Efficient Batch Update of Unique Identifiers in a Distributed Hash Table for Resources in a Mobile Host

Resources in a distributed system can be identified using identifiers based on random numbers. When using a distributed hash table to resolve such identifiers to network locations, the straightforward approach is to store the network location directly in the hash table entry associated with an identifier. When a mobile host contains a large number of resources, this requires that all of the associated hash table entries must be updated when its network address changes. We propose an alternative approach where we store a host identifier in the entry associated with a resource identifier and the actual network address of the host in a separate host entry. This can drastically reduce the time required for updating the distributed hash table when a mobile host changes its network address. We also investigate under which circumstances our approach should or should not be used. We evaluate and confirm the usefulness of our approach with experiments run on top of OpenDHT.Comment: To be presented at the 2010 International Workshop on Cloud Computing, Applications and Technologie

On rational Eisenstein primes and the rational cuspidal groups of modular Jacobian varieties

Let $N$ be a non-squarefree positive integer and let $\ell$ be an odd prime such that $\ell^2$ does not divide $N$. Consider the Hecke ring $\mathbb{T}(N)$ of weight $2$ for $\Gamma_0(N)$, and its rational Eisenstein primes of $\mathbb{T}(N)$ containing $\ell$, defined in Section 3. If $\mathfrak{m}$ is such a rational Eisenstein prime, then we prove that $\mathfrak{m}$ is of the form $(\ell, ~\mathcal{I}^D_{M, N})$, where the ideal $\mathcal{I}^D_{M, N}$ of $\mathbb{T}(N)$ is also defined in Section 3. Furthermore, we prove that $\mathcal{C}(N)[\mathfrak{m}] \neq 0$, where $\mathcal{C}(N)$ is the rational cuspidal group of $J_0(N)$. To do this, we compute the precise order of the cuspidal divisor $\mathcal{C}^D_{M, N}$, defined in Section 4, and the index of $\mathcal{I}^D_{M, N}$ in $\mathbb{T}(N)\otimes \mathbb{Z}_\ell$.Comment: Many arguments are clarified, and many details are filled i

Determining Rights to Resell: Kirtsaeng v. John Wiley & Sons

This commentary previews an upcoming Supreme Court case, Kirtsaeng v. John Wiley & Sons, in which the Court will decide whether the first sale doctrine applies to foreign-made copies. Broadly, the case will determine the ability of manufacturers to control the distribution of foreign-made copies once they have been sold and asks the Court to resolve a circuit split on the correct interpretation of the relevant provisions of the Copyright Act

Comparison of Different Temperatures on Bending Properties of Six Niti Endodontic File Systems

Introduction: Manufacturers claim that modern NiTi files with proprietary heat treatment transform at higher temperatures, thus staying more martensite and being more resistant to cyclic fatigue and more flexible. There are some studies comparing the effect of body temperature and room temperature on cyclic fatigue of these newer NiTi files. However, there is not yet a study published for evaluating the relationship between bending properties of NiTi instruments and temperature following the ISO 3630-1 guideline. The objective of this study was to evaluate how temperature affects the bending properties of six different brands of NiTi rotary instruments with different transformation temperature ranges. Methods: Six commercially available NiTi files were selected for this experiment. The tested files included K3 40/.04 (Sybron Endo, Orange, CA), ProFile Series 29 Green Size 6 (Dentsply Tulsa Dental Specialties), K3XF 40/.04 (Sybron Endo, Orange, CA), Vortex Blue 40/.04 (Dentsply Tulsa Dental Specialties), ProFile Vortex 40/.04 (Dentsply Tulsa Dental Specialties), and HyFlex CM™ 40/.04 (Coltène/Whaledent Inc., Cuyahoga Falls, OH). The Austenite finish temperatures of the files were 9.6 ± 0.5, 17.6 ± 0.6, 24.9 ± 1.1, 35.4 ± 1.2, 45.7 ± 0.9, and 60.3 ± 3.1, respectively. The bending properties of the files were measured using a torsiometer (Sa bri Dental Enterprises, Inc. Downers Grove IL) following ISO 3630-1 guidelines. Twelve of each file type were grouped into 3 groups based on temperatures. Each temperature group had a total of 72 files. Group 1 measured the bending moment (g.cm) at 9±2°C, group 2 at 23±2°C, and group 3 at 35±2°C. The data was statistically analyzed by ANOVA and post hoc HSD (P\u3c0.05) Results: For all tested files, the bending moment of the files increased as the temperature rose from 9to 23 to 35°C. At all temperatures, HyFlex CM was significantly more flexible than other files. ProFile Vortex, K3XF, and Vortex Blue showed similar flexibility with each other. They were significantly more flexible than ProFile Series 29, which was significantly more flexible than K3. Conclusion: Testing temperature and brand of the files were significant independent variables affecting the flexibility of the files