TY  - JOUR
A1  - Bauman, Spenser
A1  - Bolz, Carl Friedrich
A1  - Hirschfeld, Robert
A1  - Kirilichev, Vasily
A1  - Pape, Tobias
A1  - Siek, Jeremy G.
A1  - Tobin-Hochstadt, Sam
T1  - Pycket: A Tracing JIT for a Functional Language
JF  - ACM SIGPLAN notices
N2  - We present Pycket, a high-performance tracing JIT compiler for Racket. Pycket supports a wide variety of the sophisticated features in Racket such as contracts, continuations, classes, structures, dynamic binding, and more. On average, over a standard suite of benchmarks, Pycket outperforms existing compilers, both Racket's JIT and other highly-optimizing Scheme compilers. Further, Pycket provides much better performance for Racket proxies than existing systems, dramatically reducing the overhead of contracts and gradual typing. We validate this claim with performance evaluation on multiple existing benchmark suites.
 The Pycket implementation is of independent interest as an application of the RPython meta-tracing framework (originally created for PyPy), which automatically generates tracing JIT compilers from interpreters. Prior work on meta-tracing focuses on bytecode interpreters, whereas Pycket is a high-level interpreter based on the CEK abstract machine and operates directly on abstract syntax trees. Pycket supports proper tail calls and first-class continuations. In the setting of a functional language, where recursion and higher-order functions are more prevalent than explicit loops, the most significant performance challenge for a tracing JIT is identifying which control flows constitute a loop-we discuss two strategies for identifying loops and measure their impact.
KW  - Experimentation
KW  - Languages
KW  - Measurement
KW  - Performance
KW  - JIT compilers
KW  - contracts
KW  - tracing
KW  - functional languages
KW  - Racket
Y1  - 2015
U6  - https://doi.org/10.1145/2784731.2784740
SN  - 0362-1340
SN  - 1558-1160
VL  - 50
IS  - 9
SP  - 22
EP  - 34
PB  - Association for Computing Machinery
CY  - New York
ER  - 
TY  - JOUR
A1  - Neumann, Anne
A1  - von Hirschhausen, Christian
T1  - Natural Gas: An Overview of a Lower-Carbon Transformation Fuel
JF  - Review of environmental economics and policy
N2  - This article provides an overview of the natural gas industry, which we view as a bridge fuel toward a lower-carbon energy system in many countries and regions around the world. Based on a review of the literature, an econometric analysis of natural gas prices and contracts, and the authors' experience with the natural gas industry, this introductory article to the symposium on the Prospects for Natural Gas in a Lower-Carbon Context provides an overview of research on natural gas markets over the last decade and examines various features of the natural gas industry, including its technical structure, activities in the value-added chain, trade and market trends, short- and long-term price developments, and the geopolitical landscape. More specifically, we describe the natural gas sector and provide an overview of production, reserves, and consumption. We also examine the evolution of long-term contracts between producers and large-scale buyers of natural gas and present some recent empirical evidence. Finally, we discuss the changing geopolitics of natural gas, focusing in particular on the future roles of the United States as a potential natural gas exporter and Asia as the major importing region. (JEL: L11, L95, Q49).
KW  - L11
KW  - L95
KW  - Q49
KW  - natural gas
KW  - low-carbon economy
KW  - global markets
KW  - prices
KW  - contracts
Y1  - 2015
U6  - https://doi.org/10.1093/reep/reu022
SN  - 1750-6816
SN  - 1750-6824
VL  - 9
IS  - 1
SP  - 64
EP  - 84
PB  - Oxford Univ. Press
CY  - Oxford
ER  -