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Analysis of Optical Access Network Implementation in Peščenica Municipality
No full textSvrha istraživanja diplomskog rada je analizirati tip naselja u koji pripada općina Peščenica, korištenjem podataka o broju stanovnika i površine, te primijeniti odgovarajući model kako bi se utvrdili troškovi polaganja svjetlovodne pristupne mreže.U radu je napravljeno anketno istraživanjem koje obuhvaća stanovnike sa područja općine Peščenice, kako bi dobili informacije o tipu usluge koju korisnici koriste i samoj cijeni usluge. Pomoću cijene usluge,izračunava se dobit operatora korištenjem svjetlovodne infrastrukture na općini Peščenica.The purpose of the research thesis is to analyze the type of settlement in which it belongs to the municipality of Peščenica, using data on the number of inhabitants and areas, applying the appropriate model to determine the cost of laying the fiber access network. The paper is a survey that will include residents from the municipalities of Peščenice, in order to obtain information on the type of services used by users and only valued services. Using the price of services, we will calculate the profit of the operator using the fiber optic infrastructure in the municipality of Peščenica
Operation of an aircraft piston engine during pilots flight training
No full textCilj ovog završnog rada je prikaz i usporedba snimljenih parametara motora u različitim fazama pilotskog školovanja. U radu je opisana tehničko-eksploatacijska karakteristika tipičnog školskog zrakoplova i njegovog motora, a za primjer su uzeti zrakoplov Cessna 172N i motor Lycoming O-320. Detaljnije je opisan izgled, rad i funkcije zrakoplovnog uređaja EDM 900, dizajniran od tvrtke J.P Instruments. Opisan je tijek školovanja pilota prije dobivanja licence i objašnjene su vježbe iz kojih će se snimati podatci motora kao i očekivanja samih podataka. Pomoću snimljenih podataka parametara motora, prikazani su njihovi trendovi i vrijednosti za vrijeme leta u različitim fazama školovanja.The aim of this paper is to present and compare the recorded engine parameters in different phases of pilot training. The paper describes the technical and operational characteristics of a typical school aircraft and its engine, where aircraft Cessna 172N and the Lycoming O-320 engine are taken as examples. The operation, benefits and display of the aircraft instrument EDM 900 aircraft, designed by J.P Instruments, are described in more detail. The course of pilot training before obtaining a license is described and the exercises from which the engine data will be recorded are explained, as well as the expectations of the data themselves. Using the recorded data of engine parameters, their trends and values during the flight in different phases of schooling are shown
Analysis of Routine and Periodic Maintenance of Roads in Split - Dalmatia County
No full textJavna cesta po kojoj se odvija promet tijekom svog trajanja mora ispunjavati bitne zahtjeve i druge uvjete propisane Zakonima i tehničkim propisima. Pravni subjekt koji upravlja i gospodari cestom u Splitsko – dalmatinskoj županiji je Županijska uprava za ceste Split i ona je dužna osigurati održavanje cesta, tako da se tijekom njihovog trajanja očuvaju bitni zahtjevi i osigura održavanje, na način da se ne naruše svojstva ceste prvenstveno u pogledu sigurnosti prometa. Održavanje cesta se može obavljati redovno i izvanredno. U redovno održavanje pripadaju radovi na cestama manjeg opsega, koji se obavljaju tijekom cijele godine, dok izvanredno održavanje spada u grupu zahtjevnijih i opsežnijih radova čiji je cilj dugotrajnije uređenje i poboljšanje pojedinih dijelova ceste. Održavanje cesta odvija se po prioritetima, gdje se najviše ulaže u državne cesta, a zatim županijske i lokalne ceste. Kao prijedlog poboljšanja sustava održavanja predlaže se predavanje veće pozornosti sigurnosti, uslužnosti i edukaciji djelatnika, te ulaganju u inovativne sustave, koji uvelike olakšavaju cijelu organizaciju i obavljanje radova održavanja cesta te smanjuju uložena financijskih sredstava.Public road on which the traffic takes place, during its duration must meet the essential requirements and conditions prescribed by the Laws and technical regulations. The legal entity that manages the roads in the Split – Dalmatian County is the Split County Road Administration and it is obliged to ensure maintenance of roads, so that during their duration the essential requirements are preserved and maintained and that the road properties are not impaired in terms of traffic safety. Road maintenance can be done as routine and periodic. Routine maintenance includes works of smaller extent, which are preformed throughout the entire year, while periodic maintenance belongs to the group od more demanding and extensive works, aimed at longer term arrangement and improvement of certain parts of the roads. Road maintenance is done by priorities, where the most investment is put in state roads, followed by the county and local roads. To improve maintenance system, it is proposed to pay more attention to safety, service and education of the employees, and to invest in innovative systems, which can greatly improve the organization and performance of road maintenance and cost reduction
Determining the influence of outside air temperature on the performance of a aircraft piston engine in operation
No full textVanjska temperatura zraka koja se razlikuje od standardne ima značajan efekt na performanse zrakoplovnog motora u eksploataciji. Kada je temperatura zraka na određenoj visini veća od standardne, performanse motora su slabije, suprotno tome kada je temperatura zraka niža od standardne, performanse motora su bolje. Stoga je u ovom radu prikazan utjecaj temperature na performanse motora od strane proizvođača samog motora te pomoću podataka snimljenih u zraku.Outside air temperature that differs from the standard has a significant effect on the performance of the aircraft engine in operation. When the air temperature at a certain altitude is higher than standard, the engine performance is lower, in contrast when the air temperature is lower than standard, the engine performance is better. Therefore, this paper presents the influence of temperature on engine performance by the engine manufacturer himself using data recorded in the air
Freight Transport Inspection Procedures
No full textInspekcijske procedure pri transportu robe predstavljaju kontrolne nadzore kvalitete robe koja se transportira, a najčešće se roba kontrolira pri uvozu robe iz trećih zemalja. Inspekcijske procedure zakonski su određene. U Republici Hrvatskoj inspekcijske procedure provodi Državni inspektorat. Među odjelima Državnog inspektorata u ovom radu bit će istaknuti: Sanitarni inspektorat, Veterinarski inspektorat i Fitosanitarni inspektorat. To su inspektorati koji su u najvećem doticaju s robom kod njezinog transporta. Svaki inspektorat specijaliziran je za određenu vrstu robe i svaki ima svoje zahtjeve i pravila koja se zakonski određuju.Inspection procedures for the transport of goods represent a control overview of the quality of the goods being transported, and most often the goods are controlled for the import of goods when they are coming from third party countries. Inspection procedures are legally determined. In the Republic of Croatia, the inspection procedure is carried out by the State Inspectorate. Among the different departments of the State Inspectorate, this paper will highlight: The Sanitary Inspectorate, the Veterinary Inspectorate and the Phytosanitary Inspectorate. These are the inspectorates that are most in contact with the goods during their transport. Each inspectorate specializes in a particular type of goods and each has its own requirements and rules that are legally determined
Rocket System Attitude Control with Thrust Vectoring during Launch
No full textRazvojem svemirske industrije javljaju se inovativne tehnološke izvedbe raketa, naročito u zadnje vrijeme. Lansiranje nekog objekta u orbitu i izvan nje jako je skupo zato što su donedavno određeni raketni sustavi odbacivani u ocean ili su izgorjeli u orbiti. Javila se ideja o opetovanom korištenju raketnih sustava, npr. dodatne pogonske rakete (booster) koje samostalno slijeću na Zemljinu površinu s jako velikom preciznošću, što utječe na pad cijene lansiranja rakete u orbitu ili izvan nje. Da bi se to postiglo, potrebna je jako sofisticirana tehnologija upravljanja jednim takvim sustavom. Ovaj rad obrađuje raketnu tehnologiju kroz povijest, ključne znanstvenike koji su svoj život posvetili svemirskim sustavima, pojavu vektoriranog potiska (Thrust Vector Control – TVC) i primjenu u današnje vrijeme. Obrađen je osnovni princip funkcioniranja rakete i njene komponente te izvedbe TVC-a kod raketa. Prikazan je način upravljanja raketom PID regulatorom i osnove stabilnosti rakete. Nakon toga slijede parametri modela rakete s pripadajućim komponentama, od geometrije do karakteristika pogonskog motora, gimbal aktuatora i mogući odabir elektroničkih komponenti. Izrađena je i simulacija lansiranja rakete i upravljanje njenim uzdužnim položajem s jednim od najraširenijih regulatora − PID regulatorom. Simulacija upravljanja izvedena je u Matlab/Simulinku. U simulaciji su putem 3DOF elementa dobiveni podaci o ponašanju rakete u lansiranju za različite željene postavke rakete i ponašanje PID regulatora te aktuatora u upravljanju uzdužnim položajem rakete.With the development of the space industry, innovative technological designs of rockets are emerging, especially recently. Launching an object into orbit and beyond is very expensive because until recently, certain missile systems were dropped into the ocean or burned in orbit. The idea of reusable rocket systems, such as additional booster rockets, which land independently on the Earth's surface with very high precision, has arisen, which affects the fall in the price of launching a rocket into orbit or beyond. To achieve this, a very sophisticated technology is needed to manage one such system. This paper deals with rocket technology throughout history, key scientists who have dedicated their lives to space systems, the emergence of vector thrust (TVC) and its application today. It is discussed about basic principle of the functioning of the rocket and its component, as well as the performance of the TVC. The method of PID controller rocket control and the basics of rocket stability are presented. This is followed by the parameters of the rocket model with the associated components, from the geometry to the characteristics of the propulsion engine, the gimbal actuator and the possible selection of electronic components. A simulation of rocket launch and control of its longitudinal position with one of the most widespread regulators - PID regulator was also made. The control simulation was performed in Matlab / Simulink. In the simulation, data on the rocket's behavior in launch for various desired rocket states and the behavior of the PID controller and actuator in controlling the longitudinal position of the rocket were obtained via the 3DOF element
Analysis of Aircraft Accidents Caused by Unlawful Interference
No full textZračni promet slovi kao najsigurniji za putovanja ali uz sve vrste zaštita i sigurnosnih mjera dolazi do nesreća ili ozbiljnih nezgoda. Terorizam u zračnom prometu nije novost, a metode napada se razvijaju uz upotrebu dostupnog oružja. Sigurnosne preporuke i standardi propisani na međunarodnoj razini se također moraju razvijati sukladno razvoju terorizma. Cilj istrage zrakoplovne nesreće i nezgode nije pronaći krivca nego izrada izvješća koji sadrži sigurnosne mjere te preporuke za prevenciju. U ovom će diplomskom radu biti pojašnjena djela nezakonitog ometanja zračnog prometa koja mogu uzrokovati nesreće ili ozbiljne nezgode. Detaljnije će se pojasniti cijeli proces istraživanja zrakoplovnih nesreća te popratne regulative za izvođenje procesa istrage. Analitički će se prikazati zrakoplovne nesreće na zračnim lukama u Bruxellesu, Atatürku i Teheranu te popratne sigurnosne mjere nakon nesreća.Air traffic is regarded as the safest for travel, but with all kinds of protection and safety measures accidents or serious accidents can occur. Terrorism in air traffic is not new and methods of attack develop with the use of available weaponry. Safety measures and prescribed standards on the international level must also develop in line with the development of terrorism. The aim of the investigation of accident and incident is not to find the culprit but to produce reports which contain safety measures. In this graduate thesis acts of unlawful interference that can cause accidents or incidents will be explained. The entire process of investigating airplane accidents and the accompanying regulations for conducting the investigation process will be explained in further detail. Airplane accidents on airport in Brussels, Atatürk and Terhan will be analytically presented with the supporting safety measures after the accidents
Model for Improvement of Railway Transport Energy Efficiency and Traffic Safety by Means of Advanced Power-Train Technologies and Remote Narrow-Band Sensor Networks
No full textPrijedlog sustava za povećanje energetske učinkovitosti i sigurnosti željezničkoga prijevoza temelji se na postupcima usredotočenim na specifične domene pogonskih sustava i željezničke infrastrukture uz korištenje strukturiranih skupova podataka, pokazatelja i indeksa kao ulaznih podataka za upravljanje voznim misijama. U radu se predlaže novi model za upravljanje voznim misijama željezničkih vozila, optimiran na temelju podataka iz udaljenih senzorskih mreža. Pritom hibridni pogon s više izvora energije, odnosno spremnikom električne energije, poboljšava energetsku efikasnost pri prometovanju brdsko-planinskim trasama, dok je za ispunjenje vozne misije u nepovoljnim vremenskim uvjetima potrebno i poznavanje stanja trase u određenom lokacijskom i vremenskom intervalu. Zbog složenosti takvog sustava potrebno je računalno podržano dinamičko upravljanje s učinkovitim matematičkim modelima. Ulazni parametri modela hibridnog pogona željezničke vuče ograničeni su na lokalne domenske varijable, te je stoga u radu predloženo udaljeno prikupljanje minimalne grupe informacija potrebnih za prediktivno upravljanje s ciljem istodobnog povećanja sigurnosti prijevoza. Predloženi postupak prikupljanja informacija temelji se na ekspertnom prometno-tehnološkom znanju i tehnološkim mogućnostima senzorskih mreža četvrte i pete generacije (4G/5G). Dobiveni se rezultati koriste u simulacijskom okruženju za sintezu i provjeru predloženog modela upravljanja željezničkim prijevozom.The proposal for a system to increase energy efficiency and railway transport safety is based on procedures focused on specific domains of drive systems and railway infrastructure using structured datasets, indicators and indices as inputs for management of driving missions. The thesis proposes a new model for the management of driving missions, optimized based on the data from remote sensor networks. On the other hand, a hybrid drive with multiple energy sources, that is, an electrical energy storage system, improves the energy efficiency when operating on mountain routes, while the knowledge of a minimal data set describing the condition of the route at a specific location and time interval is required to fulfill the driving mission under adverse weather conditions. Due to the complexity of such a system, computer-aided dynamic management based on efficient mathematical models is required. The input parameters of the hybrid traction drive model are limited to local domain variables, and therefore, the paper proposes a predictive management scheme aimed at simultaneous increase of transport safety. The proposed information collection process is based on expert traffic technology knowledge and technological capabilities of the fourth and fifth generation (4G/5G) sensor networks. The results obtained are used in a simulation environment for the synthesis and validation of the proposed model of railway transport management. This thesis initially proposes a quasi-static model of a conventional diesel - electric locomotive. The proposed model designed based on the known parameters of the locomotive drive assembly, such as the rated power of the diesel engine and the output electric power of the generator unit, and the electrical traction system power input. For the purpose of deriving the fuel consumption model and the related exhaust emissions model, as well as the traction force and traction power characteristics of the propulsion system, the characteristics of a similar diesel engine and generator are matched and their fuel consumption data were taken from the available literature for the purpose of adjustment (scaling) in order to correspond to the power characteristics of the target engine-generator unit of the considered diesel-electric locomotive. Thus-defined conventional locomotive model is then used for the hypothetical conversion of the locomotive into a battery-hybrid and fully-electric battery-based variants by adding a suitable battery energy storage system of sufficiently large capacity, in parallel to the generator in the former case, or standalone in the latter case. In addition, an appropriately optimized energy management strategy has been devised in order to keep the battery state-of-charge within predefined limits, while aiding the conventional propulsion system during its operation, and also facilitating recuperation of a portion of the train potential energy during descending by converting its kinetic energy to electrical energy through regenerative braking by means of traction electrical motors. A new approach to rail freight haul by combined use of conventional diesel-electric and battery-electric locomotives for different characteristic scenarios of individual and joint (tandem) operation is also considered herein. In order to manage power flows between the conventional and battery electric locomotives, and to ensure an additional level of safety aimed at maintaining the battery state-of-charge charge above the minimum recommended value of 20% in demanding traction conditions, the driver’s Notch command reduction rule is also included, which intercepts and conditions the accelerator command set by the driver. Simulation models of battery-electric and conventional diesel-electric locomotives are compared and simulated in different tandem and stand-alone combinations for the considered mountainous rail route and the case of a return journey, including realistic railway slopes and speed limits. The work presented herein also describes the development of the comprehensive model of a battery-hybrid diesel-electric locomotive extended with additional data related to the state of the railway infrastructure, which are obtained from a remote network of wireless sensors based on the application of fourth and fifth generation narrow-band communication technologies. The data used in the model refer to two key parameters that define the track conditions, i.e. the wheel-to-railway coefficient of adhesion and the average head wind speed, which, in turn, correspond to the changing weather conditions on the track. These data are then used within the freight train model to predict its driving dynamics, and are also used to find the optimal parameters of the battery state-of-charge controller for different operating modes, thus avoiding unnecessary and harmful deep battery discharging within the battery-hybrid dieselelectric locomotive. For the selected profile of the mountain railway route managed by the Croatian national railway company (Croatian railways, HŽ), an energy efficiency assessment is also performed, corresponding to a comparative assessment of fuel consumption of conventional and hybrid battery locomotives using a return journey simulation scenario, which includes realistic route slopes and train speed limitations. The obtained simulation results have shown that utilization of a battery-hybrid locomotive can result in significant energy savings and reduction in fuel consumption by up to 16.5%, which is also reflected in the proportional reduction of greenhouse gas emissions. Extended simulation model involving variable track conditions has been able to identify the necessary adjustment of driver behavior (i.e., change of driving mode and need for braking) under variable wheel-to-rails adhesion conditions. These modifications of the locomotive operating mode also resulted in increased travel time under worsened track conditions (compared to the reference case with constant adhesion and head wind) in accordance with the limitations of the locomotive traction system. Deteriorated track conditions (i.e. reduced adhesion and increased head wind) also result in increased fuel consumption and deeper discharge of the battery energy storage system within the battery-hybrid diesel-electric locomotive due to suboptimal operation of the main drive (i.e. diesel engine-generator set and traction electric motors). In particular, in the case of reduced adhesion, the potential for collecting the kinetic energy of the freight train via traction electric motor drive is significantly reduced, while an increase in head wind generally results in increased energy consumption. The presented results have shown that an optimized battery state-of-charge controller that uses track status information from the remote wireless sensors network can maintain the battery state-of-charge above the minimum recommended value of 20%, which has not been the case with the state-of-charge controller with constant parameters. Therefore, the optimized controller is capable of preventing deep discharges of the battery, and, thus to reduce its degradation and the associated reduction of battery life, while maintaining fuel consumption at an acceptable level for the specific highly-demanding driving scenario. The results also indicate that the train model that includes track condition data from remote sensors can predictively determine the duration of a running mission on the railway segment in question and to predict possible unplanned train stops due to unfavorable meteorological conditions on the track. Based on the established correlation of friction coefficient, ambient temperature and absolute air humidity, a fuzzy logic-based algorithm for classifying the state of adhesion between wheels and rails on the railway line has been derived with the aim of warning the driver of changes in braking and traction force potential on the individual parts of the route based on air humidity and temperature measurements from the remote sensors network. The fuzzy route classification algorithm and the appropriate driver’s intervention in the case of reduced braking and traction force potential is facilitated through the reduction of train speed (which inherently also increases the traffic safety and facilitates easier emergency stopping), and the overall concept has been tested by computer simulations. The proposed track condition classification algorithm effectively alerts the driver to timely reduce the train speed on critical sections where poor track adhesion conditions are detected. This is extremely important for the next generation of autonomously driven railway vehicles, which, due to the lack of a driver and his driving experience on a certain traffic route, have to use a predictive sensor network, whose data availability becomes a critical safety factor at higher train speeds. Moreover, such systems with predictive warnings significantly contribute to the reduction of excessive cognitive load of train drivers and increase the safety of the train transportation process, especially in difficult weather and geographical conditions. This ultimately contributes to the overall increased safety of rail traffic in terms of increasing the stability of the railway timetables. The final part of the paper presents a technological and economic analysis conducted under the condition of expected battery life and the associated expected capacity drop of 20% during battery operation, where the hybrid locomotive can maintain the same traction performance as the conventional one. Based on the current installation costs of contemporary lithium-ion batteries, it is expected that the investment costs in hybridization could be recouped approximately three times within the expected battery life. Furthermore, the obtained simulation results for a battery-electric locomotive show that such a locomotive is the most energy efficient solution, but is able to cross the considered mountain route only at very low loads. If additional battery charging is introduced in the middle of the route, the battery-electric locomotive in independent operation can achieve an increase in traction as well as improved driving characteristics. In tandem operations, a battery-electric locomotive can provide significant fuel savings of up to 20% associated with the simultaneous use with the dieselelectric locomotive, especially if a double-charging scenario is considered, which is also reflected in the proportional reduction in greenhouse gases emissions. If electricity costs are also taken into account, conventional tandem configurations plus a battery locomotive can provide savings of up to 22%. While these savings may not be able to justify the estimated cost of a brand new battery-electric locomotive based on the current costs of battery-powered energy storage systems, this may not be the case when considering long-term use, given the current declining trends of battery purchase costs
Investigating the Vulnerability of Terminal Devices in a Smart Home Environment
No full textRad daje pregled funkcionalnosti koncepta Interneta stvari (eng. Internet of Things - IoT), navodi i objašnjava princip rada komunikacijskih tehnologija koje se koriste u okruženju pametnog doma. Unutar rada se također navode i opisuju alati i metode koje napadači koriste prilikom izvođenja kibernetičkog napada. Za odabrane uređaje u radu izrađena je analiza ranjivosti za slučaj kada se napada prvo usmjerivač pa nakon toga IoT uređaji unutar mreže. Rezultat ispitivanja objašnjen je i analiziran, te su iznesene sigurnosne smjernice vezane uz IoT uređaje u okruženju pametnog doma.The paper provides an overview of the functionality of IoT concept, it states and explains the working principle of communication technologies used in a smart home environment. The paper also lists and describes the tools and methods that attackers are using when performing a cyber-attack. For selected devices, an analysis of the vulnerability was performed in case when the router is attacked first and then the IoT devices within the network. The result of the examination was explained and analyzed, additionally, safety guidelines related to IoT devices in a smart home environment were presented
Comparative Analysis of the Weight and Balance Specifics of the Dash8-Q400 and ATR 72 Aircraft
No full textZračni promet je prometna grana u kojoj je prioritet sigurnost prilikom prijevoza putnika, prtljage i robe. Ovaj završni rad obuhvaća sve pojmove potrebne za analizu specifičnosti uravnoteženja i opterećenja zrakoplova Dash8-q400 i ATR 72, kako bi se moglo ukazati na sličnosti i razlike zrakoplova i njihovu sigurnost leta. Za potrebe analize navedeni zrakoplovi pripadaju zračnim prijevoznicima Croatia Airlines i Air Serbia. Let zrakoplova omogućuju aerodinamičke sile koje djeluju na zrakoplov tijekom leta, a kako bi se let mogao sigurno odvijati i zrakoplov uzletjeti i sletjeti, potrebno je odrediti centar težišta zrakoplova te održati maksimalne dopuštene mase zrakoplova unutar propisanih granica. Granice su propisane za svaki zrakoplov posebno, te se u ovom radu razlikuju. Potrebno je prikupiti sve važne informacije o zrakoplovu jer svako pomicanje putnika, tereta ili robe može dovesti do pomicanja izvan granica. Nakon prikupljenih informacija, izrađuje se lista uravnoteženja i opterećenja zrakoplova te usporedna analiza njezine specifičnosti.Air traffic is one of the traffic branches in which priority is safety during transport of the passengers, goods and luggage. This final paper includes all concepts required for analysis specifics of weight and balance of the Dash8-q400 and ATR 72 aircraft, so we could see similarities and diversities of an aircraft and safety of their flights. For puproses of analysis, listed aircraft belong to carriers Croatia Airlines and Air Serbia. Airplane flight enables aerodynamic forces which affects on aircraft during flight, and so that the flight could procees safely and aircfraft could take off and land, it is required to determine center of gravity of an aircraft and keep maximum allowed masses inside allowed boundaries. Limits are prescribed for each aircraft seprately, so in this paper, they are different. Iti s necessary to gather all important informations about airplane and flight, so we could equally deploy their masses, because every moving of passengers, loads od goods, could lead to moving beyond boundries. After informations are collected, weight and balance sheet is being created, and comparative analysis of their specifics