Spatial and Compositional Biases Introduced by Position Sensitive Detection Systems in APT: A Simulation Approach

2019 ◽  
Vol 25 (2) ◽  
pp. 418-424 ◽  
Author(s):  
C. Bacchi ◽  
G. Da Costa ◽  
F. Vurpillot
Keyword(s):  
Detection System ◽  
Atom Probe ◽  
Signal Loss ◽  
Loss Mechanism ◽  
Multiple Events ◽  
Detection Systems ◽  
Statistical Correction ◽  
Position Sensitive ◽  
Position Sensitive Detectors ◽  
The Impact

AbstractDue to the low capacity of contemporary position-sensitive detectors in atom probe tomography (APT) to detect multiple events, material analyses that exhibit high numbers of multiple events are the most subject to compositional biases. To solve this limitation, some researchers have developed statistical correction algorithms. However, those algorithms are only efficient when one is confronted with homogeneous materials having nearly the same evaporation field between elements. Therefore, dealing with more complex materials must be accompanied by a better understanding of the signal loss mechanism during APT experiments. By modeling the evaporation mechanism and the whole APT detection system, it may be possible to predict compositional and spatial biases induced by the detection system. This paper introduces a systematic study of the impact of the APT detection system on material analysis through the development of a simulation tool.

scholarly journals A Transparent Anode Array Detector for 3d Atom Probes

1998 ◽  
Vol 4 (S2) ◽  
pp. 80-81
Author(s):  
M. K. Miller
Keyword(s):  
Three Dimensional ◽  
Ccd Camera ◽  
Atom Probe ◽  
Single Atom ◽  
Array Detector ◽  
Detector Position ◽  
Spatial Coordinates ◽  
Position Sensitive ◽  
Position Sensitive Detectors ◽  
The Impact

In a three dimensional atom probe, the identity and spatial coordinates of the atoms field evaporated from the specimen are determined. Their identity is calculated from the flight time from the specimen to the single atom detector. The x and y coordinates of the atom in the specimen are determined from the coordinates of its impact position on the position-sensitive detector and the z coordinate is determined from its position in the evaporation sequence. These data may then be reconstructed to visualize and quantify the distribution of all the elements in the specimen. Several types of position-sensitive detectors have been used including a wedge-and-strip detector (position-sensitive atom probe), a 10 by 10 array of anodes (tomographic atom probe), and a gateable CCD camera (optical atom probe). The wedge-and strip and the CCD camera detectors both suffer from the limitation that if more than one atom strikes the detector on a field evaporation pulse then the impact positions cannot be determined in many cases.

scholarly journals Synthetic Minority Oversampling Technique for Optimizing Classification Tasks in Botnet and Intrusion-Detection-System Datasets

2020 ◽  
Vol 10 (3) ◽  
pp. 794 ◽  
Author(s):  
David Gonzalez-Cuautle ◽  
Aldo Hernandez-Suarez ◽  
Gabriel Sanchez-Perez ◽  
Linda Karina Toscano-Medina ◽  
Jose Portillo-Portillo ◽  
...  
Keyword(s):  
Intrusion Detection ◽  
Learning Algorithm ◽  
Search Algorithm ◽  
Detection System ◽  
Optimization Procedure ◽  
Algorithm Optimization ◽  
Detection Systems ◽  
Lack Of Information ◽  
Supervised Learning Algorithms ◽  
The Impact

Presently, security is a hot research topic due to the impact in daily information infrastructure. Machine-learning solutions have been improving classical detection practices, but detection tasks employ irregular amounts of data since the number of instances that represent one or several malicious samples can significantly vary. In highly unbalanced data, classification models regularly have high precision with respect to the majority class, while minority classes are considered noise due to the lack of information that they provide. Well-known datasets used for malware-based analyses like botnet attacks and Intrusion Detection Systems (IDS) mainly comprise logs, records, or network-traffic captures that do not provide an ideal source of evidence as a result of obtaining raw data. As an example, the numbers of abnormal and constant connections generated by either botnets or intruders within a network are considerably smaller than those from benign applications. In most cases, inadequate dataset design may lead to the downgrade of a learning algorithm, resulting in overfitting and poor classification rates. To address these problems, we propose a resampling method, the Synthetic Minority Oversampling Technique (SMOTE) with a grid-search algorithm optimization procedure. This work demonstrates classification-result improvements for botnet and IDS datasets by merging synthetically generated balanced data and tuning different supervised-learning algorithms.

scholarly journals Possible application of a compact electronics for multilayer muon high-speed radiography to volcanic cones

2013 ◽  
Vol 3 (1) ◽  
pp. 1-30
Author(s):  
H. K. M. Tanaka ◽  
I. Yokoyama
Keyword(s):  
Failure Rate ◽  
High Speed ◽  
Lava Dome ◽  
Detection System ◽  
Readout System ◽  
Muon Radiography ◽  
Position Sensitive ◽  
Definition Of ◽  
Position Sensitive Detectors ◽  
Usu Volcano

Abstract. A compact data taking electronics was developed for high-speed multi-layer muon radiography in order to minimize the operation failure rate. By requesting a linear trajectory within the number of redundant position sensitive detectors (PSDs), the background (BG) events produced by vertical electromagnetic (EM) showers are effectively reduced. In order to confirm the feasibility of this method, the system comprising 4 PSD layers were tested by imaging the internal structure of a parasitic cone and the adjacent craterlets formed in the 1910 eruption at the base of Usu volcano, Hokkaido with a conventional (MURG08) readout system (Kusagaya et al., 2012; Tanaka et al., 2012). The new mountain has been believed to be a cryptodome since its formation. According As knowledge on lava domes is are accumulated at various volcanoes, the definition of "cryptodome" is now doubted in its validity. The results of the preliminary 290-h muon radiographic survey revealed that the "cryptodome" is not underlain by any lava mass and that a main craterlet is accompanied by magma intrusions at shallow depths. The former verifies that the new mountain is not a cryptodome but a volcanogenetic mound, and the latter interprets the phreatic explosions forming the craterlets as intrusions of magma into the aquifer. However, a higher data taking failure rate was observed with a software-based MURG08 system when the size of the active area of the detection system was enlarged to improve the detection ability of the system. The newly developed MURG12 is a complete hardware-based electronics system that can simultaneously process signals from 192 scintillation counters of data size of 600 kbps ch−1 without operation failure. We anticipate that the observation speed would be further improved by employing MURG12. At the base of Usu volcano, in 20th century, four eruptions occurred. Some of them demonstrated three characteristic magma intrusions. First, a magma branch remained at a depth leaving an upheaval of the ground, second, it rose and reached aquifers causing phreatic explosions but not extruded, and third, it reacted with aquifers causing phreatic explosions and further extruded over the ground forming a lava dome. In order to clarify the eruption mechanism of Usu, it is necessary for us to image many parasitic cones. Based on the result of the test measurement, we anticipate that MURG12 would be a strong tool for high-speed muon radiography.

Atom probes of the future

1994 ◽  
Vol 52 ◽  
pp. 834-835
Author(s):  
T. F. Kelly ◽  
P. P. Camus ◽  
D. J. Larson ◽  
L. M. Holzman
Keyword(s):  
Three Dimensional ◽  
Atom Probe ◽  
Atomic Scale ◽  
3D Images ◽  
New Era ◽  
Atom Probes ◽  
Position Sensitive ◽  
Third Dimension ◽  
Position Sensitive Detectors ◽  
Very High

Atom probe microscopy, which is based on the first ever atomic-scale imaging technique, field ion microscopy (FIM), has entered a new era in its development. Three-dimensional atom probes (3DAP) are now operating which produce 3D images with atomic scale resolution. It appears that the technology will soon be at hand to make 3DAPs do everything that their predecessor, the conventional atom probe, now does and also reach the third dimension. These microscopes will be simpler, smaller, faster, and much more powerful than the conventional atom probe. Several developments are responsible for this suggestion. 1) Rapid pulsing schemes are being developed which will make it possible to achieve on the order of 106 pulses per second. 2) Highspeed position-sensitive detectors (PSDs) have been designed which can detect several ions in a givenpulse with very high precision. 3) New specimen geometries will soon become possible which will revolutionize the atom probe. Let us consider the ramifications of each of these developments in turn.

Performance of the multiple events position sensitive detector used in the tomographic atom probe

1995 ◽  
Vol 87-88 ◽  
pp. 428-437 ◽  
Author(s):  
B. Deconihout ◽  
A. Bostel ◽  
M. Bouet ◽  
J.M. Sarrau ◽  
P. Bas ◽  
...  
Keyword(s):  
Atom Probe ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
Multiple Events ◽  
Tomographic Atom Probe ◽  
Position Sensitive

Research of the Liquid Level Detection System for Integral Stereolithography System

2013 ◽  
Vol 347-350 ◽  
pp. 32-35 ◽  
Author(s):  
Guang Shen Xu ◽  
Da Hai Yan ◽  
Ya Ning Wang ◽  
Kong Liang Ju
Keyword(s):  
Detection System ◽  
Data Acquisition System ◽  
Electrical Signal ◽  
Liquid Level ◽  
Accuracy Requirement ◽  
Position Sensitive ◽  
Position Sensitive Detectors ◽  
Processing Circuit ◽  
Laser Liquid ◽  
Liquid Level Detection

To improve the dimension accuracy of integral stereolithography (SL) system, the resin liquid level in SL system need controlled. Based on the measuring principle of laser triangulation, a laser liquid level detection system for SL system has been developed. The laser liquid level detection system consists of light source, Position Sensitive Detectors (PSD), PSD signal processing circuit and data acquisition system. According to the principle that electrical signal of PSD changes when resin liquid level vary, a PSD is employed to detect the liquid level height in the liquid level detection system. Confirmation experiment is conduct to test the accuracy of the detection system, and the experiment results indicated that deviation is 0.34% in the range of 6mm, and satisfy the accuracy requirement of integral SL system.

scholarly journals An Adversarial Approach for Intrusion Detection Systems Using Jacobian Saliency Map Attacks (JSMA) Algorithm

Computers ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 58
Author(s):  
Ayyaz Ul Haq Qureshi ◽  
Hadi Larijani ◽  
Mehdi Yousefi ◽  
Ahsan Adeel ◽  
Nhamoinesu Mtetwa
Keyword(s):  
Neural Network ◽  
Intrusion Detection ◽  
Intelligent Systems ◽  
Detection System ◽  
Saliency Map ◽  
Intrusion Detection Systems ◽  
Specific Information ◽  
Detection Systems ◽  
Digital World ◽  
The Impact

In today’s digital world, the information systems are revolutionizing the way we connect. As the people are trying to adopt and integrate intelligent systems into daily lives, the risks around cyberattacks on user-specific information have significantly grown. To ensure safe communication, the Intrusion Detection Systems (IDS) were developed often by using machine learning (ML) algorithms that have the unique ability to detect malware against network security violations. Recently, it was reported that the IDS are prone to carefully crafted perturbations known as adversaries. With the aim to understand the impact of such attacks, in this paper, we have proposed a novel random neural network-based adversarial intrusion detection system (RNN-ADV). The NSL-KDD dataset is utilized for training. For adversarial attack crafting, the Jacobian Saliency Map Attack (JSMA) algorithm is used, which identifies the feature which can cause maximum change to the benign samples with minimum added perturbation. To check the effectiveness of the proposed adversarial scheme, the results are compared with a deep neural network which indicates that RNN-ADV performs better in terms of accuracy, precision, recall, F1 score and training epochs.

scholarly journals Possible application of compact electronics for multilayer muon high-speed radiography to volcanic cones

2013 ◽  
Vol 2 (2) ◽  
pp. 263-273 ◽  
Author(s):  
H. K. M. Tanaka ◽  
I. Yokoyama
Keyword(s):  
High Speed ◽  
Lava Dome ◽  
Detection System ◽  
Readout System ◽  
Detection Ability ◽  
Muon Radiography ◽  
Position Sensitive ◽  
Definition Of ◽  
Position Sensitive Detectors ◽  
Usu Volcano

Abstract. Compact data-taking electronics were developed for high-speed multilayer muon radiography in order to minimize operation failure rates. By requiring a linear trajectory within the position sensitive detectors (PSDs), the background (BG) events produced by vertical electromagnetic (EM) showers are effectively reduced. In order to confirm the feasibility of this method, the system comprising four PSD layers was tested by imaging the internal structure of a parasitic cone and the adjacent craterlets formed in the 1910 eruption at the base of the Usu volcano, Hokkaido with a conventional (MURG08) readout system (Kusagaya et al., 2012; Uchida et al., 2009). The new mountain is believed to be a cryptodome since its formation. As knowledge on lava domes is accumulated at various volcanoes, the definition of "cryptodome" is now doubted in its validity. The results of the preliminary 290 h muon radiographic survey revealed that the "cryptodome" is not underlain by any lava mass and that a main craterlet is accompanied by magma intrusions at shallow depths. The former verifies that the new mountain is not a cryptodome but a volcanogenetic mound, and the latter interprets the phreatic explosions forming the craterlets as intrusions of magma into the aquifer. However, a higher data taking failure rate was observed with a software-based MURG08 system when the size of the active area of the detection system was enlarged to improve the detection ability of the system. The newly developed MURG12 is a complete electronics system that can simultaneously process signals from 192 scintillation counters with a data size of 600 kbps ch−1 without operation failure. We anticipate that the observation speed would be further improved by employing MURG12. At the base of the Usu volcano, in the 20th century, four eruptions occurred. Some of them demonstrated three characteristic stages of magma intrusions. First, a magma branch remained at a depth leaving an upheaval of the ground; second, it rose and reached aquifers causing phreatic explosions without extrusions; and third, it reacted with aquifers causing phreatic explosions and further extruded over the ground forming a lava dome. In order to clarify the eruption mechanism of Usu, it is necessary for us to image many parasitic cones. Based on the result of the test measurement, we anticipate that MURG12 would be a strong tool for high-speed muon radiography.

Characterisation of multilayer materials using a position-sensitive atom probe

1990 ◽  
Vol 48 (4) ◽  
pp. 624-625
Author(s):  
RAD Mackenzie ◽  
G D W Smith ◽  
A. Cerezo ◽  
J A Liddle ◽  
CRM Grovenor ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Information ◽  
Chemical Vapour ◽  
Atom Probe ◽  
Organic Chemical ◽  
Growth Stages ◽  
Multiple Quantum ◽  
Quartz Wool ◽  
Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

scholarly journals Design of a Microwave Power Detection System in the 5G-Communication Frequency Band

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2674
Author(s):  
Qingying Ren ◽  
Wen Zuo ◽  
Jie Xu ◽  
Leisheng Jin ◽  
Wei Li ◽  
...  
Keyword(s):  
Frequency Band ◽  
Microwave Power ◽  
Communication Systems ◽  
Detection System ◽  
Measurement Sensitivity ◽  
Detection Range ◽  
Detection Systems ◽  
Detection Frequency ◽  
Communication Frequency ◽  
5G Communication

At present, the proposed microwave power detection systems cannot provide a high dynamic detection range and measurement sensitivity at the same time. Additionally, the frequency band of these detection systems cannot cover the 5G-communication frequency band. In this work, a novel microwave power detection system is proposed to measure the power of the 5G-communication frequency band. The detection system is composed of a signal receiving module, a power detection module and a data processing module. Experiments show that the detection frequency band of this system ranges from 1.4 GHz to 5.3 GHz, the dynamic measurement range is 70 dB, the minimum detection power is −68 dBm, and the sensitivity is 22.3 mV/dBm. Compared with other detection systems, the performance of this detection system in the 5G-communication frequency band is significantly improved. Therefore, this microwave power detection system has certain reference significance and application value in the microwave signal detection of 5G communication systems.

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