A5013620492- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Logic, programming, and type systems
- Parallel Computing and Optimization Techniques
- Plasma Diagnostics and Applications
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Security and Verification in Computing
- Advanced SAR Imaging Techniques
- Software Engineering Research
- Atomic and Molecular Physics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Software Testing and Debugging Techniques
- Soil Moisture and Remote Sensing
- Formal Methods in Verification
- Distributed and Parallel Computing Systems
- Advanced Malware Detection Techniques
- Cryospheric studies and observations
- Homotopy and Cohomology in Algebraic Topology
- Distributed systems and fault tolerance
- Mass Spectrometry Techniques and Applications
- Gyrotron and Vacuum Electronics Research
- Software System Performance and Reliability
- Cloud Computing and Resource Management
- Landslides and related hazards
Max Planck Institute for Plasma Physics
2015-2024
Leipzig University of Applied Sciences
2024
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2023-2024
Oracle (United States)
2012-2023
Max Planck Society
2004-2021
University of Padua
2021
National Agency for New Technologies, Energy and Sustainable Economic Development
2021
University of Bonn
2018
Embraer (Brazil)
2015-2017
Kantar Health (Brazil)
2014-2016
Building high-performance virtual machines is a complex and expensive undertaking; many popular languages still have low-performance implementations. We describe new approach to machine (VM) construction that amortizes much of the effort in initial by allowing be implemented with modest additional effort. The relies on abstract syntax tree (AST) interpretation where node can rewrite itself more specialized or general node, together an optimizing compiler exploits structure interpreter. uses...
A typical points-to analysis such as Andersen's or Steensgaard's may lose precision because it ignores the branching structure of analyzed program. Moreover, typically focuses on objects only, not considering instructions manipulating primitive values. We argue that an approach leads to unnecessary loss, for example, when constants true and false flow out method calls. propose a novel lightweight called SkipFlow interprocedurally tracks both primitives objects, explicitly captures code using...
Recently Cederbaum et al. [Phys. Rev. Lett. 79, 4778 (1997)] predicted a new decay channel of excited atoms and molecules termed interatomic Coulombic (ICD). In ICD the deexcitation energy is transferred via virtual photon exchange to neighboring atom, which releases it by electron emission. We report on an experimental observation in $2s$ ionized neon dimers. The process unambiguously identified detecting two ${\mathrm{N}\mathrm{e}}^{1+}$ fragments coincidence, yielding clean, background...
Version 6 of Sun Microsystems' Java HotSpot™ VM ships with a redesigned version the client just-in-time compiler that includes several research results last years. The is at heart configuration used by default for interactive desktop applications. For such applications, low startup and pause times are more important than peak performance. This paper outlines new architecture shows how it interacts VM. It presents intermediate representation now uses static single-assignment (SSA) form linear...
An abstract syntax tree (AST) interpreter is a simple and natural way to implement programming language. However, it also considered the slowest approach because of high overhead virtual method dispatch. Language implementers therefore define bytecodes speed up interpretation, at cost introducing inflexible hard maintain bytecode formats. We present novel implementing AST interpreters in which modified during interpretation incorporate type feedback. This rewriting general powerful mechanism...
The ITER neutral beam system will be equipped with radio-frequency (RF) negative ion sources, based on the IPP Garching prototype source design. Up to 100 kW at 1 MHz is coupled RF driver, out of which plasma expands into main chamber. Compared arc driven sources are maintenance free and without evaporation tungsten. modularity driver concept permits supply large volumes. (one driver) demonstrated operation in hydrogen deuterium up one hour relevant parameters. ELISE test facility operating...
We present a compiler intermediate representation (IR) that allows dynamic speculative optimizations for high-level languages. The IR is graph-based and contains nodes fixed to control flow as well floating nodes. Side-effecting include framestate maps values back the original program. Guard dynamically check assumptions and, on failure, deoptimize interpreter continues execution. Guards implicitly use program position of last side-effecting node. Therefore, they can be represented freely in...
We present Truffle, a novel framework for implementing managed languages in Java™. The language implementer writes an AST interpreter, which is integrated our that allows tree rewriting during interpretation. Tree rewrites incorporate type feedback and other profiling information into the tree, thus specializing augmenting it with run-time information. When reaches stable state, partial evaluation compiles optimized machine code. done by Graal, just-in-time compiler of Java VM (a variation...
A highly productive platform accelerates the production of research results. The design a Virtual Machine (VM) written in Java™ programming language can be simplified through exploitation interfaces, type and memory safety, automated management (garbage collection), exception handling, reflection. Moreover, modern Java IDEs offer time-saving features such as refactoring, auto-completion, code navigation. Finally, annotations enable compiler extensions for low-level “systems programming”...
Most high-performance dynamic language virtual machines duplicate semantics in the interpreter, compiler, and runtime system. This violates principle to not repeat yourself. In contrast, we define languages solely by writing an interpreter. The interpreter performs specializations, e.g., augments interpreted program with type information profiling information. Compiled code is derived automatically using partial evaluation while incorporating these specializations. makes practical context of...
The neutral beam injection systems for the international fusion experiment ITER used heating, current drive, and diagnostic purposes are based on RF-driven negative hydrogen ion sources with a source area of roughly 0.9 m × 1.9 m. operate at 0.3 Pa in deuterium using total available RF generator power 800 kW per frequency 1 MHz. In order to fulfill challenging requirements beyond (like DEMOnstration plant, DEMO), worldwide developments underway addressing topics plasma generation, extraction...
Abstract ITER is of key importance in the European fusion roadmap as it aims to prove scientific and technological feasibility a future energy source. The EUROfusion consortium labs within Europe contributing preparation exploitation operation aspires exploit outcomes view DEMO. paper provides an overview major progress obtained recently, carried out frame new (initiated 2021) work-package called ‘ Pr eparation I TER O peration’ (PrIO). directly supported by eleven PrIO contributions given...
Dynamic code evolution is a technique to update program while it running. In an object-oriented language such as Java, this can be seen replacing set of classes by new versions. We modified existing high-performance virtual machine allow arbitrary changes the definition loaded classes. Besides adding and deleting fields methods, we also any kind class interface hierarchy. Our approach focuses on increasing developer productivity during debugging. Changes applied at point Java suspended. The...
The number and complexity of attacks on computer systems are increasing. This growth necessitates proper defense mechanisms. Intrusion detection play an important role in detecting disrupting before they can compromise software. Multivariant execution is intrusion mechanism that executes several slightly different versions, called variants, the same program lockstep. variants built to have identical behavior under normal conditions. However, when attack, there detectable differences their...
Arbitrary program extension at run time in language-based VMs, e.g., Java's dynamic class loading, comes a startup cost: high memory footprint and slow warmup. Cloud computing amplifies the overhead. Microservices serverless cloud functions lead to small, self-contained applications that are started often. Slow directly affect hosting costs, can also break service-level agreements. Many limited prescribed set of pre-tested classes, i.e., use closed-world assumption deployment time. For such...
SPIDER is one of the two projects ITER Neutral Beam Test Facility (NBTF) under construction in Padova, Italy, at Consorzio RFX premises; it will have a 100 keV beam source with full-size prototype radiofrequency (RF) ion for Injector (NBI), designed to operate pulse length up 3600 s, featuring ITER-like filter field configuration, caesium oven layout and wide set diagnostics.These features allow reproducing operation like as cannot be done any other existing test facility.SPIDER realization...
Differential synthetic aperture radar interferometry (DInSAR) has been widely applied since the pioneering space-borne experiment in 1989, and subsequently with launch of ERS-1 program 1992. The DInSAR technique is well assessed case SAR data, whereas data acquired from aerial platforms, such as airplanes, helicopters, drones, effective application this still a challenging task, mainly due to limited accuracy information provided by navigation systems mounted onboard platforms. first...
Abstract Since negative hydrogen ion sources for neutral beam injection (NBI) systems rely on the surface production of ions, Cs is injected to lower work function extraction electrode surface. The adsorbed layers are affected by residual gases from given non-UHV conditions as well reactive species during plasma phases, which leads a complex chemistry and occurrence temporal changes function. To control get insight into its dynamics, an absolute diagnostic has been developed with...
We present an optimized implementation of the linear scan register allocation algorithm for Sun Microsystems' Java HotSpot™ client compiler. Linear is especially suitable just-in-time compilers because it faster than common graph-coloring approach and yields results nearly same quality.Our allocator improves basic by adding more advanced optimizations: It makes use lifetime holes, splits intervals if pressure too high, models constraints target architecture with fixed intervals. Three...
Method inlining is considered to be one of the most important optimizations in a compiler. However, poor heuristic can lead significant degradation program's running time. Therefore, it that an inliner has effective controls whether method inlined or not. An component any are features characterize decision. These often correspond caller and callee methods. not always apparent what for this problem relative importance these features. Compiler writers developing heuristics may exclude critical...
This paper describes how high-precision digital elevation models (DEMs) are obtained over the Wadden Sea using AeS-1 airborne interferometric radar. The is an intertidal zone along coast having height variations less than 5 m 30 km and free of vegetation. resulting DEM has a grid spacing 2.5 absolute accuracy cm root mean square (rms), as verified by theodolite measurements. radar system, processing techniques, test area, results, verification procedure.