Search results for: recursive structure
2282 Design of a Tuning Fork type UWB Patch Antenna
Authors: A. H. M. Zahirul Alam, Rafiqul Islam, Sheroz Khan
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In this paper a tuning fork type structure of Ultra Wideband (UWB) antenna is proposed. The antenna offers excellent performance for UWB system, ranging from 3.7 GHz to 13.8 GHz. The antenna exhibits a 10 dB return loss bandwidth over the entire frequency band. The rectangular patch antenna is designed on FR4 substrate and fed with 50 ohms microstrip line by optimizing the width of partial ground, the width and position of the feedline to operate in UWB. The rectangular patch is then modified to tuning fork structure by maintaining UWB frequency range.Keywords: Ultra wide band, antenna, microstrip, partial groundplane.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19742281 Wear and Mechanical Properties of Nodular Iron Modified with Copper
Authors: J. Ramos, V. Gil, A. F. Torres
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In this research (using induction furnace process) nodular iron with three different percentages of copper (residual, 0.5% and 1,2%) was obtained. Chemical analysis was performed by mass spectrometry and microstructures were characterized by Optical Microscopy (ASTM E3) and Scanning Electron Microscopy (SEM). The study of mechanical behavior was carried out in a mechanical test machine (ASTM E8) and a Pin on disk tribometer (ASTM G99) was used to assess wear resistance. It is observed that the dissolution of copper in crystal lattice increases the pearlite structure improving the wear and hardness behavior, but producing a contrary effect on the energy absorption.
Keywords: Ferritic and perlite structure, mechanical properties, nodular iron, wear.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22702280 Fractional-Order Modeling of GaN High Electron Mobility Transistors for Switching Applications
Authors: Anwar H. Jarndal, Ahmed S. Elwakil
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In this paper, a fraction-order model for pad parasitic effect of GaN HEMT on Si substrate is developed and validated. Open de-embedding structure is used to characterize and de-embed substrate loading parasitic effects. Unbiased device measurements are implemented to extract parasitic inductances and resistances. The model shows very good simulation for S-parameter measurements under different bias conditions. It has been found that this approach can improve the simulation of intrinsic part of the transistor, which is very important for small- and large-signal modeling process.Keywords: Fractional-order modeling, GaN HEMT, Si-substrate, open de-embedding structure.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11122279 On the Wreath Product of Group by Some Other Groups
Authors: Basmah H. Shafee
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In this paper, we will generate the wreath product 11 12 M wrM using only two permutations. Also, we will show the structure of some groups containing the wreath product 11 12 M wrM . The structure of the groups founded is determined in terms of wreath product k (M wrM ) wrC 11 12 . Some related cases are also included. Also, we will show that 132K+1 S and 132K+1 A can be generated using the wreath product k (M wrM ) wrC 11 12 and a transposition in 132K+1 S and an element of order 3 in 132K+1 A . We will also show that 132K+1 S and 132K+1 A can be generated using the wreath product 11 12 M wrM and an element of order k +1.Keywords: Group presentation, group generated by n-cycle, Wreath product, Mathieu group.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12032278 Improvement of Short Channel Effects in Cylindrical Strained Silicon Nanowire Transistor
Authors: Fatemeh Karimi, Morteza Fathipour, Hamdam Ghanatian, Vala Fathipour
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In this paper we investigate the electrical characteristics of a new structure of gate all around strained silicon nanowire field effect transistors (FETs) with dual dielectrics by changing the radius (RSiGe) of silicon-germanium (SiGe) wire and gate dielectric. Indeed the effect of high-κ dielectric on Field Induced Barrier Lowering (FIBL) has been studied. Due to the higher electron mobility in tensile strained silicon, the n-type FETs with strained silicon channel have better drain current compare with the pure Si one. In this structure gate dielectric divided in two parts, we have used high-κ dielectric near the source and low-κ dielectric near the drain to reduce the short channel effects. By this structure short channel effects such as FIBL will be reduced indeed by increasing the RSiGe, ID-VD characteristics will be improved. The leakage current and transfer characteristics, the threshold-voltage (Vt), the drain induced barrier height lowering (DIBL), are estimated with respect to, gate bias (VG), RSiGe and different gate dielectrics. For short channel effects, such as DIBL, gate all around strained silicon nanowire FET have similar characteristics with the pure Si one while dual dielectrics can improve short channel effects in this structure.Keywords: SNWT (silicon nanowire transistor), Tensile Strain, high-κ dielectric, Field Induced Barrier Lowering (FIBL), cylindricalnano wire (CW), drain induced barrier lowering (DIBL).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20082277 The Effect of Social Structural Change on the Traditional Turkish Houses Becoming Unusable
Authors: Gamze Fahriye Pehlivan, Tulay Canitez
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The traditional Turkish houses becoming unusable are a result of the deterioration of the balanced interaction between users and house (human and house) continuing during the history. Especially depending upon the change in social structure, the houses becoming neglected do not meet the desires of the users and do not have the meaning but the shelter are becoming unusable and are being destroyed. A conservation policy should be developed and renovations should be made in order to pass the traditional houses carrying the quality of a cultural and historical document presenting the social structure, the lifestyle and the traditions of its own age to the next generations and to keep them alive.
Keywords: House, social structural change, social structural, traditional Turkish houses.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17072276 Optimization of Structure of Section-Based Automated Lines
Authors: R. Usubamatov, M. Z. Abdulmuin
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Automated production lines with so called 'hard structures' are widely used in manufacturing. Designers segmented these lines into sections by placing a buffer between the series of machine tools to increase productivity. In real production condition the capacity of a buffer system is limited and real production line can compensate only some part of the productivity losses of an automated line. The productivity of such production lines cannot be readily determined. This paper presents mathematical approach to solving the structure of section-based automated production lines by criterion of maximum productivity.
Keywords: optimization production line, productivity, sections
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13252275 Design of Coherent Thermal Emission Source by Excitation of Magnetic Polaritons between Metallic Gratings and an Opaque Metallic Film
Authors: Samah G. Babiker, Yong Shuai, Mohamed Osman Sid-Ahmed, Ming Xie, Mu Lei
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The present paper studies a structure consisting of a periodic metallic grating, coated on a dielectric spacer atop an opaque metal substrate, using coherent thermal emission source in the infrared region. It has been theoretically demonstrated that by exciting surface magnetic polaritons between metallic gratings and an opaque metallic film, separated by a dielectric spacer, large emissivity peaks are almost independent of the emission angle and they can be achieved at the resonance frequencies. The reflectance spectrum of the proposed structure shows two resonances dip, which leads to a sharp emissivity peak. The relations of the reflection and absorption properties and the influence of geometric parameters on the radiative properties are investigated by rigorous coupled-wave analysis (RCWA). The proposed structure can be easily constructed, using micro/nanofabrication and can be used as the coherent thermal emission source.
Keywords: Coherent thermal emission, Polartons, Reflectance, Resonance frequency, Rigorous coupled wave analysis (RCWA).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21682274 Another Structure of Weakly Left C-wrpp Semigroups
Authors: Enxiao Yuan, Xiaomin Zhang
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It is known that a left C-wrpp semigroup can be described as curler structure of a left band and a C-wrpp semigroup. In this paper, we introduce the class of weakly left C-wrpp semigroups which includes the class of weakly left C-rpp semigroups as a subclass. We shall particularly show that the spined product of a left C-wrpp semigroup and a right normal band is a weakly left C-wrpp semifroup. Some equivalent characterizations of weakly left C-wrpp semigroups are obtained. Our results extend that of left C-wrpp semigroups.
Keywords: Left C-wrpp semigroup, left quasi normal regular band, weakly left C-wrpp semigroup.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12952273 Design of the Mathematical Model of the Respiratory System Using Electro-acoustic Analogy
Authors: M. Rozanek, K. Roubik
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The article deals with development, design and implementation of a mathematical model of the human respiratory system. The model is designed in order to simulate distribution of important intrapulmonary parameters along the bronchial tree such as pressure amplitude, tidal volume and effect of regional mechanical lung properties upon the efficiency of various ventilatory techniques. Therefore exact agreement of the model structure with the lung anatomical structure is required. The model is based on the lung morphology and electro-acoustic analogy is used to design the model.Keywords: Model of the respiratory system, total lung impedance, intrapulmonary parameters.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18372272 A New Physical Modeling for Multiquantum Well Structure APD Considering Nonuniformity of Electric Field in Active Regin
Authors: F. Barzegar, M. H. Sheikhi
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In the present work we model a Multiquantum Well structure Separate Absorption and Charge Multiplication Avalanche Photodiode (MQW-SACM-APD), while the Absorption region coincide with the MQW. We consider the nonuniformity of electric field using split-step method in active region. This model is based on the carrier rate equations in the different regions of the device. Using the model we obtain the photocurrent, and dark current. As an example, InGaAs/InP SACM-APD and MQW-SACM-APD are simulated. There is a good agreement between the simulation and experimental results.Keywords: Avalanche Photodiode, Physical Model, MultiquantumWell, Split Step Method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15242271 The AI Application and Talent Demand of Taiwan High-Tech Manufacturing Industry
Authors: Shi-Yu Lu, Chung-Han Yeh, Li-Ping Chen, Yu-Cheng Chang
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This paper uses both quantitative and qualitative approaches to survey the current status of AI-related applications and the structure of key AI jobs in Taiwan's high-tech manufacturing industry, as well as the demand for professional AI talents, skills, and training. The result shows that AI applications and talent demand vary from different industries in many aspects, including technologies used, talent structure, and training methods. This paper serves as a reference for the government to establish appropriate talent training programs, and to reduce the demand gap for professional AI talents in Taiwan manufacturers.
Keywords: Artificial intelligence, manufacturing, talent, training.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3942270 The Effects of Applied Negative Bias Voltage on Structure and Optical Properties of α-C:H Films
Authors: X. L. Zhou, S. Tunmee, I. Toda, K. Komatsu, S. Ohshio, H. Saitoh
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Hydrogenated amorphous carbon (a-C:H) films have been synthesized by a radio frequency plasma enhanced chemical vapor deposition (rf-PECVD) technique with different bias voltage from 0.0 to -0.5 kV. The Raman spectra displayed the polymer-like hydrogenated amorphous carbon (PLCH) film with 0.0 to -0.1 and a-C:H films with -0.2 to -0.5 kV of bias voltages. The surface chemical information of all films were studied by X-ray photoelectron spectroscopy (XPS) technique, presented to C-C (sp2 and sp3) and C-O bonds, and relative carbon (C) and oxygen (O) atomics contents. The O contamination had affected on structure and optical properties. The true density of PLCH and a-C:H films were characterized by X-ray refractivity (XRR) method, showed the result as in the range of 1.16-1.73 g/cm3 that depending on an increasing of bias voltage. The hardness was proportional to the true density of films. In addition, the optical properties i.e. refractive index (n) and extinction coefficient (k) of these films were determined by a spectroscopic ellipsometry (SE) method that give formation to in 1.62-2.10 (n) and 0.04-0.15 (k) respectively. These results indicated that the optical properties confirmed the Raman results as presenting the structure changed with applied bias voltage increased.
Keywords: Negative bias voltage, a-C:H film, Oxygen contamination, Optical properties.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 54502269 CEO Duality and Firm Performance: An Integration of Institutional Perceptive with Agency Theory
Authors: A. Ujunwa, P. O. Salami, A. H. Umar
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The recommendation of the committee on corporate governance for public companies in Nigeria, that the position of the CEO be separated from board chair has generated serious debate among scholars and practitioners. They have questioned the appropriateness of implementing corporate governance model that is based on Anglo-Saxon agency problem characterized by dispersed ownership structure; where markets for corporate control, legal regulation, and contractual incentives are the key governance mechanisms. This paper strives to resolve the argument by adopting an institutional perspective in testing the agency theory on board duality. The study developed a theoretical and empirical model to better understand how ownership structure influences agency conflict and how such affects firm performance. Hence, the study examines the relationship between CEO duality and firm performance using two institutional ownership structures – dispersed ownership and concentrated ownership structures. The empirical results show that CEO duality is negatively correlated with firm performance in Nigeria irrespective of the firm-s ownership structure. The findings give credence to the recommendation of the Peterside Commission on the need to separate the position of CEO from board chair.Keywords: Corporate Governance, CEO-Duality, Firm Performance.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 39802268 Computer Aided X-Ray Diffraction Intensity Analysis for Spinels: Hands-On Computing Experience
Authors: Ashish R. Tanna, Hiren H. Joshi
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The mineral having chemical compositional formula MgAl2O4 is called “spinel". The ferrites crystallize in spinel structure are known as spinel-ferrites or ferro-spinels. The spinel structure has a fcc cage of oxygen ions and the metallic cations are distributed among tetrahedral (A) and octahedral (B) interstitial voids (sites). The X-ray diffraction (XRD) intensity of each Bragg plane is sensitive to the distribution of cations in the interstitial voids of the spinel lattice. This leads to the method of determination of distribution of cations in the spinel oxides through XRD intensity analysis. The computer program for XRD intensity analysis has been developed in C language and also tested for the real experimental situation by synthesizing the spinel ferrite materials Mg0.6Zn0.4AlxFe2- xO4 and characterized them by X-ray diffractometry. The compositions of Mg0.6Zn0.4AlxFe2-xO4(x = 0.0 to 0.6) ferrites have been prepared by ceramic method and powder X-ray diffraction patterns were recorded. Thus, the authenticity of the program is checked by comparing the theoretically calculated data using computer simulation with the experimental ones. Further, the deduced cation distributions were used to fit the magnetization data using Localized canting of spins approach to explain the “recovery" of collinear spin structure due to Al3+ - substitution in Mg-Zn ferrites which is the case if A-site magnetic dilution and non-collinear spin structure. Since the distribution of cations in the spinel ferrites plays a very important role with regard to their electrical and magnetic properties, it is essential to determine the cation distribution in spinel lattice.
Keywords: Spinel ferrites, Localized canting of spins, X-ray diffraction, Programming in Borland C.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 38072267 A New Model for Discovering XML Association Rules from XML Documents
Authors: R. AliMohammadzadeh, M. Rahgozar, A. Zarnani
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The inherent flexibilities of XML in both structure and semantics makes mining from XML data a complex task with more challenges compared to traditional association rule mining in relational databases. In this paper, we propose a new model for the effective extraction of generalized association rules form a XML document collection. We directly use frequent subtree mining techniques in the discovery process and do not ignore the tree structure of data in the final rules. The frequent subtrees based on the user provided support are split to complement subtrees to form the rules. We explain our model within multi-steps from data preparation to rule generation.Keywords: XML, Data Mining, Association Rule Mining.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16312266 On the Accuracy of Basic Modal Displacement Method Considering Various Earthquakes
Authors: Seyed Sadegh Naseralavi, Sadegh Balaghi, Ehsan Khojastehfar
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Time history seismic analysis is supposed to be the most accurate method to predict the seismic demand of structures. On the other hand, the required computational time of this method toward achieving the result is its main deficiency. While being applied in optimization process, in which the structure must be analyzed thousands of time, reducing the required computational time of seismic analysis of structures makes the optimization algorithms more practical. Apparently, the invented approximate methods produce some amount of errors in comparison with exact time history analysis but the recently proposed method namely, Complete Quadratic Combination (CQC) and Sum Root of the Sum of Squares (SRSS) drastically reduces the computational time by combination of peak responses in each mode. In the present research, the Basic Modal Displacement (BMD) method is introduced and applied towards estimation of seismic demand of main structure. Seismic demand of sampled structure is estimated by calculation of modal displacement of basic structure (in which the modal displacement has been calculated). Shear steel sampled structures are selected as case studies. The error applying the introduced method is calculated by comparison of the estimated seismic demands with exact time history dynamic analysis. The efficiency of the proposed method is demonstrated by application of three types of earthquakes (in view of time of peak ground acceleration).Keywords: Time history dynamic analysis, basic modal displacement, earthquake induced demands, shear steel structures.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14212265 Light Confinement in Low Index Nanometer Areas
Authors: N. Aravantinos-Zafiris, M. M. Sigalas
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In this work we numerically examine structures which could confine light in nanometer areas. A system consisting of two silicon disks with in plane separation of a few tens of nanometers has been studied first. The normalized unitless effective mode volume, Veff, has been calculated for the two lowest whispering gallery mode resonances. The effective mode volume is reduced significantly as the gap between the disks decreases. In addition, the effect of the substrate is also studied. In that case, Veff of approximately the same value as the non-substrate case for a similar two disk system can be obtained by using disks almost twice as thick. We also numerically examine a structure consisting of a circular slot waveguide which is formed into a silicon disk resonator. We show that the proposed structure could have high Q resonances thus raising the belief that it is a very promising candidate for optical interconnects applications. The study includes several numerical calculations for all the geometric parameters of the structure. It also includes numerical simulations of the coupling between a waveguide and the proposed disk resonator leading to a very promising conclusion about its applicability.Keywords: Disk resonators, field enhancement, optical interconnect, slot waveguides.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14232264 Effect of Sintering Temperature Curve in Wick Manufactured for Loop Heat Pipe
Authors: Shen-Chun Wu, Chuo-Jeng Huang, Wun-Hong Yang, Jy-Cheng Chang, Chien-Chun Kung
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This investigation examines the effect of the sintering temperature curve in manufactured nickel powder capillary structure (wick) for a loop heat pipe (LHP). The sintering temperature curve is composed of a region of increasing temperature; a region of constant temperature and a region of declining temperature. The most important region is that in which the temperature increases, as an index in the stage in which the temperature increases. The wick of nickel powder is manufactured in the stage of fixed sintering temperature and the time between the stage of constant temperature and the stage of falling temperature. When the slope of the curve in the region of increasing temperature is unity (equivalent to 10 °C/min), the structure of the wick is complete and the heat transfer performance is optimal. The result of experiment test demonstrates that the heat transfer performance is optimal at 320W; the minimal total thermal resistance is approximately 0.18°C/W, and the heat flux is 17W/cm2; the internal parameters of the wick are an effective pore radius of 3.1 μm, a permeability of 3.25×10-13m2 and a porosity of 71%.Keywords: Loop heat pipe (LHP), capillary structure (wick), sintered temperature curve.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20942263 Evaluation of Gasoline Engine Piston with Various Coating Materials Using Finite Element Method
Authors: Nouby Ghazaly, Gamal Fouad, Ali Abd-El-Tawwab, K. A. Abd El-Gwwad
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The purpose of this paper is to examine the piston stress distribution using several thicknesses of the coating materials to achieve higher gasoline engine performance. First of all, finite element structure analysis is used to uncoated petrol piston made of aluminum alloy. Then, steel and cast-iron piston materials are conducted and compared with the aluminum piston. After that, investigation of four coating materials namely, yttria-stabilized zirconia, magnesia-stabilized zirconia, alumina, and mullite are studied for each piston materials. Next, influence of various thickness coating layers on the structure stresses of the top surfaces is examined. Comparison between simulated results for aluminum, steel, and cast-iron materials is reported. Moreover, the influences of different coating thickness on the Von Mises stresses of four coating materials are investigated. From the simulation results, it can report that the maximum Von Mises stresses and deformations for the piston materials are decreasing with increasing the coating thickness for magnesia-stabilized zirconia, yttria-stabilized zirconia, mullite and alumina coated materials.
Keywords: Structure analysis, aluminum piston, MgZrO3, YTZ, mullite and alumina.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7842262 Three Dimensional MEMS Supercapacitor Fabricated by DRIE on Silicon Substrate
Authors: Wei Sun, Ruilin Zheng, Xuyuan Chen
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Micro power sources are required to be used in autonomous microelectromechanical system (MEMS). In this paper, we designed and fabricated a three dimensional (3D) MEMS supercapacitor, which is consisting of conformal silicon dioxide/titanium/polypyrrole (PPy) layers on silicon substrate. At first, ''through-structure'' was fabricated on the silicon substrate by high-aspect-ratio deep reactive ion etching (DRIE) method, which enlarges the available surface area significantly. Then the SiO2/Ti/PPy layers grew sequentially on the ³through-structure´. Finally, the supercapacitor was investigated by electrochemical methods.
Keywords: MEMS, Supercapacitor, DRIE, 3D.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22622261 Constraint Active Contour Model with Application to Automated Three-Dimensional Airway Wall Segmentation
Authors: Kuo-Lung Lor, Chi-Hsuan Tsou, Yeun-Chung Chang, Chung-Ming Chen
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For evaluating the severity of Chronic Obstructive Pulmonary Disease (COPD), one is interested in inspecting the airway wall thickening due to inflammation. Although airway segmentations have being well developed to reconstruct in high order, airway wall segmentation remains a challenge task. While tackling such problem as a multi-surface segmentation, the interrelation within surfaces needs to be considered. We propose a new method for three-dimensional airway wall segmentation using spring structural active contour model. The method incorporates the gravitational field of the image and repelling force field of the inner lumen as the soft constraint and the geometric spring structure of active contour as the hard constraint to approximate a three-dimensional coupled surface readily for thickness measurements. The results show the preservation of topology constraints of coupled surfaces. In conclusion, our springy, soft-tissue-like structure ensures the globally optimal solution and waives the shortness following by the inevitable improper inner surface constraint.
Keywords: active contour model, airway wall, COPD, geometric spring structure
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15772260 The Nanobiotechnology of Obtaining of Collagen Gels from Marin Fish Skin and Yours Reological Properties for using Like New Materials in Dental Medicine
Authors: Anamaria Bechir, Rodica Sirbu, Minodora Leca, Maria Maris, Dan Artenie Maris, Emilia Mihaela Cadar, Marius Maris
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This paper aims at presenting the biotechnology used to obtain collagen-based gels from shark (Squalus acanthias) and brill skin, marine fish growing in the Black Sea. Due to the structure of its micro-fibres, collagen can be considered a nanomaterial; in order to use collagen-based matrixes as biomaterial, rheological studies must be performed first, to state whether they are stable or not. For the triple-helix structure to remain stable within these gels at room or human body temperature, they must be stabilized by reticulation.Keywords: Collagen, biotechnology, reticulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29752259 Simulation for Input-Output Energy Structure in Agriculture: Bangladesh
Authors: M. S. Alam, M. R. Alam, Nusrat Jahan Imu
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This paper presents a computer simulation model based on system dynamics methodology for analyzing the dynamic characteristics of input energy structure in agriculture and Bangladesh is used here as a case study for model validation. The model provides an input energy structure linking the major energy flows with human energy and draft energy from cattle as well as tractors and/or power tillers, irrigation, chemical fertilizer and pesticide. The evaluation is made in terms of different energy dependent indicators. During the simulation period, the energy input to agriculture increased from 6.1 to 19.15 GJ/ha i.e. 2.14 fold corresponding to energy output in terms of food, fodder and fuel increase from 71.55 to 163.58 GJ/ha i.e. 1.28 fold from the base year. This result indicates that the energy input in Bangladeshi agricultural production is increasing faster than the energy output. Problems such as global warming, nutrient loading and pesticide pollution can associate with this increasing input. For an assessment, a comparative statement of input energy use in agriculture of developed countries (DCs) and least developed countries (LDCs) including Bangladesh has been made. The performance of the model is found satisfactory to analyze the agricultural energy system for LDCs
Keywords: Agriculture, energy indicator, system dynamics, energy flows.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25722258 Design of Variable Fractional-Delay FIR Differentiators
Authors: Jong-Jy Shyu, Soo-Chang Pei, Min-Han Chang
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In this paper, the least-squares design of variable fractional-delay (VFD) finite impulse response (FIR) digital differentiators is proposed. The used transfer function is formulated so that Farrow structure can be applied to realize the designed system. Also, the symmetric characteristics of filter coefficients are derived, which leads to the complexity reduction by saving almost a half of the number of coefficients. Moreover, all the elements of related vectors or matrices for the optimal process can be represented in closed forms, which make the design easier. Design example is also presented to illustrate the effectiveness of the proposed method.
Keywords: Differentiator, variable fractional-delay filter, FIR filter, least-squares method, Farrow structure.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14162257 How to Modernise the European Competition Network (ECN)
Authors: Dorota Galeza
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This paper argues that networks, such as the ECN and the American network, are affected by certain small events which are inherent to path dependence and preclude the full evolution towards efficiency. It is advocated that the American network is superior to the ECN in many respects due to its greater flexibility and longer history. This stems in particular from the creation of the American network, which was based on a small number of cases. Such a structure encourages further changes and modifications which are not necessarily radical. The ECN, by contrast, was established by legislative action, which explains its rigid structure and resistance to change. This paper is an attempt to transpose the superiority of the American network on to the ECN. It looks at concepts such as judicial cooperation, harmonisation of procedure, peer review and regulatory impact assessments (RIAs), and dispute resolution procedures.
Keywords: Antitrust, Competition, Networks, Path Dependence.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16122256 Speaker Identification Using Admissible Wavelet Packet Based Decomposition
Authors: Mangesh S. Deshpande, Raghunath S. Holambe
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Mel Frequency Cepstral Coefficient (MFCC) features are widely used as acoustic features for speech recognition as well as speaker recognition. In MFCC feature representation, the Mel frequency scale is used to get a high resolution in low frequency region, and a low resolution in high frequency region. This kind of processing is good for obtaining stable phonetic information, but not suitable for speaker features that are located in high frequency regions. The speaker individual information, which is non-uniformly distributed in the high frequencies, is equally important for speaker recognition. Based on this fact we proposed an admissible wavelet packet based filter structure for speaker identification. Multiresolution capabilities of wavelet packet transform are used to derive the new features. The proposed scheme differs from previous wavelet based works, mainly in designing the filter structure. Unlike others, the proposed filter structure does not follow Mel scale. The closed-set speaker identification experiments performed on the TIMIT database shows improved identification performance compared to other commonly used Mel scale based filter structures using wavelets.Keywords: Speaker identification, Wavelet transform, Feature extraction, MFCC, GMM.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19832255 FEA for Transient Responses of an S-Shaped Force Transducer with a Viscoelastic Absorber Using a Nonlinear Complex Spring
Authors: T. Yamaguchi, Y. Fujii, A. Takita, T. Kanai
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To compute dynamic characteristics of nonlinear viscoelastic springs with elastic structures having huge degree-of-freedom, Yamaguchi proposed a new fast numerical method using finite element method [1]-[2]. In this method, restoring forces of the springs are expressed using power series of their elongation. In the expression, nonlinear hysteresis damping is introduced. In this expression, nonlinear complex spring constants are introduced. Finite element for the nonlinear spring having complex coefficients is expressed and is connected to the elastic structures modeled by linear solid finite element. Further, to save computational time, the discrete equations in physical coordinate are transformed into the nonlinear ordinary coupled equations using normal coordinate corresponding to linear natural modes. In this report, the proposed method is applied to simulation for impact responses of a viscoelastic shock absorber with an elastic structure (an S-shaped structure) by colliding with a concentrated mass. The concentrated mass has initial velocities and collides with the shock absorber. Accelerations of the elastic structure and the concentrated mass are measured using Levitation Mass Method proposed by Fujii [3]. The calculated accelerations from the proposed FEM, corresponds to the experimental ones. Moreover, using this method, we also investigate dynamic errors of the S-shaped force transducer due to elastic mode in the S-shaped structure.
Keywords: Transient response, Finite Element analysis, Numerical analysis, Viscoelastic shock absorber, Force transducer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17562254 An Optimized Design of Non-uniform Filterbank
Authors: Ram Kumar Soni, Alok Jain, Rajiv Saxena
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The tree structured approach of non-uniform filterbank (NUFB) is normally used in perfect reconstruction (PR). The PR is not always feasible due to certain limitations, i.e, constraints in selecting design parameters, design complexity and some times output is severely affected by aliasing error if necessary and sufficient conditions of PR is not satisfied perfectly. Therefore, there has been generalized interest of researchers to go for near perfect reconstruction (NPR). In this proposed work, an optimized tree structure technique is used for the design of NPR non-uniform filterbank. Window functions of Blackman family are used to design the prototype FIR filter. A single variable linear optimization is used to minimize the amplitude distortion. The main feature of the proposed design is its simplicity with linear phase property.Keywords: Tree structure, NUFB, QMF, NPR.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17382253 Unsupervised Texture Classification and Segmentation
Authors: V.P.Subramanyam Rallabandi, S.K.Sett
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An unsupervised classification algorithm is derived by modeling observed data as a mixture of several mutually exclusive classes that are each described by linear combinations of independent non-Gaussian densities. The algorithm estimates the data density in each class by using parametric nonlinear functions that fit to the non-Gaussian structure of the data. This improves classification accuracy compared with standard Gaussian mixture models. When applied to textures, the algorithm can learn basis functions for images that capture the statistically significant structure intrinsic in the images. We apply this technique to the problem of unsupervised texture classification and segmentation.Keywords: Gaussian Mixture Model, Independent Component Analysis, Segmentation, Unsupervised Classification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1593