scholarly journals Selection of the type of cooling for an overclocked Raspberry Pi 4B minicomputer processor operating at maximum load conditions

2021 ◽  
Vol 18 ◽  
pp. 55-60
Author(s):  
Jakub Machowski ◽  
Mariusz Dzieńkowski
Keyword(s):  
Maximum Load ◽  
Operating Conditions ◽  
Raspberry Pi ◽  
Lower Efficiency ◽  
Limit Values ◽  
Active Cooling ◽  
Extensive Documentation ◽  
Cheap Alternative ◽  
Processor Load ◽  
Selection Of

The Raspberry Pi is a computer platform that is widely used in education, has a very large community and extensive documentation. Therefore, it can be a good and cheap alternative to a traditional computer, a TV streaming device or a console for less demanding games. In the case of observing a lower efficiency of the microcomputer, one of many possibilities of improvement, which this device offers is overclocking the processor. It is associated with a proper selection of parameters (voltage, clocking) and software in order to achieve the highest possible performance of the dedicated Raspbian system. However, increasing the work efficiency causes the temperature rise up to the limit values. Therefore, an appropriate, i.e. effective, kind of cooling should be applied. Taking all these circumstances into account, an experiment was developed in which temperature measurements were taken during the maximum processor load on all cores at the clock setting that enabled reaching the highest performance. During the research three cases were considered: without the use of cooling, with passive cooling and with active cooling. The results showed that only the use of active cooling clearly improves the operating conditions of the device, due to lowering the temperature by about 16°C compared to the situation without cooling or with the use of a passive radiator.

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.

An Accurate Solution of the Gas Lubricated, Flat Sector Thrust Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 82-88 ◽  
Author(s):  
I. Etsion ◽  
D. P. Fleming
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Thickness Distribution ◽  
Maximum Load ◽  
Accurate Solution ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Practical Design ◽  
Minimum Film Thickness

A flat sector shaped pad geometry for gas lubricated thrust bearings is analyzed considering both pitch and roll angles of the pad and the true film thickness distribution. Maximum load capacity is achieved when the pad is tilted so as to create a uniform minimum film thickness along the pad trailing edge. Performance characteristics for various geometries and operating conditions of gas thrust bearings are presented in the form of design curves. A comparison is made with the rectangular slider approximation. It is found that this approximation is unsafe for practical design, since it always overestimates load capacity.

Adaptation Application to Engine Modelling

2007 ◽  
Author(s):  
Jude Iyinbor
Keyword(s):  
Measurement Data ◽  
Engine Performance ◽  
Performance Model ◽  
Operating Conditions ◽  
Adaptation Process ◽  
Design Point ◽  
Component Map ◽  
Important Measurement ◽  
Unknown Component ◽  
Selection Of

The optimisation of engine performance by predictive means can help save cost and reduce environmental pollution. This can be achieved by developing a performance model which depicts the operating conditions of a given engine. Such models can also be used for diagnostic and prognostic purposes. Creating such models requires a method that can cope with the lack of component parameters and some important measurement data. This kind of method is said to be adaptive since it predicts unknown component parameters that match available target measurement data. In this paper an industrial aeroderivative gas turbine has been modelled at design and off-design points using an adaptation approach. At design point, a sensitivity analysis has been used to evaluate the relationships between the available target performance parameters and the unknown component parameters. This ensured the proper selection of parameters for the adaptation process which led to a minimisation of the adaptation error and a comprehensive prediction of the unknown component and available target parameters. At off-design point, the adaptation process predicted component map scaling factors necessary to match available off-design point performance data.

scholarly journals Material Origins of Accelerated Operational Wear of RD-33 Engine Blades

2020 ◽  
Author(s):  
Adam Kozakiewicz ◽  
Stanislaw Jóźwiak ◽  
Przemysław Jóźwiak ◽  
Stanisław Kachel
Keyword(s):  
Chemical Composition ◽  
Construction Material ◽  
Operating Conditions ◽  
Design Stage ◽  
Strength Analysis ◽  
Jet Engine ◽  
Emergency Situations ◽  
Low Pressure Turbine ◽  
Propulsion Unit ◽  
Selection Of

The structural and strength analysis of the material used to construct such an important engine element as the turbine is of great significance, both at the design stage as well as during tests and expertises related to emergency situations. Bearing in mind the conditions above mentioned, the paper presents the results of research on the chemical composition, morphology and phased structure of the metallic construction material used to produce the blades of the high and low pressure turbine of the RD-33 jet engine, which is the propulsion unit of the MiG-29 aircraft. The data obtained as a result of the material tests of the blades allowed, on the basis of the analysis of chemical composition and phased structure, to determine the grade of the alloy used to construct the tested elements of the jet engine turbine. The structural stability of the material was found to be lower in comparison with engine operating conditions, which manifested itself as a clear decrease in the resistance properties of the blade material. The results obtained can be used as a basis for analyzing the life span of an object or a selection of material replacements, which enable to produce the analyzed engine element.

scholarly journals The Business Service Sector in India, Ireland and Poland. A Comparative Analysis

2019 ◽  
Vol 22 (2) ◽  
pp. 159-172
Author(s):  
Arkadiusz Mroczek
Keyword(s):  
Comparative Analysis ◽  
Service Sector ◽  
Operating Conditions ◽  
Business Service ◽  
Literature Study ◽  
Location Factors ◽  
Current Growth ◽  
Characteristic Features ◽  
Selection Of ◽  
Made In

The fast growth of the service sector is one of the characteristic features of the contemporary economy. Amongst other CEE countries, Poland is one of the emerging locations for this sector. The aim of the paper is to examine and compare the business service sector in India, Ireland and Poland. Both India and Ireland are exceptional locations for this industry, so comparing the state and operating conditions in Poland with those countries can be insightful. A literature study is used to determine the motives of companies undertaking offshore investments, upon which a selection of location factors is made. In the empirical part, those factors are analyzed in a descriptive way. This allows us to draw conclusions concerning this sector in Poland. This country, to some extent, possesses selected positive features of both India and Ireland, which explains the current growth of the sector.

scholarly journals Selection of efficient ships according to the criterion of marginal price at the feasibility study

2021 ◽  
pp. 172-181
Author(s):  
Oksana Y. Vasileva ◽  
Marina V. Nikulina Nikulina ◽  
Juri I. Platov Platov
Keyword(s):  
Fuel Consumption ◽  
Feasibility Study ◽  
Information Technologies ◽  
Optimization Methods ◽  
Relevant Information ◽  
Operating Conditions ◽  
Initial Stage ◽  
Level Of Use ◽  
High Level ◽  
Selection Of

The article deals with the problem of selecting efficient ships by the feasibility study in which brake power, main dimensions, payload, speed and fuel consumption are determined. The necessity of using the proposed selection at the initial stage of the ship's design is justified; the problems that arise at the present time are denoted. The purpose of the article is to propose a criterion for the selection of efficient vessels, "tied" to the operating conditions, based on the marginal cost of the ship. A method for its determination is presented. At the same time, annual revenues and operating costs should be determined by modern methods of business planning for the operation of the fleet. When searching for the parameters of the ship, the optimal fuel consumption is determined. The rest of the costs can be found according to the coefficients "tied" to the fuel consumption and calculated on the basis of existing prototypes. The results of calculations by the proposed method are shown; its merits and opportunities for improvement are noted with the availability of relevant information. The conclusion is made about the convenience and applicability of the proposed option for selecting efficient ship for the feasibility study based on optimization methods for determining the parameters of vessels under conditions of a high level of use of information technologies.

The system of components dosing in compound feed

2021 ◽  
pp. 62-70
Author(s):  
S. Yu. Bulatov ◽  
V. N. Nechaev ◽  
A. G. Sergeev
Keyword(s):  
Animal Husbandry ◽  
Technological Parameters ◽  
Optimal Diet ◽  
Limit Values ◽  
Feed Production ◽  
Predominant Type ◽  
Dosing Accuracy ◽  
Selection Of ◽  
Poultry Farming

Feed production, feeding of animals and poultry is an integral part of animal husbandry and poultry farming. Proper feeding of animals and poultry, which implies the making of an optimal diet with the input of useful premixes and vitamins, can increase their productivity. In Russia the predominant type of feeding is complete feed, which includes compound feed. Regardless of the type of feed in the process of its production, it is necessary to observe the proportions of its components. Dispensers are used for dosing, which depending on the purpose, are divided into mass and volume. We have made an attempt to generalize, systematize and implement the accumulated experience in the form of a scheme that allows us to understand the principle of operation of modern systems for dosing feed components, in which augers are used as feeding mechanisms. The purpose of the research was to build a scheme for selecting parameters and develop a methodology for studying the dosage system of feed components based on it. The results of the analysis of intellectual property protection documents and scientifi c works in the fi eld of dosing have been used to make a scheme for selecting parameters of the feed components dosing system. The results of observations on the operation of the developed system under production conditions and design features have been also taken into account. As a result of the research developed the scheme of selection of the operating parameters of the dosing system, revealed its shortcomings in the form of lower dosing accuracy with the decrease in the mass of the weighed components and the long search settings when composing the new diet. The methods have been developed to address the identifi ed defi ciencies in the determination of limit values of technological parameters.

scholarly journals A Proposed New Approach for the Assessment of Selected Operating Conditions of the High Voltage Cable Line

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5275
Author(s):  
Michał Borecki
Keyword(s):  
Correction Factor ◽  
External Environment ◽  
Extreme Temperature ◽  
Operating Conditions ◽  
Positive Temperature ◽  
Cable Line ◽  
Line System ◽  
New Approach ◽  
Selection Of ◽  
Calculation Models

Calculation models for the selection of cable lines used for expansion and modernization in the energy system and energy transmission planning are recognized tools supporting decision-making in both the energy sector and energy policy. At the same time, the above calculation models contain a large number of correction factors taking into account the temperature of the external environment at various points, the mutual influence of which is not taken into account. This means limitations to today’s common approaches to solutions, especially with regard to the required safety buffer for cable line selection. To meet this challenge, this article presents a parameter that takes into account the change and difference in temperature at various points in the external environment in the analyzed cable line systems. The purpose of this paper was to develop a new approach to the selection of a cable line in order to minimize failure during operation. For this purpose, possible temperature cases that may occur during line operation in different countries and at different rated voltages have been identified. Simulation models for individual cable line layouts were developed and the extreme temperature cases of the line operation for the maximum negative and positive temperature difference between the cable core and the external environment were considered in detail. The development of the curve of the change of the correction factor for the difference in the operating temperature of the cable line will allow for a more precise selection of the cable line parameters and the shortening of the current calculation model in terms of cable selection. In addition, this article presents a comparison of the change in the value of the correction factor from the change in temperature of a selected phase of a cable line system.

scholarly journals A GTCC-Based Underwater HMM Target Classifier with Fading Channel Compensation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Shameer K. Mohammed ◽  
Supriya M. Hariharan ◽  
Suraj Kamal
Keyword(s):  
Fading Channel ◽  
Rayleigh Fading ◽  
Automatic Target Recognition ◽  
Operating Conditions ◽  
Real Field ◽  
Classifier Performance ◽  
Acoustic Target ◽  
Artificial Neural Network Ann ◽  
Underwater Target ◽  
Selection Of

Underwater acoustic target classifiers are found to have many applications in military and security areas where a higher degree of prediction accuracy is needed that makes classifier efficiency and reliability an interesting subject. Classifiers are often trained with known acoustic target specimens with their characteristic feature set and tested with measurements obtained from the sonar that is deployed in the surveillance or observation zone. The selection of source-specific deterministic features in automatic target recognition (ATR) system is very significant, since it determines the reliability, efficiency, and success rate of the classifier. The robustness of the gammatone cepstral coefficients (GTCC) in combination with the statistical Euclidean distance, artificial neural network (ANN), and hidden Markov model (HMM) classifiers has been investigated, and its performance is compared with that of other feature extraction schemes. The classifier performance has been analyzed in Rayleigh fading conditions, based on which the performance is enhanced by incorporating an autoregressive (AR) Rayleigh fading channel compensation. The performance of the classifier in different operating conditions is investigated, with underwater target signals consisting of the real field data collected during expedition, and the results are presented in this paper.

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