Time/Space Aware Event Correlation

2010 ◽  
pp. 43-74
Author(s):  
Eiko Yoneki
Keyword(s):  
Ubiquitous Computing ◽  
Event Semantics ◽  
Wireless Devices ◽  
Event Correlation ◽  
Event Monitoring ◽  
Time Space ◽  
Event Model ◽  
High Scalability ◽  
Spatio Temporal ◽  
New Vision

Ubiquitous computing, with a dramatic increase in the event monitoring capabilities of wireless devices and sensors, requires more complex temporal and spatial resolution in event correlation. In this chapter, we describe two aspects of event correlation to support such environments: event modelling including spatio-temporal information, and composite event semantics with interval-based semantics for efficient indexing, filtering, and matching. It includes a comparative study of existing event correlation work. The described durative event model, combined with interval-semantics, provides a new vision for data processing in ubiquitous computing. This makes it possible to extend the functionality of simple publish/subscribe filters to stateful subscriptions, parametrisation, and computation of aggregates, while maintaining high scalability.

scholarly journals New methods for retrieval of chlorophyll red fluorescence from hyper-spectral satellite instruments: simulations and application to GOME-2 and SCIAMACHY

2016 ◽  
Author(s):  
J. Joiner ◽  
Y. Yoshida ◽  
L. Guanter ◽  
E. M. Middleton
Keyword(s):  
Spatial Scales ◽  
Temporal Structure ◽  
Emission Feature ◽  
Ozone Monitoring Instrument ◽  
Additional Information ◽  
Time Space ◽  
Hyper Spectral ◽  
Spatio Temporal ◽  
Gas Measurements ◽  
Satellite Instruments

Abstract. Global satellite measurements of solar-induced fluorescence (SIF) from chlorophyll over land and ocean have proven useful for a number of different applications related to physiology, phenology, and productivity of plants and phytoplankton. Terrestrial chlorophyll fluorescence is emitted throughout the red and far-red spectrum, producing two broad peaks near 683 and 736 nm. From ocean surfaces, phytoplankton fluorescence emissions are entirely from the red region. Studies using satellite-derived SIF over land have focused almost exclusively on measurements in the far- red, since those are the most easily obtained with existing instrumentation. Here, we examine new ways to use existing hyper-spectral satellite data sets to retrieve red SIF over both land and ocean. Our approach offers noise reductions as compared with previously published solar line filling retrievals by making use of the oxygen (O2) γ-band that is not affected by SIF. The O2 γ-band in conjunction with solar Fraunhofer lines help to anchor the O2 B-band that provides additional information on red SIF. Biases due to instrumental artifacts that vary in time, space, and with instrument, must be addressed in order to obtain reasonable results. The satellite instruments that we use were designed to make atmospheric trace- gas measurements and are therefore not optimal for observing SIF; they have coarse spatial resolution and only moderate spectral resolution (∼0.5 nm). Nevertheless, these instruments offer a unique opportunity to compare red and far-red terrestrial SIF at regional spatial scales. Our eight year record of red SIF observations over land with the Global Ozone Monitoring Instrument 2 (GOME-2) allows for the first time reliable global mapping of monthly anomalies. These anomalies are shown to have similar spatio-temporal structure as those in the far-red, particularly for drought-prone regions. There is a somewhat larger percentage response in the red as compared with the far-red for these areas that are sensitive to soil moisture, although the differences are within the specified uncertainties that are dominated by systematic errors. We also demonstrate that high quality ocean fluorescence line height retrievals can be achieved with GOME-2 and similar instruments by utilizing the full complement of radiance measurements that span the red SIF emission feature.

scholarly journals RESEARCH ON CONSTRUCTION METHOD OF SPATIO-TEMPORAL DATA MODEL BASED ON BEHAVIOR-EVENT

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 591-594
Author(s):  
J. W. Li ◽  
Y. Ma ◽  
J. W. Jiang ◽  
W. D. Chen ◽  
N. Yu ◽  
...  
Keyword(s):  
Data Model ◽  
Logical Structure ◽  
Physical Structure ◽  
Temporal Data ◽  
Model Based ◽  
Time Space ◽  
Before And After ◽  
Spatio Temporal ◽  
Temporal Objects ◽  
Organic Combination

Abstract. Starting from the object-oriented idea, this paper analyses the existing event-based models and the logical relationship between behavioral cognition and events, and discusses the continuity of behavioral cognition on the time axis from the perspective of temporal and spatial cognition. A geospatial data model based on behavioral-event is proposed. The physical structure and logical structure of the model are mainly designed, and the four-dimensional model of “time, space, attribute and event” is constructed on the axis. The organic combination of the four models can well describe the internal mechanism and rules of geographical objects. The expression of data model based on behavior-event not only elaborates the basic information of geospatial objects, but also records the changes of related events caused by the changes of geographic Entities' behavior, and expresses the relationship between spatial and temporal objects before and after the changes of behavior cognition. This paper also designs an effective method to organize spatio-temporal data, so as to realize the effective management and analysis of spatio-temporal data and meet the requirements of storage, processing and mining of large spatio-temporal data.

scholarly journals Análise da Variação Espaço-Temporal das Áreas Verdes e da Qualidade Ambiental em Áreas Urbanas, Recife-PE (Analysis of the Time-Space Variation of Green Areas and the Environmental Quality in Urban Areas, Recife-PE)

2015 ◽  
Vol 7 (6) ◽  
pp. 1196
Author(s):  
Tiago Henrique de Oliveira ◽  
José Gleidson Dantas ◽  
Josiclêda Domiciano Galvíncio ◽  
Rejane Magalhães de Mendonça Pimentel ◽  
Milton Botler
Keyword(s):  
Land Use ◽  
Environmental Quality ◽  
Urban Areas ◽  
Rapid Change ◽  
Large Temperature ◽  
Natural Soil ◽  
Area Index ◽  
Time Space ◽  
Green Areas ◽  
Spatio Temporal

As rápidas mudanças do uso e cobertura do solo em ambiente urbano apresentam grande impacto nas relações entre os ciclos energéticos e hidrológicos sobre a superfície. O município do Recife, através da Lei de Uso e Ocupação do Solo de 1996 (Lei nº 16.176/96) define área verde como “toda área de domínio público ou privado, em solo natural,onde predomina qualquer forma de vegetação, distribuída em seus diferentes estratos: Arbóreo, Arbustivo e Herbáceo /Forrageira, nativa ou exótica”. O objetivo deste artigo é analisar a variação espacial das áreas verdes disponíveis no município do Recife e a evolução espaço-temporal da qualidade ambiental na RPA 4 através do computo do Índice de umidade (NDWI), Índice de Área Foliar (IAF) e Temperatura da superfície em imagens TM Landsat. Foi realizada uma classificação supervisionada na ortofotocarta Recife onde as áreas verdes foram exportadas para polígonos, permitindo a sua quantificação. Para as imagens TM foi aplicada parte da metodologia SEBAL. As áreas verdes ocupam 45,58% do Recife. Os transectos lineares e perfis permitiram visualizar mais facilmente as mudanças espaço-temporais ocorridos na RPA-4. Foi visualizada grande diferença de temperatura entre as áreas vegetadas e as áreas mais urbanizadas. Palavras-chave: Uso e ocupação do solo; área urbana, áreas vegetadas, sensoriamento remoto; MAXVER. A B S T R A C T The rapid change of use and land cover in urban environment poses great impact on relations between energy and hydrological cycles on the surface. The municipality of Recife, through the Land Use Legislation from 1996 (Law No. 16.176/96) defines green area as ";;;;;;any public or private domain area, in natural soil, where overcrows any form of vegetation, distributed in its different layers: Arboreal, shrubby and Herbaceous Forage, native or exotic";;;;;;. The goal of this paper is to analyze the spatial variation of available green areas in the city of Recife and the spatio-temporal evolution of environmental quality in the Political Administrative Region 4, known as RPA-4, through the calculation of moisture content (NDWI), leaf area index (LAI) and the surface temperature from Landsat TM images. Supervised classification was performed on orthophoto Reef where the green areas were exported to polygons, allowing its quantification. For the TM images, it has been applied the methodology SEBAL. The green areas occupy 45.58% of Recife. The linear transects and profiles allowed to show more easily space-time changes occurring in the RPA-4. Large temperature differences have been displayed between the most vegetated areas and more urbanized areas. Key-words: Land use; urban areas; vegetated area, remote sensing; MAXVER.

Plague Time: Space, Fear, and Emergency Statecraft in Early Modern Italy

2021 ◽  
Vol 44 (2) ◽  
pp. 87-111
Author(s):  
Nicholas A. Eckstein
Keyword(s):  
Eighteenth Century ◽  
Seventeenth Century ◽  
Early Modern ◽  
Analytical Framework ◽  
Temporal Dimension ◽  
Early Modern Italy ◽  
Time Space ◽  
Contingent Response ◽  
Spatio Temporal ◽  
Historical Examination

Michel Foucault argued famously that early modern European governors responded to plague by quarantining entire urban populations and placing citizens under minute surveillance. For Foucault, such sixteenth- and seventeenth-century policies were the first steps towards an authoritarian paradigm that would only emerge in full in the eighteenth century. The present article argues that Foucault’s model is too abstracted to function as a tool for the historical examination of specific emergencies, and it proposes an alternative analytical framework. Addressing itself to actual events in early modern Italy, the article reveals that when plague threatened, Florentine and Bolognese health officials projected themselves into a spatio-temporal dimension in which official actions and perceptions were determined solely by the spread of contagion. This dimension, “plague time,” was not a stage on the irresistible journey towards Foucault’s “utopia of the perfectly governed city.” A contingent response to a recurrent existential menace, plague time rose and fell in response to events, and may be understood as a season.

A Lightweight Authentication and Encryption Protocol for Secure Communications Between Resource-Limited Devices Without Hardware Modification

2018 ◽  
pp. 1-46
Author(s):  
Piotr Ksiazak ◽  
William Farrelly ◽  
Kevin Curran
Keyword(s):  
Ubiquitous Computing ◽  
Secure Communications ◽  
Wireless Devices ◽  
Authentication Protocols ◽  
It Industry ◽  
Processing Power ◽  
Resource Limited ◽  
Encryption Algorithms ◽  
Lightweight Authentication ◽  
Lightweight Encryption

In this chapter, the authors examine the theoretical context for the security of wireless communication between ubiquitous computing devices and present an implementation that addresses this need. The number of resource-limited wireless devices utilized in many areas of the IT industry is growing rapidly. Some of the applications of these devices pose real security threats that can be addressed using authentication and cryptography. Many of the available authentication and encryption software solutions are predicated on the availability of ample processing power and memory. These demands cannot be met by most ubiquitous computing devices; thus, there is a need to apply lightweight cryptography primitives and lightweight authentication protocols that meet these demands in any application of security to devices with limited resources. The analysis of the lightweight solutions is divided into lightweight authentication protocols and lightweight encryption algorithms. The authors present a prototype running on the nRF9E5 microcontroller that provides necessary authentication and encryption on resource-limited devices.

The Context-Security Nexus in Ubiquitous Computing

2016 ◽  
pp. 660-679
Author(s):  
M. Fahim Ferdous Khan ◽  
Ken Sakamura
Keyword(s):  
Access Control ◽  
Ubiquitous Computing ◽  
Context Awareness ◽  
Contextual Information ◽  
Healthcare Services ◽  
Context Aware ◽  
Context Sensitive ◽  
Access Control Models ◽  
Spatio Temporal ◽  
The Right

Context-awareness is a quintessential feature of ubiquitous computing. Contextual information not only facilitates improved applications, but can also become significant security parameters – which in turn can potentially ensure service delivery not to anyone anytime anywhere, but to the right person at the right time and place. Specially, in determining access control to resources, contextual information can play an important role. Access control models, as studied in traditional computing security, however, have no notion of context-awareness; and the recent works in the nascent field of context-aware access control predominantly focus on spatio-temporal contexts, disregarding a host of other pertinent contexts. In this paper, with a view to exploring the relationship of access control and context-awareness in ubiquitous computing, the authors propose a comprehensive context-aware access control model for ubiquitous healthcare services. They explain the design, implementation and evaluation of the proposed model in detail. They chose healthcare as a representative application domain because healthcare systems pose an array of non-trivial context-sensitive access control requirements, many of which are directly or indirectly applicable to other context-aware ubiquitous computing applications.

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