My work focused on the study of road effects and mitigation of negative impacts of roads on wildlife. Two different studies were conducted on Interstate 15, in southern Utah. My first study reported on road effects on small mammal communities. The results suggested that overall, there was no clear effect on small mammal populations relative to distance from the road. Most small mammal species did not appear to be negatively affected by the presence of the road. Instead, the road seemed to have either a neutral or a positive effect. The abundance and diversity of small mammals responded more markedly to microhabitat than to the presence of the highway. I suggest that other factors such as water runoff during rainy periods may be responsible for the detected patterns by increasing primary productivity in areas close to the road. I conclude that roads may often provide favorable micro-habitat in the desert landscape for many small mammals and that the disturbance caused by the highway use (e.g., noise, road surface vibration) seemed to have a negligible effect on these organisms . My second study examined the effectiveness of a mitigation strategy to reduce mule deer (Odocoileus hemionus) road mortality. Mitigation included exclusion fencing, earthen escape ramps, and underpass crossing structures . Results comparing mortality data before and after the mitigation showed 76-96% reductions of deer vehicle collisions. There was no evidence that the mitigation caused "end-of-the-fence" problems, i.e., higher mortality at the ends of the exclusion fencing . Results from underpass camera monitoring showed an increasing deer use of the underpasses over time. The volume of crossings recorded on new underpass structures approached the volume of crossings observed in a 20-year-old control underpass. My results suggest that human use and location of structures influenced deer use of underpasses. Overall results show that the mitigation strategy was effective and has reduced the number of deer-vehicle accidents while allowing easier wildlife movement across the landscape. I presented future maintenance recommendations to assure a long-term success for this strategy.

abstract: Urban-induced heating is a challenge to the livability and health of city dwellers. It is a complex issue that many cities are facing, and a more urgent hazard in hot urban deserts (HUDs) than elsewhere due to already high temperatures and aridity. The challenge compounds in the absence of more localized heat mitigation understanding. In addition, over-reliance on evidence from temperate regions is disconnected from the actualities of extreme bioclimatic dynamics found in HUDs. This dissertation is an integration of a series of studies that inform urban climate relationships specific to HUDs. This three-paper dissertation demonstrates heat mitigation aspirational goals from actualities, depicts local urban thermal drivers in Kuwait, and then tests morphological sensitivity of selected thermal modulation strategies in one neighborhood in Kuwait City. The first paper is based on a systematic literature review where evidence from morphological mitigation strategies in HUDs were critically reviewed, synthesized and integrated. Metrics, measurements, and methods were extracted to examine the applicability of the different strategies, and a content synthesis identified the levels of strategy success. Collective challenges and uncertainties were interpreted to compare aspirational goals from actualities of morphological mitigation strategies. The second paper unpacks the relationship of urban morphological attributes in influencing thermal conditions to assess latent magnitudes of heat amelioration strategies. Mindful of the challenges presented in the first study, a 92-day summer field-measurement campaign captured system dynamics of urban thermal stimuli within sub-diurnal phenomena. A composite data set of sub-hourly air temperature measurements with sub-meter morphological attributes was built, statistically analyzed, and modeled. Morphological mediation effects were found to vary hourly with different patterns under varying weather conditions in non-linear associations. Results suggest mitigation interventions be investigated and later tested on a site- use and time-use basis. The third paper concludes with a simulation-based study to conform on the collective findings of the earlier studies. The microclimate model ENVI-met 4.4, combined with field measurements, was used to simulate the effect of rooftop shade-sails in cooling the near ground thermal environment. Results showed significant cooling effects and thus presented a novel shading approach that challenges orthodox mitigation strategies in HUDs. / Dissertation/Thesis / Doctoral Dissertation Design, Environment and the Arts 2019

The development and adaptation of gear technologies to local fisheries has been a management-oriented research strategy commonly used to mitigate the ecological effects of pelagic longline (PLL) gear on bycatch species. Grenada’s PLL fishery primarily targets yellowfin tuna, however while minimal, their bycatch of blue marlin and white marlin exceeds the Total Allowable Catch (TAC) allowed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). A switch to circle hooks may benefit these nontargeted, bycatch species by reducing catch rates and haulback mortality, as well as increasing post-release survival. To determine differences in performance, assessments of 16/0 circle hooks and 9/0 J hooks were alternated over 26 sets between January and June 2018. Catch, mortality, hook location, length and grade of fish were compared between hook types. No differences in haulback mortality rate for all species, or yellowfin tuna grade were found between hook types. However, significantly fewer billfish collectively (t= 2.36, p= 0.028), and sailfish specifically (t= 3.04, p=0.005), were caught on circle hooks. Additionally, tuna caught with circle hooks had a 69% greater chance of external hooking compared to J hooks (X2 = 4.38 p=0.036). All other species analyzed had statistically similar catch rates regardless of hook type (p < 0.05), including, yellowfin tuna. The results of this study indicate the Grenadian PLL can reduce its impact on billfish bycatch by using 16/0 circle hooks without incurring negative effects on their tuna catch rate or grade. This research provides further evidence that circle hooks should be the recommended gear type when using a bycatch mitigation approach to manage PLL fisheries.

A study is conducted to test the dynamics of the 33ft Wave-Adaptive Modular Vessel (WAM-V) when outfitted with different suspension systems.  Instrumented with an array of sensors, the vessel is tested with two different suspension arrangements to characterize how they affect WAM-V dynamics, and to ultimately select a suspension that is most suitable for the 33ft WAM-V and other vessels that are planned for the future. Optimizing the suspension can reduce the magnitude of accelerations at the payload tray, benefiting both the operator and the payload.  Reduced accelerations can significantly improve comfort and risk of injury to the operator, while also lessening the likelihood of any damage to any sensitive cargo onboard.  The stock suspension components are characterized through in-house tests conducted at the Center for Vehicle Systems and Safety (CVeSS) at Virginia Tech (VT).  Based on the stock characterizations, new suspension components are chosen to better fit the needs of the 33ft WAM-V. Sea trials are conducted with both suspension systems at the Combatant Craft Division (CCD), a division of the Naval Surface Warfare Center, Carderock Division (NSWCCD), in Norfolk, VA to quantitatively and qualitatively determine the differences between the two suspensions.  The 33ft WAM-V is instrumented with a series of accelerometers and potentiometers for measuring accelerations and displacements.  The data is analyzed for the sea trials conducted at CCD and the results of the analysis indicate that the suspension selection can significantly affect the transmission of shock and vibrations from the pontoons to the operator or payload tray.  Both suspensions are able to mitigate a significant amount of the shocks seen at the pontoons, however, the results do not definitively show which suspension is the better of the two.  This is due to the fact that each suspension is not subjected to the exact same wave conditions, and  therefore the resulting suspension dynamics vary.  For instance, during a 2-foot wave event, the new suspension attenuates more shock than the stock suspension, 76% versus 71%.  However, during a 4-foot wave event, the stock suspension attenuates more shock than the new suspension, 66% versus 60%. Additionally, the suspension selection can significantly influence the ride height.  The stock suspension provides a 70/30 ratio between extension and compression stroke, while the new suspension provides a 50/50 ratio.  The more balanced split between the extension and compression strokes allow for better utilizing the total available stroke for the suspension in both directions.  This significantly reduces the resulting high-g impacts since the suspension does not frequently bottom out when the vessel is subjected to a large wave. It is recommended that the results of this study be extended through laboratory dynamic testing that allows for more repeatable dynamic events than sea trials in order to better establish the influence of each suspension parameter on the vessel dynamics.  Such tests will also allow for a better understanding of the dynamics of the vessel in response to various inputs at the pontoons, both subjectively (visually) and objectively (through measurements). / Master of Science

Future magnetic fusion reactors such as tokamaks will need innovative, fast, deep-fueling systems to inject frozen deuterium-tritium pellets at high speeds and high repetition rates into the hot plasma core. There have been several studies and concepts for pellet injectors generated, and different devices have been proposed. In addition to fueling, recent studies show that it may be possible to disrupt edge localized mode (ELM) formation by injecting pellets or gas into the fusion plasma. The system studied is capable of doing either at a variety of plasma and pellet velocities, volumes, and repetition rates that can be controlled through the formation conditions of the plasma. In magnetic or inertial fusion reactors, hydrogen, its isotopes, and lithium are used as fusion fueling materials. Lithium is considered a fusion fuel and not an impurity in fusion reactors as it can be used to produce fusion energy and breed fusion products. Lithium hydride and lithium deuteride may serve as good ablating sleeves for plasma formation in an ablation-dominated electrothermal plasma source to propel fusion pellets. Previous studies have shown that pellet exit velocities, greater 3 km/s, are possible using low-z propellant materials. In this work, a comprehensive study of solid lithium hydride and deuteride as a pellet propellant is conducted using the ETFLOW code, and relationships between propellants, source and barrel geometry, pellet volume and aspect ratio, and pellet velocity are determined for pellets ranging in volume from 1 to 100 mm3. / Master of Science

Nowadays, botnet attacks that aim to overwhelm the network layer by malformed packets and other means are usually mitigated by hardware intrusion detection systems. Application layer botnet attacks, on the other hand, are still a problem. In case of web applications, these attacks contain legitimate traffic that needs to be processed. If enough bots partake in this attack, it can lead to inaccessibility of services provided and other problems, which in turn can lead to financial loss. In this thesis, we propose a detection and mitigation system that can detect botnet attacks in realtime using statistical approach. This system is divided into several modules that together cooperate on the detection and mitigation. These parts can be further expanded. During the testing phase, the system was able to capture approximately 60% of botnet attacks that often focused on spam, login attacks and also DDoS. The number of false positive addresses is below 5%.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17877号 / 工博第3786号 / 新制||工||1579(附属図書館) / 30697 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 角 哲也, 教授 牛島 省, 准教授 竹門 康弘, 准教授 Sameh Ahmed Kantoush / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19977号 / 工博第4221号 / 新制||工||1653(附属図書館) / 33073 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 川﨑 雅史, 教授 中川 大, 准教授 久保田 善明 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20681号 / 工博第4378号 / 新制||工||1680(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 角 哲也, 准教授 竹門 康弘, 准教授 Sameh Kantoush / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21155号 / 農博第2281号 / 新制||農||1059(附属図書館) / 学位論文||H30||N5129(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 川島 茂人, 教授 星野 敏, 教授 藤原 正幸 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM