scholarly journals A Modern Approaches for Modeling Time-Varying Database Models

2019 ◽  
pp. 25-32
Author(s):  
NASHWAN ALROMEMA ◽  
FAHAD ALOTAIBI
Keyword(s):  
State Of The Art ◽  
Research Work ◽  
Ease Of Use ◽  
Time Varying ◽  
Comparison Study ◽  
Database Applications ◽  
Modeling Approaches ◽  
Monitoring Applications ◽  
Different Types ◽  
Database Models

Time-varying data models store data related to time instances and offer different types of timestamping. These modeling approaches are considered as one of the most important parts of many database applications like metrological, banking, biomedical, accounting, scheduling, reservation systems, sensor based systems, real-time monitoring applications and applications involving maintenance of huge records. This research work introduces the state-of-the-art modeling approaches of Time-varying data. Furthermore we will show how to represent a running example using different approaches and give a comparison study of storage, and the ease of use of each model.

Electrostatic Aberration Correction in LV-SEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 746-747 ◽  
Author(s):  
D.J. Maas ◽  
A. Henstra ◽  
M.P.C.M. Krijn ◽  
S.A.M. Mentink
Keyword(s):  
Electron Microscope ◽  
Low Voltage ◽  
State Of The Art ◽  
Spherical Aberration ◽  
Positive Definite ◽  
Ease Of Use ◽  
Objective Lens ◽  
Time Varying ◽  
Voltage Electron ◽  
Aberration Corrected

The resolution of a low-voltage electron microscope is limited by the chromatic and spherical aberration of the objective lens, see Fig. 1. The design of state-of-the-art objective lenses is optimised for minimal aberrations. Any significant improvement of the resolution requires an aberration corrector. Recently, correction of both Cc and Cs has been demonstrated in SEM, using a combination of magnetic and electrostatic quadrupoles and octupoles (Zach and Haider, 1995). The present paper presents an alternative design, which is based on a purely electrostatic concept, potentially simplifying the ease-of-use of an aberration corrected microscope.In 1936 Scherzer showed that the fundamental lens aberrations of round lenses are positive definite, in absence of time-varying fields and/or space charge. Negative lens aberrations, required for the correction of Cc and Cs, can only be obtained using non-round lenses, e.g. quadrupoles and octupoles (Scherzer, 1947).

Researchers’ article sharing through institutional repositories and ResearchGate: A comparison study

2020 ◽  
pp. 096100062096284
Author(s):  
Youngseek Kim ◽  
Jong Sir Oh
Keyword(s):  
Ease Of Use ◽  
Institutional Repository ◽  
Comparison Study ◽  
Community Benefit ◽  
Factors Affecting ◽  
Individual Motivation ◽  
Institutional Repositories ◽  
Motivation Factors ◽  
Different Types ◽  
Survey Responses

The present study examined whether social and individual motivation factors influence researchers’ article-sharing intentions through their use of institutional repository or ResearchGate and how these factors differ between the two types of platforms. For this study, we employed a theoretical framework that integrated the Theory of Planned Behavior, community considerations, and reciprocity to examine social and individual motivation factors affecting researchers’ article-sharing intentions through the use of institutional repositories or ResearchGate. We employed diverse statistical analyses including Cronbach’s alpha, principal components factor analysis, multiple regression, and t-test based on a total of 492 survey responses from institutional repository and ResearchGate users. The results of this research revealed that institutional repository users’ article-sharing intentions were led by perceived community benefit, career benefit, and career risk whereas ResearchGate users’ intentions were led by subjective norms, perceived reciprocity, career benefit, career risk, and ease of use of the platform. These results demonstrate the need to develop different types of support and article-sharing policies for both institutional repository and ResearchGate users to facilitate or increase their article-sharing behaviors.

scholarly journals Intrusion Detection with Unsupervised Techniques for Network Management Protocols over Smart Grids

2020 ◽  
Vol 10 (7) ◽  
pp. 2276 ◽  
Author(s):  
Rafael Alejandro Vega Vega ◽  
Pablo Chamoso-Santos ◽  
Alfonso González Briones ◽  
José-Luis Casteleiro-Roca ◽  
Esteban Jove ◽  
...  
Keyword(s):  
Network Management ◽  
Smart Grids ◽  
Hebbian Learning ◽  
State Of The Art ◽  
Research Work ◽  
Data Capture ◽  
Novel Approach ◽  
Different Types ◽  
Electricity Grids ◽  
Proper Operation

The present research work focuses on overcoming cybersecurity problems in the Smart Grid. Smart Grids must have feasible data capture and communications infrastructure to be able to manage the huge amounts of data coming from sensors. To ensure the proper operation of next-generation electricity grids, the captured data must be reliable and protected against vulnerabilities and possible attacks. The contribution of this paper to the state of the art lies in the identification of cyberattacks that produce anomalous behaviour in network management protocols. A novel neural projectionist technique (Beta Hebbian Learning, BHL) has been employed to get a general visual representation of the traffic of a network, making it possible to identify any abnormal behaviours and patterns, indicative of a cyberattack. This novel approach has been validated on 3 different datasets, demonstrating the ability of BHL to detect different types of attacks, more effectively than other state-of-the-art methods.

Optimal Hedge Ratio and Hedging Effectiveness in Stock Futures Market: Evidence from National Stock Exchange, India

2019 ◽  
Vol 118 (3) ◽  
pp. 137-152
Author(s):  
A. Shanthi ◽  
R. Thamilselvan
Keyword(s):  
Banking Sector ◽  
Stock Exchange ◽  
Research Work ◽  
Futures Market ◽  
Least Square ◽  
Time Varying ◽  
Hedge Ratio ◽  
Hedging Effectiveness ◽  
Out Of Sample ◽  
Optimal Hedge

The major objective of the study is to examine the performance of optimal hedge ratio and hedging effectiveness in stock futures market in National Stock Exchange, India by estimating the following econometric models like Ordinary Least Square (OLS), Vector Error Correction Model (VECM) and time varying Multivariate Generalized Autoregressive Conditional Heteroscedasticity (MGARCH) model by evaluating in sample observation and out of sample observations for the period spanning from 1st January 2011 till 31st March 2018 by accommodating sixteen stock futures retrieved through www.nseindia.com by considering banking sector of Indian economy. The findings of the study indicate both the in sample and out of sample hedging performances suggest the various strategies obtained through the time varying optimal hedge ratio, which minimizes the conditional variance performs better than the employed alterative models for most of the underlying stock futures contracts in select banking sectors in India. Moreover, the study also envisage about the model selection criteria is most important for appropriate hedge ratio through risk averse investors. Finally, the research work is also in line with the previous attempts Myers (1991), Baillie and Myers (1991) and Park and Switzer (1995a, 1995b) made in the US markets

scholarly journals Multiple objects tracking in the UAV system based on hierarchical deep high-resolution network

2021 ◽  
Author(s):  
Wei Huang ◽  
Xiaoshu Zhou ◽  
Mingchao Dong ◽  
Huaiyu Xu
Keyword(s):  
High Resolution ◽  
Object Tracking ◽  
High Performance ◽  
State Of The Art ◽  
Class Imbalance ◽  
Unified Framework ◽  
Multiple Objects ◽  
Tracking Process ◽  
Objects Tracking ◽  
Different Types

AbstractRobust and high-performance visual multi-object tracking is a big challenge in computer vision, especially in a drone scenario. In this paper, an online Multi-Object Tracking (MOT) approach in the UAV system is proposed to handle small target detections and class imbalance challenges, which integrates the merits of deep high-resolution representation network and data association method in a unified framework. Specifically, while applying tracking-by-detection architecture to our tracking framework, a Hierarchical Deep High-resolution network (HDHNet) is proposed, which encourages the model to handle different types and scales of targets, and extract more effective and comprehensive features during online learning. After that, the extracted features are fed into different prediction networks for interesting targets recognition. Besides, an adjustable fusion loss function is proposed by combining focal loss and GIoU loss to solve the problems of class imbalance and hard samples. During the tracking process, these detection results are applied to an improved DeepSORT MOT algorithm in each frame, which is available to make full use of the target appearance features to match one by one on a practical basis. The experimental results on the VisDrone2019 MOT benchmark show that the proposed UAV MOT system achieves the highest accuracy and the best robustness compared with state-of-the-art methods.

scholarly journals Durable Continuous-Flow Mechanical Circulatory Support: State of the Art

Hearts ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 127-138
Author(s):  
Antonio Loforte ◽  
Luca Botta ◽  
Silvia Boschi ◽  
Gregorio Gliozzi ◽  
Giulio Giovanni Cavalli ◽  
...  
Keyword(s):  
Heart Transplantation ◽  
Continuous Flow ◽  
Mechanical Circulatory Support ◽  
State Of The Art ◽  
Ease Of Use ◽  
Circulatory Support ◽  
Pulse Modulation ◽  
Ventricular Assist ◽  
Old Patients ◽  
Number Of Patients

Implantable mechanical circulatory support (MCS) systems for ventricular assist device (VAD) therapy have emerged as an important strategy due to a shortage of donor organs for heart transplantation. A growing number of patients are receiving permanent assist devices, while fewer are undergoing heart transplantation (Htx). Continuous-flow (CF) pumps, as devices that can be permanently implanted, show promise for the treatment of both young and old patients with heart failure (HF). Further improvement of these devices will decrease adverse events, enable pulse modulation of continuous blood flow, and improve automatic remote monitoring. Ease of use for patients could also be improved. We herein report on the current state of the art regarding implantable CF pumps for use as MCS systems in the treatment of advanced refractory HF.

scholarly journals Fighting Together against the Pandemic: Learning Multiple Models on Tomography Images for COVID-19 Diagnosis

AI ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 261-273
Author(s):  
Mario Manzo ◽  
Simone Pellino
Keyword(s):  
Network Architecture ◽  
State Of The Art ◽  
Ensemble Classification ◽  
Effective Vaccine ◽  
Rt Pcr ◽  
Neural Network Architecture ◽  
Experimental Phase ◽  
Different Types ◽  
Polymerase Chain ◽  
Better Than

COVID-19 has been a great challenge for humanity since the year 2020. The whole world has made a huge effort to find an effective vaccine in order to save those not yet infected. The alternative solution is early diagnosis, carried out through real-time polymerase chain reaction (RT-PCR) tests or thorax Computer Tomography (CT) scan images. Deep learning algorithms, specifically convolutional neural networks, represent a methodology for image analysis. They optimize the classification design task, which is essential for an automatic approach with different types of images, including medical. In this paper, we adopt a pretrained deep convolutional neural network architecture in order to diagnose COVID-19 disease from CT images. Our idea is inspired by what the whole of humanity is achieving, as the set of multiple contributions is better than any single one for the fight against the pandemic. First, we adapt, and subsequently retrain for our assumption, some neural architectures that have been adopted in other application domains. Secondly, we combine the knowledge extracted from images by the neural architectures in an ensemble classification context. Our experimental phase is performed on a CT image dataset, and the results obtained show the effectiveness of the proposed approach with respect to the state-of-the-art competitors.

scholarly journals Does the Opening of High-Speed Railway Lines Reduce the Carbon Intensity of China’s Resource-Based Cities?

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4648
Author(s):  
Zhipeng Tang ◽  
Ziao Mei ◽  
Jialing Zou
Keyword(s):  
High Speed ◽  
National Average ◽  
Carbon Intensity ◽  
Time Varying ◽  
Low Carbon ◽  
High Speed Railway ◽  
Different Types ◽  
Endogenous Selection ◽  
Mode Of Development ◽  
The Impact

The carbon intensity of China’s resource-based cities (RBCs) is much higher than the national average due to their relatively intensive mode of development. Low carbon transformation of RBCs is an important way to achieve the goal of reaching the carbon emissions peak in 2030. Based on the panel data from 116 RBCs in China from 2003 to 2018, this study takes the opening of high-speed railway (HSR) lines as a quasi-experiment, using a time-varying difference-in-difference (DID) model to empirically evaluate the impact of an HSR line on reducing the carbon intensity of RBCs. The results show that the opening of an HSR line can reduce the carbon intensity of RBCs, and this was still true after considering the possibility of problems with endogenous selection bias and after applying the relevant robustness tests. The opening of an HSR line is found to have a significant reducing effect on the carbon intensity of different types of RBC, and the decline in the carbon intensity of coal-based cities is found to be the greatest. Promoting migration of RBCs with HSR lines is found to be an effective intermediary way of reducing their carbon intensity.

scholarly journals Cash Flow Bullwhip—Literature Review and Research Perspectives

Logistics ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 8
Author(s):  
Hicham Lamzaouek ◽  
Hicham Drissi ◽  
Naima El Haoud
Keyword(s):  
Literature Review ◽  
Customer Service ◽  
Cash Flow ◽  
State Of The Art ◽  
Research Work ◽  
Bullwhip Effect ◽  
Research Perspectives ◽  
Financial Perspective ◽  
The Impact ◽  
Exhaustive List

The bullwhip effect is a pervasive phenomenon in all supply chains causing excessive inventory, delivery delays, deterioration of customer service, and high costs. Some researchers have studied this phenomenon from a financial perspective by shedding light on the phenomenon of cash flow bullwhip (CFB). The objective of this article is to provide the state of the art in relation to research work on CFB. Our ambition is not to make an exhaustive list, but to synthesize the main contributions, to enable us to identify other interesting research perspectives. In this regard, certain lines of research remain insufficiently explored, such as the role that supply chain digitization could play in controlling CFB, the impact of CFB on the profitability of companies, or the impacts of the omnichannel commerce on CFB.

scholarly journals Modified Nanoclays/Straw Fillers as Functional Additives of Natural Rubber Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec
Keyword(s):  
Natural Rubber ◽  
Raw Materials ◽  
Research Work ◽  
Damping Properties ◽  
Main Research ◽  
Functional Additives ◽  
Different Types ◽  
Elastomeric Materials ◽  
Research Goal ◽  
The Impact

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.

Sign in / Sign up

Export Citation Format

Share Document