180 research outputs found

    Optimized Prediction of Fluency of L2 English Based on Interpretable Network Using Quantity of Phonation and Quality of Pronunciation

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    This paper presents results of a joint project between an engineering team of a university and an educational team of another to develop an online fluency assessment system for Japanese learners of English. A picture description corpus of English spoken by 90 learners and 10 native speakers was used, where fluency was rated by other 10 native raters for each speaker manually. The assessment system was built to predict the averaged manual scores. For system development, a special focus was put on two separate purposes. The assessment system was trained in such an analytical way that teachers can know and discuss which speech features contribute more to fluency prediction, and in such a technical way that teachers' knowledge can be involved for training the system, which can be further optimized using an interpretable network. Experiments showed that quality-of-pronunciation features are much more helpful than quantity-of-phonation features, and the optimized system reached an extremely high correlation of 0.956 with the averaged manual scores, which is higher than the maximum of inter-rater correlations (0.910)

    Doping Dependence on Two Sizes of Superconducting Gaps on Tl1223 by Tunneling Spectroscopy at 4.2K

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    AbstractWe present tunneling results on tri-layered cuprate superconductors TlBa2Ca2Cu3O8.5+δ (Tl1223) with two different hole concentration, which are an over-doped Tl1223 with TC ∼ 112K (OD-112K) and a slightly over-doped Tl1223 with TC ∼ 126K (SOD-126K). The tunneling conductances on both samples exhibited two sizes of gaps originated from outer (OP) and inner (IP) CuO2 planes. The superconducting gap at each planes, Δ(OP)/e ≈ Vp(OP) and Δ(IP)/e ≈ Vp(IP) on OD-112K are observed that Vp(OP) is 22 ± 2mV and Vp(IP) is 37 ± 4mV. Similarly, Vp(OP) is 26 ± 2mV and Vp(IP) is 39 ± 3mV on SOD-126K. Although both Vp(OP) and Vp(IP) decrease with increasing oxygen contents, ΔVp(OP) = Vp(OP)(SOD-126K) - Vp(OP)(OD-112K) is larger than ΔVp(IP) for IP. Moreover, ΔVp(plane) Vp(IP) - Vp(OP) increases with overdoping. These results as a function of doping implies the OP might control the variation of TC dominantly

    Tweakable HCTR: A BBB Secure Tweakable Enciphering Scheme

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    \textsf{HCTR}, proposed by Wang et al., is one of the most efficient candidates of tweakable enciphering schemes that turns an nn-bit block cipher into a variable input length tweakable block cipher. Wang et al. have shown that \textsf{HCTR} offers a cubic security bound against all adaptive chosen plaintext and chosen ciphertext adversaries. Later in FSE 2008, Chakraborty and Nandi have improved its bound to O(σ2/2n)O(\sigma^2 / 2^n), where σ\sigma is the total number of blocks queried and nn is the block size of the block cipher. In this paper, we propose \textbf{tweakable \textsf{HCTR}} that turns an nn-bit tweakable block cipher to a variable input length tweakable block cipher by replacing all the block cipher calls of \textsf{HCTR} with tweakable block cipher. We show that when there is no repetition of the tweak, tweakable \textsf{HCTR} enjoys the optimal security against all adaptive chosen plaintext and chosen ciphertext adversaries. However, if the repetition of the tweak is limited, then the security of the construction remains close to the security bound in no repetition of the tweak case. Hence, it gives a graceful security degradation with the maximum number of repetition of tweaks

    Analysis of comorbid factors that increase the COPD assessment test scores

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    Background: The chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) is a concise health status measure for COPD. COPD patients have a variety of comorbidities, but little is known about their impact on quality of life. This study was designed to investigate comorbid factors that may contribute to high CAT scores. Methods: An observational study at Keio University and affiliated hospitals enrolled 336 COPD patients and 67 non-COPD subjects. Health status was assessed by the CAT, the St. Georges Respiratory Questionnaire (SGRQ), and all components of the Medical Outcomes Study Short-Form 36-Item (SF-36) version 2, which is a generic measure of health. Comorbidities were identified based on patients’ reports, physicians’ records, and questionnaires, including the Frequency Scale for the Symptoms of Gastro-esophageal reflux disease (GERD) and the Hospital Anxiety and Depression Scale. Dual X-ray absorptiometry measurements of bone mineral density were performed. Results: The CAT showed moderate-good correlations with the SGRQ and all components of the SF-36. The presence of GERD, depression, arrhythmia, and anxiety was significantly associated with a high CAT score in the COPD patients. Conclusions: Symptomatic COPD patients have a high prevalence of comorbidities. A high CAT score should alert the clinician to a higher likelihood of certain comorbidities such as GERD and depression, because these diseases may co-exist unrecognize

    Beyond Birthday Bound Secure MAC in Faulty Nonce Model

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    Encrypt-then-MAC (EtM) is a popular mode for authenticated encryption (AE). Unfortunately, almost all designs following the EtM paradigm, including the AE suites for TLS, are vulnerable against nonce misuse. A single repetition of the nonce value reveals the hash key, leading to a universal forgery attack. There are only two authenticated encryption schemes following the EtM paradigm which can resist nonce misuse attacks, the GCM-RUP (CRYPTO-17) and the GCM/2+ (INSCRYPT-12). However, they are secure only up to the birthday bound in the nonce respecting setting, resulting in a restriction on the data limit for a single key. In this paper we show that nEHtM, a nonce-based variant of EHtM (FSE-10) constructed using a block cipher, has a beyond birthday bound (BBB) unforgeable security that gracefully degrades under nonce misuse. We combine nEHtM with the CENC (FSE-06) mode of encryption using the EtM paradigm to realize a nonce-based AE, CWC+. CWC+ is very close (requiring only a few more xor operations) to the CWC AE scheme (FSE-04) and it not only provides BBB security but also gracefully degrading security on nonce misuse

    Trick or Tweak: On the (In)security of OTR’s Tweaks

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    Tweakable blockcipher (TBC) is a powerful tool to design authenticated encryption schemes as illustrated by Minematsu\u27s Offset Two Rounds (OTR) construction. It considers an additional input, called tweak, to a standard blockcipher which adds some variability to this primitive. More specifically, each tweak is expected to define a different, independent pseudo-random permutation. In this work we focus on OTR\u27s way to instantiate a TBC and show that it does not achieve such a property for a large amount of parameters. We indeed describe collisions between the input masks derived from the tweaks and explain how they result in practical attacks against this scheme, breaking privacy, authenticity, or both, using a single encryption query, with advantage at least 1/4. We stress however that our results do not invalidate the OTR construction as a whole but simply prove that the TBC\u27s input masks should be designed differently

    Genetic variation in TIMP1 but not MMPs predict excess FEV1 decline in two general population-based cohorts

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    BACKGROUND: An imbalance in matrix metalloproteases (MMPs) and tissue inhibitors of MMPs (TIMPs) contributes to chronic obstructive pulmonary disease (COPD) development. Longitudinal studies investigating Single Nucleotide Polymorphisms (SNPs) in MMPs and TIMPs with respect to COPD development and lung function decline in the general population are lacking. METHODS: We genotyped SNPs in MMP1 (G-1607GG), MMP2 (-1306 C/T), MMP9 (3 tagging SNPs), MMP12 (A-82G and Asn357Ser) and TIMP1 (Phe124Phe and Ile158Ile) in 1390 Caucasians with multiple FEV1 measurements from a prospective cohort study in the general population. FEV1 decline was analyzed using linear mixed effect models adjusted for confounders. Analyses of the X-chromosomal TIMP1 gene were stratified according to sex. All significant associations were repeated in an independent general population cohort (n=1152). RESULTS: MMP2 -1306 TT genotype carriers had excess FEV1 decline (-4.0 ml/yr, p=0.03) compared to wild type carriers. TIMP1 Ile158Ile predicted significant excess FEV1 decline in both males and females. TIMP1 Phe124Phe predicted significant excess FEV1 decline in males only, which was replicated (p=0.10) in the second cohort. The MMP2 and TIMP1 Ile158Ile associations were not replicated. Although power was limited, we did not find associations with COPD development. CONCLUSIONS: We for the first time show that TIMP1 Phe124Phe contributes to excess FEV1 decline in two independent prospective cohorts, albeit not quite reaching conventional statistical significance in the replication cohort. SNPs in MMPs evidently do not contribute to FEV1 decline in the general population

    Pathology of the human pituitary adenomas

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    This article describes pertinent aspects of histochemical and molecular changes of the human pituitary adenomas. The article outlines individual tumor groups with general, specific and molecular findings. The discussion further extends to the unusual adenomas or carcinomas. The description in this article are pertinent not only for the practicing pathologists who are in the position of making proper diagnosis, but also for the pituitary research scientists who engage in solving basic problems in pituitary neoplasms by histochemistry and molecular biology

    A New Algorithm for the Unbalanced Meet-in-the-Middle Problem

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    A collision search for a pair of nn-bit unbalanced functions (one is RR times more expensive than the other) is an instance of the meet-in-the-middle problem, solved with the familiar standard algorithm that follows the tradeoff TM=NTM=N, where TT and MM are time and memory complexities and N=2nN=2^n. By combining two ideas, unbalanced interleaving and Oorschot-Wiener parallel collision search, we construct an alternative algorithm that follows T2M=R2NT^2 M = R^2 N, where MRM\le R. Among others, the algorithm solves the well-known open problem: how to reduce the memory of unbalanced collision search
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