Directory of Open Access Journals (Sweden)
Daniel R Zerbino
Full Text Available BACKGROUND: Despite the short length of their reads, micro-read sequencing technologies have shown their usefulness for de novo sequencing. However, especially in eukaryotic genomes, complex repeat patterns are an obstacle to large assemblies. PRINCIPAL FINDINGS: We present a novel heuristic algorithm, Pebble, which uses paired-end read information to resolve repeats and scaffold contigs to produce large-scale assemblies. In simulations, we can achieve weighted median scaffold lengths (N50 of above 1 Mbp in Bacteria and above 100 kbp in more complex organisms. Using real datasets we obtained a 96 kbp N50 in Pseudomonas syringae and a unique 147 kbp scaffold of a ferret BAC clone. We also present an efficient algorithm called Rock Band for the resolution of repeats in the case of mixed length assemblies, where different sequencing platforms are combined to obtain a cost-effective assembly. CONCLUSIONS: These algorithms extend the utility of short read only assemblies into large complex genomes. They have been implemented and made available within the open-source Velvet short-read de novo assembler.
Heuristics in Conflict Resolution
Drescher, Christian; Kaufmann, Benjamin; Schaub, Torsten
2010-01-01
Modern solvers for Boolean Satisfiability (SAT) and Answer Set Programming (ASP) are based on sophisticated Boolean constraint solving techniques. In both areas, conflict-driven learning and related techniques constitute key features whose application is enabled by conflict analysis. Although various conflict analysis schemes have been proposed, implemented, and studied both theoretically and practically in the SAT area, the heuristic aspects involved in conflict analysis have not yet received much attention. Assuming a fixed conflict analysis scheme, we address the open question of how to identify "good'' reasons for conflicts, and we investigate several heuristics for conflict analysis in ASP solving. To our knowledge, a systematic study like ours has not yet been performed in the SAT area, thus, it might be beneficial for both the field of ASP as well as the one of SAT solving.
Heuristic optimization in penumbral image for high resolution reconstructed image
International Nuclear Information System (INIS)
Penumbral imaging is a technique which uses the fact that spatial information can be recovered from the shadow or penumbra that an unknown source casts through a simple large circular aperture. The size of the penumbral image on the detector can be mathematically determined as its aperture size, object size, and magnification. Conventional reconstruction methods are very sensitive to noise. On the other hand, the heuristic reconstruction method is very tolerant of noise. However, the aperture size influences the accuracy and resolution of the reconstructed image. In this article, we propose the optimization of the aperture size for the neutron penumbral imaging.
High Resolution K-Band Spectroscopy of Selected M Dwarfs
Nakajima, Tadashi
2013-06-01
We propose to obtain high-resolution K-band spectra of selected M dwarfs to study stellar properties such as effective temperature and metallicity. M dwarfs are under scrutiny as potential planet hosts. They have sufficiently low masses and small radii that exoplanets induce considerably larger reflex velocities and transit depths than an identical planet would around larger, more massive hosts. The low temperatures of M dwarfs imply short-period planets are in the habitable zone. However, due to the cool atmosphere, the characterization of M dwarfs at visible wavelengths has been rather difficult and the previously known stellar parameters have been rather crude. Recently a new method to use medium resolution K-band spectroscopy to determine the effective temperature and metallicity was devised. The purposes of this proposal is to examine the validity of the new method with a spectral resolution one order of magnitude higher and, if possible, to find a better method to determine the stellar properties.
High-resolution wide-band Fast Fourier Transform spectrometers
Klein, Bernd; Krämer, Ingo; Bell, Andreas; Meyer, Klaus; Güsten, Rolf
2012-01-01
We describe the performance of our latest generations of sensitive wide-band high-resolution digital Fast Fourier Transform Spectrometer (FFTS). Their design, optimized for a wide range of radio astronomical applications, is presented. Developed for operation with the GREAT far infrared heterodyne spectrometer on-board SOFIA, the eXtended bandwidth FFTS (XFFTS) offers a high instantaneous bandwidth of 2.5 GHz with 88.5 kHz spectral resolution and has been in routine operation during SOFIA's Basic Science since July 2011. We discuss the advanced field programmable gate array (FPGA) signal processing pipeline, with an optimized multi-tap polyphase filter bank algorithm that provides a nearly loss-less time-to-frequency data conversion with significantly reduced frequency scallop and fast sidelobe fall-off. Our digital spectrometers have been proven to be extremely reliable and robust, even under the harsh environmental conditions of an airborne observatory, with Allan-variance stability times of several 1000 se...
An Algorithm in VC－++ for Improving Ground Resolution of TM Band 6
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
@@It is well known that Landsat TM images and remotesensing data sets are widely used in the geological fields.There are 7 different bands of wavelength, of which the sixth one has a much lower ground resolution compared with those of the other six bands. Nevertheless, the Landsat TM images are of important significance of the rock spectrum reflection and geothermal exploration. The raising of the ground resolution of TM band 6 to those of the other bands is not only in teresting but also valuable. This paper illustrates an algo rithm for the increase of ground resolution of the band 6 that is feasible in the following 5 steps, based on the combination of multi-variable regression with semi variogram and on the fusion of the data from other six bands: (1) Testing the correlation between band 6andoneof bands 1－5, 7.
Resolution of the Band Gap Prediction Problem for Materials Design.
Crowley, Jason M; Tahir-Kheli, Jamil; Goddard, William A
2016-04-01
An important property with any new material is the band gap. Standard density functional theory methods grossly underestimate band gaps. This is known as the band gap problem. Here, we show that the hybrid B3PW91 density functional returns band gaps with a mean absolute deviation (MAD) from experiment of 0.22 eV over 64 insulators with gaps spanning a factor of 500 from 0.014 to 7 eV. The MAD is 0.28 eV over 70 compounds with gaps up to 14.2 eV, with a mean error of -0.03 eV. To benchmark the quality of the hybrid method, we compared the hybrid method to the rigorous GW many-body perturbation theory method. Surprisingly, the MAD for B3PW91 is about 1.5 times smaller than the MAD for GW. Furthermore, B3PW91 is 3-4 orders of magnitude faster computationally. Hence, B3PW91 is a practical tool for predicting band gaps of materials before they are synthesized and represents a solution to the band gap prediction problem. PMID:26944092
An idiogram on pachytene bivalents with high resolution multiple bands of zebrafish (Danio rerio)
Institute of Scientific and Technical Information of China (English)
YI; Meisheng(易梅生); YU; Qixing; (余其兴); HUANG; Lin(黄琳)
2002-01-01
Well spread pachytene bivalents with high-resolution multiple bands of zebrafish were obtained after the testes were treated with alkaline hypotonic solution and high chloroform fixative solution. This might be the pattern with the largest number of multiple bands obtained from fish chromosomes so far published. Both the number and character of the bands in each bivalent were stable. According to the principles of ISCN (1978) and ISCN (1981), an idiogram of 599 bands was set up, and the detailed description of the landmark system and the band positions were given.
Thermal infrared band imagery provides key information for detecting wild fires, mapping land surface energy fluxes and evapotranspiration, monitoring urban heat fluxes and drought monitoring. Thermal infrared (TIR) imagery at fine resolution is required for field scale applications. However, therma...
2015-01-01
How can we advance knowledge? Which methods do we need in order to make new discoveries? How can we rationally evaluate, reconstruct and offer discoveries as a means of improving the ‘method’ of discovery itself? And how can we use findings about scientific discovery to boost funding policies, thus fostering a deeper impact of scientific discovery itself? The respective chapters in this book provide readers with answers to these questions. They focus on a set of issues that are essential to the development of types of reasoning for advancing knowledge, such as models for both revolutionary findings and paradigm shifts; ways of rationally addressing scientific disagreement, e.g. when a revolutionary discovery sparks considerable disagreement inside the scientific community; frameworks for both discovery and inference methods; and heuristics for economics and the social sciences.
Heuristic revision by Heuristic Space Exploration
Taillandier, Patrick
2009-01-01
International audience Heuristics are often used to solve complex problems. Indeed, such problem-specific knowledge, when pertinent, helps to efficiency find good solutions to complex problems. Unfortunately, acquiring and maintaining a heuristic set can be fastidious. In order to face this problem, a approach consists in revising the heuristic sets by means of experiments. In this paper, we are interested in a specific revision method of this type based on the exploration of the heuristic...
Performance of high-resolution X-band radar for rainfall measurement in The Netherlands
Directory of Open Access Journals (Sweden)
C. Z. van de Beek
2010-02-01
Full Text Available This study presents an analysis of 195 rainfall events gathered with the X-band weather radar SOLIDAR and a tipping bucket rain gauge network near Delft, The Netherlands, between May 1993 and April 1994. The aim of this paper is to present a thorough analysis of a climatological dataset using a high spatial (120 m and temporal (16 s resolution X-band radar. This makes it a study of the potential for high-resolution rainfall measurements with non-polarimetric X-band radar over flat terrain. An appropriate radar reflectivity – rain rate relation is derived from measurements of raindrop size distributions and compared with radar – rain gauge data. The radar calibration is assessed using a long-term comparison of rain gauge measurements with corresponding radar reflectivities as well as by analyzing the evolution of the stability of ground clutter areas over time. Three different methods for ground clutter correction as well as the effectiveness of forward and backward attenuation correction algorithms have been studied. Five individual rainfall events are discussed in detail to illustrate the strengths and weaknesses of high-resolution X-band radar and the effectiveness of the presented correction methods. X-band radar is found to be able to measure the space-time variation of rainfall at high resolution, far greater than what can be achieved by rain gauge networks or a typical operational C-band weather radar. On the other hand, SOLIDAR can suffer from receiver saturation, wet radome attenuation as well as signal loss along the path. During very strong convective situations the signal can even be lost completely. In combination with several rain gauges for quality control, high resolution X-band radar is considered to be suitable for rainfall monitoring over relatively small (urban catchments. These results offer great prospects for the new high resolution polarimetric doppler X-band radar IDRA.
Performance of high-resolution X-band radar for rainfall measurement in The Netherlands
Directory of Open Access Journals (Sweden)
C. Z. van de Beek
2009-09-01
Full Text Available This study presents an analysis of 195 rainfall events gathered with the X-band weather radar SOLIDAR and a tipping bucket rain gauge network near Delft, The Netherlands, between May 1993 and April 1994. The high spatial (120 m and temporal (16 s resolution of the radar combined with the extent of the database make this study a climatological analysis of the potential for high-resolution rainfall measurement with non-polarimetric X-band radar over completely flat terrain. An appropriate radar reflectivity – rain rate relation is derived from measurements of raindrop size distributions and compared with radar – rain gauge data. The radar calibration is assessed using a long-term comparison of rain gauge measurements with corresponding radar reflectivities as well as by analyzing the evolution of the stability of ground clutter areas over time. Three different methods for ground clutter correction as well as the effectiveness of forward and backward attenuation correction algorithms have been studied. Five individual rainfall events are discussed in detail to illustrate the strengths and weaknesses of high-resolution X-band radar and the effectiveness of the presented correction methods. X-band radar is found to be able to measure the space-time variation of rainfall at high resolution, far greater than can be achieved by rain gauge networks or a typical operational C-band weather radar. On the other hand, SOLIDAR can suffer from receiver saturation, wet radome attenuation as well as signal loss along the path. During very strong convective situations the signal can even be lost completely. In combination with several rain gauges for quality control, high resolution X-band radar is considered to be suitable for rainfall monitoring over relatively small (urban catchments. These results offer great prospects for the new high resolution polarimetric doppler X-band radar IDRA.
Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS
Energy Technology Data Exchange (ETDEWEB)
Kozyukhin, S., E-mail: sergkoz@igic.ras.ru [Russian Academy of Science, Institute of General and Inorganic Chemistry (Russian Federation); Golovchak, R. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Kovalskiy, A. [Lehigh University, Department of Materials Science and Engineering (United States); Shpotyuk, O. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Jain, H. [Lehigh University, Department of Materials Science and Engineering (United States)
2011-04-15
High-resolution X-ray photoelectron spectroscopy (XPS) is used to study regularities in the formation of valence band electronic structure in binary As{sub x}Se{sub 100-x}, As{sub x}S{sub 100-x}, Ge{sub x}Se{sub 100-x} and Ge{sub x}S{sub 100-x} chalcogenide vitreous semiconductors. It is shown that the highest occupied energetic states in the valence band of these materials are formed by lone pair electrons of chalcogen atoms, which play dominant role in the formation of valence band electronic structure of chalcogen-rich glasses. A well-expressed contribution from chalcogen bonding p electrons and more deep s orbitals are also recorded in the experimental valence band XPS spectra. Compositional dependences of the observed bands are qualitatively analyzed from structural and compositional points of view.
Design of a High Resolution X-band Dopler Polarimetric Radar
Figueras i Ventura, J.
2009-01-01
The impact of the increase in anthropogenic aerosols on the global climate and the precipitation cycle is not yet fully understood. One of the reasons for that is the lack of sound measurements. In particular, high temporal and spatial resolution measurements of precipitation, coupled with measurements from other instruments, would be desired to better understand such complex processes. IRCTR has design a high resolution X-band Doppler Polarimetric Weather Radar called IDRA (IRCTR Drizzle Rad...
Band-pass-filter for secondary electrons in ultra-high resolution SEM
Czech Academy of Sciences Publication Activity Database
Konvalina, Ivo; Mika, Filip; Müllerová, Ilona; Krátký, Stanislav
Göttingen: DGE, 2015, s. 378-379. [Microscopy Conference 2015. Göttingen (DE), 06.09.2015-11.09.2015] R&D Projects: GA TA ČR(CZ) TE01020118 Institutional support: RVO:68081731 Keywords : Band-pass- filter * SEM * ultra-high resolution Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
Madsen, Soren N.; Carsey, Frank D.; Turtle, Elizabeth P.
2003-01-01
The topographic data set obtained by MOLA has provided an unprecedented level of information about Mars' geologic features. The proposed flight of JIMO provides an opportunity to accomplish a similar mapping of and comparable scientific discovery for the Jovian moons through us of an interferometric imaging radar analogous to the Shuttle radar that recently generated a new topographic map of Earth. A Ka-band single pass across-track synthetic aperture radar (SAR) interferometer can provide very high resolution surface elevation maps. The concept would use two antennas mounted at the ends of a deployable boom (similar to the Shuttle Radar Topographic Mapper) extended orthogonal to the direction of flight. Assuming an orbit altitude of approximately 100 km and a ground velocity of approximately 1.5 km/sec, horizontal resolutions at the 10 meter level and vertical resolutions at the sub-meter level are possible.
A high-resolution oxygen A-band spectrometer (HABS and its radiation closure
Directory of Open Access Journals (Sweden)
Q. Min
2014-02-01
Full Text Available The pressure dependence of oxygen A-band absorption enables the retrieval of the vertical profiles of aerosol and cloud properties from oxygen A-band spectrometry. To improve the understanding of oxygen A-band inversions and utility, we developed a high-resolution oxygen A-band spectrometer (HABS, and deployed it at Howard University Beltsville site during the NASA Discover Air-Quality Field Campaign in July 2011. The HABS has the ability to measure solar direct-beam and zenith diffuse radiation through a telescope automatically. It exhibits excellent performance: stable spectral response ratio, high signal-to-noise ratio (SNR, high spectrum resolution (0.16 nm, and high Out-of-Band Rejection (10−5. To evaluate the spectra performance of HABS, a HABS simulator has been developed by combing the discrete ordinates radiative transfer (DISORT code with the High Resolution Transmission (HTRAN database HITRAN2008. The simulator uses double-k approach to reduce the computational cost. The HABS measured spectra are consistent with the related simulated spectra. For direct-beam spectra, the confidence intervals (95% of relative difference between measurements and simulation are (−0.06, 0.05 and (−0.08, 0.09 for solar zenith angles of 27° and 72°, respectively. The main differences between them occur at or near the strong oxygen absorption line centers. They are mainly caused by the noise/spikes of HABS measured spectra, as a result of combined effects of weak signal, low SNR, and errors in wavelength registration and absorption line parameters. The high-resolution oxygen A-band measurements from HABS can constrain the active radar retrievals for more accurate cloud optical properties, particularly for multi-layer clouds and for mixed-phase clouds.
Performance of high-resolution X-band weather radar networks - the PATTERN example
Lengfeld, K.; Clemens, M.; Münster, H.; Ament, F.
2014-12-01
This publication intends to prove that a network of low-cost local area weather radars (LAWR) is a reliable and scientifically valuable complement to nationwide radar networks. A network of four LAWRs has been installed in northern Germany within the framework of the Precipitation and Attenuation Estimates from a High-Resolution Weather Radar Network (PATTERN) project observing precipitation with a temporal resolution of 30 s, a range resolution of 60 m and a sampling resolution of 1° in the azimuthal direction. The network covers an area of 60 km × 80 km. In this paper, algorithms used to obtain undisturbed precipitation fields from raw reflectivity data are described, and their performance is analysed. In order to correct operationally for background noise in reflectivity measurements, noise level estimates from the measured reflectivity field are combined with noise levels from the last 10 time steps. For detection of non-meteorological echoes, two different kinds of clutter algorithms are applied: single-radar algorithms and network-based algorithms. Besides well-established algorithms based on the texture of the logarithmic reflectivity field (TDBZ) or sign changes in the reflectivity gradient (SPIN), the advantage of the unique features of the high temporal and spatial resolution of the network is used for clutter detection. Overall, the network-based clutter algorithm works best with a detection rate of up to 70%, followed by the classic TDBZ filter using the texture of the logarithmic reflectivity field. A comparison of a reflectivity field from the PATTERN network with the product from a C-band radar operated by the German Meteorological Service indicates high spatial accordance of both systems in the geographical position of the rain event as well as reflectivity maxima. Long-term statistics from May to September 2013 prove very good accordance of the X-band radar of the network with C-band radar, but, especially at the border of precipitation events
High resolution 4. 2 K near band-gap photoluminescence spectrum of mercuric iodide
Energy Technology Data Exchange (ETDEWEB)
Bao, X.J.; Schlesinger, T.E. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA (USA)); James, R.B. (Theoretical Division, Sandia National Laboratories, Livermore, CA (USA)); Ortale, C.; van den Berg, L. (EG G Energy Measurement, Inc. Goleta, CA (USA))
1990-09-15
We have investigated in detail (resolution up to 0.35 A) the near-band-gap 4.2 K photoluminescence spectrum of undoped Hgl{sub 2} in its red tetragonal form. At least 26 emission lines are resolved in the wavelength region between 5290 and 5400 A. Many of these are reported for the first time. We have also tabulated the steplike emission lines between 5220 and 5290 A.
High resolution 4.2 K near band-gap photoluminescence spectrum of mercuric iodide
Bao, X. J.; Schlesinger, T. E.; James, R. B.; Ortale, C.; van den Berg, L.
1990-09-01
We have investigated in detail (resolution up to 0.35 Å) the near-band-gap 4.2 K photoluminescence spectrum of undoped Hgl2 in its red tetragonal form. At least 26 emission lines are resolved in the wavelength region between 5290 and 5400 Å. Many of these are reported for the first time. We have also tabulated the steplike emission lines between 5220 and 5290 Å.
Probe-Fed Stacked Microstrip Patch Antenna for High-Resolution Polarimetric C-Band SAR
DEFF Research Database (Denmark)
Granholm, Johan; Skou, Niels
2000-01-01
The paper describes a C-band, dual-linear polarization wideband antenna for use in the next-generation of the Danish high-resolution, airborne polarimetric synthetic aperture radar (SAR) system, EMISAR. The design and performance of a probe-fed, stacked microstrip patch element, operating from 4.......9 GHz to 5.7 GHz and a small 2×2-element test-array of these are discussed....
Performance of high-resolution X-band weather radar networks – the PATTERN example
Directory of Open Access Journals (Sweden)
K. Lengfeld
2014-08-01
Full Text Available This publication intends to proof that a network of low-cost local area weather radars (LAWR is a reliable and scientifically valuable complement to nationwide radar networks. A network of four LAWRs has been installed in northern Germany within the framework of the project Precipitation and Attenuation Estimates from a High-Resolution Weather Radar Network (PATTERN observing precipitation with temporal resolution of 30 s, azimuthal resolution of 1° and spatial resolution of 60 m. The network covers an area of 60 km × 80 km. In this paper algorithms used to obtain undisturbed precipitation fields from raw reflectivity data are described and their performance is analysed. In order to correct for background noise in reflectivity measurements operationally, noise level estimates from the measured reflectivity field is combined with noise levels from the last 10 time steps. For detection of non-meteorological echoes two different kinds of clutter filters are applied: single radar algorithms and network based algorithms that take advantage of the unique features of high temporal and spatial resolution of the network. Overall the network based clutter filter works best with a detection rate of up to 70%, followed by the classic TDBZ filter using the texture of the logarithmic reflectivity field. A comparison of a reflectivity field from the PATTERN network with the product from a C-band radar operated by the German Meteorological Service indicates high spatial accordance of both systems in geographical position of the rain event as well as reflectivity maxima. A longterm study derives good accordance of X-band radar of the network with C-band radar. But especially at the border of precipitation events the standard deviation within a range gate of the C-band radar with range resolution of 1 km is up to 3 dBZ. Therefore, a network of high-resolution low-cost LAWRs can give valuable information on the small scale structure of rain events in areas of
High resolution spectral analysis of oxygen. III. Laboratory investigation of the airglow bands
Drouin, Brian J.; Yu, Shanshan; Elliott, Ben M.; Crawford, Timothy J.; Miller, Charles E.
2013-10-01
We report the first high spectral resolution laboratory measurements of simulated oxygen A-band night glow. Our static discharge system approximates the conditions of the mesospheric oxygen night glow - suggesting O(1D) + O2 (X ^3Σ _g^-) → O(3P) + O2 (b ^1Σ _g^+) → O2 (X ^3Σ _g^-) + hν as the primary source of the emission. Additionally, use of the static cell has enabled us to collect spectra for all six molecular oxygen isotopologues using isotopically enriched samples. The (0,0), (0,1), and (1,1) b - X vibrational bands were observed for all six isotopologues. The (1,2) and (2,2) bands were also observed for 16O2. The frequencies of the observed (0,1) transitions resolved discrepancies in Raman data for 16O17O, 17O2, and 17O18O, enabling us to improve the vibrational parameterization of the ground electronic state global fit. Rotationally resolved intensities were determined for the (0,0), (0,1), and (1,1) bands. The experimental band intensity ratios I(0,0)/I(0,1) = 13.53(24); I(1,1)/I(1,0) = 11.9(65); I(0,0)/I(0,2) = 503(197); and I(1,1)/I(1,2) = 5.6(19) are in excellent agreement with the recent mesospheric remote sensing data and calculated Franck-Condon factors.
Double Bright Band Observations with High-Resolution Vertically Pointing Radar, Lidar, and Profiles
Emory, Amber E.; Demoz, Belay; Vermeesch, Kevin; Hicks, Michael
2014-01-01
On 11 May 2010, an elevated temperature inversion associated with an approaching warm front produced two melting layers simultaneously, which resulted in two distinct bright bands as viewed from the ER-2 Doppler radar system, a vertically pointing, coherent X band radar located in Greenbelt, MD. Due to the high temporal resolution of this radar system, an increase in altitude of the melting layer of approximately 1.2 km in the time span of 4 min was captured. The double bright band feature remained evident for approximately 17 min, until the lower atmosphere warmed enough to dissipate the lower melting layer. This case shows the relatively rapid evolution of freezing levels in response to an advancing warm front over a 2 h time period and the descent of an elevated warm air mass with time. Although observations of double bright bands are somewhat rare, the ability to identify this phenomenon is important for rainfall estimation from spaceborne sensors because algorithms employing the restriction of a radar bright band to a constant height, especially when sampling across frontal systems, will limit the ability to accurately estimate rainfall.
A High-Resolution Study of Near-Infrared Diffuse Interstellar Bands
Rawlings, M G; Kerr, T H
2014-01-01
We present high-resolution echelle spectroscopic observations of the two near- infrared (NIR) Diffuse Interstellar Bands (DIBs) at 13175 A and 11797.5 A. The DIBs have been observed in a number of diffuse interstellar medium sightlines that exhibit a wide range of visual extinctions. Band profiles are similar to those seen in narrow DIBs, clearly asymmetric and can be closely fitted in most cases using two simple Gaussian components. Gaussian fits were generally found to be more successful than fits based on a multiple-cloud model using a template DIB profile. For a sample of 9 objects in which both bands are observed, the strength of both NIR DIBs generally increases with A(V), and we report a correlation between the two observed bands over a large A(V) range and widely-separated lines of sight. The strength of the two bands is also compared against those of two visual DIBs and the diffuse ISM aliphatic dust absorption feature at 3.4 microns previously detected in the same sightlines. We find that the NIR DI...
Analysis of several high-resolution infrared bands of spiropentane, C5H8
Energy Technology Data Exchange (ETDEWEB)
Maki, Arthur G.; Price, Joseph E.; Harzan, J.; Nibler, Joseph W.; Weber, Alfons; Masiello, Tony; Blake, Thomas A.
2015-06-01
he high-resolution infrared absorption spectrum of spiropentane (C5H8) has been measured from 200 to 4000 cm 1, and a detailed analysis is presented for eight bands in the region from 700 to 2200 cm 1. Two fundamental perpendicular bands were analyzed, m22 and m24 near 1050 and 780 cm 1, respectively, along with two fundamental parallel bands, m14 and m16 near 1540 and 990 cm1, respectively. Two other fundamentals, m17 and m23, are seen as intense overlapping bands near 880 cm*1 and are Coriolis-coupled, producing a complex mixture in which only P-branch transitions could be tentatively assigned for m17. In addition, three binary combination bands were fit at about 1570, 2082, and 2098 cm*1 which are assigned as either 2m24 or m5 + m16 in the first case, m4 + m22 in the second case, and 2m22 in the latter case. The two l-type resonance constants, q+ and q*, were determined for each of the two perpendicular fundamentals m22 and m24. Those two constants were also responsible for splittings observed in the K = 3 levels of m24. For the ground state the order of the split K = 2 B1/B2 levels has been reversed from that reported previously, based on the measurements and assignments for the m24 band. Rovibrational parameters deduced from the analyses are compared with those obtained from density functional Gaussian calculations at the anharmonic level.
Archer, Charles J.; Blocksome, Michael A.; Heidelberger, Philip; Kumar, Sameer; Parker, Jeffrey J.; Ratterman, Joseph D.
2011-06-07
Methods, compute nodes, and computer program products are provided for heuristic status polling of a component in a computing system. Embodiments include receiving, by a polling module from a requesting application, a status request requesting status of a component; determining, by the polling module, whether an activity history for the component satisfies heuristic polling criteria; polling, by the polling module, the component for status if the activity history for the component satisfies the heuristic polling criteria; and not polling, by the polling module, the component for status if the activity history for the component does not satisfy the heuristic criteria.
Microradarnet: AN Innovative High-Resolution Low-Cost X-Band Weather Radar Network
Turso, S.; Zambotto, M.; Gabella, M.; Orione, F.; Notarpietro, R.; Perona, G.
2009-09-01
In this paper, an innovative micro radar network for meteorological purposes has been presented. The key aspects of this network, named MicroRadarNet (MRN), are a short range strategy (about thirty kilometers) and the implementation of effective enhancing techniques. High resolution spatial and temporal data is processed in real-time, yielding a synthetic and consistent evaluation of the information coming from the sensor network. This approach implies in turn a sensible reduction of the overall operational costs, including management and maintenance aspects, if compared to the traditional long range C-band approach.
Compressed Sensing/Sparse-Recovery Approach for Improved Range Resolution in Narrow-Band Radar
Costanzo, Sandra
2016-01-01
A compressed sensing/sparse-recovery procedure is adopted to obtain enhanced range resolution capability from the processing of data acquired with narrow-band SFCW radars. A mathematical formulation for the proposed approach is reported and validity limitations are fully discussed, by demonstrating the ability to identify a great number of targets, up to 20, in the range direction. Both numerical and experimental validations are presented, by assuming also noise conditions. The proposed method can be usefully applied for the accurate detection of parameters with very small variations, such as those involved in the monitoring of soil deformations or biological objects. PMID:27022617
High Resolution Emission Spectroscopy of the Vibration-Rotation Bands of Hbo and Hbs.
Li, G.; Ram, R. S.; Hargreaves, R. J.; Bernath, P. F.; Li, H.
2012-06-01
The vibration-rotation spectra of HBO and HBS have been investigated at high resolution using a Fourier transform spectrometer. The HBO molecules were produced in a high temperature furnace from the reaction of H2O vapor with boron by heating a mixture of crystalline boron and boron oxide (B2O3) at a temperature ˜1350°C. The spectra were recorded in the 1100-2200 cm-1 and 1700-4000 cm-1 wavenumber regions covering the ν3 and ν1 fundamentals, respectively. In total 24 vibrational bands involving 30 vibrational levels of H11BO and 12 bands involving 18 levels of H10BO have been rotationally analyzed. After combining the existing microwave and infrared measurements, the absolute term values have been determined for a number of vibrationally-excited states of H11BO and H10BO. The HBS molecules were formed by the reaction of CS2 and water vapor with crystalline boron at a temperature ˜1300°C. The spectra were recorded in the 850-1500 cm-1 and 1750-4000 cm-1 wavenumber regions covering the ν3 and ν1 frequency regions. In total 29 vibrational bands involving 33 vibrationally-excited levels of H11BS and 9 bands involving 12 vibrational levels of H10BS have been analyzed. The fitted spectroscopic parameters agree very well with the results of our {ab initio} calculations. {L}-resonance interactions observed between the 0200 (Σ) and 0220 (Δ) levels of HBO and HBS were analyzed using a 2×2 matrix to yield deperturbed constants.
Recursive heuristic classification
Wilkins, David C.
1994-01-01
The author will describe a new problem-solving approach called recursive heuristic classification, whereby a subproblem of heuristic classification is itself formulated and solved by heuristic classification. This allows the construction of more knowledge-intensive classification programs in a way that yields a clean organization. Further, standard knowledge acquisition and learning techniques for heuristic classification can be used to create, refine, and maintain the knowledge base associated with the recursively called classification expert system. The method of recursive heuristic classification was used in the Minerva blackboard shell for heuristic classification. Minerva recursively calls itself every problem-solving cycle to solve the important blackboard scheduler task, which involves assigning a desirability rating to alternative problem-solving actions. Knowing these ratings is critical to the use of an expert system as a component of a critiquing or apprenticeship tutoring system. One innovation of this research is a method called dynamic heuristic classification, which allows selection among dynamically generated classification categories instead of requiring them to be prenumerated.
Aerosol profile information from high resolution oxygen A-Band measurements from space
Directory of Open Access Journals (Sweden)
A. Geddes
2014-06-01
Full Text Available Aerosols are an important factor of the Earth climatic system and they play a key role for air quality and public health. Observations of the oxygen A-Band at 760 nm can provide information on the vertical distribution of aerosols from passive satellite sensors, that can be of great interest for operational monitoring applications with high coverage if the aerosol information is obtained with sufficient precision, accuracy and vertical resolution. To address this issue, retrieval simulations of the aerosol vertical profile retrieval from O2 A Band observations by GOSAT, the upcoming OCO-2 and Sentinel 5-P mission and the proposed CarbonSat mission have been carried out. Precise retrievals of AOD within the boundary layer were found to favour low resolution, high SNR instruments such as Sentinel-5 P, whereas higher resolution instruments such as OCO-2 showed greater performance at higher altitudes and in information content above the boundary layer. Accurate retrievals of the AOD in the 0–2 km range appears difficult from all studied instruments and the retrieval errors typically exceed a value of 0.05. Constraining the surface albedo is a promising and effective way of improving the retrieval of aerosol, but the required level of a priori knowledge is very high. Due to the limited information content of the aerosol profile retrieval, the use of a parameterised aerosol distribution has been assessed and we show that the AOD and height of an aerosol layer can be retrieved well if the aerosol layer is uplifted to the free troposphere but errors are often large for aerosol layers in the boundary layer. Additional errors will be introduced by incorrect assumptions on surface pressure and aerosol type which can both bias retrieved AOD and height by up to 40%. We conclude the aerosol profile retrievals from O2 A Band using existing or upcoming satellite sensors will only provide limited information on aerosols in the boundary layer but such
Disentangling the representativeness heuristic from the availability heuristic
Braga, João Pedro Niza
2015-01-01
Tese de doutoramento, Psicologia (Cognição Social), Universidade de Lisboa, Faculdade de Psicologia, 2015 Most judgments, predictions and decisions rely on simplifying reasoning heuristics, such as representativeness and availability heuristics. Representativeness heuristic relies on a judgment of similarity between a categorical prototype and a target. Availability heuristic relies on the accessibility of instances. A crucial assumption of Heuristics and Biases research progra...
Additive Pattern Database Heuristics
Felner, A; Korf, R E; 10.1613/jair.1480
2011-01-01
We explore a method for computing admissible heuristic evaluation functions for search problems. It utilizes pattern databases, which are precomputed tables of the exact cost of solving various subproblems of an existing problem. Unlike standard pattern database heuristics, however, we partition our problems into disjoint subproblems, so that the costs of solving the different subproblems can be added together without overestimating the cost of solving the original problem. Previously, we showed how to statically partition the sliding-tile puzzles into disjoint groups of tiles to compute an admissible heuristic, using the same partition for each state and problem instance. Here we extend the method and show that it applies to other domains as well. We also present another method for additive heuristics which we call dynamically partitioned pattern databases. Here we partition the problem into disjoint subproblems for each state of the search dynamically. We discuss the pros and cons of each of these methods a...
OBJECT ORIENTED DESIGN HEURISTICS
Directory of Open Access Journals (Sweden)
DEEPALI GUPTA
2011-01-01
Full Text Available Object-oriented design is a process of identifying relevant objects, factoring them into classes, organizing hierarchically, and establishing dynamic collaborations among the objects. It is a difficult process especially for novice designers. In order to guide the novices, software engineers used some hints, guidelines and tips to communicate design experience from the expert. Design heuristic is common solution to design problems that developers encounter during software development. Heuristic is defined as the use of general knowledge gained by experience. Design heuristics are design experience from object-oriented developers. It is small and simpledesign expertise. This knowledge from the experienced designers is used to guide the novices. The purpose of this paper is to document design heuristics of object-oriented approach from literature study.
A HIGH-RESOLUTION ATLAS OF URANIUM-NEON IN THE H BAND
Energy Technology Data Exchange (ETDEWEB)
Redman, Stephen L.; Terrien, Ryan; Mahadevan, Suvrath; Ramsey, Lawrence W.; Bender, Chad F. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Ycas, Gabriel G. [Department of Physics, University of Colorado, Boulder, CO 80309 (United States); Osterman, Steven N. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); Diddams, Scott A.; Quinlan, Franklyn [Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305 (United States); Lawler, James E. [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States); Nave, Gillian [Atomic Physics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)
2012-03-01
We present a high-resolution (R Almost-Equal-To 50,000) atlas of a uranium-neon (U/Ne) hollow-cathode spectrum in the H band (1454-1638 nm) for the calibration of near-infrared spectrographs. We obtained this U/Ne spectrum simultaneously with a laser-frequency comb spectrum, which we used to provide a first-order calibration to the U/Ne spectrum. We then calibrated the U/Ne spectrum using the recently published uranium line list of Redman et al., which is derived from high-resolution Fourier transform spectrometer measurements. These two independent calibrations allowed us to easily identify emission lines in the hollow-cathode lamp that do not correspond to known (classified) lines of either uranium or neon, and to compare the achievable precision of each source. Our frequency comb precision was limited by modal noise and detector effects, while the U/Ne precision was limited primarily by the signal-to-noise ratio (S/N) of the observed emission lines and our ability to model blended lines. The standard deviation in the dispersion solution residuals from the S/N-limited U/Ne hollow-cathode lamp was 50% larger than the standard deviation of the dispersion solution residuals from the modal-noise-limited laser-frequency comb. We advocate the use of U/Ne lamps for precision calibration of near-infrared spectrographs, and this H-band atlas makes these lamps significantly easier to use for wavelength calibration.
Quantitative H and K band spectroscopy of Galactic OB-stars at medium resolution
Repolust, T; Hanson, M M; Kudritzki, R P; Mokiem, M R
2005-01-01
In this paper we have analyzed 25 Galactic O and early B-stars by means of H and K band spectroscopy, with the primary goal to investigate to what extent a lone near-IR spectroscopy is able to recover stellar and wind parameters derived in the optical. Most of the spectra have been taken with SUBARU IRCS, at a resolution of 12,000, and with a very high S/N (200 or better). In order to synthesize the strategic H/He lines, we have used our recent, line-blanketed version of FASTWIND. First we investigated the predicted behaviour of the strategic lines. In contradiction to what one expects from the optical in the O-star regime, almost all photospheric H/HeI/HeII H/K band lines become stronger if the gravity decreases. Concerning H and HeII, this finding is related to the behaviour of Stark broadening as a function of electron density, which in the line cores is different for members of lower (optical) and higher (IR) series. Regarding HeI, the predicted behaviour is due to some subtle NLTE effects resulting in a ...
OBJECT ORIENTED DESIGN HEURISTICS
DEEPALI GUPTA; Mr. RAKESH KUMAR
2011-01-01
Object-oriented design is a process of identifying relevant objects, factoring them into classes, organizing hierarchically, and establishing dynamic collaborations among the objects. It is a difficult process especially for novice designers. In order to guide the novices, software engineers used some hints, guidelines and tips to communicate design experience from the expert. Design heuristic is common solution to design problems that developers encounter during software development. Heurist...
A High-Resolution Atlas of Uranium-Neon in the H Band
Redman, Stephen L; Terrien, Ryan; Mahadevan, Suvrath; Ramsey, Lawrence W; Bender, Chad F; Osterman, Steven N; Diddams, Scott A; Quinlan, Franklyn; Lawler, James E; Nave, Gillian
2011-01-01
We present a high-resolution (R ~ 50 000) atlas of a uranium-neon (U/Ne) hollow-cathode spectrum in the H-band (1454 nm to 1638 nm) for the calibration of near-infrared spectrographs. We obtained this U/Ne spectrum simultaneously with a laser-frequency comb spectrum, which we used to provide a first-order calibration to the U/Ne spectrum. We then calibrated the U/Ne spectrum using the recently-published uranium line list of Redman et al. (2011), which is derived from high-resolution Fourier transform spectrometer measurements. These two independent calibrations allowed us to easily identify emission lines in the hollow cathode lamp that do not correspond to known (classified) lines of either uranium or neon, and to compare the achievable precision of each source. Our frequency comb precision was limited by modal noise and detector effects, while the U/Ne precision was limited primarily by the signal-to-noise ratio (S/N) of the observed emission lines and our ability to model blended lines. The standard deviat...
Heuristics for speeding up gaze estimation
DEFF Research Database (Denmark)
Leimberg, Denis; Vester-Christensen, Martin; Ersbøll, Bjarne Kjær;
2005-01-01
A deformable template method for eye tracking on full face images is presented. The strengths of the method are that it is fast and retains accuracy independently of the resolution. We compare the method with a state of the art active contour approach, showing that the heuristic method is more ac...
Enhanced ATR algorithm for high resolution multi-band sonar imagery
Aridgides, Tom; Fernández, Manuel
2008-04-01
An improved automatic target recognition (ATR) processing string has been developed. The overall processing string consists of pre-processing, subimage adaptive clutter filtering (SACF), normalization, detection, data regularization, feature extraction, optimal subset feature selection, feature orthogonalization and classification processing blocks. A new improvement was made to the processing string, data regularization, which entails computing the input data mean, clipping the data to a multiple of its mean and scaling it, prior to feature extraction. The classified objects of 3 distinct strings are fused using the classification confidence values and their expansions as features, and using "summing" or log-likelihood-ratio-test (LLRT) based fusion rules. The utility of the overall processing strings and their fusion was demonstrated with new high-resolution three-frequency band sonar imagery. The ATR processing strings were individually tuned to the corresponding three-frequency band data, making use of the new processing improvement, data regularization, which resulted in a 3:1 reduction in false alarms. Two significant fusion algorithm improvements were made. First, a nonlinear 2nd order (Volterra) feature LLRT fusion algorithm was developed. Second, a repeated application of a subset Volterra feature selection / feature orthogonalization / LLRT fusion block was utilized. It was shown that cascaded Volterra feature LLRT fusion of the ATR processing strings outperforms baseline summing and single-stage Volterra feature LLRT algorithms, yielding significant improvements over the best single ATR processing string results, and providing the capability to correctly call the majority of targets while maintaining a very low false alarm rate.
Heuristic methods for messenger problem
Kobzareva, Maria
2011-01-01
This work describes static and dynamic problems with one messenger or multiple number of messengers and suggests a possibility of solving such problems with modified heuristic methods. To solve messenger problem, modified nearest neighbor heuristic, modified insertion heuristic and modified exchange heuristic are used. The main contribution of this work are applications, developed in MS Excel, programmed with Visual Basic for Application, that can solve static and dynamic problems with one me...
Estrada, Fernando
2010-01-01
In this paper we have presented arguments for heuristics on economics research. In particular, have been important aspects that show how the tradition of the theory, to make principle simplicity to represent many empirical data of experience or information, was one of the goals set by the fathers of the discipline: Adam Smith, John Stuart Mill, and Jeremy Bentham.
A cooperative hyper-heuristic search framework
Ouelhadj, Djamila; Petrovic, S.
2010-01-01
In this paper, we aim to investigate the role of cooperation between low level heuristics within a hyper-heuristic framework. Since different low level heuristics have different strengths and weaknesses, we believe that cooperation can allow the strengths of one low level heuristic to compensate for the weaknesses of another. We propose an agent-based cooperative hyper-heuristic framework composed of a population of heuristic agents and a cooperative hyper-heuristic agent. The heuristic agent...
Directory of Open Access Journals (Sweden)
Rahman Momeni
2016-01-01
Full Text Available Detailed land cover information is valuable for mapping complex urban environments. Recent enhancements to satellite sensor technology promise fit-for-purpose data, particularly when processed using contemporary classification approaches. We evaluate this promise by comparing the influence of spatial resolution, spectral band set and classification approach for mapping detailed urban land cover in Nottingham, UK. A WorldView-2 image provides the basis for a set of 12 images with varying spatial and spectral characteristics, and these are classified using three different approaches (maximum likelihood (ML, support vector machine (SVM and object-based image analysis (OBIA to yield 36 output land cover maps. Classification accuracy is evaluated independently and McNemar tests are conducted between all paired outputs (630 pairs in total to determine which classifications are significantly different. Overall accuracy varied between 35% for ML classification of 30 m spatial resolution, 4-band imagery and 91% for OBIA classification of 2 m spatial resolution, 8-band imagery. The results demonstrate that spatial resolution is clearly the most influential factor when mapping complex urban environments, and modern “very high resolution” or VHR sensors offer great advantage here. However, the advanced spectral capabilities provided by some recent sensors, coupled with contemporary classification approaches (especially SVMs and OBIA, can also lead to significant gains in mapping accuracy. Ongoing development in instrumentation and methodology offer huge potential here and imply that urban mapping opportunities will continue to grow.
Heuristics for Multidimensional Packing Problems
DEFF Research Database (Denmark)
Egeblad, Jens
minimum height container required for the items. The main contributions of the thesis are three new heuristics for strip-packing and knapsack packing problems where items are both rectangular and irregular. In the two first papers we describe a heuristic for the multidimensional strip-packing problem that...... results of this heuristic are among the best published in the literature both for two- and three-dimensional strip-packing problems for irregular shapes. In the third paper, we introduce a heuristic for two- and three-dimensional rectangular knapsack packing problems. The two-dimensional heuristic uses...... promising. A heuristic for a three-dimensional knapsack packing problem involving furniture is presented in the fourth paper. The heuristic is based on a variety of techniques including tree-search, wall-building, and sequential placement. The solution process includes considerations regarding stability and...
International Nuclear Information System (INIS)
Following the previous detection of H3(+) in the southern auroral zone of Jupiter from its 2nu2 band, a search was made for the fundamental at 4 microns. Up to 42 lines of this band were detected in emission, at high resolution, on the auroral spot of each hemisphere. A rotational temperature was derived for the southern and northern zones, respectively, of 1000 + or - 40K and 835 + or - 50 K. The intensity of the lines was on the average two times stronger in the south than in the north. The 2nu2 band, which was sought in the north only on this occasion, was not detectable. A purely thermal mechanism for the H3(+) production is implied. Spatial extension and temporal variability of the excitation is discussed. 20 refs
Hu, Chuanmin; Chen, Zhiqiang; Clayton, Tonya D.; Swarzenski; Brock, John C.; Muller-Karger, Frank E.
2004-01-01
Using Tampa Bay, FL as an example, we explored the potential for using MODIS medium-resolution bands (250- and 500-m data at 469-, 555-, and 645-nm) for estuarine monitoring. Field surveys during 21–22 October 2003 showed that Tampa Bay has Case-II waters, in that for the salinity range of 24–32 psu, (a) chlorophyll concentration (11 to 23 mg m−3), (b) colored dissolved organic matter (CDOM) absorption coefficient at 400 nm (0.9 to 2.5 m−1), and (c) total suspended sediment concentration (TSS: 2 to 11 mg L−1) often do not co-vary. CDOM is the only constituent that showed a linear, inverse relationship with surface salinity, although the slope of the relationship changed with location within the bay. The MODIS medium-resolution bands, although designed for land use, are 4–5 times more sensitive than Landsat-7/ETM+ data and are comparable to or higher than those of CZCS. Several approaches were used to derive synoptic maps of water constituents from concurrent MODIS medium-resolution data. We found that application of various atmospheric-correction algorithms yielded no significant differences, due primarily to uncertainties in the sensor radiometric calibration and other sensor artifacts. However, where each scene could be groundtruthed, simple regressions between in situ observations of constituents and at-sensor radiances provided reasonable synoptic maps. We address the need for improvements of sensor calibration/characterization, atmospheric correction, and bio-optical algorithms to make operational and quantitative use of these medium-resolution bands.
A Tutorial on Heuristic Methods
DEFF Research Database (Denmark)
Vidal, Rene Victor Valqui; Werra, D. de; Silver, E.
1980-01-01
In this paper we define a heuristic method as a procedure for solving a well-defined mathematical problem by an intuitive approach in which the structure of the problem can be interpreted and exploited intelligently to obtain a reasonable solution. Issues discussed include: (i) the measurement of...... the quality of a heuristic method, (ii) different types of heuristic procedures, (iii) the interactive role of human beings and (iv) factors that may influence the choice or testing of heuristic methods. A large number of references are included....
Obtaining Maxwell's equations heuristically
Diener, Gerhard; Weissbarth, Jürgen; Grossmann, Frank; Schmidt, Rüdiger
2013-02-01
Starting from the experimental fact that a moving charge experiences the Lorentz force and applying the fundamental principles of simplicity (first order derivatives only) and linearity (superposition principle), we show that the structure of the microscopic Maxwell equations for the electromagnetic fields can be deduced heuristically by using the transformation properties of the fields under space inversion and time reversal. Using the experimental facts of charge conservation and that electromagnetic waves propagate with the speed of light, together with Galilean invariance of the Lorentz force, allows us to finalize Maxwell's equations and to introduce arbitrary electrodynamics units naturally.
The NIRSPEC Brown Dwarf Spectroscopic Survey II: High-Resolution J-Band Spectra of M, L and T Dwarfs
McLean, I S; McGovern, M R; Burgasser, A J; Kirkpatrick, J D; Rice, E L; Kim, S S; Lean, Ian S. Mc; Govern, Mark R. Mc; Burgasser, Adam J.; Rice, Emily L.; Kim, Sungsoo S.
2006-01-01
We present a sequence of high resolution (R~20,000 or 15 km/s) infrared spectra of stars and brown dwarfs spanning spectral types M2.5 to T6. Observations of 16 objects were obtained using eight echelle orders to cover part of the J-band from 1.165-1.323 micron with NIRSPEC on the Keck II telescope. By comparing opacity plots and line lists, over 200 weak features in the J-band are identified with either FeH or H2O transitions. Absorption by FeH attains maximum strength in the mid-L dwarfs, while H2O absorption becomes systematically stronger towards later spectral types. Narrow resolved features broaden markedly after the M to L transition. Our high resolution spectra also reveal that the disappearance of neutral Al lines at the boundary between M and L dwarfs is remarkably abrupt, presumably because of the formation of grains. Neutral Fe lines can be traced to mid-L dwarfs before Fe is removed by condensation. The neutral potassium (K I) doublets that dominate the J-band have pressure broadened wings that c...
Performance of high-resolution X-band radar for rainfall measurement in the Netherlands
Beek, van de C.Z.; Leijnsel, H.; Stricker, J.N.M.; Uijlenhoet, R.; Russchenberg, H.W.J.
2010-01-01
This study presents an analysis of 195 rainfall events gathered with the X-band weather radar SOLIDAR and a tipping bucket rain gauge network near Delft, The Netherlands, between May 1993 and April 1994. The aim of this paper is to present a thorough analysis of a climatological dataset using a high
Performance of high-resolution X-band radar for rainfall measurement in The Netherlands
Van de Beek, C.Z.; Leijnse, H.; Stricker, J.N.M.; Uijlenhoet, R.; Russchenberg, H.W.J.
2010-01-01
This study presents an analysis of 195 rainfall events gathered with the X-band weather radar SOLIDAR and a tipping bucket rain gauge network near Delft, The Netherlands, between May 1993 and April 1994. The aim of this paper is to present a thorough analysis of a climatological dataset using a high
Temperatures and metallicities of M giants in the galactic Bulge from low-resolution K-band spectra
Schultheis, M; Nandakumar, G
2016-01-01
With the existing and upcoming large multi-fibre low-resolution spectrographs, the question arises how precise stellar parameters such as Teff and [Fe/H] can be obtained from low-resolution K-band spectra with respect to traditional photometric temperature measurements. Until now, most of the effective temperatures in galactic Bulge studies come directly from photometric techniques. Uncertainties in interstellar reddening and in the assumed extinction law could lead to large systematic errors. We aim to obtain and calibrate the relation between Teff and the $\\rm ^{12}CO$ first overtone bands for M giants in the galactic Bulge covering a wide range in metallicity. We use low-resolution spectra for 20 M giants with well-studied parameters from photometric measurements covering the temperature range 3200 < Teff < 4500 K and a metallicity range from 0.5 dex down to -1.2 dex and study the behaviour of Teff and [Fe/H] on the spectral indices. We find a tight relation between Teff and the $\\rm ^{12}CO(2-0)$ ba...
Sphere Recognition: Heuristics and Examples
Joswig, Michael; Lutz, Frank H.; Tsuruga, Mimi
2014-01-01
Heuristic techniques for recognizing PL spheres using the topological software polymake are presented. These methods have been successful very often despite sphere recognition being known to be hard (for dimensions $d \\ge 3$) or even undecidable (for $d \\ge 5$). A deeper look into the simplicial complexes for which the heuristics failed uncovered a trove of examples having interesting topological and combinatorial properties.
Integrative heuristic teaching versus edutainment
Mileyeva, Мarina
2013-01-01
The paper discusses the urgent modernization necessity of both modern educational process and the English language teaching at the technological university, the importance and efficiency of creativity and heuristic approach being highlighted. Some scenario episodes of a specially designed innovative heuristic performance illustrate the results of its introduction, the dominant role of the English language in personal and professional students’ competence formation being stated.
Nakamura, Yoshitaka; Yoshikawa, Eiichi; Akita, Manabu; Morimoto, Takeshi; Ushio, Tomoo; Kawasaki, Zen-Ichiro; Saito, Toshiya; Nishida, Takashi; Sakazume, Norio
We propose a high-resolution precipitation and lightning monitoring for meteorological application. This monitoring is mainly utilized the Ku-band broadband radar (BBR) and the VHF broadband digital interferometer (DITF). The BBR can accurately measure the radar reflectivity factor and the mean Doppler velocity with 5 m resolution over a range from 40 m to several kilometers for 10 W power using a pulse compression technique. The two or more DITFs make us visualize lightning channel propagations in three dimensions. Moreover, we add new functions that integrate these observation data and disclose integration analyses results with the quasi real-time information disclosure system. Initial observations for severe storms with lightning during summer and winter thunderstorm season by these monitoring instruments indicate that we obtain detailed precipitation distribution and detect active convective cells with lightning discharges.
X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope
DEFF Research Database (Denmark)
Vernet, J.; Dekker, H.; D'Odorico, S.;
2011-01-01
X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope (VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 t...
Design of a High Resolution X-band Dopler Polarimetric Radar
Figueras i Ventura, J.
2009-01-01
The impact of the increase in anthropogenic aerosols on the global climate and the precipitation cycle is not yet fully understood. One of the reasons for that is the lack of sound measurements. In particular, high temporal and spatial resolution measurements of precipitation, coupled with measureme
High resolution Halpha spectroscopy and R-band photometry of Swift J1357.2-0933
Casares, Jorge; Torres, Manuel A. P.; Negueruela, Ignacio; Gonzalez-Fernandez, Carlos; Corral-Santana, Jesus M.; Zurita, Cristina; Llano, Sergio Rodriguez
2011-03-01
We report on high resolution Halpha spectroscopy and time-resolved photometry of the optical counterpart to the X-ray transient Swift J1357.2-0933 in outburst (Krimm et al. ATEL #3138). SPECTROSCOPY: Six 30-33 min spectra were obtained on the nights of 2011 Feb 25-27 using the IDS Spectrograph on the 2.5m Isaac Newton Telescope (INT) at the Observatorio del Roque de Los Muchachos. The observations were performed with the H1800V grating and a slit width 1.6 arcsec to yield a spectral coverage of 6270-7000 Angs with a 30 km/s FWHM spectral resolution at Halpha..
High resolution dopant profiling in the SEM, image widths and surface band-bending
International Nuclear Information System (INIS)
To study the mechanisms of dopant contrast in secondary electron (SE) imaging in the SEM, we have measured the image widths of a series of thin p-doped layers in Si, from 1 nm upwards. We have used computer modelling to simulate the effects of surface band-bending due to a realistic density of surface states on the Si, and we have also calculated the magnitude of the external patch fields. We have found a good correlation between the intensity widths and slopes of experimentally measured SE images of thin p-doped layers and the calculated widths and slopes of the energy distributions across these layers at a depth of 5-10 nm below the surface. This is consistent with the mean escape depth of SEs in Si being about 7 nm. We conclude that doping contrast in the SEM is mainly a function of bulk built-in voltages modified by surface band-bending effects within about 5-10 nm of the surface.
Study of the high resolution spectrum of 32S16O18O: The ν1 and ν3 bands
Ulenikov, O. N.; Bekhtereva, E. S.; Krivchikova, Yu. V.; Zamotaeva, V. A.; Buttersack, T.; Sydow, C.; Bauerecker, S.
2016-01-01
The high resolution infrared spectrum of the 32S16O18O molecule was recorded for the first time with a Bruker IFS 120 HR Fourier transform interferometer in the region of 930-1580 cm-1 where the bands ν1 and ν3 are located. More than 3000 and about 2400 transitions were assigned in the experimental spectrum with the maximum values of quantum numbers Jmax. /Kamax. equal to 58/23 and 68/23 to the bands ν1 and ν3, respectively. The further weighted fit of experimentally assigned transitions was made with the Hamiltonian model which takes into account Coriolis resonance interaction between the vibrational states (100) and (001). The 81 microwave transitions of the states (100) and (001) known from the literature also were taken into account. As the result, a set of 26 fitted parameters was obtained which reproduces the experiment-based 2690 ro-vibrational energy values of the two bands with the drms = 1.8 ×10-4 cm-1. Microwave transitions are also reproduced with the accuracy close to experimental uncertainty.
Zhou, Qian; Pang, Jinchao; Li, Xinghui; Ni, Kai; Tian, Rui
2015-11-10
In this study, a new flat-field concave grating miniature spectrometer is proposed with improved resolution across a wide spectral band. A mirror is added to a conventional concave grating spectrometer and placed near the existing detector array, allowing a wide spectral band to be divided into two adjacent subspectral bands. One of these bands is directly detected by the detector, and the other is indirectly analyzed by the same detector after being reflected by the mirror. These two subspectral bands share the same entrance slit, concave grating, and detector, which allows for a compact size, while maintaining an improved spectral resolution across the entire spectral band. The positions of the mirror and other parameters of the spectrometer are designed by a computer procedure and the optical design software ZEMAX. Simulation results show that the resolution of this kind of flat-field concave grating miniature spectrometer is better than 1.6 nm across a spectral band of 700 nm. Experiments based on three laser sources reveal that the measured resolutions are comparable to the simulated ones, with a maximum relative error between them of less than 19%. PMID:26560772
High-resolution Multi-band Imaging for Validation and Characterization of Small Kepler Planets
Everett, Mark E; Ciardi, David R; Horch, Elliott P; Howell, Steve B; Crepp, Justin R; Silva, David R
2014-01-01
High-resolution ground-based optical speckle and near-infrared adaptive optics images are taken to search for stars in close angular proximity to host stars of candidate planets identified by the NASA Kepler Mission. Neighboring stars are a potential source of false positive signals. These stars also blend into Kepler light curves, affecting estimated planet properties, and are important for an understanding of planets in multiple star systems. Deep images with high angular resolution help to validate candidate planets by excluding potential background eclipsing binaries as the source of the transit signals. A study of 18 Kepler Object of Interest stars hosting a total of 28 candidate and validated planets is presented. Validation levels are determined for 18 planets against the likelihood of a false positive from a background eclipsing binary. Most of these are validated at the 99% level or higher, including 5 newly-validated planets in two systems: Kepler-430 and Kepler-431. The stellar properties of the ca...
High-resolution multi-band imaging for validation and characterization of small Kepler planets
International Nuclear Information System (INIS)
High-resolution ground-based optical speckle and near-infrared adaptive optics images are taken to search for stars in close angular proximity to host stars of candidate planets identified by the NASA Kepler Mission. Neighboring stars are a potential source of false positive signals. These stars also blend into Kepler light curves, affecting estimated planet properties, and are important for an understanding of planets in multiple star systems. Deep images with high angular resolution help to validate candidate planets by excluding potential background eclipsing binaries as the source of the transit signals. A study of 18 Kepler Object of Interest stars hosting a total of 28 candidate and validated planets is presented. Validation levels are determined for 18 planets against the likelihood of a false positive from a background eclipsing binary. Most of these are validated at the 99% level or higher, including five newly validated planets in two systems: Kepler-430 and Kepler-431. The stellar properties of the candidate host stars are determined by supplementing existing literature values with new spectroscopic characterizations. Close neighbors of seven of these stars are examined using multi-wavelength photometry to determine their nature and influence on the candidate planet properties. Most of the close neighbors appear to be gravitationally bound secondaries, while a few are best explained as closely co-aligned field stars. Revised planet properties are derived for each candidate and validated planet, including cases where the close neighbors are the potential host stars.
X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope
Vernet, Joel; D'Odorico, S; Kaper, L; Kjaergaard, P; Hammer, F; Randich, S; Zerbi, F; Groot, P M; Hjorth, J; Guinouard, I; Navarro, R; Adolfse, T; Albers, P W; Amans, J -P; Andersen, J J; Andersen, M I; Binetruy, P; Bristow, P; Castillo, R; Chemla, F; Christensen, L; Conconi, P; Conzelmann, R; Dam, J; De Caprio, V; Postigo, A De Ugarte; Delabre, B; Di Marcantonio, P; Downing, M; Elswijk, E; Finger, G; Fischer, G; Flores, H; Francois, P; Goldoni, P; Guglielmi, L; Haigron, R; Hanenburg, H; Hendriks, I; Horrobin, M; Horville, D; Jessen, N C; Kerber, F; Kern, L; Kiekebusch, M; Kleszcz, P; Klougart, J; Kragt, J; Larsen, H H; Lizon, J -L; Lucuix, C; Mainieri, V; Manuputy, R; Martayan, C; Mason, E; Mazzoleni, R; Michaelsen, N; Modigliani, A; Moehler, S; Møller, P; Sørensen, A Norup; Nørregaard, P; Peroux, C; Patat, F; Pena, E; Pragt, J; Reinero, C; Riga, F; Riva, M; Roelfsema, R; Royer, F; Sacco, G; Santin, P; Schoenmaker, T; Spano, P; Sweers, E; Ter Horst, R; Tintori, M; Tromp, N; van Dael, P; van der Vliet, H; Venema, L; Vidali, M; Vinther, J; Vola, P; Winters, R; Wistisen, D; Wulterkens, G; Zacchei, A
2011-01-01
X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope(VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 to 2500 nm. It is designed to maximize the sensitivity in this spectral range through dichroic splitting in three arms with optimized optics, coatings, dispersive elements and detectors. It operates at intermediate spectral resolution (R~4,000 - 17,000, depending on wavelength and slit width) with fixed echelle spectral format (prism cross-dispersers) in the three arms. It includes a 1.8"x4" Integral Field Unit as an alternative to the 11" long slits. A dedicated data reduction package delivers fully calibrated two-dimensional and extracted spectra over the full wavelength range. We describe the main characteristics of the instrument and present its performance as measured during commissioning, science verification and ...
High-resolution multi-band imaging for validation and characterization of small Kepler planets
Energy Technology Data Exchange (ETDEWEB)
Everett, Mark E.; Silva, David R. [National Optical Astronomy Observatory, 950 North Cherry Avenue Tucson, AZ 85719 (United States); Barclay, Thomas; Howell, Steve B. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ciardi, David R. [NASA Exoplanet Science Institute, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Horch, Elliott P. [Department of Physics, Southern Connecticut State University, 501 Crescent Street, New Haven, CT 06515 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States)
2015-02-01
High-resolution ground-based optical speckle and near-infrared adaptive optics images are taken to search for stars in close angular proximity to host stars of candidate planets identified by the NASA Kepler Mission. Neighboring stars are a potential source of false positive signals. These stars also blend into Kepler light curves, affecting estimated planet properties, and are important for an understanding of planets in multiple star systems. Deep images with high angular resolution help to validate candidate planets by excluding potential background eclipsing binaries as the source of the transit signals. A study of 18 Kepler Object of Interest stars hosting a total of 28 candidate and validated planets is presented. Validation levels are determined for 18 planets against the likelihood of a false positive from a background eclipsing binary. Most of these are validated at the 99% level or higher, including five newly validated planets in two systems: Kepler-430 and Kepler-431. The stellar properties of the candidate host stars are determined by supplementing existing literature values with new spectroscopic characterizations. Close neighbors of seven of these stars are examined using multi-wavelength photometry to determine their nature and influence on the candidate planet properties. Most of the close neighbors appear to be gravitationally bound secondaries, while a few are best explained as closely co-aligned field stars. Revised planet properties are derived for each candidate and validated planet, including cases where the close neighbors are the potential host stars.
Anagnostou, Marios N.; Kalogiros, John; Marzano, Frank S.; Anagnostou, Emmanouil N.; Baldini, Luca; Nikolopoulos, EfThymios; Montopoli, Mario; Picciotti, Errico
2014-05-01
operational, low-frequency (C-band or S-ban) and high-power weather radars. The above hypothesis is examined using data collected during the HyMEX 2012 Special Observation Period (Nov-Feb) the urban and sub-urban complex terrain area in the Central Italy (CI). The area is densely populated and it includes the high-density populated urban and industrial area of Rome. The orography of CI is quite complex, going from sea level to nearly 3000 m in less than 150 km. The CI area involves many rivers, including two major basins: the Aniene-Tiber basin (1000 km long) and the Aterno-Pescara basin (300 km long), respectively on the west and on the east side of the Apennines ridge. Data include observations from i) the National Observatory of Athens' X-band polarimetric weather radar (XPOL), ii) two X-band miniradars (WR25X located in CNR, WR10X located in Rome Sapienza), iii) a dense network of raingauges and disdrometers (i.e. Parsivel type and 2D-video type). In addition, the experimental area is also covered from the nearby the National Research Council (CNR)'s C-band dual-polarization weather radar (Polar55C), which were involved also in the analysis. A number of storm events are selected and compared with the nearby C-band radar to investigate the potential of using high-resolution and microphysically-derived rainfall based on X-band polarimetric radar observations. Events have been discriminated on the basis of rainfall intensity and hydrological response. Results reveal that in contrast with the other two rainfall sources (in situ and C-band radar), X-band radar rainfall estimates offer an improved representation of the local precipitation variability, which turns to have a significant impact in simulating the peak flows associated with these events.
Arcsecond Resolution at 4 Meters Wavelength: The 74 MHz Band on the Very Large Array
Perley, R. A.
2001-12-01
Although the foundations of interferometric imaging were developed with instruments operating at meter wavelengths, most of the development of the techniques, and the subsequent science, have been done at increasingly shorter wavelengths. Two of the key reasons for the lack of a high-resolution imaging capability at meter wavelengths are the extreme difficulties in correcting for ionospheric phase corruption, and the complication and expense of image formation from the non-coplanar data taken by the Very Large Array. However, the techniques of self-calibration and image formation which have been developed for interferometry at shorter wavelengths can be modified and extended to handle the more difficult problems posed by long-wavelength, long-baseline interferometry. The differences between long- and short-wavelength imaging are only a matter of degree, not of principle. To test these techniques, and to demonstrate the potential of arcsecond resolution imaging at meter wavelengths, the Naval Research Laboratory and the National Radio Astronomy Observatory have outfitted the Very Large Array with receivers operating at a wavelength of 4 meters. Extensive tests with this new capability have shown that even simple extensions of the self-calibration methods developed for higher frequency data are sufficient to permit good imaging at this very long wavelength. More sophisticated variants of these techniques are now under development, and will soon allow full phase correction over the entire eleven-degree primary beam at the VLA's full resolution of 25 arcseconds. In addition, modern computers have provided the necessary capability to permit development of sophisticated, multi-faceted imaging techniques, allowing full primary beam imaging while avoiding the aberrations which accompany simple two-dimensional inversion of non-coplanar visibility data. Thus, both historical limitations have been bypassed, and true diffraction-limited, wide-field imaging at meter wavelengths
High resolution observations with Artemis-IV and the NRH. I. Type IV associated narrow-band bursts
Bouratzis, C.; Hillaris, A.; Alissandrakis, C. E.; Preka-Papadema, P.; Moussas, X.; Caroubalos, C.; Tsitsipis, P.; Kontogeorgos, A.
2016-02-01
Context. Narrow-band bursts appear on dynamic spectra from microwave to decametric frequencies as fine structures with very small duration and bandwidth. They are believed to be manifestations of small scale energy release through magnetic reconnection. Aims: We analyzed 27 metric type IV events with embedded narrow-band bursts, which were observed by the ARTEMIS-IV radio spectrograph from 30 June 1999 to 1 August 2010. We examined the morphological characteristics of isolated narrow-band structures (mostly spikes) and groups or chains of structures. Methods: The events were recorded with the SAO high resolution (10 ms cadence) receiver of ARTEMIS-IV in the 270-450 MHz range. We measured the duration, spectral width, and frequency drift of ~12 000 individual narrow-band bursts, groups, and chains. Spike sources were imaged with the Nançay radioheliograph (NRH) for the event of 21 April 2003. Results: The mean duration of individual bursts at fixed frequency was ~100 ms, while the instantaneous relative bandwidth was ~2%. Some bursts had measurable frequency drift, either positive or negative. Quite often spikes appeared in chains, which were closely spaced in time (column chains) or in frequency (row chains). Column chains had frequency drifts similar to type-IIId bursts, while most of the row chains exhibited negative frequently drifts with a rate close to that of fiber bursts. From the analysis of NRH data, we found that spikes were superimposed on a larger, slowly varying, background component. They were polarized in the same sense as the background source, with a slightly higher degree of polarization of ~65%, and their size was about 60% of their size in total intensity. Conclusions: The duration and bandwidth distributions did not show any clear separation in groups. Some chains tended to assume the form of zebra, lace stripes, fiber bursts, or bursts of the type-III family, suggesting that such bursts might be resolved in spikes when viewed with high
Heuristic Methods for Security Protocols
Qurat ul Ain Nizamani; Emilio Tuosto
2009-01-01
Model checking is an automatic verification technique to verify hardware and software systems. However it suffers from state-space explosion problem. In this paper we address this problem in the context of cryptographic protocols by proposing a security property-dependent heuristic. The heuristic weights the state space by exploiting the security formulae; the weights may then be used to explore the state space when searching for attacks.
High-resolution spectroscopy of the C2 Swan 0-0 band from Comet P/Halley
Lambert, D. L.; Sheffer, Y.; Danks, A. C.; Arpigny, C.; Magain, P.
1990-04-01
High-resolution spectra of the C2 Swan system's 0-0 band from Comet P/Halley in March 1986 show that the populations of the upper state's rotational levels may be described by two rotational temperatures. The low rotational levels provide a low temperature, Trot = about 600 - 700 K. The higher levels correspond to about 3200 K. If a contribution from the 3200-K molecules is subtracted from the populations of the low-J-prime levels, the latter are characterized by Trot = about 190 K. A comparison with recent predictions for C2 molecules fluorescing in sunlight shows that the observed and predicted level populations are in good agreement for J-prime greater than about 15, but there is a sharp disagreement for the low rotational levels.
High-resolution spectroscopy of the C2 Swan 0-0 band from Comet P/Halley
International Nuclear Information System (INIS)
High-resolution spectra of the C2 Swan system's 0-0 band from Comet P/Halley in March 1986 show that the populations of the upper state's rotational levels may be described by two rotational temperatures. The low rotational levels provide a low temperature, Trot = about 600 - 700 K. The higher levels correspond to about 3200 K. If a contribution from the 3200-K molecules is subtracted from the populations of the low-J-prime levels, the latter are characterized by Trot = about 190 K. A comparison with recent predictions for C2 molecules fluorescing in sunlight shows that the observed and predicted level populations are in good agreement for J-prime greater than about 15, but there is a sharp disagreement for the low rotational levels. 26 refs
Full-C-band, sub-GHz-resolution Nyquist-filtering (de)interleaver in photonic integrated circuit
Zhuang, Leimeng; Corcoran, Bill; Burla, Maurizio; Roeloffzen, Chris G H; Leinse, Arne; Schröder, Jochen; Lowery, Arthur J
2015-01-01
Nyquist wavelength division (de)multiplexing (N-WDM) is a highly promising technique for next-generation high-speed elastic networks. In N-WDM, Nyquist filtering is an essential function that governs the channel spectral efficiency. However, most Nyquist filter implementations to date require either expensive, power-hungry digital electronics or complex arrangements of bulky optical components, hindering their adoption for important functions such as Nyquist channel shaping and reconfigurable optical add-drop multiplexers (ROADMs) for Nyquist super-channels. Here, we present a distinctive solution with low-cost, power-efficient, and simple-device natures, which is an on-chip optical Nyquist-filtering (de)interleaver featuring sub-GHz resolution and a near-rectangular passband with 8% transition band. This unprecedented performance is provided by a simple photonic integrated circuit comprising a two-ring-resonator-assisted Mach-Zehnder interferometer, which features high circuit compactness using high-index-co...
Smith, Verne V; Shetrone, Matthew D; Meszaros, Szabolcs; Prieto, Carlos Allende; Bizyaev, Dmitry; Perez, Ana Garcia; Majewski, Steven R; Schiavon, Ricardo; Holtzman, Jon; Johnson, Jennifer A
2012-01-01
High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier Transform Spectrometer (FTS), are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the SDSS III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. Measured chemical abundances include the cosmochemically important isotopes 12C, 13C, 14N, and 16O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. A comparison of the abundances derived here with published values for these stars reveals consistent results to ~0.1 dex. The APOGEE spectral region and linelist is, thus, well-suited for probing both Galactic chemical evolution, as well as inter...
Energy Technology Data Exchange (ETDEWEB)
Heo, Sung [Analytical Engineering Group, Samsung Advanced Institute of Technology, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803 (Korea, Republic of); College of Information and Communication Engineering, Sungkyunkwan University, Cheoncheon-dong 300, Jangan-gu, Suwon 440-746 (Korea, Republic of); Lee, Hyung-Ik; Park, Jong-Bong; Ko, Dong-Su; Chung, JaeGwan; Kim, KiHong; Kim, Seong Heon; Yun, Dong-Jin; Ham, YongNam; Park, Gyeong Su [Analytical Engineering Group, Samsung Advanced Institute of Technology, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803 (Korea, Republic of); Song, Taewon [Energy lab, Samsung Advanced Institute of Technology, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803 (Korea, Republic of); Lee, Dongho, E-mail: dhlee0333@gmail.com; Nam, Junggyu [PV Development Team, Energy Solution Business Division, Samsung SDI, 467 Beonyeong-ro, Cheonan-si, Chungcheongnam-do 331-330 (Korea, Republic of); Kang, Hee Jae [Department of Physics, Chungbuk National University, Gaesin-dong, Heungdeok-gu, Cheongju, 361-763 (Korea, Republic of); Choi, Pyung-Ho; Choi, Byoung-Deog, E-mail: bdchoi@skku.edu [College of Information and Communication Engineering, Sungkyunkwan University, Cheoncheon-dong 300, Jangan-gu, Suwon 440-746 (Korea, Republic of)
2015-06-29
To investigate the band gap profile of Cu(In{sub 1−x},Ga{sub x})(Se{sub 1−y}S{sub y}){sub 2} of various compositions, we measured the band gap profile directly as a function of in-depth using high-resolution reflection energy loss spectroscopy (HR-REELS), which was compared with the band gap profile calculated based on the auger depth profile. The band gap profile is a double-graded band gap as a function of in-depth. The calculated band gap obtained from the auger depth profile seems to be larger than that by HR-REELS. Calculated band gaps are to measure the average band gap of the spatially different varying compositions with respect to considering its void fraction. But, the results obtained using HR-REELS are to be affected by the low band gap (i.e., out of void) rather than large one (i.e., near void). Our findings suggest an analytical method to directly determine the band gap profile as function of in-depth.
International Nuclear Information System (INIS)
To investigate the band gap profile of Cu(In1−x,Gax)(Se1−ySy)2 of various compositions, we measured the band gap profile directly as a function of in-depth using high-resolution reflection energy loss spectroscopy (HR-REELS), which was compared with the band gap profile calculated based on the auger depth profile. The band gap profile is a double-graded band gap as a function of in-depth. The calculated band gap obtained from the auger depth profile seems to be larger than that by HR-REELS. Calculated band gaps are to measure the average band gap of the spatially different varying compositions with respect to considering its void fraction. But, the results obtained using HR-REELS are to be affected by the low band gap (i.e., out of void) rather than large one (i.e., near void). Our findings suggest an analytical method to directly determine the band gap profile as function of in-depth
Heuristics for chemical compound matching.
Hattori, Masahiro; Okuno, Yasushi; Goto, Susumu; Kanehisa, Minoru
2003-01-01
We have developed an efficient algorithm for comparing two chemical compounds, where the chemical structure is treated as a 2D graph consisting of atoms as vertices and covalent bonds as edges. Based on the concept of functional groups in chemistry, 68 atom types (vertex types) are defined for carbon, nitrogen, oxygen, and other atomic species with different environments, which has enabled detection of biochemically meaningful features. Maximal common subgraphs of two graphs can be found by searching for maximal cliques in the association graph, and we have introduced heuristics to accelerate the clique finding. Our heuristic procedure is controlled by some adjustable parameters. Here we applied our procedure to the latest KEGG/LIGAND database with different sets of parameters, and demonstrated the correlation of parameters in our algorithm with the distribution of similarity scores and/or the execution time. Finally, we showed the effectiveness of our heuristics for compound pairs along metabolic pathways. PMID:15706529
Martinis, Sandro
2010-01-01
This thesis is an outcome of the project “Flood and damage assessment using very high resolution SAR data” (SAR-HQ), which is embedded in the interdisciplinary oriented RIMAX (Risk Management of Extreme Flood Events) programme, funded by the Federal Ministry of Education and Research (BMBF). It comprises the results of three scientific papers on automatic near real-time flood detection in high resolution X-band synthetic aperture radar (SAR) satellite data for operational rapid mapping activi...
Regarding Chilcott's "Structural Functionalism as a Heuristic Device" Heuristically.
Blot, Richard K.
1998-01-01
The heuristic value of Chilcott's essay lies less in its support for structural functionalism and more in its concern to reexamine theory in the work of earlier educational anthropologists for what earlier theories and practices can add to current research. (SLD)
Czech Academy of Sciences Publication Activity Database
Pracna, Petr; Ceausu-Velcescu, A.; Horneman, V. M.
2012-01-01
Roč. 113, č. 11 (2012), s. 1220-1225. ISSN 0022-4073 R&D Projects: GA MŠk LC06071 Institutional support: RVO:61388955 Keywords : chloroform * high-resolution IR spectroscopy * fundamental bands Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.380, year: 2012
Heuristic Strategies in Finance – An Overview
Marianna Lyra
2010-01-01
This paper presents a survey on the application of heuristic optimization techniques in the broad field of finance. Heuristic algorithms have been extensively used to tackle complex financial problems, which traditional optimization techniques cannot efficiently solve. Heuristic optimization techniques are suitable for non-linear and non-convex multi-objective optimization problems. Due to their stochastic features and their ability to iteratively update candidate solutions, heuristics can ex...
Yamanaka, Masahito; Teranishi, Tatsuhiro; Kawagoe, Hiroyuki; Nishizawa, Norihiko
2016-01-01
Optical coherence microscopy (OCM) is a label-free, high-resolution, three-dimensional (3D) imaging technique based on optical coherence tomography (OCT) and confocal microscopy. Here, we report that the 1700-nm spectral band has the great potential to improve the imaging depth in high-resolution OCM imaging of animal tissues. Recent studies to improve the imaging depth in OCT revealed that the 1700-nm spectral band is a promising choice for imaging turbid scattering tissues due to the low attenuation of light in the wavelength region. In this study, we developed high-resolution OCM by using a high-power supercontinuum source in the 1700-nm spectral band, and compared the attenuation of signal-to-noise ratio between the 1700-nm and 1300-nm OCM imaging of a mouse brain under the condition of the same sensitivity. The comparison clearly showed that the 1700-nm OCM provides larger imaging depth than the 1300-nm OCM. In this 1700-nm OCM, the lateral resolution of 1.3 μm and the axial resolution of 2.8 μm, when a refractive index was assumed to be 1.38, was achieved. PMID:27546517
Compact Ku-Band T/R Module for High-Resolution Radar Imaging of Cold Land Processes
Andricos, Constantine; Yueh, Simon H.; Krimskiy, Vladimir A.; Rahmat-Samii, Yahya
2010-01-01
Global measurement of terrestrial snow cover is critical to two of the NASA Earth Science focus areas: (1) climate variability and change and (2) water and energy cycle. For radar backscatter measurements, Ku-band frequencies, scattered mainly within the volume of the snowpack, are most suitable for the SWE (snow-water equivalent) measurements. To isolate the complex effects of different snowpack (density and snowgrain size), and underlying soil properties and to distinctly determine SWE, the space-based synthetic aperture radar (SAR) system will require a dual-frequency (13.4 and 17.2 GHz) and dual polarization approach. A transmit/receive (T/R) module was developed operating at Ku-band frequencies to enable the use of active electronic scanning phased-array antenna for wide-swath, high-resolution SAR imaging of terrestrial snow cover. The T/R module has an integrated calibrator, which compensates for all environmental- and time-related changes, and results in very stable power and amplitude characteristics. The module was designed to operate over the full frequency range of 13 to 18 GHz, although only the two frequencies, 13.4 GHz and 17.2 GHz, will be used in this SAR radar application. Each channel of the transmit module produces > 4 W (35 dbm) over the operating bandwidth of 20 MHz. The stability requirements of self-correction scheme, which does real-time amplitude calibration so that the module characteristics are continually corrected. All the calibration circuits are within the T/R module. The timing and calibration sequence is stored in a control FPGA (field-programmable gate array) while an internal 128K 8bit high-speed RAM (random access memory) stores all the calibration values. The module was designed using advanced components and packaging techniques to achieve integration of the electronics in a 2 x6.5x1-in. (5x17x2.5-cm) package. The module size allows 4 T/R modules to feed the 16 16-element subarray on an antenna panel. The T/R module contains
A tensor-based selection hyper-heuristic for cross-domain heuristic search
Asta, Shahriar; Özcan, Ender
2015-01-01
Hyper-heuristics have emerged as automated high level search methodologies that manage a set of low level heuristics for solving computationally hard problems. A generic selection hyper-heuristic combines heuristic selection and move acceptance methods under an iterative single point-based search framework. At each step, the solution in hand is modified after applying a selected heuristic and a decision is made whether the new solution is accepted or not. In this study, we represent the trail...
International Nuclear Information System (INIS)
The spin-polarized surface band structure of the three-dimensional (3D) quantum spin Hall phase of Bi1-xSbx (x=0.12-0.13) was studied by spin- and angle-resolved photoemission spectroscopy (SARPES) using a high-yield spin polarimeter equipped with a high-resolution electron spectrometer. The spin-integrated spectra were also measured and compared to those of Bi1-xSbx with x=0.04. Band dispersions of the edge states were fully elucidated between the two time-reversal-invariant points, Γ-bar and M-bar, of the (111) surface Brillouin zone. The observed spin-polarized band dispersions at x=0.12-0.13 indicate an odd number of the band crossing at the Fermi energy, giving unambiguous evidence that this system is a 3D strong topological insulator, and determine the 'mirror chirality' to be -1, which excludes the existence of a Dirac point in the middle of the Γ-bar-M-bar line. The present research demonstrates that the SARPES measurement with energy resolution ≤50 meV is one of the critical techniques for complementing the topological band theory for spins and spin currents.
Heuristic for teaching systems thinking
Reynolds, Martin
2011-01-01
Systems thinking in practice is a heuristic framework based upon ideas of boundary critique for guiding the use and development of tools from different traditions in managing complex realities. Three interrelated features of the framework are drawn out – contexts of systemic change, practitioners as change agents, and tools as systems constructs that can themselves change through adaptation. A range of tools associated with the Systems tradition have demonstrable capacity to change and adapt ...
Jönsson, H.; Ryde, N.; Harper, G. M.; Cunha, K.; Schultheis, M.; Eriksson, K.; Kobayashi, C.; Smith, V. V.; Zoccali, M.
2014-04-01
Context. Possible main formation sites of fluorine in the Universe include asymptotic giant branch (AGB) stars, the ν-process in Type II supernova, and/or Wolf-Rayet stars. The importance of the Wolf-Rayet stars has theoretically been questioned and they are probably not needed in modeling the chemical evolution of fluorine in the solar neighborhood. It has, however, been suggested that Wolf-Rayet stars are indeed needed to explain the chemical evolution of fluorine in the bulge. The molecular spectral data, needed to determine the fluorine abundance, of the often used HF-molecule has not been presented in a complete and consistent way and has recently been debated in the literature. Aims: We intend to determine the trend of the fluorine-oxygen abundance ratio as a function of a metallicity indicator in the bulge to investigate the possible contribution from Wolf-Rayet stars. Additionally, we present here a consistent HF line list for the K- and L-bands including the often used 23 358.33 Å line. Methods: High-resolution near-infrared spectra of eight K giants were recorded using the spectrograph CRIRES mounted at the VLT. A standard setting was used that covered the HF molecular line at 23 358.33 Å. The fluorine abundances were determined using spectral fitting. We also re-analyzed five previously published bulge giants observed with the Phoenix spectrograph on Gemini using our new HF molecular data. Results: We find that the fluorine-oxygen abundance in the bulge probably cannot be explained with chemical evolution models that only include AGB stars and the ν-process in supernovae Type II, that is a significant amount of fluorine production in Wolf-Rayet stars is most likely needed to explain the fluorine abundance in the bulge. For the HF line data, we find that a possible reason for the inconsistencies in the literature, where two different excitation energies were used, is two different definitions of the zero-point energy for the HF molecule and therefore
Oladunjoye, Michael Adeyinka; Olayinka, Abel Idowu; Alaba, Mustapha; Adabanija, Moruffdeen Adedapo
2016-02-01
The quest for solid mineral resource as an alternative for oil income in Nigeria presents opportunity to diversify the resource base of the country. To fill some information gap on the long abandoned Ajase and Gbede Banded Iron Formations (BIF) in Ogbomoso area, Southwestern Nigeria, high resolution aeromagnetic data of Ogbomoso - Sheet 222 was interpreted; to provide a better understanding of the mode of occurrence of the iron ore and associated structural features and geologic model. These were accomplished by subjecting reduced-to-pole (RTP) residual aeromagnetic intensity map to various data filtering and processing involving total horizontal derivative, vertical derivative, Upward Continuation (UC), Downward Continuation (DC), Euler Deconvolution at different Spectral Indices (SI), and Analytical signal using Geosoft Oasis Montaj 6.4.2 (HJ) data processing and analysis software. The resultants maps were overlain, compared and or plotted on RTP residual aeromagnetic intensity map and or geological map and interpreted in relation to the surface geological map. Positive magnetic anomalies observed on the RTP residual aeromagnetic intensity map ranged from 2.1 to 94.0 nT and associated with contrasting basement rocks, Ajase and Gbede BIF; while negative magnetic anomalies varied between -54.7 nT and -2.8 nT and are associated with intrusive bodies. Interpreted lineaments obtained from total horizontal derivative map were separated into two categories namely ductile and brittle based on their character vis-à-vis magnetic anomalies on RTP intensity map. Whilst the brittle lineaments were interpreted as fracture or faults; the ductile lineaments were interpreted as folds or representing the internal fabric of the rock units. In addition prominent magnetic faults mainly due to offset of similar magnetic domain/gradient were also interpreted. The iron ore mineralization is distributed within the eastern portion of the study area with Ajase BIF at relatively greater
Analysis of the High-Resolution Fourier Spectrum of the ν6 Band of the cis-C2h2d2 Molecule
Konov, I. A.; Chertavskikh, Yu. V.; Fomchenko, A. L.; Aslapovskaya, Yu. S.; Zhdanovich, S. A.; Sydow, C.
2016-03-01
The spectrum of the ν6 band of the cis-ethylene-d2 molecule (cis-C2H2D2) is recorded with a Bruker IFS 125 HR Fourier spectrometer in the range 580-1210 cm-1 with resolution of 0.0021 cm-1. An analysis of the experimental spectrum allows more than 1500 transitions belonging to this band to be assigned that by more than 2.5 times greater than it has been known in the literature so far. The obtained experimental data are then used to determine the model parameters of the molecule (the effective Hamiltonian in the A-reduction and I'- representation). Strong resonance interaction with the band ν4 forbidden in absorption by the symmetry of a molecule is taken into account. 10 parameters of the Hamiltonian obtained by solving inverse spectroscopic problem reproduce 427 initial experimental energies (more than 1500 transitions) with accuracy close to the experimental uncertainty.
A genetic programming hyper-heuristic approach to automated packing
Hyde, Matthew
2010-01-01
This thesis presents a programme of research which investigated a genetic programming hyper-heuristic methodology to automate the heuristic design process for one, two and three dimensional packing problems. Traditionally, heuristic search methodologies operate on a space of potential solutions to a problem. In contrast, a hyper-heuristic is a heuristic which searches a space of heuristics, rather than a solution space directly. The majority of hyper-heuristic research papers, so far, hav...
International Nuclear Information System (INIS)
The simplest Criegee intermediate CH2OO is important in atmospheric chemistry. It has been detected in the reaction of CH2I + O2 with various spectral methods, including infrared spectroscopy; infrared absorption of CH2OO was recorded at resolution 1.0 cm−1 in our laboratory. We have improved our system and recorded the infrared spectrum of CH2OO at resolution 0.25 cm−1 with rotational structures partially resolved. Observed vibrational wavenumbers and relative intensities are improved from those of the previous report and agree well with those predicted with quantum-mechanical calculations using the MULTIMODE method on an accurate potential energy surface. Observed rotational structures also agree with the simulated spectra according to theoretical predictions. In addition to derivation of critical vibrational and rotational parameters of the vibrationally excited states to confirm the assignments, the spectrum with improved resolution provides new assignments for bands 2ν9 at 1234.2 cm−1 and ν5 at 1213.3 cm−1; some hot bands and combination bands are also tentatively assigned
Wang, Fei; Qin, Zhihao; Li, Wenjuan; Song, Caiying; Karnieli, Arnon; Zhao, Shuhe
2015-01-01
Land surface temperature (LST) images retrieved from the thermal infrared (TIR) band data of Moderate Resolution Imaging Spectroradiometer (MODIS) have much lower spatial resolution than the MODIS visible and near-infrared (VNIR) band data. The coarse pixel scale of MODIS LST images (1000 m under nadir) have limited their capability in applying to many studies required high spatial resolution in comparison of the MODIS VNIR band data with pixel scale of 250-500 m. In this paper we intend to develop an efficient approach for pixel decomposition to increase the spatial resolution of MODIS LST image using the VNIR band data as assistance. The unique feature of this approach is to maintain the thermal radiance of parent pixels in the MODIS LST image unchanged after they are decomposed into the sub-pixels in the resulted image. There are two important steps in the decomposition: initial temperature estimation and final temperature determination. Therefore the approach can be termed double-step pixel decomposition (DSPD). Both steps involve a series of procedures to achieve the final result of decomposed LST image, including classification of the surface patterns, establishment of LST change with normalized difference of vegetation index (NDVI) and building index (NDBI), reversion of LST into thermal radiance through Planck equation, and computation of weights for the sub-pixels of the resulted image. Since the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) with much higher spatial resolution than MODIS data was on-board the same platform (Terra) as MODIS for Earth observation, an experiment had been done in the study to validate the accuracy and efficiency of our approach for pixel decomposition. The ASTER LST image was used as the reference to compare with the decomposed LST image. The result showed that the spatial distribution of the decomposed LST image was very similar to that of the ASTER LST image with a root mean square error (RMSE) of 2
Directory of Open Access Journals (Sweden)
Yun Du
2016-04-01
Full Text Available Monitoring open water bodies accurately is an important and basic application in remote sensing. Various water body mapping approaches have been developed to extract water bodies from multispectral images. The method based on the spectral water index, especially the Modified Normalized Difference Water Index (MDNWI calculated from the green and Shortwave-Infrared (SWIR bands, is one of the most popular methods. The recently launched Sentinel-2 satellite can provide fine spatial resolution multispectral images. This new dataset is potentially of important significance for regional water bodies’ mapping, due to its free access and frequent revisit capabilities. It is noted that the green and SWIR bands of Sentinel-2 have different spatial resolutions of 10 m and 20 m, respectively. Straightforwardly, MNDWI can be produced from Sentinel-2 at the spatial resolution of 20 m, by upscaling the 10-m green band to 20 m correspondingly. This scheme, however, wastes the detailed information available at the 10-m resolution. In this paper, to take full advantage of the 10-m information provided by Sentinel-2 images, a novel 10-m spatial resolution MNDWI is produced from Sentinel-2 images by downscaling the 20-m resolution SWIR band to 10 m based on pan-sharpening. Four popular pan-sharpening algorithms, including Principle Component Analysis (PCA, Intensity Hue Saturation (IHS, High Pass Filter (HPF and À Trous Wavelet Transform (ATWT, were applied in this study. The performance of the proposed method was assessed experimentally using a Sentinel-2 image located at the Venice coastland. In the experiment, six water indexes, including 10-m NDWI, 20-m MNDWI and 10-m MNDWI, produced by four pan-sharpening algorithms, were compared. Three levels of results, including the sharpened images, the produced MNDWI images and the finally mapped water bodies, were analysed quantitatively. The results showed that MNDWI can enhance water bodies and suppressbuilt
Efficient Heuristic Variable Ordering of OBDDs
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
An efficient heuristic algorithm for variable ordering of OBDDs, the WDHA (Weight-and-Distance based Heuristic Algorithm), is presented. The algorithm is based on the heuristics implied in the circuit structure graph. To scale the heuristics, pi- weight, node- weight, average- weight and pi- distance in the circuit structure graph are defined. As any of the heuristics is not a panacea for all circuits, several sub-algorithms are proposed to cope with various cases. One is a direct method that uses pi- weight and pi- distance. The others are based on the depth-first-search (DFS) traversal of the circuit structure graph, with each focusing on one of the heuristics. An adaptive order selection strategy is adopted in WDHA. Experimental results show that WDHA is efficient in terms of BDD size and run time, and the dynamic OBDD variable ordering is more attractive if combined with WDHA.
Intuition and Heuristics in Mathematics
Directory of Open Access Journals (Sweden)
Sultanova L. B.
2013-01-01
Full Text Available The article is devoted to philosophy of mathematics. Mathematical heuristics, being a complex of methods for solving the non-standard problems of mathematics (such problems which have no known algorithms to be solved, is the main subject of the research. As a specific mechanism for thinking, generating elements of guesswork needed as the basis of mathematical heuristics, the author considers intuition. In the work, the author uses Descartes’s, Poincaré’s, Hadamard’s and Piaget’s findings. Based on Descartes’s concept of rational intuition, the author develops the concept of heuristic intuition. As a result, the author turns to the question of possibility of a complete translation of the user-derived mathematical statements in a discourse, in fact, that means a maximum depth of mathematical proof, i.e. its maximum rationalization. For this purpose, it is necessary to re-attract the intuition since it is able to transform the intuitive elements into the discourse ones. Therefore, from this point of view, the rationale is intuitively derived mathematical proof should be no more than a “multilayer” creative process. In general, the author, based on Poincaré’s research, proves that the essence of mathematical creativity is not to «sort out» and «choose». Referring to examples for illustration, the author reveals moments of «interference» of intuition, even in the process of solving school problems. Therefore, it is currently impossible to ignore the phenomenon of intuition and the results that have been historically derived a theory of knowledge in the study of creative mechanisms.
Evolved preambles for MAX-SAT heuristics
Rigo, Luis O
2011-01-01
MAX-SAT heuristics normally operate from random initial truth assignments to the variables. We consider the use of what we call preambles, which are sequences of variables with corresponding single-variable assignment actions intended to be used to determine a more suitable initial truth assignment for a given problem instance and a given heuristic. For a number of well established MAX-SAT heuristics and benchmark instances, we demonstrate that preambles can be evolved by a genetic algorithm such that the heuristics are outperformed in a significant fraction of the cases.
Directory of Open Access Journals (Sweden)
F. S. Marzano
2010-09-01
Full Text Available X-band Synthetic Aperture Radars (X-SARs, able to image the Earth's surface at metric resolution, may provide a unique opportunity to measure rainfall over land with spatial resolution of about few hundred meters, due to the atmospheric moving-target degradation effects. This capability has become very appealing due to the recent launch of several X-SAR satellites, even though several remote sensing issues are still open. This work is devoted to: (i explore the potential of X-band high-resolution detection and retrieval of rainfall fields from space using X-SAR signal backscattering amplitude and interferometric phase; (ii evaluate the effects of spatial resolution degradation by precipitation and inhomogeneous beam filling when comparing to other satellite-based sensors. Our X-SAR analysis of precipitation effects has been carried out using both a TerraSAR-X (TSX case study of Hurricane "Gustav" in 2008 over Mississippi (USA and a COSMO-SkyMed (CSK X-SAR case study of orographic rainfall over Central Italy in 2009. For the TSX case study the near-surface rain rate has been retrieved from the normalized radar cross section by means of a modified regression empirical algorithm (MREA. A relatively simple method to account for the geometric effect of X-SAR observation on estimated rainfall rate and first-order volumetric effects has been developed and applied. The TSX-retrieved rain fields have been compared to those estimated from the Next Generation Weather Radar (NEXRAD in Mobile (AL, USA. The rainfall detection capability of X-SAR has been tested on the CSK case study using the repeat-pass coherence response and qualitatively comparing its signature with ground-based Mt. Midia C-band radar in central Italy. A numerical simulator to represent the effect of the spatial resolution and the antenna pattern of TRMM satellite Precipitation Radar (PR and Microwave Imager (TMI, using high-resolution TSX-retrieved rain images, has been also set up in
High resolution observations with Artemis-IV and the NRH. I. Type IV associated narrow-band bursts
Bouratzis, C; Alissandrakis, C E; Preka-Papadema, P; Moussas, X; Caroubalos, C; Tsitsipis, P; Kontogeorgos, A
2016-01-01
Narrow band bursts appear on dynamic spectra from microwave to decametric frequencies as fine structures with very small duration and bandwidth. They are thought to mark small scale magnetic reconnection. We analyzed 27 metric type-IV events with narrow band bursts observed by the ARTEMIS-IV radiospectrograph in 30/6/1999-1/8/2010. We examined the morphological characteristics of isolated narrow-band bursts and groups or chains of spikes. The events were recorded with the SAO (10 ms cadence) receiver of ARTEMIS-IV in the 270-450 MHz range. We measured the duration, spectral width, and frequency drift of ~12000 individual narrow-band bursts, groups, and chains. Spike sources were imaged with the NRH for the event of 21 April 2003. The mean duration of individual bursts at fixed frequency was ~100 ms, while the instantaneous relative bandwidth was ~2%. Some bursts had measurable frequency drift, positive or negative. Often spikes appeared in chains, which were closely spaced in time (column chains) or in freque...
Otto, T.; Russchenberg, H.W.J.
2013-01-01
In 2007, the horizontally scanning polarimetric X-band radar IDRA (IRCTR Drizzle Radar) was installed on top of the 213 m high mast at the Dutch meteorological observatory Cabauw Experimental Site for Atmospheric Research (CESAR) at Netherlands. This radar complements a large variety of measurement
Cooperative heuristic multi-agent planning
De Weerdt, M.M.; Tonino, J.F.M.; Witteveen, C.
2001-01-01
In this paper we will use the framework to study cooperative heuristic multi-agent planning. During the construction of their plans, the agents use a heuristic function inspired by the FF planner (l3l). At any time in the process of planning the agents may exchange available resources, or they may r
The inherence heuristic is inherent in humans
Hampton, J A
2014-01-01
[Open Peer Commentary] The inherence heuristic is too broad as a theoretical notion. The authors are at risk of applying their own heuristic in supporting itself. Nonetheless the article provides useful insight into the ways in which people overestimate the coherence and completeness of their understanding of the world.
Modeling reproductive decisions with simple heuristics
Directory of Open Access Journals (Sweden)
Peter Todd
2013-10-01
Full Text Available BACKGROUND Many of the reproductive decisions that humans make happen without much planning or forethought, arising instead through the use of simple choice rules or heuristics that involve relatively little information and processing. Nonetheless, these heuristic-guided decisions are typically beneficial, owing to humans' ecological rationality - the evolved fit between our constrained decision mechanisms and the adaptive problems we face. OBJECTIVE This paper reviews research on the ecological rationality of human decision making in the domain of reproduction, showing how fertility-related decisions are commonly made using various simple heuristics matched to the structure of the environment in which they are applied, rather than being made with information-hungry mechanisms based on optimization or rational economic choice. METHODS First, heuristics for sequential mate search are covered; these heuristics determine when to stop the process of mate search by deciding that a good-enough mate who is also mutually interested has been found, using a process of aspiration-level setting and assessing. These models are tested via computer simulation and comparison to demographic age-at-first-marriage data. Next, a heuristic process of feature-based mate comparison and choice is discussed, in which mate choices are determined by a simple process of feature-matching with relaxing standards over time. Parental investment heuristics used to divide resources among offspring are summarized. Finally, methods for testing the use of such mate choice heuristics in a specific population over time are then described.
"A Heuristic for Visual Thinking in History"
Staley, David J.
2007-01-01
This article details a heuristic history teachers can use in assigning and evaluating multimedia projects in history. To use this heuristic successfully, requires more than simply following the steps in the list or stages in a recipe: in many ways, it requires a reorientation in what it means to think like an historian. This article, as much as…
Planning Graph Heuristics for Belief Space Search
Bryce, D; Smith, D E; 10.1613/jair.1869
2011-01-01
Some recent works in conditional planning have proposed reachability heuristics to improve planner scalability, but many lack a formal description of the properties of their distance estimates. To place previous work in context and extend work on heuristics for conditional planning, we provide a formal basis for distance estimates between belief states. We give a definition for the distance between belief states that relies on aggregating underlying state distance measures. We give several techniques to aggregate state distances and their associated properties. Many existing heuristics exhibit a subset of the properties, but in order to provide a standardized comparison we present several generalizations of planning graph heuristics that are used in a single planner. We compliment our belief state distance estimate framework by also investigating efficient planning graph data structures that incorporate BDDs to compute the most effective heuristics. We developed two planners to serve as test-beds for our inve...
HISTORY AND TERRITORY HEURISTICS FOR MONTE CARLO GO
BRUNO BOUZY
2006-01-01
Recently, the Monte Carlo approach has been applied to computer go with promising success. INDIGO uses such an approach which can be enhanced with specific heuristics. This paper assesses two heuristics within the 19 × 19 Monte Carlo go framework of INDIGO: the territory heuristic and the history heuristic, both in their internal and external versions. The external territory heuristic is more effective, leading to a 40-point improvement on 19 × 19 boards. The external history heuristic brings...
International Nuclear Information System (INIS)
Infrared and Raman spectra of mono 13C fully deuterated acetylene, 13C12CD2, have been recorded and analysed to obtain detailed information on the C—D stretching fundamentals and associated combination, overtone, and hot bands. Infrared spectra were recorded at an instrumental resolution ranging between 0.006 and 0.01 cm−1 in the region 1800–7800 cm−1. Sixty new bands involving the ν1 and ν3 C—D stretching modes also associated with the ν4 and ν5 bending vibrations have been observed and analysed. In total, 5881 transitions have been assigned in the investigated spectral region. In addition, the Q branch of the ν1 fundamental was recorded using inverse Raman spectroscopy, with an instrumental resolution of about 0.003 cm−1. The transitions relative to each stretching mode, i.e., the fundamental band, its first overtone, and associated hot and combination bands involving bending states with υ4 + υ5 up to 2 were fitted simultaneously. The usual Hamiltonian appropriate to a linear molecule, including vibration and rotation l-type and the Darling–Dennison interaction between υ4 = 2 and υ5 = 2 levels associated with the stretching states, was adopted for the analysis. The standard deviation for each global fit is ≤0.0004 cm−1, of the same order of magnitude of the measurement precision. Slightly improved parameters for the bending and the ν2 manifold have been also determined. Precise values of spectroscopic parameters deperturbed from the resonance interactions have been obtained. They provide quantitative information on the anharmonic character of the potential energy surface, which can be useful, in addition to those reported in the literature, for the determination of a general anharmonic force field for the molecule. Finally, the obtained values of the Darling–Dennison constants can be valuable for understanding energy flows between independent vibrations
Albert, S.; Albert, K. K.; Quack, M.; Lerch, Ph.
2010-06-01
One of the great challenges of astronomical infrared spectroscopy is the identification of the Unidentified Infrared Bands (UIBs) found in several interstellar objects. Polycyclic Aromatic Hydrocarbons (PAHs) have been proposed to be the carrier of the UIBs. For that reason we have started to investigate the rotationally resolved FTIR spectrum of the bicyclic naphthalene as a simple prototypical spectrum for a PAH infrared spectrum. These investigations at very high resolution, ΔνMulas, G. Malloci and C. Joblin, Phys. Chem. Chem. Phys. 2009,11, 3443. M.H. Kabir, S. Kasahara, W. Demtroeder, Y. Tatamitani, A. Doi, H. Kato and M. Baba, J. Chem. Phys. 2003, 119, 3691.
Trishchenko, Alexander; Luo, Yi; Khlopenkov, Konstantin; Park, William; Wang, Shusen
The time series of spatially-enhanced MODIS surface albedo for the Arctic circumpolar zone (9,000km × 9,000km) are generated as the Canada Centre for Remote Sensing (CCRS) contribution to the Canadian component of the International Polar Year (IPY) Program. The imagery is obtained by a fusion of MODIS bands B1-B2 observed at 250-meter spatial resolution with bands B3-B7 observed at 500-meter spatial resolution to satisfy the Global Climate Observing System (GCOS) requirements for spatial resolution of satellite products for climate. The fusion method employed an adaptive regression and normalization to preserve the image radiometric properties. A new cloud and cloud shadow detection method and clear-sky compositing scheme were employed for the 250m multi-spectral data. Unlike standard MODIS products divided into separate thematic categories, this new product is spatially continuous over the entire circumpolar area and includes all surface types: land, ocean, snow/ice. New bi-directional reflectance distribution model based on POLDER multiangular observations is employed. This model accounts better for the hot-spot effect and makes distinction between surfaces covered by a canopy and surfaces with specular reflection, such as water and snow/ice. By the end of the IPY in 2009, a decade long (2000-2009) time series of these data at 10-day intervals will be available to document the state and variability of the Arctic region at high spatial and temporal resolution. This study is conducted at the Canada Centre for Remote Sensing (CCRS), Earth Sciences Sector of the Department of Natural Resources Canada as part of the Project J35 of the Program on "Enhancing Resilience in a Changing Climate" and the "Climate Change and Ecosystem Impact" Project supported by the Canadian Space Agency through the Government Related Initiatives Program (GRIP). The MODIS data were acquired through the NASA Distributed Active Archive Center (DAAC).
Comparison of Heuristics for Inhibitory Rule Optimization
Alsolami, Fawaz
2014-09-13
Knowledge representation and extraction are very important tasks in data mining. In this work, we proposed a variety of rule-based greedy algorithms that able to obtain knowledge contained in a given dataset as a series of inhibitory rules containing an expression “attribute ≠ value” on the right-hand side. The main goal of this paper is to determine based on rule characteristics, rule length and coverage, whether the proposed rule heuristics are statistically significantly different or not; if so, we aim to identify the best performing rule heuristics for minimization of rule length and maximization of rule coverage. Friedman test with Nemenyi post-hoc are used to compare the greedy algorithms statistically against each other for length and coverage. The experiments are carried out on real datasets from UCI Machine Learning Repository. For leading heuristics, the constructed rules are compared with optimal ones obtained based on dynamic programming approach. The results seem to be promising for the best heuristics: the average relative difference between length (coverage) of constructed and optimal rules is at most 2.27% (7%, respectively). Furthermore, the quality of classifiers based on sets of inhibitory rules constructed by the considered heuristics are compared against each other, and the results show that the three best heuristics from the point of view classification accuracy coincides with the three well-performed heuristics from the point of view of rule length minimization.
Mukhopadhyay, Indra
2016-07-01
This paper reports the analysis of the high resolution (0.0019 cm-1) Fourier transform infrared (FTIR) spectrum for asymmetrically deuterated methanol CHD2OH (methanol-D2) at a low temperature for the CD2 wagging band for the lowest lying trans-species (e0). In spite of the complexity and perturbation in the spectra, assignments were possible for the CD2 wagging band for a maximum K value of 10. In total, about 500 spectral lines have been assigned. Analysis of the spectral lines has been performed in terms of state dependent molecular parameters, Q-branch origins and asymmetry splitting. Assignments have been thoroughly confirmed using combination relations (see text). The catalogue of the assigned transition wavenumbers will help identification and prediction of far infrared (FIR) optically pumped CO2 lasers. The absorption lines close to the several 10R and 10P CO2 laser lines have also been identified. These should help experimentalists to optimize the power of the emission FIR laser lines and to predict new lines and should prove valuable as a laboratory support for interstellar detection in "Radio Astronomy". To our knowledge this is the first time such vibrational infrared (IR) high resolution study in CHD2OH is being performed.
High resolution analysis of 32S18O2 spectra: The ν1 and ν3 interacting bands
Ulenikov, O. N.; Bekhtereva, E. S.; Krivchikova, Yu. V.; Morzhikova, Yu. B.; Buttersack, T.; Sydow, C.; Bauerecker, S.
2015-11-01
Highly accurate, ~(1 - 2) ×10-4cm-1, ro-vibrational spectrum of S18O2 was recorded with Bruker IFS 120 HR Fourier transform interferometer in the region of 1050-1400 cm-1 where the bands ν1 and ν3 are located. About 1560 and 1840 transitions were assigned in the experimental spectrum with the maximum values of quantum numbers Jmax. /Kamax. equal to 65/22 and 58/16 to the bands ν3 and ν1, respectively. The further weighted fit of experimentally assigned transitions was made with the Hamiltonian model which takes into account Coriolis resonance interaction between the vibrational states (100) and (001). To make the ro-vibrational analysis physically more suitable, the initial values of main spectroscopic parameters have been estimated from the values of corresponding parameters of the S16O2 species on the basis of the results of the Isotopic Substitution theory. Finally, the set of 23 spectroscopic parameters obtained from the fit reproduces values of 1292 initial "experimental" ro-vibrational energy levels (about 3400 transitions assigned in the experimental spectrum) with the drms = 0.00015cm-1. Also, the ground state parameters of the S18O2 molecule were improved.
High-Resolution N-Band Observations of the Nova RS Ophiuchi with the Keck Interferometer Nuller
Barry, R. K.; Danchi, W. C.; Sokoloski, J. L.; Koresko, C.; Wisniewski, J. P.; Serabyn, E.; Traub, W.; Kuchner, M.; Greenhouse, M. A.
2007-01-01
We report new observations of the nova RS Ophiuchi (RS Oph) using the Keck Interferometer Nulling Instrument, approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. The Keck Interferometer Nuller (KIN) operates in K-band from 8 to 12.5 pm in a nulling mode, which means that the central broad-band interference fringe is a dark fringe - with an angular width of 25 mas at mid band - rather than the bright fringe used ill a conventional optical interferometer. In this mode the stellar light itself is suppressed by the destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. By subsequently shifting the neighboring bright fringe onto the center of the source brightness distribution and integrating, a second spatial regime dominated by light from the central portion of the source is almost simultaneously sampled. The nulling technique is the sparse aperture equivalent of the conventional corongraphic technique used in filled aperture telescopes. By fitting the unique KIK inner and outer spatial regime data, we have obtained an angular size of the mid-infrared continuum of 6.2, 4.0. or 5.4 mas for a disk profile, gaussian profile (fwhm), and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission located in the inner spatial regime relative to the outer regime. There is also evidence of a 9.7 micron silicate feature seen outside of this region. Importantly, we see spectral lines excited by the nova flash in the outer region before the blast wave reaches these regions. These lines are from neutral, weakly excited atoms which support the following interpretation. We discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power
A new heuristic for the quadratic assignment problem
Zvi Drezner
2002-01-01
We propose a new heuristic for the solution of the quadratic assignment problem. The heuristic combines ideas from tabu search and genetic algorithms. Run times are very short compared with other heuristic procedures. The heuristic performed very well on a set of test problems.
A Direct Heuristic Algorithm for Linear Programming
Indian Academy of Sciences (India)
S K Sen; A Ramful
2000-02-01
An (3) mathematically non-iterative heuristic procedure that needs no artificial variable is presented for solving linear programming problems. An optimality test is included. Numerical experiments depict the utility/scope of such a procedure.
Hermawati, Setia; Lawson, Glyn
2016-09-01
Heuristics evaluation is frequently employed to evaluate usability. While general heuristics are suitable to evaluate most user interfaces, there is still a need to establish heuristics for specific domains to ensure that their specific usability issues are identified. This paper presents a comprehensive review of 70 studies related to usability heuristics for specific domains. The aim of this paper is to review the processes that were applied to establish heuristics in specific domains and identify gaps in order to provide recommendations for future research and area of improvements. The most urgent issue found is the deficiency of validation effort following heuristics proposition and the lack of robustness and rigour of validation method adopted. Whether domain specific heuristics perform better or worse than general ones is inconclusive due to lack of validation quality and clarity on how to assess the effectiveness of heuristics for specific domains. The lack of validation quality also affects effort in improving existing heuristics for specific domain as their weaknesses are not addressed. PMID:27184309
An Improved Heuristic Ant-Clustering Algorithm
Institute of Scientific and Technical Information of China (English)
Yunfei Chen; Yushu Liu; Jihai Zhao
2004-01-01
An improved heuristic ant-clustering algorithm(HAC)is presented in this paper. A device of ＇memory bank＇ is proposed,which can bring forth heuristic knowledge guiding ant to move in the bi-dimension grid space.The device experiments on real data sets and synthetic data sets.The results demonstrate that HAC has superiority in misclassification error rate and runtime over the classical algorithm.
Energy Technology Data Exchange (ETDEWEB)
Di Lonardo, G.; Fusina, L., E-mail: luciano.fusina@unibo.it; Canè, E.; Tamassia, F. [Dipartimento di Chimica Industriale “Toso Montanari,” Università di Bologna, Viale Risorgimento 4, I-40136 Bologna (Italy); Martínez, R. Z.; Bermejo, D. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, 28006 Madrid (Spain)
2015-09-07
Infrared and Raman spectra of mono {sup 13}C fully deuterated acetylene, {sup 13}C{sup 12}CD{sub 2}, have been recorded and analysed to obtain detailed information on the C—D stretching fundamentals and associated combination, overtone, and hot bands. Infrared spectra were recorded at an instrumental resolution ranging between 0.006 and 0.01 cm{sup −1} in the region 1800–7800 cm{sup −1}. Sixty new bands involving the ν{sub 1} and ν{sub 3} C—D stretching modes also associated with the ν{sub 4} and ν{sub 5} bending vibrations have been observed and analysed. In total, 5881 transitions have been assigned in the investigated spectral region. In addition, the Q branch of the ν{sub 1} fundamental was recorded using inverse Raman spectroscopy, with an instrumental resolution of about 0.003 cm{sup −1}. The transitions relative to each stretching mode, i.e., the fundamental band, its first overtone, and associated hot and combination bands involving bending states with υ{sub 4} + υ{sub 5} up to 2 were fitted simultaneously. The usual Hamiltonian appropriate to a linear molecule, including vibration and rotation l-type and the Darling–Dennison interaction between υ{sub 4} = 2 and υ{sub 5} = 2 levels associated with the stretching states, was adopted for the analysis. The standard deviation for each global fit is ≤0.0004 cm{sup −1}, of the same order of magnitude of the measurement precision. Slightly improved parameters for the bending and the ν{sub 2} manifold have been also determined. Precise values of spectroscopic parameters deperturbed from the resonance interactions have been obtained. They provide quantitative information on the anharmonic character of the potential energy surface, which can be useful, in addition to those reported in the literature, for the determination of a general anharmonic force field for the molecule. Finally, the obtained values of the Darling–Dennison constants can be valuable for understanding energy flows
Multi-stage hyper-heuristics for optimisation problems
Kheiri, Ahmed
2014-01-01
There is a growing interest towards self configuring/tuning automated general-purpose reusable heuristic approaches for combinatorial optimisation, such as, hyper-heuristics. Hyper-heuristics are search methodologies which explore the space of heuristics rather than the solutions to solve a broad range of hard computational problems without requiring any expert intervention. There are two common types of hyper-heuristics in the literature: selection and generation methodologies. This work foc...
A rescheduling heuristic for the single machine total tardiness problem
JC Nyirenda
2006-01-01
In this paper, we propose a rescheduling heuristic for scheduling N jobs on a single machine in order to minimise total tardiness. The heuristic is of the interchange type and constructs a schedule from the modified due date (MDD) schedule. Unlike most interchange heuristics that consider interchanges involving only two jobs at a time, the newly proposed heuristic uses interchanges that may involve more than two jobs at any one time. Experimental results show that the heuristic is effective a...
A graph-based hyper heuristic for timetabling problems
Burke, Edmund; MacCloumn, Barry; Meisels, Amnon; Petrovic, Sanja; Qu, Rong
2007-01-01
This paper presents an investigation of a simple generic hyper-heuristic approach upon a set of widely used constructive heuristics (graph coloring heuristics) in timetabling. Within the hyperheuristic framework, a Tabu Search approach is employed to search for permutations of graph heuristics which are used for constructing timetables in exam and course timetabling problems. This underpins a multi-stage hyper-heuristic where the Tabu Search employs permutations upon a different number of gra...
Danchi, William
2008-01-01
We report new observations of the nova RS Ophiuchi using the Keck Interferometer Nulling Instrument (KIN), approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. These observations represent the first scientific results from the KIN, which operates in N-band from 8 to 12.5 microns. The nulling technique is the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture telescopes. By fitting the unique KIN inner and outer spatial regime data, we have obtained an angular size of the mid-infrared continuum of 6.2,4.0, or 5.4 mas for a disk profile, Gaussian profile, and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf relative to the outer regime. There are also nebular emission lines and evidence of hot silicate dust in the outer spatial region, centered at approximately 2.5E14 cm from the WD, that are not found in the inner regime. The nova flash in the outer spatial regime evidently excited these features before the blast wave reached these regions. These identifications support the following interpretation. The dust appears to be present between outbursts and was not created during the outburst event. We further discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power and potential of the nulling technique which has been developed for the detection of Earthlike planets around nearby stars for the Terrestrial Planet Finder Mission and Darwin missions.
Directory of Open Access Journals (Sweden)
Sajid Shah
2015-05-01
Full Text Available Rain nowcasting is an essential part of weather monitoring. It plays a vital role in human life, ranging from advanced warning systems to scheduling open air events and tourism. A nowcasting system can be divided into three fundamental steps, i.e., storm identification, tracking and nowcasting. The main contribution of this work is to propose procedures for each step of the rain nowcasting tool and to objectively evaluate the performances of every step, focusing on two-dimension data collected from short-range X-band radars installed in different parts of Italy. This work presents the solution of previously unsolved problems in storm identification: first, the selection of suitable thresholds for storm identification; second, the isolation of false merger (loosely-connected storms; and third, the identification of a high reflectivity sub-storm within a large storm. The storm tracking step of the existing tools, such as TITANand SCIT, use only up to two storm attributes, i.e., center of mass and area. It is possible to use more attributes for tracking. Furthermore, the contribution of each attribute in storm tracking is yet to be investigated. This paper presents a novel procedure called SALdEdA (structure, amplitude, location, eccentricity difference and areal difference for storm tracking. This work also presents the contribution of each component of SALdEdA in storm tracking. The second order exponential smoothing strategy is used for storm nowcasting, where the growth and decay of each variable of interest is considered to be linear. We evaluated the major steps of our method. The adopted techniques for automatic threshold calculation are assessed with a 97% goodness. False merger and sub-storms within a cluster of storms are successfully handled. Furthermore, the storm tracking procedure produced good results with an accuracy of 99.34% for convective events and 100% for stratiform events.
Jawak, Shridhar D.; Luis, Alvarinho J.
2013-01-01
Here, we discuss the improvements in urban classification that were made using the spatial-spectral-angular information from a WorldView-2 (WV-2) multiangle image sequence. In this study, we evaluate the use of multiangle high resolution WV-2 panchromatic (PAN) and multispectral image (MSI) data for extracting urban geospatial information. Current multiangular WV-2 data were classified into misclassification-prone surfaces, such as vegetation, water bodies, and man-made features, using a cluster of normalized difference spectral index ratios (SIR). A novel multifold methodology protocol was designed to estimate the consequences of multiangularity and germane PAN-sharpening algorithms on the spectral characteristics (distortions) of satellite data and on the resulting land use/land cover (LU/LC) mapping using an array of SIRs. Eight existing PAN-sharpening algorithms were used for data fusion, followed by estimation of multiple SIRs to mitigate spectral distortions arising from the multiangularity of the data. This research highlights the benefits of using traditional PAN-sharpening techniques with a specific set of SIRs on land cover mapping based on five available tiles of satellite data. The research provides a method to overcome the atmospherically triggered spectral distortions of multiangular acquisitions, which will facilitate better mapping and understanding of the earth's surface.
Chojnowski, S Drew; Wisniewski, John P; Majewski, Steven R; Hall, Matthew; Shetrone, Matthew; Beaton, Rachael; Burton, Adam; Damke, Guillermo; Eikenberry, Steve; Hasselquist, Sten; Holtzman, Jon A; Meszaros, Szabolcs; Nidever, David; Schneider, Donald P; Wilson, John; Zasowski, Gail; Bizyaev, Dmitry; Brewington, Howard; Brinkmann, J; Ebelke, Garrett; Frinchaboy, Peter M; Kinemuchi, Karen; Malanushenko, Elena; Malanushenko, Viktor; Marchante, Moses; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey
2014-01-01
APOGEE has amassed the largest ever collection of multi-epoch, high-resolution (R~22,500), H-band spectra for B-type emission line (Be) stars. The 128/238 APOGEE Be stars for which emission had never previously been reported serve to increase the total number of known Be stars by ~6%. We focus on identification of the H-band lines and analysis of the emission peak velocity separations (v_p) and emission peak intensity ratios (V/R) of the usually double-peaked H I and non-hydrogen emission lines. H I Br11 emission is found to preferentially form in the circumstellar disks at an average distance of ~2.2 stellar radii. Increasing v_p toward the weaker Br12--Br20 lines suggests these lines are formed interior to Br11. By contrast, the observed IR Fe II emission lines present evidence of having significantly larger formation radii; distinctive phase lags between IR Fe II and H I Brackett emission lines further supports that these species arise from different radii in Be disks. Several emission lines have been iden...
First high-resolution analysis of the 4ν1+ν3 band of nitrogen dioxide near 1.5 μm
International Nuclear Information System (INIS)
The high-resolution absorption spectrum of the 4ν1+ν3 band of the 14N16O2 molecule was recorded by CW-Cavity Ring Down Spectroscopy between 6575 and 6700 cm-1. The assignments involve energy levels of the (4,0,1) vibrational state with rotational quantum numbers up to Ka=8 and N=48. A large majority of the spin-rotation energy levels were reproduced within their experimental uncertainty using a theoretical model which takes explicitly into account the Coriolis interactions between the spin-rotational levels of the (4,0,1) vibrational state and those of the (4,2,0) and of (0,9,0) dark states, the anharmonic interactions between the (4,2,0) and (0,9,0) states together with the electron spin-rotation resonances within the (4,0,1), (4,2,0) and (0,9,0) states. Precise vibrational energies, rotational, spin-rotational, and coupling constants were determined for the {(4,2,0), (0,9,0), (4,0,1)} triad of interacting states. Using these parameters and the value of the transition dipole-moment operator determined from a fit of a selection of experimental line intensities, the synthetic spectrum of the 4ν1+ν3 band was generated and is provided as Supplementary Material.
Barry, Richard K.; Danchi, W. C.; Traub, W.; Kuchner, M.; Wisniewski, J. P.; Akeson, R.; Colavita, M.; Greenhouse, M, A.; Koresko, C.; Serabyn, E.; Sokoloski, J. L.
2008-01-01
We report observations of the nova RS 0phiuchi using the Keck Interferometer Nuller (KIN) taken approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. The KIN operates in N-band from approx. 8 to 12.5 microns in a nulling mode - the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture te1escopes. In this mode the stellar light is suppressed by a destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. In a second, constructive-fringe mode, the instrument detects primarily the light from the central, bright source. These are the outer and inner spatial regimes, resprectively. We will describe the capabilities of the KIN, including these unique modes, and outline how they were key in our discovery that dust does not appear to be created in the outburst as in previous models, but instead was created between nova events. We also show how these first results from the KIN are consistent with Spitzer data. The KIN data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf (WD) relative to the outer regime. There are also nebular emission lines and evidence of hot silicate dust in the outer spatial region, centered at approximately 17 AU from the WD, that are not found in the inner regime. The KIN and Spitzer data suggest that these emissions were excited by the nova flash in the outer spatial regime before the blast wave reached these regions. We describe the present results in terms of a new model for dust creation in recurrent novae that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power and potential of the nulling technique which has been developed for the detection of Earth
Parallel Heuristics for Scalable Community Detection
Energy Technology Data Exchange (ETDEWEB)
Lu, Howard; Kalyanaraman, Anantharaman; Halappanavar, Mahantesh; Choudhury, Sutanay
2014-05-17
Community detection has become a fundamental operation in numerous graph-theoretic applications. It is used to reveal natural divisions that exist within real world networks without imposing prior size or cardinality constraints on the set of communities. Despite its potential for application, there is only limited support for community detection on large-scale parallel computers, largely owing to the irregular and inherently sequential nature of the underlying heuristics. In this paper, we present parallelization heuristics for fast community detection using the Louvain method as the serial template. The Louvain method is an iterative heuristic for modularity optimization. Originally developed by Blondel et al. in 2008, the method has become increasingly popular owing to its ability to detect high modularity community partitions in a fast and memory-efficient manner. However, the method is also inherently sequential, thereby limiting its scalability to problems that can be solved on desktops. Here, we observe certain key properties of this method that present challenges for its parallelization, and consequently propose multiple heuristics that are designed to break the sequential barrier. Our heuristics are agnostic to the underlying parallel architecture. For evaluation purposes, we implemented our heuristics on shared memory (OpenMP) and distributed memory (MapReduce-MPI) machines, and tested them over real world graphs derived from multiple application domains (internet, biological, natural language processing). Experimental results demonstrate the ability of our heuristics to converge to high modularity solutions comparable to those output by the serial algorithm in nearly the same number of iterations, while also drastically reducing time to solution.
Phase Selection Heuristics for Satisfiability Solvers
Chen, Jingchao
2011-01-01
In general, a SAT Solver based on conflict-driven DPLL consists of variable selection, phase selection, Boolean Constraint Propagation, conflict analysis, clause learning and its database maintenance. Optimizing any part of these components can enhance the performance of a solver. This paper focuses on optimizing phase selection. Although the ACE (Approximation of the Combined lookahead Evaluation) weight is applied to a lookahead SAT solver such as March, so far, no conflict-driven SAT solver applies successfully the ACE weight, since computing the ACE weight is time-consuming. Here we apply the ACE weight to partial phase selection of conflict-driven SAT solvers. This can be seen as an improvement of the heuristic proposed by Jeroslow-Wang (1990). We incorporate the ACE heuristic and the existing phase selection heuristics in the new solver MPhaseSAT, and select a phase heuristic in a way similar to portfolio methods. Experimental results show that adding the ACE heuristic can improve the conflict-driven so...
Energy Technology Data Exchange (ETDEWEB)
Chojnowski, S. Drew; Majewski, Steven R.; Hall, Matthew; Beaton, Rachael; Burton, Adam; Damke, Guillermo; Wilson, John [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Whelan, David G. [Department of Physics, Austin College, 900 N. Grand Ave., Sherman, TX 75090 (United States); Wisniewski, John P. [Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Shetrone, Matthew [Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400 Austin, Texas 78712-1205 (United States); Eikenberry, Steve [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Hasselquist, Sten; Holtzman, Jon A.; Brewington, Howard; Brinkmann, J. [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059 (United States); Mészáros, Szabolcs [ELTE Gothard Astrophysical Observatory, 1H-9704 Szombathely, Szent Imre herceg st. 112 (Hungary); Nidever, David [Department of Astronomy, University of Michigan, 830 Dennison, 500 Church St., Ann Arbor, MI 48109-1042 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Zasowski, Gail [Department of Physics and Astronomy, Johns Hopkins University, Bloomberg Center for Physics and Astronomy, Room 366, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Bizyaev, Dmitry, E-mail: drewski@virginia.edu [Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States); and others
2015-01-01
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has amassed the largest ever collection of multi-epoch, high-resolution (R∼22,500), H-band spectra for B-type emission line (Be) stars. These stars were targeted by APOGEE as telluric standard stars and subsequently identified via visual inspection as Be stars based on H i Brackett series emission or shell absorption in addition to otherwise smooth continua and occasionally non-hydrogen emission features. The 128/238 APOGEE Be stars for which emission had never previously been reported serve to increase the total number of known Be stars by ∼6%. Because the H band is relatively unexplored compared to other wavelength regimes, we focus here on identification of the H-band lines and analysis of the emission peak velocity separations (Δv{sub p}) and emission peak intensity ratios (V/R) of the usually double-peaked H i and non-hydrogen emission lines. H i Br11 emission is found to preferentially form in the circumstellar disks at an average distance of ∼2.2 stellar radii. Increasing Δv{sub p} toward the weaker Br12–Br20 lines suggests these lines are formed interior to Br11. By contrast, the observed IR Fe ii emission lines present evidence of having significantly larger formation radii; distinctive phase lags between IR Fe ii and H i Brackett emission lines further supports that these species arise from different radii in Be disks. Several emission lines have been identified for the first time including C i 16895, a prominent feature in the spectra for almost a fifth of the sample and, as inferred from relatively large Δv{sub p} compared to the Br11–Br20, a tracer of the inner regions of Be disks. Emission lines at 15760 Å and 16781 Å remain unidentified, but usually appear along with and always have similar line profile morphology to Fe ii 16878. Unlike the typical metallic lines observed for Be stars in the optical, the H-band metallic lines, such as Fe ii 16878, never exhibit any
Agent Based Patient Scheduling Using Heuristic Algorithm
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Juliet A Murali
2010-01-01
Full Text Available This paper describes about an agent based approach to patient scheduling using experience based learning. A heuristic algorithm is also used in the proposed framework. The evaluation on different learning techniques shows that the experience based learning (EBL gives better solution. The processing time decreases as the experience increases. The heuristic algorithm make use of EBL in calculating the processing time. The main objective of this patient scheduling system is to reduce the waiting time of patient in hospitals and to complete their treatment in minimum required time. The framework is implemented in JADE. In this approach the patients and resources are represented as patient agents (PA and resource agents (RA respectively. Even though mathematical model give optimal solution, the computational complexity increases for large size problems. Heuristic solution gives better solution for large size problems. The comparisons of the proposed framework with other scheduling rules shows that an agent based approach to patient scheduling using EBL is better.
Intelligent System Design Using Hyper-Heuristics
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Nelishia Pillay
2015-07-01
Full Text Available Determining the most appropriate search method or artificial intelligence technique to solve a problem is not always evident and usually requires implementation of the different approaches to ascertain this. In some instances a single approach may not be sufficient and hybridization of methods may be needed to find a solution. This process can be time consuming. The paper proposes the use of hyper-heuristics as a means of identifying which method or combination of approaches is needed to solve a problem. The research presented forms part of a larger initiative aimed at using hyper-heuristics to develop intelligent hybrid systems. As an initial step in this direction, this paper investigates this for classical artificial intelligence uninformed and informed search methods, namely depth first search, breadth first search, best first search, hill-climbing and the A* algorithm. The hyper-heuristic determines the search or combination of searches to use to solve the problem. An evolutionary algorithm hyper-heuristic is implemented for this purpose and its performance is evaluated in solving the 8-Puzzle, Towers of Hanoi and Blocks World problems. The hyper-heuristic employs a generational evolutionary algorithm which iteratively refines an initial population using tournament selection to select parents, which the mutation and crossover operators are applied to for regeneration. The hyper-heuristic was able to identify a search or combination of searches to produce solutions for the twenty 8-Puzzle, five Towers of Hanoi and five Blocks World problems. Furthermore, admissible solutions were produced for all problem instances.
International Nuclear Information System (INIS)
We present the results of infrared K- (2.2 μm) and L'-band (3.8 μm) high-spatial-resolution (<0.''2) imaging observations of nearby gas- and dust-rich infrared luminous merging galaxies, assisted by the adaptive optics system on the Subaru 8.2 m telescope. We investigate the presence and frequency of red K – L' compact sources, which are sensitive indicators of active galactic nuclei (AGNs), including AGNs that are deeply buried in gas and dust. We observed 29 merging systems and confirmed at least one AGN in all but one system. However, luminous dual AGNs were detected in only four of the 29 systems (∼14%), despite our method's being sensitive to buried AGNs. For multiple nuclei sources, we compared the estimated AGN luminosities with supermassive black hole (SMBH) masses inferred from large-aperture K-band stellar emission photometry in individual nuclei. We found that mass accretion rates onto SMBHs are significantly different among multiple SMBHs, such that larger-mass SMBHs generally show higher mass accretion rates when normalized to SMBH mass. Our results suggest that non-synchronous mass accretion onto SMBHs in gas- and dust-rich infrared luminous merging galaxies hampers the observational detection of kiloparsec-scale multiple active SMBHs. This could explain the significantly smaller detection fraction of kiloparsec-scale dual AGNs when compared with the number expected from simple theoretical predictions. Our results also indicate that mass accretion onto SMBHs is dominated by local conditions, rather than by global galaxy properties, reinforcing the importance of observations to our understanding of how multiple SMBHs are activated and acquire mass in gas- and dust-rich merging galaxies.
A brief discussion on the art of heuristic teaching method
Yin-jiang ZHAO
2014-01-01
Heuristic teaching method is widely advocated in our country. Level of heuristic teaching method should be paid more attention to improve teaching quality, and comprehensive mind is also needed. Heuristic teaching method takes the dominant position due to its wide adaptability and vitality. The art of heuristic teaching method lies in the fact that it could drive the students’ motivation to learn. Knowledge and inspiration, is the essence of teaching art.
Applying usability heuristics to radiotherapy systems
International Nuclear Information System (INIS)
Background and purpose: Heuristic evaluations have been used to evaluate safety of medical devices by identifying and assessing usability issues. Since radiotherapy treatment delivery systems often consist of multiple complex user-interfaces, a heuristic evaluation was conducted to assess the potential safety issues of such a system. Material and methods: A heuristic evaluation was conducted to evaluate the treatment delivery system at Princess Margaret Hospital (Toronto, Canada). Two independent evaluators identified usability issues with the user-interfaces and rated the severity of each issue. Results: The evaluators identified 75 usability issues in total. Eighteen of them were rated as high severity, indicating the potential to have a major impact on patient safety. A majority of issues were found on the record and verify system, and many were associated with the patient setup process. While the hospital has processes in place to ensure patient safety, recommendations were developed to further mitigate the risks of potential consequences. Conclusions: Heuristic evaluation is an efficient and inexpensive method that can be successfully applied to radiotherapy delivery systems to identify usability issues and improve patient safety. Although this study was conducted only at one site, the findings may have broad implications for the design of these systems.
Heuristic estimates in shortest path algorithms
W.H.L.M. Pijls (Wim)
2006-01-01
textabstractShortest path problems occupy an important position in Operations Research as well as in Arti¯cial Intelligence. In this paper we study shortest path algorithms that exploit heuristic estimates. The well-known algorithms are put into one framework. Besides we present an interesting appli
Heuristic estimates in shortest path algorithms
Pijls, Wim
2006-01-01
textabstractShortest path problems occupy an important position in Operations Research as well as in Arti¯cial Intelligence. In this paper we study shortest path algorithms that exploit heuristic estimates. The well-known algorithms are put into one framework. Besides we present an interesting application of binary numbers in the shortest path theory.
Structural Functionalism as a Heuristic Device.
Chilcott, John H.
1998-01-01
Argues that structural functionalism as a method for conducting fieldwork and as a format for the analysis of ethnographic data remains a powerful model, one that is easily understood by professional educators. As a heuristic device, functionalist theory can help in the solution of a problem that is otherwise incapable of theoretical…
Randomized Heuristics for Exploiting Jacobian Scarcity
Lyons, Andrew; Safro, Ilya
2009-01-01
Griewank and Vogel introduced the notion of Jacobian scarcity, which generalizes the properties of sparsity and rank to capture a kind of deficiency in the degrees of freedom of the Jacobian matrix $F'(mathbf{x}).$ We describe new randomized heuristics that exploit scarcity for the optimized evaluation of collections of Jacobian-vector or Jacobian-transpose-vector products.
The Heuristic Interpretation of Box Plots
Lem, Stephanie; Onghena, Patrick; Verschaffel, Lieven; Van Dooren, Wim
2013-01-01
Box plots are frequently used, but are often misinterpreted by students. Especially the area of the box in box plots is often misinterpreted as representing number or proportion of observations, while it actually represents their density. In a first study, reaction time evidence was used to test whether heuristic reasoning underlies this…
A tabu-search heuristic for solving the multi-depot vehicle scheduling problem
Directory of Open Access Journals (Sweden)
Gilmar D'Agostini Oliveira Casalinho
2014-08-01
Full Text Available Currently the logistical problems are relying quite significantly on Operational Research in order to achieve greater efficiency in their operations. Among the problems related to the vehicles scheduling in a logistics system, the Multiple Depot Vehicle Scheduling Problem (MDVSP has been addressed in several studies. The MDVSP presupposes the existence of depots that affect the planning of sequences to which travel must be performed. Often, exact methods cannot solve large instances encountered in practice and in order to take them into account, several heuristic approaches are being developed. The aim of this study was thus to solve the MDVSP using a meta-heuristic based on tabu-search method. The main motivation for this work came from the indication that only recently the use of meta-heuristics is being applied to MDVSP context (Pepin et al. 2008 and, also, the limitations listed by Rohde (2008 in his study, which used the branch-and-bound in one of the steps of the heuristic presented to solve the problem, which has increased the time resolution. The research method for solving this problem was based on adaptations of traditional techniques of Operational Research, and provided resolutions presenting very competitive results for the MDVSP such as the cost of the objective function, number of vehicles used and computational time.
Pancino, E; Zoccali, M; Carrera, R
2010-01-01
Globular clusters show abundance variations for light elements that are not yet well understood. The preferred explanation involves a self-enrichment scenario, with two subsequent generations of stars. Observations of main sequence stars allow us to investigate the signature of this chemically processed material without the complicating effects of internal mixing. Our goal is to investigate the C-N anti-correlation with low-resolution spectroscopy of 20-50 stars fainter than the first dredge-up in seven globular clusters (NGC288, NGC1851, NGC5927, NGC6352, NGC6388, and Pal12) with different properties. We complemented our observations with 47~Tuc archival data, with four additional clusters from the literature (M15, M22, M55, NGC362), and with additional literature data on NGC288. In this first paper, we measured the strength of CN and CH band indices, and we investigated the anti-correlation and bimodality of these indices. We compared r_CN, the ratio of stars belonging to the CN-strong and weak groups, with...
Heuristics Made Easy: An Effort-Reduction Framework
Shah, Anuj K.; Oppenheimer, Daniel M.
2008-01-01
In this article, the authors propose a new framework for understanding and studying heuristics. The authors posit that heuristics primarily serve the purpose of reducing the effort associated with a task. As such, the authors propose that heuristics can be classified according to a small set of effort-reduction principles. The authors use this…
Heuristic Diagrams as a Tool to Teach History of Science
Chamizo, Jose A.
2012-01-01
The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The…
A Variable-Selection Heuristic for K-Means Clustering.
Brusco, Michael J.; Cradit, J. Dennis
2001-01-01
Presents a variable selection heuristic for nonhierarchical (K-means) cluster analysis based on the adjusted Rand index for measuring cluster recovery. Subjected the heuristic to Monte Carlo testing across more than 2,200 datasets. Results indicate that the heuristic is extremely effective at eliminating masking variables. (SLD)
Georgieva, A.; Jordanov, Ivan
2009-01-01
In this paper a new heuristic hybrid technique for bound-constrained global optimization is proposed. We developed iterative algorithm called GLPτS that uses genetic algorithms, LPτ low-discrepancy sequences of points and heuristic rules to find regions of attraction when searching a global minimum of an objective function. Subsequently Nelder-Mead Simplex local search technique is used to refine the solution. The combination of the three techniques (Genetic algorithms, LPτO Low-discrepancy s...
Heuristic Evaluation of E-Learning Courses: A Comparative Analysis of Two E-Learning Heuristic Sets
Zaharias, Panagiotis; Koutsabasis, Panayiotis
2012-01-01
Purpose: The purpose of this paper is to discuss heuristic evaluation as a method for evaluating e-learning courses and applications and more specifically to investigate the applicability and empirical use of two customized e-learning heuristic protocols. Design/methodology/approach: Two representative e-learning heuristic protocols were chosen…
Conflict Resolution of Chinese Chess Endgame Knowledge Base
Chen, Bo-Nian; Liu, Pangfang; Hsu, Shun-Chin; Hsu, Tsan-Sheng
Endgame heuristics are often incorperated as part of the evaluation function used in Chinese Chess programs. In our program, Contemplation, we have proposed an automatic strategy to construct a large set of endgame heuristics. In this paper, we propose a conflict resolution strategy to eliminate the conflicts among the constructed heuristic databases, which is called endgame knowledge base. In our experiment, the correctness of the obtained constructed endgame knowledge base is sufficiently high for practical usage.
McCarthy, James K.; Jacobson, Eric J.; Kilduff, Timothy M.; Estes, Ronald W.; Levine, Peter A.; Mills, Steven D.; Elvidge, Chris; Miller, Steven D.
2013-09-01
This paper examines the feasibility and potential benefits of enhancing the spatial resolution of the VIIRS DNB channel for the JPSS-2 mission and beyond, by modifying the on-chip pixel binning recipe used in the DNB CCD to aggregate detector area within the scan swath. Presently the DNB delivers 16 cross-scan samples similar in size to the detectors in the VIIRS Moderate Resolution Bands. The relatively low-cost enhancement proposed would instead bin the pixels of the existing DNB CCD into 32 cross-scan samples, each half as large in track and scan, effectively doubling the spatial resolution of DNB in each dimension to match the VIIRS Imaging Bands at nadir. Other potential benefits include, for unresolved point sources, improved detection sensitivity and SNR. Smaller DNB image pixels would be less spatiallymixed, and therefore better suited to many quantitative analyses. DNB geolocation accuracy would also benefit from the increased spatial resolution, but less so for regions approaching edge-of-scan. To implement the maximum DNB spatial resolution enhancement over the full cross-track scan swath would require design and hardware modifications to the focal plane electronics (FPIE) to increase certain CCD clock rates. This paper explores the performance of this option, alongside other options that (if constrained to use the existing FPIE design with minimal changes) would not provide the enhanced DNB spatial resolution all the way out to the edges of the cross-track scan. These would instead offer other benefits, such as better maintaining SNR to edge-of-scan and, if away from nadir DNB sampling matched the I-bands, better enabling future environmental products merging the enhanced DNB data with existing VIIRS spectral band data.
On the heuristic nature of medical decision-support systems.
Aliferis, C F; Miller, R A
1995-03-01
In the realm of medical decision-support systems, the term "heuristic systems" is often considered to be synonymous with "medical artificial intelligence systems" or with "systems employing informal model(s) of problem solving". Such a view may be inaccurate and possibly impede the conceptual development of future systems. This article examines the nature of heuristics and the levels at which heuristic solutions are introduced during system design and implementation. The authors discuss why heuristics are ubiquitous in all medical decision-support systems operating at non-trivial domains, and propose a unifying definition of heuristics that encompasses formal and ad hoc systems. System developers should be aware of the heuristic nature of all problem solving done in complex real world domains, and characterize their own use of heuristics in describing system development and implementation. PMID:9082138
MULTI QUERY OPTIMIZATION USING HEURISTIC APPROACH
Directory of Open Access Journals (Sweden)
S. D. Pandao
2012-08-01
Full Text Available Now a day, it is very common to see that complex queriesare being vastly used in the real time database applications.These complex queries often have a lot of common subexpressions,either within a single query or across multiplesuch queries run as a batch. Multi-query optimization aimsat exploiting common sub-expressions to reduce evaluationcost. Multi-query optimization has often been viewed asimpractical, since earlier algorithms were exhaustive, andexplore a doubly exponential search space.This work demonstrates that multi-queryoptimization using heuristics is practical, and providessignificant benefits. The cost-based heuristic algorithms:basic Volcano-SH and Volcano-RU, which are based onsimple modifications to the Volcano search strategy. Thealgorithms are designed to be easily added to existingoptimizers. The study shows that the presented algorithmsprovide significant benefits over traditional optimization,at a very acceptable overhead in optimization time.
Heuristic Based Task Scheduling In Grid
Directory of Open Access Journals (Sweden)
Manpreet Singh
2012-09-01
Full Text Available Grid computing is concerned with coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organizations. Efficient scheduling of complex applications in a grid environment reveals several challenges due to its high heterogeneity, dynamic behavior and space shared utilization. Objectives of scheduling algorithms are increase in system throughput, efficiency and reduction in task completion time. The main focus of this paper is to highlight the merits of resource and task selection technique based on certain heuristics.
Heuristics for the economic dispatch problem
Energy Technology Data Exchange (ETDEWEB)
Flores, Benjamin Carpio [Centro Nacional de Controle de Energia (CENACE), Mexico, D.F. (Mexico). Dept. de Planificacion Economica de Largo Plazo], E-mail: benjamin.carpo@cfe.gob.mx; Laureano Cruces, A.L.; Lopez Bracho, R.; Ramirez Rodriguez, J. [Universidad Autonoma Metropolitana (UAM), Mexico, D.F. (Brazil). Dept. de Sistemas], Emails: clc@correo.azc.uam.mx, rlb@correo.azc.uam.mx, jararo@correo.azc.uam.mx
2009-07-01
This paper presents GRASP (Greedy Randomized Adaptive Search Procedure), Simulated Annealing (SAA), Genetic (GA), and Hybrid Genetic (HGA) Algorithms for the economic dispatch problem (EDP), considering non-convex cost functions and dead zones the only restrictions, showing the results obtained. We also present parameter settings that are specifically applicable to the EDP, and a comparative table of results for each heuristic. It is shown that these methods outperform the classical methods without the need to assume convexity of the target function. (author)
A Heuristic Molecular Model of Hydrophobic Interactions
Hummer, G.; Garde, S.; Garcia, A. E.; Pohorille, A.; Pratt, L. R.
1995-01-01
Hydrophobic interactions provide driving forces for protein folding, membrane formation, and oil-water separation. Motivated by information theory, the poorly understood nonpolar solute interactions in water are investigated. A simple heuristic model of hydrophobic effects in terms of density fluctuations is developed. This model accounts quantitatively for the central hydrophobic phenomena of cavity formation and association of inert gas solutes; it therefore clarifies the underlying physics...
Heuristic programmation for ultrasonic automatic control
International Nuclear Information System (INIS)
A study concerning the automatic characterization of flaws is presented. During a first step where simplification was looked for, the use of an ultrasonic transducer with two degrees of freedom allowed the development of a new method of non destructive testing. Its scope has been illustrated by several tests. Extension prospects to 3-D testing have been investigated, and heuristic procedures have been applied in order to limit testing complexity, and to maintain duration within acceptable limits
Anchoring Heuristic and the Equity Premium Puzzle
Siddiqi, Hammad
2015-01-01
What happens when the anchoring and adjustment heuristic of Tversky and Kahneman (1974) is incorporated in the standard consumption-based capital asset pricing model (CCAPM)? The surprising finding is that it not only resolves the high equity-premium and low risk-free rate puzzles with a low risk-aversion coefficient, but also provides a unified framework for understanding countercyclical equity-premium, excess volatility, size, value, and momentum effects, and abnormal returns and volatiliti...
Heuristic Programming of Educational - Research Activity
Stoev, Alexey
HEURISTIC PROGRAMMING OF EDUCATIONAL - RESEARCH ACTIVITY OF THE STUDENTS OF ASTRONOMY AT PUBLIC ASTRONOMICAL OBSERVATORIES A.Stoev Yu. Gagarin Public Astronomical Observatory Stara Zagora Bulgaria Seeking for optimal conditions of the students’ investigation skills development is exceptionally actual task in Astronomy school at Public astronomical observatory. The didactic plan of its solving is connected with a realization of the concept of the problematic approach in astronomical education. In addition different means of astronomical educative activity organization are used depending on the didactic task. In some cases they are algorithmic but in others - mainly heuristic. Educational - research skills are defined as skills of scientific method use in the conditions of seeking for educational problem solving the astronomical educational - research task. The influence of the system of heuristic programming didactic means on the process of teaching and the use of system of didactic means for out of the school education on astronomy aimed mainly to this activity rule are analyzed. In conclusion the process of optimization of the didactic conditions for students’ self-organization during the individual or collective completion of the educational - research astronomical tasks at the transition from secondary to high education.
Heuristic reusable dynamic programming: efficient updates of local sequence alignment.
Hong, Changjin; Tewfik, Ahmed H
2009-01-01
Recomputation of the previously evaluated similarity results between biological sequences becomes inevitable when researchers realize errors in their sequenced data or when the researchers have to compare nearly similar sequences, e.g., in a family of proteins. We present an efficient scheme for updating local sequence alignments with an affine gap model. In principle, using the previous matching result between two amino acid sequences, we perform a forward-backward alignment to generate heuristic searching bands which are bounded by a set of suboptimal paths. Given a correctly updated sequence, we initially predict a new score of the alignment path for each contour to select the best candidates among them. Then, we run the Smith-Waterman algorithm in this confined space. Furthermore, our heuristic alignment for an updated sequence shows that it can be further accelerated by using reusable dynamic programming (rDP), our prior work. In this study, we successfully validate "relative node tolerance bound" (RNTB) in the pruned searching space. Furthermore, we improve the computational performance by quantifying the successful RNTB tolerance probability and switch to rDP on perturbation-resilient columns only. In our searching space derived by a threshold value of 90 percent of the optimal alignment score, we find that 98.3 percent of contours contain correctly updated paths. We also find that our method consumes only 25.36 percent of the runtime cost of sparse dynamic programming (sDP) method, and to only 2.55 percent of that of a normal dynamic programming with the Smith-Waterman algorithm. PMID:19875856
Cultural heuristics in risk assessment of HIV/AIDS.
Bailey, Ajay; Hutter, Inge
2006-01-01
Behaviour change models in HIV prevention tend to consider that risky sexual behaviours reflect risk assessments and that by changing risk assessments behaviour can be changed. Risk assessment is however culturally constructed. Individuals use heuristics or bounded cognitive devices derived from broader cultural meaning systems to rationalize uncertainty. In this study, we identify some of the cultural heuristics used by migrant men in Goa, India to assess their risk of HIV infection from different sexual partners. Data derives from a series of in-depth interviews and a locally informed survey. Cultural heuristics identified include visual heuristics, heuristics of gender roles, vigilance and trust. The paper argues that, for more culturally informed HIV/AIDS behaviour change interventions, knowledge of cultural heuristics is essential. PMID:16923649
A grouping hyper-heuristic framework: application on graph colouring
Elhag, Anas; Özcan, Ender
2015-01-01
Grouping problems are hard to solve combinatorial optimisation problems which require partitioning of objects into a minimum number of subsets while a given objective is simultaneously optimised. Selection hyper-heuristics are high level general purpose search methodologies that operate on a space formed by a set of low level heuristics rather than solutions. Most of the recently proposed selection hyper-heuristics are iterative and make use of two key methods which are employed successively;...
Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry
Rappoport, Dmitrij; Galvin, Cooper J.; Zubarev, Dmitry; Aspuru-Guzik, Alan
2014-01-01
While structures and reactivities of many small molecules can be computed efficiently and accurately using quantum chemical methods, heuristic approaches remain essential for modeling complex structures and large-scale chemical systems. Here, we present a heuristics-aided quantum chemical methodology applicable to complex chemical reaction networks such as those arising in cell metabolism and prebiotic chemistry. Chemical heuristics offer an expedient way of traversing high-dimensional reacti...
The limited value of precise tests of the recognition heuristic
Thorsten Pachur
2011-01-01
The recognition heuristic models the adaptive use and dominant role of recognition knowledge in judgment under uncertainty. Of the several predictions that the heuristic makes, empirical tests have predominantly focused on the proposed noncompensatory processing of recognition. Some authors have emphasized that the heuristic needs to be scrutinized based on precise tests of the exclusive use of recognition. Although precise tests have clear merits, I critically evaluate the value of such test...
A fast greedy heuristic for scheduling modular projects
Huysmans, Martijn; Coolen, Kris; F Talla Nobibon; Leus, Roel
2015-01-01
This article describes a heuristic for scheduling so-called ‘modular’ projects. Exact solutions to this NP-hard problem can be obtained with existing branch-and-bound and dynamic-programming algorithms, but only for small to medium-size instances. The proposed heuristic, by contrast, can be used even for large instances, or when instances are particularly difficult because of their characteristics, such as a low network density. The proposed heuristic draws from existing results in the litera...
Locally optimal heuristic for modularity maximization of networks
Cafieri, Sonia; Hansen, Pierre; Liberti, Leo
2011-01-01
International audience Community detection in networks based on modularity maximization is currently done with hierarchical divisive or agglomerative as well as partitioning heuristics, hybrids, and, in a few papers, exact algorithms. We consider here the case of hierarchical networks in which communities should be detected and propose a divisive heuristic which is locally optimal in the sense that each of the successive bipartitions is done in a provably optimal way. This heuristic is com...
Bidirectional A*: comparing balanced and symmetric heuristic methods
Post, Henk; Pijls, Wim
2006-01-01
textabstractA widely known algorithm for ¯nding the shortest path in a network is Bidirectional A*. The version of bidirectional A* that is considered the most appropriate hitherto, uses so-called balanced heuristic estimates. In this paper, we focus on symmetric heuristic estimates. First, we show that bidirectional A* using the symmetric heuristic estimate provides us with a feasible approximation. Next a framework is introduced for solving the shortest path problem exactly. It turns out th...
A heuristic evaluation of the Facebook's advertising tool beacon
Jamal, A.; Cole, M.
2009-01-01
Interface usability is critical to the successful adoption of information systems. The aim of this study is to evaluate interface of Facebook's advertising tool Beacon by using privacy heuristics [4]. Beacon represents an interesting case study because of the negative media and user backlash it received. The findings of heuristic evaluation suggest violation of privacy heuristics [4]. Here, analysis identified concerns about user choice and consent, integrity and security of data, and awarene...
Symbiosis of Search and Heuristics for Random 3-SAT
Mijnders, Sid; de Wilde, Boris; Heule, Marijn
2014-01-01
When combined properly, search techniques can reveal the full potential of sophisticated branching heuristics. We demonstrate this observation on the well-known class of random 3-SAT formulae. First, a new branching heuristic is presented, which generalizes existing work on this class. Much smaller search trees can be constructed by using this heuristic. Second, we introduce a variant of discrepancy search, called ALDS. Theoretical and practical evidence support that ALDS traverses the search...
Runtime analysis of search heuristics on software engineering problems
Institute of Scientific and Technical Information of China (English)
Per Kristian LEHRE; Xin YAO
2009-01-01
Many software engineering tasks can potentially be automated using search heuristics. However, much work is needed in designing and evaluating search heuristics before this approach can be routinely applied to a software engineering problem. Experimental methodology should be complemented with theoretical analysis to achieve this goal.Recently, there have been significant theoretical advances in the runtime analysis of evolutionary algorithms (EAs) and other search heuristics in other problem domains. We suggest that these methods could be transferred and adapted to gain insight into the behaviour of search heuristics on software engineering problems while automating software engineering.
A Graph Search Heuristic for Shortest Distance Paths
Energy Technology Data Exchange (ETDEWEB)
Chow, E
2005-03-24
This paper presents a heuristic for guiding A* search for finding the shortest distance path between two vertices in a connected, undirected, and explicitly stored graph. The heuristic requires a small amount of data to be stored at each vertex. The heuristic has application to quickly detecting relationships between two vertices in a large information or knowledge network. We compare the performance of this heuristic with breadth-first search on graphs with various topological properties. The results show that one or more orders of magnitude improvement in the number of vertices expanded is possible for large graphs, including Poisson random graphs.
Heuristic determination of quantitative data for knowledge acquisition in medicine.
Giuse, D A; Giuse, N B; Bankowitz, R A; Miller, R A
1991-06-01
Knowledge acquisition for medical knowledge bases can be aided by programs that suggest possible values for portions of the data. The paper presents an experiment which was used in designing a heuristic to help the process of knowledge acquisition. The heuristic helps to determine numerical data from stylized literature excerpts in the context of knowledge acquisition for the QMR medical knowledge base. Quantitative suggestions from the heuristics are shown to agree substantially with the data incorporated in the final version of the knowledge base. The experiment shows the potential of knowledge base specific heuristics in simplifying the task of knowledge base creation. PMID:1868695
Victimized by Phishing: A Heuristic - Systematic Perspective
Directory of Open Access Journals (Sweden)
ZHENGCHUAN XU
2012-12-01
Full Text Available Phishing has become an ever - present, ever - increasing thr eat to information security, yet theory - based, systematic research on the behavioral aspect of this phenomenon is rather limited. In this paper, we propose the Heuristic - Systematic Model (HSM as an overarching theory to solidify the theory base for this l ine of research. We note the theoretical synergy between HSM and other theories used in previous research, and illustrate how HSM can be used to develop a research model investigating the psychological mechanism underlying the effectiveness of phishing att acks
A Framework for Quantum Search Heuristics
Hogg, T
1996-01-01
A quantum algorithm for combinatorial search is presented that provides a simple framework for utilizing search heuristics. The algorithm is evaluated in a new case that is an unstructured version of the graph coloring problem. It performs significantly better than the direct use of quantum parallelism, on average, in cases corresponding to previously identified phase transitions in search difficulty. The conditions underlying this improvement are described. Much of the algorithm is independent of particular problem instances, making it suitable for implementation as a special purpose device.
HIDING SENSITIVE ASSOCIATION RULE USING HEURISTIC APPROACH
Directory of Open Access Journals (Sweden)
Kasthuri S
2013-01-01
Full Text Available Data mining is the process of identifying patterns from large amount of data. Association rule mining aims to discover dependency relationships across attributes. It may also disclose sensitive information. With extensive application of data mining techniques to various domains, privacy preservation becomes mandatory. Association rule hiding is one of the techniques of privacy preserving data mining to protect the sensitive association rules generated by association rule mining. This paper adopts heuristic approach for hiding sensitive association rules. The proposed technique makes the representative rules and hides the sensitive rules.
Paraphrase Identification using Semantic Heuristic Features
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Zia Ul-Qayyum
2012-11-01
Full Text Available Paraphrase Identification (PI problem is to classify that whether or not two sentences are close enough in meaning to be termed as paraphrases. PI is an important research dimension with practical applications in Information Extraction (IE, Machine Translation, Information Retrieval, Automatic Identification of Copyright Infringement, Question Answering Systems and Intelligent Tutoring Systems, to name a few. This study presents a novel approach of paraphrase identification using semantic heuristic features envisaging improving the accuracy compared to state-of-the-art PI systems. Finally, a comprehensive critical analysis of misclassifications is carried out to provide insightful evidence about the proposed approach and the corpora used in the experiments.
A Heuristic Molecular Model of Hydrophobic Interactions
Hummer, G; García, A E; Pohorille, A; Pratt, L R
1995-01-01
Hydrophobic interactions provide driving forces for protein folding, membrane formation, and oil-water separation. Motivated by information theory, the poorly understood nonpolar solute interactions in water are investigated. A simple heuristic model of hydrophobic effects in terms of density fluctuations is developed. This model accounts quantitatively for the central hydrophobic phenomena of cavity formation and association of inert gas solutes; it therefore clarifies the underlying physics of hydrophobic effects and permits important applications to conformational equilibria of nonpolar solutes and hydrophobic residues in biopolymers.
Advances in heuristic signal processing and applications
Chatterjee, Amitava; Siarry, Patrick
2013-01-01
There have been significant developments in the design and application of algorithms for both one-dimensional signal processing and multidimensional signal processing, namely image and video processing, with the recent focus changing from a step-by-step procedure of designing the algorithm first and following up with in-depth analysis and performance improvement to instead applying heuristic-based methods to solve signal-processing problems. In this book the contributing authors demonstrate both general-purpose algorithms and those aimed at solving specialized application problems, with a spec
Heuristic theory of positron-helium scattering.
Drachman, R. J.
1971-01-01
An error in a previous modified adiabatic approximation (Drachman, 1966), due to a lack of generality in the form of the short-range correlation part of the wave function for L greater than zero, is corrected heuristically by allowing the monopole suppression parameter to depend on L. An L-dependent local potential is constructed to fit the well-known positron-hydrogen s, p, and d wave phase shifts below the rearrangement threshold. The same form of potential yields a positron-helium cross-section in agreement with a recent experimental measurement near threshold.
Efficient heuristics for the Rural Postman Problem
Directory of Open Access Journals (Sweden)
GW Groves
2005-06-01
Full Text Available A local search framework for the (undirected Rural Postman Problem (RPP is presented in this paper. The framework allows local search approaches that have been applied successfully to the well–known Travelling Salesman Problem also to be applied to the RPP. New heuristics for the RPP, based on this framework, are introduced and these are capable of solving significantly larger instances of the RPP than have been reported in the literature. Test results are presented for a number of benchmark RPP instances in a bid to compare efficiency and solution quality against known methods.
THE ABURAS HEURISTIC: A MODIFIED HEURISTIC FOR SCHEDULING UNRELATED PARALLEL MACHINE PROBLEMS
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H.M. Aburas
2012-01-01
Full Text Available
ENGLISH ABSTRACT: Scheduling problems form an important class of decision-making problems where two types of decision have to be taken: allocation and sequencing. Scheduling is primarily considered with resource allocation; sequencing, however, is concerned with the order of jobs to be performed on the allocated resource (Sipper and Bulfin [8]. This paper proposes the use of a new heuristic called ABURAS, which is designed to minimize the makespan of an unrelated parallel machine scheduling problem. To evaluate the performance of the suggested heuristic, a real scheduling problem involving roof truss manufacturing at a major housing construction company is investigated. The ABURAS heuristic shows superiority in terms of reduced makespan over originally developed heuristics.
AFRIKAANSE OPSOMMING: Skeduleringsvraagtukke vorm 'n belangrike versameling van besluitvormingsprobleme wat gekenmerk word deur toedeling en volgorde. Skedules hou verband met die toewysing van hulpbronne, terwyl sekwensie verband hou met volgorde. ’n Nuwe sogenaamde ABURAS-skeduleringsheuristiek word voorgehou vir praktyktoepassing. Die toepassingsprosedure word beskryf, en die heuristiek word toegepas by 'n onderneming wat dakkappe vervaardig. Die praktyktoepassing lewer bemoedigende resultate.
Further heuristics for $k$-means: The merge-and-split heuristic and the $(k,l)$-means
Nielsen, Frank; Nock, Richard
2014-01-01
Finding the optimal $k$-means clustering is NP-hard in general and many heuristics have been designed for minimizing monotonically the $k$-means objective. We first show how to extend Lloyd's batched relocation heuristic and Hartigan's single-point relocation heuristic to take into account empty-cluster and single-point cluster events, respectively. Those events tend to increasingly occur when $k$ or $d$ increases, or when performing several restarts. First, we show that those special events ...
How do people judge risks: availability heuristic, affect heuristic, or both?
Pachur, Thorsten; Hertwig, Ralph; Steinmann, Florian
2012-09-01
How does the public reckon which risks to be concerned about? The availability heuristic and the affect heuristic are key accounts of how laypeople judge risks. Yet, these two accounts have never been systematically tested against each other, nor have their predictive powers been examined across different measures of the public's risk perception. In two studies, we gauged risk perception in student samples by employing three measures (frequency, value of a statistical life, and perceived risk) and by using a homogeneous (cancer) and a classic set of heterogeneous causes of death. Based on these judgments of risk, we tested precise models of the availability heuristic and the affect heuristic and different definitions of availability and affect. Overall, availability-by-recall, a heuristic that exploits people's direct experience of occurrences of risks in their social network, conformed to people's responses best. We also found direct experience to carry a high degree of ecological validity (and one that clearly surpasses that of affective information). However, the relative impact of affective information (as compared to availability) proved more pronounced in value-of-a-statistical-life and perceived-risk judgments than in risk-frequency judgments. Encounters with risks in the media, in contrast, played a negligible role in people's judgments. Going beyond the assumption of exclusive reliance on either availability or affect, we also found evidence for mechanisms that combine both, either sequentially or in a composite fashion. We conclude with a discussion of policy implications of our results, including how to foster people's risk calibration and the success of education campaigns. PMID:22564084
Case-Based Reasoning as a Heuristic Selector in a Hyper-Heuristic for Course Timetabling Problems
Petrovic, Sanja; Qu, Rong
2002-01-01
This paper studies Knowledge Discovery (KD) using Tabu Search and Hill Climbing within Case-Based Reasoning (CBR) as a hyper-heuristic method for course timetabling problems. The aim of the hyper-heuristic is to choose the best heuristic(s) for given timetabling problems according to the knowledge stored in the case base. KD in CBR is a 2-stage iterative process on both case representation and the case base. Experimental results are analysed and related research issues for future work are dis...
HEURISTIC DISCRETIZATION METHOD FOR BAYESIAN NETWORKS
Directory of Open Access Journals (Sweden)
Mariana D.C. Lima
2014-01-01
Full Text Available Bayesian Network (BN is a classification technique widely used in Artificial Intelligence. Its structure is a Direct Acyclic Graph (DAG used to model the association of categorical variables. However, in cases where the variables are numerical, a previous discretization is necessary. Discretization methods are usually based on a statistical approach using the data distribution, such as division by quartiles. In this article we present a discretization using a heuristic that identifies events called peak and valley. Genetic Algorithm was used to identify these events having the minimization of the error between the estimated average for BN and the actual value of the numeric variable output as the objective function. The BN has been modeled from a database of Bit’s Rate of Penetration of the Brazilian pre-salt layer with 5 numerical variables and one categorical variable, using the proposed discretization and the division of the data by the quartiles. The results show that the proposed heuristic discretization has higher accuracy than the quartiles discretization.
Advances in heuristically based generalized perturbation theory
International Nuclear Information System (INIS)
A distinctive feature of heuristically based generalized perturbation theory methodology consists in the systematic use of importance conservation concepts. As well known, this use leads to fundamental reciprocity relationship. Instead, the alternative variational and differential one approaches make a consistent use of the properties and adjoint functions. The equivalence between the importance and the adjoint functions have been demonstrated in important cases. There are some instances, however, in which the commonly known operator governing the adjoint function are not adequate. In this paper ways proposed to generalize this rules, as adopted with the heuristic generalized perturbation theory methodology, are illustrated. When applied to the neutron/nuclide field characterizing the core evolution in a power reactor system, in which also an intensive control variable (ρ) is defined, these rules leas to an orthogonality relationship connected to this same control variable. A set of ρ-mode eigenfunctions may be correspondingly defined and an extended concept of reactivity (generalizing that commonly associated with the multiplication factor) proposed as more directly indicative of the controllability of a critical reactor system. (author). 25 refs
Yoshino, K.; Esmond, J. R.; Cheung, A. S.-C.; Freeman, D. E.; Parkinson, W. H.
1992-01-01
Results are presented on measurements, conducted in the wavelength region 180-195 nm, and at different pressures of oxygen (between 2.5-760 torr) in order to separate the pressure-dependent absorption from the main cross sections, of the absorption cross sections of the Schumann-Runge bands in the window region between the rotational lines of S-R bands of O2. The present cross sections supersede the earlier published cross sections (Yoshino et al., 1983). The combined cross sections are presented graphically; they are available at wavenumber intervals of about 0.1/cm from the National Space Science Data Center. The Herzberg continuum cross sections are derived after subtracting calculated contributions from the Schumann-Runge bands. These are significantly smaller than any previous measurements.
Heuristic methods for single link shared backup path protection
DEFF Research Database (Denmark)
Haahr, Jørgen Thorlund; Stidsen, Thomas Riis; Zachariasen, Martin
2014-01-01
heuristic algorithms and lower bound methods for the SBPP planning problem. Experimental results show that the heuristic algorithms are able to find good quality solutions in minutes. A solution gap of less than 3.5 % was achieved for 5 of 7 benchmark instances (and a gap of less than 11 % for the remaining...
Heuristic methods for shared backup path protection planning
DEFF Research Database (Denmark)
Haahr, Jørgen Thorlund; Stidsen, Thomas Riis; Zachariasen, Martin
2012-01-01
present heuristic algorithms and lower bound methods for the SBPP planning problem. Experimental results show that the heuristic algorithms are able to find good quality solutions in minutes. A solution gap of less than 3.5% was achieved for more than half of the benchmark instances (and a gap of less...
HEURISTIC OPTIMIZATION AND ALGORITHM TUNING APPLIED TO SORPTIVE BARRIER DESIGN
While heuristic optimization is applied in environmental applications, ad-hoc algorithm configuration is typical. We use a multi-layer sorptive barrier design problem as a benchmark for an algorithm-tuning procedure, as applied to three heuristics (genetic algorithms, simulated ...
On the empirical performance of (T,s,S) heuristics
Babai, M. Zied; Syntetos, Aris A.; Teunter, Ruud
2010-01-01
The periodic (T,s,S) policies have received considerable attention from the academic literature. Determination of the optimal parameters is computationally prohibitive, and a number of heuristic procedures have been put forward. However, these heuristics have never been compared in an extensive empi
Heuristic aspect’s of innjvation education strategies
Малая, Н. В.
2013-01-01
The article touches upon the issues of heuristic aspect in the didactical and pedagogical activity. The specific of heuristic is expressed: it implies the process of methodological thinking towards the theory of education; the creative process and the perspectives of its development taken as a whole; and demonstrates the mechanisms of its use for improvement of innovation aspects in teaching strategies.
A polynomial-time heuristic for Circuit-SAT
Capasso, Francesco
2005-01-01
In this paper is presented an heuristic that, in polynomial time and space in the input dimension, determines if a circuit describes a tautology or a contradiction. If the circuit is neither a tautology nor a contradiction, then the heuristic finds an assignment to the circuit inputs such that the circuit is satisfied.
Heuristic Inquiry: A Personal Journey of Acculturation and Identity Reconstruction
Djuraskovic, Ivana; Arthur, Nancy
2010-01-01
Heuristic methodology attempts to discover the nature and meaning of phenomenon through internal self-search, exploration, and discovery. Heuristic methodology encourages the researcher to explore and pursue the creative journey that begins inside one's being and ultimately uncovers its direction and meaning through internal discovery (Douglass &…
Automating the packing heuristic design process with genetic programming.
Burke, Edmund K; Hyde, Matthew R; Kendall, Graham; Woodward, John
2012-01-01
The literature shows that one-, two-, and three-dimensional bin packing and knapsack packing are difficult problems in operational research. Many techniques, including exact, heuristic, and metaheuristic approaches, have been investigated to solve these problems and it is often not clear which method to use when presented with a new instance. This paper presents an approach which is motivated by the goal of building computer systems which can design heuristic methods. The overall aim is to explore the possibilities for automating the heuristic design process. We present a genetic programming system to automatically generate a good quality heuristic for each instance. It is not necessary to change the methodology depending on the problem type (one-, two-, or three-dimensional knapsack and bin packing problems), and it therefore has a level of generality unmatched by other systems in the literature. We carry out an extensive suite of experiments and compare with the best human designed heuristics in the literature. Note that our heuristic design methodology uses the same parameters for all the experiments. The contribution of this paper is to present a more general packing methodology than those currently available, and to show that, by using this methodology, it is possible for a computer system to design heuristics which are competitive with the human designed heuristics from the literature. This represents the first packing algorithm in the literature able to claim human competitive results in such a wide variety of packing domains. PMID:21609273
Sabar, Nasar; Ayob, Masri; Kendall, Graham; Qu, Rong
2014-01-01
Hyper-heuristic approaches aim to automate heuristic design in order to solve multiple problems instead of designing tailor-made methodologies for individual problems. Hyper-heuristics accomplish this through a high level heuristic (heuristic selection mechanism and an acceptance criterion). This automates heuristic selection, deciding whether to accept or reject the returned solution. The fact that different problems or even instances, have different landscape structures and complexity, the ...
In Part 2 of this series of DFT optimization studies of '-maltotetraose, we present results at the B3LYP/6-311++G** level of theory for conformations denoted “band-flips” and “kinks”. Recent experimental X-ray studies have found examples of amylose fragments with conformations distorted from the us...
Directory of Open Access Journals (Sweden)
Pornnarong Siripiyasing
2007-01-01
Full Text Available This research is the first comparative chromosome analysis report of Thai wild boar (Sus scrofa jubatus and its relationship to domestic pig (S. s. domestica by conventional staining, G-banding and high-resolution technique. Blood samples of the Thai wild boar were taken from two males and two females kept in Nakhon Ratchasima Zoo. After standard whole blood lymphocyte culture at 37 oC for 72 hr. in the presence of colchicine, the metaphase spreads were performed on microscopic slides and airdried. Conventional staining, G-banding and high-resolution technique were applied to stain the chromosomes. The results showed that the number of diploid chromosomes of Thai wild boar was 2n (diploid = 38, and the fundamental numbers (NF were 62 in the male and female. The type of autosomes were 12 metacentric, 14 submetacentric, 4 acrocentric and 6 telocentric chromosomes, with X and Y chromosomes being metacentric chromosomes. We found that chromosomes 1, 5, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, X and Y had the same Gbanding and high-resolution technique patterns as those of domestic pig chromosomes. Chromosomes 2, 3, 4, 6, 9 and 15 are similar to those of domestic pig chromosomes. These results show the evolutionary relationship between the Thai wild boar and the domestic pig.
Heuristics-Guided Exploration of Reaction Mechanisms
Bergeler, Maike; Proppe, Jonny; Reiher, Markus
2015-01-01
For the investigation of chemical reaction networks, the efficient and accurate determination of all relevant intermediates and elementary reactions is inevitable. The complexity of such a network may grow rapidly, in particular if reactive species are involved that might cause a myriad of side reactions. Without automation, a complete investigation of complex reaction mechanisms is tedious and possibly unfeasible. Therefore, only the expected dominant reaction paths of a chemical reaction network (e.g., a catalytic cycle or an enzymatic cascade) are usually explored in practice. Here, we present a computational protocol that constructs such networks in a parallelized and automated manner. Molecular structures of reactive complexes are generated based on heuristic rules and subsequently optimized by electronic-structure methods. Pairs of reactive complexes related by an elementary reaction are then automatically detected and subjected to an automated search for the connecting transition state. The results are...
A Hybrid Heuristics for Irregular Flight Recovery
Institute of Scientific and Technical Information of China (English)
ZHAO Xiu-li; ZHU Jin-fu; GAO Qiang
2010-01-01
Adverse weather conditions, congestion at airports, and mechanical failures often disrupt regular flight schedules. The irregular flight recovery problem aims to recover these schedules through reassignments of flights and cancellations. In this article, we develop the classic resource assignment model for the irregular flight recovery problem, and a new hybrid heuristic procedure based on greedy random adaptive search procedure (GRASP) and simulated annealing algorithm is presented to solve this problem. As compared with the original GRASP method, the proposed algorithm demonstrates quite a high global optimization capability. Computational experiments on large-scale problems show that the proposed procedure is able to generate feasible revised flight schedules of good quality in less than five seconds.
Global Heuristic Search on Encrypted Data (GHSED)
Halloush, Maisa
2009-01-01
Important document are being kept encrypted in remote servers. In order to retrieve these encrypted data, efficient search methods needed to enable the retrieval of the document without knowing the content of the documents In this paper a technique called a global heuristic search on encrypted data (GHSED) technique will be described for search in an encrypted files using public key encryption stored on an untrusted server and retrieve the files that satisfy a certain search pattern without revealing any information about the original files. GHSED technique would satisfy the following: (1) Provably secure, the untrusted server cannot learn anything about the plaintext given only the cipher text. (2) Provide controlled searching, so that the untrusted server cannot search for a word without the user's authorization. (3) Support hidden queries, so that the user may ask the untrusted server to search for a secret word without revealing the word to the server. (4) Support query isolation, so the untrusted server ...
The Recognition Heuristic: A Review of Theory and Tests
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Thorsten ePachur
2011-07-01
Full Text Available The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a that recognition is often an ecologically valid cue; (b that people often follow recognition when making inferences; (c that recognition supersedes further cue knowledge; (d that its use can produce the less-is-more effect—the phenomenon that lesser states of recognition knowledge can lead to more accurate inferences than more complete states. After we contrast the recognition heuristic to other related concepts, including availability and fluency, we carve out, from the existing findings, some boundary conditions of the use of the recognition heuristic as well as key questions for future research. Moreover, we summarize developments concerning the connection of the recognition heuristic with memory models. We suggest that the recognition heuristic is used adaptively and that, compared to other cues, recognition seems to have a special status in decision making. Finally, we discuss how systematic ignorance is exploited in other cognitive mechanisms (e.g., estimation and preference.
The recognition heuristic: a review of theory and tests.
Pachur, Thorsten; Todd, Peter M; Gigerenzer, Gerd; Schooler, Lael J; Goldstein, Daniel G
2011-01-01
The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a) that recognition is often an ecologically valid cue; (b) that people often follow recognition when making inferences; (c) that recognition supersedes further cue knowledge; (d) that its use can produce the less-is-more effect - the phenomenon that lesser states of recognition knowledge can lead to more accurate inferences than more complete states. After we contrast the recognition heuristic to other related concepts, including availability and fluency, we carve out, from the existing findings, some boundary conditions of the use of the recognition heuristic as well as key questions for future research. Moreover, we summarize developments concerning the connection of the recognition heuristic with memory models. We suggest that the recognition heuristic is used adaptively and that, compared to other cues, recognition seems to have a special status in decision making. Finally, we discuss how systematic ignorance is exploited in other cognitive mechanisms (e.g., estimation and preference). PMID:21779266
International Nuclear Information System (INIS)
We have constructed a high-resolution grazing-incidence spectrometer designed for measuring the ion temperature of low-Z elements, such as Li+ or Li2+, which radiate near 199 Å and 135 Å, respectively. Based on measurements at the Livermore Electron Beam Ion Trap we have shown that the instrumental resolution is better than 48 mÅ at the 200 Å setting and better than 40 mÅ for the 135-Å range. Such a high spectral resolution corresponds to an instrumental limit for line-width based temperature measurements of about 45 eV for the 199 Å Li+ and 65 eV for the 135 Å Li2+ lines. Recently obtained survey spectra from the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory show the presence of these lithium emission lines and the expected core ion temperature of approximately 70 eV is sufficiently high to demonstrate the feasibility of utilizing our high-resolution spectrometer as an ion-temperature diagnostic
On the Importance of Elimination Heuristics in Lazy Propagation
DEFF Research Database (Denmark)
Madsen, Anders Læsø; Butz, Cory J.
2012-01-01
elimination orders on-line. This paper considers the importance of elimination heuristics in LP when using Variable Elimination (VE) as the message and single marginal computation algorithm. It considers well-known cost measures for selecting the next variable to eliminate and a new cost measure. The...... empirical evaluation examines dierent heuristics as well as sequences of cost measures, and was conducted on real-world and randomly generated Bayesian networks. The results show that for most cases performance is robust relative to the cost measure used and in some cases the elimination heuristic can have...
The beauty of simple models: Themes in recognition heuristic research
Directory of Open Access Journals (Sweden)
Daniel G. Goldstein
2011-07-01
Full Text Available The advantage of models that do not use flexible parameters is that one can precisely show to what degree they predict behavior, and in what situations. In three issues of this journal, the recognition heuristic has been examined carefully from many points of view. We comment here on four themes, the use of optimization models to understand the rationality of heuristics, the generalization of the recognition input beyond a binary judgment, new conditions for less-is-more effects, and the importance of specifying boundary conditions for cognitive heuristics.
Solving Large Clustering Problems with Meta-Heuristic Search
DEFF Research Database (Denmark)
Turkensteen, Marcel; Andersen, Kim Allan; Bang-Jensen, Jørgen
In Clustering Problems, groups of similar subjects are to be retrieved from data sets. In this paper, Clustering Problems with the frequently used Minimum Sum-of-Squares Criterion are solved using meta-heuristic search. Tabu search has proved to be a successful methodology for solving optimization...... problems, but applications to large clustering problems are rare. The simulated annealing heuristic has mainly been applied to relatively small instances. In this paper, we implement tabu search and simulated annealing approaches and compare them to the commonly used k-means approach. We find that the meta-heuristic...
Heuristic Portfolio Trading Rules with Capital Gain Taxes
DEFF Research Database (Denmark)
Fischer, Marcel; Gallmeyer, Michael
2016-01-01
We study the out-of-sample performance of portfolio trading strategies used when an investor faces capital gain taxation and proportional transaction costs. Overlaying simple tax trading heuristics on trading strategies improves out-of-sample performance. For medium to large transaction costs, no...... trading strategy can outperform a 1/N trading strategy augmented with a tax heuristic, not even the most tax and transaction cost-efficient buy-and-hold strategy. Overall, the best strategy is 1/N augmented with a heuristic that allows for a fixed deviation in absolute portfolio weights. Our results thus...
Theory of randomized search heuristics foundations and recent developments
Doerr, Benjamin
2011-01-01
Randomized search heuristics such as evolutionary algorithms, genetic algorithms, evolution strategies, ant colony and particle swarm optimization turn out to be highly successful for optimization in practice. The theory of randomized search heuristics, which has been growing rapidly in the last five years, also attempts to explain the success of the methods in practical applications. This book covers both classical results and the most recent theoretical developments in the field of randomized search heuristics such as runtime analysis, drift analysis and convergence. Each chapter of this boo
International Nuclear Information System (INIS)
The introduction of room temperature continuous wave external-cavity quantum cascade lasers (EC-QCLs) with narrow linewidths has greatly facilitated high resolution spectroscopy over wide spectral ranges in the mid-infrared (MIR) region. Using the wide tuning range of an EC-QCL we have measured the absolute line strengths of many P-branch transitions of the stretching dyad of the ν3 fundamental band of 28SiH4 between 2096 and 2178 cm−1. Furthermore, the high spectral resolution available has enabled us to resolve and measure representative examples of the tetrahedral splittings associated with each component of the P-branch. The positions of these components are in excellent agreement with spherical top data system (STDS) predictions and theoretical transitions from the TDS spectroscopic database for spherical top molecules. These are the first measurements of these line strengths of 28SiH4 and are an example of the applicability of high-powered, widely tunable EC-QCLs to high resolution spectroscopy. - Highlights: • We measured the line strengths of transitions of the ν3 fundamental of 28SiH4. • We used a cw external-cavity quantum cascade laser with narrow linewidth. • The high resolution available enabled us to resolve the tetrahedral splittings. • We observe excellent agreement with spherical top data system predictions. • Excellent agreement with TDS spectroscopic database for spherical top molecules
Yoshio Inoue; Eiji Sakaiya; Cuizhen Wang
2014-01-01
The comprehensive relationship of backscattering coefficient (σ0) values from two current X-band SAR sensors (COSMO-SkyMed and TerraSAR-X) with canopy biophysical variables were investigated using the SAR images acquired at VV polarization and shallow incidence angles. The difference and consistency of the two sensors were also examined. The chrono-sequential change of σ0 in rice paddies during the transplanting season revealed that σ0 reached the value of nearby water surfaces a day before t...
Bashiri, Mahdi; Karimi, Hossein
2012-07-01
Quadratic assignment problem (QAP) is a well-known problem in the facility location and layout. It belongs to the NP-complete class. There are many heuristic and meta-heuristic methods, which are presented for QAP in the literature. In this paper, we applied 2-opt, greedy 2-opt, 3-opt, greedy 3-opt, and VNZ as heuristic methods and tabu search (TS), simulated annealing, and particle swarm optimization as meta-heuristic methods for the QAP. This research is dedicated to compare the relative percentage deviation of these solution qualities from the best known solution which is introduced in QAPLIB. Furthermore, a tuning method is applied for meta-heuristic parameters. Results indicate that TS is the best in 31%of QAPs, and the IFLS method, which is in the literature, is the best in 58 % of QAPs; these two methods are the same in 11 % of test problems. Also, TS has a better computational time among heuristic and meta-heuristic methods.
Economic tour package model using heuristic
Rahman, Syariza Abdul; Benjamin, Aida Mauziah; Bakar, Engku Muhammad Nazri Engku Abu
2014-07-01
A tour-package is a prearranged tour that includes products and services such as food, activities, accommodation, and transportation, which are sold at a single price. Since the competitiveness within tourism industry is very high, many of the tour agents try to provide attractive tour-packages in order to meet tourist satisfaction as much as possible. Some of the criteria that are considered by the tourist are the number of places to be visited and the cost of the tour-packages. Previous studies indicate that tourists tend to choose economical tour-packages and aiming to visit as many places as they can cover. Thus, this study proposed tour-package model using heuristic approach. The aim is to find economical tour-packages and at the same time to propose as many places as possible to be visited by tourist in a given geographical area particularly in Langkawi Island. The proposed model considers only one starting point where the tour starts and ends at an identified hotel. This study covers 31 most attractive places in Langkawi Island from various categories of tourist attractions. Besides, the allocation of period for lunch and dinner are included in the proposed itineraries where it covers 11 popular restaurants around Langkawi Island. In developing the itinerary, the proposed heuristic approach considers time window for each site (hotel/restaurant/place) so that it represents real world implementation. We present three itineraries with different time constraints (1-day, 2-day and 3-day tour-package). The aim of economic model is to minimize the tour-package cost as much as possible by considering entrance fee of each visited place. We compare the proposed model with our uneconomic model from our previous study. The uneconomic model has no limitation to the cost with the aim to maximize the number of places to be visited. Comparison between the uneconomic and economic itinerary has shown that the proposed model have successfully achieved the objective that
G. Bruni; Reinoso Rondinel, R.R.(Ricardo); Ten Veldhuis, J.A.E.; H. W. J. Russchenberg; Clemens, F.H.L.R.
2013-01-01
This study aims to assess the impact of different temporal and spatial rainfall resolutions on the hydrological response of a higly urbanized area. The catchment under study is one of the pilot locations of RainGain Interreg IVB project, which aims at improving fine-scale measurement and prediction of rainfall to enhance urban pluvial flood prediction within cities. Heavy rain precipitation can cause catastrophic flooding events over urbanized areas. Accurate information about rainfall is nee...
Miller, John R.; Pérez-Priego, Óscar; Zarco-Tejada, Pablo J.; Fereres Castiel, Elías; Sepulcre-Cantó, Guadalupe
2005-01-01
A high spectral resolution spectrometer with 0.065-nm full-width half-maximum was used for collecting spectral measurements in an orchard field under three water stress treatments. The study was part of the FluorMOD project funded by the European Space Agency to develop a leaf-canopy reflectance model to simulate the effects of fluorescence. Water deficit protocols generated a gradient in solar-induced Chlorophyll fluorescence emission and tree physiological measures. Diurnal steady-state Chl...
First high resolution analysis of the ν1 +ν2 and ν2 +ν3 bands of S18O2
Ulenikov, O. N.; Bekhtereva, E. S.; Gromova, O. V.; Zamotaeva, V. A.; Kuznetsov, S. I.; Sydow, C.; Maul, C.; Bauerecker, S.
2016-08-01
The Fourier-transformed infrared spectra of the ν1 +ν2 and ν2 +ν3 bands of S18O2 were recorded for the first time in the region 1580-1850 cm-1 and theoretically analyzed. About 940 and 1210 transitions were assigned in the experimental spectra with the maximum values of quantum numbers Jmax. / Kamax. equal to 60/20 and 60/21 to the bands ν1 +ν2 and ν2 +ν3 . The weighted fit of experimentally assigned transitions was made with the Hamiltonian model which takes into account Coriolis resonance interaction between the vibrational states (110) and (011) and Fermi interaction between the states (110) and (030). To make the ro-vibrational analysis physically more suitable, the initial values of main spectroscopic parameters have been estimated from the values of corresponding parameters of the S16O2 species on the basis of the results of the isotopic substitution theory. Finally, the set of 26 spectroscopic parameters obtained from the fit reproduces values of 1229 initial "experimental" ro-vibrational energy levels (about 2150 transitions assigned in the experimental spectra) with the drms = 1.8 ×10-4cm-1 .
The Comparison between the Statistical Heuristic Search and A
Institute of Scientific and Technical Information of China (English)
张Po; 张铃
1989-01-01
In order to further unravel the principle and performance of the statistical heuristic seach algorithm S A,in this paper,in comparison with A * search,the hypothesis,performance and computational complexity of SA are discussed.
Heuristic Portfolio Trading Rules with Capital Gain Taxes
DEFF Research Database (Denmark)
Fischer, Marcel; Gallmeyer, Michael
strategy is not dominated out-of-sample by a variety of optimizing trading strategies, except the parametric portfolios of Brandt, Santa-Clara, and Valkanov (2009). With dividend and realization-based capital gain taxes, the welfare costs of the taxes are large with the cost being as large as 30% of wealth...... in some cases. Overlaying simple tax trading heuristics on these trading strategies improves out-of-sample performance. In particular, the 1/N trading strategy's welfare gains improve when a variety of tax trading heuristics are also imposed. For medium to large transaction costs, no trading strategy...... can outperform a 1/N trading strategy augmented with a tax heuristic, not even the most tax- and transaction-cost efficient buy-and-hold strategy. Overall, the best strategy is 1/N augmented with a heuristic that allows for a fixed deviation in absolute portfolio weights. Our results show that the...
Adapting the Locales Framework for Heuristic Evaluation of Groupware
Directory of Open Access Journals (Sweden)
Saul Greenberg
2000-05-01
Full Text Available Heuristic evaluation is a rapid, cheap and effective way for identifying usability problems in single user systems. However, current heuristics do not provide guidance for discovering problems specific to groupware usability. In this paper, we take the Locales Framework and restate it as heuristics appropriate for evaluating groupware. These are: 1 Provide locales; 2 Provide awareness within locales; 3 Allow individual views; 4 Allow people to manage and stay aware of their evolving interactions; and 5 Provide a way to organize and relate locales to one another. To see if these new heuristics are useful in practice, we used them to inspect the interface of Teamwave Workplace, a commercial groupware product. We were successful in identifying the strengths of Teamwave as well as both major and minor interface problems.
Scheduling constrained tools using heuristic techniques
Maram, Venkataramana; Rahman, Syariza Abdul; Maram, Sandhya Rani
2015-12-01
One of the main challenge to the current manufacturing production planning is to provide schedules of operations to maximize resource utilization to yield highest overall productivity. This is achieved by scheduling available resources to activities. There can be many different real time scenarios with different combination of input resources to produce parts. In this paper, the problem is simplified to single machine with individual process times and due dates to represent the real world scheduling problem. The main objective function is to minimize the total tardiness or late jobs. Nearest greedy method of assignment problem algorithm is used to find the initial solution followed by Simulated Annealing (SA) algorithm for the improvement part. Simulated Annealing is one of the meta-heuristic techniques in solving combinatorial optimization problem. The general purpose Microsoft Visual C++ is used to developed algorithm for finding the best solution. The proposed hybrid approach able to generate best schedule in 7th and optimal in 170th iteration with tardiness 8 and 7 hours respectively.
Direct Heuristic Algorithm for Linear Programming
Directory of Open Access Journals (Sweden)
I. Ramesh Babu
2013-08-01
Full Text Available Many applications in business and economics involve a process called optimization, in which we will be required to find the minimum cost, the maximum profit, or the minimum use of resources, where a decision maker may want to utilize limited available resources in the best possible manner. The limited resources may include material, money, manpower, space and time. Linear Programming provides various methods of solving such problems. The formulation of linear programming problem as a mathematical model is one type of optimization problem called linear programming. There are various methods for solving the linear programming problems. Some of them are approximation algorithm , branch and bound methods, cutting plane method etc. Other than Gomory’s cutting plane method, Branch and bound method LPP along with the DHALP (Direct heuristic algorithm for linear programming algorithm which is more efficient than these existing methods will be used for solving linear programming problems. An optimality test will also be included in this. Numerical experiments will depict the utility/scope of such a procedure.
Heuristic Medicine: The Methodists and Metalepsis.
Webster, Colin
2015-09-01
In the first century B.C.E., a group of Greek physicians called the Methodists denied that medicine could be based on such "hidden causes" as humors, atoms, or elements. They argued that the inner workings of the body were ultimately unknowable, existing beyond the limits of human knowledge and inference. Yet they insisted that medical certainty was still possible, claiming that every disease shared one of three directly apprehensible "manifest commonalities"--stricture, laxity, or some mixture of the two. Medicine could therefore be a science; it was simply noncausal in structure. This essay examines these medical theories in light of Herbert Simon's concept of "bounded rationality," suggesting that the Methodists were proposing a type of medical "heuristic" in response to the limitations of human knowledge and processing power. At the same time, the essay suggests that such an epistemology had its consequences, setting up an ontological crunch whereby the demands formerly placed on diseases and their causes transferred to "affections" and the commonalities, with successive generations of Methodists disagreeing about the status of symptoms, signs, and diseased states. Borrowing vocabulary from the Methodists themselves, the essay calls the consequent ontological slippage between causes and effects "metalepsis". PMID:26685524
Heuristic Modeling for TRMM Lifetime Predictions
Jordan, P. S.; Sharer, P. J.; DeFazio, R. L.
1996-01-01
Analysis time for computing the expected mission lifetimes of proposed frequently maneuvering, tightly altitude constrained, Earth orbiting spacecraft have been significantly reduced by means of a heuristic modeling method implemented in a commercial-off-the-shelf spreadsheet product (QuattroPro) running on a personal computer (PC). The method uses a look-up table to estimate the maneuver frequency per month as a function of the spacecraft ballistic coefficient and the solar flux index, then computes the associated fuel use by a simple engine model. Maneuver frequency data points are produced by means of a single 1-month run of traditional mission analysis software for each of the 12 to 25 data points required for the table. As the data point computations are required only a mission design start-up and on the occasion of significant mission redesigns, the dependence on time consuming traditional modeling methods is dramatically reduced. Results to date have agreed with traditional methods to within 1 to 1.5 percent. The spreadsheet approach is applicable to a wide variety of Earth orbiting spacecraft with tight altitude constraints. It will be particularly useful to such missions as the Tropical Rainfall Measurement Mission scheduled for launch in 1997, whose mission lifetime calculations are heavily dependent on frequently revised solar flux predictions.
Heuristic Evaluation of Three Jordanian University Websites
Directory of Open Access Journals (Sweden)
Layla HASAN
2013-10-01
Full Text Available Generally, universities have complex and large websites, which include a collection of many sub-sites related to the different parts of universities (e.g. registration unit, faculties, departments. Managers of academic institutions and educational websites need to know types of usability problems that could be found on their websites. This would shed the light on possible weak aspects on their websites, which need to be improved, in order to reap the advantages of usable educational websites. There is a lack of research which provides detailed information regarding the types of specific usability problems that could be found on universities websites in general, and specifically in Jordan. This research employed the heuristic evaluation method to comprehensively evaluate the usability of three large public university websites in Jordan (Hashemite University, the University of Jordan, and Yarmouk University. The evaluation involves testing all pages related to the selected universities faculties and their corresponding departments. A list of 34 specific types of usability problems, which could be found on a Jordanian university website, was identified. The results provide a description regarding the common types of the problems found on the three Jordanian university sites, together with their numbers and locations on the website.
Grammatical evolution hyper-heuristic for combinatorial optimization problems
Sabar, Nasar; Ayob, Masri; Kendall, Graham; Qu, Rong
2013-01-01
Designing generic problem solvers that perform well across a diverse set of problems is a challenging task. In this work, we propose a hyper-heuristic framework to automatically generate an effective and generic solution method by utilizing grammatical evolution. In the proposed framework, grammatical evolution is used as an online solver builder, which takes several heuristic components (e.g., different acceptance criteria and different neighborhood structures) as inputs and evolves template...
Improvement of Web Design Using the Heuristic Evaluation Method
Maja Strgar Kurecic
2005-01-01
The paper deals with the problems of information presentation efficacy on Web. Research on how to design more functional and more attractive Web pages has been conducted. The graphic design heuristics for the Web have been defined, which could help designers to improve the efficacy of organization and information design on Web. Also, these rules present the basic criteria for objective evaluation of the Web design. The usage of the heuristic evaluation method, as the method for evaluation of ...
Why SA Can Beat the Exponential Explosion in Heuristic Search
Institute of Scientific and Technical Information of China (English)
无
1990-01-01
In tree(or graph)search,most algorithms mainly use the local heuristic information of each individual node.But in he statistical heuristic search algorithms the global information about subtrees is usesd effecively so that the computational complexity is greatly reduced.In this paper the problem of how the global information can be extracted from the local one is discussed.Some features of SA are also concerned.
Hybrid Heuristic Approaches for Tactical Berth Allocation Problem
DEFF Research Database (Denmark)
Iris, Cagatay; Larsen, Allan; Pacino, Dario;
Tactical berth allocation problem deals with: the berth allocation (as- signs and schedules vessels to berth-positions), and the quay crane (QC) assignment (finds number of QCs that will serve). In this work, we strengthen the current mathematical models (MM) with novel lower bounds and valid...... inequalities. And, we propose a hybrid heuristic which combines MM with greedy and search heuristics. Results show that problem can be solved efficiently respect to optimality and computational time....
The Novel Heuristic for Data Transmission Dynamic Scheduling Problems
Hao Xu; Yue Zhao; Li-Ning Xing; You Zhou
2013-01-01
The data transmission dynamic scheduling is a process that allocates the ground stations and available time windows to the data transmission tasks dynamically for improving the resource utilization. A novel heuristic is proposed to solve the data transmission dynamic scheduling problem. The characteristic of this heuristic is the dynamic hybridization of simple rules. Experimental results suggest that the proposed algorithm is correct, feasible, and available. The dynamic hybridization of sim...
Gene-Machine, a new search heuristic algorithm
Woods, Alfredo Garcia
2013-01-01
This paper introduces Gene-Machine, an efficient and new search heuristic algorithm, based in the building-block hypothesis. It is inspired by natural evolution, but does not use some of the concepts present in genetic algorithms like population, mutation and generation. This heuristic exhibits good performance in comparison with genetic algorithms, and can be used to generate useful solutions to optimization and search problems.
Migration and integration research: filling in Penninx's heuristic model
2013-01-01
Rinus Penninx's groundbreaking work has helped to systematise and classify existing research in the field of migration and ethnic studies. His heuristic model makes an important distinction between immigration and integration research and, within the latter, between socio-economic, ethno-cultural and legal-political dimensions. Written as a tribute to Penninx, this volume consists of contributions by 15 of his former PhD students covering all the main categories of his heuristic model.
Heuristic integrative learning as an alternative to edyuteynmentu
Marina Mileeva
2013-01-01
The article discusses the urgent need for the modernization of the modern educational process and, in particular, the teaching of English in a technological university. Emphasizes the importance and highlights the effectiveness of introducing creativity and heuristic methods of instruction. As illustrated with fragments of the script innovative heuristic theatrical set-off and discuss the results of its implementation. Approved by the dominant role of foreign language in the formation of both...
Neural basis of scientific innovation induced by heuristic prototype.
Directory of Open Access Journals (Sweden)
Junlong Luo
Full Text Available A number of major inventions in history have been based on bionic imitation. Heuristics, by applying biological systems to the creation of artificial devices and machines, might be one of the most critical processes in scientific innovation. In particular, prototype heuristics propositions that innovation may engage automatic activation of a prototype such as a biological system to form novel associations between a prototype's function and problem-solving. We speculated that the cortical dissociation between the automatic activation and forming novel associations in innovation is critical point to heuristic creativity. In the present study, novel and old scientific innovations (NSI and OSI were selected as experimental materials in using learning-testing paradigm to explore the neural basis of scientific innovation induced by heuristic prototype. College students were required to resolve NSI problems (to which they did not know the answers and OSI problems (to which they knew the answers. From two fMRI experiments, our results showed that the subjects could resolve NSI when provided with heuristic prototypes. In Experiment 1, it was found that the lingual gyrus (LG; BA18 might be related to prototype heuristics in college students resolving NSI after learning a relative prototype. In Experiment 2, the LG (BA18 and precuneus (BA31 were significantly activated for NSI compared to OSI when college students learned all prototypes one day before the test. In addition, the mean beta-values of these brain regions of NSI were all correlated with the behavior accuracy of NSI. As our hypothesis indicated, the findings suggested that the LG might be involved in forming novel associations using heuristic information, while the precuneus might be involved in the automatic activation of heuristic prototype during scientific innovation.
Classifying pedestrian shopping behaviour according to implied heuristic choice rules
Shigeyuki Kurose; Aloys W J Borgers; Timmermans, Harry J. P.
2001-01-01
Our aim in this paper is to build and test a model which classifies and identifies pedestrian shopping behaviour in a shopping centre by using temporal and spatial choice heuristics. In particular, the temporal local-distance-minimising, total-distance-minimising, and global-distance-minimising heuristic choice rules and spatial nearest-destination-oriented, farthest-destination-oriented, and intermediate-destination-oriented choice rules are combined to classify and identify the stop sequenc...
Proximity search heuristics for wind farm optimal layout
DEFF Research Database (Denmark)
Fischetti, Martina; Monaci, Michele
2015-01-01
A heuristic framework for turbine layout optimization in a wind farm is proposed that combines ad-hoc heuristics and mixed-integer linear programming. In our framework, large-scale mixed-integer programming models are used to iteratively refine the current best solution according to the recently......-proposed proximity search paradigm. Computational results on very large scale instances involving up to 20,000 potential turbine sites prove the practical viability of the overall approach....
Angal, Amit; Xiong, Xiaoxiong; Choi, Tae-young; Chander, Gyanesh; Wu, Aisheng
2010-01-01
Remote sensing imagery is effective for monitoring environmental and climatic changes because of the extent of the global coverage and long time scale of the observations. Radiometric calibration of remote sensing sensors is essential for quantitative & qualitative science and applications. Pseudo-invariant ground targets have been extensively used to monitor the long-term radiometric calibration stability of remote sensing sensors. This paper focuses on the use of the Sonoran Desert site to monitor the radiometric stability of the Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. The results are compared with the widely used Libya 4 Desert site in an attempt to evaluate the suitability of the Sonoran Desert site for sensor inter-comparison and calibration stability monitoring. Since the overpass times of ETM+ and MODIS differ by about 30 minutes, the impacts due to different view geometries or test site Bi-directional Reflectance Distribution Function (BRDF) are also presented. In general, the long-term drifts in the visible bands are relatively large compared to the drift in the near-infrared bands of both sensors. The lifetime Top-of-Atmosphere (TOA) reflectance trends from both sensors over 10 years are extremely stable, changing by no more than 0.1% per year (except ETM+ Band 1 and MODIS Band 3) over the two sites used for the study. The use of a semi-empirical BRDF model can reduce the impacts due to view geometries, thus enabling a better estimate of sensor temporal drifts.
Improvement of Web Design Using the Heuristic Evaluation Method
Directory of Open Access Journals (Sweden)
Maja Strgar Kurecic
2005-12-01
Full Text Available The paper deals with the problems of information presentation efficacy on Web. Research on how to design more functional and more attractive Web pages has been conducted. The graphic design heuristics for the Web have been defined, which could help designers to improve the efficacy of organization and information design on Web. Also, these rules present the basic criteria for objective evaluation of the Web design. The usage of the heuristic evaluation method, as the method for evaluation of the Web page graphic design has been suggested.The empirical part of the work comprises heuristic evaluation of the Web page graphic design according to the suggested heuristics, redesigning the Web pages of the Faculty of Graphic Arts according to the heuristic evaluation report and user testing by means of a poll. Analyzing the results obtained by user testing, it is proved that by the redesign according to the suggested graphic design heuristics for the Web, it is possible to create aesthetically and functionally better Web pages.
Interliminal Design: Understanding cognitive heuristics to mitigate design distortion
Directory of Open Access Journals (Sweden)
Andrew McCollough
2014-12-01
Full Text Available Cognitive heuristics are mental shortcuts adapted over time to enable rapid interpretation of our complex environment. They are intrinsic to human cognition and resist modification. Heuristics applied outside the context to which they are best suited are termed cognitive bias, and are the cause of systematic errors in judgment and reasoning. As both a cognitive and intuitive discipline, design by individuals is vulnerable to context-inappropriate heuristic usage. Designing in groups can act positively to counterbalance these tendencies, but is subject to heuristic misuse and biases particular to social environments. Mismatch between desired and actual outcomes– termed here, design distortion – occurs when such usage goes unnoticed and unaddressed, and can affect multiple dimensions of a system. We propose a methodology, interliminal design, emerging from the Program in Collaborative Design at Pacific Northwest College of Art, to specifically address the influence of cognitive heuristics in design. This adaptive approach involves reflective, dialogic, inquiry-driven practices intended to increase awareness of heuristic usage, and identify aspects of the design process vulnerable to misuse on both individual and group levels. By facilitating the detection and mitigation of potentially costly errors in judgment and decision-making that create distortion, such metacognitive techniques can meaningfully improve design.
Heuristic Reasoning in Chemistry: Making decisions about acid strength
McClary, LaKeisha; Talanquer, Vicente
2011-07-01
The characterization of students' reasoning strategies is of central importance in the development of instructional strategies that foster meaningful learning. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to facilitate the development of more analytical ways of thinking. The central goal of this qualitative study was thus to investigate heuristic reasoning as used by organic chemistry college students, focusing our attention on their ability to predict the relative acid strength of chemical compounds represented using explicit composition and structural features (i.e., structural formulas). Our results indicated that many study participants relied heavily on one or more of the following heuristics to make most of their decisions: reduction, representativeness, and lexicographic. Despite having visual access to reach structural information about the substances included in each ranking task, many students relied on isolated composition features to make their decisions. However, the specific characteristics of the tasks seemed to trigger heuristic reasoning in different ways. Although the use of heuristics allowed students to simplify some components of the ranking tasks and generate correct responses, it often led them astray. Very few study participants predicted the correct trends based on scientifically acceptable arguments. Our results suggest the need for instructional interventions that explicitly develop college chemistry students' abilities to monitor their thinking and evaluate the effectiveness of analytical versus heuristic reasoning strategies in different contexts.
SHARP - I. A high-resolution multi-band view of the infra-red Einstein ring of JVAS B1938+666
Lagattuta, D J; Fassnacht, C D; Auger, M W; Koopmans, L V E; McKean, J P
2012-01-01
We present new mass models for the gravitational lens system B1938+666, using multi-wavelength data acquired from Keck adaptive optics (AO) and Hubble Space Telescope (HST) observations. These models are the first results from the Strong-lensing at High Angular Resolution Program (SHARP), a project designed to study known quadruple-image and Einstein ring lenses using high-resolution imaging, in order to probe their mass distributions in unprecedented detail. Here, we specifically highlight differences between AO- and HST-derived lens models, finding that -- at least when the lens and source galaxies are both bright and red, and the system has a high degree of circular symmetry -- AO-derived models place significantly tighter constraints on model parameters. Using this improved precision, we infer important physical properties about the B1938+666 system, including the mass density slope of the lensing galaxy (gamma = 2.045), the projected dark matter mass fraction within the Einstein radius (M_dark/M_lens = 0...
An Intelligent Hyper-heuristic Framework for CHeSC 2011
Misir, Mustafa; Verbeeck, Katja; De Causmaecker, Patrick; Vanden Berghe, Greet
2012-01-01
The present study proposes a new selection hyper-heuristic providing several adaptive features to cope with the requirements of managing different heuristic sets. The approach suggested provides an intelligent way of selecting heuristics, determines effective heuristic pairs and adapts the parameters of certain heuristics online. In addition, an adaptive list-based threshold accepting mechanism has been developed. It enables deciding whether to accept or not the solutions generated by the sel...
A Novel Heuristic for Scheduling of Independent jobs on Grid Resources
Jyoti Bansal; Dr. Shaveta Rani; Dr. Paramjit Singh
2015-01-01
This Paper proposes a novel batch mode scheduling heuristic for scheduling of independent jobs on heterogeneous Grid resources. Proposed heuristic works in two stages, in the first stage Min-Min heuristic is being followed for the assignment of jobs to the resources & in the second stage jobs are being transferred from heavily loaded resource to the lightly loaded resource to achieve load balancing. The proposed heuristic and various existing heuristics were tested and compared within a grid ...
An apprenticeship learning hyper-heuristic for vehicle routing in HyFlex
Asta, Shahriar; Özcan, Ender
2014-01-01
Apprenticeship learning occurs via observations while an expert is in action. A hyper-heuristic is a search method or a learning mechanism that controls a set of low level heuristics or combines different heuristic components to generate heuristics for solving a given computationally hard problem. In this study, we investigate into a novel apprenticeship-learning-based approach which is used to automatically generate a hyper-heuristic for vehicle routing. This approach itself can be considere...
MaxStd: A Task Scheduling Heuristic for Heterogeneous Computing Environment
Directory of Open Access Journals (Sweden)
Ehsan Ullah Munir
2008-01-01
Full Text Available In this study, a new task scheduling heuristic, maximum standard deviation (MaxStd is proposed which considers that task for scheduling first, which has maximum standard deviation of the expected execution time on different machines. Experimentation results verify the effectiveness of proposed heuristic in different scenarios and comparison with the existing heuristics implies that proposed heuristic outperforms existing heuristics in terms of makespan.
Borup, Morten; Grum, Morten; Linde, Jens Jørgen; Mikkelsen, Peter Steen
2016-08-01
Numerous studies have shown that radar rainfall estimates need to be adjusted against rain gauge measurements in order to be useful for hydrological modelling. In the current study we investigate if adjustment can improve radar rainfall estimates to the point where they can be used for modelling overflows from urban drainage systems, and we furthermore investigate the importance of the aggregation period of the adjustment scheme. This is done by continuously adjusting X-band radar data based on the previous 5-30 min of rain data recorded by multiple rain gauges and propagating the rainfall estimates through a hydraulic urban drainage model. The model is built entirely from physical data, without any calibration, to avoid bias towards any specific type of rainfall estimate. The performance is assessed by comparing measured and modelled water levels at a weir downstream of a highly impermeable, well defined, 64 ha urban catchment, for nine overflow generating rain events. The dynamically adjusted radar data perform best when the aggregation period is as small as 10-20 min, in which case it performs much better than static adjusted radar data and data from rain gauges situated 2-3 km away.
Energy Technology Data Exchange (ETDEWEB)
Domenech, J. L.; Cueto, M.; Herrero, V. J.; Tanarro, I. [Molecular Physics Department, Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain); Tercero, B.; Cernicharo, J. [Department of Astrophysics, CAB, INTA-CSIC, Crta Torrejon-Ajalvir Km 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Fuente, A., E-mail: jl.domenech@csic.es [Observatorio Astronomico Nacional, Apdo. 112, E-28803 Alcala de Henares (Spain)
2013-07-01
The high-resolution spectrum of the {nu}{sub 4} band of NH{sub 3}D{sup +} has been measured by difference frequency IR laser spectroscopy in a multipass hollow cathode discharge cell. From the set of molecular constants obtained from the analysis of the spectrum, a value of 262817 {+-} 6 MHz ({+-}3{sigma}) has been derived for the frequency of the 1{sub 0}-0{sub 0} rotational transition. This value supports the assignment to NH{sub 3}D{sup +} of lines at 262816.7 MHz recorded in radio astronomy observations in Orion-IRc2 and the cold prestellar core B1-bS.
Werwein, Viktor; Brunzendorf, Jens; Serdyukov, Anton; Werhahn, Olav; Ebert, Volker
2016-05-01
Nitrous oxide (N2O) is one of the most important greenhouse gases in the terrestrial atmosphere and is routinely measured with ground-based FTIR networks like the Total Carbon Column Observing Network (TCCON). A spectral window for the TCCON retrievals is the 14N216O 0002-0000-band region from 4375 to 4445 cm-1 (2.250-2.285 μm). In our study, we present the first high-resolution Fourier transform spectrometer measurements of self-broadening and self-shift coefficients in the range of 53-1019 hPa for the lines R0e-R40e of this band. The line parameters were determined at 296 K using metrologically validated temperature, and pressure values, which were traced back to the SI-units. The averaged estimated relative uncertainties for the coverage factor of k = 2 (two times the standard deviation) are 0.3% and 9.5% with a standard deviation of 0.1% and 5.3% for the self-broadening and the self-shift coefficients, respectively. Vacuum line positions, determined for the first time by taking the self-shift coefficients into account are also reported with an estimated averaged relative uncertainty of 1.1 ∗ 10-8 for k = 2 and a standard deviation of 3 ∗ 10-9. A well-defined uncertainty assessment for the measured line parameters is given.
Meta-heuristic algorithms as tools for hydrological science
Yoo, Do Guen; Kim, Joong Hoon
2014-12-01
In this paper, meta-heuristic optimization techniques are introduced and their applications to water resources engineering, particularly in hydrological science are introduced. In recent years, meta-heuristic optimization techniques have been introduced that can overcome the problems inherent in iterative simulations. These methods are able to find good solutions and require limited computation time and memory use without requiring complex derivatives. Simulation-based meta-heuristic methods such as Genetic algorithms (GAs) and Harmony Search (HS) have powerful searching abilities, which can occasionally overcome the several drawbacks of traditional mathematical methods. For example, HS algorithms can be conceptualized from a musical performance process and used to achieve better harmony; such optimization algorithms seek a near global optimum determined by the value of an objective function, providing a more robust determination of musical performance than can be achieved through typical aesthetic estimation. In this paper, meta-heuristic algorithms and their applications (focus on GAs and HS) in hydrological science are discussed by subject, including a review of existing literature in the field. Then, recent trends in optimization are presented and a relatively new technique such as Smallest Small World Cellular Harmony Search (SSWCHS) is briefly introduced, with a summary of promising results obtained in previous studies. As a result, previous studies have demonstrated that meta-heuristic algorithms are effective tools for the development of hydrological models and the management of water resources.
A new heuristic for task scheduling in heterogeneous computing environment
Institute of Scientific and Technical Information of China (English)
Ehsan Ullah MUNIR; Jian-zhong LI; Sheng-fei SHI; Zhao-nian ZOU; Qaisar RASOOL
2008-01-01
Heterogeneous computing (HC) environment utilizes diverse resources with different computational capabilities to solve computing-intensive applications having diverse computational requirements and constraints. The task assignment problem in HC environment can be formally defined as for a given set of tasks and machines,assigning tasks to machines to achieve the minimum makespan. In this paper we propose a new task scheduling heuristic,high standard deviation first (HSTDF),which considers the standard deviation of the expected execution time of a task as a selection criterion. Standard deviation of the ex-pected execution time of a task represents the amount of variation in task execution time on different machines. Our conclusion is that tasks having high standard deviation must be assigned first for scheduling. A large number of experiments were carried out to check the effectiveness of the proposed heuristic in different scenarios,and the comparison with the existing heuristics (Max-min,Sufferage,Segmented Min-average,Segmented Min-min,and Segmented Max-min) clearly reveals that the proposed heuristic outperforms all existing heuristics in terms of average makespan.
Heuristics for Hierarchical Partitioning with Application to Model Checking
DEFF Research Database (Denmark)
Möller, Michael Oliver; Alur, Rajeev
2001-01-01
heuristic function. We argue for a heuristic function based on four criteria: the number of enclosed connections, the number of components, the number of touched connections and the depth of the structure. We report on an application in the context of formal verification, where our algorithm serves as a......Given a collection of connected components, it is often desired to cluster together parts of strong correspondence, yielding a hierarchical structure. We address the automation of this process and apply heuristics to battle the combinatorial and computational complexity. We define a cost function...... that captures the quality of a structure relative to the connections and favors shallow structures with a low degree of branching. Finding a structure with minimal cost is NP-complete. We present a greedy polynomial-time algorithm that approximates good solutions incrementally by local evaluation of a...
Applications of Meta-heuristics to Power and Energy Fields
Fukuyama, Yoshikazu
Considering deregulation in power systems and the energy conservation law, power and energy systems require more cost and energy reduction for system planning, operation, and control. Optimization techniques such as linear and nonlinear programming techniques have been utilized as one of the methods for realization of the reduction. Recently, meta-heuristics such as genetic algorithm, simulated annealing, tabu search, and particle swarm optimization have been paid attention as other options for realization of the reduction. In power and energy society, we had one technical committee and one special issue on applications of meta-heuristics for power system. Moreover, panel sessions and tutorials have been held in IEEE and IFAC. This paper presents applications of meta-heuristics to power and energy fields from the practical application point of view.
A Greedy Double Swap Heuristic for Nurse Scheduling
Choy, Murphy
2012-01-01
One of the key challenges of nurse scheduling problem (NSP) is the number of constraints placed on preparing the timetable, both from the regulatory requirements as well as the patients' demand for the appropriate nursing care specialists. In addition, the preferences of the nursing staffs related to their work schedules add another dimension of complexity. Most solutions proposed for solving nurse scheduling involve the use of mathematical programming and generally considers only the hard constraints. However, the psychological needs of the nurses are ignored and this resulted in subsequent interventions by the nursing staffs to remedy any deficiency and often results in last minute changes to the schedule. In this paper, we present a staff preference optimization framework which is solved with a greedy double swap heuristic. The heuristic yields good performance in speed at solving the problem. The heuristic is simple and we will demonstrate its performance by implementing it on open source spreadsheet soft...
A Comparison of Genetic Programming Variants for Hyper-Heuristics
Energy Technology Data Exchange (ETDEWEB)
Harris, Sean [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-03-01
Modern society is faced with ever more complex problems, many of which can be formulated as generate-and-test optimization problems. General-purpose optimization algorithms are not well suited for real-world scenarios where many instances of the same problem class need to be repeatedly and efficiently solved, such as routing vehicles over highways with constantly changing traffic flows, because they are not targeted to a particular scenario. Hyper-heuristics automate the design of algorithms to create a custom algorithm for a particular scenario. Hyper-heuristics typically employ Genetic Programming (GP) and this project has investigated the relationship between the choice of GP and performance in Hyper-heuristics. Results are presented demonstrating the existence of problems for which there is a statistically significant performance differential between the use of different types of GP.
Heuristic versus statistical physics approach to optimization problems
International Nuclear Information System (INIS)
Optimization is a crucial ingredient of many calculation schemes in science and engineering. In this paper we assess several classes of methods: heuristic algorithms, methods directly relying on statistical physics such as the mean-field method and simulated annealing; and Hopfield-type neural networks and genetic algorithms partly related to statistical physics. We perform the analysis for three types of problems: (1) the Travelling Salesman Problem, (2) vector quantization, and (3) traffic control problem in multistage interconnection network. In general, heuristic algorithms perform better (except for genetic algorithms) and much faster but have to be specific for every problem. The key to improving the performance could be to include heuristic features into general purpose statistical physics methods. (author)
Hybrid Heuristic-Based Artificial Immune System for Task Scheduling
sanei, Masoomeh
2011-01-01
Task scheduling problem in heterogeneous systems is the process of allocating tasks of an application to heterogeneous processors interconnected by high-speed networks, so that minimizing the finishing time of application as much as possible. Tasks are processing units of application and have precedenceconstrained, communication and also, are presented by Directed Acyclic Graphs (DAGs). Evolutionary algorithms are well suited for solving task scheduling problem in heterogeneous environment. In this paper, we propose a hybrid heuristic-based Artificial Immune System (AIS) algorithm for solving the scheduling problem. In this regard, AIS with some heuristics and Single Neighbourhood Search (SNS) technique are hybridized. Clonning and immune-remove operators of AIS provide diversity, while heuristics and SNS provide convergence of algorithm into good solutions, that is balancing between exploration and exploitation. We have compared our method with some state-of-the art algorithms. The results of the experiments...
The impact of choice context on consumers' choice heuristics
DEFF Research Database (Denmark)
Mueller Loose, Simone; Scholderer, Joachim; Corsi, Armando M.;
2012-01-01
Context effects in choice settings have received recent attention but little is known about the impact of context on choice consistency and the extent to which consumers apply choice heuristics. The sequence of alternatives in a choice set is examined here as one specific context effect. We compare...... how a change from a typical price order to a sensory order in wine menus affects consumer choice. We use pre-specified latent heuristic classes to analyse the existence of different choice processes, which begins to untangle the ‘black box’ of how consumers choose. Our findings indicate that in the...... absence of price order, consumers are less price-sensitive, pay more attention to visually salient cues, are less consistent in their choices and employ other simple choice heuristics more frequently than price. Implications for consumer research, marketing and consumer policy are discussed....
Discovery and problem solving: Triangulation as a weak heuristic
Rochowiak, Daniel
1987-01-01
Recently the artificial intelligence community has turned its attention to the process of discovery and found that the history of science is a fertile source for what Darden has called compiled hindsight. Such hindsight generates weak heuristics for discovery that do not guarantee that discoveries will be made but do have proven worth in leading to discoveries. Triangulation is one such heuristic that is grounded in historical hindsight. This heuristic is explored within the general framework of the BACON, GLAUBER, STAHL, DALTON, and SUTTON programs. In triangulation different bases of information are compared in an effort to identify gaps between the bases. Thus, assuming that the bases of information are relevantly related, the gaps that are identified should be good locations for discovery and robust analysis.
The inherence heuristic as a source of essentialist thought.
Salomon, Erika; Cimpian, Andrei
2014-10-01
Humans are essentialists: They believe hidden "essences" underlie membership in natural and social kinds. Although essentialism has well-established implications for important societal issues (e.g., discrimination), little is known about its origins. According to a recent proposal, essentialism emerges from a broader inherence heuristic-an intuitive tendency to explain patterns in terms of the inherent properties of their constituents (e.g., we have orange juice for breakfast [pattern] because citrus aromas [inherent feature] wake us up). We tested two predictions of this proposal-that reliance on the inherence heuristic predicts endorsement of essentialist beliefs, even when adjusting for potentially confounding variables (Studies 1 and 2), and that reducing reliance on the inherence heuristic produces a downstream reduction in essentialist thought (Studies 3 and 4). The results were consistent with these predictions and thus provided evidence for a new theoretical perspective on the cognitive underpinnings of psychological essentialism. PMID:25037751
A greedy double swap heuristic for nurse scheduling
Directory of Open Access Journals (Sweden)
Murphy Choy
2012-10-01
Full Text Available One of the key challenges of nurse scheduling problem (NSP is the number of constraints placed on preparing the timetable, both from the regulatory requirements as well as the patients’ demand for the appropriate nursing care specialists. In addition, the preferences of the nursing staffs related to their work schedules add another dimension of complexity. Most solutions proposed for solving nurse scheduling involve the use of mathematical programming and generally considers only the hard constraints. However, the psychological needs of the nurses are ignored and this resulted in subsequent interventions by the nursing staffs to remedy any deficiency and often results in last minute changes to the schedule. In this paper, we present a staff preference optimization framework solved with a greedy double swap heuristic. The heuristic yields good performance in speed at solving the problem. The heuristic is simple and we will demonstrate its performance by implementing it on open source spreadsheet software.
The FF Planning System: Fast Plan Generation Through Heuristic Search
Hoffmann, J; 10.1613/jair.855
2011-01-01
We describe and evaluate the algorithmic techniques that are used in the FF planning system. Like the HSP system, FF relies on forward state space search, using a heuristic that estimates goal distances by ignoring delete lists. Unlike HSP's heuristic, our method does not assume facts to be independent. We introduce a novel search strategy that combines hill-climbing with systematic search, and we show how other powerful heuristic information can be extracted and used to prune the search space. FF was the most successful automatic planner at the recent AIPS-2000 planning competition. We review the results of the competition, give data for other benchmark domains, and investigate the reasons for the runtime performance of FF compared to HSP.
Two Effective Heuristics for Beam Angle Optimization in Radiation Therapy
Yarmand, Hamed
2013-01-01
In radiation therapy, mathematical methods have been used for optimizing treatment planning for delivery of sufficient dose to the cancerous cells while keeping the dose to critical surrounding structures minimal. This optimization problem can be modeled using mixed integer programming (MIP) whose solution gives the optimal beam orientation as well as optimal beam intensity. The challenge, however, is the computation time for this large scale MIP. We propose and investigate two novel heuristic approaches to reduce the computation time considerably while attaining high-quality solutions. We introduce a family of heuristic cuts based on the concept of 'adjacent beams' and a beam elimination scheme based on the contribution of each beam to deliver the dose to the tumor in the ideal plan in which all potential beams can be used simultaneously. We show the effectiveness of these heuristics for intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) on a clinical liver case.
... gastric banding before deciding to have the procedure. Advertisements for a device or procedure may not include ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...
Bio-Inspired Meta-Heuristics for Emergency Transportation Problems
Directory of Open Access Journals (Sweden)
Min-Xia Zhang
2014-02-01
Full Text Available Emergency transportation plays a vital role in the success of disaster rescue and relief operations, but its planning and scheduling often involve complex objectives and search spaces. In this paper, we conduct a survey of recent advances in bio-inspired meta-heuristics, including genetic algorithms (GA, particle swarm optimization (PSO, ant colony optimization (ACO, etc., for solving emergency transportation problems. We then propose a new hybrid biogeography-based optimization (BBO algorithm, which outperforms some state-of-the-art heuristics on a typical transportation planning problem.
Heuristic Reduction Algorithm Based on Pairwise Positive Region
Institute of Scientific and Technical Information of China (English)
QI Li; LIU Yu-shu
2007-01-01
To guarantee the optimal reduct set, a heuristic reduction algorithm is proposed, which considers the distinguishing information between the members of each pair decision classes. Firstly the pairwise positive region is defined, based on which the pairwise significance measure is calculated between the members of each pair classes. Finally the weighted pairwise significance of attribute is used as the attribute reduction criterion, which indicates the necessity of attributes very well. By introducing the noise tolerance factor, the new algorithm can tolerate noise to some extent. Experimental results show the advantages of our novel heuristic reduction algorithm over the traditional attribute dependency based algorithm.
A Heuristic Algorithm for QoS Multicast Routing
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
In recent years, QoS multicast routing has continued to be a very important research topic in the areas of net-works. This paper presents a heuristic algorithm for the QoS multicast routing (HAQMR). This heuristic algorithmdeals with delay and bandwidth constraints and has low cost. The HAQMR attempts to significantly reduce the overheadfor constructing a multicast tree. the proof for correctness of the HAQMR is given, and the performance of the HAQMRis evaluated by simulations. The study shows that HAQMR provides an available approach to QoS multicast routing.
A new heuristic algorithm for general integer linear programming problems
Institute of Scientific and Technical Information of China (English)
GAO Pei-wang; CAI Ying
2006-01-01
A new heuristic algorithm is proposed for solving general integer linear programming problems.In the algorithm,the objective function hyperplane is used as a cutting plane,and then by introducing a special set of assistant sets,an efficient heuristic search for the solution to the integer linear program is carried out in the sets on the objective function hyperplane.A simple numerical example shows that the algorithm is efficient for some problems,and therefore,of practical interest.
New heuristic algorithm for dynamic traffic in WDM optical networks
Directory of Open Access Journals (Sweden)
A. Rodríguez García
2015-12-01
Full Text Available This paper presents the results from the simulation of Snake One, a new heuristic algorithm, and the comparison made between three heuristic algorithms: Genetic Algorithms, Simulated Annealing, and Tabu Search, using blocking probability and network utilization as standard indicators. The simulation exercise was conducted on WDM NSFNET under dynamic traffic conditions. The results show a substantial decrease of blocking. However, this causes a relative network utilization growth. There are also load intervals which lead to performance improvement, decreasing the number of blocked requests.
Optimizing GoTools' Search Heuristics using Genetic Algorithms
Pratola, Matthew; Wolf, Thomas
2003-01-01
GoTools is a program which solves life & death problems in the game of Go. This paper describes experiments using a Genetic Algorithm to optimize heuristic weights used by GoTools' tree-search. The complete set of heuristic weights is composed of different subgroups, each of which can be optimized with a suitable fitness function. As a useful side product, an MPI interface for FreePascal was implemented to allow the use of a parallelized fitness function running on a Beowulf cluster. The aim ...
A heuristic for the minimization of open stacks problem
Fernando Masanori Ashikaga; Nei Yoshihiro Soma
2009-01-01
It is suggested here a fast and easy to implement heuristic for the minimization of open stacks problem (MOSP). The problem is modeled as a traversing problem in a graph (Gmosp) with a special structure (Yanasse, 1997b). It was observed in Ashikaga (2001) that, in the mean experimental case, Gmosp has large cliques and high edge density. This information was used to implement a heuristic based on the extension-rotation algorithm of Pósa (1976) for approximation of Hamiltonian Circuits. Additi...
Nghia, Nguyen Duc; Binh, Huynh Thi Thanh
2008-01-01
We have introduced the heuristic algorithm for solving BDMST problem, called CBRC. The experiment shows that CBRC have best result than the other known heuristic algorithm for solving BDMST prolem on Euclidean instances. The best solution found by the genetic algorithm which uses best heuristic algorithm or only one heuristic algorithm for initialization the population is not better than the best solution found by the genetic algorithm which uses mixed heuristic algorithms (randomized heurist...
A heuristic two-dimensional presentation of microsatellite-based data applied to dogs and wolves
Directory of Open Access Journals (Sweden)
Foerster Martin
2007-07-01
Full Text Available Abstract Methods based on genetic distance matrices usually lose information during the process of tree-building by converting a multi-dimensional matrix into a phylogenetic tree. We applied a heuristic method of two-dimensional presentation to achieve a better resolution of the relationship between breeds and individuals investigated. Four hundred and nine individuals from nine German dog breed populations and one free-living wolf population were analysed with a marker set of 23 microsatellites. The result of the two-dimensional presentation was partly comparable with and complemented a model-based analysis that uses genotype patterns. The assignment test and the neighbour-joining tree based on allele sharing estimate allocated 99% and 97% of the individuals according to their breed, respectively. The application of the two-dimensional presentation to distances on the basis of the proportion of shared alleles resulted in comparable and further complementary insight into inferred population structure by multilocus genotype data. We expect that the inference of population structure in domesticated species with complex breeding histories can be strongly supported by the two-dimensional presentation based on the described heuristic method.
Crossover control in selection hyper-heuristics: case studies using MKP and HyFlex
Drake, John H.
2014-01-01
Hyper-heuristics are a class of high-level search methodologies which operate over a search space of heuristics rather than a search space of solutions. Hyper-heuristic research has set out to develop methods which are more general than traditional search and optimisation techniques. In recent years, focus has shifted considerably towards cross-domain heuristic search. The intention is to develop methods which are able to deliver an acceptable level of performance over a variety of different ...
Performance comparison of selection hyper-heuristics on new HyFlex domains
Almutairi, Alhanof Khalid S
2015-01-01
Since most real-world computational problems are difficult to solve, significant attention has been drawn to design an automatic mechanism for selecting heuristics and increasing the generality of the search approach. Hyper-heuristics are high-level search mechanisms which aim to solve a range of difficult combinatorial optimisation problems by operating in the space of heuristics rather than space of solutions, which differs from the traditional approach. Hyper-heuristics are classified into...
Comparison of heuristic approaches for the multiple depot vehicle scheduling problem
Pepin, A.S.; Desaulniers, Guy; Hertz, Alain; Huisman, Dennis
2006-01-01
textabstractGiven a set of timetabled tasks, the multi-depot vehicle scheduling problem is a well-known problem that consists of determining least-cost schedules for vehicles assigned to several depots such that each task is accomplished exactly once by a vehicle. In this paper, we propose to compare the performance of five different heuristic approaches for this problem, namely, a heuristic \\\\mip solver, a Lagrangian heuristic, a column generation heuristic, a large neighborhood search heuri...
Keith Marzilli Ericson; Amanda Starc
2012-01-01
We examine heuristic decision rules in consumer choice on health insurance exchanges using data from the Massachusetts Connector. Consumers may have difficulty making optimal choices in a complex environment. The heuristic "choose the cheapest plan" is suggested by the decision context, previous research, and the data: about 20% of enrollees choose the cheapest plan possible. We find evidence of this heuristic in many models, but while heuristics may play a role, preference heterogeneity is a...
A global heuristically search algorithm for DNA encoding
Institute of Scientific and Technical Information of China (English)
Zhang Kai; Pan Linqiang; Xu Jin
2007-01-01
A new efficient algorithm is developed to design DNA words with equal length for DNA computing. The algorithm uses a global heuristic optimizing search approach and converts constraints to a carry number to accelerate the convergence, which can generate a DNA words set satisfying some thermodynamic and combinatorial constraints. Based on the algorithm, a software for DNA words design is developed.
Heuristic Scheduling Algorithm Oriented Dynamic Tasks for Imaging Satellites
Directory of Open Access Journals (Sweden)
Maocai Wang
2014-01-01
Full Text Available Imaging satellite scheduling is an NP-hard problem with many complex constraints. This paper researches the scheduling problem for dynamic tasks oriented to some emergency cases. After the dynamic properties of satellite scheduling were analyzed, the optimization model is proposed in this paper. Based on the model, two heuristic algorithms are proposed to solve the problem. The first heuristic algorithm arranges new tasks by inserting or deleting them, then inserting them repeatedly according to the priority from low to high, which is named IDI algorithm. The second one called ISDR adopts four steps: insert directly, insert by shifting, insert by deleting, and reinsert the tasks deleted. Moreover, two heuristic factors, congestion degree of a time window and the overlapping degree of a task, are employed to improve the algorithm’s performance. Finally, a case is given to test the algorithms. The results show that the IDI algorithm is better than ISDR from the running time point of view while ISDR algorithm with heuristic factors is more effective with regard to algorithm performance. Moreover, the results also show that our method has good performance for the larger size of the dynamic tasks in comparison with the other two methods.
Chain Gang: A Framegame for Teaching Algorithms and Heuristics.
Thiagarajan, Sivasailam; Pasigna, Aida L.
1985-01-01
Describes basic structure of a framegame, Chain Gang, in which self-instructional modules teach a cognitive skill. Procedures are presented for loading new content into the game's basic framework to teach algorithms or heuristics and for game modification to suit different situations. Handouts used in the basic game are appended. (MBR)
An Improved Heuristic Algorithm of Attribute Reduction in Rough Set
Institute of Scientific and Technical Information of China (English)
ShunxiangWu; MaoqingLi; WentingHuang; SifengLiu
2004-01-01
This paper introduces background of rough set theory, then proposes a new algorithm for finding optimal reduction and make comparison between the original algorithm and the improved one by the experiment about the nine standard data set in UL database to explain the validity of the improved heuristic algorithm.
How cognitive heuristics can explain social interactions in spatial movement.
Seitz, Michael J; Bode, Nikolai W F; Köster, Gerta
2016-08-01
The movement of pedestrian crowds is a paradigmatic example of collective motion. The precise nature of individual-level behaviours underlying crowd movements has been subject to a lively debate. Here, we propose that pedestrians follow simple heuristics rooted in cognitive psychology, such as 'stop if another step would lead to a collision' or 'follow the person in front'. In other words, our paradigm explicitly models individual-level behaviour as a series of discrete decisions. We show that our cognitive heuristics produce realistic emergent crowd phenomena, such as lane formation and queuing behaviour. Based on our results, we suggest that pedestrians follow different cognitive heuristics that are selected depending on the context. This differs from the widely used approach of capturing changes in behaviour via model parameters and leads to testable hypotheses on changes in crowd behaviour for different motivation levels. For example, we expect that rushed individuals more often evade to the side and thus display distinct emergent queue formations in front of a bottleneck. Our heuristics can be ranked according to the cognitive effort that is required to follow them. Therefore, our model establishes a direct link between behavioural responses and cognitive effort and thus facilitates a novel perspective on collective behaviour. PMID:27581483
The afforestation problem: a heuristic method based on simulated annealing
DEFF Research Database (Denmark)
Vidal, Rene Victor Valqui
1992-01-01
This paper presents the afforestation problem, that is the location and design of new forest compartments to be planted in a given area. This optimization problem is solved by a two-step heuristic method based on simulated annealing. Tests and experiences with this method are also presented....
Development of Heuristic Bias Detection in Elementary School
De Neys, Wim; Feremans, Vicky
2013-01-01
Although human reasoning is often biased by intuitive heuristics, recent studies have shown that adults and adolescents detect the biased nature of their judgments. The present study focused on the development of this critical bias sensitivity by examining the detection skills of young children in elementary school. Third and 6th graders were…
Aristotle's 'completeness test' as Heuristics for an Account of Dynamicity
DEFF Research Database (Denmark)
Seibt, Johanna
2015-01-01
heuristic leads to a class of inferential data (aspectual inferences) that analytical ontologists have all but overlooked so far. In addition, I suggest that the passage also can offer some ideas about how one might formulate, in mereological terms, a component of an implicit definition of dynamicity....
The Electrophysiological Correlates of Scientific Innovation Induced by Heuristic Information
Luo, Junlong; Du, Xiumin; Tang, Xiaochen; Zhang, Entao; Li, Haijiang; Zhang, Qinglin
2013-01-01
In this study, novel and old scientific innovations (NSI and OSI) were selected as materials to explore the electrophysiological correlates of scientific innovation induced by heuristic information. Using event-related brain potentials (ERPs) to do so, college students solved NSI problems (for which they did not know the answers) and OSI problems…
Heuristic Concentration and Tabu Search: A Nose to Nose Comparison
Rosing, Kenneth; ReVelle, C.S.
1997-01-01
textabstractIn 1997 two papers applying the metaheuristics Tabu Search (TS) and Heuristic Concentration (HC) to the p-median problem were published in consecutive volumes of the European Journal of Operational Research. Here we apply the method of HC some of the data sets which were used for computational experience in the paper on TS and briefly set out the results.
Divergence of Scientific Heuristic Method and Direct Algebraic Instruction
Calucag, Lina S.
2016-01-01
This is an experimental study, made used of the non-randomized experimental and control groups, pretest-posttest designs. The experimental and control groups were two separate intact classes in Algebra. For a period of twelve sessions, the experimental group was subjected to the scientific heuristic method, but the control group instead was given…
Heuristic Reasoning in Chemistry: Making Decisions about Acid Strength
McClary, Lakeisha; Talanquer, Vicente
2011-01-01
The characterization of students' reasoning strategies is of central importance in the development of instructional strategies that foster meaningful learning. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to facilitate the development of more…
Prototypes Are Key Heuristic Information in Insight Problem Solving
Yang, Wenjing; Dietrich, Arne; Liu, Peiduo; Ming, Dan; Jin, Yule; Nusbaum, Howard C.; Qiu, Jiang; Zhang, Qinglin
2016-01-01
Evidence from a range of fields indicates that inventions are often inspired by drawing a parallel to solutions found in nature. However, the cognitive mechanism of this process is not well understood. The cognitive mechanism of heuristic prototype in scientific innovation was tested with 3 experiments. First, 84 historical accounts of important…
Compensatory Reading among ESL Learners: A Reading Strategy Heuristic
Ismail, Shaik Abdul Malik Mohamed; Petras, Yusof Ede; Mohamed, Abdul Rashid; Eng, Lin Siew
2015-01-01
This paper aims to gain an insight to the relationship of two different concepts about reading comprehension, namely, the linear model of comprehension and the interactive compensatory theory. Drawing on both the above concepts, a heuristic was constructed about three different reading strategies determined by the specific ways the literal,…
A Heuristic Hierarchical Scheme for Academic Search and Retrieval
DEFF Research Database (Denmark)
Amolochitis, Emmanouil; Christou, Ioannis T.; Tan, Zheng-Hua;
2013-01-01
and a graph-theoretic computed score that relates the paper’s index terms with each other. We designed and developed a meta-search engine that submits user queries to standard digital repositories of academic publications and re-ranks the repository results using the hierarchical heuristic scheme. We evaluate...
Heuristical Strategies on the Study Theme "The Unsaturated Hydrocarbons -- Alkenes"
Naumescu, Adrienne Kozan; Pasca, Roxana-Diana
2011-01-01
The influence of heuristical strategies upon the level of two experimental classes is studied in this paper. The didactic experiment took place at secondary school in Cluj-Napoca, in 2008-2009 school year. The study theme "The Unsaturated Hydrocarbons--Alkenes" has been efficiently learned by using the most active methods: laboratory…
Heuristic Concentration and Tabu Search: A Nose to Nose Comparison
K.E. Rosing (Kenneth); C.S. ReVelle
1997-01-01
textabstractIn 1997 two papers applying the metaheuristics Tabu Search (TS) and Heuristic Concentration (HC) to the p-median problem were published in consecutive volumes of the European Journal of Operational Research. Here we apply the method of HC some of the data sets which were used for computa
Heuristics guide cooperative behaviors in public goods game
Wang, Yongjie; Chen, Tong
2015-12-01
In public goods game (PGG), player's cooperative behavior is not pure economical rationality, but social preference and prosocial intuition play extremely important roles as well. Social preference and prosocial intuition can be guided by heuristics from one's neighbors in daily life. To better investigate the impacts of heuristics on the evolution of cooperation, four types of agents are introduced into our spatial PGG. Through numerical simulations, results show that the larger percentages of cooperators with independent thought, the easier emergence and maintenance of collective cooperative behaviors. Additionally, we find that differentia heuristic capability has great effect on the equilibrium of PGG. Cooperation can be obviously promoted, when heuristic capability of cooperators with independent thought is stronger than that of defectors with independent thought. Finally, we observe that cooperators with independent thought and defectors with independent thought are favorable for the formation of some high quality clusters, which can resist the invasion between each other. Our work may help us understand more clearly the mechanism of cooperation in real world.
Discrepancy and backjumping heuristics for flexible job shop scheduling
Ben Hmida, Abir; Haouari, Mohamed; Huguet, Marie-José; Lopez, Pierre
2008-01-01
International audience This paper presents an improved discrepancy-based method, called CDDS, after being adapted to solve the flexible job shop problem in a precedent work. We propose applying discrepancy on some pertinent variables chosen by using two types of heuristics. The method is tested on different problem instances from literature.
Heuristics for Routing Heterogeneous Unmanned Vehicles with Fuel Constraints
Directory of Open Access Journals (Sweden)
David Levy
2014-01-01
Full Text Available This paper addresses a multiple depot, multiple unmanned vehicle routing problem with fuel constraints. The objective of the problem is to find a tour for each vehicle such that all the specified targets are visited at least once by some vehicle, the tours satisfy the fuel constraints, and the total travel cost of the vehicles is a minimum. We consider a scenario where the vehicles are allowed to refuel by visiting any of the depots or fuel stations. This is a difficult optimization problem that involves partitioning the targets among the vehicles and finding a feasible tour for each vehicle. The focus of this paper is on developing fast variable neighborhood descent (VND and variable neighborhood search (VNS heuristics for finding good feasible solutions for large instances of the vehicle routing problem. Simulation results are presented to corroborate the performance of the proposed heuristics on a set of 23 large instances obtained from a standard library. These results show that the proposed VND heuristic, on an average, performed better than the proposed VNS heuristic for the tested instances.
Xu, Li-Hong; Jiang, Xingjie; Shi, Hongyu; Lees, R. M.; McKellar, A. R. W.; Tokaryk, D. W.; Appadoo, D. R. T.
2011-07-01
High-resolution Fourier transform spectra of trans-acrolein, H 2C dbnd C(H) sbnd C(H) dbnd O, have been recorded in the 10 μm region at both room and cooled temperatures on the modified Bomem DA3.002 at the National Research Council of Canada and the Bruker IFS 125HR spectrometer at the far infrared beam line of the Canadian Light Source in Saskatoon. Vibrational fundamentals analyzed so far include the ν11, ν16 and ν14 bands centered at 911.3, 958.7 and 992.7 cm -1 corresponding respectively to the A' in-plane dbnd CH 2-rocking mode, the A″ out-of-plane dbnd CH 2-wagging mode, and the A″ wagging mode highly mixed between the ⩾C sbnd H vinyl and ⩾C sbnd H formyl groups [Vibrational mode descriptions are based on Y.N. Panchenko, P. Pulay, F. Török, J. Mol. Spectrosc. 34 (1976) 283-289.] As well, the ν16 + ν18 - ν18 hot band centred at 957.6 cm -1 has been analyzed, where ν18 is the low-frequency (157.9 cm -1) A″ ⩾C sbnd C ⪕ torsional mode. The ν11 band is a/ b type while the ν16, ν14 and ν16 + ν18 - ν18 bands are c-type. The assigned transitions of each band have been fitted to a Watson asymmetric rotor Hamiltonian, with ground state parameters fixed to values obtained from rotational analyses in the literature. As well, a combined 3-state fit for ν11, ν16 and ν14 was carried out including Coriolis and Z1 constants which account for J and Δ K interactions. Transition dipole moments have been calculated for each of the fundamentals using the ab initio B3LYP method and 6-311++G ∗∗ basis set. For the A' vibrational modes, we have also evaluated transition dipole a- and b-components in the principal axis system from vibrational displacements and dipole moment derivatives. Our ab initio results predict that the ν11 in-plane dbnd CH 2 rocking mode has an a-type transition strength about three times greater than the b-type, which is consistent with our observations. Our ab initio force field analysis gives vibrational mode
HHaaHMM: A Hyper-Heuristic as a Hidden Markov Model
Van Onsem, Willem; Demoen, Bart; De Causmaecker, Patrick
2014-01-01
A new hyper-heuristic algorithm is presented. The approach uses an expectation-maximization strategy in order to find the most likely compressed representation of the hyper-heuristic process. The approach is in principle to calculate a good heuristic at any point in time given the old data.
Fluency Heuristic: A Model of How the Mind Exploits a By-Product of Information Retrieval
Hertwig, Ralph; Herzog, Stefan M.; Schooler, Lael J.; Reimer, Torsten
2008-01-01
Boundedly rational heuristics for inference can be surprisingly accurate and frugal for several reasons. They can exploit environmental structures, co-opt complex capacities, and elude effortful search by exploiting information that automatically arrives on the mental stage. The fluency heuristic is a prime example of a heuristic that makes the…
Koichu, Boris; Berman, Abraham; Moore, Michael
2007-01-01
The relationships between heuristic literacy development and mathematical achievements of middle school students were explored during a 5-month classroom experiment in two 8th grade classes (N = 37). By heuristic literacy we refer to an individual's capacity to use heuristic vocabulary in problem-solving discourse and to approach scholastic…
Local search heuristics for the probabilistic dial-a-ride problem
DEFF Research Database (Denmark)
Ho, Sin C.; Haugland, Dag
2011-01-01
evaluation procedure in a pure local search heuristic and in a tabu search heuristic. The quality of the solutions obtained by the two heuristics have been compared experimentally. Computational results confirm that our neighborhood evaluation technique is much faster than the straightforward one, and for...
Automated Detection of Heuristics and Biases among Pathologists in a Computer-Based System
Crowley, Rebecca S.; Legowski, Elizabeth; Medvedeva, Olga; Reitmeyer, Kayse; Tseytlin, Eugene; Castine, Melissa; Jukic, Drazen; Mello-Thoms, Claudia
2013-01-01
The purpose of this study is threefold: (1) to develop an automated, computer-based method to detect heuristics and biases as pathologists examine virtual slide cases, (2) to measure the frequency and distribution of heuristics and errors across three levels of training, and (3) to examine relationships of heuristics to biases, and biases to…
Social biases determine spatiotemporal sparseness of ciliate mating heuristics.
Clark, Kevin B
2012-01-01
Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate's initial subjective bias, responsiveness, or preparedness, as defined by Stevens' Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The present
Heuristics to Evaluate Interactive Systems for Children with Autism Spectrum Disorder (ASD.
Directory of Open Access Journals (Sweden)
Kamran Khowaja
Full Text Available In this paper, we adapted and expanded a set of guidelines, also known as heuristics, to evaluate the usability of software to now be appropriate for software aimed at children with autism spectrum disorder (ASD. We started from the heuristics developed by Nielsen in 1990 and developed a modified set of 15 heuristics. The first 5 heuristics of this set are the same as those of the original Nielsen set, the next 5 heuristics are improved versions of Nielsen's, whereas the last 5 heuristics are new. We present two evaluation studies of our new heuristics. In the first, two groups compared Nielsen's set with the modified set of heuristics, with each group evaluating two interactive systems. The Nielsen's heuristics were assigned to the control group while the experimental group was given the modified set of heuristics, and a statistical analysis was conducted to determine the effectiveness of the modified set, the contribution of 5 new heuristics and the impact of 5 improved heuristics. The results show that the modified set is significantly more effective than the original, and we found a significant difference between the five improved heuristics and their corresponding heuristics in the original set. The five new heuristics are effective in problem identification using the modified set. The second study was conducted using a system which was developed to ascertain if the modified set was effective at identifying usability problems that could be fixed before the release of software. The post-study analysis revealed that the majority of the usability problems identified by the experts were fixed in the updated version of the system.
Durga: A heuristically-optimized data collection strategy for volumetric magnetic resonance imaging
Anand, Christopher Kumar; Curtis, Andrew Thomas; Kumar, Rakshit
2008-02-01
A heuristic design method for rapid volumetric magnetic resonance imaging data acquisition trajectories is presented, using a series of second-order cone optimization subproblems. Other researchers have considered non-raster data collection trajectories and under-sampled data patterns. This work demonstrates that much higher rates of under-sampling are possible with an asymmetric set of trajectories, with very little loss in resolution, but the addition of noise-like artefacts. The proposed data collection trajectory, Durga, further minimizes collection time by incorporating short un-refocused excitation pulses, resulting in above 98% collection efficiency for balanced steady state free precession imaging. The optimization subproblems are novel, in that they incorporate all requirements, including data collection (coverage), physicality (device limits), and signal generation (zeroth- and higher- moment properties) in a single convex problem, which allows the resulting trajectories to exhibit a higher collection efficiency than any existing trajectory design.
Fuzzy adaptive parameter control of a late acceptance hyper-heuristic
Jackson, Warren G.; Özcan, Ender; Robert I. John
2014-01-01
A traditional iterative selection hyper-heuristic which manages a set of low level heuristics relies on two core components, a method for selecting a heuristic to apply at a given point, and a method to decide whether or not to accept the result of the heuristic application. In this paper, we present an initial study of a fuzzy system to control the list-size parameter of late- acceptance move acceptance method as a selection hyper-heuristic component. The performance of the fuzzy controlled ...
A perturbative clustering hyper-heuristic framework for the Danish railway system
DEFF Research Database (Denmark)
Mohammad Pour, Shahrzad; Rasmussen, Kourosh Marjani; Burke, Edmund K.
heuristics and employs an adaptive choice function as a robust learning mechanism. The results of adaptive clustering hyper-heuristic are compared with two exact and heuristic assignment algorithms from the literature and with the random hyper-heuristic framework on 12 datasets. In comparison with the exact......, we propose a perturbative clustering hyper-heuristic framework. The framework improves an initial solution by reassigning outliers (those tasks that are far away) to a better cluster choice at each iteration while taking balanced crews workloads into account. The framework introduces five lowlevel...... formulation, the proposed framework could obtain promising results and solved the data instances up to 5000 number of tasks. In comparison with heuristic assignment and the random hyper-heuristic, the framework yielded approximately 11%, 27% and 10%,13% mprovement on total distance and the maximum distance...
The use of meta-heuristics for airport gate assignment
DEFF Research Database (Denmark)
Cheng, Chun-Hung; Ho, Sin C.; Kwan, Cheuk-Lam
2012-01-01
proposed to generate good solutions within a reasonable timeframe. In this work, we attempt to assess the performance of three meta-heuristics, namely, genetic algorithm (GA), tabu search (TS), simulated annealing (SA) and a hybrid approach based on SA and TS. Flight data from Incheon International Airport......Improper assignment of gates may result in flight delays, inefficient use of the resource, customer’s dissatisfaction. A typical metropolitan airport handles hundreds of flights a day. Solving the gate assignment problem (GAP) to optimality is often impractical. Meta-heuristics have recently been...... are collected to carry out the computational comparison. Although the literature has documented these algorithms, this work may be a first attempt to evaluate their performance using a set of realistic flight data....
Deterministic algorithm with agglomerative heuristic for location problems
Kazakovtsev, L.; Stupina, A.
2015-10-01
Authors consider the clustering problem solved with the k-means method and p-median problem with various distance metrics. The p-median problem and the k-means problem as its special case are most popular models of the location theory. They are implemented for solving problems of clustering and many practically important logistic problems such as optimal factory or warehouse location, oil or gas wells, optimal drilling for oil offshore, steam generators in heavy oil fields. Authors propose new deterministic heuristic algorithm based on ideas of the Information Bottleneck Clustering and genetic algorithms with greedy heuristic. In this paper, results of running new algorithm on various data sets are given in comparison with known deterministic and stochastic methods. New algorithm is shown to be significantly faster than the Information Bottleneck Clustering method having analogous preciseness.
Heuristic for Stochastic Online Flowshop Problem with Preemption Penalties
Directory of Open Access Journals (Sweden)
Mohammad Bayat
2013-01-01
Full Text Available The deterministic flowshop model is one of the most widely studied problems; whereas its stochastic equivalent has remained a challenge. Furthermore, the preemptive online stochastic flowshop problem has received much less attention, and most of the previous researches have considered a nonpreemptive version. Moreover, little attention has been devoted to the problems where a certain time penalty is incurred when preemption is allowed. This paper examines the preemptive stochastic online flowshop with the objective of minimizing the expected makespan. All the jobs arrive overtime, which means that the existence and the parameters of each job are unknown until its release date. The processing time of the jobs is stochastic and actual processing time is unknown until completion of the job. A heuristic procedure for this problem is presented, which is applicable whenever the job processing times are characterized by their means and standard deviation. The performance of the proposed heuristic method is explored using some numerical examples.
Using heuristics to solve the dedicated aircraft recovery problem
DEFF Research Database (Denmark)
Løve, Michael; Sørensen, Kim Riis; Larsen, Jesper;
2001-01-01
The Dedicated Aircraft Recovery Problem (DARP) involves decisions concerning aircraft to flight assignments in situations where unforeseen events have disrupted the existing flight schedule, e.g. bad weather causing flight delays. The dedicated aircraft recovery problem aims to recover these flight...... schedules through a series of reassignments of aircraft to flights, delaying of flights and cancellations of flights. This article describes an effective method to solve DARP. A heuristic is implemented, which is able to generate feasible revised flight schedules of good quality in less than 10 seconds when...... applied to real flight schedules with disruptions from British Airways. The heuristic is able to consider delays, cancellations and reassignments simultaneously and balance the trade-off between these options. It is also demonstrated that different strategies can be applied to prioritize these options...
A heuristic approach to incremental and reactive scheduling
Odubiyi, Jide B.; Zoch, David R.
1989-01-01
An heuristic approach to incremental and reactive scheduling is described. Incremental scheduling is the process of modifying an existing schedule if the initial schedule does not meet its stated initial goals. Reactive scheduling occurs in near real-time in response to changes in available resources or the occurrence of targets of opportunity. Only minor changes are made during both incremental and reactive scheduling because a goal of re-scheduling procedures is to minimally impact the schedule. The described heuristic search techniques, which are employed by the Request Oriented Scheduling Engine (ROSE), a prototype generic scheduler, efficiently approximate the cost of reaching a goal from a given state and effective mechanisms for controlling search.
Theoretical Expectation versus Practical Performance of Jackson’s Heuristic
Directory of Open Access Journals (Sweden)
Nodari Vakhania
2015-01-01
Full Text Available A basic 2-approximation heuristic was suggested by Jackson in early 50s last century for scheduling jobs with release times and due dates to minimize the maximum job lateness. The theoretical worst-case bound of 2 helps a little in practice, when the solution quality is important. The quality of the solution delivered by Jackson’s heuristic is closely related to the maximum job processing time pmax that occurs in a given problem instance and with the resultant interference with other jobs that such a long job may cause. We use the relationship of pmax with the optimal objective value to obtain more accurate approximation ratio, which may drastically outperform the earlier known worst-case ratio of 2. This is proved, in practice, by our computational experiments.
Theory of Randomized Search Heuristics in Combinatorial Optimization
DEFF Research Database (Denmark)
The rigorous mathematical analysis of randomized search heuristics(RSHs) with respect to their expected runtime is a growing research area where many results have been obtained in recent years. This class of heuristics includes well-known approaches such as Randomized Local Search (RLS...... to a mathematical analysis. This is different to the classical design of (randomized) algorithms which are developed with their theoretical analysis of runtime (and proof of correctness) in mind. Despite these obstacles, research from the last about 15 years has shown how to apply the methods for the probabilistic...... analysis of randomized algorithms to RSHs. Mostly, the expected runtime of RSHs on selected problems is analzyed. Thereby, we understand why and when RSHs are efficient optimizers and, conversely, when they cannot be efficient. The tutorial will give an overview on the analysis of RSHs for solving...
Heuristic procedures for transmission planning in competitive electricity markets
International Nuclear Information System (INIS)
The network structure of the power system, in an electricity market under the pool model, may have severe impacts on market performance, reducing market efficiency considerably, especially when producers bid strategically. In this context network re-enforcement plays a major role and proper strategies of transmission planning need to be devised. This paper presents, for pool-model electricity markets, two heuristic procedures to select the most effective subset of lines that would reduce the impacts on the market, from a set of predefined candidate lines and within the allowed budget for network expansion. A set of indices that account for the economic impacts of the re-enforcing of the candidate lines, both in terms of construction cost and market efficiency, are proposed and used as sensitivity indices in the heuristic procedure. The proposed methods are applied and compared with reference to an 18-bus test system. (author)
Heuristics for production scheduling problem with machining and assembly operations
Directory of Open Access Journals (Sweden)
P.M. Khodke
2012-01-01
Full Text Available This work deals with production scheduling problem in an assembly flow shop, having parts machining followed by their subsequent assembly operations. Limited heuristics available on the problem, are based on unrealistic assumption that every part is processed on all machines. In this paper, two heuristics NEH_BB and Disjunctive are proposed to solve assembly flow shop scheduling problem where every part may not be processed on each machine. Exhaustive computational experiments are conducted with 60 trials each. The methods are found to be applicable to large size problems. The objective functions used for comparison are makespan and computational time. Disjunctive method takes very less computational time as compared to NEH_BB and hence claimed to be the better among available approaches for finding solution in assembly flow shop problems.
Social interaction as a heuristic for combinatorial optimization problems
Fontanari, Jose F
2010-01-01
We investigate the performance of a variant of Axelrod's model for dissemination of culture - the Adaptive Culture Heuristic (ACH) - on solving an NP-Complete optimization problem, namely, the classification of binary input patterns of size $F$ by a Boolean Binary Perceptron. In this heuristic, $N$ agents, characterized by binary strings of length $F$ which represent possible solutions to the optimization problem, are fixed at the sites of a square lattice and interact with their nearest neighbors only. The interactions are such that the agents' strings (or cultures) become more similar to the low-cost strings of their neighbors resulting in the dissemination of these strings across the lattice. Eventually the dynamics freezes into a homogeneous absorbing configuration in which all agents exhibit identical solutions to the optimization problem. We find through extensive simulations that the probability of finding the optimal solution is a function of the reduced variable $F/N^{1/4}$ so that the number of agen...
Task Assignment Heuristics for Parallel and Distributed CFD Applications
Lopez-Benitez, Noe; Djomehri, M. Jahed; Biswas, Rupak
2003-01-01
This paper proposes a task graph (TG) model to represent a single discrete step of multi-block overset grid computational fluid dynamics (CFD) applications. The TG model is then used to not only balance the computational workload across the overset grids but also to reduce inter-grid communication costs. We have developed a set of task assignment heuristics based on the constraints inherent in this class of CFD problems. Two basic assignments, the smallest task first (STF) and the largest task first (LTF), are first presented. They are then systematically costs. To predict the performance of the proposed task assignment heuristics, extensive performance evaluations are conducted on a synthetic TG with tasks defined in terms of the number of grid points in predetermined overlapping grids. A TG derived from a realistic problem with eight million grid points is also used as a test case.
Nuclear fuel management optimization using adaptive evolutionary algorithms with heuristics
International Nuclear Information System (INIS)
Adaptive Evolutionary Algorithms in combination with expert knowledge encoded in heuristics have proved to be a robust and powerful optimization method for the design of optimized PWR fuel loading pattern. Simple parallel algorithmic structures coupled with a low amount of communications between computer processor units in use makes it possible for workstation clusters to be employed efficiently. The extension of classic evolution strategies not only by new and alternative methods but also by the inclusion of heuristics with effects on the exchange probabilities of the fuel assemblies at specific core positions leads to the RELOPAT optimization code of the Technical University of Braunschweig. In combination with the new, neutron-physical 3D nodal core simulator PRISM developed by SIEMENS the PRIMO loading pattern optimization system has been designed. Highly promising results in the recalculation of known reload plans for German PWR's new lead to a commercially usable program. (author)
Reactive Search: Machine Learning For Memory-Based Heuristics
Battiti, Roberto; Brunato, Mauro
2005-01-01
Most state-of-the-art heuristics are characterized by a certain number of choices and free parameters, whose appropriate setting is a subject that raises issues of research methodology. In some cases, these parameters are tuned through a feedback loop that includes the user as a crucial learning component: depending on preliminary algorithm tests some parameter values are changed by the user, and different options are tested until acceptable results are obtained. Therefore, the quality of res...
HEURISTICAL FEATURE EXTRACTION FROM LIDAR DATA AND THEIR VISUALIZATION
Ghosh, S.; B. Lohani
2012-01-01
Extraction of landscape features from LiDAR data has been studied widely in the past few years. These feature extraction methodologies have been focussed on certain types of features only, namely the bare earth model, buildings principally containing planar roofs, trees and roads. In this paper, we present a methodology to process LiDAR data through DBSCAN, a density based clustering method, which extracts natural and man-made clusters. We then develop heuristics to process these clu...
New Heuristic Distributed Parallel Algorithms for Searching and Planning
Institute of Scientific and Technical Information of China (English)
无
1995-01-01
This paper proposes new heuristic distributed parallel algorithms for searching and planning,which are based on the concepts of wave concurrent propagations and competitive activation mechanisms.These algorithms are characterized by simplicity and clearness of control strategies for earching,and distinguished abilities in many aspects,such as high speed processing,wide suitability for searching AND/OR implicit graphs,and ease in hardware implementation.
DESIGN OF MULTI-SERVICE SDH NETWORKS: FORMULATION AND HEURISTICS
Institute of Scientific and Technical Information of China (English)
Xi Kang; Ge Ning; Feng Chongxi
2003-01-01
Multi-service SDH networks support both packet- and circuit-switched traffic. Op-timal design of such a network means to guarantee the circuit connections and configure a logicalpacket-switched topology with lowest congestion. This letter first formulates the problem as amixed integer linear programming, which achieves optima] solution but has high computation.Then a heuristic algorithm is proposed to yield near-optimal solution efficiently. Performance ofthe algorithm is verified by an example.
A hierarchy of heuristic-based models of crowd dynamics
Degond, Pierre; Appert-Rolland, Cécile; Moussaid, Mehdi; Pettré, Julien; Theraulaz, Guy
2013-01-01
We derive a hierarchy of kinetic and macroscopic models from a noisy variant of the heuristic behavioral Individual-Based Model of Moussaid et al, PNAS 2011, where the pedestrians are supposed to have constant speeds. This IBM supposes that the pedestrians seek the best compromise between navigation towards their target and collisions avoidance. We first propose a kinetic model for the probability distribution function of the pedestrians. Then, we derive fluid models and propose three differe...
Multiobjective hyper heuristic scheme for system design and optimization
Rafique, Amer Farhan
2012-11-01
As system design is becoming more and more multifaceted, integrated, and complex, the traditional single objective optimization trends of optimal design are becoming less and less efficient and effective. Single objective optimization methods present a unique optimal solution whereas multiobjective methods present pareto front. The foremost intent is to predict a reasonable distributed pareto-optimal solution set independent of the problem instance through multiobjective scheme. Other objective of application of intended approach is to improve the worthiness of outputs of the complex engineering system design process at the conceptual design phase. The process is automated in order to provide the system designer with the leverage of the possibility of studying and analyzing a large multiple of possible solutions in a short time. This article presents Multiobjective Hyper Heuristic Optimization Scheme based on low level meta-heuristics developed for the application in engineering system design. Herein, we present a stochastic function to manage meta-heuristics (low-level) to augment surety of global optimum solution. Generic Algorithm, Simulated Annealing and Swarm Intelligence are used as low-level meta-heuristics in this study. Performance of the proposed scheme is investigated through a comprehensive empirical analysis yielding acceptable results. One of the primary motives for performing multiobjective optimization is that the current engineering systems require simultaneous optimization of conflicting and multiple. Random decision making makes the implementation of this scheme attractive and easy. Injecting feasible solutions significantly alters the search direction and also adds diversity of population resulting in accomplishment of pre-defined goals set in the proposed scheme.
Local search heuristics: Fitness Cloud versus Fitness Landscape
Collard, Philippe; Verel, Sébastien; Clergue, Manuel
2004-01-01
International audience This paper introduces the concept of fitness cloud as an alternative way to visualize and analyze search spaces than given by the geographic notion of fitness landscape. It is argued that the fitness cloud concept overcomes several deficiencies of the landscape representation. Our analysis is based on the correlation between fitness of solutions and fitnesses of nearest solutions according to some neighboring. We focus on the behavior of local search heuristics, such...
Adaptive probabilistic roadmap construction with multi-heuristic local planning
Isto, Pekka
2003-01-01
The motion planning problem means the computation of a collision-free motion for a movable object among obstacles from the given initial placement to the given end placement. Efficient motion planning methods have many applications in many fields, such as robotics, computer aided design, and pharmacology. The problem is known to be PSPACE-hard. Because of the computational complexity, practical applications often use heuristic or incomplete algorithms. Probabilistic roadmap is a probabilistic...
Optimised search heuristic combining valid inequalities and tabu search
Fernandes, Susana; Ramalhinho-Louren??o, Helena
2008-01-01
This paper presents an Optimised Search Heuristic that combines a tabu search method with the verification of violated valid inequalities. The solution delivered by the tabu search is partially destroyed by a randomised greedy procedure, and then the valid inequalities are used to guide the reconstruction of a complete solution. An application of the new method to the Job-Shop Scheduling problem is presented.
A Simple, Heuristic Derivation of our "No Backreaction" Results
Green, Stephen R
2016-01-01
We provide a simple discussion of our results on the backreaction effects of density inhomogeneities in cosmology, without mentioning one-parameter families or weak limits. Emphasis is placed on the manner in which "averaging" is done and the fact that one is solving Einstein's equation. The key assumptions and results that we rigorously derived within our original mathematical framework are thereby explained in a heuristic way.
Fast and frugal food choices: uncovering individual decision heuristics
Scheibehenne, Benjamin; Todd, Peter M.; Miesler, Linda
2007-01-01
Research on food decision making is often based on the assumption that people take many different aspects into account and weight and add them according to their personally assessed importance. Yet there is a growing body of research suggesting that people's decisions can often be better described by simple heuristics—rules of thumb that people use to make choices based on only a few important pieces of information. To test empirically whether a simple heuristic is able to account for individ...
Exploring Middle School Students' Heuristic Thinking about Probability
Mistele, Jean May
2014-01-01
ABSTRACT This descriptive qualitative study examines six eighth-grade students' thinking while solving probability problems. This study aimed to gather direct information on students' problem solving processes informed by the heuristics and biases framework. This study used purposive sampling (Patton, 1990) to identify eighth-grade students who were knowledgeable about probability and had reached the formal operational stage of cognitive development. These criterion were necessary to redu...
Compatibility Heuristics for Modern Mobile Games : Mobile games, Game testing.
Gitau, Paul
2010-01-01
The purpose of this study was to demonstrate ways to perform a compatibility test for a modern mobile game. These tests were performed by running a tastephone midlet to the mobile handset to determine its characteristics and the equivalent implementation. Compatibility check test was also aimed to help a specified mobile game application to run successfully into a mobile phone. Compatibility heuristics for modern mobile games was also designed to study the factors that shoul...
Confucius VS Socrates in “heuristic teaching theory”
Institute of Scientific and Technical Information of China (English)
白福梅; 李绍青
2014-01-01
<正>I.Introduction The"heuristic teaching theory"is world-famous;it is one of Confucius’greatest inventions.But many people think that it was invented by Socrates,an ancient Greek philosopher,which is no surprising to Western scholars who even can’t speak without mentioning Socrates.What is worse,in China there are many
Investigation of Search Heuristics in Manufacturing Optimization and Decision Support
Le, Nguyen Anh Tuan
2009-01-01
In this high level of global competition in manufacturing industry, manufacturing firms especially in developing countries have been facing many difficulties to cope with rapidly changes of customer requirements in terms of quality and speed. One of many reasons for these firms to be suffered at the moment is their lack of advanced manufacturing technology. In this dissertation, an investigation will be carried out on search heuristics capability in finding good solution for manufacturing ...
Exposure optimization in indoor wireless networks by heuristic network planning
Plets, David; Joseph, Wout; Vanhecke, Kris; Martens, Luc
2013-01-01
Due to the increased use of indoor wireless networks and the concern about human exposure to radio-frequency sources, exposure awareness has increased during recent years. However, current-day network planners rarely take into account electric-field strengths when designing networks. Therefore, in this paper, a heuristic indoor network planner for exposure calculation and optimization of wireless networks is developed, jointly optimizing coverage and exposure, for homogeneous or heterogeneous...
Detecting Pipe Bursts Using Heuristic and CUSUM Methods
Bakker, M.; Jung, D.; Vreeburg, J.; Van der Roer, M.; Lansey, K.; Rierveld, L.
2014-01-01
Pipe bursts in a drinking water distribution system lead to water losses, interruption of supply, and damage to streets and houses due to the uncontrolled water flow. To minimize the negative consequences of pipe bursts, an early detection is necessary. This paper describes a heuristic burst detection method, which continuously compares forecasted and measured values of the water demand. The forecasts of the water demand were generated by an adaptive water demand forecasting model. To test th...
Hybrid heuristic for multi-carrier transportation plans
Landa-Silva, Dario; Wang, Yijun; Donovan, Paul; Kendall, Graham
2011-01-01
This paper describes a hybrid heuristic approach to construct transportation plans for a singlecustomer multi-carrier scenario that arises at 3T Logistics Ltd, a UK company that provides outsourced transportation planning and management services. The problem consists on planning the delivery, using a set of carrier companies, of a set of shipments from a warehouse to different consignees across the UK. The problem tackled resembles a vehicle routing problem with time windows but there are sev...
Bio-Inspired Meta-Heuristics for Emergency Transportation Problems
Min-Xia Zhang; Bei Zhang; Yu-Jun Zheng
2014-01-01
Emergency transportation plays a vital role in the success of disaster rescue and relief operations, but its planning and scheduling often involve complex objectives and search spaces. In this paper, we conduct a survey of recent advances in bio-inspired meta-heuristics, including genetic algorithms (GA), particle swarm optimization (PSO), ant colony optimization (ACO), etc., for solving emergency transportation problems. We then propose a new hybrid biogeography-based optimization (BBO) algo...
Discovery of IPv6 router interface addresses via heuristic methods
Gray, Matthew D.
2015-01-01
With the assignment of the last available blocks of public IPv4 addresses from Internet Assigned Numbers Authority, there is continued pressure for widespread IPv6 adoption. Because the IPv6 address space is orders of magnitude larger than the IPv4 address space, researchers need new methods and techniques to accurately measure and characterize growth in IPv6. This thesis focuses on IPv6 router infrastructure and examines the possibility of using heuristic methods in order to discover IPv6 ro...
Restricted Dynamic Programming Heuristic for Precedence Constrained Bottleneck Generalized TSP
Salii, Y.
2015-01-01
We develop a restricted dynamical programming heuristic for a complicated traveling salesman problem: a) cities are grouped into clusters, resp. Generalized TSP; b) precedence constraints are imposed on the order of visiting the clusters, resp. Precedence Constrained TSP; c) the costs of moving to the next cluster and doing the required job inside one are aggregated in a minimax manner, resp. Bottleneck TSP; d) all the costs may depend on the sequence of previously visited clusters, resp. Seq...
A Greedy Heuristic for Single Machine Sequencing with Precedence Constraints
Howard J. Weiss
1981-01-01
We present a greedy heuristic for the n job/1 machine scheduling problem with precedence constraints. This method is useful whenever the manager's optimization criteria is the sum of weighted or unweighted completion times, the sum of weighted or unweighted flow times, (with or without release dates), the sum of weighted or unweighted working times, the sum of weighted or unweighted lateness, average completion time, average flow time, average waiting time or average lateness. The greedy heur...
Visualization for Hyper-Heuristics: Back-End Processing
Energy Technology Data Exchange (ETDEWEB)
Simon, Luke [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-03-01
Modern society is faced with increasingly complex problems, many of which can be formulated as generate-and-test optimization problems. Yet, general-purpose optimization algorithms may sometimes require too much computational time. In these instances, hyperheuristics may be used. Hyper-heuristics automate the design of algorithms to create a custom algorithm for a particular scenario, finding the solution significantly faster than its predecessor. However, it may be difficult to understand exactly how a design was derived and why it should be trusted. This project aims to address these issues by creating an easy-to-use graphical user interface (GUI) for hyper-heuristics and an easy-to-understand scientific visualization for the produced solutions. To support the development of this GUI, my portion of the research involved developing algorithms that would allow for parsing of the data produced by the hyper-heuristics. This data would then be sent to the front-end, where it would be displayed to the end user.
Heuristic Synthesis of Reversible Logic – A Comparative Study
Directory of Open Access Journals (Sweden)
Chua Shin Cheng
2014-01-01
Full Text Available Reversible logic circuits have been historically motivated by theoretical research in low-power, and recently attracted interest as components of the quantum algorithm, optical computing and nanotechnology. However due to the intrinsic property of reversible logic, traditional irreversible logic design and synthesis methods cannot be carried out. Thus a new set of algorithms are developed correctly to synthesize reversible logic circuit. This paper presents a comprehensive literature review with comparative study on heuristic based reversible logic synthesis. It reviews a range of heuristic based reversible logic synthesis techniques reported by researchers (BDD-based, cycle-based, search-based, non-search-based, rule-based, transformation-based, and ESOP-based. All techniques are described in detail and summarized in a table based on their features, limitation, library used and their consideration metric. Benchmark comparison of gate count and quantum cost are analysed for each synthesis technique. Comparing the synthesis algorithm outputs over the years, it can be observed that different approach has been used for the synthesis of reversible circuit. However, the improvements are not significant. Quantum cost and gate count has improved over the years, but arguments and debates are still on certain issues such as the issue of garbage outputs that remain the same. This paper provides the information of all heuristic based synthesis of reversible logic method proposed over the years. All techniques are explained in detail and thus informative for new reversible logic researchers and bridging the knowledge gap in this area.
Tuning Parameters in Heuristics by Using Design of Experiments Methods
Arin, Arif; Rabadi, Ghaith; Unal, Resit
2010-01-01
With the growing complexity of today's large scale problems, it has become more difficult to find optimal solutions by using exact mathematical methods. The need to find near-optimal solutions in an acceptable time frame requires heuristic approaches. In many cases, however, most heuristics have several parameters that need to be "tuned" before they can reach good results. The problem then turns into "finding best parameter setting" for the heuristics to solve the problems efficiently and timely. One-Factor-At-a-Time (OFAT) approach for parameter tuning neglects the interactions between parameters. Design of Experiments (DOE) tools can be instead employed to tune the parameters more effectively. In this paper, we seek the best parameter setting for a Genetic Algorithm (GA) to solve the single machine total weighted tardiness problem in which n jobs must be scheduled on a single machine without preemption, and the objective is to minimize the total weighted tardiness. Benchmark instances for the problem are available in the literature. To fine tune the GA parameters in the most efficient way, we compare multiple DOE models including 2-level (2k ) full factorial design, orthogonal array design, central composite design, D-optimal design and signal-to-noise (SIN) ratios. In each DOE method, a mathematical model is created using regression analysis, and solved to obtain the best parameter setting. After verification runs using the tuned parameter setting, the preliminary results for optimal solutions of multiple instances were found efficiently.
Recipient design in human communication: Simple heuristics or perspective taking?
Directory of Open Access Journals (Sweden)
Mark eBlokpoel
2012-09-01
Full Text Available Humans have a remarkable capacity for tuning their communicative behaviors to different addressees, a phenomenon also known as recipient design. It remains unclear how this tuning of communicative behavior is implemented during live human interactions. Classical theories of communication postulate that recipient design involves perspective taking, i.e., the communicator selects her behavior based on her hypotheses about beliefs and knowledge of the recipient. More recently, researchers have argued that perspective taking is computationally too costly to be a plausible mechanism in everyday human communication. These researchers propose that computationally simple mechanisms, or heuristics, are exploited to perform recipient design. Such heuristics may be able to adapt communicative behavior to an addressee with no consideration for the addressee's beliefs and knowledge. To test whether the simpler of the two mechanisms is sufficient for explaining the `how' of recipient design we studied communicators' behaviors in the context of a non-verbal communicative task (the Tacit Communication Game, TCG. We found that the specificity of the observed trial-by-trial adjustments made by communicators is parsimoniously explained by perspective taking, but not by simple heuristics. This finding is important as it suggests that humans do have a computationally efficient way of taking beliefs and knowledge of a recipient into account.
Aldana Jague, Emilien; Goulding, Keith; Heckrath, Goswin; Macdonald, Andy; Poulton, Paul; Stevens, Antoine; Van Wesemael, Bas; Van Oost, Kristof
2014-05-01
patterns of SOC at a very high spatial resolution (changes in experimental plots. This study used multi-band images with wavelengths between 450-1000nm taken at low altitude and at the landscape scale with a Tetracam Mini-MCA6. Images were taken of plots on section 9 on Broadbalk (continuous wheat) in November 2013 using a UAV-platform (Octocopter) at an altitude of 120m. The different images obtained were corrected for vignetting, noise and geometric deformation then stitched and georeferenced; the radiance was converted for reflectance with white calibration panels. Also, the vegetation effect (a cover mean of 10%) was removed by linear spectral unmixing. Finally, the spectra was calibrated and validated with SOC (0-5cm) measurements from 57 soil samples (37 calibration samples and 20 for the validation) taken along transect. The resulting map of SOC contents has a resolution of 10cm and an associated error of about the same magnitude as that for routine laboratory analyses (i.e. 0.2%). The map shows clear differences between plots relating to the different long-term fertilizer and organic manure inputs.
Sabar, Nasar; Ayob, Masri; Kendall, Graham; Qu, Rong
2015-01-01
Hyper-heuristics are search methodologies that aim to provide high-quality solutions across a wide variety of problem domains, rather than developing tailor-made methodologies for each problem instance/domain. A traditional hyper-heuristic framework has two levels, namely, the high level strategy (heuristic selection mechanism and the acceptance criterion) and low level heuristics (a set of problem specific heuristics). Due to the different landscape structures of different problem instances,...
Mathematical models and heuristic solutions for container positioning problems in port terminals
DEFF Research Database (Denmark)
Kallehauge, Louise Sibbesen
2008-01-01
by constructing mathematical programming formulations of the problem and developing an efficient heuristic algorithm for its solution. The thesis consists of an introduction, two main chapters concerning new mathematical formulations and a new heuristic for the CPP, technical issues, computational......, are discussed. The second part presents an efficient solution algorithm for the CPP. Based on a number of new concepts, an event-based construction heuristic is developed and its ability to solve real-life problem instances is established. The backbone of the algorithm is a list of events...... algorithm which is also robust to changes in parameters and input data. Two improvement routines are presented, one imbedded in the basic heuristic and the other constituting a repair algorithm with the purpose of improving an initial heuristic solution. The heuristic algorithm performance and a wide range...
Modified strip packing heuristics for the rectangular variable-sized bin packing problem
Directory of Open Access Journals (Sweden)
FG Ortmann
2010-06-01
Full Text Available Two packing problems are considered in this paper, namely the well-known strip packing problem (SPP and the variable-sized bin packing problem (VSBPP. A total of 252 strip packing heuristics (and variations thereof from the literature, as well as novel heuristics proposed by the authors, are compared statistically by means of 1170 SPP benchmark instances in order to identify the best heuristics in various classes. A combination of new heuristics with a new sorting method yields the best results. These heuristics are combined with a previous heuristic for the VSBPP by the authors to find good feasible solutions to 1357 VSBPP benchmark instances. This is the largest statistical comparison of algorithms for the SPP and the VSBPP to the best knowledge of the authors.
Directory of Open Access Journals (Sweden)
Wahyudin P. Syam
2012-01-01
Full Text Available This study improved and comprehensively compared three Meta heuristics to minimize make-span (Cmax for Flexible Flow-Shop (FFC Scheduling Problem. This problem is known to be NP-Hard. This study proposed an improvement for three Meta heuristic searches which are Genetic Algorithm (GA, Simulated Annealing (SA, and Tabu Search (TS. SA and TS are known as deterministic improvement heuristic search. Meanwhile, GA is known as stochastic improvement heuristic search. In addition, in this paper, the three Meta heuristic searches were compared to the GA developed by Kahraman et al. by using a computational analysis. The results for the experiments conducted show that the improved Meta heuristics are better and the TS is the most effective and efficient algorithm to solve FFC scheduling problems.
An O(N log N) Expected Time Merge Heuristic for the Planar ETSP
Chadha, Ritu; Allison, Donald C. S.
1988-01-01
We discuss a new heuristic for solving the Euclidean Traveling Salesman Problem (ETSP). This heuristic is a convex hull-based method and makes use of the Delaunay triangulation of the set of cities to compute a tour for the given set of cities. We conjecture that the expected running time for this algorithm is O(N log N), implying that a new and faster ETSP heuristic is now available.
The planning of order picking in a warehouse by heuristic algorithms
URŠIČ, JAKOB
2014-01-01
Planning of order picking is essential process in every warehouse. In this thesis, we developed a simple warehouse simulator, which allows us to do various searches on path finding for a certain amount of items for one or more robots, using the A* algorithm. Heuristic guidance of search is mainly based on heuristic evaluation. We have implemented five different heuristic estimates, which we tested experimentally on examples with different warehouse configurations and with different numbers of...
Development of New Heuristics for the Euclidean Traveling SalesmanProblem
Tunnell, Thurman W.; Lenwood S. Heath
1989-01-01
Many heuristics have been developed to approximate optimal tours for the Euclidean Traveling Salesman Problem (ETSP). While much progress has been made, there are few quick heuristics which consistently produce tours within 4 percent of the optimal solution. This project examines a few of the well known heuristics and introduces two improvements, Maxdiff and Checks. Most algorithms, during tour constrution, add a city to the subtour because the city best satisfies some criterion. Maxdiff,...
A heuristic for the minimization of open stacks problem
Directory of Open Access Journals (Sweden)
Fernando Masanori Ashikaga
2009-08-01
Full Text Available It is suggested here a fast and easy to implement heuristic for the minimization of open stacks problem (MOSP. The problem is modeled as a traversing problem in a graph (Gmosp with a special structure (Yanasse, 1997b. It was observed in Ashikaga (2001 that, in the mean experimental case, Gmosp has large cliques and high edge density. This information was used to implement a heuristic based on the extension-rotation algorithm of Pósa (1976 for approximation of Hamiltonian Circuits. Additionally, an initial path for Pósa's algorithm is derived from the vertices of an ideally maximum clique in order to accelerate the process. Extensive computational tests show that the resulting simple approach dominates in time and mean error the fast actually know Yuen (1991 and 1995 heuristic to the problem.Sugerimos uma heurística rápida e de implementação simples para o problema de minimização de pilhas abertas (MOSP. O problema é modelado como um problema de percorrimento de arcos no grafo (Gmosp associado (Yanasse, 1997b. Foi observado em Ashikaga (2001 que o grafo Gmosp possui grandes cliques e uma alta densidade de arestas. Esta informação foi utilizada para implementar uma heurística baseada no algoritmo Extensão-Rotação de Pósa (1976 para aproximação de Circuitos Hamiltonianos. O caminho inicial para o algoritmo de Pósa é obtido a partir dos vértices de uma aproximação do maior clique do grafo para acelerar o processo. Testes computacionais extensivos mostram que a abordagem domina tanto em tempo quanto em erro médio a mais rápida heurística conhecida de Yuen (1991 e 1995.
International Nuclear Information System (INIS)
The goal of this research project was to examine factors, on the basis of regulatory focus theory and the heuristics and biases approach, that influence decision-making processes of experts at nuclear power plants. Findings show that this group applies anchoring (heuristic) when evaluating conjunctive and disjunctive events and that they maintain a constant regulatory focus characteristic. No influence of the experts' characteristic regulatory focus on cognitive heuristics could be established. Theoretical and practical consequences on decision-making behavior of experts are presented. Finally, a method for measuring the use of heuristics especially in the nuclear industry is discussed.
Heuristical Feature Extraction from LIDAR Data and Their Visualization
Ghosh, S.; Lohani, B.
2011-09-01
Extraction of landscape features from LiDAR data has been studied widely in the past few years. These feature extraction methodologies have been focussed on certain types of features only, namely the bare earth model, buildings principally containing planar roofs, trees and roads. In this paper, we present a methodology to process LiDAR data through DBSCAN, a density based clustering method, which extracts natural and man-made clusters. We then develop heuristics to process these clusters and simplify them to be sent to a visualization engine.
Heuristic algorithm for off-lattice protein folding problem
Institute of Scientific and Technical Information of China (English)
CHEN Mao; HUANG Wen-qi
2006-01-01
Enlightened by the law of interactions among objects in the physical world, we propose a heuristic algorithm for solving the three-dimensional (3D) off-lattice protein folding problem. Based on a physical model, the problem is converted from a nonlinear constraint-satisfied problem to an unconstrained optimization problem which can be solved by the well-known gradient method. To improve the efficiency of our algorithm, a strategy was introduced to generate initial configuration. Computational results showed that this algorithm could find states with lower energy than previously proposed ground states obtained by nPERM algorithm for all chains with length ranging from 13 to 55.
Obesity Heuristic, New Way on Artificial Immune Systems
Directory of Open Access Journals (Sweden)
M. A. El-Dosuky
2012-12-01
Full Text Available There is a need for new metaphors from immunology to flourish the application areas of ArtificialImmune Systems. A metaheuristic called Obesity Heuristic derived from advances in obesity treatment isproposed. The main forces of the algorithm are the generation omega-6 and omega-3 fatty acids. Thealgorithm works with Just-In-Time philosophy; by starting only when desired. A case study of datacleaning is provided. With experiments conducted on standard tables, results show that Obesity Heuristicoutperforms other algorithms, with 100% recall. This is a great improvement over other algorithms
A Heuristic Algorithm on QoS Routing
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
This paper focuses on solving the delay-constrained least-cost ro uting problem, and propose a simple,distributed heuristic solution, called dist ributed recursive delay constrained leastcost (DR-DCLC) unicast routing algo rithm. DR-DCLC only requires local information to find the near optimal solut io n.The correctness of DR-DCLC is proued by showing that it is always capable of constr ucting a loop-free-delay-constrained path wthin finite time, if such a path e xi sts. Simulation is also used to compare DR-DCLC to the optimal DCLC algorithm a nd other algorithms.
Resource Management in Satellite Communication Systems: Heuristic Schemes and Algorithms
Directory of Open Access Journals (Sweden)
Shahaf I. Wayer
2012-01-01
Full Text Available The high cost of frequency bandwidth in satellite communication emphasizes the need for good algorithms to cope with the resource allocation problem. In systems using DVB-S2 links, the optimization of resource allocation may be related to the classical multi-knapsack problem. Resource management should be carried out according to the requests of subscribers, their priority levels, and assured bandwidths. A satisfaction measure is defined to estimate the allocation processes. Heuristic algorithms together with some innovative scaling schemes are presented and compared using Monte Carlo simulation based on a traffic model introduced here.
A New Approach to Tuning Heuristic Parameters of Genetic Algorithms
Czech Academy of Sciences Publication Activity Database
Holeňa, Martin
2006-01-01
Roč. 3, č. 3 (2006), s. 562-569. ISSN 1790-0832. [AIKED'06. WSEAS International Conference on Artificial Intelligence, Knowledge Engineering and Data Bases. Madrid, 15.02.2006-17.02.2006] R&D Projects: GA ČR(CZ) GA201/05/0325; GA ČR(CZ) GA201/05/0557 Institutional research plan: CEZ:AV0Z10300504 Keywords : evolutionary optimization * genetic algorithms * heuristic parameters * parameter tuning * artificial neural network s * convergence speed * population diversity Subject RIV: IN - Informatics, Computer Science
Using Neural Networks to Tune Heuristic Parameters in Evolutionary Optimization
Czech Academy of Sciences Publication Activity Database
Holeňa, Martin
Athens : WSEAS Press, 2006 - (Espi, P.; Giron-Sierra, J.; Drigas, A.), s. 1-6 ISBN 960-8457-41-6. [AIKED'06. WSEAS International Conference on Artificial Intelligence, Knowledge Engineering and Data Bases. Madrid (ES), 15.02.2006-17.02.2006] R&D Projects: GA ČR(CZ) GA201/05/0325 Institutional research plan: CEZ:AV0Z10300504 Keywords : evolutionary optimization * genetic algorithms * heuristic parameters * parameter tuning * artificial neural network s * convergence speed * population diversity Subject RIV: IN - Informatics, Computer Science
The Erosion of Well-being: a Heuristic Mathematical Model
Thron, Chris
2015-01-01
This paper presents a heuristic mathematical model of the changes over time in the statistical distribution of well-being of individuals in a society. The model predicts that when individuals overvalue the more overtly conspicuous aspects of well-being in their lifestyle choices, then under certain conditions the average well-being of the overall population may experience continuous decline. We investigate the influence of various effects, including the incidence of personal misfortune, heterogeneity in the population, and economic and/or technological progress.
Mixed Integer Programming and Heuristic Scheduling for Space Communication Networks
Lee, Charles H.; Cheung, Kar-Ming
2012-01-01
In this paper, we propose to solve the constrained optimization problem in two phases. The first phase uses heuristic methods such as the ant colony method, particle swarming optimization, and genetic algorithm to seek a near optimal solution among a list of feasible initial populations. The final optimal solution can be found by using the solution of the first phase as the initial condition to the SQP algorithm. We demonstrate the above problem formulation and optimization schemes with a large-scale network that includes the DSN ground stations and a number of spacecraft of deep space missions.
An Analysis of a Heuristic Procedure to Evaluate Tail (independence
Directory of Open Access Journals (Sweden)
Marta Ferreira
2014-01-01
Full Text Available Measuring tail dependence is an important issue in many applied sciences in order to quantify the risk of simultaneous extreme events. A usual measure is given by the tail dependence coefficient. The characteristics of events behave quite differently as these become more extreme, whereas we are in the class of asymptotic dependence or in the class of asymptotic independence. The literature has emphasized the asymptotic dependent class but wrongly infers that tail dependence will result in the overestimation of extreme value dependence and consequently of the risk. In this paper we analyze this issue through simulation based on a heuristic procedure.
Improved Heuristics for Multi-Stage Requirements Planning Systems
Joseph D. Blackburn; Robert A. Millen
1982-01-01
Most of the recent studies of heuristic lot-sizing techniques for multi-stage material requirements planning systems have investigated the problem in the context of a single stage. In this paper, the multi-stage problem is first modeled analytically to indicate the potential errors inherent in the commonly proposed single-pass, stage-by-stage approaches (e.g., Wagner-Whitin). Then, based on this analysis, several simple cost modifications are suggested to improve the global optimality of thes...
Heuristic-based scheduling algorithm for high level synthesis
Mohamed, Gulam; Tan, Han-Ngee; Chng, Chew-Lye
1992-01-01
A new scheduling algorithm is proposed which uses a combination of a resource utilization chart, a heuristic algorithm to estimate the minimum number of hardware units based on operator mobilities, and a list-scheduling technique to achieve fast and near optimal schedules. The schedule time of this algorithm is almost independent of the length of mobilities of operators as can be seen from the benchmark example (fifth order digital elliptical wave filter) presented when the cycle time was increased from 17 to 18 and then to 21 cycles. It is implemented in C on a SUN3/60 workstation.
Diagnostic Problem Solving Using First Principles and Heuristics
Institute of Scientific and Technical Information of China (English)
沈一栋; 童Fu; 等
1996-01-01
is paper proposes an approach to diagnostic reasoning with the following distinct features:(1)A diagnostic system is formulated in FOL with equality, particularly in the form of program clauses;(2)The abnormality of system components is determined in terms of either experiential knowledge of domain experts of behavioral description of components;(3)Heuristics is fully used not only to assist in judging the abnormalits of system components,but also to guide the diagnosis;(4)A unique diagnosis will be computed for a given observation,provided that certain essential I-O information is supplemented when demanded.
Some heuristic procedures for analyzing random vibration of nonlinear oscillators.
Crandall, S. H.
1971-01-01
The stationary response of a lightly damped nonlinear oscillator subjected to wideband random excitation can be examined as an example of thermal equilibrium. It may be assumed that the response consists of a series of free-vibration cycles with small random fluctuations in phase and amplitude. Certain statistical properties of the response can be estimated by averaging corresponding properties of the free vibration with respect to cycle amplitude distributions. Such heuristic procedures for determining the expected frequency and the autocorrelation function of the stationary response are outlined. Some additional results concerning first-passage problems for nonlinear oscillators are included.
A heuristic tool for exposure reduction in indoor wireless networks
Plets, David; Joseph, Wout; Vanhecke, Kris; Martens, Luc
2012-01-01
A heuristic indoor network planner for exposure calculation and optimization in wireless networks is developed. The model for the electric-field strength in the vicinity of an access point is presented and the WiFi networks are optimized in order not to exceed a maximal electric-field strength at a certain separation from the access points. The influence of the maximally allowed field strength and the assumed minimal separation between the access point and the human is assessed for a typical ...
Concentrated Hitting Times of Randomized Search Heuristics with Variable Drift
DEFF Research Database (Denmark)
Lehre, Per Kristian; Witt, Carsten
2014-01-01
Drift analysis is one of the state-of-the-art techniques for the runtime analysis of randomized search heuristics (RSHs) such as evolutionary algorithms (EAs), simulated annealing etc. The vast majority of existing drift theorems yield bounds on the expected value of the hitting time for a target...... precise sharp-concentration results on the running time of a simple EA on standard benchmark problems, including the class of general linear functions. The usefulness of the theorem outside the theory of RSHs is demonstrated by deriving tail bounds on the number of cycles in random permutations. All...
Heuristic and computer calculations for the magnitude of metric spaces
Willerton, Simon
2009-01-01
The notion of the magnitude of a compact metric space was considered in arXiv:0908.1582 with Tom Leinster, where the magnitude was calculated for line segments, circles and Cantor sets. In this paper more evidence is presented for a conjectured relationship with a geometric measure theoretic valuation. Firstly, a heuristic is given for deriving this valuation by considering 'large' subspaces of Euclidean space and, secondly, numerical approximations to the magnitude are calculated for squares, disks, cubes, annuli, tori and Sierpinski gaskets. The valuation is seen to be very close to the magnitude for the convex spaces considered and is seen to be 'asymptotically' close for some other spaces.
March dl: Adding Adaptive Heuristics and a New Branching Strategy
Marijn J.H. Heule; Hans van Maaren
2006-01-01
We introduce the march dl satisfiability (SAT) solver, a successor of march eq. The latter was awarded state-of-the-art in two categories during the Sat 2004 competition. The focus lies on presenting those features that are new in march dl. Besides a description, each of these features is illustrated with some experimental results. By extending the pre-processor, using adaptive heuristics, and by using a new branching strategy, march dl is able to solve nearly all benchmarks faster than its ...
SMMH - A Parallel Heuristic for Combinatorial Optimization Problems
International Nuclear Information System (INIS)
The process of finding one or more optimal solutions for answering combinatorial optimization problems bases itself on the use of algorithms instances. Those instances usually have to explore a very large search spaces. Heuristics search focusing on the use of High-Order Hopfield neural networks is a largely deployed technique for very large search space. It can be established a very powerful analogy towards the dynamics evolution of a physics spin-glass system while minimizing its own energy and the energy function of the network. This paper presents a new approach for solving combinatorial optimization problems through parallel simulations, based on a High-Order Hopfield neural network using MPI specification
SMMH--A Parallel Heuristic for Combinatorial Optimization Problems
International Nuclear Information System (INIS)
The process of finding one or more optimal solutions for answering combinatorial optimization problems bases itself on the use of algorithms instances. Those instances usually have to explore a very large search spaces. Heuristics search focusing on the use of High-Order Hopfield neural networks is a largely deployed technique for very large search space. It can be established a very powerful analogy towards the dynamics evolution of a physics spin-glass system while minimizing its own energy and the energy function of the network. This paper presents a new approach for solving combinatorial optimization problems through parallel simulations, based on a High-Order Hopfield neural network using MPI specification
Heuristic Ant Colony Optimization with Applications in Communication Systems
Directory of Open Access Journals (Sweden)
Mateus de P. Marques
2014-05-01
Full Text Available This work explores the heuristic optimization algorithm based on ant colonies (ACO, deployed on complex optimization problems, aiming to achieve an iterative and feasible method which is able to solve NP and NP-Hard problems related to wireless networks. Furthermore, the convergence and performance of the Ant Colony Optimization algorithm for continuous domains are addressed through dozens of benchmark functions, which in turn, differ on each other regarding the number of dimensions and the difficulty w.r.t. the optimization (number of local optima. Finally, the applicability of the ACO is depicted in an minimum power control problem for CDMA networks.
New Heuristics for Interfacing Human Motor System using Brain Waves
Directory of Open Access Journals (Sweden)
Mohammed El-Dosuky
2012-09-01
Full Text Available There are many new forms of interfacing human users to machines. We persevere here electric-mechanical form of interaction between human and machine. The emergence of brain-computer interface allows mind-to-movement systems. The story of the Pied Piper inspired us to devise some new heuristics for interfacing human motor system using brain waves, by combining head helmet and LumbarMotionMonitor. For the simulation we use java GridGain. Brain responses of classified subjects during training indicates that Probe can be the best stimulus to rely on in distinguishing between knowledgeable and not knowledgeable
New Heuristics for Interfacing Human Motor System using Brain Waves
Mohammed El-Dosuky; Ahmed El-Bassiouny; Taher Hamza; Magdy Rashad
2012-01-01
There are many new forms of interfacing human users to machines. We persevere here electric-mechanical form of interaction between human and machine. The emergence of brain-computer interface allows mind-to-movement systems. The story of the Pied Piper inspired us to devise some new heuristics for interfacing human motor system using brain waves, by combining head helmet and LumbarMotionMonitor. For the simulation we use java GridGain. Brain responses of classified subjects during training in...
March dl: Adding Adaptive Heuristics and a New Branching Strategy
Directory of Open Access Journals (Sweden)
Marijn J.H. Heule
2006-03-01
Full Text Available We introduce the march dl satisfiability (SAT solver, a successor of march eq. The latter was awarded state-of-the-art in two categories during the Sat 2004 competition. The focus lies on presenting those features that are new in march dl. Besides a description, each of these features is illustrated with some experimental results. By extending the pre-processor, using adaptive heuristics, and by using a new branching strategy, march dl is able to solve nearly all benchmarks faster than its predecessor. Moreover, various instances which were beyond the reach of march eq, can now be solved - relatively easily - due to these new features.
A heuristic for efficient data distribution management in distributed simulation
Gupta, Pankaj; Guha, Ratan K.
2005-05-01
In this paper, we propose an algorithm for reducing the complexity of region matching and efficient multicasting in data distribution management component of High Level Architecture (HLA) Run Time Infrastructure (RTI). The current data distribution management (DDM) techniques rely on computing the intersection between the subscription and update regions. When a subscription region and an update region of different federates overlap, RTI establishes communication between the publisher and the subscriber. It subsequently routes the updates from the publisher to the subscriber. The proposed algorithm computes the update/subscription regions matching for dynamic allocation of multicast group. It provides new multicast routines that exploit the connectivity of federation by communicating updates regarding interactions and routes information only to those federates that require them. The region-matching problem in DDM reduces to clique-covering problem using the connections graph abstraction where the federations represent the vertices and the update/subscribe relations represent the edges. We develop an abstract model based on connection graph for data distribution management. Using this abstract model, we propose a heuristic for solving the region-matching problem of DDM. We also provide complexity analysis of the proposed heuristics.
Heuristic for Task-Worker Assignment with Varying Learning Slopes
Directory of Open Access Journals (Sweden)
Wipawee Tharmmaphornphilas
2010-04-01
Full Text Available Fashion industry has variety products, so the multi-skilled workers are required to improve flexibility in production and assignment. Generally the supervisor will assign task to the workers based on skill and skill levels of worker. Since in fashion industry new product styles are launched more frequently and the order size tends to be smaller, the workers always learn when the raw material and the production process changes. Consequently they require less time to produce the succeeding units of a task based on their learning ability. Since the workers have both experience and inexperience workers, so each worker has different skill level and learning ability. Consequently, the assignment which assumed constant skill level is not proper to use. This paper proposes a task-worker assignment considering worker skill levels and learning abilities. Processing time of each worker changes along production period due to a worker learning ability. We focus on a task-worker assignment in a fashion industry where tasks are ordered in series; the number of tasks is greater than the number of workers. Therefore, workers can perform multiple assignments followed the precedence restriction as an assembly line balancing problem. The problem is formulated in an integer linear programming model with objective to minimize makespan. A heuristic is proposed to determine the lower bound (LB and the upper bound (UB of the problem and the best assignment is determined. The performance of the heuristic method is tested by comparing quality of solution and computational time to optimal solutions.
New tests of cumulative prospect theory and the priority heuristic
Directory of Open Access Journals (Sweden)
Michael H. Birnbaum
2008-04-01
Full Text Available Previous tests of cumulative prospect theory (CPT and of the priority heuristic (PH found evidence contradicting these two models of risky decision making. However, those tests were criticized because they had characteristics that might ``trigger'' use of other heuristics. This paper presents new tests that avoid those characteristics. Expected values of the gambles are nearly equal in each choice. In addition, if a person followed expected value (EV, expected utility (EU, CPT, or PH in these tests, she would shift her preferences in the same direction as shifts in EV or EU. In contrast, the transfer of attention exchange model (TAX and a similarity model predict that people will reverse preferences in the opposite direction. Results contradict the PH, even when PH is modified to include a preliminary similarity evaluation using the PH parameters. New tests of probability-consequence interaction were also conducted. Strong interactions were observed, contrary to PH. These results add to the growing bodies of evidence showing that neither CPT nor PH is an accurate description of risky decision making.
Fuel lattice design using heuristics and new strategies
Energy Technology Data Exchange (ETDEWEB)
Ortiz S, J. J.; Castillo M, J. A.; Torres V, M.; Perusquia del Cueto, R. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Pelta, D. A. [ETS Ingenieria Informatica y Telecomunicaciones, Universidad de Granada, Daniel Saucedo Aranda s/n, 18071 Granada (Spain); Campos S, Y., E-mail: juanjose.ortiz@inin.gob.m [IPN, Escuela Superior de Fisica y Matematicas, Unidad Profesional Adolfo Lopez Mateos, Edif. 9, 07738 Mexico D. F. (Mexico)
2010-10-15
This work show some results of the fuel lattice design in BWRs when some allocation pin rod rules are not taking into account. Heuristics techniques like Path Re linking and Greedy to design fuel lattices were used. The scope of this work is to search about how do classical rules in design fuel lattices affect the heuristics techniques results and the fuel lattice quality. The fuel lattices quality is measured by Power Peaking Factor and Infinite Multiplication Factor at the beginning of the fuel lattice life. CASMO-4 code to calculate these parameters was used. The analyzed rules are the following: pin rods with lowest uranium enrichment are only allocated in the fuel lattice corner, and pin rods with gadolinium cannot allocated in the fuel lattice edge. Fuel lattices with and without gadolinium in the main diagonal were studied. Some fuel lattices were simulated in an equilibrium cycle fuel reload, using Simulate-3 to verify their performance. So, the effective multiplication factor and thermal limits can be verified. The obtained results show a good performance in some fuel lattices designed, even thought, the knowing rules were not implemented. A fuel lattice performance and fuel lattice design characteristics analysis was made. To the realized tests, a dell workstation was used, under Li nux platform. (Author)
Fuel lattice design using heuristics and new strategies
International Nuclear Information System (INIS)
This work show some results of the fuel lattice design in BWRs when some allocation pin rod rules are not taking into account. Heuristics techniques like Path Re linking and Greedy to design fuel lattices were used. The scope of this work is to search about how do classical rules in design fuel lattices affect the heuristics techniques results and the fuel lattice quality. The fuel lattices quality is measured by Power Peaking Factor and Infinite Multiplication Factor at the beginning of the fuel lattice life. CASMO-4 code to calculate these parameters was used. The analyzed rules are the following: pin rods with lowest uranium enrichment are only allocated in the fuel lattice corner, and pin rods with gadolinium cannot allocated in the fuel lattice edge. Fuel lattices with and without gadolinium in the main diagonal were studied. Some fuel lattices were simulated in an equilibrium cycle fuel reload, using Simulate-3 to verify their performance. So, the effective multiplication factor and thermal limits can be verified. The obtained results show a good performance in some fuel lattices designed, even thought, the knowing rules were not implemented. A fuel lattice performance and fuel lattice design characteristics analysis was made. To the realized tests, a dell workstation was used, under Li nux platform. (Author)
A Heuristic Task Scheduling Algorithm for Heterogeneous Virtual Clusters
Directory of Open Access Journals (Sweden)
Weiwei Lin
2016-01-01
Full Text Available Cloud computing provides on-demand computing and storage services with high performance and high scalability. However, the rising energy consumption of cloud data centers has become a prominent problem. In this paper, we first introduce an energy-aware framework for task scheduling in virtual clusters. The framework consists of a task resource requirements prediction module, an energy estimate module, and a scheduler with a task buffer. Secondly, based on this framework, we propose a virtual machine power efficiency-aware greedy scheduling algorithm (VPEGS. As a heuristic algorithm, VPEGS estimates task energy by considering factors including task resource demands, VM power efficiency, and server workload before scheduling tasks in a greedy manner. We simulated a heterogeneous VM cluster and conducted experiment to evaluate the effectiveness of VPEGS. Simulation results show that VPEGS effectively reduced total energy consumption by more than 20% without producing large scheduling overheads. With the similar heuristic ideology, it outperformed Min-Min and RASA with respect to energy saving by about 29% and 28%, respectively.
Automatic Overset Grid Generation with Heuristic Feedback Control
Robinson, Peter I.
2001-01-01
An advancing front grid generation system for structured Overset grids is presented which automatically modifies Overset structured surface grids and control lines until user-specified grid qualities are achieved. The system is demonstrated on two examples: the first refines a space shuttle fuselage control line until global truncation error is achieved; the second advances, from control lines, the space shuttle orbiter fuselage top and fuselage side surface grids until proper overlap is achieved. Surface grids are generated in minutes for complex geometries. The system is implemented as a heuristic feedback control (HFC) expert system which iteratively modifies the input specifications for Overset control line and surface grids. It is developed as an extension of modern control theory, production rules systems and subsumption architectures. The methodology provides benefits over the full knowledge lifecycle of an expert system for knowledge acquisition, knowledge representation, and knowledge execution. The vector/matrix framework of modern control theory systematically acquires and represents expert system knowledge. Missing matrix elements imply missing expert knowledge. The execution of the expert system knowledge is performed through symbolic execution of the matrix algebra equations of modern control theory. The dot product operation of matrix algebra is generalized for heuristic symbolic terms. Constant time execution is guaranteed.
Hybrid Evolutionary-Heuristic Algorithm for Capacitor Banks Allocation
Barukčić, Marinko; Nikolovski, Srete; Jović, Franjo
2010-11-01
The issue of optimal allocation of capacitor banks concerning power losses minimization in distribution networks are considered in this paper. This optimization problem has been recently tackled by application of contemporary soft computing methods such as: genetic algorithms, neural networks, fuzzy logic, simulated annealing, ant colony methods, and hybrid methods. An evolutionaryheuristic method has been proposed for optimal capacitor allocation in radial distribution networks. An evolutionary method based on genetic algorithm is developed. The proposed method has a reduced number of parameters compared to the usual genetic algorithm. A heuristic stage is used for improving the optimal solution given by the evolutionary stage. A new cost-voltage node index is used in the heuristic stage in order to improve the quality of solution. The efficiency of the proposed two-stage method has been tested on different test networks. The quality of solution has been verified by comparison tests with other methods on the same test networks. The proposed method has given significantly better solutions for time dependent load in the 69-bus network than found in references.
On Backtracking in Real-time Heuristic Search
Bulitko, Valeriy K
2009-01-01
Real-time heuristic search algorithms are suitable for situated agents that need to make their decisions in constant time. Since the original work by Korf nearly two decades ago, numerous extensions have been suggested. One of the most intriguing extensions is the idea of backtracking wherein the agent decides to return to a previously visited state as opposed to moving forward greedily. This idea has been empirically shown to have a significant impact on various performance measures. The studies have been carried out in particular empirical testbeds with specific real-time search algorithms that use backtracking. Consequently, the extent to which the trends observed are characteristic of backtracking in general is unclear. In this paper, we present the first entirely theoretical study of backtracking in real-time heuristic search. In particular, we present upper bounds on the solution cost exponential and linear in a parameter regulating the amount of backtracking. The results hold for a wide class of real-t...
Optimal Rapid Restart of Heuristic Methods of NP Hard Problems
Institute of Scientific and Technical Information of China (English)
侯越先; 王芳
2004-01-01
Many heuristic search methods exhibit a remarkable variability in the time required to solve some particular problem instances. Their cost distributions are often heavy-tailed. It has been demonstrated that, in most cases, rapid restart (RR) method can prominently suppress the heavy-tailed nature of the instances and improve computation efficiency. However, it is usually time-consuming to check whether an algorithm on a specific instance is heavy-tailed or not. Moreover, if the heavy-tailed distribution is confirmed and the RR method is relevant, an optimal RR threshold should be chosen to facilitate the RR mechanism. In this paper, an approximate approach is proposed to quickly check whether an algorithm on a specific instance is heavy-tailed or not.The method is realized by means of calculating the maximal Lyapunov exponent of its generic running trace.Then a statistical formula to estimate the optimal RR threshold is educed. The method is based on common nonparametric estimation, e. g. , Kernel estimation. Two heuristic methods are selected to verify our method. The experimental results are consistent with the theoretical consideration perfectly.
Goal representation heuristic dynamic programming on maze navigation.
Ni, Zhen; He, Haibo; Wen, Jinyu; Xu, Xin
2013-12-01
Goal representation heuristic dynamic programming (GrHDP) is proposed in this paper to demonstrate online learning in the Markov decision process. In addition to the (external) reinforcement signal in literature, we develop an adaptively internal goal/reward representation for the agent with the proposed goal network. Specifically, we keep the actor-critic design in heuristic dynamic programming (HDP) and include a goal network to represent the internal goal signal, to further help the value function approximation. We evaluate our proposed GrHDP algorithm on two 2-D maze navigation problems, and later on one 3-D maze navigation problem. Compared to the traditional HDP approach, the learning performance of the agent is improved with our proposed GrHDP approach. In addition, we also include the learning performance with two other reinforcement learning algorithms, namely Sarsa(λ) and Q-learning, on the same benchmarks for comparison. Furthermore, in order to demonstrate the theoretical guarantee of our proposed method, we provide the characteristics analysis toward the convergence of weights in neural networks in our GrHDP approach. PMID:24805221
Heuristic control of the Utah/MIT dextrous robot hand
Bass, Andrew H., Jr.
1987-01-01
Basic hand grips and sensor interactions that a dextrous robot hand will need as part of the operation of an EVA Retriever are analyzed. What is to be done with a dextrous robot hand is examined along with how such a complex machine might be controlled. It was assumed throughout that an anthropomorphic robot hand should perform tasks just as a human would; i.e., the most efficient approach to developing control strategies for the hand would be to model actual hand actions and do the same tasks in the same ways. Therefore, basic hand grips that human hands perform, as well as hand grip action were analyzed. It was also important to examine what is termed sensor fusion. This is the integration of various disparate sensor feedback paths. These feedback paths can be spatially and temporally separated, as well as, of different sensor types. Neural networks are seen as a means of integrating these varied sensor inputs and types. Basic heuristics of hand actions and grips were developed. These heuristics offer promise of control dextrous robot hands in a more natural and efficient way.
Sabar, Nasser R; Ayob, Masri; Kendall, Graham; Qu, Rong
2015-02-01
Hyper-heuristics are search methodologies that aim to provide high-quality solutions across a wide variety of problem domains, rather than developing tailor-made methodologies for each problem instance/domain. A traditional hyper-heuristic framework has two levels, namely, the high level strategy (heuristic selection mechanism and the acceptance criterion) and low level heuristics (a set of problem specific heuristics). Due to the different landscape structures of different problem instances, the high level strategy plays an important role in the design of a hyper-heuristic framework. In this paper, we propose a new high level strategy for a hyper-heuristic framework. The proposed high-level strategy utilizes a dynamic multiarmed bandit-extreme value-based reward as an online heuristic selection mechanism to select the appropriate heuristic to be applied at each iteration. In addition, we propose a gene expression programming framework to automatically generate the acceptance criterion for each problem instance, instead of using human-designed criteria. Two well-known, and very different, combinatorial optimization problems, one static (exam timetabling) and one dynamic (dynamic vehicle routing) are used to demonstrate the generality of the proposed framework. Compared with state-of-the-art hyper-heuristics and other bespoke methods, empirical results demonstrate that the proposed framework is able to generalize well across both domains. We obtain competitive, if not better results, when compared to the best known results obtained from other methods that have been presented in the scientific literature. We also compare our approach against the recently released hyper-heuristic competition test suite. We again demonstrate the generality of our approach when we compare against other methods that have utilized the same six benchmark datasets from this test suite. PMID:24951713
Electron band theory 1952-1962
International Nuclear Information System (INIS)
Work undertaken by the Theoretical Physics Division between 1952 and 1965 to obtain an understanding of electrons in metals, with uranium and the actinides and the structurally-important transition metals as the main targets is examined. A main result of that period was a conviction that the majority of the physical properties of all metals, except the 4f rare-earth series and the actinides beyond uranium, were dominated by band effects which could be described well enough for most purposes by simple one-electron calculations with simple self-consistent fields. The period from 1960 on showed increasingly clearly the necessity of incorporating relativistic spin-orbit coupling terms in the heavy metals, and some 'local exchange field' correction to the fields close to nuclei. The problems of the non-local interaction of spins - highly important for alloy theory and for antiferromagnetic instability -required the evolution of computers large enough to produce wave-functions at all wave-vectors for all bands so that the susceptibility at arbitrary wave-vector could be computed. This work has not proved to be very illuminating so far, and much interest again focusses today on heuristic arguments that give qualitative descriptions of band structures, such as canonical d-bands to account for crystal structure. (UK)
Shear Banding of Complex Fluids
Divoux, Thibaut; Fardin, Marc A.; Manneville, Sebastien; Lerouge, Sandra
2016-01-01
Even in simple geometries, many complex fluids display nontrivial flow fields, with regions where shear is concentrated. The possibility for such shear banding has been known for several decades, but in recent years, we have seen an upsurge in studies offering an ever-more precise understanding of the phenomenon. The development of new techniques to probe the flow on multiple scales with increasing spatial and temporal resolution has opened the possibility for a synthesis of the many phenomena that could only have been thought of separately before. In this review, we bring together recent research on shear banding in polymeric and soft glassy materials and highlight their similarities and disparities.
A Sensitivity-Based Heuristic Search for Constrained Optimization in Complex Systems
Institute of Scientific and Technical Information of China (English)
无
1999-01-01
On the basis of sensitivity analysis, an algorithm presented in this paper does a multi-dimensional heuristic search for the optimal solution of complex systems in the feasible intervals of components reliability. Compared with some existing methods, the algorithm both has heuristic speciality that it is modest and easy to implement, and obtains the optimal solution as exact methods do.
How to make a greedy heuristic for the asymmetric traveling salesman problem competitive
Goldengorin, B.; Jäger, G.
2005-01-01
It is widely confirmed by many computational experiments that a greedy type heuristics for the Traveling Salesman Problem (TSP) produces rather poor solutions except for the Euclidean TSP. The selection of arcs to be included by a greedy heuristic is usually done on the base of cost values. We propo
Yeates, Keith Owen; Bigler, Erin D.; Dennis, Maureen; Gerhardt, Cynthia A.; Rubin, Kenneth H.; Stancin, Terry; Taylor, H. Gerry; Vannatta, Kathryn
2007-01-01
The authors propose a heuristic model of the social outcomes of childhood brain disorder that draws on models and methods from both the emerging field of social cognitive neuroscience and the study of social competence in developmental psychology/psychopathology. The heuristic model characterizes the relationships between social adjustment, peer…
Managing Heuristics as a Method of Inquiry in Autobiographical Graphic Design Theses
Ings, Welby
2011-01-01
This article draws on case studies undertaken in postgraduate research at AUT University, Auckland. It seeks to address a number of issues related to heuristic inquiries employed by graphic design students who use autobiographical approaches when developing research-based theses. For this type of thesis, heuristics as a system of inquiry may…
The Role of Heuristic Methods as a Decision-Making Tool in Aggregate Production Planning
Mahmood B. Ridha
2015-01-01
This study aims to explain the role of heuristic methods in the decision making process and as a tool for knowledge capture. As a result, we conclude that heuristic methods give better support to the decision maker than mathematical models in many cases especially when time and cost are critical factors in decision making.
Goltz, Sonia M.
2013-01-01
In the present analysis the author utilizes the groups as patches model (Goltz, 2009, 2010) to extend fairness heuristic theory (Lind, 2001) in which the concept of fairness is thought to be a heuristic that allows individuals to match responses to consequences they receive from groups. In this model, individuals who are reviewing possible groups…
Heuristic Reasoning and Beliefs on Immigration: An Approach to an Intercultural Education Programme
Navarro, Santiago Palacios; Lopez de Arechavaleta, Blanca Olalde
2010-01-01
People use mental shortcuts to simplify the amount of information they receive from the environment. Heuristic reasoning can be included among these mental shortcuts. In general, heuristics is useful for making fast decisions and judgements, but in certain cases, it may lead to systematic errors because some relevant aspects presented in the given…
Xie, Ying; Coffland, David; Yang, Fangyun
2012-01-01
Multimodal feedback could promote college students' conceptual, procedural and heuristic knowledge learning. This study used an experimental design to investigate the interaction effects of instructor's narrated feedback (with procedural feedback delivered visually and heuristic feedback auditorily) and gender on their post-test performance of a…
A simple optimised search heuristic for the job-shop scheduling problem
Fernandes, Susana; Ramalhinho-Louren??o, Helena
2007-01-01
This paper presents a simple Optimised Search Heuristic for the Job Shop Scheduling problem that combines a GRASP heuristic with a branch-and-bound algorithm. The proposed method is compared with similar approaches and leads to better results in terms of solution quality and computing times.
General k-opt submoves for the Lin-Kernighan TSP heuristic
DEFF Research Database (Denmark)
Helsgaun, Keld
2009-01-01
Local search with k-exchange neighborhoods, k-opt, is the most widely used heuristic method for the traveling salesman problem (TSP). This paper presents an effective implementation of k-opt in LKH-2, a variant of the Lin–Kernighan TSP heuristic. The effectiveness of the implementation is...
Using Heuristic Task Analysis to Create Web-Based Instructional Design Theory
Fiester, Herbert R.
2010-01-01
The first purpose of this study was to identify procedural and heuristic knowledge used when creating web-based instruction. The second purpose of this study was to develop suggestions for improving the Heuristic Task Analysis process, a technique for eliciting, analyzing, and representing expertise in cognitively complex tasks. Three expert…
Heuristic algorithms for constructing optimized structures of linear multihop lightwave networks
Banerjee, Subrata; Mukherjee, Biswanath; Sarkar, Dillip
1994-02-01
We propose to exploit the capabilities of emerging lightwave technology in order to construct photonic implementations of 'adaptive' and 'optimized' distributed queue dual bus (DQDB) structures. Two sets of heuristic optimization algorithms are formulated. The performance of these heuristics are compared, some of their properties are analyzed, while their other attractive properties are highlighted via numerical examples.
DEFF Research Database (Denmark)
Gamst, M.
2014-01-01
better than using a standard IP-solver; however, it is still unable to solve several instances. The proposed heuristics generally have good performance. Especially, the First Come First Serve scheduling heuristic combined with a routing strategy, which proposes several good routes for each demand, has...
Editorial for the Special Issue on Automated Design and Assessment of Heuristic Search Methods
Ochoa, Gabriela; Preuss, Mike; Bartz-Beielstein, Thomas; Schoenauer, Marc
2012-01-01
Heuristic search algorithms have been successfully applied to solve many problems in practice. Their design, however, has increased in complexity as the number of parameters and choices for operators and algorithmic components is also expanding. There is clearly the need of providing the final user with automated tools to assist the tuning, design and assessment of heuristic optimisation methods.
Wahid, Juliana; Hussin, Naimah Mohd
2016-08-01
The construction of population of initial solution is a crucial task in population-based metaheuristic approach for solving curriculum-based university course timetabling problem because it can affect the convergence speed and also the quality of the final solution. This paper presents an exploration on combination of graph heuristics in construction approach in curriculum based course timetabling problem to produce a population of initial solutions. The graph heuristics were set as single and combination of two heuristics. In addition, several ways of assigning courses into room and timeslot are implemented. All settings of heuristics are then tested on the same curriculum based course timetabling problem instances and are compared with each other in terms of number of population produced. The result shows that combination of saturation degree followed by largest degree heuristic produce the highest number of population of initial solutions. The results from this study can be used in the improvement phase of algorithm that uses population of initial solutions.
New Meta-Heuristic for Combinatorial Optimization Problems:Intersection Based Scaling
Institute of Scientific and Technical Information of China (English)
Peng Zou; Zhi Zhou; Ying-Yu Wan; Guo-Liang Chen; Jun Gu
2004-01-01
Combinatorial optimization problems are found in many application fields such as computer science, engineering and economy. In this paper, a new efficient meta-heuristic, Intersection-Based Scaling (IBS for abbreviation),is proposed and it can be applied to the combinatorial optimization problems. The main idea of IBS is to scale the size of the instance based on the intersection of some local optima, and to simplify the search space by extracting the intersection from the instance, which makes the search more efficient. The combination of IBS with some local search heuristics of different combinatorial optimization problems such as Traveling Salesman Problem (TSP) and Graph Partitioning Problem (GPP) is studied, and comparisons are made with some of the best heuristic algorithms and meta-heuristic algorithms. It is found that it has significantly improved the performance of existing local search heuristics and significantly outperforms the known best algorithms.
The Stratway Program for Strategic Conflict Resolution: User's Guide
Hagen, George E.; Butler, Ricky W.; Maddalon, Jeffrey M.
2016-01-01
Stratway is a strategic conflict detection and resolution program. It provides both intent-based conflict detection and conflict resolution for a single ownship in the presence of multiple traffic aircraft and weather cells defined by moving polygons. It relies on a set of heuristic search strategies to solve conflicts. These strategies are user configurable through multiple parameters. The program can be called from other programs through an application program interface (API) and can also be executed from a command line.
Efficient Heuristic Based on Clustering Approach for OLSR
Directory of Open Access Journals (Sweden)
Ali Choukri
2013-01-01
Full Text Available Due to the dynamic nature of mobile ad hoc network (MANET, the quality of service (QoS requires several improvements. The present papercomeswithin the framework of research to optimize QoS in MANET. In this paper, we propose a novel version of OLSR based on the clustering approach which is inspired from Lin and Chu heuristic and adapted to beimplemented inOLSR. We studied its stability and we compared its performances to those of standard OLSR. The metrics we used in evaluating network performances were average end-to-end delay, control routing overhead, and packet delivery ratio. Experimental results show that our alternative significantly reduces the traffic reserved to monitoring the network, which positively influences other performances such as throughput, delay, and loss.
A heuristic solution for the stability problem in conventional submarines
Directory of Open Access Journals (Sweden)
M. Sinclair
2003-12-01
Full Text Available Seafaring vessels must meet a few very obvious conditions in order to be of any use. The one condition is that they should stay afloat when loaded. The other condition is that they should float upright and with a level keel. The technical terms for these conditions are gravitational stability and trim. In practice some very precise numerical values are calculated for certain parameters in order to describe these conditions. After each refit of a submarine, the numerical values for the parameters referred to above must be recalculated. In the conventional submarines used by the South African Navy these new values must then be translated into the physical redistribution of weights housed in bays in the keel of the submarine. This paper discusses the problem of how this redistribution must be done in order to minimise the amount of work necessary. A heuristic algorithm is proposed by means of which a satisfactory redistribution may economically be computed.
A Heuristic Algorithm for Core Selection in Multicast Routing
Institute of Scientific and Technical Information of China (English)
Manas Ranjan Kabat; Manoj Kumar Patel; Chita Ranjan Tripathy
2011-01-01
With the development of network multimedia technology,more and more real-time multimedia applications need to transmit information using multicast.The basis of multicast data transmission is to construct a multicast tree.The main problem concerning the construction of a shared multicast tree is selection of a root of the shared tree or the core point.In this paper,we propose a heuristic algorithm for core selection in multicast routing.The proposed algorithm selects core point by considering both delay and inter-destination delay variation.The simulation results show that the proposed algorithm performs better than the existing algorithms in terms of delay variation subject to the end-to-end delay bound.The mathematical time complexity and the execution time of the proposed algorithm are comparable to those of the existing algorithms.
Heuristic Quasi-physical Algorithm for Protein Structure Prediction
Institute of Scientific and Technical Information of China (English)
Liu Jingfa; Huang Wenqi
2006-01-01
A three-dimensional off-lattice protein model with two species of monomers, hydrophobic and hydrophilic, is studied. Enlightened by the law of reciprocity among things in the physical world, a heuristic quasi-physical algorithm for protein structure prediction problem is put forward. First, by elaborately simulating the movement of the smooth elastic balls in the physical world,the algorithm finds low energy configurations for a given monomer chain. An "off-trap" strategy is then proposed to get out of local minima. Experimental results show promising performance. For all chains with lengths 13 ≤ n ≤ 55, the proposed algorithm finds states with lower energy than the putative ground states reported in literatures. Furthermore, for chain lengths n = 21, 34, and 55,the algorithm finds new low energy configurations different from those given in literatures.
Heuristic Optimization for the Discrete Virtual Power Plant Dispatch Problem
DEFF Research Database (Denmark)
Petersen, Mette Kirschmeyer; Hansen, Lars Henrik; Bendtsen, Jan Dimon;
2014-01-01
Problem. First NP-completeness of the Discrete Virtual Power Plant Dispatch Problem is proved formally. We then proceed to develop tailored versions of the meta-heuristic algorithms Hill Climber and Greedy Randomized Adaptive Search Procedure (GRASP). The algorithms are tuned and tested on portfolios of...... varying sizes. We find that all the tailored algorithms perform satisfactorily in the sense that they are able to find sub-optimal, but usable, solutions to very large problems (on the order of 10 5 units) at computation times on the scale of just 10 seconds, which is far beyond the capabilities of the...... optimal algorithms we have tested. In particular, GRASP Sorted shows the most promising performance, as it is able to find solutions that are both agile (sorted) and well balanced, and consistently yields the best numerical performance among the developed algorithms....
On two pictures in the heuristic approach to gravity
Nikishov, A I
2007-01-01
We examine the heuristic approach to constant gravitational field by Dehnen, H\\"onl and Westpfahl, extending it everywhere beyond linear approximation. Then it becomes flexible to accommodate possible modifications of General Relativity. We have found that two pictures introduced in the related paper by Thirring are helpful in better understanding some features of gravitation. In particular, this approach suggest that the privileged system for constant gravitational field must be the isotropic one and that the requirement of gauge invariance in gravitation theory may be a luxury; it is sufficient to take care that the nonphysical degrees of freedom do not invalidate calculations. It follows from this approach that gravitational constant should depend on gravitational field and some universality in the form of metric of an asymmetric body is suggested.
Multiple Features Subset Selection using Meta-Heuristic Function
Directory of Open Access Journals (Sweden)
L. S. Maurya
2011-11-01
Full Text Available This paper is being presented on Multiple Features Subset Selection Using Meta-heuristic Function. Classification problems require selection of a subset of attributes or features from a much larger dataset to represent the patterns to be classified. Many excellent multiple feature selection method such as Hill Climbing (HC, Simulated Annealing (SA, Genetic Algorithms (GAs, Tabu Search (TS has been prevalent amongst research community. However, these approaches still encounter when the multiple feature of dataset is available and it need to choose those attribute which is best amongst the available features. So, in this paper basically considering the issue of multiple features are analyzed as well as implemented and tested on different dataset. The experiment is being conducted abalone dataset. It may conclude that the algorithm shows highest accuracy amongst all other method which is being used in this paper, Therefore we are focusing on the classification of multiple features
A comparison of heuristic search algorithms for molecular docking.
Westhead, D R; Clark, D E; Murray, C W
1997-05-01
This paper describes the implementation and comparison of four heuristic search algorithms (genetic algorithm, evolutionary programming, simulated annealing and tabu search) and a random search procedure for flexible molecular docking. To our knowledge, this is the first application of the tabu search algorithm in this area. The algorithms are compared using a recently described fast molecular recognition potential function and a diverse set of five protein-ligand systems. Statistical analysis of the results indicates that overall the genetic algorithm performs best in terms of the median energy of the solutions located. However, tabu search shows a better performance in terms of locating solutions close to the crystallographic ligand conformation. These results suggest that a hybrid search algorithm may give superior results to any of the algorithms alone. PMID:9263849
A New Heuristic for Feature Selection by Consistent Biclustering
Mucherino, Antonio
2010-01-01
Given a set of data, biclustering aims at finding simultaneous partitions in biclusters of its samples and of the features which are used for representing the samples. Consistent biclusterings allow to obtain correct classifications of the samples from the known classification of the features, and vice versa, and they are very useful for performing supervised classifications. The problem of finding consistent biclusterings can be seen as a feature selection problem, where the features that are not relevant for classification purposes are removed from the set of data, while the total number of features is maximized in order to preserve information. This feature selection problem can be formulated as a linear fractional 0-1 optimization problem. We propose a reformulation of this problem as a bilevel optimization problem, and we present a heuristic algorithm for an efficient solution of the reformulated problem. Computational experiments show that the presented algorithm is able to find better solutions with re...
Processing Metonymy a Domain-Model Heuristic Graph Traversal Approach
Bouaud, J; Zweigenbaum, P; Bouaud, Jacques; Bachimont, Bruno; Zweigenbaum, Pierre
1996-01-01
We address here the treatment of metonymic expressions from a knowledge representation perspective, that is, in the context of a text understanding system which aims to build a conceptual representation from texts according to a domain model expressed in a knowledge representation formalism. We focus in this paper on the part of the semantic analyser which deals with semantic composition. We explain how we use the domain model to handle metonymy dynamically, and more generally, to underlie semantic composition, using the knowledge descriptions attached to each concept of our ontology as a kind of concept-level, multiple-role qualia structure. We rely for this on a heuristic path search algorithm that exploits the graphic aspects of the conceptual graphs formalism. The methods described have been implemented and applied on French texts in the medical domain.
PROBLEM SOLVING IN SCHOOL MATHEMATICS BASED ON HEURISTIC STRATEGIES
Directory of Open Access Journals (Sweden)
NOVOTNÁ, Jarmila
2014-03-01
Full Text Available The paper describes one of the ways of developing pupils’ creative approach to problem solving. The described experiment is a part of a longitudinal research focusing on improvement of culture of problem solving by pupils. It deals with solving of problems using the following heuristic strategies: Analogy, Guess – check – revise, Systematic experimentation, Problem reformulation, Solution drawing, Way back and Use of graphs of functions. Most attention is paid to the question whether short-term work, in this case only over the period of three months, can result in improvement of pupils’ abilities to solve problems whose solving algorithms are easily accessible. It also answers the question which strategies pupils will prefer and with what results. The experiment shows that even short-term work can bear positive results as far as pupils’ approach to problem solving is concerned.
Heuristic method for reactive energy management in distribution feeders
International Nuclear Information System (INIS)
This paper proposes an efficient method for solving shunt capacitors sizing problem in radial distribution feeders. For this typical multi-objective optimisation problem, the optimal number, sizes and locations of fixed shunt capacitors are determined using a sensitivity-based heuristic solution. In this method, based on Markov chains, the number of variables to be optimised is reduced by using the node sensitivities to locate capacitors. Only a limited number of critical nodes satisfy the problem constraints and are considered for receiving standard shunt capacitors that maximise a net saving function. In order to overcome any over-compensation, the voltage admissible limits, imposed by many authors, are substituted by a new constraint on the branch reactive currents. To demonstrate the effectiveness and feasibility of the proposed approach, comparative studies were conducted on several test systems. The results we got were promising compared to those given by previous published techniques.
Spatial electric load forecasting using an evolutionary heuristic
Directory of Open Access Journals (Sweden)
E. M. Carreno
2010-08-01
Full Text Available A method for spatial electric load forecasting using elements from evolutionary algorithms is presented. The method uses concepts from knowledge extraction algorithms and linguistic rules' representation to characterize the preferences for land use into a spatial database. The future land use preferences in undeveloped zones in the electrical utility service area are determined using an evolutionary heuristic, which considers a stochastic behavior by crossing over similar rules. The method considers development of new zones and also redevelopment of existing ones. The results are presented in future preference maps. The tests in a real system from a midsized city show a high rate of success when results are compared with information gathered from the utility planning department. The most important features of this method are the need for few data and the simplicity of the algorithm, allowing for future scalability.
Weidenbach, C.
1994-01-01
Minimal resolution restricts the applicability of resolution and factorization to minimal literals. Minimality is an abstract criterion. It is shown that if the minimality criterion satisfies certain properties minimal resolution is sound and complete. Hyper resolution, ordered resolution and lock resolution are known instances of minimal resolution. We also introduce new instances of the general completeness result, correct some mistakes in existing literature and give some general redundanc...
IMPACT OF HEURISTIC STRATEGIES ON PUPILS’ ATTITUDES TO PROBLEM SOLVING
Directory of Open Access Journals (Sweden)
NOVOTNÁ, Jarmila
2015-03-01
Full Text Available The paper is a sequel to the article (Novotná et al., 2014, where the authors present the results of a 4-month experiment whose main aim was to change pupils’ culture of problem solving by using heuristic strategies suitable for problem solving in mathematics education. (Novotná et al., 2014 focused on strategies Analogy, Guess – check – revise, Systematic experimentation, Problem reformulation, Solution drawing, Working backwards and Use of graphs of functions. This paper focuses on two other heuristic strategies convenient for improvement of pupils’ culture of problem solving: Introduction of an auxiliary element and Omitting a condition. In the first part, the strategies Guess – Check – Revise, Working backwards, Introduction of an auxiliary element and Omitting a condition are characterized in detail and illustrated by examples of their use in order to capture their characteristics. In the second part we focus on the newly introduced strategies and analyse work with them in lessons using the tools from (Novotná et al., 2014. The analysis of results of the experiment indicates that, unlike in case of the strategy Introduction of an auxiliary element, successful use of the strategy Omitting a condition requires longer teacher’s work with the pupils. The following analysis works with the strategy Systematic experimentation, which seemed to be the easiest to master in (Novotná et al., 2014; we focus on the dangers it bears when it is used by pupils. The conclusion from (Novotná et al., 2014, which showed that if pupils are introduced to an environment that supports their creativity, their attitude towards problem solving changes in a positive way already after the period of four months, is confirmed.
Heuristic modeling of macromolecule release from PLGA microspheres.
Szlęk, Jakub; Pacławski, Adam; Lau, Raymond; Jachowicz, Renata; Mendyk, Aleksander
2013-01-01
Dissolution of protein macromolecules from poly(lactic-co-glycolic acid) (PLGA) particles is a complex process and still not fully understood. As such, there are difficulties in obtaining a predictive model that could be of fundamental significance in design, development, and optimization for medical applications and toxicity evaluation of PLGA-based multiparticulate dosage form. In the present study, two models with comparable goodness of fit were proposed for the prediction of the macromolecule dissolution profile from PLGA micro- and nanoparticles. In both cases, heuristic techniques, such as artificial neural networks (ANNs), feature selection, and genetic programming were employed. Feature selection provided by fscaret package and sensitivity analysis performed by ANNs reduced the original input vector from a total of 300 input variables to 21, 17, 16, and eleven; to achieve a better insight into generalization error, two cut-off points for every method was proposed. The best ANNs model results were obtained by monotone multi-layer perceptron neural network (MON-MLP) networks with a root-mean-square error (RMSE) of 15.4, and the input vector consisted of eleven inputs. The complicated classical equation derived from a database consisting of 17 inputs was able to yield a better generalization error (RMSE) of 14.3. The equation was characterized by four parameters, thus feasible (applicable) to standard nonlinear regression techniques. Heuristic modeling led to the ANN model describing macromolecules release profiles from PLGA microspheres with good predictive efficiency. Moreover genetic programming technique resulted in classical equation with comparable predictability to the ANN model. PMID:24348037
Heuristic modeling of macromolecule release from PLGA microspheres
Directory of Open Access Journals (Sweden)
Szlęk J
2013-12-01
Full Text Available Jakub Szlęk,1 Adam Pacławski,1 Raymond Lau,2 Renata Jachowicz,1 Aleksander Mendyk11Department of Pharmaceutical Technology and Biopharmaceutics, Jagiellonian University Medical College, Krakow, Poland; 2School of Chemical and Biomedical Engineering, Nanyang Technological University (NTU, SingaporeAbstract: Dissolution of protein macromolecules from poly(lactic-co-glycolic acid (PLGA particles is a complex process and still not fully understood. As such, there are difficulties in obtaining a predictive model that could be of fundamental significance in design, development, and optimization for medical applications and toxicity evaluation of PLGA-based multiparticulate dosage form. In the present study, two models with comparable goodness of fit were proposed for the prediction of the macromolecule dissolution profile from PLGA micro- and nanoparticles. In both cases, heuristic techniques, such as artificial neural networks (ANNs, feature selection, and genetic programming were employed. Feature selection provided by fscaret package and sensitivity analysis performed by ANNs reduced the original input vector from a total of 300 input variables to 21, 17, 16, and eleven; to achieve a better insight into generalization error, two cut-off points for every method was proposed. The best ANNs model results were obtained by monotone multi-layer perceptron neural network (MON-MLP networks with a root-mean-square error (RMSE of 15.4, and the input vector consisted of eleven inputs. The complicated classical equation derived from a database consisting of 17 inputs was able to yield a better generalization error (RMSE of 14.3. The equation was characterized by four parameters, thus feasible (applicable to standard nonlinear regression techniques. Heuristic modeling led to the ANN model describing macromolecules release profiles from PLGA microspheres with good predictive efficiency. Moreover genetic programming technique resulted in classical equation with
Daalhuizen, J.J.; Person, F.E.O.K.; Gattol, V.
2013-01-01
Both systematic and heuristic methods are common practice when designing. Yet, in teaching students how to design, heuristic methods are typically only granted a secondary role. So, how do designers and students develop a mindset for using heuristic methods? In this paper, we study how prior knowled
Shear Banding of Complex Fluids
Divoux, Thibaut; Fardin, Marc-Antoine; Manneville, Sebastien; Lerouge, Sandra
2015-01-01
Even in simple geometries many complex fluids display non-trivial flow fields, with regions where shear is concentrated. The possibility for such shear banding has been known since several decades, but the recent years have seen an upsurge of studies offering an ever more precise understanding of the phenomenon. The development of new techniques to probe the flow on multiple scales and with increasing spatial and temporal resolution has opened the possibility for a synthesis of the many pheno...
International Nuclear Information System (INIS)
We report oscillator strengths for six strong vibrational bands between 105.0 and 115.2 nm, associated with transitions from the v = 0 level of the X 1Σ+ ground state to the v = 0 and 1 levels of the B 1Σ+, C 1Σ+, and E 1Π states, in 12C16O, 12C17O, 12C18O, 13C16O, and 13C18O. These measurements extend the development of a comprehensive database of line positions, oscillator strengths, and linewidths of photodissociating transitions for all astrophysically relevant CO isotopologues. The E-X bands, in particular, play central roles in CO photodissociation and fractionation models of interstellar clouds and circumstellar disks including the early solar nebula. The resolving powers of the room-temperature measurements, R = 300,000-400,000, allow for the analysis of individual line strengths within bands; the measurements reveal J-dependences in the branch intensities of the C(v = 0,1)-X(0) and E(v = 0,1)-X(0) bands in all isotopologues. Minimal or no isotopologue dependence was found in the f-values of the C(v = 0,1)-X(0) and E(v = 0,1)-X(0) bands at a ∼5% uncertainty level. Revised dissociation branching ratios for the C(v = 0,1) and E(v = 0,1) levels are computed based on these f-values. The weak isotopologue dependence of the f-values presented here eliminates this mechanism as an explanation for the large 17O enrichments seen in recent laboratory photolysis experiments on CO at wavelengths from 105 to 108 nm
Hierarchical heuristic search using a Gaussian mixture model for UAV coverage planning.
Lin, Lanny; Goodrich, Michael A
2014-12-01
During unmanned aerial vehicle (UAV) search missions, efficient use of UAV flight time requires flight paths that maximize the probability of finding the desired subject. The probability of detecting the desired subject based on UAV sensor information can vary in different search areas due to environment elements like varying vegetation density or lighting conditions, making it likely that the UAV can only partially detect the subject. This adds another dimension of complexity to the already difficult (NP-Hard) problem of finding an optimal search path. We present a new class of algorithms that account for partial detection in the form of a task difficulty map and produce paths that approximate the payoff of optimal solutions. The algorithms use the mode goodness ratio heuristic that uses a Gaussian mixture model to prioritize search subregions. The algorithms search for effective paths through the parameter space at different levels of resolution. We compare the performance of the new algorithms against two published algorithms (Bourgault's algorithm and LHC-GW-CONV algorithm) in simulated searches with three real search and rescue scenarios, and show that the new algorithms outperform existing algorithms significantly and can yield efficient paths that yield payoffs near the optimal. PMID:24691199
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A A Eicher
2012-09-01
Full Text Available Magnetic Resonance Imaging provides a non-invasive means to study the neural correlates of Fetal Alcohol Spectrum Disorder (FASD - the most common form of preventable mental retardation worldwide. One approach aims to detect brain abnormalities through an assessment of volume and shape of two sub-cortical structures, the caudate nucleus and hippocampus. We present a method for automatically segmenting these structures from high-resolution MR images captured as part of an ongoing study into the neural correlates of FASD. Our method incorporates an Active Shape Model, which is used to learn shape variation from manually segmented training data. A modified discrete Geometrically Deformable Model is used to generate point correspondence between training models. An ASM is then created from the landmark points. Experiments were conducted on the image search phase of ASM segmentation, in order to find the technique best suited to segmentation of the hippocampus and caudate nucleus. Various popular image search techniques were tested, including an edge detection method and a method based on grey profile Mahalanobis distance measurement. A novel heuristic image search method was also developed and tested. This heuristic method improves image segmentation by taking advantage of characteristics specific to the target data, such as a relatively homogeneous tissue colour in target structures. Results show that ASMs that use the heuristic image search technique produce the most accurate segmentations. An ASM constructed using this technique will enable researchers to quickly, reliably, and automatically segment test data for use in the FASD study.
Combined heuristics for determining order quantity under time-varying demands
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
The time-varying demands for a certain period are often assumed to be less than the basic economic order quantity (EOQ) so that total replenishment quantity rather than economic order quantity is normally considered by most of the heuristics.This acticle focuses on a combined heuristics method for determining order quantity under generalized time-varying demands.The independent policy (IP),abnormal independent policy (AIP) and dependent policies are studied and compared.Using the concepts of normal/abnormal periods and the properties of dependent policies,a dependent policy-based heuristics (DPH) is proposed for solving the order quantity problems with a kind of time-varying demands pattern under which the first period is normal.By merging the Silver-Meal (S-M) heuristics and the dependent policy-based heuristics (DPH),a combined heuristics (DPH/S-M) is developed for solving order quantity problems with generalized time-varying demands.The experimentation shows that (1) for the problem with one normal period,no matter which position the normal period stands,the DPH/S-M could not guarantee better than the S-M heuristics,however it is superior to the S-M heuristics in the case that the demands in the abnormal periods are in descending order,and (2) The DPH/S-M is superior to the S-M heuristics for problems with more than one normal period,and the more the number of normal periods,the greater the improvements.
A Fault—Tolerant and Heuristic Routing Algorithm for Faulty Hypercubes
Institute of Scientific and Technical Information of China (English)
闵有力; 闵应骅
1995-01-01
A fault-tolerant and heuristic routing algorithm for faulty hypercube systems is described.To improve the efficiency,the algorithm adopts a heuristic backtracking strategy and each node has an array to record its all neighbors' faulty link information to avoid unnecessary searching for the known faulty links.Furthermore,the faulty link information is dynamically accumulated and the technique of heuristically searching for optimal link is used.The algorithm routes messages through the minimum feasible path between the sender and receiver if at least one such path exists,and takes the optimal path with higher probability when faulty links exist in the faulty hypercube.
HSM2:A New Heuristic State Minimization Algorithm for Finite State Machine
Institute of Scientific and Technical Information of China (English)
Heng Hu; Hong-Xi Xue; Ji-Nian Bian
2004-01-01
This paper proposes a heuristic state minimization algorithm (HSM2) for finite state machines (FSM). HSM2 focuses on the generation and adjustment of the closed cover. First an initial closed cover is generated by heuristically selecting proper maximal compatibles to satisfy all the covering and closure conditions,and then it is adjusted to be a minimal or near minimal closed cover by heuristically removing repeated states.Experimental results show that the algorithm is faster and obtains better or the same solutions compared with conventional methods.
A Variable Depth Sequential Search Heuristic for the Quadratic Assignment Problem
Paul, Gerald
2009-01-01
We develop a variable depth search heuristic for the quadratic assignment problem. The heuristic is based on sequential changes in assignments analogous to the Lin-Kernighan sequential edge moves for the traveling salesman problem. We treat unstructured problem instances of sizes 60 to 400. When the heuristic is used in conjunction with robust tabu search, we measure performance improvements of up to a factor of 15 compared to the use of robust tabu alone. The performance improvement increases as the problem size increases.
A Comparative Study of Meta-heuristic Algorithms for Solving Quadratic Assignment Problem
Directory of Open Access Journals (Sweden)
Gamal Abd El-Nasser A. Said
2014-01-01
Full Text Available Quadratic Assignment Problem (QAP is an NP-hard combinatorial optimization problem, therefore, solving the QAP requires applying one or more of the meta-heuristic algorithms. This paper presents a comparative study between Meta-heuristic algorithms: Genetic Algorithm, Tabu Search, and Simulated annealing for solving a real-life (QAP and analyze their performance in terms of both runtime efficiency and solution quality. The results show that Genetic Algorithm has a better solution quality while Tabu Search has a faster execution time in comparison with other Meta-heuristic algorithms for solving QAP.
Ant based heuristic for os service distribution on ad hoc networks
Heimfarth, Tales; Janacik, Peter
2006-01-01
This paper presents a basic and an extended heuristic to distribute operating system (OS) services over mobile ad hoc networks. The heuristics are inspired by the foraging behavior of ants and are used within our NanoOS, an OS for distributed applications. The NanoOS offers an uniform environment of execution and the code of the OS is distributed among nodes. We propose a basic and an extended swarm optimization based heuristic to control the service migration in order to reduce the com...
Comparing the performance of different meta-heuristics for unweighted parallel machine scheduling
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Adamu, Mumuni Osumah
2015-08-01
Full Text Available This article considers the due window scheduling problem to minimise the number of early and tardy jobs on identical parallel machines. This problem is known to be NP complete and thus finding an optimal solution is unlikely. Three meta-heuristics and their hybrids are proposed and extensive computational experiments are conducted. The purpose of this paper is to compare the performance of these meta-heuristics and their hybrids and to determine the best among them. Detailed comparative tests have also been conducted to analyse the different heuristics with the simulated annealing hybrid giving the best result.
A personification heuristic Genetic Algorithm for Digital Microfluidics-based Biochips Placement
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Jingsong Yang
2013-06-01
Full Text Available A personification heuristic Genetic Algorithm is established for the placement of digital microfluidics-based biochips, in which, the personification heuristic algorithm is used to control the packing process, while the genetic algorithm is designed to be used in multi-objective placement results optimizing. As an example, the process of microfluidic module physical placement in multiplexed in-vitro diagnostics on human physiological fluids is simulated. The experiment results show that personification heuristic genetic algorithm can achieve better results in multi-objective optimization, compare to the parallel recombinative simulated annealing algorithm.
International Nuclear Information System (INIS)
A coded imaging and decoding (image reconstruction) scheme was developed for diagnosing a hot and dense region emitting hard x-rays and neutrons in laser-fusion plasmas. Because the imager was a uniformly redundant array of penumbral aperture (URPA) arranged in an M-matrix, URPA leads to N times (N: the total number of apertures) enhancement of signal intensity in comparison with a single penumbral aperture. A recorded penumbral image was reconstructed by a computer-based heuristic method to reduce artifacts caused by noises contained in a penumbral image. Applicability of this technique was investigated by imaging x-rays emitted from laser-produced plasmas, demonstrating a spatial resolution of 16 μm. Under the present conditions, the spatial resolution was determined dominantly by a detector resolution (10.5 μm) and a signal-to-noise ratio of the obtained penumbral image.
Layer-layout-based heuristics for loading homogeneous items into a single container
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
The container loading problem (CLP) is a well-known NP-hard problem. Due to the computation complexity, heuristics is an often-sought approach. This article proposes two heuristics to pack homogeneous rectangular boxes into a single container. Both algorithms adopt the concept of building layers on one face of the container, but the first heuristic determines the layer face once for all, while the second treats the remaining container space as a reduced-sized container after one layer is loaded and, hence, selects the layer face dynamically. To handle the layout design problem at a layer's level, a block-based 2D packing procedure is also developed. Numerical studies demonstrate the efficiency of the heuristics.
A Comparison of Heuristics with Modularity Maximization Objective using Biological Data Sets
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Pirim Harun
2016-01-01
Full Text Available Finding groups of objects exhibiting similar patterns is an important data analytics task. Many disciplines have their own terminologies such as cluster, group, clique, community etc. defining the similar objects in a set. Adopting the term community, many exact and heuristic algorithms are developed to find the communities of interest in available data sets. Here, three heuristic algorithms to find communities are compared using five gene expression data sets. The heuristics have a common objective function of maximizing the modularity that is a quality measure of a partition and a reflection of objects’ relevance in communities. Partitions generated by the heuristics are compared with the real ones using the adjusted rand index, one of the most commonly used external validation measures. The paper discusses the results of the partitions on the mentioned biological data sets.
HYPER HEURISTIC BASED ON GREAT DELUGE AND ITS VARIANTS FOR EXAM TIMETABLING PROBLEM
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Ei Shwe Sin
2012-02-01
Full Text Available Today, University Timetabling problems are occurred annually and they are often hard andtime consuming to solve. This paper describes Hyper Heuristics (HH method based on Great Deluge(GD and its variants for solving large, highly constrained timetabling problems from different domains.Generally, in hyper heuristic framework, there are two main stages: heuristic selection and moveacceptance. This paper emphasizes on the latter stage to develop Hyper Heuristic (HH framework. Themain contribution of this paper is that Great Deluge (GD and its variants: Flex Deluge(FD, Nonlinear(NLGD, Extended Great Deluge(EGD are used as move acceptance method in HH by combiningReinforcement learning (RL.These HH methods are tested on exam benchmark timetabling problem andbest results and comparison analysis are reported.
Hyper Heuristic Based on Great Deluge and its Variants for Exam Timetabling Problem
Directory of Open Access Journals (Sweden)
Ei Shwe Sin
2012-01-01
Full Text Available Today, University Timetabling problems are occurred annually and they are often hard and time consuming to solve. This paper describes Hyper Heuristics (HH method based on Great Deluge (GD and its variants for solving large, highly constrained timetabling problems from different domains. Generally, in hyper heuristic framework, there are two main stages: heuristic selection and move acceptance. This paper emphasizes on the latter stage to develop Hyper Heuristic (HH framework. The main contribution of this paper is that Great Deluge (GD and its variants: Flex Deluge(FD, Nonlinear(NLGD, Extended Great Deluge(EGD are used as move acceptance method in HH by combining Reinforcement learning (RL.These HH methods are tested on exam benchmark timetabling problem and best results and comparison analysis are reported.
Optimization of pressurized water reactor shuffling by simulated annealing with heuristics
International Nuclear Information System (INIS)
Simulated-annealing optimization of reactor core loading patterns is implemented with support for design heuristics during candidate pattern generation. The SIMAN optimization module uses the advanced nodal method of SIMULATE-3 and the full cross-section detail of CASMO-3 to evaluate accurately the neutronic performance of each candidate, resulting in high-quality patterns. The use of heuristics within simulated annealing is explored. Heuristics improve the consistency of optimization results for both fast- and slow-annealing runs with no penalty from the exclusion of unusual candidates. Thus, the heuristic application of designer judgment during automated pattern generation is shown to be effective. The capability of the SIMAN module to find and evaluate families of loading patterns that satisfy design constraints and have good objective performance within practical run times is demonstrated. The use of automated evaluations of successive cycles to explore multicycle effects of design decisions is discussed
Heuristic learning parameter identification for surveillance and diagnostics of nuclear power plants
International Nuclear Information System (INIS)
An Artifical Intelligence Heuristic Learning Algorithm for System parameter identification has been developed. This algorithm has been applied to the on-line surveillance of a pressure loop, simulating the dynamics of pressure disturbances in a PWR plant
Heuristic Optimization Applied to an Intrinsically Difficult Problem: Birds Formation Flight
DEFF Research Database (Denmark)
Filippone, Antonino
1996-01-01
The birds formation flight is studied by means oftheoretical aerodynamics, heuristic methods anddistributed systems. A simplified aerodynamic analog is presented, and calculations of drag savings and flight range are shown for sometypical cases, including the line abreast flightwith various...
Structure-Based Local Search Heuristics for Circuit-Level Boolean Satisfiability
Belov, Anton
2011-01-01
This work focuses on improving state-of-the-art in stochastic local search (SLS) for solving Boolean satisfiability (SAT) instances arising from real-world industrial SAT application domains. The recently introduced SLS method CRSat has been shown to noticeably improve on previously suggested SLS techniques in solving such real-world instances by combining justification-based local search with limited Boolean constraint propagation on the non-clausal formula representation form of Boolean circuits. In this work, we study possibilities of further improving the performance of CRSat by exploiting circuit-level structural knowledge for developing new search heuristics for CRSat. To this end, we introduce and experimentally evaluate a variety of search heuristics, many of which are motivated by circuit-level heuristics originally developed in completely different contexts, e.g., for electronic design automation applications. To the best of our knowledge, most of the heuristics are novel in the context of SLS for S...
A Decentralized Heuristic Approach towards Resource Allocation in Femtocell Networks
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Kyung-Geun Lee
2013-06-01
Full Text Available Femtocells represent a novel configuration for existing cellular communication, contributing towards the improvement of coverage and throughput. The dense deployment of these femtocells causes significant femto-macro and femto-femto interference, consequently deteriorating the throughput of femtocells. In this study, we compare two heuristic approaches, i.e., particle swarm optimization (PSO and genetic algorithm (GA, for joint power assignment and resource allocation, within the context of the femtocell environment. The supposition made in this joint optimization is that the discrete power levels are available for the assignment. Furthermore, we have employed two variants of each PSO and GA: inertia weight and constriction factor model for PSO, and twopoint and uniform crossover for GA. The two proposed algorithms are in a decentralized manner, with no involvement of any centralized entity. The comparison is carried out between the two proposed algorithms for the aforementioned joint optimization problem. The contrast includes the performance metrics: including average objective function, min–max throughput of the femtocells, average throughput of the femto users, outage rate and time complexity. The results demonstrate that the decentralized PSO constriction factor outperforms the others in terms of the aforementioned performance metrics.
AliquotG: an improved heuristic algorithm for genome aliquoting.
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Zelin Chen
Full Text Available An extant genome can be the descendant of an ancient polyploid genome. The genome aliquoting problem is to reconstruct the latter from the former such that the rearrangement distance (i.e., the number of genome rearrangements necessary to transform the former into the latter is minimal. Though several heuristic algorithms have been published, here, we sought improved algorithms for the problem with respect to the double cut and join (DCJ distance. The new algorithm makes use of partial and contracted partial graphs, and locally minimizes the distance. Our test results with simulation data indicate that it reliably recovers gene order of the ancestral polyploid genome even when the ancestor is ancient. We also compared the performance of our method with an earlier method using simulation data sets and found that our algorithm has higher accuracy. It is known that vertebrates had undergone two rounds of whole-genome duplication (2R-WGD during early vertebrate evolution. We used the new algorithm to calculate the DCJ distance between three modern vertebrate genomes and their 2R-WGD ancestor and found that the rearrangement rate might have slowed down significantly since the 2R-WGD. The software AliquotG implementing the algorithm is available as an open-source package from our website (http://mosas.sysu.edu.cn/genome/download_softwares.php.
Evaluation of Meta-Heuristic Algorithms for Stable Feature Selection
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Maysam Toghraee
2016-07-01
Full Text Available Now a days, developing the science and technology and technology tools, the ability of reviewing and saving the important data has been provided. It is needed to have knowledge for searching the data to reach the necessary useful results. Data mining is searching for big data sources automatically to find patterns and dependencies which are not done by simple statistical analysis. The scope is to study the predictive role and usage domain of data mining in medical science and suggesting a frame for creating, assessing and exploiting the data mining patterns in this field. As it has been found out from previous researches that assessing methods can not be used to specify the data discrepancies, our suggestion is a new approach for assessing the data similarities to find out the relations between the variation in data and stability in selection. Therefore we have chosen meta heuristic methods to be able to choose the best and the stable algorithms among a set of algorithms
Probabilistic dual heuristic programming-based adaptive critic
Herzallah, Randa
2010-02-01
Adaptive critic (AC) methods have common roots as generalisations of dynamic programming for neural reinforcement learning approaches. Since they approximate the dynamic programming solutions, they are potentially suitable for learning in noisy, non-linear and non-stationary environments. In this study, a novel probabilistic dual heuristic programming (DHP)-based AC controller is proposed. Distinct to current approaches, the proposed probabilistic (DHP) AC method takes uncertainties of forward model and inverse controller into consideration. Therefore, it is suitable for deterministic and stochastic control problems characterised by functional uncertainty. Theoretical development of the proposed method is validated by analytically evaluating the correct value of the cost function which satisfies the Bellman equation in a linear quadratic control problem. The target value of the probabilistic critic network is then calculated and shown to be equal to the analytically derived correct value. Full derivation of the Riccati solution for this non-standard stochastic linear quadratic control problem is also provided. Moreover, the performance of the proposed probabilistic controller is demonstrated on linear and non-linear control examples.
Teaching Evolution: A Heuristic Study of Personal and Cultural Dissonance
Grimes, Larry G.
Darwinian evolution is a robustly supported scientific theory. Yet creationists continue to challenge its teaching in American public schools. Biology teachers in all 50 states are responsible for teaching science content standards that include evolution. As products of their backgrounds and affiliations teachers bring personal attitudes and beliefs to their teaching. The purpose of this study was to explore how biology teachers perceive, describe, and value their teaching of evolution. This research question was explored through a heuristic qualitative methodology. Eight veteran California high school biology teachers were queried as to their beliefs, perceptions, experiences and practices of teaching evolution. Both personal and professional documents were collected. Data was presented in the form of biographical essays that highlight teachers' backgrounds, experiences, perspectives and practices of teaching evolution. Of special interest was how they describe pressure over teaching evolution during a decade of standards and No Child Left Behind high-stakes testing mandates. Five common themes emerged. Standards have increased the overall amount of evolution that is taught. High-stakes testing has decreased the depth at which evolution is taught. Teacher belief systems strongly influence how evolution is taught. Fear of creationist challenges effect evolution teaching strategies. And lastly, concern over the potential effects of teaching evolution on student worldviews was mixed. Three categories of teacher concern over the potential impact of evolution on student worldviews were identified: Concerned, Strategist, and Carefree. In the final analysis teacher beliefs and attitudes still appeared to he the most important factor influencing how evolution is taught.
Hybrid Experiential-Heuristic Cognitive Radio Engine Architecture and Implementation
Directory of Open Access Journals (Sweden)
Ashwin Amanna
2012-01-01
Full Text Available The concept of cognitive radio (CR focuses on devices that can sense their environment, adapt configuration parameters, and learn from past behaviors. Architectures tend towards simplified decision-making algorithms inspired by human cognition. Initial works defined cognitive engines (CEs founded on heuristics, such as genetic algorithms (GAs, and case-based reasoning (CBR experiential learning algorithms. This hybrid architecture enables both long-term learning, faster decisions based on past experience, and capability to still adapt to new environments. This paper details an autonomous implementation of a hybrid CBR-GA CE architecture on a universal serial radio peripheral (USRP software-defined radio focused on link adaptation. Details include overall process flow, case base structure/retrieval method, estimation approach within the GA, and hardware-software lessons learned. Unique solutions to realizing the concept include mechanisms for combining vector distance and past fitness into an aggregate quantification of similarity. Over-the-air performance under several interference conditions is measured using signal-to-noise ratio, packet error rate, spectral efficiency, and throughput as observable metrics. Results indicate that the CE is successfully able to autonomously change transmit power, modulation/coding, and packet size to maintain the link while a non-cognitive approach loses connectivity. Solutions to existing shortcomings are proposed for improving case-base searching and performance estimation methods.
A Heuristic Approach to Examining Volatile Equilibrium at Titan's Surface
Samuelson, Robert E.
1999-01-01
R. D. Lorenz, J. I. Lunine, and C. P. McKay have shown in a manuscript accepted for publication that, for a given ethane abundance and surface temperature, the nitrogen and methane abundances in Titan's atmosphere can be calculated, yielding a surface pressure that can be compared with the observed value. This is potentially a very valuable tool for examining the evolution of Titan's climatology. Its validity does depend on two important assumptions, however: 1) that the atmosphere of Titan is in global radiative equilibrium, and 2) that volatiles present are in vapor equilibrium with the surface. The former assumption has been shown to be likely, but the latter has not. Water vapor in the Earth's atmosphere, in fact, is generally not very close to equilibrium in a global sense. In the present work a heuristic approach is used to examine the likelihood that methane vapor is in equilibrium with Titan's surface. Plausible climate scenerios are examined that are consistent with methane vapor abundances derived from Voyager IRIS data. Simple precipitation and surface diffusion models are incorporated into the analysis. It is tentatively inferred that methane may be in surface equilibrium near the poles, but that equilibrium at low latitudes is more difficult to establish.
A proposed heuristic methodology for searching reloading pattern
International Nuclear Information System (INIS)
A new heuristic method for loading pattern search has been developed to overcome shortcomings of the algorithmic approach. To reduce the size of vast solution space, general shuffling rules, a regionwise shuffling method, and a pattern grouping method were introduced. The entropy theory was applied to classify possible loading patterns into groups with similarity between them. The pattern search program was implemented with use of the PROLOG language. A two-group nodal code MEDIUM-2D was used for analysis of power distribution in the core. The above mentioned methodology has been tested to show effectiveness in reducing of solution space down to a few hundred pattern groups. Burnable poison rods were then arranged in each pattern group in accordance with burnable poison distribution rules, which led to further reduction of the solution space to several scores of acceptable pattern groups. The method of maximizing cycle length (MCL) and minimizing power-peaking factor (MPF) were applied to search for specific useful loading patterns from the acceptable pattern groups. Thus, several specific loading patterns that have low power-peaking factor and large cycle length were successfully searched from the selected pattern groups. (Author)
Geometry optimization of bimetallic clusters using an efficient heuristic method
Lai, Xiangjing; Xu, Ruchu; Huang, Wenqi
2011-10-01
In this paper, an efficient heuristic algorithm for geometry optimization of bimetallic clusters is proposed. The algorithm is mainly composed of three ingredients: the monotonic basin-hopping method with guided perturbation (MBH-GP), surface optimization method, and iterated local search (ILS) method, where MBH-GP and surface optimization method are used to optimize the geometric structure of a cluster, and the ILS method is used to search the optimal homotop for a fixed geometric structure. The proposed method is applied to Cu38-nAun (0 ≤ n ≤ 38), Ag55-nAun (0 ≤ n ≤ 55), and Cu55-nAun (0 ≤ n ≤ 55) clusters modeled by the many-body Gupta potential. Comparison with the results reported in the literature indicates that the present method is highly efficient and a number of new putative global minima missed in the previous papers are found. The present method should be a promising tool for the theoretical determination of ground-state structure of bimetallic clusters. Additionally, some key elements and properties of the present method are also analyzed.
THE HEURISTIC POTENTIAL OF ANOMIE THEORY IN MODERN CRIMINOLOGY
Directory of Open Access Journals (Sweden)
Alexander Vladislavovich Pletnev
2015-01-01
Full Text Available This article deals with modern English theories of anomie. They can be used in Russian criminology. The main goal of article consists in detection of actual theories of anomie and definition of prospects of their use. As modern theories of anomie are poorly submitted in the Russian sociological and criminological literature, the subject of research is actual. This work contains the analysis of opportunities for adoption of modern conceptions of anomie of individual in Russian practice. During research development of the theory of anomie in the history of sociology was considered. The problem of anomie was admitted actual antique Greece. Anomie which is today concerned with normlessness and related to alienation is associated primarily with the works of Durkheim and Merton. Anomia developed in research by MacIver and Srole as a characteristic of individuals and related to the breakdown of the individual’s sense of attachment to society. Results of theoretical research show that theories of anomie of the personality have the greatest heuristic potential for modern Russian science. Other important conclusion of research is one that the anomie can have some sources of emergence. Further studying of this subject is necessary because English-language theories of anomie contain a set of theoretical and empirical results which can be used in the Russian criminology.
Study of heuristics in ant system for nuclear reload optimisation
International Nuclear Information System (INIS)
A Pressurized Water Reactor core must be reloaded every time the fuel burnup reaches a level when it is not possible to sustain nominal power operation. The nuclear core fuel reload optimization consists in finding a burned-up and fresh-fuel-assembly loading pattern that maximizes the number of effective full power days, minimizing the relationship cost/benefit. This problem is NP-hard, meaning that complexity grows exponentially with the number of fuel assemblies in the core. Besides that, the problem is non-linear and its search space is highly discontinual and multimodal. In this work a parallel computational system based on Ant Colony System (ACS) called Artificial-Ant-Colony Networks is used to solve the nuclear reactor core fuel reload optimization problem, with compatibles heuristics. ACS is a system based on artificial agents that uses the reinforcement learning technique and was originally developed to solve the Traveling Salesman Problem, which is conceptually similar to the nuclear fuel reload problem. (author)
SOS-Heuristic for Intelligent Exploration of Search Space in CSOP
Wassim, Jaziri
2008-01-01
We have proposed in this work a constraints satisfaction and optimization approach to orient the search process in optimization problems. We have developed a generic approach that allows to solve simultaneously the task of optimization and of constraints satisfaction based on an intelligent search heuristic : the SOS-Heuristic. The experiments concern a spatial optimization problem related to a distribution of crops on agricultural parcels to minimize the runoff risk. The application of a hyb...
A hybrid adaptive large neighborhood search heuristic for lot-sizing with setup times
Muller, Laurent Flindt; Spoorendonk, Simon; Pisinger, David
2012-01-01
This paper presents a hybrid of a general heuristic framework and a general purpose mixed-integer programming (MIP) solver. The framework is based on local search and an adaptive procedure which chooses between a set of large neighborhoods to be searched. A mixed integer programming solver and its built-in feasibility heuristics is used to search a neighborhood for improving solutions. The general reoptimization approach used for repairing solutions is specifically suited for combinatorial pr...
A Heuristic Approach to Risk Analysis in Computer-Assisted Medical Management
Miller, Perry L.
1982-01-01
The paper describes the heuristic approach to risk analysis taken by ATTENDING, an Artificial Intelligence system designed to critique a physician's plan of anesthetic management. To critique a physician's plan, the system must know about the different risks and risk tradeoffs involved in a patient's management. It must also be able to manipulate this knowledge in a flexible way. The paper discusses the three principles on which ATTENDING's heuristic approach to risk is based, and also descri...
Directory of Open Access Journals (Sweden)
D. A. Viattchenin
2009-01-01
Full Text Available A method for constructing a subset of labeled objects which is used in a heuristic algorithm of possible clusterization with partial training is proposed in the paper. The method is based on data preprocessing by the heuristic algorithm of possible clusterization using a transitive closure of a fuzzy tolerance. Method efficiency is demonstrated by way of an illustrative example.
Application of different heuristic classes in memory-based and stimulus-based decisions
Kwiatkowski, Lukasz
2014-01-01
This paper studies the drivers of heuristic application in different decision types. The study compares differences in frequencies of heuristic classes' such as recognition, one-reason choice and trade-off applied in, respectively, memory-based and stimulus-based choices as well as in high and low involvement decisions. The study has been conducted online among 205 participants from 28 countries. NSBE - UNL
A Heuristic Criterion for Instability to Fragmentation in Rotating, Interstellar Clouds
Boss, Alan Paul
1982-01-01
A heuristic criterion, based on linear perturbation analysis, is applied to the initial growth of density perturbations in isothermal or adiabatic gas clouds, with initially uniform density and uniform rotation. The heuristic criterion is shown to be consistent with the available results from numerical calculations of cloud collapse. The criterion predicts that perturbations varying as cos (m(phi)) will be most likely to grow when )pi is small, unless the cloud is nearly pressureless.
A marketing science perspective on recognition-based heuristics (and the fast-and-frugal paradigm)
John Hauser
2011-01-01
Marketing science seeks to prescribe better marketing strategies (advertising, product development, pricing, etc.). To do so we rely on models of consumer decisions grounded in empirical observations. Field experience suggests that recognition-based heuristics help consumers to choose which brands to consider and purchase in frequently-purchased categories, but other heuristics are more relevant in durable-goods categories. Screening with recognition is a rational screening rule when advertis...
A heuristic for the inventory management of smart vending machine systems
Yang-Byung Park; Jun-Soo Yoo
2012-01-01
Purpose: The purpose of this paper is to propose a heuristic for the inventory management of smart vending machine systems with product substitution under the replenishment point, order-up-to level policy and to evaluate its performance.Design/methodology/approach: The heuristic is developed on the basis of the decoupled approach. An integer linear mathematical model is built to determine the number of product storage compartments and replenishment threshold for each smart vending machine in ...
A heuristic for the inventory management of smart vending machine systems
Park, Yang-Byung
2012-01-01
Purpose: The purpose of this paper is to propose a heuristic for the inventory management of smart vending machine systems with product substitution under the replenishment point, order-up-to level policy and to evaluate its performance. Design/methodology/approach: The heuristic is developed on the basis of the decoupled approach. An integer linear mathematical model is built to determine the number of product storage compartments and replenishment threshold for each smart vending machin...
Directory of Open Access Journals (Sweden)
Stanimirović Ivan
2009-01-01
Full Text Available We introduce a heuristic method for the single resource constrained project scheduling problem, based on the dynamic programming solution of the knapsack problem. This method schedules projects with one type of resources, in the non-preemptive case: once started an activity is not interrupted and runs to completion. We compare the implementation of this method with well-known heuristic scheduling method, called Minimum Slack First (known also as Gray-Kidd algorithm, as well as with Microsoft Project.
Greedy heuristics for minimization of number of terminal nodes in decision trees
Hussain, Shahid
2014-10-01
This paper describes, in detail, several greedy heuristics for construction of decision trees. We study the number of terminal nodes of decision trees, which is closely related with the cardinality of the set of rules corresponding to the tree. We compare these heuristics empirically for two different types of datasets (datasets acquired from UCI ML Repository and randomly generated data) as well as compare with the optimal results obtained using dynamic programming method.
A Heuristic Genetic Algorithm for No-Wait Flowshop Scheduling Problem
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
No-wait flowshop scheduling problems with the objective to minimize the total flow time is an important sequencing problem in the field of developing production plans and has a wide engineering background.Genetic algorithm (GA) has the capability of global convergence and has been proven effective to solve NP-hard combinatorial optimization problems, while simple heuristics have the advantage of fast local convergence and can be easily implemented.In order to avoid the defect of slow convergence or premature, a heuristic genetic algorithm is proposed by incorporating the simple heuristics and local search into the traditional genetic algorithm.In this hybridized algorithm, the structural information of no-wait flowshops and high-effective heuristics are incorporated to design a new method for generating initial generation and a new crossover operator.The computational results show the developed heuristic genetic algorithm is efficient and the quality of its solution has advantage over the best known algorithm.It is suitable for solving the large scale practical problems and lays a foundation for the application of meta-heuristic algorithms in industrial production.
A Role of Heuristics Miner Algorithm in the Business Process System
Directory of Open Access Journals (Sweden)
Saravanan .M.S
2011-03-01
Full Text Available The main idea of process mining is to extract knowledge or information from event logs recorded by an information system. Till now, the information in these event logs was rarely used to analyze the underlying processes. Process mining aims at improving this by providing techniques and tools for discovering process, organizational, social, and performance information from event logs. Process mining has become a bright research area. In this paper we discuss the challenging process mining domain and demonstrate a heuristics driven process mining algorithm; the so called Heuristics Miner in detail. Heuristics Miner is a practical applicable mining algorithm that can deal with noise, and can be used to express the main behavior that is not all details and exceptions, registered in an event log. The business process system has a complex process system, which deals about many cases or audit trail entries and various event logs. This paper deals about the role of Heuristics Miner algorithm in the field of Business process system, also the Heuristics Miner algorithm is compared with the other mining algorithm such as α-algorithm. Hence, we analyzed that, is it possible to develop a control flow process mining algorithm such as Heuristics Miner algorithm can discover all the common control flow structures and is robust to noisy logs at once? This paper attempts to provide an answer to this question.
Band structure of semiconductors
Tsidilkovski, I M
2013-01-01
Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio
International Nuclear Information System (INIS)
In this note, three vibrational bands of the electronic transition A2Σ+-X2Π of the N2O+ radical (000-100, 100-100, and 001-101) were theoretically analysed. Starting from Hamiltonian models proposed for this kind of molecule, their parameters were calculated using a Levenberg-Marquardt fit procedure in order to reduce the root mean square deviation from the experimental transitions below to 0.01 cm−1. The main objective of this work is to obtain new and reliable values for rotational constant B″ and the spin-orbit interaction parameter A of the analysed vibrational levels of the X2Π electronic state of this molecule
Lessa, L L; Martins, A S; Fellows, C E
2015-10-28
In this note, three vibrational bands of the electronic transition A(2)Σ(+)-X(2)Π of the N2O(+) radical (000-100, 100-100, and 001-101) were theoretically analysed. Starting from Hamiltonian models proposed for this kind of molecule, their parameters were calculated using a Levenberg-Marquardt fit procedure in order to reduce the root mean square deviation from the experimental transitions below to 0.01 cm(-1). The main objective of this work is to obtain new and reliable values for rotational constant B″ and the spin-orbit interaction parameter A of the analysed vibrational levels of the X(2)Π electronic state of this molecule. PMID:26520556
The heuristic value of redundancy models of aging.
Boonekamp, Jelle J; Briga, Michael; Verhulst, Simon
2015-11-01
Molecular studies of aging aim to unravel the cause(s) of aging bottom-up, but linking these mechanisms to organismal level processes remains a challenge. We propose that complementary top-down data-directed modelling of organismal level empirical findings may contribute to developing these links. To this end, we explore the heuristic value of redundancy models of aging to develop a deeper insight into the mechanisms causing variation in senescence and lifespan. We start by showing (i) how different redundancy model parameters affect projected aging and mortality, and (ii) how variation in redundancy model parameters relates to variation in parameters of the Gompertz equation. Lifestyle changes or medical interventions during life can modify mortality rate, and we investigate (iii) how interventions that change specific redundancy parameters within the model affect subsequent mortality and actuarial senescence. Lastly, as an example of data-directed modelling and the insights that can be gained from this, (iv) we fit a redundancy model to mortality patterns observed by Mair et al. (2003; Science 301: 1731-1733) in Drosophila that were subjected to dietary restriction and temperature manipulations. Mair et al. found that dietary restriction instantaneously reduced mortality rate without affecting aging, while temperature manipulations had more transient effects on mortality rate and did affect aging. We show that after adjusting model parameters the redundancy model describes both effects well, and a comparison of the parameter values yields a deeper insight in the mechanisms causing these contrasting effects. We see replacement of the redundancy model parameters by more detailed sub-models of these parameters as a next step in linking demographic patterns to underlying molecular mechanisms. PMID:26362219
Mixed Integer Programming and Heuristic Scheduling for Space Communication
Lee, Charles H.; Cheung, Kar-Ming
2013-01-01
Optimal planning and scheduling for a communication network was created where the nodes within the network are communicating at the highest possible rates while meeting the mission requirements and operational constraints. The planning and scheduling problem was formulated in the framework of Mixed Integer Programming (MIP) to introduce a special penalty function to convert the MIP problem into a continuous optimization problem, and to solve the constrained optimization problem using heuristic optimization. The communication network consists of space and ground assets with the link dynamics between any two assets varying with respect to time, distance, and telecom configurations. One asset could be communicating with another at very high data rates at one time, and at other times, communication is impossible, as the asset could be inaccessible from the network due to planetary occultation. Based on the network's geometric dynamics and link capabilities, the start time, end time, and link configuration of each view period are selected to maximize the communication efficiency within the network. Mathematical formulations for the constrained mixed integer optimization problem were derived, and efficient analytical and numerical techniques were developed to find the optimal solution. By setting up the problem using MIP, the search space for the optimization problem is reduced significantly, thereby speeding up the solution process. The ratio of the dimension of the traditional method over the proposed formulation is approximately an order N (single) to 2*N (arraying), where N is the number of receiving antennas of a node. By introducing a special penalty function, the MIP problem with non-differentiable cost function and nonlinear constraints can be converted into a continuous variable problem, whose solution is possible.
Evaluation of adjustment functions in a heuristic algorithm
International Nuclear Information System (INIS)
At present the techniques of evolution al computation receive an increasing attention in the scientific and technological areas. This situation is due to its enormous potential in the optimization applied to problems of discussed computational complexity. In the nuclear area these techniques are used in diverse problems of combinatory optimization related with designing cores of power reactors. A distinctive characteristic of the evolution al and/or meta-heuristic algorithms is that appeal in each one from their applications to an adjustment function, fitness or of quality. This function allows to discriminate or to evaluate potentials solutions of the problem to solve. The definition of this situation is very important since it allows following the search of the algorithm toward different regions of the search space. In this work the impact that has the election of this function in the quality of the found solution is shown. The optimization technique by ant colonies or Acs (ant colony system) was used applied to the radial design of fuel cells for a boiling water power reactor. The notable results of the Acs allowed to propose the adjustment method of the importance and with this to obtain adjustment functions that guide the search of solutions of collective algorithms efficiently, basic capacity to develop the proposal of emulation of the natural selection and to investigate the possibility that on order of specify goals, to obtain the corresponding decision variables. A variety of re tro-exit (re tro-out) complementary process of feedback (re tro-in) that opens extended application perspectives of be feasible. (Author)
International Nuclear Information System (INIS)
An overview of the theoretical and experimental efforts in obtaining a photonic band gap, a frequency band in three-dimensional dielectric structures in which electromagnetic waves are forbidden, is presented
Band parameters of phosphorene
DEFF Research Database (Denmark)
Lew Yan Voon, L. C.; Wang, J.; Zhang, Y.;
2015-01-01
Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory are co...
Flat Band Quastiperiodic Lattices
Bodyfelt, Joshua; Flach, Sergej; Danieli, Carlo
2014-03-01
Translationally invariant lattices with flat bands (FB) in their band structure possess irreducible compact localized flat band states, which can be understood through local rotation to a Fano structure. We present extension of these quasi-1D FB structures under incommensurate lattices, reporting on the FB effects to the Metal-Insulator Transition.
Low-frequency band gap mechanism of torsional vibration of lightweight elastic metamaterial shafts
Li, Lixia; Cai, Anjiang
2016-07-01
In this paper, the low-frequency band gap mechanism of torsional vibration is investigated for a kind of light elastic metamaterial (EM) shafts architecture comprised of a radial double-period element periodically as locally resonant oscillators with low frequency property. The dispersion relations are calculated by a method combining the transfer matrix and a lumped-mass method. The theoretical results agree well with finite method simulations, independent of the density of the hard material ring. The effects of the material parameters on the band gaps are further explored numerically. Our results show that in contrast to the traditional EM shaft, the weight of our proposed EM shaft can be reduced by 27% in the same band gap range while the vibration attenuation is kept unchanged, which is very convenient to instruct the potential engineering applications. Finally, the band edge frequencies of the lower band gaps for this light EM shaft are expressed analytically using physical heuristic models.
DEFF Research Database (Denmark)
Daalhuizen, Jaap; Person, Oscar; Gattol, Valentin
activities in the basic design cycle: (1) analysis, (2) synthesis, (3) simulation, (4) evaluation and (5) decision-making. The results of the study showed that knowledge and preference both influence method usage. Additionally, the results showed that for all activities except evaluation, knowledge......Both systematic and heuristic methods are common practice when designing. Yet, in teaching students how to design, heuristic methods are typically only granted a secondary role. So, how do designers and students develop a mindset for using heuristic methods? In this paper, we study how prior...... knowledge (about heuristic methods and their usage) and preference (for using heuristic methods) relate to the reported use of heuristic methods when designing. Drawing on a survey among 304 students enrolled in a master-level course on design theory and methodology, we investigated method usage for five...
DEFF Research Database (Denmark)
Daalhuizen, Jaap; Person, Oscar; Gattol, Valentin
Both systematic and heuristic methods are common practice when designing. Yet, in teaching students how to design, heuristic methods are typically only granted a secondary role. So, how do designers and students develop a mindset for using heuristic methods? In this paper, we study how prior...... knowledge (about heuristic methods and their usage) and preference (for using heuristic methods) relate to the reported use of heuristic methods when designing. Drawing on a survey among 304 students enrolled in a master-level course on design theory and methodology, we investigated method usage for five...... activities in the basic design cycle: (1) analysis, (2) synthesis, (3) simulation, (4) evaluation and (5) decision-making. The results of the study showed that knowledge and preference both influence method usage. Additionally, the results showed that for all activities except evaluation, knowledge...
Conceptual space systems design using meta-heuristic algorithms
Kim, Byoungsoo
criteria. Two meta-heuristic optimization algorithms, Genetic Algorithms (GAs) and Simulated Annealing (SA), were used to optimize the formulated (simply bounded) Constrained Combinatorial Conceptual Space Systems Design Model. GAs and SA were demonstrated on the SAMPEX (Solar Anomalous & Magnetospheric Particle Explorer) Space System. The Conceptual Space Systems Design Model developed in this thesis can be used as an assessment tool to evaluate and validate Space System proposals.
Meta-Heuristic Combining Prior Online and Offline Information for the Quadratic Assignment Problem.
Sun, Jianyong; Zhang, Qingfu; Yao, Xin
2014-03-01
The construction of promising solutions for NP-hard combinatorial optimization problems (COPs) in meta-heuristics is usually based on three types of information, namely a priori information, a posteriori information learned from visited solutions during the search procedure, and online information collected in the solution construction process. Prior information reflects our domain knowledge about the COPs. Extensive domain knowledge can surely make the search effective, yet it is not always available. Posterior information could guide the meta-heuristics to globally explore promising search areas, but it lacks local guidance capability. On the contrary, online information can capture local structures, and its application can help exploit the search space. In this paper, we studied the effects of using this information on metaheuristic's algorithmic performances for the COPs. The study was illustrated by a set of heuristic algorithms developed for the quadratic assignment problem. We first proposed an improved scheme to extract online local information, then developed a unified framework under which all types of information can be combined readily. Finally, we studied the benefits of the three types of information to meta-heuristics. Conclusions were drawn from the comprehensive study, which can be used as principles to guide the design of effective meta-heuristic in the future. PMID:23757559
Choosing a heuristic and root node for edge ordering in BDD-based network reliability analysis
International Nuclear Information System (INIS)
In the Binary Decision Diagram (BDD)-based network reliability analysis, heuristics have been widely used to obtain a reasonably good ordering of edge variables. Orderings generated using different heuristics can lead to dramatically different sizes of BDDs, and thus dramatically different running times and memory usages for the analysis of the same network. Unfortunately, due to the nature of the ordering problem (i.e., being an NP-complete problem) no formal guidelines or rules are available for choosing a good heuristic or for choosing a high-performance root node to perform edge searching using a particular heuristic. In this work, we make novel contributions by proposing heuristic and root node selection methods based on the concept of boundary sets for the BDD-based network reliability analysis. Empirical studies show that the proposed selection methods can help to generate high-performance edge ordering for most of studied cases, enabling the efficient BDD-based reliability analysis of large-scale networks. The proposed methods are demonstrated on different types of networks, including square lattice networks, torus lattice networks and de Bruijn networks
Heuristics and representational change in two-move matchstick arithmetic tasks
Directory of Open Access Journals (Sweden)
Michael Öllinger
2006-01-01
Full Text Available Insight problems are problems where the problem solver struggles to find a solution until * aha! * the solution suddenly appears. Two contemporary theories suggest that insight problems are difficult either because problem solvers begin with an incorrect representation of the problem, or that problem solvers apply inappropriate heuristics to the problem. The relative contributions of representational change and inappropriate heuristics on the process of insight problem solving was studied with a task that required the problem solver to move two matchsticks in order to transform an incorrect arithmetic statement into a correct one. Problem solvers (N = 120 worked on two different types of two-move matchstick arithmetic problems that both varied with respect to the effectiveness of heuristics and to the degree of a necessary representational change of the problem representation. A strong influence of representational change on solution rates was found whereas the influence of heuristics hadminimal effects on solution rates. That is, the difficulty of insight problems within the two-move matchstick arithmetic domain is governed by the degree of representational change required. A model is presented that details representational change as the necessary condition for ensuring that appropriate heuristics can be applied on the proper problem representation.
Directory of Open Access Journals (Sweden)
Kusrini Kusrini
2007-01-01
Full Text Available There are plenty well-known algorithms for solving Travelling Salesman Program (TSP, such as: Linear Programming (LP, Genetic Algorithm (GA, Nearest Neighbourhood Heuristic (NNH and Cheapest Insertion Heuristic (CIH. This paper will talk about TSP implementation by using CIH algorithm. The writer uses Borland Delphi 6 and Interbase 6 as tool for implementing TSP. CIH algorithm has been implemented successfully. By determining count of connected cities and distances between them, the traveled route and total route length to visit all cities in a cities network were obtained. However, this algorithm implementation has not yet be able to solve route searching if there are two cities have different load or there are 2 cities that is not connected. Abstract in Bahasa Indonesia : Ada banyak algoritma untuk memecahkan masalah Travelling Salesman Problem (TSP, diantaranya: Linear Programming (LP, Algoritma Genetik, Nearest Neighbourhood Heuristic (NNH and Cheapest Insertion Heuristic (CIH. Makalah ini akan membahas tentang implementasi algoritma CIH untuk menyelesaikan TSP. Penulis menggunakan Borland Delphi 6 dan Interbase 6 sebagai tool dalam implementasi TSP. Algoritma CIH telah berhasil diimplementasikan. Dengan mengetahui jumlah kota yang terhubung dan jarak diantaranya, rute perjalanan dan total panjang rute untuk mengunjungi semua kota dalam jaringan dapat diketahui. Namun demikian, implementasi algoritma belum mampu menyelesaikan masalah pencarian rute jika ada 2 kota yang mimiliki bobot yang berbeda dengan melihat arahnya dan jika ada 2 buah kota yang tidak terhubung. Kata kunci: TSP, cheapest, insertion, heuristics, basis data.
FDK Half-Scan with a Heuristic Weighting Scheme on a Flat Panel Detector-Based Cone Beam CT (FDKHSCW
Directory of Open Access Journals (Sweden)
Ruola Ning
2006-09-01
Full Text Available A cone beam circular half-scan scheme is becoming an attractive imaging method in cone beam CT since it improves the temporal resolution. Traditionally, the redundant data in the circular half-scan range is weighted by a central scanning plane-dependent weighting function; FDK algorithm is then applied on the weighted projection data for reconstruction. However, this scheme still suffers the attenuation coefficient drop inherited with FDK when the cone angle becomes large. A new heuristic cone beam geometry-dependent weighting scheme is proposed based on the idea that there exists less redundancy for the projection data away from the central scanning plane. The performance of FDKHSCW scheme is evaluated by comparing it to the FDK full-scan (FDKFS scheme and the traditional FDK half-scan scheme with Parker's fan beam weighting function (FDKHSFW. Computer simulation is employed and conducted on a 3D Shepp-Logan phantom. The result illustrates a correction of FDKHSCW to the attenuation coefficient drop in the off-scanning plane associated with FDKFS and FDKHSFW while maintaining the same spatial resolution.
Empathy as a neuropsychological heuristic in social decision-making
DEFF Research Database (Denmark)
Ramsøy, Thomas Z.; Skov, Martin; Macoveanu, Julian;
2015-01-01
’s relative ability to understand others’ thoughts, emotions, and intentions—acts as an individual factor that alleviates conflict resolution in social decision-making. We test this by using a framed, iterated prisoners’ dilemma (PD) game in two settings. In a behavioral experiment, we find that individual...
Band-selective radiofrequency pulses
Geen, Helen; Freeman, Ray
A theoretical treatment is given of the general problem of designing amplitude-modulated radiofrequency pulses that will excite a specified band of frequencies within a high-resolution NMR spectrum with uniform intensity and phase but with negligible excitation elsewhere. First a trial pulse envelope is defined in terms of a finite Fourier series and its frequency-domain profile calculated through the Bloch equations. The result is compared with the desired target profile to give a multidimensional error surface. The method of simulated annealing is then used to find the global minimum on this surface and the result refined by standard gradient-descent optimization. In this manner, a family of new shaped radio-frequency pulses, known as BURP ( band-selective, uniform response, pure-phase) pulses, has been created. These are of two classes—pulses that excite or invert z magnetization and those that act as general-rotation πr/2 or π pulses irrespective of the initial condition of the nuclear magnetization. It was found convenient to design the latter class as amplitude-modulated time-symmetric pulses. Tables of Fourier coefficients and pulse-shape ordinates are given for practical implementation of BURP pulses, together with the calculated frequency-domain responses and experimental verifications. Examples of the application of band-selective pulses in conventional and multidimensional spectroscopy are given. Pure-phase pulses of this type should also find applications in magnetic resonance imaging where refocusing schemes are undesirable.
Biases and Heuristics in Decision Making and Their Impact on Autonomy.
Blumenthal-Barby, J S
2016-05-01
Cognitive scientists have identified a wide range of biases and heuristics in human decision making over the past few decades. Only recently have bioethicists begun to think seriously about the implications of these findings for topics such as agency, autonomy, and consent. This article aims to provide an overview of biases and heuristics that have been identified and a framework in which to think comprehensively about the impact of them on the exercise of autonomous decision making. I analyze the impact that these biases and heuristics have on the following dimensions of autonomy: understanding, intentionality, absence of alienating or controlling influence, and match between formally autonomous preferences or decisions and actual choices or actions. PMID:27111357
A nuclear heuristic for application to metaheuristics in-core fuel management optimization
International Nuclear Information System (INIS)
The In-Core Fuel Management Optimization (ICFMO) is a well-known problem of nuclear engineering whose features are complexity, high number of feasible solutions, and a complex evaluation process with high computational cost, thus it is prohibitive to have a great number of evaluations during an optimization process. Heuristics are criteria or principles for deciding which among several alternative courses of action are more effective with respect to some goal. In this paper, we propose a new approach for the use of relational heuristics for the search in the ICFMO. The Heuristic is based on the reactivity of the fuel assemblies and their position into the reactor core. It was applied to random search, resulting in less computational effort concerning the number of evaluations of loading patterns during the search. The experiments demonstrate that it is possible to achieve results comparable to results in the literature, for future application to metaheuristics in the ICFMO. (author)
Institute of Scientific and Technical Information of China (English)
Bo HUANG; Yamin SUN
2005-01-01
This paper proposes and evaluates two improved Petri net (PN)-based hybrid search strategies and their applications to flexible manufacturing system (FMS) scheduling.The algorithms proposed in some previous papers,which combine PN simulation capabilities with A* heuristic search within the PN reachability graph,may not find an optimum solution even with an admissible heuristic function.To remedy the defects an improved heuristic search strategy is proposed,which adopts a different method for selecting the promising markings and reserves the admissibility of the algorithm.To speed up the search process,another algorithm is also proposed which invokes faster termination conditions and still guarantees that the solution found is optimum.The scheduling results are compared through a simple FMS between our algorithms and the previous methods.They are also applied and evaluated in a set of randomly-generated FMSs with such characteristics as multiple resources and alternative routes.
Analysis of Petri net model and task planning heuristic algorithms for product reconfiguration
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Reconfiguration planning is recognized as an important factor for reducing the cost of manufacturing reconfigurable products, and the associated main task is to generate a set of optimal or near-optimal reconfiguration sequences using some effect algorithms. A method is developed to generate a Petri net as the reconfiguration tree to represent two-state-transit of product, which solved the representation problem of reconfiguring interfaces replacement. Relating with this method, two heuristic algorithms are proposed to generate task sequences which considering economics to search reconfiguration paths effectively. At last,an objective evaluation is applied to compare these two heuristic algorithms to other ones. The developed reconfiguration task planning heuristic algorithms can generate better strategies and plans for reconfiguration. The research finds are exemplified with struts reconfiguration of reconfigurable parallel kinematics machine (RPKM).
A heuristic algorithm for a multi-product four-layer capacitated location-routing problem
Directory of Open Access Journals (Sweden)
Mohsen Hamidi
2014-01-01
Full Text Available The purpose of this study is to solve a complex multi-product four-layer capacitated location-routing problem (LRP in which two specific constraints are taken into account: 1 plants have limited production capacity, and 2 central depots have limited capacity for storing and transshipping products. The LRP represents a multi-product four-layer distribution network that consists of plants, central depots, regional depots, and customers. A heuristic algorithm is developed to solve the four-layer LRP. The heuristic uses GRASP (Greedy Randomized Adaptive Search Procedure and two probabilistic tabu search strategies of intensification and diversification to tackle the problem. Results show that the heuristic solves the problem effectively.
Meta-heuristics in cellular manufacturing: A state-of-the-art review
Directory of Open Access Journals (Sweden)
Tamal Ghosh
2011-01-01
Full Text Available Meta-heuristic approaches are general algorithmic framework, often nature-inspired and designed to solve NP-complete optimization problems in cellular manufacturing systems and has been a growing research area for the past two decades. This paper discusses various meta-heuristic techniques such as evolutionary approach, Ant colony optimization, simulated annealing, Tabu search and other recent approaches, and their applications to the vicinity of group technology/cell formation (GT/CF problem in cellular manufacturing. The nobility of this paper is to incorporate various prevailing issues, open problems of meta-heuristic approaches, its usage, comparison, hybridization and its scope of future research in the aforesaid area.
Kato, Tomohiro; Hasegawa, Mikio
Chaotic dynamics has been shown to be effective in improving the performance of combinatorial optimization algorithms. In this paper, the performance of chaotic dynamics in the asymmetric traveling salesman problem (ATSP) is investigated by introducing three types of heuristic solution update methods. Numerical simulation has been carried out to compare its performance with simulated annealing and tabu search; thus, the effectiveness of the approach using chaotic dynamics for driving heuristic methods has been shown. The chaotic method is also evaluated in the case of a combinatorial optimization problem in the real world, which can be solved by the same heuristic operation as that for the ATSP. We apply the chaotic method to the DNA fragment assembly problem, which involves building a DNA sequence from several hundred fragments obtained by the genome sequencer. Our simulation results show that the proposed algorithm using chaotic dynamics in a block shift operation exhibits the best performance for the DNA fragment assembly problem.
Heuristic algorithm for RCPSP with the objective of minimizing activities' cost
Institute of Scientific and Technical Information of China (English)
Liu Zhenyuan; Wang Hongwei
2006-01-01
Resource-constrained project scheduling problem(RCPSP) is an important problem in research on project management. But there has been little attention paid to the objective of minimizing activities' cost with the resource constraints that is a critical sub-problem in partner selection of construction supply chain management because the capacities of the renewable resources supplied by the partners will effect on the project scheduling. Its mathematic model is presented firstly, and analysis on the characteristic of the problem shows that the objective function is non-regular and the problem is NP-complete following which the basic idea for solution is clarified. Based on a definition of preposing activity cost matrix, a heuristic algorithm is brought forward. Analyses on the complexity of the heuristics and the result of numerical studies show that the heuristic algorithm is feasible and relatively effective.