Polynomial-complexity deadlock avoidance policies for sequentialresource allocation systems

The development of efficient deadlock avoidance policies (DAPs) for sequential resource allocation systems (RASs) is a problem of increasing interest in the scientific community, largely because of its relevance to the design of large-scale flexibly automated manufacturing systems. Much of the work on this problem existing in the literature is focused on the so-called single-unit RAS model, which is the simplest model in the considered class of RASs. Furthermore, due to a well-established result stating that, even for single-unit RASs, the computation of the maximally permissive DAP is intractable (NP-hard), many researchers (including our group) have focused on obtaining good suboptimal policies which are computationally tractable (scalable) and provably correct. In the first part of the paper, it is shown, however, that for a large subset (in fact, a majority) of single-unit RASs, the optimal DAP can be obtained in real-time with a computational cost which is a polynomial function of the system size (i.e., the number of resource types and the distinct route stages of the processes running through the system). The implications of this result for the entire class of single-unit RASs are also explored. With a result on the design of optimal DAPs for single-unit RASs, the second part of the paper concentrates on the development of scalable and provably correct DAPs for the more general case of conjunctive RASs     

Reading in Arabic orthography: the effect of vowels and context on reading accuracy of poor and skilled native Arabic readers in reading paragraphs, sentences, and isolated words

This study investigated the effect of vowels and context on the reading accuracy of poor and skilled native Arabic readers in reading paragraphs, sentences, and words. Central to this study is the belief that reading theory today should consider additional variables, especially when explaining the reading process in Arabic orthography among poor and normal/skilled readers. This orthography has not been studied. Reading theory today is the sum of conclusions from studies conducted in Latin orthography. The subjects were 77 native Arabic speakers, 34 of them poor readers and 44 normal/skilled readers. The subjects had to read in Arabic 15 paragraphs, 60 sentences, and 210 words. There were three reading conditions: fully vowelized, partially vowelized, and unvowelized texts. The results showed that vowels and contexts were important variables to facilitate word recognition in poor and normal/skilled readers in Arabic orthography.     

Optical imaging of anatomical maps derived from magnetic resonanceimages using time-independent optical sources

Presents a model suitable for computing images of absorption cross sections of thick tissue structures illuminated at near infrared (NIR) wavelengths from tomographic projection data. Image reconstruction is accomplished by solving a system of linear equations derived from transport theory. Reconstruction results using different algebraic solvers are shown for anatomical maps of the breast, derived from magnetic resonance imaging data, containing two simulated pathologies, in which case qualitatively good reconstructions were obtained. Evaluation of magnetic resonance (MR) data to optimize NIR optical tomographic imaging methods and to assess the feasibility of a combined MR-optical measurement scheme is discussed     

Relevance of pharmacokinetics and pharmacodynamics

This ex post facto study investigated the relationship of social support from two workplace sources, unit managers and registered nurse (RNs) coworkers, to work-related stress among staff nurses. Sample participants included 51 full-time RNs from a variety of clinical specialties in one nursing organization. The three theoretical components--affect, affirmation, and aid--were measured by the Norbeck Social Support Questionnaire. The Nursing Stress Scale was used to quantify the levels of perceived work-related stress. Statistically significant negative correlations were found between affect from unit managers (r = -299; P = 0.15) and aid from coworkers (r = -.294; P = .036) on levels of perceived work-related stress. Additionally, the increased age of the subjects (r = -.342; P = .007), years of nursing experience (r = -252; P = .037), and length of employment (r = -329; P = .009) had a negative relationship with work stress. The results of this research demonstrated that two components of social support--affect (emotional support) from unit managers and aid (services, information, materials) from coworkers--were linked to lower stress scores in this sample of staff nurses.     

The influence of trigger configurations and laminate lay-up on the failure mode of composite crush cylinders

In this paper the results are presented of a test program on the energy absorption of composite cylinders loaded in compression. The influence of the laminate lay-up and of the trigger configuration were determined. Two different failure modes for the different laminates and triggers were observed: a splaying mode and a fragmentation mode. The splaying mode is more efficient in absorbing energy. The failure mode did not change during the crushing process.     

Cable insulation density profile determined from ultrasonicvelocity measurements

Density results obtained on the same cable sample with a column and from ultrasonic measurements are reported. A calibration curve relating ultrasonic velocity and cable insulation density is given for PE and crosslinked PE (XLPE) cables. The limits and advantages of deducing density profiles of cable insulation using a focused, ultrasound beam rather than the more time-consuming column measurements are discussed     

Candida fungemia in neonates treated with fluconazole: report of forty cases, including eight with meningitis

PURPOSE OF THE STUDY: To assess efficacy and safety of fluconazole in neonates with Candida fungemia. STUDY DESIGN: Multicenter prospective protocol of all fungemias appearing between January 1, 1993, and December 31, 1997, in four major university hospitals. RESULTS: Forty neonates, 28 of them with very low birth weight (<1500 g; 30.5 median gestation week), with documented Candida albicans fungemia were treated with intravenous fluconazole in a daily dosage of 6 mg/kg once daily for 6 to 48 days. Thirty-four received fluconazole as monotherapy and 6 received it in combination with amphotericin B. Thirty-two (80%) were cured; 4 of them relapsed despite at least 14 days of therapy, but they were ultimately cured without sequelae. Eight other neonates died, 4 because of fungal infection and 4 because of prematurity or hemorrhage or lung failure, with fungemia (20% overall and 10% attributable mortality). Two neonates had elevated liver enzymes during fluconazole therapy and 2 others had elevated serum creatinine during fluconazole monotherapy. In none of them did these abnormalities necessitate discontinuation of antifungal therapy. In 8 neonates fungal meningitis developed as a complication of fungemia. All but 3 fungemias were C. albicans; 3 were Candida parapsilosis. CONCLUSIONS: Fluconazole was safe and effective antifungal therapy even in complicated or Candida fungemia in neonates and in infants with very low birth weight.