scholarly journals Optimal source placement for point coverage in active multistatic sonar networks

2019 ◽  
Vol 67 (1) ◽  
pp. 63-74
Author(s):  
Emily Craparo ◽  
Mumtaz Karatas
Keyword(s):  
Point Coverage

scholarly journals Possible approach to detecting the mysterious Saturnian convective dynamo through gravitational sounding

2020 ◽  
Vol 644 ◽  
pp. A48
Author(s):  
Shanhong Liu ◽  
Dali Kong ◽  
Jianguo Yan
Keyword(s):  
Gravitational Field ◽  
Orbit Determination ◽  
Radiation Belt ◽  
Fluid Motion ◽  
Precise Orbit Determination ◽  
Precise Location ◽  
Polar Orientation ◽  
Tracking Time ◽  
Convective Fluid ◽  
Point Coverage

Context. Planetary dynamo research is mathematically and numerically difficult. Forward calculations are numerically expensive and subject to much uncertainty in key magnetohydrodynamics parameters. For a gaseous planet such as Saturn, even the precise location of its dynamo and typical convective strength are unknown, which further complicates studies. Aims. We test the idea of inversely probing Saturnian convective dynamo through gravitational sounding, based on the principle that the convective fluid motion can distort the internal density distribution and hence induce the gravitational anomaly. Methods. The Cassini Grand Finale mission has reported unprecedentedly accurate measurements of the gravitational field of Saturn. An unexplained nonaxisymmetric component of the gravitational field was detected in the data. By performing precise orbit determination (POD) simulations, we studied the possibility that the Cassini spacecraft might sense the dynamo-related nonaxisymmetric gravitational signature in the Grand Finale phase. In addition, further extensively simulated missions of various orbit configurations were carried out in order to explore promising mission strategies that might fulfill the objective of detecting the Saturnian convective dynamo. Results. Our POD simulations show that the gravity science carried out in the Cassini Grand Finale mission is insufficient to determine weak nonaxisymmetric gravitational moments because good subspacecraft-point coverage is lacking. The origin of the unexplained Saturnian gravity remains a puzzle. However, it is positively indicated by our simulations that future gravitational sounding is probably able to detect dynamo-related gravity when the subspacecraft-point coverage of a mission is sufficient. We suggest that the mission orbits be purposely designed into a near-polar orientation with a height of about 6000 km at periapsis and a moderate eccentricity of 0.5. A total POD tracking time of five months would enable the detection of the secular nonaxisymmetric gravitational moments that are caused by the deep convective dynamo of Saturn. The orbit strategy can facilitate engineering implementation by keeping the spacecraft marginally away from the Saturn radiation belt throughout the mission.

scholarly journals Coverage Assessment For Community-Based Management Of Acute Malnutrition In Rural And Urban Ghana: A Comparative Cross-Sectional Study. 

2021 ◽  
Author(s):  
Joana Apenkwa ◽  
Sam K Newton ◽  
Samuel Kofi Amponsah ◽  
Reuben Osei-Antwi ◽  
Emmanuel Nakua ◽  
...  
Keyword(s):  
Severe Acute Malnutrition ◽  
Qualitative Approach ◽  
Rural District ◽  
Urban Setting ◽  
Acute Malnutrition ◽  
Rural Setting ◽  
Community Based ◽  
Cross Sectional ◽  
Study District ◽  
Point Coverage

Abstract Background: Ghana for years has implemented the Community-based Management of Acute Malnutrition (CMAM) among children in order to reduce malnutrition prevalence. However, the prevalence of malnutrition remains high. This study aimed to determine CMAM coverage levels in the Ahafo Ano South (AAS), a rural district, and Kumasi Subin sub-metropolis (KSSM), an urban district. Methods: The study was a cross-sectional comparative study with a mixed-methods approach. In all, 497 mother/caregiver and child under-five pairs were surveyed using a quantitative approach while qualitative methods were used to study 25 service providers and 40 mother/ caregivers who did not participate in the quantitative survey. Four types of coverage indicators were assessed: point coverage (defined as the number of Severe Acute Malnutrition cases [SAM] in treatment divided by total number of Severe Acute Malnutrition cases in the study district), geographical coverage (defined as total number of health facilities delivering treatment for SAM divided by total number of healthcare facilities in the study district), and treatment coverage (defined as children with SAM receiving therapeutic care divided by total number of SAM children in the study district) and program coverage (defined as number of SAM cases in the CMAM programme ÷ Number of SAM cases that should be in the programme). The qualitative approach was used to support the assessment of the coverage indicators. Data were analyzed using STATA version 14, and Atlas.ti, version 7.5 for the quantitative and qualitative data respectivelyResults: Geographically, only 6% of the facilities in the urban communities were participating in the CMAM programme as against 29% of rural district facilities. The districts had point coverage of 41% and 10% for the urban and rural districts respectively. The urban setting recorded a SAM prevalence of 52% as against 36% in the rural setting. The proportion of SAM children enrolled in CMAM was higher in KSSM when compared with AAS; 41% and 33% respectively. In both districts, the most likely factors to attract mothers/caregivers to utilize the CMAM services were: ‘free services’ and ‘a cured child.’ The qualitative approach showed that coverage improvement in both districts is hampered by barriers such: distance, transportation cost, lack of trained personnel in the communities for community mobilization and home visits, and insufficient feeds. Conclusion: To improve CMAM coverage, there is the need to train health workers to embark on aggressive health education strategies to encourage mothers/caregivers of malnourished children to utilize CMAM while ensuring that services reach those who need them. Trial registration: This study is approved and registered with The Kwame Nkrumah University of Science and Technology Committee on Human Research, Ethics and Publications (CHRPE/AP/314/15)

THE NECESSITY OF THE STRONG α-CUTS OF A FUZZY SET

2001 ◽  
Vol 09 (02) ◽  
pp. 249-262 ◽  
Author(s):  
INÉS COUSO ◽  
SUSANA MONTES ◽  
PEDRO GIL
Keyword(s):  
Fuzzy Set ◽  
Unknown Parameter ◽  
New Interpretation ◽  
The Relationship ◽  
Point Coverage

Some aspects of the relationship between Goodman and Nguyen's one-point coverage interpretation of a fuzzy set and Zadeh's possibilistic interpretation are discussed. As a result of this, we derive a new interpretation of the strong α-cut of a normalized fuzzy set, namely that of being the most precise set we are sure to contain an unknown parameter with probability greater than or equal to 1-α.

scholarly journals Solving Point Coverage Problem in Wireless Sensor Networks Using Whale Optimization Algorithm

2021 ◽  
Author(s):  
Mahnaz Toloueiashtian ◽  
Mehdi Golsorkhtabaramiri ◽  
Seyed Yaser Bozorgi Rad
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Optimization Algorithm ◽  
Energy Use ◽  
Whale Optimization Algorithm ◽  
Wireless Sensor ◽  
Dynamic Power Management ◽  
Coverage Problem ◽  
Whale Optimization ◽  
Point Coverage

Todays, dynamic power management methods that decrease the energy use of sensor networks after their design and deployment are of paramount importance. In Wireless Sensor Networks (WSN), coverage and detection quality are one aspect of service quality and power consumption reduction aspect. The aim of the coverage problem is to monitor at least one node at each point in the targeted area and is divided into three categories: border, area, and point coverage. In point coverage, which is our interest, the problem is to cover specific points of the environment scattered on the surface of the environment; their position is decided on and called the goal. In this paper, a new metaheuristic algorithm based on Whale Optimization Algorithm (WOA) is proposed. The proposed algorithm tries to find the Best Solution (BS) based on three operations exploration, spiral attack, and siege attack. Several scenarios, including medium, hard and complex problems, are designed to evaluate the proposed technique, and it is compared to Genetic Algorithm (GA) and Ant Colony Optimization (ACO) based on time complexity criteria in providing a suitable coverage, network lifetime, energy consumption. The simulation results show that the proposed algorithm performs better than the compared ones in most scenarios.

scholarly journals Rancangan Program Simulasi Penentuan Letak Lokasi Antena Terbaik Menggunakan Algoritma Fletcher-Powell

2011 ◽  
Vol 2 (2) ◽  
pp. 1107
Author(s):  
Ngarap Imanuel Manik Manik
Keyword(s):  
Information Technology ◽  
Program Evaluation ◽  
Computer Program ◽  
Model Calculation ◽  
Information Delivery ◽  
Calculation Process ◽  
A Company ◽  
Antenna Location ◽  
Point Coverage

To meet the needs of information delivery to be rapid, mobile and safe needed a model calculation of the best antenna location and utilization of transmission media. One model that can be used takes advantages of wireless as well as models Flether-Powell algorithm, which combines mathematics with information technology. The algorithm can calculate the best position of a transmitter with reference of maximum received intensity amount in all the Main Point Coverage. To simplify the calculation process a computer program is developed written in Borland C. the program evaluation results show that by utilizing this application a company can place transmitters better and more effectively. 

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