SW development and HIL testing for engine monitoring module

Diplomová práce popisuje vývojovou techniku model based design a její použití pro návrh a testování algoritmů. Popis této techniky je proveden na příkladu praktického využití v praxi při vývoji modulu monitorování stavu motoru ve spolupráci se společností Unis. Vývoj v oblasti současné letecké techniky klade velký důraz na monitorování životnosti zařízení. Podle výstupů algoritmu se dají naplánovat preventivní opravy s ohledem na aktuální podmínky opotřebení a provozování. Implementace algoritmů je provedena v prostředí Matlab/Simulink s následným testováním na platformě dSpaceThe thesis describes Model Based Design process and it’s application for design and testing of algorithms. The description of this approach is done on example of practical application for development of the Engine Monitoring Module in collaboration with Unis company. The development of the aerospace industry nowadays is focused on continuous monitoring of equipment. The outputs of these algorithms can be used for planning the maintenance with respect to operative modes and conditions. Monitoring algorithms are implemented in Matlab/Simulink environment and are tested on dSpace platform.

On the selection of secondary indices in relational databases

An important problem in the physical design of databases is the selection of secondary indices. In general, this problem cannot be solved in an optimal way due to the complexity of the selection process. Often use is made of heuristics such as the well-known ADD and DROP algorithms. In this paper it will be shown that frequently used cost functions can be classified as super- or submodular functions. For these functions several mathematical properties have been derived which reduce the complexity of the index selection problem. These properties will be used to develop a tool for physical database design and also give a mathematical foundation for the success of the before-mentioned ADD and DROP algorithms

Diagnosing performance management and performance budgeting systems: A case study of the U.S. Navy

We present here a case study of an organization within the U.S. Navy that created a new organizational construct and performance management system. We explore the issues faced by naval leaders as they attempt to use their performance information to make resource allocation decisions at the sub-organization level, and base budgets at the organization and service (navy) level. We attempt to diagnose many of the practical problems a government organization encounters when implementing a performance management system, to include trying to inform budgets, and make recommendations on actions that would improve the strength of the performance system. We find in the organization a good conceptual framework, organizational enthusiasm, and reasonable attempts to link disparate information systems into a coherent whole. The good intentions are hindered, however, by inadequate accounting systems, a lack of understanding of cost accounting methods, weak use of terminology and longstanding institutional attitudes. This case confirms challenges associated with both performance management systems and performance budgeting found in the literature, and we offer recommendations for public officials considering such endeavors

CSL model checking of Deterministic and Stochastic Petri Nets

Deterministic and Stochastic Petri Nets (DSPNs) are a widely used high-level formalism for modeling discrete-event systems where events may occur either without consuming time, after a deterministic time, or after an exponentially distributed time. The underlying process dened by DSPNs, under certain restrictions, corresponds to a class of Markov Regenerative Stochastic Processes (MRGP). In this paper, we investigate the use of CSL (Continuous Stochastic Logic) to express probabilistic properties, such a time-bounded until and time-bounded next, at the DSPN level. The verication of such properties requires the solution of the steady-state and transient probabilities of the underlying MRGP. We also address a number of semantic issues regarding the application of CSL on MRGP and provide numerical model checking algorithms for this logic. A prototype model checker, based on SPNica, is also described

LINVIEW: Incremental View Maintenance for Complex Analytical Queries

Many analytics tasks and machine learning problems can be naturally expressed by iterative linear algebra programs. In this paper, we study the incremental view maintenance problem for such complex analytical queries. We develop a framework, called LINVIEW, for capturing deltas of linear algebra programs and understanding their computational cost. Linear algebra operations tend to cause an avalanche effect where even very local changes to the input matrices spread out and infect all of the intermediate results and the final view, causing incremental view maintenance to lose its performance benefit over re-evaluation. We develop techniques based on matrix factorizations to contain such epidemics of change. As a consequence, our techniques make incremental view maintenance of linear algebra practical and usually substantially cheaper than re-evaluation. We show, both analytically and experimentally, the usefulness of these techniques when applied to standard analytics tasks. Our evaluation demonstrates the efficiency of LINVIEW in generating parallel incremental programs that outperform re-evaluation techniques by more than an order of magnitude.Comment: 14 pages, SIGMO