bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying Cross and Direct Network Effects in Online Consumer-to-Consumer Platforms
Authors: Chu Junhong , Manchanda Puneet 
Published: July 2016

Consumer-to-consumer (C2C) platforms have become a major engine of growth in Internet commerce. This is especially true in countries such as China, which are experiencing a big rush toward e-commerce. The emergence of such platforms gives researchers the unique opportunity to investigate the evolution of such platforms by focusing on the growth of both buyers and sellers. In this research, we build a utility-based model to quantify both cross and direct network effects on Alibaba Group’s Taobao.com, the world’s largest online C2C platform (based in China). Specifically, we investigate the relative contributions of different factors that affect the growth of buyers and sellers on the platform. Our results suggest that the direct network effects do not play a big role in the platform’s growth (we detect a small positive direct network effect on buyer growth and no direct network effect on seller growth). More importantly, we find a significant, large and positive cross-network effect on both sides of the platform. In other words, the installed base of either side of the platform has propelled the growth of the other side (and thus the overall growth). Interestingly, this cross-network effect is asymmetric with the installed base of sellers having a much larger effect on the growth of buyers than vice versa. The growth in the number of buyers is driven primarily by the seller’s installed base and product variety with increasing importance of product variety. The growth in the number of sellers is driven by buyer’s installed base, buyer quality, and product price with increasing importance of buyer quality. We also investigate the nature of these cross-network effects over time. We find that the cross-network effect of sellers on buyers increases and then decreases to reach a stable level. By contrast, the cross-network effect of buyers on sellers is relatively stable. We discuss the policy implications of these findings for C2C platforms in general and Taobao in particular. Data, as supplemental material, are available at https://doi.org/10.1287/mksc.2016.0976 .
CARACTERÍSTICAS EPIDEMIOLÓGICAS E CLÍNICAS DOS CASOS NOTIFICADOS DA TUBERCULOSE NA CIDADE DE TIANGUÁ, CEARÁ, BRASIL (2008-2013)
Authors: Santos Germana Fontenele , Frota Rafael Gonzalez , Moraes Carlos Eduardo Barros , Oliveira Maria Auxiliadora Silva 
Published: July 2016

O presente trabalho teve como objetivo descrever as características clínico-epidemiológicas dos casos notificados da tuberculose na cidade de Tianguá, CE. Trata-se de um estudo retrospectivo, descritivo, do tipo quantitativo, sendo exploratório com análise documental, tomando como fonte de informação os casos de tuberculose notificados no Sistema de Informação de Agravos de Notificação (SINAN) notificados entre os anos 2008 e 2013. As variáveis analisadas foram: gênero, escolaridade, faixa etária, tipo de entrada, forma clínica e co-infecção e HIV. Foram registrados 98 casos de tuberculose à Secretaria Municipal de Saúde do município. Desses, 65,3% são do gênero masculino. A faixa etária mais acometida pela doença foi a de 40 a 59 anos com 40,8%. Com relação à escolaridade, foram predominantes os indivíduos com até Ensino Fundamental. O índice de analfabetismo foi de 16,4%. Foi verificada uma predominância de 85,7% da forma pulmonar. De acordo com a distribuição dos casos, segundo coinfecção tuberculose-HIV, houve prevalência de indivíduos com tuberculose não infectados pelo HIV.
Simple approach to thieno[3,2-d]pyrimidines as new scaffolds of antimicrobial activities
Authors: Hafez Hend N. , El-Gazzar Abdel-Rhman B. A. , Zaki Magdi E. A. 
Published: July 2016

Abstract
6ʹ-(4-Chlorophenyl)-spiro[cyclohexane-1,2ʹ-thieno[3,2-d][1,3] oxazin]-4ʹ(1ʹH)-one (1) was synthesized and used as a starting material for the synthesis of a novel series of spiro compounds having biologically active sulfonamide 2a-e and 3ʹ-(4-acetylphenyl)-6ʹ- (4-chlorophenyl)-1ʹH-spiro[cyclohexane-1,2ʹ-thieno[3,2-d] pyrimidine-4ʹ(3ʹH)-one (3). Compound 2a was used as a key intermediate for the synthesis of sulfonyl carbothioamide derivatives 4a-c. Also, compound 3 was used as an intermediate for the synthesis of 3ʹH-spiro[cyclohexane-1,2ʹ-thieno[3,2-d]pyrimidin]-3ʹ-yl] phenyl}-2-imino-4-(substituted phenyl and/or thienyl)-1,2-dihydropyridine- 3-carbonitrile derivatives 5a-e, 3ʹH-spiro[cyclohexane- 1,2ʹ- thieno[3,2-d]pyrimidin]-3ʹ-yl]phenyl}-2-oxo-4-(substituted phenyl and/or thienyl)-1,2-dihydropyridine-3-carbonitrile derivatives 6a-e, and 4-[(2Z)-3-substituted-arylprop-2-enoyl] phenyl-1ʹH-spiro[cyclohexane-1,2ʹ-thieno[3,2-d]pyrimidine derivatives 7a-e. Cyclocondensation of 7a-e with hydrazine hydrate produced 6ʹ-(4-chlorophenyl)-3ʹ-[4-(5-substituted aryl-4,5-dihydro- 1H-pyrazol-3-yl)phenyl]-1ʹH-spiro[cyclohexane-1,2ʹ-thieno- [3,2-d]pyrimidin]-4ʹ(3ʹH)-ones 8a-e but with hydroxylamine hydrochloride afforded the corresponding isoxazoline derivatives 9a-e. Also, cyclocondensation by thiourea afforded 2-thioxo-1,2- dihydropyrimidin-4-yl)-phenyl-spiro-{cyclohexanethieno[3,2-d] pyrimidin}-4-one derivatives 10a-e. The new compounds were investigated for antimicrobial activity. Compounds 2c, 8b,c, 9b and 10b were the most potent ones against both Gram-negative and Gram-positive bacteria. Compound 8c exhibited higher antifungal activity towards the examined fungi with MIC of 1-2 μmol mL-1 compared to ketoconazole (MIC 2-3 μmol mL-1 ).
Application of instrumented nanoindentation in preformulation studies of pharmaceutical active ingredients and excipients
Authors: Egart Mateja , Janković Biljana , Srčič Stane 
Published: July 2016

Abstract
Nanoindentation allows quantitative determination of a material’s response to stress such as elastic and plastic deformation or fracture tendency. Key instruments that have enabled great advances in nanomechanical studies are the instrumented nanoindenter and atomic force microscopy. The versatility of these instruments lies in their capability to measure local mechanical response, in very small volumes and depths, while monitoring time, displacement and force with high accuracy and precision.
This review highlights the application of nanoindentation for mechanical characterization of pharmaceutical materials in the preformulation phase (primary investigation of crystalline active ingredients and excipients). With nanoindentation, mechanical response can be assessed with respect to crystal structure. The technique is valuable for mechanical screening of a material at an early development phase in order to predict and better control the processes in which a material is exposed to stress such as milling and compression.
Robust LQR and LQI control with actuator failure of a 2DOF unmanned bicycle robot stabilized by an inertial wheel
Authors: Owczarkowski Adam , Horla Dariusz 
Published: July 2016

Abstract
Essential ingredients for robust control are the ability to cope with different types of system behavior following modeling imperfections and the ability to assure a certain performance level. In this paper, we propose to use an actuator fault-tolerant control law to govern, during experiments, the stabilization of a bicycle robot with an inertial wheel in order to take into account unmodeled uncertainty introduced by using a linearized model in an LQR fashion. Our proposal is illustrated by signal plots and the values of performance indices obtained from a set of experiments.
An adaptive multi-spline refinement algorithm in simulation based sailboat trajectory optimization using onboard multi-core computer systems
Authors: Dębski Roman 
Published: July 2016

Abstract
A new dynamic programming based parallel algorithm adapted to on-board heterogeneous computers for simulation based trajectory optimization is studied in the context of “high-performance sailing”. The algorithm uses a new discrete space of continuously differentiable functions called the multi-splines as its search space representation. A basic version of the algorithm is presented in detail (pseudo-code, time and space complexity, search space auto-adaptation properties). Possible extensions of the basic algorithm are also described. The presented experimental results show that contemporary heterogeneous on-board computers can be effectively used for solving simulation based trajectory optimization problems. These computers can be considered micro high performance computing (HPC) platforms-they offer high performance while remaining energy and cost efficient. The simulation based approach can potentially give highly accurate results since the mathematical model that the simulator is built upon may be as complex as required. The approach described is applicable to many trajectory optimization problems due to its black-box represented performance measure and use of OpenCL.
A modified K3M thinning algorithm
Authors: Tabedzki Marek , Saeed Khalid , Szczepański Adam 
Published: July 2016

Abstract
The K3M thinning algorithm is a general method for image data reduction by skeletonization. It had proved its feasibility in most cases as a reliable and robust solution in typical applications of thinning, particularly in preprocessing for optical character recognition. However, the algorithm had still some weak points. Since then K3M has been revised, addressing the best known drawbacks. This paper presents a modified version of the algorithm. A comparison is made with the original one and two other thinning approaches. The proposed modification, among other things, solves the main drawback of K3M, namely, the results of thinning an image after rotation with various angles.
A comprehensive survey on formal concept analysis, its research trends and applications
Authors: Singh Prem Kumar , Aswani Kumar Cherukuri , Gani Abdullah 
Published: July 2016

Abstract
In recent years, FCA has received significant attention from research communities of various fields. Further, the theory of FCA is being extended into different frontiers and augmented with other knowledge representation frameworks. In this backdrop, this paper aims to provide an understanding of the necessary mathematical background for each extension of FCA like FCA with granular computing, a fuzzy setting, interval-valued, possibility theory, triadic, factor concepts and handling incomplete data. Subsequently, the paper illustrates emerging trends for each extension with applications. To this end, we summarize more than 350 recent (published after 2011) research papers indexed in Google Scholar, IEEE Xplore, ScienceDirect, Scopus, SpringerLink, and a few authoritative fundamental papers.
Electroless Deposition of Composite Nickel-Phosphorous Coatings with Diamond Dispersoid
Authors: Petrova M. , Georgieva M. , Chakarova V. , Dobreva E. 
Published: July 2016

AbstractThe composite Ni-P coating with diamond particles (D) deposited on the flexible substrates of pressed polyethylene terephthalate material (PET) was obtained, to be used in the development of efficient, flexible grinding and polishing tools. The optimal conditions of the hydrodynamic regime, deposition time and temperature were found. The influence of the concentration and size of the D particles (3/7 ÷ 225/300 μm) on the coating thickness and number of co-deposited particles were studied. By Scanning Electron Microscopy (SEM) images were defined the morphology of dispersion coatings and number of co-deposited particles in them, and Energy Dispersive Spectroscopy (EDS/INCA) was used to determine the elemental chemical composition of the composite coatings.
Tribological Characteristic of Titanium Alloy Surface Layers Produced by Diode Laser Gas Nitriding
Authors: Lisiecki A. , Piwnik J. 
Published: July 2016

AbstractIn order to improve the tribological properties of titanium alloy Ti6Al4V composite surface layers Ti/TiN were produced during laser surface gas nitriding by means of a novel high power direct diode laser with unique characteristics of the laser beam and a rectangular beam spot. Microstructure, surface topography and microhardness distribution across the surface layers were analyzed. Ball-on-disk tests were performed to evaluate and compare the wear and friction characteristics of surface layers nitrided at different process parameters, base metal of titanium alloy Ti6Al4V and also the commercially pure titanium. Results showed that under dry sliding condition the commercially pure titanium samples have the highest coefficient of friction about 0.45, compared to 0.36 of titanium alloy Ti6Al4V and 0.1-0.13 in a case of the laser gas nitrided surface layers. The volume loss of Ti6Al4V samples under such conditions is twice lower than in a case of pure titanium. On the other hand the composite surface layer characterized by the highest wear resistance showed almost 21 times lower volume loss during the ball-on-disk test, compared to Ti6Al4V samples.
Kinetics of Corrosion Process in H2SO4 and HNO3 Aqueous Solutions of Lead Free Sn-Ag-Cu Solder Alloys
Authors: Guśpiel J. , Wierzbicka-Miernik A. , Reczyński W. 
Published: July 2016

Abstract
This paper presents the results of the corrosion resistance of Sn-Ag-Cu alloys in air-saturated aqueous solutions containing NO3-, SO42- ions, whose concentration was equivalent to their contents in acid rains and in concentrations 10 - 100 times higher. The Ag, Cu and Sn concentrations in the corrosive media were determined using the Atomic Absorption Spectrometry. The specific dissolution rate and corrosion current were derived using the a rotating disc technique. The corrosion rate of Sn- Ag-Cu alloys depends on pH of the examined solutions and on the concentration of oxygen near the phase boundary. In the whole range of concentrations of the applied H2SO4 + HNO3 mixtures of acids, the pure Sn was more corrosion resistant than eutectic alloy as well as the near eutectic one, following the sequence: Sn>Sn3.66Ag0.91Cu>3.8Ag0.7Cu.
Analysis of Stress and Strain Fields in and around Inclusions of Various Shapes in a Cylindrical Specimen Loaded in Tension
Authors: Neimitz A. , Janus U. 
Published: July 2016

Abstract
A numerical analysis is performed of the stress field in and around inclusions of various shapes. Inclusions both stiffer and more compliant than the metal matrix are analysed. The critical stresses required for inclusion fracture are estimated after observation of cavities and inclusions by scanning electron microscopy. Real inclusions were observed after performing uniaxial loading to different amounts of overall strain. The material tested was Hardox-400 steel.
Stress-Induced Anisotropy and Stress Dependence of Saturation Magnetostriction in the Jiles-Atherton-Sablik Model of the Magnetoelastic Villari Effect
Authors: Szewczyk R. 
Published: July 2016

Abstract
The paper presents the results of the magnetoelastic Villari effect modelling in high-permeability Mn0.51Zn0.44Fe2.05O4 ferrite. Modelling was performed on the basis of measurements of magnetoelastic characteristics of frame-shaped samples. For the modelling, the corrected Jiles-Atherton-Sablik model was used. On the base of modelling results, the stress dependence of parameter k and stress-induced anisotropy were estimated. As a result the changes of saturation magnetostriction of Mn0.51Zn0.44Fe2.05O4 ferrite subjected to stresses were calculated. Such changes were previously observed experimentally. However, the phenomenon of stress-induced sign change of saturation magnetostriction was never previously explained quantitatively
Microstructural Analysis of Sintered Gradient Materials Based on Distaloy SE Powder
Authors: Zarębski K. , Nykiel M. 
Published: July 2016

Abstract
The study describes the microstructural analysis of cylindrically-shaped functionally graded products sintered from iron powder with scheduled graded structure on the cross-section running from the core to the surface layer of the sinter. Different types of structure were produced using Distaloy SE powder in two compositions - one without the addition of carbon, and another with 0.6wt% C. Two methods were used to fill the die cavity and shape the products. The first method involving a two-step compaction of individual layers. The second method using an original technique of die filling enabled the formation of transition zone between the outer layer and the core still at the stage of product shaping. As part of microstructural analysis, structural constituents were identified and voids morphology was examined. Studies covered the effect of the type of the applied method on properties of the graded zone obtained in the manufactured products
Selected Parameters of Micro-Jet Cooling Gases in Hybrid Spraying Process
Authors: Szczucka-Lasota B. , Węgrzyn T. , Stanik Z. , Piwnik J. , Sidun P. 
Published: July 2016

Abstract
The innovative technology, like thermal spraying with a micro-jet cooling is one of the important modification of classical ultrasonic spraying methods. Using of micro-stream with gases like argon or nitrogen allows to cool the coating immediately after spraying, and thereby reduce the time of transition during the injection of each layer. As a result of the process, the fine dispersive structure of coatings is obtained during the shorter time in comparable to the classical high velocity oxygen fuel process (HVOF). The parameter of process and the type of stream equipment determine the quality of the obtained structure and thermal stress in the coating. The article presents the relationship between selected parameters of hybrid process and properties of the coatings. The presented technology should be adapted to the actual production of protective coating for machines and construction working in wear conditions.
Application of Image Processing to Predict Compressive Behavior of Aluminum Foam
Authors: Kim Sanghoon , Chung Hyup Jae , Rhee Kyongyop 
Published: July 2016

Abstract
An image processing technique was used to model the internal structure of aluminum foam in finite element analysis in order to predict the compressive behavior of the material. Finite element analysis and experimental tests were performed on aluminum foam with densities of 0.2, 0.25, and 0.3 g/cm3. It was found that although the compressive strength predicted from the finite element analysis was higher than that determined experimentally, the predicted compressive stress-strain curves exhibited a tendency similar to those determined from experiments for both densities. However, the behavior of the predicted compressive stress-strain curves was different from the experimental one as the applied strain increased. The difference between predicted and experimental stress-strain curves in a high strain range was due to contact between broken aluminum foam walls by the large deformation.
Analysis of the Thermal and Magnetic Properties of Amorphous Fe61Co10Zr2.5Hf2.5Me2W2B20 (Where Me = Mo, Nb, Ni Or Y) Ribbons
Authors: Gruszka K. , Nabiałek M. , Szota M. , Bloch K. , Gondro J. , Pietrusiewicz P. , Sandu A.V. , Al Bakri A.M. Mustafa , Walters S. , Walters K. , Garus S. , Dośpiał M. , Mizera J. 
Published: July 2016

Abstract
The paper presents the results of structural and magnetic properties and thermal stability for a group of functional materials based on Fe61Co10Zr2.5Hf2.5Me2W2B20 (where Me = Mo, Nb, Ni or Y). Samples were obtained in the form of ribbons using melt-spinning method. The X-ray diffraction patterns of investigated samples confirmed their amorphous structure. Based on the analysis of DSC curves characteristic temperatures: glass forming temperature (Tg), crystallization temperature (Tx) and temperature range of the supercooled liquid ΔTx were determined. Small addition of transition metals elements has strong influence on magnetic and thermal parameters of studied materials. The comprehensive studies revealed that in terms of magnetic properties the Ni-addition resulted in highest reduction in coercivity and anisotropy field.
Primary Creep Behaviour of Two-Phase Titanium Alloy with Various Microstructure
Authors: Ziaja W. , Motyka M. , Kubiak K. , Sieniawski J. 
Published: July 2016

Abstract
Creep and fatigue properties of two-phase titanium alloys show strong dependence on microstructure, especially morphology of the α and β phases which can be controlled to certain extent by proper selection of hot working and heat treatment conditions. In the paper the creep behaviour of Ti-6Al-2Mo-2Cr alloy (VT3-1) at elevated temperature was modelled. Finite element analyses of primary creep stage were carried out taking into account some microstructural features of the two-phase alloy that were included in the physical model and different properties of α and β phases. In order to verify results of calculations distinct types of microstructure were developed in the alloy by heat treatment and creep tests were carried out at elevated temperature (450°C) at various stress levels. Based on the FEM simulations the effect of changes of some microstructure features on primary creep strain development was estimated.
Evaluation of Force-Time Changes During Impact of Hybrid Laminates Made of Titanium and Fibrous Composite
Authors: Jakubczak P. , Surowska B. , Bieniaś J. 
Published: July 2016

AbstractFibre metal laminates (FML) are the modern hybrid materials with potential wide range of applications in aerospace technology due to their excellent mechanical properties (particularly fatigue strength, resistance to impacts) and also excellent corrosion resistance. The study describes the resistance to low velocity impacts in Ti/CFRP laminates. Tested laminates were produced in autoclave process. The laminates were characterized in terms of their response to impacts in specified energy range (5J, 10J, 20J). The tests were performed in accordance with ASTM D7137 standard. The laminates were subjected to impacts by means of hemispherical impactor with diameter of 12,7 mm. The following values have been determined: impact force vs. time, maximum force and the force at which the material destruction process commences (Pi). It has been found that fibre titanium laminates are characterized by high resistance to impacts. This feature is associated with elasto-plastic properties of metal and high rigidity of epoxy - fibre composite. It has been observed that Ti/CFRP laminates are characterized by more instable force during impact in stage of stabilization of impactor-laminate system and stage of force growth that glass fibre laminates. It has been observed more stable force decrease in stage of stress relaxation and withdrawal of the impactor. In energy range under test, the laminates based on titanium with glass and carbon fibres reinforcement demonstrate similar and high resistance to low-velocity impact, measured by means of failure initiation force and impact maximum force.
Formation of Hard Composite Layer on Tool Steel by Laser Alloying
Authors: Bonek M. 
Published: July 2016

Abstract
Investigations include alloying the PMHSS6-5-3 steel surface layer with carbide and ceramic powders WC, VC, TiC, SiC, Si3N4 and Al2O3, using the high power diode laser (HPDL). Laser treatment is especially promising for solving contemporary surface engineering problems making it possible to focus precisely the delivered energy in the form of heat in the surface layer. The structural mechanism was determined of surface layers development, effect was studied of alloying parameters, method on structure refinement and influence of these factors on the mechanical properties of surface layer, and especially on its abrasive wear resistance. The fine grained martensite structure is responsible for hardness increase of the alloyed layer. The tribological wear relationships were determined for laser treated surface layers, determining friction coefficient, and wear trace shape developed due to the abrasive wear of the investigated surfaces. Comparison of the laser treatment parameters and tribological properties of surface layer after remelting and alloying with hard particles of the PMHSS6-5-3 steel using the high power diode laser to obtain the optimum service properties is the outcome of the investigations carried out.