2,250 research outputs found
A methodology for the evaluation of program cost and schedule risk for the SEASAT program
An interactive computerized project management software package (RISKNET) is designed to analyze the effect of the risk involved in each specific activity on the results of the total SEASAT-A program. Both the time and the cost of each distinct activity can be modeled with an uncertainty interval so as to provide the project manager with not only the expected time and cost for the completion of the total program, but also with the expected range of costs corresponding to any desired level of significance. The nature of the SEASAT-A program is described. The capabilities of RISKNET and the implementation plan of a RISKNET analysis for the development of SEASAT-A are presented
Critical scaling for yield is independent from distance to isostaticity
Using discrete element simulations, we demonstrate that critical behavior for
yielding in soft disk and sphere packings is independent of distance to
isostaticity over a wide range of dimensionless pressures. Jammed states are
explored via quasistatic shear at fixed pressure, and the statistics of the
dimensionless shear stress of these states obey a scaling description
with diverging length scale . The critical
scaling functions and values of the scaling exponents are nearly independent of
distance to isostaticity despite the large range of pressures studied. Our
results demonstrate that yielding of jammed systems represents a distinct
nonequilibrium critical transition from the isostatic critical transition which
has been demonstrated by previous studies. Our results may also be useful in
deriving nonlocal rheological descriptions of granular materials, foams,
emulsions, and other soft particulate materials
Weakness of Will: Holton's View and a Criticism
I presented an adjusted account of Richard Holton's understanding of weakness of will. The account I uphold is similar to Holton's account in as much as it relies on resolutions and unreasonable revisions to them. However, I offer an additional criterion to evaluating an agent for weakness of will: an agent is weak-willed if the agent unreasonably fails to form a resolution. Unreasonably failing to form a resolution turns out to be failing to form a resolution when an agent judges the action as the best thing to do and the agent believing that if the resolution was formed, the agent would follow through.No embargoAcademic Major: Philosoph
The role of grain dynamics in determining the onset of sediment transport
Sediment transport occurs when the nondimensional fluid shear stress
at the bed surface exceeds a minimum value . A large collection of
data, known as the Shields curve, shows that is primarily a function
of the shear Reynolds number . It is commonly assumed that
occurs when the -dependent fluid
forces are too large to maintain static equilibrium for a typical surface
grain. A complimentary approach, which remains relatively unexplored, is to
identify as the applied shear stress at which grains
cannot stop moving. With respect to grain dynamics, can be viewed
as the viscous time scale for a grain to equilibrate to the fluid flow divided
by the typical time for the fluid force to accelerate a grain over the
characteristic bed roughness. We performed simulations of granular beds sheared
by a model fluid, varying only these two time scales. We find that the critical
Shields number obtained from the model mimics the
Shields curve and is insensitive to the grain properties, the model fluid flow,
and the form of the drag law. Quantitative discrepancies between the model
results and the Shields curve are consistent with previous calculations of lift
forces at varying . Grains at low find more stable
configurations than those at high due to differences in the grain
reorganization dynamics. Thus, instead of focusing on mechanical equilibrium of
a typical grain at the bed surface, may be better
described by the stress at which mobile grains cannot find a stable
configuration and stop moving.Comment: to appear in Phys. Rev. Fluid
Congestion Pricing: Long-Term Economic and Land-Use Effects
We employ a spatially disaggregated general equilibrium model of a regional economy that incorporates decisions of residents, firms, and developers integrated with a spatially disaggregated strategic transportation planning (START) model that features mode, time period, and route choice to evaluate economic effects of congestion pricing. First, we evaluate the long-run effects of a road-pricing policy based on the integrated model of land use, strategic transport, and regional economy (LUSTRE) and compare them with the short-term effects obtained from the START model alone. We then look at distributional effects of the policy in question and point out differences and similarities in the short run versus the long run. Finally, we analyze the mechanisms at the source of the economic and land-use effects induced by the road-pricing policy.traffic congestion, welfare analysis, CGE modeling, cordon tolls, distributional effects
Determining the Onset of Hydrodynamic Erosion in Turbulent Flow
We revisit the longstanding question of the onset of sediment transport
driven by a turbulent fluid flow via laboratory measurements. We use particle
tracking velocimetry to quantify the fluid flow as well as the motion of
individual grains. As we increase the flow speed above the transition to
sediment transport, we observe that an increasing fraction of grains are
transported downstream, although the average downstream velocity of the
transported grains remains roughly constant. However, we find that the fraction
of mobilized grains does not vanish sharply at a critical flow rate.
Additionally, the distribution of the fluctuating velocities of non-transported
grains becomes broader with heavier tails, meaning that unambiguously
separating mobile and static grains is not possible. As an alternative
approach, we quantify the statistics of grain velocities by using a mixture
model consisting of two forms for the grain velocities: a decaying-exponential
tail, which represents grains transported downstream, and a peaked distribution
centered at zero velocity, which represents grains that fluctuate due to the
turbulent flow but remain in place. Our results suggest that more sophisticated
statistical measures may be required to quantify grain motion near the onset of
sediment transport, particularly in the presence of turbulence.Comment: 9 pages, 7 figure
Long-Term Consequences of Congestion Pricing: A Small Cordon in the Hand Is Worth Two in the Bush
We evaluate and compare the long-term economic effects of three cordon-based road pricing schemes applied to the Washington, DC, metropolitan area. To conduct this analysis, we employ a spatially disaggregated general equilibrium model of a regional economy that incorporates the decisions of residents, firms, and developers, integrated with a spatially disaggregated strategic transportation planning model that features mode, time period, and route choice. We find that all cordon pricing schemes increase welfare of the residents, as well as lead to GDP growth. At the optimum, the larger cordon and a double cordon lead to higher benefits than the small cordon encompassing downtown core. Nevertheless, the small cordon seems to be a safer bet because when the toll charge is set suboptimally, the net benefits from the small cordon compared to the optimum change negligibly, while the net benefits from the larger cordon decline sharply as the charge deviates from the optimal level.traffic congestion, cordon tolls, land use, welfare analysis, road pricing, general equilibrium, simulation, Washington DC
Pengaruh Penyuluhan Kesehatan Terhadap Pengetahuan Perilaku Klien Hipertensi Di Puskesmas Bahu Manado
: Background: Hypertension is high blood pressure that is settled that the cause may not be known (essential hypertension, idiopathic or primary) or associated with other diseases (secondary hypertension). Based on data from Bahu Health Centers Manado mentioned in the period January 2014 to March 2014 there were a total of 207 patients with hypertension. Purpose of this research was to find out effect of health education on the knowledge of the client's behavior hypertension in Bahu Health Centers Manado. The research method used is pre experimental design with “One group Pre test post test” in one group. Sample in this study were 59 people, data processed by Wilcoxon Sign Rank test with significance (α) = 0.05. Results showed that there was a effect of health education on knowledge of the client's behavior hypertension in Bahu Health Centers Manado, where before it was given health education clients have less knowledge of the behavior of both (56%) and health education was given after the client has knowledge of good behavior (100%). based on Wilcoxon statistical test obtained r = 0.000, which meant p was smaller than α (0,05). Conclusion of this research there was a effect of health education on knowledge of the client's behavior hypertension in Bahu Health Centers Manado. Suggestion this research can be made in the new source in improving the quality of healthcare by making health counseling
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