5576984
Real-Time Mining of Partial Periodic Patterns
27963436
Optimistic similarity-based real-time concurrency control
Serializability is unnecessarily strict for real-time systems because most transactions in such systems occur periodically and changes among data values over a few consecutive periods are often insignificant. Hence, data values produced within a short interval can be treated as "similar" and interchangeable. This notion of similarity allows higher concurrency than serializability. The author discusses a similarity-based optimistic real-time concurrency control protocol. The protocol can outperform the similarity stack protocol (SSP) and does not rely on prior knowledge of worst-case execution time (WCET) and data requirements of transactions. Moreover, when similarity is not applicable, the protocol can be reduced to the ordinary optimistic protocol and accept serializable histories.
7497035
A Lower Bound for the Number of Edges in a Graph Containing No Two Cycles of the Same Length
In 1975, P. Erdős proposed the problem of determining the maximum number $f(n)$ of edges in a simple graph of $n$ vertices in which any two cycles are of different lengths. In this paper, it is proved that $$f(n)\geq n+32t-1$$ for $t=27720r+169 \,\ (r\geq 1)$ and $n\geq {{6911}\over {16}}t^{2}+{{514441}\over {8}}t-{{3309665}\over {16}}$. Consequently, $\liminf _{n \to \infty} {f(n)-n \over \sqrt n} \geq \sqrt {2 + {2562 \over 6911}}.$
11729796
Ecodynamics and Dissolved Gas Chemistry Routines for Ocean Circulation Models
Abstract Interactions between oceanic nitrate ecology and circulation determine the marine distribution of dissolved, climate relevant trace gases such as dimethyl sulfide (DMS) and carbonyl sulfide (OCS), and a variety of hydrocarbons. Our group is constructing a suite of ecosystem/reaction/transport models, which link nitrate to the chemistry of volatiles near the sea–air interface. In this paper, we describe programs which will be inserted into the high resolution Parallel Ocean Program. Major features of the coding include: (1) ecodynamics represented in seven biological compartments (phytoplankton, zooplankton, bacteria, detritus, nitrate, ammonium and dissolved organic nitrogen). Light limited primary production is computed, along with nitrogen cycling among the bioentities. (2) Photochemistry for the volatile species DMS, OCS, the methyl halides, nonmethane hydrocarbons (NMHC) and ammonia. DMS and the halides are emitted by phytoplankton, while OCS and NMHC are produced by photolysis of dissolved organic material. Ammonia is exuded by animals and bacteria. Removal mechanisms for the gases include consumption by organisms, hydrolysis, chlorination and interfacial transfer. (3) Explicit, efficient and mass conserving numerical solutions for the biological and chemical continuity equations. Production and loss forms are generalized and automated so that they are readily applied to new constituents. Ecology and the chemical transformations are exposed qualitatively to begin, and are then expressed as differential and differencing equations. The structure of the program is described in terms of the major subroutines and their purposes. Results are provided from both one- and three-dimensional sample runs. Computational aspects such as performance and code availability are discussed.
8193810
On the size of graphs with all cycle having distinct length
Abstract Let ƒ(n) be the maximum number of edges in a graph on n vertices in which no two cycles have the same length. In 1975, Erdős raised the question of determining ƒ(n ) (see Bondy and Murty (1976)). In this note, we prove that for n ⩾36·5 t 2 −4·5 t +1 one has ƒ(n)⩾n+9t−1 . We conjecture that lim (ƒ(n)−n)/√n⩽√3 .
5168740
The challenges in developing digital collections of phonograph records
To facilitate long-term preservation and sustain the utility of phonograph records, an efficient and economical workflow management system for digitization is necessary. We describe in this paper the digitization process for building an online digital collection of phonograph records and our procedure for creating the ground-truth data, which is essential for developing an efficient metadata and content capturing system. We also discuss the challenges of defining metadata for phonograph records and their packaging to enhance access and use across traditional boundaries