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Mismatch modeling and compensation for robust speaker verification


The effects of strain rate and saturation on a micro-cracked marble Original Research Article Engineering Geology, Volume 82, Issue 3, 5 January 2006, Pages 137-144 Y?lmaz Mahmuto?lu
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Abstract

It is well known rock masses contain several types of weakness planes varying from micro-fissure to fault in size. The fracture frequency, degree of saturation and time are the basic rock parameters affecting its behaviour. However, in most cases, it is practically difficult to test heavily fractured rock in laboratory environment. In this study, the effects of micro cracks, strain rate and water saturation on strength are discussed using a small-scale physical experiments. It is attempted to detach the grain boundaries of coarse-grained rock specimens of the Mu?la marble by thermal treatment that would serve as a small-scale physical simulation of fractures in rock masses and enable a discussion of the variations in time dependent mechanical behaviour. An experimental study was conducted on marble specimens induced thermally by micro-cracks in different frequencies. The thermal treatment periods being 24 h in inert atmospheric condition were varied for each test specimen except categories A and G. Effective porosity increased up to 2.4% after the last thermal cycle of category F. Then conventional compression tests with different strain rates were carried out using a servo-controlled testing machine on both dry and saturated specimens. It is concluded that both lowering strain rates and increasing porosity related with thermally induced micro cracks have important effects on strength and failure path. The progressive failure entirely occurs along the grain boundaries fissured by cyclical treatment and inter-granular deformation depends upon degree of thermal influence. The small-scaled laboratory model enabled to demonstrate that parameters such as joint frequency, time and saturation have a significant effect on mechanical behaviour of rock masses.

Article Outline

1. Introduction 2. Material and method 2.1. Physical properties of the test material 2.2. The method and procedure for the modelling of micro-cracks 3. Strain controlled tests on the model material 3.1. Effects of strain rate and water–saturation on peak strength 4. Conclusions Acknowledgements References

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Boosting by weighting critical and erroneous samples Original Research Article Neurocomputing, Volume 69, Issues 7-9, March 2006, Purchase Pages 679-685 Vanessa Gómez-Verdejo, Manuel Ortega-Moral, Jerónimo $ 31.50 Arenas-García, Aníbal R. Figueiras-Vidal
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Abstract

Real Adaboost is a well-known and good performance boosting method used to build machine ensembles for classification. Considering that its emphasis function can be decomposed in two factors that pay separated attention to sample errors and to their proximity to the classification border, a generalized emphasis function that combines both components by means of a selectable parameter, λ, is presented. Experiments show that simple methods of selecting λ frequently offer better performance and smaller ensembles.

Article Outline

1. Introduction 2. A revision of Real Adaboost 3. Boosting by weighting boundary and erroneous samples

4. Experiments 5. Conclusions and future work References Vitae

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A Constructive Genetic Algorithm for permutation flowshop scheduling Original Research Article Computers & Industrial Engineering, Volume 55, Issue 1, Purchase August 2008, Pages 195-207 Marcelo Seido Nagano, Rubén Ruiz, Luiz Antonio Nogueira $ 37.95 Lorena
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Abstract

The general flowshop scheduling problem is a production problem where a set of n jobs have to be processed with identical flow pattern on m machines. In permutation flowshops the sequence of jobs is the same on all machines. A significant research effort has been devoted for sequencing jobs in a flowshop minimizing the makespan. This paper describes the application of a Constructive Genetic Algorithm (CGA) to makespan minimization on flowshop scheduling. The CGA was proposed recently as an alternative to traditional GA approaches, particularly, for evaluating schemata directly. The population initially formed only by schemata, evolves controlled by recombination to a population of well-adapted structures (schemata instantiation). The CGA implemented is based on the NEH classic heuristic and a local search heuristic used to define the fitness functions. The parameters of the CGA are calibrated using a Design of Experiments (DOE) approach. The computational results are compared against some other successful algorithms from the literature on Taillard’s well-known standard benchmark. The computational experience shows that this innovative CGA approach provides competitive results for flowshop scheduling problems.

Article Outline

1. Introduction 2. Genetic algorithm for the PFSP 3. Constructive Genetic Algorithm for the PFSP 3.1. CGA modeling 3.2. Evolution process 3.2.1. Initial population 3.2.2. Selection 3.2.3. Recombination 3.2.4. The algorithm 3.2.5. Calibration of parameters by means of Design of Experiments 4. Computational results 5. Conclusions and future research Acknowledgements References

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Mechanisms of the central mode particle formation during pulverized coal combustion Original Research
Article

Proceedings of the Combustion Institute, Volume 32, Issue Purchase $ 31.50 2, 2009, Pages 2075-2082 Dunxi Yu, Minghou Xu, Hong Yao, Xiaowei Liu, Ke Zhou, Lin Li, Chang Wen
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Abstract

Ash particles produced from pulverized coal combustion are considered to be tri-modally distributed. These include the well-known ultrafine and coarse modes, and a central mode that is less reported but attracts increasing attention. This work presents a preliminary study on the formation mechanisms of the

central mode particles during pulverized coal combustion. Experiments of four sized and density-separated coal samples were carried out in a laboratory drop-tube furnace under various controlled conditions. Experimental data show that the ash particle size distributions have an evident central mode at 4 ?m

for all coal samples. Increasing combustion temperature leads to an increase in the central mode particle formation, which is thought to be due to enhanced char fragmentation. The small-size coal sample produces a larger amount of the central mode particles, reasonably due to abundant fine particles in the parent coal sample. Under similar combustion conditions, both the Heavy (>2.0 g/cm ) and Light (<1.4 g/cm ) coal fractions produce a central mode, indicating that not only the included minerals but also the excluded minerals contribute to the formation of the central mode particles.
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Article Outline

1. Introduction 2. Experimental 2.1. Coal sample preparation and their characteristics 2.2. Char and PM sample preparation and characterization 3. Results and discussion 3.1. The modality of particle mass fraction size distributions 3.2. Formation of the central particle mode 3.2.1. Char fragmentation 3.2.2. Contribution of original fine particles 3.2.3. Contribution of excluded minerals 4. Conclusions Acknowledgements References

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Current status of Kampo (Japanese herbal) medicines in Japanese clinical practice guidelines Original

Research Article

Complementary Therapies in Medicine, Volume 17, Issue 3, Purchase June 2009, Pages 147-154 $ 31.50 Yoshiharu Motoo, Ichiro Arai, Ichinosuke Hyodo, Kiichiro Tsutani
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Summary

Background and aims

Kampo (Japanese herbal) medicines are often used in clinical practice in Japan. However, it is unclear how Kampo medicines are quoted and evaluated in current clinical practice guidelines (CPGs). Here, we systematically reviewed Japanese CPGs, and aimed to reveal how Kampo medicines are described in the CPGs.

Materials and methods

We reviewed the quasi-comprehensive list of Japanese CPGs available from the Toho University Medical Media Center (TUMMC) having the largest data base on Japanese CPGs, and also used a hand search. CPGs containing Kampo products were classified into three types based on how Kampo was handled. CPGs that provided recommendations based on evidence were classified as “type A”. Those which cited references but did not provide any recommendations were classified as “type B”. Those which described the Kampo practice or Kampo-related terms without providing any relevant references were classified as “type C”.

Results

By the end of March of 2007, 35 (10.1%) of 346 CPGs listed by TUMMC contained descriptions of Kampo products. We discovered one Kampo-related

CPGs in a hand search process. Of these 36 CPGs, 6 were “type A”, 13 were “type B”, and 17 were “type C”. Although results from pertinent randomized controlled trials (RCTs) were available, we noticed that some well-known RCTs studying Kampo medicines are missing in corresponding CPGs.

Conclusions

We revealed that the citation rate of Kampo medicines in CPGs was approximately 10% and that some pivotal trials for Kampo medicines were not quoted in CPGs. Kampo medicines in CPGs should be assessed more comprehensively and scientifically.

Article Outline

Introduction Materials and methods Search for CPGs Search for descriptions of Kampo products within CPGs Organization and content of the CPG list Classification of CPGs Results Number of CPGs containing Kampo products Classification of CPG Examples of type A, B, and C CPGs Discussion Evidence for Kampo products is not enough Confusing Kampo nomenclature hinders CPG authors CPGs do not focus on individual Kampo products Acknowledgements References

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Hard turning of tempered DIN 100Cr6 steel with coated and no coated CBN inserts Original Research Article Journal of Materials Processing Technology, Volume 179, Purchase Issues 1-3, 20 October 2006, Pages 146-153 Gustavo de Siqueira Galoppi, Marco Stipkovic Filho, Gilmar $ 37.95 Ferreira Batalha
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Abstract

Recent improvements in the machine tools technology (specially the stiffness and positioning accuracy) as well as the advent of the cubic boron nitride (CBN) ceramic cutting tools made the finishing operations for machining hardened steel parts possible, using tools with defined cutting geometry in substitution to the traditional grinding operations. The advantages presented by the hard turning are sufficiently attractive for many plants, however these are still reluctant to adopt and substitute a well known and dominated process (grinding) for other one not totally understood. Aiming to expand the knowledge of the processing effects of hard turning on the finishing of the machined workpiece, as well as the effects on the tool wear life. Series of experiments with seven different types of CBN inserts had been carried out using inserts with wiper geometry, coated with TiAlN and TiN as well as with no coated ones. The cutting parameters had been specified in such a form to cover the entire field recommended by tool suppliers. The machined part was an axle of DIN 100Cr6 steel tempered to 62 HRc. All the machining operations were carried out at a Mazak-Quick-Turn using an tool holder DCLNR-164D with insert geometry ISO CNGA120408SO1020 with edge with T preparation with 0.102 mm × 20° The . tool wear control was carried out using an optic microscope Zollern Saturn and a roughness profiler Hommelwerk T8000. Following parameters were parameters were determined: VBMAX, Ra, material removal rate and the tool life determined by the Taylor's equation obtained for theoretically ideal cutting conditions.

Preliminary analyses of the results compares with the literature indicating that they are significant.

Article Outline

1. Introduction 2. Tools for the hard turning [12], [13], [14] and [15] 2.1. Tool wear on hard turning 3. Machine tools and the hard turning accuracy [2] 3.1. Dimensional accuracy and precision [7] 4. Experimental methodology and materials 4.1. Workpieces 4.2. CNC turn machine 4.3. Cutting tools and machining parameters 4.4. Experimental conditions and cutting parameters 4.5. Surface profiler Hommelwerke T8000 5. Experimental results for the tool life and wear 5.1. Cratering wear 5.2. Tool breakage 5.3. Tool life 6. Conclusions References

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Quantum-beam technology: A versatile tool for developing polymer electrolyte fuel-cell membranes Original Research Article Journal of Power Sources, Volume 195, Issue 18, 15 September 2010, Pages 5848-5855 Tetsuya Yamaki
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Abstract

This paper describes the versatile application of quantum beam-based technology to the development of proton exchange membranes (PEMs) for fuel-cell applications. The γ-ray or electron-beam induced radiation grafting offers a way to prepare PEMs; typically, the radical-initiated polymerization of a styrene or styrene-derivative monomer on a base polymer is followed by a sulfonation step. Novel PEMs were previously obtained using radiation-crosslinked fluoropolymers as the base material. Interestingly, combining this radiation-crosslinking process with the well-known chemical crosslinker method enabled one to obtain the “multiply”-crosslinked PEMs, in which both the main and grafted chains have covalently bridged structures leading to a high durability. The bombardment of heavy ions accelerated to MeV or higher energies produces a continuous trail of excited and ionized molecules in polymers, which is known as a latent track. The approach using this ion-track technology is based on the chemical etching and/or modification of each track with diameters of tens to hundreds of nanometers. The resulting “nano-structure controlled” PEM was found to have perfect one-dimensional proton-conductive pathways parallel to its thickness direction, while, in contrast, other existing PEMs mostly exhibited proton transport in the three-dimensional random media. The hierarchical structures of the PEMs, ranging from nanometers to micrometers, were revealed by small-angle neutron scattering experiments using a cold or thermal neutron beam. The information in such a wide length scale led to a deep insight into the dynamic properties inside the PEM from a molecular to macroscopic level, which can provide feedback for the reconsideration and optimization of the preparation procedure. As demonstrated above in the author's studies, it is important to understand that every quantum beam is different, thereby making the right beam choice.

Article Outline

1. Introduction 2. What we must know about quantum-beam technology 3. γ-ray and electron beam-based technique 3.1. Radiation grafting

3.2. Radiation crosslinking 3.3. Recent progress 4. Application of swift heavy ion beams 4.1. Ion-track technology and strategy for PEM preparations 4.2. Ion track grafted membranes 4.3. PEMs prepared by filling track-etched pores 5. Neutron beam application and future directions 5.1. Small-angle neutron scattering (SANS) 5.2. Linkage with theoretical aspects 6. Conclusions Acknowledgements References


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