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排序方式: 共有138条查询结果,搜索用时 15 毫秒
1.
Two new methods are proposed to implement the exclusive-OR and exclusive-NOR functions on the transistor level. The first method uses non-complementary signal inputs and the least number of transistors. The other one improves the performance of the prior method but two more transistors are utilized. Both of them have been fully simulated by HSPICE on a SUN SPARC 2 workstation  相似文献   
2.
While experimenting with the growth of metal-containing amorphous carbon (a-c:Me) thin films using two different growth processes, self-assembled multilayered structures were observed. One of the processes is a reactive magnetron sputter deposition process. The other process is a mass selective ion beam deposition process. Despite of the differences in the growth method and the growth condition, self-assembled multilayered thin films, consisting of alternating dark layer and bright layer, were obtained in both processes. Based on the consideration of energy for atomic diffusion in the thin films, the growth mechanism is discussed.  相似文献   
3.
Abstract

With growing pressures for collaborative information systems (IS) partnerships, Enterprise Resource Planning (ERP) implementation has been an important activity for improving supply chains efficiency in Small and Medium-Sized Enterprises (SMEs). Historically ERP consultants usually take a product-selling approach in SMEs, providing limited management consultancy services. However, a more constructive role for management consultants has become an emerging and challenging issue. This study explored the involvement of management consultants in ERP implementation, particularly with internal managers, ERP consultants and other project members. Extensive interviews were conducted with management consultants as well as 47 project members from four different SMEs in Taiwan employing ERP consultants. Using a grounded theory methodology, prior literature was used to sensitize the findings to key concepts of importance. The results were then analyzed and we described how owner-managers regard management consultants and how the consultants use role negotiation skills to work with both internal managers and ERP consultants. The study found resistance toward management consultants primarily from managers in SMEs, and not owner-managers. The relationships between management consultants and SME managers also differed from similar relationships in large organizations. Suggestions are also provided for academics and practitioners along with areas for future research to extend these exploratory findings.  相似文献   
4.
A handwritten Chinese character recognition method based on primitive and compound fuzzy features using the SEART neural network model is proposed. The primitive features are extracted in local and global view. Since handwritten Chinese characters vary a great deal, the fuzzy concept is used to extract the compound features in structural view. We combine the two categories of features and use a fast classifier, called the Supervised Extended ART (SEART) neural network model, to recognize handwritten Chinese characters. The SEART classifier has excellent performance, is fast, and has good generalization and exception handling abilities in complex problems. Using the fuzzy set theory in feature extraction and the neural network model as a classifier is helpful for reducing distortions, noise and variations. In spite of the poor thinning, a 90.24% recognition rate on average for the 605 test character categories was obtained. The database used is CCL/HCCR3 (provided by CCL, ITRI, Taiwan). The experiment not only confirms the feasibility of the proposed system, but also suggests that applying the fuzzy set theory and neural networks to recognition of handwritten Chinese characters is an efficient and promising approach.  相似文献   
5.
6.
ZnO nanowires were produced using an electrospinning method and used in gas sensors for the detection of ethanol at 220 °C. This electrospinning technique allows the direct placement of ZnO nanowires during their synthesis to bridge the sensor electrodes. An excellent sensitivity of nearly 90% was obtained at a low ethanol concentration of 10 ppm, and the rest obtained at higher ethanol concentrations, up to 600 ppm, all equal to or greater than 90%.  相似文献   
7.
Carbon nanotubes (CNTs) have been fabricated by microwave plasma-enhanced chemical vapor deposition for detecting the presence of ethanol vapor. The conductance of the CNTs decreases when the sensors are successively exposed to ethanol vapor at room temperature. The surface of the CNTs was modified in oxygen plasma to elevate the detection sensitivity for ethanol. Successful utilization of CNTs in gas sensors may open a new window for the development of novel nanostructure gas devices.  相似文献   
8.
Laboratory-scale temperature-controlled reactors were used to generate experimental data of thermophilic composting of vegetable waste. By fitting in experimental data of thermophilic composting, the obtained empirical model (also verified by F-test) appeared to be a quadratic form. The empirical model can be used to predict operating conditions (ratio of predried vegetable waste to rice husks, aeration rate, and reaction temperature and time) for thermophilic composting of vegetable waste in the subtropical region. Moreover, an innovative method for investigating kinetic behavior of thermophilic composting (an exoenzyme-catalyzed reaction followed by a multienzyme-catalyzed reaction) is proposed. The two biochemical reactions of thermophilic composting of vegetable waste followed Monod-type kinetics with the specific substrate utilization rate constants k1 and k2 of 0.026 and 4.5 mg COD∕mg VSS∕day, respectively. Accordingly, the exoenzyme-catalyzed reaction kinetically controls the overall process of thermophilic composting of vegetable waste.  相似文献   
9.
The relationship between the dielectric properties (dielectric constant, ε lam and loss factor, ε lam ) and thickness of FR-4 laminates was investigated. Thickness variations for laminates reinforced by the same style and number of plies of glass cloth were predominantly due to differences in the resin content. At each measurement frequency, values of both ε lam and ε lam were found to vary in an approximate linear manner with changes in the volume fraction of resin,V rsn . An empirical equation was derived that gives the dielectric constant of an FR-4 laminate, ε lam , as a function of the volume fraction of resin,V rsn , and the frequency at which the measurement was performed (between 1 kHz and 1 GHz). An alternative expression was also determined that permits the calculation of ε lam in the same frequency range from just the dielectric thickness of the laminate, providing the effective thickness of the reinforcement is known. The effective thickness of one style of glass cloth (2116) was experimentally determined to be 1.6 mils/ply. Effective thicknesses of most other common woven glass reinforcements used in FR-4 laminates were calculated and tabulated. The empirical relationships should be a valuable aid to electrical designers and others who need to know the frequency dependence of the dielectric properties of FR-4 laminates having different glass-to-resin ratios. Presented, in part, at the Fall 1988 Meeting of the IPC in Anaheim, California  相似文献   
10.
SiC/AIN composites with controlled interfacial solid solution were employed in the present work for investigating the effects of interfacial bonding and A1N polytypes on the mechanical properties. Platelike A1N polytypes and interfacial bonding were found to have substantial effects on the flexural strength, hardness, and fracture toughness.  相似文献   
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