Design of optimal correlation filters for hybrid vision systems

Research is underway at the NASA Johnson Space Center on the development of vision systems that recognize objects and estimate their position by processing their images. This is a crucial task in many space applications such as autonomous landing on Mars sites, satellite inspection and repair, and docking of space shuttle and space station. Currently available algorithms and hardware are too slow to be suitable for these tasks. Electronic digital hardware exhibits superior performance in computing and control; however, they take too much time to carry out important signal processing operations such as Fourier transformation of image data and calculation of correlation between two images. Fortunately, because of the inherent parallelism, optical devices can carry out these operations very fast, although they are not quite suitable for computation and control type operations. Hence, investigations are currently being conducted on the development of hybrid vision systems that utilize both optical techniques and digital processing jointly to carry out the object recognition tasks in real time. Algorithms for the design of optimal filters for use in hybrid vision systems were developed. Specifically, an algorithm was developed for the design of real-valued frequency plane correlation filters. Furthermore, research was also conducted on designing correlation filters optimal in the sense of providing maximum signal-to-nose ratio when noise is present in the detectors in the correlation plane. Algorithms were developed for the design of different types of optimal filters: complex filters, real-value filters, phase-only filters, ternary-valued filters, coupled filters. This report presents some of these algorithms in detail along with their derivations

Challenges in Delivering Cross-Agency Integrated e-Services: The OBLS Project

This case study describes how the Ministry of Trade and Industry and the Infocomm Development Authority, as lead agencies, jointly initiated and managed the implementation of a one-stop business licensing portal called OBLS (Online Business Licensing Service, https://licenses.business.gov.sg/) in the Singapore public sector. While the mandate from the top for this strategic cross-agency project was strong, there were many hurdles in the form of people, process and technology that had to be overcome. The case study highlights these issues and challenges, and illustrates how they were successfully overcome for delivering cross-agency integrated e-Service for new business license application

Challenges in Delivering Cross-Agency Integrated E-Services: The OBLS Project

This case study describes how the Ministry of Trade and Industry, and the Infocomm Development Authority, as lead agencies, jointly initiated and managed the implementation of a one-stop business licensing portal called OBLS (Online Business Licensing Service – https://licenses.business.gov.sg/ ) in the Singapore public sector. While mandate from the top for this strategic cross-agency project was strong, there were many hurdles in the form of people, process and technology that had to be overcome. The case study highlights these issues and challenges, and illustrates how they were successfully overcome for delivering cross-agency integrated e-Service for new business license application

Synthesis, photoluminescence and electrochemical properties of 2,7-diarylfluorene derivatives

A new class of highly fluorescent 9,9'-bis-(alkyl)-2,7-diarylfluorene having electron withdrawing or electron donating groups on the p-phenyl positions were synthesized and characterized. The highly luminescent fluorene derivatives, 1-6 showed blue emission (376-416 nm), narrow FWHM (~50 nm), high quantum yield (ΦF=0·12-0·87) and short fluorescence lifetimes, τF=0·23-1·14 ns. The HOMO levels of 9,9'-bis-(alkyl)-fluorene were tuned by the ρ-substituents at 2,7-phenyl group. Hammett correlation with EHOMO of these new molecules provides an effective tool to predict the HOMO level of similar molecules prior to the synthesis. These data indicate that they are useful as emitting materials for organic light emitting devices, OLEDs

Synthesis, photophysical and electrochemical properties of 2,8-diaryl-dibenzothiophene derivatives for organic electronics

A series of 2,8-p-diaryldibenzothiophene derivatives were synthesized and characterized. These molecules have electron withdrawing or electron donating groups at the para phenyl position, which alters the electronic properties of these derivatives. The quantum yield, fluorescence lifetime, singlet, triplet and EHOMO energy levels of these compounds were determined by fluorescence, phosphorescence and cyclic voltammetry. A plot of Hammett constants of the para substituents vs EHOMO revealed a linear relationship. The usefulness of these molecules in organic light emitting diodes, OLEDs is discussed vis-à-vis the energy levels and properties

Study on antibiotic use among geriatric patients based on anatomical therapeutic classification or defined daily dose methodology and world health organization-essential medicine list access, watch and reserve concept in tertiary care hospital of South India

Background: Geriatric patients are more vulnerable to infections and need special consideration on antibiotic use. Resistance to antibiotics among infectious bacteria has developed within a short span. There is a direct correlation between the consumption of antibiotics and the development of resistance. And surprisingly very few literatures were available on antibiotic consumption in geriatric population using defined daily dose (DDD) concept which paved the idea to conduct this study.Methods: A prospective observational study was carried out from November 2018 to April 2019. A total of 206 prescriptions of elderly patients were included in the study. The antibiotics were categorized by anatomical therapeutic classification (ATC) and DDD indicator/1000 inhabitants/day (DID) was used to figure out antibiotic consumption.Results: About 25.2% of patients were treated with antibiotics for respiratory tract infections. The patients received antibiotics empirically (53.8%) and without bacteriological investigation (58.73%). The overall consumption of antibiotics was 20.47 DID in which oral antibiotics was (8.5 DID) 42% and parenteral antibiotics (11.8 DID) 58%. Cephalosporins was observed to be the most consumed antibiotics (33.2%), specifically cefotaxime (14.6%) and ceftriaxone (12.6%). Moreover, 54.4% of antibiotics consumed from watch category of World Health Organisation (WHO) essential medicines list (EML) which was completely against WHO standard proportion.Conclusions: Higher consumption of cephalosporins, which falls into watch category was analysed in geriatric patients. These broad-spectrum antibiotics have high potential to develop antimicrobial resistance. A strict antibiotic policy is needed to be framed that enhance rational prescribing practices in geriatrics

Simultaneous estimation of states and inputs in a planar solid oxide fuel cell using nonlinear adaptive observer design

An adaptive nonlinear observer design for the planar solid oxide fuel cell (SOFC) is presented in this work. This observer is based on a lumped parameter model of the SOFC and it can simultaneously estimate the inputs and the states of the system. Considering the inputs as unknown parameters is advantageous because some of the input parameters are not practically measurable in a SOFC stack. The asymptotic stability of the proposed observer is proven using the Lyapunov function method and is based on the concept of input-to-state stability for cascaded systems. The simulations show that the developed observer can track the temperature and species concentration profiles in the planar SOFC during step changes in the input variables and can simultaneously predict the input variables. The adaptive observer presented is valid for a wide operating range, requires fewer variables to be measured, and is robust to fluctuations in the input variables

Photoconduction in Alq3

Photoelectronic properties of Alq3 were studied by photoconductivity measurements in thin film, sandwich (ITO/Alq3/LiF/Al) devices. We find that the photocurrent is dominated by bulk generation of carriers for incident photon energies greater than 2.75 eV. The quantum efficiency of photocarrier generation has been measured from carrier collection measurements to be about 10%. The quantum efficiency is largely independent of electric field. This enables a direct measurement of the electric field dependence of mobility using photoconductivity measurements, which is used for quantitative analysis of the dark forward current in these devices. Photoconductivity measurements were also used to obtain (\mu_{0n} \tau_n) product which can be used as a measure of material quality. For Alq3, we find that the value of (\mu_{0n} \tau_n) product was between 3x10^{-15} cm^2/V to 8x10^{-15} cm^2/V for different samples. In forward bias, at high field the photocurrent shows saturation accompanied by a phase shift. These effects are attributed to space charge effects in the device.Comment: 12 figure