Baigiamajame magistro darbe atlikta mokslo darbų, skirtų automobilio rato sąveikai su skirtingos būklės ir savybių kelio danga tyrimams analizė. Atlikti eksperimentiniai tyrimai, kurių metu ištirti temperatūros pokyčiai ratui sąveikaujant su kelio danga ir jų įtaka sankybio rodikliams. Surinkti, susisteminti, statistiškai apdoroti ir išanalizuoti 2011 ir 2012 metais išmatuoto valstybinės reikšmės kelių naujos asfalto dangos ir rato sukibimo koeficiento duomenys. Pateikiamos baigiamojo darbo išvados. Darbą sudaro 6 dalys: įvadas, mokslo darbų analizė, eksperimentiniai automobilio rato sukibimo su kelio danga parametrų tyrimai, valstybinės reikšmės kelių naujos asfalto dangos ir rato sukibimo koeficiento tyrimas ir vertinimas, išvados, literatūros sąrašas. Darbo apimtis – 65 p. teksto be priedų, 46 iliustr., 10 lent., 32 bibliografiniai šaltiniai. Atskirai pridedami darbo priedai. / In this master thesis is performed a research studies analysis about car wheel and road interaction . Car wheel interaction with road pavement tests were performed and temperature changes which affect grip is examined. Collected, structured and statistically analyzed 2011 and 2012 year wheel traction data. The conclusions is presented. The paper consists of six parts: introduction, analysis of scientific articles and studies, experimental study of car wheel grip with road surface parameters, new asphalt pavement grip research and evaluation, conclusions, references. Pages - 65 p. text, 46 pictures., 10 tables., 32 bibliographic sources. Appendixes.

Šiame darbe nagrinėjamos bepiločio skraidančio sparno aerodinaminės charakteristikos. Pasirinktas sparno profilis EPPLER 328. Pirmiausia išanalizuojami skaitiniai aerodinaminių charakteristikų tyrimo metodai. Atlikus skaičiavimus pagal pasirinktus aspektus, naudojant programą XFLR5 gauti duomenys apibendrinami bei išanalizuojami. Ištirtos keliamosios jėgos koeficientų, pasipriešinimo jėgos koeficientų, aerodinaminės kokybės reikšmės esant atitinkamiems atakos kampams. Naudojantis tyrimo rezultatais padarytas bepilotis skraidančio sparno orlaivis ir atlikti skrydžiai. Visa informacija apibendrinama ir pateikiamos gautų rezultatų išvados. Darbo apimtis – 66 p. teksto be priedų, 39 paveikslai, 6 lentelės, 24 bibliografiniai šaltiniai. / The investigation analyzes unmanned flying wing aerodynamic characteristics. Choosen airfoil EPPLER 328. Firstly, analyzing theoretical calculation methods. All relative data compared and analyzed after calculation with program XFLR5. Analyzed lift force coefficient, drag force coefficient, aerodynamic coefficient under realative angles of attack. Unmanned flying wing was built using the results of compared and analyzed aerodynamic data and test flights were made. All information summarized and produced conclusion. Thesis consists of: 66 p. text without appendixes, 39 pictures, 6 tables, 24 bibliographical entries.

Baigiamajame magistro darbe apžvelgiamos sklandytuvų motorizavimo tendencijos, būdai bei reikiama teorinė medžiaga. Nagrinėjamas papildomas pasipriešinimo padidėjimas dėl motorizavimo elektros varikliu, tiriamos būsimos motorizuoto sklandytuvo LAK-12 tiesiaeigio skridimo bei kilimo charakteristikos. Darbo gale pateikiami gauti rezultatai bei suformuluojamos išvados. / The theses provides an overview of the engine types used for motorizing gliders, tendency and theoretical material. Additional drag due to engine and propeller blades were studied as well as straight and level flight and climb performance. The results and conclusions are given at the end.

Baigiamajame magistro darbe teoriškai tiriami statybinio parakinio įrenginio vidinės balistikos hidrodinaminiai ir termodinaminiai procesai. Be to, modeliuojami garso slopintuvai ir teoriškai tiriamas jų efektyvumas. Darbe padarytos vidinės balistikos, kaip mokslo, statybinių viniašaudžių ir garso slopintuvų tipų apžvalgos. Atliktas skaitinis vidinės balistikos ir dujų plėtimosi procesų modeliavimas. Pateikti modeliavimo rezultatai ir jų analizė. / The topic of Master thesis is research of powder-actuated hydrodynamic ant thermodynamic processes in pyrotechnic tube. Also were made 3d models of suppressors and modeled their effectiveness. Internal ballistics, powder-actuated tools and suppressors reviews were made. Performed calculations of internal ballistics and gas extension processes. Presented results and analysis.

New dynamic signal control methods such as fuzzy logic and artificial intelligence developed recently mainly focused on isolated intersection. In this study, a Fuzzy Logic Control for a Diamond Interchange incorporating with Fuzzy Ramp System (FLDI) has been developed. The signalization of two closely spaced intersections in a diamond interchange is a complicated problem that includes both increasing the diamond interchange capacity and reduce delays at the same time. The model comprises of three main modules. The Fuzzy Phase Timing module controls the current phase green time extension, the Phase Selection module select the next phase based on the pre-defined phase sequence or phase logics and the Fuzzy Ramp module determines the cycle time of the ramp meter bases on current traffic volumes and conditions of the interchanges and the motorways. The developed FLDI model has been compared with the traffic actuated simulation with respects to flow rates and the average delays of the vehicles. The model of an actual diamond interchange is described and simulated by using AIMSUN (Advanced Interactive Microscopic Simulator for Urban and Non-Urban Network) software. Simulation results show the FLDI model outperformed the traffic actuated models with lower system total travel time, average delay and improvements in downstream average speed and average delay.

Ramp metering, one of the most effective solutions for improving motorway traffic flows, is playing increasingly important role in traffic management systems. Because of its capability to handle nonlinear and non-stationary problems, fuzzy logic based ramp metering algorithms have been always considered as an extremely suitable control measures to handle a complex nonlinear traffic system. This thesis proposes a genetic fuzzy approach to design a traffic-responsive ramp control algorithm for an isolated onramp. For a local ramp meter algorithm, the problem could be described as the inflow optimization of on-ramp, based on the evaluation of motorway traffic condition. If the inflow of on-ramp is considered as the decision variable, the ramp control problem could be treated as a nonlinear optimization problem of maximizing the evaluation function. The adaptive genetic fuzzy approach is actually a control approach to maximize the inflow of on-ramp under the restriction of evaluation function. In this thesis, a well-known fuzzy logic based ramp metering algorithms developed by Bogenberger is introduced and implemented with an on-ramp congestion model of Constellation Drive Interchange in a stochastic microscopic traffic simulator, Aimsun. To improve the performance of fuzzy control system, genetic algorithm is applied to tune the parameterized membership function of each fuzzy input to maintain the flow density of motorway blow the estimated congestion density. The performances of the genetic fuzzy logic control ramp metering are compared with FLC (fuzzy logic control) ramp metering by means of the percentage change of TTT (Total Travel Time) based on no control condition in Aimsun. The simulation results show the genetic fuzzy ramp metering has a more significant improvement on TTT and more strong stability to maintain system flow density than FLC ramp metering.

Improving intersection safety and efficiency are the primary goals of alternative intersection designs. These designs seek to improve on traditional traffic control methods, often by reducing intersection conflict points, reducing or eliminating time-wasting signal phases, or both. However, public opposition to these new designs can be a large barrier to implementation of alternative intersections despite their known safety and efficiency benefits.<br><br>This study evaluated current public perception and factors influencing that perception for four alternative intersection designs - the roundabout, the restricted crossing U-turn (also known as J-turn and reduced conflict intersection), the displaced left turn (also known as the continuous flow intersection), and the diverging diamond interchange (also known as the double crossover diamond interchange). <br><br>To achieve this objective, a survey instrument was designed and distributed to a target sample of 1,000 adults residing in the State of Indiana. The survey solicited participant awareness of these designs, acceptance of a potential implementation of the design in their community, and driver confidence using the design along with participant socio-demographic data. Descriptive and inferential statistical analysis was then conducted. <br><br>The survey results indicate that residents of Indiana are not aware of designs not currently widely implemented in the state, that opposition to these rarer designs is prominent, and that drivers were generally less confident in their ability to safely navigate these unfamiliar designs. Younger respondents, male respondents, more highly educated respondents, respondents who travel more often or for farther distances, and respondents who rate their own driving ability highly are more likely to be aware, accepting, and confident using alternative designs. <br><br>The results of this study will inform future outreach efforts pertaining to alternative intersections by improving transportation agency understanding of public opinions and primary concerns regarding these designs and provide potential paths for improving public perception. <br>

<p dir="ltr">The emergence of time-dependent data provides researchers with unparalleled opportunities to investigate disaggregated levels of safety performance on roadway infrastructures. A disaggregated crash risk analysis uses both time-dependent data (e.g., hourly traffic, speed, weather conditions and signal controls) and fixed data (e.g., geometry) to estimate hourly crash probability. Despite abundant research on crash risk analysis, coordinated signalized intersections continue to require further investigation due to both the complexity of the safety problem and the relatively small number of past studies that investigated the risk factors of coordinated signalized intersections. This dissertation aimed to develop robust crash risk prediction models to better understand the risk factors of coordinated signalized intersections and to identify practical safety countermeasures. The crashes first were categorized into three types (same-direction, opposite-direction, and right-angle) within several crash-generating scenarios. The data needed were organized in hourly observations and included the following factors: road geometric features, traffic movement volumes, speeds, weather precipitation and temperature, and signal control settings. Assembling hourly observations for modeling crash risk was achieved by synchronizing and linking data sources organized at different time resolutions. Three different non-crash sampling strategies were applied to the following three statistical models (Conditional Logit, Firth Logit, and Mixed Logit) and two machine learning models (Random Forest and Penalized Support Vector Machine). Important risk factors, such as the presence of light rain, traffic volume, speed variability, and vehicle arrival pattern of downstream, were identified. The Firth Logit model was selected for implementation to signal coordination practice. This model turned out to be most robust based on its out-of-sample prediction performance and its inclusion of important risk factors. The implementation examples of the recommended crash risk model to building daily risk profiles and to estimating the safety benefits of improved coordination plans demonstrated the model’s practicality and usefulness in improving safety at coordinated signals by practicing engineers.</p>

<p dir="ltr">Most road fatalities are caused by human error. To help mitigate this issue and enhance overall transportation safety, companies are turning to advanced driver assistance systems and autonomous vehicle development. Perception, a key module of these systems, mostly uses light detection and ranging (LiDAR) sensors and enables efficient obstacle detection and environment mapping. Extensive research on the use of LiDAR for autonomous driving has been documented in the literature. Yet still, several researchers and practitioners have advocated continued investigation of LiDAR placement alternatives. To address this research need, this thesis research begins with a comprehensive review of different sensor technologies – camera, radio detection and ranging, global positioning system, and inertial measurement units – and exploring their inherent strengths and limitations. Next, the thesis research developed a methodological multiple criteria framework and implemented it in the context of LiDAR placement optimization. Given the numerous criteria and placement alternatives associated with LiDAR placement, multi-criteria decision analysis (MCDA) was identified as an effective tool for LiDAR placement optimization. MCDA has been applied to some extent in decision-making regarding autonomous vehicle development. However, its application in LiDAR placement optimization remains unexplored. In evaluating the LiDAR placement alternatives, the research first established the placement alternatives and then developed a comprehensive yet diverse set of criteria – point density, blind spot regions, sensor cost, power consumption, sensor redundancy, ease of installation, and aesthetics. The data collection methods included the CARLA simulator, sensor datasheets, and questionnaire surveys. The relative importance among the evaluation criteria was established using weighting techniques such as respondent-assigned weighting, equal weighting, and randomly generated weighting. Then, to standardize the different measurement units, scaling was carried out using value functions developed for each criterion using data from the respondents. Finally, the weighted and scaled criteria measures were amalgamated to obtain the overall evaluation score for each alternative LiDAR placement design. This enabled the ranking of the placement designs and the identification of the best-performing and worst-performing designs. Hence, the optimization method used is the enumeration technique. The findings of this study serve as a reference for future similar efforts that seek to optimize LiDAR placements based on select criteria. Further, it is expected that the thesis’s framework will contribute to an enhanced understanding of the overall impact of LiDAR placement on autonomous vehicles, thus enabling the cost-effective design of their placement and, ultimately, improving AV operational outcomes, including traffic safety.</p>

<p>Road networks are significantly affected by traffic signal operations, which contribute from 5% to 10% of all traffic delay in the United States. It is therefore important for agencies to systematically monitor signal performance to identify locations where operations do not function as desired and where mobility could be improved.</p> <p><br></p> <p>Currently, most signal performance evaluations are derived from infrastructure-based Automated Traffic Signal Performance Measures (ATSPMs). These performance measures rely on high-resolution detector and phase information that is collected at 10 Hz and reported via TCP/IP connections. Even though ATSPMs have proven to be a valid approach to estimate signal performance, significant initial capital investment required for infrastructure deployment can represent an obstacle for agencies attempting to scale these techniques. Further, fixed vehicle detection zones can create challenges in the accuracy and extent of the calculated performance measures.</p> <p><br></p> <p>High-resolution connected vehicle (CV) trajectory data has recently become commercially available. With over 500 billion vehicle position records generated each month in the United States, this data set provides unique opportunities to derive accurate signal performance measures without the need for infrastructure upgrades. This dissertation provides a comprehensive suite of CV-based techniques to generate actionable and scalable traffic signal performance measures.</p> <p><br></p> <p>Turning movements of vehicles at intersections are automatically identified from attributes included in the commercial CV data set to facilitate movement-level analyses. Then, a trajectory-based visualization from which relevant performance measures can be extracted is presented. Subsequently, methodologies to identify signal retiming opportunities are discussed. An approach to evaluate closely-coupled intersections, which is particularly challenging with detector-based techniques, is then presented. Finally, a data-driven methodology to enhance the scalability of trajectory-based traffic signal performance estimations by automatically mapping relevant intersection geometry components is provided.</p> <p><br></p> <p>The trajectory data processing procedures provided in this dissertation can aid agencies make data-driven decisions on resource allocation and signal system modifications. The presented techniques are transferable to any location where CV data is available, and the scope of analysis can be easily varied from the movement to intersection, corridor, region, and state level.</p>