Search results for: mode superposition method
17347 Reliability Analysis of Heat Exchanger Cycle Using Non-Parametric Method
Authors: Apurv Kulkarni, Shreyas Badave, B. Rajiv
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Non-parametric reliability technique is useful for assessment of reliability of systems for which failure rates are not available. This is useful when detection of malfunctioning of any component is the key purpose during ongoing operation of the system. The main purpose of the Heat Exchanger Cycle discussed in this paper is to provide hot water at a constant temperature for longer periods of time. In such a cycle, certain components play a crucial role and this paper presents an effective way to predict the malfunctioning of the components by determination of system reliability. The method discussed in the paper is feasible and this is clarified with the help of various test cases.Keywords: heat exchanger cycle, k-statistics, PID controller, system reliability
Procedia PDF Downloads 39117346 Modeling Dynamics and Control of Transversal Vibration of an Underactuated Flexible Plate Using Controlled Lagrangian Method
Authors: Mahmood Khalghollah, Mohammad Tavallaeinejad, Mohammad Eghtesad
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The method of Controlled Lagrangian is an energy shaping control technique for under actuated Lagrangian systems. Energy shaping control design methods are appealing as they retain the underlying nonlinear dynamics and can provide stability results that hold over larger domain than can be obtained using linear design and analysis. In the present study, controlled lagrangian is employed for designing a controller in an under actuated rotating flexible plate system. In the system of rotating flexible plate, due to its nonlinear characteristics and coupled dynamics of rigid and flexible components, controller design is a known challenge. In this paper, controller objectives are considered to be vibration reduction of flexible component and position control of the tip of the plate. To achieve the goals, a method based on both kinetic and potential energy shaping is introduced. The stability of the closed-loop system is investigated and proved around its equilibrium points. Moreover, the proposed controller is shown to be robust against disturbance and plant uncertainties.Keywords: controlled lagrangian, underactuated system, flexible rotating plate, disturbance
Procedia PDF Downloads 45017345 Integrated Best Worst PROMETHEE to Evaluate Public Transport Service Quality
Authors: Laila Oubahman, Duleba Szabolcs
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Public transport stakeholders aim to increase the ridership ratio by encouraging citizens to use common transportation modes. For this sight, improving service quality is a crucial option to reach the quality desired by users and reduce the gap between desired and perceived quality. Multi-criteria decision aid has been applied in literature in recent decades because it provides efficient models to assess the most impacting criteria on the overall assessment. In this paper, the PROMETHEE method is combined with the best-worst approach to construct a consensual model that avoids rank reversal to support stakeholders in ameliorating service quality.Keywords: best-worst method, MCDA, PROMETHEE, public transport
Procedia PDF Downloads 21017344 An Enhanced Approach in Validating Analytical Methods Using Tolerance-Based Design of Experiments (DoE)
Authors: Gule Teri
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The effective validation of analytical methods forms a crucial component of pharmaceutical manufacturing. However, traditional validation techniques can occasionally fail to fully account for inherent variations within datasets, which may result in inconsistent outcomes. This deficiency in validation accuracy is particularly noticeable when quantifying low concentrations of active pharmaceutical ingredients (APIs), excipients, or impurities, introducing a risk to the reliability of the results and, subsequently, the safety and effectiveness of the pharmaceutical products. In response to this challenge, we introduce an enhanced, tolerance-based Design of Experiments (DoE) approach for the validation of analytical methods. This approach distinctly measures variability with reference to tolerance or design margins, enhancing the precision and trustworthiness of the results. This method provides a systematic, statistically grounded validation technique that improves the truthfulness of results. It offers an essential tool for industry professionals aiming to guarantee the accuracy of their measurements, particularly for low-concentration components. By incorporating this innovative method, pharmaceutical manufacturers can substantially advance their validation processes, subsequently improving the overall quality and safety of their products. This paper delves deeper into the development, application, and advantages of this tolerance-based DoE approach and demonstrates its effectiveness using High-Performance Liquid Chromatography (HPLC) data for verification. This paper also discusses the potential implications and future applications of this method in enhancing pharmaceutical manufacturing practices and outcomes.Keywords: tolerance-based design, design of experiments, analytical method validation, quality control, biopharmaceutical manufacturing
Procedia PDF Downloads 8217343 Experimental Study on Strengthening Systems of Reinforced Concrete Cantilever Slabs
Authors: Aymen H. Khalil, Ashraf M. Heniegal, Bassam A. Abdelsalam
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There are many problems related to cantilever slabs such as the time-dependent deformation, corrosion problems of steel reinforcement, and lack of experimental studies on the strength of strengthened cantilever slabs. This paper presents an investigation to evaluate the behavior of reinforced concrete cantilever slabs after strengthening with different techniques. Six medium scale specimens, divided into three groups, were tested along with a control slab. The first group consists of two specimens which were repaired and strengthened using reinforced concrete jacket above with and without shear connector bars, whereas the second group contained two slabs which were strengthened using two strips of two layers of glass fiber reinforced polymer (GFRP) covering 60% and 90% from the cantilever length. The last group involves two specimens strengthened with two steel plates. In one specimen, the steel plates were glued to the surface using epoxy resin. The second specimen, the steel plates were affixed to the concrete surface using expansion bolts. The loading was conducted in two phases. Firstly, the samples were subjected to 40% of the ultimate load of the control slab. Secondly, the specimens reloaded after being strengthened up to failure. The load-deflection, steel strain, concrete strain, failure mode, toughness, and ductility index are discussed in this paper.Keywords: repair, strengthened, GFRP layers, reloaded, jacketing, cantilever slabs
Procedia PDF Downloads 20017342 Combination of Topology and Rough Set for Analysis of Power System Control
Authors: M. Kamel El-Sayed
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In this research, we have linked the concept of rough set and topological structure to the creation of a new topological structure that assists in the analysis of the information systems of some electrical engineering issues. We used non-specific information whose boundaries do not have an empty set in the top topological structure is rough set. It is characterized by the fact that it does not contain a large number of elements and facilitates the establishment of rules. We used this structure in reducing the specifications of electrical information systems. We have provided a detailed example of this method illustrating the steps used. This method opens the door to obtaining multiple topologies, each of which uses one of the non-defined groups (rough set) in the overall information system.Keywords: electrical engineering, information system, rough set, rough topology, topology
Procedia PDF Downloads 45417341 Iterative Solver for Solving Large-Scale Frictional Contact Problems
Authors: Thierno Diop, Michel Fortin, Jean Deteix
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Since the precise formulation of the elastic part is irrelevant for the description of the algorithm, we shall consider a generic case. In practice, however, we will have to deal with a non linear material (for instance a Mooney-Rivlin model). We are interested in solving a finite element approximation of the problem, leading to large-scale non linear discrete problems and, after linearization, to large linear systems and ultimately to calculations needing iterative methods. This also implies that penalty method, and therefore augmented Lagrangian method, are to be banned because of their negative effect on the condition number of the underlying discrete systems and thus on the convergence of iterative methods. This is in rupture to the mainstream of methods for contact in which augmented Lagrangian is the principal tool. We shall first present the problem and its discretization; this will lead us to describe a general solution algorithm relying on a preconditioner for saddle-point problems which we shall describe in some detail as it is not entirely standard. We will propose an iterative approach for solving three-dimensional frictional contact problems between elastic bodies, including contact with a rigid body, contact between two or more bodies and also self-contact.Keywords: frictional contact, three-dimensional, large-scale, iterative method
Procedia PDF Downloads 21317340 Ge₁₋ₓSnₓ Alloys with Tuneable Energy Band Gap on GaAs (100) Substrate Manufactured by a Modified Magnetron Co-Sputtering
Authors: Li Qian, Jinchao Tong, Daohua Zhang, Weijun Fan, Fei Suo
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Photonic applications based on group IV semiconductors have always been an interest but also a challenge for the research community. We report manufacturing group IV Ge₁₋ₓSnₓ alloys with tuneable energy band gap on (100) GaAs substrate by a modified radio frequency magnetron co-sputtering. Images were taken by atomic force microscope, and scanning electron microscope clearly demonstrates a smooth surface profile, and Ge₁₋ₓSnₓ nano clusters are with the size of several tens of nanometers. Transmittance spectra were measured by Fourier Transform Infrared Spectroscopy that showed changing energy gaps with the variation in elementary composition. Calculation results by 8-band k.p method are consistent with measured gaps. Our deposition system realized direct growth of Ge₁₋ₓSnₓ thin film on GaAs (100) substrate by sputtering. This simple deposition method was modified to be able to grow high-quality photonic materials with tuneable energy gaps. This work provides an alternative and successful method for fabricating Group IV photonic semiconductor materials.Keywords: GeSn, crystal growth, sputtering, photonic
Procedia PDF Downloads 14817339 Ray Tracing Modified 3D Image Method Simulation of Picocellular Propagation Channel Environment
Authors: Fathi Alwafie
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In this paper we present the simulation of the propagation characteristics of the picocellular propagation channel environment. The first aim has been to find a correct description of the environment for received wave. The result of the first investigations is that the environment of the indoor wave significantly changes as we change the electric parameters of material constructions. A modified 3D ray tracing image method tool has been utilized for the coverage prediction. A detailed analysis of the dependence of the indoor wave on the wide-band characteristics of the channel: Root Mean Square (RMS) delay spread characteristics and mean excess delay, is also investigated.Keywords: propagation, ray tracing, network, mobile computing
Procedia PDF Downloads 40217338 Stability Enhancement of a Large-Scale Power System Using Power System Stabilizer Based on Adaptive Neuro Fuzzy Inference System
Authors: Agung Budi Muljono, I Made Ginarsa, I Made Ari Nrartha
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A large-scale power system (LSPS) consists of two or more sub-systems connected by inter-connecting transmission. Loading pattern on an LSPS always changes from time to time and varies depend on consumer need. The serious instability problem is appeared in an LSPS due to load fluctuation in all of the bus. Adaptive neuro-fuzzy inference system (ANFIS)-based power system stabilizer (PSS) is presented to cover the stability problem and to enhance the stability of an LSPS. The ANFIS control is presented because the ANFIS control is more effective than Mamdani fuzzy control in the computation aspect. Simulation results show that the presented PSS is able to maintain the stability by decreasing peak overshoot to the value of −2.56 × 10−5 pu for rotor speed deviation Δω2−3. The presented PSS also makes the settling time to achieve at 3.78 s on local mode oscillation. Furthermore, the presented PSS is able to improve the peak overshoot and settling time of Δω3−9 to the value of −0.868 × 10−5 pu and at the time of 3.50 s for inter-area oscillation.Keywords: ANFIS, large-scale, power system, PSS, stability enhancement
Procedia PDF Downloads 30717337 OCR/ICR Text Recognition Using ABBYY FineReader as an Example Text
Authors: A. R. Bagirzade, A. Sh. Najafova, S. M. Yessirkepova, E. S. Albert
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This article describes a text recognition method based on Optical Character Recognition (OCR). The features of the OCR method were examined using the ABBYY FineReader program. It describes automatic text recognition in images. OCR is necessary because optical input devices can only transmit raster graphics as a result. Text recognition describes the task of recognizing letters shown as such, to identify and assign them an assigned numerical value in accordance with the usual text encoding (ASCII, Unicode). The peculiarity of this study conducted by the authors using the example of the ABBYY FineReader, was confirmed and shown in practice, the improvement of digital text recognition platforms developed by Electronic Publication.Keywords: ABBYY FineReader system, algorithm symbol recognition, OCR/ICR techniques, recognition technologies
Procedia PDF Downloads 17117336 Fuzzy Multi-Criteria Decision-Making Based on Ignatian Discernment Process
Authors: Pathinathan Theresanathan, Ajay Minj
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Ignatian Discernment Process (IDP) is an intense decision-making tool to decide on life-issues. Decisions are influenced by various factors outside of the decision maker and inclination within. This paper develops IDP in the context of Fuzzy Multi-criteria Decision Making (FMCDM) process. Extended VIKOR method is a decision-making method which encompasses even conflict situations and accommodates weightage to various issues. Various aspects of IDP, namely three ways of decision making and tactics of inner desires, are observed, analyzed and articulated within the frame work of fuzzy rules. The decision-making situations are broadly categorized into two types. The issues outside of the decision maker influence the person. The inner feeling also plays vital role in coming to a conclusion. IDP integrates both the categories using Extended VIKOR method. Case studies are carried out and analyzed with FMCDM process. Finally, IDP is verified with an illustrative case study and results are interpreted. A confused person who could not come to a conclusion is able to take decision on a concrete way of life through IDP. The proposed IDP model recommends an integrated and committed approach to value-based decision making.Keywords: AHP, FMCDM, IDP, ignatian discernment, MCDM, VIKOR
Procedia PDF Downloads 26117335 Segmentation Using Multi-Thresholded Sobel Images: Application to the Separation of Stuck Pollen Grains
Authors: Endrick Barnacin, Jean-Luc Henry, Jimmy Nagau, Jack Molinie
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Being able to identify biological particles such as spores, viruses, or pollens is important for health care professionals, as it allows for appropriate therapeutic management of patients. Optical microscopy is a technology widely used for the analysis of these types of microorganisms, because, compared to other types of microscopy, it is not expensive. The analysis of an optical microscope slide is a tedious and time-consuming task when done manually. However, using machine learning and computer vision, this process can be automated. The first step of an automated microscope slide image analysis process is segmentation. During this step, the biological particles are localized and extracted. Very often, the use of an automatic thresholding method is sufficient to locate and extract the particles. However, in some cases, the particles are not extracted individually because they are stuck to other biological elements. In this paper, we propose a stuck particles separation method based on the use of the Sobel operator and thresholding. We illustrate it by applying it to the separation of 813 images of adjacent pollen grains. The method correctly separated 95.4% of these images.Keywords: image segmentation, stuck particles separation, Sobel operator, thresholding
Procedia PDF Downloads 13317334 Study on Seismic Assessment of Earthquake-Damaged Reinforced Concrete Buildings
Authors: Fu-Pei Hsiao, Fung-Chung Tu, Chien-Kuo Chiu
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In this work, to develop a method for detailed assesses of post-earthquake seismic performance for RC buildings in Taiwan, experimental data for several column specimens with various failure modes (flexural failure, flexural-shear failure, and shear failure) are used to derive reduction factors of seismic capacity for specified damage states. According to the damage states of RC columns and their corresponding seismic reduction factors suggested by experimental data, this work applies the detailed seismic performance assessment method to identify the seismic capacity of earthquake-damaged RC buildings. Additionally, a post-earthquake emergent assessment procedure is proposed that can provide the data needed for decision about earthquake-damaged buildings in a region with high seismic hazard. Finally, three actual earthquake-damaged school buildings in Taiwan are used as a case study to demonstrate application of the proposed assessment method.Keywords: seismic assessment, seismic reduction factor, residual seismic ratio, post-earthquake, reinforced concrete, building
Procedia PDF Downloads 40117333 Behavior of Beam-Column Nodes Reinforced Concrete in Earthquake Zones
Authors: Zaidour Mohamed, Ghalem Ali Jr., Achit Henni Mohamed
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This project is destined to study pole junctions of reinforced concrete beams subjected to seismic loads. A literature review was made to clarify the work done by researchers in the last three decades and especially the results of the last two years that were studied for the determination of the method of calculating the transverse reinforcement in the different nodes of a structure. For implementation efforts in the columns and beams of a building R + 4 in zone 3 were calculated using the finite element method through software. These results are the basis of our work which led to the calculation of the transverse reinforcement of the nodes of the structure in question.Keywords: beam–column joints, cyclic loading, shearing force, damaged joint
Procedia PDF Downloads 55117332 Non-Invasive Imaging of Tissue Using Near Infrared Radiations
Authors: Ashwani Kumar Aggarwal
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NIR Light is non-ionizing and can pass easily through living tissues such as breast without any harmful effects. Therefore, use of NIR light for imaging the biological tissue and to quantify its optical properties is a good choice over other invasive methods. Optical tomography involves two steps. One is the forward problem and the other is the reconstruction problem. The forward problem consists of finding the measurements of transmitted light through the tissue from source to detector, given the spatial distribution of absorption and scattering properties. The second step is the reconstruction problem. In X-ray tomography, there is standard method for reconstruction called filtered back projection method or the algebraic reconstruction methods. But this method cannot be applied as such, in optical tomography due to highly scattering nature of biological tissue. A hybrid algorithm for reconstruction has been implemented in this work which takes into account the highly scattered path taken by photons while back projecting the forward data obtained during Monte Carlo simulation. The reconstructed image suffers from blurring due to point spread function. This blurred reconstructed image has been enhanced using a digital filter which is optimal in mean square sense.Keywords: least-squares optimization, filtering, tomography, laser interaction, light scattering
Procedia PDF Downloads 31617331 Petra: Simplified, Scalable Verification Using an Object-Oriented, Compositional Process Calculus
Authors: Aran Hakki, Corina Cirstea, Julian Rathke
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Formal methods are yet to be utilized in mainstream software development due to issues in scaling and implementation costs. This work is about developing a scalable, simplified, pragmatic, formal software development method with strong correctness properties and guarantees that are easy prove. The method aims to be easy to learn, use and apply without extensive training and experience in formal methods. Petra is proposed as an object-oriented, process calculus with composable data types and sequential/parallel processes. Petra has a simple denotational semantics, which includes a definition of Correct by Construction. The aim is for Petra is to be standard which can be implemented to execute on various mainstream programming platforms such as Java. Work towards an implementation of Petra as a Java EDSL (Embedded Domain Specific Language) is also discussed.Keywords: compositionality, formal method, software verification, Java, denotational semantics, rewriting systems, rewriting semantics, parallel processing, object-oriented programming, OOP, programming language, correct by construction
Procedia PDF Downloads 14617330 Study of a Few Additional Posterior Projection Data to 180° Acquisition for Myocardial SPECT
Authors: Yasuyuki Takahashi, Hirotaka Shimada, Takao Kanzaki
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A Dual-detector SPECT system is widely by use of myocardial SPECT studies. With 180-degree (180°) acquisition, reconstructed images are distorted in the posterior wall of myocardium due to the lack of sufficient data of posterior projection. We hypothesized that quality of myocardial SPECT images can be improved by the addition of data acquisition of only a few posterior projections to ordinary 180° acquisition. The proposed acquisition method (180° plus acquisition methods) uses the dual-detector SPECT system with a pair of detector arranged in 90° perpendicular. Sampling angle was 5°, and the acquisition range was 180° from 45° right anterior oblique to 45° left posterior oblique. After the acquisition of 180°, the detector moved to additional acquisition position of reverse side once for 2 projections, twice for 4 projections, or 3 times for 6 projections. Since these acquisition methods cannot be done in the present system, actual data acquisition was done by 360° with a sampling angle of 5°, and projection data corresponding to above acquisition position were extracted for reconstruction. We underwent the phantom studies and a clinical study. SPECT images were compared by profile curve analysis and also quantitatively by contrast ratio. The distortion was improved by 180° plus method. Profile curve analysis showed increased of cardiac cavity. Analysis with contrast ratio revealed that SPECT images of the phantoms and the clinical study were improved from 180° acquisition by the present methods. The difference in the contrast was not clearly recognized between 180° plus 2 projections, 180° plus 4 projections, and 180° plus 6 projections. 180° plus 2 projections method may be feasible for myocardial SPECT because distortion of the image and the contrast were improved.Keywords: 180° plus acquisition method, a few posterior projections, dual-detector SPECT system, myocardial SPECT
Procedia PDF Downloads 29617329 Obstacle Classification Method Based on 2D LIDAR Database
Authors: Moohyun Lee, Soojung Hur, Yongwan Park
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In this paper is proposed a method uses only LIDAR system to classification an obstacle and determine its type by establishing database for classifying obstacles based on LIDAR. The existing LIDAR system, in determining the recognition of obstruction in an autonomous vehicle, has an advantage in terms of accuracy and shorter recognition time. However, it was difficult to determine the type of obstacle and therefore accurate path planning based on the type of obstacle was not possible. In order to overcome this problem, a method of classifying obstacle type based on existing LIDAR and using the width of obstacle materials was proposed. However, width measurement was not sufficient to improve accuracy. In this research, the width data was used to do the first classification; database for LIDAR intensity data by four major obstacle materials on the road were created; comparison is made to the LIDAR intensity data of actual obstacle materials; and determine the obstacle type by finding the one with highest similarity values. An experiment using an actual autonomous vehicle under real environment shows that data declined in quality in comparison to 3D LIDAR and it was possible to classify obstacle materials using 2D LIDAR.Keywords: obstacle, classification, database, LIDAR, segmentation, intensity
Procedia PDF Downloads 35517328 Cross Professional Team-Assisted Teaching Effectiveness
Authors: Shan-Yu Hsu, Hsin-Shu Huang
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The main purpose of this teaching research is to design an interdisciplinary team-assisted teaching method for trainees and interns and review the effectiveness of this teaching method on trainees' understanding of peritoneal dialysis. The teaching research object is the fifth and sixth-grade trainees in a medical center's medical school. The teaching methods include media teaching, demonstration of technical operation, face-to-face communication with patients, special case discussions, and field visits to the peritoneal dialysis room. Evaluate learning effectiveness before, after, and verbally. Statistical analysis was performed using the SPSS paired-sample t-test to analyze whether there is a difference in peritoneal dialysis professional cognition before and after teaching intervention. Descriptive statistics show that the average score of the previous test is 74.44, the standard deviation is 9.34, the average score of the post-test is 95.56, and the standard deviation is 5.06. The results of the t-test of the paired samples are shown as p-value = 0.006, showing the peritoneal dialysis professional cognitive test. Significant differences were observed before and after. The interdisciplinary team-assisted teaching method helps trainees and interns to improve their professional awareness of peritoneal dialysis. At the same time, trainee physicians have positive feedback on the inter-professional team-assisted teaching method. This teaching research finds that the clinical ability development education of trainees and interns can provide cross-professional team-assisted teaching methods to assist clinical teaching guidance.Keywords: monitor quality, patient safety, health promotion objective, cross-professional team-assisted teaching methods
Procedia PDF Downloads 14817327 Use the Null Space to Create Starting Point for Stochastic Programming
Authors: Ghussoun Al-Jeiroudi
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Stochastic programming is one of the powerful technique which is used to solve real-life problems. Hence, the data of real-life problems is subject to significant uncertainty. Uncertainty is well studied and modeled by stochastic programming. Each day, problems become bigger and bigger and the need for a tool, which does deal with large scale problems, increase. Interior point method is a perfect tool to solve such problems. Interior point method is widely employed to solve the programs, which arise from stochastic programming. It is an iterative technique, so it is required a starting point. Well design starting point plays an important role in improving the convergence speed. In this paper, we propose a starting point for interior point method for multistage stochastic programming. Usually, the optimal solution of stage k+1 is used as starting point for the stage k. This point has the advantage of being close to the solution of the current program. However, it has a disadvantage; it is not in the feasible region of the current program. So, we suggest to take this point and modifying it. That is by adding to it a vector in the null space of the matrix of the unchanged constraints because the solution will change only in the null space of this matrix.Keywords: interior point methods, stochastic programming, null space, starting points
Procedia PDF Downloads 42117326 Stagnation Point Flow Over a Stretching Cylinder with Variable Thermal Conductivity and Slip Conditions
Authors: M. Y. Malik, Farzana Khan
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In this article, we discuss the behavior of viscous fluid near stagnation point over a stretching cylinder with variable thermal conductivity. The effects of slip conditions are also encountered. Thermal conductivity is considered as a linear function of temperature. By using homotopy analysis method and Fehlberg method we compare the graphical results for both momentum and energy equations. The effect of different parameters on velocity and temperature fields are shown graphically.Keywords: slip conditions, stretching cylinder, heat generation/absorption, stagnation point flow, variable thermal conductivity
Procedia PDF Downloads 42517325 Low-Surface Roughness and High Optical Quality CdS Thin Film Grown by Modified Chemical Surface Deposition Method
Authors: A. Elsayed, M. H. Dewaidar, M. Ghali
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We report on deposition of smooth, pinhole-free, low-surface roughness ( < 4nm) and high optical quality cadmium sulfide (CdS) thin films on glass substrates using our new method based on chemical surface deposition principle. In this method, cadmium acetate and thiourea are used as reactants under special growth conditions for deposition of CdS films. X-ray diffraction (XRD) measurements were used to examine the crystal structure properties of the deposited CdS films. In addition, UV-vis transmittance and low-temperature (4K) photoluminescence (PL) measurements were performed for quantifying optical properties of the deposited films. Interestingly, we found that XRD pattern of the deposited films has dramatically changed when the growth temperature was raised during the reaction. Namely, the XRD measurements reveal a structural change of CdS film from Cubic to Hexagonal phase upon increase in the growth temperature from 75 °C to 200 °C. Furthermore, the deposited films show high optical quality as confirmed from observation of both sharp edge in the transmittance spectra and strong PL intensity at room temperature. Also, we found a strong effect of the growth conditions on the optical band gap of the deposited films; where remarkable red-shift in the absorption edge with temperature is clearly seen in both transmission and PL spectra. Such tuning of both optical band gap and crystal structure of the deposited CdS films; can be utilized for tuning the electronic bands alignments between CdS and other light harvesting materials, like CuInGaSe or CdTe, for potential improvement in the efficiency of all-solution processed solar cells devices based on these heterostructures.Keywords: thin film, CdS, new method, optical properties
Procedia PDF Downloads 26117324 Numerical Simulation of High Strength Steel Hot-Finished Elliptical Hollow Section Subjected to Uniaxial Eccentric Compression
Authors: Zhengyi Kong, Xueqing Wang, Quang-Viet Vu
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In this study, the structural behavior of high strength steel (HSS) hot-finished elliptical hollow section (EHS) subjected to uniaxial eccentric compression is investigated. A finite element method for predicting the cross-section resistance of HSS hot-finished EHS is developed using ABAQUS software, which is then verified by comparison with previous experiments. The validated finite element method is employed to carry out parametric studies for investigating the structural behavior of HSS hot-finished EHS under uniaxial eccentric compression and evaluate the current design guidance for HSS hot-finished EHS. Different parameters, such as the radius of the larger and smaller outer diameter of EHS, thickness of EHS, eccentricity, and material property, are considered. The resulting data from 84 finite element models are used to obtain the relationship between the cross-section resistance of HSS hot-finished EHS and cross-section slenderness. It is concluded that current design provisions, such as EN 1993-1-1, BS 5950-1, AS4100, and Gardner et al., are conservative for predicting the HSS hot-finished EHS under uniaxial eccentric compression.Keywords: hot-finished, elliptical hollow section, uniaxial eccentric compression, finite element method
Procedia PDF Downloads 14017323 Texture Observation of Bending by XRD and EBSD Method
Authors: Takashi Sakai, Yuri Shimomura
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The crystal orientation is a factor that affects the microscopic material properties. Crystal orientation determines the anisotropy of the polycrystalline material. And it is closely related to the mechanical properties of the material. In this paper, for pure copper polycrystalline material, two different methods; X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD); and the crystal orientation were analyzed. In the latter method, it is possible that the X-ray beam diameter is thicker as compared to the former, to measure the crystal orientation macroscopically relatively. By measurement of the above, we investigated the change in crystal orientation and internal tissues of pure copper.Keywords: bending, electron backscatter diffraction, X-ray diffraction, microstructure, IPF map, orientation distribution function
Procedia PDF Downloads 33017322 Method of False Alarm Rate Control for Cyclic Redundancy Check-Aided List Decoding of Polar Codes
Authors: Dmitry Dikarev, Ajit Nimbalker, Alexei Davydov
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Polar coding is a novel example of error correcting codes, which can achieve Shannon limit at block length N→∞ with log-linear complexity. Active research is being carried to adopt this theoretical concept for using in practical applications such as 5th generation wireless communication systems. Cyclic redundancy check (CRC) error detection code is broadly used in conjunction with successive cancellation list (SCL) decoding algorithm to improve finite-length polar code performance. However, there are two issues: increase of code block payload overhead by CRC bits and decrease of CRC error-detection capability. This paper proposes a method to control CRC overhead and false alarm rate of polar decoding. As shown in the computer simulations results, the proposed method provides the ability to use any set of CRC polynomials with any list size while maintaining the desired level of false alarm rate. This level of flexibility allows using polar codes in 5G New Radio standard.Keywords: 5G New Radio, channel coding, cyclic redundancy check, list decoding, polar codes
Procedia PDF Downloads 23817321 A Method for Processing Unwanted Target Caused by Reflection in Secondary Surveillance Radar
Authors: Khanh D.Do, Loi V.Nguyen, Thanh N.Nguyen, Thang M.Nguyen, Vu T.Tran
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Along with the development of Secondary surveillance radar (SSR) in air traffic surveillance systems, the Multipath phenomena has always been a noticeable problem. This following article discusses the geometrical aspect and power aspect of the Multipath interference caused by reflection in SSR and proposes a method to deal with these unwanted multipath targets (ghosts) by false-target position predicting and adaptive target suppressing. A field-experiment example is mentioned at the end of the article to demonstrate the efficiency of this measure.Keywords: multipath, secondary surveillance radar, digital signal processing, reflection
Procedia PDF Downloads 16417320 Dust Ion Acoustic Shock Waves in Dissipative Superthermal Plasmas
Authors: Hamid Reza Pakzad
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In this paper, the properties of dust-ion-acoustic (DIA) shock waves in an unmagnetized dusty plasma, whose constituents are inertial ions, superthermal electrons, and stationary dust particles, are investigated by employing the reductive perturbation method. The dissipation is taken into account the kinematic viscosity among the plasma constituents. It is shown that the basic features of DIA shock waves are significantly modified by the effects of electron superthermality and ion kinematic viscosity.Keywords: reductive perturbation method, dust ion acoustic shock wave, superthermal electron, dissipative plasmas
Procedia PDF Downloads 31417319 Analysis of Thermal Damage Characteristics of High Pressure Turbine Blade According to Off-Design Operating Conditions
Authors: Seon Ho Kim, Minho Bang, Seok Min Choi, Young Moon Lee, Dong Kwan Kim, Hyung Hee Cho
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Gas turbines are heat engines that convert chemical energy into electrical energy through mechanical energy. Since their high energy density per unit volume and low pollutant emissions, gas turbines are classified as clean energy. In order to obtain better performance, the turbine inlet temperature of the current gas turbine is operated at about 1600℃, and thermal damage is a very serious problem. Especially, these thermal damages are more prominent in off-design conditions than in design conditions. In this study, the thermal damage characteristics of high temperature components of a gas turbine made of a single crystal material are studied numerically for the off-design operating conditions. The target gas turbine is configured as a reheat cycle and is operated in peak load operation mode, not normal operation. In particular, the target gas turbine features a lot of low-load operation. In this study, a commercial code, ANSYS 18.2, was used for analyzing the thermal-flow coupling problems. As a result, the flow separation phenomenon on the pressure side due to the flow reduction was remarkable at the off-design condition, and the high heat transfer coefficient at the upper end of the suction surface due to the tip leakage flow was appeared.Keywords: gas turbine, single crystal blade, off-design, thermal analysis
Procedia PDF Downloads 21617318 A New Complex Method for Integrated Warehouse Design in Aspect of Dynamic and Static Capacity
Authors: Tamas Hartvanyi, Zoltan Andras Nagy, Miklos Szabo
Abstract:
The dynamic and static capacity are two opposing aspect of warehouse design. Static capacity optimization aims to maximize the space-usage for goods storing, while dynamic capacity needs more free place to handling them. They are opposing by the building structure and the area utilization. According to Pareto principle: the 80% of the goods are the 20% of the variety. From the origin of this statement, it worth to store the big amount of same products by fulfill the space with minimal corridors, meanwhile the rest 20% of goods have the 80% variety of the whole range, so there is more important to be fast-reachable instead of the space utilizing, what makes the space fulfillment numbers worse. The warehouse design decisions made in present practice by intuitive and empiric impressions, the planning method is formed to one selected technology, making this way the structure of the warehouse homogeny. Of course the result can’t be optimal for the inhomogeneous demands. A new innovative model based on our research will be introduced in this paper to describe the technic capacities, what makes possible to define optimal cluster of technology. It is able to optimize the space fulfillment and the dynamic operation together with this cluster application.Keywords: warehouse, warehouse capacity, warehouse design method, warehouse optimization
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