Construction of dynamic stochastic simulation models using knowledge-based techniques

Over the past three decades, computer-based simulation models have proven themselves to be cost-effective alternatives to the more structured deterministic methods of systems analysis. During this time, many techniques, tools and languages for constructing computer-based simulation models have been developed. More recently, advances in knowledge-based system technology have led many researchers to note the similarities between knowledge-based programming and simulation technologies and to investigate the potential application of knowledge-based programming techniques to simulation modeling. The integration of conventional simulation techniques with knowledge-based programming techniques is discussed to provide a development environment for constructing knowledge-based simulation models. A comparison of the techniques used in the construction of dynamic stochastic simulation models and those used in the construction of knowledge-based systems provides the requirements for the environment. This leads to the design and implementation of a knowledge-based simulation development environment. These techniques were used in the construction of several knowledge-based simulation models including the Advanced Launch System Model (ALSYM)

Nickel hydrogen battery expert system

The Hubble Telescope Battery Testbed at MSFC uses the Nickel Cadmium (NiCd) Battery Expert System (NICBES-2) which supports the evaluation of performance of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort is summarized which was used to modify NICBES-2 to accommodate Nickel Hydrogen (NiH2) battery environment now in MSFC testbed. The NICBES-2 is implemented on a Sun Microsystem and is written in SunOS C and Quintus Prolog. The system now operates in a multitasking environment. NICBES-2 spawns three processes: serial port process (SPP); data handler process (DHP); and the expert system process (ESP) in order to process the telemetry data and provide the status and action advice. NICBES-2 performs orbit data gathering, data evaluation, alarm diagnosis and action advice and status and history display functions. The adaptation of NICBES-2 to work with NiH2 battery environment required modification to all of the three component processes

Development of nickel hydrogen battery expert system

The Hubble Telescope Battery Testbed employs the nickel-cadmium battery expert system (NICBES-2) which supports the evaluation of performances of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 also provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort to modify NICBES-2 to accommodate nickel-hydrogen battery environment in testbed is described

Analysis of Monitoring Tools for Java Applications

Abstract. Runtime Monitoring is performed during the execution of software to detect anomalies in them. Currently several tools are available that help in developing the monitors. We analyze the prominent monitoring tools available for Java applications based on two features, the properties that can be monitored using these tools and the specification language used to specify the monitorable properties. The analysis performed will help the users and developers better evaluate the characteristics of different monitoring tools available in order to select the one suitable for their application

On Modeling and Analysis of MIMO Wireless Mesh Networks with Triangular Overlay Topology

Multiple input multiple output (MIMO) wireless mesh networks (WMNs) aim to provide the last-mile broadband wireless access to the Internet. Along with the algorithmic development for WMNs, some fundamental mathematical problems also emerge in various aspects such as routing, scheduling, and channel assignment, all of which require an effective mathematical model and rigorous analysis of network properties. In this paper, we propose to employ Cartesian product of graphs (CPG) as a multichannel modeling approach and explore a set of unique properties of triangular WMNs. In each layer of CPG with a single channel, we design a node coordinate scheme that retains the symmetric property of triangular meshes and develop a function for the assignment of node identity numbers based on their coordinates. We also derive a necessary-sufficient condition for interference-free links and combinatorial formulas to determine the number of the shortest paths for channel realization in triangular WMNs

ADAPT: A Game Inspired Attack-Defense And Performance Metric Taxonomy

Abstract. Game theory has been researched extensively in network security demonstrating an advantage of modeling the interactions between attackers and defenders. Game theoretic defense solutions have continuously evolved in most recent years. One of the pressing issues in composing a game theoretic defense system is the development of consistent quantifiable metrics to select the best game theoretic defense model. We survey existing game theoretic defense, information assurance, and risk assessment frameworks that provide metrics for information and network security and performance assessment. Coupling these frameworks, we propose a game theoretic approach to attack-defense and performance metric taxonomy (ADAPT). ADAPT uses three classifications of metrics: (i) Attacker, (ii) Defender (iii) Performance. We proffer ADAPT with an attempt to aid game theoretic performance metrics. We further propose a game decision system (GDS) that uses ADAPT to compare competing game models. We demonstrate our approach using a distributed denial of service (DDoS) attack scenario. Keywords: Game Theory, Taxonomy, Security Management INTRODUCTION Game theory has received increased attention from network security researchers, investigating defense solutions. The game theory approach has the advantage of modeling the interactions between attackers and defenders, where players have the ability to analyze other player's behavior. This may enable an administrator to develop better strategic defenses for the system. For instance, when there are many actions available to the attacker and defender, it becomes difficult to develop solution strategies. Hamilton, et al. [1] outlined the areas of game theory which are relevant to information warfare using course of actions with predicted outcomes and what-if scenarios. Jiang, et al. In this paper, we attempt to address limitations in research through the proposed game theoretic attack-defense and performance metric taxonomy (ADAPT), which is a taxonomy of game related metrics. We define a game as the interactions between two players with conflicting goals. In our case these players are the attacker (hacker) and system administrator (defender). Game metrics are a set of tools which are used to measure the various kinds of impact a game model has on each of its players. We classify these game metrics based on their impact on attacker, defender, and the performance of the game model on the system which is being run. Prior research has shown, with the use of game theory, how the interaction should take place based on the strategy and the strategy selected from the game model. In this traditional scenario one game model is assessed relative to a particular attack. He, et al. [6] proposed a Game Theoretical Attack-Defense Model (GTADM), similar to ADAPT, that quantifies the probability of threats in constructing a risk assessment framework. We extend these general game theory steps and concepts proposed in He, et al. [6] with the use of ADAPT being able to assess competing game models and select the game model which is suitable for defense. This provides a defender with a preliminary view of multiple game models associated to a particular attack

Computer organization, design, and architecture, fifth edition

Suitable for a one- or two-semester undergraduate or beginning graduate course in computer science and computer engineering, Computer Organization, Design, and Architecture, Fifth Edition presents the operating principles, capabilities, and limitations of digital computers to enable the development of complex yet efficient systems. With 11 new sect

COMBINATIONAL LOGIC SYNTHESIS FROM AN HDL DESCRIPTION.

Hardware Description Languages are used to input the details of a digital system into an automatic design system. An algorithm to synthesize combinational logic from the description in one such language (DDL) is discussed. A sample implementation and the cost comparison are provided

USE OF DDL IN AN AUTOMATIC LSI DESIGN AND TEST SYSTEM.

Breadboard implementations of hardware are traditionally used to work out the final changes in a design. This approach may not be suitable for a large scale integrated circuit design environment, especially when the complexity of the circuit is high. A thorough computer evaluation of the design would be a proper alternative, to minimize the costs of mask fabrication and wafer processing. The use of a Hardware Description Language to aid in the initial design evaluations and logic synthesis aspects of an automatic LSI design system is discussed. The Hardware Description Language selection process is described

Automatic Hardware Synthesis

The complexity of the circuit that can fit cm an integrated circuit (IC) chip has readied the level of a million transistors with the advent of Very-Large-Scale Integration (VLSI). Several automatic synthesis systems have evolved that “aid” the human designer in managing this complexity. This paper surveys such efforts. The synthesis is viewed as the process of transforming a high-level design specification into a lower level design specification that includes more structural details, leading to the physical design of the IC. The characteristics of ten automatic synthesis systems are summarized. Copyright © 1983 by The Institute of Electrical and Electronics Engineers, Inc