5329853
Generating Tests for Control Portion of SDL Specifications
ABSTRACT The signal SAVE construct is one of the features distinguishing SDL from convent specification and programming languages. On the other hand, this feature increase testing SDL-specified software. We present a testing approach consisting of the foll SDL specifications are first abstracted into finite state machines with save constructs machines are transformed to equivalent finite state machines without save construc are selected from the resulting finite state machines. In particular, we give a fault m selection. We come up with an equivalent transformation method which works for constructs for which equivalent FSMs exist. We also investigate the detection of fa queue.
8980668
Generating Synchronizable Test Sequences Based on Finite State Machine with Distributed Ports
In the area of testing communication systems, the interfaces between systems to be tested and their testers have great impact on test generation and fault detectability. Several types of such interfaces have been standardized by the International Standardization Organization (ISO). A general distributed test architecture, containing distributed interfaces, has been presented in the literature for testing distributed systems based on the Open Distributing Processing (ODP) Basic Reference Model (BRM), which is a generalized version of ISO distributed test architecture. We study in this paper the issue of test selection with respect to such an test architecture. In particular, we consider communication systems that can be modeled by finite state machines with several distributed interfaces, called ports. A test generation method is developed for generating test sequences for such finite state machines, which is based on the idea of synchronizable test sequences. 
 
Starting from the initial effort by Sarikaya, a certain amount of work has been done for generating test sequences for finite state machines with respect to the ISO distributed test architecture, all based on the idea of modifying existing test generation methods to generate synchronizable test sequences. However, none studies the fault coverage provided by their methods. We investigate the issue of fault coverage and point out a fact that the methods given in the literature for the distributed test architecture cannot ensure the same fault coverage as the corresponding original testing methods. We also study the limitation of fault detectability in the distributed test architecture.
53228070
Transaction reordering with application to synchronized scans
Traditional workload management methods mainly focus on the current system status while information about the interaction between queued and running transactions is largely ignored. An exception to this is the transaction reordering method, which reorders the transaction sequence submitted to the RDBMS and improves the transaction throughput by considering both the current system status and information about the interaction between queued and running transactions. The existing transaction reordering method only considers the reordering opportunities provided by analyzing the lock conflict information among multiple transactions. This significantly limits the applicability of the transaction reordering method. In this paper, we extend the existing transaction reordering method into a general transaction reordering framework that can incorporate various factors as the reordering criteria. We show that by analyzing the resource utilization information of transactions, the transaction reordering method can also improve the system throughput by increasing the resource sharing opportunities among multiple transactions. We provide a concrete example on synchronized scans and demonstrate the advantages of our method through experiments with a commercial parallel RDBMS.
52837469
MedSearch: a specialized search engine for medical information
People are thirsty for medical information. Existing Web search engines cannot handle medical search well because they do not consider its special requirements. Often a medical information searcher is uncertain about his exact questions and unfamiliar with medical terminology. Therefore, he prefers to pose long queries, describing his symptoms and situation in plain English, and receive comprehensive, relevant information from search results. This paper presents MedSearch, a specialized medical Web search engine, to address these challenges. MedSearch can assist ordinary Internet users to search for medical information, by accepting queries of extended length, providing diversified search results, and suggesting related medical phrases.
6634048
Content-based filtering for efficient online materialized view maintenance
Real-time materialized view maintenance has become increasingly popular, especially in real-time data warehousing and data streaming environments. Upon updates to base relations, maintaining the corresponding materialized views can bring a heavy burden to the RDBMS. A traditional method to mitigate this problem is to use the where clause condition in the materialized view definition to detect whether an update to a base relation is relevant and can affect the materialized view. However, this detection method does not consider the content in the base relations and hence misses a large number of filtering opportunities. In this paper, we propose a content-based method for detecting irrelevant updates to base relations of a materialized view. At the cost of using more space, this method increases the probability of catching irrelevant updates by judiciously designing filtering relations to capture the content in the base relations. Based on the content-based method, a prototype real-time data warehouse has been implemented on top of IBM's System S using IBM DB2. Using an analytical model and our prototype, we show that the content-based method can catch most (or all) irrelevant updates to base relations that are missed by the traditional method. Thus, when the fraction of irrelevant updates is non-negligible, the load on the RDBMS due to materialized view maintenance can be significantly reduced.
60885883
Trace-equivalent transformation of nondeterministic finite state machines to avoid internal actions
6937739
A comparison of three methods for join view maintenance in parallel RDBMS
In a typical data warehouse, materialized views are used to speed up query execution. Upon updates to the base relations in the warehouse, these materialized views must also be maintained. The need to maintain these materialized views can have a negative impact on performance that is exacerbated in parallel RDBMSs, since simple single-node updates to base relations can give rise to expensive all-node operations for materialized view maintenance. We present a comparison of three materialized join view maintenance methods in a parallel RDBMS, which we refer to as the naive, auxiliary relation, and global index methods. The last two methods improve performance at the cost of using more space. The results of this study show that the method of choice depends on the environment, in particular, the update activity on base relations and the amount of available storage space.