Microstructural effects on the stress corrosion cracking behavior of medium and high strength steels

Metallurgical and Materials Transactions A - The effects of variations in microstructure and strength level on the stress corrosion cracking susceptibility of three medium to high strength steels,...     

A proof technique for concurrency control and recovery algorithms for replicated databases

A replicated database is a distributed database in which copies of some data items are stored redundantly at multiple sites. In such a system, an execution of transactions iscorrect if it is equivalent to a serial execution of those transactions on a one copy database. We show that in any serializable execution, if all transactions see the failures and recoveries of data item copies in a consistent order, then the execution is correct. We model this condition using a modified type of serialization graph, and show that if this graph is acyclic then the corresponding execution is correct. We demonstrate the value of this model by using it to prove the correctness of an algorithm for synchronizing access to a replicated database. Philip A. Bernstein is Professor of Information Technology at the Wang Institute of Graduate Studies. Previously, he was Vice President Software at Sequoia Systems, Associate at Harvard University, and a researcher at Computer Corporation of America, where he was codesigner of four distributed database systems. Professor Bernstein's research focuses on the theory and implementation of database systems and transaction processing systems. He is an Associate Editor of ACM Transactions on Database Systems, and on the editorial board of this journal. Nathan Goodman is a senior consulting engineer at Encore Computer Corporation. Previously he was with Sequoia Systems, where he developed a transaction processing system for a fault-tolerant multiprocessor computer. Prior to that he was with Computer Corporation of America, where he participated in the design of three distributed systems: SDD-1, the first relational distributed DBMS; Multibase, a system for querying relational and nonrelational distributed databases; and DDM, a distributed DBMS based on ADA. Dr. Goodman was a professor Computer Science at Harvard University and Boston University. He has done research on query optimization, concurrency control, and failure recovery.Research supported by the National Science Foundation, grant number MCS79-07762, and by the Office of Naval Research, contract number N00014-80-C-674.     

Gaussian Maximum Likelihood and Contextual Classification Algorithms for Multicrop Classification Experiments Using Thematic Mapper and Multispectral Scanner Sensor Data

In this paper we present the results of a study of performance of a previously proposed classification technique on real remotesensor imagery. Testing has been achieved in the framework of an analysis of variance experiment designed to compare thematic mapper (TM) versus multispectral scanner (MSS) image data under the view-point of classification accuracy. The improvements of TM relative to MSS consist in (Fl) three additional spectral bands, (F2) increased radiometric resolution, and (F3) increased spatial resolution. The impacts of factors FI-F3, with or without context (factor F4), were evaluated by a four-factor analysis of the variance experiment, by repeated classification runs on 1) a TM data set, and 2) suitably degraded versions of the same set. Figures of increase/decrease in classification accuracy due to any combinations of the four factors have been computed, along with the corresponding levels of significance. Simultaneously acquired TM and MSS data sets have been used, together with photographic data acquired in coincidence with the satellite overpass (as control data for classification accuracy computation). The relaxation algorithms proposed in a previous paper have been used to assess the impact of the contextual factor.     

First measurement of B(E2) values from sigma

HG B?rner  J Jolie  S Robinson  RF Casten  J Cizewski 《Canadian Metallurgical Quarterly》1990,42(6):R2271-R2274

Quantitative 1H MRS in the evaluation of mesial temporal lobe epilepsy in vivo

Hippocampal metabolite concentrations were determined by localized in vivo proton magnetic resonance spectroscopy (1H MRS) in eleven patients suffering from refractory mesial temporal lobe epilepsy (MTLE), as well as in eleven age-matched healthy volunteers, and compared with patient history, postoperative outcome and histopathology. Main results are: 1) In patients, the decrease in N-acetylaspartate (NAA) concentrations was highly significant ipsilateral, and less but still significant contralateral to the electroencephalogram-defined focus, as compared to controls. 2) The decrease in ipsilateral NAA measured preoperatively correlates with the degree of hippocampal sclerosis but 3) does not reliably predict postoperative outcome, although there is a trend toward better outcome in patients with a marked decrease of NAA. 4) Hippocampal NAA decrease (ipsi- and contralateral) is highly correlated with early onset age of epileptic seizures. 5) Among patients with similar onset age in early childhood, there is a strong association between duration of the disease and contralateral (and, though less clear-cut, ipsilateral) NAA loss. These results are concordant with the notion of a generally progressive worsening and complicating course of symptoms in poorly controlled MTLE.     

Psychiatric disorders in refugees and asylum seekers: psychological trauma as a cause?

Posttraumatic stress disorder was diagnosed in two patients, men aged 26 and 29, an asylum seeker from the Middle East and a refugee from former Yugoslavia respectively. They had experienced severe psychotraumatic events. They were referred to a clinic for traumatised refugees and asylum seekers. Their psychiatric disturbances did not fit posttraumatic stress disorder, however. The former suffered from a schizophrenic disorder, the latter from psychosis and depression based on alcohol dependence. Growing awareness of the high prevalence of traumatic experiences in the population leads to a contextual shift in therapists regarding their understanding of the short and long term effects of traumatization in their patients. Exclusive focus on the traumatic history, however, biases the diagnostic process and could lead to wrong conclusions about a causal relationship between traumatic experiences and the psychopathology observed in the patient. When treating asylum seekers or refugees the risk of jumping to this false conclusion is even higher, partially due to cultural and language barriers.