bluuebunny/crossref_metadata_2025 huggingface dataset:
Equalization Enhanced Phase Noise in Coherent Optical Systems with Digital Pre- and Post-Processing
Authors: Kakkar Aditya , Rodrigo Navarro Jaime , Schatz Richard , Pang Xiaodan , Ozolins Oskars , Louchet Hadrien , Jacobsen Gunnar , Popov Sergei
Published: March 2016

We present an extensive study of equalization enhanced phase noise (EEPN) in coherent optical system for all practical electronic dispersion compensation configurations. It is shown that there are only eight practicable all-electronic impairment mitigation configurations. The non-linear and time variant analysis reveals that the existence and the cause of EEPN depend on the digital signal processing (DSP) schemes. There are three schemes that in principle do not cause EEPN. Analysis further reveals the statistical equivalence of the remaining five system configurations resulting in EEPN. In three of them, EEPN is due to phase noise of the transmitting laser, while in the remaining two, EEPN is caused by the local oscillator. We provide a simple look-up table for the system designer to make an informative decision regarding practicable configuration choice and design.
A High-Temperature Solar Selective Absorber Based upon Periodic Shallow Microstructures Coated by Multi-Layers Using Atomic Layer Deposition
Authors: Shimizu Makoto , Akutsu Hiroki , Tsuda Shinichiro , Iguchi Fumitada , Yugami Hiroo
Published: March 2016

Regarding the fabrication of solar selective absorbers, the ability to create microstructures on top of metal surfaces is a promising technology. Typically, these materials are able to possess spectrally-selective absorption properties for high-temperature usage. Solar-selective absorbers that function at temperatures up to 700 °C and possess shallow honeycomb cylindrical microcavities coated with a metal-dielectric multi-layer have been investigated. Honeycomb array cylindrical microcavities were fabricated on W substrate with interference lithography and multi-layers consisting of Pt nano-film sandwiched by Al2O3 layers were created for a uniform coating via atomic layer deposition. The absorbance spectrum of fabricated samples reveals results consistent with a simulation based on a rigorous coupled-wave analysis method. A solar absorbance value of 0.92 and a hemispherical total emittance value of 0.18 at 700 °C was determined from the fabricated solar-selective absorber. Additionally, thermal stability of up to 700 °C was confirmed in vacuum.
Preparation of Well-Defined Propargyl-Terminated Tetra-Arm Poly(N-isopropylacrylamide)s and Their Click Hydrogels Crosslinked with β-cyclodextrin
Authors: Wang Jianquan , Zhu Zhe , Jin Xin , Li Zhujun , Shao Yizhen , Shao Ziqiang
Published: March 2016

As an important class of reversible deactivation radical polymerization (RDRP), reversible addition fragmentation chain transfer (RAFT) polymerization has attracted great attention attributed to its facile and flexible features to prepare well-defined polymers with different complex structures. In addition, the combination of RAFT with click chemistry provides more effective strategies to fabricate advanced functional materials. In this work, a series of temperature responsive tetra-arm telechelic poly(N-isopropylacrylamide)s (PNIPAs) with propargyl end groups were prepared for the first time through RAFT and subsequent aminolysis/Michael addition modification. The temperature sensitivities of their aqueous solutions were researched via turbidity measurement. It was found that the phase transition temperature of obtained PNIPAs increased with their molecular weights ascribed to their distinctions in the hydrophobic/hydrophilic balance. Subsequently, β-cyclodextrin (β-CD) functionalized with azide moieties was used to crosslink the prepared propargyl-terminated tetra-arm PNIPAs through click chemistry, fabricating corresponding hydrogels with thermoresponse. Similar to their precursors, the hydrogels demonstrated the same dependence of volume phase transition temperature (VPTT) on their molecular weights. In addition, the incorporation of β-CD and the residual groups besides crosslinking may provide a platform for imparting additional functions such as inclusion and adsorption as well as further functionalization.
Anhydrides-Cured Bimodal Rubber-Like Epoxy Asphalt Composites: From Thermosetting to Quasi-Thermosetting
Authors: Kang Yang , Jin Rui , Wu Qiang , Pu Liang , Song Mingyu , Cheng Jixiang , Yu Pengfei
Published: March 2016

The present engineering practices show the potential that epoxy asphalt composites (EACs) would be a better choice to obtain long life for busy roads. To understand the service performance–related thermorheological properties of prepared bimodal anhydrides-cured rubber-like EACs (REACs), a direct tensile tester, dynamic shear rheometer and mathematical model were used. Tensile tests demonstrate that all the REACs reported here are more flexible than previously reported anhydrides-cured REACs at both 20 and 0 °C. The better flexibility is attributed to the change of bimodal networks, in which cross-linked short chains decreased and cross-linked long chains increased, relatively. Strain sweeps show that all the REACs have linear viscoelastic (LVE) properties when their strains are smaller than 1.0% from −35 to 120 °C. Temperature sweeps illustrate that the thermorheological properties of REACs evolve from thermosetting to quasi-thermosetting with asphalt content, and all the REACs retain solid state and show elastic properties in the experimental temperature range. A Cole–Cole plot and Black diagram indicate that all the REACs are thermorheologically simple materials, and the master curves were constructed and well-fitted by the Generalized Logistic Sigmoidal models. This research provides a facile approach to tune the thermorheological properties of the REACs, and the cheaper quasi-thermosetting REAC facilitates their advanced applications.
Thermosensitive Behavior and Antibacterial Activity of Cotton Fabric Modified with a Chitosan-poly(N-isopropylacrylamide) Interpenetrating Polymer Network Hydrogel
Authors: Wang Boxiang , Wu Xiaolin , Li Jia , Hao Xu , Lin Jie , Cheng Dehong , Lu Yanhua
Published: March 2016

To increase the themosensitive behavior and antibacterial activity of cotton fabric, a series of poly (N-isopropylacrylamide)/chitosan (PNIPAAm/Cs) hydrogels was synthesized by interpenetrating polymer network (IPN) technology using a redox initiator. The IPN PNIPAAm/Cs hydrogel was characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results indicated that the IPN PNIPAAm/Cs hydrogel has a lower critical solution temperature (LCST) at 33 °C. The IPN hydrogel was then used to modify cotton fabric using glutaric dialdehyde (GA) as a crosslinking agent following a double-dip-double-nip process. The results demonstrated that the modified cotton fabric showed obvious thermosensitive behavior and antibacterial activity. The contact angle of the modified cotton fabric has a sharp rise around 33 °C, and the modified cotton fabric showed an obvious thermosensitive behavior. The bacterial reduction of modified cotton fabric against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were more than 99%. This study presents a valuable route towards smart textiles and their applications in functional clothing.
Biodegradable Polymer Membranes Applied in Guided Bone/Tissue Regeneration: A Review
Authors: Wang Jiaolong , Wang Lina , Zhou Ziyu , Lai Hanjian , Xu Pan , Liao Lan , Wei Junchao
Published: March 2016

Polymer membranes have been widely used in guided tissue regeneration (GTR) and guided bone regeneration (GBR). In this review, various commercially available membranes are described. Much attention is paid to the recent development of biodegradable polymers applied in GTR and GBR, and the important issues of biodegradable polymeric membranes, including their classification, latest experimental research and clinical applications, as well as their main challenges are addressed. Herein, natural polymers, synthetic polymers and their blends are all introduced. Pure polymer membranes are biodegradable and biocompatible, but they lack special properties such as antibacterial properties, osteoconductivity, and thus polymer membranes loaded with functional materials such as antibacterial agents and growth factors show many more advantages and have also been introduced in this review. Despite there still being complaints about polymer membranes, such as their low mechanical properties, uncontrollable degradation speed and some other drawbacks, these problems will undoubtedly be conquered and biodegradable polymers will have more applications in GTR and GBR.
Inflation Protected Investment Strategies
Authors: Mahlstedt Mirco , Zagst Rudi
Published: March 2016

In this paper, a dynamic inflation-protected investment strategy is presented, which is based on traditional asset classes and Markov-switching models. Different stock market, as well as inflation regimes are identified, and within those regimes, the inflation hedging potential of stocks, bonds, real estate, commodities and gold are investigated. Within each regime, we determine optimal investment portfolios driven by the investment idea of protection from losses due to changing inflation if inflation is rising or high, but decoupling the performance from inflation if inflation is low. The results clearly indicate that these asset classes behave differently in different stock market and inflation regimes. Whereas in the long-run, we agree with the general opinion in the literature that stocks and bonds are a suitable hedge against inflation, we observe for short time horizons that the hedging potential of each asset class, especially of real estate and commodities, depend strongly on the state of the current market environment. Thus, our approach provides a possible explanation for different statements in the literature regarding the inflation hedging properties of these asset classes. A dynamic inflation-protected investment strategy is developed, which combines inflation protection and upside potential. This strategy outperforms standard buy-and-hold strategies, as well as the well-known 1 N -portfolio.
Identification of Village Building via Google Earth Images and Supervised Machine Learning Methods
Authors: Guo Zhiling , Shao Xiaowei , Xu Yongwei , Miyazaki Hiroyuki , Ohira Wataru , Shibasaki Ryosuke
Published: March 2016

In this study, a method based on supervised machine learning is proposed to identify village buildings from open high-resolution remote sensing images. We select Google Earth (GE) RGB images to perform the classification in order to examine its suitability for village mapping, and investigate the feasibility of using machine learning methods to provide automatic classification in such fields. By analyzing the characteristics of GE images, we design different features on the basis of two kinds of supervised machine learning methods for classification: adaptive boosting (AdaBoost) and convolutional neural networks (CNN). To recognize village buildings via their color and texture information, the RGB color features and a large number of Haar-like features in a local window are utilized in the AdaBoost method; with multilayer trained networks based on gradient descent algorithms and back propagation, CNN perform the identification by mining deeper information from buildings and their neighborhood. Experimental results from the testing area at Savannakhet province in Laos show that our proposed AdaBoost method achieves an overall accuracy of 96.22% and the CNN method is also competitive with an overall accuracy of 96.30%.
An Automatic Procedure for Early Disaster Change Mapping Based on Optical Remote Sensing
Authors: Ma Yong , Chen Fu , Liu Jianbo , He Yang , Duan Jianbo , Li Xinpeng
Published: March 2016

Disaster change mapping, which can provide accurate and timely changed information (e.g., damaged buildings, accessibility of road and the shelter sites) for decision makers to guide and support a plan for coordinating emergency rescue, is critical for early disaster rescue. In this paper, we focus on optical remote sensing data to propose an automatic procedure to reduce the impacts of optical data limitations and provide the emergency information in the early phases of a disaster. The procedure utilizes a series of new methods, such as an Optimizable Variational Model (OptVM) for image fusion and a scale-invariant feature transform (SIFT) constraint optical flow method (SIFT-OFM) for image registration, to produce product maps including cloudless backdrop maps and change-detection maps for catastrophic event regions, helping people to be aware of the whole scope of the disaster and assess the distribution and magnitude of damage. These product maps have a rather high accuracy as they are based on high precision preprocessing results in spectral consistency and geometric, which compared with traditional fused and registration methods by visual qualitative or quantitative analysis. The procedure is fully automated without any manual intervention to save response time. It also can be applied to many situations.
Early Detection and Quantification of Almond Red Leaf Blotch Using High-Resolution Hyperspectral and Thermal Imagery
Authors: López-López Manuel , Calderón Rocío , González-Dugo Victoria , Zarco-Tejada Pablo , Fereres Elías
Published: March 2016

Red leaf blotch is one of the major fungal foliar diseases affecting almond orchards. High-resolution thermal and hyperspectral airborne imagery was acquired from two flights and compared with concurrent field visual evaluations for disease incidence and severity. Canopy temperature and vegetation indices were calculated from thermal and hyperspectral imagery and analyzed for their ability to detect the disease at early stages. The classification methods linear discriminant analysis and support vector machine, using linear and radial basis kernels, were applied to a combination of these vegetation indices in order to quantify and discriminate between red leaf blotch severity levels. Chlorophyll and carotenoid indices and chlorophyll fluorescence were effective in detecting red leaf blotch at the early stages of disease development. Linear models showed higher power to separate between asymptomatic trees and those affected by advanced stages of disease development while the non-linear model was better in discriminating asymptomatic plants from those at early stages of red leaf blotch development. Leaf-level measurements of stomatal conductance, chlorophyll content, chlorophyll fluorescence, photochemical reflectance index, and spectral reflectance showed no significant differences between healthy leaves and the green areas of symptomatic leaves. This study demonstrated the feasibility of early detecting and quantifying red leaf blotch using high-resolution hyperspectral imagery.
Registration of Long-Strip Terrestrial Laser Scanning Point Clouds Using RANSAC and Closed Constraint Adjustment
Authors: Zheng Li , Yu Manzhu , Song Mengxiao , Stefanidis Anthony , Ji Zheng , Yang Chaowei
Published: March 2016

The registration of long-strip, terrestrial laser scanning (TLS) point clouds is a prerequisite for various engineering tasks, including tunnels, bridges, and roads. An artificial target-based registration method is proposed in this paper to automatically calculate registration parameters (i.e., rotation, translation) of scanned pairs without initial estimations. The approach is based on the well-known Random Sample Consensus (RANSAC) method and effectively searches the point cloud for corresponding returns from a system of artificial targets. In addition, Closed Constraint Adjustment (CCA) is integrated into the registration method to significantly reduce the accumulative error. Experimental results demonstrate the robustness and feasibility of the proposed approach. It is a promising approach to register automatically long strips with limited external control points with satisfactory precision.
Integrating Global Satellite-Derived Data Products as a Pre-Analysis for Hydrological Modelling Studies: A Case Study for the Red River Basin
Authors: Simons Gijs , Bastiaanssen Wim , Ngô Le , Hain Christopher , Anderson Martha , Senay Gabriel
Published: March 2016

With changes in weather patterns and intensifying anthropogenic water use, there is an increasing need for spatio-temporal information on water fluxes and stocks in river basins. The assortment of satellite-derived open-access information sources on rainfall (P) and land use/land cover (LULC) is currently being expanded with the application of actual evapotranspiration (ETact) algorithms on the global scale. We demonstrate how global remotely sensed P and ETact datasets can be merged to examine hydrological processes such as storage changes and streamflow prior to applying a numerical simulation model. The study area is the Red River Basin in China in Vietnam, a generally challenging basin for remotely sensed information due to frequent cloud cover. Over this region, several satellite-based P and ETact products are compared, and performance is evaluated using rain gauge records and longer-term averaged streamflow. A method is presented for fusing multiple satellite-derived ETact estimates to generate an ensemble product that may be less susceptible, on a global basis, to errors in individual modeling approaches. Subsequently, monthly satellite-derived rainfall and ETact are combined to assess the water balance for individual subcatchments and types of land use, defined using a global land use classification improved based on auxiliary satellite data. It was found that a combination of TRMM rainfall and the ensemble ETact product is consistent with streamflow records in both space and time. It is concluded that monthly storage changes, multi-annual streamflow and water yield per LULC type in the Red River Basin can be successfully assessed based on currently available global satellite-derived products.
Assessing the Impact of Climate Variability on Cropland Productivity in the Canadian Prairies Using Time Series MODIS FAPAR
Authors: Dong Taifeng , Liu Jiangui , Shang Jiali , Qian Budong , Huffman Ted , Zhang Yinsuo , Champagne Catherine , Daneshfar Bahram
Published: March 2016

Cropland productivity is impacted by climate. Knowledge on spatial-temporal patterns of the impacts at the regional scale is extremely important for improving crop management under limiting climatic factors. The aim of this study was to investigate the effects of climate variability on cropland productivity in the Canadian Prairies between 2000 and 2013 based on time series of MODIS (Moderate Resolution Imaging Spectroradiometer) FAPAR (Fraction of Absorbed Photosynthetically Active Radiation) product. Key phenological metrics, including the start (SOS) and end of growing season (EOS), and the cumulative FAPAR (CFAPAR) during the growing season (between SOS and EOS), were extracted and calculated from the FAPAR time series with the Parametric Double Hyperbolic Tangent (PDHT) method. The Mann-Kendall test was employed to assess the trends of cropland productivity and climatic variables, and partial correlation analysis was conducted to explore the potential links between climate variability and cropland productivity. An assessment using crop yield statistical data showed that CFAPAR can be taken as a surrogate of cropland productivity in the Canadian Prairies. Cropland productivity showed an increasing trend in most areas of Canadian Prairies, in general, during the period from 2000 to 2013. Interannual variability in cropland productivity on the Canadian Prairies was influenced positively by rainfall variation and negatively by mean air temperature.
Pi-SAR-L2 Observation of the Landslide Caused by Typhoon Wipha on Izu Oshima Island
Authors: Watanabe Manabu , Thapa Rajesh , Shimada Masanobu
Published: March 2016

Pi-SAR-L2 full polarimetic data observed in four different observational directions over a landslide area on Izu Oshima Island, induced by Typhoon Wipha on 16 October 2013, were analyzed to clarify the most appropriate L-band full polarimetric parameters and observational direction to detect a landslide area. Japanese airborne Pi-SAR-L2 and PiSAR-L data were used in this analysis. Several L-band full polarimetric parameters, including backscattering coefficient (σ°), coherence between two polarimetric states, four-component decomposition parameters (double-bounce/volume/surface/helix scattering), and eigenvalue decomposition parameters (entropy/α/anisotropy), were calculated to determine the most appropriate parameters for detecting landslide areas. The change in land cover from forest before the disaster to bare soil after the disaster was detected well by α, and coherence between HH and VV. Observational data from the bottom to the top of the landslide detected the landslide well, whereas observations from the opposite sides were not as useful, indicating that a smaller local incident angle is better to distinguish landslide and forested areas. Soil from the landslide intruded into the urban areas; however, none of the full polarimetric parameters showed any significant differences between the landslide-affected urban areas after the disaster and unaffected areas before the disaster.
Optical Models for Remote Sensing of Colored Dissolved Organic Matter Absorption and Salinity in New England, Middle Atlantic and Gulf Coast Estuaries USA
Authors: Keith Darryl , Lunetta Ross , Schaeffer Blake
Published: March 2016

Ocean color algorithms have been successfully developed to estimate chlorophyll a and total suspended solids concentrations in coastal and estuarine waters but few have been created to estimate light absorption due to colored dissolved inorganic matter (CDOM) and salinity from the spectral signatures of these waters. In this study, we used remotely sensed reflectances in the red and blue-green portions of the visible spectrum retrieved from Medium Resolution Imaging Spectrometer (MERIS) and the International Space Station (ISS) Hyperspectral Imager for the Coastal Ocean (HICO) images to create a model to estimate CDOM absorption. CDOM absorption results were then used to develop an algorithm to predict the surface salinities of coastal bays and estuaries in New England, Middle Atlantic, and Gulf of Mexico regions. Algorithm-derived CDOM absorptions and salinities were successfully validated using laboratory measured absorption values over magnitudes of ~0.1 to 7.0 m−1 and field collected CTD data from oligohaline to polyhaline (S less than 5 to 18–30) environments in Narragansett Bay (Rhode Island); the Neuse River Estuary (North Carolina); Pensacola Bay (Florida); Choctawhatchee Bay (Florida); St. Andrews Bay (Florida); St. Joseph Bay (Florida); and inner continental shelf waters of the Gulf of Mexico.
Remote Sensing of the North American Laurentian Great Lakes’ Surface Temperature
Authors: Moukomla Sitthisak , Blanken Peter
Published: March 2016

The Great Lakes Surface Temperature (GLST) is the key to understanding the effects of climate change on the Great Lakes (GL). This study provides the first techniques to retrieve pixel-based GLST under all sky conditions by merging skin temperature derived from the MODIS Land Surface Temperature (MOD11L2) and the MODIS Cloud product (MOD06L2) from 6 July 2001 to 31 December 2014, resulting in 18,807 scenes in total 9373 (9434) scenes for MOD11L2 (MOD06L2). The pixel-based GLST under all sky conditions was well-correlated with the in situ observations (R2 = 0.9102) with a cool bias of −1.10 °C and a root mean square error (RMSE) of 1.39 °C. The study also presents the long-term trends of GLST. Contrary to expectations, it decreased slightly due to the impact of an anomalously cold winter in 2013–2014.
A New Soil Moisture Agricultural Drought Index (SMADI) Integrating MODIS and SMOS Products: A Case of Study over the Iberian Peninsula
Authors: Sánchez Nilda , González-Zamora Ángel , Piles María , Martínez-Fernández José
Published: March 2016

A new index for agricultural drought monitoring is presented based on the integration of different soil/vegetation remote sensing observations. The synergistic fusion of the surface soil moisture (SSM) from the Soil Moisture and Ocean Salinity (SMOS) mission, with the Moderate Resolution Imaging Spectroradiometer (MODIS) derived land surface temperature (LST), and water/vegetation indices for agricultural drought monitoring was tested. The rationale of the approach is based on the inverse relationship between LST, vegetation condition and soil moisture content. Thus, the proposed Soil Moisture Agricultural Drought Index (SMADI) combines the soil and temperature conditions while including the lagged response of vegetation. SMADI was retrieved every eight days at 500 m spatial resolution for the whole Iberian Peninsula (IP) from 2010 to 2014, and a time lag of eight days was used to account for the plant response to the varying soil/climatic conditions. The results of SMADI compared well with other agricultural indices in a semiarid area in the Duero basin, in Spain, and also with a climatic index in areas of the Iberian Peninsula under contrasted climatic conditions. Based on a standard classification of drought severity, the proposed index allowed for a coherent description of the drought conditions of the IP during the study period.
Exploring Long Term Spatial Vegetation Trends in Taiwan from AVHRR NDVI3g Dataset Using RDA and HCA Analyses
Authors: Tsai Hui , Lin Yu-Hao , Yang Ming-Der
Published: March 2016

Due to 4000 m elevation variation with temperature differences equivalent to 50 degrees of latitudinal gradient, exploring Taiwan’s spatial vegetation trends is valuable in terms of diverse ecosystems and climatic types covering a relatively small island with an area of 36,000 km2. This study analyzed Taiwan’s spatial vegetation trends with controlling environmental variables through redundancy (RDA) and hierarchical cluster (HCA) analyses over three decades (1982–2012) of monthly normalized difference vegetation index (NDVI) derived from the Advanced Very High Resolution Radiometer (AVHRR) NDVI3g data for 19 selected weather stations over the island. Results showed two spatially distinct vegetation response groups. Group 1 comprises weather stations which remained relatively natural showing a slight increasing NDVI tendency accompanied with rising temperature, whereas Group 2 comprises stations with high level of human development showing a slight decreasing NDVI tendency associated with increasing temperature-induced moisture stress. Statistically significant controlling variables include climatic factors (temperature and precipitation), orographic factors (mean slope and aspects), and anthropogenic factor (population density). Given the potential trajectories for future warming, variable precipitation, and population pressure, challenges, such as land-cover and water-induced vegetation stress, need to be considered simultaneously for establishing adequate adaptation strategies to combat climate change challenges in Taiwan.
The Impact of Forest Density on Forest Height Inversion Modeling from Polarimetric InSAR Data
Authors: Wang Changcheng , Wang Lei , Fu Haiqiang , Xie Qinghua , Zhu Jianjun
Published: March 2016

Forest height is of great significance in analyzing the carbon cycle on a global or a local scale and in reconstructing the accurate forest underlying terrain. Major algorithms for estimating forest height, such as the three-stage inversion process, are depending on the random-volume-over-ground (RVoG) model. However, the RVoG model is characterized by a lot of parameters, which influence its applicability in forest height retrieval. Forest density, as an important biophysical parameter, is one of those main influencing factors. However, its influence to the RVoG model has been ignored in relating researches. For this paper, we study the applicability of the RVoG model in forest height retrieval with different forest densities, using the simulated and real Polarimetric Interferometric SAR data. P-band ESAR datasets of the European Space Agency (ESA) BioSAR 2008 campaign were selected for experiments. The test site was located in Krycklan River catchment in Northern Sweden. The experimental results show that the forest density clearly affects the inversion accuracy of forest height and ground phase. For the four selected forest stands, with the density increasing from 633 to 1827 stems/Ha, the RMSEs of inversion decrease from 4.6 m to 3.1 m. The RVoG model is not quite applicable for forest height retrieval especially in sparsely vegetated areas. We conclude that the forest stand density is positively related to the estimation accuracy of the ground phase, but negatively correlates to the ground-to-volume scattering ratio.
Spectroscopic Terahertz Imaging at Room Temperature Employing Microbolometer Terahertz Sensors and Its Application to the Study of Carcinoma Tissues
Authors: Kašalynas Irmantas , Venckevičius Rimvydas , Minkevičius Linas , Sešek Aleksander , Wahaia Faustino , Tamošiūnas Vincas , Voisiat Bogdan , Seliuta Dalius , Valušis Gintaras , Švigelj Andrej , Trontelj Janez
Published: March 2016

A terahertz (THz) imaging system based on narrow band microbolometer sensors (NBMS) and a novel diffractive lens was developed for spectroscopic microscopy applications. The frequency response characteristics of the THz antenna-coupled NBMS were determined employing Fourier transform spectroscopy. The NBMS was found to be a very sensitive frequency selective sensor which was used to develop a compact all-electronic system for multispectral THz measurements. This system was successfully applied for principal components analysis of optically opaque packed samples. A thin diffractive lens with a numerical aperture of 0.62 was proposed for the reduction of system dimensions. The THz imaging system enhanced with novel optics was used to image for the first time non-neoplastic and neoplastic human colon tissues with close to wavelength-limited spatial resolution at 584 GHz frequency. The results demonstrated the new potential of compact RT THz imaging systems in the fields of spectroscopic analysis of materials and medical diagnostics.
Improved Tuning Fork for Terahertz Quartz-Enhanced Photoacoustic Spectroscopy
Authors: Sampaolo Angelo , Patimisco Pietro , Giglio Marilena , Vitiello Miriam , Beere Harvey , Ritchie David , Scamarcio Gaetano , Tittel Frank , Spagnolo Vincenzo
Published: March 2016

We report on a quartz-enhanced photoacoustic (QEPAS) sensor for methanol (CH3OH) detection employing a novel quartz tuning fork (QTF), specifically designed to enhance the QEPAS sensing performance in the terahertz (THz) spectral range. A discussion of the QTF properties in terms of resonance frequency, quality factor and acousto-electric transduction efficiency as a function of prong sizes and spacing between the QTF prongs is presented. The QTF was employed in a QEPAS sensor system using a 3.93 THz quantum cascade laser as the excitation source in resonance with a CH3OH rotational absorption line located at 131.054 cm−1. A minimum detection limit of 160 ppb in 30 s integration time, corresponding to a normalized noise equivalent absorption NNEA = 3.75 × 10−11 cm−1W/Hz½, was achieved, representing a nearly one-order-of-magnitude improvement with respect to previous reports.
LS Channel Estimation and Signal Separation for UHF RFID Tag Collision Recovery on the Physical Layer
Authors: Duan Hanjun , Wu Haifeng , Zeng Yu , Chen Yuebin
Published: March 2016

In a passive ultra-high frequency (UHF) radio-frequency identification (RFID) system, tag collision is generally resolved on a medium access control (MAC) layer. However, some of collided tag signals could be recovered on a physical (PHY) layer and, thus, enhance the identification efficiency of the RFID system. For the recovery on the PHY layer, channel estimation is a critical issue. Good channel estimation will help to recover the collided signals. Existing channel estimates work well for two collided tags. When the number of collided tags is beyond two, however, the existing estimates have more estimation errors. In this paper, we propose a novel channel estimate for the UHF RFID system. It adopts an orthogonal matrix based on the information of preambles which is known for a reader and applies a minimum-mean-square-error (MMSE) criterion to estimate channels. From the estimated channel, we could accurately separate the collided signals and recover them. By means of numerical results, we show that the proposed estimate has lower estimation errors and higher separation efficiency than the existing estimates.
A Virtual Environment to Improve the Detection of Oral-Facial Malfunction in Children with Cerebral Palsy
Authors: Martín-Ruiz María-Luisa , Máximo-Bocanegra Nuria , Luna-Oliva Laura
Published: March 2016

The importance of an early rehabilitation process in children with cerebral palsy (CP) is widely recognized. On the one hand, new and useful treatment tools such as rehabilitation systems based on interactive technologies have appeared for rehabilitation of gross motor movements. On the other hand, from the therapeutic point of view, performing rehabilitation exercises with the facial muscles can improve the swallowing process, the facial expression through the management of muscles in the face, and even the speech of children with cerebral palsy. However, it is difficult to find interactive games to improve the detection and evaluation of oral-facial musculature dysfunctions in children with CP. This paper describes a framework based on strategies developed for interactive serious games that is created both for typically developed children and children with disabilities. Four interactive games are the core of a Virtual Environment called SONRIE. This paper demonstrates the benefits of SONRIE to monitor children’s oral-facial difficulties. The next steps will focus on the validation of SONRIE to carry out the rehabilitation process of oral-facial musculature in children with cerebral palsy.
Pedestrian Detection and Tracking from Low-Resolution Unmanned Aerial Vehicle Thermal Imagery
Authors: Ma Yalong , Wu Xinkai , Yu Guizhen , Xu Yongzheng , Wang Yunpeng
Published: March 2016

Driven by the prominent thermal signature of humans and following the growing availability of unmanned aerial vehicles (UAVs), more and more research efforts have been focusing on the detection and tracking of pedestrians using thermal infrared images recorded from UAVs. However, pedestrian detection and tracking from the thermal images obtained from UAVs pose many challenges due to the low-resolution of imagery, platform motion, image instability and the relatively small size of the objects. This research tackles these challenges by proposing a pedestrian detection and tracking system. A two-stage blob-based approach is first developed for pedestrian detection. This approach first extracts pedestrian blobs using the regional gradient feature and geometric constraints filtering and then classifies the detected blobs by using a linear Support Vector Machine (SVM) with a hybrid descriptor, which sophisticatedly combines Histogram of Oriented Gradient (HOG) and Discrete Cosine Transform (DCT) features in order to achieve accurate detection. This research further proposes an approach for pedestrian tracking. This approach employs the feature tracker with the update of detected pedestrian location to track pedestrian objects from the registered videos and extracts the motion trajectory data. The proposed detection and tracking approaches have been evaluated by multiple different datasets, and the results illustrate the effectiveness of the proposed methods. This research is expected to significantly benefit many transportation applications, such as the multimodal traffic performance measure, pedestrian behavior study and pedestrian-vehicle crash analysis. Future work will focus on using fused thermal and visual images to further improve the detection efficiency and effectiveness.
Geometry-Based Distributed Spatial Skyline Queries in Wireless Sensor Networks
Authors: Wang Yan , Song Baoyan , Wang Junlu , Zhang Li , Wang Ling
Published: March 2016

Algorithms for skyline querying based on wireless sensor networks (WSNs) have been widely used in the field of environmental monitoring. Because of the multi-dimensional nature of the problem of monitoring spatial position, traditional skyline query strategies cause enormous computational costs and energy consumption. To ensure the efficient use of sensor energy, a geometry-based distributed spatial query strategy (GDSSky) is proposed in this paper. Firstly, the paper presents a geometry-based region partition strategy. It uses the skyline area reduction method based on the convex hull vertices, to quickly query the spatial skyline data related to a specific query area, and proposes a regional partition strategy based on the triangulation method, to implement distributed queries in each sub-region and reduce the comparison times between nodes. Secondly, a sub-region clustering strategy is designed to group the data inside into clusters for parallel queries that can save time. Finally, the paper presents a distributed query strategy based on the data node tree to traverse all adjacent sensors’ monitoring locations. It conducts spatial skyline queries for spatial skyline data that have been obtained and not found respectively, so as to realize the parallel queries. A large number of simulation results shows that GDSSky can quickly return the places which are nearer to query locations and have larger pollution capacity, and significantly reduce the WSN energy consumption.
Application of the D3H2 Methodology for the Cost-Effective Design of Dependable Systems
Authors: Aizpurua Jose , Muxika Eñaut , Papadopoulos Yiannis , Chiacchio Ferdinando , Manno Gabriele
Published: March 2016

The use of dedicated components as a means of achieving desirable levels of fault tolerance in a system may result in high costs. A cost effective way of restoring failed functions is to use heterogeneous redundancies: components that, besides performing their primary intended design function, can also restore compatible functions of other components. In this paper, we apply a novel design methodology called D3H2 (aDaptive Dependable Design for systems with Homogeneous and Heterogeneous redundancies) to assist in the systematic identification of heterogeneous redundancies, the design of hardware/software architectures including fault detection and reconfiguration, and the systematic dependability and cost assessments of the system. D3H2 integrates parameter uncertainty and criticality analyses to model inexact failure data in dependability assessment. The application to a railway case study is presented with a focus on analysing different reconfiguration strategies as well as types and levels of redundancies.
Using Scenarios to Assess Policy Mixes for Resource Efficiency and Eco-Innovation in Different Fiscal Policy Frameworks
Authors: Bontoux Laurent , Bengtsson Daniel
Published: March 2016

There is no longer any doubt that the European Union needs to manage a transition towards a sustainable economy and society. The complexity of such an enterprise is creating major challenges that require a future oriented systemic approach, looking at the EU economy and society as a whole, and going beyond current agendas and policies. The purpose of the JRC foresight study “2035: Paths towards a sustainable EU economy” was to explore how this could be possible. Resource efficiency was at the core of the reflection. This created a context where the fiscal framework was perceived by the experts involved as essential in driving (or hindering) the evolution towards a more sustainable future. Societal values (individualistic or collaborative) were selected as the other axis around which to construct four scenarios. A large number of other drivers of change were taken into account to construct scenarios of a sufficient depth and detail to generate a systemic understanding. The scenarios were used in an original way to help experts identify which policy mixes would be best adapted to push each scenario towards a more sustainable future, while respecting its own logic and constraints. For each scenario, 6 policy domains considered the most relevant were selected among more than 50. Research and innovation, new business models and education were considered important for all four scenarios. The other domains were natural resources management, regulation, ethics, employment, transparency, governance, social protection, and systems integration. The study illustrates how powerful a policy framework which is fiscally supportive of environmental sustainability can be in supporting resource efficiency and that this can be achieved in very different ways depending on the prevailing social values. It also shows how a combination of actions in other policy areas can be used to drive sustainability further. In sum, this work illustrates how the creative use of foresight can help design policy mixes that can open the way to very different paths towards a sustainable future.
School Facilities and Sustainability-Related Concepts: A Study of Hellenic Secondary School Principals’, Teachers’, Pupils’ and Parents’ Responses
Authors: Zepatou Vasiliki , Loizidou Maria , Chaloulakou Archontoula , Spyrellis Nicolas
Published: March 2016

Effective building environment sustainability frameworks and practices need to take users’ opinions into account. For this purpose, a survey questionnaire was developed and the “Panhellenic survey of school spaces, materials and environmental-comfort conditions in secondary schools and perceptions, stances and attitudes of pupils, teachers, principals and parents towards sustainable construction and the selection and use of materials in schools that are friendly to the environment and human health” was conducted nationwide with a random stratified sample of 170 Hellenic public secondary schools. Selected findings are presented and discussed here. These show that existing school facilities are primarily rated as good and that selection and use of materials friendly to the environment and human health are extremely important. User groups believe that they should participate in planning/selecting sustainable solutions for schools. An Index of 10 School Environment Desired Outcomes associated with environmentally friendly and health-friendly materials selection and use was devised. Relevant factors were extracted and interpreted. The research establishes users’ subjective opinions that may be considered and integrated into procedures for improving school buildings, assessing and selecting environmentally friendly materials and implementing strategies for sustainable school design, building and operation.
Renewable Energy Supply and Demand for the City of El Gouna, Egypt
Authors: Wellmann Johannes , Morosuk Tatiana
Published: March 2016

The paper discusses a supply and demand scenario using renewable energy sources for the city El Gouna in Egypt as an example for a self-supplying community. All calculations are based on measured meteorological data and real power demand during the year 2013. The modeled energy system consists of a concentrating solar tower plant with thermal storage and low-temperature seawater desalination unit as well as an integrated photovoltaic plant and a wind turbine. The low-temperature desalination unit has been newly developed in order to enable the utilization of waste heat from power conversion processes by improved thermal efficiency. In the study, special attention is given to the surplus power handling generated by the photovoltaic and wind power plant. Surplus power is converted into heat and stored in the thermal storage system of the solar power plant in order to increase the capacity factor. A brief estimation of investment costs have been conducted as well in order to outline the economic performance of the modeled energy and water supply system.
Biodistribution and Lymphatic Tracking of the Main Neurotoxin of Micrurus fulvius Venom by Molecular Imaging
Authors: Vergara Irene , Castillo Erick , Romero-Piña Mario , Torres-Viquez Itzel , Paniagua Dayanira , Boyer Leslie , Alagón Alejandro , Medina Luis
Published: March 2016

The venom of the Eastern coral snake Micrurus fulvius can cause respiratory paralysis in the bitten patient, which is attributable to β-neurotoxins (β-NTx). The aim of this work was to study the biodistribution and lymphatic tracking by molecular imaging of the main β-NTx of M. fulvius venom. β-NTx was bioconjugated with the chelator diethylenetriaminepenta-acetic acid (DTPA) and radiolabeled with the radionuclide Gallium-67. Radiolabeling efficiency was 60%–78%; radiochemical purity ≥92%; and stability at 48 h ≥ 85%. The median lethal dose (LD50) and PLA2 activity of bioconjugated β-NTx decreased 3 and 2.5 times, respectively, in comparison with native β-NTx. The immune recognition by polyclonal antibodies decreased 10 times. Biodistribution of β-NTx-DTPA-67Ga in rats showed increased uptake in popliteal, lumbar nodes and kidneys that was not observed with 67Ga-free. Accumulation in organs at 24 h was less than 1%, except for kidneys, where the average was 3.7%. The inoculation site works as a depot, since 10% of the initial dose of β-NTx-DTPA-67Ga remains there for up to 48 h. This work clearly demonstrates the lymphatic system participation in the biodistribution of β-NTx-DTPA-67Ga. Our approach could be applied to analyze the role of the lymphatic system in snakebite for a better understanding of envenoming.
Natural Co-Occurrence of Mycotoxins in Foods and Feeds and Their in vitro Combined Toxicological Effects
Authors: Smith Marie-Caroline , Madec Stéphanie , Coton Emmanuel , Hymery Nolwenn
Published: March 2016

Some foods and feeds are often contaminated by numerous mycotoxins, but most studies have focused on the occurrence and toxicology of a single mycotoxin. Regulations throughout the world do not consider the combined effects of mycotoxins. However, several surveys have reported the natural co-occurrence of mycotoxins from all over the world. Most of the published data has concerned the major mycotoxins aflatoxins (AFs), ochratoxin A (OTA), zearalenone (ZEA), fumonisins (FUM) and trichothecenes (TCTs), especially deoxynivalenol (DON). Concerning cereals and derived cereal product samples, among the 127 mycotoxin combinations described in the literature, AFs+FUM, DON+ZEA, AFs+OTA, and FUM+ZEA are the most observed. However, only a few studies specified the number of co-occurring mycotoxins with the percentage of the co-contaminated samples, as well as the main combinations found. Studies of mycotoxin combination toxicity showed antagonist, additive or synergic effects depending on the tested species, cell model or mixture, and were not necessarily time- or dose-dependent. This review summarizes the findings on mycotoxins and their co-occurrence in various foods and feeds from all over the world as well as in vitro experimental data on their combined toxicity.