A permutation array (or code) of length n and distance d is a set Gamma of permutations from some fixed set of n symbols such that the Hamming distance between each distinct x;y is an element of Gamma is at least d. O...
详细信息
A permutation array (or code) of length n and distance d is a set Gamma of permutations from some fixed set of n symbols such that the Hamming distance between each distinct x;y is an element of Gamma is at least d. One motivation for coding with permutations is powerline communication. After summarizing known results, it is shown here that certain families of polynomials over finite fields give rise to permutation arrays. Additionally, several new computational constructions are given, often making use of automorphism groups. Finally, a recursive construction for permutation arrays is presented, using and motivating the more general notion of codes with constant weight composition.
A permutation array (or code) of length n and distance d is a set Gamma of permutations from some fixed set of n symbols such that the Hamming distance between each distinct x;y is an element of Gamma is at least d. O...
详细信息
A permutation array (or code) of length n and distance d is a set Gamma of permutations from some fixed set of n symbols such that the Hamming distance between each distinct x;y is an element of Gamma is at least d. One motivation for coding with permutations is powerline communication. After summarizing known results, it is shown here that certain families of polynomials over finite fields give rise to permutation arrays. Additionally, several new computational constructions are given, often making use of automorphism groups. Finally, a recursive construction for permutation arrays is presented, using and motivating the more general notion of codes with constant weight composition.
A random-like framework of the IRA-LDPC codes based on the identity column vectors(ICV) was defined and created. A new family of the IRA-LDPC codes under the constraint of the framework was investigated using algebrai...
详细信息
ISBN:
(纸本)9781509038237;9781509038220
A random-like framework of the IRA-LDPC codes based on the identity column vectors(ICV) was defined and created. A new family of the IRA-LDPC codes under the constraint of the framework was investigated using algebraic and random methods. Its structural features is that the large-sized sparse parity check matrix Hd corresponding to the information bits is extruded into two smaller-sized easy-to-compute matrices, respectively called base matrix and position matrix. The minimum decomposable unit of the parity-check matrix H is the ICV which can provide a wider selection range of code rates than the most extensively studied QC-LDPC codes. Some conditions for the IRA-LDPC code not to have any 4-girth were considered.
Stream join is a fundamental data operator for processing real-time data, but it faces computational challenges during stream inequality join (theta join operators) due to frequent updates in indexing data structures....
详细信息
ISBN:
(纸本)9798400704130
Stream join is a fundamental data operator for processing real-time data, but it faces computational challenges during stream inequality join (theta join operators) due to frequent updates in indexing data structures. To tackle this problem, we identify three key insights: 1) identifying skewed data distributions in real-time and implementing dedicated indexing structures for skewed keys to reduce index update costs;2) leveraging optimized data structures, including insert-efficient mutable and search-efficient immutable structures to optimize the search stream join process and 3) adopting learned indexes instead of conventional ones, which can provide up to 4x better performance. In this Ph.D. work, we propose novel solutions for distributed and multi-core stream join processing, including an indexing solution that uses a space-efficient dedicated filter and a two-stage data structure that effectively holds and processes sliding window items (bounded streaming contents). We are also exploring the adoption and benefits of learned indexes for real-time stream join processing. Despite non-trivial challenges like state management for distributed processing, processing guarantees, and efficient concurrency mechanisms, experiments on distributed stream processing systems show superior performance compared to state-of-the-art solutions.
The discovery and characterization of molecular interactions is crucial towards a better understanding of complex biological processes. Particularly protein-protein interactions (Le., PPIs), which are responsible for ...
详细信息
The discovery and characterization of molecular interactions is crucial towards a better understanding of complex biological processes. Particularly protein-protein interactions (Le., PPIs), which are responsible for a variety of cellular functions from intracellular signaling to enzyme-substrate specificity, have been studied broadly over the past decades. Position-specific scoring matrices (PSSM) in particular are used extensively to help determine interaction specificity or candidate interaction motifs at the residue level. However, not all studies successfully report their results as a candidate interaction motif. In many cases, this may be due to a lack of suitable tools for simple analysis and motif generation. Peptide Specificity Analyst (PeSA) was developed with the goal of filling this information gap and providing an easy to use software to aid peptide array analysis and motif generation. PeSA utilizes two models of motif creation: (1) frequency-based using a user-defined peptide list, and (2) weight-based using experimental binding results. The ability to produce motifs effortlessly will make studying, interpreting and disseminating peptide specificity results in an effortless and straightforward process.
暂无评论