Demonstration of Sustainable Development of Groundwater through Aquifer Storage and Recovery (ASR)

Water Resources Management - Sustained pumping of groundwater can lead to declining water levels in wellfields and concerns regarding the sustainability of groundwater resources. Aquifer Storage...     

Superfluids in confined geometries: Fourth sound and other modes

The hydrodynamics of superfluids in confined geometries (capillaries, porous media, etc.) is investigated theoretically. Hydrodynamic equations are derived. The mode structure is calculated, i.e., explicit expressions for the dispersion relationsq=q() are given. Experimental applications for⁴He-II and superfluid³He are discussed.     

Algorithms for processing the group K nearest-neighbor query on distributed frameworks

Distributed and Parallel Databases - Given two datasets of points (called Query and Training), the Group (K) Nearest-Neighbor (GKNN) query retrieves (K) points of the Training with the smallest sum...     

Ensuring reliability in B2B services: Fault tolerant inter-organizational workflows

In the age of Business-to-Business (B2B) collaboration, ensuring reliability of workflows underlying inter-organizational business processes is of significant importance. There are, however, quite a few challenges towards achieving seamless operation. Such challenges arise from heterogeneity in infrastructure and coordination mechanism at participant organizations, as well as time and cost associated with recovery from failure. Our research presents foundations for a reliable scheme for recovery from failure of workflow processes spanning through multiple business entities. First, a system model is adapted from the mobile computing literature that serves to establish the requirements to be enforced by each participating organization. In our model, we adopt the Maximal Sequence Path (MSP) approach from Yoo et al. (Lecture Notes in Artificial Intelligence 2132:222–236, 2001), as a means of decomposing workflows into mobile agent-driven processes that communicate via web services at each organization. This decomposition ensures defining logical points within the dynamics of a workflow instance for locating accurate and consistent states of the system for recovery in case of a failure. Then, a set of algorithms for various business scenarios are developed and presented as practical solutions. These algorithms are shown to create checkpoints such that the system is always in a globally consistent state. As such, these algorithms constitute a set of standards that can be incorporated in business process management suites that support reliable inter-organizational collaboration.     

More on Goddard and the Kallikak family photographs.

Discusses retouching of the Kallikak family photographs in H. H. Goddard's (1912) study of mental retardation and heredity, with reference to analyses by R. E. Fancher (see record 1987-31600-001) and S. J. Gould (1981), and concurs with Fancher that the retouching was probably not done for deceitful purposes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On finding optimal and near-optimal lineal spanning trees

The search for good lineal, or depth-first, spanning trees is an important aspect in the implementation of a wide assortment of graph algorithms. We consider the complexity of findingoptimal lineal spanning trees under various notions of optimality. In particular, we show that several natural problems, such as constructing a shortest or a tallest lineal tree, are NP-hard. We also address the issue of polynomial-time, near-optimization strategies for these difficult problems, showing that efficient absolute approximation algorithms cannot exist unlessP = NP.     

Throughput of a satellite channel communication

Summary The throughput of a satellite channel communication is depending upon the link protocol. It is well known that the classical HDLC protocol is inadequate when applied to satellite links instead of short terrestrial links. Several modifications have been proposed to overcome this problem. The present paper gives an analysis and evaluation of a new class of protocols called Virtual Subchannel schemes which splits the satellite link into several components; these subchannels are assigned for transmission in cyclic order and are controlled independently of each other by the classical HDLC procedure.     

Improving the performance of Invertible Bloom Lookup Tables

Invertible Bloom Lookup Tables (IBLTs) have been recently introduced as an extension of traditional Bloom filters. IBLTs store key-value pairs. Unlike traditional Bloom filters, IBLTs support both a lookup operation (given a key, return a value) and an operation that lists out all the key-value pairs stored. One issue with IBLTs is that there is a probability that a lookup operation will return “not found” for a key. In this paper, a technique to reduce this probability without affecting the storage requirement and only moderately increasing the search time is presented and evaluated. The results show that it can significantly reduce the probability of not returning a value that is actually stored in the IBLT. The overhead of the modified search procedure, compared to the standard IBLT search procedure, is small and has little impact on the average search time.     

The Role of Cations in Some Inorganic Hydrolysis Reactions

Cations which shift certain equilibria from left to right by forming a compound with one of the reaction products were investigated with respect to their kinetic role in the process. Silver ions have no influence on the rate of the hydrolysis of cyanogen iodide. Similarly, cations which form sparingly soluble carbonates do not influence the rate of hydration of carbon dioxide. On the other hand, the hydrolysis of chlorine is accelerated by Ag⁺ and, to a lesser extent, by Cd²⁺ and Fe(III). It is shown that the effect is not due simply to a bimolecular reaction between chlorine and the cation. In the case of Ag⁺, heterogeneous catalysis may play some role, in analogy with the solvolysis of organic halides. In the case of Cd²⁺, there is spectrophotometric evidence for compounds between Cl₂ and HOCl on the one hand, and the cation on the other. It is suggested that these compounds interconvert more rapidly than do the parent substances. A similar mechanism may be operative in the case of Fe(III), and, possibly, also in the case of Ag⁺.