Search results for: fundamental mode shape

Authors: Jiangbo Shi, Zeyu Gao, Chen Li

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Nuclei segmentation is a fundamental task in digital pathology analysis and can be automated by deep learning-based methods. However, the development of such an automated method requires a large amount of data with precisely annotated masks which is hard to obtain. Training with weakly labeled data is a popular solution for reducing the workload of annotation. In this paper, we propose a novel meta-learning-based nuclei segmentation method which follows the label correction paradigm to leverage data with noisy masks. Specifically, we design a fully conventional meta-model that can correct noisy masks by using a small amount of clean meta-data. Then the corrected masks are used to supervise the training of the segmentation model. Meanwhile, a bi-level optimization method is adopted to alternately update the parameters of the main segmentation model and the meta-model. Extensive experimental results on two nuclear segmentation datasets show that our method achieves the state-of-the-art result. In particular, in some noise scenarios, it even exceeds the performance of training on supervised data.

Keywords: deep learning, histopathological image, meta-learning, nuclei segmentation, weak annotations

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Authors: WooYoung Jung, V. Sim

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This paper presents numerical analysis in terms of buckling resistance strength of polymer matrix composite (PMC) infill panels system under the influence of temperature on the foam core. Failure mode under in-plane compression is investigated by means of numerical analysis with ABAQUS platform. Parameters considered in this study are contact length and both the type of foam for core and the variation of its Young's Modulus under the thermal influence. Variation of temperature is considered in static cases and only applied to core. Indeed, it is shown that the effect of temperature on the panel system mechanical properties is significance. Moreover, the variations of temperature result in the decrements of the system strength. This is due to the polymeric nature of this material. Additionally, the contact length also displays the effect on performance of infill panel. Their significance factors are based on type of polymer for core. Hence, by comparing difference type of core material, the variation can be reducing.

Keywords: buckling, contact length, foam core, temperature dependent

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Authors: Maedeh Gharazi

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Distinguishing proof of entrepreneurial open doors in the field of nutrition counseling is a focal issue in utilizing nutrition experts and addressing the needs of patients with chronic diseases better. To this end, this review has been directed keeping in mind the end goal to investigate the supply and interest patterns of diabetes sustenance advising as a fundamental stride toward recognizing the entrepreneurial open doors for nutrition advisors in Tehran, Iran. To execute this expressive overview concentrate on, a survey in light of Likert scale was sent via email to 100 dynamic experts in the field of nutrition counseling services in Tehran, of whom 52 reacted to its inquiries. At that point, the mean estimations of members' reactions were ascertained utilizing SPSS programming and contrasted to each other. The outcome acquired in view of members' reactions uncovered that the requirement for "healthful guiding as a treatment group" was basically not met in diverse age, training and salary gatherings of diabetic patients. Along these lines, nutrition counseling as a treatment group can be considered as a suitable field for entrepreneurial exercises.

Keywords: nutrition counseling, chronic diseases, diabetes, likert scale, SPSS programming

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Authors: A. Escoffier, A. Albrecht, F. Consigny

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In order to host the Football Euro in 2016, many French cities have launched architectural competitions in recent years to improve the quality of their stadiums. The winning project in Nice was designed by Wilmotte architects together with Elioth structural engineers. It has a capacity of 35,000 seats. Its roof structure consists of a complex 3D shape timber and steel lattice and is covered by 25,000m² of ETFE, 10,500m² of PES-PVC fabric and 8,500m² of photovoltaic panels. This paper focuses on the ETFE part of the cover. The stadium is one of the first constructions to use flat single layer ETFE on such a big area. Due to its relatively recent appearance in France, ETFE structures are not yet covered by any regulations and the existing codes for fabric structures cannot be strictly applied. Rather, they are considered as cladding systems and therefore have to be approved by an “Appréciation Technique d’Expérimentation” (ATEx), during which experimental tests have to be performed. We explain the method that we developed to justify the ETFE, which eventually led to bi-axial tests to clarify the allowable stress in the film.

Keywords: biaxial test, creep, ETFE, single layer, stadium roof

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Authors: Khaing Su Su Than, Hibino Yo

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Seismic evaluation is needed upon the buildings in Myanmar. Microtremor measurement was conducted in the main cities, Mandalay and Yangon. In order to evaluate the seismic properties of buildings currently under construction, seismic information was gathered for six buildings in Yangon city and four buildings in Mandalay city. The investigated buildings vary from 12m-80 m in height, and mostly public residence structures. The predominant period obtained from frequency results of the investigated buildings were given by horizontal to vertical spectral ratio (HVSR) for each building. The fundamental period results have been calculated in the form of Fourier amplitude spectra of translation along with the main structure. Based on that, the height (H)-period(T) relationship was observed as T=0.012H-0.017H in the buildings of Yangon and, observed the relationship as T=0.014H-0.019H in the buildings of Mandalay. The results showed that the relationship between height and natural period was slightly under the relationship T=0.02H that is used for Japanese reinforced concrete buildings, which indicated that the results depend on the properties and characteristics of materials used.

Keywords: HVSR, height-period relationship, microtremor, Myanmar earthquake, reinforced concrete structures

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Authors: Nandini Mukhopadhyay

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The prominence of terracotta as a building material in Bengal is well justified by its geographical location. The architectural knowledge system associated with terracotta can be comprehended in the typology of the built structures as they act as texts to interpret the knowledge. The history of Bengal has witnessed the influence of several rulers in developing the architectural vocabulary of the region. This metamorphosis of the architectural knowledge systems in the region includes the Bhakti movement, the Islamic influence, and the British rule, which led to the evolution of the use of terracotta from decorative elements to structural elements in the present-day context. This paper intends to develop an understanding of terracotta as a building material, its use in a built structure, the common problems associated with terracotta construction, and the techniques of maintenance, repair, and conservation. This paper also explores the size, shape, and geometry of the material and its varied use in temples, mosques in the region. It also takes into note that the use of terracotta was concentrated majorly to religious structures and not in the settlements of the common people. And the architectural style of temples and mosques of Bengal is hugely influenced by the houses of the common.

Keywords: terracotta, material, knowledge system, conservation

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Authors: Uche A. Nnawulezi

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This paper analyzes the advancing nature of nuclear terrorism and proliferation in the global environment and its attendant impacts. It analyzes discourse and practice with respect to the general prohibition on the utilization of fissionable radioactive materials. Thus, there has been a few ideological, reasonable and academic recommendations of policies aimed at eliminating nuclear weapons which its ultimate nightmare has remained an assault including nuclear explosion in densely populated urban areas. Likewise, this paper concentrates on safety measures aimed at preventing nuclear assaults which should not just concentrate on endeavors to prevent terrorists from exploding nuclear gadgets but should be more concerned on endeavors aimed at preventing the acquisition of nuclear weapons in the first place. The author of this paper has pointed out that the non-proliferation treaty should be vigorously supported as well as the Comprehensive Test Ban Treaty brought into force. This paper depended unequivocally on secondary sources, for example, textbooks, journals, articles, and periodicals. It concludes that the fundamental proposals made in this paper if completely used shall remain a cornerstone of efforts made in preventing the spread of nuclear weapons. At last, the only way is to eliminate stockpiles of nuclear weapons in the world or else the likelihood of nuclear terrorism remains a nightmare.

Keywords: nuclear, terrorism, proliferation, global environment

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Authors: Carlos H. Ferreira, Joana R. Pereira

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In recent decades, calls for sustainable architecture based on environmental policies have been frequent. Despite a vast number of documents, technical procedures, and publications involving these themes, conceptions, and even architectural practice are often distanced from critical and methodological reflection on the relationship between environment and architecture. Among the various issues that we could consider in this relationship, we highlight in this article the relevance of water in the environment and in the architectural design. From documentary references and works carried out, we seek contributions to a better systematization and framing of water in architectural thinking. We distinguish, on the one hand, more conceptual issues that involve the environmental relationship of water, involving its cycle, relevance in the landscape, and infrastructural commitments. On the other hand, we highlight a more operative component, focusing on the place of water in the design process, from its perception in space-shape dimensions to more specific technical requirements that involve the interdisciplinary boundaries of architecture. In both approaches to water in architectural design, we seek to contribute to greater sensitivity and efficiency in the art of designing a more sustainable future.

Keywords: sustainability, environment, water, resilience design

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Authors: Sanjoy Barua Chowdhury

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This research is an attempt to examine psychological aspect of the Buddha’s most cardinal and fundamental doctrine of Dependent Origination (paṭiccasamuppāda) along with drawing out a clear picture of the constituents from the law of causation and analyzes the mental states and motivational factors behind each constituent among twelvefold links. Meticulous research into the doctrine of Dependent Origination reveals how the main links from the doctrine of dependent origination provide a framework for psychological analysis through volitional formation (saṅkhāra), consciousness (viññāna), mentality and materiality (nāma-rūpa), contact (phassa), feeling (vedanā), craving (tanhā) and clinging (upādāna). This paper further illustrates the notion of perception (saññā) which can be found in the function of volitional formation (saṅkhāra) - a contributing factor, according to modern psychology, in the role of understanding human (puggala) motivation. The psychological analysis of dependent origination expounds the concept of personality highlighting present existence through the inter-relationship of the five faculties (pañcaupadānakkhandhā), viz., form (rūpa), feeling (vedanā), perception (saññā), volitional formation (saṅkhārā) and consciousness (viññāṇa).

Keywords: dependent origination, perception, motivational factors, feelings

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Authors: Walaa W. Diab

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The present paper offers a fundamental critique of the macroeconomic effects of fiscal policy after it surveys the theoretical and empirical literature on the macroeconomic effects of fiscal policy. It emphasizes the importance of the fiscal policy after reviewing the revolution of almost all economic schools and bringing them in one summarized figure; the paper links the developmental role of the fiscal policy with the objectives and measures of the economic transformation. Thus, the importance of this study can be seen from several perspectives: First, it reviews the theoretical harvest of fiscal policy and provides a comparison between the main revolutionary Economic thoughts; the classical school, Keynesian school, and monetarist school. Then it turns to conclude the fiscal policy from the new consensus mainstream economic schools. Finally, the study presents grouped and classified empirical pieces of evidence as it divides those empirical studies into two groups; the first for developed economies and the second for developing ones. So the study is important also for the policymakers as well as scholars as it gives its recommendations upon the last analysis in the form of ‘policy implications’. The paper also presents a deeper look into the evaluation approaches of the macroeconomic effects of fiscal policy at the empirical level. Thus it is useful for both researchers and decision makers.

Keywords: economic transformation, fiscal policy, macroeconomic effects, public spending

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Authors: Simbarashe Nzvere

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In an era dominated by digital communication, social media has become a powerful tool for political leaders to connect with the public, shape their narratives, and influence perceptions. With this much performance from political leaders, this paper will explore the dichotomy between authenticity and performance in the digital personas of political leaders. By examining how leaders craft their image on platforms such as X (Formerly Twitter), Facebook, Instagram, and Linked In, this study investigates whether these portrayals align with their true character or represent a strategic facade designed to resonate with target audiences. Utilizing case studies and content analysis, the research delves into the methods leaders employ to construct their online identities, the role of digital marketing teams in shaping these images, and the implications for public trust and political engagement. The findings highlight the complex interplay between genuine representation and strategic branding, offering insights into how social media reshapes political leadership in the 21st century.

Keywords: political leadership, social media, authenticity, public perceptions, digital persona

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Authors: Endang Ghani Ashfiya

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This study explores corporate social responsibility (CSR) planning in a downstream business of multinational oil and gas company in Indonesia from managerial perspectives. The institutional logic is employed in this research to gain a comprehensive understanding of the way the MNC manages the socio-cultural aspects in the host countries, especially in the process of translation and adaptation of the company’s CSR global guidelines. The interviews are conducted with fifteen managers in that company, both at the top managerial level and operational level. In the beginning, this research explains the Indonesian society’s conception of CSR from the managerial standpoints. The society’s understanding of the CSR concept becomes the fundamental foundations of the company in developing CSR programs. This study found the company’s approach to its CSR in two ways. First, proactive CSR which reflects the global CSR guidelines. Second, reactive CSR which do not show any explicit relations to the global guidelines, but conform with society’s demands. The findings stimulate discussions regarding the power of an MNC vis-à-vis the socio-cultural implication in society’s demand for CSR.

Keywords: corporate social responsibility planning, Indonesia, institutional logic, multinational company, oil and gas company, socio-cultural aspects

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Authors: Baghdasaryan Marinka

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The particular significance of comprehensive estimation of the increase in the operation efficiency of the mill motor electromechanical system, providing the main technological process for obtaining a metallic concentrate, as well as the technical state of the system are substantiated. The works carried out in the sphere of investigating, creating, and improving the operation modes of electric drive motors and ore-grinding mills have been studied. Analytic dependences for estimating the operation modes of the ore-grinding mills aimed at improving the ore-crashing process maintenance and technical service efficiencies have been obtained. The obtained analytic dependencies establish a link between the technological and power parameters of the electromechanical system, and allow to estimate the state of the system and reveal the controlled parameters required for the efficient management in case of changing the technological parameters. It has been substantiated that the changes in the technological factors affecting the consumption power of the drive motor do not cause an instability in the electromechanical system.

Keywords: electromechanical system, estimation, operation mode, productivity, technological process, the mill filling degree

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Authors: Norjan Jumaa, David Graham

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We present a Lattice Boltzmann Method (LBM) for multiphase flows with high viscosity and density ratios. The motion of the interface between fluids is modelled by solving the Cahn-Hilliard (CH) equation with LBM. Incompressibility of the velocity fields in each phase is imposed by using a pressure correction scheme. We use a unified LBM approach with separate formulations for the phase field, the pressure less Naiver-Stokes (NS) equations and the pressure Poisson equation required for correction of the velocity field. The implementation has been verified for various test case. Here, we present results for some complex flow problems including two dimensional single and multiple mode Rayleigh-Taylor instability and we obtain good results when comparing with those in the literature. The main focus of our work is related to interactions between aerated or non-aerated waves and structures so we also present results for both high viscosity and low viscosity waves.

Keywords: lattice Boltzmann method, multiphase flows, Rayleigh-Taylor instability, waves

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Authors: S. W. Liu, J. H. Lv, W. Z. Wang

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In recent years, the failure accidents in petrochemical industry have been frequent, and have posed great security problems in personnel and property. The improvement of petrochemical safety is highly requested in order to prevent re-occurrence of severe accident. This study focuses on surveying the failure cases occurred in petrochemical field, which were extracted from journals of engineering failure, including engineering failure analysis and case studies in engineering failure analysis. The relation of failure mode, failure mechanism, type of components, and type of materials was analyzed in this study. And the analytical results showed that failures occurred more frequently in vessels and piping among the petrochemical equipment. Moreover, equipment made of carbon steel and stainless steel accounts for the majority of failures compared to other materials. This may be related to the application of the equipment and the performance of the material. In addition, corrosion failures were the largest in number of occurrence in the failure of petrochemical equipment, in which stress corrosion cracking accounts for a large proportion. This may have a lot to do with the service environment of the petrochemical equipment. Therefore, it can be concluded that the corrosion prevention of petrochemical equipment is particularly important.

Keywords: cases analysis, corrosion, failure, petrochemical industry

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Authors: Humayun R. H. Kabir

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A reinforced concrete dome-built 60 years ago- of circular shape of diameter of 30 m was in distressed conditions due to adverse weathering effects, such as high temperature, wind, and poor maintenance. It was decided to restore the dome to its full strength for future use. A full material strength and durability check including petrography test were conducted. It was observed that the concrete strength was in acceptable range, while bars were corroded more than 40% to their original configurations. Widespread cracks were almost in every meter square. A strengthening program with filling the cracks by injection method, and carbon fiber layup and wrap was considered. Ultra Sound Pulse Velocity (UPV) test was conducted to observe crack depth. Ground Penetration Radar (GPR) test was conducted to observe internal bar conditions and internal cracks. Finally, a load test was conducted to certify the carbon fiber effectiveness, injection method procedure and overall behavior of dome.

Keywords: dome, strengthening program, carbon fiber, load test

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Authors: Yiwei Huang, Chunyu Zhao, Jingjing Ding

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Electrical Resistivity Tomography has been widely used in the medicine and the geology, such as the imaging of the lung impedance and the analysis of the soil impedance, etc. Linear Back Projection is the core algorithm of Electrical Resistivity Tomography, but the traditional Linear Back Projection can not make full use of the information of the electric field. In this paper, an imaging method of Parallel Electrode Linear Back Projection for Electrical Resistivity Tomography is proposed, which generates the electric field distribution that is not linearly related to the traditional Linear Back Projection, captures the new information and improves the imaging accuracy without increasing the number of electrodes by changing the connection mode of the electrodes. The simulation results show that the accuracy of the image obtained by the inverse operation obtained by the Parallel Electrode Linear Back Projection can be improved by about 20%.

Keywords: electrical resistivity tomography, finite element simulation, image optimization, parallel electrode linear back projection

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Authors: Mansouri Nabila, Ben Jemaa Yousra, Motamed Cina, Watelain Eric

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Research and development efforts in intelligent Advanced Driver Assistance Systems (ADAS) seek to save lives and reduce the number of on-road fatalities. For traffic and emergency monitoring, the essential but challenging task is vehicle detection and tracking in reasonably short time. This purpose needs first of all a powerful dynamic car detector model. In fact, this paper presents an optimized HOG process based on shape and motion parameters fusion. Our proposed approach mains to compute HOG by bloc feature from foreground blobs using configurable research window and pathway in order to overcome the shortcoming in term of computing time of HOG descriptor and improve their dynamic application performance. Indeed we prove in this paper that HOG by bloc descriptor combined with motion parameters is a very suitable car detector which reaches in record time a satisfactory recognition rate in dynamic outside area and bypasses several popular works without using sophisticated and expensive architectures such as GPU and FPGA.

Keywords: car-detector, HOG, motion, computing time

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Authors: Xian Xie, Qinghua Fang

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This study used quantitative and qualitative methods to explore the characteristics of flipped classroom’s influence on classroom environment of college English reading, writing, and translating, and to summarize and reflect on the teaching characteristics of college English Reading, writing, and translating. The results of the study indicated that after the flipped classroom applied to reading, writing, and translating, students’ performance was improved to a certain extent, the classroom environment was improved to some extent, students of the flipped classroom are generally satisfied with the classroom environment; students showed a certain degree of individual differences to the degree of cooperation, participation, self-responsibility, task-orientation, and the teacher leadership and innovation. The study indicated that the implementation of flipped classroom teaching mode can optimize College English reading, writing, and translating classroom environment and realize target－learner as the center in foreign language teaching and learning, but bring a greater challenge to teachers.

Keywords: classroom environment, college English reading, writing and translating, individual differences, flipped classroom

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Authors: Filip Dodigovic, Kreso Ivandic, Damir Stuhec, S. Strelec

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The general difference analysis between the former and new design concepts in geotechnical engineering is carried out. The application of new regulations results in the need for real adaptation of the computation principles of limit states, i.e. by providing a uniform way of analyzing engineering tasks. Generally, it is not possible to unambiguously match the limit state verification procedure with those in the construction engineering. The reasons are the inability to fully consistency of the common probabilistic basis of the analysis, and the fundamental effect of material properties on the value of actions and the influence of actions on resistance. Consequently, it is not possible to apply separate factorization with partial coefficients, as in construction engineering. For the slope stability analysis design procedures problems in the light of the use of limit states in relation to the concept of allowable stresses is detailed in. The quantifications of the safety margins in the slope stability analysis for both approaches is done. When analyzing the stability of the slope, by the strict application of the adopted forms from the new regulations for significant external temporary and/or seismic actions, the equivalent margin of safety is increased. The consequence is the emergence of more conservative solutions.

Keywords: allowable pressure, Eurocode 7, limit states, slope stability

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Authors: P. Kumar, D. Eisenhauer, M. M. K. Yousef, Q. Shi, A. S. G. Khalil, M. R. Saber, C. Becker, T. Pullerits, K. J. Karki

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In impedance spectroscopy (IS) the response of a photo-active device is analysed as a function of ac bias. It is widely applied in a broad class of material systems and devices. It gives access to fundamental mechanisms of operation of solar cells. We have implemented a method of IS where we modulate the light instead of the bias. This scheme allows us to analyze not only carrier dynamics but also impedance of device locally. Here, using this scheme, we have measured the frequency-dependent photocurrent response of the thin-film planar and nano-textured Si solar cells using this method. Photocurrent response is measured in range of 50 Hz to 50 kHz. Bode and Nyquist plots are used to determine characteristic lifetime of both the cells. Interestingly, the carrier lifetime of both planar and nano-textured solar cells depend on back and front contact positions. This is due to either heterogeneity of device or contacts are not optimized. The estimated average lifetime is found to be shorter for the nano-textured cell, which could be due to the influence of the textured interface on the carrier relaxation dynamics.

Keywords: carrier lifetime, impedance, nano-textured, photocurrent

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Authors: Prabhsharan Singh, Rahul Sindhu, Piyush Sikka

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The steering system is an integral part and medium through which the driver communicates with the vehicle and terrain, hence the most suitable steering geometry as per requirements must be chosen. The function of the chosen steering geometry of an All-Terrain Vehicle (ATV) is to provide the desired understeer gradient, minimum tire slippage, expected weight transfer during turning as these are requirements for a good steering geometry of a BAJA ATV. This research paper focuses on choosing the best suitable steering geometry for BAJA ATV tracks by reasoning the working principle and using fundamental trigonometric functions for obtaining these geometries on the same vehicle itself, namely Ackermann, Anti- Ackermann, Parallel Ackermann. Full vehicle analysis was carried out on Adams Car Analysis software, and graphical results were obtained for various parameters. Steering geometries were achieved by using a single versatile knuckle for frontward and rearward tie-rod placement and were practically tested with the help of data acquisition systems set up on the ATV. Each was having certain characteristics, setup, and parameters were observed for the BAJA ATV, and correlations were created between analytical and practical values.

Keywords: all-terrain vehicle, Ackermann, Adams car, Baja Sae, steering geometry, steering system, tire slip, traction, understeer gradient

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Authors: Behnam Madadnia

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For several years, 3D-shaped electronics have been rising, with many uses in home appliances, automotive, and manufacturing. One of the biggest challenges in the fabrication of 3D shape electronics, which are made by thermoforming, is repeatable and accurate component positioning, and typically there is no control over the final position of the component. This paper aims to address this issue and present a reliable approach for guiding the electronic components in the desired place during thermoforming. We have proposed a heat-control mask in the thermoforming machine to control the heating of the polymer, not allowing specific parts to be formable, which can assure the conductive traces' mechanical stability during thermoforming of the substrate. We have verified our approach's accuracy by applying our method on a real industrial semi-sphere mold for positioning 7 LEDs and one touch sensor. We measured the LEDs' position after thermoforming to prove the process's repeatability. The experiment results demonstrate that the proposed method is capable of positioning electronic components in thermoformed 3D electronics with high precision.

Keywords: 3D-shaped electronics, electronic components, thermoforming, component positioning

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Authors: Rafik Taleb, Farid Bouriche, Mehdi Boukri, Fouad Kehila

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The aim of the paper is to investigate the dynamic behavior of an unreinforced masonry (URM) building strengthened by DC-90 dampers by ambient and low-level forced vibration tests. Ambient and forced vibration techniques are usually applied to reinforced concrete or steel buildings to understand and identify their dynamic behavior, however, less is known about their applicability for masonry buildings. Ambient vibrations were measured before and after strengthening of the URM building by DC-90 dampers system. For forced vibration test, a series of low amplitude steady state harmonic forced vibration tests were conducted after strengthening using eccentric mass shaker. The resonant frequency curves, mode shapes and damping coefficients as well as stress distribution in the steel braces of the DC-90 dampers have been investigated and could be defined. It was shown that the dynamic behavior of the masonry building, even if not regular and with deformable floors, can be effectively represented. It can be concluded that the strengthening of the building does not change the dynamic properties of the building due to the fact of low amplitude excitation which do not activate the dampers.

Keywords: ambient vibrations, masonry buildings, forced vibrations, structural dynamic identification

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Authors: Mehaiguene Madjid, Touhari Fadhila, Meddi Mohamed

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The Cheliff basin offers a good hydrological example for the possibility of studying the problem which elucidated in the future, because of the unclearity in several aspects and hydraulic installation. Thus, our study of the Cheliff basin is divided into two principal parts: The spatial evaluation of the precipitation: also, the understanding of the modes of the reconstitution of the resource in water supposes a good knowledge of the structuring of the precipitation fields in the studied space. In the goal of a good knowledge of revitalizes them in water and their management integrated one judged necessary to establish a precipitation card of the Cheliff basin for a good understanding of the evolution of the resource in water in the basin and that goes will serve as basis for all study of hydraulic planning in the Cheliff basin. Then, the establishment of the precipitation card of the Cheliff basin answered a direct need of setting to the disposition of the researchers for the region and a document of reference that will be completed therefore and actualized. The hydrological study, based on the statistical hydrometric data processing will lead us to specify the hydrological terms of the assessment hydrological and to clarify the fundamental aspects of the annual flow, seasonal, extreme and thus of their variability and resources surface water.

Keywords: hydrological assessment, surface water resources, Cheliff, Algeria

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Authors: M. Najafi

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In the present paper, a large turbo-generator shaft train including a heavy-duty gas turbine engine, a coupling, and a generator is established. The method of analysis is based on finite element simplified model for lateral and torsional vibration calculation. The basic elements of rotor are the shafts and the disks which are represented as circular cross section flexible beams and rigid body elements, respectively. For more accurate results, the gyroscopic effect and bearing dynamics coefficients and function of rotation are taken into account, and for the influence of shear effect, rotor has been modeled in the form of Timoshenko beam. Lateral critical speeds, critical speed map, damped mode shapes, Campbell diagram, zones of instability, amplitudes, phase angles response due to synchronous forces of excitation and amplification factor are calculated. Also, in the present paper, the effect of imbalanced rotor and effects of changing in internal force and temperature are studied.

Keywords: rotor dynamic analysis, finite element method, shaft train, Campbell diagram

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Authors: F. Chigondo, G. Chitabati

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Hexavalent chromium is toxic and is widely used in many industries hence efficient and economical methods must be explored to remove the chromium(VI) from the environment. The removal of Cr (VI) from aqueous solutions onto polyaniline coated maize tassel was studied in batch mode at varying initial metal concentrations, adsorbent doses, pH and contact times. The residual Cr (VI) concentrations before and after adsorption were analyzed by Ultraviolet–visible spectroscopy. FTIR analysis of the polyaniline coated maize tassel showed the presence of C=C, C=N, C-H, C-N and N-H groups. Adsorption conditions were deduced to be pH of 2, adsorbent dosage 1g/L, Cr(VI) initial concentration of 40mg/L contact time of 150 minutes and agitation speed of 140rpm. Data obtained fitted best to the Langmuir isotherm (R2 = 0.972) compared to the Freundlich isotherm (R2 0.671. The maximum adsorption capacity was found to be 125mg/L. Correlation coefficients for pseudo first order and pseudo second order were 0.952 and 0.971 respectively. The adsorption process followed the pseudo-second order kinetic model. The studied polyaniline coated maize tassel can therefore be used as a promising adsorbent for the removal of Cr (VI) ion from aqueous solution.

Keywords: polyaniline-coated, maize tassels, adsorption, hexavalent chromium

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Authors: M. S. Ahmed, F. A. Mohammad

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The aim of this paper is to perform experimental modal analysis (EMA) of reinforced concrete (RC) square slabs. EMA is the process of determining the modal parameters (Natural Frequencies, damping factors, modal vectors) of a structure from a set of frequency response functions FRFs (curve fitting). Although experimental modal analysis (or modal testing) has grown steadily in popularity since the advent of the digital FFT spectrum analyzer in the early 1970’s, studying all members and materials using such method have not yet been well documented. Therefore, in this work, experimental tests were conducted on RC square specimens (0.6m x 0.6m with 40 mm). Experimental analysis is based on freely supported boundary condition. Moreover, impact testing as a fast and economical means of finding the modes of vibration of a structure was used during the experiments. In addition, Pico Scope 6 device and MATLAB software were used to acquire data, analyze and plot Frequency Response Function (FRF). The experimental natural frequencies which were extracted from measurements exhibit good agreement with analytical predictions. It is showed that EMA method can be usefully employed to perform the dynamic behavior of RC slabs.

Keywords: natural frequencies, mode shapes, modal analysis, RC slabs

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Authors: Lovro Štefan

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Background: The main purpose of the present study was to explore the correlations between physical activity and peak plantar pressure in dynamic mode. Methods: Participants were one hundred forty-six first-year university students (30.8% girls). Plantar pressure generated under each region of the foot (forefoot, midfoot, and heel) was measured by using Zebris dynamometric platform (Isny, Germany). The level of physical activity (PA) was calculated with the International Physical Activity questionnaire (IPAQ - short form). Results: In boys, forefoot peak plantar pressure was correlated with moderate PA (MPA; r=-0.21), vigorous PA (VPA; r=-0.18), and moderate-to-vigorous PA (MVPA; r=-0.28). No significant correlations with other foot regions (p>0.05) were observed. In girls, forefoot peak plantar pressure was correlated with MPA (r =-0.30), VPA (r=-0.39) and MVPA (r=-0.38). Also, heel peak pressure was significantly correlated with MPA (r=-0.33), while no significant correlations with VPA (r=0.05) and MVPA (r=-0.15) were observed. Conclusion: This study shows that different intensities of PA were mostly correlated with forefoot peak plantar pressure in both boys and girls. Therefore, strategies that reduce plantar pressure through a more active lifestyle should be implemented within the education system.

Keywords: pedobarography, youth, exercise, associations

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Authors: Amin Sedighfar, M. R. Moniri

Abstract:

Determination of state of charge (SOC) in today’s world becomes an increasingly important issue in all the applications that include a battery. In fact, estimation of the SOC is a fundamental need for the battery, which is the most important energy storage in Hybrid Electric Vehicles (HEVs), smart grid systems, drones, UPS and so on. Regarding those applications, the SOC estimation algorithm is expected to be precise and easy to implement. This paper presents an online method for the estimation of the SOC of Valve-Regulated Lead Acid (VRLA) batteries. The proposed method uses the well-known Kalman Filter (KF), and Neural Networks (NNs) and all of the simulations have been done with MATLAB software. The NN is trained offline using the data collected from the battery discharging process. A generic cell model is used, and the underlying dynamic behavior of the model has used two capacitors (bulk and surface) and three resistors (terminal, surface, and end), where the SOC determined from the voltage represents the bulk capacitor. The aim of this work is to compare the performance of conventional integration-based SOC estimation methods with a mixed algorithm. Moreover, by containing the effect of temperature, the final result becomes more accurate. 

Keywords: Kalman filter, neural networks, state-of-charge, VRLA battery

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