ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0318.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: efficient binary symbiotic; feature selection; classification; optimization
Online: 26 January 2020 (08:30:17 CET)
Feature selection is one of the main data preprocessing steps in machine learning. Its goal is to reduce the number of features by removing extra and noisy features. Feature selection methods must consider the accuracy of classification algorithms while performing feature reduction on a dataset. Meta-heuristic algorithms are the most successful and promising methods for solving this issue. The symbiotic organisms search algorithm is one of the successful meta-heuristic algorithms which is inspired by the interaction of organisms in the nature called Parasitism Commensalism Mutualism. In this paper, three engulfing binary methods based on the symbiotic organisms search algorithm are presented for solving the feature selection problem. In the first and second methods, several S-shaped and V-shaped transfer functions are used for binarizing the symbiotic organisms search algorithm, respectively. These methods are called BSOSS and BSOSV. In the third method, two new operators called BMP and BCP are presented for binarizing the symbiotic organisms search algorithm. This method is called EBSOS. The third approach presents an advanced binary version of the coexistence search algorithm with two new operators, BMP and BCP, to solve the feature selection problem, named EBSOS. The proposed methods are run on 18 standard UCI datasets and compared to base and important meta-heuristic algorithms. The test results show that the EBSOS method has the best performance among the three proposed approaches for binarization of the coexistence search algorithm. Finally, the proposed EBSOS approach was compared to other meta-heuristic methods including the genetic algorithm, binary bat algorithm, binary particle swarm algorithm, binary flower pollination algorithm, binary grey wolf algorithm, binary dragonfly algorithm, and binary chaotic crow search algorithm. The results of different experiments showed that the proposed EBSOS approach has better performance compared to other methods in terms of feature count and accuracy criteria. Furthermore, the proposed EBSOS approach was practically evaluated on spam email detection in particular. The results of this experiment also verified the performance of the proposed EBSOS approach. In addition, the proposed EBSOS approach is particularly combined with the classifiers including SVM, KNN, NB and MLP to evaluate this method performance in the detection of spam emails. The obtained results showed that the proposed EBSOS approach has significantly improved the accuracy and speed of all the classifiers in spam email detection.
ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0317.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: multi agent systems; high-dimensional; optimization; email spam; metaheuristic algorithms
Online: 26 January 2020 (08:25:07 CET)
There exist numerous high-dimensional problems in the real world which cannot be solved through the common traditional methods. The metaheuristic algorithms have been developed as successful techniques for solving a variety of complex and difficult optimization problems. Notwithstanding their advantages, these algorithms may turn out to have weak points such as lower population diversity and lower convergence rate when facing complex high-dimensional problems. An appropriate approach to solve such problems is to apply multi-agent systems along with the metaheuristic algorithms. The present paper proposes a new approach based on the multi-agent systems and the concept of agent, which is named Multi-Agent Metaheuristic (MAMH) method. In the proposed approach, several basic and powerful metaheuristic algorithms, including Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Artificial Bee Colony (ABC), Firefly Algorithm (FA), Bat Algorithm (BA), Flower Pollination Algorithm (FPA), Gray Wolf Optimizer (GWO), Whale Optimization Algorithm (WOA), Crow Search Algorithm (CSA), Farmland Fertility Algorithm (FFA), are considered as separate agents each of which sought to achieve its own goals while competing and cooperating with others to achieve the common goals. In overall, the proposed method was tested on 32 complex benchmark functions, the results of which indicated effectiveness and powerfulness of the proposed method for solving the high-dimensional optimization problems. In addition, in this paper, the binary version of the proposed approach, called Binary MAMH (BMAMH), was executed on the spam email dataset. According to the results, the proposed method exhibited a higher precision in detection of the spam emails compared to other metaheuristic algorithms and methods.
ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0316.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: Unmanned Aerial Systems (UASs); UAV; Sinkhole attack; IDS; routing security
Online: 26 January 2020 (08:16:08 CET)
Unmanned aerial systems (UASs) create an extensive fighting capability of the developed military forces. Particularly, these systems carrying confidential data are exposed to security attacks. By the wireless’s nature within these networks, they become susceptible to different kinds of attacks, hence, it seems essential to design the appropriate safety mechanism in such networks. The sinkhole attack is one of the most dangerous and threatening attacks amongst types of attack in UAS. A malicious UAV exists in such a threat attacking as a black hole for absorbing all traffic in the network. Mainly, in a Flow-based protocol, the attacker considers the requests on the route, then, it replies to the target UAV such as high quality or the best route towards Gard station. The malicious UAV is able to only insert itself on one occasion between the nodes relating to each other (such as sink node and sensor node), and act for passing packets among them. In this study, the malicious attacks are detected and purged using two stages were. In the first stage, some principles and rules are used to detect black hole, gray hole, and sinkhole attacks. In the second stage, using a smart agent-based strategy negotiation procedure for three steps, a defense mechanism is designed to prevent these attacks. The smart agent is used by reliable neighbors via the negotiation procedure for three steps, hence, the traffic formed by the malicious UAV is not considered. The suggested protocol is called SAUAS. Here, the technique is assessed through extensive simulations performed in the NS-3 environment. Based on the simulation outcomes, it is indicated that the UAS network performance metrics are enhanced based on the packet delivery rate, detection rate, false-negative rate and false-positive rate.
REVIEW Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0315.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: succinic semialdehyde dehydrogenase deficiency; gamma-amino butyric acid; organic acidurias; enzyme replacement therapy; pharmacological chaperones; clinical trials; autophagy
Online: 26 January 2020 (08:10:19 CET)
Succinic semialdehyde dehydrogenase deficiency (SSADH-D) is a genetic disorder that results from the aberrant metabolism of the neurotransmitter γ-amino butyric acid (GABA). The disease is caused by the impaired activity of the mitochondrial enzyme succinic semialdehyde dehydrogenase. SSADH-D manifests as varying degree of mental retardation, autism, ataxia and epileptic seizures, but the clinical picture is highly heterogeneous. So far, there is no approved therapy for this disease. In this review, we briefly summarize the molecular genetics of SSADH-D, the past and ongoing clinical trials and the emerging features of the molecular pathogenesis, including redox imbalance and mitochondrial dysfunction. The main aim of this review is to discuss the potential use of further therapy approaches that have so far not been tested in SSADH-D, such as pharmacological chaperones, read-through drugs and gene therapy. Special attention will also be paid to elucidating the role of patient advocacy organizations in facilitating research and in the communication between the researchers and the patients.
ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0314.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: kidney tumor; renal tumor; Unet3D; Unet+ResNet; Unet++ segmentation
Online: 26 January 2020 (08:04:01 CET)
Worldwide, hundreds of thousands of people are diagnosed with kidney cancer and this disease is more common in developed and industrialized countries. Previously, kidney cancer was known as an elderly disease and was seen in people over a certain age; nowadays it is also seen in younger individuals and it is easier to diagnose thanks to new radiological diagnostic methods. A kidney tumor is a type of cancer that is extremely aggressive and needs surgical treatment rapidly. Today, approximately 30% of patients diagnosed with kidney cancer are unfortunately noticed at the stage of metastatic disease (spread to distant organs). The biggest factor that pushes us to this study is that kidney tumors progress unlike other cancer types with little or no symptoms. Therefore, conducting such studies is extremely important for early diagnosis. In this study, we compare the Unet3D models in order to help people who are dealing with difficulties in the diagnosis of kidney cancer. Unet, Unet+ResNet and Unet++ models were compared for image segmentation.
ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0313.v1
Subject: Engineering, Civil Engineering Keywords: discharge coefficient; soft computing; machine learning; Weir; sensitivity analysis; nonlinear regression
Online: 26 January 2020 (07:55:15 CET)
This paper proposes a model based on gene expression programming for predicting discharge coefficient of triangular labyrinth weirs. The parameters influencing discharge coefficient prediction were first examined and presented as crest height ratio to the head over the crest of the weir (p/y), crest length of water to channel width (L/W), crest length of water to the head over the crest of the weir (L/y), Froude number (F=V/√(gy)) and vertex angle () dimensionless parameters. Different models were then presented using sensitivity analysis in order to examine each of the dimensionless parameters presented in this study. In addition, an equation was presented through the use of nonlinear regression (NLR) for the purpose of comparison with GEP. The results of the studies conducted by using different statistical indexes indicated that GEP is more capable than NLR. This is to the extent that GEP predicts the discharge coefficient with an average relative error of approximately 2.5% in such a manner that the predicted values have less than 5% relative error in the worst model.
ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0312.v1
Subject: Keywords: ANFIS Genetic algorithm (GA); Singular Value Decomposition (SVD); bedload; machine learning; sediment transport; sensitivity analysis
Online: 26 January 2020 (07:48:52 CET)
Densimetric Froude (Fr) is the minimum velocity required to prevent sediment deposition in pipes. Prediction of Fr is of utmost importance in numerous applications in civil engineering. In this paper through using a new hybrid method. Genetic Algorithm (GA) is used for optimum selection of membership functions of Adaptive Neuro-Fuzzy Inference System (ANFIS), and Singular Value Decomposition (SVD) method is used to compute the linear parameters of ANFIS’s results section (ANFIS-GA/SVD). Also, two different target functions are known as training error (TE) and prediction error (PE) by Pareto curve, the trade-off between these functions is selected as the optimal modeling point. First, different models will be presented using the parameters affecting Fr prediction, classifying them in different groups; then the Fr parameter will be predicted for all the different models through utilizing three different sets of data and the ANFIS-GA/SVD technique. The results of the models indicate that the best Fr prediction is obtained when independent parameters such as volumetric sediment concentration (CV), ratio of median diameter of particle size to pipe diameter (d/D), ratio of median diameter of particle size to hydraulic radius (d/R) and overall friction factor of sediment (λs) use as input variables in prediction of Fr. A sensitivity analysis is also conducted for the purpose of examining the effect of each of the dimensionless parameters on Fr prediction accuracy. Comparing the results of the suggested models with the existing regression-based equations shows that ANFIS-GA/SVD (R2=0.986, MAPE=4.397, RMSE=0.206, SI=0.053, ρ=0.026, BIAS=-0.025) is more accurate than the rest of the models.
TECHNICAL NOTE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0311.v1
Subject: Engineering, Marine Engineering Keywords: vessel cargo holds; tank washing; gas-freeing; aerating; atmosphere composition; assessment of safe atmosphere
Online: 26 January 2020 (07:43:21 CET)
Paper discussed the problem of proper process of gas-freeing and ventilation of vessel cargo tank after washing process in aim to the entrance into the tank and its inspection. Correct assessment of atmosphere composition into the cargo tank is a basic condition of safe entrance and work of a crew. It should be done following actions: assessment of flammability hazard, the presence of other toxic gases for human and oxygen concentration. In the aim ship-owner should prepare adequate procedures: before entrance, during work and on emergency situations. On a vessel the assessment performs responsibility (entitled) officer whose decisions are crucial for the safety of prosecuting operations. The one of primary problem is proper (adequate) assessment of oxygen concentration in the air into the tank (enclosed spaces) after the measurement which should be properly interpreted. It concerns basically such situations when the oxygen concentration into the tank after measure leads the value over 22% or below 20.6% of volume (mole) contribution (v/v).
ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0310.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: mathematical modeling; characteristic points; extreme pressure; hydraulic jump; pressure fluctuations; standard deviation; stilling basin
Online: 26 January 2020 (07:32:50 CET)
Pressure fluctuations beneath hydraulic jumps downstream of Ogee spillways potentially damage stilling basin beds. This paper deals with the extreme pressures underneath free hydraulic jumps along a smooth stilling basin. The experiments were conducted in a laboratory flume. From the probability distribution of measured instantaneous pressures, the pressures with different non-exceedance probabilities (P*a%) could be determined. It was verified that the maximum pressure fluctuations, as well as the negative pressures, are located at the positions closest to the spillway toe. The minimum pressure fluctuations are located at the downstream of hydraulic jumps. It was possible to assess the cumulative curves of P*a% related to the characteristic points along the basin, and different Froude numbers. To benchmark, the results, the dimensionless forms of mean pressures, standard deviations, and pressures with different non-exceedance probabilities were assessed. It was found that an existing methodology can be used to interpret the present data, and pressure distribution in similar conditions, by using a new third-order polynomial relationship for the standard deviation (σ*X) with the determination coefficient (R2) equal to 0.717. It was verified that the new optimized adjustment gives more accurate results for the estimation of the maximum extreme pressures than the minimum extreme pressures.
ARTICLE Download: 0| View: 0| Comments: 0 | doi:10.20944/preprints202001.0309.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: feature selection; hybrid optimization; Whale Optimization Algorithm; Flower Pollination Algorithm; classification; Opposition Based Learning; Email Spam Detection
Online: 26 January 2020 (07:07:23 CET)
Feature Selection (FS) in data mining is one of the most challenging and most important activities in pattern recognition. The problem of choosing a feature is to find the most important subset of the main attributes in a specific domain, and its main purpose is removing additional or unrelated features, and ultimately improving the accuracy of the classification algorithms. As a result, the problem of FS can be considered as an optimization problem, and use metaheuristic algorithms to solve it. In this paper, a new hybrid model combining whale optimization algorithm (WOA) and flower pollination algorithm (FPA) is presented for the problem of FS based on the concept of Opposition based Learning (OBL) which name is HWOAFPA. In our proposed method, using natural processes of WOA and FPA, we tried to solve the problem of optimization of FS; and on the other hand, we used an OBL method to ensure the convergence rate and accuracy of the proposed algorithm. In fact, in the proposed method, WOA create solutions in their search space using the prey siege and encircling process, bubble invasion and search for prey methods, and try to improve the solutions for the FS problem; along with this algorithm, FPA improves the solution of the FS problem with two global and local search processes in an opposite space with the solutions of the WOA. In fact, we used all of the possible solutions to the FS problem from both the solution search space and the opposite of solution search space. To evaluate the performance of the proposed algorithm, experiments were carried out in two steps. In the first stage, the experiments were performed on 10 FS datasets from the UCI data repository. In the second step, we tried to test the performance of the proposed algorithm in terms of spam e-mails detection. The results obtained from the first step showed that the proposed algorithm, performed on 10 UCI datasets, was more successful in terms of the average size of selection and classification accuracy than other basic metaheuristic algorithms. Also, the results from the second step showed that the proposed algorithm which was run on the spam e-mail dataset, performed much more accurately than other similar algorithms in terms of accuracy of detecting spam e-mails.
ARTICLE Download: 0| View: 9| Comments: 0 | doi:10.20944/preprints202001.0308.v1
Subject: Chemistry, Physical Chemistry Keywords: Dergaon Meteorite; calibration-free laser-induced breakdown spectroscopy; atomic spectroscopy; molecular spectroscopy; planetary diagnosis
Online: 26 January 2020 (04:39:18 CET)
Meteorites represent the recoverable portions of asteroids occurring between Mars and Jupiter within the solar system that reach the surface of the Earth. Meteorites are rare extraterrestrial objects studied extensively to improve understanding of planetary evolution. In this work, calibration-free laser-induced breakdown spectroscopy (CF-LIBS) evaluates quantitative elemental and molecular analysis of the Dergaon meteorite, an H 4-5 chondrite fall sample, Assam, India. Spectral signatures of H, N, O, Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Ir, are measured. Along with the atomic emission, this work reports as well molecular emission from FeO molecules. The concentration of the measured elements obtained using CF-LIBS are in close agreement with earlier reports. The elements H, N and O and their concentrations are estimated using CF-LIBS for the first time. This study applies laser spectroscopy to establish presence of Ni, Cr, Co, and Ir in meteorites. Elemental analysis forms the basis for establishment of potential molecular composition of the Dergaon meteorite. Moreover, the elemental analysis approach bodes well for in-situ analyses of extraterrestrial objects including applications in planetary rover missions.
ARTICLE Download: 0| View: 12| Comments: 0 | doi:10.20944/preprints202001.0307.v1
Subject: Chemistry, Applied Chemistry Keywords: hybrid nanocomposites; polyaniline; titanium(IV) oxide; photocatalytic gypsum plaster
Online: 26 January 2020 (04:32:12 CET)
Hybrid materials of conjugated polymer and titanium(IV) oxide have attracted considerable attention concerning potential benefits, including (i) efficient exploitation of visible light, (ii) high adsorption capacity for organic contaminants, (iii) effective charge carriers separation. The new class of the photocatalysts is promising for the removal of environmental pollutants in both aqueous and gaseous phases. For the first time, in this study, the PANI/TiO2 hybrid composite was used for the degradation of phenol in water and toluene in the gas phase. Polyaniline-TiO2 was prepared by in-situ polymerization of aniline on the TiO2 surface. The obtained hybrid material was characterized by diffuse reflectance spectroscopy (DR/UV-Vis), X-ray diffraction (XRD), fast-Fourier transformation spectroscopy (FTIR), photoluminescence (PL) spectroscopy, microscopy analysis (SEM/TEM) and thermogravimetric analysis (TGA). An insight into the mechanism was shown based on the photodegradation analysis of charge carriers scavengers. Polyaniline is an efficient TiO2 photosensitizer for photodegradation in visible light (λ> 420 nm). The trapping experiments revealed that mainly h+ and ˙OH were reactive oxygen species responsible for phenol degradation. Furthermore, the PANI-TiO2 hybrid nanocomposite was used in gypsum plaster to study the self-cleaning properties of the obtained building material. The effect of PANI-TiO2 content on hydrophilic/hydrophobic properties and crystallographic structure of gypsum was studied. The obtained PANI-TiO2 modified gypsum plaster had improved photocatalytic activity in the reaction of toluene degradation under Vis light.
ARTICLE Download: 2| View: 8| Comments: 0
Subject: Engineering, Civil Engineering Keywords: electric vehicles; gasoline vehicles; mixed-behavior; environmental awareness; road pricing
Online: 26 January 2020 (04:20:52 CET)
Governments all over the world have issued clear targets to encourage the adoption of electric vehicles (EVs) and incentives to mitigate vehicular emissions and develop the sustainable transportation system. Considering the Pro-environmental behavior (PEB) of EVs and gasoline vehicles (GVs), this paper firstly established the two-class bi-objective mixed-behavior model (TCBOMB) under fixed demand is to describe different route choice behaviors of electric vehicles (EVs) and gasoline vehicles (GVs). Then this paper investigates the existence of a road pricing for mixed-behavior EVs and GVs to decentralize the pareto-efficient flow as a mixed-behavior equilibrium flow. After solving the TCBOMB model by revised FRANK-WOLFE algorithm based on the Sioux Falls network, numerical results can not only prove the feasibility of the algorithm, but also verify the decentralization of this road pricing scheme. Finally, we conduct a case study based on Chengdu to evaluate the effectiveness of the road pricing via two measurements (〖POA〗_T and 〖POA〗_E). The results imply that uniform road pricing could decrease 2.88% ~ 47.98% total system travel time, and 0.73 % ~ 27.14 % total emissions in Chengdu, China. This research provides a new vision to consider different behaviors between EVs and GVs of the two-criteria system and provide the government with decisive suggestions for the implementation of policies such as road pricing.
ARTICLE Download: 0| View: 6| Comments: 0 | doi:10.20944/preprints202001.0305.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: classification algorithm; feature reduction; file fragments; file fragment recognition; SFS; SFFS
Online: 26 January 2020 (04:04:53 CET)
Nowadays, speed up development and use of digital devices such as smartphones have put people at risk of internet crimes. The evidence of present crimes in a computer file can be easily unreachable by changing the prefix of a file or other algorithms. In more complex cases, either file divided into different parts or the parts of a file that has information about the file type are deleted, where the file fragment recognition issue is discussed. The known files are divided into different fragments, and different classification algorithms to solve the problems of file fragment recognition. A confusion matrix measures the accuracy of type recognition. In the present study, first, the file is divided into different fragments. Then, the file fragment features, which are obtained from Binary Frequency Distribution (BFD), are reduced by 2 feature reduction algorithms; Sequential Forward Selection algorithm (SFS) as well as Sequential Floating Forward Selection algorithm (SFFS) to delete sparse features that result in increased accuracy and speed. Finally, the reduced features are given to 3 classifier algorithms, Multilayer Perceptron (MLP), Support Vector Machines (SVM), and K-Nearest Neighbor (KNN) for classification and comparison of the results. In this paper, we proposed the algorithm of file type recognition that can recognize 6 types of useful files ( pdf, txt, jpg, doc, html, exe), which may distinguish a type of file fragments with higher accuracy than the similar works done.
ARTICLE Download: 0| View: 9| Comments: 0 | doi:10.20944/preprints202001.0304.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: Internet of Things (IoT); Gray System Theory; Multi-Path Routing; GSTMPR-IoT
Online: 26 January 2020 (04:00:20 CET)
Internet of things (IoT) is a network of smart things. This indicates the ability of these physical things to transfer information with other physical things. IoT has introduced various services and daily human life depends on its reliable and accessible operation. The characteristics of these networks, such as topology dynamicity and energy constraint, challenges the routing problem in these networks. Previous routing methods could not achieve the required performance in this type of network. Therefore, developers of this network designed and developed specific methods in order to satisfy the requirements of these networks. One of the routing methods is utilization of multi-path protocols which send data to its destination using routs with separate links. One of such protocols is AOMDV routing protocol. AOMDV protocol is a multi-path protocol which uses multiple different paths for sending information in order to maintain the network traffic balance, manage and control node energy, decrease latency, etc. In this paper, this method is improved using gray system theory which chooses the best paths used for separate routes to send packets. To do this, AOMDV packet format is altered and some fields are added to it so that energy criteria, link expiration time, and signal to noise ratio can also be considered while selecting the best route. The proposed method named GSTMPR-IoT is introduced which chooses the routs with highest rank for concurrent transmission of data, using a specific routine based on the gray system theory. In order to evaluate and report the results, the proposed GSTMPR-IoT method is compared to the EECRP and AOMDV approaches with regard to throughput, packet delivery rate, end to end delay, average residual energy, and network lifetime. The results demonstrate the superior performance of the proposed GSTMPR-IoT compared to the EECRP and AOMDV approaches.
ARTICLE Download: 0| View: 6| Comments: 0 | doi:10.20944/preprints202001.0303.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: Internet of Things (IoT); physical layer attack; routing security; Average Packet Transmission
Online: 26 January 2020 (03:57:09 CET)
Through the Internet of Things (IoT) the internet scope is established by the aid of physical objects integration to classify themselves to mutual things. A physical object can be created by this inventive perception to signify itself in the digital world. Regarding the physical objects that are related to the internet, it is worth to mention that considering numerous theories and upcoming predictions, they mostly require protected structures, moreover, they are at risk of several attacks. IoTs are endangered by particular routing disobedience called physical layer attack owing to their distributed features. The physical layer attack as a security warning makes possible for the invader to abuse the resources and bandwidth of the network through overloading the network via unimportant packets. This protocol is called LSFA-IoT consisting of two key sections of the physical layer detection system and misbehavior detection system. The first section is utilized in stabilizing the status of the network. The second section is in charge of discovering the misbehavior sources within the IoT network through , the Average Packet Transmission RREQ. By detecting a malicious node, the status of the node is checked by LSFA-IoT prior to sending a data packet and in case detecting the node as malicious, no packet is sent to that node and that node is added to the detention list. Here, the technique is assessed through wide simulations performed within the NS-3 environment. Based on the results of the simulation, it is indicated that the IoT network behaviour metrics are enhanced based on the detection rate, false-negative rate, false-positive rate, and packet delivery rate.
ARTICLE Download: 1| View: 11| Comments: 0 | doi:10.20944/preprints202001.0302.v1
Subject: Life Sciences, Other Keywords: fractional SEIR stochastic model; Caputo fractional order differential equations; measles; parameter estimation
Online: 26 January 2020 (03:38:06 CET)
In this paper, we compare the performance between systems of ordinary and (Caputo) fractional differential equations depicting the susceptible-exposed-infectious-recovered (SEIR) models of diseases. In order to understand the origins of both approaches as mean-field approximations of integer and fractional stochastic processes, we introduce the fractional differential equations as approximations of some type of fractional nonlinear birth--death processes. Then, we examine validity of the two approaches against empirical courses of epidemics; we fit both of them to case counts of three measles epidemics that occurred during the pre-vaccination era in three different locations. While FDEs appear more flexible in fitting empirical data, our ODEs offered better fits to two out of three data sets. Important differences in transient dynamics between these modeling approaches are discussed.
REVIEW Download: 0| View: 8| Comments: 0 | doi:10.20944/preprints202001.0301.v1
Subject: Life Sciences, Biophysics Keywords: electromagnetic fields; mutagenicity tests; cytotoxicity; magnetic phenomena; biophysical phenomena
Online: 26 January 2020 (01:57:22 CET)
Modern life implies a constant exposure of living organisms to electromagnetic fields generated by human made technology. The question of whether or not electromagnetic fields in the non-ionizing frequency range can affect cellular functions, increasing the risk of cancer or another pathologies is currently a subject of interest for scientific community of several disciplines of physics, biology, chemistry and medicine. The first part of this short review presents briefly the possible mechanism of interaction of electromagnetic fields in cellular level based in theoretical models and experimental results. The second part refers to experimental observations published by several authors about the potential cytotoxic and genotoxic effects of electromagnetic fields. Results of researches are no yet conclusive enough to accept or reject the genotoxic, carcinogenic or cytotoxic potential of these fields. Up to date the International Agency for Research on Cancer (IARC) has classified the X, gamma and ultraviolet radiation as carcinogenic and the fields generated by radio frequencies as possibly carcinogenic.
ARTICLE Download: 1| View: 13| Comments: 0 | doi:10.20944/preprints202001.0300.v1
Subject: Earth Sciences, Other Keywords: snow; synthetic aperture radar; Sentinel-1; spatial variability; spectral scaling; topography; wet snow
Online: 26 January 2020 (01:42:48 CET)
This study investigates the spatial signatures of seasonal snow in Synthetic Aperture Radar (SAR) observations at different spatial scales and for different physiographic regions. Sentinel-1 C-band (SAR) backscattering coefficients (BSC) were analyzed in the Swiss Alps (SA), in high elevation forest and grasslands in Grand Mesa (GM), Colorado, and in North Dakota (ND) croplands. GM BSC exhibit 10dB sensitivity to wetness at small scales (~100 m) over homogeneous grassland. Sensitivity decreases to 5 dB in the presence of trees, and it is demonstrated that VH BSC sensitivity enables wet snow mapping below the tree-line. Area-variance scaling relationships show minima at ~100 m and 150-250 m respectively in barren and grasslands in SA and GM, increasing up to 1 km and longer in GM forests and ND agricultural fields. The spatial organization of BSC (as described by 1D-directional BSC wavelength spectra) exhibits multi-scaling behavior in the 100 -1,000 m range with a break at (180-360 m) that is also present in UAVSAR L-band measurements in GM. Spectral slopes in GM forested areas steepen during accumulation and flatten in the melting season with mirror behavior for grasslands reflecting changes in scattering mechanisms with snow depth and wetness, and vegetation mass and structure. Overall, this study reveals persistent patterns of SAR scattering variability spatially organized by land-cover, topography and regional winds with large inter-annual variability tied to precipitation. This dynamic scaling behavior emerges as an integral physical expression of snowpack variability that can be used to model sub-km scales and for downscaling applications.
REVIEW Download: 2| View: 19| Comments: 0 | doi:10.20944/preprints202001.0299.v1
Online: 26 January 2020 (01:28:26 CET)
Purinergic receptors are inflammatory mediators activated by extracellular nucleotides released by dying or injured cells. Several studies have described an important role for these receptors in HIV-1 entry, particularly regarding their activity on HIV-1 viral membrane fusion. Several reports identify purinergic receptor antagonists that inhibit HIV-1 membrane fusion; these drugs are suspected to act through antagonizing Env-chemokine receptor interactions. They also appear to abrogate activity of downstream mediators that potentiate activation of the NLRP3 inflammasome pathway. Here we review the literature on purinergic receptors, the drugs that inhibit their function, and the evidence implicating these receptors in HIV-1 entry.