Search results for: applied mathematics
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8822

Search results for: applied mathematics

6512 Real Time Multi Person Action Recognition Using Pose Estimates

Authors: Aishrith Rao

Abstract:

Human activity recognition is an important aspect of video analytics, and many approaches have been recommended to enable action recognition. In this approach, the model is used to identify the action of the multiple people in the frame and classify them accordingly. A few approaches use RNNs and 3D CNNs, which are computationally expensive and cannot be trained with the small datasets which are currently available. Multi-person action recognition has been performed in order to understand the positions and action of people present in the video frame. The size of the video frame can be adjusted as a hyper-parameter depending on the hardware resources available. OpenPose has been used to calculate pose estimate using CNN to produce heap-maps, one of which provides skeleton features, which are basically joint features. The features are then extracted, and a classification algorithm can be applied to classify the action.

Keywords: human activity recognition, computer vision, pose estimates, convolutional neural networks

Procedia PDF Downloads 141
6511 Dissimilar Cu/Al Friction Stir Welding: Sensitivity of the Tool Offset

Authors: Tran Hung Tra, Hao Dinh Duong, Masakazu Okazaki

Abstract:

Copper 1100 and aluminum 1050 plates with a thickness of 5.0 mm are butt-joint using friction stir welding. The tool offset is linearly varied along the welding path. Two welding regimes, using the same linear tool offset but in opposite directions, are applied for fabricating two Cu/Al plates. The material flow is dominated by both tool offset and offset history. The intermetallic compounds layer and interface morphology in each welded plate are formed in a different manner. As a result, the bonding strength and fracture behavior between two welded plates are significantly distinct. The role of interface morphology on fracture behavior is analyzed by the finite element method.

Keywords: Cu/Al dissimilar welding, offset history, interface morphology, intermetallic compounds, strength and fracture

Procedia PDF Downloads 76
6510 Multidimensional Item Response Theory Models for Practical Application in Large Tests Designed to Measure Multiple Constructs

Authors: Maria Fernanda Ordoñez Martinez, Alvaro Mauricio Montenegro

Abstract:

This work presents a statistical methodology for measuring and founding constructs in Latent Semantic Analysis. This approach uses the qualities of Factor Analysis in binary data with interpretations present on Item Response Theory. More precisely, we propose initially reducing dimensionality with specific use of Principal Component Analysis for the linguistic data and then, producing axes of groups made from a clustering analysis of the semantic data. This approach allows the user to give meaning to previous clusters and found the real latent structure presented by data. The methodology is applied in a set of real semantic data presenting impressive results for the coherence, speed and precision.

Keywords: semantic analysis, factorial analysis, dimension reduction, penalized logistic regression

Procedia PDF Downloads 443
6509 Acrylamide Concentration in Cakes with Different Caloric Sweeteners

Authors: L. García, N. Cobas, M. López

Abstract:

Acrylamide, a probable carcinogen, is formed in high-temperature processed food (>120ºC) when the free amino acid asparagine reacts with reducing sugars, mainly glucose and fructose. Cane juices' repeated heating would potentially form acrylamide during brown sugar production. This study aims to determine if using panela in yogurt cake preparation increases acrylamide formation. A secondary aim is to analyze the acrylamide concentration in four cake confections with different caloric sweetener ingredients: beet sugar (BS), cane sugar (CS), panela (P), and a panela and chocolate mix (PC). The doughs were obtained by combining ingredients in a planetary mixer. A model system made up of flour (25%), caloric sweeteners (25 %), eggs (23%), yogurt (15.7%), sunflower oil (9.4%), and brewer's yeast (2 %) was applied to BS, CS and P cakes. The ingredients of PC cakes varied: flour (21.5 %), panela chocolate (21.5 %), eggs (25.9 %), yogurt (18 %), sunflower oil (10.8 %), and brewer’s yeast (2.3 %). The preparations were baked for 45' at 180 ºC. Moisture was estimated by AOAC. Protein was determined by the Kjeldahl method. Ash percentage was calculated by weight loss after pyrolysis (≈ 600 °C). Fat content was measured using liquid-solid extraction in hydrolyzed raw ingredients and final confections. Carbohydrates were determined by difference and total sugars by the Luff-Schoorl method, based on the iodometric determination of copper ions. Finally, acrylamide content was determined by LC-MS by the isocratic system (phase A: 97.5 % water with 0.1% formic acid; phase B: 2.5 % methanol), using a standard internal procedure. Statistical analysis was performed using SPSS v.23. One-way variance analysis determined differences between acrylamide content and compositional analysis, with caloric sweeteners as fixed effect. Significance levels were determined by applying Duncan's t-test (p<0.05). P cakes showed a lower energy value than the other baked products; sugar content was similar to BS and CS, with 6.1 % mean crude protein. Acrylamide content in caloric sweeteners was similar to previously reported values. However, P and PC showed significantly higher concentrations, probably explained by the applied procedure. Acrylamide formation depends on both reducing sugars and asparagine concentration and availability. Beet sugar samples did not present acrylamide concentrations within the detection and quantification limit. However, the highest acrylamide content was measured in the BS. This may be due to the higher concentration of reducing sugars and asparagine in other raw ingredients. The cakes made with panela, cane sugar, or panela with chocolate did not differ in acrylamide content. The lack of asparagine measures constitutes a limitation. Cakes made with panela showed lower acrylamide formation than products elaborated with beet or cane sugar.

Keywords: beet sugar, cane sugar, panela, yogurt cake

Procedia PDF Downloads 66
6508 Enzymatic Remediation in Standard Crude Palm Oil for Superior Quality Oil

Authors: Haniza Ahmad, Norliza Saparin, Ahmadilfitri Md Noor, Mohd Suria Affandi Yusoff

Abstract:

Enzymatic remediation is applied in low free fatty acid (FFA) (<4%) crude palm oil (CPO) to investigate if further FFA reduction is able to take place to produce premium CPO (<1% FFA). There are four different lipase Candida Antartica brands used in this study. Samples submit to enzymatic remediation using rotary evaporator under 100mbar vacuum with rotation at 260rpm. Samples were taken at 4hours, 8hours and 24hours for analyses. FFA less than 1% was achieved after 24hours reaction with 1% enzyme and 2% glycerol. The FFA reduction was intensified with the presence of glycerol who provides more sites for fatty acid attachment. At 2% glycerol, 71-88% FFA was reduced whereas at 1% glycerol, 46-75% FFA reduced. However, partial glycerides was increased with presence of glycerol with 2% add in glycerol showed greater partial glycerides increment compared to 1% glycerol.

Keywords: enzymes, crude palm oil, free fatty acid, glycerol

Procedia PDF Downloads 322
6507 A Therapeutic Approach for Bromhidrosis with Glycopyrrolate 2% Cream: Clinical Study of 20 Patients

Authors: Vasiliki Markantoni, Eftychia Platsidaki, Georgios Chaidemenos, Georgios Kontochristopoulos

Abstract:

Introduction: Bromhidrosis, also known as osmidrosis, is a common distressing condition with a significant negative effect on patient’s quality of life. Its etiology is multifactorial. It usually affects axilla, genital skin, breasts and soles, areas where apocrine glands are mostly distributed. Therapeutic treatments include topical antibacterial agents, antiperspirants and neuromuscular blocker agents-toxins. In this study, we aimed to evaluate the efficacy and possible complications of topical glycopyrrolate, an anticholinergic agent, for treatment of bromhidrosis. Glycopyrrolate, applied topically as a cream, solution or spray at concentrations between 0,5% and 4%, has been successfully used to treat different forms of focal hyperhidrosis. Materials and Methods: Twenty patients, six males and fourteen females, meeting the criteria for bromhidrosis were treated with topical glycopyrrolate for two months. The average age was 36. Eleven patients had bromhidrosis located to the axillae, four to the soles, four to both axillae and soles and one to the genital folds. Glycopyrrolate was applied topically as a cream at concentration 2%, formulated in Fitalite. During the first month, patients were using the cream every night and thereafter twice daily. The degree of malodor was assessed subjectively by patients and scaled averagely as ‘none’, ‘mild’, ‘moderate’, and ‘severe’ with corresponding scores of 0, 1, 2, and 3, respectively. The modified Dermatology Life Quality Index (DLQI) was used to assess the quality of life. The clinical efficacy was graded by the patient scale of excellent, good, fair and poor. In the end, patients were given the power to evaluate whether they were totally satisfied with, partially satisfied or unsatisfied and possible side effects during the treatment were recorded. Results: All patients were satisfied at the end of the treatment. No patient defined the response as no improvement. The subjectively assessed score level of bromhidrosis was remarkably improved after the first month of treatment and improved slightly more after the second month. DLQI score was also improved to all patients. Adverse effects were reported in 2 patients. In the first case, topical irritation was reported. This was classed as mild (erythema and desquamation), appeared during the second month of treatment and was treated with low-potency topical corticosteroids. In the second case, mydriasis was reported, that recovered without specific treatment, as soon as we insisted to the importance of careful hygiene after cream application so as not to contaminate the periocular skin or ocular surface. Conclusions: Dermatologists often encounter patients with bromhidrosis, therefore should be aware of treatment options. To the best of our knowledge, this is the first study to evaluate the use of topical glycopyrrolate as a therapeutic approach for bromhidrosis. Our findings suggest that topical glycopyrrolate has an excellent safety profile and demonstrate encouraging results for the management of this distressful condition.

Keywords: Bromhidrosis, glycopyrrolate, topical treatment, osmidrosis

Procedia PDF Downloads 167
6506 Optimization of Process Parameters by Using Taguchi Method for Bainitic Steel Machining

Authors: Vinay Patil, Swapnil Kekade, Ashish Supare, Vinayak Pawar, Shital Jadhav, Rajkumar Singh

Abstract:

In recent days, bainitic steel is used in automobile and non-automobile sectors due to its high strength. Bainitic steel is difficult to machine because of its high hardness, hence in this paper machinability of bainitic steel is studied by using Taguchi design of experiments (DOE) approach. Convectional turning experiments were done by using L16 orthogonal array for three input parameters viz. cutting speed, depth of cut and feed. The Taguchi method is applied to study the performance characteristics of machining parameters with surface roughness (Ra), cutting force and tool wear rate. By using Taguchi analysis, optimized process parameters for best surface finish and minimum cutting forces were analyzed.

Keywords: conventional turning, Taguchi method, S/N ratio, bainitic steel machining

Procedia PDF Downloads 331
6505 Application of Fourier Series Based Learning Control on Mechatronic Systems

Authors: Sandra Baßler, Peter Dünow, Mathias Marquardt

Abstract:

A Fourier series based learning control (FSBLC) algorithm for tracking trajectories of mechanical systems with unknown nonlinearities is presented. Two processes are introduced to which the FSBLC with PD controller is applied. One is a simplified service robot capable of climbing stairs due to special wheels and the other is a propeller driven pendulum with nearly the same requirements on control. Additionally to the investigation of learning the feed forward for the desired trajectories some considerations on the implementation of such an algorithm on low cost microcontroller hardware are made. Simulations of the service robot as well as practical experiments on the pendulum show the capability of the used FSBLC algorithm to perform the task of improving control behavior for repetitive task of such mechanical systems.

Keywords: climbing stairs, FSBLC, ILC, service robot

Procedia PDF Downloads 314
6504 An Experimental Investigation on the Amount of Drag Force of Sand on a Cone Moving at Low Uniform Speed

Authors: M. Jahanandish, Gh. Sadeghian, M. H. Daneshvar, M. H. Jahanandish

Abstract:

The amount of resistance of a particular medium like soil to the moving objects is the interest of many areas in science. These include soil mechanics, geotechnical engineering, powder mechanics etc. Knowledge of drag force is also used for estimating the amount of momentum of fired objects like bullets. This paper focuses on measurement of drag force of sand on a cone when it moves at a low constant speed. A 30-degree apex angle cone has been used for this purpose. The study consisted of both loose and dense conditions of the soil. The applied speed has been in the range of 0.1 to 10 mm/min. The results indicate that the required force is basically independent of the cone speed; but, it is very dependent on the material densification and confining stress.

Keywords: drag force, sand, moving speed, friction angle, densification, confining stress

Procedia PDF Downloads 367
6503 A Neural Approach for the Offline Recognition of the Arabic Handwritten Words of the Algerian Departments

Authors: Salim Ouchtati, Jean Sequeira, Mouldi Bedda

Abstract:

In this work we present an off line system for the recognition of the Arabic handwritten words of the Algerian departments. The study is based mainly on the evaluation of neural network performances, trained with the gradient back propagation algorithm. The used parameters to form the input vector of the neural network are extracted on the binary images of the handwritten word by several methods: the parameters of distribution, the moments centered of the different projections and the Barr features. It should be noted that these methods are applied on segments gotten after the division of the binary image of the word in six segments. The classification is achieved by a multi layers perceptron. Detailed experiments are carried and satisfactory recognition results are reported.

Keywords: handwritten word recognition, neural networks, image processing, pattern recognition, features extraction

Procedia PDF Downloads 513
6502 Empirical Research on Preference for Conflict Resolution Styles of Owners and Contractors in China

Authors: Junqi Zhao, Yongqiang Chen

Abstract:

The preference for different conflict resolution styles are influenced by cultural background and power distance of two parties involving in conflict. This research put forward 7 hypotheses and tested the preference differences of the five conflict resolution styles between Chinese owner and contractor as well as the preference differences concerning the same style between two parties. The research sample includes 202 practitioners from construction enterprises in mainland China. Research result found that theories concerning conflict resolution styles could be applied in the Chinese construction industry. Some results of this research were not in line with former research, and this research also gave explanation to the differences from the characteristics of construction projects. Based on the findings, certain suggestions were made to serve as a guidance for managers to choose appropriate conflict resolution styles for a better handling of conflict.

Keywords: Chinese owner and contractor, conflict, construction project, conflict resolution styles

Procedia PDF Downloads 532
6501 Electrical Load Estimation Using Estimated Fuzzy Linear Parameters

Authors: Bader Alkandari, Jamal Y. Madouh, Ahmad M. Alkandari, Anwar A. Alnaqi

Abstract:

A new formulation of fuzzy linear estimation problem is presented. It is formulated as a linear programming problem. The objective is to minimize the spread of the data points, taking into consideration the type of the membership function of the fuzzy parameters to satisfy the constraints on each measurement point and to insure that the original membership is included in the estimated membership. Different models are developed for a fuzzy triangular membership. The proposed models are applied to different examples from the area of fuzzy linear regression and finally to different examples for estimating the electrical load on a busbar. It had been found that the proposed technique is more suited for electrical load estimation, since the nature of the load is characterized by the uncertainty and vagueness.

Keywords: fuzzy regression, load estimation, fuzzy linear parameters, electrical load estimation

Procedia PDF Downloads 540
6500 Thermal Fatigue Behavior of Austenitic Stainless Steels

Authors: Jung-Ho Moon, Tae Kwon Ha

Abstract:

Continually increasing working temperature and growing need for greater efficiency and reliability of automotive exhaust require systematic investigation into the thermal fatigue properties especially of high temperature stainless steels. In this study, thermal fatigue properties of 300 series austenitic stainless steels have been evaluated in the temperature ranges of 200-800°C and 200-900°C. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. Load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property.

Keywords: austenitic stainless steel, automotive exhaust, thermal fatigue, microstructure, load relaxation

Procedia PDF Downloads 377
6499 New Refrigerant La₀.₇Ca₀.₁₅Sr₀.₁₅Mn₁₋ₓGaₓO₃ for Application in Magnetic Refrigeration

Authors: Essebti Dhahri

Abstract:

We present a new refrigerant La₀.₇Ca₀.₁₅Sr₀.₁₅Mn₁₋ₓGaₓO₃ (x = 0.0-0.1) manganites. These compounds were prepared by the sol-gel method. The refinement of the X-ray diffraction reveals that all samples crystallize in a rhombohedral structure (space group R3 ̅c). Detailed measurements of the magnetization as a function of temperature and magnetic applied field M (µ₀H, T) were carried out. From the M(µ₀H, T) curves, we have calculated the magnetic entropy change (ΔSM) according to the Maxwell relation. The temperature dependence of the magnetization M(T) reveals a decrease of M when increasing the x content. The magnetic entropy change (ΔSM) reaches a maximum value near room temperature. It was also found that this compound exhibits a large magnetocaloric effect MCE which increases when decreasing Ga concentration. So, the studied compounds could be considered potential materials for magnetic refrigeration application.

Keywords: magnetic measurements, Rietveld refinement, magnetic refrigeration, magnetocaloric effect

Procedia PDF Downloads 88
6498 Edmodo and the Three Powerful Strategies to Maximize Students Learning

Authors: Aziz Soubai

Abstract:

The primary issue is that English as foreign language learners don’t use English outside the classroom. The only little exposure is inside the classroom, and that’s not enough to make them good language learners! Edmodo, like the other Learning Management Systems, can be used to encourage students to collaborate with each other and with global classrooms on projects where English is used- Some examples of collaboration with different schools will be mentioned and how the Substitution Augmentation Modification Redefinition (SAMR) model and its stages can be applied in the activities, especially for teachers who are hesitant to introduce technology or don’t have a lot of technical knowledge. There will also be some focus on Edmodo groups and on how flipped and blended learning can be used as an extension for classroom time and to help the teacher address language problems and improve students’ language skills, especially writing, reading and communication. It is also equally important to use Edmodo badges and certificates for motivating and engaging learners and gamifying the lesson.

Keywords: EFL learners, language classroom-learning management system, edmodo, SAMR, language skills

Procedia PDF Downloads 63
6497 Relationship between Functionality and Cognitive Impairment in Older Adult Women from the Southeast of Mexico

Authors: Estrella C. Damaris, Ingrid A. Olais, Gloria P. Uicab

Abstract:

This study explores the relationship between the level of functionality and cognitive impairment in older adult women from the south-east of Mexico. It is a descriptive, cross-sectional study; performed with 172 participants in total who attended a health institute and live in Merida, Yucatan Mexico. After a non-probabilistic sampling, Barthel and Pfeiffer scales were applied. The results show statistically significant correlation between the cognitive impairment (Pfeiffer) and the levels of independence and function (Barthel) (r =0.489; p =0.001). Both determine a dependence level so they need either a little or a lot of help. Society needs that the older woman be healthy and that the professionals of mental health develop activities to prevent and rehabilitate because cognitive impairment and function are directly related with the quality of life.

Keywords: functionality, cognition, routine activities, cognitive impairment

Procedia PDF Downloads 290
6496 2D Monte Carlo Simulation of Grain Growth under Transient Conditions

Authors: K. R. Phaneesh, Anirudh Bhat, G. Mukherjee, K. T. Kashyap

Abstract:

Extensive Monte Carlo Potts model simulations were performed on 2D square lattice to investigate the effects of simulated higher temperatures effects on grain growth kinetics. A range of simulation temperatures (KTs) were applied on a matrix of size 10002 with Q-state 64, dispersed with a wide range of second phase particles, ranging from 0.001 to 0.1, and then run to 100,000 Monte Carlo steps. The average grain size, the largest grain size and the grain growth exponent were evaluated for all particle fractions and simulated temperatures. After evaluating several growth parameters, the critical temperature for a square lattice, with eight nearest neighbors, was found to be KTs = 0.4.

Keywords: average grain size, critical temperature, grain growth exponent, Monte Carlo steps

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6495 Graphic Procession Unit-Based Parallel Processing for Inverse Computation of Full-Field Material Properties Based on Quantitative Laser Ultrasound Visualization

Authors: Sheng-Po Tseng, Che-Hua Yang

Abstract:

Motivation and Objective: Ultrasonic guided waves become an important tool for nondestructive evaluation of structures and components. Guided waves are used for the purpose of identifying defects or evaluating material properties in a nondestructive way. While guided waves are applied for evaluating material properties, instead of knowing the properties directly, preliminary signals such as time domain signals or frequency domain spectra are first revealed. With the measured ultrasound data, inversion calculation can be further employed to obtain the desired mechanical properties. Methods: This research is development of high speed inversion calculation technique for obtaining full-field mechanical properties from the quantitative laser ultrasound visualization system (QLUVS). The quantitative laser ultrasound visualization system (QLUVS) employs a mirror-controlled scanning pulsed laser to generate guided acoustic waves traveling in a two-dimensional target. Guided waves are detected with a piezoelectric transducer located at a fixed location. With a gyro-scanning of the generation source, the QLUVS has the advantage of fast, full-field, and quantitative inspection. Results and Discussions: This research introduces two important tools to improve the computation efficiency. Firstly, graphic procession unit (GPU) with large amount of cores are introduced. Furthermore, combining the CPU and GPU cores, parallel procession scheme is developed for the inversion of full-field mechanical properties based on the QLUVS data. The newly developed inversion scheme is applied to investigate the computation efficiency for single-layered and double-layered plate-like samples. The computation efficiency is shown to be 80 times faster than unparalleled computation scheme. Conclusions: This research demonstrates a high-speed inversion technique for the characterization of full-field material properties based on quantitative laser ultrasound visualization system. Significant computation efficiency is shown, however not reaching the limit yet. Further improvement can be reached by improving the parallel computation. Utilizing the development of the full-field mechanical property inspection technology, full-field mechanical property measured by non-destructive, high-speed and high-precision measurements can be obtained in qualitative and quantitative results. The developed high speed computation scheme is ready for applications where full-field mechanical properties are needed in a nondestructive and nearly real-time way.

Keywords: guided waves, material characterization, nondestructive evaluation, parallel processing

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6494 An Investigation on the Internal Quality Assurance System of Higher Education in Indonesia

Authors: Andi Mursidi

Abstract:

This study aims to investigate why the internal quality assurance system as the basis for the assessment of external quality assurance systems is not well developed at universities in Indonesia. To answer this problem, technical analysis used single instrumental case study with the respondents from ten universities. The findings of this study are the internal quality assurance system that is applied so far (1) only to gain accreditation; and (2) considered as a liability rather than as a necessity to meet the demands of quality standards. It needs strong commitment from internal stakeholders at the college/university to establish internal quality assurance systems that exceed the national standards of higher education. A high quality college/ university will have a good accreditation rank.

Keywords: internal stakeholders, internal quality assurance system, commitment, higher education

Procedia PDF Downloads 289
6493 Interferometric Demodulation Scheme Using a Mode-Locker Fiber Laser

Authors: Liang Zhang, Yuanfu Lu, Yuming Dong, Guohua Jiao, Wei Chen, Jiancheng Lv

Abstract:

We demonstrated an interferometric demodulation scheme using a mode-locked fiber laser. The mode-locked fiber laser is launched into a two-beam interferometer. When the ratio between the fiber path imbalance of interferometer and the laser cavity length is close to an integer, an interferometric fringe emerges as a result of vernier effect, and then the phase shift of the interferometer can be demodulated. The mode-locked fiber laser provides a large bandwidth and reduces the cost for wavelength division multiplexion (WDM). The proposed interferometric demodulation scheme can be further applied in multi-point sensing system such as fiber optics hydrophone array, seismic wave detection network with high sensitivity and low cost.

Keywords: fiber sensing, interferometric demodulation, mode-locked fiber laser, vernier effect

Procedia PDF Downloads 329
6492 Corpus Linguistic Methods in a Theoretical Study of Quran Verb Tense and Aspect in Translations from Arabic to English

Authors: Jawharah Alasmari

Abstract:

In inflectional morphology of verb, tense and aspect indicate action’s time either past/present or future and their period whether completed or not. The usage and meaning of tense and aspect differ in Arabic and English, therefore is no simple one -to- one mapping from an Arabic verb inflected form an appropriate English translation depends on a range of features, including immediate and wider context of use. The Quranic Arabic Corpus includes seven alternative expertly crafted English translations of each Arabic verses, which provides a test dataset for the study of appropriate Arabic to English translations of verb tense and aspect. We applied Corpus Linguistics Methods in a theoretical study of exemplary verbs, to elicit candidate verbal contexts which influence the choice of English inflection for each verse.

Keywords: Corpus linguistics methods, Arabic verb, tense and aspect, English translations

Procedia PDF Downloads 391
6491 Evolution of Microstructure through Phase Separation via Spinodal Decomposition in Spinel Ferrite Thin Films

Authors: Nipa Debnath, Harinarayan Das, Takahiko Kawaguchi, Naonori Sakamoto, Kazuo Shinozaki, Hisao Suzuki, Naoki Wakiya

Abstract:

Nowadays spinel ferrite magnetic thin films have drawn considerable attention due to their interesting magnetic and electrical properties with enhanced chemical and thermal stability. Spinel ferrite magnetic films can be implemented in magnetic data storage, sensors, and spin filters or microwave devices. It is well established that the structural, magnetic and transport properties of the magnetic thin films are dependent on microstructure. Spinodal decomposition (SD) is a phase separation process, whereby a material system is spontaneously separated into two phases with distinct compositions. The periodic microstructure is the characteristic feature of SD. Thus, SD can be exploited to control the microstructure at the nanoscale level. In bulk spinel ferrites having general formula, MₓFe₃₋ₓ O₄ (M= Co, Mn, Ni, Zn), phase separation via SD has been reported only for cobalt ferrite (CFO); however, long time post-annealing is required to occur the spinodal decomposition. We have found that SD occurs in CoF thin film without using any post-deposition annealing process if we apply magnetic field during thin film growth. Dynamic Aurora pulsed laser deposition (PLD) is a specially designed PLD system through which in-situ magnetic field (up to 2000 G) can be applied during thin film growth. The in-situ magnetic field suppresses the recombination of ions in the plume. In addition, the peak’s intensity of the ions in the spectra of the plume also increases when magnetic field is applied to the plume. As a result, ions with high kinetic energy strike into the substrate. Thus, ion-impingement occurred under magnetic field during thin film growth. The driving force of SD is the ion-impingement towards the substrates that is induced by in-situ magnetic field. In this study, we report about the occurrence of phase separation through SD and evolution of microstructure after phase separation in spinel ferrite thin films. The surface morphology of the phase separated films show checkerboard like domain structure. The cross-sectional microstructure of the phase separated films reveal columnar type phase separation. Herein, the decomposition wave propagates in lateral direction which has been confirmed from the lateral composition modulations in spinodally decomposed films. Large magnetic anisotropy has been found in spinodally decomposed nickel ferrite (NFO) thin films. This approach approves that magnetic field is also an important thermodynamic parameter to induce phase separation by the enhancement of up-hill diffusion in thin films. This thin film deposition technique could be a more efficient alternative for the fabrication of self-organized phase separated thin films and employed in controlling of the microstructure at nanoscale level.

Keywords: Dynamic Aurora PLD, magnetic anisotropy, spinodal decomposition, spinel ferrite thin film

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6490 A Bathtub Curve from Nonparametric Model

Authors: Eduardo C. Guardia, Jose W. M. Lima, Afonso H. M. Santos

Abstract:

This paper presents a nonparametric method to obtain the hazard rate “Bathtub curve” for power system components. The model is a mixture of the three known phases of a component life, the decreasing failure rate (DFR), the constant failure rate (CFR) and the increasing failure rate (IFR) represented by three parametric Weibull models. The parameters are obtained from a simultaneous fitting process of the model to the Kernel nonparametric hazard rate curve. From the Weibull parameters and failure rate curves the useful lifetime and the characteristic lifetime were defined. To demonstrate the model the historic time-to-failure of distribution transformers were used as an example. The resulted “Bathtub curve” shows the failure rate for the equipment lifetime which can be applied in economic and replacement decision models.

Keywords: bathtub curve, failure analysis, lifetime estimation, parameter estimation, Weibull distribution

Procedia PDF Downloads 446
6489 A Framework for Evaluation of Enterprise Architecture Implementation Methodologies

Authors: Babak Darvish Rouhani, Mohd Naz'ri Mahrin, Fatemeh Nikpay, Maryam Khanian Najafabadi

Abstract:

Enterprise Architecture (EA) Implementation Methodologies have become an important part of EA projects. Several implementation methodologies have been proposed, as a theoretical and practical approach, to facilitate and support the development of EA within an enterprise. A significant question when facing the starting of EA implementation is deciding which methodology to utilize. In order to answer this question, a framework with several criteria is applied in this paper for the comparative analysis of existing EA implementation methodologies. Five EA implementation methodologies including: EAP, TOGAF, DODAF, Gartner, and FEA are selected in order to compare with proposed framework. The results of the comparison indicate that those methodologies have not reached a sufficient maturity as whole due to lack of consideration on requirement management, maintenance, continuum, and complexities in their process. The framework has also ability for the evaluation of any kind of EA implementation methodologies.

Keywords: enterprise architecture, EAIM, evaluating EAIM, framework for evaluation, enterprise architecture implementation methodology

Procedia PDF Downloads 382
6488 Obtaining Composite Cotton Fabric by Cyclodextrin Grafting

Authors: U. K. Sahin, N. Erdumlu, C. Saricam, I. Gocek, M. H. Arslan, H. Acikgoz-Tufan, B. Kalav

Abstract:

Finishing is an important part of fabric processing with which a wide range of features are imparted to greige or colored fabrics for various end-uses. Especially, by the addition or impartation of nano-scaled particles to the fabric structure composite fabrics, a kind of composite materials can be acquired. Composite materials, generally shortened as composites or in other words composition materials, are engineered or naturally occurring materials made from two or more component materials with significantly different physical, mechanical or chemical characteristics remaining separate and distinctive at the macroscopic or microscopic scale within the end product structure. Therefore, the technique finishing which is one of the fundamental methods to be applied on fabrics for obtainment of composite fabrics with many functionalities was used in the current study with the same purpose. However, regardless of the finishing materials applied, the efficient life of finished product on offering desired feature is low, since the durability of finishes on the material is limited. Any increase in durability of these finishes on textiles would enhance the life of use for textiles, which will result in happier users. Therefore, in this study, since higher durability was desired for the finishing materials fixed on the fabrics, nano-scaled hollow structured cyclodextrins were chemically imparted by grafting to the structure of conventional cotton fabrics by the help of finishing technique in order to be fixed permanently. By this way, a processed and functionalized base fabric having potential to be treated in the subsequent processes with many different finishing agents and nanomaterials could be obtained. Henceforth, this fabric can be used as a multi-functional fabric due to the encapturing ability of cyclodextrins to molecules/particles via physical/chemical means. In this study, scoured and rinsed woven bleached plain weave 100% cotton fabrics were utilized because textiles made of cotton are the most demanded textile products in the textile market by the textile consumers in daily life. Cotton fabric samples were immersed in treating baths containing β-cyclodextrin and 1,2,3,4-butanetetracarboxylic acid and to reduce the curing temperature the catalyst sodium hypophosphite monohydrate was used. All impregnated fabric samples were pre-dried. The reaction of grafting was performed in dry state. The treated and cured fabric samples were rinsed with warm distilled water and dried. The samples were dried for 4 h and weighed before and after finishing and rinsing. Stability and durability of β-cyclodextrins on fabric surface against external factors such as washing as well as strength of functionalized fabric in terms of tensile and tear strength were tested. Presence and homogeneity of distribution of β-cyclodextrins on fabric surface were characterized.

Keywords: cotton fabric, cyclodextrine, improved durability, multifunctional composite textile

Procedia PDF Downloads 295
6487 An Analysis of the Differences between Three Levels Water Polo Players Based on Indicators of Efficiency

Authors: Mladen Hraste, Igor Jelaska, Ivan Granic

Abstract:

The scope of this research is the identification and explanation of differences of three levels of water polo players in some parameters of effectiveness. The sample for this study was 132 matches of the Adriatic Water Polo League in the 2013/14 competition season. Using the Kruskal-Wallis test and multiple comparisons of mean ranks for all groups at the significance level of α=0, 05, the hypothesis that there are significant differences between groups of respondents in ten of the seventeen variables of effectiveness was confirmed. There is a reasonable possibility that the differences are caused by the degree of learned and implemented tactical knowledge, the degree of scoring ability and the best selection for certain roles in the team. The results of this study can be applied to selection of teams and players, for the selection of the appropriate match concept and for organizing training process.

Keywords: scoring abilities, selection, tactical knowledge, water polo effectiveness

Procedia PDF Downloads 501
6486 Studies on the Physicochemical Properties of Biolubricants Obtained from Vegetable Oils and Their Oxidative Stability

Authors: Expedito J. S. Parente Jr., Italo C. Rios, Joao Paulo C. Marques, Rosana M. A. Saboya, F. Murilo T. Luna, Célio L. Cavalcante Jr.

Abstract:

Increasing constraints of environmental regulation around the world have led to higher demand for biodegradable products. Vegetable oils present some properties that may favor their use as biolubricants; however, there are others, such as resistance to oxidation and pour point, which affect possible commercial applications. In this study, the physicochemical properties of biolubricants synthesized from different vegetable oils were evaluated and compared with petroleum-based lubricant and pure vegetable oil. Chemical modifications applied to the original vegetable oil improved their oxidative stability and pour point significantly. The addition of commercial antioxidants to the bio-based lubricants was evaluated, yielding values of oxidative stability close to those of mineral basestock oil.

Keywords: biolubricant, vegetable oil, oxidative stability, pour point, antioxidants

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6485 Quality Fabric Optimization Using Genetic Algorithms

Authors: Halimi Mohamed Taher, Kordoghli Bassem, Ben Hassen Mohamed, Sakli Faouzi

Abstract:

Textile industry has been an important part of many developing countries economies such as Tunisia. This industry is confronted with a challenging and increasing competitive environment. Good quality management in production process is the key factor for retaining existence especially in raw material exploitation. The present work aims to develop an intelligent system for fabric inspection. In the first step, we have studied the method used for fabric control which takes into account the default length and localization in woven. In the second step, we have used a method based on the fuzzy logic to minimize the Demerit point indicator with appropriate total rollers length, so that the quality problem becomes multi-objective. In order to optimize the total fabric quality, we have applied the genetic algorithm (GA).

Keywords: fabric control, Fuzzy logic, genetic algorithm, quality management

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6484 On Modeling Data Sets by Means of a Modified Saddlepoint Approximation

Authors: Serge B. Provost, Yishan Zhang

Abstract:

A moment-based adjustment to the saddlepoint approximation is introduced in the context of density estimation. First applied to univariate distributions, this methodology is extended to the bivariate case. It then entails estimating the density function associated with each marginal distribution by means of the saddlepoint approximation and applying a bivariate adjustment to the product of the resulting density estimates. The connection to the distribution of empirical copulas will be pointed out. As well, a novel approach is proposed for estimating the support of distribution. As these results solely rely on sample moments and empirical cumulant-generating functions, they are particularly well suited for modeling massive data sets. Several illustrative applications will be presented.

Keywords: empirical cumulant-generating function, endpoints identification, saddlepoint approximation, sample moments, density estimation

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6483 Two-Stage Approach for Solving the Multi-Objective Optimization Problem on Combinatorial Configurations

Authors: Liudmyla Koliechkina, Olena Dvirna

Abstract:

The statement of the multi-objective optimization problem on combinatorial configurations is formulated, and the approach to its solution is proposed. The problem is of interest as a combinatorial optimization one with many criteria, which is a model of many applied tasks. The approach to solving the multi-objective optimization problem on combinatorial configurations consists of two stages; the first is the reduction of the multi-objective problem to the single criterion based on existing multi-objective optimization methods, the second stage solves the directly replaced single criterion combinatorial optimization problem by the horizontal combinatorial method. This approach provides the optimal solution to the multi-objective optimization problem on combinatorial configurations, taking into account additional restrictions for a finite number of steps.

Keywords: discrete set, linear combinatorial optimization, multi-objective optimization, Pareto solutions, partial permutation set, structural graph

Procedia PDF Downloads 167