Search results for "DETECT"
showing 10 items of 5902 documents
Trademarks recognition based on local regions similarities
2010
This paper deals with content based image retrieval. We propose a logo recognition algorithm based on local regions, where the trademark (or logo) image is segmented by the clustering of points of interest obtained by Harris corners detector. The minimum rectangle surrounding each cluster is detected forming the regions of interest. Global features such as Hu moments and histograms of each local region are combined to find similar logos in the database. Similarity is measured based on the integrated minimum average distance of the individual components. The results obtained demonstrate tolerance to logos distortions such as rotation, occlusion and noise.
The Cryogenic AntiCoincidence detector for ATHENA: the progress towards the final pixel design
2014
“The Hot and Energetic Universe” is the scientific theme approved by the ESA SPC for a Large mission to be flown in the next ESA slot (2028th) timeframe. ATHENA is a space mission proposal tailored on this scientific theme. It will be the first X-ray mission able to perform the so-called “Integral field spectroscopy”, by coupling a high-resolution spectrometer, the X-ray Integral Field Unit (X-IFU), to a high performance optics so providing detailed images of its field of view (5’ in diameter) with an angular resolution of 5” and fine energy-spectra (2.5eV@E<7keV). The X-IFU is a kilo-pixel array based on TES (Transition Edge Sensor) microcalorimeters providing high resolution spectroscopy …
Experimente zur Entwicklung eines implantierbaren und dauernd funktionsfähigen Glukose-Sensors auf Basis der Polarimetrie - Experiments Aimed at Enab…
1995
In vitro and in vivo experiments devised with the aim of developing a permanently implantable glucose sensor based on polarimetry are described. It was found that in ultrafiltrated human blood plasma the overall optical rotation was 94% specific for glucose, and that polarisation photometry yielded a sufficiently sensitive signal for in vivo glucose detection. The three types of capillary membrane intended for implantation that we tested, revealed an in vitro response time to glucose concentration of 10 minutes; when implanted, they maintain this over a period of weeks, during which time the same glucose concentrations can be measured daily in ultrafiltrated capillary fluid as in the blood …
Monitoring of the smoking process by multicommutation Fourier Transform Infrared spectroscopy
2007
Abstract Nicotine was selected as the target molecule for monitoring of the smoking process by multicommutation Fourier Transform Infrared spectroscopy (FTIR). The method involved the use of CHCl3 for on-line extraction of nicotine from tobacco, cigarette filters and tobacco ash from NH4OH alkalinized samples, and absorbance measurement of the characteristic band at 1316 cm−1 in the stopped-flow mode, by obtaining the peak area in the range between 1334 and 1300 cm−1. Under the best operational conditions, the procedure developed provided a detection limit of 0.05 mg mL−1 nicotine, corresponding to 0.5 mg g−1 in the solid sample, a relative standard deviation less than 2.5%, and a sampling …
Why Moving Averages?
2017
This chapter presents a brief motivation for using moving averages for trend detection, how moving averages are computed, and their two key properties: the average lag (delay) time and smoothness. The most important thing to understand right from the start is that there is a direct relationship between the average lag time and smoothness of a moving average.
Studying micro-communities in Facebook Communities
2018
In the visionary view of the future Internet, named the Next Generation Internet, a current idea is to have a user-centric approach where human behavior models will be used to define the networks or to manage services. During the last years, a great trend in current Social Media platforms is to offer the opportunity to establish and join groups of people online. Despite human behaviour in current Online Social Media have been studied in depth, characteristics of these aggregations of people in content-based communities are still unknown. In this paper, we propose an evaluation of micro-communities of users inside the big network of Facebook groups to understand how and when users are active…
Assisted labeling for spam account detection on twitter
2019
Online Social Networks (OSNs) have become increasingly popular both because of their ease of use and their availability through almost any smart device. Unfortunately, these characteristics make OSNs also target of users interested in performing malicious activities, such as spreading malware and performing phishing attacks. In this paper we address the problem of spam detection on Twitter providing a novel method to support the creation of large-scale annotated datasets. More specifically, URL inspection and tweet clustering are performed in order to detect some common behaviors of spammers and legitimate users. Finally, the manual annotation effort is further reduced by grouping similar u…
The CSI-education effect: Do potential criminals benefit from forensic TV series?
2018
Abstract Forensic series have become popular over the last two decades. They have raised the importance of forensic evidence in the eyes of the public (CSI effect). However, it has not been investigated to what extent criminals may learn about forensic evidence through these shows. We used multiple approaches to tackle this potential CSI-education effect. First, we analyzed crime statistics for crime and detection rate. Second, we asked convicted criminals about their impressions about the usefulness of crime shows for covering up a crime. Third, we asked fans of crime series and a control group of non-watchers to slip into the role of a criminal by enacting the cleaning up a murder crime s…
LC of high to moderately polar basic drugs in urine with water and detergent, and direct injection
2016
Background: Micellar LC was first proposed as a ‘green’ mode using mobile phases of water and surfactant. However, in most procedures a small amount of organic solvent is required to decrease the retention to convenient values. Results & methodology: Mixed micellar mobile phases prepared with both cationic (sodium dodecyl sulphate) and nonionic surfactant (Brij-35) modulate the retention of high to moderately polar basic drugs to practical times, eliminating the need of organic solvent. While the mobile phase is continuously recycled through the system, the stationary phase performance is maintained after repetitive injection of the samples. Discussion & conclusion: Through an exte…
Learning temporal patterns for anomaly intrusion detection
2002
For the last decade an explosive spread of computer systems and computer networks has resulted in a society that is increasingly dependent on information stored on these systems. A computer system connected to the network is accessible from another computer in this network regardless of its geographical position. Along with providing many benefits for legitimate users this technology creates almost unlimited opportunities for malicious persons, which using software vulnerabilities may successfully penetrate the networked computer systems. In order to eliminate potential devastating consequences caused by breaches in computer systems, more and more attention is drawn to the information secur…