During an under-body blast (UBB) event, an improvised explosive device (IED) delivers a high-energy blast beneath a military vehicle, exposing mounted Warfighters to considerable risk of severe lower extremity injuries. Loftis and Gillich (2014) determined that the lower leg and ankle region is the most common body region to sustain skeletal injury in military mounted combat events, comprising twenty-one percent of cases reported in the Joint Trauma Analysis and Prevention of Injuries in Combat (JTAPIC) database between 2010 and 2012. Injuries of the lower extremity are not always life-threatening. However, from a survivability standpoint, these injuries may affect the ability of the Warfighter to self-extricate and ambulate in the immediate aftermath of an UBB event. In addition, lower extremity injuries can lead to long term health complications and reduced quality of life (Dischinger et al., 2004). While some comparisons can be drawn from the study of civilian automotive crashes; the impact level, rate, location, and directions in UBB are fundamentally different for the lower extremity. Therefore, substantial research efforts to characterize and assess injuries unique to UBB are essential. The Warrior Injury Assessment Manikin (WIAMan), the Tech Demonstrator version of which was introduced by Pietsch et al. (2016), is the only anthropomorphic test device (ATD) designed to evaluate injury patterns in UBB conditions. However, there are no known injury assessment tools for the female Warfighter at this time. The overarching goal of this research effort is to determine the origin of potential differences in the response of females and males in UBB conditions. The results of this work contribute to the body of research concerning high-rate axial loading of the lower extremity and form the first detailed biomechanical account of UBB effects on female PMHS. This work will inform future decisions regarding the requirements for a valid injury assessment capability for female Warfighters in the UBB environment and the subsequent research needed to support those requirements. Ultimately, advancements can be made in modeling and simulation capabilities, injury assessment criteria, test methodologies, and design approaches for safer military ground vehicles and personal protective equipment (PPE). Improvements in these technologies will reduce morbidity and mortality rates among the U.S. Warfighter population, both male and female. / During an under-body blast (UBB) event, an improvised explosive device (IED) delivers a high-energy blast beneath a military vehicle. Energy from the explosive is imparted to the occupants primarily through the floor and seats of the vehicle, exposing the occupants to considerable risk of injuries to the lower extremity. Compared to civilian automotive crashes, the lower extremities of occupants in UBB scenarios are exposed to greater forces, applied at higher rates, and in different locations and directions. To improve current vehicle systems and personal protective equipment (PPE), it is crucial to develop tools to evaluate injuries in UBB scenarios. One such tool is a test dummy, which is designed to quantify loads, deflections, and accelerations experienced by occupants during a crash. These measured values are compared to accepted thresholds, above which injury is likely to occur. The Warrior Injury Assessment Manikin (WIAMan), which is representative of the 50th-percentile male, is the only test dummy designed to evaluate injuries in UBB conditions. However, there are no known injury assessment tools for the female Warfighter at this time. The overarching goal of this research effort is to determine the origin of potential differences in the response of females and males in UBB conditions. The results of this work contribute to the body of research concerning high-rate axial loading of the lower extremity and form the first detailed biomechanical account of UBB effects on female post-mortem human surrogates (PMHS). The results will inform the development of injury assessment tools for female Warfighters, which will ultimately lead to improvements in technologies to reduce morbidity and mortality rates among the U.S. Warfighter population, both male and female.

High transmission data rate, spectral efficiency, and reliability are necessary for future wireless communications systems. In a multipath-rich wireless channel, deploying multiple antennas at both the transmitter and receiver achieves high data rate, without increasing the total transmission power or bandwidth. When perfect knowledge of the wireless channel conditions is available at the receiver, the capacity has been shown to grow linearly with the number of antennas. However, the channel conditions must be estimated since perfect channel knowledge is never known a priori. In practice, the channel estimation procedure can be aided by transmitting pilot symbols that are known at the receiver. System performance depends on the quality of channel estimate, and the number of pilot symbols. It is desirable to limit the number of transmitted pilot symbols because pilot symbols reduce spectral efficiency. This thesis analyzes the system performance of coded multiple-input multiple-output (MIMO) systems for the quasi-static fading channel. The assumption that perfect channel knowledge is available at the receiver must be removed, in order to more accurately examine the system performance. Emphasis is placed on developing channel estimation strategies for an iterative Vertical Bell-Labs Layered Space Time (V-BLAST) architecture. The channel estimate can be sequentially improved between successive iterations of the iterative V-BLAST algorithm. For both the coded and uncoded systems, at high signal to noise ratio only a minimum number of pilot symbols per transmit antenna are required to achieve perfect channel knowledge performance. / Master of Science

Blast resistance has recently become increasingly relevant for structural engineers. Blast loads are created by explosive devices that, upon detonation, create pressure loads that are much higher than most that a structure would ever experience. While there are many types of blast loads that are impossible to adequately prepare for, methods are presently being developed to mitigate these loads. This research investigates the possibility of using synthetic fiber ropes as a means of blast resistance. This is the third phase of a multi-stage research endeavor whose goal is to analyze Snapping-Cable Energy Dissipators (SCEDs) for reducing the effects of large-scale lateral loads. Finite element models of portal frames were developed using the commercial finite element program ABAQUS and dynamic models were run for varying blasts and frame systems. Blast pressures of 100, 2,000, and 4,000 psi were applied to a steel portal frame and comparisons were made between unbraced frames and frames braced with springs of different stiffnesses. Additional tests were run to examine the effects of strain rate dependent yield on the results of the models. Parallel research is being conducted on the specific material behavior of the synthetic fiber ropes so that the models developed for this research can be revised for a more accurate determination of the effects of the ropes on structural systems subjected to blast loads. / Master of Science

[pt] Na área de biologia computacional a busca por informações relevantes em meio a volumes de dados cada vez maiores é uma atividade fundamental. Dentre outras, uma tarefa importante é a execução da ferramenta BLAST (Basic Local Alignment Search Tool), que possibilita comparar biosseqüências a fim de se descobrir homologias entre elas e inferir as demais informações pertinentes. Um dos problemas a serem resolvidos no que diz respeito ao custo de execução do BLAST se refere ao tamanho da base de dados, que vem aumentando consideravelmente nos últimos anos. Avaliar o BLAST com estrat´egias paralelas e distribuídas com apoio de agrupamento de computadores tem sido uma das estratégias mais utilizadas para obter ganhos de desempenho. Nesta dissertação, é realizada uma alocação física replicada da base de dados (de seqüências), onde cada réplica é fragmentada em partes distintas, algumas delas escolhidas como primárias. Dessa forma, é possível mostrar que se aproveitam as principais vantagens das estratégias de execução sobre bases replicadas e fragmentadas convencionais, unindo flexibilidade e paralelismo de E/S. Associada a essa alocação particular da base, são sugeridas duas formas de balanceamento dinâmico da carga de trabalho. As abordagens propostas são realizadas de maneira não intrusiva no código BLAST. São efetuados testes de desempenho variados que demonstram não somente a eficácia no equilíbrio de carga como também eficiência no processamento como um todo. / [en] A fundamental task in the area of computational biology is the search for relevant information within the large amount of available data. Among others, it is important to run tools such as BLAST - Basic Local Alignment Search Tool - effciently, which enables the comparison of biological sequences and discovery of homologies and other related information. However, the execution cost of BLAST is highly dependent on the database size, which has considerably increased. The evaluation of BLAST in distributed and parallel environments like PC clusters has been largely investigated in order to obtain better performances. This work reports a replicated allocation of the (sequences) database where each copy is also physically fragmented, with some fragments assigned as primary. This way we show that it is possible to execute BLAST with some nice characteristics of both replicated and fragmented conventional strategies, like flexibility and I/O parallelism. We propose two dynamic workload balancing strategies associated with this data allocation. We have adopted a non- intrusive approach, i.e., the BLAST code remains unchanged. These methods are implemented and practical results show that we achieve not only a balanced workload but also very good performances.

[Truncated abstract] As a consequence of the increase in terrorist incidents, many comprehensive researches, both experimental and numerical modelling of structure and blast interaction, have been conducted to examine the behaviour of civilian structures under dynamic explosion and its impact. Nevertheless most of the works in literature are limited to response of simple structures such as masonry walls, reinforced concrete beams, columns and slabs. Although these studies can provide researchers and structural engineers a good fundamental knowledge regarding blast load effect, it is more likely for blast load to act upon entire structures in actual explosion events. The interaction between blast load and structures, as well as the interaction among structural members may well affect the structural response and damage. Therefore it is necessary to analyse more realistic reinforced concrete structures in order to gain an extensive knowledge on the possible structural response under blast load effect. Among all the civilian structures, bridges are considered to be the most vulnerable to terrorist threat and hence detailed investigation in the dynamic response of these structures is essential. This thesis focuses on the study of the response of a modern cable-stayed bridge under blast loadings. ... Firstly, analysis is conducted to examine the failure of four main components namely pier, tower, concrete back span and steel composite main span under close proximity dynamic impact of a 1000 kg TNT equivalent blast load. Secondly, based on such results, the remainder of the bridge structure is then tested by utilizing the loading condition specified in the US Department of Defence (DoD) guideline with the aim to investigate the possibility of bridge collapse after the damage of these components. It is found that failure of the vertical load bearing elements (i.e. pier and tower) will lead to catastrophic collapse of the bridge. Assuming that terrorist threat cannot be avoided, hence protective measures must be implemented into the bridge structure to reduce the damage induced by explosive blast impact and to prevent bridge from collapse. As such, a safe standoff distance is determined for both the pier and tower under the blast impact of 10000 kg TNT equivalent. This information would allow the bridge designer to identify the critical location for placing blast barriers for protection purpose. For the case of bridge deck explosion, carbon fibre reinforced polymer (CFRP) is employed to examine in respect of its effectiveness in strengthening the concrete structure against blast load. In this research, appropriate contact is employed for the numerical model to account for the epoxy resin layer between the CFRP and concrete. In addition, to ensure that the CFRP can perform to its full capacity, anchors are also considered in the numerical study to minimize the chance of debonding due to the weakening of the epoxy. The results reveal that although severe damage can still be seen for locations in close proximity to the explosive charge, the use of CFRP did reduce the dynamic response of the bridge deck as compared to the unprotected case scenario. Further investigation is also carried out to examine the change in damaged zone and global response through variation in CFRP thickness.

No description available.

This work deals with character-based DNA barcoding. DNA barcoding and character-based DNA barcoding methods are described in the introduction. Another part contains information of method CAOS (Characteristic Attributes Organization), method BLOG (Barcoding with LOGic) and method BLAST. Programs are described in the practical part. The end contains results.

Explosives have become increasingly common on the battlefield worldwide. Military personnel and civilians often experience blast loading to the lower extremity due to its direct contact with the ground and floor of vehicles. The pressure and axial loading from these incidents often lead to detrimental injuries. These injuries can be due to a number of mechanisms terming them primary, secondary, tertiary, or quaternary blast injuries. Of these injuries, this study will focus on primary and tertiary injuries, specifically bone fractures, compartment syndrome, and soft tissue disruption which often result from blast loading due to these mechanisms. However, the pressure and load levels causing these injuries are unknown. Currently, the methodologies, which study the injury criteria and design of blast mitigating structures, are limited. The main limitations are the lower rates of testing (automobile), specimen limitation (cadavers, surrogates, etc.), cost, and testing repeatability. Consequently, the goal of this dissertation is to develop a realistic computational model which can be used to improve the injury criteria, personal protective equipment (PPE), and vehicular structure in a cost effective and timely manner. Three Aims were thus pursued. For Specific Aim 1, a standing lower extremity was developed, verified, and simulated with several open-air blast loading conditions. Specific Aim 2 focused on validating the lower extremity model using experimental drop tower test results. In the drop tower simulation, the lower extremity model was successfully converted into a seated posture model and setup with similar loading and boundary conditions as the experiment. Specific Aim 3 involved incorporating a boot into the standing lower extremity model and evaluating its ability to mitigate pressure waves. In summary, Specific Aims 1 and 2 developed, verified, and validated a realistic human lower extremity model for the use in blast simulations. Specific Aim 3 further confirmed the models use in developing PPE.

In this thesis, the dynamic structural response of six scaled flexural masonry walls to scaled blast loading is experimentally investigated. These walls have been tested in at an open range with charge masses ranging from 5 kg to 25 kg of Pentex-D explosive material with a TNT equivalency of 1.2, and with a constant stand-off distance of 5 m throughout testing. The field properties of the blast wave, which includes the reflected and free field pressures, were recorded. Additionally, the displacement response histories of the wall over the blast test were recorded and the post-blast damage was documented. This study puts forth several potential models for the analysis of the experimental data. The experimentally obtained blast characteristics were compared to predictions of the Kingery and Bulmash (K-B) model. The strain rates used during the study are equivalent to those developed by a number of studies for the materials used in the construction of the specimens. The results obtained through the experimental program are compared to those from a variety of single degree of freedom models, ranging from simplified linear relationships to complex stress-strain relations accounting for the effects that arise because of the increased strain rate due to blast testing. The simplified model assumes a constant stiffness, mass, and triangular pressure profile to determine the peak deflection of the specimen during an experimental test. The bilinear and nonlinear models are based on the discretization of the wall sections into a number of layers, and using strain-rate dependent, stress-strain relations of the constituent materials to generate stresses within the layers. These stresses then iv form the basis of the resistance function to determine the structural response of the test specimens. In this study, the effect of higher modes of vibration on the test specimens is not included. The bilinear and nonlinear models are then implemented to develop Pressure-Impulse (P-I) diagrams, and the effect of the strain rate on P-I diagrams is investigated. The P-I are then available to be implemented into the recent blast code for reinforced masonry flexural walls. The fitted results of the recorded experimental blast pressure parameters are shown to be adequately approximated by the software ConWep in terms of the peak pressure and specific impulse. Comparing the K-B model, which forms the theoretical basis of ConWep, to the raw pressure profile data obtained from the experimental testing, a significant variations is found in the pressure data while significant scatter is found in the impulse. The analytical results show that increasing the nonlinearity of the material accounts for; the response predicted by the single degree of freedom model more closely relates to the response of the specimens. In addition, strain rate effects have a significant impact on the potential level of protection (LOP) provided by masonry flexural walls, as it has a noticeable effect on the curves of the P-I diagram. / Thesis / Master of Applied Science (MASc)

No description available.