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91.
In this paper we have a closer look at one of the rules of the tableau calculus presented by Fitting [4], called the -rule. We prove that a modification of this rule, called the +-rule, which uses fewer free variables, is also sound and complete. We examine the relationship between the +-rule and variations of the -rule presented by Smullyan [9]. This leads to a second proof of the soundness of the +-rule. An example shows the relevance of this modification for building tableau-based theorem provers. 相似文献
92.
G. K. Burkat V. Yu. Dolmatov G. S. Aleksandrova E. D. Osmanova V. Myllymäki A. Vehanen 《Journal of Superhard Materials》2017,39(4):221-225
The influence of detonation of nanodiamonds doped with boron during the detonation synthesis (DND-boron) on the process of electrochemical deposition of zinc from a zincate electrolytic solution is investigated. It is shown that the throwing power (the coating uniformity) increases 2to 4-fold depending on the DND–boron concentration, the electrolytic conductivity remains unchanged, the corrosion resistance (as measured by the corrosion currents) of the Zn–DND-boron coating grows 2.6 times when tested in the 3% NaCl solution and 3 times in the climatic chamber. 相似文献
93.
S Ewig A Glasmacher B Ulrich K Wilhelm H Sch?fer KH Nachtsheim 《Canadian Metallurgical Quarterly》1998,114(2):444-451
STUDY OBJECTIVE: To determine predictors of mortality from pulmonary infiltrates in neutropenic patients with acute leukemia during chemotherapy, and the significance of those factors related to the underlying malignancy and its therapy as well as of those related to the severity of the illness associated with pulmonary infiltrates. DESIGN: A historical cohort study. SETTING: A university teaching hospital and tertiary referral center. PATIENTS AND METHODS: Overall, 53 patients with neutropenia during chemotherapy and with first episodes of pulmonary infiltrates during a 4-year period were studied. Prognostic analysis included 38 variables. Multivariate analyses were performed by logistic regression. RESULTS: The survival rate from pneumonia was 57% (30/53). The following eight parameters were significantly associated with death in univariate analysis: comorbidity present; development of "late" pulmonary infiltrates (> or = 14 days after hospital admission); heart rate > or = 100 beats/min; a ratio heart rate/systolic blood pressure (HR/SBP) > or = 1.2; urea nitrogen > 7 mmol/L; radiographic score > or = 3; neutropenia < 1.0x10(9)/L at the treatment end point; and failed complete remission. In a multivariate model including only parameters available at diagnosis of pulmonary infiltrates, the presence of a ratio HR/SBP > or = 1.2 and of a radiographic score > or = 3 remained independently associated with death. In a second model also including the evolutionary parameter neutropenia < or = 1.0x10(9)/L at the treatment end point, both parameters remained significant together with neutropenia <1.0x 10(9)/L at the treatment end point. The presence of a ratio HR/SBP > or = 1.2 was a strong marker of early death. CONCLUSION: Both therapy- and malignancy-associated neutropenia as well as the severity of illness associated with pulmonary infiltrates are independent prognostic factors. Patients with a ratio HR/SBP > or = 1.2 at diagnosis of pulmonary infiltrates suffer from potentially reversible acute illness, are at risk for early death and, therefore, may be appropriate candidates for treatment in an ICU. 相似文献
94.
Fluid jet polishing of optical surfaces 总被引:8,自引:0,他引:8
We present a new finishing process that is capable of locally shaping and polishing optical surfaces of complex shapes. A fluid jet system is used to guide a premixed slurry at pressures less than 6 bars to the optical surface. We used a slurry comprising water and 10% #800 SiC abrasives (21.8 mum) to reduce the surface roughness of a BK7 sample from 350 to 25 nm rms and to vary the shape of a polished sample BK7, maintaining its surface roughness of 1.6 nm rms, thereby proving both the shaping and polishing possibilities of the presented method. 相似文献
95.
A new measurement technique for the characterization of uniaxial as well as biaxial anisotropic surfaces and thin films is introduced. This technique is based on perpendicular-incidence photometric ellipsometry, in which a spectral-photometric dynamic ellipsometer with a rotating polarizer is used. This method is sensitive, contactless, nondestructive, and efficient for the estimation of anisotropic behavior. Furthermore, the spectroscopic measurement directly provides the anisotropy dispersion down to the UV wavelength range. Results on structurally anisotropic HfO(2) coatings are presented. 相似文献
96.
Traversing step obstacles with manual wheelchairs 总被引:1,自引:0,他引:1
Petzäll J 《Applied ergonomics》1996,27(5):327-341
In the public transport system, there are sometimes step obstacles, such as curbs, steps, entrance steps of vehicles, edges of lifting platforms, internal steps in vehicles, etc. This paper describes research work carried out in Sweden to specify the heights of step obstacles possible to traverse with a manual wheelchair manoeuvred by an attendant. The work included trials with the subjects manoeuvring two different kinds of wheelchairs, with dummies as occupants, over a step obstacle with adjustable height. It also included trials with a person in the wheelchair. The subjects were 20 healthy persons in the age range of 23-60 years, with no or only little experience of manoeuvring wheelchairs, chosen to represent bus drivers or other helpers. They rated their perceived feeling of effort on a 10-level rating scale with ratio properties. The occupant rated the feeling of comfort and safety in three grades. All trials were recorded using a video-camera. From the video-film, the situations and series of actions of the subjects were analysed and the length of time for each task was measured. The forces needed when traversing step obstacles with a wheelchair were calculated according to the principles of mechanics and processed by a computer for the different principal traversing situations. The results show that for the planning of systems for public transportation, where the passenger can get assistance, a step height of 50 mm is acceptable, and a step height of 100 mm can be acceptable if there is enough room to manoeuvre the wheelchair, so that it is possible to choose the most convenient way to traverse the step. Higher heights should be avoided. 相似文献
97.
98.
Idilio Drago Rafael R. R. Barbosa Ramin Sadre Aiko Pras Jürgen Schönwälder 《Journal of Network and Systems Management》2011,19(2):298-304
Following the success of the First Workshop on the Usage of NetFlow/IPFIX (Pras et al. in J Netw Syst Manag 17(4), 2009) in 2008, the European EMANICS Network of Excellence organized a second workshop
in October 2009, held at Jacobs University Bremen. This report summarizes the workshop and presents its main conclusions. 相似文献
99.
Jukka Mäkelä Markus Luoto Tiia Sutinen Kostas Pentikousis 《Multimedia Tools and Applications》2011,55(2):289-306
Multimedia delivery in mobile multiaccess network environments has emerged as a key area within the future Internet research
domain. When network heterogeneity is coupled with the proliferation of multiaccess capabilities in mobile handheld devices,
one can expect many new avenues for developing novel services and applications. New mechanisms for audio/video delivery over
multiaccess networks will define the next generation of major distribution technologies, but will require significantly more
information to operate according to their best potential. In this paper we present and evaluate a distributed information
service, which can enhance media delivery over such multiaccess networks. We describe the proposed information service, which
is built upon the new distributed control and management framework (DCMF) and the mobility management triggering functionality
(TRG). We use a testbed which includes 3G/HSPA, WLAN and WiMAX network accesses to evaluate our proposed architecture and
present results that demonstrate its value in enhancing video delivery and minimizing service disruption in an involved scenario. 相似文献
100.
This special issue collects current advances in the ongoing attempt to obtain synergies from the combination of Tests and
Proofs. 相似文献