Journal articles: 'Directional mapping'

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Deno, D. Curtis, Abhishek Bhaskaran, Dennis J. Morgan, Fikri Goksu, Katherine Batman, Gregory K. Olson, Karl Magtibay, et al. "High-resolution, live, directional mapping." Heart Rhythm 17, no. 9 (September 2020): 1621–28. http://dx.doi.org/10.1016/j.hrthm.2020.04.039.

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Huang, Chung-Lin, and Kou-Chang Chen. "Directional Moving Averaging Interpolation for Texture Mapping." Graphical Models and Image Processing 58, no. 4 (July 1996): 301–13. http://dx.doi.org/10.1006/gmip.1996.0025.

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Green, Danielle J., Alison Harris, Aleena Young, and Catherine L. Reed. "Embodied valuation: Directional action is associated with item values." Quarterly Journal of Experimental Psychology 71, no. 8 (January 1, 2018): 1734–47. http://dx.doi.org/10.1080/17470218.2017.1360370.

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We have a lifetime of experience interacting with objects we value. Although many economic theories represent valuation as a purely cognitive process independent of the sensorimotor system, embodied cognitive theory suggests that our memories for items’ value should be linked to actions we use to obtain them. Here, we investigated whether the value of real items was associated with specific directional movements toward or away from the body. Participants priced a set of food items to determine their values; they then used directional actions to classify each item as high- or low-value. To determine if value is linked to specific action mappings, movements were referenced either with respect to the object (push toward high-value items; pull away from low-value items) or the self (pull high-value items toward self; push low-value items away). Participants who were assigned (Experiment 1) or chose (Experiment 2) to use an object-referenced action mapping were faster than those using a self-referenced mapping. A control experiment (Experiment 3) using left/right movements found no such difference when action mappings were not toward/away from the body. These results indicate that directional actions toward items are associated with the representation of their value, suggesting an embodied component to economic choice.

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Tu, Chen-Hsuan, and Tzai-Hung Wen. "Mapping Anisotropic Landscape for Understanding Underlying Spatial Structure of Air Pollution." Abstracts of the ICA 1 (July 15, 2019): 1. http://dx.doi.org/10.5194/ica-abs-1-373-2019.

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Abstract. Urban air pollution problem has become a huge threat to human health in the most developing and developed countries. Therefore, monitoring air quality with high spatial and temporal resolutions is an important issue. There are two different approaches to mapping street-level distributions of air quality in time and space. One is mathematical approach, which uses numerical methods to calculate the concentration of air pollutants in each space-time grid through considering chemical transport, wind field, terrain morphology and other parameters which affect the direction and intensity of dispersion. This approach is limited by intensively computational process, so most of studies used either rough spatial grid resolution for representing large-scale regions or detailed grid resolution for small-scale areas. Numerical models with rough grid resolution could not capture detailed physical interactions in the micro-environment. The other approach is statistical approach, which used spatial interpolation techniques, such as inverse distance weighting (IDW) and Kriging methods, or established regression models, such as land-use regression (LUR), for deriving concentrations of air pollution from remote sensing or ground-level station sensor data. This approach is assumed linear associations with environmental factors and isotropic distance-decayed phenomena, which also ignores complex physical interactions.Spatial distribution of air pollution could be affected by directional background factors, such as wind fields, surface relief and so on. The spatial effects of these physical factors are not isotropic. However, recent studies used statistical modelling approaches are based on isotropic assumptions and did not consider directional variations of these factors on air quality. The purpose of the study is to develop an innovative statistical approach to measure directional effects on air quality with spatial heterogeneity. We produces anisotropic landscapes of directional fields for identifying major directions for each space-time grid through EPA’s monitoring station data to visualize space-time trend of air quality changing with directions. This study provides significant insight for understanding spatial structures behind air pollution distributions influenced by directional physical factors.

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Staehle, Felix, Bernd A. Jung, Simon Bauer, Jochen Leupold, Jelena Bock, Ramona Lorenz, Daniela Föll, and Michael Markl. "Three-directional acceleration phase mapping of myocardial function." Magnetic Resonance in Medicine 65, no. 5 (January 19, 2011): 1335–45. http://dx.doi.org/10.1002/mrm.22744.

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Pitt, Benjamin, Stephen Ferrigno, Jessica F. Cantlon, Daniel Casasanto, Edward Gibson, and Steven T. Piantadosi. "Spatial concepts of number, size, and time in an indigenous culture." Science Advances 7, no. 33 (August 2021): eabg4141. http://dx.doi.org/10.1126/sciadv.abg4141.

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In industrialized groups, adults implicitly map numbers, time, and size onto space according to cultural practices like reading and counting (e.g., from left to right). Here, we tested the mental mappings of the Tsimane’, an indigenous population with few such cultural practices. Tsimane’ adults spatially arranged number, size, and time stimuli according to their relative magnitudes but showed no directional bias for any domain on any spatial axis; different mappings went in different directions, even in the same participant. These findings challenge claims that people have an innate left-to-right mapping of numbers and that these mappings arise from a domain-general magnitude system. Rather, the direction-specific mappings found in industrialized cultures may originate from direction-agnostic mappings that reflect the correlational structure of the natural world.

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Eichkitz, Christoph Georg, Marcellus Gregor Schreilechner, Paul de Groot, and Johannes Amtmann. "Mapping directional variations in seismic character using gray-level co-occurrence matrix-based attributes." Interpretation 3, no. 1 (February 1, 2015): T13—T23. http://dx.doi.org/10.1190/int-2014-0099.1.

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Texture attributes describe the spatial arrangement of neighboring amplitudes values within a given analysis window. We chose a statistical texture classification method, the gray-level co-occurrence matrix (GLCM), and its derived attributes, to produce a semiautomated description of the spatial arrangement of seismic facies. The GLCM is a measure of how often different combinations of neighboring pixel values occur. We tested the application of directional GLCM-based attributes for the detection of seismic variability within paleoriver features. Calculation of 3D GLCM-based attributes can be done in 13 space directions. The results of GLCM-based attribute calculation differed depending on the chosen GLCM parameters (number of gray levels, analysis window, and direction of calculation). We specifically focused on how the direction of calculation influenced the computation of attributes, while keeping other parameters constant. We first tested the workflow on a 2D training image and later ran on a real seismic amplitude volume from the Vienna Basin. Based on the GLCM-based attributes, we could map the channel features and extract them as geobodies. Additionally, we generated a new set of directional GLCM-based attributes to detect spatial changes in the seismic facies. By comparing these directional attributes, we could determine areas within the channel features having higher directional variability. Areas with higher tendency to directional variations might be associated with changes in lithology, seismic facies, or with seismic anisotropy.

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Xiao, Yiqi, Ke Miao, and Chenhan Jiang. "Mapping Directional Mid-Air Unistroke Gestures to Interaction Commands: A User Elicitation and Evaluation Study." Symmetry 13, no. 10 (October 13, 2021): 1926. http://dx.doi.org/10.3390/sym13101926.

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A stroke is the basic limb movement that both humans and animals naturally and repetitiously perform. Having been introduced into gestural interaction, mid-air stroke gestures saw a wide application range and quite intuitive use. In this paper, we present an approach for building command-to-gesture mapping that exploits the semantic association between interactive commands and the directions of mid-air unistroke gestures. Directional unistroke gestures make use of the symmetry of the semantics of commands, which makes a more systematic gesture set for users’ cognition and reduces the number of gestures users need to learn. However, the learnability of the directional unistroke gestures is varying with different commands. Through a user elicitation study, a gesture set containing eight directional mid-air unistroke gestures was selected by subjective ratings of the direction in respect to its association degree with the corresponding command. We evaluated this gesture set in a following study to investigate the learnability issue, and the directional mid-air unistroke gestures and user-preferred freehand gestures were compared. Our findings can offer preliminary evidence that “return”, “save”, “turn-off” and “mute” are the interaction commands more applicable to using directional mid-air unistrokes, which may have implication for the design of mid-air gestures in human–computer interaction.

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BERAN, ZDENĚK, and SERGEJ ČELIKOVSKÝ. "CHAOS ON HYPERSPACE." International Journal of Bifurcation and Chaos 23, no. 05 (May 2013): 1350084. http://dx.doi.org/10.1142/s0218127413500843.

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In this paper, the chaotic behavior of a set-valued mapping F : X → 2X, where X is a compact space, is investigated. The existence of the generalized shadowing property in the hyperspace 2X is proved. Based on the generalized shadowing property of the set-valued mappings F and the assumption of the existence of an unstable chain recurrent point of the mapping F, it is shown that the Bernoulli system of bi-directional shifts is embedded in the sense of semiconjugacy into the image of mapping F, i.e. Smale's chaos in the set-valued system F is thereby proved.

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Petitcolin, F., F. Nerry, and M. P. Stoll. "Mapping directional emissivity at 3.7 μ m using a simple model of bi-directional reflectivity." International Journal of Remote Sensing 23, no. 17 (January 2002): 3443–72. http://dx.doi.org/10.1080/01431160110075569.

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Zhang, Sainan, Liwei Zhang, Hongwei Zhang, and Qingsong Duan. "Hadamard Directional Differentiability of the Optimal Value Function of a Quadratic Programming Problem." Asia-Pacific Journal of Operational Research 35, no. 03 (May 31, 2018): 1850012. http://dx.doi.org/10.1142/s0217595918500124.

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In this paper, we consider the stability analysis of a convex quadratic programming (QP) problem and its restricted Wolfe dual when all parameters in the problem are perturbed. Based on the continuity of the feasible set mapping, we establish the upper semi-continuity of the optimal solution mappings of the convex QP problem and the restricted Wolfe dual problem. Furthermore, by characterizing the optimal value function as a min–max optimization problem over two compact convex sets, we demonstrate the Lipschitz continuity and the Hadamard directional differentiability of the optimal value function.

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Johnson, M. T. V., J. D. Coltz, M. C. Hagen, and T. J. Ebner. "Visuomotor Processing as Reflected in the Directional Discharge of Premotor and Primary Motor Cortex Neurons." Journal of Neurophysiology 81, no. 2 (February 1, 1999): 875–94. http://dx.doi.org/10.1152/jn.1999.81.2.875.

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Johnson, M.T.V., J. D. Coltz, M. C. Hagen, and T. J. Ebner. Visuomotor processing as reflected in the directional discharge of premotor and primary motor cortex neurons. J. Neurophysiol. 81: 875–894, 1999. Premotor and primary motor cortical neuronal firing was studied in two monkeys during an instructed delay, pursuit tracking task. The task included a premovement “cue period,” during which the target was presented at the periphery of the workspace and moved to the center of the workspace along one of eight directions at one of four constant speeds. The “track period” consisted of a visually guided, error-constrained arm movement during which the animal tracked the target as it moved from the central start box along a line to the opposite periphery of the workspace. Behaviorally, the animals tracked the required directions and speeds with highly constrained trajectories. The eye movements consisted of saccades to the target at the onset of the cue period, followed by smooth pursuit intermingled with saccades throughout the cue and track periods. Initially, an analysis of variance (ANOVA) was used to test for direction and period effects in the firing. Subsequently, a linear regression analysis was used to fit the average firing from the cue and track periods to a cosine model. Directional tuning as determined by a significant fit to the cosine model was a prominent feature of the discharge during both the cue and track periods. However, the directional tuning of the firing of a single cell was not always constant across the cue and track periods. Approximately one-half of the neurons had differences in their preferred directions (PDs) of >45° between cue and track periods. The PD in the cue or track period was not dependent on the target speed. A second linear regression analysis based on calculation of the preferred direction in 20-ms bins (i.e., the PD trajectory) was used to examine on a finer time scale the temporal evolution of this change in directional tuning. The PD trajectories in the cue period were not straight but instead rotated over the workspace to align with the track period PD. Both clockwise and counterclockwise rotations occurred. The PD trajectories were relatively straight during most of the track period. The rotation and eventual convergence of the PD trajectories in the cue period to the preferred direction of the track period may reflect the transformation of visual information into motor commands. The widely dispersed PD trajectories in the cue period would allow targets to be detected over a wide spatial aperture. The convergence of the PD trajectories occurring at the cue-track transition may serve as a “Go” signal to move that was not explicitly supplied by the paradigm. Furthermore, the rotation and convergence of the PD trajectories may provide a mechanism for nonstandard mapping. Standard mapping refers to a sensorimotor transformation in which the stimulus is the object of the reach. Nonstandard mapping is the mapping of an arbitrary stimulus into an arbitrary movement. The shifts in the PD may allow relevant visual information from any direction to be transformed into an appropriate movement direction, providing a neural substrate for nonstandard stimulus-response mappings.

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Kadish, Alan, David Johnson, Willie Choe, Jeffrey Goldberger, and George Horvath. "Characterization of fibrillatory rhythms by ensemble vector directional analysis." American Journal of Physiology-Heart and Circulatory Physiology 285, no. 4 (October 2003): H1705—H1719. http://dx.doi.org/10.1152/ajpheart.01108.2001.

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Recent studies have demonstrated that fibrillatory rhythms are not random phenomena but have definable patterns. However, standard mapping techniques may have limitations in their ability to identify the organization of fibrillation. The purpose of this study was to develop and apply a method, “ensemble vector mapping,” for characterizing the spatiotemporal organization of fibrillation. Ventricular fibrillation was induced by burst pacing in normal mongrel dogs. In a separate protocol, atrial fibrillation was induced by epicardial aconitine application. Epicardial electrograms were recorded from a 112-electrode plaque array using a computerized mapping system. Vectors were created by summing orthogonal bipolar electrograms. The magnitude of the vectors was transformed using a logarithmic function, integrated over time, and normalized for local electrogram amplitude to produce an “ensemble vector” index whose magnitude is high when beat-to-beat activation direction is consistent and low when activation direction is variable. The mean index was 137 ± 36 mV/s during ventricular pacing at a cycle length of 300 ms but only 39 ± 23 mV/s during ventricular fibrillation ( P < 0.001). The ensemble vector index was also lower during atrial fibrillation (60 ± 54 mV/s) than during atrial pacing (115 ± 27 mV/s, P < 0.01 vs. atrial fibrillation) but not as low as during ventricular fibrillation ( P < 0.05, atrial vs. ventricular fibrillation). The index was also capable of distinguishing atrial tachycardia from atrial fibrillation. Ensemble vector mapping produces an objective assessment of the consistency of myocardial activation during fibrillation. The consistency of activation direction differs in different models of fibrillation and is higher during atrial than ventricular fibrillation. This technique has the potential to rapidly characterize repetitive activation patterns in fibrillatory rhythms and may help distinguish among different characteristics of fibrillatory rhythms.

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Yeung, Dennis, Dario Farina, and Ivan Vujaklija. "Directional Forgetting for Stable Co-Adaptation in Myoelectric Control." Sensors 19, no. 9 (May 13, 2019): 2203. http://dx.doi.org/10.3390/s19092203.

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Conventional myoelectric controllers provide a mapping between electromyographic signals and prosthetic functions. However, due to a number of instabilities continuously challenging this process, an initial mapping may require an extended calibration phase with long periods of user-training in order to ensure satisfactory performance. Recently, studies on co-adaptation have highlighted the benefits of concurrent user learning and machine adaptation where systems can cope with deficiencies in the initial model by learning from newly acquired data. However, the success remains highly dependent on careful weighting of these new data. In this study, we proposed a function driven directional forgetting approach to the recursive least-squares algorithm as opposed to the classic exponential forgetting scheme. By only discounting past information in the same direction of the new data, local corrections to the mapping would induce less distortion to other regions. To validate the approach, subjects performed a set of real-time myoelectric tasks over a range of forgetting factors. Results show that directional forgetting with a forgetting factor of 0.995 outperformed exponential forgetting as well as unassisted user learning. Moreover, myoelectric control remained stable after adaptation with directional forgetting over a range of forgetting factors. These results indicate that a directional approach to discounting past training data can improve performance and alleviate sensitivities to parameter selection in recursive adaptation algorithms.

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Rivai, Muhammad, Dony Hutabarat, and Zishwa Muhammad Jauhar Nafis. "2D mapping using omni-directional mobile robot equipped with LiDAR." TELKOMNIKA (Telecommunication Computing Electronics and Control) 18, no. 3 (June 1, 2020): 1467. http://dx.doi.org/10.12928/telkomnika.v18i3.14872.

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Wang, Qian, Lida Li, Chew Lim Tan, and Tao Xia. "Image Enhancement of Historical Documents Using Directional Wavelet." International Journal of Wavelets, Multiresolution and Information Processing 01, no. 03 (September 2003): 291–305. http://dx.doi.org/10.1142/s0219691303000190.

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This paper proposes a novel algorithm to clean up a large collection of historical handwritten documents kept in the National Archives of Singapore. Due to the seepage of ink over long period of storage, the front page of each document has been severely marred by the reverse side writing. Earlier attempts have been made to match both sides of a page to identify the offending strokes originating from the back so as to eliminate them with the aid of a wavelet transform. Perfect matching, however, is difficult due to document skews, differing resolutions, inadvertently missing out reverse side and warped pages during image capture. A new approach is now proposed to do away with double side mapping by using a directional wavelet transform that is able to distinguish the foreground and reverse side strokes much better than the conventional wavelet transform. Experiments have shown that the method indeed enhances the readability of each document significantly after the directional wavelet operation without the need for mapping with its reverse side.

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Fu, Zuohui, Yikun Xian, Shijie Geng, Yingqiang Ge, Yuting Wang, Xin Dong, Guang Wang, and Gerard De Melo. "ABSent: Cross-Lingual Sentence Representation Mapping with Bidirectional GANs." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 05 (April 3, 2020): 7756–63. http://dx.doi.org/10.1609/aaai.v34i05.6279.

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A number of cross-lingual transfer learning approaches based on neural networks have been proposed for the case when large amounts of parallel text are at our disposal. However, in many real-world settings, the size of parallel annotated training data is restricted. Additionally, prior cross-lingual mapping research has mainly focused on the word level. This raises the question of whether such techniques can also be applied to effortlessly obtain cross-lingually aligned sentence representations. To this end, we propose an Adversarial Bi-directional Sentence Embedding Mapping (ABSent) framework, which learns mappings of cross-lingual sentence representations from limited quantities of parallel data. The experiments show that our method outperforms several technically more powerful approaches, especially under challenging low-resource circumstances. The source code is available from https://github.com/zuohuif/ABSent along with relevant datasets.

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Skinner, Grant, Mauro Viandante, Kamal Jansen, David Thornton, Mike Rapaic, and Kanchit Jantarangsi. "Reservoir mapping: the latest development in well placement." APPEA Journal 53, no. 2 (2013): 438. http://dx.doi.org/10.1071/aj12049.

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The PTTEP Australasia Montara development wells were recently drilled using a new deep-directional electromagnetic-resistivity tool, which enabled the simultaneous real-time mapping of multiple and varied geological and fluid boundaries in a thick reservoir, through the entire length of the horizontal section. Conventionally, geosteering is undertaken using borehole-scale measurements; data at this scale requires the wellbore to come in close proximity or cross a feature before it is detected. This scale of measurement is good for finer detail features but does not allow for visualisation of the geology beyond what it is measured at or just beyond the borehole wall. Nor does it enable a refinement of the geophysical subsurface unless at points of contact between the well and the feature that needs to be avoided. To bridge the gap between surface seismic resolution and measurements obtained at the borehole scale, a new deep-directional electromagnetic tool sensitive to variable resistivities but able to identify boundaries tens of metres away was required. The past decade has shown a significant development in resistivity measurement technology providing directional resistivity at a significantly larger scale than conventional logging tools. The first generation allowed wells to be placed proactively, removing the need to cross the boundary or be very close to it before it was identified. This latest generation of proactive geosteering tools has been developed to remove this gap, allowing for a refinement in geophysical/geological models and a new methodology in geosteering, moving the game from boundary to reservoir geosteering.

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Ashrafi, Reza, Ming Li, Sophie LaRochelle, and José Azaña. "Superluminal space-to-time mapping in grating-assisted co-directional couplers." Optics Express 21, no. 5 (March 5, 2013): 6249. http://dx.doi.org/10.1364/oe.21.006249.

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Gu, Chendong, Kan Yao, Weixin Lu, Yun Lai, Huanyang Chen, Bo Hou, and Xunya Jiang. "Experimental realization of a broadband conformal mapping lens for directional emission." Applied Physics Letters 100, no. 26 (June 25, 2012): 261907. http://dx.doi.org/10.1063/1.4731877.

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Xie, Ting, Zengtai Gong, and Dapeng Li. "Generalized derivatives and optimization problems for n-dimensional fuzzy-number-valued functions." Open Mathematics 18, no. 1 (December 7, 2020): 1451–77. http://dx.doi.org/10.1515/math-2020-0081.

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Abstract In this paper, we present the concepts of generalized derivative, directional generalized derivative, subdifferential and conjugate for n-dimensional fuzzy-number-valued functions and discuss the characterizations of generalized derivative and directional generalized derivative by, respectively, using the derivative and directional derivative of crisp functions that are determined by the fuzzy mapping. Furthermore, the relations among generalized derivative, directional generalized derivative, subdifferential and convexity for n-dimensional fuzzy-number-valued functions are investigated. Finally, under two kinds of partial orderings defined on the set of all n-dimensional fuzzy numbers, the duality theorems and saddle point optimality criteria in fuzzy optimization problems with constraints are discussed.

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Simm, A., and G. Y. Tian. "EDDY CURRENTS: Investigation of directional eddy current complex measurements for defect mapping." Insight - Non-Destructive Testing and Condition Monitoring 52, no. 6 (June 1, 2010): 320–25. http://dx.doi.org/10.1784/insi.2010.52.6.320.

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Martin, Bruce, Briand Gaudet, Corey Morris, and Jennifer L. Miksis-Olds. "Using directional acoustics for mapping the spatial distribution of low frequency mammals." Journal of the Acoustical Society of America 146, no. 4 (October 2019): 2804. http://dx.doi.org/10.1121/1.5136713.

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Munford, Maxwell J., K. C. Geoffrey Ng, and Jonathan R. T. Jeffers. "Mapping the Multi‐Directional Mechanical Properties of Bone in the Proximal Tibia." Advanced Functional Materials 30, no. 46 (September 13, 2020): 2004323. http://dx.doi.org/10.1002/adfm.202004323.

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Max, Ghelman, Kopeika Natan, Rotman Stenley, Edvabsky Tal, Vax Eran, and Osovizky Alon. "Design of 4π Directional Radiation Detector based on Compton Scattering Effect." EPJ Web of Conferences 253 (2021): 07003. http://dx.doi.org/10.1051/epjconf/202125307003.

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Obtaining directional information is required in many applications such as nuclear homeland security, contamination mapping after a nuclear incident and radiological events, or during the decontamination work. However, many directional radiation detectors are based on directional shielding, made of lead or tungsten collimators, introducing two main drawbacks. The first is the size and weight, making those detectors too heavy and irrelevant for utilization in handheld devices, drone mapping, or space applications. The second drawback is the limited field of view, which requires multiple detectors to cover the whole required field of view or machinery to rotate the narrow field of view detector. We propose a novel 4π directional detector based on a segmented hollow cubic detector, which uses the Compton effect interactions with no heavy collimators. The symmetrical cubical design provides both higher efficiency and 4π detection ability. Instead of traditional two types of detectors (scatterer and absorber) structure, we use the same type of detector, based on GAGG(Ce) scintillator coupled to silicon photomultiplier. Additional advantage of the proposed detector obtained by locating the photon sensors inside the detector, behind the scintillators, which improves the radiation hardness required for space applications. Furthermore, such arrangement flattens the temperature variation across the detector, providing better gain stability. The main advantage of the proposed detector is the ability of 4pi radiation detection for high energy gamma-rays without the use of heavy collimators.

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Tan, Yunlan, Chao Li, Guangyao Li, Wenlang Luo, and Weidong Tang. "A Novel Approach for Image Enhancement via Nonsubsampled Contourlet Transform." Journal of Intelligent Systems 23, no. 3 (September 1, 2014): 345–55. http://dx.doi.org/10.1515/jisys-2013-0097.

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AbstractAn improved image enhancement approach via nonsubsampled contourlet transform (NSCT) is proposed in this article. We constructed a geometric image transform by combining nonsubsampled directional filter banks and a nonlinear mapping function. Here, the NSCT of the input image is first decomposed for L-levels and its noise standard deviation is estimated. It is followed by calculating the noise variance and threshold calculation, and computing the magnitude of the corresponding coefficients in all directional subbands. Then, the nonlinear mapping function is used to modify the NSCT coefficients for each directional subband, which keeps the coefficients of strong edges, amplifies the coefficients of weak edges, and zeros the noise coefficients. Finally, the enhanced image is reconstructed from the modified NSCT coefficients. Three experiments are carried out respectively on images from subjective vision quality and objective evaluation measures. The first experiment is the algorithm performed on images. The subsequent experiments are the information entropy and spatial frequency. The experimental results demonstrate that the proposed method can gain better performance in enhancing the low-contrast parts of an image while keeping its clear edges.

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Wu, Yinzhe, Suzan Hatipoglu, Diego Alonso-Álvarez, Peter Gatehouse, Binghuan Li, Yikai Gao, David Firmin, Jennifer Keegan, and Guang Yang. "Fast and Automated Segmentation for the Three-Directional Multi-Slice Cine Myocardial Velocity Mapping." Diagnostics 11, no. 2 (February 19, 2021): 346. http://dx.doi.org/10.3390/diagnostics11020346.

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Three-directional cine multi-slice left ventricular myocardial velocity mapping (3Dir MVM) is a cardiac magnetic resonance (CMR) technique that allows the assessment of cardiac motion in three orthogonal directions. Accurate and reproducible delineation of the myocardium is crucial for accurate analysis of peak systolic and diastolic myocardial velocities. In addition to the conventionally available magnitude CMR data, 3Dir MVM also provides three orthogonal phase velocity mapping datasets, which are used to generate velocity maps. These velocity maps may also be used to facilitate and improve the myocardial delineation. Based on the success of deep learning in medical image processing, we propose a novel fast and automated framework that improves the standard U-Net-based methods on these CMR multi-channel data (magnitude and phase velocity mapping) by cross-channel fusion with an attention module and the shape information-based post-processing to achieve accurate delineation of both epicardial and endocardial contours. To evaluate the results, we employ the widely used Dice Scores and the quantification of myocardial longitudinal peak velocities. Our proposed network trained with multi-channel data shows superior performance compared to standard U-Net-based networks trained on single-channel data. The obtained results are promising and provide compelling evidence for the design and application of our multi-channel image analysis of the 3Dir MVM CMR data.

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Beiranvand Pour, A., and M. Hashim. "INTEGRATION OF PALSAR AND ASTER SATELLITE DATA FOR GEOLOGICAL MAPPING IN TROPICS." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-2/W2 (October 19, 2015): 105–9. http://dx.doi.org/10.5194/isprsannals-ii-2-w2-105-2015.

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This research investigates the integration of the Phased Array type L-band Synthetic Aperture Radar (PALSAR) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite data for geological mapping applications in tropical environments. The eastern part of the central belt of peninsular Malaysia has been investigated to identify structural features and mineral mapping using PALSAR and ASTER data. Adaptive local sigma and directional filters were applied to PALSAR data for detecting geological structure elements in the study area. The vegetation, mineralogic and lithologic indices for ASTER bands were tested in tropical climate. Lineaments (fault and fractures) and curvilinear (anticline or syncline) were detected using PALSAR fused image of directional filters (N-S, NE-SW, and NW-SE).Vegetation index image map show vegetation cover by fusing ASTER VNIR bands. High concentration of clay minerals zone was detected using fused image map derived from ASTER SWIR bands. Fusion of ASTER TIR bands produced image map of the lithological units. Results indicate that data integration and data fusion from PALSAR and ASTER sources enhanced information extraction for geological mapping in tropical environments.

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Tóth, Emese, Ditta Ungor, Tibor Novák, Györgyi Ferenc, Balázs Bánhelyi, Edit Csapó, Miklós Erdélyi, and Mária Csete. "Mapping Fluorescence Enhancement of Plasmonic Nanorod Coupled Dye Molecules." Nanomaterials 10, no. 6 (May 29, 2020): 1048. http://dx.doi.org/10.3390/nano10061048.

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Plasmonically enhanced fluorescence is a widely studied and applied phenomenon, however, only a comparative theoretical and experimental analysis of coupled fluorophores and plasmonic nanoresonators makes it possible to uncover how this phenomenon can be controlled. A numerical optimization method was applied to design configurations that are capable of resulting in an enhancement of excitation and emission, moreover, of both phenomena simultaneously in coupled Cy5 dye molecule and gold nanorod systems. Parametric sensitivity studies revealed how the fluorescence enhancement depends on the molecule’s location, distance and orientation. Coupled systems designed for simultaneous improvement exhibited the highest (intermediate directional) total fluorescence enhancement, which is accompanied by intermediate sensitivity to the molecule’s parameters, except the location and orientation sensitivity at the excitation wavelength. Gold nanorods with a geometry corresponding to the predicted optimal configurations were synthesized, and DNA strands were used to control the Cy5 dye molecule distance from the nanorod surface via hybridization of the Cy5-labelled oligonucleotide. State-of-the-art dSTORM microscopy was used to accomplish a proof-of-concept experimental demonstration of the theoretically predicted (directional) total fluorescence enhancement. The measured fluorescence enhancement was in good agreement with theoretical predictions, thus providing a complete kit to design and prepare coupled nanosystems exhibiting plasmonically enhanced fluorescence.

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Chen, Aihua, Yong Gu, Katsumasa Takahashi, Dora E. Angelaki, and Gregory C. DeAngelis. "Clustering of Self-Motion Selectivity and Visual Response Properties in Macaque Area MSTd." Journal of Neurophysiology 100, no. 5 (November 2008): 2669–83. http://dx.doi.org/10.1152/jn.90705.2008.

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Neurons in the dorsal subdivision of the medial superior temporal area (MSTd) show directionally selective responses to both visual (optic flow) and vestibular stimuli that correspond to translational or rotational movements of the subject. Previous work has shown that MSTd neurons are clustered within the cortex according to their directional preferences for optic flow, suggesting that there may be a topographic mapping of self-motion vectors in MSTd. If MSTd provides a multisensory representation of self-motion information, then MSTd neurons may also be expected to show clustering according to their directional preferences for vestibular signals, but this has not been tested previously. We have examined clustering of vestibular signals by comparing the tuning of isolated single units (SUs) with the undifferentiated multiunit (MU) activity of several neighboring neurons recorded from the same microelectrode. We find that directional preferences for both translational and rotational vestibular stimuli, like those for optic flow, are clustered within area MSTd. MU activity often shows significant tuning for vestibular stimuli, although this MU selectivity is generally weaker for translation than for rotation. When directional tuning is observed in MU activity, the direction preference generally agrees closely with that of a simultaneously recorded SU. We also examined clustering of visual receptive field properties in MSTd by analyzing receptive field maps obtained using a reverse-correlation technique. We find that both the local directional preferences and overall spatial receptive field profiles are well clustered in MSTd. Overall, our findings have implications for how visual and vestibular signals regarding self-motion may be decoded from populations of MSTd neurons.

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Nick Kholgh, Arman, Martin Mackinlay, Sophie Garrard, Mohammad Zaman, Haifeng Wang, Chris Hibberson, Nicholas Challands, et al. "Seamless in seam – new geosteering technology delivered challenging coal seam gas project with success." APPEA Journal 62, no. 1 (May 13, 2022): 319–33. http://dx.doi.org/10.1071/aj21189.

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A recent coal seam gas (CSG) appraisal project posed several challenges. The target reserve area had limited seismic data available and yet had complex structure with several faults of variable orientations and throws between 2 and 25 m. Dual-lateral extended-reach drilling (ERD) wells needed to be drilled in order to access this reserve, with a 1000 m in-seam section for each lateral planned to maximise production. Conventional technologies for CSG projects included motor bottom hole assembly with a boundary mapping tool for geosteering in the coal seams. However, for drilling ERD wells in this unknown area, these methods were insufficient to deliver success, due to the limited mapping capabilities and drilling efficiencies. Recently there has been significant development on the directional resistivity-based mapping tool, on both the measurements and processing. The operator adopted a new mapping-while-drilling technology which has the first-in-industry tool with axial, tilted and transverse antennas integrated in one module. This new technology can provide high-resolution multilayer mapping with doubled depth of investigation, even when drilling out of the coal seam. The results from utilising this new tool, together with a rotary steerable system for directional control, were very encouraging. The new multilayer mapping-while-drilling tool mapped both the top and base of the coal seam throughout horizontal sections in-seam. In addition, it detected the coal seams during landing and after fault-crossing from up to 4 m true vertical depth away, enabling the team to navigate through complex fault zones confidently, and to deliver the project with success.

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Munford, Maxwell J., K. C. Geoffrey Ng, and Jonathan R. T. Jeffers. "Anatomical Mapping: Mapping the Multi‐Directional Mechanical Properties of Bone in the Proximal Tibia (Adv. Funct. Mater. 46/2020)." Advanced Functional Materials 30, no. 46 (November 2020): 2070301. http://dx.doi.org/10.1002/adfm.202070301.

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Bauer, John T. "The Official Automobile Blue Book, 1901–1929: Precursor to the American Road Map." Cartographic Perspectives, no. 62 (March 1, 2009): 4–27. http://dx.doi.org/10.14714/cp62.182.

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Navigating by automobile at the dawn of the twentieth century was difficult because maps appropriate for this new mode of transportation were scarce. An early solution to this problem was the route guide. Listing turn-by-turn directions between various cities, route guides helped early motorists navigate a network of unmarked, local roads. This paper focuses exclusively on the Official Automobile Blue Book, the earliest and most popular of the route guides. It contends that the Blue Book series was a precursor to the American road map because the volumes served two important functions of road maps and did so before road mapping matured into a full-fledged cartographic business. The Blue Book commercialized automobile touring and provided directional information, helping motorists navigate. Twelve Blue Book volumes, covering 1901 to 1929, form the primary sources for this research. After examining the series’ use, content, and history, the paper places the Official Automobile Blue Book within the larger context of the history of road mapping. A short review with directions for further research follows as a conclusion.

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Alhassane, Illias, Abdou Babaye Maman Sani, Sandao Issoufou, Saley Mahaman Bachir, and Ousmane Boureima. "Apport Des Images ETM+ Et Du Modèle Numérique De Terrain (MNT) A La Cartographie Des Fractures En Région Montagneuse : Secteur De Timia (Massif De l’Aïr, Nord Du Niger)." European Scientific Journal, ESJ 14, no. 9 (March 31, 2018): 103. http://dx.doi.org/10.19044/esj.2018.v14n9p103.

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Timia is located at the Aïr massifs region. This locality, which is the substratum that constituted the basement formations, has some difficulty of water supply. This present study focuses on fractures mapping to acquire the best knowledge of the fractured aquifer in Timia zone. The methodological approach is based on landsat7 image processing and DEM, especially directional filtering and shaded digital terrain models. These diverse processing has shown complementarity between the satellites images and DEM in linear mapping on the one hand and in establishing a lineaments map on the other hand. The lineament map showed that the fractures network is distributed in the following directions: N0°-N10°, N140°-N170°, N 70°- N100°, and N30°-N50°. These fractures map, which was allowed to increase the density of faults from the previous studies, were used to actualize hydrogeological knowledge and in determining the favorable sites for drilling boreholes in Timia locality.

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Yashin, I. I., I. I. Astapov, N. S. Barbashina, A. N. Dmitrieva, K. G. Kompaniets, A. A. Petrukhin, and V. V. Shutenko. "Real-Time GSE Mapping of Muon-Flux Directional Variation with the URAGAN Hodoscope." Bulletin of the Russian Academy of Sciences: Physics 83, no. 5 (May 2019): 572–75. http://dx.doi.org/10.3103/s106287381905040x.

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Klein, S., K. Lohman, R. Clover, G. C. Walker, and E. R. Signer. "A directional, high-frequency chromosomal mobilization system for genetic mapping of Rhizobium meliloti." Journal of Bacteriology 174, no. 1 (1992): 324–26. http://dx.doi.org/10.1128/jb.174.1.324-326.1992.

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St-Onge, B. "Automated forest structure mapping from high resolution imagery based on directional semivariogram estimates." Remote Sensing of Environment 61, no. 1 (July 1997): 82–95. http://dx.doi.org/10.1016/s0034-4257(96)00242-8.

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Yao, Xin-wei, Wan-liang Wang, Shuang-hua Yang, and Sheng-yong Chen. "PABM-EDCF: parameter adaptive bi-directional mapping mechanism for video transmission over WSNs." Multimedia Tools and Applications 63, no. 3 (November 18, 2011): 809–31. http://dx.doi.org/10.1007/s11042-011-0934-7.

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Jacobberger, P. A. "Mapping abandoned river channels in Mali through directional filtering of thematic mapper data." Remote Sensing of Environment 26, no. 2 (November 1988): 161–70. http://dx.doi.org/10.1016/0034-4257(88)90094-6.

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Yang, Qi, Sheng Hai Hu, and Jian Jun Yao. "Mechanism Parameters Optimization of Jumping Robot Based on Dynamic Directional Manipulability." Advanced Materials Research 490-495 (March 2012): 961–68. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.961.

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The concept of dynamic directional manipulability is taken as an evaluating index of jumping performance to quest for improvement of the jumping performance of the jumping robot in view of the mechanism design. On the basis of the jumping robot mechanism model, the dynamics equation in takeoff phase is established, and the mapping relation from the joint driving torque to the acceleration of the center of mass movement is obtained. In order to optimize the jumping performance of the robot, optimal algorithm combining with the dynamic directional measure is used to optimize the mechanism parameters of the jumping robot. The optimal result demonstrates that the research on mechanism parameters optimization of jumping robot is feasible by using the theory of the dynamic directional manipulability measure

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Zhang, Yue, Yuan Li, and Qing Lin Wang. "Omni-Directional Vision System for Mobile Robot Using Structured Lights." Applied Mechanics and Materials 288 (February 2013): 114–20. http://dx.doi.org/10.4028/www.scientific.net/amm.288.114.

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Vision system can obtain rich environmental information, and vision is one of the most important sensing methods for mobile robot navigation and positioning. An omni-directional vision system using laser illumination is presented. The system can obtain the distance information of the obstacles around the mobile robot by only one image. The principle of the vision system is expounded; the mapping relationship between the image plane and the laser plane is given based on the analysis of the system model. The system benefits from the advantages of the omni-directional vision and the structured light vision, such as large ranged environmental information, high precision and robustness, etc. Experimental results of measurement and map construction verify the vision system.

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McKay, Helen, Nathan Griffiths, Phillip Taylor, Theo Damoulas, and Zhou Xu. "Bi-directional online transfer learning: a framework." Annals of Telecommunications 75, no. 9-10 (October 2020): 523–47. http://dx.doi.org/10.1007/s12243-020-00776-1.

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Abstract Transfer learning uses knowledge learnt in source domains to aid predictions in a target domain. When source and target domains are online, they are susceptible to concept drift, which may alter the mapping of knowledge between them. Drifts in online environments can make additional information available in each domain, necessitating continuing knowledge transfer both from source to target and vice versa. To address this, we introduce the Bi-directional Online Transfer Learning (BOTL) framework, which uses knowledge learnt in each online domain to aid predictions in others. We introduce two variants of BOTL that incorporate model culling to minimise negative transfer in frameworks with high volumes of model transfer. We consider the theoretical loss of BOTL, which indicates that BOTL achieves a loss no worse than the underlying concept drift detection algorithm. We evaluate BOTL using two existing concept drift detection algorithms: RePro and ADWIN. Additionally, we present a concept drift detection algorithm, Adaptive Windowing with Proactive drift detection (AWPro), which reduces the computation and communication demands of BOTL. Empirical results are presented using two data stream generators: the drifting hyperplane emulator and the smart home heating simulator, and real-world data predicting Time To Collision (TTC) from vehicle telemetry. The evaluation shows BOTL and its variants outperform the concept drift detection strategies and the existing state-of-the-art online transfer learning technique.

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Zhang, Guangbin, Hengyan Liu, Wei Dai, Tianyao Huang, Yimin Liu, and Xiqin Wang. "Passive Joint Emitter Localization with Sensor Self-Calibration." Remote Sensing 15, no. 3 (January 23, 2023): 671. http://dx.doi.org/10.3390/rs15030671.

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This paper studies the problem surrounding distributed passive arrays (sensors) locating multiple emitters while performing self-calibration to correct possible errors in the assumed array directions. In our setting, only the angle-of-arrival (AoA) information is available for localization. However, such information may contain bias due to array directional errors. Hence, localization requires self-calibration. To achieve both, the key element behind our approach is that the received signals from the same emitter should be geometrically consistent if sensor arrays are successfully calibrated. This leads to our signal model, which is built on a mapping directly from emitter locations and array directional errors to received signals. Then we formulate an atomic norm minimization and use group sparsity to promote geometric consistency and align `ghost’ emitter locations from calibration errors. Simulations verify the effectiveness of the proposed scheme. We derive the Cramér Rao lower bound and numerically compare it to the simulations. Furthermore, we derive a necessary condition as a rule of thumb to decide the feasibility of joint localization and calibration.

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Dempe, S. "On the directional derivative of the optimal solution mapping without linear independence constraint qualification." Optimization 20, no. 4 (January 1989): 401–14. http://dx.doi.org/10.1080/02331938908843460.

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董春华, 董春华, Chunhua Dong Chunhua Dong, 肖云峰肖云峰, Yunfeng Xiao Yunfeng Xiao, 杨勇杨勇, Yong Yang Yong Yang, 韩正甫韩正甫, et al. "Directly mapping whispering gallery modes in a microsphere through modal coupling and directional emission." Chinese Optics Letters 6, no. 4 (2008): 300–302. http://dx.doi.org/10.3788/col20080604.0300.

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Clack, Christopher T. M., Anneliese Alexander, Aditya Choukulkar, and Alexander E. MacDonald. "Demonstrating the effect of vertical and directional shear for resource mapping of wind power." Wind Energy 19, no. 9 (November 6, 2015): 1687–97. http://dx.doi.org/10.1002/we.1944.

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Zhao, Bai Tong, Wen Xiu Gao, and Cheng Chang Jia. "Research on Ingot Casting Process and Properties of Poly-Silicon." Advanced Materials Research 772 (September 2013): 739–43. http://dx.doi.org/10.4028/www.scientific.net/amr.772.739.

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Temperature gradient and solidification rate are two key parameters during polysilicon directional solidification, which are varied to improve the polysilicon production process. Dendritic growth, distribution of impurities, Minority carrier lifetime and resistivity mapping are also discussed in this paper. A better quality of polysilicon ingot is presented by optimized casting process.

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Lange, Marius, Volker Bergen, Michal Klein, Manu Setty, Bernhard Reuter, Mostafa Bakhti, Heiko Lickert, et al. "CellRank for directed single-cell fate mapping." Nature Methods 19, no. 2 (January 13, 2022): 159–70. http://dx.doi.org/10.1038/s41592-021-01346-6.

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AbstractComputational trajectory inference enables the reconstruction of cell state dynamics from single-cell RNA sequencing experiments. However, trajectory inference requires that the direction of a biological process is known, largely limiting its application to differentiating systems in normal development. Here, we present CellRank (https://cellrank.org) for single-cell fate mapping in diverse scenarios, including regeneration, reprogramming and disease, for which direction is unknown. Our approach combines the robustness of trajectory inference with directional information from RNA velocity, taking into account the gradual and stochastic nature of cellular fate decisions, as well as uncertainty in velocity vectors. On pancreas development data, CellRank automatically detects initial, intermediate and terminal populations, predicts fate potentials and visualizes continuous gene expression trends along individual lineages. Applied to lineage-traced cellular reprogramming data, predicted fate probabilities correctly recover reprogramming outcomes. CellRank also predicts a new dedifferentiation trajectory during postinjury lung regeneration, including previously unknown intermediate cell states, which we confirm experimentally.

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Karbasaki, M. Miri, M. R. Balooch Shahryari, and O. Sedaghatfar. "On derivatives of fuzzy multi-dimensional mappings and applications under generalized differentiability." Journal of Intelligent & Fuzzy Systems 41, no. 1 (August 11, 2021): 1757–75. http://dx.doi.org/10.3233/jifs-210530.

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This article identifies and presents the generalized difference (g-difference) of fuzzy numbers, Fréchet and Gâteaux generalized differentiability (g-differentiability) for fuzzy multi-dimensional mapping which consists of a new concept, fuzzy g-(continuous linear) function; Moreover, the relationship between Fréchet and Gâteaux g-differentiability is studied and shown. The concepts of directional and partial g-differentiability are further framed and the relationship of which will the aforementioned concepts are also explored. Furthermore, characterization is pointed out for Fréchet and Gâteaux g-differentiability; based on level-set and through differentiability of endpoints real-valued functions a characterization is also offered and explored for directional and partial g-differentiability. The sufficient condition for Fréchet and Gâteaux g-differentiability, directional and partial g-differentiability based on level-set and through employing level-wise gH-differentiability (LgH-differentiability) is expressed. Finally, to illustrate the ability and reliability of the aforementioned concepts we have solved some application examples.

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Pour, A. B., and M. Hashim. "GEOLOGICAL FEATURES MAPPING USING PALSAR-2 DATA IN KELANTAN RIVER BASIN, PENINSULAR MALAYSIA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W1 (September 29, 2016): 65–70. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w1-65-2016.

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In this study, the recently launched Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) onboard the Advanced Land Observing Satellite-2 (ALOS-2), remote sensing data were used to map geologic structural and topographical features in the Kelantan river basin for identification of high potential risk and susceptible zones for landslides and flooding areas. A ScanSAR and two fine mode dual polarization level 3.1 images cover Kelantan state were processed for comprehensive analysis of major geological structures and detailed characterizations of lineaments, drainage patterns and lithology at both regional and district scales. Red-Green-Blue (RGB) colour-composite was applied to different polarization channels of PALSAR-2 data to extract variety of geological information. Directional convolution filters were applied to the data for identifying linear features in particular directions and edge enhancement in the spatial domain. Results derived from ScanSAR image indicate that lineament occurrence at regional scale was mainly linked to the N-S trending of the Bentong-Raub Suture Zone (BRSZ) in the west and Lebir Fault Zone in the east of the Kelantan state. Combination of different polarization channels produced image maps contain important information related to water bodies, wetlands and lithological units for the Kelantan state using fine mode observation data. The N-S, NE-SW and NNE-SSW lineament trends were identified in the study area using directional filtering. Dendritic, sub-dendritic and rectangular drainage patterns were detected in the Kelantan river basin. The analysis of field investigations data indicate that many of flooded areas were associated with high potential risk zones for hydro-geological hazards such as wetlands, urban areas, floodplain scroll, meander bend, dendritic and sub-dendritic drainage patterns, which are located in flat topograghy regions. Numerous landslide points were located in rectangular drainage system that associated with topographic slope of metamorphic and Quaternary rock units. Some large landslides were associated with N-S, NNE-SSW and NE-SW trending fault zones. Consequently, structural and topographical geology maps were produced for Kelantan river basin using PALSAR-2 data, which could be broadly applicable for landslide hazard mapping and identification of high potential risk zone for hydro-geological hazards.

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Journal articles on the topic 'Directional mapping'

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