A note on a generalized concept of effective distance

2007 ◽  
Vol 6 (4) ◽  
pp. 308-311 ◽  
Author(s):  
Karl W. Deutsch ◽  
Walter Isard
Keyword(s):  
Effective Distance

scholarly journals Effects of COVID-19 on Urban Population Flow in China

2021 ◽  
Vol 18 (4) ◽  
pp. 1617 ◽  
Author(s):  
Xiaorong Jiang ◽  
Wei Wei ◽  
Shenglan Wang ◽  
Tao Zhang ◽  
Chengpeng Lu
Keyword(s):  
Network Topology ◽  
Traffic Control ◽  
Urban Population ◽  
Deep Understanding ◽  
Clustering Coefficient ◽  
Spatial Distance ◽  
Structure Evolution ◽  
Effective Distance ◽  
Urban Hierarchy ◽  
The City

The COVID-19 epidemic has become a Public Health Emergency of International Concern. Thus, this sudden health incident has brought great risk and pressure to the city with dense population flow. A deep understanding of the migration characteristics and laws of the urban population in China will play a very positive role in the prevention and control of the epidemic situation. Based on Baidu location-based service (LBS) big data, using complex networks method and geographic visualization tools, this paper explores the spatial structure evolution of population flow network (PFN) in 368 cities of China under different traffic control situations. Effective distance models and linear regression models were established to analyze how the population flow across cities affects the spread of the epidemic. Our findings show that: (1) the scope of population flow is closely related to the administrative level of the city and the traffic control policies in various cities which adjust with the epidemic situation; The PFN mainly presents the hierarchical structure dominated by the urban hierarchy and the regional isolation structure adjacent to the geographical location.(2) through the analysis network topology structure of PFN, it is found that only the first stage has a large clustering coefficient and a relatively short average path length, which conforms to the characteristics of small world network. The epidemic situation has a great impact on the network topology in other stages, and the network structure tends to be centralized. (3) The overall migration scale of the whole country decreased by 36.85% compared with the same period of last year’s lunar calendar, and a further reduction of 78.52% in the nationwide traffic control stage after the festival. (4) Finally, based on the comparison of the effective distance and the spatial distance from the Wuhan to other destination cities, it is demonstrated that there is a higher correlation between the effective distance and the epidemic spread both in Hubei province and the whole country.

Effect of Hydrogen on Mechanical Properties of Pipeline API 5L X70 Steel

2011 ◽  
Vol 146 ◽  
pp. 213-225 ◽  
Author(s):  
T. Bellahcene ◽  
J. Capelle ◽  
Méziane Aberkane ◽  
Z. Azari
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Embrittlement ◽  
Hydrogen Absorption ◽  
Fatigue Tests ◽  
The Finite Element Method ◽  
Effective Distance ◽  
Bending Tests ◽  
Fatigue Initiation ◽  
Api 5L X70 Steel ◽  
Special Soil

The aim of this work is to study the effects of hydrogen absorption on mechanical properties of pipe API 5L X70 steel. This study is conducted in special soil solution NS4 with pH 6.7 It show that the tensile properties like yield stress, ultimate strength and elongation at failure reduced under hydrogen embrittlement. Several fatigue tests (three (03) points bending tests) on roman tile specimens with notch are performed. Fatigue initiation is detected by acoustic emission. A comparison between specimens electrolytically charged with hydrogen and specimens without hydrogen absorption is made and it has been noted that fatigue initiation time is reduced when hydrogen embrittlement occurs. The field of elastoplastic stresses near the notch is computed by the finite-element method with the Abaqus software package. Effective distance and stress are calculated with the volumetric approach and the Notch intensity Factor of the roman tile specimen is determined for each loading value used in our tests.

Pulsed Field Gradient NMR Investigation of Molecular Mobility of Trimethoxymethane in Nafion Membranes

1997 ◽  
Vol 496 ◽  
Author(s):  
Y. Wu ◽  
T. A. Za Wodzinski ◽  
M. C. Smart ◽  
S. G. Greenbaum ◽  
G.K.S. Prakash ◽  
...  
Keyword(s):  
Field Gradient ◽  
Molecular Mobility ◽  
Alternative Fuels ◽  
Direct Oxidation ◽  
Effective Distance ◽  
Pulsed Field ◽  
Self Diffusion ◽  
Lower Extent ◽  
The Difference ◽  
Nmr Signals

ABSTRACTMolecular mobility of water and trimethoxymethane (TMM) in NAFION membranes of two different equivalent weights (EW), 1100 and 1500, were investigated. Self-diffusion coefficients were determined by the NMR pulsed field gradient method, using the water and methyl protons NMR signals, in saturated NAFION samples containing concentrations of TMM in water varying between 0.5 and 14 M, and at temperatures varying from 30°C to 80°C. Diffusion of molecular species containing methyl protons is more than a factor of two slower in the 1500 EW membrane than in the 1100 EW membrane at 30°C and 1 M concentration. The difference rises to about a factor of four at 80°C and 14 M concentration. These differences are attributed to the lower extent of plasticization of the higher EW material as well as the greater effective distance between acid functional groups. NAFION samples containing methanol/water mixtures were also investigated. Comparison with the methanol results and the permeation behavior, as characterized by gas Chromatographie methods, show that more than half of the TMM is hydrolyzed to methanol as it passes through the acidic membrane. The implications of these findings for alternative fuels in direct oxidation fuel cells are discussed.

scholarly journals PERANCANGAN SISTEM OTOMATISASI CONTROL MOTOR 3 PHASE MENGGUNAKAN BLUETOOTH BERBASIS ARDUINO UNO

2019 ◽  
Vol 4 (2) ◽  
pp. 50-55
Author(s):  
Syarif Moh Rofiq Al- Ghony ◽  
Subuh Isnur Haryudo ◽  
Jati Widyo Leksono
Keyword(s):  
Control System ◽  
Electric Motor ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Data Capture ◽  
Effective Range ◽  
Effective Distance ◽  
Arduino Uno

The electric motor is a device that serves to transform electrical energy into mechanical energy of motion. In this case the designed control system motor 3 phase by Smartphones through bluetooth network to find out the effective range of extremity. The methods used in the form of data capture of measurement effective range the furthest that can be reached by bluetooth to activate relay SPDT and motor 3 phase. Results of testing the most effective distance of the otomasisasi control system of motor 3 phase maximum as far as 15 meters with a time of pause 0.5 seconds.

scholarly journals PENGIRIMAN DATA NRF24L01+ DENGAN KONDISI LINE OF SIGHT DAN NON LINE OF SIGHT

2020 ◽  
Vol 3 (2) ◽  
pp. 128-139
Author(s):  
I Gusti Made Ngurah Desnanjaya ◽  
Mohammad Dwi Alfian
Keyword(s):  
Packet Loss ◽  
Data Transmission ◽  
Large Scale ◽  
Extreme Environments ◽  
Data Communication ◽  
Sensor Nodes ◽  
Line Of Sight ◽  
Effective Distance ◽  
Communication Distance ◽  
Non Line Of Sight

Wireless Sensor Network is a wireless network technology that includes sensor nodes and embedded systems. WSN has several advantages: it is cheaper for large-scale applications, can withstand extreme environments, and data transmission is relatively more stable. One of the WSN devices is nRF24L01+. Within the specifications given, the maximum communication distance is 1.1 km. However, the most effective distance for transmitting data in line of sight and non-line of sight is still unknown. Therefore, testing and analysis are needed so that the nRF24L01+ device can be used optimally for communication and data transmission. Through testing analysis on nRF24L01+ line of sight, Kuta beach location in Bali and non-line of sight on the STMIK STIKOM Indonesia campus. The effective communication distance of the nRF24L01+ module in line of sight is between 1 and 1000 meters. The distance of 1000 meters is the limit of the effective distance for sending data, and the packet loss rate is less than 15% which is included in the medium category. Meanwhile, in the non-line of sight, the effective distance of the nRF24L01+ communication module is 20 meters, and the packet loss is close to 15%, which is a moderate level limit. With the analysis module, nRF24L01+ can be a reference in determining the effective distance on WSN nRF24L01+ in determining remote control equipment data communication.

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