Search results for: computational machine learning
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 10025

Search results for: computational machine learning

3395 A Lagrangian Hamiltonian Computational Method for Hyper-Elastic Structural Dynamics

Authors: Hosein Falahaty, Hitoshi Gotoh, Abbas Khayyer

Abstract:

Performance of a Hamiltonian based particle method in simulation of nonlinear structural dynamics is subjected to investigation in terms of stability and accuracy. The governing equation of motion is derived based on Hamilton's principle of least action, while the deformation gradient is obtained according to Weighted Least Square method. The hyper-elasticity models of Saint Venant-Kirchhoff and a compressible version similar to Mooney- Rivlin are engaged for the calculation of second Piola-Kirchhoff stress tensor, respectively. Stability along with accuracy of numerical model is verified by reproducing critical stress fields in static and dynamic responses. As the results, although performance of Hamiltonian based model is evaluated as being acceptable in dealing with intense extensional stress fields, however kinds of instabilities reveal in the case of violent collision which can be most likely attributed to zero energy singular modes.

Keywords: Hamilton's principle of least action, particle-based method, hyper-elasticity, analysis of stability

Procedia PDF Downloads 331
3394 Role of ICT and Wage Inequality in Organization

Authors: Shoji Katagiri

Abstract:

This study deals with wage inequality in organization and shows the relationship between ICT and wage in organization. To do so, we incorporate ICT’s factors in organization into our model. ICT’s factors are efficiencies of Enterprise Resource Planning (ERP), Computer Assisted Design/Computer Assisted Manufacturing (CAD/CAM), and NETWORK. The improvement of ICT’s factors decrease the learning cost to solve problem pertaining to the hierarchy in organization. The improvement of NETWORK increases the wage inequality within workers and decreases within managers and entrepreneurs. The improvements of CAD/CAM and ERP increases the wage inequality within all agent, and partially increase it between the agents in hierarchy.

Keywords: endogenous economic growth, ICT, inequality, capital accumulation

Procedia PDF Downloads 247
3393 Open Distance Learning and Curriculum Transformation: Linkages, Alignment, and Innovation

Authors: Devanandan Govender

Abstract:

Curriculum design and development in higher education is a complex and challenging process. Amongst others, the extent to which higher education curriculum responds to a country's imperatives, industry requirements, and societal demands are some important considerations. Added to this is the whole notion of sustainable development, climate change and in the South African context the issue of ‘Africanising the curriculum’ is also significant. In this paper, the author describes and analyses the various challenges related to curriculum transformation, design and development within an ODL context and how we at Unisa engage and address curriculum transformation in mainstream curriculum design and development both at course design level and programme/ qualification level.

Keywords: curriculum transformation, curriculum creep, curriculum drift, curriculum mapping

Procedia PDF Downloads 360
3392 Implementing Online Blogging in Specific Context Using Process-Genre Writing Approach in Saudi EFL Writing Class to Improve Writing Learning and Teaching Quality

Authors: Sultan Samah A. Alenezi

Abstract:

Many EFL teachers are eager to look into the best way to suit the needs of their students in EFL writing courses. Numerous studies suggest that online blogging may present a social interaction opportunity for EFL writing students. Additionally, it can foster peer collaboration and social support in the form of scaffolding, which, when viewed from the perspective of socio-cultural theory, can boost social support and foster the development of students' writing abilities. This idea is based on Vygotsky's theories, which emphasize how collaboration and social interaction facilitate effective learning. In Saudi Arabia, students are taught to write using conventional methods that are totally under the teacher's control. Without any peer contact or cooperation, students are spoon-fed in a passive environment. This study included the cognitive processes of the genre-process approach into the EFL writing classroom to facilitate the use of internet blogging in EFL writing education. Thirty second-year undergraduate students from the Department of Languages and Translation at a Saudi college participated in this study. This study employed an action research project that blended qualitative and quantitative methodologies to comprehend Saudi students' perceptions and experiences with internet blogging in an EFL process-genre writing classroom. It also looked at the advantages and challenges people faced when blogging. They included a poll, interviews, and blog postings made by students. The intervention's outcomes showed that merging genre-process procedures with blogging was a successful tactic, and the Saudi students' perceptions of this method of online blogging for EFL writing were quite positive. The socio-cultural theory constructs that Vygotsky advocates, such as scaffolding, collaboration, and social interaction, were also improved by blogging. These elements demonstrated the improvement in the students' written, reading, social, and collaborative thinking skills, as well as their positive attitudes toward English-language writing. But the students encountered a variety of problems that made blogging difficult for them. These problems ranged from technological ones, such sluggish internet connections, to learner inadequacies, like a lack of computer know-how and ineffective time management.

Keywords: blogging, process-gnere approach, saudi learenrs, writing quality

Procedia PDF Downloads 99
3391 Waste Management in a Hot Laboratory of Japan Atomic Energy Agency – 3: Volume Reduction and Stabilization of Solid Waste

Authors: Masaumi Nakahara, Sou Watanabe, Hiromichi Ogi, Atsuhiro Shibata, Kazunori Nomura

Abstract:

In the Japan Atomic Energy Agency, three types of experimental research, advanced reactor fuel reprocessing, radioactive waste disposal, and nuclear fuel cycle technology, have been carried out at the Chemical Processing Facility. The facility has generated high level radioactive liquid and solid wastes in hot cells. The high level radioactive solid waste is divided into three main categories, a flammable waste, a non-flammable waste, and a solid reagent waste. A plastic product is categorized into the flammable waste and molten with a heating mantle. The non-flammable waste is cut with a band saw machine for reducing the volume. Among the solid reagent waste, a used adsorbent after the experiments is heated, and an extractant is decomposed for its stabilization. All high level radioactive solid wastes in the hot cells are packed in a high level radioactive solid waste can. The high level radioactive solid waste can is transported to the 2nd High Active Solid Waste Storage in the Tokai Reprocessing Plant in the Japan Atomic Energy Agency.

Keywords: high level radioactive solid waste, advanced reactor fuel reprocessing, radioactive waste disposal, nuclear fuel cycle technology

Procedia PDF Downloads 143
3390 Fapitow: An Advanced AI Agent for Travel Agent Competition

Authors: Faiz Ul Haque Zeya

Abstract:

In this paper, Fapitow’s bidding strategy and approach to participate in Travel Agent Competition (TAC) is described. Previously, Fapitow is designed using the agents provided by the TAC Team and mainly used their modification for developing our strategy. But later, by observing the behavior of the agent, it is decided to come up with strategies that will be the main cause of improved utilities of the agent, and by theoretical examination, it is evident that the strategies will provide a significant improvement in performance which is later proved by agent’s performance in the games. The techniques and strategies for further possible improvement are also described. TAC provides a real-time, uncertain environment for learning, experimenting, and implementing various AI techniques. Some lessons learned about handling uncertain environments are also presented.

Keywords: agent, travel agent competition, bidding, TAC

Procedia PDF Downloads 90
3389 A New Block Cipher for Resource-Constrained Internet of Things Devices

Authors: Muhammad Rana, Quazi Mamun, Rafiqul Islam

Abstract:

In the Internet of Things (IoT), many devices are connected and accumulate a sheer amount of data. These Internet-driven raw data need to be transferred securely to the end-users via dependable networks. Consequently, the challenges of IoT security in various IoT domains are paramount. Cryptography is being applied to secure the networks for authentication, confidentiality, data integrity and access control. However, due to the resource constraint properties of IoT devices, the conventional cipher may not be suitable in all IoT networks. This paper designs a robust and effective lightweight cipher to secure the IoT environment and meet the resource-constrained nature of IoT devices. We also propose a symmetric and block-cipher based lightweight cryptographic algorithm. The proposed algorithm increases the complexity of the block cipher, maintaining the lowest computational requirements possible. The proposed algorithm efficiently constructs the key register updating technique, reduces the number of encryption rounds, and adds a new layer between the encryption and decryption processes.

Keywords: internet of things, cryptography block cipher, S-box, key management, security, network

Procedia PDF Downloads 91
3388 On the Evaluation of Different Turbulence Models through the Displacement of Oil-Water Flow in Porous Media

Authors: Sidique Gawusu, Xiaobing Zhang

Abstract:

Turbulence models play a significant role in all computational fluid dynamics based modelling approaches. There is, however, no general turbulence model suitable for all flow scenarios. Therefore, a successful numerical modelling approach is only achievable if a more appropriate closure model is used. This paper evaluates different turbulence models in numerical modelling of oil-water flow within the Eulerian-Eulerian approach. A comparison among the obtained numerical results and published benchmark data showed reasonable agreement. The domain was meshed using structured mesh, and grid test was performed to ascertain grid independence. The evaluation of the models was made through analysis of velocity and pressure profiles across the domain. The models were tested for their suitability to accurately obtain a scalable and precise numerical experience. As a result, it is found that all the models except Standard-ω provide comparable results. The study also revealed new insights on flow in porous media, specifically oil reservoirs.

Keywords: turbulence modelling, simulation, multi-phase flows, water-flooding, heavy oil

Procedia PDF Downloads 260
3387 Computational Approaches for Ballistic Impact Response of Stainless Steel 304

Authors: A. Mostafa

Abstract:

This paper presents a numerical study on determination of ballistic limit velocity (V50) of stainless steel 304 (SS 304) used in manufacturing security screens. The simulated ballistic impact tests were conducted on clamped sheets with different thicknesses using ABAQUS/Explicit nonlinear finite element (FE) package. The ballistic limit velocity was determined using three approaches, namely: numerical tests based on material properties, FE calculated residual velocities and FE calculated residual energies. Johnson-Cook plasticity and failure criterion were utilized to simulate the dynamic behaviour of the SS 304 under various strain rates, while the well-known Lambert-Jonas equation was used for the data regression for the residual velocity and energy model. Good agreement between the investigated numerical methods was achieved. Additionally, the dependence of the ballistic limit velocity on the sheet thickness was observed. The proposed approaches present viable and cost-effective assessment methods of the ballistic performance of SS 304, which will support the development of robust security screen systems.

Keywords: ballistic velocity, stainless steel, numerical approaches, security screen

Procedia PDF Downloads 142
3386 Origin of Hydrogen Bonding: Natural Bond Orbital Electron Donor-Acceptor Interactions

Authors: Mohamed Ayoub

Abstract:

We perform computational investigation using density functional theory, B3LYP with aug-cc-pVTZ basis set followed by natural bond orbital analysis (NBO), which provides best single “natural Lewis structure” (NLS) representation of chosen wavefunction (Ψ) with natural resonance theory (NRT) to provide an analysis of molecular electron density in terms of resonance structures (RS) and weights (w). We selected for the study a wide range of gas phase dimers (B…HA), with hydrogen bond dissociation energies (ΔEB…H) that span more than two orders of magnitude. We demonstrate that charge transfer from a donor Lewis-type NBO (nB:) to an acceptor non-Lewis-type NBO (σHA*) is the primary cause for H-bonding not classical electrostatic (dipole-dipole or ionic). We provide a variety of structure, and spectroscopic descriptors to support the conclusion, such as IR frequency shift (ΔνHA), H-bond penetration distance (ΔRB..H), bond order (bB..H), charge-transfer (CTB→HA) and the corresponding donor-acceptor stabilization energy (ΔE(2)).

Keywords: natural bond orbital, hydrogen bonding, electron donor, electron acceptor

Procedia PDF Downloads 426
3385 Improving the Security of Internet of Things Using Encryption Algorithms

Authors: Amirhossein Safi

Abstract:

Internet of things (IOT) is a kind of advanced information technology which has drawn societies’ attention. Sensors and stimulators are usually recognized as smart devices of our environment. Simultaneously, IOT security brings up new issues. Internet connection and possibility of interaction with smart devices cause those devices to involve more in human life. Therefore, safety is a fundamental requirement in designing IOT. IOT has three remarkable features: overall perception, reliable transmission, and intelligent processing. Because of IOT span, security of conveying data is an essential factor for system security. Hybrid encryption technique is a new model that can be used in IOT. This type of encryption generates strong security and low computation. In this paper, we have proposed a hybrid encryption algorithm which has been conducted in order to reduce safety risks and enhancing encryption's speed and less computational complexity. The purpose of this hybrid algorithm is information integrity, confidentiality, non-repudiation in data exchange for IOT. Eventually, the suggested encryption algorithm has been simulated by MATLAB software, and its speed and safety efficiency were evaluated in comparison with conventional encryption algorithm.

Keywords: internet of things, security, hybrid algorithm, privacy

Procedia PDF Downloads 447
3384 Prediction of Unsteady Heat Transfer over Square Cylinder in the Presence of Nanofluid by Using ANN

Authors: Ajoy Kumar Das, Prasenjit Dey

Abstract:

Heat transfer due to forced convection of copper water based nanofluid has been predicted by Artificial Neural network (ANN). The present nanofluid is formed by mixing copper nano particles in water and the volume fractions are considered here are 0% to 15% and the Reynolds number are kept constant at 100. The back propagation algorithm is used to train the network. The present ANN is trained by the input and output data which has been obtained from the numerical simulation, performed in finite volume based Computational Fluid Dynamics (CFD) commercial software Ansys Fluent. The numerical simulation based results are compared with the back propagation based ANN results. It is found that the forced convection heat transfer of water based nanofluid can be predicted correctly by ANN. It is also observed that the back propagation ANN can predict the heat transfer characteristics of nanofluid very quickly compared to standard CFD method.

Keywords: forced convection, square cylinder, nanofluid, neural network

Procedia PDF Downloads 308
3383 Case of an Engineering Design Class in Architectural Engineering

Authors: Myunghoun Jang

Abstract:

Most engineering colleges in South Korea have engineering design classes in order to develop and enhance a student's creativity and problem-solving ability. Many cases about engineering design class are shown in journals and magazines, but a case lasting many years is few. The engineering design class in the Department of Architectural Engineering, Jeju National University was open in 2009 and continues to this year. 3-5 teams in every year set up their problems found their solutions and produced good results. Three of the results obtained patents. The class also provides students with opportunities to improve communication skill because they have many discussions in solving their problems.

Keywords: engineering design, architectural engineering, team-based learning, construction safety

Procedia PDF Downloads 222
3382 Wave Interaction with Defects in Pressurized Composite Structures

Authors: R. K. Apalowo, D. Chronopoulos, V. Thierry

Abstract:

A wave finite element (WFE) and finite element (FE) based computational method is presented by which the dispersion properties as well as the wave interaction coefficients for one-dimensional structural system can be predicted. The structural system is discretized as a system comprising a number of waveguides connected by a coupling joint. Uniform nodes are ensured at the interfaces of the coupling element with each waveguide. Then, equilibrium and continuity conditions are enforced at the interfaces. Wave propagation properties of each waveguide are calculated using the WFE method and the coupling element is modelled using the FE method. The scattering of waves through the coupling element, on which damage is modelled, is determined by coupling the FE and WFE models. Furthermore, the central aim is to evaluate the effect of pressurization on the wave dispersion and scattering characteristics of the prestressed structural system compared to that which is not prestressed. Numerical case studies are exhibited for two waveguides coupled through a coupling joint.

Keywords: Finite Element, Prestressed Structures, Wave Finite Element, Wave Propagation Properties, Wave Scattering Coefficients.

Procedia PDF Downloads 280
3381 Overall Stability of Welded Q460GJ Steel Box Columns: Experimental Study and Numerical Simulations

Authors: Zhou Xiong, Kang Shao Bo, Yang Bo

Abstract:

To date, high-performance structural steel has been widely used for columns in construction practices due to its significant advantages over conventional steel. However, the same design approach with conventional steel columns is still adopted in the design of high-performance steel columns. As a result, its superior properties cannot be fully considered in design. This paper conducts a test and finite element analysis on the overall stability behaviour of welded Q460GJ steel box columns. In the test, four steel columns with different slenderness and width-to-thickness ratio were compressed under an axial compression testing machine. And finite element models were established in which material nonlinearity and residual stress distributions of test columns were included. Then, comparisons were made between test results and finite element result, it showed that finite element analysis results are agree well with the test result. It means that the test and finite element model are reliable. Then, we compared the test result with the design value calculated by current code, the result showed that Q460GJ steel box columns have the higher overall buckling capacity than the design value. It is necessary to update the design curves for Q460GJ steel columns so that the overall stability capacity of Q460GJ box columns can be designed appropriately.

Keywords: axial compression, box columns, global buckling, numerical simulations, Q460GJ steel

Procedia PDF Downloads 390
3380 A Robotic Cube to Preschool Children for Acquiring the Mathematical and Colours Concepts

Authors: Ahmed Amin Mousa, Tamer M. Ismail, M. Abd El Salam

Abstract:

This work presents a robot called Conceptual Robotic Cube, CR-Cube. The robot can be used as an educational tool for children from the age of three. It has a cube shape attached with a camera colours sensor. In addition, it contains four wheels to move smoothly. The researchers prepared a questionnaire to measure the efficiency of the robot. The design and the questionnaire was presented to 11 experts who agreed that the robot is appropriate for learning numbering and colours for preschool children.

Keywords: CR-Cube, robotic cube, conceptual robot, conceptual cube, colour concept, early childhood education

Procedia PDF Downloads 396
3379 Development of Al Foam by a Low-Cost Salt Replication Method for Industrial Applications

Authors: B. Soni, S. Biswas

Abstract:

Metal foams of Al find diverse applications in several industrial sectors such as in automotive and sports equipment industry as impact, acoustic and vibration absorbers, the aerospace industry as structural components in turbines and spatial cones, in the naval industry as low frequency vibration absorbers, and in construction industry as sound barriers inside tunnels, as fire proof materials and structure protection systems against explosions and even in heat exchangers, orthopedic components, and decorative items. Here, we report on the development of Al foams by a low cost and convenient technique of salt replication method with efficient control over size, geometry and distribution of the pores. Sodium bicarbonate was used as the foaming agent to form the porous refractory salt pattern. The mixed refractory salt slurry was microwave dried followed by sintering for selected time periods. Molten Al was infiltrated into the salt pattern in an inert atmosphere at a pressure of 2 bars. The final products were obtained by leaching out the refractory salt pattern. Mechanical properties of the derived samples were studied with a universal testing machine. The results were analyzed in correlation with their microstructural features evaluated with a scanning electron microscope (SEM).

Keywords: metal foam, Al, salt replication method, mechanical properties, SEM

Procedia PDF Downloads 340
3378 A Method for Reduction of Association Rules in Data Mining

Authors: Diego De Castro Rodrigues, Marcelo Lisboa Rocha, Daniela M. De Q. Trevisan, Marcos Dias Da Conceicao, Gabriel Rosa, Rommel M. Barbosa

Abstract:

The use of association rules algorithms within data mining is recognized as being of great value in the knowledge discovery in databases. Very often, the number of rules generated is high, sometimes even in databases with small volume, so the success in the analysis of results can be hampered by this quantity. The purpose of this research is to present a method for reducing the quantity of rules generated with association algorithms. Therefore, a computational algorithm was developed with the use of a Weka Application Programming Interface, which allows the execution of the method on different types of databases. After the development, tests were carried out on three types of databases: synthetic, model, and real. Efficient results were obtained in reducing the number of rules, where the worst case presented a gain of more than 50%, considering the concepts of support, confidence, and lift as measures. This study concluded that the proposed model is feasible and quite interesting, contributing to the analysis of the results of association rules generated from the use of algorithms.

Keywords: data mining, association rules, rules reduction, artificial intelligence

Procedia PDF Downloads 146
3377 A Numerical Study on the Effects of N2 Dilution on the Flame Structure and Temperature Distribution of Swirl Diffusion Flames

Authors: Yasaman Tohidi, Shidvash Vakilipour, Saeed Ebadi Tavallaee, Shahin Vakilipoor Takaloo, Hossein Amiri

Abstract:

The numerical modeling is performed to study the effects of N2 addition to the fuel stream on the flame structure and temperature distribution of methane-air swirl diffusion flames with different swirl intensities. The Open source Field Operation and Manipulation (OpenFOAM) has been utilized as the computational tool. Flamelet approach along with modified k-ε model is employed to model the flame characteristics.  The results indicate that the presence of N2 in the fuel stream leads to the flame temperature reduction. By increasing of swirl intensity, the flame structure changes significantly. The flame has a conical shape in low swirl intensity; however, it has an hour glass-shape with a shorter length in high swirl intensity. The effects of N2 dilution decrease the flame length in all swirl intensities; however, the rate of reduction is more noticeable in low swirl intensity.

Keywords: swirl diffusion flame, N2 dilution, OpenFOAM, swirl intensity

Procedia PDF Downloads 160
3376 Inappropriate Effects Which the Use of Computer and Playing Video Games Have on Young People

Authors: Maja Ruzic-Baf, Mirjana Radetic-Paic

Abstract:

The use of computers by children has many positive aspects, including the development of memory, learning methods, problem-solving skills and the feeling of one’s own competence and self-confidence. Playing on line video games can encourage hanging out with peers having similar interests as well as communication; it develops coordination, spatial relations and presentation. On the other hand, the Internet enables quick access to different information and the exchange of experiences. How kids use computers and what the negative effects of this can be depends on various factors. ICT has improved and become easy to get for everyone. In the past 12 years so many video games has been made even to that level that some of them are free to play. Young people, even some adults, had simply start to forget about the real outside world because in that other, digital world, they have found something that makes them feal more worthy as a man. This article present the use of ICT, forms of behavior and addictions to on line video games. The use of computers by children has many positive aspects, including the development of memory, learning methods, problem-solving skills and the feeling of one’s own competence and self-confidence. Playing on line video games can encourage hanging out with peers having similar interests as well as communication; it develops coordination, spatial relations and presentation. On the other hand, the Internet enables quick access to different information and the exchange of experiences. How kids use computers and what the negative effects of this can be depends on various factors. ICT has improved and become easy to get for everyone. In the past 12 years so many video games has been made even to that level that some of them are free to play. Young people, even some adults, had simply start to forget about the real outside world because in that other, digital world, they have found something that makes them feal more worthy as a man. This article present the use of ICT, forms of behavior and addictions to on line video games.

Keywords: addiction to video games, behaviour, ICT, young people

Procedia PDF Downloads 532
3375 Numerical Investigation of the Effect of Number of Waves on Heat Transfer in a Wavy Wall Enclosure

Authors: Ali Reza Tahavvor, Saeed Hosseini, Afshin Karimzadeh Fard

Abstract:

In this paper the effect of wall waviness of side walls in a two-dimensional wavy enclosure is numerically investigated. Two vertical wavy walls and straight top wall are kept isothermal and the bottom wall temperature is higher and spatially varying with cosinusoidal temperature distribution. A computational code based on Finite-volume approach is used to solve governing equations and SIMPLE method is used for pressure velocity coupling. Test is performed for several different numbers of undulations. The Prandtl number was kept constant and the Ra number denotes that the flow is laminar. Temperature and velocity fields are determined. Therefore, according to the obtained results a correlation is proposed for average Nusselt number as a function of number of side wall waves. The results indicate that the Nusselt number is highly affected by number of waves and increasing it decreases the wavy walls Nusselt number; although the Nusselt number is not highly affected by surface waviness when the number of undulations is below one.

Keywords: cavity, natural convection, Nusselt number, wavy wall

Procedia PDF Downloads 454
3374 Synthesis and Anti-Inflammatory Activity of Pyrazol-3-yl Thiazole 4-Carboxylic Acid Derivatives Targeting Enzyme in the Leukotriene Pathway

Authors: Shweta Sinha, Mukesh Doble, Manju S. L.

Abstract:

Pyrazole scaffold is an important group of compound in heterocyclic chemistry and is found to possess numerous uses in chemistry. Pyrazole derivatives are also known to possess important biological activities including antitumor, antimicrobial, antiviral, antifungal, anticancer and anti-inflammatory. Inflammation is associated with pain, allergy and asthma. Leukotrienes are mediators of various inflammatory and allergic disorders. 5-Lipoxygenase (5-LOX) is an important enzyme involved in the biosynthesis of leukotrienes and metabolism of arachidonic acid (AA) and thus targeted for anti-inflammation. In vitro inhibitory activity of pyrazol-3-yl thiazole 4-carboxylic acid derivatives is tested against enzyme 5-LOX. Most of these compounds exhibit good inhibitory activity against this enzyme. Binding mode study of these compounds is determined by computational tool. Further experiments are being done to understand the mechanism of action of these compounds in inhibiting this enzyme. To conclude, these compounds appear to be a promising target in drug design against 5-LOX.

Keywords: inflammation, inhibition, 5-lipoxygenase, pyrazole

Procedia PDF Downloads 231
3373 Stabilization of a Three-Pole Active Magnetic Bearing by Hybrid Control Method in Static Mode

Authors: Mahdi Kiani, Hassan Salarieh, Aria Alasty, S. Mahdi Darbandi

Abstract:

The design and implementation of the hybrid control method for a three-pole active magnetic bearing (AMB) is proposed in this paper. The system is inherently nonlinear and conventional nonlinear controllers are a little complicated, while the proposed hybrid controller has a piecewise linear form, i.e. linear in each sub-region. A state-feedback hybrid controller is designed in this study, and the unmeasurable states are estimated by an observer. The gains of the hybrid controller are obtained by the Linear Quadratic Regulator (LQR) method in each sub-region. To evaluate the performance, the designed controller is implemented on an experimental setup in static mode. The experimental results show that the proposed method can efficiently stabilize the three-pole AMB system. The simplicity of design, domain of attraction, uncomplicated control law, and computational time are advantages of this method over other nonlinear control strategies in AMB systems.

Keywords: active magnetic bearing, three pole AMB, hybrid control, Lyapunov function

Procedia PDF Downloads 327
3372 Developing New Algorithm and Its Application on Optimal Control of Pumps in Water Distribution Network

Authors: R. Rajabpour, N. Talebbeydokhti, M. H. Ahmadi

Abstract:

In recent years, new techniques for solving complex problems in engineering are proposed. One of these techniques is JPSO algorithm. With innovative changes in the nature of the jump algorithm JPSO, it is possible to construct a graph-based solution with a new algorithm called G-JPSO. In this paper, a new algorithm to solve the optimal control problem Fletcher-Powell and optimal control of pumps in water distribution network was evaluated. Optimal control of pumps comprise of optimum timetable operation (status on and off) for each of the pumps at the desired time interval. Maximum number of status on and off for each pumps imposed to the objective function as another constraint. To determine the optimal operation of pumps, a model-based optimization-simulation algorithm was developed based on G-JPSO and JPSO algorithms. The proposed algorithm results were compared well with the ant colony algorithm, genetic and JPSO results. This shows the robustness of proposed algorithm in finding near optimum solutions with reasonable computational cost.

Keywords: G-JPSO, operation, optimization, pumping station, water distribution networks

Procedia PDF Downloads 386
3371 Frequent-Pattern Tree Algorithm Application to S&P and Equity Indexes

Authors: E. Younsi, H. Andriamboavonjy, A. David, S. Dokou, B. Lemrabet

Abstract:

Software and time optimization are very important factors in financial markets, which are competitive fields, and emergence of new computer tools further stresses the challenge. In this context, any improvement of technical indicators which generate a buy or sell signal is a major issue. Thus, many tools have been created to make them more effective. This worry about efficiency has been leading in present paper to seek best (and most innovative) way giving largest improvement in these indicators. The approach consists in attaching a signature to frequent market configurations by application of frequent patterns extraction method which is here most appropriate to optimize investment strategies. The goal of proposed trading algorithm is to find most accurate signatures using back testing procedure applied to technical indicators for improving their performance. The problem is then to determine the signatures which, combined with an indicator, outperform this indicator alone. To do this, the FP-Tree algorithm has been preferred, as it appears to be the most efficient algorithm to perform this task.

Keywords: quantitative analysis, back-testing, computational models, apriori algorithm, pattern recognition, data mining, FP-tree

Procedia PDF Downloads 348
3370 Soft Skills: Expectations and Needs in Tourism

Authors: Susana Silva, Dora Martins

Abstract:

The recent political, economic, social technological and employment changes significantly affect the tourism organizations and consequently the changing nature of the employment experience of the tourism workforce. Such scene leads several researchers and labor analysts to reflect about what kinds of jobs, knowledge and competences are need to ensure the success to teach, to learning and to work on this sector. In recent years the competency-based approach in high education level has become of significant interest. On the one hand, this approach could leads to the forming of the key students’ competences which contribute their better preparation to the professional future and on the other hand could answer better to practical demands from tourism job market. The goals of this paper are (1) to understand the expectations of university tourism students in relation to the present and future tourism competences demands, (2) to identify the importance put on the soft skills, (3) to know the importance of high qualification to their future professional activity and (4) to explore the students perception about present and future tourist sector specificities. To this proposal, a questionnaire was designed and distributed to every students who participate on classes of Hospitality Management under degree and master from one public Portuguese university. All participants were invited, during December 2014 and September 2015, to answer the questionnaire at the moment and on presence of one researcher of this study. Fulfilled the questionnaire 202 students (72, 35,6% male and 130, 64.4% female), the mean age was 21,64 (SD=5,27), 91% (n=86) were undergraduate and 18 (9%) were master students. 80% (n=162) of our participants refers as a possibility to look for a job outside the country.42% (n=85) prefers to work in a medium-sized tourism units (with 50-249 employees). According to our participants the most valued skills in tourism are the domain of foreign languages (87.6%, n=177), the ability to work as a team (85%), the personal persistence (83%, n=168), the knowledge of the product/services provided (73.8%, n=149), and assertiveness (66.3%, n=134). 65% (n=131) refers the availability to look for a job in a home distance of 1000 kilometers and 59% (n=119) do not consider the possibility to work in another area than tourism. From the results of this study we are in the position of confirming the need for universities to maintain a better link with the professional tourism companies and to rethink some competences into their learning course model. Based on our results students, universities and companies could understand more deeply the motivations, expectations and competences need to build the future career who study and work on the tourism sector.

Keywords: human capital, employability, students’ competencies perceptions, soft skills, tourism

Procedia PDF Downloads 255
3369 A Robust Optimization Model for the Single-Depot Capacitated Location-Routing Problem

Authors: Abdolsalam Ghaderi

Abstract:

In this paper, the single-depot capacitated location-routing problem under uncertainty is presented. The problem aims to find the optimal location of a single depot and the routing of vehicles to serve the customers when the parameters may change under different circumstances. This problem has many applications, especially in the area of supply chain management and distribution systems. To get closer to real-world situations, travel time of vehicles, the fixed cost of vehicles usage and customers’ demand are considered as a source of uncertainty. A combined approach including robust optimization and stochastic programming was presented to deal with the uncertainty in the problem at hand. For this purpose, a mixed integer programming model is developed and a heuristic algorithm based on Variable Neighborhood Search(VNS) is presented to solve the model. Finally, the computational results are presented and future research directions are discussed.

Keywords: location-routing problem, robust optimization, stochastic programming, variable neighborhood search

Procedia PDF Downloads 257
3368 Multinomial Dirichlet Gaussian Process Model for Classification of Multidimensional Data

Authors: Wanhyun Cho, Soonja Kang, Sanggoon Kim, Soonyoung Park

Abstract:

We present probabilistic multinomial Dirichlet classification model for multidimensional data and Gaussian process priors. Here, we have considered an efficient computational method that can be used to obtain the approximate posteriors for latent variables and parameters needed to define the multiclass Gaussian process classification model. We first investigated the process of inducing a posterior distribution for various parameters and latent function by using the variational Bayesian approximations and important sampling method, and next we derived a predictive distribution of latent function needed to classify new samples. The proposed model is applied to classify the synthetic multivariate dataset in order to verify the performance of our model. Experiment result shows that our model is more accurate than the other approximation methods.

Keywords: multinomial dirichlet classification model, Gaussian process priors, variational Bayesian approximation, importance sampling, approximate posterior distribution, marginal likelihood evidence

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3367 Women Executives: A Panacea to Incessant Sexual Assaults in Higher Institutions, Federal Polytechnic Nekede Imo State Nigeria as a Case Study

Authors: Ujunma Nnenna Egbuawa

Abstract:

Rape or sexual assault is a hideous crime of violence done predominantly to women and occasionally to men. In institutions of higher learning, it’s mostly experienced within or outside the campus environment due to students who are from different backgrounds socially. These students also have been imbibed with conflicting ethical standards, thus act both morally and amoral with respect to their sexual urges. The most affected among these are the female students who live outside the campus environment that is suitable for any immoral activity. These female students that are victims of rape hardly would want to be identified and this has left them as habitual prey to the unsuspecting predators. The socio-cultural setting has also been a contributory factor to the psychological and physical damage these victims face throughout their time of study as female rape victims. This is an empirical study designed to elicit information from students of Federal Polytechnic Nekede Owerri Imo State Nigeria on whether they have been sexually assaulted or raped and how they handled it thereafter. This institution was used as a case study because the provost of this tertiary institution is a woman whose name is Dr( Mrs ) C.U Njoku who has made consented efforts to ensure these rape victims rise above the social stigma associated with it. This rector has also put in some measures to bring about a decline in cases of rape within and outside the campus environment. She also granted the researcher an oral interview on how she has been able to achieve these and the challenges she hitherto faced in the process. Three research questions and a hypothesis guided the study. Samples of 119 students were used and stratification was done for sex, age and the academic level of the students. 14 item questionnaires were used and data generated from the survey were analyzed using percentages. This workshop would engage the participants by investigating some courses that may help in declining the rate of rape cases within a campus. Also, necessary measures that would be taken to help in sensitizing the tertiary institutions in areas that can aid the healing procedures of these victims. The need also for guidance and counseling unit is also a necessity for the psychological survival of these rape victims. As a result, the participants would gain an increased awareness of the influence of rape and sexual assault on campus. There ought to be a paradigm shift in institutions of higher learning in policies, administrative decisions and introduction of courses that will uplift ethical standards in order to bring about a change both locally and globally.

Keywords: institutions, psychological, sexual assault, socio-cultural

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3366 Effect of Temperature Condition in Extracting Carbon Fibers on Mechanical Properties of Injection Molded Polypropylene Reinforced by Recycled Carbon Fibers

Authors: Shota Nagata, Kazuya Okubo, Toru Fujii

Abstract:

The purpose of this study is to investigate the proper condition in extracting carbon fibers as the reinforcement of composite molded by injection method. Recycled carbon fibers were extracted from wasted CFRP by pyrolyzing epoxy matrix of CFRP under air atmosphere at different temperature conditions 400, 600 and 800°C in this study. Recycled carbon fiber reinforced polypropylene (RCF/PP) pellets were prepared using twin screw extruder. The RCF/PP specimens were molded into dumbbell shaped specimens using injection molding machine. The tensile strength of recycled carbon fiber was decreased with rising pyrolysis temperature from 400 to 800°C. However, superior mechanical properties of tensile strength, tensile modulus and fracture strain of RCF/PP specimen were obtained when the extracting temperature was 600°C. Almost fibers in RCF/PP specimens were aligned in the mold filling direction in this study when the extracting temperature was 600°C. To discuss the results, the failure mechanisms of RCF/PP specimens was shown schematically. Finally, it was concluded that the temperature condition at 600°C should be selected in extracting carbon fibers as the reinforcement of RCF/PP composite molded by injection method.

Keywords: CFRP, recycled carbon fiber, injection molding, mechanical properties, fiber orientation, failure mechanism

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