Cost performance optimization of large scale wideband arrays for radio telescope applications

Author(s):  
A. El-makadema ◽  
A. K. Brown
Author(s):  
Bogdan Prisacari ◽  
German Rodriguez ◽  
Cyriel Minkenberg ◽  
Marina Garcia ◽  
Enrique Vallejo ◽  
...  

2012 ◽  
Vol 8 (S291) ◽  
pp. 375-377 ◽  
Author(s):  
Gregory Desvignes ◽  
Ismaël Cognard ◽  
David Champion ◽  
Patrick Lazarus ◽  
Patrice Lespagnol ◽  
...  

AbstractWe present an ongoing survey with the Nançay Radio Telescope at L-band. The targeted area is 74° ≲ l < 150° and 3.5° < |b| < 5°. This survey is characterized by a long integration time (18 min), large bandwidth (512 MHz) and high time and frequency resolution (64 μs and 0.5 MHz) giving a nominal sensitivity limit of 0.055 mJy for long period pulsars. This is about 2 times better than the mid-latitude HTRU survey, and is designed to be complementary with current large scale surveys. This survey will be more sensitive to transients (RRATs, intermittent pulsars), distant and faint millisecond pulsars as well as scintillating sources (or any other kind of radio faint sources) than all previous short-integration surveys.


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Weihua Huang

Multiuser fair sharing of clusters is a classic problem in cluster construction. However, the cluster computing system for hybrid big data applications has the characteristics of heterogeneous requirements, which makes more and more cluster resource managers support fine-grained multidimensional learning resource management. In this context, it is oriented to multiusers of multidimensional learning resources. Shared clusters have become a new topic. A single consideration of a fair-shared cluster will result in a huge waste of resources in the context of discrete and dynamic resource allocation. Fairness and efficiency of cluster resource sharing for multidimensional learning resources are equally important. This paper studies big data processing technology and representative systems and analyzes multidimensional analysis and performance optimization technology. This article discusses the importance of discrete multidimensional learning resource allocation optimization in dynamic scenarios. At the same time, in view of the fact that most of the resources of the big data application cluster system are supplied to large jobs that account for a small proportion of job submissions, while the small jobs that account for a large proportion only use the characteristics of a small part of the system’s resources, the expected residual multidimensionality of large-scale work is proposed. The server with the least learning resources is allocated first, and only fair strategies are considered for small assignments. The topic index is distributed and stored on the system to realize the parallel processing of search to improve the efficiency of search processing. The effectiveness of RDIBT is verified through experimental simulation. The results show that RDIBT has higher performance than LSII index technology in index creation speed and search response speed. In addition, RDIBT can also ensure the scalability of the index system.


Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3076
Author(s):  
Roddy A. R. Antayhua ◽  
Maicon D. Pereira ◽  
Nestor C. Fernandes ◽  
Fernando Rangel de Sousa

In this paper, we propose a methodology to use the received signal strength indicator (RSSI) available by the protocol stack of an installed Wireless Sensor Network (WSN) at an electric-power-system environment (EPS) as a tool for obtaining the characteristic of its communication channel. Thereby, it is possible to optimize the settings and configuration of the network after its deployment, which is usually run empirically without any previous knowledge of the channel. A study case of a hydroelectric power plant is presented, where measurements recorded over a two-month period were analyzed and treated to obtain the large-scale characteristics of the radiofrequency channel at 2.4 GHz. In addition, we showed that instantaneous RSSI data can also be used to detect specific issues in the network, such as repetitive patterns in the transmitted power level of the nodes, and information about its environment, such as the presence of external sources of electromagnetic interference. As a result, we demonstrate the practical use of the RSSI long-term data generated by the WSN for its own performance optimization and the detection of particular events in an EPS or any similar industrial environment.


2019 ◽  
Vol 11 (22) ◽  
pp. 6462 ◽  
Author(s):  
Zhao ◽  
Fang ◽  
Wu ◽  
Zhang ◽  
Wang

In order to realize the resource utilization of bloom algae from Lake Chao, this study presents the use of fresh algae to improve the mechanical and biological properties of low-density polyethylene (LDPE). In this study, the algae and LDPE were used as raw materials, maleic anhydride grafted polyethylene (PE-g-MAH), polyethylene wax (PE-wax) and white oil, and glycerin were used as the compatibilizer, lubricant, and plasticizer, respectively. The single factor experiments were conducted with these three individual factors, and the response surface methodology technique was used to optimize the process conditions. In the single factor experiments, the mechanical properties of the composites increased with additions of PE-g-MAH, PE-wax/white oil, and glycerin. Both flexural strength and flexural modulus were maximized to optimize the preparation conditions. The optimum preparation conditions were found as follows: algae powder of 15.00 wt%, LDPE of 85.00 wt%, PE-g-MAH of 4.00 wt%, lubricant of 2.67 wt%, and glycerin of 3.00 wt%. This resulted in 11.60 MPa of tensile strength, 9.95 MPa of flexural strength, and 241.00 MPa of flexural modulus. The mechanical properties of composites were greatly improved compared with the absence of additives. In addition, compared with LDPE resin, the degradability of the composite was improved, and the weight loss rate was 7.73% after 6 months. The results recommended that the composites of the algae from Lake Chao and LDPE resin could be a useful material in the packaging field. Generally, the prepared composite particles can be used to produce foam products, packaging bags, or hard packing boxes with special shapes. It is more environmentally friendly, and more able to meet the challenges of sustainable development.


2012 ◽  
Vol 542-543 ◽  
pp. 179-183
Author(s):  
Kuan Yu ◽  
Bo Zhu

In this paper, we introduced a high cost performance design of air flow control system consisting of a programmable computer controller (PCC) and 72 inverters. PCC communicates with all the inverters using USS protocol via RS485 bus, and the real-time performance of USS communication was analyzed for this system. The commissioning and analysis show that the total communication cycle time of a subnet is less than 500ms and the maximum deviation of the inverter frequency is 0.01Hz. This system can meet the requirements of high performance carbon fiber production.


2020 ◽  
Vol 6 ◽  
pp. 137-146 ◽  
Author(s):  
Jing Yang ◽  
Jiayu Chen ◽  
Zhiyong Zhang ◽  
Ming Hong ◽  
Han Li ◽  
...  

2001 ◽  
Vol 18 (1) ◽  
pp. 84-90 ◽  
Author(s):  
N. M. McClure-Griffiths ◽  
John M. Dickey ◽  
B. M. Gaensler ◽  
A. J. Green ◽  
R. F. Haynes ◽  
...  

AbstractWe present preliminary results from the Southern Galactic Plane Survey (SGPS) Test Region and Parkes data. As part of the pilot project for the Southern Galactic Plane Survey, observations of a Test Region (325·5° ≤l ≤ 333·5°; −0·5° ≤ b ≤ 3·5°) were completed in December 1998. Single-dish observations of the full survey region (253° ≤ l ≤ 358 ° |b| ≤ 1°) with the Parkes Radio Telescope were completed in March 2000. We present a sample of SGPS H I data, with particular attention to the smallest-and largest-scale structures seen in absorption and emission, respectively. On the large scale, we detect many prominent H I shells. On the small scale, we note extremely compact, cold clouds seen in H I self-absorption. We explore how these two classes of objects probe opposite ends of the H I spatial power spectrum.


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