MATLAB-based Program Research Articles

Testing and validation of wide‐area control of STATCOM using real‐time digital simulator with hybrid HIL–SIL configuration

This study presents a novel interfacing setup for testing and validating wide-area monitoring and control (WAMC) techniques used in smart grids. The main purpose of this study is to provide a realistic approach for conducting WAMC studies. In here, a wide-area controller (WAC) for a flexible AC transmission system (FACTS) device is implemented. The measurements for the WAC are collected using phasor measurements units (PMUs). Three main segments are being interfaced in this study. First, the real-power grid, the local area controller of the actual FACTS device, and the PMUs are simulated using real-time digital simulator. This simulation represents the central simulation and is interfaced with the WAC, which is realised using a MATLAB-based program. This interface represents a novel software-in-the-loop (SIL) scheme. On the other hand, an actual FACTS device is designed and interfaced to the central simulation via hardware-in-the-loop (HIL) scheme. This SIL and HIL combination makes the experimental testbed more realistic and closer to the industrial standard. Various tests are conducted to examine the performance of the developed testbed.

A HOLISTIC METHOD TO SELECT TIDAL STREAM ENERGY HOTSPOTS

Potential areas for tidal stream energy development are conventionally selected on the basis of resource assessments. For all the importance of the resource, there are other elements (technological, economic, spatial, etc.) that must be taken into account in this selection. The objective of the present work is to develop a new methodology to select tidal stream hotspots accounting for all these relevant elements, and to apply it to a case study, showing in the process how the potential for tidal energy development can be fundamentally altered by technological, economic and spatial constraints. The case study is conducted in the Bristol Channel and Severn Estuary (UK), one of the regions with the largest tidal resource in the world. First, the most energetic areas are identified by means of a hydrodynamics model, calibrated and validated with field data. Second, the method calculates the energy that can be harnessed in these areas by means of a geospatial Matlab-based program designed ad hoc, and on the basis of the power curve and dimensions of a specific tidal turbine. Third, the spatial distribution of the levelised cost of energy (LCOE) is calculated, and a number of locations are selected as potential tidal sites. The fourth element in the approach is the consideration of restrictions due to overlap with other marine uses, such as shipping. As a result, potential conflict-free areas for tidal stream energy exploitation at an economical cost are identified. Thus, the case study illustrates this holistic approach to selecting tidal stream sites and the importance of elements other than the resource, which – for all its relevance – is shown to not guarantee by itself the potential for tidal stream energy development.

The COOLER Code: A Novel Analytical Approach to Calculate Subcellular Energy Deposition by Internal Electron Emitters.

COmputation Of Local Electron Release (COOLER), a software program has been designed for dosimetry assessment at the cellular/subcellular scale, with a given distribution of administered low-energy electron-emitting radionuclides in cellular compartments, which remains a critical step in risk/benefit analysis for advancements in internal radiotherapy. The software is intended to overcome the main limitations of the medical internal radiation dose (MIRD) formalism for calculations of cellular S-values (i.e., dose to a target region in the cell per decay in a given source region), namely, the use of the continuous slowing down approximation (CSDA) and the assumption of a spherical cell geometry. To this aim, we developed an analytical approach, entrusted to a MATLAB-based program, using as input simulated data for electron spatial energy deposition directly derived from full Monte Carlo track structure calculations with PARTRAC. Results from PARTRAC calculations on electron range, stopping power and residual energy versus traveled distance curves are presented and, when useful for implementation in COOLER, analytical fit functions are given. Example configurations for cells in different culture conditions (V79 cells in suspension or adherent culture) with realistic geometrical parameters are implemented for use in the tool. Finally, cellular S-value predictions by the newly developed code are presented for different cellular geometries and activity distributions (uniform activity in the nucleus, in the entire cell or on the cell surface), validated against full Monte Carlo calculations with PARTRAC, and compared to MIRD standards, as well as results based on different track structure calculations (Geant4-DNA). The largest discrepancies between COOLER and MIRD predictions were generally found for electrons between 25 and 30 keV, where the magnitude of disagreement in S-values can vary from 50 to 100%, depending on the activity distribution. In calculations for activity distribution on the cell surface, MIRD predictions appeared to fail the most. The proposed method is suitable for Auger-cascade electrons, but can be extended to any energy of interest and to beta spectra; as an example, the 3H case is also discussed. COOLER is intended to be accessible to everyone (preclinical and clinical researchers included), and may provide important information for the selection of radionuclides, the interpretation of radiobiological or preclinical results, and the general establishment of doses in any scenario, e.g., with cultured cells in the laboratory or with therapeutic or diagnostic applications. The software will be made available for download from the DTU-Nutech website: http://www.nutech.dtu.dk/ .

A Matlab-Based Program for the Design And Simulation of Wet Cooling Towers

Computer based programs for education in chemical engineering has become an essential component to complete the program educational objectives and reach the student outcomes. There is a long list of chemical process simulators used as complement to traditional courses on process modeling, however, the field of chemical engineering cover a broad range of areas that make difficult the creation of a robust program that involve all the courses mainly the unit operations which is the heart of this discipline. The experience with these courses shows that there is still need for enhancement when trying to transfer the theoretic knowledge to computational trainings. In order to follow this line of transferring knowledge it is presented a registered application of a GUI in Matlab called CTw-UA v1.0 focused in humidification for the design of cooling towers, using the mass transfer fundamental equations for the design of cooling towers presented in highly relevant documents and popular academic books with some empirical information of different packings used in the industry. The operating conditions set by the user are the inlet and outlet temperatures of the liquid, the liquid flow, the dry and wet bulb temperatures of the inlet air, the type of packing and the relation (L/Gmin), and the outputs in the program are the number of decks of the packings, the efficiency of the tower, the air flow, the temperature profile of the air along the tower plotting the Mickley diagram, and the column dimensions, height and diameter. It was obtained the effect of the packing and inlet air conditions in the dimension of the tower, the variation of the height of the tower as a function of the outlet and inlet liquid temperatures for different packings and the variation of the efficiency and height of the tower as a function of the outlet liquid temperature. The software, which was accepted very well by a population of 90 students, was evaluated statistically in terms of clarity, precision and relevance with the application of a t test with a significance level of 5%.

A summary of light dose distribution using an IR navigation system for Photofrin-mediated Pleural PDT.

Uniform delivery of light fluence is an important goal for photodynamic therapy. We present summary results for an infrared (IR) navigation system to deliver light dose uniformly during intracavitory PDT by tracking the movement of the light source and providing real-time feedback on the light fluence rate on the entire cavity surface area. In the current intrapleural PDT protocol, 8 detectors placed in selected locations in the pleural cavity monitor the light doses. To improve the delivery of light dose uniformity, an IR camera system is used to track the motion of the light source as well as the surface contour of the pleural cavity. A MATLAB-based GUI program is developed to display the light dose in real-time during PDT to guide the PDT treatment delivery to improve the uniformity of the light dose. A dualcorrection algorithm is used to improve the agreement between calculations and in-situ measurements. A comprehensive analysis of the distribution of light fluence during PDT is presented in both phantom conditions and in clinical cases.

Retooling Laser Speckle Contrast Analysis Algorithm to Enhance Non-Invasive High Resolution Laser Speckle Functional Imaging of Cutaneous Microcirculation

Cutaneous microvasculopathy complicates wound healing. Functional assessment of gated individual dermal microvessels is therefore of outstanding interest. Functional performance of laser speckle contrast imaging (LSCI) systems is compromised by motion artefacts. To address such weakness, post-processing of stacked images is reported. We report the first post-processing of binary raw data from a high-resolution LSCI camera. Sharp images of low-flowing microvessels were enabled by introducing inverse variance in conjunction with speckle contrast in Matlab-based program code. Extended moving window averaging enhanced signal-to-noise ratio. Functional quantitative study of blood flow kinetics was performed on single gated microvessels using a free hand tool. Based on detection of flow in low-flow microvessels, a new sharp contrast image was derived. Thus, this work presents the first distinct image with quantitative microperfusion data from gated human foot microvasculature. This versatile platform is applicable to study a wide range of tissue systems including fine vascular network in murine brain without craniotomy as well as that in the murine dorsal skin. Importantly, the algorithm reported herein is hardware agnostic and is capable of post-processing binary raw data from any camera source to improve the sensitivity of functional flow data above and beyond standard limits of the optical system.

Demand-Based Optimal Design of Storage Tank with Inerter System

A parameter optimal design method for a tank with an inerter system is proposed in this study based on the requirements of tank vibration control to improve the effectiveness and efficiency of vibration control. Moreover, a response indicator and a cost control indicator are selected based on the control targets for liquid storage tanks for simultaneously minimizing the dynamic response and controlling costs. These indicators are reformulated through a random vibration analysis under virtual excitation. The problem is then transformed from a multiobjective optimization problem to a single-objective nonlinear problem using the ε-constraint method, which is consistent with the demand-based method. White noise excitation can be used to design the tank with the inerter system under seismic excitation to simplify the calculation. Subsequently, a MATLAB-based calculation program is compiled, and several optimization cases are examined under different excitation conditions. The effectiveness of the demand-based method is proven through a time history analysis. The results show that specific vibration control requirements can be met at the lowest cost with a simultaneous reduction in base shears and overturning base moments.

Effect of Kinetic Parameters on I-129 Activity from Fuel to Coolant in PWRs

Effect of kinetic model parameters on fission product (I-129) activity from fuel to coolant in PWRs has been studied in this work. First a computational model was developed for fission product release into primary coolant using ORIGEN-2 as subroutine. The model is based on set of differential equations of kinetic model which includes fuel-to-gap release model, gap-to-coolant leakage model, and Booths diffusion model. A Matlab based computer program FPAPC (Fission Product Activity in Primary Coolant) was developed. Variations of I-129 activity in Primary Heat Transport System were computed and computed values of i-129 were found in good agreement and deviations were within 2% - 3% of already published data values. Finally, the effects of coolant purification rate, diffusion constant and gas escape rate on I-129 activity were studied and results indicated that the coolant purification rate is the most sensitive parameter for fission product activity in primary circuit. For changes of 5% in steps from −10% to +10% in the coolant purification rate constant (Β), the activity variation after 200 days of reactor operation was 23.1% for the change.

Computing distance distributions from dipolar evolution data with overtones: RIDME spectroscopy with Gd(iii)-based spin labels.

Extraction of distance distributions between high-spin paramagnetic centers from relaxation induced dipolar modulation enhancement (RIDME) data is affected by the presence of overtones of dipolar frequencies. As previously proposed, we account for these overtones by using a modified kernel function in Tikhonov regularization analysis. This paper analyzes the performance of such an approach on a series of model compounds with the Gd(iii)-PyMTA complex serving as paramagnetic high-spin label. We describe the calibration of the overtone coefficients for the RIDME kernel, demonstrate the accuracy of distance distributions obtained with this approach, and show that for our series of Gd-rulers RIDME technique provides more accurate distance distributions than Gd(iii)-Gd(iii) double electron-electron resonance (DEER). The analysis of RIDME data including harmonic overtones can be performed using the MATLAB-based program OvertoneAnalysis, which is available as open-source software from the web page of ETH Zurich. This approach opens a perspective for the routine use of the RIDME technique with high-spin labels in structural biology and structural studies of other soft matter.

Seismic Optimum Design of Steel Structures Using Gradient-Based and Genetic Algorithm Methods

Optimum design of structures under time-variable loadings is a difficult task. Time-dependent behavior of constraints and cost of gradients calculations could be mentioned when applying time history loadings in the optimization problems. To overcome these difficulties, the response spectra as a seismic demand are used instead of using time history acceleration in the structural modeling. In this paper, the P-Delta effects are considered in the finite-element modeling of the frames. Furthermore, many practical constraints are included in the optimization formulation according to the Iranian national building code (Standard N. 2800). The developed MATLAB-based computer program is utilized for optimization of the low, intermediate- and relatively high-rise braced and un-braced steel frames. The obtained results of sequential quadratic programing (SQP) method are compared with the results of genetic algorithm (GA) technique for guarantying the global optimal designs. Because of the inexpensive costs of SQP method in comparison with genetic algorithm technique, SQP method could be confidently applied for obtaining the global optimum designs of the steel frames.

Crystal Identification in Dual-Layer-Offset DOI-PET Detectors Using Stratified Peak Tracking Based on SVD and Mean-Shift Algorithm

An Anger-logic based pixelated PET detector block requires a crystal position map (CPM) to assign the position of each detected event to a most probable crystal index. Accurate assignments are crucial to PET imaging performance. In this paper, we present a novel automatic approach to generate the CPMs for dual-layer offset (DLO) PET detectors using a stratified peak tracking method. In which, the top and bottom layers are distinguished by their intensity difference and the peaks of the top and bottom layers are tracked based on a singular value decomposition (SVD) and mean-shift algorithm in succession. The CPM is created by classifying each pixel to its nearest peak and assigning the pixel with the crystal index of that peak. A Matlab-based graphical user interface program was developed including the automatic algorithm and a manual interaction procedure. The algorithm was tested for three DLO PET detector blocks. Results show that the proposed method exhibits good performance as well as robustness for all the three blocks. Compared to the existing methods, our approach can directly distinguish the layer and crystal indices using the information of intensity and offset grid pattern.

A multi-year time series of marine mammal distribution in the Alaskan Arctic

The Marine Mammal Laboratory has deployed long-term, moored, passive acoustic recorders at numerous locations in the Alaskan Arctic since the BOEM-funded Chukchi Acoustics, Oceanography, and Zooplankton (CHAOZ) study began in 2010. These instruments, often collocated with oceanographic instruments, collect year-round passive acoustic data (16 kHz sampling rate, ~30% duty cycle). All acoustic recordings (100%) were analyzed using an in-house Matlab-based manual analysis program for 12 different Arctic and sub-Arctic cetacean and pinniped species, as well as for vessel, seismic airgun, and ice noise. Bowhead and beluga distributions showed similar patterns, with bimodal temporal distributions representing the fall and spring migrations. Infrequent gray whale detections (isolated on nearshore recorders) followed a similar, albeit less defined, bimodal distribution. Walrus and bearded seal calls were detected almost year-round, with peak bearded seal calling from April through June. Detections of sub-Arctic s...

Development of 3D biological effective dose distribution software program

AbstractPurposeTo develop a software program to convert physical dose distribution into biological effective dose (BED).MethodsThe MATLAB-based BED distribution software program was designed to import the radiotherapy treatment plan from the computer treatment planning system and to convert the physical dose distribution into the BED distribution. The BED calculation was based on the linear-quadratic-linear model (LQ-L model). Besides radiobiological parameters, other specific data could be fed in through the panel. The accuracy of the program was verified by comparing the BED distribution with manual calculation.ResultsThis software program was able to import the radiotherapy treatment plans and pull out pixel-wised physical dose for BED calculation, and display the isoBED lines on the computed tomographic (CT) image. The verification of BED dose distribution was performed in both phantom and clinical cases. It revealed that there were no differences between the program and manual BED calculations.ConclusionIt is feasible and practical to use this in-house BED distribution software program in clinical practices and research work. However, it should be used with caution as the validity of the program depends on the accuracy of the published biological parameters.

CTM4DOC: electronic structure analysis from X-ray spectroscopy.

Two electronic structure descriptions, one based on orbitals and the other based on term symbols, have been implemented in a new Matlab-based program, CTM4DOC. The program includes a graphical user interface that allows the user to explore the dependence of details of electronic structure in transition metal systems, both in the ground and core-hole excited states, on intra-atomic electron-electron, crystal-field and charge-transfer interactions. The program can also track the evolution of electronic structure features as the crystal-field parameters are systematically varied, generating Tanabe-Sugano-type diagrams. Examples on first-row transition metal systems are presented and the implications on the interpretation of X-ray spectra and on the understanding of low-spin, high-spin and mixed-spin systems are discussed.

Dynamic assessment of partially damaged historic masonry bridges under blast-induced ground motion using multi-point shock spectrum method

We studied the partial damage effects on historic masonry bridges exposed to blast-induced ground motion. For this purpose, a historic masonry bridge in Turkey was selected to estimate its shock spectral behaviour. In order to determine these results, first, various damage was created on the restored bridge finite element model. This damage was generally selected by searching for damaged historic masonry bridges in the literature. Various critical regions on an example bridge were detected and corresponding regions were removed from the restored finite element model. Thus, partially damaged historic masonry bridge models were obtained. Dynamic calculations of the bridge are presented by using the multi-point shock response spectrum method obtained from ground motions due to a blast load. Acceleration time histories of blast-induced ground motions are obtained depending on a deterministic shape function and a stationary process. Shock response spectra determined from ground shock time histories are simulated using a MATLAB-based BlastGM computer program developed by us. The frequency-varying shock response spectra are applied to each support of the two-span historic masonry bridge. The influences of various charge weights and distances from the charge centre are also investigated in the analyses. The results from the analyses demonstrate the importance of partial damage on the historic masonry bridge, blast-induced ground motion effects, and charge weight and distance from the blast centre.

High resolution melting curve analysis with MATLAB-based program

High resolution melting curve analysis (HRM) is an emerging new method for interrogating and characterizing DNA samples. It has been used as a powerful tool for gene mutation and single-nucleotide polymorphism (SNP) detection with high throughput and low cost. Commercially available HRM analysis systems are mostly proprietary and expensive. It lacks the flexibility for the end users and researchers to incorporate new analysis algorithms into the existing system. This paper presents the development of a MATLAB-based open software program for high resolution melting curve analysis. Key analysis functions, such as to obtain the first derivative curve using Savitzky–Golay filter, to identify the melt region, subtraction of background fluorescence and curve normalization, are introduced, followed by case studies of HRM analysis using the developed software program.

A holistic method for selecting tidal stream energy hotspots under technical, economic and functional constraints

Although a number of prospective locations for tidal stream farms have been identified, the development of a unified approach for selecting the optimum site in a region remains a current research topic. The objective of this work is to develop and apply a methodology for determining the most suitable sites for tidal stream farms, i.e. sites whose characteristics maximise power performance, minimise cost and avoid conflicts with competing uses of the marine space. Illustrated through a case study in the Bristol Channel, the method uses a validated hydrodynamics model to identify highly energetic areas and a geospatial Matlab-based program (designed ad hoc) to estimate the energy output that a tidal farm at the site with a given technology would have. This output is then used to obtain the spatial distribution of the levelised cost of energy and, on this basis, to preselect certain areas. Subsequently, potential conflicts with other functions of the marine space (e.g. fishing, shipping) are considered. The result is a selection of areas for tidal stream energy development based on a holistic approach, encompassing the relevant technical, economic and functional aspects. This methodology can lead to a significant improvement in the selection of tidal sites, thereby increasing the possibilities of project acceptance and development.

Microscopic Study of Wax Precipitation—Static Conditions

The scalability of available wax deposition models is still limited, partly due to the lack of mechanistic understanding on the wax deposition processes. In an attempt to enhance the understanding of wax deposition physical mechanisms, a systematic microscopic visualization experimental program is necessary. The static microscopic tests are performed with 100× magnification under controlled cooling rate conditions. An in-house MATLAB-based program is developed to enable measurements of morphological features such as size and aspect ratio. The two-dimensional (2-D) aspect ratio distribution of the crystals resembles a log-normal pattern with a mode of 2–3. Moreover, the 2-D size distribution of the crystals resembles an exponential decay pattern with a mode of 20–40 μm2. These tests also showed that there is no significant change in crystal aspect ratio during isothermal conditions over 48 h. In addition, it is also observed that the wax crystal precipitation rate is dependent on the cooling rate owing to ...

DetectMITE: A novel approach to detect miniature inverted repeat transposable elements in genomes.

Miniature inverted repeat transposable elements (MITEs) are prevalent in eukaryotic genomes, including plants and animals. Classified as a type of non-autonomous DNA transposable elements, they play important roles in genome organization and evolution. Comprehensive and accurate genome-wide detection of MITEs in various eukaryotic genomes can improve our understanding of their origins, transposition processes, regulatory mechanisms, and biological relevance with regard to gene structures, expression, and regulation. In this paper, we present a new MATLAB-based program called detectMITE that employs a novel numeric calculation algorithm to replace conventional string matching algorithms in MITE detection, adopts the Lempel-Ziv complexity algorithm to filter out MITE candidates with low complexity, and utilizes the powerful clustering program CD-HIT to cluster similar MITEs into MITE families. Using the rice genome as test data, we found that detectMITE can more accurately, comprehensively, and efficiently detect MITEs on a genome-wide scale than other popular MITE detection tools. Through comparison with the potential MITEs annotated in Repbase, the widely used eukaryotic repeat database, detectMITE has been shown to find known and novel MITEs with a complete structure and full-length copies in the genome. detectMITE is an open source tool (https://sourceforge.net/projects/detectmite).

Using texture analyses of contrast enhanced CT to assess hepatic fibrosis

PurposeTo determine the ability of texture analyses of contrast-enhanced CT images for distinguishing between varying degrees of hepatic fibrosis in patients with chronic liver disease using histopathology as the reference standard. Materials and methodsFollowing IRB approval, 83 patients who underwent contrast enhanced 64-MDCT of the abdomen and pelvis in the portal venous phase between 12/2005 and 01/2013 and who had a liver biopsy within 6 months of the CT were included. An in-house developed, MATLAB-based texture analysis program was employed to extract 41 texture features from each of 5 axial segmented volumes of liver. Using the Ishak fibrosis staging scale, histopathologic grades of hepatic fibrosis were correlated with texture parameters after stratifying patients into three analysis groups, comparing Ishak scales 0–2 with 3–6, 0–3 with 4–6, and 0–4 with 5–6. To assess the utility of texture features, receiver operating characteristic (ROC) curves were constructed and the area under the curve (AUC) was used to determine the performance of each feature in distinguishing between normal/low and higher grades of hepatic fibrosis. ResultsA total of 19 different texture features with 7 histogram features, one grey level co-occurrence matrix, 6 gray level run length, 1 Laws feature, and 4 gray level gradient matrix demonstrated statistically significant differences for discriminating between fibrosis groupings. The highest AUC values fell in the range of fair performance for distinguishing between different fibrosis groupings. ConclusionThese findings suggest that texture-based analyses of contrast-enhanced CT images offer a potential avenue toward the non-invasive assessment of liver fibrosis.