Journal articles on the topic 'Geo-distributed system'
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1
Oh, Kwangsung, Nan Qin, Abhishek Chandra, and Jon Weissman. "Wiera: Policy-Driven Multi-Tiered Geo-Distributed Cloud Storage System." IEEE Transactions on Parallel and Distributed Systems 31, no. 2 (February 1, 2020): 294–305. http://dx.doi.org/10.1109/tpds.2019.2935727.
2
Hildred, Joshua, Michael Abebe, and Khuzaima Daudjee. "Caerus: Low-Latency Distributed Transactions for Geo-Replicated Systems." Proceedings of the VLDB Endowment 17, no. 3 (November 2023): 469–82. http://dx.doi.org/10.14778/3632093.3632109.
Abstract:
Distributed deterministic database systems achieve high transaction throughput for geographically replicated data. Supporting transactions with ACID guarantees requires deterministic databases to order transactions globally to dictate execution order. In a geographically distributed environment, ordering transactions globally can take multiple wide-area network (WAN) round trips of messaging, which adds significant latency to transaction response times, leading to poor user experiences. To improve the response time of transactions in deterministic databases, we propose an ordering protocol that can include a transaction in the global order in a single WAN round trip to the primary regions of the data items within the transaction's read and write set. The protocol reduces the cost of determining the global order for all transactions by leveraging deterministic merging of partial sequences of transactions per geographic region. We implement the protocol in Caerus, our geo-replicated deterministic database system that serializably commits and replicates transactions after a delay of only a single WAN round trip of messaging. Using popular workload benchmarks over geographically replicated data in Azure, we show that Caerus outperforms state-of-the-art comparison systems to deliver low-latency transaction execution.
3
Shi, Bin, Dan Zhang, Honghu Zhu, Chengcheng Zhang, Kai Gu, Hongwei Sang, Heming Han, Mengya Sun, and Jie Liu. "DFOS Applications to Geo-Engineering Monitoring." Photonic Sensors 11, no. 2 (March 17, 2021): 158–86. http://dx.doi.org/10.1007/s13320-021-0620-y.
Abstract:
AbstractOptical fiber sensing technology has developed rapidly since the 1980s with the development of the optical fiber and fiber optical communication technology. It is a new type of sensing technology that uses light as a carrier and optical fiber as a medium to sense and transmit external signals (measurands). Distributed fiber optical sensors (DFOS) can continuously measure the external physical parameters distributed along the geometric path of the optical fiber. Meanwhile, the spatial distribution and change information of the measured physical parameters over time can be obtained. This technology has unmatched advantages over traditional point-wise and electrical measurement monitoring technologies. This paper summarizes the state-of-the-art research of the application of the distributed optical fiber sensing technology in geo-engineering in the past 10 years, mainly including the advantages of DFOS, the challenges in geo-engineering monitoring, related fundamental theoretical issues, sensing performance of the optical sensing cables, distributed optical fiber monitoring system for geo-engineering, and applications of optical fiber sensing technology in geo-engineering.
4
Gou, Liang, Geng Xin Zhang, Zhi Dong Xie, Zhi Ping Xu, and Hong Wei Long. "Payload-Distributed GEO Communication Satellite System and Opportunistic Network Coding Based Cooperative Information Exchange." Applied Mechanics and Materials 519-520 (February 2014): 1005–11. http://dx.doi.org/10.4028/www.scientific.net/amm.519-520.1005.
Abstract:
Fractionated Spacecraft is a concept which transforms a traditional monolithic spacecraft into a network of elements where a free-flying payload module is supported by nearby free-flying infrastructure modules. In this paper, we propose a novel concept named as Payload-Distributed GEO Communication Satellite System (PD-GEO) which divides the traditional GEO communication satellite into several modules. Those modules can be reconfigured, added, or exchanged independently from the others, and be reused over several missions. Then, for the purpose of reliable and high-efficient data transmission in this system, an opportunistic network coding based cooperative information exchange (ONC2IE) scheme was presented. Qualitative analysis and extensive simulations demonstrate the effectiveness and efficiency of ONC2IE.
5
Wang, Changxu, Yuanzhi He, and Chengwu Qi. "Analysis of Grating Lobe Effects on GEO DSC Distributed Antennas." Applied Sciences 13, no. 19 (October 1, 2023): 10912. http://dx.doi.org/10.3390/app131910912.
Abstract:
Traditional single-antenna systems have inherent limitations in terms of antenna gain, anti-interference capability, and flexibility. To overcome these challenges, satellite-mounted distributed antenna systems disperse multiple antennas at different positions on the satellite to improve the reception quality and signal-to-noise ratio of satellite signals, enhancing the performance of the satellite communication system without additional bandwidth or transmission power. However, the dispersed locations and long distances between antennas on the satellite result in less compact spacing compared to terrestrial distributed antennas, leading to the generation of a significant number of grating lobes. The distributed satellite cluster (DSC) approach revolutionizes the traditional mode of satellite utilization, enabling close collaboration among distributed loads. In this study, we analyzed the impact of grating lobes produced by DSC distributed antennas in geostationary Earth orbit (GEO) and simulated the grating lobe patterns of two 1 m circular aperture satellite antenna arrays in GEO. The simulation results revealed that the relative position change of the satellites affected the width and number of interference fringes in a certain ground area, while change in the carrier phase led to the translation of the interference fringes. To mitigate the grating lobes, we employed a sparse array technique. The simulation results demonstrated that the sparse array effectively suppressed the grating lobes but at the expense of a decrease in the sidelobe level and beamwidth.
6
Gharbia, Salem S., Laurence Gill, Paul Johnston, and Francesco Pilla. "GEO-CWB: GIS-Based Algorithms for Parametrising the Responses of Catchment Dynamic Water Balance Regarding Climate and Land Use Changes." Hydrology 7, no. 3 (July 13, 2020): 39. http://dx.doi.org/10.3390/hydrology7030039.
Abstract:
Parametrising the spatially distributed dynamic catchment water balance is a critical factor in studying the hydrological system responses to climate and land use changes. This study presents the development of a geographic information system (GIS)-based set of algorithms (geographical spatially distributed water balance model (GEO-CWB)), which is developed from integrating physical, statistical, and machine learning models. The GEO-CWB tool has been developed to simulate and predict future spatially distributed dynamic water balance using GIS environment at the catchment scale in response to the future changes in climate variables and land use through a user-friendly interface. The tool helps in bridging the gap in quantifying the high-resolution dynamic water balance components for the large catchments by reducing the computational costs. Also, this paper presents the application and validation of GEO-CWB on the Shannon catchment in Ireland as an example of a large and complicated hydrological system. It can be concluded that climate and land use changes have significant effects on the spatial and temporal patterns of the different water balance components of the catchment.
7
Nguyen, Cuong D. T., Johann K. Miller, and Daniel J. Abadi. "Detock: High Performance Multi-region Transactions at Scale." Proceedings of the ACM on Management of Data 1, no. 2 (June 13, 2023): 1–27. http://dx.doi.org/10.1145/3589293.
Abstract:
Many globally distributed data stores need to replicate data across large geographic distances. Since synchronously replicating data across such distances is slow, those systems with high consistency requirements often geo-partition data and direct all linearizable requests to the primary region of the accessed data. This significantly improves performance for workloads where most transactions access data close to where they originate from. However, supporting serializable multi-geo-partition transactions is a challenge, and they often degrade the performance of the whole system. This becomes even more challenging when they conflict with single-partition requests, where optimistic protocols lead to high numbers of aborts, and pessimistic protocols lead to high numbers of distributed deadlocks. In this paper, we describe the design of concurrency control and deadlock resolution protocols, built within a practical, complete implementation of a geographically replicated database system called Detock, that enables processing strictly-serializable multi-region transactions with near-zero performance degradation at extremely high conflict and order of magnitude higher throughput relative to state-of-the art geo-replication approaches, while improving latency by up to a factor of 5.
8
Satuluri, Victoria, and Ratna Babu Yellamati. "Design of Middleware and Software Embedded Development Kit For Area Based Distributed Mobile Cache System." International Journal of Electrical and Electronics Research 3, no. 3 (September 30, 2015): 44–49. http://dx.doi.org/10.37391/ijeer.030301.
Abstract:
Nowadays a new area-based distributed mobile cache system and a sustainable distributed Geo-cast technology enables data caching temporarily in a designated local area using short-range communication technologies such as Bluetooth and Wi-Fi. This system doesn’t need servers and infrastructure network. To enhance the short-range communications as a time-offset communication in a physical world the caching capability is needed. Due to this advantage it is sure to adopt a new location-based communication services. The proposed work is frames a developed middleware for a widespread embedded OS and a software development kit with an open application programming interface. The proposed middleware is expected to prompt the third-party developers to produce various applications using this platform and provided with some pseudo-code. And also explained the methods for using this platform by an implemented geo-location social game.
9
Jahn, M. W., P. E. Bradley, M. Al Doori, and M. Breunig. "TOPOLOGICALLY CONSISTENT MODELS FOR EFFICIENT BIG GEO-SPATIO-TEMPORAL DATA DISTRIBUTION." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-4/W5 (October 23, 2017): 65–72. http://dx.doi.org/10.5194/isprs-annals-iv-4-w5-65-2017.
Abstract:
Geo-spatio-temporal topology models are likely to become a key concept to check the consistency of 3D (spatial space) and 4D (spatial + temporal space) models for emerging GIS applications such as subsurface reservoir modelling or the simulation of energy and water supply of mega or smart cities. Furthermore, the data management for complex models consisting of big geo-spatial data is a challenge for GIS and geo-database research. General challenges, concepts, and techniques of big geo-spatial data management are presented. In this paper we introduce a sound mathematical approach for a topologically consistent geo-spatio-temporal model based on the concept of the incidence graph. We redesign DB4GeO, our service-based geo-spatio-temporal database architecture, on the way to the parallel management of massive geo-spatial data. Approaches for a new geo-spatio-temporal and object model of DB4GeO meeting the requirements of big geo-spatial data are discussed in detail. Finally, a conclusion and outlook on our future research are given on the way to support the processing of geo-analytics and -simulations in a parallel and distributed system environment.
10
Song, Weiwei, Qiong Wu, Xiaopeng Gong, Fu Zheng, and Yidong Lou. "Corrections of BDS Code Multipath Error in Geostationary Orbit Satellite and Their Application in Precise Data Processing." Sensors 19, no. 12 (June 18, 2019): 2737. http://dx.doi.org/10.3390/s19122737.
Abstract:
Multipath error is a main error source in Global Navigation Satellite System (GNSS) data processing, which cannot be removed by a differential technique because of the strong relationship with the environment around the station. The multipath effect of the code observables is more complex than that of the carrier-phase observables, especially for BeiDou Navigation Satellite System (BDS) geostationary orbit (GEO) satellites. In this contribution, we deeply analyzed the characteristic and effect on the precise data processing of GEO satellite multipath errors based on a large number of permanent GNSS stations. A linear combination of code and carrier-phase observables was used to analyze the characteristics of repeatability for BDS GEO’s multipath. Then, a correction method was proposed to eliminate the multipath error of the GEO code observables, based on wavelet transform. The experiment data were collected at 83 globally distributed stations, from multi-GNSS experiments and national BDS augmentation systems, from days 32 to 66 in 2017. The results show that the systematic multipath variation component of the GEO code observables can be obtained with wavelet transform, which can significantly contribute to correcting the multipath error of GEO satellites. The average root mean square error (RMSE) of the multipath series is decreased by approximately 19.5%, 20.2%, and 7.5% for B1, B2, and B3, respectively. In addition, some experiments, including ionospheric delay extraction and satellite clock estimation, were conducted in simulated real-time mode in order to validate the effect of the correction methods. For the ionospheric delay estimation, the average RMSE of the slant ionospheric delay is reduced by approximately 15.5%. Moreover, the multipath correction can contribute greatly to shortening the convergence time of the satellite clock estimation of the BDS GEO satellites.
11
Czauner, Brigitta, Ferenc Molnár, Marco Masetti, Teppo Arola, and Judit Mádl-Szőnyi. "Groundwater Flow System-Based Dynamic System Approach for Geofluids and Their Resources." Water 14, no. 7 (March 23, 2022): 1015. http://dx.doi.org/10.3390/w14071015.
Abstract:
The ‘Dynamic System Approach for Geofluids and their Resources’ was developed to harmonize research and the sustainable exploration of geofluids (e.g., groundwater, geothermal and hydrothermal fluids) and the related geo-resources (groundwater, geothermal energy and hydrothermal minerals). The conception is based on the basin-scale groundwater flow systems, which behave as a geologic agent, mobilize, transport and deposit matter and heat, whilst it can be evaluated quantitatively and in a distributed manner. Evaluation of these systems combined, for instance, with numerical, stochastic and isotope methods can jointly manage all types of geofluids, the related resources and the environmental consequences of their exploration and utilization. This paper describes the fundamental concepts of the approach and displays the proposed workflow and guidelines for practical applications such as groundwater vulnerability assessment, managed aquifer recharge, geothermal energy utilization, and the evaluation of hydrothermal mineral potential.
12
Peng, Zeshun, Yanfeng Zhang, Qian Xu, Haixu Liu, Yuxiao Gao, Xiaohua Li, and Ge Yu. "NeuChain." Proceedings of the VLDB Endowment 15, no. 11 (July 2022): 2585–98. http://dx.doi.org/10.14778/3551793.3551816.
Abstract:
Blockchain serves as a replicated transactional processing system in a trustless distributed environment. Existing blockchain systems all rely on an explicit ordering step to determine the global order of transactions that are collected from multiple peers. The ordering consensus can be the bottleneck since it must be Byzantine-fault tolerant and can scarcely benefit from parallel execution. In this paper, we propose an ordering-free architecture that makes ordering implicit through deterministic execution. Based on this novel architecture, we develop a permissioned blockchain system NeuChain. A number of key optimizations such as asynchronous block generation and pipelining are leveraged for high throughput and low latency. Several security mechanisms are also designed to make our system robust to malicious attacks. Our geo-distributed experimental results show that NeuChain can achieve 47.2--64.1X throughput improvement over HyperLedger Fabric and 1.6--12.2X throughput improvement over the state-of-the-art high performance blockchains.
13
Pei, Jianing, Peilin Hong, Kaiping Xue, and Defang Li. "Efficiently Embedding Service Function Chains with Dynamic Virtual Network Function Placement in Geo-Distributed Cloud System." IEEE Transactions on Parallel and Distributed Systems 30, no. 10 (October 1, 2019): 2179–92. http://dx.doi.org/10.1109/tpds.2018.2880992.
14
Brovelli, M. A., P. Boccardo, G. Bordogna, A. Pepe, M. Crespi, M. Munafò, and F. Pirotti. "URBAN GEO BIG DATA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W14 (August 23, 2019): 23–30. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w14-23-2019.
Abstract:
<p><strong>Abstract.</strong> The paper deals with the general presentation of the Urban GEO BIG DATA, a collaborative acentric and distributed Free and Open Source (FOS) platform consisting of several components: local data nodes for data and related service Web deploy; a visualization node for data fruition; a catalog node for data discovery; a CityGML modeler; data-rich viewers based on virtual globes; an INSPIRE metadata management system enriched with quality indicators for each dataset.</p><p>Three use cases in five Italian cities (Turin, Milan, Padua, Rome, and Naples) are examined: 1) urban mobility; 2) land cover and soil consumption at different resolutions; 3) displacement time series. Besides the case studies, the architecture of the system and its components will be presented.</p>
15
Khaleel, Mustafa I. "Load Balancing and Thermal-Aware in Geo-Distributed Cloud Data Centers Based on Vlans." Science Journal of University of Zakho 6, no. 3 (September 30, 2018): 113–17. http://dx.doi.org/10.25271/sjuoz.2018.6.3.515.
Abstract:
Power consumption in datacenters has become an emerging concern for the cloud providers. This poses enormous challenges for the programmers to motivate new paradigms to enhance the efficiency of cloud resources through designing innovative energy-aware algorithms. However, balancing the weights over geographically dispersed datacenters has been shown to be essential in decreasing the temperature consumption per datacenter. In this paper, we have formulated a load balancing paradigm to exploit the idea of scheduling scientific workflows over distributed cloud resources to make system outcome more efficient. The proposed heuristic works based on three constraints. First, initiating cloud resource locality for tenants and calculating the shortest distance in order to direct module applications to the closet resources and conserving more bandwidth cost. Second, selecting the most temperature aware datacenters based on geographical climate to maintain electricity cost for the providers. Third, running multiple datacenters within the same geographical location instead of housing the entire workloads in a single datacenter. This allows providers to take a tremendous advantage of sustaining the system from degradation or even unpredictable failure which in turn will frustrate the tenants. Furthermore, applications are formulated as Directed Acyclic Graph (DAG)-structured workflow. For the underlying cloud hardware, our model groups the cloud servers to communicate as if they were in the same physical location. Additionally, both modes, on-demand and reservation, are supported in our algorithm. Finally, the simulation showed that our method was able to enhance the utilization rates about 67% compared to the baseline model.
16
Abramov, Valery, Sergey Lukyanov, Ekaterina Korinets, Vladimir Bolshakov, and Tatiana Vekshina. "Digital tools for seaports geo-information support while climate change and Covid-19 pandemic." E3S Web of Conferences 258 (2021): 02020. http://dx.doi.org/10.1051/e3sconf/202125802020.
Abstract:
In article, there are presented digital tools development results for geo-information support to seaports activity within Industry 4.0 period, when while climate change and covid-19 pandemic. In study, there are used methods of data bases constructing, web-technologies and virtual reality tools. Also, there are used Foresight technologies, theory of decision making under uncertainties and risk management. As digital tools, there is proposed to use digital online platforms, which integrate heterogeneous hardware and software resources with the use of web-technologies in distributed networks and wide application of cloud services. In study, there are used data bases and tools of geo-information digital online platform EOS, including its Land Viewer product. As study result, there is demonstrated usage of geo-information support system for Russian seaport Ust-Luga. The research results presented in this article has significant scientific novelty and can be useful for private investors, public environmental organizations of the civil sector and state environmental control bodies.
17
Cheng, Jiang, Yinghui Tang, and Miaomiao Yu. "The Discrete-Time Bulk-ServiceGeo/Geo/1Queue with Multiple Working Vacations." Journal of Applied Mathematics 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/587269.
Abstract:
This paper deals with a discrete-time bulk-serviceGeo/Geo/1queueing system with infinite buffer space and multiple working vacations. Considering an early arrival system, as soon as the server empties the system in a regular busy period, he leaves the system and takes a working vacation for a random duration at timen. The service times both in a working vacation and in a busy period and the vacation times are assumed to be geometrically distributed. By using embedded Markov chain approach and difference operator method, queue length of the whole system at random slots and the waiting time for an arriving customer are obtained. The queue length distributions of the outside observer’s observation epoch are investigated. Numerical experiment is performed to validate the analytical results.
18
Shen, Qinghua, Xiaohui Liang, Xuemin Shen, Xiaodong Lin, and Henry Y. Luo. "Exploiting Geo-Distributed Clouds for a E-Health Monitoring System With Minimum Service Delay and Privacy Preservation." IEEE Journal of Biomedical and Health Informatics 18, no. 2 (March 2014): 430–39. http://dx.doi.org/10.1109/jbhi.2013.2292829.
19
Telluri, Pavan, Srinidhi Bulusu, and T. K. Ramesh. "Centralized Swarm Network." Journal of Computational and Theoretical Nanoscience 17, no. 1 (January 1, 2020): 109–14. http://dx.doi.org/10.1166/jctn.2020.8636.
Abstract:
A theoretical approach and applications for centralizing a distributed system have been discussed along with methods for indoor Geo-location for swarm robot coordination using Multi-frequency positioning technique combined with traditional method of determination of distance using accelerometer. This hybrid method of determining coordinates of bots is reliable as it depends on multiple sources. The models for centralization using a controller, without violating swarm intelligence principles is discussed.
20
Tariq, Hasan, Anas Tahir, Farid Touati, Mohammed Abdulla E. Al-Hitmi, Damiano Crescini, and Adel Ben Manouer. "Geographical Area Network—Structural Health Monitoring Utility Computing Model." ISPRS International Journal of Geo-Information 8, no. 3 (March 21, 2019): 154. http://dx.doi.org/10.3390/ijgi8030154.
Abstract:
In view of intensified disasters and fatalities caused by natural phenomena and geographical expansion, there is a pressing need for a more effective environment logging for a better management and urban planning. This paper proposes a novel utility computing model (UCM) for structural health monitoring (SHM) that would enable dynamic planning of monitoring systems in an efficient and cost-effective manner in form of a SHM geo-informatics system. The proposed UCM consists of networked SHM systems that send geometrical SHM variables to SHM-UCM gateways. Every gateway is routing the data to SHM-UCM servers running a geo-spatial patch health assessment and prediction algorithm. The inputs of the prediction algorithm are geometrical variables, environmental variables, and payloads. The proposed SHM-UCM is unique in terms of its capability to manage heterogeneous SHM resources. This has been tested in a case study on Qatar University (QU) in Doha Qatar, where it looked at where SHM nodes are distributed along with occupancy density in each building. This information was taken from QU routers and zone calculation models and were then compared to ideal SHM system data. Results show the effectiveness of the proposed model in logging and dynamically planning SHM.
21
Sun, Chunlei, Xiangming Wen, Zhaoming Lu, Wenpeng Jing, and Michele Zorzi. "Eco-Friendly Powering and Delay-Aware Task Scheduling in Geo-Distributed Edge-Cloud System: A Two-Timescale Framework." IEEE Access 8 (2020): 96468–86. http://dx.doi.org/10.1109/access.2020.2995806.
22
ATENCIA, IVAN, and PILAR MORENO. "A DISCRETE-TIME Geo/G/1 RETRIAL QUEUE WITH SERVER BREAKDOWNS." Asia-Pacific Journal of Operational Research 23, no. 02 (June 2006): 247–71. http://dx.doi.org/10.1142/s0217595906000929.
Abstract:
This paper discusses a discrete-time Geo/G/1 retrial queue with the server subject to breakdowns and repairs. The customer just being served before server breakdown completes his remaining service when the server is fixed. The server lifetimes are assumed to be geometrical and the server repair times are arbitrarily distributed. We study the Markov chain underlying the considered queueing system and present its stability condition as well as some performance measures of the system in steady-state. Then, we derive a stochastic decomposition law and as an application we give bounds for the proximity between the steady-state distributions of our system and the corresponding system without retrials. Also, we introduce the concept of generalized service time and develop a recursive procedure to obtain the steady-state distributions of the orbit and system size. Finally, we prove the convergence to the continuous-time counterpart and show some numerical results.
23
Simić, Miloš, Goran Sladić, Miroslav Zarić, and Branko Markoski. "Infrastructure as Software in Micro Clouds at the Edge." Sensors 21, no. 21 (October 22, 2021): 7001. http://dx.doi.org/10.3390/s21217001.
Abstract:
Edge computing offers cloud services closer to data sources and end-users, making the foundation for novel applications. The infrastructure deployment is taking off, bringing new challenges: how to use geo-distribution properly, or harness the advantages of having resources at a specific location? New real-time applications require multi-tier infrastructure, preferably doing data preprocessing locally, but using the cloud for heavy workloads. We present a model, able to organize geo-distributed nodes into micro clouds dynamically, allowing resource reorganization to best serve population needs. Such elasticity is achieved by relying on cloud organization principles, adapted for a different environment. The desired state is specified descriptively, and the system handles the rest. As such, infrastructure is abstracted to the software level, thus enabling “infrastructure as software” at the edge. We argue about blending the proposed model into existing tools, allowing cloud providers to offer future micro clouds as a service.
24
Martirosyan, Alexander V., Yury V. Ilyushin, and Olga V. Afanaseva. "Development of a Distributed Mathematical Model and Control System for Reducing Pollution Risk in Mineral Water Aquifer Systems." Water 14, no. 2 (January 7, 2022): 151. http://dx.doi.org/10.3390/w14020151.
Abstract:
The article is devoted to the problem of the growing need of the mineral water fields’ exploitation process automation. The implementation of control systems and mathematical modeling methods can significantly reduce the fields’ structural integrity violation and pollution of aquifers risks. This research is especially relevant for the fields with difficult conditions of mineral waters occurrence, since the insufficient accuracy of determining the fields’ operating mode parameters can lead to a severe incident. The article describes a distributed mathematical model developed from the geo-filtration equation. Based on this model, a new method for assessing the mutual influence of the fields, the production of which is carried out from one aquifer, is presented. For a more detailed study of the operating mode parameters influence on the object a physical model of the reservoir was developed. The using of Arduino sensors and the developed software allows us to construct a 3D graph of the input action and its response at the different points of the object as temperature distribution. The simulation results make it possible to use the proposed model for the automatic control system synthesis.
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Maistrenko, S. Ya, V. I. Nochvai, T. O. Dontsov-Zahreba, K. V. Khurtsylava, and I. V. Kovalets. "Geo-information web-system for presenting the results of the inventory of air pollution emis-sions in Kyiv." Mathematical machines and systems 1 (2022): 97–105. http://dx.doi.org/10.34121/1028-9763-2022-1-97-105.
Abstract:
In the current work, there has been developed for the first time a geo-information web-system for presenting the results of the inventory of air pollution emissions in Kyiv from industrial en-terprises on the basis of the processing of data from the State Statistics Service of Ukraine, as well as estimates of geo-distributed emission fields from vehicles. The system contains infor-mation on emissions of 21 pollutants, including those that are regularly monitored in Kyiv by governmental agencies. The system is available via the link http://env.kiev.ua:8080/pollutionsystem/ pollutionsystem.html. Its main features – viewing on the map the locations of industrial emission sources for the selected substance, and the corre-sponding amount of emissions – can be used even by unregistered users. The developed system can be used in combination with the existing public and state systems for monitoring of air pol-lution in Kyiv for preliminary (screening) analysis of possible causes of high levels of air pollu-tion during their observing with the monitoring systems. The paper presents a relevant example of the system application to explain the high levels of hydrogen sulfide concentrations at one of the stations in Kyiv. Another purpose of the system may be to detect shortcomings in the exist-ing inventory of industrial emissions, namely the lack of information on certain sources, as well as verification and adjustment of data on emissions from the registered sources. To fully use the system potential, it is necessary to expand its functionality in the direction of mathematical modeling of the spread of pollution due to emissions from industrial enterprises and vehicles. For this purpose, it is also necessary to integrate hydrometeorological parameters and levels of air pollution in Kyiv into the data monitoring system.
26
Sun, Xiaoying, Leping Chen, Zhengquan Zhou, Huagui Du, and Xiaotao Huang. "Impact Analysis and Compensation Methods of Frequency Synchronization Errors in Distributed Geosynchronous Synthetic Aperture Radar." Remote Sensing 16, no. 8 (April 21, 2024): 1470. http://dx.doi.org/10.3390/rs16081470.
Abstract:
Frequency synchronization error, as one of the inevitable technical challenges in distributed synthetic aperture radar (SAR), has different impacts on different SAR systems. Multi-monostatic SAR is a typical distributed configuration where frequency synchronization errors are tiny in distributed airborne and low earth orbit (LEO) SAR systems. However, due to the long time delay and long synthetic aperture time, the imaging performance of a multi-monostatic geosynchronous (GEO) SAR system is affected by frequency oscillator errors. In this paper, to investigate the frequency synchronization problem in this configuration, we firstly model the echo signals with the frequency synchronization errors, which can be divided into fixed frequency errors and random phase noise. Secondly, we talk about the impacts of the two kinds of errors on imaging performance. To solve the problem, we thirdly propose an autofocus back-projection (ABP) algorithm, which adopts the coordinate descent method and iteratively adjusts the phase error estimation until the image reaches its maximum sharpness. Based on the characteristics of the frequency synchronization errors, we further propose the Node ABP (NABP) algorithm, which greatly reduces the amount of storage and computation compared to the ABP algorithm. Finally, simulations are carried out to validate the effectiveness of the ABP and NABP algorithms.
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Sukatmadiredja, Noneng R. "PENGARUH SISTEM PENGENDALIAN MANAJEMEN DAN PENGENDALIAN INTERNAL TERHADAP KINERJA PERUSAHAAN (STUDI KASUS PADA PT. GEO-ENVIRO ABADI CONSULTAN & ENGINERING SURABAYA)." Media Mahardhika 19, no. 3 (May 28, 2021): 421–33. http://dx.doi.org/10.29062/mahardika.v19i3.268.
Abstract:
This research aims to determine the influence of management control system and internal control on the company's performance in PT. Geo-Enviro Abadi Consultan &Enginering Surabaya. Data collection using survey method through questionnaire dissemination. Sample techniques using purposive sampling amounted to 32 respondents who were distributed to accounting departments and employees who participated in the field of budgeting in the pt company area. Geo-Enviro Abadi Consultan &Enginering Surabaya. The data analysis method used is quantitative analysis using validity, reliability, classic assumption test, and double barg linear regression. The results showed that the validity test showed all items with a validity value of > from 0.3024, the reliability test results of all reliable variables with a > of 0.60, classic assumption test results of both normality, heterokedastity test and multicolinnerity test showed all results showed no conflicting symptoms and all items were normally distributed. Partial tests showed that the influence of internal control on the Company's performance had a significant positive effect with a significance of 0.002 of 3,463 influences and Management Control on the Company's performance, had an insignificant effect with a significance of 0.609> from 0.005, simultaneously.F test results showed that internal Management and Control Control had a significant effect of 0.003 with an influence of 7,384 on the company's Performance.
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Mikhailenko, Anna V., Dmitry A. Ruban, and Vladimir A. Ermolaev. "The Khadzhokh Canyon System—An Important Geosite of the Western Caucasus." Geosciences 10, no. 5 (May 14, 2020): 181. http://dx.doi.org/10.3390/geosciences10050181.
Abstract:
True diversity of geological heritage sites (geosites) is yet to be fully understood. New field studies of the Khadzhokh Canyon and its vicinities in the Western Caucasus (Mountainous Adygeya tourist destination, southwestern Russia) have allowed characterizing its geoheritage. Multiple unique features are assigned to geomorphological, stratigraphical, paleontological, palaeogeographical, sedimentary, tectonic, hydro(geo)logical, and coupled economical and geoexplorationgeoheritage types. This geoheritage is highlycomplex, and its rank is national. The unique features include (but not limited to) three canyons, Triassic stratigraphical sections, Late Jurassic coral reef, megaclast accumulations, chevron folds, and waterfalls. The geoheritage is distributed along the Khadzhokh Canyon and its branches. The configuration of thisgeositemakes it possible to propose a new category, namely dendritic geosites distinguished by continuous occurrence of geoheritage via branching stripes. Such geosites can be either natural (determined by dendritic drainage network and deep valley incision) or anthropogenic (determined by dendritic road network with lengthy road cuttings). In the former case, geosites are also geomorphosites and host viewpoint geosites.
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Bahu, Jean-Marie, Andreas Koch, Enrique Kremers, and Syed Monjur Murshed. "Towards a 3D Spatial Urban Energy Modelling Approach." International Journal of 3-D Information Modeling 3, no. 3 (July 2014): 1–16. http://dx.doi.org/10.4018/ij3dim.2014070101.
Abstract:
Today's needs to reduce the environmental impact of energy use impose dramatic changes for energy infrastructure and existing demand patterns (e.g. buildings) corresponding to their specific context. In addition, future energy systems are expected to integrate a considerable share of fluctuating power sources and equally a high share of distributed generation of electricity. Energy system models capable of describing such future systems and allowing the simulation of the impact of these developments thus require a spatial representation in order to reflect the local context and the boundary conditions. This paper describes two recent research approaches developed at EIFER in the fields of (a) geo-localised simulation of heat energy demand in cities based on 3D morphological data and (b) spatially explicit Agent-Based Models (ABM) for the simulation of smart grids. 3D city models were used to assess solar potential and heat energy demand of residential buildings which enable cities to target the building refurbishment potentials. Distributed energy systems require innovative modelling techniques where individual components are represented and can interact. With this approach, several smart grid demonstrators were simulated, where heterogeneous models are spatially represented. Coupling 3D geodata with energy system ABMs holds different advantages for both approaches. On one hand, energy system models can be enhanced with high resolution data from 3D city models and their semantic relations. Furthermore, they allow for spatial analysis and visualisation of the results, with emphasis on spatially and structurally correlations among the different layers (e.g. infrastructure, buildings, administrative zones) to provide an integrated approach. On the other hand, 3D models can benefit from more detailed system description of energy infrastructure, representing dynamic phenomena and high resolution models for energy use at component level. The proposed modelling strategies conceptually and practically integrate urban spatial and energy planning approaches. The combined modelling approach that will be developed based on the described sectorial models holds the potential to represent hybrid energy systems coupling distributed generation of electricity with thermal conversion systems.
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Breunig, Martin, Patrick Erik Bradley, Markus Jahn, Paul Kuper, Nima Mazroob, Norbert Rösch, Mulhim Al-Doori, Emmanuel Stefanakis, and Mojgan Jadidi. "Geospatial Data Management Research: Progress and Future Directions." ISPRS International Journal of Geo-Information 9, no. 2 (February 4, 2020): 95. http://dx.doi.org/10.3390/ijgi9020095.
Abstract:
Without geospatial data management, today’s challenges in big data applications such as earth observation, geographic information system/building information modeling (GIS/BIM) integration, and 3D/4D city planning cannot be solved. Furthermore, geospatial data management plays a connecting role between data acquisition, data modelling, data visualization, and data analysis. It enables the continuous availability of geospatial data and the replicability of geospatial data analysis. In the first part of this article, five milestones of geospatial data management research are presented that were achieved during the last decade. The first one reflects advancements in BIM/GIS integration at data, process, and application levels. The second milestone presents theoretical progress by introducing topology as a key concept of geospatial data management. In the third milestone, 3D/4D geospatial data management is described as a key concept for city modelling, including subsurface models. Progress in modelling and visualization of massive geospatial features on web platforms is the fourth milestone which includes discrete global grid systems as an alternative geospatial reference framework. The intensive use of geosensor data sources is the fifth milestone which opens the way to parallel data storage platforms supporting data analysis on geosensors. In the second part of this article, five future directions of geospatial data management research are presented that have the potential to become key research fields of geospatial data management in the next decade. Geo-data science will have the task to extract knowledge from unstructured and structured geospatial data and to bridge the gap between modern information technology concepts and the geo-related sciences. Topology is presented as a powerful and general concept to analyze GIS and BIM data structures and spatial relations that will be of great importance in emerging applications such as smart cities and digital twins. Data-streaming libraries and “in-situ” geo-computing on objects executed directly on the sensors will revolutionize geo-information science and bridge geo-computing with geospatial data management. Advanced geospatial data visualization on web platforms will enable the representation of dynamically changing geospatial features or moving objects’ trajectories. Finally, geospatial data management will support big geospatial data analysis, and graph databases are expected to experience a revival on top of parallel and distributed data stores supporting big geospatial data analysis.
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Omidipoor, Morteza, Ara Toomanian, Najmeh Neysani Samany, and Ali Mansourian. "Knowledge Discovery Web Service for Spatial Data Infrastructures." ISPRS International Journal of Geo-Information 10, no. 1 (December 31, 2020): 12. http://dx.doi.org/10.3390/ijgi10010012.
Abstract:
The size, volume, variety, and velocity of geospatial data collected by geo-sensors, people, and organizations are increasing rapidly. Spatial Data Infrastructures (SDIs) are ongoing to facilitate the sharing of stored data in a distributed and homogeneous environment. Extracting high-level information and knowledge from such datasets to support decision making undoubtedly requires a relatively sophisticated methodology to achieve the desired results. A variety of spatial data mining techniques have been developed to extract knowledge from spatial data, which work well on centralized systems. However, applying them to distributed data in SDI to extract knowledge has remained a challenge. This paper proposes a creative solution, based on distributed computing and geospatial web service technologies for knowledge extraction in an SDI environment. The proposed approach is called Knowledge Discovery Web Service (KDWS), which can be used as a layer on top of SDIs to provide spatial data users and decision makers with the possibility of extracting knowledge from massive heterogeneous spatial data in SDIs. By proposing and testing a system architecture for KDWS, this study contributes to perform spatial data mining techniques as a service-oriented framework on top of SDIs for knowledge discovery. We implemented and tested spatial clustering, classification, and association rule mining in an interoperable environment. In addition to interface implementation, a prototype web-based system was designed for extracting knowledge from real geodemographic data in the city of Tehran. The proposed solution allows a dynamic, easier, and much faster procedure to extract knowledge from spatial data.
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Lu, Y. L., C. W. Liu, J. W. Li, and J. W. Jiang. "CONSTRUCTION METHOD OF “CELL-CUBE” SPATIO-TEMPORAL DATA MODEL FOR BIG DATA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W10 (February 7, 2020): 25–30. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w10-25-2020.
Abstract:
Abstract. In recent years, with high accuracy, high frequency, considerable coverage of remote sensing images, map tiles, video surveillance, web crawlers, social networking platforms and other types of spatiotemporal data have exploded in geometric progression. Human society has come into the era of big data in time and space. In view of the characteristics of multi-attribute, multi-dimensional, multisource and heterogeneous spatiotemporal big data, how to make use of the emerging information technology means, combined with the geographic information data analysis means, the rapid mining and utilization of spatiotemporal big data has become a key problem to be solved. Built on the background of spatiotemporal big data and the process of geospatial cognition, this paper proposes a "cell-cube" spatiotemporal object data model. This paper constructs a model system of geo-spatiotemporal big data from the aspects of data organization, data storage and data partition, and abstracts the geo-space into an infinite number of geo-cells, and the adjacent geo-cells gather around the core cells to form geographical clusters, and the geographical clusters with similar attributes are clustered into geographical blocks. At the level of data organization, the spatial and temporal characteristics of structured data and unstructured data are considered as organizational dimensions, and a multi-factor extended cube data model is proposed. In the aspect of data storage, the organization model is further abstracted into the cell-cube structure of distributed data warehouse, and then the spatiotemporal data is stored uniformly. At the level of data segmentation, the mathematical table and space calculation method of multi-feature extended cube are proposed, and the geographical cell data division model based on connection is established. It solves the organization and management problem of spatiotemporal big data, provides a more complete data organization framework and solution for the application of geo-spatiotemporal big data, and promotes the development of deep mining of spatiotemporal extensive data in GIS. And to achieve space-time big data in the geographical space microscopic and the macroscopic unification cognition.
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Rehman, Adnanul, Jinxi Song, Fazlul Haq, Shakeel Mahmood, Muhammad Irfan Ahamad, Muhammad Basharat, Muhammad Sajid, and Muhammad Sajid Mehmood. "Multi-Hazard Susceptibility Assessment Using the Analytical Hierarchy Process and Frequency Ratio Techniques in the Northwest Himalayas, Pakistan." Remote Sensing 14, no. 3 (January 24, 2022): 554. http://dx.doi.org/10.3390/rs14030554.
Abstract:
Globally, natural hazards have become more destructive in recent times because of rapid urban development and exposure. Consequently, significant human life loss, the damage to property and infrastructure, and the collapse of the environment directed the attention of geoscientists to control the consequences and risk management in relation to geo-hazards. In this research, an effort was made to produce a compound map, geo-visualizing the susceptibility of multi-hazards, to select suitable sites for sustainable future development and other economic activities in the region. Muzaffarabad District was chosen as a case research area due to the high magnitude of hydro-meteorological and geological hazards. On the one hand, both selected geo-hazard inventories were developed using the field survey and remote sensing data. The subjective and objective weight of all the causative factors and their classes were calculated using the assembled geospatial techniques, such as the Analytical Hierarchy Process (AHP) and Frequency Ratio (FR) in the Geographic Information System (GIS). The results reveal that the most suitable areas are distributed in the southern and northwestern parts, which can be used for future sustainable development and other economic activities. In contrast, the eastern and western regions, including Muzaffarabad City, are within high and very susceptibility zones. Finally, more than 50% of the land area is located in very low and low susceptibility zones. The validation of the proposed model was checked by using three different techniques: the Receiver Operative Characteristic (ROC) curve, Seed Cell Area Index (SCAI), and Frequency Ratio (FR). Both ROCs, the Success Rate Curve (SRC) and the Predictive Rate Curve (PRC), showed the goodness of fit for both the selected geo-hazards: landslides (81.3%) and floods (93.2%), at 80.1% and 91.7%, respectively. All the validation techniques showed good fitness for both the individual and multi-hazard maps. The proposed model sets a baseline for policy implementation for all the stakeholders to minimize the risk and sustainable future development in areas of high frequent geo-hazards.
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Teyeb, Hana, Nejib Ben Hadj-Alouane, Samir Tata, and Ali Balma. "Optimal Dynamic Placement of Virtual Machines in Geographically Distributed Cloud Data Centers." International Journal of Cooperative Information Systems 26, no. 03 (August 14, 2017): 1750001. http://dx.doi.org/10.1142/s0218843017500010.
Abstract:
In geo-distributed cloud systems, a key challenge faced by cloud providers is to optimally tune and configure the underlying cloud infrastructure. An important problem in this context, deals with finding an optimal virtual machine (VM) placement, minimizing costs, while at the same time, ensuring good system performance. Moreover, due to the fluctuations of demand and traffic patterns, it is crucial to dynamically adjust the VM placement scheme over time. It should be noted that most of the existing studies, however, dealt with this problem either by ignoring its dynamic aspect or by proposing solutions that are not suitable for a geographically distributed cloud infrastructure. In this paper, exact as well as heuristic solutions based on Integer Linear programming (ILP) formulations are proposed. Our work focuses also on the problem of scheduling the VM migration by finding the best migration sequence of intercommunicating VMs that minimizes the resulting traffic on the backbone network. The proposed algorithms execute within a reasonable time frame to readjust VM placement scheme according to the perceived demand. Our aim is to use VM migration as a tool for dynamically adjusting the VM placement scheme while minimizing the network traffic generated by VM communication and migration. Finally, we demonstrate the effectiveness of our proposed algorithms by performing extensive experiments and simulation.
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Yang, Zong-Xiao, Xiao-Yao Jia, Jie-Yu Hao, and Yan-Ping Gao. "Geometry-Experiment Algorithm for Steiner Minimal Tree Problem." Journal of Applied Mathematics 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/367107.
Abstract:
It is well known that the Steiner minimal tree problem is one of the classical nonlinear combinatorial optimization problems. A visualization experiment approach succeeds in generating Steiner points automatically and showing the system shortest path, named Steiner minimum tree, physically and intuitively. However, it is difficult to form stabilized system shortest path when the number of given points is increased and irregularly distributed. Two algorithms, geometry algorithm and geometry-experiment algorithm (GEA), are constructed to solve system shortest path using the property of Delaunay diagram and basic philosophy of Geo-Steiner algorithm and matching up with the visualization experiment approach (VEA) when the given points increase. The approximate optimizing results are received by GEA and VEA for two examples. The validity of GEA was proved by solving practical problems in engineering, experiment, and comparative analysis. And the global shortest path can be obtained by GEA successfully with several actual calculations.
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Khalil, Muhammad Imran Khan, Syed Adeel Ali Shah, Amer Taj, Muhammad Shiraz, Basem Alamri, Sadia Murawwat, and Ghulam Hafeez. "Renewable-Aware Geographical Load Balancing Using Option Pricing for Energy Cost Minimization in Data Centers." Processes 10, no. 10 (October 1, 2022): 1983. http://dx.doi.org/10.3390/pr10101983.
Abstract:
It is becoming increasingly difficult to properly control the power consumption of widely dispersed data centers. Energy consumption is high because of the need to run these data centers (DCs) that handle incoming user requests. The rising cost of electricity at the data center is a contemporary problem for cloud service providers (CSPs). Recent studies show that geo-distributed data centers may share the load and save money using variable power prices and pricing derivatives in the wholesale electricity market. In this study, we evaluate the problem of reducing energy expenditures in geographically dispersed data centers while accounting for variable system dynamics, power price fluctuations, and renewable energy sources. We present a renewable energy-based load balancing employing an option pricing (RLB-Option) online algorithm based on a greedy approach for interactive task allocation to reduce energy costs. The basic idea of RLB-Option is to process incoming user requests using available renewable energy sources. In contrast, in the case of unprocessed user requests, the workload will be processed using brown energy or call option contract at each timeslot. We formulate the energy cost minimization in geo-distributed DCs as an optimization problem considering geographical load balancing, renewable energy, and an option pricing contract from the derivative market while satisfying the set of constraints. We prove that the RLB-Option can reduce the energy cost of the DCs close to that of the optimal offline algorithm with future information. Compared to standard workload allocation methods, RLB-Option shows considerable cost savings in experimental evaluations based on real-world data.
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Rutan, David A., Seiji Kato, David R. Doelling, Fred G. Rose, Le Trang Nguyen, Thomas E. Caldwell, and Norman G. Loeb. "CERES Synoptic Product: Methodology and Validation of Surface Radiant Flux." Journal of Atmospheric and Oceanic Technology 32, no. 6 (June 2015): 1121–43. http://dx.doi.org/10.1175/jtech-d-14-00165.1.
Abstract:
AbstractThe Clouds and the Earth’s Radiant Energy System Synoptic (SYN1deg), edition 3, product provides climate-quality global 3-hourly 1° × 1°gridded top of atmosphere, in-atmosphere, and surface radiant fluxes. The in-atmosphere surface fluxes are computed hourly using a radiative transfer code based upon inputs from Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS), 3-hourly geostationary (GEO) data, and meteorological assimilation data from the Goddard Earth Observing System. The GEO visible and infrared imager calibration is tied to MODIS to ensure uniform MODIS-like cloud properties across all satellite cloud datasets. Computed surface radiant fluxes are compared to surface observations at 85 globally distributed land (37) and ocean buoy (48) sites as well as several other publicly available global surface radiant flux data products. Computed monthly mean downward fluxes from SYN1deg have a bias (standard deviation) of 3.0 W m−2 (5.7%) for shortwave and −4.0 W m−2 (2.9%) for longwave compared to surface observations. The standard deviation between surface downward shortwave flux calculations and observations at the 3-hourly time scale is reduced when the diurnal cycle of cloud changes is explicitly accounted for. The improvement is smaller for surface downward longwave flux owing to an additional sensitivity to boundary layer temperature/humidity, which has a weaker diurnal cycle compared to clouds.
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Raju, T. Naga, and Dr Chittineni Suneetha. "Extended Distributed Framework for Feature Extraction in Remote Sensing Imagery with High Resolution." Webology 18, no. 2 (December 23, 2021): 1035–46. http://dx.doi.org/10.14704/web/v18i2/web18372.
Abstract:
Remote Sensing imagery is used vastly in the areas of human activities investigation, environmental changes monitoring and geo-spatial data updation in a rapidly increasing way. Humans can easily and appropriately interpret the normally shot pictures but this is a difficult task for the computer to automatically interpret information from the given images. One of the prominent phases is in finding the way to extract the projected information from the given imagery and its conversion to wrath-ful data which can be used for further research. The motto is the generation of an algorithm which aims to be very efficient during of processing of huge images that include enhancement of efficiency in processing, correlation finding amongst given data and extraction of continuous features. In order to accomplish all these purposes as stated above, we hereby put forward an algorithm Extended Feature Extraction and Detection in High Resolution Remote Sensing (HRRS) Imagery to detect rivers. The proposed system is established with Hadoop Distributed Framework in order to enhance the efficiency of total system.
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Xu, Wei, Zhengbin Wei, Pingping Huang, Weixian Tan, Bo Liu, Zhiqi Gao, and Yifan Dong. "Azimuth Multichannel Reconstruction for Moving Targets in Geosynchronous Spaceborne–Airborne Bistatic SAR." Remote Sensing 12, no. 11 (May 26, 2020): 1703. http://dx.doi.org/10.3390/rs12111703.
Abstract:
In a multichannel geosynchronous spaceborne–airborne bistatic synthetic aperture radar (GEO-SA-BiSAR) system, the airborne receiver can obtain high-resolution microwave images with good signal-to-noise ratios (SNRs) by passively receiving echoes from the desired area. Since the Doppler modulation and range history of a moving target are obviously different from a stationary target, a signal geometry model for moving targets in multichannel GEO-SA-BiSAR is established in this paper. According to simulation results, the along track velocity introduces target defocusing in azimuth, and the slant range velocity mainly causes multiple false targets. To resolve these problems, a modified multichannel reconstruction method in azimuth channel GEO-SA-BiSAR is proposed according to the azimuth multichannel impulse response of the imaged moving target. Before azimuth multichannel raw data combination, both spatial-variant range cell migration correction (RCMC) and azimuth nonlinear chirp scaling (ANLCS) should be performed to reduce the influence of the range offset and lower the Doppler bandwidth of the whole raw data, respectively. Afterward, a novel azimuth multichannel reconstruction algorithm is carried out via the modified reconstruction matrix based on the estimated target velocity. The target slant range velocity estimation is implemented by introducing the signal intensity ratio (SIR). Compared with the conventional method for the stationary target to handle the raw data of the moving target, the false targets could be obviously suppressed by using the proposed approach. Imaging results on both simulated point and distributed scene targets validate the proposed multichannel reconstruction approach.
40
Yu, J., L. Wu, Y. Yang, X. Lei, and W. He. "Global Data Spatially Interrelate System for Scientific Big Data Spatial-Seamless Sharing." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-6 (April 23, 2014): 125–30. http://dx.doi.org/10.5194/isprsarchives-xl-6-125-2014.
Abstract:
A good data sharing system with spatial-seamless services will prevent the scientists from tedious, boring, and time consuming work of spatial transformation, and hence encourage the usage of the scientific data, and increase the scientific innovation. Having been adopted as the framework of Earth datasets by Group on Earth Observation (GEO), Earth System Spatial Grid (ESSG) is potential to be the spatial reference of the Earth datasets. Based on the implementation of ESSG, SDOG-ESSG, a data sharing system named global data spatially interrelate system (GASE) was design to make the data sharing spatial-seamless. The architecture of GASE was introduced. The implementation of the two key components, V-Pools, and interrelating engine, and the prototype is presented. Any dataset is firstly resampled into SDOG-ESSG, and is divided into small blocks, and then are mapped into hierarchical system of the distributed file system in V-Pools, which together makes the data serving at a uniform spatial reference and at a high efficiency. Besides, the datasets from different data centres are interrelated by the interrelating engine at the uniform spatial reference of SDOGESSG, which enables the system to sharing the open datasets in the internet spatial-seamless.
41
Lannom, Larry, Dimitris Koureas, and Alex R. Hardisty. "FAIR Data and Services in Biodiversity Science and Geoscience." Data Intelligence 2, no. 1-2 (January 2020): 122–30. http://dx.doi.org/10.1162/dint_a_00034.
Abstract:
We examine the intersection of the FAIR principles (Findable, Accessible, Interoperable and Reusable), the challenges and opportunities presented by the aggregation of widely distributed and heterogeneous data about biological and geological specimens, and the use of the Digital Object Architecture (DOA) data model and components as an approach to solving those challenges that offers adherence to the FAIR principles as an integral characteristic. This approach will be prototyped in the Distributed System of Scientific Collections (DiSSCo) project, the pan-European Research Infrastructure which aims to unify over 110 natural science collections across 21 countries. We take each of the FAIR principles, discuss them as requirements in the creation of a seamless virtual collection of bio/geo specimen data, and map those requirements to Digital Object components and facilities such as persistent identification, extended data typing, and the use of an additional level of abstraction to normalize existing heterogeneous data structures. The FAIR principles inform and motivate the work and the DO Architecture provides the technical vision to create the seamless virtual collection vitally needed to address scientific questions of societal importance.
42
Wang, Yafeng, Hu Wang, Yamin Dang, Hongyang Ma, Changhui Xu, Qiang Yang, Yingying Ren, and Shushan Fang. "BDS and Galileo: Global Ionosphere Modeling and the Comparison to GPS and GLONASS." Remote Sensing 14, no. 21 (October 31, 2022): 5479. http://dx.doi.org/10.3390/rs14215479.
Abstract:
The ionospheric delay is one of the important error sources in the Global Navigation Satellite System (GNSS) data processing. With the rapid construction and development of GNSS, the abundant satellite resources have brought new opportunities for ionospheric monitoring. To further investigate the performances and abilities of Galileo and BDS in ionosphere modeling, we study the ionosphere modeling based on the 15th order spherical harmonic function, and 364 stations around the world are selected for global ionospheric modeling of GPS, GLONASS, Galileo and BDS systems under ionospheric quiet and active conditions, respectively. The results show that the average biases of the ionospheric models built by GPS, GLONASS and Galileo are relatively small, which are within 2 Total Electron Content Unit (TECU) as compared to the Center for Orbit Determination in Europe (CODE) global ionospheric map (GIM), while the average biases of the models built by BDS are between 6 and 8 TECU during the ionospheric quiet and active days, respectively. In addition, in order to analyze the modeling performances before and after using BDS geostationary earth orbit (GEO) satellites, BDS is divided into two groups, in which one group contains medium earth orbit (MEO), inclined geosynchronous orbit (IGSO) and GEO satellites; and the other group contains only MEO and IGSO satellites. The results show that the influence of GEO satellites on ionospheric modeling is less than 1 TECU. Due to the distribution of the stations, the 0-value region in the ionospheric model is mainly distributed in the mid and high-latitude regions of the southern hemisphere. Since the ionospheric parameters are lumped with the Differential Code Bias (DCB), we also estimate the DCB parameters and analyze their performances. The DCB estimated in ionosphere modeling shows strong stability, with the average biases of GPS, GLONASS, Galileo and BDS under 0.25 ns, 0.25 ns, 0.2 ns and 0.42 ns, respectively. We also estimate other DCB types of the four GNSS systems. The results show that the DCB is stable and shows consistency with Chinese Academy of Sciences (CAS) DCB products.
43
Li, Chao, Huimei Lu, Yong Xiang, and Rui Gao. "Geo-DMP: A DTN-Based Mobile Prototype for Geospatial Data Retrieval." ISPRS International Journal of Geo-Information 9, no. 1 (December 20, 2019): 8. http://dx.doi.org/10.3390/ijgi9010008.
Abstract:
Geospatial information is gaining immense interest and importance as we enter the era of highly developed transportation and communication. Despite the proliferation of cellular network and WiFi, on some occasions, users still face barriers to accessing geospatial data. In this paper, we design and implement a distributed prototype system with a delay/disruption tolerant network (DTN), named Geo-DMP, for cooperatively and opportunistically sharing and exchanging named geospatial contents in a device-to-device fashion. First of all, we construct a lightweight “content agent” module to bridge the gap between the application layer and the underlying DTN protocol stack. Afterwards, to profile the mobility history of users in practical geospatial environments, we present a map segmentation scheme based on road network and administrative subdivision information. Subsequently, we associate the regional movement history information with the content retrieval process to devise a hierarchical and region-oriented DTN routing scheme for both requests and responses. Finally, we conduct extensive experiments with real-world trajectories and complete implementations on the emulation platform composed of virtual machines. The experiments corroborate that Geo-DMP has the capability of successfully retrieving geospatial contents for users for most of the time under mobile circumstances with episodic connectivity. Moreover, en-route caches can be efficiently exploited to provision contents from multiple sources with less network resource consumption and shorter user-perceived latencies.
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Pulin Ch. Borah, Nabajyoti Nath,. "Distribution and Genesis of Wetlands in Nagaon District, Assam: A Geomorphological Perspective." Tuijin Jishu/Journal of Propulsion Technology 44, no. 3 (September 11, 2023): 459–66. http://dx.doi.org/10.52783/tjjpt.v44.i3.315.
Abstract:
Assam is endowed with a large number of wetlands of different kinds. The number and areas of wetlands are variously distributed over the state. Assam has a total wetlands area of 1012 sq.kms with 3514 wetlands representing the highest area under wetlands among the North Eastern states. More than 80 percent of the wetlands falls in Assam regions, which suggest that majority of the regions wetlands originates in the fluvial domain of the Brahmaputra River system. Wetland distribution in district level reveals that Nagaon District has the highest number of wetlands among all the districts of the state. Depending on their locational characteristics, the wetlands are prone to various kinds of geo-environmental problems. Therefore, with growing need of wetlands management, it has become highly imperative to study genesis and development of wetlands.
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Cho, Younghyun. "Application of NEXRAD Radar-Based Quantitative Precipitation Estimations for Hydrologic Simulation Using ArcPy and HEC Software." Water 12, no. 1 (January 17, 2020): 273. http://dx.doi.org/10.3390/w12010273.
Abstract:
Recent availability of various spatial data, especially for gridded rainfall amounts, provide a great opportunity in hydrological modeling of spatially distributed rainfall–runoff analysis. In order to support this advantage using gridded precipitation in hydrological application, (1) two main Python script programs for the following three steps of radar-based rainfall data processing were developed for Next Generation Weather Radar (NEXRAD) Stage III products: conversion of the XMRG format (binary to ASCII) files, geo-referencing (re-projection) with ASCII file in ArcGIS, and DSS file generation using HEC-GridUtil (existing program); (2) eight Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) models of ModClark and SCS Unit Hydrograph transform methods for rainfall–runoff flow simulations using both spatially distributed radar-based and basin-averaged lumped gauged rainfall were respectively developed; and (3) three storm event simulations including a model performance test, calibration, and validation were conducted. For the results, both models have relatively high statistical evaluation values (Nash–Sutcliffe efficiency—ENS 0.55–0.98 for ModClark and 0.65–0.93 for SCS UH), but it was found that the spatially distributed rainfall data-based model (ModClark) gives a better fit regarding observed streamflow for the two study basins (Cedar Creek and South Fork) in the USA, showing less requirements to calibrate the model with initial parameter values. Thus, the programs and methods developed in this research possibly reduce the difficulties of radar-based rainfall data processing (not only NEXRAD but also other gridded precipitation datasets—i.e., satellite-based data, etc.) and provide efficiency for HEC-HMS hydrologic process application in spatially distributed rainfall–runoff simulations.
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Navarro, Ana, and María-Isabel Vélez. "Obesogenic Environment Case Study from a Food and Nutrition Security Perspective: Hermosillo City." International Journal of Environmental Research and Public Health 16, no. 3 (January 31, 2019): 407. http://dx.doi.org/10.3390/ijerph16030407.
Abstract:
Obesity and certain nutritional deficiencies are global health problems that emerge in systems of interdependent individual biological and historical factors and social environmental determinants of health. Nutrition security is a framework that assumes stable access to sufficient innocuous and nutritious food (i.e., food security), health care, and sanitation, and information that in conjunction allows self-care-oriented behavior for health protection. To understand the social environment of nutrition insecurity, the object of study was the food distribution and consumption system of a marginalized community in Hermosillo, Mexico. We assessed the distribution of food establishments by social marginalization level in basic geo-statistical areas and the nutrition security status of women in underserved neighborhoods. We found that in Hermosillo >90% of food establishments included for analysis (grocery stores, supermarkets, convenience stores, and beer deposits) were distributed outside of areas with high levels of social marginalization. The nutrition security assessment suggests that low intakes of fruit and vegetables and high intakes of fat and sugar may be associated with food accessibility and acceptability factors in individual decision-making processes. Future research should take into account the variability of food system environments and address the particular needs of communities in terms of food and nutrition security.
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Miksis-Olds, Jennifer L., Eric Rehm, Bruce M. Howe, Peter F. Worcester, Georgios Haralabus, and Hanne Sagen. "Envisioning a Global Multi-Purpose Ocean Acoustic Network." Marine Technology Society Journal 55, no. 3 (May 1, 2021): 78–79. http://dx.doi.org/10.4031/mtsj.55.3.27.
Abstract:
Abstract Due to the efficient propagation of sound in water, sound in the deep ocean propagates such great distances that soundscapes are influenced not only by local conditions but also by distant sound sources. Ocean Sound is now an Essential Ocean Variable within the Global Ocean Observing System making passive acoustic monitoring routine. Active acoustic probing of the environment informs us about ocean topography, currents and temperature, and abundance and type of marine life vital to fisheries and biodiversity related interests.Efficient sound propagation is the foundation of a proposed multipurpose acoustic network. Judiciously placed low-frequency acoustic sources transmitting to globally distributed passive acoustic systems provide: (1) high temporal resolution measurements of large-scale ocean temperature/heat content variability using tomography; and (2) underwater geo-positioning (UW-GPS) and communication services enabling basin-scale underwater operation of floats, gliders, and AUVs. Every platform (fixed or moving) equipped with a hydrophone becomes a “GPS” receiver, while listening to the ocean soundscape. The combined active and passive acoustic technology will lead to multi-disciplinary discovery and improved understanding of ocean ecosystem health and biodiversity, climate variability and change, marine hazards, and maritime safety. The same system will improve the operation of gliders, floats and AUVs.
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Vivoni, Enrique R., and Kevin T. Richards. "Integrated use of GIS-based field sampling and modeling for hydrologic and water quality studies." Journal of Hydroinformatics 7, no. 4 (October 1, 2005): 235–50. http://dx.doi.org/10.2166/hydro.2005.0021.
Abstract:
Enhancements to traditional catchment-scale water quality assessments can be realized by leveraging geographical information systems (GIS) for both field data collection and hydrologic and water quality (H/WQ) modeling. In this study, we describe a GIS-based data collection system for geo-referenced environmental sampling utilizing mobile, wireless and Internet technologies. Furthermore, sampled field data is combined with historical measurements within a GIS-based semi-distributed watershed model for simulating water quantity and quality in a large regional catchment. The GIS-based sampling and modeling system is intended to streamline water quality assessments as compared to current practices. We describe an application and field study in the Williams River, New South Wales, Australia designed to assess the impacts of point and non-point source pollution on water quality. Historical data were utilized for calibrating and validating the Hydrologic Simulation Program – Fortran (HSPF) with the BASINS GIS interface over the 1988–2000 period. Results from the study indicate that short-duration, spatially extensive field campaigns provide useful data for enhancing modeling studies based on historical measurements at sparse sites. In addition, the study suggests that the conjunctive use of data collection and modeling is a step towards real-time integration of field data in hydrologic and water quality modeling efforts.
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Kersten, Tobias, and Jens-André Paffenholz. "Feasibility of Consumer Grade GNSS Receivers for the Integration in Multi-Sensor-Systems." Sensors 20, no. 9 (April 26, 2020): 2463. http://dx.doi.org/10.3390/s20092463.
Abstract:
Various GNSS applications require low-cost, small-scale, lightweight and power-saving GNSS devices and require high precision in terms of low noise for carrier phase and code observations. Applications vary from navigation approaches to positioning in geo-monitoring units up to integration in multi-sensor-systems. For highest precision, only GNSS receivers are suitable that provide access to raw data such as carrier phase, code ranges, Doppler and signal strength. A system integration is only possible if the overall noise level is known and quantified at the level of the original observations. A benchmark analysis based on a zero baseline is proposed to quantify the stochastic properties. The performance of the consumer grade GNSS receiver is determined and evaluated against geodetic GNSS receivers to better understand the utilization of consumer grade receivers. Results indicate high similarity to the geodetic receiver, even though technical limitations are present. Various stochastic techniques report normally distributed carrier-phase noise of 2 mm and code-range noise of 0.5–0.8 m. This is confirmed by studying the modified Allan standard deviation and code-minus-carrier combinations. Derived parameters serve as important indicators for the integration of GNSS receivers into multi-sensor-systems.
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Yang, Guo Xiang, Jin Yu Dong, Fa Quan Wu, Dong Wang, and Ji Hong Yang. "Study on High Cutting Slopes with Horizontal Soft-Hard Strata in Three Gorges Reservoir Area." Advanced Materials Research 168-170 (December 2010): 2595–601. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2595.
Abstract:
High cutting slopes with nearly horizontal soft-hard alternant strata are widely distributed in three gorges reservoir area, the soft and hard rocks are mainly mud stone and sandstone of Jurassic system. Sliding failure of this kind of slope is also the main geo-hazards in this area. Firstly, this paper analyzed the impact of topography, water as well as the differential weathering and combination characteristics of soft and hard rocks etc. on the sliding failure of slopes; secondly, sliding failure modes of this kind of slope were classified into four types including circular sliding, sliding along the extroversion structural surface, sliding along the mudded intercalation and wedge sliding, they were analyzed combined with case study. And lastly, support methods against the certain failure mode were put forward. The research results are significant to the support and treatment of high cutting slopes in Three gorges area.