Program Transformations for Asynchronous and Batched Query Submission

The performance of database/Web-service backed applications can be significantly improved by asynchronous submission of queries/requests well ahead of the point where the results are needed, so that results are likely to have been fetched already when they are actually needed. However, manually writing applications to exploit asynchronous query submission is tedious and error-prone. In this paper we address the issue of automatically transforming a program written assuming synchronous query submission, to one that exploits asynchronous query submission. Our program transformation method is based on data flow analysis and is framed as a set of transformation rules. Our rules can handle query executions within loops, unlike some of the earlier work in this area. We also present a novel approach that, at runtime, can combine multiple asynchronous requests into batches, thereby achieving the benefits of batching in addition to that of asynchronous submission. We have built a tool that implements our transformation techniques on Java programs that use JDBC calls; our tool can be extended to handle Web service calls. We have carried out a detailed experimental study on several real-life applications, which shows the effectiveness of the proposed rewrite techniques, both in terms of their applicability and the performance gains achieved.Comment: 14 page

Transforaminal percutaneous endoscopic lumbar discectomy versus microdiscectomy: an Indian rural experience

Background: The objective of the study was to compare surgical outcome of micro-discectomy with transforaminal percutaneous endoscopic lumbar discectomy for single level lumbar disc herniation in Indian rural population.Methods: Retrospective comparative study was designed during the period of October 2012 to June 2015, patients in the age group of 22-75 years with unremitting sciatica with/without back pain, and/or a neurological deficit that correlated with appropriate level and side of neural compression as revealed on MRI, with single level lumbar disc herniation who underwent either microdiscectomy or TPELD were included in the study. Patients were assessed on visual analogue scale (VAS) for back and leg pain, modified macnabs criteria, the Oswestry Disability Index (ODI).Results: Group I (MD) included 44 patients and Group II (TPELD) included 20 patients. Significant improvement was seen in claudication symptom post-operatively in both MD and TPELD. Mean operating time was significantly shorter in MD group (1.11 hrs vs. 1.32 hrs; p<0.01). According to modified MacNab's criteria, outcome were excellent (81.8%), good (9.09%) and fair (9.09%) in MD. Similarly, in TPELD, 80%, 15% and 5% patients had excellent, good and fair outcome respectively. In both groups, no one had a poor outcome. Thus, overall success rate was 100% in the study.Conclusions: TPELD and MD have comparable post-operative outcome in most of the efficacy parameters in Indian rural patients undergoing treatment of single level lumbar disc herniation. Additionally, TPELD offers distinct advantages such as performed under local anaesthesia, preservation of structure, lesser post-operative pain and early mobilization and discharge from hospital

FINITE ELEMENT ANALYSIS AND NATURAL FREQUENCY OPTIMIZATION OF ENGINE BRACKET

The automotive engine mounting systems are very important due to different aspects of vehicle performance. Early in improvement the building of the engine mounting system should be rapidly checked and precisely analyzed, without sample of a vehicle authorization. Engine bracket has been designed as a framework to support engine. Vibration and fatigue of engine bracket has been continuously a concern which may lead to structural failure if the resulting vibration and stresses are severe and excessive. It is a significant study which requires in-depth investigation to understand the structural characteristics and its dynamic behavior. This paper presents and focuses on some Finite Element (FE) analysis of a typical engine bracket of a car will be carried out and natural frequency will be determined

DBridge: A program rewrite tool for set-oriented query execution

We present DBridge, a novel static analysis and program transformation tool to optimize database access. Traditionally, rewrite of queries and programs are done independently, by the database query optimzier and the language compiler respectively, leaving out many optimization opportunities. Our tool aims to bridge this gap by performing holistic transformations, which include both program and query rewrite. Many applications invoke database queries multiple times with different parameter values. Such query invocations made using imperative loops are often the cause of poor performance due to random I/O and round trip delays. In practice, such performance issues are addressed by manually rewriting the application to make it set oriented. Such manual rewriting of programs is often time consuming and error prone. Guravannavar et. al. propose program analysis and transformation techniques for automatically rewriting an application to make it set oriented. DBridge implements these program transformation techniques for Java programs that use JDBC to access database. In this demonstration, we showcase the holistic program/query transformations that DBridge can perform, over a variety of scenarios taken from real-world applications. We then walk through the design of DBridge, which uses the SOOT optimization framework for static analysis. Finally, we demonstrate the performance gains achieved through the transformations

DBridge: A program rewrite tool for set-oriented query execution (demo

Abstract—We present DBridge, a novel static analysis and program transformation tool to optimize database access. Traditionally, rewrite of queries and programs are done independently, by the database query optimzier and the language compiler respectively, leaving out many optimization opportunities. Our tool aims to bridge this gap by performing holistic transformations, which include both program and query rewrite. Manyapplications invoke database queries multipletimes with different parameter values. Such query invocations made using imperative loops are often the cause of poor performance due to random I/O and roundtrip delays. In practice, such performance issues are addressed by manually rewriting the application to make it set oriented. Such manual rewriting of programs is often time consuming and error prone. Guravannavar et. al.[1] propose program analysis and transformation techniques for automatically rewriting an application to make it set oriented. DBridge implements these program transformation techniques for Java programs that use JDBC to access database. In this demonstration, we showcase the holistic program/query transformations that DBridge can perform, over a variety of scenarios taken from real-world applications. We then walk through the design of DBridge, which uses the SOOT optimization framework for static analysis. Finally, we demonstrate the performance gains achieved through the transformations. I

Program transformations for asynchronous query submission

Abstract—Synchronous execution of queries or Web service requests forces the calling application to block until the query/request is satisfied. The performance of applications can be significantly improved by asynchronous submission of queries, which allows the application to perform other processing instead of blocking while the query is executed, and to concurrently issue multiplequeries. Concurrentsubmission of multiplequeries can allow the query execution engine to better utilize multiple processors anddisks,andtoreorder diskIO requeststominimize seeks. Concurrent submission also reduces the impact of network round-trip latency and delays at the database, when processing multiple queries. However, manually writing applications to exploit asynchronous query submission is tedious. In this paper we address the issue of automatically transforming a program written assuming synchronous query submission, to one that exploits asynchronous query submission. Our program transformation method is based on dataflow analysis and is framed as a set of transformation rules. Our rules can handle query executions within loops, unlike some of the earlier work in this area. We have built a tool that implements our transformation techniqueson Javacode thatusesJDBCcalls;our tool can be extended tohandle Web service calls. We have carried out a detailed experimental study on several real-life applications rewritten using our transformation techniques. The experimental study shows the effectiveness of the proposed rewrite techniques, both in terms of their applicability and performance gains achieved. I

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Not AvailableThe importance of different tree management practices on agroforestry systems’ overall productivity is well documented for overall higher yield. Traditional agroforestry systems in India manage trees for fuelwood, fodder, fibre and other household needs for which these trees are lopped or pollarded by the farmers according to their needs. The purpose of this paper is to review the biophysical science of tree management of the woody components in simultaneous and temporal agroforestry systems with annual crops to enhance the potentials of system productivity in terms of biomass and crop yield. Evidences from field case studies have been collected to understand the application of tree management practices. A better understanding of the tree management techniques may lead to greater adoption of agroforestry in the small holder farming systems where poverty rates are high, and land management for food and agriculture remains a major concern for governments and development partners.Not Availabl

Growth, optical, and field emission properties of aligned CdS nanowires

Here, we demonstrate the synthesis of aligned CdS nanowires by a solvothermal process where the alignment of the nanowires was controlled by tuning the reaction conditions. The normal and photoassisted field emission properties of the aligned CdS nanowires were studied. The turn-on field is found to be 0.68 V/μm which is much lower than the reported values. From the I−t plot, it is shown that the emission current remains nearly constant over 4 h at preset current value of 5 μA. Upon illumination, the photofield emission current shows a reproducible switching property with a rise in the current level of almost 50% of the initial value. The field emission properties indicate promising applications in field emission based devices

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