We present a CMOS image sensor (CIS) based time-resolved fluorescence (TRF) measurement system for filter-less, highly sensitive readout of lateral-flow assay (LFA) test strips. The CIS contains a ...256 × 128 lock-in pixel (LIP) sensor array. Each pixel has a size of <inline-formula><tex-math notation="LaTeX">10 \ {\mu }\mathrm{m}</tex-math></inline-formula> × <inline-formula><tex-math notation="LaTeX">10 \ {\mu }\mathrm{m}</tex-math></inline-formula> and includes a photodiode acting as signal transducer. The LIP CIS was designed in a standard 0.18 <inline-formula><tex-math notation="LaTeX">{\mu }</tex-math></inline-formula><inline-formula><tex-math notation="LaTeX">\mathrm{m}</tex-math></inline-formula> CMOS technology specifically for TRF applications. The LIP architecture blocks interfering light when fluorophores are excited and accumulates the emitted fluorescence light to be measured over multiple cycles after excitation. This allows to detect even small amounts of fluorescence light over a wide analyte concentration range. The LIP CIS based TRF reader was characterized in terms of reproducible and uniform signal intensities with use of appropriate Europium(III) Eu 3+ chelate particles as fluorescence standards. We measured different concentrations of Eu-based nanoparticles (NP) on test strips with the TRF reader. The sensor system shows 5.1 orders of magnitude of detection dynamic range (DDR) with a limit of detection (LoD) of <inline-formula><tex-math notation="LaTeX">0.1 \ \text{ng/cm}</tex-math></inline-formula>. In addition, using human C-reactive protein (hCRP) as a model analyte, we compared the developed TRF reader with a commercial colorimetric LFA reader. For the quantification of CRP, the LIP CIS based TRF reader demonstrates a DDR of 3.6 orders of magnitude with an excellent LoD of <inline-formula><tex-math notation="LaTeX">0.05 \ \text{ng/mL}</tex-math></inline-formula>, which is 14 times better than the LoD of the commercial LFA reader.
This article deals with local and global conditions for collision-free 3-axis milling of sculptured surfaces and the selection of cutting tools for a given surface. We describe local and global ...millability results, the proof of which were published in a previous article. The theoretical background involves general offset surfaces. We present an algorithm here which, after evaluation of surface curvature, yields a differential inequality for the meridian curve of the cutting tool. This inequality is fulfilled if and only if the cutting tool is able to mill the entire surface. Besides this inequality, the optimal selection (or even design) of cutting tools involves a consideration of further characteristics, such as shape and size.
Analog/Mixed-Signal (AMS) design and verification strongly relies on more or less abstract models to make extensive simulations feasible. Maintaining consistent behavior between system model and ...implementation is crucial for a correct verification. Besides the functionality, this also involves the operating conditions: A faulty model might introduce false-positive verification results despite of e.g. an incorrect supply voltage. We propose a novel method to compare a model to its implementation and automatically generate a model safe-guard unit from transistor-level simulation data. By using the concept of system acceptance region, we transfer the information about valid operating conditions to a higher level of abstraction. We introduce this unit into a purely functional VerilogAMS model to check the validity in the simulated environment. This method can be used to significantly reduce the risk of erroneous verification results on system level.
We demonstrate our approach using a demodulator circuit of a passive RFID tag. The model is automatically augmented with additional checks derived from an exploration of the underlying circuits' parameter space. By comparing the risk of false-positive simulation results, we prove that the design risk can be significantly reduced. It is eliminated completely by introducing an additional safety-margin, which drives the coverage up to 100%.
•A novel method for automatic extraction an d synthesis of mixed-signal operating condition checks is proposed.•The method is evaluated using a novel model-coverage measure.•As an application example, a model augmentation for an RFID demodulator circuit is presented.
In order to create extremely sharp photographs, focus stacking has become a widely used method nowadays, mainly in macro or micro photography. Whereas the aspect of computationally detecting sharp ...regions of an image has been dealt with in many publications, there is only little published about the geometric background. This paper analyzes the process from a purely geometrical point of view, revealing some non-trivial aspects that may potentially also lead to improvements in a variety of applications such as the 3D scanning of small objects. It is shown that - under calibrated conditions and with certain restrictions - focus stacking of a scene leads to arbitrarily many geometrically correct perspective images of this scene, even including normal projections. The reason for this is that the process of photography never leads to purely two-dimensional images, but collinearly distorted spatial images.
Da bi se stvorile izuzetno oštre fotografije u današnje se vrijeme često koristi metoda podešavanja dubinske oštrine. Posebno je česta njezina upotreba u makro ili mikro fotografiji. Iako je tema računalnog određivanja oštrih područja slike obrađena u mnogim publikacijama, o njegovoj je geometrijskoj pozadini objavljeno malo radova. Ovaj rad analizira spomenuti postupak s čisto geometrijskog gledišta otkrivajući neke netrivijalne aspekte koji mogu dovesti do poboljšanja u mnogim njegovim primjenama kao što je 3D skeniranje malih predmeta. Pokazano je da podešavanje dubinske oštrine scene - pod kalibriranim uvjetima i uz određena ograničenja - može proizvesti po volji mnogo geometrijski ispravnih perspektivnih slika te scene, pa čak i njezinu ortogonalnu projekciju. Razlog tome je činjenica da proces fotografiranja nikada ne rezultira čistim dvodimenzionalnim slikama, već kolinearno iskrivljenim prostornim slikama.
Mathematicians with special interest in biology, physics, geography, astronomy, architecture, design, etc., and being prepared to take pictures at any time, might try to answer unusual questions like ...the followings: What do a zebra, a tiger shark, and a hard coral have in common? How is this with drying mud, wings of dragon flies, and the structures of leaves? What is the "snail king" and is there also a "worm king"? Which curves stay of the same type after being photographed? Do fishes see like we do if we look through a fisheye lens? Which geometric properties of an object have physical consequences? Which kinds of geometric patterns appear when waves are interfering? In this book you can find 180 double pages with at least as many questions of this kind. The principle to attack a problem is often similar: It starts with a photo that is for some reasons remarkable. In a short description an explanation is offered, including relevant Internet links. Additionally one can frequently find computer simulations in order to illustrate and confirm.
Developable surfaces (tangential developables, in special cases cylinders and cones) are ruled surfaces with vanishing Gaussian curvature and can therefore be unfolded to the plane without ...distortions. In this article we will survey and discuss examples of the use of developable surfaces in contemporary architecture. We also discuss software for aiding architects, designers, engineers and artists to explore their ideas for the use of developable surfaces for such purposes.
We provide a synthetic study of the top-views of spherical trochoids. These projections turn out to be higher trochoids,
i.e.
, curves generated by the superposition of more than two rotations. ...Special shapes of these trochoids show up for special choices of the spherical radii of the rolling circles. A relation to closed algebraic curves of constant width is shown. These curves allow for a kinematic generation.
U ovom radu se proučavaju tlocrti sfernih trohoida pomoću sintetičke metode. Pokazuje se da su te projekcije više trohoide, tj. krivulje nastale istovremenim djelovanjem više od dvije rotacije. Posebni oblici ovih trohoida pojavljuju se u slučajevima posebnih odabira sfernih polumjera kružnica koje se kotrljaju. Prikazana je veza sa zatvorenim algebarskim krivuljama konstantne širine. Ove krivulje dopuštaju kinematičko izvođenje.
Da bi se stvorile izuzetno oštre fotografije u današnje se vrijeme često koristi metoda podešavanja dubinske oštrine. Posebno je česta njezina upotreba u makro ili mikro fotografiji. Iako je tema ...računalnog određivanja oštrih područja slike obrađena u mnogim publikacijama, o njegovoj je geometrijskoj pozadini objavljeno malo radova.
Ovaj rad analizira spomenuti postupak s čisto geometrijskog gledišta otkrivajući neke netrivijalne aspekte koji mogu dovesti do poboljšanja u mnogim njegovim primjenama kao što je 3D skeniranje malih predmeta. Pokazano je da podešavanje dubinske oštrine scene - pod kalibriranim uvjetima i uz određena ograničenja - može proizvesti po volji mnogo geometrijski ispravnih perspektivnih slika te scene, pa čak i njezinu ortogonalnu projekciju. Razlog tome je činjenica da proces fotografiranja nikada ne rezultira čistim dvodimenzionalnim slikama, već kolinearno
iskrivljenim prostornim slikama.
Analog-/Mixed-Signal (AMS) design verification is one of the most challenging and time consuming tasks of todays complex system on chip (SoC) designs. In contrast to digital system design, AMS ...designers have to deal with a continuous state space of conservative quantities, highly nonlinear relationships, non-functional influences, etc. enlarging the number of possibly critical scenarios to infinity. In this special session we demonstrate the verification of functional properties using simulative and formal methods. We combine different approaches including automated abstraction and refinement of mixed-level models, state-space discretization as well as affine arithmetic. To reach sufficient verification coverage with reasonable time and effort, we use enhanced simulation schemes to avoid conventional simulation drawbacks.
In this paper the supply sensitivity of low-power time-domain temperature sensors in RFID sensor tags is analyzed. A common topology of recent published temperature sensors is proposed. Three ...time-domain temperature sensor topologies ("Inverted based topology", "SC delay cell with two bias sources" and "SC delay cell with common bias source") are modeled in this proposed common structure via Verilog A. A supply sensitivity analysis is performed for these three topologies. In the simulation the supply is swept first by DC supply voltage variation of ±100mV. The topology "SC delay cell with common bias source", which is the most robust design among the three topologies, achieves only 0.0006°C/mV. This result is almost 50 times smaller than other two topologies in a same defined simulation condition. In a further AC analysis this topology shows a maximal AC supply sensitivity 0.55°C/mV over a frequency range from 10Hz to 1MHz. This supply sensitivity gives a specification of RFID power management block, that the power supply rejection (PSR) of low-dropout regulator (LDO) should be -52dB to achieve an accuracy of ±1°C under a realistic condition.
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