scholarly journals Temporal Planning with Intermediate Conditions and Effects

2020 ◽  
Vol 34 (06) ◽  
pp. 9975-9982
Author(s):  
Alessandro Valentini ◽  
Andrea Micheli ◽  
Alessandro Cimatti
Keyword(s):  
Heuristic Search ◽  
Temporal Constraints ◽  
Planning Systems ◽  
Search Technique ◽  
Arbitrary Time ◽  
Temporal Planning ◽  
Definition Of ◽  
Better Than

Automated temporal planning is the technology of choice when controlling systems that can execute more actions in parallel and when temporal constraints, such as deadlines, are needed in the model. One limitation of several action-based planning systems is that actions are modeled as intervals having conditions and effects only at the extremes and as invariants, but no conditions nor effects can be specified at arbitrary points or sub-intervals.In this paper, we address this limitation by providing an effective heuristic-search technique for temporal planning, allowing the definition of actions with conditions and effects at any arbitrary time within the action duration. We experimentally demonstrate that our approach is far better than standard encodings in PDDL 2.1 and is competitive with other approaches that can (directly or indirectly) represent intermediate action conditions or effects.

Resolution and measurement in the scanning electron microscope

1987 ◽  
Vol 45 ◽  
pp. 534-537 ◽  
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Engineering Design ◽  
Resolving Power ◽  
Practical Applications ◽  
Instrument Resolution ◽  
Accurate Definition ◽  
Definition Of ◽  
Scanning Electron ◽  
Better Than

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.

A CSP-Based Approach for Temporal Constraints in Temporal Planning

2012 ◽  
Vol 35 (8) ◽  
pp. 1759
Author(s):  
Li-Hua WU ◽  
Ai-Xiang CHEN ◽  
Yun-Fei JIANG ◽  
Rui BIAN
Keyword(s):  
Temporal Constraints ◽  
Temporal Planning

scholarly journals An orthogonal terrain-following coordinate and its preliminary tests using 2-D idealized advection experiments

2014 ◽  
Vol 7 (4) ◽  
pp. 1767-1778 ◽  
Author(s):  
Y. Li ◽  
B. Wang ◽  
D. Wang ◽  
J. Li ◽  
L. Dong
Keyword(s):  
Rotation Angle ◽  
Computational Grids ◽  
Time Step ◽  
Numerical Errors ◽  
Terrain Following ◽  
Steep Terrain ◽  
Definition Of ◽  
Σ Coordinate ◽  
Basis Vectors ◽  
Better Than

Abstract. We have designed an orthogonal curvilinear terrain-following coordinate (the orthogonal σ coordinate, or the OS coordinate) to reduce the advection errors in the classic σ coordinate. First, we rotate the basis vectors of the z coordinate in a specific way in order to obtain the orthogonal, terrain-following basis vectors of the OS coordinate, and then add a rotation parameter b to each rotation angle to create the smoother vertical levels of the OS coordinate with increasing height. Second, we solve the corresponding definition of each OS coordinate through its basis vectors; and then solve the 3-D coordinate surfaces of the OS coordinate numerically, therefore the computational grids created by the OS coordinate are not exactly orthogonal and its orthogonality is dependent on the accuracy of a numerical method. Third, through choosing a proper b, we can significantly smooth the vertical levels of the OS coordinate over a steep terrain, and, more importantly, we can create the orthogonal, terrain-following computational grids in the vertical through the orthogonal basis vectors of the OS coordinate, which can reduce the advection errors better than the corresponding hybrid σ coordinate. However, the convergence of the grid lines in the OS coordinate over orography restricts the time step and increases the numerical errors. We demonstrate the advantages and the drawbacks of the OS coordinate relative to the hybrid σ coordinate using two sets of 2-D linear advection experiments.

scholarly journals 2D IPO's for Constant Speed Lines, Curves, NURBS

2019 ◽  
Author(s):  
Valere Huypens
Keyword(s):  
Major Axis ◽  
Pulse Method ◽  
Constant Speed ◽  
Sampled Data ◽  
Reference Pulse ◽  
Production Manager ◽  
Definition Of ◽  
The Right ◽  
2D And 3D ◽  
Better Than

<div>Current constant speed IPO's, usually, use Sampled-data IPO's and constant speed lines use the </div><div>wrong initialized software DDA-ipo's, which make these IPO's unusable. The Bresenham- and </div><div>midpoint IPO's are non-constant speed reference pulse IPO's with bounded inaccuracy.</div><div>By adding an ultra-fast 3-lines algorithm "PRM-cs" to the actual midpoint or Bresenham algorithms, </div><div>we convert these midpoint-ipo's to very fast, constant speed, reference pulse IPO's. </div><div>This applies to 2D-lines, 3D-lines, 2D-curves and 2D-NURBS.</div><div>The PRM-cs measures, in real-time, the length of the discrete curve and the PRM-cs is completely new. </div><div>We define the best IPO, the major axis principle and the LSD-priority. </div><div>The major axis principle holds for the actual 3D-line IPO's. These IPO's are, generally, inaccurate, </div><div>but they can be updated to constant speed 3D-line IPO's, when the production manager agrees.</div><div>The Digital Geometric Geometry (DAG) defines the discrete lines globally, but this global </div><div>definition of a discrete 3D-line, gives discrete 3D-lines whose accuracy is much less than the </div><div>accuracy of the best discrete 3D-lines (e.g. 37% worse).</div><div>We describe the three causes of the inaccurate (imperfect) discrete 3D-lines. </div><div>All existing pulse-rate or PRM-ipo's use a wrong initialization, which deteriorates the accuracy. </div><div>We determine the right initialization for the new PRM-cs and the updated PRM-ipo. </div><div>We propose the benchmark-ipo "listSIM-ipo". This constant speed IPO can, also, be used in real-</div><div>time for every 2D- and 3D-curve. </div><div>The 3rd-degree Trident NURB shows that the constant speed reference pulse method is much </div><div>better than the existing sampled-data methods.</div>

Graded Causation and Normality

2016 ◽  
Author(s):  
Joseph Y. Halpern
Keyword(s):  
Recent Work ◽  
Experimental Philosophy ◽  
Actual Causation ◽  
Definition Of ◽  
Better Than

Recent work in psychology and experimental philosophy has shown that judgments of actual causation are often influenced by consideration of defaults, typicality, and normality. This chapter shows the definition of causality introduced in Chapter 2 can be extended to defaults, typicality, and normality into account. The resulting framework takes actual causation to be both graded and comparative. Thus, it allows us to say that one cause is better than another. Examples showing the power of the approach are considered.

scholarly journals Prevalence and causes of childhood blindness in Huidong County, South China, primary ascertained by the key informants

2019 ◽  
Vol 4 (1) ◽  
pp. e000240
Author(s):  
Yanping Li ◽  
Jianhua Yan ◽  
Zhonghao Wang ◽  
Wenyong Huang ◽  
Shengsong Huang ◽  
...  
Keyword(s):  
South China ◽  
Cross Sectional Study ◽  
Anatomic Site ◽  
Cross Sectional ◽  
Childhood Blindness ◽  
Key Informants ◽  
The Public ◽  
Definition Of ◽  
Low Prevalence ◽  
Better Than

PurposeThe aim of this study is to ascertain the prevalence and causes of childhood blindness and severe visual impairment (BL/SVI) in Huidong, South China.MethodsThis cross-sectional study was conducted in early 2017 in areas of 139 816 children at the age of 0–15 as the study subjects. We used the trained key informants (KIs) to do preliminary visual test in the communities and refer those children suspected with blindness or unable to count fingers with both eyes at 5 m to hospital for further examination by paediatric ophthalmologist for causes. The WHO’s definition of BL/SVI was used, as blindness is best-corrected visual acuity worse than 0.05 in better eye and SVI is equal to or better than 0.05 but worse than 0.1 in better eye.ResultsThree hundred and fourteen KIs were trained. In total, 42 children with BL/SVI were found, and among them over half (22, 52.4%) were due to posterior segment disorders by anatomic site and 18 (42.9%) children were potentially preventable; these included BL/SVI caused by factors at children’s development in intrauterine and after birth. This established the prevalence of BL/SVI was at 0.31/1000 (95% CI 0.28 to 0.34/1000).ConclusionA low prevalence of childhood blindness was documented in this study. Establishment of surveillance system for disabled children including those with BL/SVI and better health education on eye care to the public according to the surveillance outcomes would help to reduce avoidable children’s BL/SVI further in China.

Designing the best avatar to reach millennials: gender differences in a restaurant choice

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Miguel Angel Gonzales-Chávez ◽  
Natalia Vila-Lopez
Keyword(s):  
Design Methodology ◽  
Content Type ◽  
Web Page Design ◽  
Design Attributes ◽  
Final Sample ◽  
The Feminine ◽  
Innovative Tool ◽  
Definition Of ◽  
Page Design ◽  
Better Than

PurposeThe two major purposes of this paper are as follows: first, to identify those appropriate key attributes that a commercial avatar promoting a leisure service must have in terms of likeability, expertise, credibility and attractiveness, with the final purpose of stimulating millennials' acceptance (emotions, buying intentions and electronic word of mouth [eWOM]) and second, to compare if men and women expect the same attributes in a successful avatar.Design/methodology/approachA three avatar designs were prepared for this experiment. Then, they were presented to the respondents to be evaluated changing the order of appearance for avoiding biases: (attractive/likeable, expert/credible and normal/basic avatars). The participants were recruited using an online procedure. The final sample size was 104 consumers. They provided 302 valid responses about the three different avatars. A restaurant chain Chili's in Peru was used to define this experiment.FindingsFindings of the study indicated that the design attributes of an avatar and the desired effects were related terms. Second, an expert/credible avatar worked better than an atractive/likeable one and also better than a common avatar, especially among the feminine target.Originality/valueThis paper tries to develop a guide for executives or entrepreneurs immersed in the gastronomic field in Peru, to enable them to make appropriate decisions regarding the definition of an attractive and disruptive web page design with an innovative tool: efficient commercial avatars.

High-accuracy four-dimensional trajectory prediction for civil aircraft

2012 ◽  
Vol 116 (1175) ◽  
pp. 45-66 ◽  
Author(s):  
W. Schuster ◽  
M. Porretta ◽  
W. Ochieng
Keyword(s):  
Flight Control ◽  
Three Dimensional ◽  
High Accuracy ◽  
Trajectory Prediction ◽  
Entire Duration ◽  
Civil Aircraft ◽  
Model Aircraft ◽  
Simplifying Assumptions ◽  
Definition Of ◽  
Better Than

AbstractCurrent state-of-the-art trajectory prediction tools typically model aircraft as three-dimensional point-masses, and make a number of simplifying assumptions about the actual and anticipated dynamics states of the aircraft. They are typically based on predefined settings obtained from existing databases such as Eurocontrol’s Bada rather than real-time information, including on the environment, available onboard the aircraft. This significantly limits trajectory prediction performance. This paper proposes a high-accuracy four-dimensional trajectory prediction model for use onboard civil aircraft, as well as by ground-based systems, which addresses these limitations. It is designed for strategic traffic capacity optimisation and conflict-detection and resolution over time-horizons covering the entire duration of a flight. The model incorporates a number of features including a novel flight-control-system and an enhanced flight-script that incorporates new taxonomy and content thereby enabling better definition of aircraft intent. The accuracy of the model is characterised using operational data acquired during a real flight trial. Results show that the performance of the proposed model is significantly better than the current models. Its accuracy is better than the required navigation performance for departure, en route and Non-Precision-Approach phases of flight.

The possibility of comparing line standards of length photographically

1953 ◽  
Vol 219 (1139) ◽  
pp. 500-515 ◽  
Keyword(s):  
Standard Deviation ◽  
Sufficient Accuracy ◽  
Visual Methods ◽  
Line Position ◽  
Single Measurement ◽  
Photographic Images ◽  
Suitable Definition ◽  
Definition Of ◽  
Better Than

Line standards of length, such as metres or yards, can be compared visually using micrometer microscopes to about one in ten millions in the most precise work. It seems possible that in a photographic comparison appreciably higher precision could be attained with less labour. Photographs of the lines on some line standards have been examined with a densitometer to determine the accuracy with which the distance between two photographic images of such lines could be measured. With suitable definition of line position a single measurement of this distance should have a standard deviation corresponding to less than 0.05 μ . Provided the temperature of the bars is known with sufficient accuracy it should be possible to compare two line standards to much better than one in ten millions in less than half the time taken by present visual methods. A machine for measuring the photographs is suggested. The characteristics of photographs of some lines are given in an appendix.

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