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 - Bouncken, Ricarda B. A1 - Ratzmann, Martin A1 - Tiberius, Victor A1 - Brem, Alexander T1 - Pioneering strategy in supply chain relationships BT - how coercive power and contract completeness influence innovation JF - IEEE transactions on engineering management N2 - Today, firms pursuing a pioneering strategy are often engaged in supply chain relationships to benefit from external resources and to improve their innovation. However, this effort can be impeded by power asymmetries in such relationships and especially by the execution of coercive power by their partner firm. Contracts could potentially reduce this risk of opportunistic behavior. Our survey study on 778 small to medium-sized enterprises in the European packaging and medical equipment industries examines how coercive power of the partner and the contractual arrangement between firms moderate the pioneering strategy's innovation outcomes in the short and long run. Our results confirm the negative effect of coercive power on innovation performance in both the short and long term. However, the compensating effect of rather complete contracts differs temporally. Whereas, contract completeness protects against higher dependence at the beginning of the collaboration, their effect diminishes over time. In contrast, rather incomplete contracts enhance the innovation performance in the long term, possibly complemented with trust. KW - alliances KW - coercive power KW - contracts KW - pioneering strategy KW - R&D KW - supply chain Y1 - 2020 U6 - https://doi.org/10.1109/TEM.2020.3019965 SN - 0018-9391 VL - 69 IS - 6 SP - 2826 EP - 2841 PB - IEEE 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 -