142,592 research outputs found
АНАЛИЗ РЕАЛИЗАЦИЙ АЛГОРИТМА КРИПТОГРАФИЧЕСКОГО ХЭШИРОВАНИЯ SHA-1 НА КОНВЕЙЕРНЫХ СХЕМАХ
No full textAn analysis of hardware implementations of the cryptographic hash function SHA-1 based on pipeline circuits with different numbers of logic levels was made in this paper. The hardware implementations of the hash function SHA-1 for high performance applications were described.Проведен анализ аппаратных реализаций алгоритма криптографического хэширования SHA-1 на конвейерных схемах с различным количеством уровней логики. Рассмотрены аппаратные реализации алгоритма SHA-1 для приложений, требующих высокой производительности
The first collision for full SHA-1
No full textSHA-1 is a widely used 1995 NIST cryptographic hash function standard that was officially deprecated by NIST in 2011 due to fundamental security weaknesses demonstrated in various analyses and theoretical attacks. Despite its deprecation, SHA-1 remains widely used in 2017 for document and TLS certificate signatures, and also in many software such as the GIT versioning system for integrity and backup purposes. A key reason behind the reluctance of many industry players to replace SHA-1 with a safer alternative is the fact that finding an actual collision has seemed to be impractical for the past eleven years due to the high complexity and computational cost of the attack. In this paper, we demonstrate that SHA-1 collision attacks have finally become practical by providing the first known instance of a collision. Furthermore, the prefix of the colliding messages was carefully chosen so that they allow an attacker to forge two distinct PDF documents with the same SHA-1 hash that display different arbitrarily-chosen visual contents. We were able to find this collision by combining many special cryptanalytic techniques in complex ways and improving upon previous work. In total the computational effort spent is equivalent to 263.1 calls to SHA-1’s compression function, and took approximately 6500 CPU years and 100 GPU years. While the computational power spent on this collision is larger than other public cryptanalytic computations, it is still more than 100 000 times faster than a brute force search
The Brauer-Manin Obstruction and Sha[2].
No full textWe discuss the Brauer-Manin obstruction on del Pezzo surfaces of degree 4. We outline a detailed algorithm for computing the obstruction and provide associated programs in magma. This is illustrated with the computation of an example with an irreducible cubic factor in the singular locus of the defining pencil of quadrics (in contrast to previous examples, which had at worst quadratic irreducible factors). We exploit the relationship with the Tate-Shafarevich group to give new types of examples of Sha[2], for families of curves of genus 2 of the form y^2 = f(x), where f(x) is a quintic containing an irreducible cubic factor
Uma solução de autenticação fim a fim para o LDP (Label Distribution Protocol)
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.Este trabalho propõe uma solução de autenticação para o protocolo LDP (Label Distribution Protocol) que tem por objetivo autenticar, em um escopo fim a fim, o estabelecimento de um LSP (Label Switching Path) entre um LSR (Label Switching Router) de Ingresso e o seu respectivo LSR de Egresso. Objetiva-se suprir a deficiência do protocolo LDP de não possuir um mecanismo de autenticação fim a fim definido, aplicável entre LSRs não-adjacentes. Conforme foi verificado pelo levantamento de trabalhos correlatos, atualmente é desconhecida uma solução de autenticação semelhante, que efetivamente atenda o propósito de autenticar num escopo fim a fim, o estabelecimento de LSPs no protocolo LDP. Dessa forma a solução deste trabalho é inédita no seu escopo de aplicação. A solução foi planejada para ambientes onde LSPs atravessam múltiplos domínios externos, não confiáveis entre si, e que por isso necessitam de um mecanismo de autenticação durante o estabelecimento dos LSPs. A solução faz uso de um mecanismo de autenticação, baseado em criptografia assimétrica (chave pública e privada), anexado a cada mensagem LDP. Este mecanismo possibilita ao LSR receptor verificar e autenticar o originador da mensagem LDP. Adicionalmente a solução provê integridade de dados através de um mecanismo de resumo de mensagens (hash) e também protege contra ataques de repetição através da inserção de um nonce às mensagens LDP
Caracladus montanus Sha & Zhu 1994
No full text<i>Caracladus montanus</i> Sha & Zhu, 1994 <p> <i>Caracladus montanus</i> Sha & Zhu, 1994: 172, figs 1–7; Song <i>et al.</i> 1999: 160, figs 88M–O.</p> <p> <b>Type material.</b> <b>HOLOTYPE: China:</b> <i>Jilin:</i> Changbai mountain [42°00' N, 128°01' E], 1♂ 1979-1990 (Sha & Zhu 1994). <b>PARATYPES: China:</b> <i>Jilin:</i> Changbai mountain, Baiyunfeng (“white cloud peak”) [42°00' N, 128°01' E], 1♂ 19.vi.1979, leg. Y. Zhang and C. Wang (Sha & Zhu 1994); Changbai mountain [42°00' N, 128°01' E], 1♂ 11.viii.1985, leg. C. Zhu (Sha & Zhu 1994); Changbai mountain, Xidapo (“big western slope”) [42°00' N, 128°01' E], 6♂ 9♀ 31.vii.1990, leg. Y. Sha (Sha & Zhu 1994); Changbai mountain, Xiaotianchi (“small heaven lake”) [42°05'48'' N, 128°03'50'' E], 3♂ 5♀ 04.viii.1990, leg. Y. Sha (Sha & Zhu 1994). The type material (mentioned above) is stored in the Department of Biology, Norman Bethune University of Medical Sciences in Changchun, which is now a subunit of the Jilin University, China (Sha & Zhu 1994). The material was not available for observation since establishing contacts with Jilin University was not successful..</p> <p> <b> Diagnosis. <i>Males</i></b> : Similar to <i>C. tsurusakii</i> with differences in the shape of the male palpal tibia and the embolus (Sha & Zhu 1994). In lateral view, the cephalic lobe is broadest below the eye-field (Sha & Zhu 1994: Fig. 2), but is narrowed down in <i>C. tsurusakii</i> (Fig. 45). The prolateral tibialapophysis looks like a big tooth (Sha & Zhu 1994: Fig. 4) whereas it is a glabrous blunt apophysis in <i>C. tsurusakii</i> (Fig. 42).</p> <p> <i>Females</i>: The shape of the epigynum and the vulva are different to what is seen in other <i>Caracladus</i> species. E.g. the curled copulatory duct (Sha & Zhu 1994: Fig. 7).</p> <p> <b> Description. <i>Males</i></b> : Total length: 1.85–2.07 mm (Sha & Zhu 1994). Cephalic lobe: facing forward, hairy in front of the PME (Sha & Zhu 1994: Fig. 2); shaft rather thick with some hairs (Sha & Zhu 1994: Fig. 2); sulcus absent. Eyes: PME upmost on the cephalic lobe (Sha & Zhu 1994: Fig. 2). Chelicerae: promargin with five larger teeth; retromargin with five very small denticles; stridulatory striae present (Sha & Zhu 1994). Legs: tibia I–IV with one dorsal proximal macroseta (1-1-1-1); Tm I: 0.61 (Sha & Zhu 1994). Pedipalp: paracymbium simple hook (Sha & Zhu 1994: Fig. 3); retrolateral tibial apophysis small tooth; prolateral tibial apophysis long and broad (Sha & Zhu 1994: Figs 4, 5); protegulum present (Sha & Zhu 1994: Fig. 3).</p> <p> <i>Females</i>: General appearance similar to males but without a cephalic lobe (Sha & Zhu 1994). Total length: 2.07–2.72 mm (Sha & Zhu 1994). Eyes: anterior row slightly recurved (Sha & Zhu 1994). Chelicerae: stridulatory striae present (Sha & Zhu 1994). Epigyne: ventral plate hourglass-like, visible in ventral view (Sha & Zhu 1994: Fig. 6, see remarks). Vulva: receptacula globular; copulatory duct spiral (Sha & Zhu 1994: Fig. 7).</p> <p> <b>Distribution.</b> Only known from the type locality in Jilin, China (Song <i>et al.</i> 1999).</p> <p> <b>Habitat.</b> The coordinates in the original publication correspond to a spot at ca. 2000 m a.s.l.</p> <p> <b>Phenology.</b> All records in summer time between June and August.</p> <p> <b>Remarks.</b> No specimens were available for examination. The diagnosis and description of certain structures and the coding of characters for the phylogeny on species level followed the descriptions and figures given in Sha and Zhu (1994) of which some are redrawn in Song <i>et al.</i> (1999). Misinterpretations of the figures can therefore not be excluded. It is assumed, for example, that <i>C. montanus</i> has no sulcus because Sha and Zhu (1994) mention the close resemblance to <i>C. tsurusakii</i> without mentioning a sulcus in the original description. The conformation of the epigyne is unclear to the authors. It is assumed that the ventral hourglassshaped structure represents the dorsal plate.</p>Published as part of <i>Frick, Holger & Muff, Patrick, 2009, Revision of the genus Caracladus with the description of Caracladus zamoniensis spec. nov. (Araneae, Linyphiidae, Erigoninae), pp. 1-37 in Zootaxa 1982</i> on page 17, DOI: <a href="http://zenodo.org/record/185321">10.5281/zenodo.185321</a>
PHYSIOLOGICAL EFFECTS OF THE GUA SHA MASSAGE: SCIENTIFIC REVIEW
No full textObjective: The objective of the review article is to summarize and systematize available scientific data on the physiological effects of Gua Sha massage as well as to formulate a hypothesis regarding the systemic effect it has on the body.Data sources: The data was taken from research articles published in Russian and English from 2004 to 2024. The sources included 33 randomized clinical trials, three comparative studies, seven scientific reviews, two systematic reviews, three clinical cases, and one dissertation for a doctorate in Pedagogical Sciences (specialty: physical education, sports training, recreational education, and adaptive physical education theory and methodology).Study selection: The authors reviewed 120 sources published over the last 50 years and available in the Scopus, Medline, and Elibrary bibliographic databases using the search terms “gua sha” and “Gua Sha”. The 49 most relevant publications, books authored by competent Gua Sha practitioners and research articles in peer-reviewed scientific journals, were selected for analysis. Results:An analysis of the literature brought to light that there are a multitude of physiological effects that Gua Sha massage provides, including immunostimulatory, antioxidant, anti-inflammatory, analgesic, hepatoprotective, reflex, and microcirculatory effects. A hypothesis was formulated on the integral mechanism of the gua sha massage: catalyzation of blood circulation during massage activates metabolic processes in the tissues, enhances lymphatic formation as well as lymphatic outflow, and stimulates detoxification processes, which combine to produce a regenerating, rejuvenating effect on the body.Conclusions:A more accurate scientific substantiation of this technique calls for further clinical research, as not all studies support the effectiveness of Gua Sha massage, and the mechanism of the effect it has on the body is not fully understood. The method must be exercised with caution, as cases have been recorded in which the trauma procedure has resulted in developing complications
Turbo-coded CDMA-based two-way relaying
No full textIn this contribution, we have studied the performance of a Turbo-Coded (TC) Code Division Multiple Access (CDMA) based two-way relaying scheme. More explicitly, we employ a seven-user CDMA model, where two of the CDMA users are communicating with each other with the aid of an additional relay node, while the other five CDMA users are interferers. More explicitly, two CDMA users exchange their information frames within two timeslots. Note that the conventional one-way relaying system can only transmit one information frame within two timeslots because the relay node is half-duplex, where it cannot listen and transmit simultaneously. We found that our proposed TC-CDMA two-way relaying scheme is capable of attaining over 4 dB of SNR gain at a Bit Error Rate (BER) of 10-6 when compared to a conventional non-cooperative TC-CDMA system. We also found that there is about two dB of SNR loss at a BER of 10-6, due to the error propagation from the relay node. The proposed scheme exploits the benefits of TC and CDMA schemes in order to assist the two-way relaying system to operate with a reduced transmit power. The reduction of the transmit power can also be exploited for increasing the coverage area of a cellular cell. Hence, the TC-CDMA two-way relaying scheme is a good candidate for future generation mobile system
21. Zenkoku Suihei-sha
No full textIwao Seiichi, Iyanaga Teizō, Ishii Susumu, Yoshida Shōichirō, Fujimura Jun'ichirō, Fujimura Michio, Yoshikawa Itsuji, Akiyama Terukazu, Iyanaga Shōkichi, Matsubara Hideichi. 21. Zenkoku Suihei-sha. In: Dictionnaire historique du Japon, volume 20, 1995. Lettres U, V, W, X, Y et Z. pp. 135-136
21. Zenkoku Suihei-sha
No full textIwao Seiichi, Iyanaga Teizō, Ishii Susumu, Yoshida Shōichirō, Fujimura Jun'ichirō, Fujimura Michio, Yoshikawa Itsuji, Akiyama Terukazu, Iyanaga Shōkichi, Matsubara Hideichi. 21. Zenkoku Suihei-sha. In: Dictionnaire historique du Japon, volume 20, 1995. Lettres U, V, W, X, Y et Z. pp. 135-136
Does Gua sha therapy reduce pain intensity in patients with chronic back pain?
No full textOBJECTIVE: The objective of this selective EBM review is to determine “Does Gua shatherapy reduce pain intensity in patients with chronic back pain?”
STUDY DESIGN: A systematic review of three randomized controlled trials/studies published in English between 2013-2019.
DATA SOURCES: All articles were published in peer-reviewed journals and obtained from PubMed. The studies were selected based on their applicability to the topic listed above.
OUTCOMES MEASURED: A common outcome measured across all three articles included pain intensity. Each study used the 100 mm Visual Analog Scale (VAS). Participants were asked to rate their pain before and after therapeutic interventions. A higher score indicates a higher subjective feeling of pain.
RESULTS: Saha et al. demonstrated a stronger decrease in pain intensity after Gua sha therapy compared to a patient’s previous medical regimen. The authors showed a mean change from baseline of 24.5 mm in the Gua sha treatment group compared to the mean change from baseline of 12.3 mm in the control group (p\u3c0.001). Similarly, Wang et al. showed that Gua sha therapy was more effective than acupuncture. This is demonstrated by a mean change from baseline of 59 mm after Gua sha therapy and a mean change from baseline of 49 mm after acupuncture (p=0.001). A conclusion comparing the effectiveness between Gua sha therapy and hot pack therapy could be made based on Yuen et al.’s study. However, the authors demonstrated that Gua sha therapy was effective at decreasing pain intensity as seen by F=30.11, p\u3c0.0001, and post hoc p=0.0003.
CONCLUSIONS: All three studies demonstrated that Gua sha therapy significantly decreased pain intensity in patients with chronic back pain. Additionally, Saha et al. and Wang et al. demonstrated that Gua sha therapy was more effective at decreasing pain intensity compared to their respective control groups. The control groups from all three articles included acupuncture, hot pack therapy, and original medical regimens. Further research is needed to explore treatment duration and long term success of Gua sha therapy
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