Search results for: simulation tools
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8572

Search results for: simulation tools

4732 Performance Variation of the TEES According to the Changes in Cold-Side Storage Temperature

Authors: Young-Jin Baik, Minsung Kim, Junhyun Cho, Ho-Sang Ra, Young-Soo Lee, Ki-Chang Chang

Abstract:

Surplus electricity can be converted into potential energy via pumped hydroelectric storage for future usage. Similarly, thermo-electric energy storage (TEES) uses heat pumps equipped with thermal storage to convert electrical energy into thermal energy; the stored energy is then converted back into electrical energy when necessary using a heat engine. The greatest advantage of this method is that, unlike pumped hydroelectric storage and compressed air energy storage, TEES is not restricted by geographical constraints. In this study, performance variation of the TEES according to the changes in cold-side storage temperature was investigated by simulation method.

Keywords: energy storage system, heat pump, fluid mechanics, thermodynamics

Procedia PDF Downloads 477
4731 Identification of Wiener Model Using Iterative Schemes

Authors: Vikram Saini, Lillie Dewan

Abstract:

This paper presents the iterative schemes based on Least square, Hierarchical Least Square and Stochastic Approximation Gradient method for the Identification of Wiener model with parametric structure. A gradient method is presented for the parameter estimation of wiener model with noise conditions based on the stochastic approximation. Simulation results are presented for the Wiener model structure with different static non-linear elements in the presence of colored noise to show the comparative analysis of the iterative methods. The stochastic gradient method shows improvement in the estimation performance and provides fast convergence of the parameters estimates.

Keywords: hard non-linearity, least square, parameter estimation, stochastic approximation gradient, Wiener model

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4730 Promoting the Contructor's Reputation in the Nigerian Construction Industry

Authors: Abdulkadir Adamu Shehu

Abstract:

Company’s reputation is an elusive asset. The reputation gained by companies must be preserved for sustainability of the company. However, the construction project is still suffering from declination of character due to the factors that affect their reputation. The problem led to the loss of projects, abandoning of the projects and many more. This contributed to negative impact on the contractors in the construction industry. As for today, previous studies have not investigated in this regards yet. For that reason, this paper examines the factors which could promote contractor’s reputation in the construction industry in Nigeria. To achieve this aim, 140 questionnaires were distributed to the Nigerian contractors. Based on the 67% response rate, descriptive analysis and analysis of variance (ANOVA) were the tools applied for the data obtained to be analysed. The result shows that, good communication system and improve quality of output of products are the most significant variables that can promote contractor’s reputation. The homogenous analyses indicate that there are significant different perceptions of respondents in term of the significant effects. The research concluded that contractor’s reputation in construction industry must be maintained and further research was suggested to focus on the qualitative method to have in-depth knowledge on contractor’s reputation in the construction industry.

Keywords: construction industry, contractor’s reputation, effects of delay, Nigeria

Procedia PDF Downloads 425
4729 Optimization of Slider Crank Mechanism Using Design of Experiments and Multi-Linear Regression

Authors: Galal Elkobrosy, Amr M. Abdelrazek, Bassuny M. Elsouhily, Mohamed E. Khidr

Abstract:

Crank shaft length, connecting rod length, crank angle, engine rpm, cylinder bore, mass of piston and compression ratio are the inputs that can control the performance of the slider crank mechanism and then its efficiency. Several combinations of these seven inputs are used and compared. The throughput engine torque predicted by the simulation is analyzed through two different regression models, with and without interaction terms, developed according to multi-linear regression using LU decomposition to solve system of algebraic equations. These models are validated. A regression model in seven inputs including their interaction terms lowered the polynomial degree from 3rd degree to 1st degree and suggested valid predictions and stable explanations.

Keywords: design of experiments, regression analysis, SI engine, statistical modeling

Procedia PDF Downloads 180
4728 A Golay Pair Based Synchronization Algorithm for Distributed Multiple-Input Multiple-Output System

Authors: Weizhi Zhong, Xiaoyi Lu, Lei Xu

Abstract:

In order to solve the problem of inaccurate synchronization for distributed multiple-input multiple-output (MIMO) system in multipath environment, a golay pair aided timing synchronization method is proposed in this paper. A new synchronous training sequence based on golay pair is designed. By utilizing the aperiodic auto-correlation complementary property of the new training sequence, the fine timing point is obtained at the receiver. Simulation results show that, compared with the tradition timing synchronization approaches, the proposed algorithm can provide high accuracy in synchronization, especially under multipath condition.

Keywords: distributed MIMO system, golay pair, multipath, synchronization

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4727 Economic and Technical Study for Hybrid (PV/Wind) Power System in the North East of Algeria

Authors: Nabila Louai, Fouad Khaldi, Houria Benharchache

Abstract:

In this paper, the case of meeting a household’s electrical energy demand with hybrid systems has been examined. The objective is to study technological feasibility and economic viability of the electrification project by a hybrid system (PV/ wind) of a residential home located in Batna-Algeria and to reduce the emissions from traditional power by using renewable energy. An autonomous hybrid wind/photovoltaic (PV)/battery power system and a PV/Wind grid connected system, has been carried out using Hybrid Optimization Model for Electric Renewable (HOMER) simulation software. As a result, it has been found that electricity from the grid can be supplied at a lower price than electricity from renewable energy at this moment.

Keywords: batna, household, hybrid system, renewable energy, techno-economy

Procedia PDF Downloads 593
4726 Knowledge Based Liability for ISPs’ Copyright and Trademark Infringement in the EU E-Commerce Directive: Two Steps Behind the Philosophy of Computing Mind

Authors: Mohammad Sadeghi

Abstract:

The subject matter of this article is the efficiency of current knowledge standard to afford the legal integration regarding criteria and approaches to ISP knowledge standards, to shield ISP and copyright, trademark and other parties’ rights in the online information society. The EU recognizes the knowledge-based liability for intermediaries in the European Directive on Electronic Commerce, but the implication of all parties’ responsibility for combating infringement has been immolated by dominating attention on liability due to the lack of the appropriate legal mechanism to devote each party responsibility. Moreover, there is legal challenge on the applicability of knowledge-based liability on hosting services and information location tools service. The aim of this contribution is to discuss the advantages and disadvantages of ECD knowledge standard through case law with a special emphasis on duty of prevention and constructive knowledge role on internet service providers (ISP s’) to achieve fair balance between all parties rights.

Keywords: internet service providers, liability, copyright infringement, hosting, caching, mere conduit service, notice and takedown, E-commerce Directive

Procedia PDF Downloads 517
4725 Simulation of Piezoelectric Laminated Smart Structure under Strong Electric Field

Authors: Shun-Qi Zhang, Shu-Yang Zhang, Min Chen

Abstract:

Applying strong electric field on piezoelectric actuators, on one hand very significant electroelastic material nonlinear effects will occur, on the other hand piezo plates and shells may undergo large displacements and rotations. In order to give a precise prediction of piezolaminated smart structures under large electric field, this paper develops a finite element (FE) model accounting for both electroelastic material nonlinearity and geometric nonlinearity with large rotations based on the first order shear deformation (FSOD) hypothesis. The proposed FE model is applied to analyze a piezolaminated semicircular shell structure.

Keywords: smart structures, piezolamintes, material nonlinearity, strong electric field

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4724 Organisational Mindfulness Case Study: A 6-Week Corporate Mindfulness Programme Significantly Enhances Organisational Well-Being

Authors: Dana Zelicha

Abstract:

A 6-week mindfulness programme was launched to improve the well being and performance of 20 managers (including the supervisor) of an international corporation in London. A unique assessment methodology was customised to the organisation’s needs, measuring four parameters: prioritising skills, listening skills, mindfulness levels and happiness levels. All parameters showed significant improvements (p < 0.01) post intervention, with a remarkable increase in listening skills and mindfulness levels. Although corporate mindfulness programmes have proven to be effective, the challenge remains the low engagement levels at home and the implementation of these tools beyond the scope of the intervention. This study has offered an innovative approach to enforce home engagement levels, which yielded promising results. The programme launched with a 2-day introduction intervention, which was followed by a 6-week training course (1 day a week; 2 hours each). Participants learned all basic principles of mindfulness such as mindfulness meditations, Mindfulness Based Stress Reduction (MBSR) techniques and Mindfulness Based Cognitive Therapy (MBCT) practices to incorporate into their professional and personal lives. The programme contained experiential mindfulness meditations and innovative mindfulness tools (OWBA-MT) created by OWBA - The Well Being Agency. Exercises included Mindful Meetings, Unitasking and Mindful Feedback. All sessions concluded with guided discussions and group reflections. One fundamental element of this programme was engagement level outside of the workshop. In the office, participants connected with a mindfulness buddy - a team member in the group with whom they could find support throughout the programme. At home, participants completed online daily mindfulness forms that varied according to weekly themes. These customised forms gave participants the opportunity to reflect on whether they made time for daily mindfulness practice, and to facilitate a sense of continuity and responsibility. At the end of the programme, the most engaged team member was crowned the ‘mindful maven’ and received a special gift. The four parameters were measured using online self-reported questionnaires, including the Listening Skills Inventory (LSI), Mindfulness Attention Awareness Scale (MAAS), Time Management Behaviour Scale (TMBS) and a modified version of the Oxford Happiness Questionnaire (OHQ). Pre-intervention questionnaires were collected at the start of the programme, and post-intervention data was collected 4-weeks following completion. Quantitative analysis using paired T-tests of means showed significant improvements, with a 23% increase in listening skills, a 22% improvement in mindfulness levels, a 12% increase in prioritising skills, and an 11% improvement in happiness levels. Participant testimonials exhibited high levels of satisfaction and the overall results indicate that the mindfulness programme substantially impacted the team. These results suggest that 6-week mindfulness programmes can improve employees’ capacities to listen and work well with others, to effectively manage time and to experience enhanced satisfaction both at work and in life. Limitations noteworthy to consider include the afterglow effect and lack of generalisability, as this study was conducted on a small and fairly homogenous sample.

Keywords: corporate mindfulness, listening skills, organisational well being, prioritising skills, mindful leadership

Procedia PDF Downloads 268
4723 Defining a Framework for Holistic Life Cycle Assessment of Building Components by Considering Parameters Such as Circularity, Material Health, Biodiversity, Pollution Control, Cost, Social Impacts, and Uncertainty

Authors: Naomi Grigoryan, Alexandros Loutsioli Daskalakis, Anna Elisse Uy, Yihe Huang, Aude Laurent (Webanck)

Abstract:

In response to the building and construction sectors accounting for a third of all energy demand and emissions, the European Union has placed new laws and regulations in the construction sector that emphasize material circularity, energy efficiency, biodiversity, and social impact. Existing design tools assess sustainability in early-stage design for products or buildings; however, there is no standardized methodology for measuring the circularity performance of building components. Existing assessment methods for building components focus primarily on carbon footprint but lack the comprehensive analysis required to design for circularity. The research conducted in this paper covers the parameters needed to assess sustainability in the design process of architectural products such as doors, windows, and facades. It maps a framework for a tool that assists designers with real-time sustainability metrics. Considering the life cycle of building components such as façades, windows, and doors involves the life cycle stages applied to product design and many of the methods used in the life cycle analysis of buildings. The current industry standards of sustainability assessment for metal building components follow cradle-to-grave life cycle assessment (LCA), track Global Warming Potential (GWP), and document the parameters used for an Environmental Product Declaration (EPD). Developed by the Ellen Macarthur Foundation, the Material Circularity Indicator (MCI) is a methodology utilizing the data from LCA and EPDs to rate circularity, with a "value between 0 and 1 where higher values indicate a higher circularity+". Expanding on the MCI with additional indicators such as the Water Circularity Index (WCI), the Energy Circularity Index (ECI), the Social Circularity Index (SCI), Life Cycle Economic Value (EV), and calculating biodiversity risk and uncertainty, the assessment methodology of an architectural product's impact can be targeted more specifically based on product requirements, performance, and lifespan. Broadening the scope of LCA calculation for products to incorporate aspects of building design allows product designers to account for the disassembly of architectural components. For example, the Material Circularity Indicator for architectural products such as windows and facades is typically low due to the impact of glass, as 70% of glass ends up in landfills due to damage in the disassembly process. The low MCI can be combatted by expanding beyond cradle-to-grave assessment and focusing the design process on disassembly, recycling, and repurposing with the help of real-time assessment tools. Design for Disassembly and Urban Mining has been integrated within the construction field on small scales as project-based exercises, not addressing the entire supply chain of architectural products. By adopting more comprehensive sustainability metrics and incorporating uncertainty calculations, the sustainability assessment of building components can be more accurately assessed with decarbonization and disassembly in mind, addressing the large-scale commercial markets within construction, some of the most significant contributors to climate change.

Keywords: architectural products, early-stage design, life cycle assessment, material circularity indicator

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4722 Dual-Network Memory Model for Temporal Sequences

Authors: Motonobu Hattori

Abstract:

In neural networks, when new patters are learned by a network, they radically interfere with previously stored patterns. This drawback is called catastrophic forgetting. We have already proposed a biologically inspired dual-network memory model which can much reduce this forgetting for static patterns. In this model, information is first stored in the hippocampal network, and thereafter, it is transferred to the neocortical network using pseudo patterns. Because, temporal sequence learning is more important than static pattern learning in the real world, in this study, we improve our conventional dual-network memory model so that it can deal with temporal sequences without catastrophic forgetting. The computer simulation results show the effectiveness of the proposed dual-network memory model.

Keywords: catastrophic forgetting, dual-network, temporal sequences, hippocampal

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4721 An Integrated Web-Based Workflow System for Design of Computational Pipelines in the Cloud

Authors: Shuen-Tai Wang, Yu-Ching Lin

Abstract:

With more and more workflow systems adopting cloud as their execution environment, it presents various challenges that need to be addressed in order to be utilized efficiently. This paper introduces a method for resource provisioning based on our previous research of dynamic allocation and its pipeline processes. We present an abstraction for workload scheduling in which independent tasks get scheduled among various available processors of distributed computing for optimization. We also propose an integrated web-based workflow designer by taking advantage of the HTML5 technology and chaining together multiple tools. In order to make the combination of multiple pipelines executing on the cloud in parallel, we develop a script translator and an execution engine for workflow management in the cloud. All information is known in advance by the workflow engine and tasks are allocated according to the prior knowledge in the repository. This proposed effort has the potential to provide support for process definition, workflow enactment and monitoring of workflow processes. Users would benefit from the web-based system that allows creation and execution of pipelines without scripting knowledge.

Keywords: workflow systems, resources provisioning, workload scheduling, web-based, workflow engine

Procedia PDF Downloads 154
4720 Multiclass Support Vector Machines with Simultaneous Multi-Factors Optimization for Corporate Credit Ratings

Authors: Hyunchul Ahn, William X. S. Wong

Abstract:

Corporate credit rating prediction is one of the most important topics, which has been studied by researchers in the last decade. Over the last decade, researchers are pushing the limit to enhance the exactness of the corporate credit rating prediction model by applying several data-driven tools including statistical and artificial intelligence methods. Among them, multiclass support vector machine (MSVM) has been widely applied due to its good predictability. However, heuristics, for example, parameters of a kernel function, appropriate feature and instance subset, has become the main reason for the critics on MSVM, as they have dictate the MSVM architectural variables. This study presents a hybrid MSVM model that is intended to optimize all the parameter such as feature selection, instance selection, and kernel parameter. Our model adopts genetic algorithm (GA) to simultaneously optimize multiple heterogeneous design factors of MSVM.

Keywords: corporate credit rating prediction, Feature selection, genetic algorithms, instance selection, multiclass support vector machines

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4719 The Effect of Pulsator on Washing Performance in a Front-Loading Washer

Authors: Eung Ryeol Seo, Hee Tae Lim, Eunsuk Bang, Soon Cheol Kweon, Jeoung-Kyo Jeoung, Ji-Hoon Choic

Abstract:

The object of this study is to investigate the effect of pulsator on washing performance quantitatively for front-loading washer. The front-loading washer with pulsator shows washing performance improvement of 18% and the particle-based body simulation technique has been applied to figure out the relation between washing performance and mechanical forces exerted on textile during washing process. As a result, the mechanical forces, such as collision force and strain force, acting on the textile have turned out to be about twice numerically. The washing performance improvement due to additional pulsate system has been utilized for customers to save 50% of washing time.

Keywords: front-loading washer, mechanical force, fabric movement, pulsator, time-saving

Procedia PDF Downloads 259
4718 Directionally-Sensitive Personal Wearable Radiation Dosimeter

Authors: Hai Huu Le, Paul Junor, Moshi Geso, Graeme O’Keefe

Abstract:

In this paper, the authors propose a personal wearable directionally-sensitive radiation dosimeter using multiple semiconductor CdZnTe detectors. The proposed dosimeter not only measures the real-time dose rate but also provide the direction of the radioactive source. A linear relationship between radioactive source direction and the radiation intensity measured by each detectors is established and an equation to determine the source direction is derived by the authors. The efficiency and accuracy of the proposed dosimeter is verified by simulation using Geant4 package. Results have indicated that in a measurement duration of about 7 seconds, the proposed dosimeter was able to estimate the direction of a 10μCi 137/55Cs radioactive source to within 2 degrees.

Keywords: dose rate, Geant4 package, radiation dosimeter, radioactive source direction

Procedia PDF Downloads 321
4717 Reviewing Soil Erosion in Greece

Authors: Paschalis Koutalakis, George N. Zaimes, Valasia Iakovoglou, Konstantinos Ioannou

Abstract:

Mitigating soil erosion, especially in Mediterranean countries such as Greece, is essential in order to maintain environmental and agricultural sustainability. In this paper, scientific publications related to soil erosion studies in Greece were reviewed and categorized. To accomplish this, the online search engine of Scopus was used. The key words were “soil”, “erosion” and “Greece.” An analysis of the published articles was conducted at three levels: i) type of publication, ii) chronologic and iii) thematic. A hundred and ten publications published in scientific journals were reviewed. The results showed that the awareness regarding the soil erosion in Greece has increased only in the last decades. The publications covered a wide range of thematic categories such as the type of studied areas, the physical phenomena that trigger and influence the soil erosion, the negative anthropogenic impacts on them, the assessment tools that were used in order to examine the threat and the proper management. The analysis of these articles was significant and necessary in order to find the scientific gaps of soil erosion studies in Greece and help enhance the sustainability of soil management in the future.

Keywords: climate change, agricultural sustainability, environmental sustainability, soil management

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4716 Technical and Economic Analysis Effects of Various Parameters on the Performance of Heat Recovery System on Gas Complex Turbo Generators

Authors: Hefzollah Mohammadian, Mohammad Bagher Heidari

Abstract:

This paper deals with the technical and economic effects of various parameters on the performance of heat recovery system on gas complex turbo generator. Given the importance of this issue, that is the main goal of economic efficiency and reduces costs; this project has been implemented similar plans in which the target is the implementation of specific patterns. The project will also help us in the process of gas refineries and the actual efficiency of the process after adding a system to analyze the turbine and predict potential problems and fix them and take appropriate measures according to the results of simulation analysis and results of the process gain. The results of modeling and the effect of different parameters on this line, have been done using Thermo Flow.

Keywords: turbo compressor, turbo generator, heat recovery boiler, gas turbines

Procedia PDF Downloads 299
4715 International Broadcasting of Public Diplomacy in the Era of Social Media in Nigeria

Authors: Henry Okechukwu Onyeiwu

Abstract:

In today’s Nigerian digital age, the landscape of public diplomacy has been significantly altered by the rise of social media platforms like YouTube, Facebook, Twitter, and Instagram. In recent years, social media platforms have emerged as powerful tools for public diplomacy, transforming how countries communicate with both domestic and global audiences. International broadcasting as a tool of public diplomacy has undergone a significant transformation. Traditional methods of state-run media and controlled broadcasting have evolved to incorporate the dynamic, interactive, and decentralized nature of digital platforms. Understanding how Nigerian governments engages in international broadcasting of public diplomacy, the influence of social media on broadcasting public diplomacy, focusing on the advantages and disadvantages of controlling media outlets for diplomatic purposes and also covers the changing nature of global communication in this digital era. As countries navigate the complexities of international relations, the effectiveness of controlled media in shaping public perception and engagement raises significant questions worth exploring. The vast amount of content available can make it challenging to capture and retain audience attention. The ease of spreading false information on social media requires international broadcasters to maintain credibility and counteract misleading narratives. Addressing these challenges requires a comprehensive research that integrates digital communication tools, cultural sensitivity, cybersecurity measures and ongoing evaluation to enhance Nigeria’s international broadcasting of public diplomacy. This study employed a mixed-methods approach, combining qualitative and quantitative research methods. A content analysis of Nigeria’s international broadcasting content was conducted to assess its themes, narratives, and engagement strategies. Additionally, surveys and interviews with communications professionals, diplomats, and social media users were carried out to gather insights on perceptions and effectiveness of public diplomacy initiatives. It has highlighted some of the present trends in technology and the international environmental in which public diplomacy must work, and show how the past can illuminate the road for those navigating this new world. The rise of the social network creates more opportunities than it closes for public diplomacy. This evolution highlights the increasing importance of engagement, mutual understanding, and cooperation in international relations. By Adopting a more inclusive and participatory approach, public diplomacy can more effectively address global challenges and build stronger, more resilient relationships between nations. As Nigeria navigates the complexities of its international relations, this abstract will provide a vital examination of how it can better utilize the dual platforms of international broadcasting and social media in its public diplomacy efforts. The outcome will bear significance not only for Nigeria but also for other nations grappling with similar challenges in the digital age. As social media continues to play a crucial role in public diplomacy, understanding the dynamics of controlled media outlets becomes ever more critical. This abstract shed light on the advantages and disadvantages of such control, ultimately contributing valuable insights to practitioners in the field of diplomacy as they adapt to the rapidly changing communication landscape.

Keywords: international broadcasting, public diplomacy, social media, international relation, polities

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4714 Neural Network Motion Control of VTAV by NARMA-L2 Controller for Enhanced Situational Awareness

Authors: Igor Astrov, Natalya Berezovski

Abstract:

This paper focuses on a critical component of the situational awareness (SA), the control of autonomous vertical flight for vectored thrust aerial vehicle (VTAV). With the SA strategy, we proposed a neural network motion control procedure to address the dynamics variation and performance requirement difference of flight trajectory for a VTAV. This control strategy with using of NARMA-L2 neurocontroller for chosen model of VTAV has been verified by simulation of take-off and forward maneuvers using software package Simulink and demonstrated good performance for fast stabilization of motors, consequently, fast SA with economy in energy can be asserted during search-and-rescue operations.

Keywords: NARMA-L2 neurocontroller, situational awareness, vectored thrust aerial vehicle, aviation

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4713 Building Information Modeling Applied for the Measurement of Water Footprint of Construction Supplies

Authors: Julio Franco

Abstract:

Water is used, directly and indirectly, in all activities of the construction productive chain, making it a subject of worldwide relevance for sustainable development. The ongoing expansion of urban areas leads to a high demand for natural resources, which in turn cause significant environmental impacts. The present work proposes the application of BIM tools to assist the measurement of the water footprint (WF) of civil construction supplies. Data was inserted into the model as element properties, allowing them to be analyzed by element or in the whole model. The WF calculation was automated using parameterization in Autodesk Revit software. Parameterization was associated to the materials of each element in the model so that any changes in these elements directly alter the results of WF calculations. As a case study, we applied into a building project model to test the parameterized calculus of WF. Results show that the proposed parameterization successfully automated WF calculations according to design changes. We envision this tool to assist the measurement and rationalization of the environmental impact in terms of WF of construction projects.

Keywords: building information modeling, BIM, sustainable development, water footprint

Procedia PDF Downloads 146
4712 The Effect of the Rain Intensity on the Hydrodynamic Behavior of the Low-Floor ChéLiffe

Authors: Ahmed Abbas

Abstract:

Land degradation in the Lower Cheliff region leads to loss of their fertility, physical and chemical properties by secondary salinization and film forming surface or surface crust. The main factor related to runoff and soil erosion is their susceptibility to crusting caused by the impact of raindrops, which causes the reduction of the filterability of the soil. The present study aims to investigate the hydrodynamic behavior of five types of soil taken from the plain of low Cheliff under simulated rainfall by using two intensities, one moderate, and others correspond to heavy rains at low kinetic energies. Experimental results demonstrate the influence of chemical and mechanical physical properties of soils on their hydrodynamic behavior and the influence of heavy rain on the modality of the reduction in the filterability and the amount of transported sediment.

Keywords: erosion, hydrodynamic behavior, rain simulation, soil

Procedia PDF Downloads 281
4711 Study of Parameters Influencing Dwell Times for Trains

Authors: Guillaume Craveur

Abstract:

The work presented here shows a study on several parameters identified as influencing dwell times for trains. Three kinds of rolling stocks are studied for this project and the parameters presented are the number of passengers, the allocation of passengers, their priorities, the platform station height, the door width and the train design. In order to make this study, a lot of records have been done in several stations in Paris (France). Then, in order to study these parameters, numerical simulations are completed. The goal is to quantify the impact of each parameter on the dwelling times. For example, this study highlights the impact of platform height and the presence of steps between the platform and the train. Three types of station platforms are concerned by this study : ‘optimum’ station platform which is 920 mm high, standard station platform which is 550 mm high, and high station platform which is 1150 mm high and different kinds of steps exist in order to fill these gaps. To conclude, this study shows the impact of these parameters on dwell times and their impact in function of the size of population.

Keywords: dwell times, numerical tools, rolling stock, platforms

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4710 Characterization of Plunging Water Jets in Crossflows: Experimental and Numerical Studies

Authors: Mina Esmi Jahromi, Mehdi Khiadani

Abstract:

Plunging water jets discharging into turbulent crossflows are capable of providing efficient air water interfacial area, which is desirable for the process of mass transfer. Although several studies have been dedicated to the air entrainment by water jets impinging into stagnant water, very few studies have focused on the water jets in crossflows. This study investigates development of the two-phase flow as a result of the jet impingements into crossflows by means of image processing technique and CFD simulations. Investigations are also conducted on the oxygen transfer and a correlation is established between the aeration properties and the oxygenation capacity of water jets in crossflows. This study helps the optimal design and the effective operation of the industrial and the environmental equipment incorporating water jets in crossflows.

Keywords: air entrainment, CFD simulation, image processing, jet in crossflow, oxygen transfer, two-phase flow

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4709 A Numerical and Experimental Analysis of the Performance of a Combined Solar Unit for Air Conditioning and Water Desalination

Authors: Zied Guidara, Alexander Morgenstern, Aref Younes Maalej

Abstract:

In this paper, a desiccant solar unit for air conditioning and desalination is presented first. Secondly, a dynamic modelling study of the desiccant wheel is developed. After that, a simulation study and an experimental investigation of the behaviour of desiccant wheel are developed. The experimental investigation is done in the chamber of commerce in Freiburg-Germany. Indeed, the variations of calculated and measured temperatures and specific humidity of dehumidified and rejected air are presented where a good agreement is found when comparing the model predictions with experimental data under the considered range of operating conditions. Finally, the study of the compartments of desalination and water condensation shows that the unit can produce an acceptable quantity of water at the same time of the air conditioning operation.

Keywords: air conditioning, desalination, condensation, design, desiccant wheel

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4708 Blind Speech Separation Using SRP-PHAT Localization and Optimal Beamformer in Two-Speaker Environments

Authors: Hai Quang Hong Dam, Hai Ho, Minh Hoang Le Ngo

Abstract:

This paper investigates the problem of blind speech separation from the speech mixture of two speakers. A voice activity detector employing the Steered Response Power - Phase Transform (SRP-PHAT) is presented for detecting the activity information of speech sources and then the desired speech signals are extracted from the speech mixture by using an optimal beamformer. For evaluation, the algorithm effectiveness, a simulation using real speech recordings had been performed in a double-talk situation where two speakers are active all the time. Evaluations show that the proposed blind speech separation algorithm offers a good interference suppression level whilst maintaining a low distortion level of the desired signal.

Keywords: blind speech separation, voice activity detector, SRP-PHAT, optimal beamformer

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4707 Mobility Management via Software Defined Networks (SDN) in Vehicular Ad Hoc Networks (VANETs)

Authors: Bilal Haider, Farhan Aadil

Abstract:

A Vehicular Ad hoc Network (VANET) provides various services to end-users traveling on the road at high speeds. However, this high-speed mobility of mobile nodes can cause frequent service disruptions. Various mobility management protocols exist for managing node mobility, but due to their centralized nature, they tend to suffer in the VANET environment. In this research, we proposed a distributed mobility management protocol using software-defined networks (SDN) for VANETs. Instead of relying on a centralized mobility anchor, the mobility functionality is distributed at multiple infrastructural nodes. The protocol is based on the classical Proxy Mobile IP version 6 (PMIPv6). It is evident from simulation results that this work has improved the network performance with respect to nodes throughput, delay, and packet loss.

Keywords: SDN, VANET, mobility management, optimization

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4706 Survival and Hazard Maximum Likelihood Estimator with Covariate Based on Right Censored Data of Weibull Distribution

Authors: Al Omari Mohammed Ahmed

Abstract:

This paper focuses on Maximum Likelihood Estimator with Covariate. Covariates are incorporated into the Weibull model. Under this regression model with regards to maximum likelihood estimator, the parameters of the covariate, shape parameter, survival function and hazard rate of the Weibull regression distribution with right censored data are estimated. The mean square error (MSE) and absolute bias are used to compare the performance of Weibull regression distribution. For the simulation comparison, the study used various sample sizes and several specific values of the Weibull shape parameter.

Keywords: weibull regression distribution, maximum likelihood estimator, survival function, hazard rate, right censoring

Procedia PDF Downloads 438
4705 Failure Analysis and Fatigue Life Estimation of a Shaft of a Rotary Draw Bending Machine

Authors: B. Engel, Sara Salman Hassan Al-Maeeni

Abstract:

Human consumption of the Earth's resources increases the need for a sustainable development as an important ecological, social, and economic theme. Re-engineering of machine tools, in terms of design and failure analysis, is defined as steps performed on an obsolete machine to return it to a new machine with the warranty that matches the customer requirement. To understand the future fatigue behavior of the used machine components, it is important to investigate the possible causes of machine parts failure through design, surface, and material inspections. In this study, the failure modes of the shaft of the rotary draw bending machine are inspected. Furthermore, stress and deflection analysis of the shaft subjected to combined torsion and bending loads are carried out by an analytical method and compared with a finite element analysis method. The theoretical fatigue strength, correction factors, and fatigue life sustained by the shaft before damaged are estimated by creating a stress-cycle (S-N) diagram. In conclusion, it is seen that the shaft can work in the second life, but it needs some surface treatments to increase the reliability and fatigue life.

Keywords: failure analysis, fatigue life, FEM analysis, shaft, stress analysis

Procedia PDF Downloads 291
4704 A Collaborative Teaching and Learning Model between Academy and Industry for Multidisciplinary Engineering Education

Authors: Moon-Soo Kim

Abstract:

In order to cope with the increasing demand for multidisciplinary learning between academy and industry, a collaborative teaching and learning model and related operational tools enabling applications to engineering education are essential. This study proposes a web-based collaborative framework for interactive teaching and learning between academy and industry as an initial step for the development of a web- and mobile-based integrated system for both engineering students and industrial practitioners. The proposed web-based collaborative teaching and learning framework defines several entities such as learner, solver and supporter or sponsor for industrial problems, and also has a systematic architecture to build information system including diverse functions enabling effective interaction among the defined entities regardless of time and places. Furthermore, the framework, which includes knowledge and information self-reinforcing mechanism, focuses on the previous problem-solving records as well as subsequent learners’ creative reusing in solving process of new problems.

Keywords: collaborative teaching and learning model, academy and industry, web-based collaborative framework, self-reinforcing mechanism

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4703 Towards Efficient Reasoning about Families of Class Diagrams Using Union Models

Authors: Tejush Badal, Sanaa Alwidian

Abstract:

Class diagrams are useful tools within the Unified Modelling Language (UML) to model and visualize the relationships between, and properties of objects within a system. As a system evolves over time and space (e.g., products), a series of models with several commonalities and variabilities create what is known as a model family. In circumstances where there are several versions of a model, examining each model individually, becomes expensive in terms of computation resources. To avoid performing redundant operations, this paper proposes an approach for representing a family of class diagrams into Union Models to represent model families using a single generic model. The paper aims to analyze and reason about a family of class diagrams using union models as opposed to individual analysis of each member model in the family. The union algorithm provides a holistic view of the model family, where the latter cannot be otherwise obtained from an individual analysis approach, this in turn, enhances the analysis performed in terms of speeding up the time needed to analyze a family of models together as opposed to analyzing individual models, one model at a time.

Keywords: analysis, class diagram, model family, unified modeling language, union model

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