Search results for: graph diameter
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1862

Search results for: graph diameter

1682 The Influence of the Diameter of the Flow Conducts on the Rheological Behavior of a Non-Newtonian Fluid

Authors: Hacina Abchiche, Mounir Mellal, Imene Bouchelkia

Abstract:

The knowledge of the rheological behavior of the used products in different fields is essential, both in digital simulation and the understanding of phenomenon involved during the flow of these products. The fluids presenting a nonlinear behavior represent an important category of materials used in the process of food-processing, chemical, pharmaceutical and oil industries. The issue is that the rheological characterization by classical rheometer cannot simulate, or take into consideration, the different parameters affecting the characterization of a complex fluid flow during real-time. The main objective of this study is to investigate the influence of the diameter of the flow conducts or pipe on the rheological behavior of a non-Newtonian fluid and Propose a mathematical model linking the rheologic parameters and the diameter of the conduits of flow. For this purpose, we have developed an experimental system based on the principal of a capillary rheometer.

Keywords: rhéologie, non-Newtonian fluids, experimental stady, mathematical model, cylindrical conducts

Procedia PDF Downloads 253
1681 Programmed Speech to Text Summarization Using Graph-Based Algorithm

Authors: Hamsini Pulugurtha, P. V. S. L. Jagadamba

Abstract:

Programmed Speech to Text and Text Summarization Using Graph-based Algorithms can be utilized in gatherings to get the short depiction of the gathering for future reference. This gives signature check utilizing Siamese neural organization to confirm the personality of the client and convert the client gave sound record which is in English into English text utilizing the discourse acknowledgment bundle given in python. At times just the outline of the gathering is required, the answer for this text rundown. Thus, the record is then summed up utilizing the regular language preparing approaches, for example, solo extractive text outline calculations

Keywords: Siamese neural network, English speech, English text, natural language processing, unsupervised extractive text summarization

Procedia PDF Downloads 183
1680 Ultraviolet Visible Spectroscopy Analysis on Transformer Oil by Correlating It with Various Oil Parameters

Authors: Rajnish Shrivastava, Y. R. Sood, Priti Pundir, Rahul Srivastava

Abstract:

Power transformer is one of the most important devices that are used in power station. Due to several fault impending upon it or due to ageing, etc its life gets lowered. So, it becomes necessary to have diagnosis of oil for fault analysis. Due to the chemical, electrical, thermal and mechanical stress the insulating material in the power transformer degraded. It is important to regularly assess the condition of oil and the remaining life of the power transformer. In this paper UV-VIS absorption graph area is correlated with moisture content, Flash point, IFT and Density of Transformer oil. Since UV-VIS absorption graph area varies accordingly with the variation in different transformer parameters. So by obtaining the correlation among different oil parameters for oil with respect to UV-VIS absorption area, decay contents of transformer oil can be predicted

Keywords: breakdown voltage (BDV), interfacial Tension (IFT), moisture content, ultra violet-visible rays spectroscopy (UV-VIS)

Procedia PDF Downloads 616
1679 Experimental and Finite Element Analysis of Large Deformation Characteristics of Magnetic Responsive Hydrogel Nanocomposites Membranes

Authors: Mallikarjunachari Gangapuram

Abstract:

Stimuli-responsive hydrogel nanocomposite membranes are gaining significant attention these days due to their potential applications in various engineering fields. For example, sensors, soft actuators, drug delivery, remote controlled therapy, water treatment, shape morphing, and magnetic refrigeration are few advanced applications of hydrogel nanocomposite membranes. In this work, hydrogel nanocomposite membranes are synthesized by embedding nanometer-sized (diameter - 300 nm) Fe₃O₄ magnetic particles into the polyvinyl alcohol (PVA) polymer. To understand the large deformation characteristics of these membranes, a well-known experimental method ball indentation technique is used. Different designing parameters such as membrane thickness, the concentration of magnetic particles and ball diameter on the viscoelastic properties are studied. All the experiments are carried out without and with a static magnetic field. Finite element simulations are carried out to validate the experimental results. It is observed, the creep response decreases and Young’s modulus increases as the thickness and concentration of magnetic particles increases. Image analysis revealed the hydrogel membranes are undergone global deformation for ball diameter 18 mm and local deformation when the diameter decreases from 18 mm to 0.5 mm.

Keywords: ball indentation, hydrogel membranes, nanocomposites, Young's modulus

Procedia PDF Downloads 104
1678 Rationale of Eye Pupillary Diameter for the UV Protection for Sunglasses

Authors: Liliane Ventura, Mauro Masili

Abstract:

Ultraviolet (UV) protection is critical for sunglasses, and mydriasis, as well as miosis, are relevant parameters to consider. The literature reports that for sunglasses, ultraviolet protection is critical because sunglasses can cause the opposite effect if the lenses do not provide adequate UV protection due to the greater dilation of the pupil when wearing sunglasses. However, the scientific literature does not properly quantify to support this rationale. The reasoning may be misleading by ignoring not only the inherent absorption of UV by the sunglass lens materials but also by ignoring the absorption of the anterior structures of the eye, i.e., the cornea and aqueous humor. Therefore, we estimate the pupil diameter and calculate the solar ultraviolet influx through the pupil of the human eye for two situations of an individual wearing and not wearing sunglasses. We quantify the dilation of the pupil as a function of the luminance of the surrounding. Therefore, we calculate the influx of solar UV through the pupil of the eye for two situations for an individual wearing sunglass and for the eyes free of shade. A typical boundary condition for the calculation is an individual in an upright position wearing sunglasses, staring at the horizon as if the sun is in the zenith. The calculation was done for the latitude of the geographic center of the state of São Paulo (-22º04'11.8'' S) from sunrise to sunset. A model from the literature is used for determining the sky luminance. The initial approach is to obtain pupil diameter as a function of luminance. Therefore, as a preliminary result, we calculate the pupil diameter as a function of the time of day, as the sun moves, for a particular day of the year. The working range for luminance is daylight (10⁻⁴ – 10⁵ cd/m²). We are able to show how the pupil adjusts to brightness change (~2 - ~7.8 mm). At noon, with the sun higher, the direct incidence of light on the pupil is lower if compared to mid-morning or mid-afternoon, when the sun strikes more directly into the eye. Thus, the pupil is larger at midday. As expected, the two situations have opposite behaviors since higher luminance implies a smaller pupil. With these results, we can progress in the short term to obtain the transmittance spectra of sunglasses samples and quantify how light attenuation provided by the spectacles affects pupil diameter.

Keywords: sunglasses, UV protection, pupil diameter, solar irradiance, luminance

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1677 Investigation of Bubble Growth During Nucleate Boiling Using CFD

Authors: K. Jagannath, Akhilesh Kotian, S. S. Sharma, Achutha Kini U., P. R. Prabhu

Abstract:

Boiling process is characterized by the rapid formation of vapour bubbles at the solid–liquid interface (nucleate boiling) with pre-existing vapour or gas pockets. Computational fluid dynamics (CFD) is an important tool to study bubble dynamics. In the present study, CFD simulation has been carried out to determine the bubble detachment diameter and its terminal velocity. Volume of fluid method is used to model the bubble and the surrounding by solving single set of momentum equations and tracking the volume fraction of each of the fluids throughout the domain. In the simulation, bubble is generated by allowing water-vapour to enter a cylinder filled with liquid water through an inlet at the bottom. After the bubble is fully formed, the bubble detaches from the surface and rises up during which the bubble accelerates due to the net balance between buoyancy force and viscous drag. Finally when these forces exactly balance each other, it attains a constant terminal velocity. The bubble detachment diameter and the terminal velocity of the bubble are captured by the monitor function provided in FLUENT. The detachment diameter and the terminal velocity obtained is compared with the established results based on the shape of the bubble. A good agreement is obtained between the results obtained from simulation and the equations in comparison with the established results.

Keywords: bubble growth, computational fluid dynamics, detachment diameter, terminal velocity

Procedia PDF Downloads 359
1676 Power Iteration Clustering Based on Deflation Technique on Large Scale Graphs

Authors: Taysir Soliman

Abstract:

One of the current popular clustering techniques is Spectral Clustering (SC) because of its advantages over conventional approaches such as hierarchical clustering, k-means, etc. and other techniques as well. However, one of the disadvantages of SC is the time consuming process because it requires computing the eigenvectors. In the past to overcome this disadvantage, a number of attempts have been proposed such as the Power Iteration Clustering (PIC) technique, which is one of versions from SC; some of PIC advantages are: 1) its scalability and efficiency, 2) finding one pseudo-eigenvectors instead of computing eigenvectors, and 3) linear combination of the eigenvectors in linear time. However, its worst disadvantage is an inter-class collision problem because it used only one pseudo-eigenvectors which is not enough. Previous researchers developed Deflation-based Power Iteration Clustering (DPIC) to overcome problems of PIC technique on inter-class collision with the same efficiency of PIC. In this paper, we developed Parallel DPIC (PDPIC) to improve the time and memory complexity which is run on apache spark framework using sparse matrix. To test the performance of PDPIC, we compared it to SC, ESCG, ESCALG algorithms on four small graph benchmark datasets and nine large graph benchmark datasets, where PDPIC proved higher accuracy and better time consuming than other compared algorithms.

Keywords: spectral clustering, power iteration clustering, deflation-based power iteration clustering, Apache spark, large graph

Procedia PDF Downloads 150
1675 On Differential Growth Equation to Stochastic Growth Model Using Hyperbolic Sine Function in Height/Diameter Modeling of Pines

Authors: S. O. Oyamakin, A. U. Chukwu

Abstract:

Richard's growth equation being a generalized logistic growth equation was improved upon by introducing an allometric parameter using the hyperbolic sine function. The integral solution to this was called hyperbolic Richard's growth model having transformed the solution from deterministic to a stochastic growth model. Its ability in model prediction was compared with the classical Richard's growth model an approach which mimicked the natural variability of heights/diameter increment with respect to age and therefore provides a more realistic height/diameter predictions using the coefficient of determination (R2), Mean Absolute Error (MAE) and Mean Square Error (MSE) results. The Kolmogorov-Smirnov test and Shapiro-Wilk test was also used to test the behavior of the error term for possible violations. The mean function of top height/Dbh over age using the two models under study predicted closely the observed values of top height/Dbh in the hyperbolic Richard's nonlinear growth models better than the classical Richard's growth model.

Keywords: height, Dbh, forest, Pinus caribaea, hyperbolic, Richard's, stochastic

Procedia PDF Downloads 443
1674 Study on the Effects of Grassroots Characteristics on Reinforced Soil Performance by Direct Shear Test

Authors: Zhanbo Cheng, Xueyu Geng

Abstract:

Vegetation slope protection technique is economic, aesthetic and practical. Herbs are widely used in practice because of rapid growth, strong erosion resistance, obvious slope protection and simple method, in which the root system of grass plays a very important role. In this paper, through changing the variables value of grassroots quantity, grassroots diameter, grassroots length and grassroots reinforce layers, the direct shear tests were carried out to discuss the change of shear strength indexes of grassroots reinforced soil under different reinforce situations, and analyse the effects of grassroots characteristics on reinforced soil performance. The laboratory test results show that: (1) in the certain number of grassroots diameter, grassroots length and grassroots reinforce layers, the value of shear strength, and cohesion first increase and then reduce with the increasing of grassroots quantity; (2) in the certain number of grassroots quantity, grassroots length and grassroots reinforce layers, the value of shear strength and cohesion rise with the increasing of grassroots diameter; (3) in the certain number of grassroots diameter, and grassroots reinforce layers, the value of shear strength and cohesion raise with the increasing of grassroots length in a certain range of grassroots quantity, while the value of shear strength and cohesion first rise and then decline with the increasing of grassroots length when the grassroots quantity reaches a certain value; (4) in the certain number of grassroots quantity, grassroots diameter, and grassroots length, the value of shear strength and cohesion first climb and then decline with the increasing of grassroots reinforced layers; (5) the change of internal friction angle is small in different parameters of grassroots. The research results are of importance for understanding the mechanism of vegetation protection for slopes and determining the parameters of grass planting.

Keywords: direct shear test, reinforced soil, grassroots characteristics, shear strength indexes

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1673 Roller Pump-Induced Tubing Rupture during Cardiopulmonary Bypass

Authors: W. G. Kim, C. H. Jo

Abstract:

We analyzed the effects of variations in the diameter of silicone rubber and polyvinyl chloride (PVC) tubings on the likelihood of tubing rupture during modeling of accidental arterial line clamping in cardiopulmonary bypass with a roller pump. A closed CPB circuit constructed with a roller pump was tested with both PVC and silicone rubber tubings of 1/2, 3/8, and 1/4 inch internal diameter. Arterial line pressure was monitored, and an occlusive clamp was placed across the tubing distal to the pressure monitor site to model an accidental arterial line occlusion. A CCD camera with 512(H) x 492(V) pixels was installed above the roller pump to measure tubing diameters at pump outlet, where the maximum deformations (distension) of the tubings occurred. Quantitative measurement of the changes of tubing diameters with the change of arterial line pressure was performed using computerized image processing techniques. A visible change of tubing diameter was generally noticeable by around 250 psi of arterial line pressure, which was already very high. By 1500 psi, the PVC tubings showed an increase of diameter of between 5-10 %, while the silicone rubber tubings showed an increase between 20-25 %. Silicone rubber tubings of all sizes showed greater distensibility than PVC tubings of equivalent size. In conclusion, although roller-pump induced tubing rupture remains a theoretical problem during cardiopulmonary bypass in terms of the inherent mechanism of the pump, in reality such an occurrence is impossible in real clinical conditions.

Keywords: roller pump, tubing rupture, cardiopulmonary bypass, arterial line

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1672 Memetic Algorithm for Solving the One-To-One Shortest Path Problem

Authors: Omar Dib, Alexandre Caminada, Marie-Ange Manier

Abstract:

The purpose of this study is to introduce a novel approach to solve the one-to-one shortest path problem. A directed connected graph is assumed in which all edges’ weights are positive. Our method is based on a memetic algorithm in which we combine a genetic algorithm (GA) and a variable neighborhood search method (VNS). We compare our approximate method with two exact algorithms Dijkstra and Integer Programming (IP). We made experimentations using random generated, complete and real graph instances. In most case studies, numerical results show that our method outperforms exact methods with 5% average gap to the optimality. Our algorithm’s average speed is 20-times faster than Dijkstra and more than 1000-times compared to IP. The details of the experimental results are also discussed and presented in the paper.

Keywords: shortest path problem, Dijkstra’s algorithm, integer programming, memetic algorithm

Procedia PDF Downloads 436
1671 Mesoporous Material Nanofibers by Electrospinning

Authors: Sh. Sohrabnezhad, A. Jafarzadeh

Abstract:

In this paper, MCM-41 mesoporous material nanofibers were synthesized by an electrospinning technique. The nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), and nitrogen adsorption–desorption measurement. Tetraethyl orthosilicate (TEOS) and polyvinyl alcohol (PVA) were used as a silica source and fiber forming source, respectively. TEM and SEM images showed synthesis of MCM-41 nanofibers with a diameter of 200 nm. The pore diameter and surface area of calcined MCM-41 nanofibers was 2.2 nm and 970 m2/g, respectively. The morphology of the MCM-41 nanofibers depended on spinning voltages.

Keywords: electrospinning, electron microscopy, fiber technology, porous materials, X-ray techniques

Procedia PDF Downloads 222
1670 An Alternative Richards’ Growth Model Based on Hyperbolic Sine Function

Authors: Samuel Oluwafemi Oyamakin, Angela Unna Chukwu

Abstract:

Richrads growth equation being a generalized logistic growth equation was improved upon by introducing an allometric parameter using the hyperbolic sine function. The integral solution to this was called hyperbolic Richards growth model having transformed the solution from deterministic to a stochastic growth model. Its ability in model prediction was compared with the classical Richards growth model an approach which mimicked the natural variability of heights/diameter increment with respect to age and therefore provides a more realistic height/diameter predictions using the coefficient of determination (R2), Mean Absolute Error (MAE) and Mean Square Error (MSE) results. The Kolmogorov-Smirnov test and Shapiro-Wilk test was also used to test the behavior of the error term for possible violations. The mean function of top height/Dbh over age using the two models under study predicted closely the observed values of top height/Dbh in the hyperbolic Richards nonlinear growth models better than the classical Richards growth model.

Keywords: height, diameter at breast height, DBH, hyperbolic sine function, Pinus caribaea, Richards' growth model

Procedia PDF Downloads 365
1669 Determination of Selected Engineering Properties of Giant Palm Seeds (Borassus Aethiopum) in Relation to Its Oil Potential

Authors: Rasheed Amao Busari, Ahmed Ibrahim

Abstract:

The engineering properties of giant palms are crucial for the reasonable design of the processing and handling systems. The research was conducted to investigate some engineering properties of giant palm seeds in relation to their oil potential. The ripe giant palm fruit was sourced from some parts of Zaria in Kaduna State and Ado Ekiti in Ekiti State, Nigeria. The mesocarps of the fruits collected were removed to obtain the nuts, while the collected nuts were dried under ambient conditions for several days. The actual moisture content of the nuts at the time of the experiment was determined using KT100S Moisture Meter, with moisture content ranged 17.9% to 19.15%. The physical properties determined are axial dimension, geometric mean diameter, arithmetic mean diameter, sphericity, true and bulk densities, porosity, angles of repose, and coefficients of friction. The nuts were measured using a vernier caliper for physical assessment of their sizes. The axial dimensions of 100 nuts were taken and the result shows that the size ranges from 7.30 to 9.32cm for major diameter, 7.2 to 8.9 cm for intermediate diameter, and 4.2 to 6.33 for minor diameter. The mechanical properties determined were compressive force, compressive stress, and deformation both at peak and break using Instron hydraulic universal tensile testing machine. The work also revealed that giant palm seed can be classified as an oil-bearing seed. The seed gave 18% using the solvent extraction method. The results obtained from the study will help in solving the problem of equipment design, handling, and further processing of the seeds.

Keywords: giant palm seeds, engineering properties, oil potential, moisture content, and giant palm fruit

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1668 Relation of Mean Platelet Volume with Serum Paraoxonase-1 Activity and Brachial Artery Diameter and Intima Media Thickness in Diabetic Patients with Respect to Obesity and Diabetic Complications

Authors: Pınar Karakaya, Meral Mert, Yildiz Okuturlar, Didem Acarer, Asuman Gedikbasi, Filiz Islim, Teslime Ayaz, Ozlem Soyluk, Ozlem Harmankaya, Abdulbaki Kumbasar

Abstract:

Objective: To evaluate the relation of mean platelet volume (MPV) levels with serum paraoxonase-1 activity and brachial artery diameter and intima media thickness in diabetic patients with respect to obesity and diabetic complications. Methods: A total of 201 diabetic patients grouped with respect to obesity [obese (n=89) and non-obese (n=112) and diabetic complications [with (n=50) or without (n=150) microvascular complications and with (n=91) or without (n=108) macrovascular complications] groups were included. Data on demographic and lifestyle characteristics of patients, anthropometric measurements, diabetes related microvascular and macrovascular complications, serum levels for MPV, bBrachial artery diameter and intima media thickness (IMT) and serum paraoxonase and arylesterase activities were recorded. Correlation of MPV values to paraoxonase and arylesterase activities as well as to brachial artery diameter and IMT was evaluated in study groups. Results: Mean(SD) paraoxonase and arylesterase values were 119.8(37.5) U/L and 149.0(39.9) U/L, respectively in the overall population with no significant difference with respect to obesity and macrovascular diabetic complications, whereas significantly lower values for paraoxonase (107.5(30.7) vs. 123.9(38.8) U/L, p=0.007) and arylesterase (132.1(30.2) vs. 154.7(41.2) U/L, p=0.001) were noted in patients with than without diabetic microvascular complications. Mean(SD) MPV values were 9.10 (0.87) fL in the overall population with no significant difference with respect to obesity and diabetic complications. No significant correlation of MPV values to paraoxonase, arylesterase activities, to brachial artery diameter and IMT was noted in the overall study population as well as in study groups. Conclusion: In conclusion, our findings revealed a significant decrease I PON-1 activity in diabetic patients with microvascular rather than macrovascular complications, whereas regardless of obesity and diabetic complications, no increase in thrombogenic activity and no relation of thrombogenic activity with PON-1 activity and brachial artery diameter and IMK.

Keywords: atherosclerosis, diabetes mellitus, microvascular complications, macrovascular complications, obesity, paraoxonase

Procedia PDF Downloads 323
1667 Encapsulation of Volatile Citronella Essential oil by Coacervation: Efficiency and Release Kinetic Study

Authors: Rafeqah Raslan, Mastura AbdManaf, Junaidah Jai, Istikamah Subuki, Ana Najwa Mustapa

Abstract:

The volatile citronella essential oil was encapsulated by simple coacervation and complex coacervation using gum Arabic and gelatin as wall material. Glutaraldehyde was used in the methodology as crosslinking agent. The citronella standard calibration graph was developed with R2 equal to 0.9523 for the accurate determination of encapsulation efficiency and release study. The release kinetic was analyzed based on Fick’s law of diffusion for polymeric system and linear graph of log fraction release over log time was constructed to determine the release rate constant, k and diffusion coefficient, n. Both coacervation methods in the present study produce encapsulation efficiency around 94%. The capsules morphology analysis supported the release kinetic mechanisms of produced capsules for both coacervation process.

Keywords: simple coacervation, complex coacervation, encapsulation efficiency, release kinetic study

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1666 Single-Walled Carbon Nanotube Synthesis by Chemical Vapor Deposition Using Platinum-Group Metal Catalysts

Authors: T. Maruyama, T. Saida, S. Naritsuka, S. Iijima

Abstract:

Single-walled carbon nanotubes (SWCNTs) are generally synthesized by chemical vapor deposition (CVD) using Fe, Co, and Ni as catalysts. However, due to the Ostwald ripening of metal catalysts, the diameter distribution of the grown SWCNTs is considerably wide (>2 nm), which is not suitable for electronics applications. In addition, reduction in the growth temperature is desirable for fabricating SWCNT devices compatible with the LSI process. Herein, we performed SWCNT growth by alcohol catalytic CVD using platinum-group metal catalysts (Pt, Rh, and Pd) because these metals have high melting points, and the reduction in the Ostwald ripening of catalyst particles is expected. Our results revealed that web-like SWCNTs were obtained from Pt and Rh catalysts at growth temperature between 500 °C and 600 °C by optimizing the ethanol pressure. The SWCNT yield from Pd catalysts was considerably low. By decreasing the growth temperature, the diameter and chirality distribution of SWCNTs from Pt and Rh catalysts became small and narrow. In particular, the diameters of most SWCNTs grown using Pt catalysts were below 1 nm and their diameter distribution was considerably narrow. On the contrary, SWCNTs can grow from Rh catalysts even at 300 °C by optimizing the growth condition, which is the lowest temperature recorded for SWCNT growth. Our results demonstrated that platinum-group metals are useful for the growth of small-diameter SWCNTs and facilitate low-temperature growth.

Keywords: carbon nanotube, chemical vapor deposition, catalyst, platinum, rhodium, palladium

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1665 Stress Concentration Trend for Combined Loading Conditions

Authors: Aderet M. Pantierer, Shmuel Pantierer, Raphael Cordina, Yougashwar Budhoo

Abstract:

Stress concentration occurs when there is an abrupt change in geometry, a mechanical part under loading. These changes in geometry can include holes, notches, or cracks within the component. The modifications create larger stress within the part. This maximum stress is difficult to determine, as it is directly at the point of the minimum area. Strain gauges have yet to be developed to analyze stresses at such minute areas. Therefore, a stress concentration factor must be utilized. The stress concentration factor is a dimensionless parameter calculated solely on the geometry of a part. The factor is multiplied by the nominal, or average, stress of the component, which can be found analytically or experimentally. Stress concentration graphs exist for common loading conditions and geometrical configurations to aid in the determination of the maximum stress a part can withstand. These graphs were developed from historical data yielded from experimentation. This project seeks to verify a stress concentration graph for combined loading conditions. The aforementioned graph was developed using CATIA Finite Element Analysis software. The results of this analysis will be validated through further testing. The 3D modeled parts will be subjected to further finite element analysis using Patran-Nastran software. The finite element models will then be verified by testing physical specimen using a tensile testing machine. Once the data is validated, the unique stress concentration graph will be submitted for publication so it can aid engineers in future projects.

Keywords: stress concentration, finite element analysis, finite element models, combined loading

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1664 Numerical Determination of Transition of Cup Height between Hydroforming Processes

Authors: H. Selcuk Halkacı, Mevlüt Türköz, Ekrem Öztürk, Murat Dilmec

Abstract:

Various attempts concerning the low formability issue for lightweight materials like aluminium and magnesium alloys are being investigated in many studies. Advanced forming processes such as hydroforming is one of these attempts. In last decades sheet hydroforming process has an increasing interest, particularly in the automotive and aerospace industries. This process has many advantages such as enhanced formability, the capability to form complex parts, higher dimensional accuracy and surface quality, reduction of tool costs and reduced die wear compared to the conventional sheet metal forming processes. There are two types of sheet hydroforming. One of them is hydromechanical deep drawing (HDD) that is a special drawing process in which pressurized fluid medium is used instead of one of the die half compared to the conventional deep drawing (CDD) process. Another one is sheet hydroforming with die (SHF-D) in which blank is formed with the act of fluid pressure and it takes the shape of die half. In this study, transition of cup height according to cup diameter between the processes was determined by performing simulation of the processes in Finite Element Analysis. Firstly SHF-D process was simulated for 40 mm cup diameter at different cup heights chancing from 10 mm to 30 mm and the cup height to diameter ratio value in which it is not possible to obtain a successful forming was determined. Then the same ratio was checked for a different cup diameter of 60 mm. Then thickness distributions of the cups formed by SHF-D and HDD processes were compared for the cup heights. Consequently, it was found that the thickness distribution in HDD process in the analyses was more uniform.

Keywords: finite element analysis, HDD, hydroforming sheet metal forming, SHF-D

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1663 Plotting of an Ideal Logic versus Resource Outflow Graph through Response Analysis on a Strategic Management Case Study Based Questionnaire

Authors: Vinay A. Sharma, Shiva Prasad H. C.

Abstract:

The initial stages of any project are often observed to be in a mixed set of conditions. Setting up the project is a tough task, but taking the initial decisions is rather not complex, as some of the critical factors are yet to be introduced into the scenario. These simple initial decisions potentially shape the timeline and subsequent events that might later be plotted on it. Proceeding towards the solution for a problem is the primary objective in the initial stages. The optimization in the solutions can come later, and hence, the resources deployed towards attaining the solution are higher than what they would have been in the optimized versions. A ‘logic’ that counters the problem is essentially the core of the desired solution. Thus, if the problem is solved, the deployment of resources has led to the required logic being attained. As the project proceeds along, the individuals working on the project face fresh challenges as a team and are better accustomed to their surroundings. The developed, optimized solutions are then considered for implementation, as the individuals are now experienced, and know better of the consequences and causes of possible failure, and thus integrate the adequate tolerances wherever required. Furthermore, as the team graduates in terms of strength, acquires prodigious knowledge, and begins its efficient transfer, the individuals in charge of the project along with the managers focus more on the optimized solutions rather than the traditional ones to minimize the required resources. Hence, as time progresses, the authorities prioritize attainment of the required logic, at a lower amount of dedicated resources. For empirical analysis of the stated theory, leaders and key figures in organizations are surveyed for their ideas on appropriate logic required for tackling a problem. Key-pointers spotted in successfully implemented solutions are noted from the analysis of the responses and a metric for measuring logic is developed. A graph is plotted with the quantifiable logic on the Y-axis, and the dedicated resources for the solutions to various problems on the X-axis. The dedicated resources are plotted over time, and hence the X-axis is also a measure of time. In the initial stages of the project, the graph is rather linear, as the required logic will be attained, but the consumed resources are also high. With time, the authorities begin focusing on optimized solutions, since the logic attained through them is higher, but the resources deployed are comparatively lower. Hence, the difference between consecutive plotted ‘resources’ reduces and as a result, the slope of the graph gradually increases. On an overview, the graph takes a parabolic shape (beginning on the origin), as with each resource investment, ideally, the difference keeps on decreasing, and the logic attained through the solution keeps increasing. Even if the resource investment is higher, the managers and authorities, ideally make sure that the investment is being made on a proportionally high logic for a larger problem, that is, ideally the slope of the graph increases with the plotting of each point.

Keywords: decision-making, leadership, logic, strategic management

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1662 Human Posture Estimation Based on Multiple Viewpoints

Authors: Jiahe Liu, HongyangYu, Feng Qian, Miao Luo

Abstract:

This study aimed to address the problem of improving the confidence of key points by fusing multi-view information, thereby estimating human posture more accurately. We first obtained multi-view image information and then used the MvP algorithm to fuse this multi-view information together to obtain a set of high-confidence human key points. We used these as the input for the Spatio-Temporal Graph Convolution (ST-GCN). ST-GCN is a deep learning model used for processing spatio-temporal data, which can effectively capture spatio-temporal relationships in video sequences. By using the MvP algorithm to fuse multi-view information and inputting it into the spatio-temporal graph convolution model, this study provides an effective method to improve the accuracy of human posture estimation and provides strong support for further research and application in related fields.

Keywords: multi-view, pose estimation, ST-GCN, joint fusion

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1661 Computer Simulation Approach in the 3D Printing Operations of Surimi Paste

Authors: Timilehin Martins Oyinloye, Won Byong Yoon

Abstract:

Simulation technology is being adopted in many industries, with research focusing on the development of new ways in which technology becomes embedded within production, services, and society in general. 3D printing (3DP) technology is fast developing in the food industry. However, the limited processability of high-performance material restricts the robustness of the process in some cases. Significantly, the printability of materials becomes the foundation for extrusion-based 3DP, with residual stress being a major challenge in the printing of complex geometry. In many situations, the trial-a-error method is being used to determine the optimum printing condition, which results in time and resource wastage. In this report, the analysis of 3 moisture levels for surimi paste was investigated for an optimum 3DP material and printing conditions by probing its rheology, flow characteristics in the nozzle, and post-deposition process using the finite element method (FEM) model. Rheological tests revealed that surimi pastes with 82% moisture are suitable for 3DP. According to the FEM model, decreasing the nozzle diameter from 1.2 mm to 0.6 mm, increased the die swell from 9.8% to 14.1%. The die swell ratio increased due to an increase in the pressure gradient (1.15107 Pa to 7.80107 Pa) at the nozzle exit. The nozzle diameter influenced the fluid properties, i.e., the shear rate, velocity, and pressure in the flow field, as well as the residual stress and the deformation of the printed sample, according to FEM simulation. The post-printing stability of the model was investigated using the additive layer manufacturing (ALM) model. The ALM simulation revealed that the residual stress and total deformation of the sample were dependent on the nozzle diameter. A small nozzle diameter (0.6 mm) resulted in a greater total deformation (0.023), particularly at the top part of the model, which eventually resulted in the sample collapsing. As the nozzle diameter increased, the accuracy of the model improved until the optimum nozzle size (1.0 mm). Validation with 3D-printed surimi products confirmed that the nozzle diameter was a key parameter affecting the geometry accuracy of 3DP of surimi paste.

Keywords: 3D printing, deformation analysis, die swell, numerical simulation, surimi paste

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1660 A Combinatorial Representation for the Invariant Measure of Diffusion Processes on Metric Graphs

Authors: Michele Aleandri, Matteo Colangeli, Davide Gabrielli

Abstract:

We study a generalization to a continuous setting of the classical Markov chain tree theorem. In particular, we consider an irreducible diffusion process on a metric graph. The unique invariant measure has an atomic component on the vertices and an absolutely continuous part on the edges. We show that the corresponding density at x can be represented by a normalized superposition of the weights associated to metric arborescences oriented toward the point x. A metric arborescence is a metric tree oriented towards its root. The weight of each oriented metric arborescence is obtained by the product of the exponential of integrals of the form ∫a/b², where b is the drift and σ² is the diffusion coefficient, along the oriented edges, for a weight for each node determined by the local orientation of the arborescence around the node and for the inverse of the diffusion coefficient at x. The metric arborescences are obtained by cutting the original metric graph along some edges.

Keywords: diffusion processes, metric graphs, invariant measure, reversibility

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1659 Two-Level Graph Causality to Detect and Predict Random Cyber-Attacks

Authors: Van Trieu, Shouhuai Xu, Yusheng Feng

Abstract:

Tracking attack trajectories can be difficult, with limited information about the nature of the attack. Even more difficult as attack information is collected by Intrusion Detection Systems (IDSs) due to the current IDSs having some limitations in identifying malicious and anomalous traffic. Moreover, IDSs only point out the suspicious events but do not show how the events relate to each other or which event possibly cause the other event to happen. Because of this, it is important to investigate new methods capable of performing the tracking of attack trajectories task quickly with less attack information and dependency on IDSs, in order to prioritize actions during incident responses. This paper proposes a two-level graph causality framework for tracking attack trajectories in internet networks by leveraging observable malicious behaviors to detect what is the most probable attack events that can cause another event to occur in the system. Technically, given the time series of malicious events, the framework extracts events with useful features, such as attack time and port number, to apply to the conditional independent tests to detect the relationship between attack events. Using the academic datasets collected by IDSs, experimental results show that the framework can quickly detect the causal pairs that offer meaningful insights into the nature of the internet network, given only reasonable restrictions on network size and structure. Without the framework’s guidance, these insights would not be able to discover by the existing tools, such as IDSs. It would cost expert human analysts a significant time if possible. The computational results from the proposed two-level graph network model reveal the obvious pattern and trends. In fact, more than 85% of causal pairs have the average time difference between the causal and effect events in both computed and observed data within 5 minutes. This result can be used as a preventive measure against future attacks. Although the forecast may be short, from 0.24 seconds to 5 minutes, it is long enough to be used to design a prevention protocol to block those attacks.

Keywords: causality, multilevel graph, cyber-attacks, prediction

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1658 Droplet Entrainment and Deposition in Horizontal Stratified Two-Phase Flow

Authors: Joshua Kim Schimpf, Kyun Doo Kim, Jaseok Heo

Abstract:

In this study, the droplet behavior of under horizontal stratified flow regime for air and water flow in horizontal pipe experiments from a 0.24 m, 0.095 m, and 0.0486 m size diameter pipe are examined. The effects of gravity, pipe diameter, and turbulent diffusion on droplet deposition are considered. Models for droplet entrainment and deposition are proposed that considers developing length. Validation for experimental data dedicated from the REGARD, CEA and Williams, University of Illinois, experiment were performed using SPACE (Safety and Performance Analysis Code for Nuclear Power Plants).

Keywords: droplet, entrainment, deposition, horizontal

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1657 Larger Diameter 22 MM-PDC Cutter Greatly Improves Drilling Efficiency of PDC Bit

Authors: Fangyuan Shao, Wei Liu, Deli Gao

Abstract:

With the increasing speed of oil and gas exploration, development and production at home and abroad, the demand for drilling speed up technology is becoming more and more critical to reduce the development cost. Highly efficient and personalized PDC bit is important equipment in the bottom hole assembly (BHA). Therefore, improving the rock-breaking efficiency of PDC bits will help reduce drilling time and drilling cost. Advances in PDC bit technology have resulted in a leapfrogging improvement in the rate of penetration (ROP) of PDC bits over roller cone bits in soft to medium-hard formations. Recently, with the development of PDC technology, the diameter of the PDC tooth can be further expanded. The maximum diameter of the PDC cutter used in this paper is 22 mm. According to the theoretical calculation, under the same depth of cut (DOC), the 22mm-PDC cutter increases the exposure of the cutter, and the increase of PDC cutter diameter helps to increase the cutting area of the PDC cutter. In order to evaluate the cutting performance of the 22 mm-PDC cutter and the existing commonly used cutters, the 16 mm, 19 mm and 22 mm PDC cutter was selected put on a vertical turret lathe (VTL) in the laboratory for cutting tests under different DOCs. The DOCs were 0.5mm, 1.0 mm, 1.5 mm and 2.0 mm, 2.5 mm and 3 mm, respectively. The rock sample used in the experiment was limestone. Results of laboratory tests have shown the new 22 mm-PDC cutter technology greatly improved cutting efficiency. On the one hand, as the DOC increases, the mechanical specific energy (MSE) of all cutters decreases, which means that the cutting efficiency increases. On the other hand, under the same DOC condition, the larger the cutter diameter is, the larger the working area of the cutter is, which leads to higher the cutting efficiency. In view of the high performance of the 22 mm-PDC cutters, which was applied to carry out full-scale bit field experiments. The result shows that the bit with 22mm-PDC cutters achieves a breakthrough improvement of ROP than that with conventional 16mm and 19mm cutters in offset well drilling.

Keywords: polycrystalline diamond compact, 22 mm-PDC cutters, cutting efficiency, mechanical specific energy

Procedia PDF Downloads 172
1656 Efficient Heuristic Algorithm to Speed Up Graphcut in Gpu for Image Stitching

Authors: Tai Nguyen, Minh Bui, Huong Ninh, Tu Nguyen, Hai Tran

Abstract:

GraphCut algorithm has been widely utilized to solve various types of computer vision problems. Its expensive computational cost encouraged many researchers to improve the speed of the algorithm. Recent works proposed schemes that work on parallel computing platforms such as CUDA. However, the problem of low convergence speed prevents the usage of GraphCut for real time applications. In this paper, we propose global suppression heuristic to boost the conver-gence process of the algorithm. A parallel implementation of GraphCut algorithm on CUDA designed for the image stitching problem is introduced. Our method achieves up to 3× time boost on the graph of size 80 × 480 compared to the best sequential GraphCut algorithm while achieving satisfactory stitched images, suitable for panorama applications. Our source code will be soon available for further research.

Keywords: CUDA, graph cut, image stitching, texture synthesis, maxflow/mincut algorithm

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1655 Variability of Covariance of Selected Skeletal Diameters of Female in a Longitudinal Physical Training Programme

Authors: Dhananjoy Shaw, Seema Sharma (Kaushik)

Abstract:

Anthropometry helps in associating the physical properties of an individual with their racial, cultural, and psychological attributes. Numerous research studies have included different skeletal diameters as a variable. However, most of the studies suggest their inclusion describing specific characteristics/traits of the body. However, there seems to be a scarcity of literature related to the effect of any kind of longitudinal physical training on human skeletal diameters. Hence, the present investigation was conducted to study the variability of covariance of selected skeletal diameters of females in a longitudinal physical training programme. The sample for the study was 78 college going students of the University of Delhi, classified equally in three groups, i.e. viz. (a) Progressive load of training or conditioning group coded as PLT; (b) Constant load of training or non-conditioning group coded as CLT; and (c) No-load or control or sedentary group coded as NL. Collectively, mean age of the sample was 19.54±1.79 years. The randomly selected samples were given maximum consideration to maintain their homogeneity. The variables included biacromial diameter, biiliocristal diameter, bitrochantaerion diameter, humeral bicondylar, femoral bicondylar, wrist diameter, ankle diameter, and foot breadth. Multi-group repeated measure design was adopted for the experimentation. Each group was measured four times after completion of each of the three meso-cycles of six-weeks duration. The measurements were taken following the standard landmarks and procedures. Mean, standard deviation, analysis of co-variance and its post-hoc analysis were computed to analyze the data statistically. The study concluded that both the progressive and constant load of physical training bring changes in the selected skeletal diameters of females. It also reflected the increase due to growth also along with training.

Keywords: longitudinal, physical training, skeletal diameters, step progression load

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1654 Development of Surface Modification Technology for Control Element Drive Mechanism Nozzle and Fatigue Enhancement of Ni-Based Alloys

Authors: Auezhan Amanov, Inho Cho, Young-Sik Pyun

Abstract:

Control element drive mechanism (CEDM) nozzle is manufactured as welded on the reactor vessel and currently uses Alloy 690 material. The top of the reactor is equipped with about 100 CEDM nozzles with an internal diameter of about 70 mm. Relatively large Inlet/Outlet nozzles are equipped with two outlet nozzles and four inlet nozzles on the reactor wall. The inner diameter of the nozzle is vulnerable to stress corrosion cracking (SCC), and in order to solve this problem, an ultrasonic nanocrystal surface modification (UNSM) treatment is performed on the inner diameter of the nozzle and the weld surface. The ultimate goal is to improve the service life of parts by applying compressive residual stress and suppressing primary water stress corrosion cracking (PWSCC). The main purpose is to design and fabricate a UNSM treatment device for the internal diameter processing of CEDM nozzles and inlet/outlet nozzles. In order to develop the system, the basic technology such as the development of UNSM tooling is developed and the mechanical properties and fatigue performance of before and after UNSM treatment of reactor nozzle material made of Ni-based alloys using the specimen are compared and evaluated. The inner diameter of the nozzle was treated by a newly developed UNSM treatment under the optimized treatment parameters. It was found that the mechanical properties and fatigue performance of nozzle were improved in comparison with the untreated nozzle, which may be attributed to the increase in hardness, induced compressive residual stress.

Keywords: control element drive mechanism nozzle, fatigue, Ni-based alloy, ultrasonic nanocrystal surface modification, UNSM

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1653 On Hyperbolic Gompertz Growth Model (HGGM)

Authors: S. O. Oyamakin, A. U. Chukwu,

Abstract:

We proposed a Hyperbolic Gompertz Growth Model (HGGM), which was developed by introducing a stabilizing parameter called θ using hyperbolic sine function into the classical gompertz growth equation. The resulting integral solution obtained deterministically was reprogrammed into a statistical model and used in modeling the height and diameter of Pines (Pinus caribaea). Its ability in model prediction was compared with the classical gompertz growth model, an approach which mimicked the natural variability of height/diameter increment with respect to age and therefore provides a more realistic height/diameter predictions using goodness of fit tests and model selection criteria. The Kolmogorov-Smirnov test and Shapiro-Wilk test was also used to test the compliance of the error term to normality assumptions while using testing the independence of the error term using the runs test. The mean function of top height/Dbh over age using the two models under study predicted closely the observed values of top height/Dbh in the hyperbolic gompertz growth models better than the source model (classical gompertz growth model) while the results of R2, Adj. R2, MSE, and AIC confirmed the predictive power of the Hyperbolic Monomolecular growth models over its source model.

Keywords: height, Dbh, forest, Pinus caribaea, hyperbolic, gompertz

Procedia PDF Downloads 415