SIMULATION OF EGNOS SATELLITE NAVIGATION SIGNAL USAGE FOR AIRCRAFT LPV PRECISION INSTRUMENT APPROACH

Satellite navigation has become a very important topic in the air transport industry along with its application in instrument approach procedures. Recently, extracted statistical characteristics of the European Geostationary Navigation Overlay Service (EGNOS) satellite signal have been made available from real measurements in the Czech Republic. The numerical modeling approach is taken for a feasibility study of automatic aircraft control during the Localizer Performance with Vertical Guidance (LPV) precision approach based on such navigation data. The model incorporates Kalman filtering of the stochastic navigation signal, feed-back control of L-410 aircraft dynamics and the calculation of approach progress along the predefined procedure. Evaluation of the performance of the system prototype is performed using the scenarios developed with a strong interest in altitude control. The specific scenario is focused on a curved approach which offers a huge advantage of the approaches based on the Satellite-based Augmentation System (SBAS) compared to ones with the Instrument Landing System (ILS). Outputs of simulation executions are statistically analyzed and assessed against predefined navigation performance goals equivalent to ILS categories with a positive outcome.

Enhancement of Routing Protocols for Mobile Adhoc Network

The primaryaim of an ad-hoc network routing protocol is accurate and efficient route creation between node pairs so that messages may be delivered promptly. Route creation need to be done with reduced overhead and bandwidth. This paper presents a scheme to reduce bandwidth and power by the hibernation of nodes for a limited time. The effect of our proposal is then studied by simulation under various conditions and the analysis of the simulation results is done to comprehend the working of our protocol in various areas and how it fares in an application specific scenario.

Making the use of scenarios in LCA easier: the superstructure approach

Purpose Much progress has recently been made in modelling future background systems for LCA by including future scenario data, e.g. from Integrated Assessment Models (IAMs), into life cycle inventory (LCI) databases. A key problem is, however, that this yields potentially dozens of scenario LCI databases (i.e. LCI databases that represent different scenarios and reference years), instead of a single background database, which is very impractical for LCA modelling purposes. This paper proposes an approach to overcome this problem. Methods The approach consists of transforming all scenario LCI databases into a single superstructure database and an associated scenario difference file. The superstructure database is also a regular LCI database, but is constructed to contain all unique exchanges (elementary and intermediate flows) and processes that exist across all scenario LCI databases. The scenario difference file stores the differences between all scenarios and can be used to turn the superstructure into a specific scenario LCI database. This is very fast as it can be done in memory during LCA calculations. Results and discussion A key advantage of the superstructure approach is that a single LCI database can be used to represent different background systems. Therefore, the practitioner does not need to re-link a foreground system to multiple LCI databases, which is work-intensive and invites modelling errors. LCA results for all scenarios and reference years can be calculated automatically. We also illustrate how the superstructure approach has been implemented in the Activity Browser open source LCA software. Although this paper introduces the superstructure approach for background scenarios, it can also be used to model foreground scenarios, and even, as implemented in the Activity Browser, combinations of background and foreground scenarios. Finally, we briefly discuss further challenges that need to be addressed for a more widespread use of background scenarios in LCA. Conclusions The superstructure approach presents a practical solution for making the use of future background scenarios more wide-spread and, therefore, to overcome the problem of performing prospective LCA with temporally inconsistent foreground and background systems. The implementation in the Activity Browser makes the approach available for anyone and may serve as inspiration for other LCA software to implement the superstructure approach or a similar concept. While this may be an important technical milestone, additional coordination between data providers, scenario generators, LCA practitioners, and software developers will be required to further facilitate the use of background scenarios in prospective LCA studies.

Implementing the flipped classroom model in teaching a translation module in Vietnam

This study provided a novel flipped classroom model with a detailed combination of in-class and out-of-class activities to teach a Vietnamese-English Translation module. The study aimed to (1) provide an in-depth insight into how the model was actually implemented in a specific scenario to make the teaching-learning process more interesting and meaningful, and (2) investigate the effectiveness of the flipped classroom model towards learners’ translation performance through various assessments. 39 English-majored juniors at Banking University of Ho Chi Minh City, Vietnam participated in the study during the second semester of the 2018-2019 academic year. The study implemented a case-study mixed method design, applying assessment analysis and content analysis of one specific learning scenario to clarify how the flipped learning model contributed to the training process. Results show that a careful design of the flipped model contributed to the relevant literature on how to implement flipped learning in actual classroom settings, but also effectively improved learners’ performance in translation studies.

Agent-Based Simulation to Measure the Effectiveness of Citizen Sensing Applications—The Case of Missing Children

Citizen sensing applications need to have a number of users defined that ensures their effectiveness. This is not a straightforward task because neither the relationship between the size of the userbase or its effectiveness is easily quantified, nor is it clear which threshold for the number of users would make the application ‘effective’. This paper presents an approach for estimating the number of users needed for location-based crowdsourcing applications to work successfully, depending on the use case, the circumstances, and the criteria of success. It circumvents various issues, ethical or practical, in performing real-world controlled experiments and tackles this challenge by developing an agent-based modelling and simulation framework. This framework is tested on a specific scenario, that of missing children and the search for them. The search is performed with the contribution of citizens being made aware of the disappearance through a mobile application. The result produces an easily reconfigurable testbed for the effectiveness of citizen sensing mobile applications, allowing the study of the marginal utility of new users of the application. The resulting framework aims to be the digital twin of a real urban scenario, and it has been designed to be easily adapted and support decisions on the feasibility, evaluation, and targeting of the deployment of spatial crowdsourcing applications.

CSPM

Security and privacy in cloud systems are critical. To address security and privacy concerns, many security patterns, privacy patterns, and non-pattern-based knowledge have been reported. However, knowing which pattern or combination of patterns to use in a specific scenario is challenging due to the sheer volume of options and the layered cloud stack. To deal with security and privacy in cloud services, this study proposes the cloud security and privacy metamodel (CSPM). CSPM uses a consistent approach to classify and handle existing security and privacy patterns. In addition, CSPM is used to develop a security and privacy awareness process to develop cloud systems. The effectiveness and practicality of CSPM is demonstrated via several case studies.

A systematic approach to the selection of the optimal capacity for liquid hydrocarbons offloading infrastructure and the sequence of exploration stages of a group of prospects

This paper validates and establishes the concept that the optimality of the decision on the timing of exploration, development and production stages for each field, as well as the performance of the combined transport infrastructure, may depend on the results of a specific scenario at one of the objects under consideration, as exemplified by three individual fields at different stages of development and with individual production and economic parameters. Nevertheless, by varying the values of the required parameters (e.g., shipping terminal capacity), we can determine their values that will result in maximizing expected profit from the project in any of the possible scenarios. The models and methods developed within this research represent a systemic approach to resolving the issue, and can be applied to developing the optimal strategy for additional study and development of the cluster of neighboring fields.

Towards Safety Barrier Analysis of Hydrogen Powered Maritime Vessels

This paper focuses on the use of safety barrier analysis, during the design phase of a vessel powered by cryogenic hydrogen, to identify possible weaknesses in the architecture. Barrier analysis can be used to evaluate a series of scenarios that have been identified in the industry as critical. The performance evaluation of such barriers in a specific scenario can lead to either the approval of the design, if a safety threshold is met, or the inclusion of additional barriers to mitigate risk even further. By conducting a structured analysis, it is possible to identify key barriers that need to be included in the system, intended both as physical barriers (sensors, cold box) and as administrative barriers (checklist, operator training). The method chosen for this study is the Barrier and Operational Risk Analysis (BORA) method. This method, developed for the analysis of hydrocarbon releases, is described in the paper and adapted for the analysis of cryogenic hydrogen releases. A case study is presented using the BORA method, developing the qualitative barrier analysis. The qualitative section of the method can be easily adapted to vessels of different class and size adopting the same storage solution. The barrier analysis provides a general framework to analyze the system and check that the safety requirements defined by the ship operator and maritime certification societies are met.

Factors for the Automation of the Creation of Virtual Reality Experiences to Raise Awareness of Occupational Hazards on Construction Sites

Two of the differential characteristics of the AECO sector (architecture, engineering, construction and operation) are barriers for the mass creation of training materials for its workers. On the one hand, the workplace is unique and changing over time; on the other, the aging trend of its workers and the unattractive nature of the industry for new generations of professionals. These two problems can be tackled by virtual reality technologies, which allow the agile creation of all kinds of scenarios, while their current technology may be attractive to young people and intuitive for everyone. This work shows the results of an investigation that seeks to provide automated tools based on virtual reality experiences to support learning in occupational risk prevention. This objective is part of the development of a culture for prevention, which allows the treatment of the human factor, with all its complexity and casuistry. The proposal includes the development of a process and tools that allow replicating the specific scenario where the work will be carried out, incorporating risks and probable incidents, systematically establishing cause-effect relationships, incorporating a narrative (storytelling) that provides emotional meaning to users and Lastly, the creation of a workflow that facilitates the agile development of these virtual reality experiences for each specific work.