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Journal articles on the topic 'Snapshoot'

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Author: Grafiati

Published: 4 June 2021

Last updated: 19 February 2022

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1

Sugiono, Arif, and Dian Fordian. "JENIS KAPABILITAS DINAMIS PELAKU RINTISAN START UP ENTREPRENEUR (Studi Pada Pelaku Subsektor Gastronomi di Industri Kreatif)." AdBispreneur 4, no. 2 (January 21, 2020): 89. http://dx.doi.org/10.24198/adbispreneur.v4i2.23012.

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The purpose of this study was to identify the types of dynamic capabilities for start-up entrepreneurs in the creative industries gastronomy sub-sector where the Organization Life Cycle stage is at the entrepreneurial stage. The method used was a snapshot case study with a naturalistic descriptive type. The informants were determined using purposive techniques with some criteria that are in accordance with the focus and locus of research. Data were collected through in-depth interviews, observation, and literature study. Data were analyzed using an interactive model. The results showed that there are several types of dynamic capabilities that start-up entrepreneurs need: the ability to choose and design organizational structures, the accuracy of the choice of information technology types, and the ability to design market-oriented strategies. Based on the results of the research above, the startup entrepreneurs are required to have a renewal ability to sustain managerial skills to analyze and adapt to the dynamics of the internal and external environment that changes amicably. Tujuan penelitian ini adalah mengidentifikasi jenis kapabilitas dinamis yang diperlukan bagi para pelaku start up entrepreneur di sub sektor gastronomi industri kreatif yang tahap Organization Life Cycle berada pada tahap entrepreneurial. Metode yang digunakan adalah snapshoot case study dengan type deskriptif naturalistic. Penentuan informan menggunakan teknik purposive, dengan beberapa krieria yang sesuai dengan fokus dan lokus penelitian. Teknik pengambilan data melalui wawancara mendalam, observasi dan studi pustaka. Analisis data menggunakan model interaktif. Hasil penelitian menunjukkan ada beberapa jenis kapabilitas dinamis yang sangat diperlukan bagi pelaku rintisan start up entrepreneur, yaitu kemampuan memilih dan mendesain struktur organisasi, ketepatan pemilihan jenis teknologi informasi dan kemampuan mendesain strategi yang berorientasi pasar. Berdasarkan hasil penelitian di atas, maka pelaku rintisan start up entrepreneur dituntut untuk memiliki renewal ability untuk menopang managerial skill, sehingga mampu menganalisa dinamika lingkungan internal dan eksternal.

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Bok, Kyoungsoo, Gihoon Kim, Jongtae Lim, and Jaesoo Yoo. "Historical Graph Management in Dynamic Environments." Electronics 9, no. 6 (May 28, 2020): 895. http://dx.doi.org/10.3390/electronics9060895.

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Since dynamic graph data continuously change over time, it is necessary to manage historical data for accessing a snapshot graph at a specific time. In this paper, we propose a new historical graph management scheme that consists of an intersection snapshot and a delta snapshot to enhance storage utilization and historical graph accessibility. The proposed scheme constantly detects graph changes and calculates a common subgraph ratio between historical graphs over time. If the common subgraph ratio is lower than a threshold value, the intersection snapshot stores the common subgraphs within a time interval. A delta snapshot stores the subgraphs that are not contained in the intersection snapshot. Several delta snapshots are connected to the intersection snapshot to maintain the modified subgraph over time. The efficiency of storage space is improved by managing common subgraphs stored in the intersection snapshot. Furthermore, the intersection and delta snapshots can be connected to search a graph at a specific time. We show the superiority of the proposed scheme through various performance evaluations.

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3

Muhamad, M., Saryani, and N. I. Khabibi. "Monitoring of the tourism village of the mount merapi slope area through the global sustainable tourism council (gstc) snapshoot assessment system." IOP Conference Series: Earth and Environmental Science 683, no. 1 (March 1, 2021): 012113. http://dx.doi.org/10.1088/1755-1315/683/1/012113.

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4

Pratono, Aluisius Hery, and Godo Tjahjono. "How does materialistic attitude influence the impact of corporate brand on the customers’ intention to donate to corporates’ charity?" Humanomics 33, no. 4 (November 13, 2017): 484–98. http://dx.doi.org/10.1108/h-07-2016-0052.

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Purpose The purpose of this paper is to determine the impact of corporate brand equity and corporate brand credibility on customer’s intention to donate the charity program. To understand the complex relationship, this study points out the moderating effect of the materialistic attitude. Design/methodology/approach The empirical study involved a survey of young customers in Indonesia telecommunication industry. The data collection involved face-to-face interviews among 409 respondents in Jakarta Indonesia between December 2015 and January 2016. Findings This study indicates a positive impact of corporate brand equity and brand credibility on their customers’ intention to support the social charity. However, materialistic attitude slightly changes the impact direction of corporate brand on the customers’ intention to participate. Research limitations/implications This research relies on a cross-sectional observation, which was one snapshoot observation in specific time. Second, this study uses interview to help the respondents understand the questionnaires; this may imply on the level of objectiveness of respondents. Practical/implications This paper extends the discussion on the altruism theory and corporate brands by establishing a critical linkage between materialistic attitude, corporate brand credibility and consumers’ intention to charity. Under high materialistic attitude, corporations are encouraged to promote strong business ethics. Originality/value This study makes a contribution to the deepening understanding on altruism theory and conscious corporate responsibility through raising a concern on marketing practices, which entails a potential fraud from charity ethics.

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5

Ramadaniati, Hesty U., Ya P. Lee, and Jeffery D. Hughes. "Snapshot versus continuous documentation of pharmacists’ interventions: are snapshots worthwhile?" Journal of Pharmacy Practice and Research 44, no. 4 (December 2014): 205–12. http://dx.doi.org/10.1002/jppr.1029.

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6

Bond, Howard E., Laura K. Fullton, Karen G. Schaefer, Robin Ciardullo, and Michael Sipior. "HST Snapshot images of Planetary Nebulae." Symposium - International Astronomical Union 180 (1997): 211–12. http://dx.doi.org/10.1017/s0074180900130347.

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During Cycle 5 of the HST General Observer program we have been carrying out a “snapshot” survey of central stars of planetary nebulae. The snapshots are short exposures in the V (F555W) and I (F814W) filters, taken with the Wide Field Planetary Camera (WFPC2) during brief scheduling opportunities.

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7

Gößnitzer, Clemens, and Shawn Givler. "A New Method to Determine the Impact of Individual Field Quantities on Cycle-to-Cycle Variations in a Spark-Ignited Gas Engine." Energies 14, no. 14 (July 8, 2021): 4136. http://dx.doi.org/10.3390/en14144136.

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Cycle-to-cycle variations (CCV) in spark-ignited (SI) engines impose performance limitations and in the extreme limit can lead to very strong, potentially damaging cycles. Thus, CCV force sub-optimal engine operating conditions. A deeper understanding of CCV is key to enabling control strategies, improving engine design and reducing the negative impact of CCV on engine operation. This paper presents a new simulation strategy which allows investigation of the impact of individual physical quantities (e.g., flow field or turbulence quantities) on CCV separately. As a first step, multi-cycle unsteady Reynolds-averaged Navier–Stokes (uRANS) computational fluid dynamics (CFD) simulations of a spark-ignited natural gas engine are performed. For each cycle, simulation results just prior to each spark timing are taken. Next, simulation results from different cycles are combined: one quantity, e.g., the flow field, is extracted from a snapshot of one given cycle, and all other quantities are taken from a snapshot from a different cycle. Such a combination yields a new snapshot. With the combined snapshot, the simulation is continued until the end of combustion. The results obtained with combined snapshots show that the velocity field seems to have the highest impact on CCV. Turbulence intensity, quantified by the turbulent kinetic energy and turbulent kinetic energy dissipation rate, has a similar value for all snapshots. Thus, their impact on CCV is small compared to the flow field. This novel methodology is very flexible and allows investigation of the sources of CCV which have been difficult to investigate in the past.

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8

Roberts, Allen D. "Past, current, and projected landscape configurational effects on streamflow within the Rocky River HUC-8 watershed of the Charlotte metropolitan region." H2Open Journal 1, no. 2 (November 12, 2018): 112–30. http://dx.doi.org/10.2166/h2oj.2018.108.

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AbstractThis study examined past, current, and projected landscape configuration (LC) impacts on streamflow within a 3,553 square kilometer (km2) Hydrologic Unit Code (HUC)-8 Rocky River (RR) watershed of the Charlotte, North Carolina metropolitan region (CMR). Utilizing a monthly model, Thornthwaite Water Balance (TWB) simulations incorporating LC (blended contagion (CON)-adjusted curve numbers (CNs)) derived from two previous (2001, 2006) and one current (2011) US scale land cover/land use (LC/LU) time snapshots outperformed a blended original (ORG) CN watershed model during the 15-year (180-month) period from January 1999 to December 2013. Findings were confirmed using evaluations from several statistically based, hydrologic model performance predictors. Five-year comparisons of the 2001 time snapshot with the 2006 time snapshot and 2011 time snapshot indicated the least underestimation/overestimation of measured streamflow occurred during the 2001 time snapshot. This period had the highest measured runoff and points towards LC influences on streamflow simulation being potentially more quantifiable during periods of greater watershed precipitation. Watershed LC/LU and climatic data were also projected to the 2030 time snapshot under five different scenarios. Streamflow was projected to be about 2.6% higher in volume than what was estimated for the current (2011) time snapshot using a blended CON-adjusted TWB model.

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9

Häcker, P., and B. Yang. "Single snapshot DOA estimation." Advances in Radio Science 8 (October 1, 2010): 251–56. http://dx.doi.org/10.5194/ars-8-251-2010.

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Abstract. In array signal processing, direction of arrival (DOA) estimation has been studied for decades. Many algorithms have been proposed and their performance has been studied thoroughly. Yet, most of these works are focused on the asymptotic case of a large number of snapshots. In automotive radar applications like driver assistance systems, however, only a small number of snapshots of the radar sensor array or, in the worst case, a single snapshot is available for DOA estimation. In this paper, we investigate and compare different DOA estimators with respect to their single snapshot performance. The main focus is on the estimation accuracy and the angular resolution in multi-target scenarios including difficult situations like correlated targets and large target power differences. We will show that some algorithms lose their ability to resolve targets or do not work properly at all. Other sophisticated algorithms do not show a superior performance as expected. It turns out that the deterministic maximum likelihood estimator is a good choice under these hard conditions.

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10

Wilkinson, P. N., A. Polatidis, D. R. Henstock, A. C. S. Readhead, W. Xu, T. J. Pearson, G. Taylor, and R. C. Vermeulen. "The Caltech-Jodrell Bank (CJ) VLBI Snapshot Surveys." Symposium - International Astronomical Union 158 (1994): 367–69. http://dx.doi.org/10.1017/s0074180900107946.

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Two large VLBI surveys are currently underway which utilise the snapshot technique pioneered on the VLA. With a 12–16 telescope array three ~ 20 min snapshots are sufficient to make excellent hybrid maps. Recent advances in data analysis techniques enable surveys of several hundred sources to be undertaken and reduced in under two years.

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11

Molteno, Timothy C. A., and Keith W. Payne. "FastFix Albatross Data: Snapshots of Raw GPS L-1 Data from Southern Royal Albatross." Data 6, no. 4 (April 7, 2021): 37. http://dx.doi.org/10.3390/data6040037.

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This dataset contains 4-millisecond snapshots of the GPS radio spectrum stored by wildlife tracking tags deployed on adult Southern Royal Albatross (Diomedea epomophora) in New Zealand. Approximately 60,000 snapshots were recovered from nine birds over two southern-hemisphere summers in 2012 and 2013. The data can be post-processed using snapshot positioning algorithms, and are made available as a test dataset for further development of these algorithms. Included are post-processed position estimates for reference, as well as test data from stationary tags positioned under various test conditions for the purposes of characterizing tag performance.

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12

Ren, Xiao Guang, Yu Hua Tang, and Xin Hai Xu. "Format Optimization for Periodical Snapshot Output in CFD Simulation." Applied Mechanics and Materials 457-458 (October 2013): 910–18. http://dx.doi.org/10.4028/www.scientific.net/amm.457-458.910.

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Computational Fluid Dynamics (CFD) simulation often needs to periodically output the intermediate results to files in the form of snapshots for visualization or restart, which seriously impacts the performance. Traditional CFD simulation takes ASCII format with typesetting in the snapshot output process, which results in precision loss of the data in the snapshot array and more storage space occupancy than the original binary format. In this paper, we propose the binary non-typesetting format optimization for the snapshot output in CFD simulation, aiming at eliminating the impact of ASCII format. In our optimization method, the snapshot array is output in binary format without typesetting. On one hand, it reserves the original binary precision in the output files, while the ASCII format always has precision loss, which seriously impacts the accuracy of CFD simulation; On the other hand, non-typesetting provide the opportunity of output the snapshot as a continuous memory block, which will signally improve the efficiency of the output. We design the multiply output mode framework for CFD applications through the combination of ASCII typesetting format and binary non-typesetting format. We implement this multiply output mode framework in the open source CFD software OpenFOAM. Experimental results on Tianhe-2 supercomputer demonstrate that our binary non-typesetting format optimization technique can achieve good optimization effect for the periodical snapshot output in CFD application.

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13

Hou, Yuguan, Tongyu Zhang, and Shaochuan Wu. "CC-MUSIC: An Optimization Estimator for Mutual Coupling Correction of L-Shaped Nonuniform Array with Single Snapshot." Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/969042.

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For the case of the single snapshot, the integrated SNR gain could not be obtained without the multiple snapshots, which degrades the mutual coupling correction performance under the lower SNR case. In this paper, a Convex Chain MUSIC (CC-MUSIC) algorithm is proposed for the mutual coupling correction of the L-shaped nonuniform array with single snapshot. It is an online self-calibration algorithm and does not require the prior knowledge of the correction matrix initialization and the calibration source with the known position. An optimization for the approximation between the no mutual coupling covariance matrix without the interpolated transformation and the covariance matrix with the mutual coupling and the interpolated transformation is derived. A global optimization problem is formed for the mutual coupling correction and the spatial spectrum estimation. Furthermore, the nonconvex optimization problem of this global optimization is transformed as a chain of the convex optimization, which is basically an alternating optimization routine. The simulation results demonstrate the effectiveness of the proposed method, which improve the resolution ability and the estimation accuracy of the multisources with the single snapshot.

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14

Zar'in, Arika Umi, and Novita Intan Arovah. "Physical Activities and Construct of Health Belief Models in the Special Region of Yogyakarta in the Era of Pandemy Covid-19." Budapest International Research and Critics in Linguistics and Education (BirLE) Journal 4, no. 2 (April 20, 2021): 698–709. http://dx.doi.org/10.33258/birle.v4i2.1831.

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This study aims to determine (1) the pattern, level and status of physical activity, (2) differences in the level of physical activity based on the construct status of the health belief model and (3) the relationship between physical activity status and the construct status of the health belief model in the people of the Special Region of Yogyakarta. This research is a cross-sectional observational survey research on the DIY community as many as 390 people using convenience sampling technique with online questionnaire. Physical activity is measured using the Global Physical activity Questionnaire (GPAQ) which calculates the metabolic equivalent of task (MetS) per week, while the health belief model construct is measured using the adaptation instrument from the COVID-19 snapshoot and monitoring (COSMO-WHO). The pattern of physical activity is seen by the level of physical activity in three domains (work, transport and leisure or recreation). The difference in the level of total physical activity in the construct of health belief model uses kruskall-wallis, while the relationship between physical activity status and constructs in health belief is tested by using chi square with a confidence level of 5%. The results of this study indicate that the physical activity pattern of the DIY community is dominated by recreational activities, with an average of 868.37 Mets / week, followed by the work domain with an average of 521.28 Mets / week and the transport domain with an average of 233.54 Mets / week. People who fall into the category of moderate physical activity status are 71%. DIY people who have a high level of HBM status tend to have sufficient physical activity status with a sig value of 0,000 in all constructs. It can be concluded that there is a relationship between the HBM construct and the physical activity status in the new normal era in the DIY community with high HBM status, so they will have a better level of physical activity status than those who have low HBM status, with a correlation value of 0.89 which meaning very strong.

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15

Li, Lianwei, Yangfeng Xu, Cunjin Xue, Yuxuan Fu, and Yuanyu Zhang. "A Process-Oriented Approach to Identify Evolutions of Sea Surface Temperature Anomalies with a Time-Series of a Raster Dataset." ISPRS International Journal of Geo-Information 10, no. 8 (July 23, 2021): 500. http://dx.doi.org/10.3390/ijgi10080500.

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It is important to consider where, when, and how the evolution of sea surface temperature anomalies (SSTA) plays significant roles in regional or global climate changes. In the comparison of where and when, there is a great challenge in clearly describing how SSTA evolves in space and time. In light of the evolution from generation, through development, and to the dissipation of SSTA, this paper proposes a novel approach to identifying an evolution of SSTA in space and time from a time-series of a raster dataset. This method, called PoAIES, includes three key steps. Firstly, a cluster-based method is enhanced to explore spatiotemporal clusters of SSTA, and each cluster of SSTA at a time snapshot is taken as a snapshot object of SSTA. Secondly, the spatiotemporal topologies of snapshot objects of SSTA at successive time snapshots are used to link snapshot objects of SSTA into an evolution object of SSTA, which is called a process object. Here, a linking threshold is automatically determined according to the overlapped areas of the snapshot objects, and only those snapshot objects that meet the specified linking threshold are linked together into a process object. Thirdly, we use a graph-based model to represent a process object of SSTA. A node represents a snapshot object of SSTA, and an edge represents an evolution between two snapshot objects. Using a number of child nodes from an edge’s parent node and a number of parent nodes from the edge’s child node, a type of edge (an evolution relationship) is identified, which shows its development, splitting, merging, or splitting/merging. Finally, an experiment on a simulated dataset is used to demonstrate the effectiveness and the advantages of PoAIES, and a real dataset of satellite-SSTA is used to verify the rationality of PoAIES with the help of ENSO’s relevant knowledge, which may provide new references for global change research.

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Hu, Wei Wei, Chang Ming Wang, and Ai Jun Zhang. "Application of Weighted Projection PM Algorithm in Estimation of DOA." Applied Mechanics and Materials 300-301 (February 2013): 746–49. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.746.

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In order to improve the decreasing resolution ability of Propagator Method (PM) algorithm under the environments like low signal noise ratio and small number of snapshots, a new weighted projection PM algorithm is proposed in this paper. This algorithm orthogonalizes noise subspace to get a new one, gains the signal subspace with the relationship between it and noise subspace, and weights the signal subspace and noise subspace with values gained by projecting integral value of steering vector in the field around the signals to each element of subspace. Simulation results show that the proposed method can keep computation simple, and also can decrease signal noise ratio threshold and snapshots threshold, so it has the better resolution ability and higher precision in snapshot deficient and low signal noise ratio scenario.

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17

Becker, Stephanie. "The Snapshots of A. Thomas Nelson: A Case Study in the Preservation of Early 20th-century Vernacular Albums." Collections: A Journal for Museum and Archives Professionals 14, no. 2 (June 2018): 171–93. http://dx.doi.org/10.1177/155019061801400205.

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Throughout the early 20th century, A. Thomas Nelson took snapshots while traveling the United States and Canada. His wife, Catherine Nelson, made a selection of these and placed them within eight photographic albums, later acquired by the George Eastman Museum in Rochester, New York. Using one of these, “Snapshots from Travels in the United States and Canada (1904–1940),” as a case study, this article explores preservation practices for early 20th-century vernacular albums. While such albums are a valuable part of any collection, they present many complex preservation challenges due to the variety of materials contained within a single object. Critical questions about cataloging, digitizing, and rehousing methods guide decisions on how to stabilize the album's fragile condition and allow for access. This case study offers insight for collection managers and archivists who find themselves caring for similar snapshot albums.

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18

Xiaoguang, Ren, and Xu Xinhai. "AP-IO: Asynchronous Pipeline I/O for Hiding Periodic Output Cost in CFD Simulation." Scientific World Journal 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/273807.

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Computational fluid dynamics (CFD) simulation often needs to periodically output intermediate results to files in the form of snapshots for visualization or restart, which seriously impacts the performance. In this paper, we present asynchronous pipeline I/O (AP-IO) optimization scheme for the periodically snapshot output on the basis of asynchronous I/O and CFD application characteristics. InAP-IO, dedicated background I/O processes or threads are in charge of handling the file write in pipeline mode, therefore the write overhead can be hidden with more calculation than classic asynchronous I/O. We design the framework ofAP-IOand implement it in OpenFOAM, providing CFD users with a user-friendly interface. Experimental results on theTianhe-2supercomputer demonstrate thatAP-IOcan achieve a good optimization effect for the periodical snapshot output in CFD application, and the effect is especially better for massively parallel CFD simulations, which can reduce the total execution time up to about 40%.

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Mukherjee, Sayak, David Stewart, William Stewart, Lewis L. Lanier, and Jayajit Das. "Connecting the dots across time: reconstruction of single-cell signalling trajectories using time-stamped data." Royal Society Open Science 4, no. 8 (August 2017): 170811. http://dx.doi.org/10.1098/rsos.170811.

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Single-cell responses are shaped by the geometry of signalling kinetic trajectories carved in a multidimensional space spanned by signalling protein abundances. It is, however, challenging to assay a large number (more than 3) of signalling species in live-cell imaging, which makes it difficult to probe single-cell signalling kinetic trajectories in large dimensions. Flow and mass cytometry techniques can measure a large number (4 to more than 40) of signalling species but are unable to track single cells. Thus, cytometry experiments provide detailed time-stamped snapshots of single-cell signalling kinetics. Is it possible to use the time-stamped cytometry data to reconstruct single-cell signalling trajectories? Borrowing concepts of conserved and slow variables from non-equilibrium statistical physics we develop an approach to reconstruct signalling trajectories using snapshot data by creating new variables that remain invariant or vary slowly during the signalling kinetics. We apply this approach to reconstruct trajectories using snapshot data obtained from in silico simulations, live-cell imaging measurements, and, synthetic flow cytometry datasets. The application of invariants and slow variables to reconstruct trajectories provides a radically different way to track objects using snapshot data. The approach is likely to have implications for solving matching problems in a wide range of disciplines.

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20

Hosseinizadeh, A., P. Schwander, A. Dashti, R. Fung, R. M. D'Souza, and A. Ourmazd. "High-resolution structure of viruses from random diffraction snapshots." Philosophical Transactions of the Royal Society B: Biological Sciences 369, no. 1647 (July 17, 2014): 20130326. http://dx.doi.org/10.1098/rstb.2013.0326.

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The advent of the X-ray free-electron laser (XFEL) has made it possible to record diffraction snapshots of biological entities injected into the X-ray beam before the onset of radiation damage. Algorithmic means must then be used to determine the snapshot orientations and thence the three-dimensional structure of the object. Existing Bayesian approaches are limited in reconstruction resolution typically to 1/10 of the object diameter, with the computational expense increasing as the eighth power of the ratio of diameter to resolution. We present an approach capable of exploiting object symmetries to recover three-dimensional structure to high resolution, and thus reconstruct the structure of the satellite tobacco necrosis virus to atomic level. Our approach offers the highest reconstruction resolution for XFEL snapshots to date and provides a potentially powerful alternative route for analysis of data from crystalline and nano-crystalline objects.

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Chen, Chen, Anrin Chakraborti, and Radu Sion. "PD-DM: An efficient locality-preserving block device mapper with plausible deniability." Proceedings on Privacy Enhancing Technologies 2019, no. 1 (January 1, 2019): 153–71. http://dx.doi.org/10.2478/popets-2019-0009.

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Abstract Encryption protects sensitive data from unauthorized access, yet is not sufficient when users are forced to surrender keys under duress. In contrast, plausible deniability enables users to not only encrypt data but also deny its existence when challenged. Most existing plausible deniability work (e.g. the successful and unfortunately now-defunct TrueCrypt) tackles “single snapshot” adversaries, and cannot handle the more realistic scenario of adversaries gaining access to a device at multiple time points. Such “multi-snapshot” adversaries can simply observe modifications between snapshots and detect the existence of hidden data. Existing ideas handling “multi-snapshot” scenarios feature prohibitive overheads when deployed on practically-sized disks. This is mostly due to a lack of data locality inherent in certain standard access-randomization mechanisms, one of the building blocks used to ensure plausible deniability. In this work, we show that such randomization is not necessary for strong plausible deniability. Instead, it can be replaced by a canonical form that permits most of writes to be done sequentially. This has two key advantages: 1) it reduces the impact of seek due to random accesses; 2) it reduces the overall number of physical blocks that need to be written for each logical write. As a result, PD-DM increases I/O throughput by orders of magnitude (10–100× in typical setups) over existing work while maintaining strong plausible deniability against multi-snapshot adversaries. Notably, PD-DM is the first plausible-deniable system getting within reach of the performance of standard encrypted volumes (dm-crypt) for random I/O.

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Paik, Ji Woong, Joon-Ho Lee, and Wooyoung Hong. "An Enhanced Smoothed L0-Norm Direction of Arrival Estimation Method Using Covariance Matrix." Sensors 21, no. 13 (June 27, 2021): 4403. http://dx.doi.org/10.3390/s21134403.

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An enhanced smoothed l0-norm algorithm for the passive phased array system, which uses the covariance matrix of the received signal, is proposed in this paper. The SL0 (smoothed l0-norm) algorithm is a fast compressive-sensing-based DOA (direction-of-arrival) estimation algorithm that uses a single snapshot from the received signal. In the conventional SL0 algorithm, there are limitations in the resolution and the DOA estimation performance, since a single sample is used. If multiple snapshots are used, the conventional SL0 algorithm can improve performance in terms of the DOA estimation. In this paper, a covariance-fitting-based SL0 algorithm is proposed to further reduce the number of optimization variables when using multiple snapshots of the received signal. A cost function and a new null-space projection term of the sparse recovery for the proposed scheme are presented. In order to verify the performance of the proposed algorithm, we present the simulation results and the experimental results based on the measured data.

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23

Gerstoft, Peter, Christoph Mecklenbrauker, Santosh Nannuru, and Geert Leus. "DOA Estimation in Heteroscedastic Noise with sparse Bayesian Learning." Applied Computational Electromagnetics Society 35, no. 11 (February 5, 2021): 1439–40. http://dx.doi.org/10.47037/2020.aces.j.351188.

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We consider direction of arrival (DOA) estimation from long-term observations in a noisy environment. In such an environment the noise source might evolve, causing the stationary models to fail. Therefore a heteroscedastic Gaussian noise model is introduced where the variance can vary across observations and sensors. The source amplitudes are assumed independent zero-mean complex Gaussian distributed with unknown variances (i.e., source powers), leading to stochastic maximum likelihood (ML) DOA estimation. The DOAs are estimated from multi-snapshot array data using sparse Bayesian learning (SBL) where the noise is estimated across both sensors and snapshots.

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Wang, Sheng, Monica Garcia, Andreas Ibrom, and Peter Bauer-Gottwein. "Temporal interpolation of land surface fluxes derived from remote sensing – results with an unmanned aerial system." Hydrology and Earth System Sciences 24, no. 7 (July 22, 2020): 3643–61. http://dx.doi.org/10.5194/hess-24-3643-2020.

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Abstract. Remote sensing imagery can provide snapshots of rapidly changing land surface variables, e.g. evapotranspiration (ET), land surface temperature (Ts), net radiation (Rn), soil moisture (θ), and gross primary productivity (GPP), for the time of sensor overpass. However, discontinuous data acquisitions limit the applicability of remote sensing for water resources and ecosystem management. Methods to interpolate between remote sensing snapshot data and to upscale them from an instantaneous to a daily timescale are needed. We developed a dynamic soil–vegetation–atmosphere transfer model to interpolate land surface state variables that change rapidly between remote sensing observations. The “Soil–Vegetation, Energy, water, and CO2 traNsfer” (SVEN) model, which combines the snapshot version of the remote sensing Priestley–Taylor Jet Propulsion Laboratory ET model and light use efficiency GPP models, now incorporates a dynamic component for the ground heat flux based on the “force-restore” method and a water balance “bucket” model to estimate θ and canopy wetness at a half-hourly time step. A case study was conducted to demonstrate the method using optical and thermal data from an unmanned aerial system at a willow plantation flux site (Risoe, Denmark). Based on model parameter calibration with the snapshots of land surface variables at the time of flight, SVEN interpolated UAS-based snapshots to continuous records of Ts, Rn, θ, ET, and GPP for the 2016 growing season with forcing from continuous climatic data and the normalized difference vegetation index (NDVI). Validation with eddy covariance and other in situ observations indicates that SVEN can estimate daily land surface fluxes between remote sensing acquisitions with normalized root mean square deviations of the simulated daily Ts, Rn, θ, LE, and GPP of 11.77 %, 6.65 %, 19.53 %, 14.77 %, and 12.97 % respectively. In this deciduous tree plantation, this study demonstrates that temporally sparse optical and thermal remote sensing observations can be used to calibrate soil and vegetation parameters of a simple land surface modelling scheme to estimate “low-persistence” or rapidly changing land surface variables with the use of few forcing variables. This approach can also be applied with remotely-sensed data from other platforms to fill temporal gaps, e.g. cloud-induced data gaps in satellite observations.

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Spaniolas, Stelios, Christos Bazakos, Gregory A. Tucker, and Malcolm J. Bennett. "Comparison of SNP-Based Detection Assays for Food Analysis: Coffee Authentication." Journal of AOAC INTERNATIONAL 97, no. 4 (July 1, 2014): 1114–20. http://dx.doi.org/10.5740/jaoacint.13-237.

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Abstract Recently, DNA-based authentication methods were developed to serve as complementary approaches to analytical chemistry techniques. The single nucleotide polymorphism (SNP)-based reaction chemistries, when combined with the existing detection methods, could result in numerous analytical approaches, all with particular advantages and disadvantages. The dual aim of this study was (a) to develop SNP-based analytical assays such as the single-base primer extension (SNaPShotTM) and pyrosequencing in order to differentiate Arabica and Robusta varieties for the authentication of coffee beans and (b) to compare the performances of SNaPshot, pyrosequencing and the previously developed polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using an Agilent 2100 Bioanalyzer on the basis of linearity (R2) and LOD, expressed as percentage of the adulterant species, using green coffee beans (Arabica and Robusta) as a food model. The results showed that SNaPshot analysis exhibited the best LOD, whereas pyrosequencing revealed the best linearity (R2 = 0.997). The PCR-RFLP assay using the Agilent 2100 Bioanalyzer could prove to be a very useful method for a laboratory that lacks sequencing facilities but it can be used only if a SNP creates/deletes a restriction site.

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Thomas, Philipp. "Making sense of snapshot data: ergodic principle for clonal cell populations." Journal of The Royal Society Interface 14, no. 136 (November 2017): 20170467. http://dx.doi.org/10.1098/rsif.2017.0467.

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Population growth is often ignored when quantifying gene expression levels across clonal cell populations. We develop a framework for obtaining the molecule number distributions in an exponentially growing cell population taking into account its age structure. In the presence of generation time variability, the average acquired across a population snapshot does not obey the average of a dividing cell over time, apparently contradicting ergodicity between single cells and the population. Instead, we show that the variation observed across snapshots with known cell age is captured by cell histories, a single-cell measure obtained from tracking an arbitrary cell of the population back to the ancestor from which it originated. The correspondence between cells of known age in a population with their histories represents an ergodic principle that provides a new interpretation of population snapshot data. We illustrate the principle using analytical solutions of stochastic gene expression models in cell populations with arbitrary generation time distributions. We further elucidate that the principle breaks down for biochemical reactions that are under selection, such as the expression of genes conveying antibiotic resistance, which gives rise to an experimental criterion with which to probe selection on gene expression fluctuations.

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Simarro, Gonzalo, Daniel Calvete, Paola Souto, and Jorge Guillén. "Camera Calibration for Coastal Monitoring Using Available Snapshot Images." Remote Sensing 12, no. 11 (June 6, 2020): 1840. http://dx.doi.org/10.3390/rs12111840.

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Joint intrinsic and extrinsic calibration from a single snapshot is a common requirement in coastal monitoring practice. This work analyzes the influence of different aspects, such as the distribution of Ground Control Points (GCPs) or the image obliquity, on the quality of the calibration for two different mathematical models (one being a simplification of the other). The performance of the two models is assessed using extensive laboratory data (i.e., snapshots of a grid). While both models are able to properly adjust the GCPs, the simpler model gives a better overall performance when the GCPs are not well distributed over the image. Furthermore, the simpler model allows for better recovery of the camera position and orientation.

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Hou, Tianfeng, Staf Roels, and Hans Janssen. "The use of proper orthogonal decomposition for the simulation of highly nonlinear hygrothermal performance." MATEC Web of Conferences 282 (2019): 02018. http://dx.doi.org/10.1051/matecconf/201928202018.

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In this paper, the use of proper orthogonal decomposition for simulating nonlinear heat, air and moisture transfer is investigated via two applications: HAMSTAD benchmarks 2 and 3. Moreover, the potential of the reduced models constructed by proper orthogonal decomposition for simulating new problems with longer simulation periods is assessed. To illustrate the feasibilities of proper orthogonal decomposition method in the field of building physics, the accuracies of the reduced models are compared with the standard finite element method. The outcomes show that with a sufficient number of construction modes and a relatively large amount of snapshots, proper orthogonal decomposition method can deliver accurate results. In addition, guidelines on selecting an appropriate amount of simulation snapshot and construction modes are provided.

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Kollmann, Stephan A., Martin Kleppmann, and Alastair R. Beresford. "Snapdoc: Authenticated snapshots with history privacy in peer-to-peer collaborative editing." Proceedings on Privacy Enhancing Technologies 2019, no. 3 (July 1, 2019): 210–32. http://dx.doi.org/10.2478/popets-2019-0044.

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Abstract Document collaboration applications, such as Google Docs or Microsoft Office Online, need to ensure that all collaborators have a consistent view of the shared document, and usually achieve this by relying on a trusted server. Other existing approaches that do not rely on a trusted third party assume that all collaborating devices are trusted. In particular, when inviting a new collaborator to a group, one needs to choose between a) keeping past edits private and sending only the latest state (a snapshot) of the document; or b) allowing the new collaborator to verify her view of the document is consistent with other honest devices by sending the full history of (signed) edits. We present a new protocol which allows an authenticated snapshot to be sent to new collaborators while both hiding the past editing history, and allowing them to verify consistency. We evaluate the costs of the protocol by emulating the editing history of 270 Wikipedia pages; 99% of insert operations were processed within 11.0 ms; 64.9 ms for delete operations. An additional benefit of authenticated snapshots is a median 84% reduction in the amount of data sent to a new collaborator compared to a basic protocol that transfers a full edit history.

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Wang, Wei, Lin Zou, and Xuegang Wang. "A Novel Two-Level Nested STAP Strategy for Clutter Suppression in Airborne Radar." Mathematical Problems in Engineering 2019 (June 4, 2019): 1–16. http://dx.doi.org/10.1155/2019/2540858.

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Nested arrays have been studied recently in array signal processing field because of their closed-form expressions for the sensor locations and achievable degrees of freedom (DOFs). In this paper, the concept of nesting is further extended to space-time adaptive processing (STAP). Different from the traditional uniform-STAP method that calculates the clutter plus noise covariance matrix (CNCM) and performs the STAP filter direct using the data snapshots collected from the uniform linear array (ULA) and the transmitting pulses with uniform pulse repetition interval (PRI), we present a new optimum two-level nested STAP (O2LN-STAP) strategy which employs an optimum two-level nested array (O2LNA) and an optimum two-level nested PRI (O2LN-PRI) to exploit the enhanced DOFs embedded in the space-time O2LN structure. Similar to the difference coarray perspective, we first construct a virtual space-time snapshot from the direct covariance matrix of the received signals. Then, a new CNCM estimation corresponding to the virtual space-time snapshot can be computed by the spatial-temporal smoothing technique for STAP filter. Furthermore, the comparative simulations and analyses with the traditional uniform-STAP and the recently reported coprime-STAP are carried out to verify the effectiveness of the O2LN-STAP approach.

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Liu, Xiao, Miguel Ángel Ribot, Adrià Gusi-Amigó, Adria Rovira-Garcia, Jaume Sanz Subirana, and Pau Closas. "Cloud-Based Single-Frequency Snapshot RTK Positioning." Sensors 21, no. 11 (May 26, 2021): 3688. http://dx.doi.org/10.3390/s21113688.

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With great potential for being applied to Internet of Things (IoT) applications, the concept of cloud-based Snapshot Real Time Kinematics (SRTK) was proposed and its feasibility under zero-baseline configuration was confirmed recently by the authors. This article first introduces the general workflow of the SRTK engine, as well as a discussion on the challenges of achieving an SRTK fix using actual snapshot data. This work also describes a novel solution to ensure a nanosecond level absolute timing accuracy in order to compute highly precise satellite coordinates, which is required for SRTK. Parameters such as signal bandwidth, integration time and baseline distances have an impact on the SRTK performance. To characterize this impact, different combinations of these settings are analyzed through experimental tests. The results show that the use of higher signal bandwidths and longer integration times result in higher SRTK fix rates, while the more significant impact on the performance comes from the baseline distance. The results also show that the SRTK fix rate can reach more than 93% by using snapshots with a data size as small as 255 kB. The positioning accuracy is at centimeter level when phase ambiguities are resolved at a baseline distance less or equal to 15 km.

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Qinghua Yang, Qinghua Yang. "Compact static infrared broadband snapshot imaging spectrometer." Chinese Optics Letters 12, no. 3 (2014): 031201–31205. http://dx.doi.org/10.3788/col201412.031201.

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Rosenberg, Jessica. "Snapshot." Feminist Studies 26, no. 2 (2000): 377. http://dx.doi.org/10.2307/3178539.

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Harvey, Lawrence. "Snapshot." Philosophers' Magazine, no. 52 (2011): 99–101. http://dx.doi.org/10.5840/tpm20115220.

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Richter, Duncan J. "Snapshot." Philosophers' Magazine, no. 78 (2017): 65–67. http://dx.doi.org/10.5840/tpm20177879.

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Fowler, Bret. "Snapshot." English Journal 77, no. 7 (November 1988): 99. http://dx.doi.org/10.2307/818956.

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Kolatkar, Arun, and Vinay Dharwadker. "Snapshot." Chicago Review 38, no. 1/2 (1992): 44. http://dx.doi.org/10.2307/25305546.

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Doppelt, Suzanne. "Snapshot." Vacarme 6, no. 1 (1998): 77. http://dx.doi.org/10.3917/vaca.006.0077.

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McIntyre, P. "Snapshot." Canadian Medical Association Journal 178, no. 12 (June 3, 2008): 1582. http://dx.doi.org/10.1503/cmaj.080098.

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Katsiaficas, George. "Snapshot." New Political Science 22, no. 3 (September 2000): 317–18. http://dx.doi.org/10.1080/713687955.

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Naas, Michael. "Snapshot." Oxford Literary Review 32, no. 2 (December 2010): v—vii. http://dx.doi.org/10.3366/olr.2010.0101.

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Katsiaficas, George. "Snapshot." New Political Science 25, no. 1 (March 2003): 3. http://dx.doi.org/10.1080/0739314032000071190.

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Katsiaficas, George. "Snapshot." New Political Science 20, no. 1 (March 1998): 5. http://dx.doi.org/10.1080/07393149808429809.

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Katsiaficas, George. "Snapshot." New Political Science 20, no. 3 (September 1998): 261. http://dx.doi.org/10.1080/07393149808429828.

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Torres, Rodolfo D., and George Katsiaficas. "Snapshot." New Political Science 20, no. 4 (December 1998): 373–78. http://dx.doi.org/10.1080/07393149808429836.

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Katsiaficas, George. "Snapshot." New Political Science 21, no. 3 (September 1999): 301. http://dx.doi.org/10.1080/07393149908429873.

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Marris, Emma. "Snapshot." Nature 450, no. 7173 (December 2007): 1136. http://dx.doi.org/10.1038/4501136c.

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48

Kouwenhoven, Bill. "Snapshot." Afterimage 35, no. 6 (May 1, 2008): 2–3. http://dx.doi.org/10.1525/aft.2008.35.6.2.

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Law, Rebecca. "Snapshot." Spiritus: A Journal of Christian Spirituality 19, no. 2 (2019): 355. http://dx.doi.org/10.1353/scs.2019.0046.

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Ishar, Rishabh, Eurika Kaiser, Marek Morzyński, Daniel Fernex, Richard Semaan, Marian Albers, Pascal S. Meysonnat, Wolfgang Schröder, and Bernd R. Noack. "Metric for attractor overlap." Journal of Fluid Mechanics 874 (July 12, 2019): 720–55. http://dx.doi.org/10.1017/jfm.2019.447.

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We present the first general metric for attractor overlap (MAO) facilitating an unsupervised comparison of flow data sets. The starting point is two or more attractors, i.e. ensembles of states representing different operating conditions. The proposed metric generalizes the standard Hilbert-space distance between two snapshot-to-snapshot ensembles of two attractors. A reduced-order analysis for big data and many attractors is enabled by coarse graining the snapshots into representative clusters with corresponding centroids and population probabilities. For a large number of attractors, MAO is augmented by proximity maps for the snapshots, the centroids and the attractors, giving scientifically interpretable visual access to the closeness of the states. The coherent structures belonging to the overlap and disjoint states between these attractors are distilled by a few representative centroids. We employ MAO for two quite different actuated flow configurations: a two-dimensional wake with vortices in a narrow frequency range and three-dimensional wall turbulence with a broadband spectrum. In the first application, seven control laws are applied to the fluidic pinball, i.e. the two-dimensional flow around three circular cylinders whose centres form an equilateral triangle pointing in the upstream direction. These seven operating conditions comprise unforced shedding, boat tailing, base bleed, high- and low-frequency forcing as well as two opposing Magnus effects. In the second example, MAO is applied to three-dimensional simulation data from an open-loop drag reduction study of a turbulent boundary layer. The actuation mechanisms of 38 spanwise travelling transversal surface waves are investigated. MAO compares and classifies these actuated flows in agreement with physical intuition. For instance, the first feature coordinate of the attractor proximity map correlates with drag for the fluidic pinball and for the turbulent boundary layer. MAO has a large spectrum of potential applications ranging from a quantitative comparison between numerical simulations and experimental particle-image velocimetry data to the analysis of simulations representing a myriad of different operating conditions.

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