1,162 research outputs found
Projected Changes in Semi Permanent Systems of Indian Summer Monsoon in CORDEX-SA Framework
The semi-permanent systems such as Seasonal Heat Low (HL), Monsoon Trough (MT), Tibetan Anticyclone (TA), Tropical Easterly Jet (TEJ) and Low Level Jet (LLJ) or Somali jet are observed over Indian region during Indian summer monsoon season (June through September). These systems play a vital role in defining the strength of the Indian summer monsoon rainfall as a whole. Here we evaluate the ability of Consortium for Small-Scale Modeling (COSMO) regional Climate Model (COSMO-CLM), a high resolution regional climate model within the Coordinated Regional Climate Downscaling Experiment for South Asia (CORDEX-SA) framework, to simulate these systems of Indian summer monsoon. The historical runs of the COSMO-CLM for the period 1951-2000 are analysed. Overall the COSMO-CLM is able to simulate these components reasonably well. Possible changes in the position and the strength of these systems and their role in changing rainfall pattern over India are examined to assess the impact of global warming, under the RCP 4.5 simulations towards the end of the century (2051-2100). The analysis shows that the semi permanent systems may not strengthen in the future as compared to the present climate. The summer monsoon rainfall does not show uniform changes over the region. It is likely to enhance over the southern parts of the country, south of 20?S while it is projected to decrease in the northern parts under the global warming scenario
On some aspects of initialization and forecasts in the Indian monsoon region.
Application of a dynamic initialization scheme for balancing initial wind and pressure fields for a one-level primitive equation model in the Indian region has been investigated. For this purpose, the model equations are integrated forward and backward around the initial time following the Euler backward time-difference scheme without restoration of any variable. For comparison, the initial wind-pressure balance has also been constructed from the observed horizontal motion field by a hierarchy of models of increasing complexity, using the geostrophic relation, the linear balance equation and the nonlinear balance equation. Furthermore, the 48 h forecasts are prepared using the balanced initial data derived from the static nonlinear balance equation and the dynamic initialization scheme. The forecast results from both initialization schemes are compared and discussed. The results obtained from the dynamic initialization scheme are found to be either slightly superior or comparable to those based on the static initialization scheme
Diurnal variation of lightning activity over the Indian region
Satellite (LIS) based lightning flash grid (0.5° × 0.5°) data for the Indian land mass region covering from 8°–33°N and 73°–86°E for a period of 4 years (1998–2001) were used to study the diurnal variation with one hour time resolution. The analysis revealed that there exists a strong diurnal cycle in the lightning activity with a prominent peak around 1000 UTC. An examination of seasonal diurnal variation suggests that the lightning activity was found highest in premonsoon and lowest in the postmonsoon seaso
Markov chain models for pre-monsoon season thunderstorms over Pune
The probabilistic distribution of the thunderstorm phenomenon during the pre-monsoon season (1 March to 18 June) over Pune, a tropical Indian station, has been examined with the help of Markov chain models using daily thunderstorm data for a period of 11 years (1970-80). The data have also been tested using Akaike's information criterion. This test has clearly indicated that the first-order Markov chain model is the best fit model for thunderstorm forecasting, which has described the appropriate period (8 days) of occurrence of thunderstorm phenomenon over Pune. Further, the steady-state probabilities and mean recurrence time of thunderstorm days and non-thunderstorm days have also been calculated for the first- and second-order Markov chain models. These computations have revealed that the observed and theoretical values of steady-state probabilities are realistically matched
Study of thunderstorm and rainfall activity over the Indian region
Thirty years (1951-1980) of mean monthly thunderstorms days (TS) and rainfall (RF) amounts for 260 Indian observatories spread uniformly over the country were used to obtain their monthly, seasonal and zonal percentage of occurrence from all India totals. The study has revealed that there is a time lag of one month in the occurrence of peak activity of TS and RF. Seasonal analysis of these two parameters suggest that rainfall yield associated with postmonsoon season TS seems to be higher than the premonsoon season. Six zone analysis of TS and RF has suggested that there exists a wide range of variation in both parameters month after month in that zones, but the 30 year mean percentage of occurrence seems to be more or less equal in magnitude in each zone
Monitoring Partially Synchronous Distributed Systems using SMT Solvers
In this paper, we discuss the feasibility of monitoring partially synchronous
distributed systems to detect latent bugs, i.e., errors caused by concurrency
and race conditions among concurrent processes. We present a monitoring
framework where we model both system constraints and latent bugs as
Satisfiability Modulo Theories (SMT) formulas, and we detect the presence of
latent bugs using an SMT solver. We demonstrate the feasibility of our
framework using both synthetic applications where latent bugs occur at any time
with random probability and an application involving exclusive access to a
shared resource with a subtle timing bug. We illustrate how the time required
for verification is affected by parameters such as communication frequency,
latency, and clock skew. Our results show that our framework can be used for
real-life applications, and because our framework uses SMT solvers, the range
of appropriate applications will increase as these solvers become more
efficient over time.Comment: Technical Report corresponding to the paper accepted at Runtime
Verification (RV) 201
Enzymatic Routes for Chiral Amine Synthesis: Protein Engineering and Process Optimization
Sayali Shantaram Vikhrankar,1 Seema Satbhai,2 Priyanka Kulkarni,2 Ranjit Ranbhor,3 Vibin Ramakrishnan,4 Prashant Kodgire1 1Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, MP, India; 2Sevit Healthcare Private Limited, Pune, MH, India; 3Pergament & Cepeda LLP, Florham Park, NJ, USA; 4Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, IndiaCorrespondence: Ranjit Ranbhor, Pergament & Cepeda LLP, 25A Hanover Road, Florham Park, NJ, 07932, USA, Tel +1 973 967 0490, Email [email protected]: Chiral amines are essential motifs in pharmaceuticals, agrochemicals, and specialty chemicals. While traditional chemical routes to chiral amines often lack stereoselectivity and require harsh conditions, biocatalytic methods using engineered enzymes can offer high efficiency and selectivity under sustainable conditions. This review discusses recent advances in protein engineering of transaminases, oxidases, and other enzymes to improve catalytic performance. Strategies such as directed evolution, immobilization, and computational redesign have expanded substrate scope and enhanced efficiency. Furthermore, process optimization guided by techno-economic assessments has been crucial for establishing viable biomanufacturing routes. Combining state-of-the-art enzyme engineering with multifaceted process development will enable scalable, economical enzymatic synthesis of diverse chiral amine targets.Keywords: chiral amines, biocatalysis, protein engineering, ω-transaminases, sitagliptin, enzyme immobilization, co-factor regeneratio
A high-performance matrix-matrix multiplication methodology for CPU and GPU architectures
Current compilers cannot generate code that can compete with hand-tuned code in efficiency, even for a simple kernel like matrix–matrix multiplication (MMM). A key step in program optimization is the estimation of optimal values for parameters such as tile sizes and number of levels of tiling. The scheduling parameter values selection is a very difficult and time-consuming task, since parameter values depend on each other; this is why they are found by using searching methods and empirical techniques. To overcome this problem, the scheduling sub-problems must be optimized together, as one problem and not separately. In this paper, an MMM methodology is presented where the optimum scheduling parameters are found by decreasing the search space theoretically, while the major scheduling sub-problems are addressed together as one problem and not separately according to the hardware architecture parameters and input size; for different hardware architecture parameters and/or input sizes, a different implementation is produced. This is achieved by fully exploiting the software characteristics (e.g., data reuse) and hardware architecture parameters (e.g., data caches sizes and associativities), giving high-quality solutions and a smaller search space. This methodology refers to a wide range of CPU and GPU architectures
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Recent changes in populations of Critically Endangered Gyps vultures in India
SummaryPopulations of the White-rumped VultureGyps bengalensis, Indian VultureG. indicusand Slender-billed VultureG. tenuirostrisdeclined rapidly during the mid-1990s all over their ranges in the Indian subcontinent because of poisoning due to veterinary use of the non-steroidal anti-inflammatory drug diclofenac. This paper reports results from the latest in a series of road transect surveys conducted across northern, central, western and north-eastern India since the early 1990s. Results from the seven comparable surveys now available were analysed to estimate recent population trends. Populations of all three species of vulture remained at a low level. The previously rapid decline of White-rumped Vulture has slowed and may have reversed since the ban on veterinary use of diclofenac in India in 2006. A few thousand of this species, possibly up to the low tens of thousands, remained in India in 2015. The population of Indian Vulture continued to decline, though probably at a much slower rate than in the 1990s. This remains the most numerous of the three species in India with about 12,000 individuals in 2015 and a confidence interval ranging from a few thousands to a few tens of thousands. The trend in the rarest species, Slender-billed Vulture, which probably numbers not much more than 1,000 individuals in India, cannot be determined reliably.</jats:p
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