The dynamics and control of large flexible space structures-V

A general survey of the progress made in the areas of mathematical modelling of the system dynamics, structural analysis, development of control algorithms, and simulation of environmental disturbances is presented. The use of graph theory techniques is employed to examine the effects of inherent damping associated with LSST systems on the number and locations of the required control actuators. A mathematical model of the forces and moments induced on a flexible orbiting beam due to solar radiation pressure is developed and typical steady state open loop responses obtained for the case when rotations and vibrations are limited to occur within the orbit plane. A preliminary controls analysis based on a truncated (13 mode) finite element model of the 122m. Hoop/Column antenna indicates that a minimum of six appropriately placed actuators is required for controllability. An algorithm to evaluate the coefficients which describe coupling between the rigid rotational and flexible modes and also intramodal coupling was developed and numerical evaluation based on the finite element model of Hoop/Column system is currently in progress

The dynamics and control of large flexible space structures-IV

The effects of solar radiation pressure as the main environmental disturbance torque were incorporated into the model of the rigid orbiting shallow shell and computer simulation results indicate that within the linear range the rigid modal amplitudes are excited in proportion to the area to mass ratio. The effect of higher order terms in the gravity-gradient torque expressions previously neglected was evaluated and found to be negligible for the size structures under consideration. A graph theory approach was employed for calculating the eigenvalues of a large flexible system by reducing the system (stiffness) matrix to lower ordered submatrices. The related reachability matrix and term rank concepts are used to verify controllability and can be more effective than the alternate numerical rank tests. Control laws were developed for the shape and orientation control of the orbiting flexible shallow shell and numerical results presented

Evaluation of Change Factors for Web Service Change Management

AbstractService oriented architecture (SOA) is a smart designing principle which has been evolved for integrating business tasks. Business activities that have to be designed based on SOA are implemented via web services. Using web services (WS) one can exchange data between different applications and different platforms. Service providers register their services in the service registry and consumer obtains the required services from the same. The main concern in this routine which directly sways business growth rate is change management. Change management is an emerging issue in web service computing where clients might want to change the obtained services at some period of time. But in order to do it they should be requesting the provider programmers each and every time and separate payment has to be done for that task. In order to reduce this complexity we propose a new model for implementing change requests by business analysts themselves. Here we propose a new dynamic schema driven business logic model using Finite State Machine (FSM) to accomplish WS change management in a best manner so that business growth rate can be increased. This model is distinctively done for business analysts to perform changes in the services on their own instead of depending on the programmers. Furthermore a predictive model is contrived using cellular automata for supporting business analysts. The predictive model includes the change factors like order of execution; similarity measure, schema validation, and mapping function and time/space complexity which appears when a particular change request is executed

Synthesis and Antimicrobial Activity of 2-(Aminoacid ester)-3-(6-methyl-2-pyridyl)-3,4-dihydro-2H-1,3,2 λ5- benzoxazaphosphinin-2-thiones

Synthesis of 2-(aminoacid ester)-3-(6-methyl-2-pyridyl)-3,4-dihydro-2H-1,3,2λ5-benzoxazaphosphinin-2-thiones (3a–j) was accomplished through a two-step process. It involves the prior preparation of 2-chloro-3-(6-methyl-2-pyridyl)-3,4-dihydro-2H-1,3,2λ5-benzoxazaphosphinin-2-thione monochloride (2) and its subsequent reaction with the aminoacid ester hydrochlorides in dry tetrahydrofuran-toluene in the presence of triethylamine at various temperatures. These compounds were characterizedby IR, 1H, 13C, 31P NMR and mass spectral data.Keywords: 2-[(6-methyl-2-pyridyl) amino] methylphenol, 1,3,2-benzoxazaphosphinin-2-thione, antimicrobial activit

Is deep venous thrombosis a common complication in patients treated with Ilizarov external fixator?

Background: Determining the incidence of deep venous thrombosis (DVT), a prospective study, in patients treated with Ilizarov external fixators for lower extremity fractures, fracture non unions or deformity correction.Methods: A Prospective, observational and cross sectional study. 49 Patients with complex lower extremity injuries, deformities and non-union of fractures were treated with Ilizarov external fixator application, were assessed clinically and radiological (Venous Doppler) at regular intervals- 6 days post-surgery then at 6 weeks, 12 weeks and between 4 to 6 months post-operative. None were given chemoprophylaxis for the prevention of DVT and everyone were assessed pre operatively with a questionnaire and wells criteria was taken for assessment of high risk for developing venous thrombosis. There were 41 men and 8 women, 85.75% of the study group is of age 30 to 60 years.Results: Only 1 of 49 patients developed radiological evident DVT within 6 days of surgery. Patients who underwent application of Ilizarov external fixator electively for deformity correction, osteomyelitis and non-union showed no clinical or radiological evident signs of DVT.Conclusions: The incidence of DVT and PTE is minimal when patients without chemoprophylaxis underwent lower limb Ilizarov external fixator application for acute trauma and electively for deformity correction, treatment of non-union and osteomyelitis. However further comparative and randomized studies need to be done to confirm our results

Genome-wide identification and transcriptional profiling of small heat shock protein gene family under diverse abiotic stress conditions in Sorghum bicolor (L.)

The small heat shock proteins (sHsps/Hsp20s) are the molecular chaperones that maintain proper folding, trafficking and disaggregation of proteins under diverse abiotic stress conditions. In the present investigation, a genome-wide scan revealed the presence of a total of 47 sHsps in Sorghum bicolor (SbsHsps), distributed across 10 subfamilies, the major subfamily being P (plastid) group with 17 genes. Chromosomes 1 and 3 appear as the hot spot regions for SbsHsps, and majority of them were found acidic, hydrophilic, unstable and intron less. Interestingly, promoter analysis indicated that they are associated with both biotic and abiotic stresses, as well as plant development. Sorghum sHsps exhibited 15 paralogous and 20 orthologous duplications. Expression analysis of 15 genes selected from different subfamilies showed high transcript levels in roots and leaves implying that they are likely to participate in the developmental processes. SbsHsp genes were highly induced by diverse abiotic stresses inferring their critical role in mediating the environmental stress responses. Gene expression data revealed that SbsHsp-02 is a candidate gene expressed in all the tissues under varied stress conditions tested. Our results contribute to the understanding of the complexity of SbsHsp genes and help to analyse them further for functional validation

Comparative Analysis of common Edge Detection Algorithms using Pre-processing Technique

Edge detection is the process of segmenting an image by detecting discontinuities in brightness. So far, several standard segmentation methods have been widely used for edge detection. However, due to inherent quality of images, these methods prove ineffective if they are applied without any preprocessing. In this paper, an image preprocessing approach has been adopted in order to get certain parameters that are useful to perform better edge detection with the standard edge detection methods. The proposed preprocessing approach involves median filtering to reduce the noise in image and then Edge Detection technique is carried out. And atlast Standard edge detection methods can be applied to the resultant preprocessing image and its Simulation results are show that our preprocessed approach when used with a standard edge detection method enhances its performance