Digital color imaging Sharma, G.; Trussell, H.J.
IEEE transactions on image processing,
07/1997, Letnik:
6, Številka:
7
Journal Article
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This paper surveys current technology and research in the area of digital color imaging. In order to establish the background and lay down terminology, fundamental concepts of color perception and ...measurement are first presented using vector-space notation and terminology. Present-day color recording and reproduction systems are reviewed along with the common mathematical models used for representing these devices. Algorithms for processing color images for display and communication are surveyed, and a forecast of research trends is attempted. An extensive bibliography is provided.
Energy-efficiency is the critical requirement for the battery operated portable devices exhibiting compute-intensive image/video processing applications. The color interpolation is the most energy ...consuming operation used within these devices to reconstruct the full resolution color image. In this paper, three approximate color interpolation architectures are proposed by exploiting the relative significance of the computations. These architectures provide high energy efficiency at the cost of small degradation in quality. Further, novel energy scalable color interpolation algorithm and its architecture (ES-COINA) are proposed that provide improved quality-energy trade-off. The efficacy of the proposed architectures is evaluated using various quality metrics by simulating them with different benchmark images from Kodak dataset. The proposed architectures are implemented on Artix-7 FPGA board and compared over the existing. Further, the proposed and existing architectures are implemented on Cadence RTL Compiler and synthesized with 180nm technology file. The simulation results show that the proposed approximate architectures provide 88%, 71.3%, and 46% reduced energy consumption over the best-known color interpolation architecture with a little degradation in quality. Further, the proposed ES-COINA reduces the energy consumption by 21% which can be extended to 92.6% when switched from high quality to high energy-efficient mode of operation.
As power demand constantly (and rapidly) increases and with the introduction of many sophisticated electronic devices, power quality issues are becoming a major problem for the power sector. In this ...context, issues of power quality, voltage swells and sags have become rather common. Custom power devices are generally used to solve this problem. A dynamic voltage restorer (DVR) is the most efficient and effective modern custom power device used in power distribution networks. In this paper a new DVR model is presented. The proposed DVR has a molten carbonate fuel cell (MCFC) as its DC source of supply with an ultra-capacitor along with a fuzzy controller as its controlling unit. The complete model is implemented in MATLAB/SIMULINK and the output of the proposed model is compared with conventional DVR model with a simple DC voltage source and a capacitor with the same fuzzy controller
The genotoxic effects of malathion was evaluated using chromosome aberration, sister chromatid exchange (SCE) and sperm abnormality assays in mice. All the three acute doses (2.5, 5 and 10
mg/kg) of ...malathion tested in the present study, induced significant dose-dependent increase in the frequency of chromosome aberrations and sperm abnormalities, but did not affect the total sperm count. The highest acute dose induced a >12-fold increase in the frequency of chromosome aberrations, two-fold increase in the frequency of SCEs and four-fold increase in the frequency of sperms with abnormal head morphology following intraperitoneal (i.p.) exposure. Further, a significant increase in the frequency of SCEs was observed, but the increase was not dose-dependent. At higher doses, malathion induced a moderate delay in cell cycle as evident from the increase in average generation time (AGT). The present findings suggest that technical grade malathion is a potent genotoxic agent and may be regarded as a potential germ cell mutagen also.
Polythiophenes are the promising candidates for polymer photovoltaic devices due to their stability and absorption in near-red region of visible spectrum. In this paper, the optical, electrical, and ...photovoltaic properties of device fabricated with the blend of poly(phenyl azo methane thiophene) (PPAT) (donor) and thiazole yellow (TY) (acceptor) (70:30 by weight ratio), sandwiched between ITO and Al electrodes have been reported. The observed strong quenching in the fluorescence of PPAT after blending it with TY indicates the rapid and effective separation of photo-induced electron and hole and subsequent transfer of electron from PPAT to TY and holes from TY to PPAT. The absorption spectrum of the blend shows a super-imposition of both components indicating that there is no charge transfer at the ground state. The thermal annealing shows significant improvement in both optical and photoelectrical properties of the blend, as can be seen from the recorded current–voltage characteristics (
J–
V) of the device in dark and under illumination. This change is also evidenced by the modification in absorption spectrum on annealing resulting in red shifts, due to the donor component. The appearance of red shift may by attributed to the molecular diffusion of TY out to the PPAT matrix on annealing, resulting in a rise to the TY clusters. The growth of TY clusters lead to the formation of percolation paths and therefore improves photocurrent. By annealing the device under applied external voltage, both the electrical and photovoltaic properties of the device have been improved. The enhancement in photocurrent, quantum collection efficiency (EQE), and fill factor of annealed device may be due to an increase in carrier mobility after annealing the device.
Abstract Background In patients admitted for heart failure (HF), unrecognized elevation of left ventricular end-diastolic pressure (LVEDP) at the time of discharge may have a role in the high ...rehospitalization rate for HF on follow-up. Methods and Results In a small, prospective study (n = 50), patients admitted for HF were randomized to management guided by daily noninvasive estimated LVEDP monitoring (Group I, open) to a target LVEDP of <20 mm Hg or management based on clinical assessment alone without knowledge of the estimated LVEDP (Group II, blinded). Noninvasive estimated LVEDP was measured by the VeriCor monitor, which uses the Valsalva maneuver to derive the LVEDP. The primary endpoints were the reduction of estimated LVEDP at discharge and the HF rehospitalization rate on follow-up. Estimated LVEDP was significantly reduced at discharge in the open group compared with the blinded group (mean estimated LVEDP 19.7 ± 1.3 mm Hg vs 25.6 ± 1.5 mm Hg, respectively, P = 0.01). The rehospitalization rates for HF on follow-up were significantly improved in the open group compared with the blinded group (at 1 month: 0% vs 25%, respectively P = .05; at 3 months: 0% vs 32% P = .01; at 6 months: 4% vs 36% P = .01; at 1 year: 16% vs 48% P = .03). Conclusions When HF is managed by clinical assessment only, estimated LVEDPs remain high at discharge, resulting in early and frequent rehospitalization for HF. Therapy guided by estimated LVEDP monitoring optimizes filling pressures and reduces HF rehospitalization rates.
We have investigated the blend of semiconducting materials (iron(II) phthalocyanine (FePc)) with TiO2 nano crystals (NC) for photovoltaic application. The photo-induced electron transfer in composite ...of TiO2 with FePc is studied by means of photoluminescence (PL) of the blend as well as photo-action spectra of the device. The quenching of the PL and occurrence of broad absorption have been interpreted as an electron transfer between an organic semiconductor and TiO2 (NC) in excited state. Also, the effects of hole mobility and light intensity on the device properties have been analyzed. The observation of an increase in photocurrent of the device (consisting of TiO2) is interpreted by the formation of an interconnecting network of FePc with TiO2 nano particle and formation of bulk hetero junction between aluminum (Al) and indium tin oxide (ITO) electrodes. The electron transfer between FePc and TiO2 is induced by photo excitation. The experimental results were explained with the help of a model that describes total current density as a function of injected carriers as donor/acceptor interface and contributed photo-generated current is due to the efficient dissociation of excitons.
We report the improvement of the light-harvesting property in the bulk heterojunction organic polymer solar cell based on poly(3-hexylthiophene) (P3HT) and PC70BM, with the incorporation of a ...near-infrared absorbing squaraine (SQ) dye, bis4-(2,6-di-tert-butyl)vinyl-pyrylium squaraine (TBU-SQ). With the incorporation of TBU-SQ dye (2.5% by wt) in a P3HT:PC70BM (1:1 wt ratio) blend, the power conversion efficiency (PCE) has been enhanced up to 4.55% as compared to 3.47% for the device based on the P3HT:PC70BM binary blend. The improvement in the photovoltaic performance with the incorporation of TBU-SQ attributed to the improvement in the light-harvesting efficiency in the near-infrared region of solar spectrum and increased exciton dissociation into free charge carriers in the ternary blended film. The PCE has been further enhanced to 5.15% when the thermally annealed P3HT:TBU-SQ:PC70BM blend was used as the photoactive layer. It was observed that the absorption profile of the active layer was broadened upon thermal treatment as a result of the red shift as well as widening of the P3HT absorption band and the slight red shift of the TBU-SQ absorption peak in the blended film. The improved light-harvesting property of the thermally annealed film and balanced charge transport in the device were attributed to the improvement in the PCE. These results show that TBU-SQ is a promising molecular sensitizer for increasing the PCE of P3HT:PC70BM-based polymer solar cells.
Follicle-stimulating hormone (FSH) stimulates antral follicles to grow, but its role in earlier stages (pre-antral) of follicle development, if any, is obscure. Aim of this study was to study the ...expression of follicle-stimulating hormone receptor (FSHR) gene in different sizes of pre-antral follicles (PFs) (<150, 200, 250, 300, 350, 400 μm) and to find out an optimum dose of FSH for better growth, development and steroidogenesis of PFs in vitro. Buffalo ovaries were collected from a local abattoir, and PFs were isolated by mechanical method. A semi-quantitative RT-PCR amplification strategy was used for mRNA expression, while FSHR protein was localized by immunohistochemistry. Isolated pre-antral follicles (80-85 μm) were cultured in TCM-199 supplemented with 10% foetal bovine serum, 1% ITS and 30 ng/ml EGF served as control medium. Addition of three different doses of FSH (0.5, 1.0, 2.0 μg/ml) in control medium was considered as treatment groups. A single 2.184-kb receptor mRNA transcript was present in all sizes (<150-400 μm) of follicles. Follicle-stimulating hormone receptor was also localized immunohistochemically in granulosa cells of all sizes of follicles. Survival and growth rate of follicles significantly (p < 0.05) increased following supplementation of FSH at a concentration of 1.0 μg/ml and the culture medium also showed a significantly (p < 0.05) greater accumulation of oestradiol and progesterone. In conclusion, FSHR is expressed in all sizes of PFs and in vitro survival, growth and steroidogenesis of follicles are optimally stimulated by 1.0 μg/ml FSH. These findings demonstrate that FSH has an important role during the recruitment, growth and development of buffalo ovarian PFs.
Leucine-to-phenylalanine substitution at residue L1014 in the voltage-gated sodium channel, target site of action for dichlorodiphenyltrichloroethane (DDT) and pyrethroids, is the most common ...knockdown resistance (kdr) mutation reported in several insects conferring resistance against DDT and pyrethroids. Here, we report presence of two coexisting alternative transversions, A>T and A>C, on the third codon position of L1014 residue in malaria vector Anopheles subpictus Grassi (species A) from Jamshedpur (India), both leading to the same amino acid substitution of Leu-to-Phe with allelic frequencies of 19 and 67%, respectively. A single primer-introduced restriction analysis—polymerase chain reaction (PIRA-PCR) was devised for the identification of L1014F-kdr mutation in An. subpictus resulting from either type of point mutation. Genotyping of samples with PIRA-PCR revealed high frequency (82%) of L1014F-kdr mutation in the study area.
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