34,654 research outputs found
Agent-based modeling: a systematic assessment of use cases and requirements for enhancing pharmaceutical research and development productivity.
A crisis continues to brew within the pharmaceutical research and development (R&D) enterprise: productivity continues declining as costs rise, despite ongoing, often dramatic scientific and technical advances. To reverse this trend, we offer various suggestions for both the expansion and broader adoption of modeling and simulation (M&S) methods. We suggest strategies and scenarios intended to enable new M&S use cases that directly engage R&D knowledge generation and build actionable mechanistic insight, thereby opening the door to enhanced productivity. What M&S requirements must be satisfied to access and open the door, and begin reversing the productivity decline? Can current methods and tools fulfill the requirements, or are new methods necessary? We draw on the relevant, recent literature to provide and explore answers. In so doing, we identify essential, key roles for agent-based and other methods. We assemble a list of requirements necessary for M&S to meet the diverse needs distilled from a collection of research, review, and opinion articles. We argue that to realize its full potential, M&S should be actualized within a larger information technology framework--a dynamic knowledge repository--wherein models of various types execute, evolve, and increase in accuracy over time. We offer some details of the issues that must be addressed for such a repository to accrue the capabilities needed to reverse the productivity decline
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Learning the lessons from the developed world: e-banking security in Nigeria
In the past decade banks invested heavily in internet technology so as to engage in e-business and e-commerce activities. However, this development exposed banks to threats, such as online fraud. Consequently, there was a need to adopt security measures and controls to mitigate such threats. Banks in developed countries have developed a level of âbest practiceâ to reduce such online threats. The objective of this study was to explore the extent to which banks in the developing world were benefitting from the experiences of banks in the developed world in terms of how they address online security threats. Case studies of two Nigerian Banks were undertaken using interviews and short questionnaire. The findings show respondents perceived the level of threats to e-banking in Nigeria to be low. When adopting e-banking security controls, the case study banks placed more emphasis on the technical dimension than the human dimension. Senior management commitment is a significant barrier to adopting best practice, which is highlighted in limited financial resources being provided for new investment in training or customer education. The study concludes that senior managers need to change their perceptions and priorities towards IT security to reduce the vulnerability of their e-banking services
Coherent structures: Comments on mechanisms
There is now overwhelming evidence that in most turbulent flows there exist regions moving with the flow where the velocity and vorticity have a characteristic structure. These regions are called coherent structures because within them the large-scale distributions of velocity and/or vorticity remain coherent even as these structures move through the flow and interact with other structures. Since the flow enters and leaves the bounding surfaces of these structures, a useful definition for coherent structures is that they are open volumes with distinctive large-scale vorticity distributions. Possible fruitful directions for the study of the dynamics of coherent structures are suggested. Most coherent structures research to data was concentrated on measurement and kinematical analysis; there is now a welcome move to examine the dynamics of coherent structures, by a variety of different methods. A few of them will be described
Quantifying the Impact of Exogenous Non-Economic Factors on UK Transport Oil Demand
This paper attempts to quantify the impact of exogenous non-economic factors on UK transport oil demand (in addition to income, price, and fuel efficiency) by estimating the demand relationship for oil transport for 1960-2007 using the Structural Time Series Model. From this, the relative impact on UK transport oil demand from income, price, and efficiency are quantified. Moreover, the impact of the non-economic factors is also quantified, based on the premise that the estimated stochastic trend represents behavioural responses to changes in socio-economic factors and changes in lifestyles and attitudes. The estimated elasticities for income, price and efficiency are 0.6, -0.1, and -0.3 respectively and it is shown that for efficiency and price the overall contribution is relatively small, whereas the contribution from income and non-economic factors is relatively large. This has important implications for policy makers keen to reduce transport oil consumption and associated emissions, but not willing to reduce the trend rate of economic growth. Taxes and improved efficiency only have a limited impact; hence, a major thrust of policy should perhaps be on educating and informing consumers to persuade them to change their lifestyle and attitudes and thus reduce their consumption through the non-economic instruments route.Transport oil demand; Structural Time Series Model, STSM; Underlying Energy Demand Trend, UEDT; Exogenous Non-Economic Factors, ExNEF.
Granular Flow in a Vertically Vibrating Hopper
The behavior of the flow of glass spheres in a vertically vibrating hopper is examined. A two-dimensional hopper is mounted on a shaker that provides sinusoidal, vertical vibrations. Both the frequency and amplitude of the vibrations are adjustable. Hopper discharge rates and flow patterns are measured as the acceleration amplitude of the vibrations is increased from 0 to 4g's. Comparisons are made with unvibrated hopper flows and with a two-dimensional discrete element simulation model
Multimode interference devices for focusing in microfluidic channels
Low-cost, compact, automated optical microsystems for chemical analysis, such as microflow cytometers for identification of individual biological cells, require monolithically integrated microlenses for focusing in microfluidic channels, to enable high-resolution scattering and fluorescence measurements. The multimode interference device (MMI), which makes use of self-imaging in multimode waveguides, is shown to be a simple and effective alternative to the microlens for microflow cytometry. The MMIs have been designed, realized, and integrated with microfluidic channels in a silica-based glass waveguide material system. Focal spot sizes of 2.4 ”m for MMIs have been measured at foci as far as 43.7 ”m into the microfluidic channel
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