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991.
992.
ABSTRACT This paper deals with the political geography of regional economic development under Fordism and its transition to post-Fordism. It summarises international, national and regional trends in Fordist accumulation and regulation. Second, it indicates haw Fordism dissolves and is replaced by a so tar insufficiently perceived and defined "post-Fordism." A general sketch of the political and economic geography for this, perhaps, new stage in capitalist development is put forward. Third, the authors discuss which elements in different institutional and neo-Marxian theories of the state are the most helpful to understand the role of the state under Fordism and the transition to post-Fordism. 相似文献
993.
Erik Reimhult Bengt Kasemo Fredrik H??k 《International journal of molecular sciences》2009,10(4):1683-1696
We have investigated the pathway by which unilamellar POPC liposomes upon adsorption undergo rupture and form a supported lipid bilayer (SLB) on a SiO2 surface. Biotinylated lipids were selectively incorporated in the outer monolayer of POPC liposomes to create liposomes with asymmetric lipid compositions in the outer and inner leaflets. The specific binding of neutravidin and anti-biotin to SLBs formed by liposome fusion, prior to and after equilibrated flip-flop between the upper and lower monolayers in the SLB, were then investigated. It was concluded that the lipids in the outer monolayer of the vesicle predominantly end up on the SLB side facing the SiO2 substrate, as demonstrated by having maximum 30–40% of lipids in the liposome outer monolayer orienting towards the bulk after forming the SLB. 相似文献
994.
We explore three important avenues of research in algorithmic graph-minor theory, which all stem from a key min-max relation
between the treewidth of a graph and its largest grid minor. This min-max relation is a keystone of the Graph Minor Theory
of Robertson and Seymour, which ultimately proves Wagner’s Conjecture about the structure of minor-closed graph properties.
First, we obtain the only known polynomial min-max relation for graphs that do not exclude any fixed minor, namely, map graphs
and power graphs. Second, we obtain explicit (and improved) bounds on the min-max relation for an important class of graphs
excluding a minor, namely, K
3,k
-minor-free graphs, using new techniques that do not rely on Graph Minor Theory. These two avenues lead to faster fixed-parameter
algorithms for two families of graph problems, called minor-bidimensional and contraction-bidimensional parameters, which
include feedback vertex set, vertex cover, minimum maximal matching, face cover, a series of vertex-removal parameters, dominating
set, edge dominating set, R-dominating set, connected dominating set, connected edge dominating set, connected R-dominating set, and unweighted TSP tour. Third, we disprove a variation of Wagner’s Conjecture for the case of graph contractions
in general graphs, and in a sense characterize which graphs satisfy the variation. This result demonstrates the limitations
of a general theory of algorithms for the family of contraction-closed problems (which includes, for example, the celebrated
dominating-set problem). If this conjecture had been true, we would have had an extremely powerful tool for proving the existence
of efficient algorithms for any contraction-closed problem, like we do for minor-closed problems via Graph Minor Theory. 相似文献
995.
An algorithm is proposed for computing which sensor additions make a diagnosis requirement specification regarding fault detectability and isolability attainable for a given linear differential-algebraic model. Restrictions on possible sensor locations can be given, and if the diagnosis specification is not attainable with any available sensor addition, the algorithm provides the solutions that maximize specification fulfillment. Previous approaches with similar objectives have been based on the model structure only. Since the proposed algorithm utilizes the analytical expressions, it can handle models where structural approaches fail. 相似文献
996.
Erik Giesa 《信息安全与通信保密》2007,(1):55-56
我们知道,如果企业将业务连续性作为关键目标,那么运营必须保持24×7全天候运行。最佳实践表明,颇为有效的方法是利用地理冗余在不同的地理位置建立多个数据中心或站点,且将应用和数据复制到这些中心或站点。需要复制所有内容吗?大可不必,仅需复制那些关键任务应用和数据即可。 相似文献
997.
998.
999.
Erik Bruun 《Analog Integrated Circuits and Signal Processing》1997,12(1):71-78
The definition of the current conveyor is reviewed and a multiple-output second generation current conveyor (CCII) is shown to combine the different generations of current conveyors presently existing. Next, noise sources are introduced, and a general noise model for the current conveyor is described. This model is used for the analysis of selected examples of current conveyor based operational amplifier configurations and the noise performance of these configurations is compared. Finally, the noise model is developed for a CMOS current conveyor implementation, and approaches to an optimization of the noise performance are discussed. It is concluded that a class AB implementation can yield a lower noise output for the same dynamic range than a class A implementation. For both the class A implementation and the class AB implementation it is essential to design low noise current mirrors and current sources, and with the class AB design, the current mirror and current source noise can be reduced by using small values of bias current without compromising the maximum available output current. 相似文献
1000.
Modern wire rod rolling is characterized by high finish rolling speed and requirements on close tolerances and well defined mechanical properties of the rolled product. In some senses the technological development has run in advance of the scientific knowledge of the phenomena involved in the process. Thus at present no laboratory mill is in operation for rolling speeds above 40 m/s. The modern technologies on thermomechanical rolling and sizing give certain phenomena difficult to handle for the mills, and especially finish rolling at low reductions and temperatures performed in three‐roll units sometimes give surprises on grain size distribution and allied properties of the wire rod. Traditional plastic analysis has proven not to be sufficient to analyse the processes involved in high speed rolling of close tolerance wire rod with well‐defined properties. Simulations by means of the Finite Element Method on the other hand have proven to be a powerful tool for this kind of analysis, even if the initial difficulties in creating a suitable model require certain care. Also the calculation capacity must be sufficient for making relevant three‐dimensional thermomechanically coupled studies. The high speed rolling of wire rod can be simulated under full‐scale conditions, and with correct boundary condition in the high‐speed laboratory wire rod mill at Örebro University. By utilizing both conventional two‐high stands and three‐roll units it has been possible to design a laboratory rolling mill for any rolling condition that can occur in wire rod mills. Rolling speeds up to 80 m/s can be combined with thermomechanical rolling in any interesting temperature range, and with total flexibility of reductions. Further, fundamental studies of high‐speed deformations can be performed in full‐scale and with correct frictional conditions and geometries. Thanks to the flexibility in layout and combinations with other equipment in the laboratory also other processes can be simulated. 相似文献