Fine-grain Method Research Articles

Fine-grain watermarking for intellectual property protection

The current online digital world, consisting of thousands of newspapers, blogs, social media, and cloud file sharing services, is providing easy and unlimited access to a large treasure of text contents. Making copies of these text contents is simple and virtually costless. As a result, producers and owners of text content are interested in the protection of their intellectual property (IP) rights. Digital watermarking has become crucially important in the protection of digital contents. Out of all, text watermarking poses many challenges, since text is characterized by a low capacity to embed a watermark and allows only a restricted number of alternative syntactic and semantic permutations. This becomes even harder when authors want to protect not just a whole book or article, but each single sentence or paragraph, a problem well known to copyright law. In this paper, we present a fine-grain text watermarking method that protects even small portions of the digital content. The core method is based on homoglyph characters substitution for latin symbols and whitespaces. It allows to produce a watermarked version of the original text, preserving the anonymity of the users according to the right to privacy. In particular, the embedding and extraction algorithms allow to continuously protect the watermark through the whole document in a fine-grain fashion. It ensures visual indistinguishability and length preservation, meaning that it does not cause overhead to the original document, and it is robust to the copy and past of small excerpts of the text. We use a real dataset of 1.8 million New York articles to evaluate our method. We evaluate and compare the robustness against common attacks, and we propose a new measure for partial copy and paste robustness. The results show the effectiveness of our approach providing an average length of 101 characters needed to embed the watermark and allowing to protect paragraph-long excerpt or smaller the 94.5% of the times.

Social and urban form determinants of vehicle ownership; evidence from a developing country

The car is the most preferred mode of travel among middle and high-income urban residents in Iran, where the car ownership has been growing at a rate of 15% per year and the evidence shows that vehicle ownership and use are strongly supported by urban development patterns. However, the specification of this relationship is not the same as western societies. Thus, this paper investigates the vehicle ownership and usage in three residential neighborhoods of Shiraz, a city in the southwest of Iran and its association to urban form characteristics and development pattern. The data on land use and urban form characteristics were primarily extracted from the existing secondary sources and GIS but in a disaggregated fine-grain method, whereas the data on household characteristics and vehicle ownership were purposefully collected through a household questionnaire survey. A nested logit model (NLM) based on the Discrete Choice Theory (DCT) was then applied to explore the impacts of socio-economic status (SES) and urban form factors on the car ownership choices of households. The results and the associated policy implications can be helpful in defining a strategic framework for community planning and design in order to reduce the level of car ownership and usage.

A Matrix Partitioning Interface to PaToH in MATLAB

We present the PaToH MATLAB Matrix Partitioning Interface. The interface provides support for hypergraph-based sparse matrix partitioning methods which are used for efficient parallelization of sparse matrix–vector multiplication operations. The interface also offers tools for visualizing and measuring the quality of a given matrix partition. We propose a novel, multilevel, 2D coarsening-based 2D matrix partitioning method and implement it using the interface. We have performed extensive comparison of the proposed method against our implementation of orthogonal recursive bisection and fine-grain methods on a large set of publicly available test matrices. The conclusion of the experiments is that the new method can compete with the fine-grain method while also suggesting new research directions.

Luminescence chronology of non‐glacial sediments in Changeable Lake, Russian High Arctic, and implications for limited Eurasian ice‐sheet extent during the LGM

AbstractA 10.5 m core from Changeable Lake in the Severnaya Zemlya Archipelago just north of the Taymyr Peninsula intersects ca. 30 cm of diamicton at its base, interpreted as a basal till. Because the upper 10.13 m of this core consists of non‐glacial sediments, a maximum numeric age for these non‐glacial sediments would provide a clear lower limit to the timing of the last glaciation in the area of Changeable Lake. Radiocarbon (14C) dating of several materials from this core yielded widely scattered results. Consequently we applied photonic dating to sediments above the diamicton. The experimental single‐aliquot‐regenerative (SAR) dose fine‐grain method was applied to two samples, using the ‘double SAR’ approach. With one exception, these fine‐grain SAR results and the results of application of the SAR method to sand‐sized quartz grains from two samples, at ca. 9.95 m and ca. 10.05 m depth, are discrepant with age estimates from the multi‐aliquot infrared‐photon‐stimulated luminescence (IR‐PSL) method applied to fine grains. Multi‐aliquot IR‐PSL dating of 10 samples produces ages increasing monotonically from ca. 4 ka at 2 m to 53 ± 4 ka at 9.97 m. These self‐consistent multi‐aliquot IR‐PSL ages, along with limiting 14C ages of >47 ka at ca. 10 m, provide direct evidence that glacial ice did not advance over this lake basin during the Last Glacial Maximum, and thus delimit the northeastern margin of the Barents–Kara Sea ice‐sheet to somewhere west of this archipelago. The last regional glaciation probably occurred during marine isotope stage (MIS) 4 or earlier. Copyright © 2004 John Wiley & Sons, Ltd.

Parallel, multigrain iterative solvers for hiding network latencies on MPPs and networks of clusters

Parallel iterative solvers are often the only means of solving large linear systems and eigenproblems. However, these solvers are usually implemented in a fine-grain manner and can incur significant performance penalties due to synchronization overheads on large MPPs. This problem is exacerbated in clusters of workstations (COWs) and SMPs that are interconnected via a hierarchy of networks. In this paper, we describe a novel scheme for hiding the synchronization overheads, and thus improving scalability, of block iterative solvers that employ a correction equation through an inner iterative method. Block methods are not only robust in the presence of eigenvalue multiplicities and multiple right-hand sides, but provide better latency tolerance by performing more floating-point operations between synchronizations. We take a different approach to inducing latency tolerance by increasing the granularity at which the correction equation is solved for each block vector. This is accomplished by splitting the processors into smaller subgroups which are then used to solve the correction for each block vector concurrently. The rest of the algorithm is still performed in fine grain. We call this combination of fine and coarse-grain parallelism multigrain parallelism. We implemented a multigrain, block Jacobi–Davidson algorithm for computing the extreme eigenvalues of a symmetric matrix. We obtained improvements of 45–50% over both the block and non-block implementations of the fine-grain method when testing on an IBM SP and on a collection of clusters of Sun workstations.

Thermoluminescence dating of archaeological artefacts from the Middle Neolithic, Bronze Age and the Roman Empire period.

Thermoluminescence (TL) dating was applied for artefacts found near the small village of Michelstetten, Lower Austria. Settlements in this region can be traced hack a long time and, according to archaeologists, the discovered artefacts may be as old as 6000 years. A modified sample preparation technique based on the fine-grain method was developed. This technique results in a higher reproducibility and reduces the overall preparation time. For some artefacts the new information of the TL dating leads to an unforeseen re-interpretation of the archaeological age. Furthermore, an iron furnace from the period of the Roman Empire could be dated. For the first time, it was possible to estimate correctly the point of time of the burn-down of an ancient wooden house via an analysis of the house's clay plaster. The fire took place in the sixth century; this was confirmed by dating ceramic artefacts.