bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescent PCDTBT Nanoparticles with Tunable Size for Versatile Bioimaging
Authors: Cheruku Srujan , D’Olieslaeger Lien , Smisdom Nick , Smits Joeri , Vanderzande Dirk , Maes Wouter , Ameloot Marcel , Ethirajan Anitha
Published: August 2019

Conjugated polymer nanoparticles exhibit very interesting properties for use as bio-imaging agents. In this paper, we report the synthesis of PCDTBT (poly([9-(1’-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophene-diyl)) nanoparticles of varying sizes using the mini-emulsion and emulsion/solvent evaporation approach. The effect of the size of the particles on the optical properties is investigated using UV-Vis absorption and fluorescence emission spectroscopy. It is shown that PCDTBT nanoparticles have a fluorescence emission maximum around 710 nm, within the biological near-infrared “optical window”. The photoluminescence quantum yield shows a characteristic trend as a function of size. The particles are not cytotoxic and are taken up successfully by human lung cancer carcinoma A549 cells. Irrespective of the size, all particles show excellent fluorescent brightness for bioimaging. The fidelity of the particles as fluorescent probes to study particle dynamics in situ is shown as a proof of concept by performing raster image correlation spectroscopy. Combined, these results show that PCDTBT is an excellent candidate to serve as a fluorescent probe for near-infrared bio-imaging.
Generalized Dynamic Analytical Model of Piezoelectric Materials for Characterization Using Electrical Impedance Spectroscopy
Authors: de Castilla Hector , Bélanger Pierre , Zednik Ricardo J.
Published: August 2019

Piezoelectric materials have the intrinsic reversible ability to convert a mechanical strain into an electric field and their applications touch our daily lives. However, the complex physical mechanisms linking mechanical and electrical properties make these materials hard to understand. Computationally onerous models have historically been unable to adequately describe dynamic phenomena inside real piezoelectric materials, and are often limited to over-simplified first-order analytical, quasi-static, or unsatisfying phenomenological numerical approaches. We present a generalized dynamic analytical model based on first-principles that is efficiently computable and better describes these exciting materials, including higher-order coupling effects. We illustrate the significance of this model by applying it to the important 3m crystal symmetry class of piezoelectric materials that includes lithium niobate, and show that the model accurately predicts the experimentally observed impedance spectrum. This dynamic behavior is a function of almost all intrinsic properties of the piezoelectric material, so that material properties, including mechanical, electrical, and dielectric coefficients, can be readily and simultaneously extracted for any size crystal, including at the nanoscale; the only prior knowledge required is the crystal class of the material system. In addition, the model’s analytical approach is general in nature, and can increase our understanding of traditional and novel ferroelectric and piezoelectric materials, regardless of crystal size or orientation.
Thermal Cycling Effect on Transformation Temperatures of Different Transformation Sequences in TiNi-Based Shape Memory Alloys
Authors: Wu Shyi-Kaan , Chang Yi-Ching
Published: August 2019

In TiNi-based shape memory alloys (SMAs), the effects of thermal cycling on the transformation peak temperatures of B2 ↔ B19′, B2 ↔ R, B2 ↔ B19, B2 ↔ R ↔ B19′, and B2 ↔ B19 ↔ B19′ one-stage and two-stage transformations have been investigated and compared. Experimental results of the differential scanning calorimeter and hardness tests indicate that the alloy’s intrinsic hardness and the shear strain, s, associated with martensitic transformation, are two important factors, due to their relation to the ease of introducing dislocations during cycling. The temperature decrease by cycling for one-stage transformation was in the order of B2 ↔ B19′ > B2 ↔ B19 > B2 ↔ R according to the orders of magnitude of their s values. This phenomenon also affected the suppression of B19 ↔ B19′ and R ↔ B19′ transformation peak temperatures in two-stage transformation. Both Ti50Ni48Fe2 and Ti48.7Ni51.3 SMAs aged at 450 °C for 4 h exhibited B2 ↔ R ↔ B19′ transformation, but the hardness of the latter was much higher than that of the former due to the precipitation hardening of the Ti3Ni4 precipitates. This causesd the decrease of the R ↔ B19′ transformation peak temperature in the Ti50Ni48Fe2 SMA to be much higher than that in Ti48.7Ni51.3 SMAs aged at 450 °C for 4 h, which directly affected the sequential B2 ↔ R transformation of Ti50Ni48Fe2 SMA in the next thermal cycle and decreased this transformation peak temperature. The Ti48Ni52 SMA aged at 600 °C for 150 h underwent B2 ↔ B19′ transformation and then B2 → R → B19′/B19′ → B2 transformation as the cycle number increased, in which the B2 ↔ R transformation peak temperature raised slightly by cycling. This characteristic is uncommon and may have resulted from the strain field around the thermal-cycled dislocations favoring the formation of the R-phase.
Numerical Solution of Heston-Hull-White Three-Dimensional PDE with a High Order FD Scheme
Authors: Ullah Malik Zaka
Published: August 2019

A new numerical method for tackling the three-dimensional Heston–Hull–White partial differential equation (PDE) is proposed. This PDE has an application in pricing options when not only the asset price and the volatility but also the risk-free rate of interest are coming from stochastic nature. To solve this time-dependent three-dimensional PDE as efficiently as possible, high order adaptive finite difference (FD) methods are applied for the application of method of lines. It is derived that the new estimates have fourth order of convergence on non-uniform grids. In addition, it is proved that the overall procedure is conditionally time-stable. The results are upheld via several numerical tests.
NP-Hardness of the Problem of Optimal Box Positioning
Authors: Galatenko Alexei V. , Nersisyan Stepan A. , Zhuk Dmitriy N.
Published: August 2019

We consider the problem of finding a position of a d-dimensional box with given edge lengths that maximizes the number of enclosed points of the given finite set P ⊂ R d , i.e., the problem of optimal box positioning. We prove that while this problem is polynomial for fixed values of d, it is NP-hard in the general case. The proof is based on a polynomial reduction technique applied to the considered problem and the 3-CNF satisfiability problem.
Three-Step Projective Methods for Solving the Split Feasibility Problems
Authors: Suantai Suthep , Eiamniran Nontawat , Pholasa Nattawut , Cholamjiak Prasit
Published: August 2019

In this paper, we focus on studying the split feasibility problem (SFP) in Hilbert spaces. Based on the CQ algorithm involving the self-adaptive technique, we introduce a three-step iteration process for approximating the solution of SFP. Then, the convergence results are established under mild conditions. Numerical experiments are provided to show the efficiency in signal processing. Some comparisons to various methods are also provided in this paper.
Credit Risk Contagion and Systemic Risk on Networks
Authors: Dolfin Marina , Knopoff Damian , Limosani Michele , Xibilia Maria Gabriella
Published: August 2019

This paper proposes a model of the dynamics of credit contagion through non-performing loans on financial networks. Credit risk contagion is modeled in the context of the classical SIS (Susceptibles-Infected-Susceptibles) epidemic processes on networks but with a fundamental novelty. In fact, we assume the presence of two different classes of infected agents, and then we differentiate the dynamics of assets subject to idiosyncratic risk from those affected by systemic risk by adopting a SIIS (Susceptible-Infected1-Infected2-Susceptible) model. In the recent literature in this field, the effect of systemic credit risk on the performance of the financial network is a hot topic. We perform numerical simulations intended to explore the roles played by two different network structures on the long-term behavior of assets affected by systemic risk in order to analyze the effect of the topology of the underlying network structure on the spreading of systemic risk on the structure. Random graphs, i.e., the Erdös–Rényi model, are considered “benchmark” network structures while core-periphery structures are often indicated in the literature as idealized structures, although they are able to capture interesting, specific features of real-world financial networks. Moreover, as a matter of comparison, we also perform numerical experiments on small-world networks.
Analysis of a Semi-Open Queuing Network with a State Dependent Marked Markovian Arrival Process, Customers Retrials and Impatience
Authors: Kim Chesoong , Dudin Sergey , Dudin Alexander , Samouylov Konstantin
Published: August 2019

We consider a queuing network with single-server nodes and heterogeneous customers. The number of customers, which can obtain service simultaneously, is restricted. Customers that cannot be admitted to the network upon arrival make repeated attempts to obtain service. The service time at the nodes is exponentially distributed. After service completion at a node, the serviced customer can transit to another node or leave the network forever. The main features of the model are the mutual dependence of processes of customer arrivals and retrials and the impatience and non-persistence of customers. Dynamics of the network are described by a multidimensional Markov chain with infinite state space, state inhomogeneous behavior and special structure of the infinitesimal generator. The explicit form of the generator is derived. An effective algorithm for computing the stationary distribution of this chain is recommended. The expressions for computation of the key performance measures of the network are given. Numerical results illustrating the importance of the account of the mentioned features of the model are presented. The model can be useful for capacity planning, performance evaluation and optimization of various wireless telecommunication networks, transportation and manufacturing systems.
Light Intensity and Nitrogen Concentration Impact on the Biomass and Phycoerythrin Production by Porphyridium purpureum
Authors: Sosa-Hernández Juan Eduardo , Rodas-Zuluaga Laura Isabel , Castillo-Zacarías Carlos , Rostro-Alanís Magdalena , de la Cruz Reynaldo , Carrillo-Nieves Danay , Salinas-Salazar Carmen , Fuentes Grunewald Claudio , Llewellyn Carole A. , Olguín Eugenia J. , Lovitt Robert W. , Iqbal Hafiz M. N. , Parra-Saldívar Roberto
Published: August 2019

Several factors have the potential to influence microalgae growth. In the present study, nitrogen concentration and light intensity were evaluated in order to obtain high biomass production and high phycoerythrin accumulation from Porphyridium purpureum. The range of nitrogen concentrations evaluated in the culture medium was 0.075–0.450 g L−1 and light intensities ranged between 30 and 100 μmol m−2 s−1. Surprisingly, low nitrogen concentration and high light intensity resulted in high biomass yield and phycoerythrin accumulation. Thus, the best biomass productivity (0.386 g L−1 d−1) and biomass yield (5.403 g L−1) were achieved with NaNO3 at 0.075 g L−1 and 100 μmol m−2 s−1. In addition, phycoerythrin production was improved to obtain a concentration of 14.66 mg L−1 (2.71 mg g−1 of phycoerythrin over dry weight). The results of the present study indicate that it is possible to significantly improve biomass and pigment production in Porphyridium purpureum by limiting nitrogen concentration and light intensity.
Bioactive Capnosanes and Cembranes from the Soft Coral Klyxum flaccidum
Authors: Tseng Wan-Ru , Ahmed Atallah F. , Huang Chiung-Yao , Tsai Yi-Ying , Tai Chi-Jen , Orfali Raha S. , Hwang Tsong-Long , Wang Yi-Hsuan , Dai Chang-Feng , Sheu Jyh-Horng
Published: August 2019

Two new capnosane-based diterpenoids, flaccidenol A (1) and 7-epi-pavidolide D (2), two new cembranoids, flaccidodioxide (3) and flaccidodiol (4), and three known compounds 5 to 7 were characterized from the marine soft coral Klyxum flaccidum, collected off the coast of the island of Pratas. The structures of the new compounds were determined by extensive spectroscopic analyses, including 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, and spectroscopic data comparison with related structures. The rare capnosane diterpenoids were isolated herein from the genus Klyxum for the first time. The cytotoxicity of compounds 1 to 7 against the proliferation of a limited panel of cancer cell lines was assayed. The isolated diterpenoids also exhibited anti-inflammatory activity through suppression of superoxide anion generation and elastase release in the N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLF/CB)-stimulated human neutrophils. Furthermore, 1 and 7 also exhibited cytotoxicity toward the tested cancer cells, and 7 could effectively inhibit elastase release. It is worth noting that the biological activities of 7 are reported for the first time in this paper.
Effects of Powder Preparation and Sintering Temperature on Properties of Spark Plasma Sintered Ti-48Al-2Cr-8Nb Alloy
Authors: Wang Zhenhua , Sun Haoxuan , Du Yulei , Yuan Juntang
Published: August 2019

TiAl alloy has become a key element in aerospace and automotive engine development due to its favorable high temperature mechanical properties and low density. In this paper, high performance TiAl alloy was prepared using atomized Ti-48Al-2Cr-8Nb powder by spark plasma sintering. This paper analyzed the variation of density, microstructure, Vickers hardness, and fracture strength of TiAl alloys prepared with spherical pre-alloyed powder (named as SP powder) and pre-alloyed powder after 12 h of ball milling (named as MP powder) at different sintering temperatures. The results indicate that the density, Vickers hardness, and room temperature (25 °C) bending strength of Ti-48Al-2Cr-8Nb alloy sintered using MP powder, are significantly higher than that of TiAl alloy sintered using SP powder. Specifically, the densification temperature of the MP powder sintered specimen is reduced by 100 °C, the Vickers hardness is increased by 15%, and the room temperature bending strength is increased by 51.9% at a sintering temperature of 1250 °C. The microstructure analysis shows that the Ti-48Al-2Cr-8Nb alloy has the best bending strength when it has a fine grain phase structure.
In-Situ Synchrotron X-Ray Diffraction of Ti-6Al-4V During Thermomechanical Treatment in the Beta Field
Authors: Warchomicka Fernando , Canelo-Yubero David , Zehetner Egon , Requena Guillermo , Stark Andreas , Poletti Cecilia
Published: August 2019

This work aims to identify the mechanisms of restoration occurring in Ti-6Al-4V during hot plastic deformation and subsequent heat treatment. The allotropic phase transformation that occurs during cooling distorts the interpretation of the restoration mechanisms taking place at high temperatures. Therefore, analysis of deformed samples by conventional microscopy have led to controversies in the interpretation of the main dynamic restoration mechanism. Additionally, static restoration of the microstructure can occur during slow cooling, modifying the microstructure. These facts were mainly the reasons why discontinuous dynamic recrystallization and/or dynamic recovery has been reported as the main dynamic restoration mechanism for Ti-6Al-4V. In this work, we use in-situ synchrotron X-ray diffraction combined with conventional microscopy to determine the dynamic and static mechanisms of restoration during and after deformation at different strain rates. The results show dynamic recovery as main mechanism of restoration during deformation in the β field, denoted by sub-grain formation and a misorientation dependency of the strain rate. After deformation, static recrystallization, grain growth, and coarsening of the β grains can be observed, especially at strain rates higher than 0.1 s−1. It is also demonstrated that the nucleation of new grains can occur within the very first seconds of the isothermal heat treatment.
Endothelium-Dependent Vasorelaxant Effect of Prunus Persica Branch on Isolated Rat Thoracic Aorta
Authors: Kim Bumjung , Kim Kwang-Woo , Lee Somin , Jo Cheolmin , Lee Kyungjin , Ham Inhye , Choi Ho-Young
Published: August 2019

Peach (Prunus persica (L.) Batsch) is a popular fruit consumed by people worldwide, owing to its pleasant flavor and high mineral nutrient content. A few plants from the genus Prunus, such as Prunus yedoensis, Prunus cerasus, and Prunus serotina have shown vasorelaxant and vasodilatory effects, to date, no study has investigated the vasorelaxation effects of the P. persica branch extract (PPE). The vasorelaxant effect of PPE was endothelium-dependent, and it was related to the NO-sGC-cGMP, vascular prostacyclin, and muscarinic receptor transduction pathway. K+ channels, such as the BKCa, KV, and KATP channels, were partially associated with PPE-induced vasorelaxation. PPE was effective in relaxing serotonin (5-HT)- or angiotensin II-induced contraction; furthermore, PPE attenuated Ca2+-induced vasoconstriction by IP3 receptors in the SR membrane, but its vasorelaxant effect was not associated with the influx of extracellular Ca2+ via receptor-operative Ca2+ channels or voltage-dependent Ca2+ channels. Recognizing the rising use of functional foods for hypertension treatment, our findings imply that PPE may be a natural antihypertensive agent.
Pray the White Way: Religious Expression in the NFL in Black and White
Authors: Scholes Jeffrey
Published: August 2019

Athletes, particularly players in the National Football League, have repeatedly invoked God in order to glorify, praise, or even credit the divine with success on the field. This essay examines the ways in which different types of religious language used to bring God onto the gridiron are received and evaluated along racial lines. I seek to show that speech by athletes, in particular black football players, that communicates a God who is partisan and intervenes in action on the field is routinely dismissed by fellow players, the media, and religious authorities who favor a God who either intervenes softly and generally or is above the game altogether. I contend that a double standard is applied to this theological debate due to a disregard of historical African American theology and to hegemonic white evangelical norms that police such discourse.
Modeling Parallel Robot Kinematics for 3T2R and 3T3R Tasks Using Reciprocal Sets of Euler Angles
Authors: Schappler Moritz , Tappe Svenja , Ortmaier Tobias
Published: August 2019

Industrial manipulators and parallel robots are often used for tasks, such as drilling or milling, that require three translational, but only two rotational degrees of freedom (“3T2R”). While kinematic models for specific mechanisms for these tasks exist, a general kinematic model for parallel robots is still missing. This paper presents the definition of the rotational component of kinematic constraints equations for parallel robots based on two reciprocal sets of Euler angles for the end-effector orientation and the orientation residual. The method allows completely removing the redundant coordinate in 3T2R tasks and to solve the inverse kinematics for general serial and parallel robots with the gradient descent algorithm. The functional redundancy of robots with full mobility is exploited using nullspace projection.
Optimization of a Kitting Line: A Case Study
Authors: Comand Nicola , Minto Riccardo , Boschetti Giovanni , Faccio Maurizio , Rosati Giulio
Published: August 2019

Assembly kitting lines typically deal with components that present different quantities in the final kit. Re-configurable feeders are not advisable for low quantity components since this solution leads to high inefficiency, due to the time required for retooling and for the feeding rate unbalance between the components. On the other hand a fully flexible feeder can increase the flexibility of the system at the cost of reducing the throughput. An assembly kitting problem was therefore addressed in different ways for low quantity components and high quantity components, studying the two different subsystems that compose a hybrid flexible assembly system. To optimize the re-configurable feeders, which supply the high quantity components, the opening sequence of a system composed by several hoppers was analyzed. We propose a solution which replaces the weighing device with a vision inspection system, showing its impact on the productivity of the line. A model coded into a Matlab script was developed to perform the optimization of the system and understand its behavior. Furthermore a fully flexible assembly system was developed in the laboratory in order to test the kitting of the low quantity components with the proposed subsystem. Finally the Overall Equipment Effectiveness of the line was calculated to evaluate the possible improvements obtained by the proposed solution.
PolSAR Image Classification via Learned Superpixels and QCNN Integrating Color Features
Authors: Zhang Xinzheng , Xia Jili , Tan Xiaoheng , Zhou Xichuan , Wang Tao
Published: August 2019

Polarimetric synthetic aperture radar (PolSAR) image classification plays an important role in various PolSAR image application. And many pixel-wise, region-based classification methods have been proposed for PolSAR images. However, most of the pixel-wise methods can not model local spatial relationship of pixels due to negative effects of speckle noise, and most of the region-based methods fail to figure out the regions with the similar polarimetric features. Considering that color features can provide good visual expression and perform well for image interpretation, in this work, based on the PolSAR pseudo-color image over Pauli decomposition, we propose a supervised PolSAR image classification approach combining learned superpixels and quaternion convolutional neural network (QCNN). First, the PolSAR RGB pseudo-color image is formed under Pauli decomposition. Second, we train QCNN with quaternion PolSAR data converted by RGB channels to extract deep color features and obtain pixel-wise classification map. QCNN treats color channels as a quaternion matrix excavating the relationship among the color channels effectively and avoiding information loss. Third, pixel affinity network (PAN) is utilized to generate the learned superpixels of PolSAR pseudo-color image. The learned superpixels allow the local information exploitation available in the presence of speckle noise. Finally, we fuse the pixel-wise classification result and superpixels to acquire the ultimate pixel-wise PolSAR image classification map. Experiments on three real PolSAR data sets show that the proposed approach can obtain 96.56%, 95.59%, and 92.55% accuracy for Flevoland, San Francisco and Oberpfaffenhofen data set, respectively. And compared with state-of-the-art PolSAR image classification methods, the proposed algorithm can obtained competitive classification results.
Comparison of Changes in Urban Land Use/Cover and Efficiency of Megaregions in China from 1980 to 2015
Authors: Zhang Shu , Fang Chuanglin , Kuang Wenhui , Sun Fengyun
Published: August 2019

Urban land use/cover and efficiency are important indicators of the degree of urbanization. However, research about comparing their changes at the megaregion level is relatively rare. In this study, we depicted the differences and inequalities of urban land and efficiency among megaregions in China using China’s Land Use/cover Dataset (CLUD) and China’s Urban Land Use/cover Dataset (CLUD-Urban). Furthermore, we analyzed regional inequality using the Theil index. The results indicated that the Guangdong-Hong Kong-Macao Great Bay Area had the highest proportion of urban land (8.03%), while the Chengdu-Chongqing Megaregion had the highest proportion of developed land (64.70%). The proportion of urban impervious surface area was highest in the Guangdong-Hong Kong-Macao Great Bay Area (75.16%) and lowest in the Chengdu-Chongqing Megaregion (67.19%). Furthermore, the highest urban expansion occurred in the Yangtze River Delta (260.52 km2/a), and the fastest period was 2000–2010 (298.19 km2/a). The decreasing Theil index values for the urban population and economic density were 0.305 and 1.748, respectively, in 1980–2015. This study depicted the development trajectory of different megaregions, and will expect to provide a valuable insight and new knowledge on reasonable urban growth modes and sustainable goals in urban planning and management.
Mapping Irrigated Areas Using Sentinel-1 Time Series in Catalonia, Spain
Authors: Bazzi Hassan , Baghdadi Nicolas , Ienco Dino , El Hajj Mohammad , Zribi Mehrez , Belhouchette Hatem , Escorihuela Maria Jose , Demarez Valérie
Published: August 2019

Mapping irrigated plots is essential for better water resource management. Today, the free and open access Sentinel-1 (S1) and Sentinel-2 (S2) data with high revisit time offers a powerful tool for irrigation mapping at plot scale. Up to date, few studies have used S1 and S2 data to provide approaches for mapping irrigated plots. This study proposes a method to map irrigated plots using S1 SAR (synthetic aperture radar) time series. First, a dense temporal series of S1 backscattering coefficients were obtained at plot scale in VV (Vertical-Vertical) and VH (Vertical-Horizontal) polarizations over a study site located in Catalonia, Spain. In order to remove the ambiguity between rainfall and irrigation events, the S1 signal obtained at plot scale was used conjointly to S1 signal obtained at a grid scale (10 km × 10 km). Later, two mathematical transformations, including the principal component analysis (PCA) and the wavelet transformation (WT), were applied to the several SAR temporal series obtained in both VV and VH polarization. Irrigated areas were then classified using the principal component (PC) dimensions and the WT coefficients in two different random forest (RF) classifiers. Another classification approach using one dimensional convolutional neural network (CNN) was also performed on the obtained S1 temporal series. The results derived from the RF classifiers with S1 data show high overall accuracy using the PC values (90.7%) and the WT coefficients (89.1%). By applying the CNN approach on SAR data, a significant overall accuracy of 94.1% was obtained. The potential of optical images to map irrigated areas by the mean of a normalized differential vegetation index (NDVI) temporal series was also tested in this study in both the RF and the CNN approaches. The overall accuracy obtained using the NDVI in RF classifier reached 89.5% while that in the CNN reached 91.6%. The combined use of optical and radar data slightly enhanced the classification in the RF classifier but did not significantly change the accuracy obtained in the CNN approach using S1 data.
Modeling Mid-Season Rice Nitrogen Uptake Using Multispectral Satellite Data
Authors: Brinkhoff James , Dunn Brian W. , Robson Andrew J. , Dunn Tina S. , Dehaan Remy L.
Published: August 2019

Mid-season nitrogen (N) application in rice crops can maximize yield and profitability. This requires accurate and efficient methods of determining rice N uptake in order to prescribe optimal N amounts for topdressing. This study aims to determine the accuracy of using remotely sensed multispectral data from satellites to predict N uptake of rice at the panicle initiation (PI) growth stage, with a view to providing optimum variable-rate N topdressing prescriptions without needing physical sampling. Field experiments over 4 years, 4–6 N rates, 4 varieties and 2 sites were conducted, with at least 3 replicates of each plot. One WorldView satellite image for each year was acquired, close to the date of PI. Numerous single- and multi-variable models were investigated. Among single-variable models, the square of the NDRE vegetation index was shown to be a good predictor of N uptake (R 2 = 0.75, RMSE = 22.8 kg/ha for data pooled from all years and experiments). For multi-variable models, Lasso regularization was used to ensure an interpretable and compact model was chosen and to avoid over fitting. Combinations of remotely sensed reflectances and spectral indexes as well as variety, climate and management data as input variables for model training achieved R 2 < 0.9 and RMSE < 15 kg/ha for the pooled data set. The ability of remotely sensed data to predict N uptake in new seasons where no physical sample data has yet been obtained was tested. A methodology to extract models that generalize well to new seasons was developed, avoiding model overfitting. Lasso regularization selected four or less input variables, and yielded R 2 of better than 0.67 and RMSE better than 27.4 kg/ha over four test seasons that weren’t used to train the models.
Application of Laplace Domain Waveform Inversion to Cross-Hole Radar Data
Authors: Meng Xu , Liu Sixin , Xu Yi , Fu Lei
Published: August 2019

Full waveform inversion (FWI) can yield high resolution images and has been applied in Ground Penetrating Radar (GPR) for around 20 years. However, appropriate selection of the initial models is important in FWI because such an inversion is highly nonlinear. The conventional way to obtain the initial models for GPR FWI is ray-based tomogram inversion which suffers from several inherent shortcomings. In this paper, we develop a Laplace domain waveform inversion to obtain initial models for the time domain FWI. The gradient expression of the Laplace domain waveform inversion is deduced via the derivation of a logarithmic object function. Permittivity and conductivity are updated by using the conjugate gradient method. Using synthetic examples, we found that the value of the damping constant in the inversion cannot be too large or too small compared to the dominant frequency of the radar data. The synthetic examples demonstrate that the Laplace domain waveform inversion provide slightly better initial models for the time domain FWI than the ray-based inversion. Finally, we successfully applied the algorithm to one field data set, and the inverted results of the Laplace-based FWI show more details than that of the ray-based FWI.
Characterization of Total-Phosphorus (TP) Pretreatment Microfluidic Chip Based on a Thermally Enhanced Photocatalyst for Portable Analysis of Eutrophication
Authors: Jung Dong Geon , Jung Daewoong , Kong Seong Ho
Published: August 2019

To minimize conventional total-phosphorus (TP) analysis systems, TP pretreatment microfluidic chip is proposed and characterized in this paper. Phosphorus (P) is one of the most important elements in ecosystem but it causes the eutrophication due to its overdose. TP analysis systems are increasingly receiving attention as a means to prevent eutrophication. Even though conventional TP analysis systems have high accuracy and sensitivity, they are not frequently utilized outside the laboratory because of their bulky size, complicated pretreatment processes, long response times, and high cost. Thus, there is a growing need to develop portable TP analysis systems. The microfluidic chip in this study is proposed with the aim of simplifying and minimizing TP analysis by replacing the conventional pretreatment process with a new method employing a thermally enhanced photocatalytic reaction that can be applied directly to a microfluidic chip of small size. The fabricated TP pretreatment microfluidic chip with thermally enhanced photocatalyst (TiO2) was optimized compared to the conventional pretreatment equipment (autoclave). The optimum pretreatment conditions using the proposed chip were pretreatment time of 10 min and temperature of 75 °C. The optimized pretreatment process using the proposed microfluidic chip showed similar performance to the conventional pretreatment method, even with shorter pretreatment time. The shorter pretreatment time and small size are advantages that enable the TP analysis system to be minimized. Therefore, the proposed TP pretreatment microfluidic chip based on thermally enhanced photocatalytic reaction in this study will be utilized to develop a portable TP analysis system.
An Improved Impact Source Locating System Using FBG Rosette Array
Authors: Chen Bo-Lian , Shin Chow-Shing
Published: August 2019

For structures vulnerable to foreign object impact damages, it would be desirable to detect and locate any occurrence of such impacts. This can be achieved by monitoring the stress waves generated by an impact together with certain source localization algorithms. Being small, electromagnetic influence immune and durable, Fiber Bragg grating (FBG) sensors are advantageous for this task. One drawback of FBGs for this purpose is their uneven directional sensitivity, which limits its localization ability to within 50° on either side of the fiber axis. Beyond this range, the signal is too weak and masked by noises and the location errors increase abruptly. Two approaches have been tested on a 0.8 m × 0.8 m × 6 mm plate for possible improvement on the system accuracy: firstly, an interrogation scheme with stronger light source intensity and steeper edge filter is employed to enhance the signal-to-noise ratio and system sensitivity; secondly, rosettes with two orthogonal FBGs are cascaded together to replace single FBGs to alleviate the directional sensitivity problem. It was found that a four-fold increase in signal to noise ratio contributed by stronger light source does improve the location accuracy, but only marginally. For the rosette approach, the relative positions of the Bragg wavelength of the FBGs and the light source spectrum are crucial to accuracy. Three different wavelength configurations have been tested and the reasons for their success or failure are discussed. It was shown that with an optimal wavelength configuration, the rosette array can virtually extend the good location accuracy to all over the plate.
Design and Mechanical Sensitivity Analysis of a MEMS Tuning Fork Gyroscope with an Anchored Leverage Mechanism
Authors: Li Zezhang , Gao Shiqiao , Jin Lei , Liu Haipeng , Guan Yanwei , Peng Shigang
Published: August 2019

This paper presents the design and analysis of a new micro-electro-mechanical system (MEMS) tuning fork gyroscope (TFG), which can effectively improve the mechanical sensitivity of the gyroscope sense-mode by the designed leverage mechanism. A micromachined TFG with an anchored leverage mechanism is designed. The dynamics and mechanical sensitivity of the design are theoretically analyzed. The improvement rate of mechanical sensitivity (IRMS) is introduced to represent the optimization effect of the new structure compared with the conventional one. The analytical solutions illustrate that the IRMS monotonically increases with increased stiffness ratio of the power arm (SRPA) but decreases with increased stiffness ratio of the resistance arm (SRRA). Therefore, three types of gyro structures with different stiffness ratios are designed. The mechanical sensitivities increased by 79.10%, 81.33% and 68.06% by theoretical calculation. Additionally, FEM simulation demonstrates that the mechanical sensitivity of the design is in accord with theoretical results. The linearity of design is analyzed, too. Consequently, the proposed new anchored leverage mechanism TFG offers a higher displacement output of sense mode to improve the mechanical sensitivity.
Traps and Opportunities of Czech Small-Scale Beef Cattle Farming
Authors: Krejčí Igor , Moulis Pavel , Pitrová Jana , Tichá Ivana , Pilař Ladislav , Rydval Jan
Published: August 2019

Small farmers represent a majority of the European Union (EU) farming sector and are considered the cornerstone of both the current and future sustainable EU agriculture. The dynamic complexity of livestock systems hinders the understanding of its behaviour, as well as recognizing the causes of problems and sources of resistance to applied policies and strategies. Livestock system behaviour needs to be understood in order to find leverage points and identify efficient solutions. The presented study depicts issues of small-scale beef cattle farmers in the market environment from a systemic perspective. The common complexity of managing a company increases with biological processes characterized by very long time periods, especially in the case of beef cattle farming. The scenarios analysed by the computer simulation model presented in the study evaluate the benefits of basic diversification into meat processing and a farm-to-table approach. The direct contact of the farmer with the final consumers represents increased demand and requirements on farmers’ entrepreneurship; nevertheless, such a strategy is a significant growth driver that allows faster maximisation of the farm’s output, accelerates the return of the investments, strengthens the market position of the farmer, and increases the farm’s sustainability.
Sustainable Board of Directors: Evidence from the Research Productivity of Professors Serving on Boards in the Korean Market
Authors: Choi Daeheon , Chung Chune Young , Park Changhyeon , Young Jason
Published: August 2019

We examine the relationship between the expertise of outside directors from academia and firms’ financial performance using a unique dataset on the research publications of such directors. Specifically, we use research publication history in finance or an academic concentration in business or law as a proxy for expertise and measure the influence of this expertise on Korean financial firms’ short-term and long-term performance. We find a positive (negative) association between research intensity (a business or law concentration) and short-term corporate performance. Firms with greater information and agency problems appear to benefit more from research-intensive academic outside directors than other firms do. Thus, we propose that firms in emerging economies elect research-intensive academic outside directors to contribute to sustainable corporate governance and firm performance.
One Concept, Many Opinions: How Scientists in Germany Think About the Concept of Bioeconomy
Authors: Priefer Carmen , Meyer Rolf
Published: August 2019

The official bioeconomy strategies in Europe and Germany pursue a technology-based implementation pathway and stipulate a wide range of objectives to be achieved with a bio-based economy. Reviews of the scientific and societal debate have shown that the technology fix meets criticism and that there is a controversial discussion about possible ways to shape the transition process. Against this background, an online survey was carried out among scientists involved in a regional bioeconomy research program in southern Germany in order to gain insight into their understanding of a bioeconomy. Moreover, the survey provides information about cooperation and major challenges in the future development of three biomass utilization pathways: biogas, lignocellulose, and microalgae. The analysis showed that a resource-oriented understanding of a bioeconomy is favored. The political objectives for a European bioeconomy are widely accepted, and it is expected that ongoing research can significantly contribute to achieving these goals. The two different pathways for shaping the bioeconomy that are discussed in the debate—the technology-based approach and the socio-ecological approach—are considered compatible rather than contrary. Up to now, scientific cooperation has prevailed, while cooperation with societal stakeholders and end-users has played a minor role.
Network Analysis of Seed Flow, a Traditional Method for Conserving Tartary Buckwheat (Fagopyrum tataricum) Landraces in Liangshan, Southwest China
Authors: Song Yingjie , Fang Qiong , Jarvis Devra , Bai Keyu , Liu Dongmei , Feng Jinchao , Long Chunlin
Published: August 2019

The Yi ethnic group in Liangshan Prefecture, Sichuan Province in Southwest China have cultivated Tartary buckwheat (Fagopyrum tataricum) for at least a thousand years. Tartary buckwheat landraces are maintained through their traditional seed system. Field work and social network methodologies were used to analyze the seed sources and their flows, and to create a seed network map. Self-saving, exchanging with neighbors and relatives, and purchasing from the market were the main means farmers used to save and exchange Tartary buckwheat seeds. The flow of seed within villages was higher than between villages. Wedding dowry was an important pathway for seed flow among all of the villages. Of the 13 Tartary buckwheat landraces maintained, four landraces were exchanged frequently. The seed exchange network structure was affected by the number of Tartary buckwheat landraces, the age of nodal households, geographic environment, culture, and cultural groups. Nodal households play an important role in the conservation and on-farm management of Tartary buckwheat landraces.
Double Screen Innovation: Building Sustainable Core Competence through Knowledge Management
Authors: Yin Ximing , Chen Jin , Zhao Chuang
Published: August 2019

How to exploit the precipitated internal and external knowledge to build dynamic capability in the era of big data remains a big challenge for innovation and business sustainability. This paper documents a novel perspective to address this challenge by exploring the double screen innovation knowledge management practice in Commercial Aircraft Corporation of China Ltd. (COMAC). Drawing from the literature on knowledge management and knowledge-based view, this paper elaborates how the new type of knowledge management practice represented by the case of Double Screen Innovation (DSI) in COMAC could help enterprise build sustainable core competence, which provides new perspective for multi-level knowledge management towards business sustainability. DSI, as a novel way of knowledge management, optimizes the micro-level knowledge co-creation and sharing and macro-level organizational learning mechanisms to accelerate the knowledge accumulation and dissemination within the organization. The process of knowledge creation, transformation, and application helps to integrate and transform big data into useful business information, thus provides an endless driving force conducive to the establishment and promotion of the core competencies of enterprises.
Roles of Environmental System Knowledge in Promoting University Students’ Environmental Attitudes and Pro-Environmental Behaviors
Authors: Janmaimool Piyapong , Khajohnmanee Samattaphong
Published: August 2019

This study aims to investigate the role of environmental system knowledge in promoting pro-environmental behaviors. Relationships between environmental knowledge and environmental attitudes as well as environmental knowledge and pro-environmental behaviors were analyzed. Environmental system knowledge includes knowledge of political ecology, sustainable development, environment and ecology, and environmental situations. This study included 128 students enrolling in the elective course entitled “Environment and Development” provided by the King Mongkut’s University of Technology Thonburi in Bangkok city of Thailand and 150 students who were not participating in this course. The results revealed that environmental attitudes of students participating in the course was significantly higher than that of students not attending the course. Only knowledge of the environment and ecology highly correlated with environmental attitudes; on the other hand, diverse environmental knowledge significantly correlated with pro-environmental behaviors. The result also demonstrated that indirect impact environmental behaviors reported by both groups were statistically different, but there was no significant difference in direct impact environmental behaviors. This study suggested that environmental knowledge provided through a formal education could promote environmental attitudes, but it may not contribute to students’ engagement in direct impact environmental behaviors.
Towards Sustainable Mobility through a Change in Values. Evidence in 12 European Countries
Authors: de las Heras-Rosas Carlos Javier , Herrera Juan
Published: August 2019

The research carried out, as well as the measures taken to promote the use of sustainable transport in our cities, do not fully achieve their purpose. The Wertraitionalirat concept introduced by Max Weber in 1922 stated: “The use of public transport arises more from a system of values with which the person identifies than from the quality of the transport offered”. This assertion made at the beginning of the 20th century is still valid, where the means, infrastructure and advances achieved do not obtain a proportional response from citizens. The aim of this work is, through this approach, to find variables that complement research on urban mobility habits. For this purpose, data from the International Social Survey Program (ISSP) and the European Social Survey (ESS) are used to analyse postmodern values and citizens’ environmental awareness, linking these to sustainable mobility habits in 12 European countries. The results suggest that a higher index of postmodern values implies greater environmental awareness, which would lead to a greater use of sustainable transport, although there are variables related to environmental knowledge and risk which indicate that greater environmental education and awareness is needed.
The Hosoya Entropy of Graphs Revisited
Authors: Ghorbani Modjtaba , Dehmer Matthias , Mowshowitz Abbe , Tao Jin , Emmert-Streib Frank
Published: August 2019

In this paper we extend earlier results on Hosoya entropy (H-entropy) of graphs, and establish connections between H-entropy and automorphisms of graphs. In particular, we determine the H-entropy of graphs whose automorphism group has exactly two orbits, and characterize some classes of graphs with zero H-entropy.
High Capacity HEVC Video Hiding Algorithm Based on EMD Coded PU Partition Modes
Authors: Li Zhonghao , Meng Laijin , Jiang Xinghao , Li Zhaohong
Published: August 2019

Data hiding in videos has been a big concern as their rich redundancy can be used for embedding a lot of secret information. Further, as high efficiency video coding (HEVC) introduces many innovative technologies compared with the previous standard, H.264, it has gradually become the mainstream. Therefore, it is valuable to develop new information hiding algorithms by using novel features of HEVC. A HEVC video data hiding algorithm based on prediction unit (PU) partition modes from inter prediction process is proposed in this paper. Firstly, code units (CUs) in two sizes of 8 × 8 and 16 × 16 are selected for embedding, then the PU partition modes in these CUs are coded by a spatial coding method. After that, two specific hiding algorithms by modifying coded PU partition modes in CUs of 8 × 8 and 16 × 16 are proposed, respectively. Experimental results show that the proposed algorithm has achieved excellent performance with high visual quality, and high embedding capacity and low bitrate increase in both high- and low-resolution videos compressed with different quantization parameters (QPs). Compared with the state-of-the-art work, the proposed algorithm achieves a much higher capacity while keeping quite high visual quality with little increase of bitrate.