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.
Measured-predicted molecular spectra at band-line resolution
Freeman, G. N.; Akagi, T.; Barton, P. B. C.
2016-10-01
Early ERIM measurements of hot-through-cold gas (CO2, H2O, N2) emission-absorption spectra are replicated by modern line-band computations that incorporate independent fundamental line strength-frequency information. Close agreement is achieved for all cases by empirical adjustment of the line broadening function. Line spectra for CO2 and H2O computed at 0.001 cm-1 resolution were integrated to 3.2 and 14 cm-1 using a triangular slit function consistent with ERIM measurements for the 4.3 and 2.7 μm spectral regions. Band spectra computed at 0.1 cm-1 resolution give close agreement with spectra generated at higher resolution. The findings demonstrate a merged line-band model for nonuniform path radiance and transmittance based on the line-sum spectral cross section for each piecewise-uniform path segment. The band-and-line transmittance become equivalent at high spectral resolution.
High-resolution wide-band Fast Fourier Transform spectrometers
Klein, Bernd; Hochgürtel, Stefan; 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 B...
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.
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...
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.
A high-resolution, four-band SAR testbed with real-time image formation
Energy Technology Data Exchange (ETDEWEB)
Walker, B.; Sander, G.; Thompson, M.; Burns, B.; Fellerhoff, R.; Dubbert, D.
1996-03-01
This paper describes the Twin-Otter SAR Testbed developed at Sandia National Laboratories. This SAR is a flexible, adaptable testbed capable of operation on four frequency bands: Ka, Ku, X, and VHF/UHF bands. The SAR features real-time image formation at fine resolution in spotlight and stripmap modes. High-quality images are formed in real time using the overlapped subaperture (OSA) image-formation and phase gradient autofocus (PGA) algorithms.
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.
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.
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...
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...
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...
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.
NLTE Analysis of High Resolution H-band Spectra. I. Neutral Silicon
Zhang, Junbo; Pan, Kaike; Prieto, Carlos Allende; Liu, Chao
2016-01-01
We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si I) lines in the near-infrared (near-IR) H-band. We derived the differential Si abundances for 13 sample stars with high-resolution H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), as well as from optical spectra, both under local thermodynamical equilibrium (LTE) and NLTE conditions. We found that the differences between the Si abundances derived from the H-band and from optical lines for the same stars are less than 0.1 dex when the NLTE effects included, and that NLTE reduces the line-to-line scatter in the H-band spectra for most sample stars. These results suggest that our Si atomic model is appropriate for studying the formation of H-band Si lines. Our calculations show that the NLTE corrections of the Si I H-band lines are negative, i.e. the final Si abundances will be overestimated in LTE. The correc...
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
A high-resolution study of near-infrared diffuse interstellar bands
Energy Technology Data Exchange (ETDEWEB)
Rawlings, M. G. [National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903 (United States); Adamson, A. J. [Gemini Observatory, 670 N. A' ohoku Place, University Park, Hilo, HI 96720 (United States); Kerr, T. H., E-mail: mrawling@nrao.edu, E-mail: aadamson@gemini.edu, E-mail: t.kerr@jach.hawaii.edu [Joint Astronomy Centre, 660 N. A' ohoku Place, University Park, Hilo, HI 96720 (United States)
2014-11-20
We present high-resolution echelle spectroscopic observations of the two near-infrared (NIR) diffuse interstellar bands (DIBs) at 13175 Å and 11797.5 Å. 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 nine 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 μm previously detected in the same sightlines. We find that the NIR DIBs do not exhibit notable (anti)correlations with either. Implications of these observations on possible DIB carrier species are discussed.
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.
NLTE Analysis of High Resolution H-band Spectra. II. Neutral Magnesium
Zhang, Junbo; Pan, Kaike; Prieto, Carlos Allende; Liu, Chao
2016-01-01
Aiming at testing the validity of our magnesium atomic model and investigating the effects of non-local thermodynamical equilibrium (NLTE) on the formation of the H-band neutral magnesium lines, we derive the differential Mg abundances from selected transitions for 13 stars either adopting or relaxing the assumption of local thermodynamical equilibrium (LTE). Our analysis is based on high-resolution and high signal-to-noise ratio H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and optical spectra from several instruments. The absolute differences between the Mg abundances derived from the two wavelength bands are always less than 0.1 dex in the NLTE analysis, while they are slightly larger for the LTE case. This suggests that our Mg atomic model is appropriate for investigating the NLTE formation of the H-band Mg lines. The NLTE corrections for the Mg I H-band lines are sensitive to the surface gravity, becoming larger for smaller log g values, and strong lines are more...
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.
Directory of Open Access Journals (Sweden)
Charles R. Lane
2014-12-01
Full Text Available Although remote sensing technology has long been used in wetland inventory and monitoring, the accuracy and detail level of wetland maps derived with moderate resolution imagery and traditional techniques have been limited and often unsatisfactory. We explored and evaluated the utility of a newly launched high-resolution, eight-band satellite system (Worldview-2; WV2 for identifying and classifying freshwater deltaic wetland vegetation and aquatic habitats in the Selenga River Delta of Lake Baikal, Russia, using a hybrid approach and a novel application of Indicator Species Analysis (ISA. We achieved an overall classification accuracy of 86.5% (Kappa coefficient: 0.85 for 22 classes of aquatic and wetland habitats and found that additional metrics, such as the Normalized Difference Vegetation Index and image texture, were valuable for improving the overall classification accuracy and particularly for discriminating among certain habitat classes. Our analysis demonstrated that including WV2’s four spectral bands from parts of the spectrum less commonly used in remote sensing analyses, along with the more traditional bandwidths, contributed to the increase in the overall classification accuracy by ~4% overall, but with considerable increases in our ability to discriminate certain communities. The coastal band improved differentiating open water and aquatic (i.e., vegetated habitats, and the yellow, red-edge, and near-infrared 2 bands improved discrimination among different vegetated aquatic and terrestrial habitats. The use of ISA provided statistical rigor in developing associations between spectral classes and field-based data. Our analyses demonstrated the utility of a hybrid approach and the benefit of additional bands and metrics in providing the first spatially explicit mapping of a large and heterogeneous wetland system.
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.
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.
Ferraris, Vinicius; Wei, Qi; Chabert, Marie
2016-01-01
Archetypal scenarios for change detection generally consider two images acquired through sensors of the same modality. However, in some specific cases such as emergency situations, the only images available may be those acquired through different kinds of sensors. More precisely, this paper addresses the problem of detecting changes between two multi-band optical images characterized by different spatial and spectral resolutions. This sensor dissimilarity introduces additional issues in the context of operational change detection. To alleviate these issues, classical change detection methods are applied after independent preprocessing steps (e.g., resampling) used to get the same spatial and spectral resolutions for the pair of observed images. Nevertheless, these preprocessing steps tend to throw away relevant information. Conversely, in this paper, we propose a method that more effectively uses the available information by modeling the two observed images as spatial and spectral versions of two (unobserved)...
Gigerenzer, Gerd; Gaissmaier, Wolfgang
2011-01-01
As reflected in the amount of controversy, few areas in psychology have undergone such dramatic conceptual changes in the past decade as the emerging science of heuristics. Heuristics are efficient cognitive processes, conscious or unconscious, that ignore part of the information. Because using heuristics saves effort, the classical view has been that heuristic decisions imply greater errors than do "rational" decisions as defined by logic or statistical models. However, for many decisions, the assumptions of rational models are not met, and it is an empirical rather than an a priori issue how well cognitive heuristics function in an uncertain world. To answer both the descriptive question ("Which heuristics do people use in which situations?") and the prescriptive question ("When should people rely on a given heuristic rather than a complex strategy to make better judgments?"), formal models are indispensable. We review research that tests formal models of heuristic inference, including in business organizations, health care, and legal institutions. This research indicates that (a) individuals and organizations often rely on simple heuristics in an adaptive way, and (b) ignoring part of the information can lead to more accurate judgments than weighting and adding all information, for instance for low predictability and small samples. The big future challenge is to develop a systematic theory of the building blocks of heuristics as well as the core capacities and environmental structures these exploit.
A low power MICS band phase-locked loop for high resolution retinal prosthesis.
Yang, Jiawei; Skafidas, Efstratios
2013-08-01
Ultra low power dissipation is essential in retinal prosthesis and many other biomedical implants. Extensive research has been undertaken in designing low power biomedical transceivers, however to date, most effort has been focused on low frequency inductive links. For higher frequency, more robust and more complex applications, such as Medical Implant Communication Service (MICS) band multichannel transceivers, power consumption remains high. This paper explores the design of micro-power data links at 400 MHz for a high resolution retinal prosthesis. By taking advantage of advanced small geometry CMOS technology and precise transistor-level modeling, we successfully utilized subthreshold FET operation, which has been historically limited to low frequency circuits due to the inadequate transistor operating speed in and near weak inversion; we have implemented a low power MICS transceiver. Particularly, a low power, MICS band multichannel phase-locked loop (PLL) that employs a subthreshold voltage controlled oscillator (VCO) and digital synchronous dividers has been implemented on a 65-nm CMOS. A design methodology is presented in detail with the demonstration of EKV model parameters extraction. This PLL provides 600- mVpp quadrature oscillations and exhibits a phase noise of -102 dBc/Hz at 200-kHz offset, while only consuming 430- μW from a 1-V supply. The VCO has a gain (KVCO) of 12 MHz/V and is designed to operate in the near-weak inversion region and consumes 220- μA DC current. The designed PLL has a core area of 0.54 mm(2). It satisfies all specifications of MICS band operation with the advantage of significant reduction in power which is crucial for high resolution retinal prosthesis.
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.
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 ...
Detections of Diffuse Interstellar Bands in the SDSS Low-resolution Spectra
Yuan, Haibo
2012-01-01
Diffuse interstellar bands (DIBs) have been discovered for almost a century, but their nature remains one of the most challenging problems in astronomical spectroscopy. Most recent work to identify and investigate the properties and carriers of DIBs concentrates on high-resolution spectroscopy of selected sight-lines. In this paper, we report detections of DIBs in the Sloan Digital Sky Survey (SDSS) low-resolution spectra of a large sample of Galactic stars. Using a template subtraction method, we have successfully identified the DIBs $\\lambda$$\\lambda$5780, 6283 in the SDSS spectra of a sample of about 2,000 stars and measured their strengths and radial velocities. The sample is by far the largest ever assembled. The targets span a large range of reddening, E(B-V) ~ 0.2 -- 1.0, and are distributed over a large sky area and involve a wide range of stellar parameters (effective temperature, surface gravity and metallicity), confirming that the carriers of DIBs are ubiquitous in the diffuse interstellar medium ...
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.
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.
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...
Srinivas, B; Kulick, S N; Doran, Christine; Kulick, Seth
1995-01-01
There are currently two philosophies for building grammars and parsers -- Statistically induced grammars and Wide-coverage grammars. One way to combine the strengths of both approaches is to have a wide-coverage grammar with a heuristic component which is domain independent but whose contribution is tuned to particular domains. In this paper, we discuss a three-stage approach to disambiguation in the context of a lexicalized grammar, using a variety of domain independent heuristic techniques. We present a training algorithm which uses hand-bracketed treebank parses to set the weights of these heuristics. We compare the performance of our grammar against the performance of the IBM statistical grammar, using both untrained and trained weights for the heuristics.
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.
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...
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...
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
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...
Lightfoot, J.; Wyrowski, F.; Muders, D.; Boone, F.; Davis, L.; Shepherd, D.; Wilson, C.
2006-07-01
The ALMA (Atacama Large Millimeter Array) Pipeline Heuristics system is being developed to automatically reduce data taken with the standard observing modes. The goal is to make ALMA user-friendly to astronomers who are not experts in radio interferometry. The Pipeline Heuristics system must capture the expert knowledge required to provide data products that can be used without further processing. Observing modes to be processed by the system include single field interferometry, mosaics and single dish `on-the-fly' maps, and combinations of these modes. The data will be produced by the main ALMA array, the ALMA Compact Array (ACA) and single dish antennas. The Pipeline Heuristics system is being developed as a set of Python scripts. For interferometry these use as data processing engines the CASA/AIPS++ libraries and their bindings as CORBA objects within the ALMA Common Software (ACS). Initial development has used VLA and Plateau de Bure data sets to build and test a heuristic script capable of reducing single field data. In this paper we describe the reduction datapath and the algorithms used at each stage. Test results are presented. The path for future development is outlined.
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...
Brunetti, G
2002-01-01
In the framework of the study of extragalactic radio sources, we will focus on the importance of the spatial resolution at different wavelengths, and of the combination of observations at different frequency bands. In particular, a substantial step forward in this field is now provided by the new generation X-ray telescopes which are able to image radio sources in between 0.1--10 keV with a spatial resolution comparable with that of the radio telescopes (VLA) and of the optical telescopes. After a brief description of some basic aspects of acceleration mechanisms and of the radiative processes at work in the extragalactic radio sources, we will focus on a number of recent radio, optical and X-ray observations with arcsec resolution, and discuss the deriving constraints on the physics of these sources.
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.
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...
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.
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
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...
X-shooter: A medium-resolution, wide-band spectrograph for the VLT
L. Kaper; S. D'Odorico; F. Hammer; R. Pallavicini; P. Kjaergaard Rasmussen; H.A. Dekker; P. Francois; P. Goldoni; I. Guinouard; P.J. Groot; J. Hjorth; M. Horrobin; R. Navarro; F. Royer; P. Santin; J. Vernet; F. Zerbi
2007-01-01
X-shooter is the first second-generation instrument for the ESO Very Large Telescope, and will be installed in 2008. It is intended to become the most powerful optical & near-infrared medium-resolution spectrograph in the world, with a unique spectral coverage from 300 to 2500 nm in one shot. The X-
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...... characteristics of the instrument and present its performance as measured during commissioning, science verification and the first months of science operations. © ESO, 2011....
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....
Energy Technology Data Exchange (ETDEWEB)
Smith, Verne V.; Cunha, Katia [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Shetrone, Matthew D. [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Meszaros, Szabolcs; Allende Prieto, Carlos [Instituto d' Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain); Bizyaev, Dmitry [Apache Point Observatory, Sunspot, NM 88349 (United States); Garcia Perez, Ana; Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Schiavon, Ricardo [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5UX (United Kingdom); Holtzman, Jon [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Johnson, Jennifer A., E-mail: vsmith@noao.edu [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)
2013-03-01
High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory Fourier transform spectrometer, are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the Sloan Digital Sky Survey 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. The red giant sample studied here was chosen to probe which chemical elements can be derived reliably from the H-band APOGEE spectral region. These red giants consist of two K-giants ({alpha} Boo and {mu} Leo), two M-giants ({beta} And and {delta} Oph), and one thermally pulsing asymptotic giant branch (TP-AGB) star of spectral type MS (HD 199799). Measured chemical abundances include the cosmochemically important isotopes {sup 12}C, {sup 13}C, {sup 14}N, and {sup 16}O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. The K and M giants exhibit the abundance signature of the first dredge-up of CN-cycle material, while the TP-AGB star shows clear evidence of the addition of {sup 12}C synthesized during {sup 4}He-burning thermal pulses and subsequent third dredge-up. A comparison of the abundances derived here with published values for these stars reveals consistent results to {approx}0.1 dex. The APOGEE spectral region and linelist is thus well suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants via high-resolution spectroscopy.
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
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%.
Zhuang, Leimeng; Zhu, Chen; Corcoran, Bill; Burla, Maurizio; Roeloffzen, Chris G H; Leinse, Arne; Schröder, Jochen; Lowery, Arthur J
2016-03-21
Modern optical communications rely on high-resolution, high-bandwidth filtering to maximize the data-carrying capacity of fiber-optic networks. Such filtering typically requires high-speed, power-hungry digital processes in the electrical domain. Passive optical filters currently provide high bandwidths with low power consumption, but at the expense of resolution. Here, we present a passive filter chip that functions as an optical Nyquist-filtering interleaver featuring sub-GHz resolution and a near-rectangular passband with 8% roll-off. This performance is highly promising for high-spectral-efficiency Nyquist wavelength division multiplexed (N-WDM) optical super-channels. The chip provides a simple two-ring-resonator-assisted Mach-Zehnder interferometer, which has a sub-cm2 footprint owing to the high-index-contrast Si3N4/SiO2 waveguide, while manifests low wavelength-dependency enabling C-band (> 4 THz) coverage with more than 160 effective free spectral ranges of 25 GHz. This device is anticipated to be a critical building block for spectrally-efficient, chip-scale transceivers and ROADMs for N-WDM super-channels in next-generation optical communication networks. PMID:27136769
Zhuang, Leimeng; Zhu, Chen; Corcoran, Bill; Burla, Maurizio; Roeloffzen, Chris G H; Leinse, Arne; Schröder, Jochen; Lowery, Arthur J
2016-03-21
Modern optical communications rely on high-resolution, high-bandwidth filtering to maximize the data-carrying capacity of fiber-optic networks. Such filtering typically requires high-speed, power-hungry digital processes in the electrical domain. Passive optical filters currently provide high bandwidths with low power consumption, but at the expense of resolution. Here, we present a passive filter chip that functions as an optical Nyquist-filtering interleaver featuring sub-GHz resolution and a near-rectangular passband with 8% roll-off. This performance is highly promising for high-spectral-efficiency Nyquist wavelength division multiplexed (N-WDM) optical super-channels. The chip provides a simple two-ring-resonator-assisted Mach-Zehnder interferometer, which has a sub-cm2 footprint owing to the high-index-contrast Si3N4/SiO2 waveguide, while manifests low wavelength-dependency enabling C-band (> 4 THz) coverage with more than 160 effective free spectral ranges of 25 GHz. This device is anticipated to be a critical building block for spectrally-efficient, chip-scale transceivers and ROADMs for N-WDM super-channels in next-generation optical communication networks.
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.
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
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.
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.
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...
Energy Technology Data Exchange (ETDEWEB)
Su Xiaoxing, E-mail: xxsu@bjtu.edu.c [School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044 (China); Li Jianbao; Wang Yuesheng [Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044 (China)
2010-05-15
If the energy bands of a phononic crystal are calculated by the finite difference time domain (FDTD) method combined with the fast Fourier transform (FFT), good estimation of the eigenfrequencies can only be ensured by the postprocessing of sufficiently long time series generated by a large number of FDTD iterations. In this paper, a postprocessing method based on the high-resolution spectral estimation via the Yule-Walker method is proposed to overcome this difficulty. Numerical simulation results for three-dimensional acoustic and two-dimensional elastic systems show that, compared with the classic FFT-based postprocessing method, the proposed method can give much better estimation of the eigenfrequencies when the FDTD is run with relatively few iterations.
Iwakuni, Kana; Sera, Hideyuki; Abe, Masashi; Sasada, Hiroyuki
2015-06-01
Sub-Doppler resolution spectroscopy of the fundamental bands of H35Cl and H37Cl has been carried out from 87 to 90 THz using a comb-referenced difference-frequency-generation (DFG) spectrometer. While the frequencies of the pump and signal waves are locked to that of the individual nearest comb mode, the repetition rate of the comb is varied for sweeping the idler frequency. Therefore, the relative uncertainty of the frequency scale is 10-11, and the spectral resolution remains about 250 kHz even when the spectrum is accumulated for a long time. The hyperfine structures caused by chlorine nucleus are resolved for the R(0) to R(4) transitions. The figure depicts wavelength-modulation spectrum of the R(0) transition of H35Cl. Three Lamb dips correspond to the F= 0, 1, and -1 components left to right, and the others with arrows are cross-over resonances which are useful for determining the weak F=-1 component frequencies for the R(1) to R(3) transitions. We have determined 49 and 44 transition frequencies of H35Cl and H37Cl with an uncertainty of 10 kHz. Six molecular constants of the vibrational excited state for each isotopomer are determined. They reproduce the determined frequencies with a standard deviation of about 10 kHz.
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.
Paranoid thinking as a heuristic.
Preti, Antonio; Cella, Matteo
2010-08-01
Paranoid thinking can be viewed as a human heuristic used by individuals to deal with uncertainty during stressful situations. Under stress, individuals are likely to emphasize the threatening value of neutral stimuli and increase the reliance on paranoia-based heuristic to interpreter events and guide their decisions. Paranoid thinking can also be activated by stress arising from the possibility of losing a good opportunity; this may result in an abnormal allocation of attentional resources to social agents. A better understanding of the interplay between cognitive heuristics and emotional processes may help to detect situations in which paranoid thinking is likely to exacerbate and improve intervention for individuals with delusional disorders. PMID:20712733
High-resolution FTIR spectroscopic analysis of the ν11 and ν2 + ν7 bands of 13C2D4
Gabona, M. G.; Tan, T. L.
2016-06-01
The FTIR spectrum of the ν11 band of 13C2D4 was recorded at a resolution of 0.0063 cm-1 in the 2130-2250 cm-1 region. This band was perturbed by the unobserved ν2 + ν7 band. By fitting 862 infrared transitions for the ν11 band with a rms deviation of 0.0024 cm-1 using a Watson's A-reduced Hamiltonian in the Ir representation including a Coriolis coupling constant, the rovibrational constants for the ν11 = 1 state and three rotational constants for the ν2 = ν7 = 1 state of 13C2D4 were derived for the first time. The band centers of ν11 and ν2 + ν7 were determined to be 2193.75982(25) cm-1 and 2184.613(11) cm-1 respectively.
Ulrich, Werner; Reynolds, Martin
Critical systems heuristics (CSH) is a framework for reflective professional practice organised around the central tool of boundary critique. This paper, written jointly by the original developer, Werner Ulrich, and Martin Reynolds, an experienced practitioner of CSH, offers a systematic introduction to the idea and use of boundary critique. Its core concepts are explained in detail and their use is illustrated by means of two case studies from the domain of environmental planning and management. A particular focus is on working constructively with tensions between opposing perspectives as they arise in many situations of professional intervention. These include tensions such as ‘situation' versus ‘system', ‘is' versus ‘ought' judgements, concerns of ‘those involved' versus ‘those affected but not involved', stakeholders' ‘stakes' versus ‘stakeholding issues', and others. Accordingly, boundary critique is presented as a participatory process of unfolding and questioning boundary judgements rather than as an expert-driven process of boundary setting. The paper concludes with a discussion of some essential skills and considerations regarding the practice of boundary critique.
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...
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.
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
Yamanaka, Masahito; Teranishi, Tatsuhiro; Kawagoe, Hiroyuki; Nishizawa, Norihiko
2016-08-01
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.
Energy Technology Data Exchange (ETDEWEB)
Delach, J.A.; Rosengren, S.S.; Kaplan, L.; Greenstein, R.M.; Cassidy, S.B.; Benn, P.A.
1994-08-01
The development of probes containing segments of DNA from chromosome region 15q11-q13 provides the opportunity to confirm the diagnosis of Prader-Willi syndrome (PWS) and Angelman syndrome (AS) by fluorescence in situ hybridization (FISH). We have evaluated FISH studies and high resolution chromosome banding studies in 14 patients referred to confirm or rule out AS. In four patients (three from the PWS category and 1 from the AS group) chromosome analysis suggested that a deletion was present but FISH failed to confirm the finding. In one AS group patient, FISH identified a deletion not detectable by high resolution banding. Review of the clinical findings in the discrepant cases suggested that FISH results were correct and high resolution findings were erroneous. Studies with a chromosome 15 alpha satellite probe (D15Z) on both normal and abnormal individuals suggested that incorrect interpretation of chromosome banding may occasionally be attributable to alpha satellite polymorphism but other variation of 15q11-q13 chromosome bands also contributes to misinterpretation. We conclude that patients who have been reported to have a cytogenetic deletion of 15q11-q13 and who have clinical findings inconsistent with PWS and AS should be re-evaluated by molecular genetic techniques. 31 refs., 3 figs., 2 tabs.
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)
Expert systems development utilizing heuristic methods.
Lewis, John N.
1996-01-01
Approved for public release; distribution is unlimited. This thesis analyzes the diagnostic domain and isolates the heuristics employed by experts to arrive at diagnostic solutions. These heuristic methods are then generalized in order to arrive at a series of heuristic rules that can be applied to a wide range of diagnostic processes independent of there respective domain. To test the validity of the generalized heuristics, a prototype expert system was created targeting th...
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...
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 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...
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)
Fei Wang
2014-12-01
Full Text Available 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
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
Heuristics for Multidimensional Packing Problems
DEFF Research Database (Denmark)
Egeblad, Jens
In this thesis we consider solution methods for packing problems. Packing problems occur in many different situations both directly in the industry and as sub-problems of other problems. High-quality solutions for problems in the industrial sector may be able to reduce transportation and production......) and may be defined in any number of dimensions. Solution methods are based on theory from both computational geometry and operations research. The scientific contributions of this thesis are presented in the form of six papers and a section which introduces the many problem types and recent solution...... of items. The heuristic was developed in collaboration with an industrial partner and is now being used to solve hundreds of problems every day as part of their planning process. A simple heuristic for optimizing a placement of items with respect to balance and moment of inertia is presented in the fifth...
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 ...
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
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
K.S. Boparai; F.J.C. van den Broek; S. van Eeden; P. Fockens; E. Dekker
2011-01-01
Hyperplastic polyposis syndrome (HPS) is associated with colorectal cancer and is characterized by multiple hyperplastic polyps, sessile serrated adenomas (SSAs) and adenomas. Narrow band imaging (NBI) may improve the detection of polyps in HPS. We aimed to compare polyp miss rates with NBI with tho
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...
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...
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.
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.
Orphal, J.; Frenzel, A.; Grothe, H.; Redlich, B.; Scheffler, D.; Willner, H.; Zetzsch, C.
1998-09-01
For the first time, high-resolution infrared gas-phase absorption spectra of the BrNO2molecule were recorded using a Fourier-transform spectrometer. In this paper, the ν4bands of the79BrNO2and81BrNO2isotopomers around 1670 cm-1are investigated. Although the spectra are highly congested, rotational and centrifugal distortion constants for the ground andv4= 1 states of79BrNO2and81BrNO2were determined. The results show that BrNO2is a planar molecule ofC2νsymmetry and confirm predictions from a recentab initiostudy.
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.
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.
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.
Bane, Michael K; Thompson, Christopher D; Robertson, Evan G; Appadoo, Dominique R T; McNaughton, Don
2011-04-21
High resolution FTIR spectra have been recorded in the region 250-770 cm(-1) using synchrotron radiation and over 2000 transitions to the ν(8) and ν(12) states of the short lived species ketenimine have been assigned. Ground state combination differences combined with published microwave transitions were used to refine the constants for the ground vibrational state. Rotational and centrifugal distortion parameters for the v(8) = 1 and v(12) = 1 levels were determined by co-fitting transitions, and treating a strong a-axis Coriolis interaction. Selection rules for the observed ν(12) transitions indicate that they arise solely from "perturbation allowed" intensity resulting from this Coriolis interaction.
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...
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...
Heuristic approach to train rescheduling
Directory of Open Access Journals (Sweden)
Mladenović Snežana
2007-01-01
Full Text Available Starting from the defined network topology and the timetable assigned beforehand, the paper considers a train rescheduling in respond to disturbances that have occurred. Assuming that the train trips are jobs, which require the elements of infrastructure - resources, it was done by the mapping of the initial problem into a special case of job shop scheduling problem. In order to solve the given problem, a constraint programming approach has been used. A support to fast finding "enough good" schedules is offered by original separation, bound and search heuristic algorithms. In addition, to improve the time performance, instead of the actual objective function with a large domain, a surrogate objective function is used with a smaller domain, if there is such. .
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
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.
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.
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.
Imanishi, Masatoshi
2013-01-01
We present the results of infrared K- (2.2 micron) and L'-band (3.8 micron) high-spatial-resolution (<0.2 arcsec) imaging observations of nearby gas- and dust-rich infrared luminous merging galaxies, assisted by the adaptive optics (AO) 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 s...
Wang, Ya; Hong, Zhenxiang; Zeng, Zhicheng; Ji, Kaifan; Goode, Philip R; Cao, Wenda; Ji, Haisheng
2016-01-01
In this paper, we report our first-step results of high resolution He\\,\\textsc{i} 10830 \\AA\\ narrow-band imaging (bandpass: 0.5 {\\AA}) of an M1.8 class two-ribbon flare on July 5, 2012. The flare was observed with the 1.6 meter aperture New Solar Telescope at Big Bear Solar Observatory. For this unique data set, sunspot dynamics during flaring were analyzed for the first time. By directly imaging the upper chromosphere, running penumbral waves are clearly seen as an outward extension of umbral flashes, both take the form of absorption in the 10830 \\AA\\ narrow-band images. From a space-time image made of a slit cutting across a flare ribbon and the sunspot, we find that the dark lanes for umbral flashes and penumbral waves are obviously broadened after the flare. The most prominent feature is the sudden appearance of an oscillating absorption strip inside the ribbon when it sweeps into the sunspot's penumbral and umbral regions. During each oscillation, outwardly propagating umbral flashes and subsequent penum...
First far-infrared high resolution analysis of the ν6 band of phosgene 35Cl2CO and 35Cl37ClCO
Flaud, J.-M.; Tchana, F. Kwabia; Lafferty, W. J.; Manceron, L.; Ndao, M.
2016-08-01
A Fourier transform spectrum of phosgene (Cl2CO) has been recorded in the 22.5 μm spectral region at a resolution of 0.00102 cm-1 using a Bruker IFS125HR spectrometer coupled to synchrotron radiation leading to the observation of the ν6 vibrational bands of the two isotopologues 35Cl2CO and 35Cl37ClCO. The corresponding upper state ro-vibrational levels were fit using Watson-type Hamiltonians. In this way it was possible to reproduce the upper state ro-vibrational levels to within the experimental uncertainty i.e. ∼0.30 × 10-3 cm-1. Very accurate rotational and centrifugal distortion constants were derived from the fit together with the following band centers: ν0(ν6,35Cl2CO) = 443.172062(15) cm-1, ν0(ν6,35Cl37ClCO) = 440.534956(17) cm-1.
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...
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.
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...
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...
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...
A heuristic approach to automated nipple detection in digital mammograms.
Jas, Mainak; Mukhopadhyay, Sudipta; Chakraborty, Jayasree; Sadhu, Anup; Khandelwal, Niranjan
2013-10-01
In this paper, a heuristic approach to automated nipple detection in digital mammograms is presented. A multithresholding algorithm is first applied to segment the mammogram and separate the breast region from the background region. Next, the problem is considered separately for craniocaudal (CC) and mediolateral-oblique (MLO) views. In the simplified algorithm, a search is performed on the segmented image along a band around the centroid and in a direction perpendicular to the pectoral muscle edge in the MLO view image. The direction defaults to the horizontal (perpendicular to the thoracic wall) in case of CC view images. The farthest pixel from the base found in this direction can be approximated as the nipple point. Further, an improved version of the simplified algorithm is proposed which can be considered as a subclass of the Branch and Bound algorithms. The mean Euclidean distance between the ground truth and calculated nipple position for 500 mammograms from the Digital Database for Screening Mammography (DDSM) database was found to be 11.03 mm and the average total time taken by the algorithm was 0.79 s. Results of the proposed algorithm demonstrate that even simple heuristics can achieve the desired result in nipple detection thus reducing the time and computational complexity.
Agent Based Patient Scheduling Using Heuristic Algorithm
Directory of Open Access Journals (Sweden)
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
Directory of Open Access Journals (Sweden)
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.
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.
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.
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.
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.
Fast heuristics for a dynamic paratransit problem
Cremers, M.L.A.G.; Klein Haneveld, W.K.; van der Vlerk, M.H.
2008-01-01
In a previous paper we developed a non-standard two-stage recourse model for the dynamic day-ahead paratransit planning problem. Two heuristics, which are frequently applied in the recourse model, contain many details which leads to large CPU times to solve instances of relatively small size. In thi
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…
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…
Teaching a Heuristic Approach to Information Retrieval.
Ury, Connie Jo; And Others
1997-01-01
Discusses lifelong learning and the need for information retrieval skills, and describes how Northwest Missouri State University incorporates a heuristic model of library instruction in which students continually evaluate and refine information-seeking practices while progressing through all levels of courses in diverse disciplines. (Author/LRW)
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…
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…
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...
A Modularity Degree Based Heuristic Community Detection Algorithm
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Dongming Chen
2014-01-01
Full Text Available A community in a complex network can be seen as a subgroup of nodes that are densely connected. Discovery of community structures is a basic problem of research and can be used in various areas, such as biology, computer science, and sociology. Existing community detection methods usually try to expand or collapse the nodes partitions in order to optimize a given quality function. These optimization function based methods share the same drawback of inefficiency. Here we propose a heuristic algorithm (MDBH algorithm based on network structure which employs modularity degree as a measure function. Experiments on both synthetic benchmarks and real-world networks show that our algorithm gives competitive accuracy with previous modularity optimization methods, even though it has less computational complexity. Furthermore, due to the use of modularity degree, our algorithm naturally improves the resolution limit in community detection.
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…
Reising, Steven C.; Kangaslahti, Pekka; Brown, Shannon T.; Tanner, Alan B.; Padmanabhan, Sharmila; Parashare, Chaitali; Montes, Oliver; Dawson, Douglas E.; Gaier, Todd C.; Khayatian, Behrouz; Bosch-Lluis, Xavier; Nelson, Scott P.; Johnson, Thaddeus; Hadel, Victoria; Gilliam, Kyle L.; Razavi, Behzad
2013-04-01
Current satellite ocean altimeters include nadir-viewing, co-located 18-34 GHz microwave radiometers to measure wet-tropospheric path delay. Due to the area of the surface instantaneous fields of view (IFOV) at these frequencies, the accuracy of wet path retrievals is substantially degraded near coastlines, and retrievals are not provided over land. Retrievals are flagged as not useful about 40 km from the world's coastlines. A viable approach to improve their capability is to add wide-band millimeter-wave window channels at 90 to 170 GHz, yielding finer spatial resolution for a fixed antenna size. In addition, NASA's Surface Water and Ocean Topography (SWOT) mission in formulation (Phase A) is planned for launch in late 2020. The primary objectives of SWOT are to characterize ocean sub-mesoscale processes on 10-km and larger scales in the global oceans, and to measure the global water storage in inland surface water bodies and the flow rate of rivers. Therefore, an important new science objective of SWOT is to transition satellite radar altimetry into the coastal zone. The addition of millimeter-wave channels near 90, 130 and 166 GHz to current Jason-class radiometers is expected to improve retrievals of wet-tropospheric delay in coastal areas and to enhance the potential for over-land retrievals. The Ocean Surface Topography Science Team Meeting recommended in 2012 to add these millimeter-wave channels to the Jason Continuity of Service (CS) mission. To reduce the risks associated with wet-tropospheric path delay correction over coastal areas and fresh water bodies, we are developing an airborne radiometer with 18.7, 23.8 and 34.0 GHz microwave channels, as well as millimeter-wave window channels at 90, 130 and 166 GHz, and temperature sounding above 118 as well as water vapor sounding below 183 GHz for validation of wet-path delay. For nadir-viewing space-borne radiometers with no moving parts, two-point internal calibration sources are necessary, and the
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
A HEURISTIC CASCADING FUZZY LOGIC APPROACH TO REACTIVE NAVIGATION FOR UAV
Yew-Chung Chak; Renuganth Varatharajoo
2014-01-01
ABSTRACT: The capability of navigating Unmanned Aerial Vehicles (UAVs) safely in unknown terrain offers huge potential for wider applications in non-segregated airspace. Flying in non-segregated airspace present a risk of collision with static obstacles (e.g., towers, power lines) and moving obstacles (e.g., aircraft, balloons). In this work, we propose a heuristic cascading fuzzy logic control strategy to solve for the Conflict Detection and Resolution (CD&R) problem, in which the contro...
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)
Heuristic Based Task Scheduling In Grid
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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.
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...
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 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
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.
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.
A HYBRID HEURISTIC ALGORITHM FOR THE CLUSTERED TRAVELING SALESMAN PROBLEM
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Mário Mestria
2016-04-01
Full Text Available ABSTRACT This paper proposes a hybrid heuristic algorithm, based on the metaheuristics Greedy Randomized Adaptive Search Procedure, Iterated Local Search and Variable Neighborhood Descent, to solve the Clustered Traveling Salesman Problem (CTSP. Hybrid Heuristic algorithm uses several variable neighborhood structures combining the intensification (using local search operators and diversification (constructive heuristic and perturbation routine. In the CTSP, the vertices are partitioned into clusters and all vertices of each cluster have to be visited contiguously. The CTSP is -hard since it includes the well-known Traveling Salesman Problem (TSP as a special case. Our hybrid heuristic is compared with three heuristics from the literature and an exact method. Computational experiments are reported for different classes of instances. Experimental results show that the proposed hybrid heuristic obtains competitive results within reasonable computational time.
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...
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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.
Proposing New Heuristic Approaches for Preventive Maintenance Scheduling
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majid Esmailian
2013-08-01
Full Text Available The purpose of preventive maintenance management is to perform a series of tasks that prevent or minimize production breakdowns and improve reliability of production facilities. An important objective of preventive maintenance management is to minimize downtime of production facilities. In order to accomplish this objective, personnel should efficiently allocate resources and determine an effective maintenance schedule. Gopalakrishnan (1997 developed a mathematical model and four heuristic approaches to solve the preventive maintenance scheduling problem of assigning skilled personnel to work with tasks that require a set of corresponding skills. However, there are several limitations in the prior work in this area of research. The craft combination problem has not been solved because the craft combination is assumed as given. The craft combination problem concerns the computation of all combinations of assigning multi skilled workers to accomplishment of a particular task. In fact, determining craft combinations is difficult because of the exponential number of craft combinations that are possible. This research provides a heuristic approach for determining the craft combination and four new heuristic approach solution for the preventive maintenance scheduling problem with multi skilled workforce constraints. In order to examine the new heuristic approach and to compare the new heuristic approach with heuristic approach of Gopalakrishnan (1997, 81 standard problems have been generated based on the criterion suggested by from Gopalakrishnan (1997. The average solution quality (SQ of the new heuristic approaches is 1.86% and in old heuristic approaches is 8.32%. The solution time of new heuristic approaches are shorter than old heuristic approaches. The solution time of new heuristic approaches is 0.78 second and old heuristic approaches is 6.43 second, but the solution time of mathematical model provided by Gopalakrishnan (1997 is 152 second.
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...
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.
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
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.
Victimized by Phishing: A Heuristic - Systematic Perspective
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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 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.
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.
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.
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.
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...
A heuristic model of alcohol dependence.
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Zhen Qi
Full Text Available BACKGROUND: Substance dependence poses a critical health problem. Sadly, its neurobiological mechanisms are still unclear, and this lack of real understanding is reflected in insufficient treatment options. It has been hypothesized that alcohol effects are due to an imbalance between neuroexcitatory and neuroinhibitory amino acids. However, glutamate and GABA interact with other neurotransmitters, which form a complicated network whose functioning evades intuition and should be investigated systemically with methods of biomedical systems analysis. METHODS AND RESULTS: We present a heuristic model of neurotransmitters that combines a neurochemical interaction matrix at the biochemical level with a mobile describing the balances between pairs of neurotransmitters at the physiological and behavioral level. We investigate the effects of alcohol on the integrated neurotransmitter systems at both levels. The model simulation results are consistent with clinical and experimental observations. The model demonstrates that the drug diazepam for symptoms of alcohol withdrawal effectively reduces the imbalances between neurotransmitters. Moreover, the acetylcholine signal is suggested as a novel target for treatment of symptoms associated with alcohol withdrawal. CONCLUSIONS: Efficient means of integrating clinical symptoms across multiple levels are still scarce and difficult to establish. We present a heuristic model of systemic neurotransmitter functionality that permits the assessment of genetic, biochemical, and pharmacological perturbations. The model can serve as a tool to represent clinical and biological observations and explore various scenarios associated with alcohol dependence and its treatments. It also is very well suited for educational purposes.
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.
A Geographical Heuristic Routing Protocol for VANETs
Directory of Open Access Journals (Sweden)
Luis Urquiza-Aguiar
2016-09-01
Full Text Available Vehicular ad hoc networks (VANETs leverage the communication system of Intelligent Transportation Systems (ITS. Recently, Delay-Tolerant Network (DTN routing protocols have increased their popularity among the research community for being used in non-safety VANET applications and services like traffic reporting. Vehicular DTN protocols use geographical and local information to make forwarding decisions. However, current proposals only consider the selection of the best candidate based on a local-search. In this paper, we propose a generic Geographical Heuristic Routing (GHR protocol that can be applied to any DTN geographical routing protocol that makes forwarding decisions hop by hop. GHR includes in its operation adaptations simulated annealing and Tabu-search meta-heuristics, which have largely been used to improve local-search results in discrete optimization. We include a complete performance evaluation of GHR in a multi-hop VANET simulation scenario for a reporting service. Our study analyzes all of the meaningful configurations of GHR and offers a statistical analysis of our findings by means of MANOVA tests. Our results indicate that the use of a Tabu list contributes to improving the packet delivery ratio by around 5% to 10%. Moreover, if Tabu is used, then the simulated annealing routing strategy gets a better performance than the selection of the best node used with carry and forwarding (default operation.
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 &…
Swift and Smart Decision Making: Heuristics that Work
Hoy, Wayne K.; Tarter, C. J.
2010-01-01
Purpose: The aim of this paper is to examine the research literature on decision making and identify and develop a set of heuristics that work for school decision makers. Design/methodology/approach: This analysis is a synthesis of the research on decision-making heuristics that work. Findings: A set of nine rules for swift and smart decision…
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...
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...
Alkadrou, Abdulsamee; Rotger, Maud; Bermejo, Dionisio; Domenech, Jose Luis; Boudon, Vincent
2016-06-01
High resolution stimulated Raman spectra of 13C_2H_4 in the regions of the ν_2 and ν_3 Raman active modes have been recorded at at two temperatures (145 and 296 K) based on the quasi continuous-wave (cw) stimulated Raman spectrometer at Instituto de Estructura de la Materia (CSIC) in Madrid. A tensorial formalism adapted to X2Y4 planar asymmetric tops with D2h symmetry has been developed in Dijon and a program suite called D2hTDS (now part of the XTDS/SPVIEW spectroscopic software was proposed to calculate their high-resolution spectra. The effective Hamiltonian operator, involving a polyad structure, and transition moment (dipole moment and polarizability) operators can be systematically expanded to carry out global analyses of many rovibrational bands. A total of 103 and 51 lines corresponding to ν_2 and ν_3 Raman active modes have been assigned and fitted in frequency with a global root mean square deviation of 0.54 × 10-3 cm-1 and 0.36 × 10-3 cm-1, respectively. The figures below shows the stimulated Raman spectrum of the ν_2 and ν_3 bands of 13C_2H_4, compared to the simulation at 296 K. Raballand W, Rotger M, Boudon V, Loëte M. J Mol Spectrosc 2003;217:239-48. Wenger Ch, Boudon V, Rotger M, Champion JP, Sanzharov M. J Mol Spectrosc 2008;251:102-13.
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 ...
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...
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...
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 .
Directory of Open Access Journals (Sweden)
Zhipeng Wang
2015-12-01
Full Text Available Spectral bands of the Visible Infrared Imaging Radiometer Suite (VIIRS instrument aboard the Suomi National Polar-orbiting Partnership (S-NPP satellite are spatially co-registered. The accuracy of the band-to-band registration (BBR is one of the key spatial parameters that must be characterized. Unlike its predecessor, the Moderate Resolution Imaging Spectroradiometer (MODIS, VIIRS has no on-board calibrator specifically designed to perform on-orbit BBR characterization. To circumvent this problem, a BBR characterization method for VIIRS reflective solar bands (RSB based on regularly-acquired lunar images has been developed. While its results can satisfactorily demonstrate that the long-term stability of the BBR is well within ±0.1 moderate resolution band pixels, undesired seasonal oscillations have been observed in the trending. The oscillations are most obvious between the visible/near-infrared bands and short-/middle wave infrared bands. This paper investigates the oscillations and identifies their cause as the band/spectral dependence of the centroid position and the seasonal rotation of the lunar images over calibration events. Accordingly, an improved algorithm is proposed to quantify the rotation and compensate for its impact. After the correction, the seasonal oscillation in the resulting BBR is reduced from up to 0.05 moderate resolution band pixels to around 0.01 moderate resolution band pixels. After removing this spurious seasonal oscillation, the BBR, as well as its long-term drift are well determined.
Collective Intelligence Heuristic: An Experimental Evidence
Stefanelli, Federica; Bagnoli, Franco; Guazzini, Andrea
2016-01-01
The main intreest of this study was to investigate the phenomenon of collective intelligence in an anonymous virtual environment developed for this purpose. In particular, we were interested in studiyng how dividing a fixed community in different group size, which, in different phases of the experiment, works to solve tasks of different complexity, influences the social problem solving process. The experiments, which have involved 216 university students, showed that the cooperative behaviour is stronger in small groups facing complex tasks: the cooperation probability negatively correlated with both the group size and easiness of task. Individuals seem to activate a collective intelligence heuristics when the problem is too complex. Some psychosocial variables were considered in order to check how they affect the cooperative behaviour of participants, but they do not seem to have a significant impact on individual cooperation probability, supporting the idea that a partial de-individualization operates in vi...
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.
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.
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...
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.
Heuristic Portfolio Trading Rules with Capital Gain Taxes
DEFF Research Database (Denmark)
Fischer, Marcel; Gallmeyer, Michael
2016-01-01
, 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......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...... show that the best trading strategies balance diversification considerations and tax considerations....
The beauty of simple models: Themes in recognition heuristic research
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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 search methods are able to return solutions of very high quality....
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.
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
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.
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.
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.
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.
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 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 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.
Cigna, Francesca; Novellino, Alessandro; Jordan, Colm J.; Sowter, Andrew; Ramondini, Massimo; Calcaterra, Domenico
2014-10-01
In the context of recent advances in InSAR processing techniques to retrieve higher persistent scatterer and coherent target densities over unfavourable land cover classes, this study tests the Intermittent Small Baseline Subset (ISBAS) approach to update the landslide inventory around the town of Piana degli Albanesi (Italy), an area where only 2% of the land appears suitable to generate radar scatterers based on a pre-survey feasibility assessment. ISBAS processing of 38 ascending mode and 36 descending mode COSMO-SkyMed StripMap HIMAGE SAR scenes at 3m resolution allows identification of ~726,000 and ~893,000 coherent and intermittently coherent pixels for the ascending and descending data stacks respectively. Observed improvements in the number of ISBAS solutions for the ascending mode are greater than 40 times compared to the conventional SBAS approach, not only for urban and rocky terrains, but also rural and vegetated land covers. Line of sight ground motion rates range between -6.4 and +5.5 mm/yr in 2008-2011, although the majority of the processed area shows general stability, with average rates of -0.6 mm/yr in the ascending and -0.1 mm/yr in the descending mode results. Interpretation of the ISBAS deformation rates, integrated with targeted field surveys and aerial photo-interpretation, provides a new and more complete picture of landslide distribution, state of activity and intensity in the test area, and allows depiction of very slow and extremely slow landslide processes even in areas difficult to access, with unprecedented coverage of results.
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.
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...
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...
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.
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....
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.
New insights into diversification of hyper-heuristics.
Ren, Zhilei; Jiang, He; Xuan, Jifeng; Hu, Yan; Luo, Zhongxuan
2014-10-01
There has been a growing research trend of applying hyper-heuristics for problem solving, due to their ability of balancing the intensification and the diversification with low level heuristics. Traditionally, the diversification mechanism is mostly realized by perturbing the incumbent solutions to escape from local optima. In this paper, we report our attempt toward providing a new diversification mechanism, which is based on the concept of instance perturbation. In contrast to existing approaches, the proposed mechanism achieves the diversification by perturbing the instance under solving, rather than the solutions. To tackle the challenge of incorporating instance perturbation into hyper-heuristics, we also design a new hyper-heuristic framework HIP-HOP (recursive acronym of HIP-HOP is an instance perturbation-based hyper-heuristic optimization procedure), which employs a grammar guided high level strategy to manipulate the low level heuristics. With the expressive power of the grammar, the constraints, such as the feasibility of the output solution could be easily satisfied. Numerical results and statistical tests over both the Ising spin glass problem and the p -median problem instances show that HIP-HOP is able to achieve promising performances. Furthermore, runtime distribution analysis reveals that, although being relatively slow at the beginning, HIP-HOP is able to achieve competitive solutions once given sufficient time.
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.
Faye; Kou; Farrenq; Guelachvili
1999-10-01
The extension of high-resolution observation of the electronic emission spectrum of (14)N(2) toward the infrared domain is presented. To date, rotational analysis of the widely investigated spectrum of the N(2) molecule was done in a spectral domain ranging from 2500 cm(-1) to the UV. We have recorded for the first time the infrared part of the (14)N(2) spectrum from 1250 to 2250 cm(-1), using the Fourier transform spectrometer of Laboratoire de Photophysique Moléculaire (LPPM) at an unapodized resolution of 0.0043 cm(-1). A complete rotational analysis is performed for the (1 --> 0), (2 --> 1), (0 <-- 1), (1 <-- 2) bands of the B(3)Pi(g)-W(3)Delta(u) system, not included in any previous analysis. Spectroscopic parameters for the v = 0, v = 1, v = 2 levels of the B(3)Pi(g) and the W(3)Delta(u) states, consistent with those previously reported but with improved accuracy, are obtained from the experimental wavenumbers by a nonlinear least-squares procedure. Copyright 1999 Academic Press.
Faye, A.; Kou, Q.; Farrenq, R.; Guelachvili, G.
1999-10-01
The extension of high-resolution observation of the electronic emission spectrum of 14N2 toward the infrared domain is presented. To date, rotational analysis of the widely investigated spectrum of the N2 molecule was done in a spectral domain ranging from 2500 cm-1 to the UV. We have recorded for the first time the infrared part of the 14N2 spectrum from 1250 to 2250 cm-1, using the Fourier transform spectrometer of Laboratoire de Photophysique Moléculaire (LPPM) at an unapodized resolution of 0.0043 cm-1. A complete rotational analysis is performed for the (1 → 0), (2 → 1), (0 ← 1), (1 ← 2) bands of the B3Πg-W3Δu system, not included in any previous analysis. Spectroscopic parameters for the v = 0, v = 1, v = 2 levels of the B3Πg and the W3Δu states, consistent with those previously reported but with improved accuracy, are obtained from the experimental wavenumbers by a nonlinear least-squares procedure.
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...
... 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 ...
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.
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.
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.
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.
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...
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 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 compa...... 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....
A Heuristic Hierarchical Scheme for Academic Search and Retrieval
DEFF Research Database (Denmark)
Amolochitis, Emmanouil; Christou, Ioannis T.; Tan, Zheng-Hua;
2013-01-01
We present PubSearch, a hybrid heuristic scheme for re-ranking academic papers retrieved from standard digital libraries such as the ACM Portal. The scheme is based on the hierarchical combination of a custom implementation of the term frequency heuristic, a time-depreciated citation score...... 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......, and by more than 907.5% in terms of LEX. We also re-rank the top-10 results of a subset of the original 58 user queries produced by Google Scholar, Microsoft Academic Search, and ArnetMiner; the results show that PubSearch compares very well against these search engines as well. The proposed scheme can...
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.
Institute of Scientific and Technical Information of China (English)
练秋生; 张钧芹; 陈书贞
2013-01-01
The conventional super-resolution algorithms on sparse representation reconstruct the high resolution image using one-stage high/low resolution dictionary pairs with inadequate detail information.In order to recover detail information as much as possible,two-stage dictionaries are explored in this paper.Then we train jointly multiple-frequency-band dictionaries consisting of low frequency (LF) dictionaries,middle frequency (MF) dictionaries and high frequency (HF) dictionaries,and simultaneously exploit the prediction relation of LF component,MF component and HF component to recover middle and high frequency information.Considering that there are many repetitive structures in the natural image,nonlocal self-similarity information is combined properly with iterative back-projection procedure to post-process the image.Experimental results demonstrate that the proposed algorithm has remarkable improvement in peak signal-to-noise ratio,structural similarity and visual quality compared with the other learning-based algorithms.%常规基于稀疏表示的超分辨率算法使用一级高低分辨字典重构图像,恢复细节信息不充分.本文利用两级字典恢复尽可能多的细节信息；然后构造联合低频字典、中频字典、高频字典的分频带字典,利用图像低频、中频、高频三者之间的预测关系,恢复图像中的高频信息.利用图像的非局部相似性,将其与迭代反向投影算法相结合,进行图像的后处理.实验结果表明,与其他几种基于学习的算法相比,本算法无论是在峰值信噪比、结构相似性指标,还是视觉效果上都有显著的提高.
Lemaire, J. L.; Eidelsberg, M.; Heays, A. N.; Gavilan, L.; Federman, S. R.; Stark, G.; Lyons, J. R.; de Oliveira, N.; Joyeux, D.
2016-08-01
Our knowledge of astronomical environments containing CO depends on accurate molecular data to reproduce and interpret observations. The constant improvement in UV space instrumentation, both in sensitivity and resolution, requires increasingly detailed laboratory data. Following a long-term experimental campaign at the SOLEIL Synchrotron facility, we have acquired complete datasets on the CO isotopologues in the vacuum ultraviolet. Absorption spectra were recorded using the Fourier-transform spectrometer installed on the DESIRS beamline, providing a resolving power R > 106 in the 8-12 eV range. Such resolution allows the analysis of individual line positions and strengths in electronic transitions and the location of perturbations. We continue our previous work on A-X bands of 12C16O and 13C16O, reporting here measurements for the 13C18O isotopologue. Gas column densities in the differentially-pumped system were calibrated using the B {}1{{{Σ }}}+-X {}1{{{Σ }}}+({v}\\prime =0,v\\prime\\prime =0) band. Absorption bands are analyzed by synthesizing line and band profiles and fitting them to measured spectra. New results for A {}1{{\\Pi }}({v}\\prime =0{--}10)-X {}1{{{Σ }}}+(v\\prime\\prime =0) bands include precise line assignments, term values, band-integrated oscillator strengths as well as individual ro-vibrational oscillator strengths and Hönl-London corrections. For ({v}\\prime =1) our results are compared with earlier studies. The interpretation of mixed perturbing bands, complementing an earlier study, is also presented as well as precise line assignments and term values for the B {}1{{{Σ }}}+-X {}1{{{Σ }}}+(0-0) band calibrator, and the nearby B-X (1-0) and C {}1{{{Σ }}}+-X {}1{{{Σ }}}+(0-0) bands.
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
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...... 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...
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.
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...
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.
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...
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.
Petri nets SM-cover-based on heuristic coloring algorithm
Tkacz, Jacek; Doligalski, Michał
2015-09-01
In the paper, coloring heuristic algorithm of interpreted Petri nets is presented. Coloring is used to determine the State Machines (SM) subnets. The present algorithm reduces the Petri net in order to reduce the computational complexity and finds one of its possible State Machines cover. The proposed algorithm uses elements of interpretation of Petri nets. The obtained result may not be the best, but it is sufficient for use in rapid prototyping of logic controllers. Found SM-cover will be also used in the development of algorithms for decomposition, and modular synthesis and implementation of parallel logic controllers. Correctness developed heuristic algorithm was verified using Gentzen formal reasoning system.
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.
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...
An improved heuristic for one-machine scheduling with delays constraints
Institute of Scientific and Technical Information of China (English)
杜东雷; 韩继业; 陈礴
1997-01-01
An improved heuristic is proposed for one-machine scheduling problem with delay constraints,thus an open problem raised by Wikum et al.is solved.The heuristic solves the corresponding unit-execution-time problem optimally.
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...
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…
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.
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.
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
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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.
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…
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.
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…
Polyhedrical Heuristics of Periodical Qualities in the Numerical Divisibility Variation
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José Ricardo Díaz Caballero
2013-06-01
Full Text Available The present work demonstrate how this polyhedral heuristic is also revealed in the Set of NaturalNumbers, where it is manifested numerical regularities similar to he platonic polyhedra developmentswhich open a wide field for the study of new numerical regularities as those associated to the periodicityvariation of its divisibility.
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.
New computations concerning the Cohen-Lenstra heuristics
Williams, H.C.; Riele, H.J.J. te
2002-01-01
Let $h(p)$ denote the class number of the real quadratic field formed by adjoining $sqrt{p}$, where $p$ is a prime, to the rationals. The Cohen-Lenstra heuristics suggest that the probability that $h(p)=k$ (a given odd positive integer) is given by $Cw(k)/k$, where $C$ is an explicit constant and $w
Heuristic Scheduling Algorithm Oriented Dynamic Tasks for Imaging Satellites
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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.
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 Placement Routines for Two-Dimensional Bin Packing Problem
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L. Wong
2009-01-01
Full Text Available Problem statement: Cutting and packing (C and P problems are optimization problems that are concerned in finding a good arrangement of multiple small items into one or more larger objects. Bin packing problem is a type of C AND P problems. Bin packing problem is an important industrial problem where the general objective is to reduce the production costs by maximizing the utilization of the larger objects and minimizing the material used. Approach: In this study, we considered both oriented and non-oriented cases of Two-Dimensional Bin Packing Problem (2DBPP where a given set of small rectangles (items, was packed without overlaps into a minimum number of identical large rectangles (bins. We proposed heuristic placement routines called the Improved Lowest Gap Fill, LGFi and LGFiOF for solving non-oriented and oriented cases of 2DBPP respectively. Extensive computational experiments using benchmark data sets collected from the literature were conducted to assess the effectiveness of the proposed routines. Results: The computational results were compared with some well known heuristic placement routines. The results showed that the LGFi and LGFiOF are competitive when compared with other heuristic placement routines. Conclusion: Both LGFi and LGFiOF produced better packing quality compared to other heuristic placement routines.
Heuristic Evaluation on Mobile Interfaces: A New Checklist
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Rosa Yáñez Gómez
2014-01-01
Full Text Available The rapid evolution and adoption of mobile devices raise new usability challenges, given their limitations (in screen size, battery life, etc. as well as the specific requirements of this new interaction. Traditional evaluation techniques need to be adapted in order for these requirements to be met. Heuristic evaluation (HE, an Inspection Method based on evaluation conducted by experts over a real system or prototype, is based on checklists which are desktop-centred and do not adequately detect mobile-specific usability issues. In this paper, we propose a compilation of heuristic evaluation checklists taken from the existing bibliography but readapted to new mobile interfaces. Selecting and rearranging these heuristic guidelines offer a tool which works well not just for evaluation but also as a best-practices checklist. The result is a comprehensive checklist which is experimentally evaluated as a design tool. This experimental evaluation involved two software engineers without any specific knowledge about usability, a group of ten users who compared the usability of a first prototype designed without our heuristics, and a second one after applying the proposed checklist. The results of this experiment show the usefulness of the proposed checklist for avoiding usability gaps even with nontrained developers.
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
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,…
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…
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
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…
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…
Developing heuristics for Web communication: an introduction to this special issue
Geest, van der Thea; Spyridakis, Jan H.
2000-01-01
This article describes the role of heuristics in the Web design process. The five sets of heuristics that appear in this issue are also described, as well as the research methods used in their development. The heuristics were designed to help designers and developers of Web pages or sites to conside
Aldana Jague, Emilien; Goulding, Keith; Heckrath, Goswin; Macdonald, Andy; Poulton, Paul; Stevens, Antoine; Van Wesemael, Bas; Van Oost, Kristof
2014-05-01
Soil organic C (SOC) contents in arable landscapes change as a function of management, climate and topography (Johnston et al, 2009). Traditional methods to measure soil C stocks are labour intensive, time consuming and expensive. Consequently, there is a need for developing low-cost methods for monitoring SOC contents in agricultural soils. Remote sensing methods based on multi-spectral images may help map SOC variation in surface soils. Recently, the costs of both Unmanned Aerial Vehicles (UAVs) and multi-spectral cameras have dropped dramatically, opening up the possibility for more widespread use of these tools for SOC mapping. Long-term field experiments with distinct SOC contents in adjacent plots, provide a very useful resource for systematically testing remote sensing approaches for measuring SOC. This study focusses on the Broadbalk Wheat Experiment at Rothamsted (UK). The Broadbalk experiment started in 1843. It is widely acknowledged to be the oldest continuing agronomic field experiment in the world. The initial aim of the experiment was to test the effects of different organic manures and inorganic fertilizers on the yield of winter wheat. The experiment initially contained 18 strips, each about 320m long and 6m wide, separated by paths of 1.5-2.5m wide. The strips were subsequently divided into ten sections (>180 plots) to test the effects of other factors (crop rotation, herbicides, pesticides etc.). The different amounts and combinations of mineral fertilisers (N,P,K,Na & Mg) and Farmyard Manure (FYM) applied to these plots for over 160 years has resulted in very different SOC contents in adjacent plots, ranging between 0.8% and 3.5%. In addition to large inter-plot variability in SOC there is evidence of within-plot trends related to the use of discard areas between plots and movement of soil as a result of ploughing. The objectives of this study are (i) to test whether low-altitude multi-band imagery can be used to accurately predict spatial
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
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.
Heuristics to Evaluate Interactive Systems for Children with Autism Spectrum Disorder (ASD.
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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.
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...
Reising, Steven; Kangaslahti, Pekka; Tanner, Alan; Padmanabhan, Sharmila; Montes, Oliver; Parashare, Chaitali; Bosch-Lluis, Xavier; Hadel, Victoria; Johnson, Thaddeus; Brown, Shannon; Khayatian, Behrouz; Dawson, Douglas; Gaier, Todd; Razavi, Behzad
2014-05-01
Current satellite ocean altimeters include nadir-viewing, co-located 18-34 GHz microwave radiometers to measure wet-tropospheric path delay. Due to the size of the surface instantaneous fields of view (IFOV) at these frequencies, the accuracy of wet path retrievals is substantially degraded near coastlines, and retrievals are not provided over land. Retrievals are flagged as not useful within approximately 40 km of the world's coastlines. A viable approach to improve their capability is to add wide-band high-frequency millimeter-wave window channels in the 90-180 GHz band, thereby achieving finer spatial resolution for a limited antenna size. In this context, the upcoming NASA/CNES/CSA Surface Water and Ocean Topography (SWOT) mission is in formulation and planned for launch in late 2020. The primary objectives of SWOT are to characterize ocean mesoscale and sub-mesoscale processes on 10-km and larger scales in the global oceans and provide measurements of the global water storage in inland surface water bodies and the flow rate of rivers. Therefore, an important new science objective of SWOT is to transition satellite altimetry from the open ocean into the coastal zone and over inland water. The addition of 90-180 GHz millimeter-wave window-channel radiometers to current Jason-class 18-34 GHz radiometers is expected to improve retrievals of wet-tropospheric delay in coastal areas and to enhance the potential for over-land retrievals. In 2012 the Ocean Surface Topography Science Team Meeting recommended to add high-frequency millimeter-wave radiometers to the Jason Continuity of Service (CS) mission. To reduce the risks of wet-tropospheric path delay measurement over coastal areas and inland water bodies, we have designed, developed and fabricated a new airborne radiometer, combining three high-frequency millimeter-wave window channels at 90, 130 and 168 GHz, along with Jason-series microwave channels at 18.7, 23.8 and 34.0 GHz, and validation channels sounding
Heuristic Portfolio Trading Rules with Capital Gain Taxes
DEFF Research Database (Denmark)
Fischer, Marcel; Gallmeyer, Michael
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 best trading......We study the out-of-sample performance of portfolio trading strategies when an investor faces capital gain taxation and proportional transaction costs. Under no capital gain taxation and no transaction costs, we show that, consistent with DeMiguel, Garlappi, and Uppal (2009), a simple 1/N trading...... 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...
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.
Four Data Visualization Heuristics to Facilitate Reflection in Personal Informatics
DEFF Research Database (Denmark)
Cuttone, Andrea; Petersen, Michael Kai; Larsen, Jakob Eg
2014-01-01
In this paper we discuss how to facilitate the process of reflection in Personal Informatics and Quantified Self systems through interactive data visualizations. Four heuristics for the design and evaluation of such systems have been identified through analysis of self-tracking devices and apps....... Dashboard interface paradigms in specific self-tracking devices (Fitbit and Basis) are discussed as representative examples of state of the art in feedback and reflection support. By relating to existing work in other domains, such as event related representation of time series multivariate data...... in financial analytics, it is discussed how the heuristics could guide designs that would further facilitate reflection in self-tracking personal informatics systems....
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.
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 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.
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...
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.
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...
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...
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.
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
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.
Heuristic Solution Approaches to the Double TSP with Multiple Stacks
DEFF Research Database (Denmark)
Petersen, Hanne Løhmann
2006-01-01
This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries...... are developed for the problem and used with each of the heuristics. Finally some computational results are given along with lower bounds on the objective value....
Heuristic Solution Approaches to the Double TSP with Multiple Stacks
DEFF Research Database (Denmark)
Petersen, Hanne Løhmann
This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries...... are developed for the problem and used with each of the heuristics. Finally some computational results are given along with lower bounds on the objective value....
Automatic Choice of Scheduling Heuristics for Parallel/Distributed Computing
Directory of Open Access Journals (Sweden)
Clayton S. Ferner
1999-01-01
Full Text Available Task mapping and scheduling are two very difficult problems that must be addressed when a sequential program is transformed into a parallel program. Since these problems are NP‐hard, compiler writers have opted to concentrate their efforts on optimizations that produce immediate gains in performance. As a result, current parallelizing compilers either use very simple methods to deal with task scheduling or they simply ignore it altogether. Unfortunately, the programmer does not have this luxury. The burden of repartitioning or rescheduling, should the compiler produce inefficient parallel code, lies entirely with the programmer. We were able to create an algorithm (called a metaheuristic, which automatically chooses a scheduling heuristic for each input program. The metaheuristic produces better schedules in general than the heuristics upon which it is based. This technique was tested on a suite of real scientific programs written in SISAL and simulated on four different network configurations. Averaged over all of the test cases, the metaheuristic out‐performed all eight underlying scheduling algorithms; beating the best one by 2%, 12%, 13%, and 3% on the four separate network configurations. It is able to do this, not always by picking the best heuristic, but rather by avoiding the heuristics when they would produce very poor schedules. For example, while the metaheuristic only picked the best algorithm about 50% of the time for the 100 Gbps Ethernet, its worst decision was only 49% away from optimal. In contrast, the best of the eight scheduling algorithms was optimal 30% of the time, but its worst decision was 844% away from optimal.
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...
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...
Heuristics for Hierarchical Partitioning with Application to Model Checking
DEFF Research Database (Denmark)
Möller, Michael Oliver; Alur, Rajeev
2001-01-01
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 heuristic...... studies. A longer version of this paper is available as technical report BRICS Research Series RS-00-21. Basic Research in Computer Science, Center of the Danish National Research Foundation....
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.
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...
A heuristic model for the development of production capabilities
Kremljak, Zvonko; Polajnar, Andrej; Buchmeister, Borut
2005-01-01
Managers in production environments face a high level of uncertainty in their decision making due to the major, rapidly developing changes defining the environments in which their organisations operate. This means that managers donot possess complete information about future events, do not know all the possible alternatives or the consequences of all their possible decisions. Overcoming this uncertainty requires the development of heuristic tools, whichcan offer satisfactory, if not optimal, ...
When less is more: evolutionary origins of the affect heuristic.
Directory of Open Access Journals (Sweden)
Jerald D Kralik
Full Text Available The human mind is built for approximations. When considering the value of a large aggregate of different items, for example, we typically do not summate the many individual values. Instead, we appear to form an immediate impression of the likeability of the option based on the average quality of the full collection, which is easier to evaluate and remember. While useful in many situations, this affect heuristic can lead to apparently irrational decision-making. For example, studies have shown that people are willing to pay more for a small set of high-quality goods than for the same set of high-quality goods with lower-quality items added [e.g. 1]. We explored whether this kind of choice behavior could be seen in other primates. In two experiments, one in the laboratory and one in the field, using two different sets of food items, we found that rhesus monkeys preferred a highly-valued food item alone to the identical item paired with a food of positive but lower value. This finding provides experimental evidence that, under certain conditions, macaque monkeys follow an affect heuristic that can cause them to prefer less food. Conservation of this affect heuristic could account for similar 'irrational' biases in humans, and may reflect a more general complexity reduction strategy in which averages, prototypes, or stereotypes represent a set or group.
General heuristics algorithms for solving capacitated arc routing problem
Fadzli, Mohammad; Najwa, Nurul; Masran, Hafiz
2015-05-01
In this paper, we try to determine the near-optimum solution for the capacitated arc routing problem (CARP). In general, NP-hard CARP is a special graph theory specifically arises from street services such as residential waste collection and road maintenance. By purpose, the design of the CARP model and its solution techniques is to find optimum (or near-optimum) routing cost for a fleet of vehicles involved in operation. In other words, finding minimum-cost routing is compulsory in order to reduce overall operation cost that related with vehicles. In this article, we provide a combination of various heuristics algorithm to solve a real case of CARP in waste collection and benchmark instances. These heuristics work as a central engine in finding initial solutions or near-optimum in search space without violating the pre-setting constraints. The results clearly show that these heuristics algorithms could provide good initial solutions in both real-life and benchmark instances.
Meta Heuristic Algorithms for Vehicle Routing Problem with Stochastic Demands
Directory of Open Access Journals (Sweden)
Geetha Shanmugam
2011-01-01
Full Text Available Problem statement: The shipment of goods from manufacturer to the consumer is a focal point of distribution logistics. In reality, the demand of consumers is not known a priori. This kind of distribution is dealt by Stochastic Vehicle Routing Problem (SVRP which is a NP-hard problem. In this proposed work, VRP with stochastic demand is considered. A probability distribution is considered as a random variable for stochastic demand of a customer. Approach: In this study, VRPSD is resolved using Meta heuristic algorithms such as Genetic Algorithm (GA, Particle Swarm Optimization (PSO and Hybrid PSO (HPSO. Dynamic Programming (DP is used to find the expected cost of each route generated by GA, PSO and HPSO. Results: The objective is to minimize the total expected cost of a priori route. The fitness value of a priori route is calculated using DP. In proposed HPSO, the initial particles are generated based Nearest Neighbor Heuristic (NNH. Elitism is used in HPSO for updating the particles. The algorithm is implemented using MATLAB7.0 and tested with problems having different number of customers. The results obtained are competitive in terms of execution time and memory usage. Conclusion: The computational time is reduced as polynomial time as O(nKQ time and the memory required is O(nQ. The ANOVA test is performed to compare the proposed HPSO with other heuristic algorithms.
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.
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.
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.
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,...
Institute of Scientific and Technical Information of China (English)
杨湘婧; 徐祥德; 陈宏尧; 马舒庆; 陈渭民
2011-01-01
L波段高空气象探测系统的更新换代,提高了大气探测精度,L波段＂秒级＂数据为垂直高分辨率廓线探测信息的获取提供了气象要素再分析的基础平台。为了探讨L波段探空垂直高分辨数据应用的可行性,考虑到用于对比分析的其他观测系统获取＂秒级＂＂高时间密度＂同步观测数据的设备条件,本文重点选用了JICA（中日气象灾害合作研究中心项目）PBL（行星边界层）通量铁塔梯度观测系统来进行对比分析,并构造L波段探空再分析与通量铁塔近地层气象信息相关模型。研究结果表明,L波段探空垂直高分辨率廓线近地层数据能够较好地描述大气边界层内近地层温、湿、压;所建立的温、湿、压模型具有推算PBL铁塔近地层的温、湿、压的可行性。研究结论可为L波段高分辨率垂直廓线再分析平台及其对大气结构描述可行性提供具有应用价值的技术基础。基于L波段高分辨率垂直廓线再分析信息平台的构造,将有助于开发全国L波段探空在数值模式应用方面的潜力,推进探空垂直高分辨信息在数值模式同化系统中新技术的发展。%The renewal of L-band upper-air meteorological sounding system increases the atmospheric sounding precision,and the L-band ＂seconds level＂ data offer the basis platform of ＂seconds level＂ meteorological element data reanalysis for the L-band vetical high resolution profile.In order to discuss the application feasibility of L-band sounding vertical high resolution data,considering the acquisition conditions of other observation system ＂high time density＂ synchronous observation data,this paper selects the JICA （Japan International Co-operation Agency） PBL（planetary boundary layer） flux tower gradient observation to compare with,and also constructs the correlation model of L-band sounding data and flux tower surface layer meteorological information
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.
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,...
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 cases with 144 users and 4 vehicles it is demonstrated that the computation time can be reduced by a factor larger than 27....
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.
Combining heuristic and statistical techniques in landslide hazard assessments
Cepeda, Jose; Schwendtner, Barbara; Quan, Byron; Nadim, Farrokh; Diaz, Manuel; Molina, Giovanni
2014-05-01
As a contribution to the Global Assessment Report 2013 - GAR2013, coordinated by the United Nations International Strategy for Disaster Reduction - UNISDR, a drill-down exercise for landslide hazard assessment was carried out by entering the results of both heuristic and statistical techniques into a new but simple combination rule. The data available for this evaluation included landslide inventories, both historical and event-based. In addition to the application of a heuristic method used in the previous editions of GAR, the availability of inventories motivated the use of statistical methods. The heuristic technique is largely based on the Mora & Vahrson method, which estimates hazard as the product of susceptibility and triggering factors, where classes are weighted based on expert judgment and experience. Two statistical methods were also applied: the landslide index method, which estimates weights of the classes for the susceptibility and triggering factors based on the evidence provided by the density of landslides in each class of the factors; and the weights of evidence method, which extends the previous technique to include both positive and negative evidence of landslide occurrence in the estimation of weights for the classes. One key aspect during the hazard evaluation was the decision on the methodology to be chosen for the final assessment. Instead of opting for a single methodology, it was decided to combine the results of the three implemented techniques using a combination rule based on a normalization of the results of each method. The hazard evaluation was performed for both earthquake- and rainfall-induced landslides. The country chosen for the drill-down exercise was El Salvador. The results indicate that highest hazard levels are concentrated along the central volcanic chain and at the centre of the northern mountains.
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.
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
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...
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.
A Heuristic Algorithm for optimizing Page Selection Instructions
Li, Qing'an; Chen, Yong; Wu, Wei; Xu, Wenwen
2010-01-01
Page switching is a technique that increases the memory in microcontrollers without extending the address buses. This technique is widely used in the design of 8-bit MCUs. In this paper, we present an algorithm to reduce the overhead of page switching. To pursue small code size, we place the emphasis on the allocation of functions into suitable pages with a heuristic algorithm, thereby the cost-effective placement of page selection instructions. Our experimental results showed the optimization achieved a reduction in code size of 13.2 percent.
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
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 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.
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.
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.
Heuristics for Synthesizing Robust Networks with a Diameter Constraint
Directory of Open Access Journals (Sweden)
Harsha Nagarajan
2014-01-01
Full Text Available Robustness of a network in the presence of node or link failures plays an important role in the design of the network. A key factor that quantifies this robustness is the algebraic connectivity of the network. In this paper, the authors address the problem of finding a network that maximizes the algebraic connectivity of the network while ensuring that the length of the shortest path joining any two nodes in the network is within a given bound. This paper presents k-opt and tabu search heuristics for finding feasible solutions for this network synthesis problem. Computational results are also presented to corroborate the performance of the proposed algorithms.
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...
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...
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.
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.
Heuristic algorithm for optical character recognition of Arabic script
Yarman-Vural, Fatos T.; Atici, A.
1996-02-01
In this paper, a heuristic method is developed for segmentation, feature extraction and recognition of the Arabic script. The study is part of a large project for the transcription of the documents in Ottoman Archives. A geometrical and topological feature analysis method is developed for segmentation and feature extraction stages. Chain code transformation is applied to main strokes of the characters which are then classified by the hidden Markov model (HMM) in the recognition stage. Experimental results indicate that the performance of the proposed method is impressive, provided that the thinning process does not yield spurious branches.
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.
Hannemann, S.; Duijn, van E.J.; Ubachs, W.M.G.
2005-01-01
With the use of a novel titanium: sapphire laser source delivering, upon fourth harmonic generation, narrowband and tunable radiation in the deep-UV, spectroscopic studies were performed on weak Schumann-Runge bands of oxygen. Improved values for rotational and fine structure molecular parameters fo
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.
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...
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
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.
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.
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.
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.
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...
Energy Technology Data Exchange (ETDEWEB)
Stark, G. [Department of Physics, Wellesley College, Wellesley, MA 02481 (United States); Heays, A. N. [Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden (Netherlands); Lyons, J. R. [School of Earth and Space Exploration, Arizona State University, 781 South Terrace Road, Tempe, AZ 85281 (United States); Smith, P. L. [93 Pleasant Street, Watertown, MA 02472 (United States); Eidelsberg, M.; Lemaire, J. L.; Gavilan, L. [Observatoire de Paris, 5 place Jules Janssen, F-92195 Meudon (France); Federman, S. R. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); De Oliveira, N.; Joyeux, D.; Nahon, L., E-mail: gstark@wellesley.edu [Synchrotron SOLEIL, Orme de Merisiers, St. Aubin, BP 48, F-91192 Gif sur Yvette Cedex (France)
2014-06-10
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 {sup 1}Σ{sup +} ground state to the v = 0 and 1 levels of the B {sup 1}Σ{sup +}, C {sup 1}Σ{sup +}, and E {sup 1}Π states, in {sup 12}C{sup 16}O, {sup 12}C{sup 17}O, {sup 12}C{sup 18}O, {sup 13}C{sup 16}O, and {sup 13}C{sup 18}O. 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 {sup 17}O enrichments seen in recent laboratory photolysis experiments on CO at wavelengths from 105 to 108 nm.
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
Gastric banding surgery - your diet; Obesity - diet after banding; Weight loss - diet after banding ... about any problems you are having with your diet, or about other issues related to your surgery ...
Iliotibial band syndrome - aftercare
IT band syndrome - aftercare; Iliotibial band friction syndrome - aftercare ... If you have iliotibial band syndrome you may notice: Mild pain on the outside of your knee when you begin to exercise, which goes ...
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…
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
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…
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…
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 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…
Tolerance based contract-or-patch heuristic for the asymmetric TSP
Goldengorin, Boris; Jaeger, Gerold; Molitor, Paul; Erlebach, T
2006-01-01
In this paper we improve the quality of a recently suggested class of construction heuristics for the Asymmetric Traveling Salesman Problem (ATSP), namely the Contract-or-Patch heuristic. Our improvement is based on replacing the selection of each path to be contracted after deleting a heaviest arc
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…
Usable guidelines for usable websites? An analysis of five e-government heuristics
Welle Donker-Kuijer, Marieke; Jong, de Menno; Lentz, Leo
2010-01-01
Many government organizations use web heuristics for the quality assurance of their websites. Heuristics may be used by web designers to guide the decisions about a website in development, or by web evaluators to optimize or assess the quality of an existing website. Despite their popularity, very l
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.
An Ant Colony based Hyper-Heuristic Approach for the Set Covering Problem
Directory of Open Access Journals (Sweden)
Alexandre Silvestre FERREIRA
2015-12-01
Full Text Available The Set Covering Problem (SCP is a NP-hard combinatorial optimization problem that is challenging for meta-heuristic algorithms. In the optimization literature, several approaches using meta-heuristics have been developed to tackle the SCP and the quality of the results provided by these approaches highly depends on customized operators that demands high effort from researchers and practitioners. In order to alleviate the complexity of designing metaheuristics, a methodology called hyper-heuristic has emerged as a possible solution. A hyper-heuristic is capable of dynamically selecting simple low-level heuristics accordingly to their performance, alleviating the design complexity of the problem solver and obtaining satisfactory results at the same time. In a previous study, we proposed a hyper-heuristic approach based on Ant Colony Optimization (ACO-HH for solving the SCP. This paper extends our previous efforts, presenting better results and a deeper analysis of ACO-HH parameters and behavior, specially about the selection of low-level heuristics. The paper also presents a comparison with an ACO meta-heuristic customized for the SCP.
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.
Efficient Heuristic Based on Clustering Approach for OLSR
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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.
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.
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.
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.
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...
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.
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 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
We consider a Virtual Power Plant, which is given the task of dispatching a fluctuating power supply to a portfolio of flexible consumers. The flexible consumers are modeled as discrete batch processes, and the associated optimization problem is denoted the Discrete Virtual Power Plant Dispatch...... 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...
A boundedness result for the direct heuristic dynamic programming.
Liu, Feng; Sun, Jian; Si, Jennie; Guo, Wentao; Mei, Shengwei
2012-08-01
Approximate/adaptive dynamic programming (ADP) has been studied extensively in recent years for its potential scalability to solve large state and control space problems, including those involving continuous states and continuous controls. The applicability of ADP algorithms, especially the adaptive critic designs has been demonstrated in several case studies. Direct heuristic dynamic programming (direct HDP) is one of the ADP algorithms inspired by the adaptive critic designs. It has been shown applicable to industrial scale, realistic and complex control problems. In this paper, we provide a uniformly ultimately boundedness (UUB) result for the direct HDP learning controller under mild and intuitive conditions. By using a Lyapunov approach we show that the estimation errors of the learning parameters or the weights in the action and critic networks remain UUB. This result provides a useful controller convergence guarantee for the first time for the direct HDP design. PMID:22397949
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
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
DEFF Research Database (Denmark)
Daalhuizen, Jaap; Person, Oscar; Gattol, Valentin
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...
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
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.
Directory of Open Access Journals (Sweden)
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.
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.
Comparing the performance of different meta-heuristics for unweighted parallel machine scheduling
Directory of Open Access Journals (Sweden)
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 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.
A personification heuristic Genetic Algorithm for Digital Microfluidics-based Biochips Placement
Directory of Open Access Journals (Sweden)
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.
Heuristics and operational research in emergency situations and civil defence education
Directory of Open Access Journals (Sweden)
Paun J. Bereš
2014-06-01
Full Text Available This paper presents problem solving using heuristics and operational research in order to make appropriate decisions in emergency situations with a particular emphasis on the application of a heuristic model of team training for emergency situations. It is intended for military command and teaching personnel as well as for civil defense personnel (Department of Emergency Management and local government authorities (administrative district chiefs and mayors - commanders. The heuristic approach to problem solving should enable adequate decision making for command staff from the local to the national level after the proclamation of emergency and a state of emergency in some regions or the whole territory of Serbia.
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...
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
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.
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.
Bang, Dan; Fusaroli, Riccardo; Tylén, Kristian; Olsen, Karsten; Latham, Peter E; Lau, Jennifer Y F; Roepstorff, Andreas; Rees, Geraint; Frith, Chris D; Bahrami, Bahador
2014-05-01
In a range of contexts, individuals arrive at collective decisions by sharing confidence in their judgements. This tendency to evaluate the reliability of information by the confidence with which it is expressed has been termed the 'confidence heuristic'. We tested two ways of implementing the confidence heuristic in the context of a collective perceptual decision-making task: either directly, by opting for the judgement made with higher confidence, or indirectly, by opting for the faster judgement, exploiting an inverse correlation between confidence and reaction time. We found that the success of these heuristics depends on how similar individuals are in terms of the reliability of their judgements and, more importantly, that for dissimilar individuals such heuristics are dramatically inferior to interaction. Interaction allows individuals to alleviate, but not fully resolve, differences in the reliability of their judgements. We discuss the implications of these findings for models of confidence and collective decision-making.
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.
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...
Unified heuristics to solve routing problem of reverse logistics in sustainable supply chain
Anbuudayasankar, S. P.; Ganesh, K.; Lenny Koh, S. C.; Mohandas, K.
2010-03-01
A reverse logistics problem, motivated by many real-life applications, is examined where bottles/cans in which products are delivered from a processing depot to customers in one period are available for return to the depot in the following period. The picked-up bottles/cans need to be adjusted in the place of delivery load. This problem is termed as simultaneous delivery and pick-up problem with constrained capacity (SDPC). We develop three unified heuristics based on extended branch and bound heuristic, genetic algorithm and simulated annealing to solve SDPC. These heuristics are also designed to solve standard travelling salesman problem (TSP) and TSP with simultaneous delivery and pick-up (TSDP). We tested the heuristics on standard, derived and randomly generated datasets of TSP, TSDP and SDPC and obtained satisfying results with high convergence in reasonable time.
A Comparison of Heuristics with Modularity Maximization Objective using Biological Data Sets
Directory of Open Access Journals (Sweden)
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.
The White ceiling heuristic and the underestimation of Asian-American income.
Directory of Open Access Journals (Sweden)
Chris C Martin
Full Text Available The belief that ethnic majorities dominate ethnic minorities informs research on intergroup processes. This belief can lead to the social heuristic that the ethnic majority sets an upper limit that minority groups cannot surpass, but this possibility has not received much attention. In three studies of perceived income, we examined how this heuristic, which we term the White ceiling heuristic leads people to inaccurately estimate the income of a minority group that surpasses the majority. We found that Asian Americans, whose median income has surpassed White median income for nearly three decades, are still perceived as making less than Whites, with the least accurate estimations being made by people who strongly believe that Whites are privileged. In contrast, income estimates for other minorities were fairly accurate. Thus, perceptions of minorities are shaped both by stereotype content and a heuristic.
Bang, Dan; Fusaroli, Riccardo; Tylén, Kristian; Olsen, Karsten; Latham, Peter E; Lau, Jennifer Y F; Roepstorff, Andreas; Rees, Geraint; Frith, Chris D; Bahrami, Bahador
2014-05-01
In a range of contexts, individuals arrive at collective decisions by sharing confidence in their judgements. This tendency to evaluate the reliability of information by the confidence with which it is expressed has been termed the 'confidence heuristic'. We tested two ways of implementing the confidence heuristic in the context of a collective perceptual decision-making task: either directly, by opting for the judgement made with higher confidence, or indirectly, by opting for the faster judgement, exploiting an inverse correlation between confidence and reaction time. We found that the success of these heuristics depends on how similar individuals are in terms of the reliability of their judgements and, more importantly, that for dissimilar individuals such heuristics are dramatically inferior to interaction. Interaction allows individuals to alleviate, but not fully resolve, differences in the reliability of their judgements. We discuss the implications of these findings for models of confidence and collective decision-making. PMID:24650632
Exemplars in the mist: the cognitive substrate of the representativeness heuristic.
Nilsson, Håkan; Juslin, Peter; Olsson, Henrik
2008-06-01
The idea that people often make probability judgments by a heuristic short-cut, the representativeness heuristic, has been widely influential, but also criticized for being vague. The empirical trademark of the heuristic is characteristic deviations between normative probabilities and judgments (e.g., the conjunction fallacy, base-rate neglect). In this article the authors contrast two hypotheses concerning the cognitive substrate of the representativeness heuristic, the prototype hypothesis (Kahneman & Frederick, 2002) and the exemplar hypothesis (Juslin & Persson, 2002), in a task especially designed to elicit representativeness effects. Computational modelling and an experiment reveal that representativeness effects are evident early in training and persist longer in a more complex task environment and that the data are best accounted for by a model implementing the exemplar hypothesis. PMID:18419587
A Heuristic and Hybrid Method for the Tank Allocation Problem in Maritime Bulk Shipping
DEFF Research Database (Denmark)
Vilhelmsen, Charlotte; Larsen, Jesper; Lusby, Richard Martin
and strength as well as other operational constraints. The problem of finding a feasible solution to this tank allocation problem has been shown to be NP-Complete. We approach the problem on a tactical level where requirements for computation time are strict while solution quality is less important than simply...... have created a hybrid method that first runs the heuristic and if the heuristic fails to solve the problem, then runs the modified optimality based method on the parts of the problem that the heuristic did not solve. This hybrid method cuts between 90% and 94% of the average running times compared...... finding a feasible solution. We have developed a heuristic that can efficiently find feasible cargo allocations. Computational results show that it can solve 99% of the considered instances within 0.4 seconds and all of them if allowed longer time. We have also modified an optimality based method from...
A heuristic and hybrid method for the tank allocation problem in maritime bulk shipping
DEFF Research Database (Denmark)
Vilhelmsen, Charlotte; Larsen, Jesper; Lusby, Richard Martin
2016-01-01
and strength as well as other operational constraints. The problem of finding a feasible solution to this tank allocation problem has been shown to be NP-Complete. We approach the problem on a tactical level where requirements for computation time are strict while solution quality is less important than simply...... have created a hybrid method that first runs the heuristic and if the heuristic fails to solve the problem, then runs the modified optimality based method on the parts of the problem that the heuristic did not solve. This hybrid method cuts between 90 and 94 % of the average running times compared...... finding a feasible solution. We have developed a heuristic that can efficiently find feasible cargo allocations. Computational results show that it can solve 99 % of the considered instances within 0.4 s and all of them if allowed longer time. We have also modified an optimality based method from...
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
Intensified crystallization in complex media: heuristics for crystallization of platform chemicals
Urbanus, J.; Roelands, C.P.M.; Verdoes, D.; Horst, J.H. ter
2012-01-01
This paper presents heuristics for the integration of fermentation with the appropriate crystallization based in-situ product recovery (ISPR) technique. Here techniques, such as co-crystallization (CC), evaporative crystallization (EC), template induced crystallization (TIC), cooling crystallization
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.
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)
Heuristic Scheduling in Grid Environments: Reducing the Operational Energy Demand
Bodenstein, Christian
In a world where more and more businesses seem to trade in an online market, the supply of online services to the ever-growing demand could quickly reach its capacity limits. Online service providers may find themselves maxed out at peak operation levels during high-traffic timeslots but too little demand during low-traffic timeslots, although the latter is becoming less frequent. At this point deciding which user is allocated what level of service becomes essential. The concept of Grid computing could offer a meaningful alternative to conventional super-computing centres. Not only can Grids reach the same computing speeds as some of the fastest supercomputers, but distributed computing harbors a great energy-saving potential. When scheduling projects in such a Grid environment however, simply assigning one process to a system becomes so complex in calculation that schedules are often too late to execute, rendering their optimizations useless. Current schedulers attempt to maximize the utility, given some sort of constraint, often reverting to heuristics. This optimization often comes at the cost of environmental impact, in this case CO 2 emissions. This work proposes an alternate model of energy efficient scheduling while keeping a respectable amount of economic incentives untouched. Using this model, it is possible to reduce the total energy consumed by a Grid environment using 'just-in-time' flowtime management, paired with ranking nodes by efficiency.
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 heuristic method for solving triangle packing problem
Institute of Scientific and Technical Information of China (English)
CHEN Chuan-bo; HE Da-hua
2005-01-01
Given a set of triangles and a rectangle container, the triangle packing problem is to determine ifthese triangles can be placed into the container without overlapping. Triangle packing problem is a special case of polygon packing problem and also NP-hard, so it is unlikely that an efficient and exact algorithm can be developed to solve this problem. In this paper, a new concept of rigid placement is proposed, based on which a discrete solution space called rigid solution space is constructed. Each solution in the rigid solution space can be built by continuously applying legal rigid placements one by one until all the triangles are placed into the rectangle container without overlapping. The proposed Least-Destruction-First (LDF) strategy determines which rigid placement has the privilege to go into the rectangle container. Based on this, a heuristic algorithm is proposed to solve the problem.Combining Least-Destruction-First strategy with backtracking, the corresponding backtracking algorithm is proposed. Computational results show that our proposed algorithms are efficient and robust. With slight modification, these techniques can be conveniently used for solving polygon packing problem.
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.
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.
THE HEURISTIC POTENTIAL OF ANOMIE THEORY IN MODERN CRIMINOLOGY
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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.
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.
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
A Heuristic Clustering Algorithm for Mining Communities in Signed Networks
Institute of Scientific and Technical Information of China (English)
Bo Yang; Da-You Liu
2007-01-01
Signed network is an important kind of complex network, which includes both positive relations and negative relations. Communities of a signed network are defined as the groups of vertices, within which positive relations are dense and between which negative relations are also dense. Being able to identify communities of signed networks is helpful for analysis of such networks. Hitherto many algorithms for detecting network communities have been developed. However, most of them are designed exclusively for the networks including only positive relations and are not suitable for signed networks.So the problem of mining communities of signed networks quickly and correctly has not been solved satisfactorily. In this paper, we propose a heuristic algorithm to address this issue. Compared with major existing methods, our approach has three distinct features. First, it is very fast with a roughly linear time with respect to network size. Second, it exhibits a good clustering capability and especially can work well with complex networks without well-defined community structures.Finally, it is insensitive to its built-in parameters and requires no prior knowledge.
Solving SAT problem by heuristic polarity decision-making algorithm
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This paper presents a heuristic polarity decision-making algorithm for solving Boolean satisfiability (SAT). The algorithm inherits many features of the current state-of-the-art SAT solvers, such as fast BCP, clause recording, restarts, etc. In addition, a preconditioning step that calculates the polarities of variables according to the cover distribution of Karnaugh map is introduced into DPLL procedure, which greatly reduces the number of conflicts in the search process. The proposed approach is implemented as a SAT solver named DiffSat. Experiments show that DiffSat can solve many "real-life" instances in a reasonable time while the best existing SAT solvers, such as Zchaff and MiniSat, cannot. In particular, DiffSat can solve every instance of Bart benchmark suite in less than 0.03 s while Zchaff and MiniSat fail under a 900 s time limit. Furthermore, DiffSat even outperforms the outstanding incomplete algorithm DLM in some instances.
A Decentralized Heuristic Approach towards Resource Allocation in Femtocell Networks
Directory of Open Access Journals (Sweden)
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.
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...
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.
Selart, Marcus; Kuvaas, Bård; Boe, Ole; Takemura, Kazuhisa
2006-01-01
In the present study it was shown that decision heuristics and confidence judgements play important roles in the building of preferences. Based on a dual-process account of thinking, the study compared people who did well versus poorly on a series of decision heuristics and overconfidence judgement tasks. The two groups were found to differ with regard to their information search behaviour in introduced multiattribute choice tasks. High performers on the judgemental tasks were less influenced...
Situated cognition and narrative heuristic: evidence from retail investors and their brokers
Tarim, Emre
2016-01-01
In this paper, I discuss how a situated cognition perspective can reveal the socially constructed nature of seemingly psychological heuristics and errors in market actors’ judgements and decisions in financial markets. In doing so, I present a complementary approach to the heuristics and biases research in psychology and behavioural finance. More specifically, I draw on the narrative mode of knowing and explanation in real market settings as a framework to understand the content and the proce...
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.
Salcedo-Sanz, S.
2016-10-01
Meta-heuristic algorithms are problem-solving methods which try to find good-enough solutions to very hard optimization problems, at a reasonable computation time, where classical approaches fail, or cannot even been applied. Many existing meta-heuristics approaches are nature-inspired techniques, which work by simulating or modeling different natural processes in a computer. Historically, many of the most successful meta-heuristic approaches have had a biological inspiration, such as evolutionary computation or swarm intelligence paradigms, but in the last few years new approaches based on nonlinear physics processes modeling have been proposed and applied with success. Non-linear physics processes, modeled as optimization algorithms, are able to produce completely new search procedures, with extremely effective exploration capabilities in many cases, which are able to outperform existing optimization approaches. In this paper we review the most important optimization algorithms based on nonlinear physics, how they have been constructed from specific modeling of a real phenomena, and also their novelty in terms of comparison with alternative existing algorithms for optimization. We first review important concepts on optimization problems, search spaces and problems' difficulty. Then, the usefulness of heuristics and meta-heuristics approaches to face hard optimization problems is introduced, and some of the main existing classical versions of these algorithms are reviewed. The mathematical framework of different nonlinear physics processes is then introduced as a preparatory step to review in detail the most important meta-heuristics based on them. A discussion on the novelty of these approaches, their main computational implementation and design issues, and the evaluation of a novel meta-heuristic based on Strange Attractors mutation will be carried out to complete the review of these techniques. We also describe some of the most important application areas, in
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.
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.
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...
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.
Directory of Open Access Journals (Sweden)
G. Esteve-Asensio
2009-01-01
Full Text Available We propose and compare three novel heuristics for the calculation of the optimal cell radius in mobile networks based on Wideband Code Division Multiple Access (WCDMA technology. The proposed heuristics solve the problem of the load assignment and cellular radius calculation. We have tested our approaches with experiments in multiservices scenarios showing that the proposed heuristics maximize the cell radius, providing the optimum load factor assignment. The main application of these algorithms is strategic planning studies, where an estimation of the number of Nodes B of the mobile operator, at a national level, is required for economic analysis. In this case due to the large number of different scenarios considered (cities, towns, and open areas other methods than simulation need to be considered. As far as we know, there is no other similar method in the literature and therefore these heuristics may represent a novelty in strategic network planning studies. The proposed heuristics are implemented in a strategic planning software tool and an example of their application for a case in Spain is presented. The proposed heuristics are used for telecommunications regulatory studies in several countries.
A Role of Heuristics Miner Algorithm in the Business Process System
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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.
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.
Ultrafast CARS with Improved Spectral Resolution
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Lochbrunner S.
2013-03-01
Full Text Available Molecular vibrations are investigated by time and frequency resolved CARS applying ultrafast excitation and picosecond probing for high spectral resolution. Enhanced spectral structure and beating phenomena are demonstrated for coalescing Raman bands.
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)
Choosing the best heuristic for seeded alignment of DNA sequences
Directory of Open Access Journals (Sweden)
Buhler Jeremy
2006-03-01
Full Text Available Abstract Background Seeded alignment is an important component of algorithms for fast, large-scale DNA similarity search. A good seed matching heuristic can reduce the execution time of genomic-scale sequence comparison without degrading sensitivity. Recently, many types of seed have been proposed to improve on the performance of traditional contiguous seeds as used in, e.g., NCBI BLASTN. Choosing among these seed types, particularly those that use information besides the presence or absence of matching residue pairs, requires practical guidance based on a rigorous comparison, including assessment of sensitivity, specificity, and computational efficiency. This work performs such a comparison, focusing on alignments in DNA outside widely studied coding regions. Results We compare seeds of several types, including those allowing transition mutations rather than matches at fixed positions, those allowing transitions at arbitrary positions ("BLASTZ" seeds, and those using a more general scoring matrix. For each seed type, we use an extended version of our Mandala seed design software to choose seeds with optimized sensitivity for various levels of specificity. Our results show that, on a test set biased toward alignments of noncoding DNA, transition information significantly improves seed performance, while finer distinctions between different types of mismatches do not. BLASTZ seeds perform especially well. These results depend on properties of our test set that are not shared by EST-based test sets with a strong bias toward coding DNA. Conclusion Practical seed design requires careful attention to the properties of the alignments being sought. For noncoding DNA sequences, seeds that use transition information, especially BLASTZ-style seeds, are particularly useful. The Mandala seed design software can be found at http://www.cse.wustl.edu/~yanni/mandala/.
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.
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.
Band Interaction between Chiral Doublet Bands
Institute of Scientific and Technical Information of China (English)
QI Bin; ZHANG Shuang-Quan; WANG Shou-Yu; MENG Jie
2010-01-01
@@ Band interaction between the chiral doublet bands based on πh11/2(×) vh-111/2 configuration is investigated in the particle rotor model with different triaxial deformation γ. The variation of chiral partner states with γvalues is understood qualitatively based on the basic picture of two interaction levels, which is confirmed further by the calculated overlap integral of wave functions at different γ values. It is found that the interaction strengths ofchiral partner states are obvionsly different for odd spins and even ones.
Stillman, R.
2013-01-01
This website presents practice-based research related to solo simultaneous instrumental performance ('one-man band'). The site was conceived as a creative and widely accessible platform for music and ideas resulting from one-man band activates carried out between 2008 and 2013. Central to this project is an interest in how one-man band technique informs compositional process, including studio production. Through presentation and analysis of the author’s own creative practice, the site exp...
Directory of Open Access Journals (Sweden)
David Glenn Clark
2012-05-01
Full Text Available Background: Aphasic individuals exhibit greater difficulty understanding complex sentences, but there is little consensus regarding what makes one sentence more complicated than another. In addition, aphasic individuals might make use of heuristic strategies for understanding sentences. This research is a comparison of specific predictions derived from two approaches to the quantification of sentence complexity, one based on the hierarchical structure of sentences (trees, and the other based on Dependency Locality Theory (DLT. Complexity metrics derived from these theories are evaluated under various assumptions of heuristic use.Method: A set of complexity metrics was derived from each general theory of sentence complexity. Each metric was paired with assumptions of heuristic use. Probability spaces were generated that summarized the possible patterns of performance across 16 different sentence structures. The maximum likelihood of comprehension scores of 42 aphasic individuals was then computed for each probability space and the expected scores from the best-fitting points in the space were recorded for comparison to the actual scores. Predictions were then compared using measures of fit quality derived from linear mixed effects models.Results: All three of the metrics that provide the most consistently accurate predictions of patient scores rely on storage costs based on the DLT. Patients appear to employ an Agent-Theme heuristic, but vary in their tendency to accept heuristically generated interpretations. Furthermore, the ability to apply the heuristic may be degraded in proportion to aphasia severity. Conclusion: The results suggest that storage (i.e., allocation of cognitive resources for anticipated syntactic constituents is a key resource degraded by aphasia, but aphasic individuals may vary in their tendency to use or accept heuristically generated interpretations.
EMISAR: C- and L-band polarimetric and interferometric SAR
DEFF Research Database (Denmark)
Christensen, Erik Lintz; Dall, Jørgen; Skou, Niels;
1996-01-01
EMISAR is a C- and L-band fully polarimetric (i.e. 4 complex channel per frequency) synthetic aperture radar designed for remote sensing with high demands for resolution (2 m), polarization discrimination, and absolute radiometric and polarimetric calibration. The present installation has one 3-a......-axes stabilized antenna (C- or L-band) and two flush mounted C-band antennas providing the system with cross track and repeat track interferometric capabilities...
Synoptic versus orographic control on stationary convective banding
Barrett, Andrew I.; Gray, Suzanne L; Kirshbaum, Daniel J.; Roberts, Nigel M.; Schultz, David M.; Fairman Jr, Jonathan G.
2015-01-01
Quasi-stationary convective bands can cause large localised rainfall accumulations and are often anchored by topographic features. Here, the predictability of and mechanisms causing one such band are determined using ensembles of the Met Office Unified Model at convection-permitting resolution (1.5 km grid length). The band was stationary over the UK for 3 h and produced rainfall accumulations of up to 34 mm. The amount and location of the predicted rainfall was highly variable despite only s...
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
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.
PIJNACKER, LP; FERWERDA, MA
1995-01-01
Banding techniques were carried out on metaphase chromosomes of zebrafish (Danio rerio) embryos. The karyotypes with the longest chromosomes consist of 12 metacentrics, 26 submetacentrics, and 12 subtelocentrics (2n = 50). All centromeres are C-band positive. Eight chromosomes have a pericentric C-b
Skirka, Nicholas; Hume, Donald
2007-01-01
This article discusses how to use stretch bands for improving total body fitness and quality of life. A stretch band exercise program offers a versatile and inexpensive option to motivate participants to exercise. The authors suggest practical exercises that can be used in physical education to improve or maintain muscular strength and endurance,…
Stratway: A Modular Approach to Strategic Conflict Resolution
Hagen, George E.; Butler, Ricky W.; Maddalon, Jeffrey M.
2011-01-01
In this paper we introduce Stratway, a modular approach to finding long-term strategic resolutions to conflicts between aircraft. The modular approach provides both advantages and disadvantages. Our primary concern is to investigate the implications on the verification of safety-critical properties of a strategic resolution algorithm. By partitioning the problem into verifiable modules much stronger verification claims can be established. Since strategic resolution involves searching for solutions over an enormous state space, Stratway, like most similar algorithms, searches these spaces by applying heuristics, which present especially difficult verification challenges. An advantage of a modular approach is that it makes a clear distinction between the resolution function and the trajectory generation function. This allows the resolution computation to be independent of any particular vehicle. The Stratway algorithm was developed in both Java and C++ and is available through a open source license. Additionally there is a visualization application that is helpful when analyzing and quickly creating conflict scenarios.
Accurate evaluation of lowest band gaps in ternary locally resonant phononic crystals
Institute of Scientific and Technical Information of China (English)
Wang Gang; Shao Li-Hui; Liu Yao-Zong; Wen Ji-Hong
2006-01-01
Based on a better understanding of the lattice vibration modes, two simple spring-mass models are constructed in order to evaluate the frequencies on both the lower and upper edges of the lowest locally resonant band gaps of the ternary locally resonant phononic crystals. The parameters of the models are given in a reasonable way based on the physical insight into the band gap mechanism. Both the lumped-mass methods and our models are used in the study of the influences of structural and the material parameters on frequencies on both edges of the lowest gaps in the ternary locally resonant phononic crystals. The analytical evaluations with our models and the theoretical predictions with the lumped-mass method are in good agreement with each other. The newly proposed heuristic models are helpful for a better understanding of the locally resonant band gap mechanism, as well as more accurate evaluation of the band edge frequencies.
Resolution propositions; Proposition de resolution
Energy Technology Data Exchange (ETDEWEB)
NONE
2003-05-01
To put a resolution to the meeting in relation with the use of weapons made of depleted uranium is the purpose of this text. The situation of the use of depleted uranium by France during the Gulf war and other recent conflicts will be established. This resolution will give the most strict recommendations face to the eventual sanitary and environmental risks in the use of these kind of weapons. (N.C.)
Review on use of Swarm Intelligence Meta heuristics in Scheduling of FMS
Directory of Open Access Journals (Sweden)
Hamesh babu Nanvala,
2011-04-01
Full Text Available Due to the high complexity of Flexible Manufacturing Systems(FMS scheduling problem, approaches that guarantee to find the optimal solution are feasible only for small size instance of the problemswith lot of computational effort and time. In contrast, approaches based on meta heuristics are capable of finding good and “near to optimal” solutions to problem instances of realistic size, in a generally smaller computation time. This work provided a review on the use of swarm intelligence meta heuristics to the scheduling of flexible manufacturing problem. The two main areas of swarm intelligence that are prominently appeared in the literature relevant to this problems are ant colony optimization (ACO and particle swarmoptimization (PSO. By reviewing the literature related to use of swarm intelligence meta heuristics to FMS scheduling problem, and commented on the basis of the review.
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)
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).
Science writing heuristic effects on students' understanding of the nature of science
Hickerson, Caroline E.
Recently there has been a shift in science education that has encouraged teachers to place less emphasis on science content and more emphasis on teaching the Nature of Science. Thus, it is helpful for science educators to be aware of teaching strategies that produce better nature of science learning outcomes. The literature review focuses on the known benefits of using the Science Writing Heuristic. This research focused on the effectiveness of the Science Writing Heuristic in improving Nature of Science learning outcomes among biology students. The data from this research suggests that the Science Writing Heuristic does help students learn the Nature of Science but that this learning is not a significant improvement as compared to more traditional teaching methods. However, more research is needed, as the sample size and research time were a limiting factor in this study.
Knee model: Comparison between heuristic and rigorous solutions for the Schumann resonance problem
Galuk, Yu. P.; Nickolaenko, A. P.; Hayakawa, M.
2015-12-01
Rapid development of computers allows for application of the direct numerical solution of the global electromagnetic resonance problem in the Earth-ionosphere cavity. Direct numerical solutions exploit the cavity models with the given conductivity profile of atmosphere such as exponential or the knee profiles. These profiles are usually derived from the knee model by Mushtak and Williams (2002) developed for obtaining the realistic ELF propagation constant. It is usually forgotten that profiles of the knee model are only a convenient approximate interpretation for the heuristic relations used in computations. We demonstrate that the rigorous full wave solution of the electromagnetic problem for such profiles deviates from that obtained in the knee model. Therefore the direct numerical solutions must also depart from the heuristic one. We evaluate deviations of the heuristic knee model data from those pertinent to equivalent profile of atmospheric conductivity.
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.
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.
A hop count based heuristic routing protocol for mobile delay tolerant networks.
You, Lei; Li, Jianbo; Wei, Changjiang; Dai, Chenqu; Xu, Jixing; Hu, Lejuan
2014-01-01
Routing in delay tolerant networks (DTNs) is a challenge since it must handle network partitioning, long delays, and dynamic topology. Meanwhile, routing protocols of the traditional mobile ad hoc networks (MANETs) cannot work well due to the failure of its assumption that most network connections are available. In this paper, we propose a hop count based heuristic routing protocol by utilizing the information carried by the peripatetic packets in the network. A heuristic function is defined to help in making the routing decision. We formally define a custom operation for square matrices so as to transform the heuristic value calculation into matrix manipulation. Finally, the performance of our proposed algorithm is evaluated by the simulation results, which show the advantage of such self-adaptive routing protocol in the diverse circumstance of DTNs. PMID:25110736
A Hop Count Based Heuristic Routing Protocol for Mobile Delay Tolerant Networks
Directory of Open Access Journals (Sweden)
Lei You
2014-01-01
Full Text Available Routing in delay tolerant networks (DTNs is a challenge since it must handle network partitioning, long delays, and dynamic topology. Meanwhile, routing protocols of the traditional mobile ad hoc networks (MANETs cannot work well due to the failure of its assumption that most network connections are available. In this paper, we propose a hop count based heuristic routing protocol by utilizing the information carried by the peripatetic packets in the network. A heuristic function is defined to help in making the routing decision. We formally define a custom operation for square matrices so as to transform the heuristic value calculation into matrix manipulation. Finally, the performance of our proposed algorithm is evaluated by the simulation results, which show the advantage of such self-adaptive routing protocol in the diverse circumstance of DTNs.
A Fast Method for Heuristics in Large-Scale Flow Shop Scheduling
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Fast computation methods are needed for the heuristics of flow shop scheduling problems in practical manufacturing environments. This paper describes a generalized flow shop model, which is an extension of the classical model, in which not all machines are available at time zero. The general completion-time computing method is used to compute completion time of generalized flow shops. The transform classical flow shop to generalized shop (TCG) method is used to transform classical schedules into generalized schedules with less jobs. INSERT and SWAP, extended from job-insertion and pair-wise exchange which are fundamental procedures used in most heuristics for classical flow shops, reduce the CPU time by 1/2 and 1/3, respectively. The CPU time of 14 job-insertion and pair-wise exchange-based heuristics are analyzed with and without the TCG method. The results show that TCG considerably reduces the CPU time.
Takahashi, Kazuhiko; Naemura, Masahide
2005-12-01
This paper proposes a human body posture estimation method based on analysis of human silhouette and Kalman filter. The proposed method is based on both the heuristically extraction method of estimating the significant points of human body and the contour analysis of the human silhouette. The 2D coordinates of the human body's significant points, such as top of the head, and tips of feet, are located by applying the heuristically extraction method to the human silhouette, those of tips of hands are obtained by using the result of the contour analysis, and the joints of elbows and knees are estimated by introducing some heuristic rules to the contour image of the human silhouette. The estimated results are optimized and tracked by using Kalman filter. The proposed estimation method is implemented on a personal computer and runs in real-time. Experimental results show both the feasibility and the effectiveness of the proposed method for estimating human body postures.
Directory of Open Access Journals (Sweden)
Cleyton Rodrigues
2012-12-01
Full Text Available Many researchers in Artificial Intelligence seek for new algorithms to reduce the amount of memory/ time consumed for general searches in Constraint Satisfaction Problems. These improvements are accomplished by the use of heuristics which either prune useless tree search branches or even indicate the path to reach the (optimal solution faster than the blind version of the search. Many heuristics were proposed in the literature, like the Least Constraining Value (LCV. In this paper we propose a new pre-processing search heuristic to reduce the amount of backtracking calls, namely the Least Suggested Value First: a solution whenever the LCV solely cannot measure how much a value is constrained. In this paper, we present a pedagogical example, as well as the preliminary results.
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.
A nuclear heuristic for application to metaheuristics in-core fuel management optimization
Energy Technology Data Exchange (ETDEWEB)
Meneses, Anderson Alvarenga de Moura, E-mail: ameneses@lmp.ufrj.b [COPPE/Federal University of Rio de Janeiro, RJ (Brazil). Nuclear Engineering Program; Dalle Molle Institute for Artificial Intelligence (IDSIA), Manno-Lugano, TI (Switzerland); Gambardella, Luca Maria, E-mail: luca@idsia.c [Dalle Molle Institute for Artificial Intelligence (IDSIA), Manno-Lugano, TI (Switzerland); Schirru, Roberto, E-mail: schirru@lmp.ufrj.b [COPPE/Federal University of Rio de Janeiro, RJ (Brazil). Nuclear Engineering Program
2009-07-01
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)
A heuristic for the inventory management of smart vending machine systems
Directory of Open Access Journals (Sweden)
Yang-Byung Park
2012-12-01
Full Text Available 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 the system and the Clarke and Wright’s savings algorithm is applied to route vehicles for inventory replenishments of smart vending machines that share the same delivery days. Computational experiments are conducted on several small-size test problems to compare the proposed heuristic with the integrated optimization mathematical model with respect to system profit. Furthermore, a sensitivity analysis is carried out on a medium-size test problem to evaluate the effect of the customer service level on system profit using a computer simulation.Findings: The results show that the proposed heuristic yielded pretty good solutions with 5.7% error rate on average compared to the optimal solutions. The proposed heuristic took about 3 CPU minutes on average in the test problems being consisted of 10 five-product smart vending machines. It was confirmed that the system profit is significantly affected by the customer service level.Originality/value: The inventory management of smart vending machine systems is newly treated. Product substitutions are explicitly considered in the model. The proposed heuristic is effective as well as efficient. It can be easily modified for application to various retail vending settings under a vendor-managed inventory scheme with POS system.
Iliotibial band friction syndrome.
Lavine, Ronald
2010-07-20
Published articles on iliotibial band friction syndrome have been reviewed. These articles cover the epidemiology, etiology, anatomy, pathology, prevention, and treatment of the condition. This article describes (1) the various etiological models that have been proposed to explain iliotibial band friction syndrome; (2) some of the imaging methods, research studies, and clinical experiences that support or call into question these various models; (3) commonly proposed treatment methods for iliotibial band friction syndrome; and (4) the rationale behind these methods and the clinical outcome studies that support their efficacy.
Directory of Open Access Journals (Sweden)
Lopez-Loces Mario C.
2016-06-01
Full Text Available Internet shopping has been one of the most common online activities, carried out by millions of users every day. As the number of available offers grows, the difficulty in getting the best one among all the shops increases as well. In this paper we propose an integer linear programming (ILP model and two heuristic solutions, the MinMin algorithm and the cellular processing algorithm, to tackle the Internet shopping optimization problem with delivery costs. The obtained results improve those achieved by the state-of-the-art heuristics, and for small real case scenarios ILP delivers exact solutions in a reasonable amount of time.
Heuristic model of education and a prototype of a system for remote siren activation in emergency
Paun Josif Bereš; Kristian Paun Bereš
2013-01-01
A heuristic models of methodical innovation with special emphasis on training of team members to work in emergency situations, where each team member must be aware of the importance of their work, must know and apply a methodology for finding the best solutions and feel satisfaction with the results as an individual and as a part of that team, are proposed in this paper. Heuristic approach to the problems of teaching in emergency situations should allow team members to come up with the creati...
Aging and strategic retrieval processes: reducing false memories with a distinctiveness heuristic.
Dodson, Chad S; Schacter, Daniel L
2002-09-01
The authors show that a strategic retrieval process--the distinctiveness heuristic--is a powerful mechanism for reducing false memories in the elderly. Individuals studied words, pictures, or both types of items and then completed a recognition test on which the studied items appeared once, whereas the new words appeared twice. After studying either pictures only or a mixture of pictures and words, both younger and older adults falsely recognized fewer repeated new words than did participants who studied words. Studying pictures provided a basis for using a distinctiveness heuristic during the recognition test: Individuals inferred that the absence of memory for picture information indicates that an item is "new." PMID:12243382
Recognising the recognition heuristic for what it is (and what it's not
Directory of Open Access Journals (Sweden)
Ben R. Newell
2011-07-01
Full Text Available The diversity, ingenuity and differences of opinion displayed in the articles of the recent special issues on the recognition heuristic are testament to the power and theoretical fertility of a simple idea about the role of recognition in decision making. In this brief comment I mention a number of these papers, but my focus is on points of agreement and disagreement with the conclusions drawn by Gigerenzer and Goldstein (2011 in their review of a decade's worth of research on the recognition heuristic.
The effects of Polya's heuristic and diary writing on children's problem solving
Hensberry, Karina K. R.; Jacobbe, Tim
2012-03-01
This paper presents the results of a study that aimed at increasing students' problem-solving skills. Polya's (1985) heuristic for problem solving was used and students were required to articulate their thought processes through the use of a structured diary. The diary prompted students to answer questions designed to engage them in the phases of Polya's (1985) heuristic. While it appeared as though most students did not internalise the diary questions, further analysis of students' responses indicated that most students showed improvement in their solution strategies. These results indicate that having students write about their thinking may be beneficial for developing their problem-solving skills.
A greedy construction heuristic for the liner service network design problem
DEFF Research Database (Denmark)
Brouer, Berit Dangaard
The Liner Service Network Design Problem (LSN-DP) is the problem of constructing a set of routes for a heterogeneous vessel fleet of a global liner shipping operator. Routes in the liner shipping context are non-simple, cyclic routes constructed for a specific vessel type. The problem...... is challenging due to the size of a global liner shipping operation and due to the hub-and-spoke network design, where a high percentage of the total cargo is transshipped. We present the first construction heuristic for large scale instances of the LSN-DP. The heuristic is able to find a solution for a real...
Some Heuristics and Results for Small Cycles of the Discrete Logarithm
Holden, Joshua; Moree, Pieter
2004-01-01
Brizolis asked the question: does every prime p have a pair (g,h) such that h is a fixed point for the discrete logarithm with base g? The first author previously extended this question to ask about not only fixed points but also two-cycles, and gave heuristics (building on work of Zhang, Cobeli, Zaharescu, Campbell, and Pomerance) for estimating the number of such pairs given certain conditions on g and h. In this paper we extend these heuristics and prove results for some of them, building ...
A CDT-Based Heuristic Zone Design Approach for Economic Census Investigators
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Changixu Cheng
2015-01-01
Full Text Available This paper addresses a special zone design problem for economic census investigators that is motivated by a real-world application. This paper presented a heuristic multikernel growth approach via Constrained Delaunay Triangulation (CDT. This approach not only solved the barriers problem but also dealt with the polygon data in zoning procedure. In addition, it uses a new heuristic method to speed up the zoning process greatly on the premise of the required quality of zoning. At last, two special instances for economic census were performed, highlighting the performance of this approach.
Hybridization of Meta-heuristics for Optimizing Routing protocol in VANETs
Directory of Open Access Journals (Sweden)
R.R Sedamkar
2016-02-01
Full Text Available The goal of VANET is to establish a vehicular communication system which is reliable and fast which caters to road safety and road safety. In VANET where network fragmentation is frequent with no central control, routing becomes a challenging task. Planning an optimal routing plan for tuning parameter configuration of routing protocol for setting up VANET is very crucial. This is done by defining an optimization problem where hybridization of meta-heuristics is defined. The paper contributes the idea of combining meta-heuristic algorithm to enhance the performance of individual search method for optimization problem
Deterministic and heuristic models of forecasting spare parts demand
Directory of Open Access Journals (Sweden)
Ivan S. Milojević
2012-04-01
of preventive maintenance, the number of assets on which the preventive maintenance procedures are performed and the technology of maintaining procedures are known, then the range and the quantity of spare parts needed to perform these procedures are also known. Heuristic forecasting is related to the experts. Armed forces use it for the assessment of combat situation, taking into account the opponent's and its own action tactics, forecasting enemy's intentions, analyzing the plan of operations, making decision for the plan of action, etc. In this case, relatively unregulated systems are those in which there is no data about the observed phenomenon and its development in the past. In addition to the fact that the above data does not exist, there is a need for spare parts demand forecasts for the purpose of decision making and inventory management. This primarily relates to the period of transition from an unregulated to a regulated system. In this case, forecasting has a limited range. No forecasting can be done for a longer period; the forecasting is reduced to the next relevant interval, i.e. to the interval relevant for the system. The application of another, relatively simple model which uses computer techniques has no particular limitations, but for that reason its results are time-limited; results are obtained only for the subsequent relevant period. The results of this model have a very limited range in planning. This model is applicable mainly in unregulated systems. It is suitable for so-called condition 'clearing'. After one or two closed cycles, a situation is brought to order, but then much more sensitive models are needed.
Sjogren, W. L.; Gottlieb, P.; Muller, P. M.; Wollenhaupt, W. R.
1972-01-01
The experiment which derives data from three lunar-orbiting objects, the command-service module (CSM), the lunar module (LM), and the subsatellite in the S-band is described. Each provides detailed information on the near-side lunar gravitational field. The primary emphasis is on the low-altitude (20 km) CSM data. The LM data cover a very short time span and are somewhat redundant with the CSM data. The resolution of the high-altitude (100 km) CSM data is not as great as that of the low altitude data. The low-altitude CSM and LM data coverage and the complementary coverage obtained during the Apollo 14 mission are presented. The experiment uses the same technique of gravity determination employed on the Lunar Orbiter, in the data of which the large anomalies called mascons were first observed. The data consist of variations in the spacecraft speed as measured by the Earth-based radio tracking system.
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CSF oligoclonal banding - slideshow
... presentations/100145.htm CSF oligoclonal banding - series—Normal anatomy ... Overview The cerebrospinal fluid (CSF) serves to supply nutrients to the central nervous system (CNS) and collect waste products, as well as ...
Gutin, Gregory; Goldengorin, Boris; Huang, Jing
2008-01-01
Optimization heuristics are often compared with each other to determine which one performs best by means of worst-case performance ratio reflecting the quality of returned solution in the worst case. The domination number is a complement parameter indicating the quality of the heuristic in hand by d