Magistro baigiamojo darbo teorinėje dalyje analizuojami įvairūs virpesių lygio mažinimo būdai bei schemos laivuose. Aprašoma virpesių klasifikacija, pagrindiniai virpesių žadintojai laive, virpesių skaičiavimo būdai. Eksperimentinėje dalyje pateikiama kelto „Optima Seaways“ siurblio virpesių matavimo metodika. Nagrinėjami reiso Klaipėda-Karlshamnas-Klaipėda metu atliktų matavimų rezultatai bei nustatomos tiriamo siurblio padidinto virpesių lygio priežastys. Paskutinėje darbo dalyje pateikiamas racionalus sprendimas, reikalaujantis minimalių lėšų ir laiko sanaudų, tiriamo siurblio virpesių lygio sumažinimui. / The theoretical part of the Master’s thesis analyzes various vibration reduction systems and schemes in ships. Classification of vibrations on board, main vibration sources and vibration calculations are presented. The experimental part presents methodic for vibration measuring of ferry “Optima Seaways” pump. Vibration data, received during passage Klaipėda- Karlshamn- Klaipėda, is analyzed and reason of high pump vibration level is identified. Last part of thesis presents rational solution, with minimal cost and time expenses, for reduction of pump vibration level.

Šiame baigiamajame magistro darbe nagrinėjama elektromagnetinė situacija Kyviškių aerodrome, Apžvelgti iki šiol atlikti moksliniai darbai bei publikuoti straipsniai šia tematika. Teorinėje dalyje paaiškinta radionavigacijos samprata, tūpimo pagal prietaisus sistemos charakteristikos, kategorijos, sudėtinės dalys, sistemos išdėstymas aerodrome. Išsamiau aptariamas elektromagnetinės spinduliuotės poveikis žmogaus organizmui. Trumpai pristatoma radiolokatoriaus elektromagnetinio srauto tankio skaičiavimo metodika. Taip pat palyginti teoriniai bei praktiniai elektromagnetinės spinduliuotės skaičiavimų rezultatai. / Electromagnetic situation in Kyviškės aerodrome is analysed in this Master thesis. Scientific researches and articles relevant to this topic were reviewed here. Radionavigation conception, instrumental landing system characteristics, categories, components, collocation in an airfield are explained in the theoretical part of this thesis. Electromagnetic radiation effect on human body was represented more carefully. The teorical electromagnetic radiation datum were compared with practical evaluation datum.

Baigiamajame magistro darbe aptariamos bendros aviacijos avarijų ir incidentų tyrimo metodikos, jų pritaikymo būdai, privalumai ir trūkumai. Taip pat išnagrinėjamas avarijų ir incidentų ryšys, bendrosios aviacijos įtaka aviacijos rinkoje bei jai būdingi bruožai. Plačiau aptariamas žmogiškasis faktorius bei su juo susiję naujausi tyrimo metodai. Pristatoma Lietuvos bendroji aviacija, jos aktyvumo ir avaringumo lygis nuo 2000–2010 metų. Detaliau išnagrinėjamos su ja susijusios avarijos ir pavojingi incidentai. Pateikiama išsami jų analizė, taikant įvairius tyrimo metodus. Taip pat gauti duomenys lyginami su Lietuvos komercine aviacija bei JAV, Europos, Vokietijos ir Australijos duomenimis. Galiausiai apibendrinami gauti rezultatai ir atsižvelgiant į juos pateikiamos rekomendacijos Lietuvos avaringumui mažinti. Darbą sudaro 7 dalys: įvadas, teorinė dalis, metodologinė dalis, tiriamoji dalis, išvados ir siūlymai, literatūros sąrašas bei priedai. Darbo apimtis – 81 p. teksto be priedų, 45 iliustr., 4 lent., 38 bibliografiniai šaltiniai. Atskirai pridedami darbo priedai. / This final paper of master studies discusses the methodologies of analyzing aviation accidents and incidents, their advantages and disadvantages, as well as the ways of applying these methodologies. Additionally, the link between aviation accidents and incidents is discussed as well as the general aviation, its characteristics and influence on entire aviation industry. Furthermore, the human factor and the most current methodologies of analyzing it are introduced. This paper also presents Lithuania general aviation, its activity and safety level from 2000 to 2010. By applying various methodology and approaches, the more detailed analysis is given to the accidents and incidents, which are related to aforementioned safety level. The attained data is compared with the statistics of Lithuania commercial aviation, USA, Europe, Germany and Australia. Finally, the obtained results are summarized, and taking them into consideration, recommendations of the ways to reduce the number of accidents and incidents in Lithuania are formulated. The paper consists of 7 pieces: introduction, theoretical piece, methodological piece, practical piece, summary and recommendations, references and annexes. The paper size – 81 p. of text without docket, 45 figures, 4 tables, 38 references. Docket are included separately.

Skrydžio saugos užtikrinimas – tai pagrindinis lėktuvo pilotų darbo uždavinys kiekvieno reiso metu. Tinkama daugianarės skrydžio įgulos sąveika yra bene svarbiausias veiksnys garantuojantis skrydžio saugumą ir efektyvumą. Pagrindinis magistro baigiamojo darbo tikslas – ištirti netinkamą daugianarės įgulos sąveiką, dėl kurios įvyksta įvairaus pobūdžio lėktuvų avarijos ar katastrofos, išanalizuoti pilotų sąveiką sąlygojančius veiksnius ir pateikti galimus siūlymus, panašioms situacijoms išvengti ateityje. Nustatant ir tiriant netinkamą sąveiką sąlygojančius veiksnius, įvertinama ir jų svarba bendrai skrydžio saugai. Pagrindiniai netinkamo bendro pilotų darbo veiksniai:  Netinkamas kapitono vadovavimo stilius;  Nuovargis:  Stresas;  Netinkamas bendravimas. Vėliau šie veiksniai yra praktiškai patvirtinami analizuojant jau įvykusias aviakatastrofas. Ieškomos objektyvios netinkamos pilotų sąveikos priežastys kiekvienos avarijos metu. Daugumoje ištirtų įvykių aptikti kritiniai momentai, kuomet pilotams galimai imantis atitinkamai siūlomų veiksmų, dar įmanomas įvykio evoliucijos laike pakeitimas ir aviakatastrofos išvengimas. / Flight safety assurance is the main task for aircraft pilots during their every flight. Appropriate multi-crew cooperation is probably the most important factor that guarantees effective and safe flight. The main object of this master’s thesis is to analize inadequate multi-crew cooperation which leads to various airplane crashes, to research factors, that affect cooperation of pilots and to suggest probabale solutions, in order to avoid similar situations in the future. After identifying and researching factors that cause inadequate cooperation, the importance of elements for flight safety is also evaluated. The main factors for inappropriate mutual work between the pilots are:  Inappropriate commanding style of captain;  Fatigue;  Stress;  Inappropriate communication. Later these factors are practically confirmed while analizing airplane crashes. During every accident, a search is made for the objective factors that caused an appearance of inadequate cooperation of pilots. Critical moments were found in the most of the crashes, when taking the suggested action there is still a possibility to change the further evoliution of the happening and aircraft crash avoidance.

Baigiamajame darbe buvo atlikta mokslinių darbų analizė darbo zonų tematika. Pateikiamos pagrindinės darbo zonos atsiradimo priežastys. Kelio darbo vietos suklasifikuotos pagal keletą kriterijų ir aprašomos darbo zonų valdymo galimybės. Darbe išskiriamos dvi pagrindinės darbo zonų problemos: eismo saugumo ir transporto priemonių intensyvumo. Analizuojamos darbo zonų spūsčių automobilių keliuose sukeliamos problemos. Darbe pateikiami transporto priemonių intensyvumo pagrindiniai parametrai ir veiksniai, turintys jiems įtakos. Atlikti eksperimentiniai tyrimai pasirinktose darbo zonose ir gauti rezultatai apibendrinami. Darbo apimtis – 72 psl. teksto be priedų, 39 iliustr., 12 lent., 26 bibliografinių šaltinių. / The final work was carried out research work analyzes the work zone topics. Contains the main work area causes. Multiple jobs are grouped according to several criteria and a description of the work zone management capabilities. The paper distinguishes between two areas of work problems: traffic safety and transport intensity. Analyzed areas of work on the roads caused congestion problems. The paper presents the vehicle parameters and the intensity of the main factors influencing them. Tests were performed in selected areas of work and the results obtained are summarized. Thesis consists of: 72 p. texts without appendixes, 39 pictures, 12 tables, 26 bibliographical entries.

Baigiamajame darbe išanalizuota mokslinės literatūros šaltiniai, kuriuose buvo tirti ir išnagrinėti riedmenų ašidėžių temperatūrų kitimo procesai, temperatūrų pasiskirstymas ašidėžės ir aširačio mazgo elementuose. Išanalizuoti ašidėžių temperatūrų kitimo greičiai esant guolių gedimams, pateiktos ašidėžių liekamojo resurso prognozės. Išnagrinėti tyrimai pagrindžiantys riedmenų automatinės kontrolės prietaisų išdėstymo atstumų atitikimą saugių eismo sąlygų reikalavimams. Darbe pateikta realiomis sąlygomis atliktų bandymų rezultatų analizė. Nustatytos ašidėžių mazgo kaitimo tendencijos. Pateikta pagrindinių faktorių galinčių įtakoti ašidėžių kaitimo intensyvumą. Atliktas gautų bandymo rezultatų palyginimas si literatūros šaltiniuose pateiktais duomenimis ir nurodytos galimos bandymų rezultatų ir literatūros šaltinių duomenų neatitikimo priežastys. Pateiktos rekomendacijos, kuriomis remiantis galima padidinti traukinių eismo saugą ir išvengti avarinių situacijų dėl ašidėžių mazgo galimų defektų ir galima prognozuoti liekamąjį darbo resursą. Nurodytos tolesnių papildomų tyrimų kryptys. Baigiamąjį darbą sudaro 3 pagrindinės dalys, išvados, siūlymai bei literatūros sąrašas. Darbo apimtis – 74 p. teksto be priedų, 49 iliustr., 12 lentelių, 29 literatūros šaltiniai. / In the final analysis of the scientific literature sources that have been investigated and examine the axle box temperature variation processes, temperature axle box and of the wheelset node items. Parse axle box temperature variation speeds at bearing failures, the axle box residual resource forecast. The studies on which the automatic control devices layout distances with safe traffic conditions. Work in real terms of the results of the tests carried out. The axle box assembly heating trends. The main factors which could influence the axle box heating. The comparison of the results of the test carried out si literature reference data and the results of the tests and literature data the reasons. Recommendations on the basis of which can be increased traffic safety and avoid emergency situations of axle box node of possible defects and predict the residual labor resource. Additional studies to further directions. The final work of 3 basic parts, conclusions, suggestions and references. The scope of the work to 74 p. text without additives, 49pictures, 12 tables, 29 bibliographical entries.

Baigiamajame magistro darbe apžvelgiama dyzelinių degalų gamyba, sudėtis ir jų priedai. Aprašyti dyzelinių variklių išskiriami teršalai bei jų mažinimo principai. Nagrinėjamos degalų mišinių struktūrinės ypatybės bei savybės. Išnagrinėti mišinių gavimo būdai ir įrenginiai. Atlikti eksperimentiniai tyrimai, kurių metu skirtingais kiekiais ir esant skirtingiems parametrams buvo maišomas dyzelinas su vandeniu ir įvairiais stabilizuojančiais priedais. Gautos degalų mišinio vandens dalelių dydžio priklausomybės. Nagrinėta stabilizuojančių priedų įtaka vandens dalelių dydžiui bei mišinio išsisluoksniavimo laikui. Apskaičiuotas mokėtinas taršos mokestis naudojant gryną dyzeliną ir degalų mišinį. Pateiktos darbo išvados. Darbą sudaro 8 dalys: įvadas, dyzelinių degalų apžvalga, dyzelinių variklių deginių sudėties analizė, degalų mišinių įtaka variklio darbingumui, mišinių gavimo būdai ir įrenginiai, atlikti eksperimentiniai tyrimai, ekonominis įvertinimas, išvados. Darbo apimtis − 65 p. teksto be priedų, 39 paveikslai, 13 lentelių. Atskirai pridedami darbo priedai. / This Master Thesis rewievs diesel fuel production, composition and accessories. Discribed the emissions, resulting from diesel engines and their reduction. Examined structural features and properties of the fuel blends and fuel emulsions. Overview of formulas obtained getting stable emulsions. Receiving experimental studies in which different quantities of diesel and water were mixed with certain parameters. The resulting particle size dependence of water in the emulsion. Visited additives on particle size and mixture of delamination time. Polution tax calculated using pure diesel fuel and fuel blend. Work consists of 8 parts: introduction, overview of diesel fuel in diesel engines, exhaust composition analysis of the fuel blends on the engine capacity to work, blends of receipt of techniques and equipment to carry out experimental studies, economic evaluation, and conclusions. Work volume: 65 pages without additions, 39 illustrations, 13 tables. Additions to work.

Darbe tiriamos galimybės vertinti laivo supimosi intensyvumą taikant klasikinės ir hidrodinaminės laivo supimosi skaičiavimo metodikas. Prognozavimo galimybių įvertinimui atliekamas laivo DTMB 5415 supimosi eksperimentas reguliariose bangose – matuojamas laivo bortinis, kilinis ir vertikalusis supimasis laivui stovint lagu bangoms ir esant išilginiam bangavimui. Pateikiama informacija apie supimosi eksperimento eigą, paruošimą, naudojamą laboratorinę įrangą ir bandymo rezultatų apdorojimą. Laivo supimosi skaičiavimai atliekami taikant hidrodinaminę skaičiojamosios skysčių dinamikos kompiuterinę programą „FLOW-3D“, klasikinę supimosi skaičiavimų metodiką ir kompiuterine programa „Seakeeper“ paremta hidrodinamine plokščiųjų skerspjūvių teorija. Gauti rezultatai palyginami su eksperimento rezultatais. / Paper analysis the most popular classical and hyrodinamical seakeeping methods for preliminary seakeeping performance prediction. Seakeeping test in regular waves has been performed for validation of seakeeping prediction methods for model DTMB 5415. Roll, pitch and heave motions have been measured for beam and head seas wave headings. The paper supplys Information about seakeeping test procees, preparation instructions for test, required laboratory equipment and seakeeping test data analysis. Computational fluid dynamics software „FLOW - 3D“ have been used for motion response prediction in regular waves, classical seakeeping theory method and strip theory based software Seakeeper. Computed results have been compared with seakeeping eksperimental data.

The Indiana Department of Transportation (INDOT) manages and maintains over 3,000 miles of interstates across the state. Assessing lane marking quality is an important part of agency asset tracking and typically occurs annually. The current process requires agency staff to travel the road and collect representative measurements. This is quite challenging for high volume multi-lane facilities. Furthermore, it does not scale well to the additional 5,200 centerline miles of non-interstate routes. <div><br></div><div>Modern vehicles now have technology on them called “Lane Keep Assist” or LKA, that monitor lane markings and notify the driver if they are deviating from the lane. This thesis evaluates the feasibility of monitoring when the LKA systems can and cannot detect lane markings as an alternative to traditional pavement marking asset management techniques. This information could also provide guidance on what corridors are prepared for level 3 autonomous vehicle travel and which locations need additional attention. </div><div><br></div><div>In this study, a 2019 Subaru Legacy with LKA technology was utilized to detect pavement markings in both directions along Interstates I-64, I-65, I-69, I-70, I-74, I90, I-94 and I-465 in Indiana during the summer of 2020. The data was collected in the right most lane for all interstates except for work zones that required temporary lane changes. The data was collected utilizing two go-pro cameras, one facing the dashboard collecting LKA information and one facing the roadway collecting photos of the user’s experience. Images were taken at 0.5 second frequency and were GPS tagged. Data collection occurred on over 2,500 miles and approximately 280,000 images were analyzed. The data provided outputs of: No Data, Excluded, Both Lanes Not Detected, Right Lane Not Detected, Left Lane Not Detected, and Both Lanes Detected. </div><div><br></div><div>The data was processed and analyzed to create spatial plots signifying locations where markings were detectable and locations where markings were undetected. Overall, across 2,500 miles of travel (right lane only), 77.6% of the pavement markings were classified as both detected. The study found</div><div><br></div><div>• 2.6% the lane miles were not detected on both the left and right side </div><div>• 5.2% the lane miles were not detected on the left side </div><div>• 2.0% the lane miles were not detected on the right side 8 </div><div><br></div><div>Lane changes, inclement weather, and congestion caused 12.5% of the right travel lane miles to be excluded. The methodology utilized in this study provides an opportunity to complement the current methods of evaluating pavement marking quality by transportation agencies. </div><div><br></div><div>The thesis concludes by recommending large scale harvesting of LKA from a variety of vendors so that complete lane coverage during all weather and light conditions can be collected so agencies have an accurate assessment of how their pavement markings perform with modern LKA technology. Not only will this assist in identifying areas in need of pavement marking maintenance, but it will also provide a framework for agencies and vehicle OEM’s to initiate dialog on best practices for marking lines and exchanging information.</div>

<p>  </p> <p>For decades, agencies have collected infrastructure condition assessment data using dedicated equipment that require substantial capital investments and staff time to operate/drive. However, these techniques are challenging to scale network wide. The United States has over 8 million lane miles of roadways which generate almost 3 trillion vehicle miles annually.  Connected vehicles can now provide real-time data on a wide range of parameters such as vehicle speed, location, lane markings, and 3 axis acceleration. This dissertation develops techniques to validate, utilize and leverage connected vehicle data for infrastructure assessment and monitoring.  </p> <p><br></p> <p>Opportunities to employ connected vehicle data were examined in the following areas: quality of lane marking edge lines, width of lanes (particularly temporary lanes in construction zones), and pavement roughness. Quality of lane markings was evaluated using embedded lane keep assist data and equipment. In 2020 and 2021 over 5000 miles of pavement markings were evaluated on Indiana interstates. Comparisons between 2020 and 2021 data showed detection increase from 80.2% to 92.3%.  Although there are no industry standards for lane keep assist data, this study demonstrated both the importance and utility of partnering with the automotive industry to develop shared vision on acceptable lane quality. </p> <p><br></p> <p>A follow-up quantitative study was performed using a LiDAR vehicle to compare LiDAR values with those that are obtained from traditional retroreflectivity measurements used for contract acceptance and maintenance decisions. A comparison of LiDAR intensity to retroreflectivity (the industry standard) on 70 miles of US-52 and US-41 in Indiana was assessed and a linear regression found that the intensity values are comparable to retroreflectivity readings with an R2 of 0.87 and 0.63 for right edge and center skip lines respectively. These results suggest that LiDAR is a viable tool for monitoring of retroreflectivity of pavement markings that are strongly correlated with existing standards, but scale much better than traditional retroreflectivity measurement techniques.</p> <p><br></p> <p>The LiDAR data also provided the opportunity to evaluate how well modern vehicles measure lane width. This dissertation reports on over 200 miles of roadway and when compared to LiDAR and field measurements had a root mean square error of 0.24 feet. This data is valuable for agencies to quickly identify system wide where lane widths fall below acceptable design standards, typically 11-feet. </p> <p> </p> <p>The final connected vehicle data set evaluated was pavement roughness and compared with traditional dedicated vehicles collecting international roughness index (IRI) data. The study evaluated a 20-mile segment in 2022, and showed a linear regression between these data sets had an R2 of over 0.7, suggesting that connected vehicle roughness data can be utilized for network level monitoring of pavement quality. Scalability of these techniques is also illustrated with graphics characterizing IRI values obtained from almost 6 million records to evaluate improvements in Indiana construction zones and over 5,800 miles of I-80 in April of 2022 and October 2022.</p> <p><br></p> <p>Although connected vehicle data for infrastructure assessment is still in its infancy, these case studies demonstrate significant opportunities for public agencies to collect selected system wide infrastructure condition in near real-time, and in many cases at a lower cost than traditional techniques. </p>