bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in Antioxidant Enzymes Activities and Lipid Peroxidase Level in Tissues of Stress-induced Rats
Authors: Chukwuebuka Nwogueze Bartholomew , Melish Elias Daubry Tarela , Ijego Asogwa Eucharia , Peggy Ohwin Ejiro , Ejime Agbonifo-Chiiokwu , Omeru Oghenerukevwe , Yabrade Toloyai Pere-Ebi , Nwanneamaka Eke Chidinma , Ikemefune Ebuwa Emmanuel
Published: July 2021

Background: Estimating the changes in the levels of oxidative stress biomarkers are vital in identifying stress related disease in living organism. This study examined changes in the activity of antioxidant enzymes and lipid peroxidase level in female Wistar rats exposed to stressors of different nature were examined. Methods: 88 apparently healthy rats within the ages of 8-12weeks and weighing between 120-180g were utilized for the study. Rats were acclimatized for 2weeks and fed with rat chaw and water ad libitum. Animals were stressed at the rate of 1hr, 3hr or 5hr per day for 1, 2 or 3weeks respectively. After the experimental protocol of stress induction, the rats werekilled via cervical dislocation and some vital organs were carefully harvested for tissue homogenates in assessing SOD, CAT and MDA antioxidants. Data collected were analyzed using Mean±SEM, ANOVA was used to compare means and LSD was used for post hoc. Results: SOD activity of the different tissues examined were significantly (p<0.05) altered irrespective of the stressor applied especially in the restraint or intruder stressors. CAT activity were significantly (p<0.05) reduced in all stressors irrespective of the rate of exposure. The study also revealed that lipid peroxidase levels were significantly (p<0.05) increased in all tissues irrespective of the rate of exposure and type of stressor applied. Conclusions: The findings validate the ability of the stressors to increase production of free radicals, thus, changes in antioxidant enzymes activities and lipid peroxidase level implies compromised cellular activity in tissues of stress-induced rats.
Chemical Compositions of the Essential Oil Extracted from the Seeds of Garcina Kola, and Its Biological Activities
Authors: Olatunde Olagoke Zacchaeus , Tian Danian , Yong Jianping , Lu Canzhong
Published: July 2021

The essential oil was obtained from the seeds of Garcina kola and its compositions were investigated by GC-MS and ICP-MS, respectively. 74 organic compounds and 9 trace elements beneficial to human health were confirmed in this oil. Then, the in vitro antioxidant and anticancer activities were evaluated accordingly. The results showed that this essential oil exhibited stronger antioxidant activity against DPPH⸱ with the scavenging rate of 94.19% at 0.2 mg/mL, as well as potent inhibition against gastric cancer, lung cancer(A549) and Hela cell lines with the inhibitions of 96.397%±0.929, 98.005%±0.513 and 94.77±2.09 respectively at 8.3 mg/mL. While it exhibited moderate inhibition against the human breast carcinoma cells (MCF-7) with the inhibition of 59.257%±4.544 at 8.3mg/mL. In consideration of Garcina kola being consumed in Nigeria for a long time, this essential oil obtained from the Garcina kola can be used in the field of food, cosmetic or drugs.
Effect of Curcuma longa Crude Extract, Curcumin and Nano Curcumin-based Gel Topical Administration on Excised Skin Wound Healing in Swiss-Webster Mice
Authors: Berbudi Afiat , Fadlillah Ali Akbar , Afni Merry , Atik Nur
Published: July 2021

Patients suffering from skin wounds often have their life heavily affected economically and socially. In general, wound healing consists of four different sequentially and overlapping phases. Interrupting those phases results in extending the healing time. Turmeric (Curcuma longa) is widely used by Indonesians to treat wounds, with curcumin as an active substance, which is proven to have various effects on improving wound healing. Therefore, this study aims to determine how the topical application of turmeric gel on affects the acceleration of wound closure. Analytical laboratory experiments were conducted on 24 male Swiss-Webster mice. Subjects were divided into four groups according to where the excision wounds were made on the back, and observed on days 0, 3, 6, 9, 12, and 15 post wound induction. The wound healing acceleration was observed after 3 (p = 0.0003), 6 (p = 0.0085), and 9 (p = 0.0023) days in C. longa-treated mice compared to the control group. However, there was no significant difference found on days 12 and 15 after wounding. In addition, the area under the curve analysis shows significant difference between the C. longa-treated group compared to the control, but not with the group treated with neither curcumin nor nano curcumin gel. In conclusion, topical application of 3% C. longa extract gel improves excised skin healing.
Basic of Medicinal Products Reimbursement: A Comparative-legal Analysis to Ukraine: An update
Authors: Maika Nataliia , Kalyniuk Natalia , Sloma Valentyna , Sheremeta Liudmyla , Kravchuk Leonid , Stefanyshyn Kateryna , Kravchuk Larysa
Published: July 2021

The feasibility of training future medical professionals on the basis of interdisciplinary integration is explored in the article. Analyzed through the lens of medical knowledge in legal knowledge, drug reimbursement as a process by which the health care system affects the availability of medicines and medical services to the public. The peculiarities of drug reimbursement in Ukraine have been investigated using the comparative legal method.
Medicinal Plants – Derived Natural Products and Phytochemical Extract as Potential Therapies for Coronavirus : Future Perspective
Authors: Ahmad S Rehan
Published: July 2021

On 11th March 2020 , the WHO has declared that the Coronavirus 2 ( SARS-CoV-2) or noval coronavirus ( COVID-19) as Global Pandemic in the whole world . Yet there is no vaccine or any kind of special treatment developed even though all the nations are testing several therapeutic molecules. Different herbs that are traditional are also being used with conventional drugs since the COVID-19 outbreak and are showing promising results in for the treatment of the patients. In this paper, we will review on the use of the natural products and its findings on how it is being used for treating and preventing the infection of COVID-19.. Only those reports were included that WHO edited in the situation. The extracts of the various herbal products and the molecules that are purified exert an anti-SARS-CoV-2 action and they inhibit the virus directly since the entry of the virus by replicating them. It is even interesting to find that some of the herb related products are able to block the C-2 receptors that are protease serine TMPRRS2. These are the proteins COVID-19 virus requires to infect the human cells. Additionally it was also seen that the that he natural products we able to inhibit proteins such as papain-like or chymotrypsin-like proteases that were required in the life cycle of the SARS-CoV-2. Hence, it is concluded that the natural products can be used in combination or alone as an alternative for preventing or treating of the novel corona virus infection.
A Single Centre, Prospective, Randomized, Open Labelled Clinical Study to Evaluate the Effectiveness of Siddha Poly Herbal Formulation, Viprotm, Towards the Management of Uncomplicated Respiratory Infection
Authors: R Arun kumar , Kumar R Maignana , M Duraivel , Basha A Ahamed , Stanley V Amalan , A Ruckmani
Published: July 2021

The objective was to evaluate the efficacy of ViproTM, a polyherbal formulation in the management of uncomplicated respiratory infection towards reducing the severity of clinical symptoms, reducing the worsening of clinical symptoms&complications and to determine its safety by detectingadverse events. The study was started after obtaining approval from Institutional Human Ethics Committee. It was a prospective, randomized controlled study done in 60 patients. Patients having uncomplicated respiratory infections, at least for less than 5 days, with clinical symptoms and signs of fever, myalgia, rhinitis, sore throat, throat pain, cough, expectoration and head ache were enrolled and randomly allocated to one of the three groups, A, B and C. Group A received standard treatment, group B ViproTM and group C ViproTM along with the standard treatment. All the patients were followed up for a period of 7 days from starting treatment. Telephonic follow up was done daily for 7 days and physical follow up on day 0, day 4 and day 7. During physical follow up, vitals & body temperature were recorded, general and systemic examination done, adverse events were noted and improvement in constitutional symptoms was assessed. Complete blood count (CBC) and nasal / throat swab for culture were done at the baseline and at the end of study. Vipro TM has demonstrated efficacy in alleviating the clinical symptoms similar to standard treatment. With regard to safety, ViproTM is associated with a few adverse events and all of them are minor in nature and subsided within 24 hours.
Drug Therapy for Refractory Trigeminal Neuralgia- A Review
Authors: Chhaparwal Yogesh , Kumar Mathangi , Chhaparwal Shubha
Published: July 2021

Trigeminal neuralgia is the most common neuralgia affecting the orofacial region. The condition characterized by sudden, severe electric shock like pain on the face with pain free periods and is termed as refractory period.Management of this condition is achieved through various drug therapies and in some cases, surgical intervention may be required. Refractory trigeminal neuralgia is a condition that is non responsive to the traditional line of therapy. This poses a challenge to the clinicians to offer the patients alternate options for pain control in these patients. In this review, an attempt has been made to discuss the various drug therapies in the management of refractory trigeminal neuralgia.
In vitro Assessment of Cytotoxic Activity of Bioactive Peptides from Momordica dioica and Solanum trilobatum against Human Colon Cancer Cells
Authors: S Rupachandra , Prateek Selvam Mario , Muthukumaran Nisha , Senthilkumar Sangamithra , Vaidhyalingam Sandhiya , K Dharshene , Natarajan Kasthuri
Published: July 2021

Plant peptides have gained attention in the medicinal field due to their high anti-microbial and anti-cancer properties. Various plant sources are being used to extract proteins and peptides to be used as a cure for a variety of diseases. The latest studies show that plant peptides are effective in the treatment of cancer due to their ability to preferentially bind to the receptors or membranes of cancer cells leading to tumour growth inhibition, cytotoxicity, decreased proliferation, and apoptosis. The peptides get internalized into the cells causing cancer cell agglutination and aggregation. In addition to acting as therapeutic agents, plant peptides are also used for the targeting of drugs specific to cancer cells. In this study, bioactive peptides were isolated from the seeds of Momordica dioica and leaves of Solanum trilobatum. They were screened and identified using HPLC and MALDI-TOF techniques. In this study, apoptosis was analyzed by the Hoechst 33342 staining method which detected the presence of condensed pycnotic nuclei in apoptotic COLO320DM and COLO205 colon cancer cellsat the maximum concentrations of 150 and 175 µg/mL of plant peptides.Further DCFH-DA staining indicated the intracellular ROS production in the treated COLO320DM and COLO205 colon cancer cells. Thus, the isolated bioactive plant peptides can be formulated towards the development of effective anticancer drugs for the treatment of colon cancer in humans.
Effect of Chronic Administration of Date Palm Seeds Extract on Some Biochemical Parameters, Oxidative Status and Caspase-3 Expression in Female Albino Rats
Authors: Mahmoud Hany S. , Zeidan Dalia W. , Almallah Amani A. , Ali Hassan Abeer Gaffer , Khalil Waleed F , Abdelrazek Heba M.A.
Published: July 2021

Date palm seeds have been debated for their beneficial effects on body health. Present study discussed the influences of chronic exposure palm date seeds extract on hepato-renal integrity and feed efficiency. Twenty one Albino female rats were randomly splitted into 3 groups. Group I, is the control and were given oral propylene glycol 10%. Group II, were given palm date seeds extract (200mg/kg body weight) dissolved in 10% propylene glycol. Group III, were given (400mg/kg body weight) palm date seeds extract dissolved in 10% propylene glycol. Treatments were given by intra gastric route daily for 60 days. Body weight, weight gain, feed efficiency ratio (FER) were determined. Serum liver and kidney functions tests were detected. Serum Super oxide dismutase (SOD) and Glutathione peroxidase (GPx) activities were estimated. Caspase-3 protein expression in kidney and liver was detected by immunohistochemistry (IHC). Results revealed improved FER in group II and III than control. Reduction in serum liver and kidney enzymes were evident in group II and III with improvement in albumin and total protein levels. Caspase-3 IHC in liver and kidney exhibited significant (P<0.05) reduction in palm date seeds extract treated groups especially in group III. Palm date seeds extract, seemed to be safe after chronic administration and has beneficial influences on liver and kidney. The beneficial effects of palm date seeds extract seemed due to its antioxidant effect that reduced hepato-renal caspase-3 protein expression.
PARP-1 inhibition attenuates the inflammatory response in the cartilage of a rat model of osteoarthritis
Authors: Liu Zili , Wang Honglin , Wang Shaoqian , Gao Jie , Niu Lei
Published: July 2021

Aims

Poly (ADP-ribose) polymerase (PARP) inhibitor has been reported to attenuate inflammatory response in rat models of inflammation. This study was designed to investigate the effect of PARP signalling in osteoarthritis (OA) cartilage inflammatory response in an OA rat model.

Methods

The OA model was established by anterior cruciate ligament transection with medial meniscectomy in Wistar rats. The poly (ADP-ribose) polymerase 1 (PARP-1) shRNA (short hairpin (sh)-PARP-1) and negative control shRNA (sh-NC) were delivered using a lentiviral vector and were intra-articularly injected into rats after surgery. The weight-bearing distribution of the hind limbs and the knee joint width were measured every two weeks. The expression levels of PARP-1, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in cartilage were determined using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot. The serum concentrations of inflammatory cytokines were detected using enzyme-linked immunosorbent assay (ELISA).

Results

PARP-1 expression level significantly increased in the cartilage of the established OA rat model. sh-PARP-1 treatment suppressed PARP-1 levels, decreased the Δ Force (the difference between the weight on ipsilateral limb and contralateral limb) and the knee joint width, inhibited cartilage matrix catabolic enzymes, and ameliorated OA cartilage degradation and attenuated inflammatory response.

Conclusion

PARP-1 inhibition attenuates OA cartilage inflammatory response in the OA rat model. Cite this article: Bone Joint Res 2021;10(7):401–410.
An RC filter for hydraulic switching control with a transmission line between valves and actuator
Authors: Haas Rainer , Lukachev Evgeny , Scheidl Rudolf
Published: July 2021

Hydraulic switching control with fast switching valves may excite unacceptable hydraulic and mechanical oscillations. Particularly if transmission lines are used, which have many oscillation modes, the avoidance of resonances by a proper timing of the switching pulses is hardly feasible. Then, passive filters may be a good solution. A simple RC filter applied to a cylinder drive with a transmission line to the switching valves is investigated by a transfer function analysis, numerical methods, and experiments. Properties of the dynamic behaviour are elucidated by approximate relations derived from the transfer function by asymptotic methods. A simple dimensioning rule recommends sizing the filter resistance close to the hydraulic impedance of the transmission line. The capacitance’s sizing is a trade off between a potential reduction of the resonance peak due to the cylinder natural frequency and a softness of the hydraulic drive system.
Towards Improved Model for User Satisfaction Assessment of Multimedia Cloud Services
Authors: Karadimce Aleksandar , Davcev Danco P.
Published: July 2021

Service providers are in constant search for appropriate tools that will help them to determine and measure the satisfaction of end-users. In terms of efficient utilization of network resources, they are constantly striving to guaranty the quality, availability, and responsibilities of the directly measurable parameters with the service-level agreements (SLA). The introduction of cloud computing technology aims to provide stable, reliable and encapsulated environment for users who use different types of mobile and desktop devices to simultaneously access shared resources that are available anywhere and at any time. However, what is lacking in this direction is an assessment of how much the end-users themselves are satisfied with the cloud-based services offered. This research has considered different cloud computing service categories, some of them have been extensively used and others are still under development. These services use a variety of organizational and infrastructure access models, making them easily accessible and practical for work. The very nature of cloud computing-based services allows dynamic allocation of resources based on end-user needs, which makes the process of evaluating the offered services complex. This research will deliver the most appropriate model for assessing the impacts of objective and subjective factors by using the Bayesian networks. The dynamic nature of these networks allows flexibility and adaptation to measure the impact of various influencing factors. The main contribution of this research is the introduction of a metrics for assessing the user satisfaction of the particular type of offered service. In that direction, this research has provided improved Quality of Experience (QoE) model for measuring and assessing the perception of the multimedia cloud-based services quality among end-users.
Efficient Position Estimation Based on GPU-Accelerated Content-based Image Retrieval
Authors: Kusamura Yuta , Amagasa Toshiyuki , Kitagawa Hiroyuki , Kozawa Yusuke
Published: July 2021

We propose an efficient position estimation method based on GPUaccelerated content-based image retrieval (CBIR). The idea is to use videos of first-person vision associated with geographical position information as the database. When a user sends a current subjective image, the system estimates the position using CBIR. Since features extracted from images are in general high-dimensional vectors, thousands of vectors are extracted even from a single image, resulting in high processing cost. On the other hand, GPUs (graphics processing unit) have contributed to accelerate various processing, while they are originally for graphics processing. Therefore, we utilize GPU to accelerate CBIR with appropriate data structures and algorithms. Moreover, our proposed method considers spatial locality of pedestrians in position estimation applications in order to improve accuracy. We demonstrate the efficiency and accuracy of the proposed method through experiments using a video dataset.
On the Use of Machine Learning for Identifying Botnet Network Traffic
Authors: Stevanovic Matija , Pedersen Jens Myrup
Published: July 2021

During the last decade significant scientific efforts have been invested in the development of methods that could provide efficient and effective botnet detection.As a result, an array of detection methods based on diverse technical principles and targeting various aspects of botnet phenomena have been defined. As botnets rely on the Internet for both communicating with the attacker as well as for implementing different attack campaigns, network traffic analysis is one of the main means of identifying their existence. In addition to relying on traffic analysis for botnet detection, many contemporary approaches use machine learning techniques for identifying malicious traffic. This paper presents a survey of contemporary botnet detection methods that rely on machine learning for identifying botnet network traffic. The paper provides a comprehensive overview on the existing scientific work thus contributing to the better understanding of capabilities, limitations and opportunities of using machine learning for identifying botnet traffic. Furthermore, the paper outlines possibilities for the future development of machine learning-based botnet detection systems.
Information Security Risk Assessment of Smartphones Using Bayesian Networks
Authors: Herland Kristian , Hämmäinen Heikki , Kekolahti Pekka
Published: July 2021

This study comprises an information security risk assessment of smartphone use in Finland using Bayesian networks. The primary research method is a knowledge-based approach to build a causal Bayesian network model of information security risks and consequences. The risks, consequences, probabilities and impacts are identified from domain experts in a 2-stage interview process with 8 experts as well as from existing research and statistics. This information is then used to construct a Bayesian network model which lends itself to different use cases such as sensitivity and scenario analysis. The identified risks’probabilities follow a long tail wherein the most probable risks include unintentional data disclosure, failures of device or network, shoulder surfing or eavesdropping and loss or theft of device. Experts believe that almost 50% of users share more information to other parties through their smartphones than they acknowledge or would be willing to share. This study contains several implications for consumers as well as indicates a clear need for increasing security awareness among smartphone users.
An Experimental Study of SmallWorld Network Models for Wireless Networks
Authors: Dong Ziqian , Wang Zheng , Xie Wen , Emelumadu Obinna , Bi Lin Chuan- , Rojas-Cessa Roberto
Published: July 2021

The concept of small world phenomenon has been observed and applied in many types of networks. This paper presents a study of two small-world network models in clustering formation and routing in wireless network, the Watts and Stragtz’s (WS) and the Newman and Watts (NW) models and evaluates their properties in term of average node degree and path length. We tested the small world phenomenon in wireless networks by simulating a wireless mobile ad hoc network with distributed routing protocols. We present the research challenges of bridging the gap between theoretical models and practical wireless network implementation. This study provides insights on how wireless networks behave under small world network models with distributed routing protocols.
Vulnerability Assessment and Experimentation of Smart Grid DNP3
Authors: Darwish Ihab , Igbe Obinna , Saadawi Tarek
Published: July 2021

Smart-grids security is becoming a challenging research area that has emerged in recent years facing the energy sector. Threats are arising every day that could cause great scale of damages in critical infrastructure. Our paper will assess vulnerabilities pertaining to internal security threats associated with the smart grid.We will perform penetration testing using various attack scenarios in a simulated virtual environment involving DNP3 protocol. Vulnerability analysis and penetration testing involving Man-in-the-middle (MITM) attack will be addressed. Ultimately, by utilizing theoretical modeling of smart-grid attacks using game theory, we will be able to optimize our detection and mitigation strategies to reduce cyber threats in DNP3 environment. Intrusion detection system (IDS) will be necessary to identify attackers targeting the smart grid infrastructure. Mitigation techniques will ensure a healthy check of the network. Performing DNP3 vulnerabilities assessment, security attacks, detections, preventions and counter measures will be our goals to achieve in this research paper.
Lazarus: Data Leakage with PGP and Resurrection of the Revoked User
Authors: Ruiz Rodrigo , Winter Rogério
Published: July 2021

The cybersecurity is the issue on the international agenda. The abuse of communication and faulty software is a common practice that brings the decade of 70. Invariably technology is the great protagonist of data leakage and loss of privacy. However, issues related to cybersecurity are founded on sociotechnical approach: technology, people, processes and environment, which interact indistinctly in a sensitive relationship. In this intricate sociotechnical environment of cybersecurity, this paper discloses a flaw in Symantec Encryption Desktop (SED), which can allow the leakage of sensitive information from governments, military and research centers around the world. In this context, as an example, the National Aeronautics and Space Administration (NASA) uses the Symantec Pretty Good Privacy (PGP) Encryption Desktop (SED). The Technology is not the main culprit for data leakage. Sometimes, the users are influenced by sophisticated marketing campaigns, which reaffirms the quality of products and services. In practice, this work is focused in the design errors and past vulnerabilities which are still present in recent technological solutions and allow data leakage and loss of privacy in a general way.
End-to-End Reliability and Optimization of Intra and Inter-Domain IMS-based Communication Networks
Authors: Kamyod Chayapol , Nielsen Rasmus Hjorth , Prasad Neeli Rashmi , Prasad Ramjee , Aunsri Nattapol
Published: July 2021

End-to-end system reliability and availability of different IMS-based network communication scenarios have been simulated and analyzed by using the combination of effective stochastic processes and models. Besides, both system reliability and availability characteristics of Intra and Inter IP multimedia subsystem (IMS) domain communication networks have been simulated and compared with different redundancy conditions. Moreover, parallel redundancies of the core IMS units were optimized at different availability or reliability standard conditions. The results demonstrate interesting system reliability characteristics of different communication scenarios and the results reveal possibility to create high reliability and availability system for the Next Generation Networks.
Adaptable Protocol Selection for Reliable Smart City Services
Authors: Elmangoush Asma , Magedanz Thomas
Published: July 2021

The Machine-to-Machine (M2M) communication intends to promote seamless interaction between connecting devices to enable the automation of decision making based on aggregated data. This forms the new Internet of Things (IoT) paradigm, which aims to increase the level of system automation by enabling devices and systems to exchange and share data, facilitating the communication for other industry branches. This article addresses the requirements of implementing reliable Smart services, with consideration to the heterogeneous traffic patterns rises from the huge variant devices. The main challenges for M2M communication are driven from integrating lowpower devices, each produce a different pattern of traffic, and low bandwidth networks. The heterogeneity of integrated communications technologies, targeted service domain and data representation, highlights the need to study the communication requirements of various services and the traffic patterns in the system.
Stochastic and reliability analysis of a propeller with model reduction
Authors: Bendaou Othmane , Rojas Jhojan Enrique , El Hami Abdelkhalak , Aannaque Abdeslam , Agouzoul Mohamed
Published: July 2021

Nowadays, design based on purely deterministic analyses has been replaced by stochastic and reliability analyses which consider the uncertainties affecting the design parameters. But from a numerical point of view, these analyses become costly for industrial mechanical applications (modelled by finite elements method) because of their great number of freedom degrees. In this work, we take an interest in reducing the CPU time for stochastic and reliability analyses of an industrial mechanical application by the modal condensation of his numerical model with the component mode synthesis method. The example of a propeller is studied to validate the proposed methods. The results of this study tend to show the considerable gain in CPU which we save by the using of our methodology.
Investigation of a side wall heated cavity by using lattice Boltzmann method
Authors: Djebali Ridha , Ganaoui Mohammed El , Sammouda Habib
Published: July 2021

The lattice Boltzmann method based on the BGK model has been used to simulate laminar natural convection in a heated rectangular cavity on the uniform grid. The hydrodynamic and thermal fields are solved by using the double populations approach. A general benchmark has been carried out to show the effects of secondary parameters at their wide range. Excellent agreement is obtained by comparison with available literature.
Identification from measurements of mechanical fields by finite element model updating strategies
Authors: Ienny Patrick , Caro-Bretelle Anne-Sophie , Pagnacco Emmanuel
Published: July 2021

Inverse problem resolution methods are widely used in the determination of material behaviour. The optimisation of the parameters, as inputs into a well-defined system, is obtained from observed outputs such as kinematic field measurements. The aim of this paper is to summarize the research concerning one inverse method, Finite Element Modelling Updating, based on the use of these field measurements. This method is based on a combination of three components, described in the following three sections. First we present the optical field measurements applied to multi-axially loaded objects, together with their performances. Then we outline the use of Finite Element Modelling for achieving a correlation between numerical fields and their experimental counterparts. Finally we describe the identification process, together with cost functions, minimisation procedure and model validation analysis.
White-light speckle image correlation applied to large-strain material characterization
Authors: Broggiato Giovanni B. , Cortese Luca
Published: July 2021

In experimental mechanics, the possibility of tracking on component surfaces the full-field stress and strain states during deformation can be utilized for many purposes such as formability limits determination, quantification of stress intensification factors, material characterization and so on. Concerning the last topic, an interesting application could be a direct identification of the elasto-plastic material response up to large deformation. It is well known, in fact, that with traditional measurement devices it is possible to retrieve the true equivalent stress versus true equivalent strain data from tensile tests only up to the onset of necking, where localization starts to occur. This work aims to show how from the knowledge of a tensile test full-field strain and of load data it will be possible to obtain the full-stress field as well as the complete material elasto-plastic behavior.
Assessment of the contact stress distribution dependent on functional and design parameters after total hip arthroplasty
Authors: Rixrath Emmanuel , Wendling-Mansuy Sylvie , Chabrand Patrick
Published: July 2021

A numerical model was developed to assess the contact stress distribution in total hip prosthesis as a function of geometrical parameters such as the clearance between the bearing surfaces, the inclination and thickness of the UHMWPE cup. The contact stress distribution model proposed is submitted to static loading considering the maximal force during gait and jogging. The results shows that the magnitude of the maximal contact stress remains constant for inclination values in the range of [0-35°] and increase significantly with the cup clearance and liner thickness for inclination values in the range of [35°-65°]. This model could be improved by considering other factors such as friction and dynamic loading conditions. This approach would permit to bring new perspectives for studying the long-term behaviour of total hip prostheses.
A 3D Chebyshev-Fourier algorithm for convection equations in low Mach number approximation
Authors: Bouloumou Ouafa , Serre Eric , Fröhlich Jochen
Published: July 2021

A three-dimensional spectral method based on Chebyshev-Chebyshev-Fourier discretizations is presented in the framework of the low Mach number approximation of Navier-Stokes equations. The working fluid is assumed to be a perfect gas with constant thermodynamic properties. The generalized Stokes problem, which arises from the time discretization by a second-order semi-implicit scheme, is solved by a preconditioned iterative Uzawa algorithm. Several validation results are presented in the case of steady and unsteady flows. This model is also evaluated for natural convection flows with large density variations in the case of a tall differentially heated cavity of aspect ratio 8. It is found that on contrary to convection at small temperature differences (Boussinesq), the 2D unsteady solution at Ra = 3.4 x 105 is unstable to 3D perturbations.
Advanced parallel computing in material forming with CIMLib
Authors: Mesri Youssef , Digonnet Hugues , Coupez Thierry
Published: July 2021

This paper presents a fully parallel multi-component Library called CIMLib. CIMLib contains a set of components that allow to build efficiently numerical simulation of a various processes mainly in material forming. We describe in this paper the main components of the library: parallel mesh partitioning, parallel remeshing, the Finite Element modeling and the parallel storage and visualization. Two large numerical simulations are presented: the first one focuses on a multi-bodies contact problem, including friction, for complex 3D forming processes. The mesh is evolving during the simulation from 52K nodes to 7M nodes and 64 cores are used to handle this application. The second simulation concerns the multiphase problems involved in the manufacturing processes of full parts. The simulation is done using 88 processors and the mesh is refined during the simulation the final mesh has over 25M nodes.
A direct numerical integration scheme for visco-hyperelastic models using radial return relaxation
Authors: Lejeunes Stéphane , Méo Stéphane , Boukamel Adnane
Published: July 2021

In this paper, a numerical integration scheme of the evolution laws for viscohyperelastic models is proposed. The starting points of the method are the exponential mapping (Reese et al., 1998) and the radial return (Weber et al., 1990; Simo, 1988). The originality of this work lies in the substitution of a differential tensorial system by a scalar one with two equations and two unknowns and in a first order Taylor expansion of them. In this way an analytical approximated exponential solution is finally obtained.
A partitioned Newton method for the interaction of a fluid and a 3D shell structure
Authors: Fernández Miguel Ángel , Gerbeau Jean-Frédéric , Gloria Antoine , Vidrascu Marina
Published: July 2021

We propose a new fluid-structure algorithm based on a domain decomposition paradigm. The method is based on the principle “linearize first, then decompose” whereas the usual schemes are generally “nonlinear in subdomains”. The proposed approach is more attractive when the complexity of the structure is high, which is the case with the structural model used in this study (nonlinear 3D shell). Another contribution of this paper is to investigate the use of a Neumann-Neumann preconditioner for the linearized problem. In particular, it is shown that when this preconditioner is adequately balanced, it tends to the Dirichlet-Neumann preconditioner because of the heterogeneity of the fluid-structure problem.
Contact problems for particles in a shear flow
Authors: Verdon Nicolas , Lefebvre-Lepot Aline , Lobry Laurent , Laure Patrice
Published: July 2021

This paper focuses on improving the description of the contact between solid particles in a fluid flow. The numerical approach used is related to the fictitious domain method for the fluid–solid problem. It is associated to a gluey particle model in order to improve the behaviour of the particles during their contacts as a Lagrangian method is applied for their displacement. The numerical methodology is validated through 2D and 3D computations describing interactions of two particles in a shear flow. The results obtained show the ability of the scheme to recover the reversibility of the Stokes equations, even for 3D configurations. Finally, another example is studied with larger number of particles.
Geometrically nonlinear analysis of thin shell by a quadrilateral finite element with in-plane rotational degrees of freedom
Authors: Boutagouga Djamel , Gouasmia Abdelhacine , Djeghaba Kamel
Published: July 2021

We present in this research article, the improvements that we made to create a four nodes flat quadrilateral shell element for geometrically nonlinear analysis, based on corotational updated lagrangian formulation. These improvements are initially related to the improvement of the in-plane behaviour by incorporation of the in-plane rotational degrees of freedom known as “drilling degrees of freedom” in the membrane displacements field formulation. In the second phase, a co-rotational spatial local system of axes which adapts well to the problems of quadrilateral elements is adopted, while ensuring simplicity and effectiveness at numerical level. The required goal being mainly to have a robust thin shell element associated with a simplified formulation. The obtained element remains economic, and showing a robust behaviour in delicate situations of tests.
Behavioural Modelling of WSN MAC Layer Security Attacks: A Sequential UML Approach
Authors: Pawar Pranav M. , Nielsen Rasmus H. , Prasad Neeli R. , Ohmori Shingo , Prasad Ramjee
Published: July 2021

Wireless sensor networks (WSNs) are growing enormously and becoming increasingly attractive for a variety of application areas such as tele-health monitoring, industry monitoring, home automation and many more. The primary weakness shared by all wireless application and technologies is the vulnerability to security attacks/threats. The performance and behaviour of a WSN are vastly affected by such attacks. In order to be able to better address the vulnerabilities of WSNs in terms of security, it is important to understand the behaviour of the attacks. This paper addresses the behavioural modelling of medium access control (MAC) security attacks in WSNs. The MAC layer is responsible for energy consumption, delay and channel utilization of the network and attacks on this layer can introduce significant degradation of the individual sensor nodes due to energy drain and in performance due to delays. The behavioural modelling of attacks will be beneficial for designing efficient and secureMAClayer protocols. The security attacks are modelled using a sequential diagram approach of Unified Modelling Language (UML). Further, a new attack definition, specific to hybrid MAC mechanisms, is proposed.
Identity Authentication and Capability Based Access Control (IACAC) for the Internet of Things
Authors: Mahalle Parikshit N. , Anggorojati Bayu , Prasad Neeli R. , Prasad Ramjee
Published: July 2021

In the last few years the Internet of Things (IoT) has seen widespreadapplication and can be found in each field. Authentication and accesscontrol are important and critical functionalities in the context of IoTto enable secure communication between devices. Mobility, dynamicnetwork topology and weak physical security of low power devices in IoTnetworks are possible sources for security vulnerabilities. It ispromising to make an authentication and access control attack resistant andlightweight in a resource constrained and distributed IoT environment.This paper presents the Identity Authentication and Capability basedAccess Control (IACAC) model with protocol evaluation and performanceanalysis. To protect IoT from man-in-the-middle, replay and denial ofservice (Dos) attacks, the concept of capability for access control isintroduced. The novelty of this model is that, it presents an integratedapproach of authentication and access control for IoT devices. Theresults of other related study have also been analyzed to validate andsupport our findings. Finally, the proposed protocol is evaluated byusing security protocol verification tool and verification results showsthat IACAC is secure against aforementioned attacks. This paper alsodiscusses performance analysis of the protocol in terms of computationaltime compared to other existing solutions. Furthermore, this paper addresseschallenges in IoT and security attacks are modelled with the use casesto give an actual view of IoT networks.
Authentication Mechanisms in the 5G System
Authors: Huang Xiaoting , Yoshizawa Takahito , Baskaran Sheeba Backia Mary
Published: July 2021

The 5G system introduces multiple new authentication mechanisms. The initial 5G specification in 3GPP Release 15 defines the initial security solution including primary and secondary authentication. Further enhancements and additional security features are added in Release 16; some of them introduce new types of authentication. As a result, the scope and meaning of ‘authentication’ has expanded. This is a new trend in the 5G system as it introduces new concepts that did not exist in the preceding generation systems. One such example is the slice authentication for which the authentication is performed at the network slice level. As a result, the authentication mechanisms become more complex. This paper clarifies the details of each of these different authentication mechanisms.
Impact of Disruptive Technology on Sustainable Enterprise Resource Planning (S-ERP)
Authors: Soprakan Chulalux , Kiattisin Supaporn
Published: July 2021

In the 21st century, we face the disruptive technology in several ways; meanwhile, the business industry still needs a sustainable system for their ultimate goal as a competitive advantage in terms of differentiation focus or cost focus. This research provides the impact result once business utilizes emerging technology in their company. For the methodology, we use factors in technology adoption from the innovation diffusion theory (IDT) for new-technology selection. In the case study, we use simulation robotic process automation (RPA) installation in the routine business process to estimate business impact. Accounting tools such as payback method (PP), net present value (NPV), internal rate of return (IRR) are used to estimate cost savings and return on investment. RPA is one of many technologies that can work collaboratively with the existing enterprise resource planning (ERP) system, new technology, and business process improvement (BPI) process. The experience results show that the RPA provides time-saving 14 times in total processes with payback result in 3.6 years and 52% IRR.
Effectiveness of Contact Tracing Using KNN for COVID-19
Authors: Venkatasen Maheshwari , Mathivanan Sandeep Kumar , Mani Prasanna , Jayagopal Prabhu , P Thanapal , Sorakaya Somanathan Manivannan , Babu K Upendra , D Elangovan
Published: July 2021

COVID-19 virus started to outbreak in China in the year January 2020. Contact tracing is an open-minded measure of control that applies to an extensive range of transmissible diseases. It is being used to fight infections like SARS, tuberculosis, smallpox, and many sexually transmitted diseases (STDs). From the moment of the lockdown, there have been a great many talks of applications helping to combat the coronavirus. Technical developers bring a solution to this problem by providing tools that help to contain the coronavirus. This kind of application is helpful, but it lacks in accuracy and privacy concerns. COVID-19 virus, irrespective of causes, solution, treatments, clinical signs, and symptoms is discussed in this paper. The main aim of this paper proposes a contact tracing using k-nearest neighbour, which shows the correct prediction of an affected person of COVID-19 based on the distance and also reduces the transmission of disease. It was tested on the WHO dataset obtained the prediction accuracy of which was carried out on clinical and quarantine data. The evaluation result shows that the contact tracing technique’s accuracy has been improved using the proposed algorithm.
Computer Vision Mobile System for Education Using Augmented Reality Technology
Authors: Tetiana Misiuk , Kondratenko Yuriy , Sidenko Ievgen , Kondratenko Galyna
Published: July 2021

This article analyzes the algorithms of computer vision, the features of the application of augmented reality technology and existing software modules, frameworks and libraries. The result is a computer vision mobile system (application) using augmented reality technology, which allows users (for example, students) to obtain additional virtual information about the research object and to be able to interact with it. The functional model of the system is formed, the process of application development using the Vuforia library is described and the results of the work are given. The result is an Android application, which using augmented reality tools, allows the user to obtain a virtual environment object in a real-world. This computer vision mobile system is intended for educational purposes, in particular for use in schools and universities for more effective interaction between users and educational material.
A Prescriptive Model for Migration to Microservices Based on SDLC Artifacts
Authors: Bajaj Deepali , Bharti Urmil , Goel Anita , Gupta S. C.
Published: July 2021

Microservices architectural style is gaining popularity in industry and is being widely adopted by large corporations like Amazon, Netflix, Spotify, eBay, and many more. Several other organizations are also preferring to migrate their existing enterprise scale applications to microservices architecture. Researchers have proposed various approaches for microservices decomposition to be used in migrating or rebuilding a monolithic application to microservices. Applying any available approach to an existing monolithic application is not a straightforward decision; thus, there is a need for guidelines that assist in the migration process. There are various challenges in a migration process because different migration approaches use different sets of input data to identify microservices. Since the available migration techniques are not structured, logically, selection of an appropriate migration strategy is a difficult decision for any system architect. So, it is a recurrent open research question – which migration technique should be adopted to get microservices for a legacy monolithic application? This paper addresses this research challenge by examining existing approaches for microservices migration and groups them based on software development life cycle (SDLC) artifacts. Our research also proposes a microservices prescriptive model (MPM) from the existing prominent microservice migration techniques. This model provides recommendation (1) for refactoring an existing legacy system to microservices, and (2) for new microservices development projects. Our study also helps in gaining more insight about greenfield and brownfield development approaches in microservices applications. Moreover, researchers and practitioners of the field can benefit from this model to further validate their migration approaches based on the available system artifacts.