String Matching

We address the problem of clustering of string patterns, in an Ensemble Methods perspective. In this approach different partitionings of the data are combined attempting to find a better and more robust partition. In this study we cover the different phases of this approach: from the generation of the partitions, the clustering ensemble, to the combination and validation of the combined result. For the generation we address, both different clustering algorithms (using both the hierarchical agglomerative concept and partitional approaches) and different similarity measures (string matching, structural resemblance). The focus of the paper is the concept of validation/selection of the final data partition. For that, an information-theoretic measure in conjunction with a variance analysis using bootstrapping is used to quantitatively measure the consistency between partitions and combined results and choose the best obtained result without the use of additional information. Experimental results on a real data set (contour images), show that this approach can be used to unsupervisedly choose the best partition amongst alternative solutions, as validated by measuring the consistency with the ground truth information.

We show that transitive closure logic (FO + TC) is strictly more powerful than deterministic transitive closure logic (FO + DTC) on nite (unordered) structures. In fact, on certain classes of graphs, such as hypercubes or regular graphs of large degree and girth, every DTC-query is bounded and therefore rst order expressible. On the other hand there are simple (FO + pos TC) queries on these classes that cannot be de ned by rst order formulae.

Semantic searching over encrypted data is a crucial task for secure information retrieval in public cloud. It aims to provide retrieval service to arbitrary words so that queries and search results are flexible. In existing semantic searching schemes, the verifiable searching does not be supported since it is dependent on the forecasted results from predefined keywords to verify the search results from cloud, and the queries are expanded on plaintext and the exact matching is performed by the extended semantically words with predefined keywords, which limits their accuracy. In this paper, we propose a secure verifiable semantic searching scheme. For semantic optimal matching on ciphertext, we formulate word transportation (WT) problem to calculate the minimum word transportation cost (MWTC) as the similarity between queries and documents, and propose a secure transformation to transform WT problems into random linear programming (LP) problems to obtain the encrypted MWTC. For verifi...

Regular expressions (regex) have long served as a foundational tool for pattern matching in computer science. This paper introduces Regex as Deterministic Aliases (RDA), a novel framework in which regex patterns are formalized as deterministic aliasing functions for reproducible classification. By treating regex not merely as pattern descriptors but as canonical alias generators, RDA enables consistent mappings between textual input and semantic categories. This perspective transforms regex from passive descriptors into active semantic classifiers, bridging formal language theory with practical applications in programming languages, data validation, natural language processing, and security. The framework ensures reproducibility, eliminates ambiguity, and provides a foundation for structured validation and deterministic computation.

Large-scale comparison of genomic DNA is of fundamental importance in annotating functional elements of genomes. To perform large comparisons efficiently, BLAST [3, and other widely used tools use seeded alignment, which compares only sequences that can be shown to share a common pattern or "seed" of matching bases. The literature suggests that the choice of seed substantially affects the sensitivity of seeded alignment, but designing and evaluating seeds is computationally challenging. This work addresses problems arising in seed design. We give the fastest known algorithm for evaluating the sensitivity of a seed in a Markov model of ungapped alignments, as well as theoretical results on which seeds are good choices. We also describe Mandala, a software tool for seed design, and show that it can be used to improve the sensitivity of alignment in practice.

We study a scenario in which a machine acts upon input from its environment by changing the environment, hence affecting its own future input. The machine is a string pattern matcher; the environment varies -for example it can be a one-character buffer. Practical experiments reveal a disparity between stable and unstable (or irregular) behaviour of the machine, depending on the initial state. We suggest a definition of stability and study its theoretical properties.

This paper presents an industrial-grade intelligent purification system for industrial wastewater, integrated as a single-file unified SCADA (Supervisory Control and Data Acquisition) solution with comprehensive functional modules. The system merges five core components, including SCADA enterprise foundation, chemical dosing control, micropollutant monitoring, energy-carbon accounting, and industrial wastewater treatment data interfaces, covering 19 key functional modules such as Modbus TCP-based PLC/RTU integration, PID-controlled chemical dosing (PAC/PAM/carbon source/pH adjustment), tamper-proof ledger with TPM 2.0/HMAC dual-signature, Scope 1/2/3 carbon accounting, Weibull-based predictive maintenance, and MLOps framework for model management.

Built on authentic national/international standards (HJ/GB/EPA/IPCC), the system features standardized water quality detection methods, industrial-grade process parameters, and region-specific carbon emission factors. It supports two operational modes (synthetic simulation for testing and Modbus TCP for on-site deployment) and provides complete deployment tools, including hardware-in-the-loop (HIL) testing scenarios, parameter calibration templates, and network security partitioning plans.

With a code framework completion rate of 90% (~3,000 lines), the system requires on-site commissioning of critical parameters (Modbus register mapping, PID tuning, chemical dosing coefficients) for optimal performance. It is open-source without copyright or patent restrictions, enabling free adaptation across environmental protection fields. The system’s modular design and integration capability lay a foundation for future fusion of multiple systems, aiming to address core challenges in industrial wastewater treatment through infinite integration and sublimation of functional advantages.

Deep Packet Inspection (DPI) involves searching a packet's header and payload against thousands of rules to detect possible attacks. The increase in Internet usage and growing number of attacks which must be searched for has meant hardware acceleration has become essential in the prevention of DPI becoming a bottleneck to a network if used on an edge or core router. In this paper we present a new multi-pattern matching algorithm which can search for the fixed strings contained within these rules at a guaranteed rate of one character per cycle independent of the number of strings or their length. Our algorithm is based on the Aho-Corasick string matching algorithm with our modifications resulting in a memory reduction of over 98% on the strings tested from the Snort ruleset. This allows the search structures needed for matching thousands of strings to be small enough to fit in the on-chip memory of an FPGA. Combined with a simple architecture for hardware, this leads to high throughput and low power consumption. Our hardware implementation uses multiple string matching engines working in parallel to search through packets. It can achieve a throughput of over 40 Gbps (OC-768) when implemented on a Stratix 3 FPGA and over 10 Gbps (OC-192) when implemented on the lower power Cyclone 3 FPGA.

We describe the first .efiicient algorithm for simultaneously matching multiple rectangular patterns of varying sizes and aspect, ratios in a rectangular text. Efficient means significantly better asymptotically than known al,qorithrns that handle one height, width, or aspect ratio at a time. Our algorithm features an interesting use of multidimensional range searching, as well as new adaptations of several known techniques for two climensional string matching. We also extend our algorithm to a dynamic setting where the set of patterns can change over time.

Pertumbuhan informasi digital yang pesat menyebabkan meningkatnya kebutuhan akan sistem pencarian yang efektif dan efisien. Mesin pencari berfungsi sebagai sistem pengambilan informasi yang memungkinkan pengguna untuk menemukan informasi relevan dengan cepat melalui proses pengindeksan, crawling, dan peringkat. Artikel ini bertujuan untuk menganalisis strategi pencarian informasi menggunakan mesin pencari berdasarkan konsep dasar dan penerapan teknik kata kunci serta operator Boolean. Metode yang digunakan mencakup studi literatur dari buku Dasar dan Konsep Mesin Pencari serta eksperimen pencarian dengan tiga skenario yang berbeda. Hasilnya menunjukkan bahwa penggunaan frasa yang spesifik, operator logika, dan fitur lanjutan seperti site: dan filetype: dapat meningkatkan akurasi, relevansi, serta kredibilitas sumber informasi. Penelitian ini menegaskan bahwa kemampuan strategi pencarian adalah aspek penting dari literasi digital mahasiswa.

Pertumbuhan informasi digital yang pesat menyebabkan meningkatnya kebutuhan akan sistem pencarian yang efektif dan efisien. Mesin pencari berfungsi sebagai sistem pengambilan informasi yang memungkinkan pengguna untuk menemukan informasi relevan dengan cepat melalui proses pengindeksan, crawling, dan peringkat. Artikel ini bertujuan untuk menganalisis strategi pencarian informasi menggunakan mesin pencari berdasarkan konsep dasar dan penerapan teknik kata kunci serta operator Boolean. Metode yang digunakan mencakup studi literatur dari buku Dasar dan Konsep Mesin Pencari serta eksperimen pencarian dengan tiga skenario yang berbeda. Hasilnya menunjukkan bahwa penggunaan frasa yang spesifik, operator logika, dan fitur lanjutan seperti site: dan filetype: dapat meningkatkan akurasi, relevansi, serta kredibilitas sumber informasi. Penelitian ini menegaskan bahwa kemampuan strategi pencarian adalah aspek penting dari literasi digital mahasiswa.

Due to the huge surge of digital information and the task of mining valuable information from huge amount of data, text processing tasks like string search has gained importance. Earlier techniques for text processing relied on following some predetermined sequence of steps or some hard coded rules. However, these techniques might soon prove to be inefficient as the amount of data generated by modern computer systems in increasing more and more. One solution to this problem lies in the development of intelligent algorithms that incorporate a certain degree of intelligence and unlike traditional algorithm are able to cope up with changing scenarios. This paper presents a string searching algorithm that incorporates a certain degree of intelligence to search for a string in a text. In the search of a string, the algorithm relies on a chance process and a certain probability at each step. An analysis of the algorithm based on the approach suggested by A. A. Markov is also presented in the paper. The expected number of average comparisons required for searching a string in a text is computed. Based on the varieties of applications that are coming up in the area of text processing and the related fields, this new algorithm aims to find its use.

This paper introduces a new family of reconstruction codes which is motivated by applications in DNA data storage and sequencing. In such applications, DNA strands are sequenced by reading some subset of their substrings. While previous works considered two extreme cases in which all substrings of some fixed length are read or substrings are read with no overlap, this work considers the setup in which consecutive substrings are read with some given minimum overlap. First, upper bounds are provided on the attainable rates of codes that guarantee unique reconstruction. Then, we present efficient constructions of asymptotically optimal codes that meet the upper bound.

Bit parallel string matching algorithms are the latest and the efficient class of algorithm for string matching. It uses the intrinsic parallelism inside a computer word is known as bit parallelism. BNDM is the most popular bit parallel string matching algorithm. This algorithm can directly use for various real world problem like as Detection of Intrusion in the network, Data extraction and mine, avoiding Plagiarism, use of Bioinformatics in various medical field. BNDM algorithm having their standard implementation where lots of bit wise operations are checking as not in bit parallel mode like as MSB of bit vector is one or not or the value of the bit vector is zero or non-zero. All these operations are the comparison based operation which are quite time consuming. If these operations are optimized or simplified in bit parallelism based operations than they have their best bit parallelism based implementation. In this paper we are found out such operations and simplified in pure bit...