635 research outputs found
Optimization in Knowledge-Intensive Crowdsourcing
We present SmartCrowd, a framework for optimizing collaborative
knowledge-intensive crowdsourcing. SmartCrowd distinguishes itself by
accounting for human factors in the process of assigning tasks to workers.
Human factors designate workers' expertise in different skills, their expected
minimum wage, and their availability. In SmartCrowd, we formulate task
assignment as an optimization problem, and rely on pre-indexing workers and
maintaining the indexes adaptively, in such a way that the task assignment
process gets optimized both qualitatively, and computation time-wise. We
present rigorous theoretical analyses of the optimization problem and propose
optimal and approximation algorithms. We finally perform extensive performance
and quality experiments using real and synthetic data to demonstrate that
adaptive indexing in SmartCrowd is necessary to achieve efficient high quality
task assignment.Comment: 12 page
Optimization methods for energy management in a microgrid system considering wind uncertainty data
Energy management in the microgrid system is generally formulated as an optimization problem. This paper focuses on the design of a distributed energy management system for the optimal operation of
the microgrid using linear and nonlinear optimization methods. Energy
management is defined as an optimal scheduling power flow problem.
Furthermore, a technical-economic and environmental study is adopted
to illustrate the impact of energy exchange between the microgrid and
the main grid by applying two management scenarios. Nevertheless, the
fluctuating effect of renewable resources especially wind, makes optimal
scheduling difficult. To increase the results reliability of the energy management system, a wind forecasting model based on the artificial intelligence of neural networks is proposed. The simulation results showed the
reliability of the forecasting model as well as the comparison between
the accuracy of optimization methods to choose the most appropriate
algorithm that ensures optimal scheduling of the microgrid generators
in the two proposed energy management scenarios allowing to prove the
interest of the bi-directionality between the microgrid and the main grid.info:eu-repo/semantics/publishedVersio
Combined optimization and regression machine learning for solar Irradiation and wind speed forecasting
Prediction of solar irradiation and wind speed are essential
for enhancing the renewable energy integration into the existing power
system grids. However, the deficiencies caused to the network operations
provided by their intermittent effects need to be investigated. Regarding
reserves management, regulation, scheduling, and dispatching, the intermittency in power output become a challenge for the system operator.
This had given the interest of researchers for developing techniques to predict wind speeds and solar irradiation over a large or short-range of temporal and spatial perspectives to accurately deal with the variable power output. Before, several statistical, and even physics, approaches have been applied for prediction. Nowadays, machine learning is widely applied to do it and especially regression models to assess them. Tuning these models is usually done following manual approaches by changing the minimum leaf size of a decision tree, or the box constraint of a support vector machine, for example, that can affect its performance. Instead of performing it manually, this paper proposes to combine optimization methods including the bayesian optimization, grid search, and random search with regression models to extract the best hyper parameters of the model. Finally, the results are compared with the manually tuned models. The Bayesian gives the best results in terms of extracting hyper-parameters by giving more accurate models.info:eu-repo/semantics/publishedVersio
MTEDS: Multivariant Time Series-Based Encoder-Decoder System for Anomaly Detection
Intrusion detection systems examine the computer or network for potential security vulnerabilities. Time series data is real-valued. The nature of the data influences the type of anomaly detection. As a result, network anomalies are operations that deviate from the norm. These anomalies can cause a wide range of device malfunctions, overloads, and network intrusions. As a result of this, the network\u27s normal operation and services will be disrupted. The paper proposes a new multi-variant time series-based encoder-decoder system for dealing with anomalies in time series data with multiple variables. As a result, to update network weights via backpropagation, a radical loss function is defined. Anomaly scores are used to evaluate performance. The anomaly score, according to the findings, is more stable and traceable, with fewer false positives and negatives. The proposed system\u27s efficiency is compared to three existing approaches: Multiscaling Convolutional Recurrent Encoder-Decoder, Autoregressive Moving Average, and Long Short Term Medium-Encoder-Decoder. The results show that the proposed technique has the highest precision of 1 for a noise level of 0.2. Thus, it demonstrates greater precision for noise factors of 0.25, 0.3, 0.35, and 0.4, and its effectiveness
New methodology to detect the effects of emotions on different biometrics in real time
Recently, some problems have appeared among medical workers during the diagnosis of some diseases due to human errors or the lack of sufficient information for the diagnosis. In medical diagnosis, doctors always resort to separating human emotions and their impact on vital parameters. In this paper, a methodology is presented to measure vital parameters more accurately while studying the effect of different human emotions on vital signs. Two designs were implemented based on the microcontroller and National Instruments (NI) myRIO. Measurements of four different vital parameters are measured and recorded in real time. At the same time, the effects of different emotions on those vital parameters are recorded and stored for use in analysis and early diagnosis. The results proved that the proposed methodology can contribute to the prediction and diagnosis of the initial symptoms of some diseases such as the seventh nerve and Parkinson’s disease. The two proposed designs are compared with the reference device (beurer) results. The design using NI myRIO achieved more accurate results and a response time of 1.4 seconds for real-time measurements compared to its counterpart based on microcontrollers, which qualifies it to work in intensive care units
Current Trends on Solid Dispersions:Past, Present, and Future
Solid dispersions have achieved significant interest as an effective means of enhancing the dissolution rate and thus the bioavailability of a range of weakly water-soluble drugs. Solid dispersions of weakly water-soluble drugs with water-soluble carriers have lowered the frequency of these problems and improved dissolution. Solid dispersion is a solubilization technology emphasizing mainly on, drug-polymer two-component systems in which drug dispersion and its stabilization is the key to formulation development. Therefore, this technology is recognized as an exceptionally useful means of improving the dissolution properties of poorly water-soluble drugs and in the latest years, a big deal of understanding has been accumulated about solid dispersion, however, their commercial application is limited. In this review article, emphasis is placed on solubility, BCS classification, and carriers. Moreover, this article presents the diverse preparation techniques for solid dispersion and gathers some of the recent technological transfers. The different types of solid dispersions based on the carrier used and molecular arrangement were underlined. Additionally, it summarizes the mechanisms, the methods of preparing solid dispersions, and the marketed drugs that are available using solid dispersion approaches
Dokaz i izdvajanje skupine A rotavirusa iz devine teladi u Sudanu.
A total of 332 fecal samples were collected from 245 diarrheic as well as 75 recovered and 12 healthy camel calves in four different areas in Sudan [north (River Nile), east (Gedarif), central to south (Sennar, Blue Nile) and west (Kordofan) States]. Using ELISA, 46 samples (13.9%) were found positive for group A rotavirus. Out of 46 ELISA positive calves, we found 35 diarrheic up to 3 months of age, 7 recovered 4-6 months of age and 4 clinically healthy 8-12 months of age. Using EM, 6 out of 22 ELISA positive samples showed the well defined wheel-like structure characteristic of rotavirus. The results indicate the significant role of rotavirus in the epidemiology of camel calf diarrhea in Sudan. Attempts to isolate the camel group A rotavirus in MA104 cell culture were carried out on 21 ELISA-positive samples with successful isolation of the virus in 18. The isolated viruses were identified by ELISA and EM. Cytopathic effects (CPE) were manifested as rounding, elongation, triangulation, vacuolation and granulation of cells while the cell sheet remains intact. The CPE appeared on days 3-5 on the first to the second passages after treatment of the inocula and the cell culture media with trypsin. To our knowledge this is the first report on the isolation of camel rotavirus in cell culture.Prikupljena su 332 uzorka fecesa od 245 devine teladi s proljevom, 75 teladi oporavljene od proljeva i 12 od zdrave devine teladi sa četiri različita područja u Sudanu: sjevernoga (područje rijeke Nila), istočnoga (područje Gedarif), središnjega i južnoga (područje Sennar, Plavi Nil) te zapadnoga područja (Kordofan). Pretragom imunoenzimnim testom 46 uzoraka (13,9%) bilo je pozitivno za skupinu A rotavirusa. Od tih 46 pozitivnih životinja imunoenzimnim testom, 35 s proljevom bilo je u dobi do tri mjeseca, sedam s preboljelim proljevom bilo je u dobi od četiri do šest mjeseci, a četiri životinje u dobi od osam do 12 mjeseci bile su klinički zdrave. Elektronskom mikroskopijom dokazane su čestice karakteristične za rotavirus u šest od 22 uzorka pozitivna pretragom imunoenzimnim testom. Rezultati ukazuju na znatnu ulogu rotavirusa u epizootiologiji proljeva u devine mladunčadi u Sudanu. Skupina A rotavirusa izdvojena je na MA104 staničnoj kulturi iz 18 od 21 uzorka pozitivnoga pretragom imunoenzimnim testom. Izdvojeni virusi bili su identificirani imunoenzimnim testom i elekronskom mikroskopijom. Citopatski učinak očitovao se zaokruživanjem stanica, njihovim izduživanjem, triangulacijom, vakuolacijom i granulacijom, dok je stanični sloj ostao netaknut. Citopatski učinak javljao se za tri do pet dana u prvoj i drugoj pasaži nakon obradbe inokula i staničnog medija tripsinom. Ovo je prvo izvješće o izdvajanju rotavirusa deva u staničnoj kulturi
Rabies Virus Infection in Livestock
Rabies is a lethal zoonotic encephalomyelitis and a major challenge to public and animal health. Livestock are affected by rabies mostly through bites of rapid dogs or wildlife carnivore\u27s species. They are considered as ‘dead-end’ hosts that do not transmit the virus. Rabies in livestock has been endemic in many developing countries for many years and diagnosed through clinical signs and dog-biting history. An introduction on rabies situation in farm animals will be given then subchapters including `rabies in bovines, rabies in small ruminants, rabies in swine and rabies in camelids. In each subchapter we shall discuss, epidemiology, modes of transmission, diagnosis and prevention and control measures
An innovative optimization approach for energy management of a microgrid system
The local association of electrical generator including
renewable energies and storage technologies approximately
installed to the client made way for a small-scale power grid
called a microgrid. In certain cases, the random nature of
renewable energy sources, combined with the variable pattern
of demand, results in issues concerning the sustainability and
reliability of the microgrid system. Furthermore, the cost of
the energy coming from conventional sources is considering as
matter to the private consumer due to its high fees. An improved
methodology combining the simplex-based linear programming
with the particle swarm optimisation approach is employed
to implement an integrated power management system. The
energy scheduling is done by assuming the consumption profile
of a smart city. two scenarios of energy management have
been suggested to illustrate the behaviour of cost and gas
emissions for an optimised energy management. The results
showed the reliability of the energy management system using
an improvemed approach in scheduling of the energy flows for
the microgrid producers, limiting the utility’s cost versus an
experiment that had already been done for a similar system using
the identical data. The outcome of the computation identified
the ideal set points of the power generators in a smart city
supplied by a microgrid, while guaranteeing the comfort of the
customers i.e without intermetency in the supply, also, reducing
the emissions of greenhouse gases and providing an optimal
exploitation cost for all smart city users. Morover, the proposed
energy management system gave an inverse relation between
economic and environmental aspects, in fact, a multi-objective
optimization approach is performed as a continuation of the
work proposed in this paperinfo:eu-repo/semantics/publishedVersio
An Efficient Index for Reachability Queries in Public Transport Networks
Computing path queries such as the shortest path in public transport networks is challenging because the path costs between nodes change over time. A reachability query from a node at a given start time on such a network retrieves all points of interest (POIs) that are reachable within a given cost budget. Reachability queries are essential building blocks in many applications, for example, group recommendations, ranking spatial queries, or geomarketing. We propose an efficient solution for reachability queries in public transport networks. Currently, there are two options to solve reachability queries. (1) Execute a modified version of Dijkstra’s algorithm that supports time-dependent edge traversal costs; this solution is slow since it must expand edge by edge and does not use an index. (2) Issue a separate path query for each single POI, i.e., a single reachability query requires answering many path queries. None of these solutions scales to large networks with many POIs. We propose a novel and lightweight reachability index. The key idea is to partition the network into cells. Then, in contrast to other approaches, we expand the network cell by cell. Empirical evaluations on synthetic and real-world networks confirm the efficiency and the effectiveness of our index-based reachability query solution
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