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

An integrated approach to correction for off-resonance effects and subject movement in diffusion MR imaging

In this paper we describe a method for retrospective estimation and correction of eddy current (EC)-induced distortions and subject movement in diffusion imaging. In addition a susceptibility-induced field can be supplied and will be incorporated into the calculations in a way that accurately reflects that the two fields (susceptibility- and EC-induced) behave differently in the presence of subject movement. The method is based on registering the individual volumes to a model free prediction of what each volume should look like, thereby enabling its use on high b-value data where the contrast is vastly different in different volumes. In addition we show that the linear EC-model commonly used is insufficient for the data used in the present paper (high spatial and angular resolution data acquired with Stejskal–Tanner gradients on a 3 T Siemens Verio, a 3 T Siemens Connectome Skyra or a 7 T Siemens Magnetome scanner) and that a higher order model performs significantly better. The method is already in extensive practical use and is used by four major projects (the WU-UMinn HCP, the MGH HCP, the UK Biobank and the Whitehall studies) to correct for distortions and subject movement

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness