Linear secret sharing schemes protect secret information from leakage and destruction by encoding secret information into multiple shares, where the secret information can be reconstructed by ...collecting a certain subsets of shares. Perfect Security, <inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>-strong Security, and Individual Security (IS) have been given as security measures of linear secret sharing schemes. Consider the threshold for each security measure, which is defined as the maximum allowable size of the set of leaked shares. Kurihara et al. have revealed that thresholds for Perfect Security and <inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>-strong Security are characterized in terms of a relative code parameter Relative Generalized Hamming Weight (RGHW). However, the threshold for IS is not yet characterized. In this paper, we focus on individual elements of secret information and give the threshold for IS (Individual Security Threshold IST) as a new security measure, where each element of secret information cannot be uniquely determined from subsets of shares with size less than or equal to the IST. We show that the IST can be characterized in terms of RGHW as well as Perfect Security and <inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>-strong Security. We also give a precoding method for secret information that can guarantee IST above a certain value in any existing linear secret sharing schemes. Moreover, we extend the notion of the IST to universal secure network coding (USNC) and present the Universal IST. We also show that the Universal IST can be represented by the code parameter Relative Generalized Rank Weight (RGRW) similarly to the IST of the linear secret sharing schemes.
By extending the notion of minimum rank distance, this paper introduces two new relative code parameters of a linear code C 1 of length n over a field extension F q m and its subcode C 2 ⊆ C 1 . One ...is called the relative dimension/intersection profile (RDIP), and the other is called the relative generalized rank weight (RGRW). We clarify their basic properties and the relation between the RGRW and the minimum rank distance. As applications of the RDIP and the RGRW, the security performance and the error correction capability of secure network coding, guaranteed independently of the underlying network code, are analyzed and clarified. We propose a construction of secure network coding scheme, and analyze its security performance and error correction capability as an example of applications of the RDIP and the RGRW. Silva and Kschischang showed the existence of a secure network coding in which no part of the secret message is revealed to the adversary even if any dim C 1 -1 links are wiretapped, which is guaranteed over any underlying network code. However, the explicit construction of such a scheme remained an open problem. Our new construction is just one instance of secure network coding that solves this open problem.
To understand how we can maximize the fabrication yield, we study the fluctuations of the cavity parameters of an ultralow-threshold Raman Si laser that employs two high-quality resonant modes of a ...photonic crystal heterostructure nanocavity. We measure the quality (Q) factors, the resonant wavelengths (λ), and the frequency spacing between the resonant modes (Δf) for 40 nanocavity-based Raman Si lasers with the same design. The Q, λ, and Δf fluctuate due to random variations of the cavity geometry and we find that 12 out of 40 devices provide laser emission. While the fluctuations of Q and λ in these 12 cavities are basically the same as those in the other 28 cavities, the detuning between Δf and the Raman shift of Si for the 12 cavities is less than 0.024 THz, which is strictly smaller than the detuning for the other 28 cavities. A large fluctuation of Δf is, thus, detrimental for the yield of Raman Si lasers. Numerical simulations reveal that a decrease in the random variations of the air hole positions and radii is important for high yields.
In this study, a conventional precipitation-hardened A6061-T6 alloy (base alloy) and a modified alloy containing excess solute magnesium (Mg) compared to the base alloy were compared in terms of ...high-cycle fatigue property. Particular attention was paid to the emergence of a distinct knee point on the fatigue life diagram together with a time-dependent strengthening (coaxing) effect in the modified alloy under various test conditions. An attempt using specimens with different defect size successfully revealed that a distinct knee, which was absent in the base alloy, was attributed to the threshold against small crack growth. The clear coaxing effect in the modified alloy was also explicitly confirmed in terms of the high ΔK value achieved by the arrested cracks regardless of the defect size. The comparative tests conducted under different environments and temperature conditions further confirmed that the crack tip strengthening, essentially caused by the strain-aging capability endowed to the modified alloy, operated most prominently in the ambient air at room temperature. Such results were rationally interpreted by incorporating a competitive interaction of solute Mg and hydrogen (H) with dislocations at the crack tip.
This paper investigates an adversarial model in the scenario of private information retrieval (PIR) from n coded storage servers, called Byzantine adversary. The Byzantine adversary is defined as the ...one altering b server responses and erasing u server responses to a user's query. In this paper, two types of Byzantine adversaries are considered; 1) the classic omniscient type that has the full knowledge on n servers as considered in existing literature, and 2) the reasonable limited-knowledge type that has information on only b+u servers, i.e., servers under the adversary's control. For these two types, this paper reveals that the resistance of a PIR scheme, i.e., the condition of b and u to correctly obtain the desired message, can be expressed in terms of a code parameter called the coset distance of linear codes employed in the scheme. For the omniscient type, the derived condition expressed by the coset distance is tighter and more precise than the estimation of the resistance by the minimum Hamming weight of the codes considered in existing researches. Furthermore, this paper also clarifies that if the adversary is limited-knowledge, the resistance of a PIR scheme could exceed that for the case of the omniscient type. Namely, PIR schemes can increase their resistance to Byzantine adversaries by allowing the limitation on adversary's knowledge.
The aim of the study was to investigate risk factors for surgical site infection (SSI) at the recipient site in oral cancer resection surgery with neck dissection and reconstruction using a free or ...pedicled myocutaneous flap.
Eighty-eight patients who underwent this procedure composed a nonrandomized retrospective cohort.
Recipient site SSIs occurred in 27 patients (30.7%). In multivariate analysis, flap necrosis (partial or total; P = .003; odds ratio OR = 12.8) and preoperative hypoalbuminemia (P = .025; OR = 3.9) were independent risk factors for recipient site SSI. In an analysis restricted to flap survival cases, free flap (vs pedicled flap; P = .026; OR = 25.0) and preoperative hypoalbuminemia (P = .014; OR = 11.0) were significant risk factors for recipient site SSI.
These results suggest that different preoperative nutritional interventions, such as a diet enriched with energy and protein, oral nutritional supplements, and, in patients with compromised swallow, enteral tube feeding or parenteral nutrition, could be important to decrease the frequency of recipient site SSIs. Pedicled and free flaps might result in SSIs for different reasons. Partial necrosis occurred more often with pedicled flaps than with free flaps and it might be important to use different techniques to decrease skin flap necrosis to lower the rate of SSIs.
Due to the legal reform on the protection of personal information in US/Japan and the enforcement of the General Data Protection Regulation (GDPR) in Europe, service providers are obliged to more ...securely manage the sensitive data stored in their server. In order to protect this kind of data, they generally employ a cryptographic encryption scheme and secure key management schemes such as a Hardware Security Module (HSM) and Trusted Platform Module (TPM). In this paper, we take a different approach based on the space-hard cipher. The space-hard cipher has an interesting property called the space hardness. Space hardness guarantees sufficient security against the adversary who gains a part of key data, e.g., 1/4 of key data. Combined with a simple network monitoring technique, we develop a practical leakage resilient scheme Virtual Vault, which is secure against the snapshot adversary who has full access to the memory in the server for a short period. Importantly, Virtual Vault is deployable by only a low-price device for network monitoring, e.g. L2 switch, and software of space-hard ciphers and packet analyzer, while typical solutions require a dedicated hardware for secure key managements such as HSM and TPM. Thus, Virtual Vault is easily added on the existing servers which do not have such dedicated hardware.
A clear cell variant of calcifying epithelial odontogenic tumor (CCEOT) affecting an extraosseous site is described. A 60-year-old male patient presented with gingival swelling on the lingual side of ...the anterior mandible. The results of biopsy suggested clear cell odontogenic carcinoma, and marginal resection of the mandible was performed. The resected specimen was composed of eosinophilic and clear cells with deposits of amyloid-like material. The clear cells exhibited granules that were positive for PAS. There was no calcification in the resected lesion. Based on these features, the conclusive diagnosis was peripheral CCEOT without calcification. No signs of recurrence were evident after 3 years of follow-up.
The primary purpose of this study was to develop survey questions to evaluate children’s ability to design experiments. The second purpose was to empirically examine how teaching to encourage ...critical thinking using Kishida and Ogura’s (2018) “watchwords for scientific experiments” affects children’s ability to plan experiments. In order to achieve these purposes, we used the experimental design confirmation sheet and experimental design worksheet we developed to teach the 6th grade elementary school science class, “Nature of Aqueous Solutions,” and also investigated the actual conditions of the students using survey questions and questionnaires. The results showed that there was no significant difference between the groups in the pre-survey question mean scores, but there was a significant difference in the post-survey question mean scores. There was also a significant increase in the mean score of the experimental design worksheet for the experimental group. In conclusion, we believe that the survey questions developed in this study can be applied to evaluate children’s ability to plan experiments. In addition, by repeating the activities of formulating an experiment plan using the experiment design confirmation sheet and experimental design worksheet created in this research, more critical thinking will be exercised to check whether the experiment plan is scientific.
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