bluuebunny/crossref_metadata_2025 huggingface dataset:
Genome-Wide Distribution of Novel Ta-3A1 Mini-Satellite Repeats and Its Use for Chromosome Identification in Wheat and Related Species
Authors: Lang Tao , Li Guangrong , Yu Zhihui , Ma Jiwei , Chen Qiheng , Yang Ennian , Yang Zujun
Published: January 2019

A large proportion of the genomes of grasses is comprised of tandem repeats (TRs), which include satellite DNA. A mini-satellite DNA sequence with a length of 44 bp, named Ta-3A1, was found to be highly accumulated in wheat genome, as revealed by a comprehensive sequence analysis. The physical distribution of Ta-3A1 in chromosomes 3A, 5A, 5B, 5D, and 7A of wheat was confirmed by nondenaturing fluorescence in situ hybridization (ND-FISH) after labeling the oligonucleotide probe. The analysis of monomer variants indicated that rapid sequence amplification of Ta-3A1 occurred first on chromosomes of linkage group 5, then groups 3 and 7. Comparative ND-FISH analysis suggested that rapid changes occurred in copy number and chromosomal locations of Ta-3A1 among the different species in the tribe Triticeae, which may have been associated with chromosomal rearrangements during speciation and polyploidization. The labeling and subsequent use of Ta-3A1 by ND-FISH may assist in the precise identification and documentation of novel wheat germplasm engineered by chromosome manipulation.
Multi-Farm Analyses Indicate a Novel Boar Pheromone Improves Sow Reproductive Performance
Authors: McGlone John J. , Garcia Arlene , Rakhshandeh Anoosh
Published: January 2019

The objective of this study was to examine the effectiveness of a novel 3-molecule boar pheromone (BOARBETTER®, BB,) to improve sow reproductive performance (breeding, conception, farrowing rates, pigs born alive, stillborn, mummies and total born). Data from 12 commercial farm sites were used to evaluate the effectiveness of BB. Each farm was used as the experimental unit in the meta-analyses. Individual sows records were collected, merged and analyzed in overall analyses. Relative to CON, BB increased the number of total born pigs per litter (13.81 ± 0.11 vs. 14.30 ± 0.11 pigs/litter, respectively; p < 0.01) and the number of pigs born alive (12.76 ± 0.14 vs. 13.13 ± 0.14 pigs/litter, respectively; p < 0.05). In the merged dataset analyses, the parity by treatment interaction was significant for total pigs and pigs born alive per litter (p < 0.01). In parities one through three, treatment with BB increased total pigs born by 0.88 per litter, and pigs born alive per litter by 0.73 pigs per litter (p < 0.05). However, BB had no effect on these parameters in sows from parities four through six. BOARBETTER® increased reproductive success, is cost effective, safe, and can meaningfully improve sow reproductive success and performance.
PDGFA in Cashmere Goat: A Motivation for the Hair Follicle Stem Cells to Activate
Authors: Pazzaglia Irene , Mercati Francesca , Antonini Marco , Capomaccio Stefano , Cappelli Katia , Dall’Aglio Cecilia , La Terza Antonietta , Mozzicafreddo Matteo , Nocelli Cristina , Pallotti Stefano , Pediconi Dario , Renieri Carlo
Published: January 2019

The cashmere hair follicle (HF) perpetually goes through cycles of growth, involution and rest. The photoperiod is the main factor in the control of seasonal coat change in cashmere goats while stem cells play a crucial role in the HF growth. Several factors, including Platelet-Derived Growth Factor A (PDGFA), Bone Morphogenetic Protein 2 (BMP2) and Lim-Homeobox gene 2 (LHX2) are implicated in HF morphogenesis and cycle. In this work, the mentioned molecules were investigated to evaluate their role in follicular cycle activation. The study was performed on skin samples collected at different periods of HF cycle and the molecular expression of PDGFA, BMP2 and LHX2 was evaluated by Real-Time PCR (qPCR) at each time point. Since PDGFA showed the most variation, the goat PDGFA gene was sequenced and the protein localization was investigated by immunohistochemistry together with PDGF receptor α (PDGFRα). PDGFA immunostaining was observed in the basal layer of the HF outer root sheath and the immunoreaction appeared stronger in the regressive HFs compared to those in the anagen phase according to qPCR analysis. PDGFRα was observed in the HF epithelium, proving the effect of PDGFA on the follicular structure. The data obtained suggest that PDGFA and BMP2 are both implicated in HF cycle in goat. In particular, PDGFA secreted by the HF is involved in the anagen activation.
Differences in Pre-Laying Behavior between Floor-Laying and Nest-Laying Pekin Ducks
Authors: Barrett Lorelle , Malecki Irek , Blache Dominique
Published: January 2019

Floor-laying in commercially farmed Pekin ducks is not well understood. This exploratory study aimed to determine if behavioral differences exist between floor-laying and nest-laying ducks. Retrospective analysis of video footage from a small commercial breeding flock (n = 60 birds) was used to quantify the behavior of floor-laying and nest-laying birds (n = 24 events per group) in the hour prior to oviposition site selection. The frequency, percentage of time spent, and duration of bouts were compared for nest box interactions, behaviors inside and outside of boxes and aggressive interactions. Some floor-laying birds did not enter or investigate nest boxes (FL-Out), whilst some floor-layers (FL-In) used nest boxes similarly to nest-laying birds (NL). Nest-building behavior differed only in location, with FL-Out performing the behavior on the shed floor and the other groups performing it primarily in boxes. FL-Out sat more, walked less, and engaged in less aggression (p < 0.05) than FL-In and NL. The occurrence of multiple birds in a nest box was strongly correlated with the number of aggressive interactions that occurred in the box (R = 0.81). Competition appears to contribute to floor-laying in Pekin ducks; FL-Out birds may not engage with nest boxes as a coping strategy to avoid agonistic behavior. These findings indicate that developing practical strategies to reduce nest box competition could help mitigate floor-laying. However, other factors such as nest design may also contribute to FL-Out birds’ reluctance to use nest boxes and require further investigation.
Synthesis, Biological Evaluation and Docking Studies of Chalcone and Flavone Analogs as Antioxidants and Acetylcholinesterase Inhibitors
Authors: Díaz-Rubio Laura , Hernández-Martínez Rufina , Estolano-Cobián Arturo , Chávez-Velasco Daniel , Salazar-Aranda Ricardo , Waksman de Torres Noemí , Rivero Ignacio A. , García-González Víctor , Ramos Marco A. , Córdova-Guerrero Iván
Published: January 2019

Several oxidative processes are related to a wide range of human chronic and degenerative diseases, like Alzheimer’s disease, which also has been related to cholinergic processes. Therefore, search for new or improved antioxidant molecules with acetylcholinesterase activity is essential to offer alternative chemotherapeutic agents to support current drug therapies. A series of chalcone (2a–2k) and flavone (3a–3k) analogs were synthesized, characterized, and evaluated as acetylcholinesterase (AChE) inhibitors, and antioxidant agents using 1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2-2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS•), and β-carotene/linoleic acid bleaching assay. Compounds more active were 3j and 2k in DPPH with EC50 of 1 × 10−8 and 5.4 × 10−3 μg/mL, respectively; 2g and 3i in ABTS (1.14 × 10−2 and 1.9 × 10−3 μg/mL); 2e, 2f, 3f, 2j, and 3j exceeded the α-tocopherol control in the β-carotene assay (98–99% of antioxidant activity). At acetylcholinesterase inhibition assay, flavones were more active than chalcones; the best results were compounds 2d and 3d (IC50 21.5 and 26.8 µg/mL, respectively), suggesting that the presence of the nitro group enhances the inhibitory activity. The docking of these two structures were made to understand their interactions with the AChE receptor. Although further in vivo testing must be performed, our results represent an important step towards the identification of improved antioxidants and acetylcholinesterase inhibitors.
Porosity Elimination in Modified Direct Laser Joining of Ti6Al4V and Thermoplastics Composites
Authors: Wang Haipeng , Chen Yang , Guo Zaoyang , Guan Yingchun
Published: January 2019

Hybrid lightweight components with strong and reliable bonding qualities are necessary for practical applications including in the automotive and aerospace industries. The direct laser joining method has been used to produce hybrid joints of Ti6Al4V and glass fiber reinforced polyamide (PA66-GF30). Prior to the laser joining process, a surface texturing treatment is carried out on Ti6Al4V to improve joint strength through the formation of interlock structures between Ti6Al4V and PA66-GF30. In order to reduce the generated micro-pores in Ti6Al4V-PA66-GF30 joints, a modified laser joining method has been proposed. Results show that only very few small micro-pores are generated in the joints produced by the modified laser joining method, and the fracture strength of the joints is significantly increased from 13.8 MPa to 41.5 MPa due to the elimination of micro-pores in the joints.
Introducing Temperature as Variable Parameter into Kinetic Models for Anaerobic Fermentation of Coffee Husk, Pulp and Mucilage
Authors: Chala Bilhate , Oechsner Hans , Müller Joachim
Published: January 2019

Primary coffee processing generates important by-products—the pulp, husk and mucilage—while producing the green coffee beans. These by-products represent a large quantity of biomass and might create an adverse impact on environment if they are left to uncontrolled natural decay. In this study, the bio-methane formation potential of coffee husk, pulp and mucilage was examined in batch assays performed at 21 °C, 30 °C and 37 °C. The mean specific methane yield (SMY) from husk, pulp, and mucilage were 159.4, 244.7 and 294.5 L kg−1 volatile solids(VS), respectively, for a fermentation temperature of 37 °C; 156.8, 234.8 and 287.1 L kg−1 VS, respectively, for 30 °C; and 139.9, 196.2 and 255.9 L kg−1 VS, respectively, for 21°C. Two kinetic models, namely, the modified Logistic model (LOG) and the modified Gompertz model (GOM), were applied to fit experimental data and the respective kinetic constants were generated. Both models exhibited a very good fit to the measured data points (R2 > 0.987). The relationship of kinetic constants of substrates with fermentation temperatures was established and inserted into the LOG and GOM models; thus, generalized LOG and GOM models were obtained to predict SMY of the substrates at any temperature between 21 °C and 37 °C.
Optical Communications and Networking Solutions for the Support of C-RAN in a 5G Environment
Authors: Eramo Vincenzo , Listanti Marco , Lavacca Francesco Giacinto
Published: January 2019

The widespread availability of mobile devices such as tablets and smartphones has led to fast-increasing mobile data traffic in the last few years [...]
Multi-Perspective Ultrasound Imaging Technology of the Breast with Cylindrical Motion of Linear Arrays
Authors: Liu Chang , Zhang Binzhen , Xue Chenyang , Zhang Wendong , Zhang Guojun , Cheng Yijun
Published: January 2019

In this paper, we propose a multi-perspective ultrasound imaging technology with the cylindrical motion of four piezoelectric micromachined ultrasonic transducer (PMUT) rotatable linear arrays. The transducer is configured in a cross shape vertically on the circle with the length of the arrays parallel to the z axis, roughly perpendicular to the chest wall. The transducers surrounded the breast, which achieves non-invasive detection. The electric rotary table drives the PMUT to perform cylindrical scanning. A breast model with a 2 cm mass in the center and six 1-cm superficial masses were used for the experimental analysis. The detection was carried out in a water tank and the working temperature was constant at 32 °C. The breast volume data were acquired by rotating the probe 90° with a 2° interval, which were 256 × 180 A-scan lines. The optimized segmented dynamic focusing technology was used to improve the image quality and data reconstruction was performed. A total of 256 A-scan lines at a constant angle were recombined and 180 A-scan lines were recombined according to the nth element as a dataset, respectively. Combined with ultrasound imaging algorithms, multi-perspective ultrasound imaging was realized including vertical slices, horizontal slices and 3D imaging. The seven masses were detected and the absolute error of the size was approximately 1 mm where even the image of the injection pinhole could be seen. Furthermore, the breast boundary could be seen clearly from the chest wall to the nipple, so the location of the masses was easier to confirm. Therefore, the validity and feasibility of the data reconstruction method and imaging algorithm were verified. It will be beneficial for doctors to be able to comprehensively observe the pathological tissue.
Optimal Unit Commitment by Considering High Penetration of Renewable Energy and Ramp Rate of Thermal Units-A case study in Taiwan
Authors: Lu Shiue-Der , Wang Meng-Hui , Kuo Ming-Tse , Tsou Ming-Chang , Liao Rui-Min
Published: January 2019

When large amounts of wind power and solar photovoltaic (PV) power are integrated into an independent power grid, the intermittent renewable energy destabilizes power output. Therefore, this study explored the unit commitment (UC) optimization problem; the ramp rate was applied to solve problems with 30 and 10 min of power shortage. The data of actual unit parameters were provided by the Taiwan Power Company. The advanced priority list method was used together with a combination of a generalized Lagrangian relaxation algorithm and a random feasible directions algorithm to solve a large-scale nonlinear mixed-integer programming UC problem to avoid local and infeasible solutions. The results showed that the proposed algorithm was superior to improved particle swarm optimization (IPSO) and simulated annealing (SA) in terms of the minimization of computation time and power generation cost. The proposed method and UC results can be effective information for unit dispatch by power companies to reduce the investment costs of power grids and the possibility of renewable energy being disconnected from the power system. Thus, the proposed method can increase the flexibility of unit dispatch and the proportion of renewable energy in power generation.
Efficient Detection Approach for DTMF Signal Detection
Authors: Yeh Cheng-Yu , Hwang Shaw-Hwa
Published: January 2019

A novel tone detection approach, designated as the multi-frequency detecting (MFD) algorithm, is presented in this work as an alternative to conventional single point detection approaches but it is an efficient way to achieve the aim of further computational load reduction for a dual-tone multi-frequency (DTMF) signal detection. The idea is that an optimal phase search is performed over the frequency band of interest in each tone detection, and then the optimal frequency response of a detector is built accordingly. In this manner, a DTMF detection task is done following one-time detection computation. This proposal demonstrates an overall computational load reduction of 80.49% and 74.06% in comparison with a discrete Fourier transform (DFT) approach and the Goertzel algorithm, respectively. This detection complexity reduction is an advantage and an important issue for applying DTMF detection technique to embedded devices.
The Evaluation Method of Particle Clustering Phenomena in RAP
Authors: Xu Guangji , Ma Tao , Fang Zhanyong , Huang Xiaoming , Zhang Weiguang
Published: January 2019

The particle clustering phenomena in reclaimed asphalt pavement (RAP) particles is one of the most important factors to affect the efficient recycling of asphalt concrete. In this study, the particle composition, clustering degree, crushing properties and clustering stability of RAP were studied by extraction test and cantabro-crushing test. It was found that the particles above 4.75 mm were composed mainly of small particles with a large degree of cluster and poor stability. The coarse particles (>4.75 mm) had a great influence on the variation of 4.75 mm sieve. Quantitative indexes of Percentage Loss rate (PL) and Stability Index (w) were proposed to evaluate the clustering degree and the stability of RAP. It provided a meaningful reference for the comparison of different RAP and the different crushing processes. In addition, the RAP could be divided into three kinds of structures, including weak cluster structure, strong cluster structure and old aggregate. The process of crushing the RAP was divided into three stages, which are weak structure-dominated, strong structure-dominated and the broken old aggregate. The weak structure had the largest degree of cluster and worst stability, resulting in a large variability of RAP, and it should be avoided in the crushing process.
Using Double Convolution Neural Network for Lung Cancer Stage Detection
Authors: Jakimovski Goran , Davcev Danco
Published: January 2019

Recently, deep learning is used with convolutional Neural Networks for image classification and figure recognition. In our research, we used Computed Tomography (CT) scans to train a double convolutional Deep Neural Network (CDNN) and a regular CDNN. These topologies were tested against lung cancer images to determine the Tx cancer stage in which these topologies can detect the possibility of lung cancer. The first step was to pre-classify the CT images from the initial dataset so that the training of the CDNN could be focused. Next, we built the double Convolution deep Neural Network with max pooling to perform a more thorough search. Finally, we used CT scans of different Tx cancer stages of lung cancer to determine the Tx stage in which the CDNN would detect possibility of lung cancer. We tested the regular CDNN against our double CDNN. Using this algorithm, doctors will have additional help in early lung cancer detection and early treatment. After extensive training with 100 epochs, we obtained the highest accuracy of 0.9962, whereas the regular CDNN obtained only 0.876 accuracy.
Polarization-Insensitive Phase Modulators Based on an Embedded Silicon-Graphene-Silicon Waveguide
Authors: Zou Xinhai , Zhang Yujia , Li Zhihui , Yang Yiwei , Zhang Shangjian , Zhang Zhiyao , Zhang Yali , Liu Yong
Published: January 2019

A polarization-insensitive phase modulator concept is presented, based on an embedded silicon-graphene-silicon waveguide. Simulation results show that the effective mode index of both transverse electric (TE) and transverse magnetic (TM) modes in the silicon-graphene-silicon waveguide undergoes almost the same variations under different biases across a broad wavelength range, in which the real-part difference is less than 1.2 × 10−3. Based on that, a polarization-insensitive phase modulator is demonstrated, with a 3-dB modulation bandwidth of 135.6 GHz and a wavelength range of over 500 nm. Moreover, it has a compact size of 60 μm, and a low insertion loss of 2.12 dB. The proposed polarization-insensitive waveguide structure could be also applied to Mach-Zehnder modulators and electro-absorption modulators.
Wind Farm Power Production Assessment: Introduction of a New Actuator Disc Method and Comparison with Existing Models in the Context of a Case Study
Authors: Simisiroglou Nikolaos , Polatidis Heracles , Ivanell Stefan
Published: January 2019

The aim of the present study is to perform a comparative analysis of two actuator disc methods (ACD) and two analytical wake models for wind farm power production assessment. To do so, wind turbine power production data from the Lillgrund offshore wind farm in Sweden is used. The measured power production for individual wind turbines is compared with results from simulations, done in the WindSim software, using two ACD methods (ACD (2008) and ACD (2016)) and two analytical wake models widely used within the wind industry (Jensen and Larsen wake models). It was found that the ACD (2016) method and the Larsen model outperform the other method and model in most cases. Furthermore, results from the ACD (2016) method show a clear improvement in the estimated power production in comparison to the ACD (2008) method. The Jensen method seems to overestimate the power deficit for all cases. The ACD (2016) method, despite its simplicity, can capture the power production within the given error margin although it tends to underestimate the power deficit.
Standards for Cyber-Physical Energy Systems—Two Case Studies from Sensor Technology
Authors: Krutwig Michael C. , Kölmel Bernhard , Tantau Adrian D. , Starosta Kejo
Published: January 2019

Cyber-physical energy systems (CPES) describe a specialization of the cyber-physical system concept, in which energy systems are transformed into intelligent energy networks. These systems provide the basis for the realization of smart microgrids and smart grids. In the last decade, numerous research projects have intensively explored the fundamentals and modeling of CPES and validated them in pilot projects. In the meantime, more and more CPES solutions have been appearing on the market and the battle for the most suitable standards has begun. This paper gives an overview of the currently available standards for CPES sensor technologies and assesses the suitability for implementation. In two case studies in the application area of operational energy management in German companies, a sensor retrofitting is described—once with proprietary technology and once using the standards Long Range (LoRa) Wide Area Network and OPC Unified Architecture (OPC UA). As a result, the shortcomings of the standards for their use in CPES are shown and discussed. OPC UA, which was originally developed for the manufacturing industry, turns out to be to be a suitable standard for a wide range of CPES implementations.
SPH Simulation of Hydraulic Jump on Corrugated Riverbeds
Authors: Gu Shenglong , Bo Fuping , Luo Min , Kazemi Ehsan , Zhang Yunyun , Wei Jiahua
Published: January 2019

This paper presents a numerical study of the hydraulic jump on corrugated riverbed using the Smoothed Particle Hydrodynamics (SPH) method. By simulating an experimental benchmark example, the SPH model is demonstrated to predict the wave profile, velocity field, and energy dissipation rate of hydraulic jump with good accuracy. Using the validated SPH model, the dynamic evolvement of the hydraulic jump on corrugated riverbed is studied focusing on the vortex pattern, jump length, water depth after hydraulic jump, and energy dissipation rate. In addition, the influences of corrugation height and length on the characteristics of hydraulic jump are parametrically investigated.
An Internet of Things-Based Environmental Quality Management System to Supervise the Indoor Laboratory Conditions
Authors: Marques Gonçalo , Pitarma Rui
Published: January 2019

Indoor air quality (IAQ) is not only a determinant of occupational health but also influences all indoor human behaviours. In most university establishments, laboratories are also used as classrooms. On one hand, indoor environment quality (IEQ) conditions supervision in laboratories is relevant for experimental activities. On the other hand, it is also crucial to provide a healthy and productive workplace for learning activities. The proliferation of cost-effective sensors and microcontrollers along with the Internet of Things (IoT) architectures enhancements, enables the development of automatic solutions to supervise the Laboratory Environmental Conditions (LEC). This paper aims to present a real-time IEQ-laboratory data collection system-based IoT architecture named iAQ Plus (iAQ+). The iAQ+ incorporates an integrated Web management system along with a smartphone application to provide a historical analysis of the LEC. The iAQ+ collects IAQ index, temperature, relative humidity and barometric pressure. The results obtained are promising, representing a meaningful contribution for IEQ supervision solutions based on IoT. iAQ+ supports push notifications to alert people in a timely way for enhanced living environments and occupational health, as well as a work mode feature, so the user can configure setpoints for laboratory mode and schoolroom mode. Using the iAQ+, it is possible to provide an integrated management of data information of the spatio-temporal variations of LEC parameters which are particularly significant not only for enhanced living environments but also for laboratory experiments.
Multi-Criteria Analysis of Potential Applications of Waste from Rock Minerals Mining
Authors: Kaźmierczak Urszula , Blachowski Jan , Górniak-Zimroz Justyna
Published: January 2019

The article describes the research on the analysis of the economic use of mining and processing waste produced and stored on the premises of active mining plants exploiting rock raw materials in the context of the reduce-recycle-reuse (3R) concept. To assess the potential economic applications of the investigated wastes, a two-stage methodology based on a multicriteria analysis using the Analytical Hierarchy Process (AHP) algorithm was proposed. Preliminary research produced an inventory of active mining plants storing mining and processing waste on their premises (62 locations). Then, preliminary qualitative analysis was carried out to assess mining waste locations at the environmental and social level consistent with the idea of circular economy—CE (20 locations). Next, in the first stage of the multi-criteria analysis, six directions of economic use of the investigated waste were analyzed and their significance was determined. These directions are use in road and railroad construction, construction, agriculture, reclamation and development of post-mining areas, food industry, and storage at landfills of mining and processing waste on the premises of a mining plant. In the result of the assessment of potential economic applications of mining waste, recommendations for directions of economic use were obtained for the six highest classified mining waste sites. The recommendations were determined in the second stage of multi-criteria analysis by deriving the local preferences (waste sites) for the alternatives (waste uses).
Recognition of American Sign Language Gestures in a Virtual Reality Using Leap Motion
Authors: Vaitkevičius Aurelijus , Taroza Mantas , Blažauskas Tomas , Damaševičius Robertas , Maskeliūnas Rytis , Woźniak Marcin
Published: January 2019

We perform gesture recognition in a Virtual Reality (VR) environment using data produced by the Leap Motion device. Leap Motion generates a virtual three-dimensional (3D) hand model by recognizing and tracking user‘s hands. From this model, the Leap Motion application programming interface (API) provides hand and finger locations in the 3D space. We present a system that is capable of learning gestures by using the data from the Leap Motion device and the Hidden Markov classification (HMC) algorithm. We have achieved the gesture recognition accuracy (mean ± SD) is 86.1 ± 8.2% and gesture typing speed is 3.09 ± 0.53 words per minute (WPM), when recognizing the gestures of the American Sign Language (ASL).
An Experimental Investigation of Moisture-Induced Softening Mechanism of Marble Based on Quantitative Analysis of Acoustic Emission Waveforms
Authors: Huang Yiming , Deng Jianhui , Zhu Jun
Published: January 2019

The decrease of strength after saturation of rocks is known as moisture-induced softening. To date, there are numerous studies on the mechanism of moisture-induced softening of different rocks. However, due to a lack of effective observational methods, the microcosmic mechanism of moisture-induced softening still needs to be understood. We collected and processed acoustic emission (AE) signals during the uniaxial compression test of marble specimens. The results of spectral and statistical analysis show that two dominant frequency bands of AE waveforms exist regardless of the specimen’s water content. Additionally, for the AE signals from the saturated specimens, the ranges of the low and high frequency bands are wider than dried rock samples. Besides, since the tensile and shear failures in the rock release low and high dominant frequency AE signals, respectively, the test results of this paper show that micro-shear and micro-tensile failures dominate the final failure of dried and saturated rocks, respectively.
Identifying Students at Risk of Failing a Subject by Using Learning Analytics for Subsequent Customised Tutoring
Authors: Simanca Fredys , Gonzalez Crespo Rubén , Rodríguez-Baena Luis , Burgos Daniel
Published: January 2019

Learning analytics (LA) has become a key area of study in educology, where it could assist in customising teaching and learning. Accordingly, it is precisely this data analysis technique that is used in a sensor—AnalyTIC—designed to identify students who are at risk of failing a course, and to prompt subsequent tutoring. This instrument provides the teacher and the student with the necessary information to evaluate academic performance by using a risk assessment matrix; the teacher can then customise any tutoring for a student having problems, as well as adapt the course contents. The sensor was validated in a study involving 39 students in the first term of the Environmental Engineering program at the Cooperative University of Colombia. Participants were all enrolled in an Algorithms course. Our findings led us to assert that it is vital to identify struggling students so that teachers can take corrective measures. The sensor was initially created based on the theoretical structure of the processes and/or phases of LA. A virtual classroom was built after these phases were identified, and the tool for applying the phases was then developed. After the tool was validated, it was established that students’ educational experiences are more dynamic when teachers have sufficient information for decision-making, and that tutoring and content adaptation boost the students’ academic performance.
Miniaturized Optical Encoder with Micro Structured Encoder Disc
Authors: Seybold Jonathan , Bülau André , Fritz Karl-Peter , Frank Alexander , Scherjon Cor , Burghartz Joachim , Zimmermann André
Published: January 2019

A novel optical incremental and absolute encoder based on an optical application-specific integrated circuit (opto-ASIC) and an encoder disc carrying micro manufactured structures is presented. The physical basis of the encoder is the diffraction of light using a reflective phase grating. The opto-ASIC contains a ring of photodiodes that represents the encryption of the encoder. It also includes the analog signal conditioning, the signal acquisition, and the control of a light source, as well as the digital position processing. The development and fabrication of the opto-ASIC is also described in this work. A laser diode was assembled in the center on top of the opto-ASIC, together with a micro manufactured polymer lens. The latter was fabricated using ultra-precision machining. The encoder disc was fabricated using micro injection molding and contains micro structures forming a blazed grating. This way, a 10-bit optical encoder with a form factor of only 1 cm3 was realized and tested successfully.
A Method for Expansion of Z-Directional Measurement Range in a Mode-Locked Femtosecond Laser Chromatic Confocal Probe
Authors: Chen Chong , Sato Ryo , Shimizu Yuki , Nakamura Taku , Matsukuma Hiraku , Gao Wei
Published: January 2019

A method is proposed to expand the Z-directional measurement range of a fiber-based dual-detector chromatic confocal probe with a mode-locked femtosecond laser source. In the dual-detector chromatic confocal probe, the Z-directional displacement of a measurement target is derived from the peak wavelength in the normalized intensity ratio from the two light intensities obtained by the two identical fiber detectors. In this paper, a new method utilizing the main-lobe and side-lobes of axial responses acquired from both the normalized intensity ratio Ia and the invert normalized intensity ratio In, which is the inverse of Ia, is proposed to obtain the seamless relationship between the peak wavelength and the Z-directional displacement of a measurement target. Theoretical calculations and experimental investigation are carried out to demonstrate the feasibility of the proposed measurement range expansion method.
Distributed Control Strategy for Smart Home Appliances Considering the Discrete Response Characteristics of the On/Off Loads
Authors: Kong De-Yin , Bao Yu-Qing , Hong Ying-Yi , Wang Bei-Bei , Huang Hong-Bin , Liu Ling , Jiang Huan-Huan
Published: January 2019

With the development of smart home technology, more and more electrical appliances can participate in demand response, providing support for active power balance of the power grid. However, the conventional centralized control method faces vast amounts of electrical appliances, resulting in problems such as communication congestion and dimension curse. This paper proposes a distributed control strategy for electrical appliances based on a multi-agent consensus algorithm. Considering the discrete response characteristics of the on/off loads, a priority ranking mechanism is established, and the customer cost function is established by a fitting method. Based on the incremental cost consensus (ICC) algorithm, the optimal power allocation of customers is realized through distributed control. Simulation and analysis of the examples verify the effectiveness of the proposed strategy.
Effect of Freeze-Thaw Cycles on Mechanical Characteristics of Bitumens and Stone Mastic Asphalts
Authors: Teltayev Bagdat B. , O. Rossi Cesare , Izmailova Galiya G. , Amirbayev Erik D.
Published: January 2019

The present article investigates in laboratory conditions the effect of cyclic freezing and thawing (CFT) on characteristics of the neat bitumen and bitumens modified with different polymers, as well as stone mastic asphalt concretes prepared with the use of the neat and the modified bitumens. Maximal and minimal temperature in cycles of freezing and thawing (FT) is accepted equal to +20 °C and −18 ± 2 °C respectively. Characteristics of low temperature resistance of bitumens (stiffness S and m-value) have been determined on bending beam rheometer at the temperatures of −24 °C, −30 °C, and −36 °C. Strength at direct tension of the stone mastic asphalt concretes has been evaluated in the device TRAVIS (Infratest Ltd., Brackenheim, Germany) at the temperatures of 0 °C, −10 °C, −20 °C, and −30 °C. Resistance of stone mastic asphalt concretes to rutting has been determined on a Hamburg wheel tracking machine. The characteristics of the bitumens have been determined in the initial condition and after 25 and 50 cycles of FT, and the characteristics of stone mastic asphalt concretes, in the initial condition and after 50 cycles of FT. The results obtained experimentally have shown that CFT impacts essentially on the investigated characteristics of bitumens and stone mastic asphalt concretes. Modification with polymers improves the mechanical characteristics of the bitumens and decreases the effect of CFT. It is also found out that when selecting a bitumen for specific climatic conditions it is necessary to take into account both the number of cycles of FT and the characteristic low temperature.
Defects Detection and Localization in Underwater Plates Using Laser Laterally Generated Pure Non-Dispersive S0 Mode
Authors: Xie Qingnan , Ni Chenyin , Shen Zhonghua
Published: January 2019

When working in humid environments, corrosion defects are easily produced in metallic plates. For defect detection in underwater plates, symmetric modes of Lamb waves are widely used because of their characteristics including long propagating distance and high sensitivity to defects. In this study, we extend our previous work by applying the laser laterally generated S0 mode to detection and localization of defects represented by artificial notches in an aluminum plate immersed in water. Pure non-dispersive S0 mode is generated in an underwater plate by lateral laser source irradiation and its fd (frequency·thickness) range is selected by theoretical calculation. Using this lateral excitation, the S0 mode is enhanced; meanwhile, the A0 mode is effectively suppressed. The mode-converted A0 mode from the incident S0 mode is used to detect and localize the defect. The results reveal a significantly improved capability to detect defects in an underwater plate using the laser laterally generated S0 mode, while that using A0 is limited due to its high attenuation. Furthermore, owing to the long propagating distance and the non-dispersion characteristics of the S0 generated by the lateral laser source, multiple defects can also be detected and localized according to the mode conversion at the defects.
The Role of Reverberation and Magnitude Spectra of Direct Parts in Contralateral and Ipsilateral Ear Signals on Perceived Externalization
Authors: Li Song , Schlieper Roman , Peissig Jürgen
Published: January 2019

Several studies show that the reverberation and spectral details in direct sounds are two essential cues for perceived externalization of virtual sound sources in reverberant environments. The present study investigated the role of these two cues in contralateral and ipsilateral ear signals on perceived externalization of headphone-reproduced binaural sound images at different azimuth angles. For this purpose, seven pairs of non-individual binaural room impulse responses (BRIRs) were measured at azimuth angles of −90°, −60°, −30°, 0°, 30°, 60°, and 90° in a listening room. The magnitude spectra of direct parts were smoothed, and the reverberation was removed, either in left or right ear BRIRs. Such modified BRIRs were convolved with a speech signal, and the resulting binaural sounds were presented over headphones. Subjects were asked to assess the degree of perceived externalization for the presented stimuli. The result of the subjective listening experiment revealed that the magnitude spectra of direct parts in ipsilateral ear signals and the reverberation in contralateral ear signals are important for perceived externalization of virtual lateral sound sources.
Modal Planning for Cooperative Non-Prehensile Manipulation by Mobile Robots
Authors: Fan Changxiang , Shirafuji Shouhei , Ota Jun
Published: January 2019

If we define a mode as a set of specific configurations that hold the same constraint, and if we investigate their transitions beforehand, we can efficiently probe the configuration space by using a manipulation planner. However, when multiple mobile robots together manipulate an object by using the non-prehensile method, the candidates for the modes and their transitions become enormous because of the numerous contacts among the object, the environment, and the robots. In some cases, the constraints on the object, which include a combination of robot contacts and environmental contacts, are incapable of guaranteeing the object’s stability. Furthermore, some transitions cannot appear because of geometrical and functional restrictions of the robots. Therefore, in this paper, we propose a method to narrow down the possible modes and transitions between modes by excluding the impossible modes and transitions from the viewpoint of statics, kinematics, and geometry. We first generated modes that described an object’s contact set from the robots and the environment while ignoring their exact configurations. Each multi-contact set exerted by the robots and the environment satisfied the condition necessary for the force closure on the object along with gravity. Second, we listed every possible transition between the modes by determining whether or not the given robot could actively change the contacts with geometrical feasibility. Finally, we performed two simulations to validate our method on specific manipulation tasks. Our method can be used in various cases of non-prehensile manipulations by using mobile robots. The mode transition graph generated by our method was used to efficiently sequence the manipulation actions before deciding the detailed configuration planning.
Application of Nanofluids in Thermal Performance Enhancement of Parabolic Trough Solar Collector: State-of-the-Art
Authors: Olia Hamed , Torabi Mohammadamin , Bahiraei Mehdi , Ahmadi Mohammad Hossein , Goodarzi Marjan , Safaei Mohammad Reza
Published: January 2019

The present review paper aims to document the latest developments on the applications of nanofluids as working fluid in parabolic trough collectors (PTCs). The influence of many factors such as nanoparticles and base fluid type as well as volume fraction and size of nanoparticles on the performance of PTCs has been investigated. The reviewed studies were mainly categorized into three different types of experimental, modeling (semi-analytical), and computational fluid dynamics (CFD). The main focus was to evaluate the effect of nanofluids on thermal efficiency, entropy generation, heat transfer coefficient enhancement, as well as pressure drop in PTCs. It was revealed that nanofluids not only enhance (in most of the cases) the thermal efficiency, convection heat transfer coefficient, and exergy efficiency of the system but also can decrease the entropy generation of the system. The only drawback in application of nanofluids in PTCs was found to be pressure drop increase that can be controlled by optimization in nanoparticles volume fraction and mass flow rate.
From the Application of Printings to Metal Inclusions in Glass: Development of Techniques
Authors: Bialek Malgorzata (Goshka)
Published: January 2019

This paper introduces the author’s practice-based research and the developed pioneering methods of application of printing inclusions and metal inclusions in glass. It also describes and examines the problems occurring during the application of printing and metal inclusions in glass and presents methods for the selection of suitable materials and techniques.
ROS-Based Human Detection and Tracking from a Wireless Controlled Mobile Robot Using Kinect
Authors: Sankar Sidagam , Tsai Chi-Yi
Published: January 2019

Human detection and tracking is an important task in artificial intelligent robotic systems, which usually require a robust target detector to work in a variety of circumstances. In complex environments where a camera is installed on a wheeled mobile robot, this task becomes much more difficult. In this paper, we present a real-time remote-control system for human detection, tracking, security, and verification in such challenging environments. Such a system is useful for security monitoring, data collection, and experimental purpose. In the proposed system, a Kinect RGB-D camera from Microsoft is used as a visual sensing device for the design of human detection and tracking. We also implemented a remote-control system on a four-wheel mobile platform with a Robot Operating System (ROS). By combining these two designs, a wireless controlled mobile platform having the feature of real-time human monitoring can be realized to handle this task efficiently. Experimental results validate the performance of the proposed system for wirelessly controlling the mobile robot to track humans in a real-world environment.
Detecting Intermediates and Products of Fast Heterogeneous Reactions on Liquid Surfaces via Online Mass Spectrometry
Authors: Colussi Agustín J. , Enami Shinichi
Published: January 2019

One of the research priorities in atmospheric chemistry is to advance our understanding of heterogeneous reactions and their effect on the composition of the troposphere. Chemistry on aqueous surfaces is particularly important because of their ubiquity and expanse. They range from the surfaces of oceans (360 million km2), cloud and aerosol drops (estimated at ~10 trillion km2) to the fluid lining the human lung (~150 m2). Typically, ambient air contains reactive gases that may affect human health, influence climate and participate in biogeochemical cycles. Despite their importance, atmospheric reactions between gases and solutes on aqueous surfaces are not well understood and, as a result, generally overlooked. New, surface-specific techniques are required that detect and identify the intermediates and products of such reactions as they happen on liquids. This is a tall order because genuine interfacial reactions are faster than mass diffusion into bulk liquids, and may produce novel species in low concentrations. Herein, we review evidence that validates online pneumatic ionization mass spectrometry of liquid microjets exposed to reactive gases as a technique that meets such requirements. Next, we call attention to results obtained by this approach on reactions of gas-phase ozone, nitrogen dioxide and hydroxyl radicals with various solutes on aqueous surfaces. The overarching conclusion is that the outermost layers of aqueous solutions are unique media, where most equilibria shift and reactions usually proceed along new pathways, and generally faster than in bulk water. That the rates and mechanisms of reactions at air-aqueous interfaces may be different from those in bulk water opens new conceptual frameworks and lines of research, and adds a missing dimension to atmospheric chemistry.
Modelling Daily Mean Surface Air Temperature Calculated from Different Methods and Its Impact on Urban-Related Warming Evaluations over Guangzhou and Shenzhen Using the WRF Model
Authors: Zhao Deming , Wu Jian
Published: January 2019

The impacts of urban surface expansion, based on satellite-derived data displaying urban surface expansion in China at different spatial scales from 1980 to 2016, were investigated using nested dynamical downscaling methods with the Weather Research and Forecasting (WRF) regional climate model at a 3.3-km resolution over a city and city cluster scale. Urban-related warming, based on daily mean surface air temperature at 2 m (SAT), calculated from the averages of four time records each day (00, 06, 12, and 18 h UTC, T4) and averages of SAT maximum (Tmax) and minimum (Tmin) (Txn), was evaluated. Differences in urban-related warming contributions calculated using T4 and Txn were small, whereas annual mean SAT and trends calculated using Txn were respectively and significantly larger and smaller than those calculated using T4 over Guangzhou and Shenzhen, excluding the trends over middle-northern Shenzhen. The differences in annual mean SAT calculated using T4 and Txn are attributed to nonlinear or asymmetric variations with time for the diurnal cycle of SAT. Meanwhile, differences in trends between T4 and Txn are interpreted as a strong trend for Tmin and a weak one for Tmax, which mitigated the trend for Txn. The impacts on the evaluations of urban-related warming contributions calculated from different methods were the largest over the areas classified as urban surfaces in both time periods (U2U), especially during intense urban-surface-expansion periods between 2000 and 2016. The subregional performances in the changes in annual mean SAT, trends, and urban-related warming are attributed to urban-surface-expansion, which induced varied changes in the diurnal cycle due to asymmetric warming during the daytime and nighttime over different subregions.
Aviation Meteorology at Several Plane Crash Sites
Authors: Safronov Alexander N.
Published: January 2019

The causes of aircraft crashes were investigated for several accidents, such as the Tu-154 and the Airbus A320-211 crashes near Sochi, Russia; the Airbus A320-232 crash near the Perpignan airport; and the Airbus A310-324 crash during landing in Moroni, Comoros Islands. Failures related to aircraft aerodynamics caused these air catastrophes. Upon encountering an upward vertical front, the airstream over the plane wing was disrupted and, as a result, the aerodynamic lifting force suddenly and dramatically decreased. The critical value of the vertical wind speed in a sea-land front (SLF) was determined to be ~0.5–1.0 m s−1. Some recommendations are proposed to prevent such aircraft accidents near coastal airfields. Forecast predictions of a sea-land breeze w-Front and of MWT (Mountain Wave Turbulence) were performed by regional atmospheric models with a resolution no lower than 2 km. Further, a possible reason for the sudden disappearance of aircraft near the coast of Florida is suggested.