100,436 research outputs found
Estimating economic severity of Air Traffic Flow Management regulations
No full textThe development of trajectory-based operations and the rolling network operations plan in European air traffic management network implies a move towards more collaborative, strategic flight planning. This opens up the possibility for inclusion of additional information in the collaborative decision-making process. With that in mind, we define the indicator for the economic risk of network elements (e.g., sectors or airports) as the expected costs that the elements impose on airspace users due to Air Traffic Flow Management (ATFM) regulations. The definition of the indicator is based on the analysis of historical ATFM regulations data, that provides an indication of the risk of accruing delay. This risk of delay is translated into a monetary risk for the airspace users, creating the new metric of the economic risk of a given airspace element. We then use some machine learning techniques to find the parameters leading to this economic risk. The metric is accompanied by an indication of the accuracy of the delay–cost prediction model. Lastly, the economic risk is transformed into a qualitative economic severity classification. The economic risks and consequently economic severity can be estimated for different temporal horizons and time periods providing an indicator which can be used by Air Navigation Service Providers to identify areas which might need the implementation of strategic measures (e.g., resectorisation or capacity provision change), and by Airspace Users to consider operation of routes which use specific airspace regions
Flexibility in strategic flight planning
No full textA deterministic model that indicates flexibility of flights at the strategic level (up to 6 months ahead) taking into account changing airspace configurations and capacity is formulated. Flexibility is quantified by means of time windows (TWs). Flights complying with TWs guarantee that they will not impact negatively any other flight. Three variants of the model and three types of TWs are tested on a large-size data instance (the European network for an entire day of traffic). The model output specifies the constrained flights (i.e., with TWs shorter than the maximum size allowed for their definition), the constraining sector-hours and provides a list of saturated sector-hours. The meaning of each of the results is explored, across the three TW model variants, as well as the capability of the model variants to assure that capacity limits will not be exceeded. The criticality index, a measure of the sector-hour saturation, is introduced. This index can be used to identify areas for potential improvements. Sharing the information obtained from the TW model results at a strategic level can help both airlines and air navigation service providers (ANSPs) to improve the network status: airlines can decide to re-route heavily constrained flights (e.g., with one minute wide TWs), whereas ANSPs could decide to re-organise the capacity provision of the saturated airspace portions. The TW model can be re-run with the proposed changes, with the goal to assess the impact on both the individual stakeholders and the network. Thus, the model offers the measure of flight flexibility, and can be used as a tool to assess the impact of changes, helping in decision-making processes of airlines and ANSPs
Capacity Sharing within Virtual Centre How much delay can be reduced?
No full textAirspace Architecture Study proposed the future Single European Airspace System, based on modern technologies that could divide the air traffic service provision from local infrastructure for data provision, enabling the decoupling of geographical location from the service provision. This decoupling would enable virtualisation where service providers could use data from the common data services, opening doors to different organisation of air traffic service provision, namely more advanced capacity sharing. Virtualisation concept is still under development and several recent studies evaluated some aspects of virtualisation in ATM, but did not yet address in detail the impacts of different Virtual Centre implementation scenarios. In this paper, we propose a linear optimisation model to evaluate the impact of virtualisation and capacity sharing in terms of delay reduction. We show that taking into account the current airspace design and air traffic management resources, even the air navigation service providers that accumulate the highest capacity-caused delays could decrease those in the range of 25-50% up to about 80% through internal collaboration. Furthermore, the decrease of over 50% of the total capacity-caused delays could be obtained if FABEC1 were to form a Virtual Centre, and the decrease of about 90% of the total European delay if the Single European Sky (SES) area would form a Virtual Centre. The analysed capacity sharing collaborations indicate the possibility of significant delay reductions, but would not be sufficient, on their own, to eliminate capacity-caused issues in Europe
Flight flexibility in strategic traffic planning: visualisation and mitigation use case
No full textThe concept of strategic traffic planning that takes into account changing airspace configurations, their capacity, and allows the quantification of flight flexibility is presented in this paper: the visualization of the results and an example of possible use. The concept is implemented through two deterministic optimization models. Here, we focus on the output of the models, which identifies the departure times, trajectories, flight flexibility and the list of saturated sector-hours throughout the day, based on the configurations used during the day. In order to make the output understandable to various stakeholders, we use a visualization tool and a set of performance indicators. The information on the saturated sectors, and their impact on flexibility (criticality index) is taken as an input in the example of mitigation action application by Air Navigation Service Providers, aimed at improving the situation. A mitigation strategy of increasing capacity of saturated airspace is implemented, and results show that the improvements in flexibility can be achieved
Aplikasi Multimedia Pembelajaran Wajan Bolic
No full textPersaingan dalam dunia pendidikan yang semakin tinggi, menuntut untuk lebih mengikuti perkembangan dari teknologi, dimana itu semua merupakan sebuah tantangan yang harus dihadapi oleh semua pihak, terutama dalam dunia pendidikan yang tidak bisa lepas dari teknologi komputer dan informatika. Teknologi internet merupakan salah satu yang sangat penting bagi pendidikan, dan tidak sedikit instansi pendidikan yang menyediakan jaringan wireless LAN untuk mempermudah pengaksesan internet sebagai sarana pembelajaran, dan menjadikan teknologi internet menjadi bahan ajar dalam kurikulum. Namun pada kenyataannya, sarana pembelajaran atau bahan ajar mengenai jaringan yang bersifat interaktif sangat minim ditemukan.
Pembelajaran konvensional yang lebih cenderung membosankan, dan kurang komunikatif dalam mentransfer pengetahuan, merupakan salah satu dari beberapa faktor yang membuat peserta didik atau siswa menjadi kurang, dalam mendalami suatu materi pelajaran. Dalam kasus ini akan mengambil contoh dalam pembelajaran jaringan. Menurut hasil penelitian materi pembelajaran yang membutuhkan materi dan praktikum, seperti pembelajaran jaringan akan sulit diserap oleh siswa atau peserta didik apabila penyampaian materi masih menggunakan metode konvensional seperti membaca buku. Oleh karena itu diperlukan proses pembelajaran yang lebih interktif
Banyak Instansi, sekolah atau kampus yang menyediakan akses internet gratis dengan menggunakan teknologi Wireless atau yang populer adalah teknologi WIFI. Oleh sebab itu, maka diperlukan sebuah media untuk menangkap signal wireless lebih kuat dengan biaya yang relative lebih murah dan daya tangkap yang lebih jauh daripada menggunakan wireless receiver biasa. Wajan bolic merupakan sebuah terobosan baru untuk memerkuat tangkapan signal wireless
ITS solutions for air cargo revenue management
No full textIn this work we present Revenue Management applications for air cargo and discuss the most relevant issues that currently limit their effectiveness. We explain how these concerns may be tackled by decreasing uncertainty on customer data and improving communication along the supply chain and we illustrate how integration with Intelligent Transportation Systems may play a key role in delivering such improvements
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Handwritten biographical information on Paulina T. McClung Merritt
No full textA handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
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