport uses. Substrate preparation was the first step of this protocol: a meticulous cleaning of the samples is applied. The main goal of the elaboration protocol is to fix enough zinc-based seeds to make them grow during the next step as desired (nanorod shaped). To improve this adhesion, a silica gel has been formulated and optimized to ensure chemical bonding between substrate and zinc seeds. The last step consists of deposing a wide carbonated organosilane to improve the superhydrophobic property of the coating. The quasi-proportionality between the reaction time and the nanorod length will be demonstrated. Water Contact (superior to 150°) and Roll-off Angle at different steps of the process will be presented. The antibacterial effect has been proved with Escherichia Coli, Staphylococcus Aureus, and Bacillus Subtilis. The mortality rate is found to be four times superior to a non-treated substrate. Photocatalytic experiences were carried out from different dyed solutions in contact with treated samples under UV irradiation. Spectroscopic measurements allow to determinate times of degradation according to the zinc quantity available on the surface. The final coating obtained is, therefore, not a monolayer but rather a set of amorphous/crystalline/amorphous layers that have been characterized by spectroscopic ellipsometry. We will show that the thickness of the nanostructured oxide layer depends essentially on the synthesis time set in the hydrothermal growth step. A green, easy-to-process and control coating with self-cleaning and antibacterial properties has been synthesized with a satisfying surface structuration.

Keywords: antibacterial, biomimetism, soft-chemistry, zinc oxide

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Authors: Viviana Ventre, Giacomo Di Tollo, Roberta Martino

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The portfolio selection problem includes the evaluation of many criteria that are difficult to compare directly and is characterized by uncertain elements. The portfolio selection problem can be modeled as a group decision problem in which several experts are invited to present their assessment. In this context, it is important to study and analyze the process of reaching a consensus among group members. Indeed, due to the various diversities among experts, reaching consensus is not necessarily always simple and easily achievable. Moreover, the concept of consensus is accompanied by the concept of false consensus, which is particularly interesting in the dynamics of group decision-making processes. False consensus can alter the evaluation and selection phase of the alternative and is the consequence of the decision maker's inability to recognize that his preferences are conditioned by subjective structures. The present work aims to investigate the dynamics of consensus attainment in a group decision problem in which equivalent portfolios are proposed. In particular, the study aims to analyze the impact of the subjective structure of the decision-maker during the evaluation and selection phase of the alternatives. Therefore, the experimental framework is divided into three phases. In the first phase, experts are sent to evaluate the characteristics of all portfolios individually, without peer comparison, arriving independently at the selection of the preferred portfolio. The experts' evaluations are used to obtain individual Analytical Hierarchical Processes that define the weight that each expert gives to all criteria with respect to the proposed alternatives. This step provides insight into how the decision maker's decision process develops, step by step, from goal analysis to alternative selection. The second phase includes the description of the decision maker's state through Markov chains. In fact, the individual weights obtained in the first phase can be reviewed and described as transition weights from one state to another. Thus, with the construction of the individual transition matrices, the possible next state of the expert is determined from the individual weights at the end of the first phase. Finally, the experts meet, and the process of reaching consensus is analyzed by considering the single individual state obtained at the previous stage and the false consensus bias. The work contributes to the study of the impact of subjective structures, quantified through the Analytical Hierarchical Process, and how they combine with the false consensus bias in group decision-making dynamics and the consensus reaching process in problems involving the selection of equivalent portfolios.

Keywords: analytical hierarchical process, consensus building, false consensus effect, markov chains, portfolio selection problem

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Authors: Taylan Kabbani, Ekrem Duman

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The design of adaptive systems that take advantage of financial markets while reducing the risk can bring more stagnant wealth into the global market. However, most efforts made to generate successful deals in trading financial assets rely on Supervised Learning (SL), which suffered from various limitations. Deep Reinforcement Learning (DRL) offers to solve these drawbacks of SL approaches by combining the financial assets price "prediction" step and the "allocation" step of the portfolio in one unified process to produce fully autonomous systems capable of interacting with its environment to make optimal decisions through trial and error. In this paper, a continuous action space approach is adopted to give the trading agent the ability to gradually adjust the portfolio's positions with each time step (dynamically re-allocate investments), resulting in better agent-environment interaction and faster convergence of the learning process. In addition, the approach supports the managing of a portfolio with several assets instead of a single one. This work represents a novel DRL model to generate profitable trades in the stock market, effectively overcoming the limitations of supervised learning approaches. We formulate the trading problem, or what is referred to as The Agent Environment as Partially observed Markov Decision Process (POMDP) model, considering the constraints imposed by the stock market, such as liquidity and transaction costs. More specifically, we design an environment that simulates the real-world trading process by augmenting the state representation with ten different technical indicators and sentiment analysis of news articles for each stock. We then solve the formulated POMDP problem using the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm, which can learn policies in high-dimensional and continuous action spaces like those typically found in the stock market environment. From the point of view of stock market forecasting and the intelligent decision-making mechanism, this paper demonstrates the superiority of deep reinforcement learning in financial markets over other types of machine learning such as supervised learning and proves its credibility and advantages of strategic decision-making.

Keywords: the stock market, deep reinforcement learning, MDP, twin delayed deep deterministic policy gradient, sentiment analysis, technical indicators, autonomous agent

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Authors: Baki Cicek, Umit Calisir

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Carbazoles have been replaced lots of studies from 1960's to present and also still continues. In 1987, the first diode device had been developed. Thanks to that study, light emitting devices have been investigated and developed and also have been used on commercial applications. Nowadays, OLED (Organic Light Emitting Diodes) technology is using on lots of electronic screen such as (mobile phone, computer monitors, televisions, etc.) Carbazoles were subject a lot of study as a semiconductor material. Although this technology is used commen and widely, it is still development stage. Metal complexes of these compounds are using at pigment dyes because of colored substances, polymer technology, medicine industry, agriculture area, preparing rocket fuel-oil, determine some of biological events, etc. Becides all of these to preparing of schiff base synthesis is going on intensely. In this study, some of novel carbazole schiff bases were synthesized starting from carbazole. For that purpose, firstly, carbazole was alkylated. After purification of N-substituted-carbazole was nitrated to sythesized 3-nitro-N-substituted and 3,6-dinitro-N-substituted carbazoles. At next step, nitro group/groups were reduced to amines. Purified with using a type of silica gel-column chromatography. At the last step of our study, with sythesized 3,6-diamino-N-substituted carbazoles and 3-amino-N-substituted carbazoles were reacted with aldehydes to condensation reactions. 3-(imino-p-hydroxybenzyl)-N-isobutyl -carbazole, 3-(imino-2,3,4-trimethoxybenzene)-N-butylcarbazole, 3-(imino-3,4-dihydroxybenzene)-N-octylcarbazole, 3-(imino-2,3-dihydroxybenzene)-N-octylkarbazole and 3,6-di(α-imino-β-naphthol) -N-hexylcarbazole compounds were synthesized. All of synthesized compounds were characterized with FT-IR, 1H-NMR, 13C-NMR, and LC-MS.

Keywords: carbazole, carbazol schiff base, condensation reactions, OLED

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Authors: Vasujeet Singh, Pruthiviraj Nemalipuri, Vivek Vitankar, Harish Chandra Das

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For the correct prediction of thermal and hydraulic performance (bed voidage, suspension density, pressure drop, heat transfer, and combustion kinetics), one should incorporate the correct parameters in the computational fluid dynamics simulation of a fluidized bed gasifier. Scarcity of fossil fuels, and to fulfill the energy demand of the increasing population, researchers need to shift their attention to the alternative to fossil fuels. The current research work focuses on hydrodynamics behavior and gasification of sawdust inside a 2D industrial scale FBG using the Eulerian-Eulerian multifluid model. The present numerical model is validated with experimental data. Further, this model extended for the prediction of gasification characteristics of sawdust by incorporating eight heterogeneous moisture release, volatile cracking, tar cracking, tar oxidation, char combustion, CO₂ gasification, steam gasification, methanation reaction, and five homogeneous oxidation of CO, CH₄, H₂, forward and backward water gas shift (WGS) reactions. In the result section, composition of gasification products is analyzed, along with the hydrodynamics of sawdust and sand phase, heat transfer between the gas, sand and sawdust, reaction rates of different homogeneous and heterogeneous reactions is being analyzed along the height of the domain.

Keywords: devolatilization, Eulerian-Eulerian, fluidized bed gasifier, mathematical modelling, sawdust gasification

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Authors: Robert Pečenko, Karin Tomažič, Igor Planinc, Sabina Huč, Tomaž Hozjan

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Timber is favourable structural material due to high strength to weight ratio, recycling possibilities, and green credentials. Despite being flammable material, it has relatively high fire resistance. Everyday engineering practice around the word is based on an outdated design of timber structures considering standard fire exposure, while modern principles of performance-based design enable use of advanced non-standard fire curves. In Europe, standard for fire design of timber structures EN 1995-1-2 (Eurocode 5) gives two methods, reduced material properties method and reduced cross-section method. In the latter, fire resistance of structural elements depends on the effective cross-section that is a residual cross-section of uncharred timber reduced additionally by so called zero strength layer. In case of standard fire exposure, Eurocode 5 gives a fixed value of zero strength layer, i.e. 7 mm, while for non-standard parametric fires no additional comments or recommendations for zero strength layer are given. Thus designers often implement adopted 7 mm rule also for parametric fire exposure. Since the latest scientific evidence suggests that proposed value of zero strength layer can be on unsafe side for standard fire exposure, its use in the case of a parametric fire is also highly questionable and more numerical and experimental research in this field is needed. Therefore, the purpose of the presented study is to use advanced calculation methods to investigate the thickness of zero strength layer and parametric charring rates used in effective cross-section method in case of parametric fire. Parametric studies are carried out on a simple solid timber beam that is exposed to a larger number of parametric fire curves Zero strength layer and charring rates are determined based on the numerical simulations which are performed by the recently developed advanced two step computational model. The first step comprises of hygro-thermal model which predicts the temperature, moisture and char depth development and takes into account different initial moisture states of timber. In the second step, the response of timber beam simultaneously exposed to mechanical and fire load is determined. The mechanical model is based on the Reissner’s kinematically exact beam model and accounts for the membrane, shear and flexural deformations of the beam. Further on, material non-linear and temperature dependent behaviour is considered. In the two step model, the char front temperature is, according to Eurocode 5, assumed to have a fixed temperature of around 300°C. Based on performed study and observations, improved levels of charring rates and new thickness of zero strength layer in case of parametric fires are determined. Thus, the reduced cross section method is substantially improved to offer practical recommendations for designing fire resistance of timber structures. Furthermore, correlations between zero strength layer thickness and key input parameters of the parametric fire curve (for instance, opening factor, fire load, etc.) are given, representing a guideline for a more detailed numerical and also experimental research in the future.

Keywords: advanced numerical modelling, parametric fire exposure, timber structures, zero strength layer

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Authors: Raya Sulaiman

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Critical discourse analysis investigates how discourse is used to abuse power relationships. Political debates constitute discourses which mirror aspects of ideologies. The Arab world has been one of the most unsettled zones in the world and has dominated global politics due to the Arab revolutions which started in 2010. This study aimed at uncovering the ideological intentions in the formulation and circulation of hegemonic political ideology in the TV political debates of the 2011 to 2012 Yemen revolution, how ideology was used as a tool of hegemony. The study specifically examined the ideologies associated with the use of protesters as a social actor. Data of the study consisted of four debates (17350 words) from four live debate programs: The Opposite Direction, In Depth, Behind the News and the Revolution Talk that were staged at Al Jazeera TV channel between 2011 and 2012. Data was readily transcribed by Al Jazeera online. Al Jazeera was selected for the study because it is the most popular TV network in the Arab world and has a strong presence, especially during the Arab revolutions. Al Jazeera has also been accused of inciting protests across the Arab region. Two debate sites were identified in the data: government and anti-government. The government side represented the president Ali Abdullah Saleh and his regime while the anti-government side represented the gathering squares who demanded the president to ‘step down’. The study analysed verbal discourse aspects of the debates using critical discourse analysis: aspects from the Social Actor Network model of van Leeuwen. This framework provides a step-by-step analysis model, and analyses discourse from specific grammatical processes into broader semantic issues. It also provides representative findings since it considers discourse as representative and reconstructed in social practice. Study findings indicated that Al Jazeera and the anti-government had similarities in terms of the ideological intentions related to the protesters. Al Jazeera victimized and incited the protesters which were similar to the anti-government. Al Jazeera used assimilation, nominalization, and active role allocation as the linguistic aspects in order to reach its ideological intentions related to the protesters. Government speakers did not share the same ideological intentions with Al Jazeera. Study findings indicated that Al Jazeera had excluded the government from its debates causing a violation to its slogan, the opinion, and the other opinion. This study implies the powerful role of discourse in shaping ideological media intentions and influencing the media audience.

Keywords: Al Jazeera network, critical discourse analysis, ideology, Yemeni revolution

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Authors: Yash Jain

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The US Center for Disease Control has recommended wearing masks to slow the spread of the virus. The research uses a video feed from a camera to conduct real-time classifications of whether or not a human is correctly wearing a mask, incorrectly wearing a mask, or not wearing a mask at all. Utilizing two distinct datasets from the open-source website Kaggle, a mask detection network had been trained. The first dataset that was used to train the model was titled 'Face Mask Detection' on Kaggle, where the dataset was retrieved from and the second dataset was titled 'Face Mask Dataset, which provided the data in a (YOLO Format)' so that the TinyYoloV3 model could be trained. Based on the data from Kaggle, two machine learning models were implemented and trained: a Tiny YoloV3 Real-time model and a two-stage neural network classifier. The two-stage neural network classifier had a first step of identifying distinct faces within the image, and the second step was a classifier to detect the state of the mask on the face and whether it was worn correctly, incorrectly, or no mask at all. The TinyYoloV3 was used for the live feed as well as for a comparison standpoint against the previous two-stage classifier and was trained using the darknet neural network framework. The two-stage classifier attained a mean average precision (MAP) of 80%, while the model trained using TinyYoloV3 real-time detection had a mean average precision (MAP) of 59%. Overall, both models were able to correctly classify stages/scenarios of no mask, mask, and incorrectly worn masks.

Keywords: datasets, classifier, mask-detection, real-time, TinyYoloV3, two-stage neural network classifier

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Authors: Lasha Mskhaladze, Guram Burchuladze, Khvicha Datunashvili

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Technological changes have an impact not only on economic but also on social elements of society which in turn has created new challenges for states’ political systems and their regimes. As a result of unprecedented growth of information technologies and communications digital democracy and electronic governance have emerged. Nowadays effective state functioning cannot be imagined without electronic governance. In Georgia, special attention is paid to the development of such new systems and establishment of electronic governance. Therefore, in parallel to intensive development of information technologies an important priority for public sector in Georgia is the development of electronic governance. In spite of the fact that today Georgia with its economic indicators satisfies the standards of western informational society, and major part of its gross domestic product comes from the service sector (59.6%), it still remains a backward country on the world map in terms of information technologies and electronic governance. E-transparency in Georgia should be based on such parameters as government accountability when the government provides citizens information about their activities; e-participation which involves government’s consideration of external expert assessments; cooperation between officials and citizens in order to solve national problems. In order to improve electronic systems the government should actively do the following: Fully develop electronic programs concerning HR and exchange of data between public organizations; develop all possible electronic services; improve existing electronic programs; make electronic services available on different mobile platforms (iPhone, Android, etc.).

Keywords: electronic transparency, electronic services, information technology, information society, electronic systems

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Authors: Tarek Abdoun, Ricardo Dobry

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This paper is a systematic effort to clarify why field liquefaction charts based on Seed and Idriss’ Simplified Procedure work so well. This is a necessary step toward integrating the states of the art (SOA) and practice (SOP) for evaluating liquefaction and its effects. The SOA relies mostly on laboratory measurements and correlations with void ratio and relative density of the sand. The SOP is based on field measurements of penetration resistance and shear wave velocity coupled with empirical or semi-empirical correlations. This gap slows down further progress in both SOP and SOA. The paper accomplishes its objective through: a literature review of relevant aspects of the SOA including factors influencing threshold shear strain and pore pressure buildup during cyclic strain-controlled tests; a discussion of factors influencing field penetration resistance and shear wave velocity; and a discussion of the meaning of the curves in the liquefaction charts separating liquefaction from no liquefaction, helped by recent full-scale and centrifuge results. It is concluded that the charts are curves of constant cyclic strain at the lower end (Vs1 < 160 m/s), with this strain being about 0.03 to 0.05% for earthquake magnitude, Mw ≈ 7. It is also concluded, in a more speculative way, that the curves at the upper end probably correspond to a variable increasing cyclic strain and Ko, with this upper end controlled by over consolidated and preshaken sands, and with cyclic strains needed to cause liquefaction being as high as 0.1 to 0.3%. These conclusions are validated by application to case histories corresponding to Mw ≈ 7, mostly in the San Francisco Bay Area of California during the 1989 Loma Prieta earthquake.

Keywords: permeability, lateral spreading, liquefaction, centrifuge modeling, shear wave velocity charts

Procedia PDF Downloads 282

Authors: Priyanka Chaudhary, M. Rizwan

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This paper presents a grid synchronization technique based on adaptive notch filter for SPV (Solar Photovoltaic) system along with MPPT (Maximum Power Point Tracking) techniques. An efficient grid synchronization technique offers proficient detection of various components of grid signal like phase and frequency. It also acts as a barrier for harmonics and other disturbances in grid signal. A reference phase signal synchronized with the grid voltage is provided by the grid synchronization technique to standardize the system with grid codes and power quality standards. Hence, grid synchronization unit plays important role for grid connected SPV systems. As the output of the PV array is fluctuating in nature with the meteorological parameters like irradiance, temperature, wind etc. In order to maintain a constant DC voltage at VSC (Voltage Source Converter) input, MPPT control is required to track the maximum power point from PV array. In this work, a variable step size P & O (Perturb and Observe) MPPT technique with DC/DC boost converter has been used at first stage of the system. This algorithm divides the dPpv/dVpv curve of PV panel into three separate zones i.e. zone 0, zone 1 and zone 2. A fine value of tracking step size is used in zone 0 while zone 1 and zone 2 requires a large value of step size in order to obtain a high tracking speed. Further, adaptive notch filter based control technique is proposed for VSC in PV generation system. Adaptive notch filter (ANF) approach is used to synchronize the interfaced PV system with grid to maintain the amplitude, phase and frequency parameters as well as power quality improvement. This technique offers the compensation of harmonics current and reactive power with both linear and nonlinear loads. To maintain constant DC link voltage a PI controller is also implemented and presented in this paper. The complete system has been designed, developed and simulated using SimPower System and Simulink toolbox of MATLAB. The performance analysis of three phase grid connected solar photovoltaic system has been carried out on the basis of various parameters like PV output power, PV voltage, PV current, DC link voltage, PCC (Point of Common Coupling) voltage, grid voltage, grid current, voltage source converter current, power supplied by the voltage source converter etc. The results obtained from the proposed system are found satisfactory.

Keywords: solar photovoltaic systems, MPPT, voltage source converter, grid synchronization technique

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