Search results for: free vibration response
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8811

Search results for: free vibration response

5211 Spin-Polarized Investigation of Ferromagnetism on Magnetic Semiconductors MnxCa1-xS in the Rock-salt Phase

Authors: B. Ghebouli, M. A. Ghebouli, H. Choutri, M. Fatmi, L. Louail

Abstract:

The structural, elastic, electronic and magnetic properties of the diluted magnetic semiconductors MnxCa1-xS in the rock-salt phase have been investigated using first-principles calculations. Features such as lattice constant, bulk modulus, elastic constants, spin-polarized band structure, total and local densities of states have been computed. We predict the values of the exchange constants and the band edge spin splitting of the valence and conduction bands. The hybridization between S-3p and Mn-3d produces small local magnetic moment on the nonmagnetic Ca and S sites. The ferromagnetism is induced due to the exchange splitting of S-3p and Mn-3d hybridized bands. The total magnetic moment per Mn of MnxCa1-xS is 4.4µB and is independent of the Mn concentration. The unfilled Mn -3d levels reduce the local magnetic moment of Mn from its free space charge value of 5µB to 4.4µB due to 3p–3d hybridization.

Keywords: semiconductors, Ab initio calculations, band-structure, magnetic properties

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5210 The Speech Act Responses of Students on the Teacher’s Request in the EFL Classroom

Authors: Agis Andriani

Abstract:

To create an effective teaching condition, the teacher requests the students as the instruction to guide the them interactively in the learning activities in the classroom. This study involves 160 Indonesian students who study English in the university, as participants in the discourse completion test, and ten of them are interviewed. The result shows that when the students response the teacher’s request, it realizes assertives, directives, commisives, expressives, and declaratives. These indicate that the students are active, motivated, and responsive in the learning process, although in the certain condition these responses are to prevent their faces from the shyness of their silence in interaction. Therefore, it needs the teacher’s creativity to give the conducive atmosphere in order to support the students’ participation in learning English.

Keywords: discourse completion test, effective teaching, request, teacher’s creativity

Procedia PDF Downloads 407
5209 A Connected Structure of All-Optical Logic Gate “NOT-AND”

Authors: Roumaissa Derdour, Lebbal Mohamed Redha

Abstract:

We present a study of the transmission of the all-optical logic gate using a structure connected with a triangular photonic crystal lattice that is improved. The proposed logic gate consists of a photonic crystal nano-resonator formed by changing the size of the air holes. In addition to the simplicity, the response time is very short, and the designed nano-resonator increases the bit rate of the logic gate. The two-dimensional finite difference time domain (2DFDTD) method is used to simulate the structure; the transmission obtained is about 98% with very negligible losses. The proposed photonic crystal AND logic gate is widely used in future integrated optical microelectronics.

Keywords: logic gates, photonic crystals, optical integrated circuits, resonant cavities

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5208 Investor Sentiment and Commodity Trading Advisor Fund Performance

Authors: Tian Lan

Abstract:

Arbitrageurs participate in a variety of techniques in response to the existence of fluctuating sentiment, resulting in sparse sentiment exposures. This paper found that Commodity Trading Advisor (CTA) funds in the top decile rated by sentiment beta outperformed those in the bottom decile by 0.33% per month on a risk-adjusted basis, with the difference being larger among skilled managers. This paper also discovered that around ten percent of Commodity Trading Advisor (CTA) funds could accurately predict market sentiment, which has a positive correlation with fund sentiment beta and acts as a determinant in fund performance. Instead of betting against mispricing, this research demonstrates that a competent manager can achieve remarkable returns by forecasting and reacting to shifts in investor sentiment.

Keywords: investment sentiment, CTA fund, market timing, fund performance

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5207 Screening for Larvicidal Activity of Aqueous and Ethanolic Extracts of Fourteen Selected Plants and Formulation of a Larvicide against Aedes aegypti (Linn.) and Aedes albopictus (Skuse) Larvae

Authors: Michael Russelle S. Alvarez, Noel S. Quiming, Francisco M. Heralde

Abstract:

This study aims to: a) obtain ethanolic (95% EtOH) and aqueous extracts of Selaginella elmeri, Christella dentata, Elatostema sinnatum, Curculigo capitulata, Euphorbia hirta, Murraya koenigii, Alpinia speciosa, Cymbopogon citratus, Eucalyptus globulus, Jatropha curcas, Psidium guajava, Gliricidia sepium, Ixora coccinea and Capsicum frutescens and screen them for larvicidal activities against Aedes aegypti (Linn.) and Aedes albopictus (Skuse) larvae; b) to fractionate the most active extract and determine the most active fraction; c) to determine the larvicidal properties of the most active extract and fraction against by computing their percentage mortality, LC50, and LC90 after 24 and 48 hours of exposure; and d) to determine the nature of the components of the active extracts and fractions using phytochemical screening. Ethanolic (95% EtOH) and aqueous extracts of the selected plants will be screened for potential larvicidal activity against Ae. aegypti and Ae. albopictus using standard procedures and 1% malathion and a Piper nigrum based ovicide-larvicide by the Department of Science and Technology as positive controls. The results were analyzed using One-Way ANOVA with Tukey’s and Dunnett’s test. The most active extract will be subjected to partial fractionation using normal-phase column chromatography, and the fractions subsequently screened to determine the most active fraction. The most active extract and fraction were subjected to dose-response assay and probit analysis to determine the LC50 and LC90 after 24 and 48 hours of exposure. The active extracts and fractions will be screened for phytochemical content. The ethanolic extracts of C. citratus, E. hirta, I. coccinea, G. sepium, M. koenigii, E globulus, J. curcas and C. frutescens exhibited significant larvicidal activity, with C. frutescens being the most active. After fractionation, the ethyl acetate fraction was found to be the most active. Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, indoles and steroids. A formulation using talcum powder–300 mg fraction per 1 g talcum powder–was made and again tested for larvicidal activity. At 2 g/L, the formulation proved effective in killing all of the test larvae after 24 hours.

Keywords: larvicidal activity screening, partial purification, dose-response assay, capsicum frutescens

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5206 Nitrogen Fixation, Cytokinin and Exopolysachharide Production by indigenous Azotobacter spp. from East Nusa Tenggara

Authors: Reginawanti Hindersah, Widiya Septiani Perdanawati, Dewi Azizah Sulaksana, Hidiyah Ayu Ma’rufah

Abstract:

Maize in some region in East Nusa Tenggara Indonesia bordering Republic Democratic of Timor Leste is important local food crop and commonly cultivated using conventional method without appropriate plant nutrition system so that productivity is still low. A way to enhance local corn yield is adding biofertilizer containing nitrogen (N2) fixing bacteria such as Azotobacter. The purpose of this research was to determine N2 fixation, cytokinin as well as exopolysachharide production capacity of six indigenous Azotobacter strains in pure culture. The N2 fixation capacities of native 3 day old Azotobacter strains added to Ashby Media varied from 0.01 to 0.39 µM/g/hour. Cytokinin production of these strain in liquid culture of N-free Media was 0.11 to 40.04 ppm while exopolysachharide content in liquid culture of Vermani Media varied from 0.4 to 27.3 g/L. This results demonstrate that some local Azotobacter strains might be used as biofertilizer.

Keywords: azotobacter, local isolate, N fixation, phythohormone, exopolysaccaride

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5205 Thermal Regions for Unmanned Aircraft Systems Route Planning

Authors: Resul Fikir

Abstract:

Unmanned Aircraft Systems (UAS) become indispensable parts of modern air power as force multiplier. One of the main advantages of UAS is long endurance. UAS have to take extra payloads to accomplish different missions but these payloads decrease endurance of aircraft because of increasing drag. There are continuing researches to increase the capability of UAS. There are some vertical thermal air currents, which can cause climb and increase endurance, in nature. Birds and gliders use thermals to gain altitude with no effort. UAS have wide wing which can use of thermals like birds and gliders. Thermal regions, which is area of 2000-3000 meter (1 NM), exist all around the world. It is free and clean source. This study analyses if thermal regions can be adopted and implemented as an assistant tool for UAS route planning. First and second part of study will contain information about the thermal regions and current applications about UAS in aviation and climbing performance with a real example. Continuing parts will analyze the contribution of thermal regions to UAS endurance. Contribution is important because planning declaration of UAS navigation rules will be in 2015.

Keywords: airways, thermals, UAS, UAS roadmap

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5204 Solar Cell Using Chemical Bath Deposited PbS:Bi3+ Films as Electron Collecting Layer

Authors: Melissa Chavez Portillo, Mauricio Pacio Castillo, Hector Juarez Santiesteban, Oscar Portillo Moreno

Abstract:

Chemical bath deposited PbS:Bi3+ as an electron collection layer is introduced between the silicon wafer and the Ag electrode the performance of the PbS heterojunction thin film solar thin film solar cells with 1 cm2 active area. We employed Bi-doping to transform it into an n-type semiconductor. The experimental results reveal that the cell response parameters depend critically on the deposition procedures in terms of bath temperature, deposition time. The device achieves an open-circuit voltage of 0.4 V. The simple and low-cost deposition method of PbS:Bi3+ films is promising for the fabrication.

Keywords: Bi doping, PbS, thin films, solar cell

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5203 Quick Response(QR) Code for Vehicle Registration and Identification

Authors: S. Malarvizhi, S. Sadiq Basha, M. Santhosh Kumar, K. Saravanan, R. Sasikumar, R. Satheesh

Abstract:

This is a web based application which provides authorization for the vehicle identification and registration. It also provides mutual authentication between the police and users in order to avoid misusage. The QR code generation in this application overcomes the difficulty in the manual registration of the vehicle documents. This generated QR code is placed in the number plates of the vehicles. The QR code is scanned using the QR Reader installed in the smart devices. The police officials can check the vehicle details and file cases on accidents, theft and traffic rules violations using QR code. In addition to vehicle insurance payments and renewals, the renewal alert is sent to the vehicle owner about payment deadline. The non-permitted vehicles can be blocked in the next check-post by sending the alert messages.

Keywords: QR code, QR reader, registration, authentication, idenfication

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5202 Catalytic Effect of Graphene Oxide on the Oxidation of Paraffin-Based Fuels

Authors: Lin-Lin Liu, Song-Qi Hu, Yin Wang

Abstract:

Paraffin-based fuels are regarded to be a promising fuel of hybrid rocked motor because of the high regression rate, low price, and environmental friendliness. Graphene Oxide (GO) is an attractive energetic material which is expected to be widely used in propellants, explosives, and some high energy fuels. Paraffin-based fuels with paraffin and GO as raw materials were prepared, and the oxidation process of the samples was investigated by thermogravimetric analysis differential scanning calorimetry (TG/DSC) under oxygen (O₂) and nitrous oxide (N₂O) atmospheres. The oxidation reaction kinetics of the fuels was estimated through the non-isothermal measurements and model-free isoconversional methods based on the experimental results of TGA. The results show that paraffin-based fuels are easier oxidized under O₂ rather than N₂O with atmospheres due to the lower activation energy; GO plays a catalytic role for the oxidation of paraffin-based fuels under the both atmospheres, and the activation energy of the oxidation process decreases with the increase of GO; catalytic effect of GO on the oxidation of paraffin-based fuels are more obvious under O₂ atmospheres than under N₂O atmospheres.

Keywords: graphene oxide, paraffin-based fuels, oxidation, activation energy, TGA

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5201 Phytochemical Profiles and Antioxidant Activity of Selected Indigenous Vegetables in Northern Mindanao, Philippines

Authors: Renee P. Baang, Romeo M. del Rosario, Nenita D. Palmes

Abstract:

The crude methanol extracts of five indigenous vegetables namely, Amarathus tricolor, Basella rubra L, Chochurus olitorius L., Ipomea batatas, and Momordica chuchinensis L., were examined for their phytochemical profile and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. The values for DPPH radical scavenging activity ranged from 7.6-89.53% with B. rubra and I. batatas having the lowest and highest values, respectively. The total flavonoid content of all five indigenous vegetables ranged from 74.65-277.3 mg quercetin equivalent per gram of dried vegetable material while the total phenolic content ranged from 1.93-6.15 mg gallic acid equivalent per gram dried material. Phytochemical screening revealed the presence of steroids, flavonoids, saponins, tannins, carbohydrates and reducing sugars, which may also be associated with the antioxidant activity shown by these indigenous vegetables.

Keywords: antioxidant, DPPH radical scavenging activity, Philippine İndigenous vegetables, phytochemical screening

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5200 Multiple Fault Diagnosis in Digital Circuits using Critical Path Tracing and Enhanced Deduction Algorithm

Authors: Mohamed Mahmoud

Abstract:

This paper has developed an effect-cause analysis technique for fault diagnosis in digital circuits. The main algorithm of our technique is based on the Enhanced Deduction Algorithm, which processes the real response of the CUT to the applied test T to deduce the values of the internal lines. An experimental version of the algorithm has been implemented in C++. The code takes about 7592 lines. The internal values are determined based on the logic values under the permanent stuck-fault model. Using a backtracking strategy guarantees that the actual values are covered by at least one solution, or no solution is found.

Keywords: enhanced deduction algorithm, backtracking strategy, automatic test equipment, verfication

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5199 Enhancing Human Security Through Conmprehensive Counter-terrorism Measures

Authors: Alhaji Khuzaima Mohammed Osman, Zaeem Sheikh Abdul Wadudi Haruna

Abstract:

This article aims to explore the crucial link between counter-terrorism efforts and the preservation of human security. As acts of terrorism continue to pose significant threats to societies worldwide, it is imperative to develop effective strategies that mitigate risks while safeguarding the rights and well-being of individuals. This paper discusses key aspects of counter-terrorism and human security, emphasizing the need for a comprehensive approach that integrates intelligence, prevention, response, and resilience-building measures. By highlighting successful case studies and lessons learned, this article provides valuable insights for policymakers, law enforcement agencies, and practitioners in their quest to address terrorism and foster human security.

Keywords: human security, risk mitigation, terrorist activities, civil liberties

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5198 Performance Analysis of Multichannel OCDMA-FSO Network under Different Pervasive Conditions

Authors: Saru Arora, Anurag Sharma, Harsukhpreet Singh

Abstract:

To meet the growing need of high data rate and bandwidth, various efforts has been made nowadays for the efficient communication systems. Optical Code Division Multiple Access over Free space optics communication system seems an effective role for providing transmission at high data rate with low bit error rate and low amount of multiple access interference. This paper demonstrates the OCDMA over FSO communication system up to the range of 7000 m at a data rate of 5 Gbps. Initially, the 8 user OCDMA-FSO system is simulated and pseudo orthogonal codes are used for encoding. Also, the simulative analysis of various performance parameters like power and core effective area that are having an effect on the Bit error rate (BER) of the system is carried out. The simulative analysis reveals that the length of the transmission is limited by the multi-access interference (MAI) effect which arises when the number of users increases in the system.

Keywords: FSO, PSO, bit error rate (BER), opti system simulation, multiple access interference (MAI), q-factor

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5197 Sliding Mode Controlled Quadratic Boost Converter

Authors: Viji Vijayakumar, R. Divya, A. Vivek

Abstract:

This paper deals with a quadratic boost converter which belongs to cascade boost family, controlled by sliding mode controller. In the cascade boost family, quadratic boost converter is the best trade-off when circuit complexity and modulator saturation is considered. Sliding mode control being a nonlinear control results in a robust and stable system when applied to switching converters which are inherently variable structured systems. The stability of this system is analyzed through Lyapunov’s approach. Analysis is done for load regulation, line regulation and step response of the system. Also these results are compared with that of PID controller based system.

Keywords: DC-DC converter, quadratic boost converter, sliding mode control, PID control

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5196 Cardiac Hypertrophy in Diabetes; The Role of Factor Forkhead Box Class O-Regulation by O-GlcNAcylation

Authors: Mohammadjavad Sotoudeheian, Navid Farahmandian

Abstract:

Cardiac hypertrophy arises in response to persistent increases in hemodynamic loads. In comparison, diabetic cardiomyopathy is defined by an abnormal myocardial changes without other cardiac-related risk factors. Pathological cardiac hypertrophy and myocardial remodeling are hallmarks of cardiovascular diseases and are risk factors for heart failure. The transcription factor forkhead box class O (FOXOs) can protect heart tissue by hostile oxidative stress and stimulating apoptosis and autophagy. FOXO proteins, as sensitive elements and mediators in response to environmental changes, have been revealed to prevent and inverse cardiac hypertrophy. FOXOs are inhibited by insulin and are critical mediators of insulin action. Insulin deficiency and uncontrolled diabetes lead to a catabolic state. FOXO1 acts downstream of the insulin-dependent pathways, which are dysregulated in diabetes. It regulates cardiomyocyte hypertrophy downstream of IGF1R/PI3K/Akt activation, which are critical regulators of cardiac hypertrophy. The complex network of signaling pathways comprising insulin/IGF-1 signaling, AMPK, JNK, and Sirtuins regulate the development of cardiovascular dysfunction by modulating the activity of FOXOs. Insulin receptors and IGF1R act via the PI3k/Akt and the MAPK/ERK pathways. Activation of Akt in response to insulin or IGF-1 induces phosphorylation of FOXOs. Increased protein synthesis induced by activation of the IGF-I/Akt/mTOR signaling pathway leads to hypertrophy. This pathway and the myostatin/Smad pathway are potent negative muscle development regulators. In cardiac muscle, insulin receptor substrates (IRS)-1 or IRS-2 activates the Akt signaling pathway and inactivate FOXO1. Under metabolic stress, p38 MAPK promotes degradation of IRS-1 and IRS-2 in cardiac myocytes and activates FOXO1, leading to cardiomyopathy. Sirt1 and FOXO1 interaction play an essential role in starvation-induced autophagy in cardiac metabolism. Inhibition of Angiotensin-II induced cardiomyocyte hypertrophy is associated with reduced FOXO1 acetylation and activation of Sirt1. The NF-κB, ERK, and FOXOs are de-acetylated by SIRT1. De-acetylation of FOXO1 induces the expression of genes involved in autophagy and stimulates autophagy flux. Therefore, under metabolic stress, FOXO1 can cause diabetic cardiomyopathy. The overexpression of FOXO1 leads to decreased cardiomyocyte size and suppresses cardiac hypertrophy through inhibition of the calcineurin–NFAT pathway. Diabetes mellitus is associated with elevation of O-GlcNAcylation. Some of its binding partners regulate the substrate selectivity of O-GlcNAc transferase (OGT). O-GlcNAcylation of essential contractile proteins may inhibit protein-protein interactions, reduce calcium sensitivity, and modulate contractile function. Uridine diphosphate (UDP)-GlcNAc is the obligatory substrate of OGT, which catalyzes a reversible post-translational protein modification. The increase of O-GlcNAcylation is accompanied by impaired cardiac hypertrophy in diabetic hearts. Inhibition of O-GlcNAcylation blocks activation of ERK1/2 and hypertrophic growth. O-GlcNAc modification on NFAT is required for its translocation from the cytosol to the nucleus, where NFAT stimulates the transcription of various hypertrophic genes. Inhibition of O-GlcNAcylation dampens NFAT-induced cardiac hypertrophic growth. Transcriptional activity of FOXO1 is enriched by improved O-GlcNAcylation upon high glucose stimulation or OGT overexpression. In diabetic conditions, the modification of FOXO1 by O-GlcNAc is promoted in cardiac troponin I and myosin light chain 2. Therefore targeting O-GlcNAcylation represents a potential therapeutic option to prevent hypertrophy in the diabetic heart.

Keywords: diabetes, cardiac hypertrophy, O-GlcNAcylation, FOXO1, Akt, PI3K, AMPK, insulin

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5195 Optimal Design of Polymer Based Piezoelectric Actuator with Varying Thickness and Length Ratios

Authors: Vineet Tiwari, R. K. Dwivedi, Geetika Srivastava

Abstract:

Piezoelectric cantilevers are exploited for their use in sensors and actuators. In this study, a unimorph cantilever beam is considered as a study element with a piezoelectric polymer Polyvinylidene fluoride (PVDF) layer bonded to a substrate layer. The different substrates like polysilicon, stainless steel and silicon nitride are tried for the study. An effort has been made to optimize and study the effect of the various parameters of the device in order to achieve maximum tip deflection. The variation of the tip displacement of the cantilever with respect to the length ratio of the nonpiezoelectric layer to the piezoelectric layer has been studied. The electric response of this unimorph cantilever beam is simulated with the help of finite element analysis software COMSOL Multiphysics.

Keywords: actuators, cantilever, piezoelectric, sensors, PVDF

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5194 The Impact of Brand Hate and Love: A Thematic Analysis of Online Emotions in Response to Disney’s Corporate Activism

Authors: Roxana D. Maiorescu-Murphy

Abstract:

Companies have recently embraced political activism as an alleged responsibility toward the communities they operate in. As a result of its recency, there is little understanding of the impact of corporate activism on consumers. In addition, embracing corporate activism engenders polarizing opinions, potentially leading to a crisis of morality shown in past literature to flourish in online settings. The present study contributes to the literature on communication management, which currently lacks research on stakeholder perceptions toward corporate activism in general and from the perspective of the stakeholders’ emotions of brand hate versus a love that they display before a specific corporate act of activism. For this purpose, the study analyzed online reactions on Twitter following Disney’s stance against Florida’s House Bill 1577 enacted in April 2022. Dubbed the “Don’t Say Gay Bill” by the left wing and the “Parental Rights Bill” by the conservative movement, the legislation triggered polarizing opinions in society and among Disney’s stakeholders, as the company announce it was taking action against it. Given the scarcity of research on corporate political activism and crises of morality, the current study enacted the case study methodology. Consequently, it answered to the research questions of how online stakeholders responded to Disney’s stance as well as why they formed such an opinion. The data were collected from Twitter over a seven-day period of analysis, namely from March 28- April 3, 2022. The period of analysis started on the day Disney announced its stance (March 28, 2022) until the reactions to its announcement petered out significantly (April 3, 2022). The final sample of analysis consisted of N=1,344 and represented Twitter comments in response to the company’s political announcement. The data were analyzed using the grounded theory methodology, which implied multiple exposures to the text and the undertaking of an inductive-deductive approach that led to the emergence of several recurrent themes. The findings revealed that the stakeholders’ prior emotions toward the company (brand hate versus brand love) did not play a greater role in their (dis)agreement with the latter’s activism than the users’ political stances. Specifically, whether they despised or hated Disney prior to this incident was less significant than their personal political stances. Above all, users were more inclined to transition from brand love to brand hate and vice versa based on the political side they viewed Disney to fall under.

Keywords: corporate political advocacy, crisis management, brand hate, brand love

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5193 Teaching Method in Situational Crisis Communication Theory: A Literature Review

Authors: Proud Arunrangsiwed

Abstract:

Crisis management strategies could be found in various curriculums, not only in schools of business, but also schools of communication. Young students, such as freshmen and sophomores of undergraduate schools, may not care about learning crisis management strategies. Moreover, crisis management strategies are not a topic art students are familiar with. The current paper discusses a way to adapt entertainment media into a crisis management lesson, and the importance of learning crisis management strategies in the school of animation. Students could learn crisis management strategies by watching movies with content about a crisis and responding to crisis responding. The students should then participate in follow up discussions related to the strategies that were used to address the crisis, as well as their success in solving the crisis.

Keywords: situational crisis communication theory, crisis response strategies, media effect, unintentional effect

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5192 Mathematical Modeling of Switching Processes in Magnetically Controlled MEMS Switches

Authors: Sergey M. Karabanov, Dmitry V. Suvorov, Dmitry Yu. Tarabrin

Abstract:

The operating principle of magnetically controlled microelectromechanical system (MEMS) switches is based on controlling the beam movement under the influence of a magnetic field. Currently, there is a MEMS switch design with a flexible ferromagnetic electrode in the form of a fixed-terminal beam, with an electrode fastened on a straight or cranked anchor. The basic performance characteristics of magnetically controlled MEMS switches (service life, sensitivity, contact resistance, fast response) are largely determined by the flexible electrode design. To ensure the stable and controlled motion of the flexible electrode, it is necessary to provide the optimal design of a flexible electrode.

Keywords: flexible electrode, magnetically controlled MEMS, mathematical modeling, mechanical stress

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5191 Change Detection Method Based on Scale-Invariant Feature Transformation Keypoints and Segmentation for Synthetic Aperture Radar Image

Authors: Lan Du, Yan Wang, Hui Dai

Abstract:

Synthetic aperture radar (SAR) image change detection has recently become a challenging problem owing to the existence of speckle noises. In this paper, an unsupervised distribution-free change detection for SAR image based on scale-invariant feature transform (SIFT) keypoints and segmentation is proposed. Firstly, the noise-robust SIFT keypoints which reveal the blob-like structures in an image are extracted in the log-ratio image to reduce the detection range. Then, different from the traditional change detection which directly obtains the change-detection map from the difference image, segmentation is made around the extracted keypoints in the two original multitemporal SAR images to obtain accurate changed region. At last, the change-detection map is generated by comparing the two segmentations. Experimental results on the real SAR image dataset demonstrate the effectiveness of the proposed method.

Keywords: change detection, Synthetic Aperture Radar (SAR), Scale-Invariant Feature Transformation (SIFT), segmentation

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5190 Structural Analysis of an Active Morphing Wing for Enhancing UAV Performance

Authors: E. Kaygan, A. Gatto

Abstract:

A numerical study of a design concept for actively controlling wing twist is described in this paper. The concept consists of morphing elements which were designed to provide a rigid and seamless skin while maintaining structural rigidity. The wing structure is first modeled in CATIA V5 then imported into ANSYS for structural analysis. Athena Vortex Lattice method (AVL) is used to estimate aerodynamic response as well as aerodynamic loads of morphing wings, afterwards a structural optimization performed via ANSYS Static. Overall, the results presented in this paper show that the concept provides efficient wing twist while preserving an aerodynamically smooth and compliant surface. Sufficient structural rigidity in bending is also obtained. This concept is suggested as a possible alternative for morphing skin applications. 

Keywords: aircraft, morphing, skin, twist

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5189 Study of Relation between Corporate Governance Mechanism and Investment Decisions Made by Companies Listed in Tehran Stock Exchange- IRAN

Authors: Roohollah Jamshidpour, Elaheh Ahmadi, Farhad Shah Veisi

Abstract:

Present research seeks to answer this question: Is there any relationship between corporate governance mechanisms and decision on corporate investments? Percentages of institutional, board of director’s, and stockholder’s ownership are among internal mechanisms of corporate governance relationship of which with investment-based decisions are studied by this research. Information on 103 companies during 1388 (2009)- 1393 (2014). Initially, research variables are identified; next, Rah Avard-e Novin software is used to gather Information. SPSS software is employed to test hypotheses with respect to descriptive and inferential statistics like correlation analysis. Research results show that percentage of institutional stockholders’ ownership has a significant direct relationship with investment decisions. For other cases, no significant relationship is observed between corporate governance mechanisms and investment decisions.

Keywords: corporate governance, company size, free floating stock, institutional investors, major shareholders

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5188 Analysis of Q-Learning on Artificial Neural Networks for Robot Control Using Live Video Feed

Authors: Nihal Murali, Kunal Gupta, Surekha Bhanot

Abstract:

Training of artificial neural networks (ANNs) using reinforcement learning (RL) techniques is being widely discussed in the robot learning literature. The high model complexity of ANNs along with the model-free nature of RL algorithms provides a desirable combination for many robotics applications. There is a huge need for algorithms that generalize using raw sensory inputs, such as vision, without any hand-engineered features or domain heuristics. In this paper, the standard control problem of line following robot was used as a test-bed, and an ANN controller for the robot was trained on images from a live video feed using Q-learning. A virtual agent was first trained in simulation environment and then deployed onto a robot’s hardware. The robot successfully learns to traverse a wide range of curves and displays excellent generalization ability. Qualitative analysis of the evolution of policies, performance and weights of the network provide insights into the nature and convergence of the learning algorithm.

Keywords: artificial neural networks, q-learning, reinforcement learning, robot learning

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5187 Microbiological Properties and Mineral Contents of Honeys from Bordj Bou Arreridj Region (Algeria)

Authors: Diafat Abdelouahab, Ekhalfi A Hammoudia, Meribai Abdelmalek A, Bahloul Ahmedb

Abstract:

The present study aimed to characterize 30 honey samples from the Bordj Bou Arreridj region (Algeria) regarding their floral origins, physicochemical parameters, mineral composition and microbial safety. Mean values obtained for physicochemical parameters were: pH 4.11, 17.17% moisture, 0.0061% ash, 370.57μS cm−1 electrical conductivity, 21.98 meq/kg free acidity, and 9.703 mg/kg HMF. The mineral content was determined by atomic absorption spectrometry. The mean values obtained were (mg/kg): Fe, 7.5714; Mg, 37.68; Na, 186,63; Zn, 3,86; Pb, 0,4869 × 10-3 ; Cd, 267 × 10-3. Aerobic mesophiles, fecal coliforms and sulphite-reducing clostridia were the microbial contaminants of interest studied. Microbiologically, the honey quality was considered good and all samples showed to be negative in respect to safety parameters. The results obtained for physicochemical characteristics of Bordj Bou Arreridj honey indicate a good quality level, adequate processing, good maturity and freshness.

Keywords: pollen analysis, physicochemical analysis, mineral content, microbial contaminants

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5186 Islamic Extremist Groups' Usage of Populism in Social Media to Radicalize Muslim Migrants in Europe

Authors: Muhammad Irfan

Abstract:

The rise of radicalization within Islam has spawned a new era of global terror. The battlefield Successes of ISIS and the Taliban are fuelled by an ideological war waged, largely and successfully, in the media arena. This research will examine how Islamic extremist groups are using media modalities and populist narratives to influence migrant Muslim populations in Europe towards extremism. In 2014, ISIS shocked the world in exporting horrifically graphic forms of violence on social media. Their Muslim support base was largely disgusted and reviled. In response, they reconfigured their narrative by introducing populist 'hooks', astutely portraying the Muslim populous as oppressed and exploited by unjust, corrupt autocratic regimes and Western power structures. Within this crucible of real and perceived oppression, hundreds of thousands of the most desperate, vulnerable and abused migrants left their homelands, risking their lives in the hope of finding peace, justice, and prosperity in Europe. Instead, many encountered social stigmatization, detention and/or discrimination for being illegal migrants, for lacking resources and for simply being Muslim. This research will examine how Islamic extremist groups are exploiting the disenfranchisement of these migrant populations and using populist messaging on social media to influence them towards violent extremism. ISIS, in particular, formulates specific encoded messages for newly-arriving Muslims in Europe, preying upon their vulnerability. Violence is posited, as a populist response, to the tyranny of European oppression. This research will analyze the factors and indicators which propel Muslim migrants along the spectrum from resilience to violence extremism. Expected outcomes are identification of factors which influence vulnerability towards violent extremism; an early-warning detection framework; predictive analysis models; and de-radicalization frameworks. This research will provide valuable tools (practical and policy level) for European governments, security stakeholders, communities, policy-makers, and educators; it is anticipated to contribute to a de-escalation of Islamic extremism globally.

Keywords: populism, radicalization, de-radicalization, social media, ISIS, Taliban, shariah, jihad, Islam, Europe, political communication, terrorism, migrants, refugees, extremism, global terror, predictive analysis, early warning detection, models, strategic communication, populist narratives, Islamic extremism

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5185 Language Developmental Trends of Mandarin-Speaking Preschoolers in Beijing

Authors: Nga Yui Tong

Abstract:

Mandarin, the official language of China, is based on the Beijing dialect and is spoken by more than one billion people from all over the world. To investigate the trends of Mandarin acquisition, 192 preschoolers are recruited by stratified random sampling. They are from 4 different districts in Beijing, 2 schools in each district, with 4 age groups, both genders, and 3 children in each stratum. The children are paired up to conduct semi-structured free play for 30 minutes. Their language output is videotaped, transcribed, and coded for the calculation of Mean Length of Utterance (MLU). Two-way ANOVA showed that the variation of MLU is significantly contributed by age, which is coherent to previous findings of other languages. This first large-scale study to investigate the developmental trend of Mandarin in young children in Beijing provides empirical evidence to the development of standards and curriculum planning for early Mandarin education. Interestingly, the gender effect in the study is insignificant, with boys showing a slightly higher MLU than girls across all age groups and settings, except the 4.5 years same-gender dyads. The societal factors in the Chinese context on parenting and gender bias are worth looking into.

Keywords: Beijing, language development, Mandarin, preschoolers

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5184 Buckling Behavior of FGM Plates Using a Simplified Shear Deformation Theory

Authors: Mokhtar Bouazza

Abstract:

In this paper, the simplified theory will be used to predict the thermoelastic buckling behavior of rectangular functionally graded plates. The material properties of the functionally graded plates are assumed to vary continuously through the thickness, according to a simple power law distribution of the volume fraction of the constituents. The simplified theory is used to obtain the buckling of the plate under different types of thermal loads. The thermal loads are assumed to be uniform, linear, and non-linear distribution through the thickness. Additional numerical results are presented for FGM plates that show the effects of various parameters on thermal buckling response.

Keywords: buckling, functionally graded, plate, simplified higher-order deformation theory, thermal loading

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5183 Hairy Beggarticks (Bidens pilosa L. - Asteraceae) Control in Sunflower Fields Using Pre-Emergence Herbicides

Authors: Alexandre M. Brighenti

Abstract:

One of the most damaging species in sunflower crops in Brazil is the hairy beggarticks (Bidens pilosa L.). The large number of seeds, the various vegetative cycles during the year, the staggered germination and the scarcity of selective and effective herbicides to control this weed in sunflower are some of attributes that hinder the effectiveness in controlling hairy beggarticks populations. The experiment was carried out with the objectives of evaluating the control of hairy beggarticks plants in sunflower crops, and to assess sunflower tolerance to residual herbicides. The treatments were as follows: S-metolachlor (1,200 and 2,400 g ai ha-1), flumioxazin (60 and 120 g ai ha-1), sulfentrazone (150 and 300 g ai ha-1) and two controls (weedy and weed-free check). Phytotoxicity on sunflower plants, percentage of control and density of hairy beggarticks plants, sunflower stand and plant height, head diameter, oil content and sunflower yield were evaluated. The herbicides flumioxazin and sulfentrazone were the most efficient in hairy beggarticks control. S-metolachlor provided acceptable control levels. S-metolachlor (1,200 g ha-1), flumioxazin (60 g ha-1) and sulfentrazone (150 g ha-1) were the most selective doses for sunflower crop.

Keywords: flumioxazin, Helianthus annuus, S-metolachlor, sulfentrazone, weeds

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5182 A Qualitative Study of COVID-19's Impact on Mental Health and Corresponding Alcohol and Other Substance Use among Indigenous Women in Toronto Canada

Authors: Kristen Emory, Jerry Flores

Abstract:

Purpose: We explore the unique and underrepresented experiences of Indigenous women living in Toronto, Canada, during the first year of the COVID-19 pandemic. The purpose of this study is to better document the impacts of COVID-19 on the mental health and well-being of Indigenous women in Toronto, Canada, in order to better understand unmet needs, as well as lay the groundwork for more targeted research and potential interventions based on these needs. Background: It has been fairly well documented that the COVID-19 pandemic has increased mental health concerns among various populations globally. There have also been numerous studies indicating increases in substance use and abuse in response to the stress of the pandemic. There is also evidence that the COVID-19 pandemic has disproportionately impacted a variety of historically marginalized populations in Canada, the US, and globally, including Indigenous populations. While these studies provide some insight into how the COVID-19 pandemic is impacting the global population, much less is known about the lived experiences of Indigenous populations during the time of COVID-19. Better understanding these experiences will allow public health professionals, governments, and non-governmental organizations better combat health inequities related to the pandemic. Methods: In-depth qualitative semi-structured virtual (due to COVID-19) interviews with 13 Indigenous women were conducted during the first year of the COVID-19 pandemic (2020). Interviews were recorded, transcribed, and analyzed by team members using Dedoose qualitative analysis software. Findings: COVID-19 negatively affected Indigenous females identifying participants’ mental health and corresponding reported increases in substance use. In addition to the daily stress of the unpredictability of life in the time of the COVID-19 pandemic, participants cited job loss, economic concerns, homeschooling, and lack of access to medical resources as primary factors in increasing their stress and decreasing mental health and wellbeing. In response to these stressors, a majority of participants cited coping mechanisms such as increased substance use to help deal with the uncertainty. In particular, alcohol and tobacco emerged as coping mechanisms to help participants cope with stress related to the pandemic (as well as its social and economic toll on respondents' lives). We will present qualitative data to be presented, including participant direct quotes, explaining their experiences with COVID-19, mental health, and increased substance use, as well as analysis and synthesis with the existing scientific evidence base. Conclusion: This research is among the good studies to our knowledge that scientifically explore the impact of COVID-19 on mental health and well-being and corresponding increases in reported substance use.

Keywords: mental health, covid-19, indigenous, inequity, anxiety, depression, stress

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