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Supriyati, Endang. "FUZZY FORMAL CONCEPT ANALYSIS UNTUK KEMIRIPAN DOKUMEN." Simetris : Jurnal Teknik Mesin, Elektro dan Ilmu Komputer 1, no. 1 (June 29, 2013): 21. http://dx.doi.org/10.24176/simet.v1i1.111.
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ABSTRAK Fuzzy logic dapat dimasukkan ke dalam ontologi untuk representasi ketidakpastian informasi yang ditemukan di banyak aplikasi domain karena kurangnya jelas batas-batas antara konsep domain. Fuzzy ontologi dihasilkan dari konsep hirarki yang telah ditetapkan. Namun, untuk membangun sebuah konsep hirarki untuk domain tertentu dapat menjadi tugas yang sulit dan membosankan. Untuk mengatasi masalah ini, diusulkan Fuzzy Formal Concept Analysis(FFCA). Titik awal dari metode diusulkan dalam paper ini adalah definisi dari konteks , relasi kemiripan pada domain ontologi kemudian memetakan ke dalam concept lattice. Dengan penggunaan tool lattice navigator,metode yang diusulkan mampu mengelompokkan domain ontology secara efektif. Kata Kunci: Ontology, Formal Concept Analysis, Fuzzy Formal Concept Analysis,konsep Lattice
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Campuzano, J. M., J. P. Bagrow, and D. ben-Avraham. "Kleinberg Navigation on Anisotropic Lattices." Research Letters in Physics 2008 (November 16, 2008): 1–4. http://dx.doi.org/10.1155/2008/346543.
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We study the Kleinberg problem of navigation in small-world networks when the underlying lattice is stretched along a preferred direction. Extensive simulations confirm that maximally efficient navigation is attained when the length r of long-range links is taken from the distribution P(r)∼r−α, when the exponent α is equal to 2, the dimension of the underlying lattice, regardless of the amount of anisotropy, but only in the limit of infinite lattice size, L→∞. For finite size lattices we find an optimal α(L) that depends strongly on L. The convergence to α=2 as L→∞ shows interesting power-law dependence on the anisotropy strength.
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VISANI, M., K. BERTET, and J. M. OGIER. "NAVIGALA: AN ORIGINAL SYMBOL CLASSIFIER BASED ON NAVIGATION THROUGH A GALOIS LATTICE." International Journal of Pattern Recognition and Artificial Intelligence 25, no. 04 (June 2011): 449–73. http://dx.doi.org/10.1142/s0218001411008634.
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This paper deals with a supervised classification method, using Galois Lattices based on a navigation-based strategy. Coming from the field of data mining techniques, most literature on the subject using Galois lattices relies on selection-based strategies, which consists of selecting/choosing the concepts which encode the most relevant information from the huge amount of available data. Generally, the classification step is then processed by a classical classifier such as the k-nearest neighbors rule or the Bayesian classifier. Opposed to these selection-based strategies are navigation-based approaches which perform the classification stage by navigating through the complete lattice (similar to the navigation in a classification tree), without applying any selection operation. Our approach, named Navigala, proposes an original navigation-based approach for supervised classification, applied in the context of noisy symbol recognition. Based on a state of the art dealing with Galois Lattices classification based methods, including a comparison between possible selection and navigation strategies, this paper proposes a description of NAVIGALA and its implementation in the context of symbol recognition. Some objective quantitative and qualitative evaluations of the approach are proposed, in order to highlight the relevance of the method.
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DUCROU, JON, and PETER EKLUND. "AN INTELLIGENT USER INTERFACE FOR BROWSING AND SEARCHING MPEG-7 IMAGES USING CONCEPT LATTICES." International Journal of Foundations of Computer Science 19, no. 02 (April 2008): 359–81. http://dx.doi.org/10.1142/s0129054108005723.
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This paper presents the evaluation of a design and architecture for browsing and searching MPEG-7 images. Our approach is novel in that it exploits concept lattices for the representation and navigation of image content. Several concept lattices provide the foundation for the system (called IMAGE-SLEUTH) each representing a different search context, one for image shape, another for color and luminance, and a third for semantic content, namely image browsing based on a metadata ontology. The test collection used for our study is a sub-set of MPEG-7 images created from the popular The Sims 2™ game. The evaluation of the IMAGE-SLEUTH program is based on usability testing among 29 subjects. The results of the study are used to build an improved second generation program – IMAGE-SLEUTH2 – however these results also indicate that image navigation via a concept lattice is a highly successful interface paradigm. Our results provide general insights for interface design using concept lattices that will be of interest to any applied research and development using concept lattices.
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HE, Chao, Xue-Qi CHENG, and Jia-Feng GUO. "Mining Hierarchical Concept Lattice for Faceted Navigation." Chinese Journal of Computers 34, no. 9 (October 15, 2011): 1589–602. http://dx.doi.org/10.3724/sp.j.1016.2011.01589.
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Stemmler, Martin, Alexander Mathis, and Andreas V. M. Herz. "Connecting multiple spatial scales to decode the population activity of grid cells." Science Advances 1, no. 11 (December 2015): e1500816. http://dx.doi.org/10.1126/science.1500816.
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Mammalian grid cells fire when an animal crosses the points of an imaginary hexagonal grid tessellating the environment. We show how animals can navigate by reading out a simple population vector of grid cell activity across multiple spatial scales, even though neural activity is intrinsically stochastic. This theory of dead reckoning explains why grid cells are organized into discrete modules within which all cells have the same lattice scale and orientation. The lattice scale changes from module to module and should form a geometric progression with a scale ratio of around 3/2 to minimize the risk of making large-scale errors in spatial localization. Such errors should also occur if intermediate-scale modules are silenced, whereas knocking out the module at the smallest scale will only affect spatial precision. For goal-directed navigation, the allocentric grid cell representation can be readily transformed into the egocentric goal coordinates needed for planning movements. The goal location is set by nonlinear gain fields that act on goal vector cells. This theory predicts neural and behavioral correlates of grid cell readout that transcend the known link between grid cells of the medial entorhinal cortex and place cells of the hippocampus.
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Carpineto, Claudio, and Giovanni Romano. "Information retrieval through hybrid navigation of lattice representations." International Journal of Human-Computer Studies 45, no. 5 (November 1996): 553–78. http://dx.doi.org/10.1006/ijhc.1996.0067.
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Atif, Jamal, Isabelle Bloch, and Céline Hudelot. "Some Relationships Between Fuzzy Sets, Mathematical Morphology, Rough Sets, F-Transforms, and Formal Concept Analysis." International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems 24, Suppl. 2 (December 2016): 1–32. http://dx.doi.org/10.1142/s0218488516400080.
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In this paper we extend some previously established links between the derivation operators used in formal concept analysis and some mathematical morphology operators to fuzzy concept analysis. We also propose to use mathematical morphology to navigate in a fuzzy concept lattice and perform operations on it. Links with other lattice-based for malisms such as rough sets and F-transforms are also established. This paper proposes a discussion and new results on such links and their potential interest.
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Shirokov, Igor, Elena Shirokova, Igor Serdyuk, and Anna Mordvinova. "Active low-element antenna array for local navigation system." ITM Web of Conferences 30 (2019): 05031. http://dx.doi.org/10.1051/itmconf/20193005031.
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The principles of constructing an active low-element antenna array for a local navigation system are presented. The results of calculation and modeling of a low-element lattice are presented. The selection of the parameters of the antenna array is produced. Comparative results of modeling a low-element array with passive and active antenna elements are presented.
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Hu, Jia Wen, Yang Biao Xie, and Xi Qiu Fan. "Design of Programmable Ship Navigation Light Controller." Advanced Materials Research 490-495 (March 2012): 1367–71. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.1367.
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In this paper, a new type of ship lights controller is presented, which is based on AVR microcontroller, and adopts modular design with isolation between electricity and electronics. The control panel uses LED lattice to indicate the actual layout of the lights and vary lights brightness. Electrical current detection device is used to monitor ship lights. So that the alarm rings when any of the lights is burnt out. The software is developed based on Windows environment, with graphical interface, so that it is easy to use. The proposed controller can be redeveloped to adapt to different configuration of different ship lights.
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Moon, Ji Young, Sasidhar Kondaraju, Wonjae Choi, and Joon Sang Lee. "Lattice Boltzmann-immersed boundary approach for vesicle navigation in microfluidic channel networks." Microfluidics and Nanofluidics 17, no. 6 (April 5, 2014): 1061–70. http://dx.doi.org/10.1007/s10404-014-1393-z.
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Villerd, Jean, Sylvie Ranwez, Michel Crampes, and David Carteret. "Using concept lattices for visual navigation assistance in large databases." International Journal of General Systems 38, no. 4 (May 2009): 405–25. http://dx.doi.org/10.1080/03081070902857829.
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Godin, Robert, Rokia Missaoui, and Alain April. "Experimental comparison of navigation in a Galois lattice with conventional information retrieval methods." International Journal of Man-Machine Studies 38, no. 5 (May 1993): 747–67. http://dx.doi.org/10.1006/imms.1993.1035.
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Ghosh, Subhroshekhar, and Kumarjit Saha. "Transmission and Navigation on Disordered Lattice Networks, Directed Spanning Forests and Brownian Web." Journal of Statistical Physics 180, no. 1-6 (July 9, 2020): 1167–205. http://dx.doi.org/10.1007/s10955-020-02604-1.
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Bolshakov, Andrey. "The three-dimensional lattice as an architectural space." MATEC Web of Conferences 212 (2018): 04005. http://dx.doi.org/10.1051/matecconf/201821204005.
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Space is the main material with which the architect works. The space organized by the means of architecture is an art environment for the life of society. With many aspects of the organization of space, which are studied in the literature, the problem of their assembly and integration remains unsolved. The paper proposes a method of assembling spatial representations in architecture-the correlation of the spatial lattice and the factors of its form-formation, considered in the system, i.e. together. The approach is that in a broad overview of the world architecture, both in its theory and in practice, from historical to modern, examples of modification of spatial grids under the influence of one or a group of dominant factors are revealed. As a result, provisions on the relationship of the geometry of spatial grids with the following factors have been revealed: publicity and privacy; architectonics, the influence of the lattice on the differentiation of the streams of human movement; the architecture’s ability to carry a message; navigation properties, evaluation of connectivity and centrality of places in the spatial lattice; evaluation of the quality of the composition through the identification of ways of order and randomness in the elements of the spatial lattice. The results of the work can be used both for theoretical understanding of the architectural space in the study and design of architecture, and in architectural education.
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Plantié, Michel, and Michel Crampes. "Visualizing and Interacting with Concept Hierarchies." International Journal on Artificial Intelligence Tools 24, no. 02 (April 2015): 1540006. http://dx.doi.org/10.1142/s0218213015400060.
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Concept Hierarchies and Formal Concept Analysis (FCA) are theoretically well grounded. They rely on line diagrams called Galois lattices for visualizing and analysing object-attribute sets. Galois lattices are visually seducing and conceptually rich for experts. However they present important drawbacks due to their concept oriented overall structure: analysing what they show is difficult for non experts, navigation is cumbersome, interaction is poor, and scalability is a deep bottleneck for visual interpretation even for experts. In this paper we introduce semantic probes as a means to overcome many of these problems and extend usability and application possibilities of traditional FCA visualization methods. Semantic probes are visual user centred objects which extract and organize reduced Galois sub-hierarchies. They are simpler, clearer, and they provide a better navigation support through a rich set of interaction possibilities. Since probe driven sub-hierarchies are limited to users' focus, scalability is under control and interpretation is facilitated. After some successful experiments, several applications are being developed with the remaining problem of finding a compromise between simplicity and conceptual expressivity.
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Li Yong, Dou Fei-Ling, Fan Ying, and Di Zeng-Ru. "Theoretical analysis on optimal navigation with total energy restriction in a two-dimensional lattice." Acta Physica Sinica 61, no. 22 (2012): 228902. http://dx.doi.org/10.7498/aps.61.228902.
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Xu, Xiaohua, Yi Han, Jia Luo, Jens Wickert, and Milad Asgarimehr. "Seeking Optimal GNSS Radio Occultation Constellations Using Evolutionary Algorithms." Remote Sensing 11, no. 5 (March 8, 2019): 571. http://dx.doi.org/10.3390/rs11050571.
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Given the great achievements of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission in providing huge amount of GPS radio occultation (RO) data for weather forecasting, climate research, and ionosphere monitoring, further Global Navigation Satellite System (GNSS) RO missions are being followingly planned. Higher spatial and also temporal sampling rates of RO observations, achievable with higher number of GNSS/receiver satellites or optimization of the Low Earth Orbit (LEO) constellation, are being studied by high number of researches. The objective of this study is to design GNSS RO missions which provide multi-GNSS RO events (ROEs) with the optimal performance over the globe. The navigation signals from GPS, GLONASS, BDS, Galileo, and QZSS are exploited and two constellation patterns, the 2D-lattice flower constellation (2D-LFC) and the 3D-lattice flower constellation (3D-LFC), are used to develop the LEO constellations. To be more specific, two evolutionary algorithms, including the genetic algorithm (GA) and the particle swarm optimization (PSO) algorithm, are used for searching the optimal constellation parameters. The fitness function of the evolutionary algorithms takes into account the spatio-temporal sampling rate. The optimal RO constellations are obtained for which consisting of 6–12 LEO satellites. The optimality of the LEO constellations is evaluated in terms of the number of global ROEs observed during 24 h and the coefficient value of variation (COV) representing the uniformity of the point-to-point distributions of ROEs. It is found that for a certain number of LEO satellites, the PSO algorithm generally performs better than the GA, and the optimal 2D-LFC generally outperforms the optimal 3D-LFC with respect to the uniformity of the spatial and temporal distributions of ROEs.
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Chen, Tao, Li Guo Chen, Ming Qiang Pan, and Li Ning Sun. "Design of a Coaxial Positioning System Based on Flexible Decoupling Beams." Advanced Materials Research 490-495 (March 2012): 2141–45. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.2141.
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To overcome the shortcomings of existing technology and achieve a type of shaft and sleeve assembly in navigate with high coaxial requirements, a novel coaxial positioning system is presented based on the flexible decoupling beams and micro-vision system. In order to meet the adjustments online and maintain posture of the shaft and sleeve, a flexible beams structure with pattern of “square lattice” is designed. Combined with micro motorized X-Y stage and clamps, the structure achieves exact coaxial positioning precision and station keeping function. The mechanics theory and finite element method are used to analysis and simulate the beams. The Hough algorithm is applied in the micro-vision system to realize the precise coaxial positioning of real-time detection and calculation. Experiments show that the coaxial positioning accuracy is better than 8μm, and the positioning device could guarantee the realization of positioning assembly in practical applications.
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Han, Yi, Jia Luo, and Xiaohua Xu. "On the Constellation Design of Multi-GNSS Reflectometry Mission Using the Particle Swarm Optimization Algorithm." Atmosphere 10, no. 12 (December 13, 2019): 807. http://dx.doi.org/10.3390/atmos10120807.
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Due to the great success of the CYclone Global Navigation Satellite System (CYGNSS) mission, the follow-on GNSS Reflectometry (GNSS-R) missions are being planned. In the perceivable future, signal sources for GNSS-R missions can originate from multiple global navigation satellite systems (GNSSs) including Global Positioning System (GPS), Galileo, GLONASS, and BeiDou. On the other hand, to facilitate the operational capability for sensing ocean, land, and ice features globally, multi-satellite low Earth orbit (LEO) constellations with global coverage and high spatio-temporal resolutions should be considered in the design of the follow-on GNSS-R constellation. In the present study, the particle swarm optimization (PSO) algorithm was applied to seek the optimal configuration parameters of 2D-lattice flower constellations (2D-LFCs) composed of 8, 24, 60, and 120 satellites, respectively, for global GNSS-R observations, and the fitness function was defined as the length of the time for the percentage coverage of the reflection observations reaches 90% of the globe. The configuration parameters for the optimal constellations are presented, and the performances of the optimal constellations for GNSS-R observations including the visited and the revisited coverages, and the spatial and temporal distributions of the reflections were further compared. Although the results showed that all four optimized constellations could observe GNSS reflections with proper temporal and spatial distributions, we recommend the optimal 24- and 60-satellite 2D-LFCs for future GNSS-R missions, taking into account both the performance and efficiency for the deployment of the GNSS-R missions.
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Mitra, Aniruddha, Felix Ruhnow, Salvatore Girardo, and Stefan Diez. "Directionally biased sidestepping of Kip3/kinesin-8 is regulated by ATP waiting time and motor–microtubule interaction strength." Proceedings of the National Academy of Sciences 115, no. 34 (August 9, 2018): E7950—E7959. http://dx.doi.org/10.1073/pnas.1801820115.
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Kinesin-8 motors, which move in a highly processive manner toward microtubule plus ends where they act as depolymerases, are essential regulators of microtubule dynamics in cells. To understand their navigation strategy on the microtubule lattice, we studied the 3D motion of single yeast kinesin-8 motors, Kip3, on freely suspended microtubules in vitro. We observed short-pitch, left-handed helical trajectories indicating that kinesin-8 motors frequently switch protofilaments in a directionally biased manner. Intriguingly, sidestepping was not directly coupled to forward stepping but rather depended on the average dwell time per forward step under limiting ATP concentrations. Based on our experimental findings and numerical simulations we propose that effective sidestepping toward the left is regulated by a bifurcation in the Kip3 step cycle, involving a transition from a two-head–bound to a one-head–bound conformation in the ATP-waiting state. Results from a kinesin-1 mutant with extended neck linker hint toward a generic sidestepping mechanism for processive kinesins, facilitating the circumvention of intracellular obstacles on the microtubule surface.
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Kłusek, Adrian, Paweł Topa, Jarosław Wąs, and Robert Lubaś. "An implementation of the Social Distances Model using multi-GPU systems." International Journal of High Performance Computing Applications 32, no. 4 (December 4, 2016): 482–95. http://dx.doi.org/10.1177/1094342016679492.
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We propose a new approach for using GPUs in large scale simulations of pedestrian evacuation. The Social Distances Model is designed for efficient modeling of pedestrian dynamics. This cellular automata based model, when implemented on the most modern GPUs, can simulate up to 106–108 entities. However, a valuable simulation of pedestrian evacuation must include various factors that govern pedestrian movement, for example, information provided by event organizers and navigation or allocation of other pedestrians. The most common method for introducing such information into simulations is the application of different floor fields. The floor fields provide “local knowledge” that affects pedestrians by modifying the transition functions of an applied cellular automaton. The main disadvantage of this method is its time consuming updating process. We propose a GPU based calculation of static and dynamic floor fields, whereby simulations that use several different floor fields can be efficiently calculated. A single GPU is able to cope with the Social Distance Model calculations, while other GPUs update dynamic floor fields constantly or when required. We also present the classic approach to performing cellular automata based simulations on systems with multiple processing units. The lattice is simply partitioned between the available GPUs. We compare these two approaches in terms of performance and functionality.
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Mu, Jiliang, Zhang Qu, Zongmin Ma, Shaowen Zhang, Yunbo Shi, Jian Gao, Xiaoming Zhang, et al. "Ensemble spin fabrication and manipulation of NV centres for magnetic sensing in diamond." Sensor Review 37, no. 4 (September 18, 2017): 419–24. http://dx.doi.org/10.1108/sr-09-2016-0163.
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Purpose This study aims to fabricate and manipulate ensemble spin of negative nitrogen-vacancy (NV−) centres optimally for future solid atomic magnetometers/gyroscope. Parameters for sample preparation most related to magnetometers/gyroscope are, in particular, the concentration and homogeneity of the NV− centres, the parameters’ microwave antenna of resonance frequency and the strength of the microwave on NV− centres. Besides, the abundance of other impurities such as neutral NV centres (NV0) and substitutional nitrogen in the lattice also plays a critical role in magnetic sensing. Design/methodology/approach The authors succeeded in fabricating the assembly of NV centres in diamond and they determined its concentration of (2-3) × 1016 cm−3 with irradiation followed by annealing under a high temperature condition. They explored a novel magnetic resonance approach to detect the weak magnetic fields that takes advantage of the solid-state electron ensemble spin of NV− centres in diamond. In particular, the authors set up a magnetic sensor on the basis of the assembly of NV centres. They succeeded in fabricating the assembly of NV centres in diamond and determined its concentration. They also clarified the magnetic field intensity measured at different positions along the antenna with different lengths, and they found the optimal position where the signal of the magnetic field reaches the maximum. Findings The authors mainly reported preparation, initialization, manipulation and measurement of the ensemble spin of the NV centres in diamond using optical excitation and microwave radiation methods with variation of the external magnetic field. They determined the optimal parameters of irradiation and annealing to generate the ensemble NV centres, and a concentration of NV− centres as high as 1016 cm−3 in diamond was obtained. In addition, they found that sensitivity of the magnetometer using this method can reach as low as 5.22 µT/Hz currently. Practical implications This research can shed light on the development of an atomic magnetometer and a gyroscope on the basis of the ensemble spin of NV centres in diamond. Social implications High concentration spin of NV− in diamond is one of the advantages compared with that of the atomic vapor cells, because it can obtain a higher concentration. When increasing the spin concentration, the spin signal is easy to detect, and macro-atomic spin magnetometer become possible. This research is the first step for solid atomic magnetometers with high spin density and high sensitivity potentially with further optimization. It has a wide range of applications from fundamental physics tests, sensor applications and navigation to detection of NMR signals. Originality/value As has been pointed out, in this research, the authors mainly worked on fabricating NV− centres with high concentration (1015-1016 cm−3) in diamond by using optimal irradiation and annealing processes, and they quantitatively defined the NV− concentration, which is important for the design of higher concentration processes in the magnetometer and gyroscope. Until now, few groups can directly define the NV− concentration. Besides, the authors optimized the microwave antenna parameters experimentally and explored the dependence between the splitting of the magnetic resonance and the magnetic fields, which dictated the minimum detectable magnetic field.
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Torres-Ruiz, Miguel, Marco Moreno-Ibarra, Wadee Alhalabi, Rolando Quintero, and Giovanni Guzmán. "Towards a microscopic model for analyzing the pedestrian mobility in an urban infrastructure." Journal of Science and Technology Policy Management 9, no. 2 (July 2, 2018): 170–88. http://dx.doi.org/10.1108/jstpm-05-2017-0023.
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Purpose Up-to-date, the simulation of pedestrian behavior is used to support the design and analysis of urban infrastructure and public facilities. The purpose of this paper is to present a microscopic model that describes pedestrian behavior in a two-dimensional space. It is based on multi-agent systems and cellular automata theory. The concept of layered-intelligent terrain from the video game industry is reused and concepts such as tracing, evasion and rejection effects related to pedestrian interactive behavior are involved. In a simulation scenario, an agent represents a pedestrian with homogeneous physical characteristics such as walking speed and height. The agents are moved through a discrete space formed by a lattice of hexagonal cells, where each one can contain up to one agent at the same time. The model was validated by using a test that is composed of 17 real data sets of pedestrian unidirectional flow. Each data set has been extracted from laboratory-controlled scenarios carried out with up to 400 people walking through a corridor whose configuration changed in form of the amplitude of its entrance doors and the amplitude of its exit doors from one experiment to another. Moreover, each data set contained different groups of coordinates that compose pedestrian trajectories. The scenarios were replicated and simulated using the proposed model, obtaining 17 simulated data sets. In addition, a measurement methodology based on Voronoi diagrams was used to compute the velocity, density and specific flow of pedestrians to build a time-series graphic and a set of heat maps for each of the real and simulated data sets. Design methodology/approach The approach consists of a multi-agent system and cellular automata theory. The obtained results were compared with other studies and a statistical analysis based on similarity measurement is presented. Findings A microscopic mobility model that describes pedestrian behavior in a two-dimensional space is presented. It is based on multi-agent systems and cellular automata theory. The concept of layered-intelligent terrain from the video game industry is reused and concepts such as tracing, evasion and rejection effects related to pedestrian interactive behavior are involved. On average, the simulated data sets are similar by 82 per cent in density and 62 per cent in velocity compared to the real data sets. It was observed that the relation between velocity and density from real scenarios could not be replicated. Research limitations/implications The main limitations are presented in the speed simulations. Although the obtained results present a similar behavior to the reality, it is necessary to introduce more variables in the model to improve the precision and calibration. Other limitation is the dimension for simulating variables at this moment 2D is presented. So the resolution of cells, making that pedestrian to occupy many cells at the same time and the addition of three dimensions to the terrain will be a good challenge. Practical implications In total, 17 data sets were generated as a case study. They contain information related to speed, trajectories, initial and ending points. The data sets were used to calibrate the model and analyze the behavior of pedestrians. Geospatial data were used to simulate the public infrastructure in which pedestrians navigate, taking into account the initial and ending points. Social implications The social impact is directly related to the behavior analysis of pedestrians to know tendencies, trajectories and other features that aid to improve the public facilities. The results could be used to generate policies oriented toward developing more consciousness in the public infrastructure development. Originality/value The general methodology is the main value of this work. Many approaches were used, designed and implemented for analyzing the pedestrians’ behavior. In addition, all the methods were implemented in plug-in for Quantum GIS. The analysis was described with heat maps and statistical approaches. In addition, the obtained results are focused on analyzing the density, speed and the relationship between these features.
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Gebbe, Martina, Jan-Niclas Siemß, Matthias Gersemann, Hauke Müntinga, Sven Herrmann, Claus Lämmerzahl, Holger Ahlers, et al. "Twin-lattice atom interferometry." Nature Communications 12, no. 1 (May 5, 2021). http://dx.doi.org/10.1038/s41467-021-22823-8.
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AbstractInertial sensors based on cold atoms have great potential for navigation, geodesy, or fundamental physics. Similar to the Sagnac effect, their sensitivity increases with the space-time area enclosed by the interferometer. Here, we introduce twin-lattice atom interferometry exploiting Bose-Einstein condensates of rubidium-87. Our method provides symmetric momentum transfer and large areas offering a perspective for future palm-sized sensor heads with sensitivities on par with present meter-scale Sagnac devices. Our theoretical model of the impact of beam splitters on the spatial coherence is highly instrumental for designing future sensors.
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Wei, Xue-Xin, Jason Prentice, and Vijay Balasubramanian. "A principle of economy predicts the functional architecture of grid cells." eLife 4 (September 3, 2015). http://dx.doi.org/10.7554/elife.08362.
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Grid cells in the brain respond when an animal occupies a periodic lattice of ‘grid fields’ during navigation. Grids are organized in modules with different periodicity. We propose that the grid system implements a hierarchical code for space that economizes the number of neurons required to encode location with a given resolution across a range equal to the largest period. This theory predicts that (i) grid fields should lie on a triangular lattice, (ii) grid scales should follow a geometric progression, (iii) the ratio between adjacent grid scales should be √e for idealized neurons, and lie between 1.4 and 1.7 for realistic neurons, (iv) the scale ratio should vary modestly within and between animals. These results explain the measured grid structure in rodents. We also predict optimal organization in one and three dimensions, the number of modules, and, with added assumptions, the ratio between grid periods and field widths.
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Gong, Ziyi, and Fangwen Yu. "A Plane-Dependent Model of 3D Grid Cells for Representing Both 2D and 3D Spaces Under Various Navigation Modes." Frontiers in Computational Neuroscience 15 (September 22, 2021). http://dx.doi.org/10.3389/fncom.2021.739515.
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Grid cells are crucial in path integration and representation of the external world. The spikes of grid cells spatially form clusters called grid fields, which encode important information about allocentric positions. To decode the information, studying the spatial structures of grid fields is a key task for both experimenters and theorists. Experiments reveal that grid fields form hexagonal lattice during planar navigation, and are anisotropic beyond planar navigation. During volumetric navigation, they lose global order but possess local order. How grid cells form different field structures behind these different navigation modes remains an open theoretical question. However, to date, few models connect to the latest discoveries and explain the formation of various grid field structures. To fill in this gap, we propose an interpretive plane-dependent model of three-dimensional (3D) grid cells for representing both two-dimensional (2D) and 3D space. The model first evaluates motion with respect to planes, such as the planes animals stand on and the tangent planes of the motion manifold. Projection of the motion onto the planes leads to anisotropy, and error in the perception of planes degrades grid field regularity. A training-free recurrent neural network (RNN) then maps the processed motion information to grid fields. We verify that our model can generate regular and anisotropic grid fields, as well as grid fields with merely local order; our model is also compatible with mode switching. Furthermore, simulations predict that the degradation of grid field regularity is inversely proportional to the interval between two consecutive perceptions of planes. In conclusion, our model is one of the few pioneers that address grid field structures in a general case. Compared to the other pioneer models, our theory argues that the anisotropy and loss of global order result from the uncertain perception of planes rather than insufficient training.
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Stanga, Paulo Eduardo, Salvador Pastor-Idoate, Ursula Reinstein, Pooja Vatas, Umangi Patel, Sander Dubovy, Dan Reinstein, and Ori Zahavi. "Navigated single-capture 3D and cross-sectional wide-field OCT of the mid and peripheral retina and vitreoretinal interface." European Journal of Ophthalmology, July 3, 2021, 112067212110261. http://dx.doi.org/10.1177/11206721211026100.
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Purpose: Assess the mid and peripheral neuroretina and vitreoretinal interface using a novel Navigated Single-Capture 3D and Cross-Sectional Wide-Field Swept-Source Optical Coherence Tomography (WF SS-OCT) technology with correlation to Multi-Wavelength Ultra-Widefield Imaging (MW UWFI) and Histopathology reference. Methods: Retrospective observational study. A total of 74 patients (148 eyes) were imaged using WF SS-OCT and Navigated Single-Capture twelve 23 mm cross-sectional radial scan pattern at 15° intervals. Image diagnosis included: congenital hypertrophy of the retinal pigment epithelium, choroidal nevus, ora serrata pearls, retinal tuft, lattice, snail track, cobblestone degeneration, retinal hole, retinal tear, degenerative retinoschisis, peripheral laser retinopexy, white without pressure, vitreous floaters, subclinical peripheral rhegmatogenous retinal detachment (RD), and tractional RD in proliferative diabetic retinopathy. WF SS-OCT images were correlated with MW UWFI and histopathological references where available. Results: WF SS-OCT successfully imaged structural features in all diagnoses with significant improvement in diagnostic capability and increased the diagnosis of specific features such as vitreoretinal attachment, full thickness hole or tear and subretinal fluid. Histopathological correlation was available for five (5) different peripheral retinal pathologies imaged by both WF SS-OCT and MW UWFI and good anatomical correlation was observed in all diagnosis. Conclusions: Navigated Single-Capture 3D and Cross-Sectional WF SS-OCT provides detailed anatomic information of the mid and peripheral neuroretina and vitreoretinal interface, allowing early recognition of vision-threatening features that may influence clinical management, particularly in an era of telemedicine or when there is limited or no access to Indirect Ophthalmoscopy with 360° Scleral Indentation.
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Prim, Sebastian, and Mikael Samuelsson. "Grow or successfully disengage? Navigating the revolution of South African tower companies." Case Writing Centre, University of Cape Town, Graduate School of Business, June 29, 2021, 1–16. http://dx.doi.org/10.1108/caseuct-2021-000001.
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Subject area of the teaching case: The case is suitable for strategy or entrepreneurship modules. It is designed to teach students about the importance of implementing formal processes when entering a growth phase as well as the complexities, unexpected costs, and benefits that growing a business can bring. Student level: The case is aimed at MBA or Master-level students or executive education programmes as part of a strategy or entrepreneurship module. Brief overview of the teaching case: Lattice Towers is a South African company in the telecommunications infrastructure sector. They are struggling to generate sufficient cash flow to sustain operations as a result of poor strategic decision-making regarding tower-build site acquisition. To compound matters, the owner has been struggling with health issues related to the stress caused by the crises that Lattice Towers is going through. Recently, however, a multinational publicly listed behemoth in the telecommunications industry, Helios Towers, offered to acquire the company. The acquisition offer seems like a saving grace to the owner; however, Lattice Towers is deeply personal to the him and he would not like to lose the brand. Furthermore, there is a tremendous opportunity for business growth due to the imminent increase in demand for tower infrastructure. But based on the challenging financial position the business currently finds itself in, he might not have the option to keep the business. Expected learning outcomes: To develop a decision-making framework and strategy to navigate the business life-cycle stages, from survival to growth Understand the concepts of uncertainty, risk, and liquidity premiums that apply to entrepreneurship Understand the stress-related implications for entrepreneurs Understand the psychological costs and benefits of entrepreneurship Understand the personal financial implications for entrepreneurship
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Phyo, Shwe Sin. "Content analysis-based documentation and exploration of research articles." Data Technologies and Applications ahead-of-print, ahead-of-print (July 6, 2021). http://dx.doi.org/10.1108/dta-07-2020-0146.
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PurposeWith the wealth of information available on the World Wide Web, it is difficult for anyone from a general user to the researcher to easily fulfill their information need. The main challenge is to categorize the documents systematically and also take into account more valuable data such as semantic information. The purpose of this paper is to develop a concept-based search system that leverages the external knowledge resources as the background knowledge for getting the accurate and efficient meaningful search results.Design/methodology/approachThe paper introduces the approach which is based on formal concept analysis (FCA) with the semantic information to support the document management in information retrieval (IR). To describe the semantic information of the documents, the system uses the popular knowledge resources WordNet and Wikipedia. By using FCA, the system creates the concept lattice as the concept hierarchy of the document and proposes the navigation algorithm for retrieving the hierarchy based on the user query.FindingsThe semantic information of the document is based on the two external popular knowledge resources; the authors find that it will be more efficient to deal with the semantic mismatch problems of user need.Originality/valueThe navigation algorithm proposed in this research is applied to the scientific articles of the National Science Foundation (NSF). The proposed system can enhance the integration and exploration of the scientific articles for the advancement of the Scientific and Engineering Research Community.
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Nguyen, Linh, Sarath Kodagoda, Ravindra Ranasinghe, and Gamini Dissanayake. "Mobile Robotic Sensors for Environmental Monitoring using Gaussian Markov Random Field." Robotica, September 1, 2020, 1–23. http://dx.doi.org/10.1017/s026357472000079x.
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SUMMARY This paper addresses the issue of monitoring spatial environmental phenomena of interest utilizing information collected by a network of mobile, wireless, and noisy sensors that can take discrete measurements as they navigate through the environment. It is proposed to employ Gaussian Markov random field (GMRF) represented on an irregular discrete lattice by using the stochastic partial differential equations method to model the physical spatial field. It then derives a GMRF-based approach to effectively predict the field at unmeasured locations, given available observations, in both centralized and distributed manners. Furthermore, a novel but efficient optimality criterion is then proposed to design centralized and distributed adaptive sampling strategies for the mobile robotic sensors to find the most informative sampling paths in taking future measurements. By taking advantage of conditional independence property in the GMRF, the adaptive sampling optimization problem is proven to be resolved in a deterministic time. The effectiveness of the proposed approach is compared and demonstrated using pre-published data sets with appealing results.
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Xiong, Yi, Yunlong Tang, Sang-In Park, and David W. Rosen. "Harnessing Process Variables in Additive Manufacturing for Design Using Manufacturing Elements." Journal of Mechanical Design 142, no. 7 (March 3, 2020). http://dx.doi.org/10.1115/1.4046069.
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Abstract Process plans in additive manufacturing (AM) have a profound impact on the performance of fabricated parts such as geometric accuracy and mechanical properties. Due to its layer-based, additive nature, AM processes can be controlled at multiple scales starting from the scan vector/pixel scale. However, most process planning methods in AM configure process settings at the part scale. This leaves large unexplored regions in the design space that may include optimal designs. To address these untapped potentials, we present a process planning strategy based on the concept of manufacturing elements (MELs) to harness process variables at low scales for design. First, we decompose a part design into multiple MELs that contain geometric and manufacturing information. Two-scale process–structure–property (PSP) relationships are then constructed for MELs and their assembly. Decision tools, including the compromise decision support problem, are employed to navigate two-scale PSP relationships for supporting designers in design exploration on process variables and optimization of process plans. The proposed strategy is illustrated with a process planning example for a lattice structure, which has multiple design goals and is to be fabricated using material extrusion.