Access histories of users visiting a web server are automatically recorded in web access logs. Conceptually, the web-log data can be regarded as a collection of clients’ access-sequences where each sequence is a list of pages accessed by a single user in a single session. This chapter presents novel indexing techniques that support efficient processing of so-called pattern queries, which consis...

To meet tightening security requirements, modern operating systems enforce mandatory access control based on formal security policies. To ensure the critical property of policy correctness, formal methods and models for both their specification and verification are used. The variety of these approaches reflects the diversity and heterogeneity of policy semantics, which makes policy engineering ...

There has been an increased demand for characterizing user access patterns using web mining techniques since the informative knowledge extracted from web server log files can not only offer benefits for web site structure improvement but also for better understanding of user navigational behavior. In this paper, we present a web usage mining method, which utilize web user usage and page linkage...

Among the major challenges of transitioning to exascale in HPC is the ubiquitous I/O bottleneck. For analysis and visualization applications in particular, this bottleneck is exacerbated by the write-onceread-many property of most scientific datasets combined with typically complex access patterns. One promising way to alleviate this problem is to recognize the application’s access patterns and...

Even though the entry barrier of writing a GPGPU program is lowered with the help of many high-level programming models, such as NVIDIA CUDA, it is still very difficult to optimize a program so as to fully utilize the given architecture’s performance. The burden of GPGPGU programmers is increasingly growing as they have to consider many parameters, especially on memory access pattern, and even ...

In this paper we show that partitioning data cache into array and scalar caches can improve cache access pattern without having to remap data, while maintaining the constant access time of a direct-mapped cache and improving the performance of L-1 cache memories. By using 4 central moments (mean, standard-deviation, skewness and kurtosis) we report on the frequency of accesses to cache sets and...

Software patterns enable an efficient transfer of design experience by documenting common solutions to recurring design problems. However, given the steadily growing number of patterns in the literature and online repositories, it can be hard for non-experts to select patterns appropriate to their needs, or even to be aware of the existing patterns. We describe an implicit culture approach for ...

In this paper, a joint transmitter and receiver design for pattern division multiple access (PDMA) is proposed. At the transmitter, pattern mapping utilizes power allocation to improve the overall sum rate, and beam allocation to enhance the access connectivity. At the receiver, hybrid detection utilizes a spatial filter to suppress the interbeam interference caused by beam domain multiplexing,...

Most modern I/O systems treat each file access independently. However, events in a computer system are driven by programs. Thus, accesses to files occur in consistent patterns and are by no means independent. The result is that modern I/O systems ignore useful information. Using traces of file system activity we show that file accesses are strongly correlated with preceding accesses. In fact, a...

Web Access Pattern (WAP), which is the sequence of accesses pursued by users frequently, is a kind of interesting and useful knowledge in practice. Sequential Pattern mining is the process of applying data mining techniques to a sequential database for the purposes of discovering the correlation relationships that exist among an ordered list of events. WAP tree mining is a sequential pattern mi...