17 research outputs found
AN APPROACH TO ANALYSIS OF NON LINEAR CHARACTERISTICS OF MARINE ENGINE\u27S SPEED REGULATORS
Marine engine speed regulators have been observed as non-linear dynamics models, those mathematical characteristics are similar to system of differential equations. Theoretical and experimental analysis of such has been done, to comprise behaviours of regulator models. Mathematical approach to equation solutions is determined by well known methods of numeric integration, but approach to Runge-Kutta method was preferred to reach reliable values of unknown system variables. Computer simulation and computer-aided design is the best tool for system modelling representation. Therefore, an acceptable software algorithm has been presented to enable understanding of software simulated analysis, and to get numerical solutions of system equations
A Dial Call Method Based on Specific Open Source Switchboard System
U radu su prikazani trendovi razvoja i implementacije VoIP nasuprot tradicionalnoj tehnologiji. Poseban naglasak dan je na statistike nekih europskih država, poveÄanje broja korisnika VoIP usluge i predviÄanja razvoja spomenutoga u bliskoj buduÄnosti. TakoÄer je prikazana primjena sustava otvorenoga koda pri ostvarivanju telefonskih poziva. Na temelju analize postojeÄeg sustava, standardnih procedura i raspoložive tehnologije, predložena je jedna metoda ostvarivanja poziva temeljena na odreÄenom sustavu otvorenoga koda telefonske centrale.In this work the trends of development and implementation of the VoIP system are presented in comparsion to the traditional technology. There is an emphasize for the statistics of some European countries, the increased number of VoIP users and a forecast of development in the near future. In addition, this paper has shown the application of open source systems in dial call procedures. Analysing the existing system, comparing the standard procedures as well as, available technologies, one dial call method has been proposed based on a specific open source switchboard system
JEDAN PRISTUP ANALIZI SILA KOJE DJELUJU NA STAPNI MEHANIZAM DIZELSKIH MOTORA
Analiza sila stapnog mehanizma pri konstrukciji dizelskih motora svakako je od prvorazrednog znaÄenja za uspjeÅ”no rjeÅ”avanje cijelog niza elemenata i za kvalitetan rad, kako motora tako i stroja koji motor pogoni. U radu se analiziraju sile koje djeluju na stapni mehanizam
s posebnom pozornoÅ”Äu na sile od tlaka plinova i sile inercije. Uporabom kompjutora u analizi moguÄe je uzeti u obzir utjecaj velikog broja parametara i izbor njihovih optimalnih vrijednosti, Å”to rezultira pouzdanom konstrukcijom, mirnim i dugotrajnim radom motora
KOMPJUTORI U NASTAVI BRODSKIH DIZELSKIH MOTORA
Prikazom karakteristiÄne tematske nastavne jedinice u kojoj je izložena jedna moguÄnost uporabe kompjutora u nastavi predmeta "Brodski dizelski motori", ilustrira se tvrdnja: Nastava s kompjutorima omoguÄuje da se skrati vrijeme potrebno za izlaganje struÄnog predmeta; uz
poveÄanje kvalitete uÄenja i povoljan utjecaj na odgoj kreativnih sposobnosti studenata
Testing TCP Traffic Congestion by Distributed Protocol Analysis and Statistical Modelling
In this paper, a solution is proposed for testing TCP congestion window process in a real-life network situation during stationary time intervals. With this respect, the architecture of hardware and expert-system-based distributed protocol analysis is presented that we used for data acquisition and testing, conducted on a major network with live traffic (Electronic Financial Transactions data transfer), as well as the appropriate algorithm for estimating the actual congestion window size from the measured data that mainly included decoding with precise time-stamps (100ns resolution locally and 1ms with GPS clock distribution) and expert-system comments, resulting from the appropriate processing of the network data, accordingly filtered prior to arriving to the special-hardware-based capture buffer. In addition, the paper presents the statistical analysis model that we developed for the evaluation whether the data belonged to the specific (in this case, normal) cumulative distribution function, or whether two data sets exhibit the same statistical distribution - the conditio sine qua non for a TCP-stable interval. Having identified such stationary intervals, it was found that the measured-data-based congestion window values exhibited very good fitting (with satisfactory statistical significance) to the truncated normal distribution. Finally, an appropriate model was developed and applied, for estimating the relevant parameters of the congestion window distribution: its mean value and the variance.
KEY WORDS: protocol analysis, TCP-IP, testing, traffic congestion, statistical analysis, parameter estimatio
Comparison of Selected Electronic Payment Methods with a Short Reference to Maritime Industry
U ovom radu prikazana je primjena osnovnih tipova platnih transakcija i elektroniÄkih sredstava plaÄanja. Prikupljanjem i
usporedbom odreÄenog broja podataka, analizirane su razliÄite primjene elektroniÄkih platnih transakcija na zahtjevnim
svjetskim tržiŔtima, s osvrtom na pomorstvo. Poseban naglasak stavljen je na zakonsku regulativu kojom Europska unija
želi definirati i Å”to bezbolnije uvesti elektroniÄki novac kako bi se izbjegle nove nestabilnosti na financijskom tržiÅ”tu.
Na temelju obrade dostupnih podataka, polazeÄi od odreÄenog pristupa naÄinu razvrstavanja platnih transakcija uz
uporabu elektroniÄkih platnih sredstava, uz istaknutu ulogu elektroniÄkog novca i primjenu u pomorstvu, predložen je
jedan od moguÄih naÄina grupiranja Äimbenika elektroniÄkog poslovanja u pomorskoj industriji.This paper has shows the application of the basic types of payment transactions and electronic means of payment.
Collecting and comparing a number of data, various types of electronic payment transactions have been analyzed
in the demanding worldwide markets, with emphasis on maritime transport. Special emphasis has been put on the
EU regulative that aims to define and gradually introduce the electronic money so the new market instabilities would
be avoided.
Based on the processing of available data, classifying certain payment transactions, using electronic means of
payment, emphasizing the role of electronic money, as well as applications in maritime transport, one possible model
of grouping the e-business transactions within maritime industry is proposed
Primjena odabranog pristupa penetracijskom testiranju raÄunalnih sustava
Nove raÄunalne tehnologije primjenjuju se u suvremenim sustavima za nadzor i upravljanje brodovima, poÄevÅ”i od navigacijskog ustava, komunikacijske opreme, propulzijskog sustava, sustava za rukovanje teretom pa sve do pomoÄnih sustava poput sustava klimatizacije i ventilacije, sustava goriva, pomoÄnog rashladnog
sustava. Uz sva tehniÄka poboljÅ”anja i tehnoloÅ”ki sofisticirane brodske sustave, sigurnost na suvremenom brodu nije zadovoljavajuÄa jer su pomorske nezgode i dalje vrlo Äeste. Sigurnost plovidbe broda uz ostale Äimbenike ovisi i o sigurnosti
brodskog raÄunalnog sustava, zato se sa sigurnoÅ”Äu raÄunalnih sustava u kontekstu pomorske sigurnosti ne smije olako postupati.
Ovaj rad obraÄuje postupak penetracijskog testiranja Black box metodom. Kratka obrada raÄunalne sigurnosti daje uvod u izvoÄenje cjelokupnog postupka testiranja kroz Äetiri faze. Uporabom raspoloživih nekomercijalnih alata i programskih okruženja za penetracijsko testiranje ostvaruju se jednostavna i dostupna sredstva
za provjeru, ali uz istaknutu moguÄnost proboja sigurnosti. Uz prikazane postupke djelovanja, rad analizira potencijalne nedostatke i daje praktiÄna rjeÅ”enja za njihovo odstranjivanje. Osim toga, pri realizaciji ovakvog pristupa svi procesi su provedeni u stvarnom radnom okruženju, s ciljem da se Äitatelju Å”to jasnije prikaže sam postupak
GPS ā Analysis of Measurement Errors and Applications
U ovom Älanku analiziraju se mjerne pogreÅ”ke uzrokovane razliÄitim Äimbenicima i tehnoloÅ”ka naÄela GPS-a (Global Positioning System). Do pogreÅ”nih podataka dolazi zbog pogreÅ”aka u satovima, smetnja zbog prolaska signala kroz atmosferu, relativistiÄkih uzroka, geometrije i orbite satelita te refleksije signala. Prikazana su rjeÅ”enja tih problema, tj. metode kojima se pogreÅ”ke nastoje eliminirati. Na temelju analiziranih podataka predložen je novi postupak koriÅ”tenja razraÄenim modelom pri izradi rasporeda vožnje u svim vrstama prijevoza ā od morskoga do cestovnog, uz minimizaciju pogreÅ”aka.This article analyses measuring errors caused by various factors, as well as technology of GPS. Incorrect data occur as of errors in clocks, disturbances while signal travels through atmosphere, relativistic causes, geometry and orbits of satellites and reflection of signals. Solutions of these problems and the elimination methods are mentioned. Based on the analyzed data, the new process of utilization is proposed, applied in transportation timetable design, with successful implementation of the error minimization