Search results for " Detection"
showing 10 items of 1676 documents
Ultrasensitive Silicon Nanowire for Real-World Gas Sensing: Noninvasive Diagnosis of Cancer from Breath Volatolome
2014
We report on an ultrasensitive, molecularly modified silicon nanowire field effect transistor that brings together the lock-and-key and cross-reactive sensing worlds for the diagnosis of (gastric) cancer from exhaled volatolome. The sensor is able to selectively detect volatile organic compounds (VOCs) that are linked with gastric cancer conditions in exhaled breath and to discriminate them from environmental VOCs that exist in exhaled breath samples but do not relate to the gastric cancer per se. Using breath samples collected from actual patients with gastric cancer and from volunteers who do not have cancer, blind analysis validated the ability of the reported sensor to discriminate betw…
Green and Integrated Wearable Electrochemical Sensor for Chloride Detection in Sweat
2022
Wearable sensors for sweat biomarkers can provide facile analyte capability and monitoring for several diseases. In this work, a green wearable sensor for sweat absorption and chloride sensing is presented. In order to produce a sustainable device, polylactic acid (PLA) was used for both the substrate and the sweat absorption pad fabrication. The sensor material for chloride detection consisted of silver-based reference, working, and counter electrodes obtained from upcycled compact discs. The PLA substrates were prepared by thermal bonding of PLA sheets obtained via a flat die extruder, prototyped in single functional layers via CO2 laser cutting, and bonded via hot-press. The effect of co…
Views selection for SIFT based object modeling and recognition
2016
In this paper we focus on automatically learning object models in the framework of keypoint based object recognition. The proposed method uses a collection of views of the objects to build the model. For each object the collection is composed of N×M views obtained rotating the object around its vertical and horizontal axis. As keypoint based object recognition using a complete set of views is computationally expensive, we focused on the definition of a selection method that creates, for each object, a subset of the initial views that visually summarize the characteristics of the object and should be suited for recognition. We select the views by determining maxima and minima of a function, …
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.
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 …
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…
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…