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排序方式: 共有578条查询结果,搜索用时 15 毫秒
61.
Process flight simulation tools can help managers understand the dynamics of new processes and technologies before they are introduced. This article tells how these exploratory tools can be used for IS project management, simple modeling of the software process, and modeling the dynamics of the IS organization in transition. 相似文献
62.
Ed Dawson Kapali Viswanathan Colin Boyd 《International Journal of Information Security》2002,1(3):189-202
Literally, the word compliance suggests conformity in fulfilling official requirements. This paper presents the results of
the analysis and design of a class of protocols called compliant cryptologic protocols (CCPs). The paper presents a notion
for compliance in cryptosystems that is conducive as a cryptologic goal. CCPs are employed in security systems used by at
least two mutually mistrusting sets of entities. The individuals in the sets of entities only trust the design of the security
system and any trusted third party the security system may include. Such a security system can be thought of as a broker between
the mistrusting sets of entities.
Published online: 15 November 2002 相似文献
63.
The effect of a new approach to group work on pupil-pupil and teacher-pupil interactions. 总被引:1,自引:0,他引:1
Blatchford Peter; Baines Ed; Rubie-Davies Christine; Bassett Paul; Chowne Anne 《Canadian Metallurgical Quarterly》2006,98(4):750
The main impetus for the SPRinG (social pedagogic research into grouping) project was to address the wide gap between the potential of group work and its limited use in schools. It is an ambitious project that developed key principles and strategies to improve the effectiveness of group work in everyday primary classes and across a whole school year. On-the-spot and video-based systematic observations showed more active, sustained engagement, more connectedness, and more higher order inferential joint reasoning within SPRinG groups than in control comparisons. The authors argue that group work can be successfully implemented into everyday school classrooms and improve pupil interactions, provided teachers take time to train pupils in the skills of group working. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
64.
部署40G技术正当时 总被引:2,自引:0,他引:2
Ed Harstead 《通讯世界》2002,8(10):46-46
当今业内普遍达成的一个共识是运营商不应单纯为追求高速度的虚名而采用40G技术,应该等待40G技术具备与现有技术相当的性价比,也就是说,当40G技术的成本降至10G技术的四倍以下时才予以采用。然而,对于何时能够降至四倍以下,则众说纷纭。例如,有人指出当前40G技术的成本是10G技术的十倍。在本文中,我们将分析40G传输技术应用障碍如何被夸大或误解,同时指出目前已投入商用的40G产品的成本已不足10G技术的四倍。从理论上讲,40G线路信号所要求的光信噪比(OSNR)高出10G信号6分贝,这意味着10G信号可以不经再生传输更远的距离。… 相似文献
65.
Detail preserving impulsive noise removal 总被引:8,自引:0,他引:8
Most image processing applications require noise elimination. For example, in applications where derivative operators are applied, any noise in the image can result in serious errors. Impulsive noise appears as a sprinkle of dark and bright spots. Transmission errors, corrupted pixel elements in the camera sensors, or faulty memory locations can cause impulsive noise. Linear filters fail to suppress impulsive noise. Thus, non-linear filters have been proposed. Windyga's peak-and-valley filter, introduced to remove impulsive noise, identifies noisy pixels and then replaces their values with the minimum or maximum value of their neighbors depending on the noise (dark or bright). Its main disadvantage is that it removes fine image details. In this work, a variation of the peak-and-valley filter is proposed to overcome this problem. It is based on a recursive minimum–maximum method, which replaces the noisy pixel with a value based on neighborhood information. This method preserves constant and edge areas even under high impulsive noise probability. Finally, a comparison study of the peak-and-valley filter, the median filter, and the proposed filter is carried-out using different types of images. The proposed filter outperforms other filters in the noise reduction and the image details preservation. However, it operates slightly slower than the peak-and-valley filter. 相似文献
66.
Violations are part of a complex matrix of judgmental behavior. The term violation is an indicator of the possibility of recent judgment errors but more so of latent errors in management and/or design. The effect of investigations in this arena do indicate a need for an extension of the classic slip/mistake taxonomy of human reliability analysis. The note attempts to initiate this extension. 相似文献
67.
de Boer E Zwartkruis-Nahuis A Heuvelink AE Harmanus C Kuijper EJ 《International journal of food microbiology》2011,144(3):561-564
Recent reports indicate that a large proportion of community-acquired Clostridium difficile infections (CA-CDI) are not linked to recent antibiotic therapy, older age, significant comorbidity or previous hospitalization. Possible community sources for CA-CDI include animals and food, and therefore a surveillance study on the prevalence of C. difficile in meat was performed. Samples of different meat species were collected from the retail trade and analyzed for the presence of C. difficile using a method that included selective enrichment in C. difficile broth, subsequent alcohol shock-treatment and plating onto C. difficile selective medium. C. difficile isolates were tested for the presence of toxin genes and were typed using PCR ribotyping. Of 500 samples tested, 8 (1.6%) were positive for the presence of C. difficile: 1 from lamb (6.3%) and 7 from chicken meat (2.7%). The isolated strains belonged to PCR ribotypes different from those that are currently most frequently found in patients with CDI in the Netherlands, except for C. difficile PCR ribotype 001 which was found in one chicken meat sample. This observation suggests that other matrices than meat may serve as a source for CA-CDI. 相似文献
68.
Concentration and bioaccumulation of dechlorane compounds in coastal environment of northern China 总被引:4,自引:0,他引:4
Jia H Sun Y Liu X Yang M Wang D Qi H Shen L Sverko E Reiner EJ Li YF 《Environmental science & technology》2011,45(7):2613-2618
Dechloranes, including Dechlorane Plus (DP), Mirex (Dechlorane), Dechlorane 602 (Dec 602), Dechlorane 603 (Dec 603), and Dechlorane 604 (Dec 604), were determined using GC-MSD for water, sediment and oyster samples collected at 15 sampling sites near the Bohai and Huanghai Sea shore area of northern China in 2008. DP and Mirex were detected in most water, sediment, and oyster samples, which indicated widespread distribution of these two compounds. The mean concentrations in water, sediment and oyster samples, respectively, were 1.8 ng/L, 2.9 ng/g dry weight (dw) and 4.1 ng/g wet weight (ww) for total DP, and 0.29 ng/L, 0.90 ng/g dw, and 2.0 ng/g ww for Mirex. Dec 602 and Dec 603 were not detected in water but in small portions of the sediment and oyster samples, showing a low level of contamination by these two chemicals in the region. Strong and significant correlations were found between total DP and Mirex concentrations in water, sediment and oyster samples, probably suggesting similar local sources of these two chemicals. Dec 604 was not found in any samples. The biota-sediment accumulation factor (BSAF) of DP, Mirex, and Dec 602 declined along with the increase of their logarithm of octanol-water partition coefficients (log Kow), possibly indicating that compounds with lower log Kow (like Mirex and Dec 602) accumulated more readily in biota. The mean fractional abundance of syn-DP (fsyn) was 0.34 in water samples, a value lower than that in Chinese commercial mixture (0.41), while the mean fsyn for surface sediment (0.44) and oyster (0.45) samples were higher than technical values. Enrichment of syn-DP in oyster was in agreement with previously reported findings in Great Lakes fish. Enrichment of syn-DP in marine surface sediments, however, is contrary to data reported for fresh water sediments. To our knowledge this is the first report of Dec 602, Dec 603, and Dec 604 in a marine environment and also the first report of Dechloranes in marine biota. 相似文献
69.
70.
Ed. Baier 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1902,5(23):1145-1150
Ohne Zusammenfassung
Mittheilung aus dem Nahrungsmittel-Untersuchungsamt der Landwirthschaftskammer für die Provinz Brandenburg. 相似文献