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排序方式: 共有981条查询结果,搜索用时 125 毫秒
51.
In this paper, we consider the stochastic fluid-flow model of a single node in a high-speed telecommunication network handling multi-class traffic. The node has multiple buffers, one for each class of traffic. The contents of these buffers are multiplexed onto a single output channel using one of the service scheduling policies: the Timed Round Robin Policy or the Static Priority Service Policy. The Quality of Service requirements for each class are based on cell loss probabilities. Using effective bandwidth methodologies and the recently developed bounds for semi-Markov modulated traffic, we solve call admission control problems for the two service scheduling policies at this node. We compare the performance of the effective bandwidth methodologies and the SMP bounds technique. We also numerically compare the performance of the two service scheduling policies. 相似文献
52.
化探样品中金含量测定的探讨 总被引:1,自引:0,他引:1
讨论了化探样品中金测定过程中的分解方法、金的富集、酸度及流速、泡塑清洗及控制等条件,严格控制各个分析环节,通过对标准样品进行分析,相对标准偏差为0.75%—3.64%,回收率为95.0%—105.0%,方法适合批量样品生产,能达到化探样品中金含量的分析要求。 相似文献
53.
Manfred Golze 《Accreditation and quality assurance》2001,6(4-5):199-202
Since October 1998 the European Commission has financed a concerted action on Information System and Qualifying Criteria for
Proficiency Testing Schemes within the 4th framework program. As a major result of this project EPTIS, the European Information
System on Proficiency Testing Schemes which is available on the Internet since March 2000, is presented in this paper. Today
EPTIS contains comprehensive information on approximately 640 proficiency testing schemes from 16 European countries providing
information on the state of the art in proficiency testing in Europe. Finally some possible approaches for interlinkages and
recognition of proficiency testing schemes are discussed. 相似文献
54.
In order to determine the quality of young Cognac spirits, mainly appreciated by the absence of defects, a new method has been developed, based on sniffing and olfactometry (GC-O) and associated with sensory and chemical analysis. During 3 years, good quality spirits selected first by Cognac merchant were analysed and selected by an original panel of tasters used to judge those spirits. The aromatic profile were established and compared. Then, the most different spirits were analysed by sniffing coupled with gas chromatography. The olfactometric profile obtained were compared. We noticed that they have all the same aromatic base constituted with 18 specific areas. Six of them were unknown and we are trying now to identify them. 相似文献
55.
The paper demonstrates conceptual parallels and relationships between intellectual capital measurement methods and the evaluation
of quality in clinical laboratories in the Slovak Republic. It explores further the contextual links of those parallels with
the tangibility (or intangibility) of quality indicators of laboratory diagnostics. It also highlights the problems which
laboratory staff in Slovakia are confronted with.
Presented at the conference Quality in the Spotlight, March 2007, Antwerp, Belgium. 相似文献
56.
A recently introduced similarity measure is extended here for comparing two-dimensional spectra. Its applicability is demonstrated with heteronuclear single-quantum correlation (HSQC) NMR spectra. For testing the compatibility of a spectrum with the proposed chemical structure, first, the spectrum is predicted on the basis of that structure and then, the proposed comparison algorithm is applied. In this context, the topics of optimization are peak picking, signal intensity measures, and optimizing the parameters of the two-dimensional comparison method. The performance is analyzed with a test set of 289 structures of organic compounds and their HSQC and 1H NMR spectra. The results obtained with HSQC spectra are better than those achieved using the previously described one-dimensional similarity test with 1H NMR spectra alone. 相似文献
57.
G. Maldener 《Chromatographia》1989,28(1-2):85-88
Summary One possible method has been demonstrated for pharmaceutical quality control which is not restricted to this field and fulfils and documents the prerequisites for reliable, accurate and precise HPLC analysis. This includes validation which shows that the method is able in principle to fulfil the requirements, the apparatus test which shows that the apparatus generally works correctly and precisely and the system suitability test which shows that the method provides accurate and precise results on this apparatus and with this column for the analysis in question when other non-equipment and non-method-induced errors are excluded. 相似文献
58.
F. Linnebank 《Accreditation and quality assurance》2000,5(9):377-380
The Netherlands Institute for Accreditation of Hospitals (NIAZ) was established at the end of 1998. It was founded by the
PACE foundation, the Society of University Hospitals, the Netherlands Association of General Hospitals and the Society of
Medical Specialists in the Netherlands. Since then in the Netherlands 19 pilot accreditations have been performed based upon
35 NIAZ-PACE standards for hospital departments and functions, and the overall standard 'quality system'. The aims and methods
of the accreditation system were inspired by examples from the other side of the Atlantic, especially from Canada. The characteristics
are: voluntary-based, self-evaluation, peer-review and aiming at continuous improvement of quality of care.
Received: 15 April 2000 · Accepted: 15 April 2000 相似文献
59.
Mingjin Liang Jiye Zhang Runhui Liu Shikai Yan Weidong Zhang Min Lin 《Chromatographia》2007,66(1-2):107-110
HPLC-DAD coupled to an electrospray tandem mass spectrometer (ESI-MS) has been developed to analysis the chemical profile
of Danning tablets. Separation was performed on a ZORBAX Extend C18 analytical column by gradient elution with acetonitrile and formate buffer (containing 12.6 mmol L−1 formic acid, adjusted to pH 5.0 with ammonia) at a flow rate of 0.8 mL−1 min. Twenty-three peaks were identifies as the major compounds in this preparation. Similarity measurements of the HPLC-UV
chromatograms were investigated by a Similarity Evaluation System for Chromatographic Fingerprinting of Traditional Chinese
Medicine (TCM) in the range of 0.84–0.99, and principal components analysis (PCA) on the quantitative analysis data was further
performed to evaluate the variation among batches. The proposed method gives chemical profiles of multi-components in one
run, and therefore can be readily utilized as a comprehensive quality control approach for TCM. 相似文献
60.
Vacuum freeze-drying is a new and high technology on agricultural product dehydrating dry, but it faces the high cost problem caused by high energy consumption. This study investigated the effect of ultrasound (US), freeze-thawing (including the freeze-air thawing (AT), freeze-water thawing (WT), freeze-ultrasound thawing (UST), and freeze-air ultrasound thawing (AT + US)) pretreatments on the vacuum freeze-drying efficiency and the quality of dried okra. The results indicated that the application of ultrasound and different freeze-thawing pretreatments reduced the drying time by 25.0%–62.50% and the total energy consumption was 24.28%–62.35% less. The AT pretreatment reduced the time by of okra slices by 62.50% and the total energy consumption was 62.35% less. The significant decrease in drying time was due to a change in the microstructure caused by pretreatment. Besides, the okra pretreated with the US retained most of the quality characteristics (flavor, color, hardness, and frangibility) among all methods, while, AT + US had the most changeable characteristics in quality, which is deprecated in our study. The okra pretreated with the US and AT, separately, had the best dry matter content loss (9.008%, 5.602%), lower chlorophyll degradation (5.05%, 5.44% less), and higher contents of total phenolics, total flavonoids, and pectin, with strong antioxidant capacity, compared to other methods. The pretreatments did not have a large effect on the functional groups and the structure of pectin, but slightly affected the viscosity. It can be concluded that AT and US pretreatment methods are better than others. 相似文献