Stimulus Generation Research Articles

FocusStack and StimServer: a new open source MATLAB toolchain for visual stimulation and analysis of two-photon calcium neuronal imaging data.

Two-photon calcium imaging of neuronal responses is an increasingly accessible technology for probing population responses in cortex at single cell resolution, and with reasonable and improving temporal resolution. However, analysis of two-photon data is usually performed using ad-hoc solutions. To date, no publicly available software exists for straightforward analysis of stimulus-triggered two-photon imaging experiments. In addition, the increasing data rates of two-photon acquisition systems imply increasing cost of computing hardware required for in-memory analysis. Here we present a Matlab toolbox, FocusStack, for simple and efficient analysis of two-photon calcium imaging stacks on consumer-level hardware, with minimal memory footprint. We also present a Matlab toolbox, StimServer, for generation and sequencing of visual stimuli, designed to be triggered over a network link from a two-photon acquisition system. FocusStack is compatible out of the box with several existing two-photon acquisition systems, and is simple to adapt to arbitrary binary file formats. Analysis tools such as stack alignment for movement correction, automated cell detection and peri-stimulus time histograms are already provided, and further tools can be easily incorporated. Both packages are available as publicly-accessible source-code repositories1.

Consumer behavior in e-tourism services: a case of Taiwan

The purpose – The prompt and efficient changes in technology during the past few decades have affected tourism industry. With new emerging technologies (internet) the method of doing business has changed; which makes it a very important factor to understand the consumer behavior and perception in order to recognize, captivate, and retain the customers in the internet based travelling industry. This paper examines the determinants which influence the consumer behavior of the potential customers to use e-tourism services and to show their interrelationship in the perspective of Taiwan. Design/Methodology – Empirical research is been used to determine the findings of this research. A questionnaire was designed based on the past studies related to the variables of the study. The questionnaire consisted of four sections each consisting of four to five statements. The demographic section was also included. A total of 402 completed questionnaires were taken into consideration. Findings – The result of this study shows that determinants considered in this study; generation of stimulus, information search and service quality have a major impact over the loyalty of the consumer which determines the consumer behavior towards the e-tourism services for travel planning purposes. Originality of the research – This is the first kind of research done over consumer behavior of youth specifically in e-tourism industry in Taiwan’s perspective and secondly as the data is collected directly from Taiwan’s youth and is empirically evaluated so we believe its results will help the organizations for making the e-tourism industry more consumer oriented in case of Taiwan.

Airborne ultrasonic tactile display contactless brain-computer interface paradigm

Airborne ultrasonic tactile display contactless brain-computer interface paradigm

Sistema de Alerta al Conductor Basado en Realimentación Vibro-Táctil

This paper proposes the design and build of a driver warning system, based on vibro-tactile feedback for preventing accidents through the generation of tactile stimuli. The system has two vibro-tactile grips devices which are easily mounted on the steering wheel of any vehicle and an electronic system based on location sensing as well as inter-vehicles communication, from which a risk level is computed on line in order to warn the driver about dangerous situations and risk zones. A model focalized on human factors is proposed and it is employed to justify the advantages of using artificial stimuli. Besides, the hardware, communication between vehicles and embedded software, are described too. Finally, experiences using the device in a racing car simulator and tests using two ordinary cars are shown.

Stimuli generation framework for testing multiple processes in VHDL

Hardware Description Languages (HDL) like VHDL are used to design and simulate programmable logic devices. Usually the description of the device under test consists of several processes. This concept introduces problems of how to test and verify complex systems. In this paper, we present a new framework called TestBenchMulti that is able to generate test stimuli for parallel VHDL designs. The framework combines Control Flow Graphs (CFGs), extension of Symbolic Execution (SE) and Satisfiability Modulo Theories (SMT) into a sequence of methods to generate stimuli capable of obtaining high code coverage. The experiments were carried out on synthesizable VHDL circuits at the behavioural level. The obtained code coverage results were confirmed in the real implementation using Xilinx FPGA hardware. DOI: http://dx.doi.org/10.5755/j01.itc.43.4.7598

A Fully Integrated BIST <inline-formula> <tex-math notation="TeX">\(\Delta \Sigma \) </tex-math></inline-formula> ADC Using the In-Phase and Quadrature Waves Fitting Procedure

This paper demonstrates a fully integrated builtin self-test (BIST) ΔΣ analog-to-digital converter (ADC) based on the proposed in-phase and quadrature waves fitting (IQWF) procedure. The IQWF procedure enables accurately measuring the phases and amplitudes of test responses so as to enhance the test accuracy of the BIST circuitry. The all-digital BIST circuitry, with on-chip stimulus generator and response analyzer, conducts single-tone functional tests to test for the ADCs characterization results such as signal-to-noise-and-distortion ratio (SNDR), dynamic range (DR), frequency response, input-referred offset, and gain error. Since the IQWF procedure is performed successively in real time, the BIST circuitry does not need huge memory to store all the output samples like conventional fast Fourier transform (FFT) analysis does. The overall hardware overhead only consists of 16.6 k digital gates. The fully integrated BIST ΔΣ ADC has been fabricated in 0.18-μm CMOS. Measurement results show that the BIST circuitry reports a peak SNDR of 88.0 dB and a DR of 92.6 dB while the corresponding FFT-based analog tests result in 88.8 and 94.1 dB, respectively. Particularly, the BIST circuitry achieves a test bandwidth as wide as the ADCs 20-kHz rated bandwidth, which is the widest to the best of our knowledge. The proposed BIST ADC can be tested without costly external test resources and is thus well suited for the applications in which conventional test resources are not available such as 3-D ICs.

On-chip sinusoidal signal generation with harmonic cancelation for analog and mixed-signal BIST applications

This work presents a technique for the on-chip generation of analog sinusoidal signals with high spectral quality and reduced circuitry resources. The proposed generation technique consists of a modified low-order analog filter, that provides a sinusoidal output as response to a DC input, combined with a harmonic cancellation strategy to improve the linearity of the generated signal. The proposed generator has the attributes of digital programming and control, low area overhead, and low design effort, which make this approach very suitable as test stimulus generator for built-in test applications. An integrated prototype designed in a 180 nm CMOS technology is presented in order to show the feasibility of the technique. Results obtained from the prototype show a THD around \(-80\) dB.

Scaling Input Stimulus Generation through Hybrid Static and Dynamic Analysis of RTL

We enhance STAR, an automatic technique for functional input vector generation for design validation. STAR statically analyzes the source code of the Register-Transfer Level (RTL) design. The STAR approach is a hybrid between RTL symbolic execution and concrete simulation that offsets the disadvantages of both. The symbolic execution, which follows the concrete simulation path, extracts constraints for that path. The guard in the path constraints is then mutated and passed to an SMT solver. A satisfiable assignment generates a valid input vector. However, STAR suffers the problem of path explosion during symbolic execution. In this article, we present an explored symbolic state caching method to attack path explosion. Explored symbolic states are states starting from which all subpaths have been explored. Each explored symbolic state is stored in the form of bitmap encoding of branches to ease comparison. When the explored symbolic state is reached again in the following symbolic execution, all subpaths can be pruned. In addition, we use two types of optimizations: (a) dynamic UD chain slicing; and (b) local conflict resolution to improve the running efficiency of STAR. We demonstrate that the results of the enhanced STAR are promising in showing high coverage on benchmark RTL designs, and the runtime of the test generation process is reduced from several hours to less than 20 minutes.

An Advanced Verification Platform Based on UVM

An advanced verification platfrom based on UVM architecture is implemented in this paper. This paper presents a hierarchical verification environment that is portable, reusable, and easy to extend, which is constructed based on an object oriented language named System Verilog. The verification platform is applied to verify a RFID (Radio Frequency Identification) tag chip which is compliant with the ISO/IEC15693 standard, communicates with a reader outside through a RF analog circuitry, completes anti-collision flow, selects card, authenticates based on SM7 algorithm and controls the writing and reading of EEPROM inside. According to the instruction supported by the tag chip is wide and variety, and further more it’s very rich in the command frame contents, the advanced verification platform which achieves the constraint-random stimulus generation, functional coverage and self-check mechanism, reduces the verification cycle, improves verification efficiency and ensures verification adequacy.

An implantable neurostimulator with an integrated high-voltage inductive power-recovery frontend

This paper present a highly-integrated neurostimulator with an on-chip inductive power-recovery frontend and high-voltage stimulus generator. In particular, the power-recovery frontend includes a high-voltage full-wave rectifier (up to 100 V AC input), high-voltage series regulators (24/5 V outputs) and a linear regulator (1.8/3.3 V output) with bandgap voltage reference. With the high voltage output of the series regulator, the proposed neurostimulator could deliver a considerably large current in high electrode-tissue contact impedance. This neurostimulator has been fabricated in a CSMC 1 μm 5/40/700 V BCD process and the total silicon area including pads is 5.8 mm2. Preliminary tests are successful as the neurostimulator shows good stability under a 13.56 MHz AC supply. Compared to previously reported works, our design has advantages of a wide induced voltage range (26–100 V), high output voltage (up to 24 V) and high-level integration, which are suitable for implantable neurostimulators.

ROS-triggered and regenerating anticancer nanosystem: An effective strategy to subdue tumor's multidrug resistance

Drug delivery strategies utilizing tumor microenvironment are recognized as a critical doorway to overcome multidrug resistance (MDR). However, the variability of tumor microenvironment at different disease stages would definitely minimize stimuli generation and eventually the therapeutic effects of these stimuli sensitive systems. Herein, we report a unique reactive oxygen species (ROS) triggered nanosystem that can replenish the ROS upon disassembly to maintain its high level. This was accomplished by a new amphiphilic polymer (TBH) composed of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS), hyaluronic acid (HA) and arylboronic ester. As a linker of TPGS to HA, arylboronic ester could efficiently degrade in response to ROS resulting in dismantling of nanosystem followed by rapid release of TPGS. Owing to ROS inducing activity of TPGS with mitochondrial respiratory complex II, ROS regeneration was observed for TBH nanosystem both in MCF-7/ADR cells and tumor tissues xenografted with MCF-7/ADR cells. Furthermore, doxorubicin-loaded TBH nanosystem (DOX-TBH) revealed higher drug cytotoxicity due to enhanced retention effect on account of ROS triggered DOX release and P-gp inhibitory mechanism of TPGS. Moreover, HA significantly improved tumor targeting capability of DOX-TBH, while ROS based triggering and regenerating mechanism lead to marked inhibition of the tumor growth in the xenograft MCF-7/ADR tumor-bearing nude mice.

Impedance frequency characterization of a vibrating wire viscosity sensor with multiharmonic signals

This paper presents a method to estimate the impedance frequency response of a vibrating wire viscosity sensor. The method is based on the application of a multiharmonic signal to the measurement circuit, which includes the sensor. The signal is composed by the harmonics that correspond to the frequencies at which the sensor’s impedance is to be estimated. The impedance is determined using least-squares (LS) multiharmonic fitting algorithms to obtain the amplitudes and phases of the harmonics of the impedance current and voltage. The stimulus generation, measurement and estimation procedure is performed by a dedicated developed measurement system. It includes a digital signal processor (DSP) to perform all the calculations, control the programmable gain instrumentation amplifiers (PGIAs) and communicate with the analog-to-digital converters (ADCs). The PGIAs and ADCs, respectively, amplify and acquire the signals across the sensor and a reference impedance which is used to limit and sample the current flowing through the wire of the sensor. An auxiliary processor connected to a digital-to-analog converter manages the stimulus generation. The system is connected by USB to a personal computer (PC) where the measurement results can be stored, interpreted and further processed.

Real-Time Processing of Multifrequency Eddy Currents Testing Signals: Design, Implementation, and Evaluation

The design, implementation, and evaluation of a real-time digital signal processing architecture to generate and process multifrequency signals for eddy currents testing is described in this paper. This architecture is implemented on a dedicated instrument whose processing core is a field-programmable gate array. Stimulus generation is achieved using direct digital synthesis with some important improvements to reduce spurious frequency components. An in-phase and in-quadrature demodulation scheme is implemented to estimate the real and imaginary parts of the probe output signal. A cascaded integrator comb decimator is used to lower the sampling frequency and then allow narrowband filtering with low resources. The proposed architecture is able to generate and process the stimulus and input data at 125 MSamples/s and to estimate the input data components at 1.25 MSamples/s rate for eddy-currents with multiple simultaneous testing frequencies between 2.5 kHz and 10 MHz. Experimental validation is performed using a set of synthetic defects and two stimulus with different spectral composition.

BCI Appliance

Event Abstract Back to Event BCI Appliance Tomasz Spustek1*, Mateusz Kruszyński2, Dawid Laszuk1, Piotr Milanowski1, Maciej Łabęcki1, Karol Augustin1, Anna Duszyk3, Rafał Kuś1, Jarosław Żygierewicz1 and Piotr Durka1 1 University of Warsaw, Faculty of Physics, ul. Hoza 69, 00-681 Warszawa, Poland, Poland 2 University of Warsaw, Faculty of Psychology, ul. Stawki 5/7, 00-183 Warszawa, Poland, Poland 3 University of Social Sciences and Humanities, ul. Chodakowska 19/31, 03-815 Warszawa, Poland, Poland Brain Computer-Interface (BCI) is a system that allows communication through direct measures of neural activity of the brain without muscle involvement. Such systems appear to be the only method of communication for people with severe neuromuscular disorders. There has been rapid development of BCI-systems for the last twenty years, but mostly in respect to accuracy and bit rate, rather than user convenience and ease of use. BCI Appliance, pioneering user-centered design of BCI systems, has been developped since 2009 at the University of Warsaw. The current prototype is a compact, tablet sized box with on/off button, which connects wirelessly to domotic and EEG acquisition devices. Presented hardware implements a unique design providing dynamic menus and stable delivery of SSVEP stimuli. The generation of stimuli is based upon an array of LEDs backlighting an LCD screen, where arbitrary symbols can be rendered within the designated fields. Each LED is independently driven by a micro-controller, which enables a precise control of its flickering frequency. The same system of fields can be used to deliver stimuli for the P300 based BCI. Software controlling the Appliance is based upon the OpenBCI framewok, developped at the University of Warsaw and released on terms of the GPL (http://openbci.pl). While the framework is multisystem and multilanguage, it is developped mostly in GNU/Linux which allows for a lightweight implementation of "Just Enough Operating System". Using the flexible structure and centralized data flow of the OpenBCI, we implemented universal user interface, which can be operated with SSVEP or P300 BCI, as well as other assistive technologies like switches and eyetrackers, with the possibility of unassisted switching between modalities by the user. It is beneficial for these users whose abilities degrade with time or those who would like to switch between the paradigms to reduce fatigue. Calibration procedures are fully automated, thus there is no need for manual fine-tuning of the parameters. This is due to advanced signal processing for feature extraction like Blind Source Separation, Canonical Correlation Analysis and classifiers based on machine learning algorithms. In this sense the software minimizes the need for a highly train personnel assisting the end-user to operate the Appliance. Keywords: brain machine interface, neuromuscular disorders, Neuroscience, brain computer-interfaces, Hardware Design Conference: 5th INCF Congress of Neuroinformatics, Munich, Germany, 10 Sep - 12 Sep, 2012. Presentation Type: Demo Topic: Neuroinformatics Citation: Spustek T, Kruszyński M, Laszuk D, Milanowski P, Łabęcki M, Augustin K, Duszyk A, Kuś R, Żygierewicz J and Durka P (2014). BCI Appliance. Front. Neuroinform. Conference Abstract: 5th INCF Congress of Neuroinformatics. doi: 10.3389/conf.fninf.2014.08.00051 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 21 Mar 2013; Published Online: 27 Feb 2014. * Correspondence: Dr. Tomasz Spustek, University of Warsaw, Faculty of Physics, ul. Hoza 69, 00-681 Warszawa, Poland, Warsaw, Poland, tspus@fuw.edu.pl Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Tomasz Spustek Mateusz Kruszyński Dawid Laszuk Piotr Milanowski Maciej Łabęcki Karol Augustin Anna Duszyk Rafał Kuś Jarosław Żygierewicz Piotr Durka Google Tomasz Spustek Mateusz Kruszyński Dawid Laszuk Piotr Milanowski Maciej Łabęcki Karol Augustin Anna Duszyk Rafał Kuś Jarosław Żygierewicz Piotr Durka Google Scholar Tomasz Spustek Mateusz Kruszyński Dawid Laszuk Piotr Milanowski Maciej Łabęcki Karol Augustin Anna Duszyk Rafał Kuś Jarosław Żygierewicz Piotr Durka PubMed Tomasz Spustek Mateusz Kruszyński Dawid Laszuk Piotr Milanowski Maciej Łabęcki Karol Augustin Anna Duszyk Rafał Kuś Jarosław Żygierewicz Piotr Durka Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

A Miniaturized Single Channel Amplifier for Various Different Electrophysiology Setup

Different electrophysiology setups allow single ion channel recordings using Lipid Bilayer Membrane (BLM) for protein insertion. Ion channels are transmembrane proteins involved in many biological process of cell life. They are used as target for drug discovery and single-molecule sensors. Synthetic nanopores can also be used as nano-coulter counters and very promising transducers for DNA sequencing. Complex protocols are under investigation to assembly ion channels on reconstituted lipid membranes. They use different setups, ranging from suspended BLM, microfluidic and lab-on-a-chip devices, planar patch clamp, tip-dip method. These studies, combined to new emerging nanopore applications, require high sensitive and high resolution instrumentation, able to detect small currents (in the pA range) over large bandwith (up to 100kHz), providing flexible voltage stimuli generation. We present a compact and complete system for single ion channels and synthetic nanopores experiment, useful for scientists and students for academic purposes, composed by:- a miniaturized low noise single channel voltage-clamp amplifier and digitizer integrated into a single ASIC, with direct connection to a computer USB port;- a software interface for real time data display and analysis featuring flexible voltage stimuli control;- customised electrode interfaces for various different electrophysiology platforms and microfluidic devices.As a proof of concept, we demonstrate the system performances using different test proteins (KcsA, Gramicidin, Alpha-hemolysin) embedded into reconstituted lipid membranes. The acquired data are presented.

Ascorbate Reduces Mouse Platelet Aggregation and Surface P‐Selectin Expression in an Ex Vivo Model of Sepsis

Compromised perfusion of the capillary bed can lead to organ failure and mortality in sepsis. We have reported that intravenous injection of ascorbate inhibits platelet adhesion and plugging in septic capillaries. In this study, we hypothesized that ascorbate reduces aggregation of platelets and their surface expression of P-selectin (a key adhesion molecule) in mice. Platelets were isolated from control mice and subjected to agents known to be released into the bloodstream during sepsis (thrombin, ADP or U46619, thromboxane A2 analog). Platelet aggregation was analyzed by aggregometry and P-selectin expression by flow cytometry. Platelet-activating agents increased aggregation and P-selectin expression. Ascorbate inhibited these increases. This inhibitory effect was NOS-independent (LNAME had no effect). In contrast to the platelet-activating agents, direct stimuli lipopolysaccharide, TNFα, or plasma from septic mice did not increase aggregation/expression, a finding consistent with the literature. The results suggest a complex mechanism of platelet aggregation and P-selectin expression in sepsis, where generation of platelet-activating stimuli is required first, before platelet aggregation and adhesion in capillaries occur. The ability of ascorbate to reduce platelet aggregation and P-selectin expression could be an important mechanism by which ascorbate inhibits capillary plugging in sepsis.

STIMONT: a core ontology for multimedia stimuli description

Affective multimedia documents such as images, sounds or videos elicit emotional responses in exposed human subjects. These stimuli are stored in affective multimedia databases and successfully used for a wide variety of research in psychology and neuroscience in areas related to attention and emotion processing. Although important all affective multimedia databases have numerous deficiencies which impair their applicability. These problems, which are brought forward in the paper, result in low recall and precision of multimedia stimuli retrieval which makes creating emotion elicitation procedures difficult and labor-intensive. To address these issues a new core ontology STIMONT is introduced. The STIMONT is written in OWL-DL formalism and extends W3C EmotionML format with an expressive and formal representation of affective concepts, high-level semantics, stimuli document metadata and the elicited physiology. The advantages of ontology in description of affective multimedia stimuli are demonstrated in a document retrieval experiment and compared against contemporary keyword-based querying methods. Also, a software tool Intelligent Stimulus Generator for retrieval of affective multimedia and construction of stimuli sequences is presented.

Impact on stereo-acuity of two presbyopia correction approaches: monovision and small aperture inlay

Some of the different currently applied approaches that correct presbyopia may reduce stereovision. In this work, stereo-acuity was measured for two methods: (1) monovision and (2) small aperture inlay in one eye. When performing the experiment, a prototype of a binocular adaptive optics vision analyzer was employed. The system allowed simultaneous measurement and manipulation of the optics in both eyes of a subject. The apparatus incorporated two programmable spatial light modulators: one phase-only device using liquid crystal on silicon technology for wavefront manipulation and one intensity modulator for controlling the exit pupils. The prototype was also equipped with a stimulus generator for creating retinal disparity based on two micro-displays. The three-needle test was programmed for characterizing stereo-acuity. Subjects underwent a two-alternative forced-choice test. The following cases were tested for the stimulus placed at distance: (a) natural vision; (b) 1.5 D monovision; (c) 0.75 D monovision; (d) natural vision and small pupil; (e) 0.75 D monovision and small pupil. In all cases the standard pupil diameter was 4 mm and the small pupil diameter was 1.6 mm. The use of a small aperture significantly reduced the negative impact of monovision on stereopsis. The results of the experiment suggest that combining micro-monovision with a small aperture, which is currently being implemented as a corneal inlay, can yield values of stereoacuity close to those attained under normal binocular vision.

Basics and applications of psychoacoustics

The field of psychoacoustics studies relations between acoustic stimuli, defined in the physical domain, and the hearing sensations elicited by these stimuli. The plenary lecture will address questions of stimulus generation and presentation. Both traditional methods and more recent methods like wave field synthesis will be touched. Concerning hearing sensations, basic magnitudes as for example absolute thresholds or loudness, but also advanced topics like pitch strength will be covered. Applications of psychoacoustics will include rather different fields such as music, noise evaluation or audiology, and address also cognitive effects as well as audio-visual interactions.

Proper Metrological Methodologies to Avoid Severe Systematic Errors When Characterizing High-Power IGBTs on the Installation Field: An Introduction

The exigency of characterizing high-power insulated-gate bipolar transistors (IGBTs) directly on-site increasingly emerges in field installations hosting multilevel converters that employ such devices by the dozen, when not by hundreds, as it is already the reality for modern modular voltage-source HVDC and flexible ac transmission systems (FACTS). Nonetheless, differently from the actualities in permanent laboratories, the typology of the instrumentation rapidly obtainable on the field is often rather restricted by the aspects of logistic, necessary timing of intervention, and ruggedness against the usually harsh environments. Commonly, the only specimens realistically expectable at short notice on a field installation are portable curve tracers (CTs), portable field oscilloscopes with nonisolated channels, passive voltage probes, current probes based on Rogowski coils, portable multimeters, and variable dc power supplies. This paper describes metrological methodologies devised to diagnose and characterize high-power IGBTs by employing solely such a limited set of instruments. The severely erroneous conclusions that possibly descend from the utilization of CTs only are highlighted, both by experiments and by a dynamic model deduced from the nature of the specific metrological context. It is shown how the additional presence of properly connected oscilloscopes and probes becomes mandatory in order to attain a proper characterization. The role of the CTs should be strictly limited to mere stimuli generators only, also because their compensation techniques against the systematic measurement errors occurring with signal and low-power transistors rarely suffice in the case of high-power devices. Additionally, the equivalent differential capacitance between the collector and emitter terminals of a high-power IGBT-diode module is characterized too. It is often insufficiently documented in the datasheets, although its values and evolution are important for the dynamics of the commutation. Experimental observations from an ABB 5SNA 1200G450300 IGBT module (4.5 kV and 1.2 kA) are discussed throughout the different sections in order to elucidate the details of the presented methodologies.