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101.
102.
103.
A glass slide bioassay was used to evaluate male twospotted spider mite,Tetranychus urticae Koch, arrestment caused by quiescent deutonymph extract. Males that were guarding quiescent deutonymphs prior to being tested were arrested by a 3-mm-diameter circle of quiescent deutonymph extract; nonguarding males and adult females were not arrested. Extracts of allT. urticae instars tested caused male arrestment, but mean arrestment duration was longest with quiescent deutonymph extract. Arrestment by volatile perception of pheromone and upwind orientation to point sources of extract were not observed. The mono- and sesquiterpene alcohols previously identified as components of the pheromone did not arrest males. HPLC separation of extract resulted in four active fractions; a subtractive bioassay showed that three were essential to elicit maximum male response. 相似文献
104.
AA Brooks MR Johnson ME Pawson A Thomas LK Phelan HI Abdalla 《Canadian Metallurgical Quarterly》1996,11(12):2724-2731
Currently, there is a paucity of data describing endometrial growth, with most studies concentrating on endometrial thickness immediately prior to implantation or embryo transfer. This study looked at the individual and combined growth profiles of 67 volunteers receiving three different hormone replacement regimens. Each treatment regimen was in excess of that considered necessary for optimal growth, and all promoted an endometrial thickness that would be considered satisfactory for embryo transfer. Three patterns of growth were identified, but overall there was a decrease in the rate of endometrial growth with duration of treatment. As expected, analysis of variance did not show a significant difference between the mean growth profiles for the three hormone replacement regimens. The correlation (r = 0.45, P < 0.0001) between rank order on day 3 and day 10 of treatment indicates that interim analysis during early treatment cannot accurately predict later thickness, but a doubling of endometrial thickness can be expected in most cases. A relationship between endometrial thickness and either the treatment dose or serum concentrations of oestradiol was not found. These findings suggest that manipulation of endometrial growth is not possible by adjustment of either the treatment dose or serum concentration. The findings indicate that treatment beyond 12 days does not promote either a clinically significant increase in endometrial thickness of an excessive thickness, suggesting that maintenance of an oocyte recipient in a pseudo-follicular phase is unlikely to be disadvantageous to implantation. 相似文献
105.
Ravi S. Prasher Patrick E. Phelan 《Journal of Superconductivity and Novel Magnetism》1997,10(5):473-484
Solid-solid thermal boundary resistance plays an important role in the thermal stability of many electronic circuits, microdevices,
and superconducting devices. The thermal boundary resistance (R
b
) at any interface causes a temperature discontinuity, which can result in heat accumulation on one side of the boundary and
raise the temperature much above the stable region, causing device failure. With the advent of high-critical-temperature (high-T
c
) superconductors, it is possible to make superconducting devices at practically achievable temperatures. As the current trend
goes toward the development of more and more high-Tc superconducting devices, the need for a better understanding of the thermal boundary resistance of high-Tc superconductors becomes mandatory. This paper compiles all the theoretical and experimental work to date onR
b
in high-Tc superconductors, both in thin-film and bulk forms, and provides a critical review of the cited works. This paper also describes
the possible effect of the superconducting state onR
b
for high-T
c
superconductors, based on the experiments for both high-Tc and low-Tc bulk superconductors, and a possible explanation for these data based on the existing theory for low-T
c
superconductors. 相似文献
106.
Extending the Unified Modeling Language for ontology development 总被引:3,自引:0,他引:3
Kenneth Baclawski Mieczyslaw K. Kokar Paul A. Kogut Lewis Hart Jeffrey Smith Jerzy Letkowski Pat Emery 《Software and Systems Modeling》2002,1(2):142-156
There is rapidly growing momentum for web enabled agents that reason about and dynamically integrate the appropriate knowledge
and services at run-time. The dynamic integration of knowledge and services depends on the existence of explicit declarative
semantic models (ontologies). We have been building tools for ontology development based on the Unified Modeling Language
(UML). This allows the many mature UML tools, models and expertise to be applied to knowledge representation systems, not
only for visualizing complex ontologies but also for managing the ontology development process. UML has many features, such
as profiles, global modularity and extension mechanisms that are not generally available in most ontology languages. However,
ontology languages have some features that UML does not support. Our paper identifies the similarities and differences (with
examples) between UML and the ontology languages RDF and DAML+OIL. To reconcile these differences, we propose a modification
to the UML metamodel to address some of the most problematic differences. One of these is the ontological concept variously
called a property, relation or predicate. This notion corresponds to the UML concepts of association and attribute. In ontology
languages properties are first-class modeling elements, but UML associations and attributes are not first-class. Our proposal
is backward-compatible with existing UML models while enhancing its viability for ontology modeling. While we have focused
on RDF and DAML+OIL in our research and development activities, the same issues apply to many of the knowledge representation
languages. This is especially the case for semantic network and concept graph approaches to knowledge representations.
Initial sbmission: 16 February 2002 / Revised submission: 15 October 2002 Published online: 2 December 2002 相似文献
107.
Usability of many call center IVRs (Interactive Voice Response systems) is dismal. Callers dislike touch-tone IVRs and seek agent assistance at the first opportunity. However, because of high agent costs, call center managers continue to seek automation with IVRs. The challenge for call centers is providing user-friendly, yet cost-efficient, customer service. This article describes a comprehensive methodology for usability re-engineering of telephone voice user interfaces based on detailed call center assessment and call flow redesign. At the core of our methodology is a data-driven IVR assessment, in which we analyze end-to-end recordings of thousands of calls to evaluate IVR cost effectiveness and usability. Because agent time is the major cost driver in call center operations, we quantify cost-effectiveness in terms of agent time saved by automation in the IVR. We identify usability problems by carefully inspecting user-path diagrams, a visual representation of the sequence of events of thousands of calls as they flow through the IVR. Such an IVR assessment leads directly into call-flow redesign. Assessment insights lead to specific suggestions on how to improve a call-flow design. In addition, the assessment enables us to estimate the cost savings of a new design, thus providing the necessary business justification. We illustrate our IVR usability and re-engineering methodology with examples from large commercial call centers, demonstrating how the staged process maximizes the payback for the call center while minimizing risk. 相似文献
108.
We present a system for generating suggestions from highly‐constrained, continuous design spaces. We formulate suggestion as sampling from a probability distribution; constraints are represented as factors that concentrate probability mass around sub‐manifolds of the design space. These sampling problems are intractable using typical random walk MCMC techniques, so we adopt Hamiltonian Monte Carlo (HMC), a gradient‐based MCMC method. We implement HMC in a high‐performance probabilistic programming language, and we evaluate its ability to efficiently generate suggestions for two different, highly‐constrained example applications: vector art coloring and designing stable stacking structures. 相似文献
109.
Rheological properties of toluene solutions of nitrile butadiene rubber, of different molecular weights (Mw, 290,000,320,000, and 450,000) and acrylonitrile contents (30 and 40 percent), were investigated at low (0.1 S?1) to medium (20,0 S?1) shear rates, in order to determine their feasibility for dip-coating applications. The effect of a surface-active additive, bentonite, and the solid content (15 and 20 wt percent) on solution viscosity was of main interest. At low zero-shear viscosity (<50 Pa·S) an excessive sagging of the wet film was experienced; at high zeroshear viscosity (>100 Pa-·S) the coating showed poor leveling. Zeroshear viscosity was found to be less affected by bentonite than oligomer-based solutions, at the same time, the solid content and the molecular weight of the polymer had more pronounced effects. With a proper balance of the parameters, seamless coating films were achieved, with excellent tensile and tear properties, and good permeation resistance against benzene. 相似文献
110.
Algorithms for determining quality/cost/price tradeoffs in saturated markets are considered. A product is modeled by d real-valued qualities whose sum determines the unit cost of producing the product. This leads to the following optimization
problem: given a set of n customers, each of whom has certain minimum quality requirements and a maximum price they are willing to pay, design a new
product and select a price for that product in order to maximize the resulting profit. 相似文献