Avaliação e Diagnóstico Ambiental: Estudo de Caso de uma Empresa Metalurgica

Objetivo:  O objetivo foi realizar um estudo de caso, aplicando o sistema SBP, como ferramenta de diagnóstico e avaliação de desempenho ambiental de uma empresa do ramo de metalurgia.   Referencial teórico: A produção metalúrgica do pó de ferro, utilizando a atomização a água, envolve uma vasta cadeia de processos desde a matéria prima até o produto final. Diversos conceitos sustentáveis devem ser incorporados no desenvolvimento deste produto, considerando-se fatores como consumo energético, tipo de energia, recursos hídricos e resíduos produzidos. Dentre as diversas ferramentas para controlar e avaliar tanto qualitativamente quanto quantitativamente esses e outros aspectos num processo produtivo industrial a metodologia SBP, mostrou-se eficiente.   Desenho/Metodologia/Abordagem: A metodologia SBP mostrou-se eficiente e de baixo custo ao apontar, por meio de indicadores, a ordem de urgência e prioridade nas ações da empresa, bem como permite identificar as oportunidades de melhoria ao longo do processo.   Resultados: De acordo com o valor de corte estabelecido de 70% de índice de desempenho, a empresa apresentou bons resultados, atingindo 76%.   Pesquisa, implicações práticas e sociais: Diferentes setores da empresa responderam ao questionário, logo uma visão sistêmica desde a alta direção da empresa até o chão de fábrica mostrou que os recursos hídricos pedem maior urgência. Esta conclusão teve alta correlação com as informações obtidas pelos pesquisadores em contato pessoal com alta direção da empresa em que a questão água é muito sensível, mesmo antes da divulgação deste trabalho.   Originalidade/Valor: O construto recursos hídricos representou a maior urgência e prioridade para a tomada de ações pela empresa. A avaliação, portanto, orientou as medidas prioritárias para a e melhoria do seu processo, reduzindo desperdícios deste recurso

Time-Specific Encryption with Constant-Size Secret-Keys Secure under Standard Assumption

In Time-Specific Encryption (TSE) [Paterson and Quaglia, SCN\u2710] system, each secret-key (resp. ciphertext) is associated with a time period t s.t. 0<=t<=T-1 (resp. a time interval [L,R] s.t. 0<=L<=R<=T-1. A ciphertext under [L,R] is correctly decrypted by any secret-key for any time t included in the interval, i.e., L<=t<=R. TSE\u27s generic construction from identity-based encryption (IBE) (resp. hierarchical IBE (HIBE)) from which we obtain a concrete TSE scheme with secret-keys of O(log T)|g| (resp. O(log^2 T)|g|) and ciphertexts of size O(log T)|g| (resp. O(1)|g|) has been proposed in [Paterson and Quaglia, SCN\u2710] (resp. [Kasamatsu et al., SCN\u2712]), where |g| denotes bit length of an element in a bilinear group G. In this paper, we propose another TSE\u27s generic construction from wildcarded identity-based encryption (WIBE). Differently from the original WIBE ([Abdalla et al., ICALP\u2706]), we consider WIBE w/o (hierarchical) key-delegatability. By instantiating the TSE\u27s generic construction, we obtain the first concrete scheme with constant-size secret-keys secure under a standard (static) assumption. Specifically, it has secret-keys of size O(1)|g| and ciphertexts of size O(log^2 T)|g|, and achieves security under the decisional bilinear Diffie-Hellman (DBDH) assumption

Downgradable Identity-Based Signatures and Trapdoor Sanitizable Signatures from Downgradable Affine MACs

Affine message authentication code (AMAC) (CRYPTO\u2714) is a group-based MAC with a specific algebraic structure. Downgradable AMAC (DAMAC) (CT-RSA\u2719) is an AMAC with a functionality that we can downgrade a message with an authentication tag while retaining validity of the tag. In this paper, we revisit DAMAC for two independent applications, namely downgradable identity-based signatures (DIBS) and trapdoor sanitizable signatures (TSS) (ACNS\u2708). DIBS are the digital signature analogue of downgradable identity-based encryption (CT-RSA\u2719), which allow us to downgrade an identity associated with a secret-key. In TSS, an entity given a trapdoor for a signed-message can partially modify the message while keeping validity of the signature. We show that DIBS can be generically constructed from DAMAC, and DIBS can be transformed into (wildcarded) hierarchical/wicked IBS. We also show that TSS can be generically constructed from DIBS. By instantiating them, we obtain the first wildcarded hierarchical/wicked IBS and the first invisible and/or unlinkable TSS. Moreover, we prove that DIBS are equivalent to not only TSS, but also their naive combination, named downgradable identity-based trapdoor sanitizable signatures

Probing Intergalactic Magnetic Fields in the GLAST Era through Pair Echo Emission from TeV Blazars

More than a dozen blazars are known to be emitters of multi-TeV gamma rays, often with strong and rapid flaring activity. By interacting with photons of the cosmic microwave and infrared backgrounds, these gamma rays inevitably produce electron-positron pairs, which in turn radiate secondary inverse Compton gamma rays in the GeV-TeV range with a characteristic time delay that depends on the properties of the intergalactic magnetic field (IGMF). For sufficiently weak IGMF, such "pair echo" emission may be detectable by the Gamma-ray Large Area Space Telescope (GLAST), providing valuable information on the IGMF. We perform detailed calculations of the time-dependent spectra of pair echos from flaring TeV blazars such as Mrk 501 and PKS 2155-304, taking proper account of the echo geometry and other crucial effects. In some cases, the presence of a weak but non-zero IGMF may enhance the detectability of echos. We discuss the quantitative constraints that can be imposed on the IGMF from GLAST observations, including the case of non-detections.Comment: 4 pages, 3 figures, minor revisions, accepted for publication in APJ

Multi-Dimensional Sub/Super-Range Signatures

In time-specific signatures (TSS) [Paterson \& Quaglia, SCN\u2710] [Ishizaka \& Kiyomoto, ISC\u2720] with $T$ numerical values, each signer is given a secret-key associated with a numerical value $t\in[0,T-1]$ and each signature on a message is generated under a numerical range $[L,R]$ s.t. $0\leq L\leq R\leq T-1$. A signer with $t$ can correctly generate a signature under $[L,R]$ if $t$ is truly included in $[L,R]$, i.e., $t\in[L,R]$. As a generalized primitive of TSS, we propose multi-dimensional \textit{sub}-range signatures (MDSBRS). As a related primitive, we also propose multi-dimensional \textit{super}-range signatures (MDSPRS). In MDSBRS (resp. MDSPRS) with $D\in\mathbb{N}$ dimensions, each secret-key is associated with a set of $D$ ranges $\{[l_i,r_i]\mid i\in[1,D]\}$ s.t. $0 \leq l_i\leq r_i\leq T_i-1$ and a threshold value $d\in[1,D]$, and it correctly produces a signature on any message under a set of $D$ ranges $\{[L_i,R_i]\mid i\in[1,D]\}$ s.t. $0 \leq L_i\leq R_i\leq T_i-1$, if and only if total number of key-ranges every one $[l_i,r_i]$ of which is a \textit{sub}-range (resp. \textit{super}-range) of the corresponded signature-range $[L_i,R_i]$, i.e., $L_i\leq l_i\leq r_i\leq R_i$ (resp. $l_i\leq L_i\leq R_i\leq r_i$), is more than $d-1$. We show that, by extending (or generalizing) an existing TSS scheme, we obtain MDSBRS and MDSPRS schemes each one of which is secure, i.e., existentially unforgeable and perfectly (signer-)private, under standard assumption and asymptotically efficient

Detecting Machine-Translated Text using Back Translation

Machine-translated text plays a crucial role in the communication of people using different languages. However, adversaries can use such text for malicious purposes such as plagiarism and fake review. The existing methods detected a machine-translated text only using the text's intrinsic content, but they are unsuitable for classifying the machine-translated and human-written texts with the same meanings. We have proposed a method to extract features used to distinguish machine/human text based on the similarity between the intrinsic text and its back-translation. The evaluation of detecting translated sentences with French shows that our method achieves 75.0% of both accuracy and F-score. It outperforms the existing methods whose the best accuracy is 62.8% and the F-score is 62.7%. The proposed method even detects more efficiently the back-translated text with 83.4% of accuracy, which is higher than 66.7% of the best previous accuracy. We also achieve similar results not only with F-score but also with similar experiments related to Japanese. Moreover, we prove that our detector can recognize both machine-translated and machine-back-translated texts without the language information which is used to generate these machine texts. It demonstrates the persistence of our method in various applications in both low- and rich-resource languages.Comment: INLG 2019, 9 page

Ectopic development of skeletal muscle induced by subcutaneous transplant of rat satellite cells

The present study analyzes the ectopic development of the rat skeletal muscle originated from transplanted satellite cells. Satellite cells (106 cells) obtained from hindlimb muscles of newborn female 2BAW Wistar rats were injected subcutaneously into the dorsal area of adult male rats. After 3, 7, and 14 days, the transplanted tissues (N = 4-5) were processed for histochemical analysis of peripheral nerves, inactive X-chromosome and acetylcholinesterase. Nicotinic acetylcholine receptors (nAChRs) were also labeled with tetramethylrhodaminelabeled alpha-bungarotoxin. the development of ectopic muscles was successful in 86% of the implantation sites. By day 3, the transplanted cells were organized as multinucleated fibers containing multiple clusters of nAChRs (N = 2-4), resembling those from non-innervated cultured skeletal muscle fibers. After 7 days, the transplanted cells appeared as a highly vascularized tissue formed by bundles of fibers containing peripheral nuclei. the presence of X chromatin body indicated that subcutaneously developed fibers originated from female donor satellite cells. Differently from the extensor digitorum longus muscle of adult male rat (87.9 +/- 1.0 mu m; N = 213), the diameter of ectopic fibers (59.1 mu m; N = 213) did not obey a Gaussian distribution and had a higher coefficient of variation. After 7 and 14 days, the organization of the nAChR clusters was similar to that of clusters from adult innervated extensor digitorum longus muscle. These findings indicate the histocompatibility of rats from 2BAW colony and that satellite cells transplanted into the subcutaneous space of adult animals are able to develop and fuse to form differentiated skeletal muscle fibers.UNIFESP, EPM, Dept Farmacol, BR-04044020 São Paulo, BrazilUNIFESP, EPM, Dept Neurol & Neurocirurgia, BR-04044020 São Paulo, BrazilUNIFESP, EPM, Dept Farmacol, BR-04044020 São Paulo, BrazilUNIFESP, EPM, Dept Neurol & Neurocirurgia, BR-04044020 São Paulo, BrazilWeb of Scienc