Connected Vehicle Technology: User and System Performance Characteristics

The emerging connected vehicle (CV) technology plays a promising role in providing more operable and safer transportation environments. Yet, many questions remain unanswered as to how various user and system characteristics of CV-enabled networks can shape the successful implementation of the technology to maximize the return on investment. This research attempts to capture the effect of multiple factors such as traffic density, market penetration, and transmission range on the communication stability and overall network performance by developing a new CONnectivity ROBustness (CONROB) model. The model was tested with data collected from microscopic simulation of a 195 sq-mile traffic network and showed a potential to capture the effect of such factors on the communication stability in CV environments. The information exchanged among CVs can also be used to estimate traffic conditions in real time by invoking the probe vehicle feature of CV technology. Since factors affecting the connectivity robustness also have an impact on the performance of traffic condition estimation models, a direct relationship between connectivity robustness and traffic condition estimation performance was established. Simulation results show that the CONROB model can be used as a tool to predict the accuracy of the estimated traffic conditions (e.g. travel times), as well as the reliability of such estimates, given specific system characteristics. The optimal deployment of road-side units (RSUs) is another important factor that affects the communication stability and the traffic conditions estimates and reliability. Thus, an optimization approach was developed to identify the optimal RSUs locations with the objective function of maximizing the connectivity robustness. Simulation results for the developed approach show that CONROB model can help identify the optimal RSUs locations. This shows the importance of CONROB model as a planning tool for CV environments. For the individual user performance characteristics, a preliminary driving simulator test bed for CV technology was developed and tested on thirty licensed drivers. Forward collision warning messages were delivered to drivers when predefined time-to-collision values take place. The findings show improved reaction times of drivers when receiving the warning messages which lend credence to the safety benefits of the CV technology

Image findings of cranial nerve pathology on [18F]-2- deoxy-D-glucose (FDG) positron emission tomography with computerized tomography (PET/CT): a pictorial essay.

This article aims to increase awareness about the utility of (18)F -FDG-PET/CT in the evaluation of cranial nerve (CN) pathology. We discuss the clinical implication of detecting perineural tumor spread, emphasize the primary and secondary (18)F -FDG-PET/CT findings of CN pathology, and illustrate the individual (18)F -FDG-PET/CT CN anatomy and pathology of 11 of the 12 CNs

Sjögren Syndrome Complicated by Mucosa-Associated Lymphoid Tissue Lymphoma and Lymphocytic Interstitial Pneumonia.

Sjögren syndrome (SS) is an autoimmune disease with exocrine glands dysfunction and multiorgan involvement. It is associated with increased risk of lymphoproliferative disorders, especially B-cell marginal zone lymphoma. While the role of F-18 Fluorodeoxyglucose position emission tomography/computed tomography (F-18 FDG PET/CT) for evaluation of lymphoma has been established, its use in patients with a chronic history of SS to evaluate for possible lymphoproliferative disorders or multiorgan involvement is limited. We present a case of chronic SS in which F-18 FDG PET/CT demonstrated FDG avid intraparotid and cervical lymph nodes pathologically proven to be mucosa-associated lymphoid tissue lymphoma. In addition, the patient had bibasilar cystic changes consistent with lymphocytic interstitial pneumonia

Crash Risk Analysis of Distracted Driving Behavior: Influence of Secondary Task Engagement and Driver Characteristics

Distracted driving has long been acknowledged as one of the main contributors to crashes in the US. According to past studies, driving behavior proved to be influenced by the socioeconomic characteristics of drivers. However, only few studies attempted to quantify that influence. The study proposed a Crash Risk Index to estimate the crash risk associated with the socioeconomic characteristics of drivers and their tendency to experience distracted driving. The analysis is conducted using data from the SHRP 2 Naturalistic Driving Study (NDS). The proposed Crash Risk Index (CRI) is developed based on a grading system of three measures: the crash risk associated with performing secondary tasks during driving, the effect of socioeconomic attributes (e.g. Age) on the likelihood of engagement in secondary tasks, and the effect of specific categories within each socioeconomic attribute (e.g. Age\u3e60) on the likelihood of engagement in secondary tasks. Logistic Regression analysis was performed on the secondary tasks, socioeconomic attributes, and the specific socioeconomic characteristics. The results identified the significant secondary tasks with high crash risk and the socioeconomic characteristics with significant effect on determining drivers’ involvement in secondary tasks among each tested parameter. These results were used to quantify the grading system measures and hence estimate the proposed CRI. This index indicates the relative crash risk associated with the socioeconomic characteristics of drivers and considering the possibility of engagement in secondary tasks. The proposed CRI and the associated grading system are plausible methods for estimating auto insurance premiums

New Concrete Technology Negates Traditional Concrete Placement in Sudan

Self-consolidating concrete, also known as self-compacting concrete (SCC), is an innovative concrete that does not require vibration for placing and compaction. The mixture qualification process of Self Compacting Concrete consists from a small, well controlled laboratory batches are tested, second, the closest mixture/s is tested in production, which includes the use of batch mixing, and placing equipment, and finally a quality assurance/control plan for the fresh and hardened properties is developed. However, this paper presents a full research addressed only a small, well controlled laboratory batches and the laboratory testing phase of the mixture qualification process. For the purpose of study, a small, well controlled laboratory batches are tested using available locally aggregates in Sudan. Therefore, Slumpflow, V-funnel, L-box shape, J-ring, and Sieve stability tests of concrete mixtures were used to determine the flowability, passing ability and segregation resistance of SCC mixtures. The produced self compacting concrete is successfully confirmed the fresh properties of SCC with Slumpflow in range of 650 to 850 mm with high viscosity and excellent segregation resistance. The hardened properties of concrete were also considered and tested. The strength of SCC was found to be same or higher than that of normally vibrated concrete with the same constituent materials. SCC has relatively higher dynamic modulus of elasticity ranged between 38 to 42 GPa, in comparison to normally vibrated concrete for the same strength range of 50 to 60 MPa. Whereas the Spilt Tensile and Flexural strength of SCC are of 2.5 MPa and 10 MPa respectively. The major difficulty which was faced in development of SCC was on account of contradictory factors that the concrete should be fully flowable but without bleeding or segregation. It is required that the cement mortar of the SCC should have higher viscosity to ensure flowability while maintaining non-sedimentation of aggregates and that was achieved by using high content of powder (fine materials less than 0.15 mm includes cementitious materials). Achievement of durable concrete structures independent of the quality of construction work by using Self Compacting Concrete (SCC) has been proposed to solve the problem of the durability of concrete structures due to the gradual reduction of adequate compaction and skilled workers and for complex shape for the prestressed and precast industries in Sudan. The features of high benefit of fluidity and self consolidation will result in a variety of potential benefits for the end-user. Other benefits of the application of this new concrete technology require effort to be achieved. Moreover, areas such as quality control, mixture development, and logistics may need modification or expand resources when develop self-compacting concrete in Sudan. Keywords: Self Compacting Concrete (SCC), Sudan, Flowability, Passing ability, Segregation Resistance Slumpflow, V-funnel, L-box shape, J-ring, and Sieve stability, Powder conten

Synthesis and anti-tumor activities of new [1,2,4]triazolo[1,5-a]pyrimidine derivatives

Condensation of 1H-1,2,4-triazol-5-amine with the appropriate sodium (E)-(2-oxocycloalkylidene)methanolate gave 7,8-dihydro-6H-cyclopenta[e][1,2,4]triazolo [1,5-a]pyrimidine, 6,7,8,9-tetrahydro-[1,2,4]triazolo[1,5-a]quinazoline, 7,8,9,10-tetra hydro-6H-cyclohepta[e][1,2,4]triazolo[1,5-a]pyrimidine and 6,7,8,9,10,11-hexahydro cycloocta[e][1,2,4]triazolo[1,5-a]pyrimidine. Structures of the newly synthesized compounds were elucidated via elemental analyses, spectral (IR, 1H NMR, 13C NMR, 2D NMR), and X-ray single crystal diffraction data. These derivatives showed potent anti-tumor cytotoxic activity in vitro using different human cancer cell lines

Validity of Finite Element Method: Analysis of Laminated Composite Decks Plates Subjected to in Plane Loading

To verify the accuracy of the present technique, buckling loads are evaluated and validated with other works available in the literature. Further comparisons were carried out and compared with the results obtained by the ANSYS package and experimental results. The good agreement with available data demonstrates the reliability of the finite element method used