Recent studies have shown that deep neural network-based models are vulnerable to intentionally crafted adversarial examples, and various methods have been proposed to defend against adversarial word-substitution attacks for neural NLP models. Howeve
r, there is a lack of systematic study on comparing different defense approaches under the same attacking setting. In this paper, we seek to fill the gap of systematic studies through comprehensive researches on understanding the behavior of neural text classifiers trained by various defense methods under representative adversarial attacks. In addition, we propose an effective method to further improve the robustness of neural text classifiers against such attacks, and achieved the highest accuracy on both clean and adversarial examples on AGNEWS and IMDB datasets by a significant margin. We hope this study could provide useful clues for future research on text adversarial defense. Codes are available at https://github.com/RockyLzy/TextDefender.
The robustness and security of natural language processing (NLP) models are significantly important in real-world applications. In the context of text classification tasks, adversarial examples can be designed by substituting words with synonyms unde
r certain semantic and syntactic constraints, such that a well-trained model will give a wrong prediction. Therefore, it is crucial to develop techniques to provide a rigorous and provable robustness guarantee against such attacks. In this paper, we propose WordDP to achieve certified robustness against word substitution at- tacks in text classification via differential privacy (DP). We establish the connection between DP and adversarial robustness for the first time in the text domain and propose a conceptual exponential mechanism-based algorithm to formally achieve the robustness. We further present a practical simulated exponential mechanism that has efficient inference with certified robustness. We not only provide a rigorous analytic derivation of the certified condition but also experimentally compare the utility of WordDP with existing defense algorithms. The results show that WordDP achieves higher accuracy and more than 30X efficiency improvement over the state-of-the-art certified robustness mechanism in typical text classification tasks.
We release a new benchmark for lexical substitution, the task of finding appropriate substitutes for a target word in a context. For writing, lexical substitution systems can assist humans by suggesting words that humans cannot easily think of. Howev
er, existing benchmarks depend on human recall as the only source of data, and therefore lack coverage of the substitutes that would be most helpful to humans. Furthermore, annotators often provide substitutes of low quality, which are not actually appropriate in the given context. We collect higher-coverage and higher-quality data by framing lexical substitution as a classification problem, guided by the intuition that it is easier for humans to judge the appropriateness of candidate substitutes than conjure them from memory. To this end, we use a context-free thesaurus to produce candidates and rely on human judgement to determine contextual appropriateness. Compared to the previous largest benchmark, our Swords benchmark has 3x as many substitutes per target word for the same level of quality, and its substitutes are 1.4x more appropriate (based on human judgement) for the same number of substitutes.
This comes Search integral part of the series of research thatinvolved under the title (Al Ketab in light of the Department of Modern Linguistics), where she studied in the first part, the curriculum at Sibawayh In the second part, the audio level, a
nd the third morphological level, and in this section I will present a study on the grammar level, which includes rules of grammatical relations in the book Sibawayh (moral clues: the presumption of attribution, customization and specialization, objectivity, question, verbal clues: connectivity, as convergence, toning).
Then substitution rules [Description structural rules in the book Sibawayh: replacement, career symmetry. Conversion rules: introduction delays, deletion.
And come to the conclusion: The concept of the deep structure of the curriculum Sibawayh than it is in the modern descriptive approach on the one hand that the manufacturing rules of submission and delay, delete and increase, is linking the deep structure and surface structure, highlights our scientific method right at all as laid down in the foundations, and the year of the principles reflect the fact that the descriptive approach, which has a close connection, but to draw attention to benefit from his approach breathes life in Arabic linguistic theory.
Highlights this search light on the study of sound in the book Sibawayh according curricula modern linguistics , turned out to us that Sibawayh realized the importance of the audio system , and was fully aware that the study sounds introduction is a
must to study the language , and also shows that he has dealt with the description ( sound operative ) , Between numbering , and select audio and accompanying movements of the members of the pronunciation.
The department Sibawayh Arab voices depending on the pronunciation control outside air from the mouth to the voices of ( silent ) and sounds ( tide and soft ) .
Then we studied the symmetry voice in the book Sibawayh ( symmetry between the consonants : symmetry next , and substitution ) , and ( symmetry full - slurring - diphthong doubled , diphthong Close together ) , and ( symmetry next , symmetry mastermind ) , and ( symmetry voice and tilt ) , and ( symmetry voice and followers).And studied voice offset in the book Sibawayh : ( offset voice and semantics ) , and ( offset voice and deletions ) , and ( offset voice and mitigation)
Used the Syrian legislatore in connection with the insurance whish is made by the
partner in the common property, the principle of real substitution, the desire to
stabilization of the transactions, to decide that the act remains true whatever the
equivalent of the thing insured partner's share in a division. In spite of the principle
of real substitution adopted by the legislatore, but the creditor's right to the insured
remains pending on the decision does not settle down for the duration of common,
and may be his fate, move to the money other than the creditor wanted it from
contracting with the partner.
And we will show in this research over the legal protection provided by the
application of the principle of real substitution in estate insurance, and that through
the study of the legal nature of the real substitution, and the impact of its application
in estate insurance.
The security of several recently proposed ciphers relies on the fact:" that
the classical methods of cryptanalysis (e.g. linear or differential attacks) are
based on probabilistic characteristics, which makes their security grow
exponentially with
the number of rounds".
So they haven’t the suitable immunity against the algebraic attacks which
becomes more powerful after XSL algorithm. in this research we will try some
method to increase the immunity of AES algorithm against the algebraic
attacks then we will study the effect of this adjustment.
