Horst Mehl’s scientific contributions

What is this page?


This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (3)


How to integrate shared variables in distributed simulation
  • Article

September 1995

·

20 Reads

·

11 Citations

ACM SIGSIM Simulation Digest

Horst Mehl

·

Although users may want to employ shared variables when they program distributed simulation applications, almost none of the currently existing distributed simulation systems does offer this facility. In this paper, we systematically present new algorithms which provide consistent shared variables for distributed simulation applications. Basically, our approach combines known techniques to realize distributed shared memory with simulation algorithms. As there are essentially two classes of distributed simulation algorithms---conservative and optimistic---we study shared variable algorithms for both of them and propose five new algorithms. Initial performance measurements of a prototype implementation are described. Potential performance degradation by the usage of shared variables is expected to depend to a high degree on the access behavior of the simulation application. Having the abstraction of shared variables available provides the user with a simple concept to design distributed simulation applications in the presence of inherent global data.


Global Virtual Time Approximation with Distributed Termination Detection Algorithms

July 1994

·

38 Reads

·

25 Citations

It is shown that distributed termination detection algorithms can be transformed into efficient algorithms to approximate the so-called Global Virtual Time (GVT) of a distributed monotonic computation. Typical instances of such computations are optimistic distributed simulations based on the timewarp principle. The transformation is exemplified for two termination detection algorithms, namely an algorithm by Dijkstra et al. and a new scheme based on the principle of "sticky flags". The general idea of the transformation is that many termination detection algorithms (viz., one for each possible GVT value) run in parallel. Each algorithm determines a specific lower bound The work of H. Mehl is supported by the German National Science Foundation (Deutsche Forschungsgemeinschaft) under grant SPP-322671.


Shared variables in distributed simulation

July 1993

·

13 Reads

·

37 Citations

ACM SIGSIM Simulation Digest

Although users may want to employ shared variables when they program distributed simulation applications, almost none of the currently existing distributed simulation systems do offer this facility. In this paper, we present new algorithms which provide the illusion of consistent shared variables in distributed simulation systems without physically shared memmory.

Citations (3)


... There, also the notion of version records is introduced, where multi versioning is used to maintain shared data in order to cope with read/write operations occurring at different logical times while avoiding unneeded rollbacks. This is an approach similar to the one proposed in [16], where a theoretical presentation of algorithms to implement a Distributed Shared Memory mechanism is provided, and one of the provided algorithms proposes to implement variables as multi-version lists where write operations install new version nodes and read operations find the most suitable version. The above approaches are different from what we propose given that instead of mapping accesses to message-passing, we support in-place access to LP state buffers. ...

Reference:

Porting Event &Cross-State Synchronization to the Cloud
How to integrate shared variables in distributed simulation
  • Citing Article
  • September 1995

ACM SIGSIM Simulation Digest

... ALPs interact with the shared state by reading and writing shared state variables (SSVs): sensing gives rise to read events, and acting gives rise to write events. SSVs are similar to space-time memory [27] and other work on shared state variables in distributed simulation (e.g., [28]), and have similar advantages in offering a more natural problem representation and improved performance when state variables must be accessed by distinct logical processes. In PDES-MAS, the shared state is maintained by a tree-structured set of logical processes referred to as Communication Logical Processes (CLP, represented as circles inFigure 6), which cluster agent models and shared state according to the agents' interaction with their environment and their accessing shared state variables. ...

Shared variables in distributed simulation
  • Citing Article
  • July 1993

ACM SIGSIM Simulation Digest

... In our proposed algorithm, we implement the similar mechanism structure suggested by the Mattern's [1,2] with the use of a matrix. This utilization of the matrix eliminates two of the variables and an array as used by the original Mattern's GVT algorithm. ...

Global Virtual Time Approximation with Distributed Termination Detection Algorithms
  • Citing Article
  • July 1994