Temporal Cadence Research Articles

Infrared Imaging Spectroscopy Using Massively Multiplexed Slit-Based Techniques and Sub-Field Motion Correction

Targeting dynamic spatially-extended phenomena in the upper solar atmosphere, a new instrument concept has been developed and tested at the Dunn Solar Telescope in New Mexico, USA, that provides wide-field, rapid-scanning, high-resolution imaging spectroscopy of the neutral helium $\lambda10830$ spectral triplet. The instrument combines a narrowband imaging channel with a novel, co-spatial, 17 parallel-long-slit, grating-based spectrograph that are simultaneously imaged on a single HgCdTe detector. Over a $170'' \times 120''$ field of view, a temporal cadence of 8.5 seconds is achieved between successive maps that critically sample the diffraction limit of the Dunn Solar Telescope at 1083 nm ($1.22 \lambda/D = 0.36''$) and provide a resolving power ($R = \lambda / \delta\lambda$) up to $\sim25000$ with a 1 nm bandwidth (i.e., 275 km sec$^{-1}$ Doppler coverage). Capitalizing on the strict simultaneity of the narrowband channel relative to each spectral image (acquired at a rate of 10 Hz), this work demonstrates that sub-field image motion introduced by atmospheric seeing may be compensated in each mapped spectral data cube. This instrument furnishes essential infrared spectral imaging capabilities for current investigations while pioneering techniques for high-resolution, wide-field, time-domain solar astronomy.

Testing the variability of the proton-to-electron mass ratio from observations of methanol in the dark cloud core L1498

The dependence of the proton-to-electron mass ratio, mu, on the local matter density was investigated using methanol emission in the dense dark cloud core L1498. Towards two different positions in L1498, five methanol transitions were detected and an extra line was tentatively detected at a lower confidence level in one of the positions. The observed centroid frequencies were then compared with their rest frame frequencies derived from least-squares fitting to a large data set. Systematic effects, as the underlying methanol hyperfine structure and the Doppler tracking of the telescope, were investigated and their effects were included in the total error budget. The comparison between the observations and the rest frame frequencies constrains potential mu variation at the level of Dmu/mu < 6 x 10^(-8), at a 3 sigma confidence level. For the dark cloud we determine a total CH3OH (A+E) beam averaged column density of 3-4 x 10^(12) cm(-2) (within roughly a factor of two), an E- to A-type methanol column density ratio of N(A-CH3OH)/N(E-CH3OH) = 1.00 +/- 0.15, a density of n(H2) = 3 x 10^5 cm^(-3) (again within a factor of two), and a kinetic temperature of Tkin = 6 +/- 1 K. In a kinetic model including the line intensities observed for the methanol lines, the n(H2) density is higher and the temperature is lower than that derived in previous studies based on different molecular species; the intensity of the 1_0 --> 1_-1 E line strength is not well reproduced.

A Bottom-Up Discursive Approach to Genetically Modified Organisms

The debate on genetically modified foods has been characterized by a heteroglosia of voices, ranging from experts, authorities, to scholars, community organizations, media, or consumers. Within such a context where there have been observed various food safety scares over the past decades or some public ignorance regarding the use of biotechnology related to food issues, the Debating Europe platform launched debates on arguments for and against GMOs. Thus citizens turn into prosumers of content regarding food safety and (de)legitimators of EU policies and/or other social institutions. In our study of the comments posted by e-citizens on four debates on GM foods launched on the Debating Europe platform, we will use framing theory (Goffman, 1974; Entman, 1993; Wynne, 2001; Cook et al., 2004) and the Integrated Crisis Mapping Model (Jin et al., 2012) for negative emotions and Plutchik’s wheel of emotions (2001) for positive emotions to determine the salience of (de)legitimating frames employed by the supporters and opponents of GM foods, and to examine the role of affective stance in the evaluation of the social actors related to GMOs. Using QDA miner and WordStat, computer assisted qualitative data analysis softwares, we will conduct a content, cluster and correspondence analysis of the (de)legitimating frames and emotion valences. Whereas the content analysis provides an insight into the frequency of frames used by e-debaters and into the key lexical items that express evaluation and affective stance related to GM foods, the explorative analyses reveal the types of (sub)clusters which prevail in the e-debaters’ comments on GM foods. The findings of this study suggest that e-citizens mainly perceive the issue of GMO through a political frame associated with anger and a health frame associated with fright.

Study on distribution status of Oncomelania hupensis - intermediate host of Schistosoma japonicum in Jiangxi Province I Analysis of distribution of O. hupensis in Poyang Lake area

To grasp the distribution status of Oncomelania hupensis snails in Poyang Lake area, so as to provide the evidence for formulating and adjusting the schistosomiasis prevention and control strategy in lake areas. The vector grid was created and sampled randomly by 200 m × 200 m in the spatial database of grassland, and the distribution of snails was investigated in the selected grid by using the method of mechanical sampling by 50 m × 50 m. At the same time, the elevation of investigation points was extracted based on the topographic map of Poyang Lake. Totally 949 and 210 investigation points were collected from the south and north of Poyang Lake areas, accounting for 3.04% and 3.21% of all the investigation points in the respective region. The number of investigation points, the appearance rate of snail frame, and the average density of alive snails were 15 231, 8.15%, and 0.463/0.1 m2, respectively. The elevation of snail distribution area of the south and north Poyang Lake areas were 11-16 m and 9-16 m respectively. The elevation of concentrated snail belts of the south Poyang Lake area were 12-13 m and 15-16 m, and the elevation of concentrated snail belts of the north Poyang Lake area was 12-14 m. The distribution of snails is in the range of 9-16 m. The suitable habitats of snail breeding are moving from the south Poyang Lake area to the north Poyang Lake area, and from high elevation to low elevation. In the future, the schistosomiasis prevention and control measures could be formulated based on the geographical characteristics of current snail distribution in order to consolidate the achievements of schistosomiasis control.

Static and Dynamic Properties of Portal Frames Composed of Built-Up Sawn Square Timber

In order to propose an alternative structural element to be used for wooden dwelling houses in rich forest area, we paid attentions to a portal frame structure which is composed of not glulam but built-up members whose raw materials are dried sawn timbers taken from plantation grown forest. For establishing design procedure of the structural element, we made two different types of portal frames and conducted, at first, basic dynamic test to estimate natural frequency and dumping factors by fixing small shake excitation machine on the portal frames, then static push-pull cyclic loading tests were conducted until failure. The natural frequency of both portal frames was almost same but the higher order frequencies were likely to be affected by the difference of shear reinforcement of built-up members by hardwood dowels. While on static properties, as both portal frames failed in brittle manner due to bending failure at column or tear off at connection plate made of compression wood, further improvement of connection system was required for obtaining more stable alternative elements to glulam.

The role of incremental parsing in syntactically conditioned word learning

In a series of three experiments, we use children’s noun learning as a probe into their syntactic knowledge as well as their ability to deploy this knowledge, investigating how the predictions children make about upcoming syntactic structure change as their knowledge changes. In the first two experiments, we show that children display a developmental change in their ability to use a noun’s syntactic environment as a cue to its meaning. We argue that this pattern arises from children’s reliance on their knowledge of verbs’ subcategorization frame frequencies to guide parsing, coupled with an inability to revise incremental parsing decisions. We show that this analysis is consistent with the syntactic distributions in child-directed speech. In the third experiment, we show that the change arises from predictions based on verbs’ subcategorization frame frequencies.

Distributed compressed video sensing based on key frame secondary reconstruction

Distributed compressed video sensing scheme combines advantages of compressive sensing and distributed video coding to get better performance, in the meantime, adapts to the limited-resource wireless multimedia sensor network. However, in the conventional distributed compressed video sensing schemes, self-similarity and high sampling rate of the key frame have not been sufficiently utilized, and the overall computational complexity increases with the development of these schemes. To solve the aforementioned problems, we propose a novel distributed compressed video sensing scheme. A new key frame secondary reconstruction scheme is proposed, which further improves the quality of key frame and decreases computational complexity. The key frame’s initial reconstruction value is deeply exploited to assist the key frame secondary reconstruction. Then, a hypotheses set acquisition algorithm based on motion estimation is proposed to improve the quality of hypotheses set by optimizing the searching window under low complexity. Experimental results demonstrate that the overall performance of the proposed scheme outperforms that of the state-of-the-art methods.

A study on effects of castling on natural frequencies of 3D undamped steel frames using finite element method

The effects of castling on natural frequencies in 3D steel frames were investigated in this study since accurate assessment of fundamental period (frequency) of a structure is an essential part of design and analysis processes. The use of LUSAS 14.03 was adopted to calculate free vibration characteristics of frames. Thin shell element was used to modeling frames. The initial results are verified by Cinitha.A, Rama Raju. K &amp; Nagesh.R. Iyer (2008) and hand calculations using UBC code.. Furthermore different parameters such as Number of stories, Height of frames, Percentage of Castling, stiffness of connections and Supports Conditions were considered in order to evaluate their effects in frame modal respond. The results of above investigation show that by increasing the percent of castling the natural frequency will increase. Also by reduction of connection rigidity fundamental frequency will reduce. In order to achieve effective earthquake design we also have to consider these two parameters. Finally some suggestions were made in order to improve steel design against earth quake effects.

Impact of the Three Gorges project on ecological environment changes and snail distribution in Dongting Lake area.

BackgroundThe Three Gorges Dam (TGD) is a remarkable, far-reaching project in China. This study was conducted to assess the impact of TGD on changes in the ecological environment, snail distribution and schistosomiasis transmission in Dongting Lake area.MethodsHydrological data were collected from 12 monitoring sites in Hunan section of Yangtze River before and after TGD was established. Data on snail distribution and human schistosomiasis infection were also collected. Correlation analyses were performed to detect the significance of snail distribution to changes in ecological environmental factors and human schistosomiasis infection.FindingsA series of ecological environmental factors have changed in Dongting Lake area following the operation of TGD. Volume of annual runoff discharged into Dongting Lake declined by 20.85%. Annual sediment volume discharged into the lake and the mean lake sedimentation rate decreased by 73.9% and 32.2%, respectively. From 2003 to 2015, occurrence rate of frames with living snails and mean density of living snails decreased overall by 82.43% and 94.35%, respectively, with annual decrements being 13.49% and 21.29%. Moreover, human infection rate of schistosomiasis had decreased from 3.38% in 2003 to 0.44% in 2015, with a reduction of 86.98%. Correlation analyses showed that mean density of living snails was significantly associated with water level (r = 0.588, p<0.001), as well as the mean elevation range of the bottomland (r = 0.374, p = 0.025) and infection rate of schistosomiasis (r = 0.865, p<0.001).ConclusionEcological environmental changes caused by the TGD were associated with distribution of snails, and might further affect the transmission and prevalence of schistosomiasis. Risk of schistosomiasis transmission still exists in Dongting Lake area and long-term monitoring is required.

Multipoint analysis of compressive fluctuations in the fast and slow solar wind

AbstractCompressible turbulence in the solar wind is a topic of much recent debate. To understand the various compressive fluctuations at scales comparable to proton characteristic lengths, we use multipoint magnetic field and density data (derived from spacecraft potential which allows higher time resolution than is typically possible than with particle instruments) from the Cluster spacecraft when they were in undisturbed intervals of slow and fast solar wind. The application of the multipoint signal resonator technique is performed for the first time, to the analysis of scalar time series. Fluctuations in the measurements of electron density and in magnitude of the magnetic field (used as a proxy for compressible magnetic fluctuations) are used as inputs in addition to the traditional vector components of the magnetic field. This analysis is performed on two streams of solar wind, one which can be classed as a slow stream and one which can be classed as a fast stream to investigate the difference in the compressible components in the two types of wind. The recovered plasma frame frequencies for the incompressible component show low propagation speed in the plasma frame consistent with previous applications of the method, while the compressible components are more scattered, some with very high phase speeds. Based on these results, we propose a picture of compressive solar wind turbulence as a mixed state of (1) linear modes such as kinetic Alfvén, kinetic slow, and ion Bernstein modes; (2) coherent structures with very small intrinsic frequencies; and (3) nonlinear or sideband modes.

Speckle statistics in adaptive optics images at visible wavelengths

Residual speckles in adaptive optics (AO) images represent a well-known limitation on the achievement of the contrast needed for faint source detection. Speckles in AO imagery can be the result of either residual atmospheric aberrations, not corrected by the AO, or slowly evolving aberrations induced by the optical system. We take advantage of the high temporal cadence (1 ms) of the data acquired by the System for Coronagraphy with High-order Adaptive Optics from R to K bands-VIS forerunner experiment at the Large Binocular Telescope to characterize the AO residual speckles at visible wavelengths. An accurate knowledge of the speckle pattern and its dynamics is of paramount importance for the application of methods aimed at their mitigation. By means of both an automatic identification software and information theory, we study the main statistical properties of AO residuals and their dynamics. We therefore provide a speckle characterization that can be incorporated into numerical simulations to increase their realism and to optimize the performances of both real-time and postprocessing techniques aimed at the reduction of the speckle noise.

Speech Activity Detection and its Evaluation in Speaker Diarization System

In speaker diarization, the speech/voice activity detection is performed to separate speech, non-speech and silent frames. Zero crossing rate and root mean square value of frames of audio clips has been used to select training data for silent, speech and nonspeech models. The trained models are used by two classifiers, Gaussian mixture model (GMM) and Artificial neural network (ANN), to classify the speech and non-speech frames of audio clip. The results of ANN and GMM classifier are compared by Receiver operating characteristics (ROC) curve and Detection ErrorTradeoff (DET) graph. It is concluded that neural network based SADcomparatively better than Gaussian mixture model based SAD.

FPGA-based SOC for hardware implementation of a local histogram-based video shot detector

In this paper, we present a video application example and its implementation in a reconfigurable system-on-chip (SOC) platform. The proposed platform employs the benefits of field programmable gate array (FPGA) technology. A prototype based on a Xilinx Virtex-5 FPGA is developed. The application includes a video shot boundary detection module based on the local histogram (LH) technique. Diverse hardware module versions corresponding to different quantization levels and architectural solutions for an LH-based shot detection system are presented. The developed modules have different hardware resource occupations and can be used in a dynamic way to allow flexible management of the target hardware system. They also show high execution time efficiency and can reach an important bandwidth that can support the most recent high-resolution video formats with a high rate of frames per second. A complete SOC-based demonstration for video summarization based on the LH is also developed. It includes the LH extraction, shot boundary detection, and key frame visualization.

The F-GAMMA programme: multi-frequency study of active galactic nuclei in theFermiera

To fully exploit the scientific potential of the Fermi mission, we initiated the F-GAMMA program. Between 2007 and 2015 it was the prime provider of complementary multi-frequency monitoring in the radio regime. We quantify the radio variability of gamma-ray blazars. We investigate its dependence on source class and examine whether the radio variability is related to the gamma-ray loudness. Finally, we assess the validity of a putative correlation between the two bands. The F-GAMMA monitored monthly a sample of about 60 sources at up to twelve radio frequencies between 2.64 and 228.39 GHz. We perform a time series analysis on the first 2.5-year dataset to obtain variability parameters. A maximum likelihood analysis is used to assess the significance of a correlation between radio and gamma-ray fluxes. We present light curves and spectra (coherent within ten days) obtained with the Effelsberg 100-m and IRAM 30-m telescopes. All sources are variable across all frequency bands with amplitudes increasing with frequency up to rest frame frequencies of around 60 - 80 GHz as expected by shock-in-jet models. Compared to FSRQs, BL Lacs show systematically lower variability amplitudes, brightness temperatures and Doppler factors at lower frequencies, while the difference vanishes towards higher ones. The time scales appear similar for the two classes. The distribution of spectral indices appears flatter or more inverted at higher frequencies for BL Lacs. Evolving synchrotron self-absorbed components can naturally account for the observed spectral variability. We find that the Fermi-detected sources show larger variability amplitudes as well as brightness temperatures and Doppler factors, than non-detected ones. Flux densities at 86.2 and 142.3 GHz correlate with 1 GeV fluxes at a significance level better than 3sigma, implying that gamma rays are produced very close to the mm-band emission region.

Evaluation of Sloped Bottom Tuned Liquid Damper for Reduction of Seismic Response of Tall Buildings

Due to migration of people to urban area, high land costs and use of light weight materials modern buildings tend to be taller, lighter and flexible. These buildings possess low damping. This increases the possibility of failure during earthquake ground motion and also affect the serviceability during wind vibrations. Out of many available techniques today, to reduce the response of structure under dynamic loading, Tuned Liquid Damper (TLD) is a recent technique to mitigate seismic response. However TLD has been used to mitigate the wind induced structural vibrations. Flat bottom TLD gives energy back to the structure after event of dynamic loading and it is termed as beating. Beating affects the performance of TLD. Study attempts to analyze the effectiveness of sloped bottom TLD for reducing seismic vibrations of structure. Concept of equivalent flat bottom LD has been used to analyze sloped bottom TLD. Finite element method (EM) is used to model the structure and the liquid in the TLD. MATLAB code is developed to study the response of structure, the liquid sloshing in the tank and the coupled fluid-structure interaction. A ten storey two bay RC frame is analyzed for few inputs of ground motion. A sinusoidal ground motion corresponding to resonance condition with fundamental frequency of frame is analyzed. In the analysis the inherent damping of structure is not considered. Observations from the study shows that sloped bottom TLD uses less amount of liquid than flat bottom TLD. Also observed that efficiency of sloped bottom TLD can be improved if it is properly tuned.

Dry-Wet Modal Analysis of Balance Frame for Mounting Hydrophone

To analyze the vibration characteristics of the balance frame for mounting hydrophone in water, the resonance frequency and modal shape of the balance frame are calculated with ANSYS Workbench software. The model results are compared between the analysis environment being in the water and in the air. Two modules in ANSYS which are Model and Acoustic Extension are adapted to carry out the dry-wet modal analysis, and the first six modes are obtained. It’s indicated from the results that the wet modal frequency is at most 40% lower than the dry mode, and the influence of the interior frame is obvious.

Oncomelania hupensis snail distribution in working areas of Yangtze River hydrologic agencies located in middle and lower reaches of Yangtze River in 2016

To understand the Oncomelania hupensis snail distribution in the working areas of Yangtze River hydrologic agencies located in the middle and lower reaches of the Yangtze River in 2016, so as to provide the evidence for assessing the risk of schistosome infection of hydrological workers and establishing the control strategies. The suspicious environments with O. hupensis snails in the above working areas were selected as study areas, and the snail situation was surveyed by the system sampling method combined with the environmental sampling method. The survey data were collected and analyzed statistically. Totally 19 working areas from 17 hydrological agencies were selected as the investigation sites, among which, 10 working areas from 9 agencies were found with O. hupensis snail distribution. The constituent ratio of the areas with snails reached to 38.81% of the investigation areas, the occurrence rate of frames with snails was 3.08%, and the average density of living snails was 0.07 /0.1 m2. By comparison, the average density of living snails and occurrence rate of frames with snails in hydrological agencies under the jurisdiction of the Middle Reaches Administrative Bureau were the most serious among three administrative bureaus of the Yangtze River Water Resources Commission. There are various degrees of O. hupensis breeding in the working areas of hydrological agencies located in the middle and lower reaches of the Yangtze River, and the hydrological workers are facing with the risk of schistosome infection.

Schistosomiasis endemic situation of national surveillance sites in Mianyang City, 2015

To master the dynamics of schistosomiasis endemic situation and influencing factors in Mianyang City, so as to provide the evidence for making the control and prevention measures. Six villages of six schistosomiasis heavy endemic counties were selected as survey sites according to the national surveillance protocol (Revision in 2014) in Mianyang City. The surveys of the incidences of schistosomiasis in population and livestock as well as the prevalence of Oncomelania hupensis snails were conducted in the 6 national surveillance sites. The serum positive rates of local residents and migrant people were 2.12% and 1.71%, respectively. The infection rate of cattle was 0. The area with snails was 9.344 8 hm2. The mean density of living snails was 0.25/0.1 m2. The occurrence rate of frames with snails was 7.07%, and no infected snails were found. The infection rates of schistosome in human and livestock are low and the prevalence of O. hupensis snails is stable in the national surveillance sites in Mianyang City. However, the schistosomiasis transmission risk still exists, therefore, we should strengthen the control measures to prevent the rebound of the endemic.

Measuring Solar Doppler Velocities in the He ii 30.38 nm Emission Using the EUV Variability Experiment (EVE)

The EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory has provided unprecedented measurements of the solar EUV irradiance at high temporal cadence with good spectral resolution and range since May 2010. The main purpose of EVE was to connect the Sun to the Earth by providing measurements of the EUV irradiance as a driver for space weather and Living With a Star studies, but after launch the instrument has demonstrated the significance of its measurements in contributing to studies looking at the sources of solar variability for pure solar physics purposes. This paper expands upon previous findings that EVE can in fact measure wavelength shifts during solar eruptive events and therefore provide Doppler velocities for plasma at all temperatures throughout the solar atmosphere from the chromosphere to hot flaring temperatures. This process is not straightforward as EVE was not designed or optimized for these types of measurements. In this paper we describe the many detailed instrumental characterizations needed to eliminate the optical effects in order to provide an absolute baseline for the Doppler shift studies. An example is given of a solar eruption on 7 September 2011 (SOL2011-09-07), associated with an X1.2 flare, where EVE Doppler analysis shows plasma ejected from the Sun in the He ii 30.38 nm emission at a velocity of almost \(120~\mbox{km}\,\mbox{s}^{-1}\) along the line-of-sight.

On uniformity of raster illumination under laser scanning

The paper considers the possibility of a flat light field creation (light raster) of a large size by laser scanning at a distance of several tens of meters with angular sizes equal to 20º×4º. It is shown that the filling of such size raster by light is possible with the use of a single laser. The uniformity of light raster illumination is achieved by choice of parameters for collimating and scanning optical systems, the speed of light spot movement on the line and frame, turnover frequency of frames, spot light overlap factor. We present findings that give the possibility to obtain relatively uniform raster illumination at laser scanning and the filling of large size raster with low power laser light from the radiation source.