Hit Density Research Articles

Graph Trilateration for Indoor Localization in Sparsely Distributed Edge Computing Devices in Complex Environments Using Bluetooth Technology

Spatial navigation patterns in indoor space usage can reveal important cues about the cognitive health of participants. In this work, we present a low-cost, scalable, open-source edge computing system using Bluetooth low energy (BLE) beacons for tracking indoor movements in a large, 1700 m2 facility used to carry out therapeutic activities for participants with mild cognitive impairment (MCI). The facility is instrumented with 39 edge computing systems, along with an on-premise fog server. The participants carry a BLE beacon, in which BLE signals are received and analyzed by the edge computing systems. Edge computing systems are sparsely distributed in the wide, complex indoor space, challenging the standard trilateration technique for localizing subjects, which assumes a dense installation of BLE beacons. We propose a graph trilateration approach that considers the temporal density of hits from the BLE beacon to surrounding edge devices to handle the inconsistent coverage of edge devices. This proposed method helps us tackle the varying signal strength, which leads to intermittent detection of beacons. The proposed method can pinpoint the positions of multiple participants with an average error of 4.4 m and over 85% accuracy in region-level localization across the entire study area. Our experimental results, evaluated in a clinical environment, suggest that an ordinary medical facility can be transformed into a smart space that enables automatic assessment of individuals’ movements, which may reflect health status or response to treatment.

Influence of the Fragment Velocity Gradient on the Hit Density under the Dynamic Condition

The influence of the fragment velocity gradient on the hit density under the dynamic missile-target meeting condition is discussed using theoretical analysis, and the analytical relationship is obtained. The results show that under static explosion conditions, the fragment hit density is independent of the velocity gradient of the fragment group. Under dynamic conditions, the distribution bandwidth of the fragments on the target becomes wider with the increase of the velocity of the missile-target meeting and the velocity gradient of the fragment group, and the increase of the fragment bandwidth decreases the fragment hit density.

English

Pseudomonas aeruginosa has developed antibiotic resistance, a major health concern worldwide, through different mechanisms including the formation of biofilms. Thus far, typing has been primarily assay based. However, the many sequences available from the US National Center for Biotechnology Information (NCBI) and the International Consortium of Pseudomonas Database (IPCD) offer alternative ways of characterizing the biofilm formation genes which would reveal novel therapeutic targets for intervention. The current study employed profile hidden Markov models (pHMMs) in the characterization of biofilm formation genes and identification of possible variations based on the different ecological niches occupied by strains of P. aeruginosa. Statistical analyses were performed in R (v. 3.1.3) to determine the significance of these variations. Validated pHMMs identified a total of 197 hits for the 13 different ecological niches, with the human metagenomes recording 144 hits (73%) while the non-human metagenomes recorded 53 hits (27%). Human metagenomes had a significantly higher density of hits, with the abscess metagenomes indicating the highest density of hits. The overall result indicated a significant variation in density of hits between the different sites within the human metagenomes. This study successfully highlighted the significant value of already sequenced metagenomes in the identification of potential targets for novel therapeutic compounds. The profile hidden Markov model successfully identified 197 unique biofilm gene clusters emphasizing its importance in analyzing different sequenced pathogenic strains. The study recommends that experimental assays could be carried out to shed further light on the different biofilm formation gene clusters.   Key words: Profile hidden Markov model, metagenomics, biofilm formation, antibiotic resistance.

Stack fabric felting to get PCM GIIc improvement and LVI tolerance

In this work, there was developed a three-axis CNC felting machine with one barbed needle. Felting is a kind of needle-punch technology for joining fabric stack by broken and pulled fibres. The density of needle hits is a valuable factor to make the required shear strength of polymeric composite materials in the specified places. Using the glass-fibre reinforced plastic (GFRP) with plain weave felted fabric, a noticeable decrease in strength with an increase in the needle hits density from 0 to 90 cm−2 is shown. For a laminated GFRP made from a stack of fabrics, it has been shown that the shear strength of the single-lap joint and the interlaminar shear fracture toughness GIIC significantly increase with an increase in the needle hits density. This is important for modern aircraft shells exposed to random low-velocity impacts during ground or flight operations.

A Characterization of the Damage Process under Buckling Load in Composite Reinforced by Flax Fibres

The purpose of this work is to analyze the damage process resulting from buckling load applied on composites reinforced by flax fibre. Continous buckling test was performed on specimens until cracks appeared on their outer face. This test was monitored with an acoustic emission system. The high sensitivity of this method allows the detection of any process or mechanism generating sound waves. Moreover, this technic has the advantage of not causing contact in the deformed zone and thus to overcome the parasitic damage that may result from the stress concentrations in these areas. A multiparametric analysis is used to identify the acoustic signatures corresponding to each damage mechanism involved in the materials, and then follow their evolution in order to identify the most critical mechanisms leading to the final breakage of the material. The presence of these damage mechanisms was confirmed post-test by microscopic observations. Three orientations of laminate specimens (0°, 90° and 45°), relative to flax fabric architecture, were tested in order to characterize and highlight on their own damage process. Similarities as differences were observed between these mechanisms. We have deduced that the high porosity rate found in our composites are resulting from manufacturing parameters. Architecture and properties of the flax fabric influenced negatively the mechanical properties later by accentuating the gap between theoretical and practical values (17% to 22.4%) and by accelerating the development of certain damages such as matrix cracking which acoustic hit density is superior to 70% and fiber/matrix decohesion which occurs very early.

ВИКОРИСТАННЯ КАРТ КОХОНЕНА ДЛЯ АНАЛІЗУ РІВНЯ ІНФОРМАЦІЙНОЇ БЕЗПЕКИ КРАЇН З УРАХУВАННЯМ ЇХ РОЗВИТКУ

The development of computer technology leads to the emergence of information threats in the country associated with the appearance of information wars and cyber terrorism. There is a need to analyze the level of information security of the country because of this reason. It is also necessary to take into account the level of country development. Two groups of indicators were selected for analysis – information security indexes and development indicators. Global Cybersecurity Index, National Cyber Security Index, ICT Development Index, Networked Readiness Index, Digital Development Level formed a group of information security indicators. Thirty-seven indicators of world development were included in another group. The dataset was generated for 159 world countries in 2018. A correlation analysis was carried out in this work to identify indicators with a close statistical relationship. As a result, 12 development indicators were selected. Non-linear normalization was also performed to bring the data into comparable values. Further research was carried out using an analytical platform Deductor Academic. Data were checked for quality, outliers, duplicates and inconsistencies. As a result, outliers were identified for three observations of the indicator “Life expectancy”, after which the data were replaced with probable values. Kohonen maps were constructed, taking into account different combinations of parameters, as a result of which the option with the lowest quantization errors and optimal hit density was chosen. Based on the results of the experiments, it was selected the method for determining the initial weights of neurons “From eigenvectors”, the neighborhood function “Stepped”, the error level for data recognition is less than 0.05, the size of the map is 24:18. As a result, seven clusters were obtained, which characterize groups of countries by the level of information security, taking into account the indicators of their development. Clusters “0” and “1” include countries with the highest level of development and information security. Group “2” characterizes countries with above-average indicators. The third cluster identifies countries with an average level of development and protection. Group “4” includes countries with indicators for which the degree is below average. The fifth cluster assesses countries with a low level of development and information security, and the sixth cluster characterizes the level of countries as very low.

Microhomology of Viral/Host DNAs and Macrostructure of Herpesviral Genome

In 2015, we described short continuous fragments of human herpesvirus DNA, identical to the cellular ones, which we called microhomology (hits) because of their small size (≥ 20 nt). We noticed that generally the increase in the density (D) of these hits in human herpesviruses is inversely proportional to a decrease in the pathogenicity of these viruses. In this small work, we are considering the question of the existence of more objective features of HHV DNA (which can accompany the dynamics of the density of hits from HHV5 to HHV7), rather than a very imprecise notion of the degree of pathogenicity of a viral infection.

MARVEL, a Tool for Prediction of Bacteriophage Sequences in Metagenomic Bins.

Here we present MARVEL, a tool for prediction of double-stranded DNA bacteriophage sequences in metagenomic bins. MARVEL uses a random forest machine learning approach. We trained the program on a dataset with 1,247 phage and 1,029 bacterial genomes, and tested it on a dataset with 335 bacterial and 177 phage genomes. We show that three simple genomic features extracted from contig sequences were sufficient to achieve a good performance in separating bacterial from phage sequences: gene density, strand shifts, and fraction of significant hits to a viral protein database. We compared the performance of MARVEL to that of VirSorter and VirFinder, two popular programs for predicting viral sequences. Our results show that all three programs have comparable specificity, but MARVEL achieves much better performance on the recall (sensitivity) measure. This means that MARVEL should be able to identify many more phage sequences in metagenomic bins than heretofore has been possible. In a simple test with real data, containing mostly bacterial sequences, MARVEL classified 58 out of 209 bins as phage genomes; other evidence suggests that 57 of these 58 bins are novel phage sequences. MARVEL is freely available at https://github.com/LaboratorioBioinformatica/MARVEL.

A large ungated TPC with GEM amplification

A Time Projection Chamber (TPC) is an ideal device for the detection of charged particle tracks in a large volume covering a solid angle of almost 4π. The high density of hits on a given particle track facilitates the task of pattern recognition in a high-occupancy environment and in addition provides particle identification by measuring the specific energy loss for each track. For these reasons, TPCs with Multiwire Proportional Chamber (MWPC) amplification have been and are widely used in experiments recording heavy-ion collisions. A significant drawback, however, is the large dead time of the order of 1 ms per event generated by the use of a gating grid, which is mandatory to prevent ions created in the amplification region from drifting back into the drift volume, where they would severely distort the drift path of subsequent tracks. For experiments with higher event rates this concept of a conventional TPC operating with a triggered gating grid can therefore not be applied without a significant loss of data. A continuous readout of the signals is the more appropriate way of operation. This, however, constitutes a change of paradigm with considerable challenges to be met concerning the amplification region, the design and bandwidth of the readout electronics, and the data handling. A mandatory prerequisite for such an operation is a sufficiently good suppression of the ion backflow from the avalanche region, which otherwise limits the tracking and particle identification capabilities of such a detector. Gas Electron Multipliers (GEM) are a promising candidate to combine excellent spatial resolution with an intrinsic suppression of ions. In this paper we describe the design, construction and the commissioning of a large TPC with GEM amplification and without gating grid (GEM-TPC). The design requirements have driven innovations in the construction of a light-weight field-cage, a supporting media flange, the GEM amplification and the readout system, which are presented in this paper. We further describe the support infrastructure such as gas, cooling and slow control. Finally, we report on the operation of the GEM-TPC in the FOPI experiment, and describe the calibration procedures which are applied to achieve the design performance of the device.

Effect of fragment dispersion on damage assessment of a directional fragment generator

Effective neutralisation of an offensive target missile can be accomplished by a defensive missile system carrying a potential kill mechanism. A directional fragment generator warhead is one of the kill mechanisms for such an application. It projects fragments in a designed beam angle. Few researchers have attempted to quantify fragment dispersion on explosion, which revealed that the fragment projection angle follows a normal distribution with wide range in standard deviation value of 0.75° and 3°. In this paper, an attempt has been made to analyse the importance of knowing the standard deviation value for assessing damage in terms of fragment hit density and kill probability. By altering the standard deviation value between 0 and 3°, the fragment spray distribution for the fragment generator warhead is generated and compared with the distribution that corresponds to a standard deviation value of 0.75°. It is observed that the hit density variation varies by −51% to 40% from the actual. On comparing the effect of standard deviation on kill probability, it is observed that it depends on the proportionate area of vulnerable component in the fragment beam. For the vulnerable area of 0.5 times (50%) of annular fragment beam area, more than or equal to eight fragments can achieve kill probability close to 1. However, for vulnerable area of 0.02 (2%) and 0.1 times (10%) of annular fragment beam area, the kill probability depends on standard deviation value.

Physics design of collimators to reduce lost particle background at the CEPC

At the CEPC (Circular Electron Positron Collider), which is proposed by the Chinese high energy physics community, the dominant background comes from radiative Bhabha scattering and the beamstrahlung effect according to preliminary research. Therefore, it is necessary to incorporate a collimator system to intercept particles that may be lost near the interaction region (IR). In this paper, we introduce some limitations in choosing the position and width of the collimators. A certain parameter range is determined which is confined by the β function and the width of the collimators. A suitable choice of the half width is made by exploring this parameter range. A simulation of the particle loss rate in the IR and the hit density in the vertex detector with and without the collimators shows that the set of parameters of the collimators we designed is appropriate and effective.

Study of beamstrahlung effects at CEPC**Supported by CAS/SAFEA International Partnership Program for Creative Research Teams, CAS and IHEP Thousand Talent and Hundred Talent programs, and grants from the State Key Laboratory of Nuclear Electronics and Particle Detectors.

The discovery of a 125 GeV Higgs boson at the LHC marked a breakthrough in particle physics. The relative lightness of the new particle has inspired consideration of a high-luminosity Circular Electron Positron Collider (CEPC) as a Higgs Factory to study the particle’s properties in an extremely clean environment. Given the high luminosity and high energy of the CEPC, beamstrahlung is one of the most important sources of beam-induced background that might degrade the detector performance. It can introduce even more background to the detector through the consequent electron-positron pair production and hadronic event generation. In this paper, beamstrahlung-induced backgrounds are estimated with both analytical methods and Monte Carlo simulation. Hit density due to detector backgrounds at the first vertex detector layer is found to be ∼0.2 hits/cm2 per bunch crossing, resulting in a low detector occupancy below 0.5%. Non-ionizing energy loss (NIEL) and total ionizing dose (TID), representing the radiation damage effects, are estimated to be ∼1011 1 MeV neq/cm2/yr and ∼300 kRad/yr, respectively.

Can camera trapping provide accurate estimates of small mammal ( Myodes rutilus and Peromyscus maniculatus ) density in the boreal forest?

Abstract Estimating population densities of small mammals (< 100g) has typically been carried out by intensive livetrapping, but this technique may be stressful to animals and the effort required is considerable. Here, we used camera traps to detect small mammal presence and assessed if this provided a feasible alternative to livetrapping for density estimation. During 2010–2012, we used camera trapping in conjunction with mark–recapture livetrapping to estimate the density of northern red-backed voles ( Myodes rutilus ) and deer mice ( Peromyscus maniculatus ) in the boreal forest of Yukon, Canada. Densities for these 2 species ranged from 0.29 to 9.21 animals/ha and 0 to 5.90 animals/ha, respectively, over the course of this investigation. We determined if hit window—the length of time used to group consecutive videos together as single detections or “hits”—has an effect on the correlation between hit rate and population density. The relationship between hit rate and density was sensitive to hit window duration for Myodes with R2 values ranging from 0.45 to 0.59, with a 90-min hit window generating the highest value. This relationship was not sensitive to hit window duration for Peromyscus , with R2 values for the tested hit windows ranging from 0.81 to 0.84. Our results indicate that camera trapping may be a robust method for estimating density of small rodents in the boreal forest when the appropriate hit window duration is selected and that camera traps may be a useful tool for the study of small mammals in boreal forest habitat.

Comparative analysis of competitive activity parameters of amateur boxers high qualification

Purpose : analyze competitive activity of boxers of high qualifications in different time periods in the development of boxing. Material : 142 analyzed boxing matches at the Olympic Games 2012. Results : present indicators of competitive activity of boxers. Shows the comparative characteristics of the battles that took place under different formulas of competitive activity in different periods of the development of amateur boxing. It is shown that increasing the skills of athletes appear to increase the density of hits in combat. As a result of innovations in the rules of the competition, boxing match was different higher intensity combat, attacking actions began to perform at a higher speed mode. Conclusions : As a result of the transition to the new formula of fighting to increase the density of the match. Also a 3-fold increase in the number of strikes indicator, surviving on target. Increased efficiency factor strikes, which leads to the expansion of effective technical and tactical actions.

An ultra-low power self-timed column-level ADC for a CMOS pixel sensor based vertex detector

The International Large Detector (ILD) is a detector concept for the future linear collider experiment. The vertex detector is the key tool to achieve high precision measurements for flavor tagging, which puts stringent requirements on the CMOS pixel sensors. Due to the cooling systems which deteriorate the material budget and increase the multiple scattering, it is important to reduce the power consumption. This paper presents an ultra-low power self-timed column-level ADC for the CMOS pixel sensors, aiming to equip the outer layers of the vertex detector. The ADC was designed to operate in two modes (active and idle) adapted to the low hit density in the outer layers. The architecture employs an enhanced sample-and-hold circuit and a self-timed technique. The total power consumption with a 3-V supply is 225μW during idle mode, which is the most frequent situation. This value rises to 425μW in the case of the active mode. It occupies an areaof 35 × 590μm2.

Track reconstruction at the ILC: the ILD tracking software

One of the key requirements for Higgs physics at the International Linear Collider ILC is excellent track reconstruction with very good momentum and impact parameter resolution. ILD is one of the two detector concepts at the ILC. Its central tracking system comprises of an outer Si-tracker, a highly granular TPC, an intermediate silicon tracker and a pixel vertex detector, and it is complemented by silicon tracking disks in the forward direction. Large hit densities from beam induced coherent electron-positron pairs at the ILC pose an additional challenge to the pattern recognition algorithms. We present the recently developed new ILD tracking software, the pattern recognition algorithms that are using clustering techniques, Cellular Automatons and Kalman filter based track extrapolation. The performance of the ILD tracking system is evaluated using a detailed simulation including dead material, gaps and imperfections.

A Self-Triggered Column-Level ADC for CMOS Pixel Sensors in High Energy Physics

CMOS pixel sensors (CPS) for the future linear collider vertex detector (VXD) have strict requirements on their analog readout electronics, particularly on the analog-to-digital converter (ADC). This paper presents a low-power and small-area 4-bit column-level ADC for the CMOS pixel sensor, foreseen to equip the outer layers of the VXD. The ADC employs a self-triggered timing and completes the conversion by performing a multi-bit/step approximation. Accounting the fact that in the outer layers, the hit density is in the order of a few per thousand, this ADC is designed to operate in two modes: active mode and inactive mode. The average energy and total capacitance are significantly reduced by a power-gating control and a switching network, respectively. The ADC is fabricated in a ${\hbox{0.35}}~\mu\hbox{m}$ CMOS process with a pixel pitch of ${\hbox{35}}~\mu\hbox{m} $ . It is implemented with 48 columns in a sensor prototype. Each column ADC occupies an area of $ 35\times 545~\mu\hbox{m}^2$ . The measured temporal noise and fixed pattern noise (FPN) are 0.94 and 0.30 mV, respectively. The power consumption, at a 3-V supply and 6.25-MS/s sampling rate, equals to ${\hbox{486}}~\mu\hbox{W}$ in its inactive mode, which is by far the most frequent. This value rises to ${\hbox{714}}~\mu\hbox{W}$ in case of the active mode. These computations indicate an average power consumption of each column in the order of ${\hbox{487}}~\mu\hbox{W}$ , assuming a typical occupancy of $ \sim {\hbox{0.5}}\%$ in the whole sensor. Its DNL and INL are 0.49/-0.28 and 0.29/-0.20 least significant bit, respectively.

Uncovering regulatory nodes in miRNA‐mediated regulation of glycome (608.7)

Glycan biosynthesis is a complex and highly non‐linear process requiring a large number of diverse proteins (glycosyltransferases, glycosidases and sugar nucleotide transporters) to act in accord. An increasing number of recent reports, including previous work from our lab, suggest a possible role of microRNAs (miRNAs), small non‐coding RNA that complement to the 3’ or 5’ untranslated region (UTR) of mRNA to attenuate translation, in the regulation of overall glycan expression (glycome) via post‐transcriptional regulation of glycan related gene expression. In this work, we hoped to identify the key regulatory nodes in glycan biosynthetic pathways that might help in the deconvolution of glycomic signals. Adding a more functional approach, we further generated a condition‐driven model with Ovarian Cancer Metastasis (OCM) to identify any glycosylation patterns. Using miRNA prediction data from microrna.org and 3’ UTR lengths from ENCODE project, a metric, called Hit Density (HD), was calculated for each of the glycogenes that incorporate factors contributing to the miRNA regulation of genes. We identified key regulatory nodes in the glycan biosynthetic pathways at the miRNA regulatory level, and show that the glycogenes are not redundant. We also show that orchestration of several events of the glycome can be regulated by miRNA that are predicted to target multiple glycogenes. Finally, bio‐functional mapping of glycan regulatory networks in OCM revealed specific glycosylation patterns, suggesting that glycan regulatory networks in condition‐driven models could impart valuable information.

A low-power and small-area column-level ADC for high frame-rate CMOS pixel sensor

CMOS pixel sensors (CPS) have demonstrated performances meeting the specifications of the International Linear Collider (ILC) vertex detector (VTX). This paper presents a low-power and small-area 4-bit column-level analog-to-digital converter (ADC) for CMOS pixel sensors. The ADC employs a self-timed trigger and completes the conversion by performing a multi-bit/step approximation. As in the outer layers of the ILC vertex detector hit density is of the order of a few per thousand, in order to reduce power consumption, the ADC is designed to work in two modes: active mode and idle mode. The ADC is fabricated in a 0.35μm CMOS process with a pixel pitch of 35μm. It is implemented with 48 columns in a sensor prototype. Each column ADC covers an area of 35 ×545μm2. The measured temporal noise and Fixed Pattern Noise (FPN) are 0.96mV and 0.40mV, respectively. The power consumption, for a 3V supply and 6.25MS/s sampling rate, is 486μW during idle time, which is by far the most frequently employed one. This value rises to 714μW in the case of the active mode. The measured differential nonlinearity (DNL) and integral nonlinearity (INL) are 0.49/−0.28 LSB and 0.29/−0.20 LSB, respectively.

Rapid detection of stand density, tree positions, and tree diameter with a 2D terrestrial laser scanner

Harvester operators that decide about tree removal during thinnings have currently no instruments to measure stand density continuously before and after the operation. We tested whether basal area can be measured rapidly for this purpose with a 2D terrestrial laser scanner. An algorithm was developed, which automatically detects trees from laser scanner point clouds, measures their position and diameter, and calculates basal area. A field test included 18 laser scans in two Norway spruce stands with a wide range of stand densities, representing situations before and after thinning. Occlusion is a problem of single laser scans, and about one-third of the trees within the scanning range were not detected. Occlusion varies with stem density and branchiness. We therefore applied a flexible scanning range, which is detected automatically based on the laser hit density distribution for each scan. Scanning ranges were between 5.5 and 8.4 m (mean = 7.3 m) in the test scans, which is below the reach of the harvester crane, but still large enough to estimate local stand density. Basal area measured with the laser scanner was unbiased only in one of the two stands. Trees not detected or trees falsely detected caused only small bias of the basal area measurement in one of the two stands. Measurement errors for individual scans were, however, often around 10 m2 ha−1.