1,552 research outputs found
Elméleti felvetések és gyakorlati tapasztalatok a projektportfólió-menedzsment hazai megjelenése kapcsán
A projektportfólió-menedzsment (PPM) abban a helyzetben válik elengedhetetlenül fontossá, amikor több projekt egyidejű megvalósításából fakadó problémákkal kell szembenézni. Miközben a projektekben történő gondolkodás számos területen egyre jellemzőbb, fel kell tenni azt a kérdést is, hogy a sok projekt együtt vajon optimális rendszert alkot-e az adott szervezetben, és megfelelően támogatja-e a versenyképességet, az erőforrások optimális felhasználását, a szervezet céljait?
A szervezetek vezetői már ráeszméltek erre a dilemmára, és a PPM-et egyre inkább alkalmazzák cégeik/intézményeik működési hatékonyságának javítására. A következőkben a szerző arra tesz kísérletet, hogy ennek az új stratégiai menedzsmenteszköznek a hazai megjelenése kapcsán, felvillantsa a téma elméleti hátterét, illetve gyakorlati használhatóságát. Mindezt úgy teszi, hogy külön hangsúlyt fektet a módszer magyarországi megjelenésének konkrét tapasztalataira is
Identification and Spectral Evaluation of Agricultural Crops on Hyperspectral Airborne Data
Hyperspectral remote sensing combined with advanced image processing techniques is an efficient tool for the identification of agricultural crops. In our study we pursued spectral analysis on a relatively small sample area using low number of training points to examine the potential of high resolution imagery. Spectral separability measurements were applied to reveal spectral overlapping between 4 crop species and for the discrimination we also used statistical comparisons such as plotting the PC values and calculating standard deviation of single band reflectance values on our classes. These statistical results were proven to be good indicators of spectral similarity and potential confusion of data samples. The classification of Spectral Angle Mapper (SAM) had an overall accuracy of 72% for the four species where the poorest results were obtained from the test points of garlic and sugar beet. Comparing the statistical analyses we concluded that spectral homogeneity does not necessarily have influence on the accuracy of mapping, whereas separability scores strongly correlate with classification results, implying also that preliminary statistical assessments can improve the efficiency of training site selection and provide useful information to specify some technical requirements of airborne hyperspectral surveys
Optimized Superconducting Nanowire Single Photon Detectors to Maximize Absorptance
Dispersion characteristics of four types of superconducting nanowire single
photon detectors, nano-cavity-array- (NCA-), nano-cavity-deflector-array-
(NCDA-), nano-cavity-double-deflector-array- (NCDDA-) and
nano-cavity-trench-array- (NCTA-) integrated (I-A-SNSPDs) devices was optimized
in three periodicity intervals commensurate with half-, three-quarter- and one
SPP wavelength. The optimal configurations capable of maximizing NbN
absorptance correspond to periodicity dependent tilting in S-orientation
(90{\deg} azimuthal orientation). In NCAI-A-SNSPDs absorptance maxima are
reached at the plasmonic Brewster angle (PBA) due to light tunneling. The
absorptance maximum is attained in a wide plasmonic-pass-band in
NCDAI_1/2*lambda-A, inside a flat-plasmonic-pass-band in NCDAI_3/4*lambda-A and
inside a narrow plasmonic-band in NCDAI_lambda-A. In NCDDAI_1/2*lambda-A bands
of strongly-coupled cavity and plasmonic modes cross, in NCDDAI_3/4*lambda-A an
inverted-plasmonic-band-gap develops, while in NCDDAI_lambda-A a narrow
plasmonic-pass-band appears inside an inverted-minigap. The absorptance maximum
is achieved in NCTAI_1/2*lambda-A inside a plasmonic-pass-band, in
NCTAI_3/4*lambda-A at inverted-plasmonic-band-gap center, while in
NCTAI_lambda-A inside an inverted-minigap. The highest 95.05% absorptance is
attained at perpendicular incidence onto NCTAI_lambda-A. Quarter-wavelength
type cavity modes contribute to the near-field enhancement around NbN segments
except in NCDAI_lambda-A and NCDDAI_3/4*lambda-A. The polarization contrast is
moderate in NCAI-A-SNSPDs (~10^2), NCDAI- and NCDDAI-A-SNSPDs make possible to
attain considerably large polarization contrast (~10^2-10^3 and ~10^3-10^4),
while NCTAI-A-SNSPDs exhibit a weak polarization selectivity (~10-10^2).Comment: 26 pages, 8 figure
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