scholarly journals Quantification and Forecasting of Cumulonimbus (Cb) Clouds Direction, Nebulosity and Occurrence With Autoregression Using 2018-2020 Dataset From Yaounde-nsimalen

2022 ◽  
Author(s):  
Mbucksek Blaise Ringnwi ◽  
DAÏKA Augustin ◽  
TSEDEPNOU Rodrigue ◽  
Bon Firmin André ◽  
Kossoumna Libaa Natali
Keyword(s):  
Traffic Management ◽  
Situational Awareness ◽  
Air Traffic Management ◽  
Future Research ◽  
Sarima Model ◽  
Augmented Dickey Fuller ◽  
Data Points ◽  
Auto Regression ◽  
Autoregressive Neural Network

Abstract This works reports the quantification and forecasting of Cumulonimbus (Cb) clouds direction, nebulosity and occurrence with auto regression using 2018-2020 dataset from Yaoundé –Nsimalen of Cameroon. Data collected for October 2018-2020 consisted of 2232 hourly observations. Codes were written to automatically align, multi-find and replace data points in excel to facilitate treating big datasets. The approach included quantification of direction generating time series from data and determination of model orders using the correlogram. The coefficients of the SARIMA model were determined using Yule-Walker equations in matrix form, the Augmented Dickey Fuller test (ADF) was used to check for stationarity assumption, Portmanteau test to check for white noise in residuals and Shapiro-Wilk test to check normality assumptions. After writing several algorithms to test different models, an Autoregressive Neural Network (ANN) was fitted and used to predict the parameters over window of 2 weeks. Autocorrelation Function (ACF) shows no correlation between residuals, with p ≤ 0.05, fitting the stationarity assumption. Average performance is 80%. A stationary wavelike occurrence of the direction has been observed, with East as the most frequented sector. Forecast of Cb parameters is important in effective air traffic management, creating situational awareness and could serve as reference for future research. The method of decomposition could be made applicable in future research to quantify/forecast cloud directions.

scholarly journals Toward ATM Resiliency: A Deep CNN to Predict Number of Delayed Flights and ATFM Delay

Aerospace ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 28
Author(s):  
Rasoul Sanaei ◽  
Brian Alphonse Pinto ◽  
Volker Gollnick
Keyword(s):  
Traffic Management ◽  
Situational Awareness ◽  
Air Traffic Management ◽  
Percentage Error ◽  
Operational Flexibility ◽  
Target Date ◽  
Deep Cnn ◽  
Stochastic Events ◽  
Demand And Capacity ◽  
Total Network

The European Air Traffic Management Network (EATMN) is comprised of various stakeholders and actors. Accordingly, the operations within EATMN are planned up to six months ahead of target date (tactical phase). However, stochastic events and the built-in operational flexibility (robustness), along with other factors, result in demand and capacity imbalances that lead to delayed flights. The size of the EATMN and its complexity challenge the prediction of the total network delay using analytical methods or optimization approaches. We face this challenge by proposing a deep convolutional neural network (DCNN), which takes capacity regulations as the input. DCNN architecture successfully improves the prediction results by 50 percent (compared to random forest as the baseline model). In fact, the trained model on 2016 and 2017 data is able to predict 2018 with a mean absolute percentage error of 22% and 14% for the delay and delayed traffic, respectively. This study presents a method to provide more accurate situational awareness, which is a must for the topic of network resiliency.

scholarly journals Combined Assessment of Software Safety and Security Requirements

2018 ◽  
Vol 20 (1) ◽  
pp. 46-69 ◽  
Author(s):  
Christian Raspotnig ◽  
Peter Karpati ◽  
Andreas L Opdahl
Keyword(s):  
Traffic Management ◽  
Modern Society ◽  
Air Traffic Management ◽  
Security Requirements ◽  
Functional Requirements ◽  
Software Safety ◽  
Secure Systems ◽  
Safety Requirements ◽  
Stakeholder Groups

Safety is a fundamental concern in modern society, and security is a precondition for safety. Ensuring safety and security of complex integrated systems requires a coordinated approach that involve different stakeholder groups going beyond safety and security experts and system developers. The authors have therefore proposed CHASSIS (Combined Harm Assessment of Safety and Security for Information Systems), a method for collaborative determination of requirements for safe and secure systems. In this article, the authors evaluate CHASSIS through industrial case studies of two small-to-medium sized suppliers to the air-traffic management (ATM) sector. The results suggest that CHASSIS is easy to use, and that handling safety and security together provides benefits because techniques, information, and knowledge can be reused. The authors conclude that further exploration and development of CHASSIS is worthwhile, but that better documentation is needed—including more detailed process guidelines—to support elicitation of security and safety requirements and to systematically relate them to functional requirements.

Combined Assessment of Software Safety and Security Requirements

2021 ◽  
pp. 666-693
Author(s):  
Christian Raspotnig ◽  
Peter Karpati ◽  
Andreas L Opdahl
Keyword(s):  
Traffic Management ◽  
Modern Society ◽  
Air Traffic Management ◽  
Security Requirements ◽  
Functional Requirements ◽  
Software Safety ◽  
Secure Systems ◽  
Safety Requirements ◽  
Stakeholder Groups

Safety is a fundamental concern in modern society, and security is a precondition for safety. Ensuring safety and security of complex integrated systems requires a coordinated approach that involve different stakeholder groups going beyond safety and security experts and system developers. The authors have therefore proposed CHASSIS (Combined Harm Assessment of Safety and Security for Information Systems), a method for collaborative determination of requirements for safe and secure systems. In this article, the authors evaluate CHASSIS through industrial case studies of two small-to-medium sized suppliers to the air-traffic management (ATM) sector. The results suggest that CHASSIS is easy to use, and that handling safety and security together provides benefits because techniques, information, and knowledge can be reused. The authors conclude that further exploration and development of CHASSIS is worthwhile, but that better documentation is needed—including more detailed process guidelines—to support elicitation of security and safety requirements and to systematically relate them to functional requirements.

ISAR imaging of helicopters using millimeter wave radars

2009 ◽  
Vol 1 (3) ◽  
pp. 171-178 ◽  
Author(s):  
Helmut Essen ◽  
Manfred Hägelen ◽  
Alfred Wahlen ◽  
Karsten Schulz ◽  
Klaus Jäger ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Traffic Management ◽  
Imaging Techniques ◽  
Air Traffic Management ◽  
Security Applications ◽  
Isar Imaging ◽  
Medium Range ◽  
Reference Images ◽  
Automotive Radars

The capabilities of millimeter wave radars have been demonstrated for a long period of time for missile seeker applications and for automotive radars. The technological advantages of this type of radar can be adapted to security applications in air traffic management at short and medium range as well as on the ground. The application discussed in this paper focuses on inverse synthetic aperture radar (ISAR) imaging techniques for the derivation of high-resolution signatures of helicopters in the air and the determination of reference images using turntable measurements.

scholarly journals Does Free Route Implementation Influence Air Traffic Management System? Case Study in Poland

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1422
Author(s):  
Ewa Dudek ◽  
Karolina Krzykowska-Piotrowska
Keyword(s):  
Traffic Management ◽  
Management System ◽  
Rating Scales ◽  
Negative Impact ◽  
Air Traffic Management ◽  
Air Traffic ◽  
Transport Safety ◽  
Traffic Management System

The issue addressed in this publication concerns new Air Traffic Management (ATM) functionality, identified in the Commission Implementing Regulation (EU) No 716/2014, known as Flexible Airspace Management and Free Route (FRA). The authors pose a question—does free route implementation influence air transport safety? What can be done to maintain the current level of safety and still implement modern solutions? To achieve the aim of this paper a developed concept of Risk Priority Number (RPN) calculation, with determination of main RPN components rating scales, in order to carry out the FMEA (Failure Mode and Effects Analysis) risk analysis of FRA implementation was done. The results allow lining up of the identified potential incompatibilities according to their criticality to the system. In effect it can be said that each modification in a management system, related to safety, influence the safety itself. Nevertheless, this influence does not always lead to negative impact.

Safety Culture and Safety-Relevant Behavior in Air Traffic Management

2015 ◽  
Vol 5 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Michaela Schwarz ◽  
K. Wolfgang Kallus
Keyword(s):  
Safety Culture ◽  
Traffic Management ◽  
Service Providers ◽  
Five Factor Model ◽  
Principal Component ◽  
Air Traffic Management ◽  
Air Traffic ◽  
Psychometric Validation ◽  
Safety Attitudes ◽  
Culture Development

Since 2010, air navigation service providers have been mandated to implement a positive and proactive safety culture based on shared beliefs, assumptions, and values regarding safety. This mandate raised the need to develop and validate a concept and tools to assess the level of safety culture in organizations. An initial set of 40 safety culture questions based on eight themes underwent psychometric validation. Principal component analysis was applied to data from 282 air traffic management staff, producing a five-factor model of informed culture, reporting and learning culture, just culture, and flexible culture, as well as management’s safety attitudes. This five-factor solution was validated across two different occupational groups and assessment dates (construct validity). Criterion validity was partly achieved by predicting safety-relevant behavior on the job through three out of five safety culture scores. Results indicated a nonlinear relationship with safety culture scales. Overall the proposed concept proved reliable and valid with respect to safety culture development, providing a robust foundation for managers, safety experts, and operational and safety researchers to measure and further improve the level of safety culture within the air traffic management context.

Determination of the International Sensitivity Index of a New Near-Patient Testing Device to Monitor Oral Anticoagulant Therapy

1997 ◽  
Vol 78 (02) ◽  
pp. 855-858 ◽  
Author(s):  
Armando Tripodi ◽  
Veena Chantarangkul ◽  
Marigrazia Clerici ◽  
Barbara Negri ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Linear Relationship ◽  
Whole Blood ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Oral Anticoagulants ◽  
Calibration Model ◽  
Testing Device ◽  
Data Points ◽  
Near Patient Testing

SummaryA key issue for the reliable use of new devices for the laboratory control of oral anticoagulant therapy with the INR is their conformity to the calibration model. In the past, their adequacy has mostly been assessed empirically without reference to the calibration model and the use of International Reference Preparations (IRP) for thromboplastin. In this study we reviewed the requirements to be fulfilled and applied them to the calibration of a new near-patient testing device (TAS, Cardiovascular Diagnostics) which uses thromboplastin-containing test cards for determination of the INR. On each of 10 working days citrat- ed whole blood and plasma samples were obtained from 2 healthy subjects and 6 patients on oral anticoagulants. PT testing on whole blood and plasma was done with the TAS and parallel testing for plasma by the manual technique with the IRP CRM 149S. Conformity to the calibration model was judged satisfactory if the following requirements were met: (i) there was a linear relationship between paired log-PTs (TAS vs CRM 149S); (ii) the regression line drawn through patients data points, passed through those of normals; (iii) the precision of the calibration expressed as the CV of the slope was <3%. A good linear relationship was observed for calibration plots for plasma and whole blood (r = 0.98). Regression lines drawn through patients data points, passed through those of normals. The CVs of the slope were in both cases 2.2% and the ISIs were 0.965 and 1.000 for whole blood and plasma. In conclusion, our study shows that near-patient testing devices can be considered reliable tools to measure INR in patients on oral anticoagulants and provides guidelines for their evaluation.

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