Input Path Research Articles

UAV 공중 네트워크를 위한 손실 없는 Polyphase I/Q 네트워크 및 능동 벡터 변조기 기반 빔-포밍 수신기

본 논문은 무인기(UAV) 기반 공중 네트워크 시스템을 위한 polyphase In-phase/Quadrature-phase(I/Q) 네트워크 기반 빔-포밍 수신부를 제안한다. 제안하는 polyphase I/Q 네트워크는 낮은 Q-factor와 높은 임피던스를 갖기 때문에 작은 손실로 벡터 변조기를 구동할 수 있다. 벡터 변조기는 가변 이득 증폭기(VGA)로 구성되며, In-phase 및 Quadrature-phase 위상 신호의 진폭 제어 및 벡터 합을 통해 위상을 가변한다. 제안하는 빔-포밍 수신부는 TSMC <TEX>$0.18{\mu}m$</TEX> CMOS 공정을 통해 구현하였다. 프로토타입은 5-6GHz 주파수 대역(-40dB 입력)에서 검증하였다. 6bit 벡터 변조기 제어를 통해 <TEX>$5.6^{\circ}$</TEX> LSB (least significant bit)로 <TEX>$360^{\circ}$</TEX> 위상 가변이 가능하다. 위상 오차는 평균 <TEX>$1.6^{\circ}$</TEX>이며, 진폭 오차는 평균 0.3dB이다. This paper presents a beam-forming receiver with polyphase In-phase/Quadrature-phase (I/Q) network for airborne communication. In beam-forming receiver, the insertion loss (IL) difference between input path increases the receiver noise figure (NF). The major element for generating IL difference is the impedance variation of phase shifter. In order to maintain a constant IL in every phase, this paper propose a lossless polyphase I/Q network based beam-forming receiver. The proposed lossless polyphase I/Q network has low Q-factor and high impedance for drive back-end VGA (Variable gain amplifier) block with low insertion loss. The 2-stage VGA controls in-phase and quadrature-phase amplitude level for vector summation. The proposed beam-forming receiver prototype is fabricated in TSMC <TEX>$0.18{\mu}m$</TEX> CMOS process. The prototype cover the <TEX>$360^{\circ}$</TEX> with <TEX>$5.6^{\circ}$</TEX> LSB. The average RMS phase error and amplitude error is approximately <TEX>$1.6^{\circ}$</TEX> and 0.3dB.

Directing user attention via visual flow on web designs

We present a novel approach that allows web designers to easily direct user attention via visual flow on web designs. By collecting and analyzing users' eye gaze data on real-world webpages under the task-driven condition, we build two user attention models that characterize user attention patterns between a pair of page components. These models enable a novel web design interaction for designers to easily create a visual flow to guide users' eyes (i.e., direct user attention along a given path) through a web design with minimal effort. In particular, given an existing web design as well as a designer-specified path over a subset of page components, our approach automatically optimizes the web design so that the resulting design can direct users' attention to move along the input path. We have tested our approach on various web designs of different categories. Results show that our approach can effectively guide user attention through the web design according to the designer's high-level specification.

Design and microfabrication of a miniature fiber optic probe with integrated lenses and mirrors for Raman and fluorescence measurements.

Fiber optics coupled to components such as lenses and mirrors have seen extensive use as probes for Raman and fluorescence measurements. Probes can be placed directly on or into a sample to allow for simplified and remote application of these optical techniques. The size and complexity of such probes however limits their application. We have used microfabrication in polydimethylsiloxane (PDMS) to create compact probes that are 0.5mm thick by 1mm wide. The miniature probes incorporate pre-aligned mirrors, lenses, and two fiber optic guides to allow separate input and output optical paths suitable for Raman and fluorescence spectroscopy measurements. The fabricated probe has 70% unidirectional optical throughput and generates no spectral artifacts in the wavelength range of 200 to 800nm. The probe is demonstrated for measurement of fluorescence within microfluidic devices and collection of Raman spectra from a pharmaceutical tablet. The fluorescence limit of detection was 6nM when using the probe to measure resorufin inside a 150-μm inner diameter glass capillary, 100nM for resorufin in a 60-μm-deep × 100-μm-wide PDMS channel, and 11nM for fluorescein in a 25-μm-deep × 80-μm-wide glass channel. It is demonstrated that the same probe can be used on different sample types, e.g., microfluidic chips and tablets. Compared to existing Raman and fluorescence probes, the microfabricated probes enable measurement in smaller spaces and have lower fabrication cost. Graphical abstract A microfabricated spectroscopic probe with integrated optics was developed for chemical detection in small spaces and in remote applications.

Gain boosting of recycling folded cascode OTA using positive feedback and introducing new input path

This study describes the analysis and design of an improved recycling folded cascode using a new input path and positive feedback which simultaneously increases transconductance considerably. The p...

Phase-induced polarization method based on processing noise signals of the natural electromagnetic field of the Earth

The paper deals with the physical fundamentals of the phase geoelectric method of induced polarization (IP) based on the extraction of information from the natural electromagnetic field of the Earth (NEMFE) in the frequency range 0.1-20.0 Hz. Scientific and technical justification is provided for the differential measurement circuit parameters of the NEMFE and the algorithm of processing of the received signals with the calculation of the IP coefficient, assuming the identity of the field characteristics in two receiving lines. The method consists in recording random noise signals from two adjacent receiving electrical dipoles with simultaneous memorizing of the amplitudes and their automatic equalization. Then the difference between the signals is calculated, with subsequent energy normalization. The presented theoretical fundamentals for the calculation of the IP coefficient of the NEMFE and the processing algorithm were tested in laboratory experiments. Under the assumption of the complete identity of the medium beneath the receiving dipoles, the IP coefficient was 0.01-0.03, due to the error in the elemental base of the analog input path. The paper also presents the results of field experiments on the Samson iron deposit in the Republic of Khakassia. The experimental work confirmed the effect of IP on the NEMFE in the anomalous area and showed that the results are consistent with theoretical and laboratory predictions and the data obtained using a KEP-M pulse system. It is concluded that this method can be used to detect productive anomalies and has an advantage of eliminating artificial sources of excitation of geologic sections.

A power control strategy to improve power system stability in the presence of wind farms using FACTS devices and predictive control

The main objective of this paper that distinguishes it from other similar articles is to employ predictive control strategy to improve the stability of power systems (4- machines and 10-machine) in presence of wind farms based on Doubly Fed Induction Generator (DFIG), using Static Synchronous Series Compensator (SSSC) and Super Capacitor Energy Storage System (SCESS). In this paper, SCESS is used to control the active power in the Grid Side Convertor (GSC) and SSSC is employed to reduce low frequency oscillations. The proposed strategy based on the predictive control can be simultaneously used to control the active and reactive power of the Rotor Side Convertor (RSC) as well as damping controller design for SCESS and SSSC. A function is used in the predictive control strategy to reduce computational complexity in selecting the input paths of Laguerre functions. Moreover, the sampling time is reduced by means of employing the exponential data weighting. Simulation results for the function-based predictive control using disturbance scenario in the field of non-linear time are compared with the other two methods, model-based predictive control and classic model (without using the predictive control). The effectiveness of the proposed strategy in improving stability is confirmed through simulation result.

Parallel processing of afferent olfactory sensory information.

The functional synaptic connectivity between olfactory receptor neurons and principal cells within the olfactory bulb is not well understood. One view suggests that mitral cells, the primary output neuron of the olfactory bulb, are solely activated by feedforward excitation. Using focal, single glomerular stimulation, we demonstrate that mitral cells receive direct, monosynaptic input from olfactory receptor neurons. Compared to external tufted cells, mitral cells have a prolonged afferent-evoked EPSC, which serves to amplify the synaptic input. The properties of presynaptic glutamate release from olfactory receptor neurons are similar between mitral and external tufted cells. Our data suggest that afferent input enters the olfactory bulb in a parallel fashion. Primary olfactory receptor neurons terminate in anatomically and functionally discrete cortical modules known as olfactory bulb glomeruli. The synaptic connectivity and postsynaptic responses of mitral and external tufted cells within the glomerulus may involve both direct and indirect components. For example, it has been suggested that sensory input to mitral cells is indirect through feedforward excitation from external tufted cells. We also observed feedforward excitation of mitral cells with weak stimulation of the olfactory nerve layer; however, focal stimulation of an axon bundle entering an individual glomerulus revealed that mitral cells receive monosynaptic afferent inputs. Although external tufted cells had a 4.1-fold larger peak EPSC amplitude, integration of the evoked currents showed that the synaptic charge was 5-fold larger in mitral cells, reflecting the prolonged response in mitral cells. Presynaptic afferents onto mitral and external tufted cells had similar quantal amplitude and release probability, suggesting that the larger peak EPSC in external tufted cells was the result of more synaptic contacts. The results of the present study indicate that the monosynaptic afferent input to mitral cells depends on the strength of odorant stimulation. The enhanced spiking that we observed in response to brief afferent input provides a mechanism for amplifying sensory information and contrasts with the transient response in external tufted cells. These parallel input paths may have discrete functions in processing olfactory sensory input.

Time optimal trajectory generation from polyline with velocity, acceleration and spatial deviation constraints

In this paper is presented a method for generating continuous and differentiable trajectory from an input path described by a polyline while maintaining accelerations and velocities constraints. The method in based on replacing the path corners with parabolic blends of constant acceleration. The complete spatial control of the resulted trajectory is obtained with a velocity reduction procedure which ensures that the trajectory doesn't deviate from the input path further than a settable value. The total time is minimized by replacing the non-maximized constant velocity sections with boost sequences containing maximized symmetrical accelerating and decelerating time frames while also keeping the velocity constraints. The method was successfully tested in practice and the results were very good even on complex input paths.

Modular Printed Circuit Boards for Broadband Characterization of Nanoelectronic Quantum Devices

We report on the development of a modular system of high-frequency printed circuit boards (PCBs) for electrical low-noise characterization of multigate quantum devices. The whole measurement setup comprises PCBs operating from room temperature to a few kelvins, and custom software to control the broadband electronics held at cryogenic and room temperature. The PCBs coupling scheme and the custom tailoring of the user panel make our platform particularly flexible. At the cryogenic stage, one board hosts the electronics for readout. It consists in a custom complementary metal–oxide–semiconductor circuit for the current sensing. It is composed by a multiplexer for a digital selection of the device under test among up to four samples, connected to a cryogenic transimpedance amplifier with two possible gains, the maximum bandwidth of 250 kHz and the minimum equivalent input noise of 10 fA/ $\sqrt {\mathrm{Hz}}$ . Such board is coupled to the PCB sample holder, where 14 low-frequency input lines bias the devices and control the gates. Four additional high-frequency input paths with a bandwidth of 1 GHz and an isolation lower than −40 dB at 3 GHz have been implemented to apply a few millivolt pulses with a minimum duration of 1 ns. The PCBs assemblage and the cryogenic electronics are electrically characterized at 4.2 K and later used to perform quantum transport spectroscopy and single-charge dynamics readout at a few microsecond scales in two silicon nanoscaled field-effect transistors.

Analysis of Sources of Error in the Input Circuit of a Modified Zero Microwave Radiometer

A calibration algorithm and formulas are obtained for evaluating the effect on the measurement accuracy of deviations in the characteristics of the components of the input path of a microwave radiometer from the nominal values. The limits on changes in the temperature of the input circuit and noise temperature of the receiver such that the changes in the output signal do not exceed the fluctuation sensitivity of the radiometer are determined.

A two-year automated dripwater chemistry study in a remote cave in the tropical south Pacific: Using [Cl−] as a conservative tracer for seasalt contribution of major cations

Stalagmite Mg/Ca and Sr/Ca ratios are commonly interpreted as proxies for past hydrologic conditions and are often used to supplement carbon and oxygen stable isotope records. While the processes that control these element ratios, including water–rock interaction, dripwater residence time, and upstream precipitation of calcite, are well understood in continental caves, there have been few investigations of dripwater Element/Ca (X/Ca) evolution in coastal marine caves where seasalt can have a strong influence on the incoming Mg/Ca ratio.We instrumented a marine cave on the remote South Pacific island of Niue to record daily cave microclimate, as well as weekly-integrated drip rates, dripwater oxygen and hydrogen isotopes, and dripwater chemistry over a period of twenty-two months. Using chloride as a conservative tracer for sea-spray, we calculate that seasalt input accounts for a large portion of dripwater Na, SO4, and Mg (89%, 93%, and 85% respectively) and a smaller portion of the Ca and Sr (19% and 17%). During the second year of this study a gradual decrease (by ∼18%) in dripwater chlorinity was observed, suggesting that an epikarst-hosted seasalt aerosol inventory was being diluted over time. Minor element to calcium ratios for B, K, Cl, SO4, Mg, Na, Sr, and Fe all strongly covary over the observation period, suggesting that although sea-spray plays a significant role in modulating incoming drip chemistry, prior calcite precipitation (PCP) dominates chemical evolution within the epikarst. During a prolonged drought episode, evaporative enrichments in dripwater δD and δ18O (+4‰ and 0.5‰, respectively) were observed to coincide with increased cation and anion concentrations, strong Ca removal via PCP, and increases in Sr/Ca and Mg/Ca ratios (28% and 34%, respectively), suggesting that concomitant enrichment in speleothem δ18O and X/Ca ratios may be interpreted as multi-proxy evidence for dry climate conditions.We use modern dripwater chemistry and empirical water-calcite distribution coefficients to predict a range of stalagmite X/Ca ratios. We then forward model a number of scenarios that could modulate stalagmite chemistry, including increased/decreased seasalt input and changing dripwater flow path through calcite, dolomite, and aragonite bedrock. One major implication from this study is that even if PCP and flow path lithology remain constant over time, changing seasalt input can drive stalagmite Mg/Ca and Sr/Ca ratios away from PCP-controlled covariation, and lead to strongly varying Sr/Mg ratios. Thus in order to interpret coastal cave stalagmite X/Ca records accurately, it is necessary to estimate seasalt input and analyze parent drip and bedrock chemistry to quantify the influence of each contributing process.

Advice complexity of disjoint path allocation

This paper contributes to the research of advice complexity of online problems. Namely, we discuss the disjoint path allocation problem in various versions, based on the choice of values of the calls, and ability to preempt. The advice complexity is measured relative to either the length of the input sequence of requests, or the length of the input path. We provide lower and upper bounds on advice complexity of optimal online algorithms for these problems, and some bounds on trade-off between competitiveness and advice complexity. One of the results is an improved lower bound of n − 1 on advice complexity for the non-preemptive version with constant values of calls. For all considered variations, the newly provided lower and upper bounds on advice complexity of optimal algorithms are linear, and therefore asymptotically tight.

Economic and Energy Performance of Brazilian Bagasse-Derived Ethanol: A Macro Perspective

The increase of global biofuel production is supported mainly by energetic policies adopted by important energy markets that aim to promote the production and use of biofuels, including the promising cellulosic-derived biofuels. Brazil is facing a challenge to attain sustainability in ethanol sector and to maintain its position as a major supplier of ethanol to world market in this new era of sustainable biofuel policies. In this paper we carried out a structural path analysis on sugarcane-derived ethanol sector and on a hypothetical bagasse-derived ethanol sector in order to identify the input paths that most influencing their economic and environmental performance. We make an empirical application to the Brazilian economy, using existing data from ethanol sector for 2005 and estimating data for the hypothetical sector. The fuel burned in the transport sector and on-site transport tasks is identified as important element for the environmental performance of both sectors. Also, sugarcane sector is identified to have relevant role in the economic performance of ethanol sector, as enzyme production has in second generation ethanol sector. The results present in this article can provide valuable information for decision-making in both biofuels to address new initiative for effective economic and environmental policies efforts.

Can one find External Source Input Expressions for which there exist Map Reduce Configurations?

An intention of MapReduce Sets for External Source Input expressions analysis has to suggest criteria how External Source Input expressions in External Source Input data can be defined in a meaningful way and how they should be compared. Similitude based MapReduce Sets for External Source Input Expression Analysis and MapReduce Sets for Assignment is expected to adhere to fundamental principles of the scientific External Source Input process that are expressiveness of External Source Input models and reproducibility of their External Source Input inference. External Source Input expressions are assumed to be elements of a External Source Input expression space or Conjecture class and External Source Input data provide “information” which of these External Source Input expressions should be used to interpret the External Source Input data. An inference External Source Input algorithm constructs the mapping between External Source Input data and External Source Input expressions, in particular by a External Source Input cost minimization process. Fluctuations in the External Source Input data often limit the External Source Input precision, which we can achieve to uniquely identify a single External Source Input expression as interpretation of the External Source Input data. We advocate an information theoretic perspective on External Source Input expression analysis to resolve this dilemma where the tradeoff between External Source Input informativeness of statistical inference External Source Input and their External Source Input stability is mirrored in the information-theoretic External Source Input optimum of high External Source Input information rate and zero communication expression error. The inference External Source Input algorithm is considered as an outlier object External Source Input path, which naturally limits the resolution of the External Source Input expression space given the uncertainty of the External Source Input data.

Real-time graphic visualization of filament band winding for fiber-reinforced cylindrical vessels

The filament winding method is widely used to manufacture lightweight, strong, composite products. To reduce winding time, the method of winding by filament band, which consists of several roving tows, is used. A computer numerical control winding machine is used with input path commands for precise winding operation. Before filament winding, users should verify by simulation that the input path is appropriate for the winding without any erroneous operation. Furthermore, prior to starting the winding operation, the usage length of each tow must to be checked because the manufacturing process stops unexpectedly if the tow on the creel runs out. In this work, we used the geodesic equation to generate a filament band surface and calculate the usage length of each tow. We also proposed a graphic display method to make the visual effect in accord with the real winding process. To verify the presented algorithm, a program for three-dimensional real-time graphic visualization of filament band winding process was developed.

14-bit 100 MS/s 121 mW pipelined ADC**Project supported by the National Key Technology R&D Program (No. 2012BAI13B07).

This paper presents a high-speed high-resolution pipelined ADC with low power and small area. The proposed ADC is designed based on the analysis of the stage scaling theory and the residual amplifiers are shared by two cascading MDACs to reduce power consumption. Shared op-amps with two split input paths are presented in this paper to eliminate the nonlinearity effects such as memory effect and crosstalk. Dynamic pre-amplified comparators are employed to decrease the static power consumption and suppress the kick-back in the comparators. This ADC is implemented in SMIC 0.18 μm CMOS process with an area of 3.1 mm2. With a sampling rate of 100 MS/s, spurious-free dynamic range (SFDR) and signal-to-noise plus distortion ratio (SNDR) of the ADC are 82.7 dB and 69.1 dB, respectively. For signals up to 100 MHz, the SFDR and SNDR achieve 81.4 dB and 65.8 dB. The power consumption is 121 mW with a 1.8 V supply voltage.

Environmental and economic hybrid life cycle assessment of bagasse-derived ethanol produced in Brazil

Purpose The goal of this study is to identify which processes contribute most to fuel CO2e emissions, energy use, and employment generation when driving a typical Brazilian flex fuel vehicle (FFV) model with bagasse-derived ethanol. A hybrid life cycle assessment (LCA) is used to report the associated impacts and a structural path analysis (SPA) is utilized to identify, quantify, and rank the highest carbon emissions, energy use, and employment generation input paths in the supply chain of bagasse-derived ethanol. Additionally, this study explores the integrated hybrid LCA approach as a tool to explain the economic impacts of bagasse-derived ethanol.

Estimation of lacustrine groundwater discharge using heat as a tracer and vertical hydraulic gradients – a comparison

Abstract. Lacustrine groundwater discharge (LGD) can play a major role in water and nutrient balances of lakes. Unfortunately, studies often neglect this input path due to methodological difficulties in the determination. In a previous study we described a method which allows the estimation of LGD and groundwater recharge using hydraulic head data and groundwater net balances based on meteorological data. The aim of this study is to compare these results with discharge rates estimated by inverse modelling of heat transport using temperature profiles measured in lake bed sediments. We were able to show a correlation between the fluxes obtained with the different methods, although the time scales of the methods differ substantially. As a consequence, we conclude that the use of hydraulic head data and meteorologically-based groundwater net balances to estimate LGD is limited to time scales similar to the calibration period.

Finding Frequent Subpaths in a Graph

The problem considered is that of finding frequent subpaths of a database of paths in a fixed undirected graph. This problem arises in applications such as predicting congestion in network and vehicular traffic. An algorithm, called AFS, based on the classic frequent itemset mining algorithm Apriori is developed, but with significantly improved efficiency over Apriori from exponential in transaction size to quadratic through exploiting the underlying graph structure. This efficiency makes AFS feasible for practical input path sizes. It is also proved that a natural generalization of the frequent subpaths problem is not amenable to any solution quicker than Apriori.

A functional circuit model of interaural time difference processing.

Inputs from the two sides of the brain interact to create maps of interaural time difference (ITD) in the nucleus laminaris of birds. How inputs from each side are matched with high temporal precision in ITD-sensitive circuits is unknown, given the differences in input path lengths from each side. To understand this problem in birds, we modeled the geometry of the input axons and their corresponding conduction velocities and latencies. Consistent with existing physiological data, we assumed a common latency up to the border of nucleus laminaris. We analyzed two biological implementations of the model, the single ITD map in chickens and the multiple maps of ITD in barn owls. For binaural inputs, since ipsi- and contralateral initial common latencies were very similar, we could restrict adaptive regulation of conduction velocity to within the nucleus. Other model applications include the simultaneous derivation of multiple conduction velocities from one set of measurements and the demonstration that contours with the same ITD cannot be parallel to the border of nucleus laminaris in the owl. Physiological tests of the predictions of the model demonstrate its validity and robustness. This model may have relevance not only for auditory processing but also for other computational tasks that require adaptive regulation of conduction velocity.