Multiwavelength Study of M8.9/3B Solar Flare from AR NOAA 10960

We present a multi-wavelength analysis of a long duration white-light solar flare (M8.9/3B) event that occurred on 4 June 2007 from NOAA AR 10960. The flare was observed by several spaceborne instruments, namely SOHO/MDI, Hinode/SOT, TRACE and STEREO/SECCHI. The flare was initiated near a small, positive-polarity, satellite sunspot at the centre of the AR, surrounded by opposite-polarity field regions. MDI images of the AR show considerable amount of changes in a small positive-polarity sunspot of delta configuration during the flare event. SOT/G-band (4305 A) images of the sunspot also suggest the rapid evolution of the positive-polarity sunspot with highly twisted penumbral filaments before the flare event, which were oriented in the counterclockwise direction. It shows the change in orientation and also remarkable disappearance of twisted penumbral filaments (~35-40%) and enhancement in umbral area (~45-50%) during the decay phase of the flare. TRACE and SECCHI observations reveal the successive activations of two helical twisted structures associated with this sunspot, and the corresponding brightening in the chromosphere as observed by the time-sequence images of SOT/Ca II H line (3968 A). The secondary-helical twisted structure is found to be associated with the M8.9 flare event. The brightening starts 6-7 min prior to the flare maximum with the appearance of secondary helical-twisted structure. The flare intensity maximizes as this structure moves away from the AR. This twisted flux-tube associated with the flare triggering, is found to be failed in eruption. The location of the flare is found to coincide with the activation site of the helical twisted structures. We conclude that the activations of successive helical twists in the magnetic flux tubes/ropes plays a crucial role in the energy build-up process and triggering of M-class solar flare without a CME.Comment: 22 pages, 12 figures, Accepted for Publication in Solar Physic

Design space exploration for providing QoS within the HARMONY framework

The HARMONY architecture (A.M. Lele and S.K. Nandy, 1999) provides mechanisms for management of network and compute resources in a mobile computing environment. In HARMONY, network resources are reserved based on the Entropy Model (A.M. Lele and S.K. Nandy, 1998), and compute guarantees are provided by off-loading tasks from the mobile units to compute servers in the backbone network. A load balancing scheme redistributes loads across all compute servers so that these are equally loaded. The paper carries out a design space exploration of the HARMONY architecture to determine parameter bounds within which quality of service can be provided

An approach to assessing the status of sealed-off fires by examination of fire indices

The advantages and disadvantages of different fire indices in common use, such as CO/O2 deficiency (def.)%, CO2/O2 def.% and CO/CO2 percentage, as well as those proposed in the literature such as the desorbed hydrocarbon index, the CO—residual gas relationship and the C/H ratio of the products of combustion, are discussed in terms of their applicability for determining the extent and intensity of underground sealed fires. Five cases of different types of fires are studied and examined using the above indices. It is inferred that characterisation of fires should be made from fire indices, such as the C/H ratio, CO/O2 def.% and the CO/CO2 percentage, temperature profile studies, pressure differential measurements in stopes and spontaneous heating characteristics of the coal concerned in relation to other mining parameters. Values of C/H ratio above 3 or 4, values of the CO/O2 def.% of > 0.5 and values of CO/CO2 of > 2 are indicative of initiation of active fires. A C/H ratio of ⩾ 20 indicates a blazing fire where wooden props may be burning

An approach towards the design and development of a flexible 5dof AUV

Present study consists the overall development aspects of an Autonomous Underwater Vehicle (AUV) such as mechanical design, modelling, software architecture, controllers and navigation in combination with the lake experiments conducted on the vehicle at a shallow depth. AUV prototype in discussion is designated, AUV-150 and is designed to operate at a depth of 150 meters. It is a cylindrical-shaped carrier with streamlined fairing to reduce hydrodynamic drag. It is embedded with active propulsion, navigation, and control systems. Propulsion system comprises thrusters for generating motion in different directions to control surge, sway, heave, pitch, and yaw. Two arrays of cross-fins have also been fixed at the two ends to provide additional stability to the AUV against roll. A lithium polymer battery powers the vehicle and a pressure hull contains its electronics and energy system. Equipped with a camera, CTD and side scan sonar as payload sensors the AUV-150 is perfectly designed for performing underwater terrain mapping as well as oceanographic survey activities. The experimental results obtained from the shallow depth operation are quite satisfactory from the operational point of view

A Study On Utilisation Of Health Services In A Muslim Slum Community Of Calcutta

A cross- sectional survey of utilization of child immunization and family planning services was carried out in a systematic random sample of 100 families from a Muslim slum community of Calcutta. 15.6% of children (1-4 years) were fully immunized (DPT, OPV & BCG). Couple protection rate was 28.4%. But interestingly, the proportion of protected eligible couples in single families (32.8%) was significantly higher than in joint families (11.6%)

Run-time Mapping Algorithm for Dynamic Workloads using Process Merging Transformations

Exploration of task mappings has an important role to achieve high performance in heterogeneous multi-processor system-on-chip (MPSoC) platforms. The application workloads in modern MPSoC-based embedded systems are becoming increasingly dynamic. Different applications concurrently execute and contend for resources in such systems. In this paper, a run-time algorithm is proposed to analytically evaluate the system throughput of to-be-executed applications (modelled as Kahn Process Networks, KPNs) in order to quickly determine a proper resource binding for these applications. Merging transformations on the KPNs are applied to capture the cases in which the number of processes in the KPN is larger than the number of available processing resources, thereby modeling the effects of binding multiple processes to a single processor. We evaluated our algorithm using a heterogeneous MPSoC system with several applications. Our experimental results revealed that during runtime, the performance of selected mapping with regard to available resources is close to the optimal performance obtained by exhaustive search and simulation. Therefore, the results clearly confirm that our algorithm is effective

SysRT: A Modular Multiprocessor RTOS Simulator for Early Design Space Exploration

Modern embedded systems increasingly accommodate several applications running concurrently on a multiprocessor platform managed by a real-time operating system (RTOS). The increasing design complexity of such systems calls for good design tools to evaluate real-time performance during the very early stages of design. To this end, fast system-level simulators that allow for efficient hardware/software co-simulation are essential. In this paper, we present SysRT, a generic and highlevel RTOS simulator that is highly suited for early design space exploration (DSE). The simulator contains different types of application models and a modular RTOS kernel model, all developed in SystemC. Efficient and precise modeling of preemptive scheduling is achieved via an event-driven simulation approach, allowing simulations to be performed much faster than cycle-accurate simulations. At the same time, the kernel model is developed to be generic and modular to support for easy plugin of new schedulers as well as new resource sharing protocols. Comparing SysRT with state-of-art simulators, it achieves faster simulation speeds with an identically small simulation error. We demonstrate the flexibility of SysRT and its benefits for early DSE using experiments with a mixed workload executing on multiprocessor platforms with different numbers of cores

Coherence Buffer: An Architectural Support for Imposing Early and Local Cache Coherence in Distributed Shared-Memory Multiprocessors

Cache coherence problem is pervasive, and a solution to this problem affects the memory performance, influences the amount of..