The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform

Kunle Olukotun - One of the best experts on this subject based on the ideXlab platform.

  • PLDI - Surgical Precision JIT compilers
    Proceedings of the 35th ACM SIGPLAN Conference on Programming Language Design and Implementation, 2014
    Co-Authors: Tiark Rompf, Arvind K. Sujeeth, Kevin J. Brown, Hyoukjoong Lee, Hassan Chafi, Kunle Olukotun
    Abstract:

    Just-in-time (JIT) compilation of running programs provides more optimization opportunities than offline compilation. Modern JIT compilers, such as those in virtual machines like Oracle's HotSpot for Java or Google's V8 for JavaScript, rely on dynamic profiling as their key mechanism to guide optimizations. While these JIT compilers offer good average performance, their behavior is a black box and the achieved performance is highly unpredictable. In this paper, we propose to turn JIT compilation into a Precision Tool by adding two essential and generic metaprogramming facilities: First, allow programs to invoke JIT compilation explicitly. This enables controlled specialization of arbitrary code at run-time, in the style of partial evaluation. It also enables the JIT compiler to report warnings and errors to the program when it is unable to compile a code path in the demanded way. Second, allow the JIT compiler to call back into the program to perform compile-time computation. This lets the program itself define the translation strategy for certain constructs on the fly and gives rise to a powerful JIT macro facility that enables "smart" libraries to supply domain-specific compiler optimizations or safety checks. We present Lancet, a JIT compiler framework for Java bytecode that enables such a tight, two-way integration with the running program. Lancet itself was derived from a high-level Java bytecode interpreter: staging the interpreter using LMS (Lightweight Modular Staging) produced a simple bytecode compiler. Adding abstract interpretation turned the simple compiler into an optimizing compiler. This fact provides compelling evidence for the scalability of the staged-interpreter approach to compiler construction. In the case of Lancet, JIT macros also provide a natural interface to existing LMS-based Toolchains such as the Delite parallelism and DSL framework, which can now serve as accelerator macros for arbitrary JVM bytecode.

  • surgical Precision jit compilers
    Programming Language Design and Implementation, 2014
    Co-Authors: Tiark Rompf, Arvind K. Sujeeth, Kevin J. Brown, Hyoukjoong Lee, Hassan Chafi, Kunle Olukotun
    Abstract:

    Just-in-time (JIT) compilation of running programs provides more optimization opportunities than offline compilation. Modern JIT compilers, such as those in virtual machines like Oracle's HotSpot for Java or Google's V8 for JavaScript, rely on dynamic profiling as their key mechanism to guide optimizations. While these JIT compilers offer good average performance, their behavior is a black box and the achieved performance is highly unpredictable. In this paper, we propose to turn JIT compilation into a Precision Tool by adding two essential and generic metaprogramming facilities: First, allow programs to invoke JIT compilation explicitly. This enables controlled specialization of arbitrary code at run-time, in the style of partial evaluation. It also enables the JIT compiler to report warnings and errors to the program when it is unable to compile a code path in the demanded way. Second, allow the JIT compiler to call back into the program to perform compile-time computation. This lets the program itself define the translation strategy for certain constructs on the fly and gives rise to a powerful JIT macro facility that enables "smart" libraries to supply domain-specific compiler optimizations or safety checks. We present Lancet, a JIT compiler framework for Java bytecode that enables such a tight, two-way integration with the running program. Lancet itself was derived from a high-level Java bytecode interpreter: staging the interpreter using LMS (Lightweight Modular Staging) produced a simple bytecode compiler. Adding abstract interpretation turned the simple compiler into an optimizing compiler. This fact provides compelling evidence for the scalability of the staged-interpreter approach to compiler construction. In the case of Lancet, JIT macros also provide a natural interface to existing LMS-based Toolchains such as the Delite parallelism and DSL framework, which can now serve as accelerator macros for arbitrary JVM bytecode.

Hiraku Matsukuma - One of the best experts on this subject based on the ideXlab platform.

  • an ultra Precision Tool nanoindentation instrument for replication of single point diamond Tool cutting edges
    Measurement Science and Technology, 2018
    Co-Authors: Yuanliu Chen, Malu Xu, Yuki Shimizu, Hiraku Matsukuma
    Abstract:

    Precision replication of the diamond Tool cutting edge is required for non-destructive Tool metrology. This paper presents an ultra-Precision Tool nanoindentation instrument designed and constructed for replication of the cutting edge of a single point diamond Tool onto a selected soft metal workpiece by precisely indenting the Tool cutting edge into the workpiece surface. The instrument has the ability to control the indentation depth with a nanometric resolution, enabling the replication of Tool cutting edges with high Precision. The motion of the diamond Tool along the indentation direction is controlled by the piezoelectric actuator of a fast Tool servo (FTS). An integrated capacitive sensor of the FTS is employed to detect the displacement of the diamond Tool. The soft metal workpiece is attached to an aluminum cantilever whose deflection is monitored by another capacitive sensor, referred to as an outside capacitive sensor. The indentation force and depth can be accurately evaluated from the diamond Tool displacement, the cantilever deflection and the cantilever spring constant. Experiments were carried out by replicating the cutting edge of a single point diamond Tool with a nose radius of 2.0 mm on a copper workpiece surface. The profile of the replicated Tool cutting edge was measured using an atomic force microscope (AFM). The effectiveness of the instrument in Precision replication of diamond Tool cutting edges is well-verified by the experimental results.

Tiark Rompf - One of the best experts on this subject based on the ideXlab platform.

  • PLDI - Surgical Precision JIT compilers
    Proceedings of the 35th ACM SIGPLAN Conference on Programming Language Design and Implementation, 2014
    Co-Authors: Tiark Rompf, Arvind K. Sujeeth, Kevin J. Brown, Hyoukjoong Lee, Hassan Chafi, Kunle Olukotun
    Abstract:

    Just-in-time (JIT) compilation of running programs provides more optimization opportunities than offline compilation. Modern JIT compilers, such as those in virtual machines like Oracle's HotSpot for Java or Google's V8 for JavaScript, rely on dynamic profiling as their key mechanism to guide optimizations. While these JIT compilers offer good average performance, their behavior is a black box and the achieved performance is highly unpredictable. In this paper, we propose to turn JIT compilation into a Precision Tool by adding two essential and generic metaprogramming facilities: First, allow programs to invoke JIT compilation explicitly. This enables controlled specialization of arbitrary code at run-time, in the style of partial evaluation. It also enables the JIT compiler to report warnings and errors to the program when it is unable to compile a code path in the demanded way. Second, allow the JIT compiler to call back into the program to perform compile-time computation. This lets the program itself define the translation strategy for certain constructs on the fly and gives rise to a powerful JIT macro facility that enables "smart" libraries to supply domain-specific compiler optimizations or safety checks. We present Lancet, a JIT compiler framework for Java bytecode that enables such a tight, two-way integration with the running program. Lancet itself was derived from a high-level Java bytecode interpreter: staging the interpreter using LMS (Lightweight Modular Staging) produced a simple bytecode compiler. Adding abstract interpretation turned the simple compiler into an optimizing compiler. This fact provides compelling evidence for the scalability of the staged-interpreter approach to compiler construction. In the case of Lancet, JIT macros also provide a natural interface to existing LMS-based Toolchains such as the Delite parallelism and DSL framework, which can now serve as accelerator macros for arbitrary JVM bytecode.

  • surgical Precision jit compilers
    Programming Language Design and Implementation, 2014
    Co-Authors: Tiark Rompf, Arvind K. Sujeeth, Kevin J. Brown, Hyoukjoong Lee, Hassan Chafi, Kunle Olukotun
    Abstract:

    Just-in-time (JIT) compilation of running programs provides more optimization opportunities than offline compilation. Modern JIT compilers, such as those in virtual machines like Oracle's HotSpot for Java or Google's V8 for JavaScript, rely on dynamic profiling as their key mechanism to guide optimizations. While these JIT compilers offer good average performance, their behavior is a black box and the achieved performance is highly unpredictable. In this paper, we propose to turn JIT compilation into a Precision Tool by adding two essential and generic metaprogramming facilities: First, allow programs to invoke JIT compilation explicitly. This enables controlled specialization of arbitrary code at run-time, in the style of partial evaluation. It also enables the JIT compiler to report warnings and errors to the program when it is unable to compile a code path in the demanded way. Second, allow the JIT compiler to call back into the program to perform compile-time computation. This lets the program itself define the translation strategy for certain constructs on the fly and gives rise to a powerful JIT macro facility that enables "smart" libraries to supply domain-specific compiler optimizations or safety checks. We present Lancet, a JIT compiler framework for Java bytecode that enables such a tight, two-way integration with the running program. Lancet itself was derived from a high-level Java bytecode interpreter: staging the interpreter using LMS (Lightweight Modular Staging) produced a simple bytecode compiler. Adding abstract interpretation turned the simple compiler into an optimizing compiler. This fact provides compelling evidence for the scalability of the staged-interpreter approach to compiler construction. In the case of Lancet, JIT macros also provide a natural interface to existing LMS-based Toolchains such as the Delite parallelism and DSL framework, which can now serve as accelerator macros for arbitrary JVM bytecode.

Yuanliu Chen - One of the best experts on this subject based on the ideXlab platform.

  • an ultra Precision Tool nanoindentation instrument for replication of single point diamond Tool cutting edges
    Measurement Science and Technology, 2018
    Co-Authors: Yuanliu Chen, Malu Xu, Yuki Shimizu, Hiraku Matsukuma
    Abstract:

    Precision replication of the diamond Tool cutting edge is required for non-destructive Tool metrology. This paper presents an ultra-Precision Tool nanoindentation instrument designed and constructed for replication of the cutting edge of a single point diamond Tool onto a selected soft metal workpiece by precisely indenting the Tool cutting edge into the workpiece surface. The instrument has the ability to control the indentation depth with a nanometric resolution, enabling the replication of Tool cutting edges with high Precision. The motion of the diamond Tool along the indentation direction is controlled by the piezoelectric actuator of a fast Tool servo (FTS). An integrated capacitive sensor of the FTS is employed to detect the displacement of the diamond Tool. The soft metal workpiece is attached to an aluminum cantilever whose deflection is monitored by another capacitive sensor, referred to as an outside capacitive sensor. The indentation force and depth can be accurately evaluated from the diamond Tool displacement, the cantilever deflection and the cantilever spring constant. Experiments were carried out by replicating the cutting edge of a single point diamond Tool with a nose radius of 2.0 mm on a copper workpiece surface. The profile of the replicated Tool cutting edge was measured using an atomic force microscope (AFM). The effectiveness of the instrument in Precision replication of diamond Tool cutting edges is well-verified by the experimental results.

  • Precision Tool setting for fabrication of a microstructure array
    CIRP Annals, 2013
    Co-Authors: Wei Gao, Yuanliu Chen, Yuki Shimizu, Kang-won Lee, Young-jin Noh, So Ito
    Abstract:

    Abstract A method is proposed for setting a new diamond cutting Tool when Tool replacement is required during the fabrication of a microstructure array on the outer surface of a roll by a fast Tool servo with a force sensor. The sectional profiles of a small reference area in the fabricated part by the replaced old Tool are detected through scanning the tip of the new Tool with a constant contact force controlled by the fast Tool servo. The new Tool can be set accurately based on the identified position of the Tool tip with respect to the reference area.

M C Ruizsanchez - One of the best experts on this subject based on the ideXlab platform.

  • could trunk diameter sensors be used in woody crops for irrigation scheduling a review of current knowledge and future perspectives
    Agricultural Water Management, 2010
    Co-Authors: María Fernanda Ortuño, W Conejero, F Moreno, A Moriana, Diego S. Intrigliolo, C Biel, C D Mellisho, Alejandro Perezpastor, Rafael Domingo, M C Ruizsanchez
    Abstract:

    The use of trunk diameter fluctuations and their derived parameters for irrigation scheduling in woody crops is reviewed. The strengths and weaknesses of these continuously measured plant-based water stress indicators compared with other discretely measured indicators for diagnosing plant water status in young and mature trees are discussed. Aspects such as sensor reading variability, signal intensity and the relationship between trunk diameter fluctuations and plant water status are analyzed in order to assess their usefulness as water stress indicators. The physiological significance of maximum and minimum daily trunk diameter and maximum daily trunk shrinkage (MDS) are also considered. Current knowledge of irrigation protocols and baselines for obtaining maximum daily trunk shrinkage reference values is discussed and new research objectives are proposed. We analyze the response of woody crops to continuous deficit irrigation scheduled by maintaining MDS signal intensity at threshold values to generate mild, moderate and severe water stress and assess the possibility of using linear variable displacement transducer (LVDT) sensors in trunk as a Precision Tool for regulated deficit irrigation scheduling. Finally, the possibility of using MDS signal intensity as a Tool to match the irrigation regime to tree water requirements is also reviewed.