48 research outputs found
The contribution of optimal turbo fan transport aircraft climb schedule to air company economy
Today airlines are challenging two opposite goals: minimization of flight fuel consumption and minimization of elapsed flight time. A well‐known cost structure and cost generators represent significant pre‐conditions for defining cost optimization strategy in an airline company. Airline company management has a limited set of tools for cost managing, which include the following documents: Performance Engineers’ Manual and Aircraft Flight Manual. In this particular paper review we discuss the problem of vertical flight path of turbo‐fan aircraft, where we point out the impact of the choice of climb technique on the overall en route flight profile costs. In temporary aircraft flight preparation process, there is no stressing out the significance of the climb phase in minimizing costs of this particular flight phase. In the paper we show the procedure of defining optimal climbing resulting minimum costs, but also optimal function operational adjustment to the climb schedule. This way of the approximation of optimal function and its adjustment to the operational use enables the application of minimal cost climbing technique in operational use of transportation aircraft. On short‐haul flights, climb phase can reduce cruise flight length up to 60% of total range. In the paper, we show the impact of climb regime on flight profile of turbo‐fan aircraft considering the usage of time, fuel and costs. The impact is shown according to the data taken from the Performance Engineers Manual. The impact stresses the importance of minimum costs climbing regime to cutting down total flight costs. It also shows the conditions which need to be fulfilled in order to apply minimum costs climbing technique. We identify the scope of CAS speed during climb and TOC for flights minimum total expenses by using minimum costs climbing technique. Conditions for achieving minimum costs climbing technique are the results of the logarithmic differential. In order to achieve optimal numerical results we used Newton‐Raphson formula.
Santrauka
Šiandien oro transporte svarbūs du tikslai: skrydžio metu sunaudojamo kuro mažinimas ir skrydžio laiko trumpinimas. Žinoma kainos struktūra ir kainos komponentės yra reikšmingos išankstinės sąlygos, padedančios sudaryti kainos optimizavimo strategiją oro transporto bendrovėje. Oro transporto bendrovės valdytojai turi ribotą sąnaudų valdymo priemonių komplektą – tai „Priežiūros inžinieriaus vadovas“ ir „Orlaivio skrydžio vadovas“. Straipsnyje aptariama turbosraigtinio lėktuvo vertikalios skrydžio krypties problema, parodomas pasirinktos kilimo technikos poveikis bendrai skrydžio kainai. Dabartiniame lėktuvo ruošimosi skrydžiui procese nėra pabrėžiama kilimo fazės įtaka bendrų skrydžio sąnaudų mažinimui. Straipsnyje pateikiama procedūra, kaip nustatyti optimalų orlaivio kilimą mažiausiomis sąnaudomis, taip pat optimalumo funkcijos korekciją kilimo plane. Optimalumo funkcijos aproksimavimas ir jos naudojimas leidžia taikyti mažiausių sąnaudų kilimo techniką lėktuve. Trumpalaikiuose skrydžiuose kilimo fazė gali sumažinti kruizinio skrydžio trukmę iki 60 proc. Straipsnyje rodoma, kaip lėktuvo kilimo režimas daro poveikį turbosraigtinio lėktuvo skrydžiui laiko, kuro ir sąnaudų požiūriu remiantis duomeni mis, paimtais iš „Priežiūros inžinieriaus vadovo“. Skaičiai rodo, kaip minimalių sąnaudų kilimo režimas sumažina bendrąsias skrydžio sąnaudas. Straipsnyje taip pat atskleidžiamos sąlygos, kurios turi būti vykdytos norint pritaikyti minimalių sąnaudų kilimo techniką. Ją naudojant nustatytas lėktuvo skrydžio greitis ir pakilimo aukštis. Minimalių sąnaudų kilimo technikos sąlygos yra logaritminio diferencialo prendiniai. Optimaliems skaitmeniniams rezultatams gauti panaudota Niutono ir Rapsono formulė.
First published online: 21 Oct 2010
Reikšminiai žodžiai: oro bendrovė, ekonomija, transporto lėktuvas, kilimas, techniniai duomenys,
optimizavimas, sąnaudos
Towards Activity Context using Software Sensors
Service-Oriented Computing delivers the promise of configuring and
reconfiguring software systems to address user's needs in a dynamic way.
Context-aware computing promises to capture the user's needs and hence the
requirements they have on systems. The marriage of both can deliver ad-hoc
software solutions relevant to the user in the most current fashion. However,
here it is a key to gather information on the users' activity (that is what
they are doing). Traditionally any context sensing was conducted with hardware
sensors. However, software can also play the same role and in some situations
will be more useful to sense the activity of the user. Furthermore they can
make use of the fact that Service-oriented systems exchange information through
standard protocols. In this paper we discuss our proposed approach to sense the
activity of the user making use of software
Hepatitis B care cascade among people with HIV/HBV coinfection in the North American AIDS Cohort Collaboration on Research and Design, 2012-2016
A care cascade is a critical tool for evaluating delivery of care for chronic infections across sequential stages, starting with diagnosis and ending with viral suppression. However, there have been few data describing the hepatitis B virus (HBV) care cascade among people living with HIV infection who have HBV coinfection. We conducted a cross-sectional study among people living with HIV and HBV coinfection receiving care between January 1, 2012 and December 31, 2016 within 13 United States and Canadian clinical cohorts contributing data to the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD). We evaluated each of the steps in this cascade, including: 1) laboratory-confirmed HBV infection, 2) tenofovir-based or entecavir-based HBV therapy prescribed, 3) HBV DNA measured during treatment, and 4) viral suppression achieved via undetectable HBV DNA. Among 3,953 persons with laboratory-confirmed HBV (median age, 50 years; 6.5% female; 43.8% were Black; 7.1% were Hispanic), 3,592 (90.9%; 95% confidence interval, 90.0-91.8%) were prescribed tenofovir-based antiretroviral therapy or entecavir along with their antiretroviral therapy regimen, 2,281 (57.7%; 95% confidence interval, 56.2-59.2%) had HBV DNA measured while on therapy, and 1,624 (41.1%; 95% confidence interval, 39.5-42.6) achieved an undetectable HBV DNA during HBV treatment. Our study identified significant gaps in measurement of HBV DNA and suppression of HBV viremia among people living with HIV and HBV coinfection in the United States and Canada. Periodic evaluation of the HBV care cascade among persons with HIV/HBV will be critical to monitoring success in completion of each step
THE CONTRIBUTION OF OPTIMAL TURBO FAN TRANSPORT AIRCRAFT CLIMB SCHEDULE TO AIR COMPANY ECONOMY
iCAP: Interactive prototyping of context-aware applications
Abstract. Although numerous context-aware applications have been developed and there have been technological advances for acquiring contextual information, it is still difficult to develop and prototype interesting context-aware applications. This is largely due to the lack of programming support available to both programmers and end-users. This lack of support closes off the context-aware application design space to a larger group of users. We present iCAP, a system that allows end-users to visually design a wide variety of context-aware applications, including those based on if-then rules, temporal and spatial relationships and environment personalization. iCAP allows users to quickly prototype and test their applications without writing any code. We describe the study we conducted to understand end-users ’ mental models of context-aware applications, how this impacted the design of our system and several applications that demonstrate iCAP’s richness and ease of use. We also describe a user study performed with 20 end-users, who were able to use iCAP to specify every application that they envisioned, illustrating iCAP’s expressiveness and usability.
Foliar penetration and translocation of 2,4,5-T in blackberry (Rubus procerus P.J. Muell.)
Parallel multiclass support vector interpretation of haemodynamic parameters for manifestation of aortic and arterial occlusive diseases
Aortic and arterial occlusive diseases are congenital conditions manifested in impedance plethysmography and are difficult to interpret. A parallel multiclass support vector classification of haemodynamic parameters computed from plethysmographic observations is proposed for diagnosis of aortoarteritis, atherosclerotic narrowing and coarctation of aorta. The proposed support vector algorithm was able to detect more precisely the presence of thrombotic occlusions at proximal and distal arteries. The proposed method provided better accuracy and sensitivity of 97.46% and 98.3% compared to principal component analysis (PCA) based backpropagation and non-weighted support vector architectures respectively. The results of the genotype were ably supported by receiver operating characteristics (ROC) curves which depict a ratio of true positive rate and false positive rate of over 0.9 for all classes as compared with ratios varying from 0.7 to 0.9 for majority of classes as observed in case of non weighted architecture. A reduction of over 60% in negative likelihood ratio with a 5% increase in negative predictive value was observed as compared to Elman and PCA based backpropagation architectures. The results were validated from angiographic findings at Grant Medical College, J.J. Hospital, and Bhabha Atomic Research Centre (BARC) all in Mumbai. The proposed method also distinguished cases with nephritic syndrome, lymphangitis, and venous disorders against those with arterial occlusive diseases. Application of the proposed method has potential to enhance performance of impedance plethysmography