scholarly journals Remarks on the Erroneous Dispersion Surfaces From a Pair of a Hyperbolic Branch and An Elliptical Arc of the Intersected Two Laue Spheres Based on the Usual Crude Approximation

2011 ◽  
Vol 02 (03) ◽  
pp. 146-153 ◽  
Author(s):  
Tetsuo Nakajima
Keyword(s):  
Crude Approximation

A Method for Setting the Clearance Angle

1972 ◽  
Vol 30 ◽  
pp. 388-389
Author(s):  
Michael T. Bucek ◽  
Howard J. Arnott
Keyword(s):  
Experimental Evidence ◽  
Light Source ◽  
Black Spot ◽  
Critical Factor ◽  
Clearance Angle ◽  
Crude Approximation ◽  
Ultrathin Sections

It is believed by the authors, with supporting experimental evidence, that as little as 0.5°, or less, knife clearance angle may be a critical factor in obtaining optimum quality ultrathin sections. The degree increments located on the knife holder provides the investigator with only a crude approximation of the angle at which the holder is set. With the increments displayed on the holder one cannot set the clearance angle precisely and reproducibly. The ability to routinely set this angle precisely and without difficulty would obviously be of great assistance to the operator. A device has been contrived to aid the investigator in precisely setting the clearance angle. This device is relatively simple and is easily constructed. It consists of a light source and an optically flat, front surfaced mirror with a minute black spot in the center. The mirror is affixed to the knife by placing it permanently on top of the knife holder.

scholarly journals A STRUCTURAL RISK-NEUTRAL MODEL OF ELECTRICITY PRICES

2009 ◽  
Vol 12 (07) ◽  
pp. 925-947 ◽  
Author(s):  
RENÉ AÏD ◽  
LUCIANO CAMPI ◽  
ADRIEN NGUYEN HUU ◽  
NIZAR TOUZI
Keyword(s):  
Electricity Market ◽  
Structural Aspect ◽  
Electricity Prices ◽  
Forward Contracts ◽  
Spot Prices ◽  
Modeling Methodology ◽  
Risk Neutral ◽  
Risk Neutral Probabilities ◽  
Crude Approximation ◽  
Forward Prices

The objective of this paper is to present a model for electricity spot prices and the corresponding forward contracts, which relies on the underlying market of fuels, thus avoiding the electricity non-storability restriction. The structural aspect of our model comes from the fact that the electricity spot prices depend on the dynamics of the electricity demand at the maturity T, and on the random available capacity of each production means. Our model explains, in a stylized fact, how the prices of different fuels together with the demand combine to produce electricity prices. This modeling methodology allows one to transfer to electricity prices the risk-neutral probabilities of the market of fuels and under the hypothesis of independence between demand and outages on one hand, and prices of fuels on the other hand, it provides a regression-type relation between electricity forward prices and forward prices of fuels. Moreover, the model produces, by nature, the well-known peaks observed on electricity market data. In our model, spikes occur when the producer has to switch from one technology to the lowest cost available one. Numerical tests performed on a very crude approximation of the French electricity market using only two fuels (gas and oil) provide an illustration of the potential interest of this model.

A theory of short period tides in a rotating basin

1976 ◽  
Vol 281 (1299) ◽  
pp. 97-111 ◽  
Keyword(s):  
Analytical Model ◽  
Lake Michigan ◽  
Diurnal Tide ◽  
Semidiurnal Tide ◽  
Variable Depth ◽  
Amplitude Response ◽  
Tidal Forcing ◽  
Nodal Lines ◽  
Short Period ◽  
Crude Approximation

An analytical model of the forced tides in a rotating and enclosed basin of variable depth is formulated which includes the effects of basin shape, the rotating Fronde number, latitude, angle of orientation and dissipation on the semidiurnal and diurnal response. To a crude approximation contra solem rotation of nodal lines of the semidiurnal tide and diurnal tide at latitudes north at 45° occurs when the frequency of tidal forcing falls between the frequencies of the transverse and longitudinal free modes of oscillation. Predicted phase responses for the semidiurnal tide agree with measurements in the seven basins studied. The anomolous response found in Lake Michigan by Mortimer & Fee is attributed to bottom friction coincidence with an appropriate angle of orientation of the basin. Amplitude response in all cases is larger than observed which cannot be accounted for generally by reasonable coefficients of friction.

scholarly journals Social norms in indirect reciprocity with ternary reputations

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Yohsuke Murase ◽  
Minjae Kim ◽  
Seung Ki Baek
Keyword(s):  
Social Norms ◽  
Social Dilemmas ◽  
Evolutionary Stability ◽  
Reputation Systems ◽  
Indirect Reciprocity ◽  
Crude Approximation ◽  
Special Case

AbstractIndirect reciprocity is a key mechanism that promotes cooperation in social dilemmas by means of reputation. Although it has been a common practice to represent reputations by binary values, either ‘good’ or ‘bad’, such a dichotomy is a crude approximation considering the complexity of reality. In this work, we studied norms with three different reputations, i.e., ‘good’, ‘neutral’, and ‘bad’. Through massive supercomputing for handling more than thirty billion possibilities, we fully identified which norms achieve cooperation and possess evolutionary stability against behavioural mutants. By systematically categorizing all these norms according to their behaviours, we found similarities and dissimilarities to their binary-reputation counterpart, the leading eight. We obtained four rules that should be satisfied by the successful norms, and the behaviour of the leading eight can be understood as a special case of these rules. A couple of norms that show counter-intuitive behaviours are also presented. We believe the findings are also useful for designing successful norms with more general reputation systems.

scholarly journals Health technology assessment and mental health

2002 ◽  
Vol 26 (7) ◽  
pp. 243-245 ◽  
Author(s):  
Angus Mackay
Keyword(s):  
Mental Health ◽  
Cost Effectiveness ◽  
Clinical Excellence ◽  
Health Technology ◽  
Health Intervention ◽  
Health Improvement ◽  
Scottish Intercollegiate Guideline Network ◽  
Health Technologies ◽  
Clinical Procedures ◽  
Crude Approximation

In company with all other branches of the NHS, those concerned with mental health are currently the target of a plethora of standards, guidelines and derivatives thereof. In England and Wales, the responsibility for the production of national clinical guidelines rests with the National Institute for Clinical Excellence (NICE), and the Commission for Health Improvement (CHI) is charged with the monitoring of performance. In Scotland, the Scottish Intercollegiate Guideline Network (SIGN) and the Clinical Standards Board for Scotland (CSBS) undertake these respective responsibilities. However, NICE is also responsible for a rather different form of activity, and one that has forced it recurringly into the media limelight in the 2 years since its creation. This is the formulation of national advice on the clinical and cost-effectiveness of new and existing health technology. Health technology is a rather pedantic, if precisely defined, term that means essentially any health intervention and it includes medicines, devices, clinical procedures and even health care settings. Post-devolution and in the wake of the establishment of the Scottish Parliament, the Health Technology Board for Scotland (HTBS) was created by statute in April 2000. This organisation shares with NICE the responsibility for issuing advice on the clinical and cost-effectiveness of health technologies, in HTBS's case primarily to NHS Scotland. Therefore, two nationally-oriented organisations exist on either side of Hadrian's Wall, responsible to their respective Parliaments for providing authoritative opinions on whether or not a particular health intervention should be provided within the NHS. A crude approximation to the subject of this advice would be ‘value for money’. While, for reasons that will be explained, such a term is potentially misleading, it does serve to identify the basic elements of the need to which this activity is a response.

scholarly journals Secular Perturbations near Mean Motion Resonances

1999 ◽  
Vol 172 ◽  
pp. 427-428
Author(s):  
A.A. Christou
Keyword(s):  
Massless Particle ◽  
Planar System ◽  
Reference Orbit ◽  
Mean Motion Resonances ◽  
Mean Motion ◽  
Planetary Satellites ◽  
Orbit Fitting ◽  
Crude Approximation ◽  
Set Up ◽  
The Masses

In this work we attempt to make progress into assessing the importance of secular interactions between planetary satellites. In recent years, discrepancies have been observed in the expected positions of small planetary satellites (Bosh & Rivkin, 1996; Roddier et al., 1998). The existing ephemerides-producing algorithms for these objects assume fixed, elliptical and inclined orbits whose rate of precession is determined by oblateness alone. Even though the masses of these satellites are quite small relative to the planet (∼ 10−9 – 10−10) their small mutual separations and the existence of much larger satellites further out leaves open the possibility that in some cases at least the fixed-orbit assumption is only a crude approximation to reality. Two important dynamical mechanisms through which these orbits may evolve are resonant or secular interactions. In order to explore the possibility of the latter we have set up a simple planar system where an satellite in a circular orbit around a spherical planet is perturbing a massless particle which moves in proximity to various mean motion resonances. We aim to examine the effect of the resonance on the particle’s reference orbit by measuring the secular frequency. The effects of oblateness have not been taken into account as they are adequately modeled by orbit-fitting theories and can thus be readily subtracted.

LOCAL LINEAR INDEPENDENT COMPONENT ANALYSIS BASED ON CLUSTERING

2000 ◽  
Vol 10 (06) ◽  
pp. 439-451 ◽  
Author(s):  
JUHA KARHUNEN ◽  
SIMONA MĂlĂROIU ◽  
MIKA ILMONIEMI
Keyword(s):  
Independent Component Analysis ◽  
Data Model ◽  
Component Analysis ◽  
Independent Component ◽  
Self Organizing Maps ◽  
Crude Approximation ◽  
Data Grouping ◽  
Grouping Algorithm ◽  
Dense Representation ◽  
Better Than

In standard Independent Component Analysis (ICA), a linear data model is used for a global description of the data. Even though linear ICA yields meaningful results in many cases, it can provide a crude approximation only for general nonlinear data distributions. In this paper a new structure is proposed, where local ICA models are used in connection with a suitable grouping algorithm clustering the data. The clustering part is responsible for an overall coarse nonlinear representation of the data, while linear ICA models of each cluster are used for describing local features of the data. The goal is to represent the data better than in linear ICA while avoiding computational difficulties related with nonlinear ICA. Several data grouping methods are considered, including standard K-means clustering, self-organizing maps, and neural gas. Connections to existing methods are discussed, and experimental results are given for artificial data and natural images. Furthermore, a general theoretical framework encompassing a large number of methods for representing data is introduced. These range from global, dense representation methods to local, very sparse coding methods. The proposed local ICA methods lie between these two extremes.

scholarly journals Effect of Damping and Yielding on the Seismic Response of 3D Steel Buildings with PMRF

2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
Alfredo Reyes-Salazar ◽  
Achintya Haldar ◽  
Ramon Eduardo Rodelo-López ◽  
Eden Bojórquez
Keyword(s):  
Seismic Response ◽  
Three Dimensional ◽  
Lateral Force ◽  
Viscous Damping ◽  
Steel Buildings ◽  
Local Response ◽  
Equivalent Viscous Damping ◽  
Response Parameter ◽  
Mdof Systems ◽  
Crude Approximation

The effect of viscous damping and yielding, on the reduction of the seismic responses of steel buildings modeled as three-dimensional (3D) complex multidegree of freedom (MDOF) systems, is studied. The reduction produced by damping may be larger or smaller than that of yielding. This reduction can significantly vary from one structural idealization to another and is smaller for global than for local response parameters, which in turn depends on the particular local response parameter. The uncertainty in the estimation is significantly larger for local response parameter and decreases as damping increases. The results show the limitations of the commonly used static equivalent lateral force procedure where local and global response parameters are reduced in the same proportion. It is concluded that estimating the effect of damping and yielding on the seismic response of steel buildings by using simplified models may be a very crude approximation. Moreover, the effect of yielding should be explicitly calculated by using complex 3D MDOF models instead of estimating it in terms of equivalent viscous damping. The findings of this paper are for the particular models used in the study. Much more research is needed to reach more general conclusions.

Reading against Time

2020 ◽  
pp. 176-215
Author(s):  
Catherine Nicholson
Keyword(s):  
Faerie Queene ◽  
Brute Force ◽  
State Of Emergency ◽  
Norms And Values ◽  
Crude Approximation ◽  
Time Reading ◽  
The Moment ◽  
The Faerie Queene

This chapter addresses the concept of “reading against time”: reading that invokes a pressing sense of necessity in order to license a departure from established readerly norms and values. Book 5 of Edmund Spenser's The Faerie Queene has long frustrated those who look to Spenser's poetry for wit, subtlety, and profound spiritual insight, and who expect to work hard and slowly for such rewards. Inspired in part by sympathy for the character of Cymoent, who reminds one that taking one's time with a text is not only a readerly achievement but a readerly luxury, the chapter makes a case for the unpoetic reader, for whom the demands and the insights of the moment supersede the values of patience and diligence on which poetic reading depends. The degree to which such readers have succeeded in extracting value from a part of Spenser's poem that has left more conscientious readers cold suggests that there is something to be said for urgency, haste, brute force, crude approximation, and willful anachronism: for all of the straitening and reductive tendencies of reading in a state of emergency. To put it another way, it is worth considering the etymological link between criticism and crisis.

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