scholarly journals Modelling an enterprise global IP network with multimedia services

2019 ◽  
Vol 6 ◽  
pp. 45-53
Author(s):  
Yoana Ivanova
Keyword(s):  
Simulation Model ◽  
Simulation Software ◽  
Multimedia Content ◽  
Multimedia Services ◽  
High Quality ◽  
Operational Costs ◽  
Ip Network ◽  
Packet Tracer ◽  
Quality Of Voice

The aim of this paper is building a simulation model of an enterprise global IP network with multimedia services using the network simulation software Cisco Packet Tracer. They are examined protocols for the realization of the VoIP service and providing multimedia content to end users with guaranteed high quality of voice and multimedia services. The result of the research is a simulation model implemented using Cisco networking devices that are selected due to their advantages compared to other device models. The applied contributions are expressed in reducing the operational costs and ensuring reliable protection and stability when the load of the network is maximum.

Novel Dielectric Stack Actuators for Dynamic Applications

2012 ◽  
Author(s):  
Sven Herold ◽  
William Kaal ◽  
Tobias Melz
Keyword(s):  
Simulation Model ◽  
Surface Resistance ◽  
Design Concept ◽  
Metal Electrodes ◽  
High Quality ◽  
Complex Material ◽  
Simulation Results ◽  
Actuator Design ◽  
Load Conditions

In order to realize dielectric elastomer stack actuators suitable for dynamic applications a new actuator design with rigid, perforated electrodes is developed. The low surface resistance of the metal electrodes predestines this concept for dynamic applications where higher currents are present. Detailed numerical analyses are performed to show the potential of this approach, to study the complex material deformation and to optimize the aperture geometry. A multilayer stack actuator is then manufactured and characterized experimentally under various load conditions to gain suitable parameters for a parametrized model. It is subsequently used to attenuate vibrations of a truss structure. By careful adjusting the parameters it functions both as passive absober and as actuator. A comparison of experimental and simulation results proves the high quality of the simulation model. The work shows the great potential of the new design concept for future applications especially in the field of smart structures.

scholarly journals Effect of the sorting track profile change on the it’s occupancy quality at train humping

2018 ◽  
Vol 216 ◽  
pp. 02012 ◽  
Author(s):  
Konstantin Kornienko ◽  
Sergei Bessonenko
Keyword(s):  
Simulation Model ◽  
High Quality ◽  
Run Off ◽  
Profile Correction ◽  
Probability Of Collision ◽  
Profile Change

To increase the hump yard capacity, it is necessary to ensure high quality of sorting track occupancy. The purpose of this paper is to study the effect of changing the track profile on the quality of its occupancy. The simulation model developed for occupancy of sorting tracks based on the calculation of the speed of the cut and taking the following into consideration was used for the study: the possibility of starting the cut movement after a stop, errors in operation of the devices in charge of the speed of releasing the cut to the track, the possibility of displacement of the cars when the next cut collides with them. A real profile of the sorting facility track was analyzed as an example of it. It was determined that the profile caused strong effect on the track occupancy quality. The sagging of the profile causes an increase in the probability of collision of the cuts with exceeding the permissible speed. An increase in the up-gradient reduces the range of the run-off distance, which in turn causes an increase in the number of car back-ins. Profile correction will allow increasing the track occupancy quality.

Dynamic Characteristics Simulation of Radiator Fin Blanking Machine Hydraulic System

2014 ◽  
Vol 687-691 ◽  
pp. 496-499
Author(s):  
Jie Wang
Keyword(s):  
Simulation Model ◽  
Dynamic Characteristics ◽  
Hydraulic System ◽  
Simulation Analysis ◽  
Good Condition ◽  
Hydraulic Cylinder ◽  
Simulation Software ◽  
Product Line ◽  
Leading Role

The hydraulic system of radiator fin blanking machine plays a leading role in the radiator fin production. Its performance directly affects the efficiency and quality of product line. The hydraulic system of blanking machine for radiator was composed of blanking circuit and support circuit. The hydraulic system realizes the cutting action using the reciprocating movement of the hydraulic cylinder. The hydraulic system simulation model was built by the simulation software of AMESim in this paper. Using the simulation model, the simulation analysis of the dynamic characteristics of hydraulic system were completed. The hydraulic system has been through the debugging and put into production, running in good condition.

Validation of Shiphandling Simulation Models

2011 ◽  
Author(s):  
Tor E. Berg ◽  
Edvard Ringen
Keyword(s):  
Simulation Model ◽  
Numerical Models ◽  
Real Life ◽  
Simulation Models ◽  
Test Scheme ◽  
High Quality ◽  
Simulation Tools ◽  
Benchmark Study ◽  
Actual Application

This paper describes the need for improved methods for validating numerical models used in shiphandling simulators. Such models vary in complexity, from rather simplistic models used for initial shiphandling training at maritime training centers to high-quality models used in the study of advanced marine operations. High-quality simulation models are also used in investigations of maritime accidents such as collisions and groundings. The SIMMAN 2008 conference presented the results of benchmarking studies of simulation tools currently used by research institutes, universities and training centers around the world. Many of these tools employ models based on numerical calculations using methods based on potential or viscous fluid flow, experiments using scale ship models (free running or captive) or semi empirical expressions based on regression analysis of previous model tests. The organizers of SIMMAN 2008 made the hull characteristics of certain ship types available for a comparative study of simulation maneuvering models. The outcome of the benchmark study (using IMO standard maneuvers as case study maneuvers) showed that simulated results varied significantly. In the opinion of the authors, there is an urgent need for new validation studies. The first part of this paper discusses the concepts of simulation model fidelity, verification and validation and the present guidelines issued by ITTC for validation of maneuvering simulation models. The second part looks at the outcomes of the SIMMAN 2008 conference and describes MARINTEK’s contribution to the benchmark study. The use of real-world measurements in model validation is briefly discussed. The need for registration of actual test conditions, as well as the types of tests that should be included in a test scheme, are presented. Finally, the authors discuss validation requirements with respect to the actual application of the selected simulation model as an engineering tool that can be transferred to training simulators used by maritime training centers. It is assumed that simplified simulation models may reduce the quality of simulator based training for ship officers. It is believed that increased quality of simulator model will improve the transfer of training from simulators to real life operations and remove some of the uncertainties related to investigation of maritime accidents.

WPC Soft: Prototype Simulation Software to Predict the Internal Changes During Hot Pressing of Wood Plastic Composites

2014 ◽  
Vol 9 (1) ◽  
pp. 45-57 ◽  
Author(s):  
Ritu Gupta ◽  
Norrozila Sulaiman ◽  
Arun Gupta ◽  
Mohammed Dalour Hossen Beg
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Hot Pressing ◽  
Simulation Software ◽  
Compression Moulding ◽  
Moulding Process ◽  
Plastic Composite ◽  
Pressing Time ◽  
Mathematical Equations

Abstract This paper proposes a simulation model for the heat transfer of the wood plastic composite (WPC), manufactured by using the compression moulding technique. A generalised one-dimensional model for transient heat transfer during hot pressing is proposed based on mathematical equations and engineering principles. Finite difference approach is applied using numerical methods, and a solution to the problem is obtained using explicit method. MATLAB is used for programming purpose. The results obtained from the simulation model are then validated with the experimental data available in the literature. It is observed that the simulation results are in close agreement with the experimental results within an acceptable range. The model is integrated with the GUI in the form of simulation software, and the user does not need knowledge of MATLAB. A case study is also performed for the application of the model. This simulation model can be useful for gaining the insight during compression moulding process and may be helpful to optimize the hot-pressing parameters to improve the quality of WPC, while reducing the pressing time.

A Cross Layer Spoofing Detection Mechanism for Multimedia Communication Services

2012 ◽  
pp. 257-272
Author(s):  
Nikos Vrakas ◽  
Costas Lambrinoudakis
Keyword(s):  
Low Cost ◽  
Cross Layer ◽  
Multimedia Services ◽  
High Quality ◽  
Detection Mechanism ◽  
Communication Services ◽  
Man In The Middle ◽  
Spoofing Detection ◽  
Cryptographic Scheme

The convergence of different network types under the same architecture offers the opportunity for low cost multimedia services. The main objective has been the high quality of the provided services. However, considering that older equipment with limited processing capabilities may be present in such environments, a tradeoff between security and service quality is inevitable. Specifically, low resource enabled devices cannot utilize state of the art security mechanisms, such as IPSec tunnels, integrity mechanisms, etc., and they simply employ HTTP Digest authentication. The lack of integrity mechanisms in particular raises many security concerns for the IMS infrastructures. Attacks such as Man in the Middle (MitM), spoofing, masquerading, and replay that can be launched in IMS environments, have been pinpointed in bibliography by various researchers. Moreover, an internal attacker may utilize his legitimate security tunnels in order to launch spoofing and identity theft attacks. This paper presents a cross-layer spoofing detection mechanism that protects SIP-based infrastructures from the majority of the aforementioned attacks without requiring an additional cryptographic scheme which would inevitably introduce considerable overheads.

Influence of technology parameters of free-cutting steel continuous casting on the billet internal structure

2020 ◽  
Vol 76 (2) ◽  
pp. 139-142
Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova
Keyword(s):  
Regression Analysis ◽  
Continuous Casting ◽  
Internal Structure ◽  
Sulfur Content ◽  
Manganese Content ◽  
High Quality ◽  
Correlation And Regression Analysis ◽  
Cutting Steel ◽  
Continuously Cast

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.

Implementasi Voip Server Berbasis IPV6 Dengan Raspberry PI

2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo
Keyword(s):  
Internet Protocol ◽  
Wireless Transmission ◽  
Raspberry Pi ◽  
Test Results ◽  
Average Delay ◽  
Ipv6 Network ◽  
Ip Network ◽  
Selection Of ◽  
Better Than

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.

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