Search results for "network [detector]"
showing 10 items of 496 documents
Oscillator strength reduction induced by external electric fields in self-assembled quantum dots and rings
2007
We have carried out continuous wave and time resolved photoluminescence experiments in self-assembled In(Ga)As quantum dots and quantum rings embedded in field effect structure devices. In both kinds of nanostructures, we find a noticeable increase of the exciton radiative lifetime with the external voltage bias that must be attributed to the field-induced polarizability of the confined electron hole pair. The interplay between the exciton radiative recombination and the electronic carrier tunneling in the presence of a stationary electric field is therefore investigated and compared with a numerical calculation based on the effective mass approximation.
Dominating Clasp of the Financial Sector Revealed by Partial Correlation Analysis of the Stock Market
2010
What are the dominant stocks which drive the correlations present among stocks traded in a stock market? Can a correlation analysis provide an answer to this question? In the past, correlation based networks have been proposed as a tool to uncover the underlying backbone of the market. Correlation based networks represent the stocks and their relationships, which are then investigated using different network theory methodologies. Here we introduce a new concept to tackle the above question--the partial correlation network. Partial correlation is a measure of how the correlation between two variables, e.g., stock returns, is affected by a third variable. By using it we define a proxy of stoc…
Gene connectivity and enzyme evolution in the human metabolic network
2019
[Background] Determining the factors involved in the likelihood of a gene being under adaptive selection is still a challenging goal in Evolutionary Biology. Here, we perform an evolutionary analysis of the human metabolic genes to explore the associations between network structure and the presence and strength of natural selection in the genes whose products are involved in metabolism. Purifying and positive selection are estimated at interspecific (among mammals) and intraspecific (among human populations) levels, and the connections between enzymatic reactions are differentiated between incoming (in-degree) and outgoing (out-degree) links.
ASPECTS OF INEQUALITY IN THE CONTEXT OF EMPLOYMENT OF PRE-SCHOOL TEACHERS IN LATVIA
2020
Policy-making in education involves social agents at national, municipal and institutional levels. National regulations and financial capacity of municipalities determine working conditions of teachers and employment aspects at all levels of the education system. For several years, discussions have been taking place in Latvia involving employers of education sector and policy makers on tackling inequalities in pay and workload principles for pre-school teachers. Situation of the pre-school teachers varies across municipalities and is affected by their financial opportunities to sustain educational institutions and ensure teachers’ salaries. In 2019, Latvian Trade Union of Education and Scie…
Discovery privacy threats via device de-anonymization in LoRaWAN
2021
LoRaWAN (Long Range WAN) is one of the well-known emerging technologies for the Internet of Things (IoT). Many IoT applications involve simple devices that transmit their data toward network gateways or access points that, in their turn, redirect data to application servers. While several security issues have been addressed in the LoRaWAN specification v1.1, there are still some aspects that may undermine privacy and security of the interconnected IoT devices. In this paper, we tackle a privacy aspect related to LoRaWAN device identity. The proposed approach, by monitoring the network traffic in LoRaWAN, is able to derive, in a probabilistic way, the unique identifier of the IoT device from…
A model of Cyber Threat Information Sharing with the Novel Network Topology
2021
The digitized environments are particularly vulnerable to various attacks. In such a situation of a security attack, detecting and responding to attacks require effective actions. One of the most significant ways to improve resilience to security attacks is to obtain accurate and timely situational aspect of the security awareness. The efficient production and utilization of situation information is achieved by sharing information with other actors in the information sharing network quickly and reliably without compromising the confidential information of one's own organization. At the same time, it should also be possible to avoid a flood of irrelevant information in the sharing network, w…
A P2P Architecture for Multimedia Content Retrieval
2006
The retrieval facilities of most Peer-to-Peer (P2P) systems are limited to queries based on unique identifiers or small sets of keywords. This approach can be highly labor-intensive and inconsistent. In this paper we investigate a scenario where a huge amount of multimedia resources are shared in a P2P network, by means of efficient content-based image and video retrieval functionalities. The challenge in such systems is to limit the number of sent messages, maximizing the usefulness of each peer contacted in the query process. We achieve this goal by the adoption of a novel algorithm for routing user queries. The proposed approach exploits compact representations of multimedia resources sh…
Information Decomposition in Multivariate Systems: Definitions, Implementation and Application to Cardiovascular Networks
2016
The continuously growing framework of information dynamics encompasses a set of tools, rooted in information theory and statistical physics, which allow to quantify different aspects of the statistical structure of multivariate processes reflecting the temporal dynamics of complex networks. Building on the most recent developments in this field, this work designs a complete approach to dissect the information carried by the target of a network of multiple interacting systems into the new information produced by the system, the information stored in the system, and the information transferred to it from the other systems; information storage and transfer are then further decomposed into amou…
Information Dynamics of the Brain, Cardiovascular and Respiratory Network during Different Levels of Mental Stress
2019
In this study, an analysis of brain, cardiovascular and respiratory dynamics was conducted combining information-theoretic measures with the Network Physiology paradigm during different levels of mental stress. Starting from low invasive recordings of electroencephalographic, electrocardiographic, respiratory, and blood volume pulse signals, the dynamical activity of seven physiological systems was probed with one-second time resolution measuring the time series of the &delta
Topology management in unstructured P2P networks using neural networks
2007
Resource discovery is an essential problem in peer-to-peer networks since there is no centralized index in which to look for information about resources. In a pure P2P network peers act as servers and clients at the same time and in the Gnutella network for example, peers know only their neighbors. In addition to developing different kinds of resource discovery algorithms, one approach is to study the different topologies or structures of the P2P network. In many cases topology management is based on either technical characteristics of the peers or their interests based on the previous resource queries. In this paper, we propose a topology management algorithm which does not predetermine fa…