Design of a fast and resource-efficient fault management system in optical networks to suit real-time multimedia applications

Today\u27s telecommunications networks are relying more and more on optical fibers as their physical medium. Currently the Wavelength Division Multiplexing technology enables hundreds of wavelengths to be multiplexed on a single fiber. Using this technology capacity can be dramatically increased, even to the order of Terabits per second. While WDM technology has given a satisfactory answer to the ever-increasing demand for capacity, there is still a problem which needs to be handled efficiently: survivability. Our proposed fault restoration system optimized between restoration cost and speed. We extended the concept of Forward Equivalence Class (FEC) in Multi Protocol Label switching (MPLS) to our proposed fault restoration system. Speed was found to be in the order of 1 to 3 microseconds using predesigned protection, depending on the configuration of the system. Optimization was done between restoration speed and cost by introducing a priority field in the packet header

Assessment of noise-induced hearing loss (NIHL) of weaving factory workers in West Bengal, India - a pilot study

Introduction: Excessive noise exposure is one of the majorly considered occupational stress for industrial workers. The operation of steel weaving machinery producing a high level of noise such as weaving machines, crimping machines, and hydraulic press machines for a prolonged period increases the risk of developing noise-induced hearing loss (NIHL).  The main aim of the study was to assess the auditory health of the workers exposed to a high level of noise in a steel weaving factory and the prevalence of NIHL among workers. Methods: 26 subjects in the age group of 25-55 years from a steel weaving industry of Chinsurah town, Hooghly district of West Bengal were randomly selected with 5 years of exposure for the study. The control group was selected from the same age group, socioeconomic status and geographical location and having no history of such exposure. The physiological parameters of the workers, noise levels in the workplace and auditory functions and the risk of NIHL were assessed by standardized protocol and statistically analyzed. Results: The study indicated that steel weaving factory workers had significantly reduced hearing functionality at 4000Hz and 6000Hz in the left ear respectively. It also revealed that the workers were exposed to high noise exposure of 131dB near weaving machine, 113dB at crimping machine, and 84dB at hydraulic press machine respectively. Conclusion: A high level of noise exposure leads to deterioration in the hearing capabilities of the steel weaving industrial workers. Implementation of ergonomic interventions in the workplace and the use of personal protective equipment (PPE) may decrease the prevalence of NIHL and can help to prevent hearing loss in workers

Knowledge, attitudes and practice survey about antimicrobial resistance and prescribing among physicians in a tertiary care teaching hospital in Eastern India

Background: Antimicrobial resistance is a worldwide problem. Reduction in antimicrobial use is necessary to limit this problem. This can be addressed through changes in prescribing behaviour. Information about the driving forces behind antimicrobial prescription can be obtained by KAP (knowledge, attitudes and practice) surveys.Methods: A self-administered 37 item questionnaire was distributed among doctors of different departments of College of Medicine & JNM Hospital, Kalyani. It focused on their awareness about the current status of antimicrobial resistance, sources of information and training about use of Antimicrobials, confidence, factors influencing decisions and appropriateness of potential interventions.Results: All doctors agreed that antimicrobial resistance is a problem in India and also in their daily practice. Doctors were lacking on the aspect of regular educational activities regarding appropriate use of antimicrobials, which they felt extremely important. Also many of them were unaware about the hospital formularies, current susceptibility pattern of common pathogens. Majority said that a local guideline would be more useful than the international one. Conclusions: This survey identified topics to address in the containment of antimicrobials resistance like dissemination of information about local antimicrobial resistance rates, the revision and dissemination of local guidelines, and emphasization on regular educational activities among physicians

Performance of Multimodel Schemes for Seasonal Precipitation over Indian Region

This study uses downscaled rainfall datasets from 16 coupled climate models at high resolution of 25 km from 1987 to 2001. The multimodel superensemble scheme is widely tested for rainfall forecast over mid-latitude, subtropical, and, especially, various regions of the monsoonal belt. A well-known statistical estimation theoretic approach, namely, Best Linear Unbiased Estimator (BLUE), is examined on 16 member models. The results are compared with superensemble methodology based on various skill scores. Results show that BLUE is providing promising forecasts. As far as comparative studies are concerned BLUE and superensemble schemes compete and show their importance from normal years to extreme rainfall years. BLUE methodology is capable of predicting draughts very well compared with other multimodel schemes. One basic advantage of BLUE is computationally less expensive than superensemble scheme. These statistical schemes like downscaling, BLUE, and superensemble can improve rainfall forecasts further, if a dense rain gauge data is provided

Constraining large scale HI bias using redshifted 21-cm signal from the post-reionization epoch

In the absence of complex astrophysical processes that characterize the reionization era, the 21-cm emission from neutral hydrogen (HI) in the post-reionization epoch is believed to be an excellent tracer of the underlying dark matter distribution. Assuming a background cosmology, it is modelled through (i) a bias function b(k,z), which relates HI to the dark matter distribution and (ii) a mean neutral fraction (x_{HI}) which sets its amplitude. In this paper, we investigate the nature of large scale HI bias. The post-reionization HI is modelled using gravity only N-Body simulations and a suitable prescription for assigning gas to the dark matter halos. Using the simulated bias as the fiducial model for HI distribution at z\leq 4, we have generated a hypothetical data set for the 21-cm angular power spectrum (C_{l}) using a noise model based on parameters of an extended version of the GMRT. The binned C_{l} is assumed to be measured with SNR \gtrsim 4 in the range 400 \leq l \leq 8000 at a fiducial redshift z=2.5. We explore the possibility of constraining b(k) using the Principal Component Analysis (PCA) on this simulated data. Our analysis shows that in the range 0.2 < k < 2 Mpc^{-1}, the simulated data set cannot distinguish between models exhibiting different k dependences, provided 1 \lesssim b(k) \lesssim 2 which sets the 2-sigma limits. This justifies the use of linear bias model on large scales. The largely uncertain x_{HI} is treated as a free parameter resulting in degradation of the bias reconstruction. The given simulated data is found to constrain the fiducial x_{HI} with an accuracy of \sim 4% (2-sigma error). The method outlined here, could be successfully implemented on future observational data sets to constrain b(k,z) and x_{HI} and thereby enhance our understanding of the low redshift Universe.Comment: 10 pages, 11 figures, 2 tables. Accepted in MNRAS. Revised to match the accepted versio

Cross-correlation of the HI 21-cm Signal and Lyman-alpha Forest: A Probe Of Cosmology

Separating the cosmological redshifted 21-cm signal from foregrounds is a major challenge. We present the cross-correlation of the redshifted 21-cm emission from neutral hydrogen (HI) in the post-reionization era with the Ly-alpha forest as a new probe of the large scale matter distribution in the redshift range z=2 to 3 without the problem of foreground contamination. Though the 21-cm and the Ly-alpha forest signals originate from different astrophysical systems, they are both expected to trace the underlying dark matter distribution on large scales. The multi-frequency angular cross-correlation power spectrum estimator is found to be unaffected by the discrete quasar sampling, which only affects the noise in the estimate. We consider a hypothetical redshifted 21-cm observation in a single field of view 1.3 degrees (FWHM) centered at z=2.2 where the binned 21-cm angular power spectrum can be measured at an SNR of 3 sigma or better across the range 500 < l < 4000 . Keeping the parameters of the 21-cm observation fixed, we have estimated the SNR for the cross-correlation signal varying the quasar angular number density n of the Ly-alpha forest survey. Assuming that the spectra have SNR ~5 in pixels of length 44 km/s, we find that a 5 sigma detection of the cross-correlation signal is possible at 600 < l < 2000 with n=4 deg^{-2}. This value of n is well within the reach of upcoming Ly-alpha forest surveys. The cross-correlation signal will be a new, independent probe of the astrophysics of the diffuse IGM, the growth of structure and the expansion history of the Universe.Comment: Revised paper, accepted to MNRA

Secure routing and trust computation in multihop infrastructureless networks

Today\u27s wireless networks rely mostly on infrastructural support for their operation. With the concept of ubiquitous computing growing more popular, research on infrastructureless networks have been rapidly growing. However, such types of networks face serious security challenges when deployed. This dissertation focuses on designing a secure routing solution and trust modeling for these infrastructureless networks. The dissertation presents a trusted routing protocol that is capable of finding a secure end-to-end route in the presence of malicious nodes acting either independently or in collusion, The solution protects the network from active internal attacks, known to be the most severe types of attacks in an ad hoc application. Route discovery is based on trust levels of the nodes, which need to be dynamically computed to reflect the malicious behavior in the network. As such, we have developed a trust computational model in conjunction with the secure routing protocol that analyzes the different malicious behavior and quantifies them in the model itself. Our work is the first step towards protecting an ad hoc network from colluding internal attack. To demonstrate the feasibility of the approach, extensive simulation has been carried out to evaluate the protocol efficiency and scalability with both network size and mobility. This research has laid the foundation for developing a variety of techniques that will permit people to justifiably trust the use of ad hoc networks to perform critical functions, as well as to process sensitive information without depending on any infrastructural support and hence will enhance the use of ad hoc applications in both military and civilian domains

Assessment of Postural effect on Work Related Musculoskeletal Disorders and Back Muscle Fatigue among the Goldsmiths of India

Background: Musculoskeletal disorders (MSD) may be defined as injuries and disorders of the muscles, nerves, tendons, ligaments, joints, cartilage and spinal disc. This may occur due to improper physical work activities or appalling workplace conditions. Awkward or extreme postures are less efficient than posture keep joints near the center of their range of motion.Objective: The objective of the current study was to assessment of postural effect on work related musculoskeletal disorders and back muscle fatigue among the goldsmiths of India.Methods: In this current study, the experiment was performed on 100 male goldsmiths. A detailed questionnaire study on discomfort feeling was done and analysis of body posture by Rapid Upper Limb Assessment was done to evaluate the work stress during their job. Electromyographic activity was collected from ten major trunk muscles sites which consist of right and left muscle.Result: From the analysis, it was revealed that musculoskeletal disorders were the major problem of the goldsmiths. Moreover questionnaire study revealed that most of the workers were affected by pain at Neck (80%), Low back (91%), Wrist (45%), Shoulder (20%). Decreased in RMS and MedF of all the ten major trunk muscles were observed at the end of the every work cycle, which indicating that muscular fatigue was induced by the Gold Smiths tasks.Conclusion: From this study it can be concluded that the goldsmiths are working in awkward and forward bending postures for prolonged period of time with the potential risks of musculoskeletal disorders primarily affecting the low-back and neck region of the body. This can be attributed by the improper design of the workstation

Occupational Health and Hazards among Health Care Workers

DOI: http://dx.doi.org/10.3126/ijosh.v3i1.9096 International Journal of Occupational Safety and Health, Vol 3 No 1 (2013) 1 -