A high-performance distributed algorithm for mining association rules

We present a new distributed association rule mining (D-ARM) algorithm that demonstrates superlinear speed-up with the number of computing nodes. The algorithm is the first D-ARM algorithm to perform a single scan over the database. As such, its performance is unmatched by any previous algorithm. Scale-up experiments over standard synthetic benchmarks demonstrate stable run time regardless of the number of computers. Theoretical analysis reveals a tighter bound on error probability than the one shown in the corresponding sequential algorithm. As a result of this tighter bound and by utilizing the combined memory of several computers, the algorithm generates far fewer candidates than comparable sequential algorithms—the same order of magnitude as the optimum.     

Software Distributed Shared Memory: a VIA‐based implementation and comparison of sequential consistency with home‐based lazy release consistency

A Distributed Shared Memory (DSM) system provides a distributed application with a shared virtual address space. This article proposes a design for implementing the DSM communication layer on top of the Virtual Interface Architecture (VIA), an industry standard for user‐level networking protocols on high‐speed clusters. User‐level communication protocols operate in user mode, thus removing the operating system kernel's overhead from the critical communication pass, and significantly diminishing communication overhead as a result. We analyze VIA's facilities and limitations in order to ascertain which implementation trade‐offs can be best applied to our development of an efficient communication substrate optimized for DSM requirements. We then implement a multithreaded version of the Home‐based Lazy Release Consistency (HLRC) protocol on top of this substrate. In addition, we compare the performance of this HLRC protocol with that of the Sequential Consistency (SC) protocol in which a Multi View (MV) memory mapping technique was used. This technique enables a fine‐grained access to shared memory, while still relying on the virtual memory hardware to track memory accesses. We perform an ‘apple‐to‐apple’ comparison on the same testbed environment and benchmark suite, and investigate the effectiveness and scalability of both protocols. Copyright © 2005 John Wiley & Sons, Ltd.     

A Scalable Parallel Algorithm for Reachability Analysis of Very Large Circuits

This paper presents a scalable method for parallelizing symbolic reachability analysis on a distributed-memory environment of workstations. We have developed an adaptive partitioning algorithm that significantly reduces space requirements. The memory balance is maintained by dynamically repartitioning the state space throughout the computation. A compact BDD representation allows coordination by shipping BDDs from one machine to another. This representation allows for different variable orders in the sending and receiving processes. The algorithm uses a distributed termination protocol, with none of the memory modules preserving a complete image of the set of reachable states. No external storage is used on the disk. Rather, we make use of the network, which is much faster.We implemented our method on a standard, loosely-connected environment of workstations, using a high-performance model checker. Initial performance evaluation of several large circuits shows that our method can handle models too large to fit in the memory of a single node. The partitioning algorithm achieves reduction in space, which is linear in the number of workstations employed. A corresponding decrease in space requirements is measured throughout the reachability analysis. Our results show that the relatively slow network does not become a bottleneck, and that computation time is kept reasonably small.     

Phase reaction and diffusion path of the SiC/Ti system

Bonding of SiC to SiC was conducted using Ti foil at bonding temperatures from 1373 to 1773 K in vacuum. The total diffusion path between SiC and Ti was investigated in detail at 1673 K using Ti foil with a thickness of 50 μm. At a bonding time of 0.3 ks, TiC at the Ti side and a mixture of Ti₅Si₃C _x and TiC at the SiC side were formed, yielding the structure sequence of β-Ti/Ti+TiC/Ti₅Si₃C _x +TiC/SiC. Furthermore, at the bonding time of 0.9 ks, a Ti₅Si₃C _x layer phase appeared between SiC and the mixture of Ti₅Si₃C _x and TiC. Upon the formation of Ti₃SiC₂ (T phase) after the bonding time of 3.6 ks, the complete diffusion path was observed as follows: β-Ti/Ti+TiC/Ti₅Si₃C _x +TiC/Ti₅Si₃C _x /Ti₃SiC₂/SiC. The activation energies for growth of TiC, Ti₅Si₃C _x , and Ti₃SiC₂ were 194, 242, and 358 kJ/mol, respectively.     

Waldenstr?m''s macroglobulinemia resulting from localized gastric lymphoplasmacytoid lymphoma

Arthritis may be the presenting manifestation of iron overload. The metacarpophalangeal joints are often involved, producing a condition that resembles osteoarthritis but at a site typically affected by rheumatoid arthritis. Treatment of the arthritis is often disappointing, but identification of the underlying disease permits institution of life-saving phlebotomy therapy.     

Untersuchungen über die Wirksamkeit von Konservierungsmitteln in anionaktiven Tensiden II

Investigations on the Efficacy of Preserving Agents in Anion Active Surfactants II The authors investigated the preserving action of p-chloro-m-cresol and of pHB-methyl/ethyl ester combination (1 + 1) in solutions of anion active surfactants. The preservatives were employed at two different concentrations. The concentration of the surfactants (lauryl sulfate and protein-fatty acid condensate as sodium, potassium and triethanolamine salts) was varied from 0.1 to 10.0 g/100 g. The pH of the solutions was 7. The deactivation of the preservatives investigated here by the anion active surfactant occurs only after a certain ratio of surfactant to preservative is reached. Under this ratio the preservatives are fully effective; above this, however, are the preservatives deactivated.     

Pressure dependence of the elastic shear modulus in V3Si

The pressure derivative of the elastic shear modulus of V₃Si is calculated from 20 to 300 K in the linear chain model for the -W compounds. The theory agrees with the experiment and predicts a different behavior for transforming and nontransforming single crystals.     

Cardiovascular and subjective effects of intravenous cocaine administration in humans

Nine volunteer subjects were tested with intravenously administered cocaine hydrochloride in doses ranging from 4 to 32 mg, as well as 10 mg of dextroamphetamine sulfate. Measures of cardiovascular and subjective effects were made. Generally parallel dose-effect functions were obtained for heart rate, blood pressure, Addiction Research Center Inventory scores, Profile of Mood Scales, and subject ratings. A substantial effect on each of these variables was recorded after 8 mg of cocaine. The increase continued and peaked at approximately 16 mg after which it usually leveled off. Ten milligrams of dextroamphetamine generally had an effect comparable to 8 to 16 mg of cocaine.