14-Bromo-12-chloro-2,16-dioxapentacyclohenicosa-3(8),10,12,14-tetraene-7,20-dione

In the title compound, C19H16BrClO4, both the fused xanthene rings and one of the cyclohexane rings adopt envelope conformations, while the other cyclohexane ring is in a chair conformation. In the crystal, molecules are linked by C-H...O hydrogen bonds, forming infinite chains running along [10-1] incorporating R22(16) ring motifs. In addition, C-H...[pi] interactions and weak [pi]-[pi] stacking interactions [centroid-centroid distance = 3.768 (3) Å] help to consolidate the packing

Large Amplitude Pitching of Supermaneuver Delta Wings Including Flow Control

The unsteady, three-dimensional Navier-Stokes equations are solved to simulate and study the aerodynamic response of a delta wing undergoing large amplitude pitching motion up to 90° angle of attack. The primary model under consideration consists of a 76° swept, sharp-edged delta wing of zero thickness, initially at zero angle of attack. The freestream Mach number and Reynolds number are 0.3 and 0.45 × 106, respectively. The governing equations are solved time-accurately using the implicit, upwind, Roe flux-difference splitting, finite-volume scheme. Both laminar and turbulent flow solutions are investigated. In the laminar flow solutions, validation of the computational results is carried out using existing experimental data, and shows good agreement. The effect of reduced frequency of the wing motion is then presented and a grid refinement study is introduced. In the turbulent flow simulations, both Baldwin-Lomax and Spalart-Allmaras turbulence models are used and the results are compared with those of the laminar solution and experimental data as well. A sinusoidal pitching motion of the wing is also investigated in the present work. The computational results provide complete information and details about the flowfield response, which are difficult to obtain from experiment. A feasibility study of using one of the flow control techniques, blowing, to enhance maneuverability is introduced. The investigation of the unsteady flow over a wide range of angles of attack provides crucial understanding of the variations of the leading edge vortex cores, their breakdown behavior, aerodynamic hysteresis, and wing aerodynamic characteristics at very high angle of attack. The current study shows that numerical simulations in the very high angle of attack range are obtainable. Such calculations were thought to be unattainable as recently as the 1980\u27s

Noise generation from interacting high speed axisymmetric jet flows Semiannual status report, 1 Jun. 1968 - 31 Dec. 1969

Far field noise generation from interacting coaxial jet flows, and nozzle operational mode

Learning to Read by \u27Rote\u27

Information about traditional Islamic (or Quranic) education dates back to its inception over 1400 years ago in the Arabian Peninsula. During this millennium, Islamic religious schools have spread with Islam to more than 40 countries, spanning half the globe and teaching tens of millions of children (although exact statistics are still unavailable). Until recently, most research on Islamic schooling was historical, focused on philosophy, and was based on secondary sources (e.g., Ahmed 1968; Nakosteen 1964; Rosenthal 1947; Tales 1939; Tritton 1957; Yacoub 1890). In the last several years, a number of investigators have begun to study the various roles these Muslim schools play in countries such as Indonesia. (Jones 1980; Shaeffer 1979), Morocco (Wagner and Lofi 1980), Ghana (Bennett 1979), Liberia (Smith 1978), and the Quranic schooling (such as the primary use of the Quran as a text and of Arabic as the language of written instruction), Muslim countries around the world may vary greatly in sociocultural traditions, language, and date and degree of Islamization. The effects of these differences have resulted in a complex and varied picture of Quranic education as it adapts to societal pressures in the contemporary world

A review of smart homes in healthcare

The technology of Smart Homes (SH), as an instance of ambient assisted living technologies, is designed to assist the homes’ residents accomplishing their daily-living activities and thus having a better quality of life while preserving their privacy. A SH system is usually equipped with a collection of inter-related software and hardware components to monitor the living space by capturing the behaviour of the resident and understanding his activities. By doing so the system can inform about risky situations and take actions on behalf of the resident to his satisfaction. The present survey will address technologies and analysis methods and bring examples of the state of the art research studies in order to provide background for the research community. In particular, the survey will expose infrastructure technologies such as sensors and communication platforms along with artificial intelligence techniques used for modeling and recognizing activities. A brief overview of approaches used to develop Human–Computer interfaces for SH systems is given. The survey also highlights the challenges and research trends in this area

Resource Allocation for Heterogeneous Traffic in LTE Virtual Networks

Cellular network virtualization is being considered as a key trend in future mobile networks towards improved resource utilization. However, virtualization scenarios need investigation to understand the considerations which should be taken into account when deploying virtualized wireless networks in practice. Towards this, we address the performance of a virtualized network in the presence of heterogeneous classes of traffic. In previous cellular network virtualization literature, both Real time (RT) and Non-Real time (NRT) traffic requests have been included without distinction. Both types are provisioned using the same algorithm for allocation of resources specified by the Network Scheduler [1]. However, different types of traffic have different characteristics [2], e.g., RT requests are delay sensitive but may need fixed bandwidth, and hence should be treated differently, especially when wireless channel conditions are factored into the scheduling. We recognize this difference and in this paper, we propose a new approach to improve scheduling of resources for RT and NRT traffic. In particular, we prioritize the traffic belonging to different virtual slices from all service providers (SP/VEs) at the Network Scheduler before allocating resources to different SP/VEs, i.e., We form a Virtual Prioritized Slice (VPS). The virtual prioritized slice is forwarded to the VPS scheduler to serve all RT requests first. Only after the RT traffic is scheduled, the NRT traffic is provisioned using proportional fairness (PF) scheduling. We show by simulation results that this new VPS approach helps outperform recently proposed resource allocation schemes

Modeling Interaction in Multi-Resident Activities

In this paper we investigate the problem of modeling multi-resident activities. Specifically, we explore different approaches based on Hidden Markov Models (HMMs) to deal with parallel activities and cooperative activities. We propose an HMM-based method, called CL-HMM, where activity labels as well as observation labels of different residents are combined to generate the corresponding sequence of activities as well as the corresponding sequence of observations on which a conventional HMM is applied. We also propose a Linked HMM (LHMM) in which activities of all residents are linked at each time step. We compare these two models to baseline models which are Coupled HMM (CHMM) and Parallel HMM (PHMM). The experimental results show that the proposed models outperform CHMM and PHMM when tested on parallel and cooperative activities

The effect of oil price shocks on the Saudi manufacturing sector

This paper aims to examine the effects of oil price shocks on the manufacturing sector in Saudi Arabia during the period 2002 – 2014, using quarterly data. A unit root test was conducted, in which the data were shown to be non-stationary in the level, and they became stationary in the first difference for all variables. The co-integration model was applied, and the results indicated that no co-integrating equation exists, which means that there is no long run effect of oil price shocks on the manufacturing sector. So, we estimate a Vector Auto Regressive model, the results of which implied that oil price shocks do not affect in the manufacturing sector in the short run, and it may have an effect on the manufacturing sector after 10 quarter according to the impulse response function

Performance of Spatial Modulation using Measured Real-World Channels

In this paper, for the first time real-world channel measurements are used to analyse the performance of spatial modulation (SM), where a full analysis of the average bit error rate performance (ABER) of SM using measured urban correlated and uncorrelated Rayleigh fading channels is provided. The channel measurements are taken from an outdoor urban multiple input multiple output (MIMO) measurement campaign. Moreover, ABER performance results using simulated Rayleigh fading channels are provided and compared with a derived analytical bound for the ABER of SM, and the ABER results for SM using the measured urban channels. The ABER results using the measured urban channels validate the derived analytical bound and the ABER results using the simulated channels. Finally, the ABER of SM is compared with the performance of spatial multiplexing (SMX) using the measured urban channels for small and large scale MIMO. It is shown that SM offers nearly the same or a slightly better performance than SMX for small scale MIMO. However, SM offers large reduction in ABER for large scale MIMO.Comment: IEEE Vehicular Technology Conference Fall 2013 (VTC-Fall 2013), Accepte