Miracle-dz/UniFAR-FTUs huggingface dataset:
Two-dimensional boundary element analysis of quartz surface wave resonators

In this paper we present the 2D fundamental solutions for the time-harmonic dynamic problems of piezoelectric materials. Given a time-harmonic line force or charge at the origin of an infinite piezoelectric solid, we derive the displacement and electric potential at an arbitrary point. The solution, obtained using the Radon transform, has an interesting feature that it can be split into two parts: singular static and regular dynamic parts. The singular static part corresponds to the static fundamental solution and the regular dynamic part provides frequency dependency. The regular part is presented in a form suitable for numerical evaluation. The implementation of the fundamental solutions into the boundary element method (BEM) for the eigen frequency problems of the surface wave resonators is outlined along with key technical features required for the successful BEM analysis.
Effects of nonlinear dispersion in EDFA's on optical communication systems

The signal-induced change of the refractive index in an erbium-doped fiber amplifier (EDFA) causes a phase modulation imposed on a signal when passing the EDFA. In this paper, we apply our extended EDFA model on an optical communication system. The model includes this phase modulation, by including the nonlinear dispersion in an EDFA, and the spontaneous emission noise. The influence of these effects on an optical communication system is examined by means of Q-factor and eye diagram. We assume an intensity modulated-direct detection (IM-DD) system operating at 193 THz (1552.5 nm) with a bit rate of 10 Gb/s in the anomalous dispersion regime and a total fiber length of 500 km. The fibers are assumed to be dispersion shifted ones, EDFAs are used to compensate for the fiber loss. By numerical simulation we obtain results for the influence of the phase modulation (nonlinear dispersion) due to the signal induced change of the refractive index in an EDFA and the spontaneous emission noise at different input peak powers. Neglecting the signal-induced change of the refractive index strongly underestimates the Q-factor in the anomalous dispersion regime. Therefore it should be included for reliable system simulations. This can be done with the numerical model presented here.
Dix ans de recherche empirique sur la comptabilité par activités: état de la situation actuelle et perspectives

For more than ten years now, several organizations have been using activity-based costing models to enhance the management of their cost. Researchers have attempted to describe these systems and to identify the factors that affect their adoption, implementation and success. The objective of this paper is to review these studies and to identify the research opportunities in this area. The results of this analysis show that the empirical research has not provided robust results that would enable management accounting academia to understand the diffusion process for activity-based costing. Researchers will need to improve the design of their study and the measurement of the constructs but also develop a typology of activity-based costing systems.
Constructing and Evaluating Evolving Web-API Networks – A Complex Network Perspective

Despite the continual increase in the number of Web-APIs available on the internet, it is still challenging for API consumers to discover appropriate Web-APIs that could satisfy their requirements. One of the main reasons for this is that Web-APIs registered on online directories such as ProgrammableWeb are in general isolated, as they are registered by diverse providers independently and progressively, ignoring continuous interactions among these APIs, which could enhance their discoverability. In this article, we propose a method for analyzing the Web service ecosystem, and a complex network based approach for constructing evolving networks for Web-APIs that are capable of enhancing their discoverability. We first conduct a two-phase analysis: We investigate mashups and Web-APIs interactions in the service ecosystem, and analyze their popularity distributions, and quantitatively measure two key node attachment dimensions within the ecosystem: Preferential Attachment and Similarity. Based on the analysis, we propose two methods for constructing evolving Web-API networks using the theoretical procedures of the Barabási-Albert and the Popularity-Similarity Optimization network models . Finally, we comprehensively evaluate the networks and map their properties with service discoverability using the ProgrammableWeb datasets. Results presented in this work will serve as a practical guide for designing a complex network-based solution for Web-API discovery.
Impact of Attitudinal Constructs on Sport Team’s Country Image and Intention to Travel

A positive team image not only constitutes a key asset for businesses but may also play key role in enhancing the fans‟ perceptions of the team‟s country image and their intention to travel to such countries. The present paper aims at measuring the impact of global fans‟ attitudinal constructs such as team attachment, team achievement and team involvement on the team‟s country image and their intention to travel to this country through the indirect impact of the sponsor‟s image. Data collected through an online survey from 710 participants showed that team country image is mainly determined by team achievement and that there is a positive relationship between the sponsor‟s image and team country image. Interestingly, the findings also showed that team achievement impacts team country image through the indirect impact of the sponsor image. The implication of this research is that having positive feelings about the team‟s country image would psychologically raise global fans‟ positive feelings about the image of this team‟s country which would, in turn, evoke the fans‟ interest to travel to this team‟s country.
A modified PWM scheme in order to obtain spatial information of AC machines without mechanical sensor

To realise the sensorless control of AC machines which are able to work even at zero speed, an additional high frequency excitation is necessary. Different schemes have been presented recently, which use an transient excitation caused by the switching of the voltage source inverter. As any additional excitation also has an impact on the current ripple and the noise emission of a machine, investigations have been made to integrate the fundamental wave and the transient excitation into one inverter control scheme. In this paper, a new modified PWM scheme is presented which enables both the fundamental wave excitation to generate the flux and the torque of the machine as well as the transient excitation necessary to obtain sensorless control signals. Simulations as well as measurement results are given to show the advantages and limits of the proposed scheme.
Optimal design of link systems using successive zooming genetic algorithm

Link-systems have been around for a long time and are still used to control motion in diverse applications such as automobiles, robots and industrial machinery. This study presents a procedure involving the use of a genetic algorithm for the optimal design of single four-bar link systems and a double four-bar link system used in diesel engine. We adopted the Successive Zooming Genetic Algorithm (SZGA), which has one of the most rapid convergence rates among global search algorithms. The results are verified by experiment and the Recurdyn dynamic motion analysis package. During the optimal design of single four-bar link systems, we found in the case of identical input/output (IO) angles that the initial and final configurations show certain symmetry. For the double link system, we introduced weighting factors for the multi-objective functions, which minimize the difference between output angles, providing balanced engine performance, as well as the difference between final output angle and the desired magnitudes of final output angle. We adopted a graphical method to select a proper ratio between the weighting factors.
Analysis of the optimal time delay for Reconstruction of Phase Space of VCG signals to identify anterior wall infarction

—Acute Myocardial Infarction (MI) can be detected through Reconstructed Phase Space (RPS) parameters. The RPS is dependent on a time delay ( τ ) that can be a ﬁxed or an optimal value based on the mutual information between a vectorcardiogram lead and its delayed version. This paper aims to assess the effect of an optimized time-delay in the detection of MI in the anterior wall using RPS parameters. For optimal τ values the sensitivity, speciﬁcity, accuracy and AUC obtained were: 64.7%, 63.2%, 57.8% and 62.3%, respectively; while for a ﬁxed τ value were, respectively, 81.3%, 74.5%, 64.9% and 70.1%.
THE APPLICATION OF ARTIFICIAL MAGNETIC CONDUCTORS IN THE BROADBAND RADAR CROSS SECTION REDUCTION OF THE MICROSTRIP ANTENNA ARRAY

A scheme for radar cross section (RCS) reduction of microstrip antenna array in wideband using artificial magnetic conductors (AMC), without compromising the radiation characteristics of the antenna array, is proposed. This design is based on the principle of passive cancelation. The novelty is that the reflection characteristics of the microstrip antenna array are also taken into consideration during the design process of AMCs. The aperiodic configuration is composed of three kinds of AMC lattices with selected dimensions and is applied to the design of microstrip antenna array for the purpose of RCS reduction. The simulated results show that the monostatic RCS is reduced over a wideband from 15.2 to 35GHz (about 79% relative bandwidth), covering the operation band (20–20.75 GHz) of the antenna array. In addition, compared with the periodic configuration, it has about 4 dB lower maximum bistatic RCS.
A FRAMEWORK TO EVALUATE ROAD USERS' SATISFACTION LEVEL

This study proposes a framework to evaluate and identify significant factor affecting road users' satisfaction level. The research is mainly focused on investing related factors that may contribute to satisfaction level of all road users on Motorway Route 7 (Bangkok - Chonburi). Two research methods are employed in this study. They are documentary research and survey research. The questionnaires are developed and separated into three main sections, which are general questions, measurement of the level of satisfaction toward each indicator and the overall satisfaction of traveling on the Motorway Route 7. A 5-point Likert scale is used to measure the level of satisfaction. The preliminary data are collected from the pilot sample of 39 road users. The results of the pilot group are presented in this paper. The proposed framework includes statistical model that can identify significant factors affecting the satisfaction. Several statistical techniques are proposed such as exploratory factor analysis and multiple regression. In addition, descriptive correlation analysis will be conducted to discover if the dependent variables contribute to the independent variable. The complete result of this study is expected to serve as a guideline for highway authorities to improve their serviceability level along the Motorway Route 7.
NUMERICAL COMPUTATION OF SAR IN HUMAN HEAD WITH TRANSPARENT SHIELDS USING TRANSMISSION LINE METHOD

|The tremendous proliferation of mobile smartphone handsets and their usage worldwide makes human life comfortable, while the radiation hazards associated with them are alarming, especially among children. There is a necessity to minimize the Electro Magnetic Field (EMF) radiation levels. For the evaluation of Radio Frequency (RF) radiation from the mobile phone, one of the dosimetric parameters used is the Speci(cid:12)c Absorption Rate (SAR). The RF radiation can be mitigated by incorporating a barrier or a shield of suitable material in the mobile handset design. In the proposed work, the analysis of SAR evaluation absorbed by the human head is determined with the performance of the shielding material called Shielding Eﬀectiveness (SE) using Transmission Line Method (TLM) mathematically. The proposed shielding materials are composed of (cid:13)exible and transparent thin (cid:12)lms. Flexible and transparent thin shielding materials are advantageous over the other shielding materials in reduced size, less weight, non-corrosiveness, and easy processing. These materials include highly conductive Silver (cid:12)lm, Silver Nanowire (AgNW) doped with PDDA (poly(diallyldimethyl-ammonium chloride)) polymer single shields, and a laminated shield comprising AgNW/PDDA with PEDOT:PSS (poly(3,4-ethylenedioxythiophene)poly-styrene sulfonate) polymer as lamination. The SARs of planar multi-layered human head models for diﬀerent ages are estimated at various mobile frequencies with these shields. Under four-layered head models at 6 GHz, adult and child heads absorb 0.0006 W/kg and 0.000024 W/kg of RF radiation using pristine Silver (cid:12)lm as a single shield. Using a single shield of Ag nanowire and PDDA, the adult and child heads absorb SARs of 0.00058 W/kg and 0.000023 W/kg, respectively. With the laminated shield of AgNW/PDDA and PEDOT:PSS as coating material, the same models are exposed to minimal amounts of 0.00054 W/kg and 0.000012 W/Kg of SAR. At 6 GHz frequency, under seven-layered head models, adult and child heads absorb 0.000047 W/kg and 0.000002 W/kg of power, respectively, using Ag (cid:12)lm. With AgNW/PDDA shield, the adult and child heads absorb SARs of 0.000046 W/kg and 0.0000019 W/kg, respectively. The SAR of 0.000043 W/kg and a negligible value of 0.0000018 W/kg are absorbed by adult and child heads individually with the help of AgNW/PDDA/PEDOT:PSS laminated shield. The results exhibit a signi(cid:12)cant amount of reduction in Speci(cid:12)c Absorption Rate with transparent shielding materials compared to SAR absorbed by the head without any shield. This maximum RF exposure rate reduction from mobile phones with the Ag Nanowire/PDDA/PEDOT:PSS laminated shield is achieved for a seven-layered child head model.
Jet Grouting at Posey Tube, Oakland, California

This paper presents an innovative seismic retrofit of the historic Posey Tube in the San Francisco Bay area of California. The tube, which forms an underwater link between the cities of Oakland and Alameda, is located between two major active faults, the Hayward Fault and the San Andreas Fault. The Posey Tube, completed in 1928, was then the first pre-cast underwater tunnel to be built in the world. Approximately 40 years later, another tube, the Webster Street Tube, was built parallel to and 152 meters (500 feet) west of the Posey Tube. Construction of the two tubes required excavation of a trench along an approximately 976-meter (3,200-foot) stretch of alignment over land and water, and backfilling of the trench with dumped fill. During a major earthquake, the t ube sandy backfill materials and the sand bedding immediately below the tubes would be susceptible to liquefaction, resulting in the loss of soil strength. Consequently, the tubes could become buoyant in the heavily liquefied material, causing substantial displacements and damage. The seismic retrofit in the Posey Tube consisted of installing jet grout columns along both sides of the Posey Tube, and while that in the Webster Street Tube was composed of pipe pile stone columns which is dis cussed in a separate paper (Lee et al., 2005). The objective of the seismic retrofit in the Posey Tube was to prevent flotation of the tube due to liquefaction of the sandy soils undern eath the tube. This was achieved by constructing a row of 1.83-m (6-ft) diameter overlapping jet grout columns on both sides of the tube, each to a depth of about 13.7 meters (45 feet) from approximately 1.5 meters (5 feet) below the crown of the tube. These two rows of columns serve as barriers to contain the liquefied, loose, saturated sand in place during a major earthquake. This innovative design concept is considered to be the first of its kind to be applied to an immer sed tube of this magnitude in the world. This paper discusses: (1) challenges confronted by the unique site and soil conditions with the use of triple fluid system of jet grouting, (2) the use of jetting specific energies to determine the overall structura l integrity of grout cores, and (3) results of field and laboratory testing that included pre - and post-construction borings, permeability testing, and unit weight/unconfined compressive strength testing. These are followed by a discussion of lessons lear nt from the jet grouting operation along the Posey Tube.
Numerical and Analytical Modeling of Unbonded Flexible Risers

This paper presents an analytical formulation and a finite element analysis of the behavior of multilayer unbonded flexible risers. The finite element model accurately incorporates all the fine details of the riser that were previously considered to be important but too difficult to simulate due to the significant associated computational cost. All layers of the riser are separately modeled, and contact interaction between layers has been accounted for. The model includes geometric nonlinearity as well as frictional effects. The analysis considers the main modes of flexible riser loading, which include internal and external pressures, axial tension, torsion, and bending. Computations were performed by employing a fully explicit time integration scheme on a parallel 16-processor cluster of computers. Consistency of simulation results was demonstrated by comparison with those of the analytical model of an identical structure. The close agreement gives confidence in both approaches.
On the generalizations of the maximum power transfer theorem

Referring to the study of the generalization of the maximum power transfer theorem, it is shown that the proposed solution in a paper by Nambiar is not generally the only one. Particularly, under the conditions that we determine, the available power of a n-terminal pair network containing sources, may be absorbed by passive loads connected at each terminal. The study is done in the case of nonreciprocity.
Low-cost Implementation of a Waveguide-based Microwave Filter in Substrate Integrated Waveguide (SIW) Technology

This paper presents the design and practical implementation of a waveguide-based microwave filter in Substrate Integrated Waveguide (SIW) technology. The use of SIW technology for implementing waveguide filters makes the presented design specially aimed for being used in undergraduate courses related to microwave engineering and filter designing. Their low cost and easiness from the filter fabrication point of view allows their use in microwave laboratory courses where students can implement their own theoretical filter designs and measure their frequency response. The requiring mechanics in the manufacturing of microwave filters in waveguide technology (both rectangular and circular) makes its use practically unfeasible in academic laboratories because of its cost. For this reason, a practical design example of a waveguide iris filter using the impedance inverter model is proposed in this paper for academic laboratories, using SIW technology. This is a low cost and easy to manufacture technology. The overall process includes the design of the ideal band-pass prototype filter using the impedance inverter and its implementation in an inductive iris-coupled waveguide filter, by using a developed electromagnetic simulator based on the mode-matching technique. Finally, the equivalent filter in SIW technology is obtained and optimized by using HFSS simulator, including a SIW to microstrip transition. A prototype of the designed filter has been fabricated and measured, showing a good agreement between measurements and simulations.
Safety lifecycle management. A flowchart presentation of the IEC 61508 overall safety lifecycle model

Safety in the process industry is currently playing an increasingly important role. In the European Union the Seveso II directive requires that companies that store certain amounts of dangerous liquids or gases shall take appropriate measures to reduce the potential risks. Concerning safety-related systems, the (draft) IEC 61508 standard is already adopted by many companies to comply with the Seveso II directive. Contrary to the older standards, IEC 61508 does not only cover the classical technical aspects, but also the business processes that are relevant for the entire safety lifecycle. The standard introduces a structure that consists of safety lifecycle models. The overall safety lifecycle describes required activities associated with safety during the entire lifecycle of the equipment, from the concept phase to the decommissioning phase. For a real operating process installation a study has been performed to investigate what steps should be taken in order to implement the IEC 61508 safety standard. This study is based on the overall safety lifecycle model and uses a flowchart approach that addresses all relevant items of the overall safety lifecycle. Copyright © 1999 John Wiley & Sons, Ltd.
Game, Set and Match (Available Only in Geoenvironmental Special Issue)

The U.S. Open, which takes place in New York City at the end of August each year, is one of four prestigious “Grand Slam” tennis events drawing players and fans from around the world, and has grown in popularity every year. In the latter part of the last decade, to accommodate increasing crowds, the United States Tennis Association (USTA) decided to expand and upgrade the facilities at the National Tennis Center in Flushing Meadows, where the tournament has been held since 1977. An integral part of this project was designing a foundation that addressed the complex history of the tournament site.
Proportional integral plus multi-frequency resonant current controller for grid-connected voltage source converter under imbalanced and distorted supply voltage conditions

This paper proposes a current control scheme for a grid-connected pulse width modulator (PWM) voltage source converter (GC-VSC) under imbalanced and distorted supply voltage conditions. The control scheme is implemented in the positive synchronously rotating reference frame and composed of a single proportional integral (PI) regulator and multi-frequency resonant controllers tuned at the frequencies of 2ω and 6ω, respectively. The experimental results, with the target of eliminating the active power oscillations and current harmonics on a prototype GC-VSC system, validate the feasibility of the proposed current control scheme during supply voltage imbalance and distortion.
Assessing the teaching and achieving of research skills

We present a method to empirically analyse the relation between faculty wide intended learning and concomitant achieved learning outcomes. The method is applied to the Master of Science in Business Administration (MSc BA) program of the Faculty of Economics and Business (FEB) of the University of Groningen. Intended learning is measured from the students’ exposure to seven research aspects taught according to course specific learning goals. The achieved learning outcomes are derived from the grades that the FEB professors gave on these research aspects when grading the students’ final Master theses. We find that the intended learning of the research aspects in the MSc BA program does not benefit the students with a previous Bachelor of Science background at the FEB. However, external students with no previous FEB background do benefit from such teaching. Because of these plausible results we expect that our method may also be relevant for accreditation committees/managers of other Business Schools. Moreover, the application results may also be interesting for professors who (intend to) teach research skills. http://dx.doi. org/10.4995/HEAd15.2015. 360