Search results for: control theory
12919 Short Review on Models to Estimate the Risk in the Financial Area
Authors: Tiberiu Socaciu, Tudor Colomeischi, Eugenia Iancu
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Business failure affects in various proportions shareholders, managers, lenders (banks), suppliers, customers, the financial community, government and society as a whole. In the era in which we have telecommunications networks, exists an interdependence of markets, the effect of a failure of a company is relatively instant. To effectively manage risk exposure is thus require sophisticated support systems, supported by analytical tools to measure, monitor, manage and control operational risks that may arise. As we know, bankruptcy is a phenomenon that managers do not want no matter what stage of life is the company they direct / lead. In the analysis made by us, by the nature of economic models that are reviewed (Altman, Conan-Holder etc.), estimating the risk of bankruptcy of a company corresponds to some extent with its own business cycle tracing of the company. Various models for predicting bankruptcy take into account direct / indirect aspects such as market position, company growth trend, competition structure, characteristics and customer retention, organization and distribution, location etc. From the perspective of our research we will now review the economic models known in theory and practice for estimating the risk of bankruptcy; such models are based on indicators drawn from major accounting firms.Keywords: Anglo-Saxon models, continental models, national models, statistical models
Procedia PDF Downloads 40512918 Incentive-Based Motivation to Network with Coworkers: Strengthening Professional Networks via Online Social Networks
Authors: Jung Lee
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The last decade has witnessed more people than ever before using social media and broadening their social circles. Social media users connect not only with their friends but also with professional acquaintances, primarily coworkers, and clients; personal and professional social circles are mixed within the same social media platform. Considering the positive aspect of social media in facilitating communication and mutual understanding between individuals, we infer that social media interactions with co-workers could indeed benefit one’s professional life. However, given privacy issues, sharing all personal details with one’s co-workers is not necessarily the best practice. Should one connect with coworkers via social media? Will social media connections with coworkers eventually benefit one’s long-term career? Will the benefit differ across cultures? To answer, this study examines how social media can contribute to organizational communication by tracing the foundation of user motivation based on social capital theory, leader-member exchange (LMX) theory and expectancy theory of motivation. Although social media was originally designed for personal communication, users have shown intentions to extend social media use for professional communication, especially when the proper incentive is expected. To articulate the user motivation and the mechanism of the incentive expectation scheme, this study applies those three theories and identify six antecedents and three moderators of social media use motivation including social network flaunt, shared interest, perceived social inclusion. It also hypothesizes that the moderating effects of those constructs would significantly differ based on the relationship hierarchy among the workers. To validate, this study conducted a survey of 329 active social media users with acceptable levels of job experiences. The analysis result confirms the specific roles of the three moderators in social media adoption for organizational communication. The present study contributes to the literature by developing a theoretical modeling of ambivalent employee perceptions about establishing social media connections with co-workers. This framework shows not only how both positive and negative expectations of social media connections with co-workers are formed based on expectancy theory of motivation, but also how such expectations lead to behavioral intentions using career success model. It also enhances understanding of how various relationships among employees can be influenced through social media use and such usage can potentially affect both performance and careers. Finally, it shows how cultural factors induced by social media use can influence relations among the coworkers.Keywords: the social network, workplace, social capital, motivation
Procedia PDF Downloads 12312917 Robust and Real-Time Traffic Counting System
Authors: Hossam M. Moftah, Aboul Ella Hassanien
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In the recent years the importance of automatic traffic control has increased due to the traffic jams problem especially in big cities for signal control and efficient traffic management. Traffic counting as a kind of traffic control is important to know the road traffic density in real time. This paper presents a fast and robust traffic counting system using different image processing techniques. The proposed system is composed of the following four fundamental building phases: image acquisition, pre-processing, object detection, and finally counting the connected objects. The object detection phase is comprised of the following five steps: subtracting the background, converting the image to binary, closing gaps and connecting nearby blobs, image smoothing to remove noises and very small objects, and detecting the connected objects. Experimental results show the great success of the proposed approach.Keywords: traffic counting, traffic management, image processing, object detection, computer vision
Procedia PDF Downloads 29412916 Active Noise Cancellation in the Rectangular Enclosure Systems
Authors: D. Shakirah Shukor, A. Aminudin, Hashim U. A., Waziralilah N. Fathiah, T. Vikneshvaran
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The interior noise control is essential to be explored due to the interior acoustic analysis is significant in the systems such as automobiles, aircraft, air-handling system and diesel engine exhausts system. In this research, experimental work was undertaken for canceling an active noise in the rectangular enclosure. The rectangular enclosure was fabricated with multiple speakers and microphones inside the enclosure. A software program using digital signal processing is implemented to evaluate the proposed method. Experimental work was conducted to obtain the acoustic behavior and characteristics of the rectangular enclosure and noise cancellation based on active noise control in low-frequency range. Noise is generated by using multispeaker inside the enclosure and microphones are used for noise measurements. The technique for noise cancellation relies on the principle of destructive interference between two sound fields in the rectangular enclosure. One field is generated by the original or primary sound source, the other by a secondary sound source set up to interfere with, and cancel, that unwanted primary sound. At the end of this research, the result of output noise before and after cancellation are presented and discussed. On the basis of the findings presented in this research, an active noise cancellation in the rectangular enclosure is worth exploring in order to improve the noise control technologies.Keywords: active noise control, digital signal processing, noise cancellation, rectangular enclosure
Procedia PDF Downloads 27212915 Electromyography Controlled Robotic Toys for Autistic Children
Authors: Uvais Qidwai, Mohamed Shakir
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This paper presents an initial study related to the use of robotic toys as teaching and therapeutic aid tools for teachers and care-givers as well as parents of children with various levels of autism spectrum disorder (ASD). Some of the most common features related to the behavior of a child with ASD are his/her social isolation, living in their own world, not being physically active, and not willing to learn new things. While the teachers, parents, and all other related care-givers do their best to improve the condition of these kids, it is usually quite an uphill task. However, one remarkable observation that has been reported by several teachers dealing with ASD children is the fact that the same children do get attracted to toys with lights and sounds. Hence, this project targets the development/modifications of such existing toys into appropriate behavior training tools which the care-givers can use as they would desire. Initially, the remote control is in hand of the trainer, but after some time, the child is entrusted with the control of the robotic toy to test for the level of interest. It has been found during the course of this study that children with quite low learning activity got extremely interested in the robot and even advanced to controlling the robot with the Electromyography (EMG). It has been observed that the children did show some hesitation in the beginning 5 minutes of the very first sessions of such interaction but were very comfortable afterwards which has been considered as a very strong indicator of the potential of this technique in teaching and rehabilitation of children with ASD or similar brain disorders.Keywords: Autism Spectrum Disorder (ASD), robotic toys, IR control, electromyography, LabVIEW based remote control
Procedia PDF Downloads 44412914 Uncanny Orania: White Complicity as the Abject of the Discursive Construction of Racism
Authors: Daphne Fietz
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This paper builds on a reflection on an autobiographical experience of uncanniness during fieldwork in the white Afrikaner settlement Orania in South Africa. Drawing on Kristeva’s theory of abjection to establish a theory of Whiteness which is based on boundary threats, it is argued that the uncanny experience as the emergence of the abject points to a moment of crisis of the author’s Whiteness. The emanating abject directs the author to her closeness or convergence with Orania's inhabitants, that is a reciprocity based on mutual Whiteness. The experienced confluence appeals to the author’s White complicity to racism. With recourse to Butler’s theory of subjectivation, the abject, White complicity, inhabits both the outside of a discourse on racism, and of the 'self', as 'I' establish myself in relation to discourse. In this view, the qualities of the experienced abject are linked to the abject of discourse on racism, or, in other words, its frames of intelligibility. It then becomes clear, that discourse on (overt) racism functions as a necessary counter-image through which White morality is established instead of questioned, because here, by White reasoning, the abject of complicity to racism is successfully repressed, curbed, as completely impossible in the binary construction. Hence, such discourse endangers a preservation of racism in its pre-discursive and structural forms as long as its critique does not encompass its own location and performance in discourse. Discourse on overt racism is indispensable to White ignorance as it covers underlying racism and pre-empts further critique. This understanding directs us towards a form of critique which does necessitate self-reflection, uncertainty, and vigilance, which will be referred to as a discourse of relationality. Such a discourse diverges from the presumption of a detached author as a point of reference, and instead departs from attachment, dependence, mutuality and embraces the visceral as a resource of knowledge of relationality. A discourse of relationality points to another possibility of White engagement with Whiteness and racism and further promotes a conception of responsibility, which allows for and highlights dispossession and relationality in contrast to single agency and guilt.Keywords: abjection, discourse, relationality, the visceral, whiteness
Procedia PDF Downloads 15812913 Gestural Pragmatic Inference among Primates: An Experimental Approach
Authors: Siddharth Satishchandran, Brian Khumalo
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Humans are able to derive semantic content from syntactic and pragmatic sources. Multimodal evidence from signaling theory, which examines communication between individuals within and across species, suggests that non-human primates possess similar syntactic and pragmatic capabilities. However, the extent remains unknown because primate pragmatics are relatively under-examined. Our paper reviews research within communication theory amongst non-human primates to understand current theoretical trends. We examine evidence for primate pragmatic capacities through observational, experimental, and theoretical work on gestures. Given fragmented theoretical perspectives, we provide a unified framework of communication for future research that contextualizes the available research under code biology. To achieve this, we rely on biological semiotics (biosemiotics), the philosophy of biology investigating prelinguistic meaning-making as a function of signs and codes. We close by discussing areas of potential research for studying gestural pragmatics amongst non-human primates, particularly chimpanzees (Pan troglodytes), Diana monkeys (Cercopithecus diana), and other potential candidates.Keywords: pragmatics, non-human primates, gestural communication, biological semiotics
Procedia PDF Downloads 3912912 Convergence Analysis of Training Two-Hidden-Layer Partially Over-Parameterized ReLU Networks via Gradient Descent
Authors: Zhifeng Kong
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Over-parameterized neural networks have attracted a great deal of attention in recent deep learning theory research, as they challenge the classic perspective of over-fitting when the model has excessive parameters and have gained empirical success in various settings. While a number of theoretical works have been presented to demystify properties of such models, the convergence properties of such models are still far from being thoroughly understood. In this work, we study the convergence properties of training two-hidden-layer partially over-parameterized fully connected networks with the Rectified Linear Unit activation via gradient descent. To our knowledge, this is the first theoretical work to understand convergence properties of deep over-parameterized networks without the equally-wide-hidden-layer assumption and other unrealistic assumptions. We provide a probabilistic lower bound of the widths of hidden layers and proved linear convergence rate of gradient descent. We also conducted experiments on synthetic and real-world datasets to validate our theory.Keywords: over-parameterization, rectified linear units ReLU, convergence, gradient descent, neural networks
Procedia PDF Downloads 14212911 Angiotensin Converting Enzyme (ACE) and Angiotensinogen (AGT) Gene Variants in Pakistani Patients of Diabetes Mellitus and Diabetic Nephropathy
Authors: Rozeena Shaikh, Syed M Shahid, Jamil Ahmad, Qaisar Mansoor, Muhammad Ismail, Abid Azhar
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Introduction: Diabetes mellitus (DM) is a prevalent non-communicable disease worldwide. In most high-income countries as well as middle-income and low- income countries. DM is among the top causes of deaths. DM may lead to many vascular complications like hypertension, nephropathy, retinopathy, neuropathy, and foot. Diabetic nephropathy (DN) characterized by persistent albuminuria is a leading cause of end stage renal failure (ESRF). Pathogenesis of diabetic nephropathy is implicated by the polymorphisms in genes encoding the components of reninangiotensin- aldosteron system (RAAS) which include angiotensinogen (AGT), angiotensin-II receptor and particularly angiotensin converting enzyme (ACE) gene. Method: Study subjects include 110 control, 110 patients with DM without hypertension, 110 patients with DM with hypertension and 110 patients with DN. Blood samples were collected for Biochemical analysis and PCR and sequencing for the specific region of both genes. Results: The frequency of DD genotype and D allele of ACE (I/D) was significantly (p<0.05) high in DM normotensive, DM hypertensive and DN patients when compared to control. The ACE G2350A genotypes and allele frequencies were significantly different (p<0.05) in DM hypertensive patients as compared to control and DN, while no difference was observed between DM normotensive and DN when compared to control. The genotypes and alleles of AGT (M268T) polymorphism were significantly different (p<0.05) in DM normotensive, DM hypertensive and DN when compared to control. Conclusion: The DD genotype and D allele of ACE (I/D), GG genotype and G allele of ACE (G2350A) and the TT genotype and T allele of AGT (M268T) polymorphism have shown a significant difference in genotype and allele frequencies between controls and patients.Keywords: genetic variations, ACE, AGT, diabetes mellitus, diabetic nephropathy, Pakistan
Procedia PDF Downloads 39212910 Reactive Power Control Strategy for Z-Source Inverter Based Reconfigurable Photovoltaic Microgrid Architectures
Authors: Reshan Perera, Sarith Munasinghe, Himali Lakshika, Yasith Perera, Hasitha Walakadawattage, Udayanga Hemapala
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This research presents a reconfigurable architecture for residential microgrid systems utilizing Z-Source Inverter (ZSI) to optimize solar photovoltaic (SPV) system utilization and enhance grid resilience. The proposed system addresses challenges associated with high solar power penetration through various modes, including current control, voltage-frequency control, and reactive power control. It ensures uninterrupted power supply during grid faults, providing flexibility and reliability for grid-connected SPV customers. Challenges and opportunities in reactive power control for microgrids are explored, with simulation results and case studies validating proposed strategies. From a control and power perspective, the ZSI-based inverter enhances safety, reduces failures, and improves power quality compared to traditional inverters. Operating seamlessly in grid-connected and islanded modes guarantees continuous power supply during grid disturbances. Moreover, the research addresses power quality issues in long distribution feeders during off-peak and night-peak hours or fault conditions. Using the Distributed Static Synchronous Compensator (DSTATCOM) for voltage stability, the control objective is nighttime voltage regulation at the Point of Common Coupling (PCC). In this mode, disconnection of PV panels, batteries, and the battery controller allows the ZSI to operate in voltage-regulating mode, with critical loads remaining connected. The study introduces a structured controller for Reactive Power Controlling mode, contributing to a comprehensive and adaptable solution for residential microgrid systems. Mathematical modeling and simulations confirm successful maximum power extraction, controlled voltage, and smooth voltage-frequency regulation.Keywords: reconfigurable architecture, solar photovoltaic, microgrids, z-source inverter, STATCOM, power quality, battery storage system
Procedia PDF Downloads 912909 Behavioral Intentions and Cognitive-Affective Effects of Exposure to YouTube Advertisements among College Students
Authors: Abd El-Basit Ahmed Hashem Mahmoud, Othman Fekry Abdelbaki
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This study attempts to investigate the exposure to YouTube ads among Egyptian college students, their attitudes towards these ads, behavioral intentions to watch them, and the effects of this exposure and to examine the relationships among these variables as well. The current study is theoretically guided by the theory of reasoned action (TRA) and cognitive-affective behavioral model (CAB) through a questionnaire survey administered to a convenience sample of 390 college students who watch YouTube videos from Cairo University, Egypt from February to May 2019. The results showed that 98.7% of respondents exposed to YouTube ads, and both of their attitudes towards YouTube ads exposure and their intentions to this exposure were moderately positive. The findings also indicated that respondents' gender had a significant impact on their intention to expose these ads. One-way ANOVA indicated that their attitudes towards exposure to YouTube ads influenced their behavioral intentions to watch these ads, and it also demonstrated that their behavioral intentions to watch these ads had an impact on the exposure to such ads. Pearson correlation revealed that there was a significant positive relationship between respondents' attitudes towards YouTube ads exposure and the cognitive, affective, and behavioral effects of this exposure.Keywords: attitudes, behavioral intentions, theory of reasoned action, YouTube ads
Procedia PDF Downloads 15412908 Dual Set Point Governor Control Structure with Common Optimum Temporary Droop Settings for both Islanded and Grid Connected Modes
Authors: Deepen Sharma, Eugene F. Hill
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For nearly 100 years, hydro-turbine governors have operated with only a frequency set point. This natural governor action means that the governor responds with changing megawatt output to disturbances in system frequency. More and more, power system managers are demanding that governors operate with constant megawatt output. One way of doing this is to introduce a second set point in the control structure called a power set point. The control structure investigated and analyzed in this paper is unique in the way that it utilizes a power reference set point in addition to the conventional frequency reference set point. An optimum set of temporary droop parameters derived based on the turbine-generator inertia constant and the penstock water start time for stable islanded operation are shown to be also equally applicable for a satisfactory rate of generator loading during its grid connected mode. A theoretical development shows why this is the case. The performance of the control structure has been investigated and established based on the simulation study made in MATLAB/Simulink as well as through testing the real time controller performance on a 15 MW Kaplan Turbine and generator. Recordings have been made using the labVIEW data acquisition platform. The hydro-turbine governor control structure and its performance investigated in this paper thus eliminates the need to have a separate set of temporary droop parameters, one valid for islanded mode and the other for interconnected operations mode.Keywords: frequency set point, hydro governor, interconnected operation, isolated operation, power set point
Procedia PDF Downloads 36712907 A Neural Network Control for Voltage Balancing in Three-Phase Electric Power System
Authors: Dana M. Ragab, Jasim A. Ghaeb
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The three-phase power system suffers from different challenging problems, e.g. voltage unbalance conditions at the load side. The voltage unbalance usually degrades the power quality of the electric power system. Several techniques can be considered for load balancing including load reconfiguration, static synchronous compensator and static reactive power compensator. In this work an efficient neural network is designed to control the unbalanced condition in the Aqaba-Qatrana-South Amman (AQSA) electric power system. It is designed for highly enhanced response time of the reactive compensator for voltage balancing. The neural network is developed to determine the appropriate set of firing angles required for the thyristor-controlled reactor to balance the three load voltages accurately and quickly. The parameters of AQSA power system are considered in the laboratory model, and several test cases have been conducted to test and validate the proposed technique capabilities. The results have shown a high performance of the proposed Neural Network Control (NNC) technique for correcting the voltage unbalance conditions at three-phase load based on accuracy and response time.Keywords: three-phase power system, reactive power control, voltage unbalance factor, neural network, power quality
Procedia PDF Downloads 19512906 The Legal Effects of Coronavirus (COVID-19) on the Implementation of Administrative Contracts in Saudi Arabia: Application of Emergency Circumstances Theory
Authors: Ali Obaid Alyami
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In Saudi Arabia, the pandemic of Coronavirus (COVID-19) has been affecting administrative contracts in many different ways. Lots of planned projects were stopped temporarily or implemented partially. Many contractors have suffered financial struggles and the absence of manpower. These administrative contracts are governed by Government Tenders and Procurement Law (GTPL) which was issued by a royal decree in 2019. This law addresses some challenges that could be stumbling blocks in the way of implementing a contract. One significant challenge is emergency circumstances that occur during the implementation of an administrative contract. The law provides some solutions for this disruption, but these solutions may not compensate for the whole damages that contractors suffer. This study will use the doctrinal methodology to analyze the rules of law and their application to the research problem. Most importantly, the issue that arises in this research is the possibility of governmental entities’ consideration, in administrative contracts, of the pandemic Coronavirus (COVID-19) as an emergency circumstance. This study points out the conditions for applying the theory of emergency circumstances on administrative contracts in addition to the definition of the theory and analyzing its elements. The other significant question is the limits on governmental entities to make a change in an administrative contract to achieve contractual rebalancing. GPTL and its implementing regulation set the conditions and limits of contractual rebalancing. However, this study finds that although GTPL provides rules for contractual rebalancing, there are some other mechanisms that contractors may take to fully compensate for the damages. For instance, when the loss cannot be minimized by GTPL, contractors might file lawsuits before the administrative judiciary. The study concludes that GTPL is a very comprehensive law system that stipulates specific rules for contractual rebalance and treats the emergency circumstances that obstruct the performance of administrative contracts.Keywords: administrative contracts, emergency circumstances, balance of contract, administrative judiciary, government tenders, procurement law
Procedia PDF Downloads 7612905 The Impact of Text Modifications on Ethiopian Students’ Reading Comprehension and Motivation
Authors: Asefa Kenefergib, Dawit Amogne, Yinager Teklesellassie
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A study investigated the effects of text modifications on reading comprehension and motivation among Ethiopian secondary school students. A total of 120 students participated, initially taking a reading comprehension pretest and completing a reading motivation questionnaire. Afterward, they were divided into three groups: control, simplified, and elaborated. Each group then took part in a reading comprehension posttest and another reading motivation questionnaire following an eight-week instructional intervention. Despite initial differences, both the simplified and elaborated text groups showed comparable levels of reading motivation and comprehension. The data were analyzed using SPSS version 25, with a one-way ANOVA used to assess the effectiveness of the modified texts in enhancing reading comprehension. The results indicated that the experimental groups performed significantly better on the posttest compared to the control group, suggesting that text modifications can positively influence students' comprehension skills. Furthermore, the impact of text modifications on student reading motivation was assessed using a one-way ANOVA. The findings revealed that both the elaborated and simplified text groups scored higher than the control group in various dimensions of reading motivation, including reading efficacy, curiosity, challenge, compliance, and reading work avoidance. However, the control and simplified groups had nearly similar mean scores in the dimension of reading competition. These results clearly demonstrate that modifying texts can enhance EFL learners' reading motivation and comprehension.Keywords: simplification, elaboration, reading motivation, reading comprehension
Procedia PDF Downloads 3912904 Filling the Gaps with Representation: Netflix’s Anne with an E as a Way to Reveal What the Text Hid
Authors: Arkadiusz Adam Gardaś
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In his theory of gaps, Wolfgang Iser states that literary texts often lack direct messages. Instead of using straightforward descriptions, authors leave the gaps or blanks, i.e., the spaces within the text that come into existence only when readers fill them with their understanding and experiences. This paper’s aim is to present Iser’s literary theory in an intersectional way by comparing it to the idea of intersemiotic translation. To be more precise, the author uses the example of Netflix’s adaption of Lucy Maud Montgomery’s Anne of Green Gables as a form of rendering a book into a film in such a way that certain textual gaps are filled with film images. Intersemiotic translation is a rendition in which signs of one kind of media are translated into the signs of the other media. Film adaptions are the most common, but not the only, type of intersemiotic translation. In this case, the role of the translator is taken by a screenwriter. A screenwriter’s role can reach beyond the direct meaning presented by the author, and instead, it can delve into the source material (here – a novel) in a deeper way. When it happens, a screenwriter is able to spot the gaps in the text and fill them with images that can later be presented to the viewers. Anne with an E, the Netflix adaption of Montgomery’s novel, may be used as a highly meaningful example of such a rendition. It is due to the fact that the 2017 series was broadcasted more than a hundred years after the first edition of the novel was published. This means that what the author might not have been able to show in her text can now be presented in a more open way. The screenwriter decided to use this opportunity to represent certain groups in the film, i.e., racial and sexual minorities, and women. Nonetheless, the series does not alter the novel; in fact, it adds to it by filling the blanks with more direct images. In the paper, fragments of the first season of Anne with an E are analysed in comparison to its source, the novel by Montgomery. The main purpose of that is to show how intersemiotic translation connected with the Iser’s literary theory can enrich the understanding of works of art, culture, media, and literature.Keywords: intersemiotic translation, film, literary gaps, representation
Procedia PDF Downloads 31612903 Singular Stochastic Control Model with Carrying Capacity of Population Management Policy for Squirrels in Durian Orchards
Authors: Sasiwimol Auepong, Raywat Tanadkithirun
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In this work, the problem that squirrels ruin durian, which is an economical fruit in Thailand, is considered. We seek the strategy for the durian farmers to eliminate the squirrels under the consideration that squirrels also provide ecosystem service. The population dynamics of squirrels are constructed to have carrying capacity since we consider the population in a confined area. A performance index indicating the total benefit of a given elimination strategy is provided. It comprises the cost of countermeasures, the loss of resources, and the ecosystem service provided by squirrels. The optimal performance index is numerically solved through the variational inequality using the finite difference method. The optimal strategy to control the squirrel population is also given numerically.Keywords: controlled stochastic differential equation, durian, finite difference method, performance index, singular stochastic control model, squirrel
Procedia PDF Downloads 9112902 Comparative Analysis of Control Techniques Based Sliding Mode for Transient Stability Assessment for Synchronous Multicellular Converter
Authors: Rihab Hamdi, Amel Hadri Hamida, Fatiha Khelili, Sakina Zerouali, Ouafae Bennis
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This paper features a comparative study performance of sliding mode controller (SMC) for closed-loop voltage control of direct current to direct current (DC-DC) three-cells buck converter connected in parallel, operating in continuous conduction mode (CCM), based on pulse-width modulation (PWM) with SMC based on hysteresis modulation (HM) where an adaptive feedforward technique is adopted. On one hand, for the PWM-based SM, the approach is to incorporate a fixed-frequency PWM scheme which is effectively a variant of SM control. On the other hand, for the HM-based SM, oncoming an adaptive feedforward control that makes the hysteresis band variable in the hysteresis modulator of the SM controller in the aim to restrict the switching frequency variation in the case of any change of the line input voltage or output load variation are introduced. The results obtained under load change, input change and reference change clearly demonstrates a similar dynamic response of both proposed techniques, their effectiveness is fast and smooth tracking of the desired output voltage. The PWM-based SM technique has greatly improved the dynamic behavior with a bit advantageous compared to the HM-based SM technique, as well as provide stability in any operating conditions. Simulation studies in MATLAB/Simulink environment have been performed to verify the concept.Keywords: DC-DC converter, hysteresis modulation, parallel multi-cells converter, pulse-width modulation, robustness, sliding mode control
Procedia PDF Downloads 16712901 Constructal Enhancement of Fins Design Integrated to Phase Change Materials
Authors: Varun Joshi, Manish K. Rathod
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The latent heat thermal energy storage system is a thrust area of research due to exuberant thermal energy storage potential. The thermal performance of PCM is significantly augmented by installation of the high thermal conductivity fins. The objective of the present study is to obtain optimum size and location of the fins to enhance diffusion heat transfer without altering overall melting time. Hence, the constructal theory is employed to eliminate, resize, and re-position the fins. A numerical code based on conjugate heat transfer coupled enthalpy porosity approached is developed to solve Navier-Stoke and energy equation.The numerical results show that the constructal fin design has enhanced the thermal performance along with the increase in the overall volume of PCM when compared to conventional. The overall volume of PCM is found to be increased by half of total of volume of fins. The elimination and repositioning the fins at high temperature gradient from low temperature gradient is found to be vital.Keywords: constructal theory, enthalpy porosity approach, phase change materials, fins
Procedia PDF Downloads 18112900 Building and Development of the Stock Market Institutional Infrastructure in Russia
Authors: Irina Bondarenko, Olga Vandina
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The theory of evolutionary economics is the basis for preparation and application of methods forming the stock market infrastructure development concept. The authors believe that the basis for the process of formation and development of the stock market model infrastructure in Russia is the theory of large systems. This theory considers the financial market infrastructure as a whole on the basis of macroeconomic approach with the further definition of its aims and objectives. Evaluation of the prospects for interaction of securities market institutions will enable identifying the problems associated with the development of this system. The interaction of elements of the stock market infrastructure allows to reduce the costs and time of transactions, thereby freeing up resources of market participants for more efficient operation. Thus, methodology of the transaction analysis allows to determine the financial infrastructure as a set of specialized institutions that form a modern quasi-stable system. The financial infrastructure, based on international standards, should include trading systems, regulatory and supervisory bodies, rating agencies, settlement, clearing and depository organizations. Distribution of financial assets, reducing the magnitude of transaction costs, increased transparency of the market are promising tasks in the solution for questions of services level and quality increase provided by institutions of the securities market financial infrastructure. In order to improve the efficiency of the regulatory system, it is necessary to provide "standards" for all market participants. The development of a clear regulation for the barrier to the stock market entry and exit, provision of conditions for the development and implementation of new laws regulating the activities of participants in the securities market, as well as formulation of proposals aimed at minimizing risks and costs, will enable the achievement of positive results. The latter will be manifested in increasing the level of market participant security and, accordingly, the attractiveness of this market for investors and issuers.Keywords: institutional infrastructure, financial assets, regulatory system, stock market, transparency of the market
Procedia PDF Downloads 13412899 A Novel Stator Resistance Estimation Method and Control Design of Speed-Sensorless Induction Motor Drives
Authors: N. Ben Si Ali, N. Benalia, N. Zarzouri
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Speed sensorless systems are intensively studied during recent years; this is mainly due to their economical benefit and fragility of mechanical sensors and also the difficulty of installing this type of sensor in many applications. These systems suffer from instability problems and sensitivity to parameter mismatch at low speed operation. In this paper an analysis of adaptive observer stability with stator resistance estimation is given.Keywords: motor drive, sensorless control, adaptive observer, stator resistance estimation
Procedia PDF Downloads 37512898 A Composite Beam Element Based on Global-Local Superposition Theory for Prediction of Delamination in Composite Laminates
Authors: Charles Mota Possatti Júnior, André Schwanz de Lima, Maurício Vicente Donadon, Alfredo Rocha de Faria
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An interlaminar damage model is combined with a beam element formulation based on global-local superposition to assess delamination in composite laminates. The variations in the mechanical properties in the laminate, generated by the presence of delamination, are calculated as a function of the displacements in the interface layers. The global-local superposition of displacement fields ensures the zig-zag behaviour of stresses and displacement, and the number of degrees of freedom (DOFs) is independent of the number of layers. The displacements and stresses are calculated as a function of DOFs commonly used in traditional beam elements. Finally, the finite element(FE) formulation is extended to handle cases of different thicknesses, and then the FE model predictions are compared with results obtained from analytical solutions and commercial finite element codes.Keywords: delamination, global-local superposition theory, single beam element, zig-zag, interlaminar damage model
Procedia PDF Downloads 11812897 Soil Enzyme Activity as Influenced by Post-emergence Herbicides Applied in Soybean [Glycine max (L.) Merrill]
Authors: Uditi Dhakad, Baldev Ram, Chaman K. Jadon, R. K. Yadav, D. L. Yadav, Pratap Singh, Shalini Meena
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A field experiment was conducted during Kharif 2021 at Agricultural Research Station, Kota, to evaluate the effect of different post-emergence herbicides applied to soybean [Glycine max (L.) Merrill] on soil enzymes activity viz. dehydrogenase, phosphatase, and urease. The soil of the experimental site was clay loam (vertisols) in texture and slightly alkaline in reaction with 7.7 pH. The soil was low in organic carbon (0.49%), medium in available nitrogen (210 kg/ha), phosphorus (23.5 P2O5 kg/ha), and high in potassium (400 K2O kg/ha) status. The results elucidated that no significant adverse effect on soil dehydrogenase, urease, and phosphatase activity was determined with the application of post-emergence herbicides over the untreated control. Two hands weeding at 20 and 40 DAS registered maximum dehydrogenase enzyme activity (0.329 μgTPF/g soil/d) closely followed by herbicides mixtures and sole herbicide while pre-emergence application of pendimethalin + imazethapyr 960 g a.i./ha and pendimethalin 1.0 kg a.i./ha significantly reduced dehydrogenase enzyme activity compared to control. Urease enzyme activity was not much affected under different weed control treatments and weedy checks. The treatments were found statistically non-significant, and values ranged between 1.16-1.25 μgNH4N/g soil/d. Phosphatase enzyme activity was also not influenced significantly due to various weed control treatments. Though maximum phosphatase enzyme activity (30.17 μgpnp/g soil/hr) was observed under two-hand weeding, followed by fomesafen + fluazifop-p-butyl 220 g a.i./ha. Herbicidal weed control measures did not influence the total bacteria, fungi, and actinomycetes population.Keywords: dehydrogenase, phosphatase, post-emergence, soil enzymes, urease.
Procedia PDF Downloads 10512896 Zarit Burden Interview among Informal Caregiver of Person with Dementia: A Systematic Review and Meta-Analysis
Authors: Nuraisyah H. Zulkifley, Suriani Ismail, Rosliza Abdul Manaf, Poh Y. Lim
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Taking care of a person with dementia (PWD) is one of the most problematic and challenging caregiving situations. Without proper support, caregiver would need to deal with the impact of caregiving that would lead to caregiver burden. One of the most common tools used to measure caregiver burden among caregivers of PWD is Zarit Burden Interview (ZBI). A systematic review has been conducted through searching Medline, Science Direct, Cochrane Library, Embase, PsycINFO, ProQuest, and Scopus databases to identify relevant articles that elaborate on intervention and outcomes on ZBI among informal caregiver of PWD. The articles were searched in October 2019 with no restriction on language or publication status. Inclusion criteria are randomized control trial (RCT) studies, participants were informal caregivers of PWD, ZBI measured as outcomes, and intervention group was compared with no intervention control or usual care control. Two authors reviewed and extracted the data from the full-text articles. From a total of 344 records, nine studies were selected and included in this narrative review, and eight studies were included in the meta-analysis. The types of interventions that were implemented to ease caregiver burden are psychoeducation, physical activity, psychosocial, and computer-based intervention. The meta-analysis showed that there is a significant difference in the mean score of ZBI (p = 0.006) in the intervention group compared to the control group after implementation of intervention. In conclusion, interventions such as psychoeducation, psychosocial, and physical activity can help to reduce the burden experiencing by the caregivers of PWD.Keywords: dementia, informal caregiver, randomized control trial, Zarit burden interview
Procedia PDF Downloads 18012895 Canine Visceral Leishmaniasis In Brazil
Authors: Elisangela Sobreira, Denise Teixeira
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Visceral leishmaniasis is a public health problem in Brazil, it is the main reservoir dog. In the period 2012-2016 78 diagnoses were performed in dogs suspected. Blood samples were collected from the cephalic vein obtaining serum used for the indirect immunofluorescence test and enzyme-linked immunosorbent assay, while it collected a drop of blood for the rapid chromatographic immunoassay. Obtained in 32 dogs positive. The test is important for the control of this disease and is used routinely in the Zoonoses Control Center.Keywords: Brazil, dogs, Leismaniasis, Zoonoses center
Procedia PDF Downloads 26212894 Examining The Effects of Parenting Style and Parents’ Social Attitudes on Social Development in Early Childhood
Authors: Amber Lim, Ted Ruffman
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A vast amount of research evidence indicates that children develop social attitudes that are similar to those of their parents. When using general measures of social attitudes, such as social dominance orientation (SDO), right-wing authoritarianism (RWA), and prejudice, studies show that parents' and children’s attitudes were correlated. However, the mechanisms behind the intergenerational transmission of attitudes remain largely unexplained. Since it was speculated that the origins of RWA could be traced back to one’s relationship with their parents, the aim of this study was to assess how parents’ social attitudes and parenting behavior are related to children’s social development. One line of research suggests that the different ways in which authoritarian and authoritative parents reason with their children may impact Theory of Mind (ToM) development. That is, inductive discipline (e.g., emphasising how the child’s actions affect others) facilitates empathy and ToM development. Conversely, past evidence shows that children have poorer ToM development when parents enforce rules without explanation. Thus, this study addresses the question of how parent behavior plays a role in the gradual acquisition of a ToM and social attitudes. Seventy parents reported their social attitudes, parenting behavior, and their child’s mental state and non-mental state vocabulary. Their children were given ToM and perspective-taking tasks, along with a friend choice task to measure racial bias and anti-fat bias. As hypothesised, parents’ use of inductive reasoning correlated with children’s performance on Theory of Mind tasks. Mothers’ inductive reasoning facilitated children’s acquisition of mental state vocabulary. Parents’ autonomy granting was associated with improved mental state vocabulary. Authoritarian parenting traits such as verbal hostility were linked to children’s racial bias. These findings highlight the importance of parent-child discussion in shaping children’s social understanding.Keywords: parenting style, prejudice, social attitudes, social understanding, theory of mind
Procedia PDF Downloads 8212893 Method for Tuning Level Control Loops Based on Internal Model Control and Closed Loop Step Test Data
Authors: Arnaud Nougues
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This paper describes a two-stage methodology derived from internal model control (IMC) for tuning a proportional-integral-derivative (PID) controller for levels or other integrating processes in an industrial environment. Focus is the ease of use and implementation speed which are critical for an industrial application. Tuning can be done with minimum effort and without the need for time-consuming open-loop step tests on the plant. The first stage of the method applies to levels only: the vessel residence time is calculated from equipment dimensions and used to derive a set of preliminary proportional-integral (PI) settings with IMC. The second stage, re-tuning in closed-loop, applies to levels as well as other integrating processes: a tuning correction mechanism has been developed based on a series of closed-loop simulations with model errors. The tuning correction is done from a simple closed-loop step test and the application of a generic correlation between observed overshoot and integral time correction. A spin-off of the method is that an estimate of the vessel residence time (levels) or open-loop process gain (other integrating process) is obtained from the closed-loop data.Keywords: closed-loop model identification, IMC-PID tuning method, integrating process control, on-line PID tuning adaptation
Procedia PDF Downloads 22312892 Argument Representation in Non-Spatial Motion Bahasa Melayu Based Conceptual Structure Theory
Authors: Nurul Jamilah Binti Rosly
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The typology of motion must be understood as a change from one location to another. But from a conceptual point of view, motion can also occur in non-spatial contexts associated with human and social factors. Therefore, from the conceptual point of view, the concept of non-spatial motion involves the movement of time, ownership, identity, state, and existence. Accordingly, this study will focus on the lexical as shared, accept, be, store, and exist as the study material. The data in this study were extracted from the Database of Languages and Literature Corpus Database, Malaysia, which was analyzed using semantics and syntax concepts using Conceptual Structure Theory - Ray Jackendoff (2002). Semantic representations are represented in the form of conceptual structures in argument functions that include functions [events], [situations], [objects], [paths] and [places]. The findings show that the mapping of these arguments comprises three main stages, namely mapping the argument structure, mapping the tree, and mapping the role of thematic items. Accordingly, this study will show the representation of non- spatial Malay language areas.Keywords: arguments, concepts, constituencies, events, situations, thematics
Procedia PDF Downloads 12912891 Nonlinear Propagation of Acoustic Soliton Waves in Dense Quantum Electron-Positron Magnetoplasma
Authors: A. Abdikian
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Propagation of nonlinear acoustic wave in dense electron-positron (e-p) plasmas in the presence of an external magnetic field and stationary ions (to neutralize the plasma background) is studied. By means of the quantum hydrodynamics model and applying the reductive perturbation method, the Zakharov-Kuznetsov equation is derived. Using the bifurcation theory of planar dynamical systems, the compressive structure of electrostatic solitary wave and periodic travelling waves is found. The numerical results show how the ion density ratio, the ion cyclotron frequency, and the direction cosines of the wave vector affect the nonlinear electrostatic travelling waves. The obtained results may be useful to better understand the obliquely nonlinear electrostatic travelling wave of small amplitude localized structures in dense magnetized quantum e-p plasmas and may be applicable to study the particle and energy transport mechanism in compact stars such as the interior of massive white dwarfs etc.Keywords: bifurcation theory, phase portrait, magnetized electron-positron plasma, the Zakharov-Kuznetsov equation
Procedia PDF Downloads 24412890 The Effects of Cross-Border Use of Drones in Nigerian National Security
Authors: H. P. Kerry
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Drone technology has become a significant discourse in a nation’s national security, while this technology could constitute a danger to national security on the one hand, on the other hand, it is used in developed and developing countries for border security, and in some cases, for protection of security agents and migrants. In the case of Nigeria, drones are used by the military to monitor and tighten security around the borders. However, terrorist groups have devised a means to utilize the technology to their advantage. Therefore, the potential danger in the widespread proliferation of this technology has become a myriad of risks. The research on the effects of cross-border use of drones in Nigerian national security looks at the negative and positive consequences of using drone technology. The study employs the use of interviews and relevant documents to obtain data while the study applied the Just War theory to justify the reason why countries use force; it further buttresses the points with what the realist theory thinks about the use of force. In conclusion, the paper recommends that the Nigerian government through the National Assembly should pass a bill for the establishment of a law that will guide the use of armed and unarmed drones in Nigeria enforced by the Nigeria Civil Aviation Authority and the office of the National Security Adviser.Keywords: armed drones, drones, cross-border, national security
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