bluuebunny/crossref_metadata_2025 huggingface dataset:
Adam Deep Learning With SOM for Human Sentiment Classification
Authors: Ali Md. Nawab Yousuf , Sarowar Md. Golam , Rahman Md. Lizur , Chaki Jyotismita , Dey Nilanjan , Tavares João Manuel R.S.
Published: July 2019

Nowadays, with the improvement in communication through social network services, a massive amount of data is being generated from user's perceptions, emotions, posts, comments, reactions, etc., and extracting significant information from those massive data, like sentiment, has become one of the complex and convoluted tasks. On other hand, traditional Natural Language Processing (NLP) approaches are less feasible to be applied and therefore, this research work proposes an approach by integrating unsupervised machine learning (Self-Organizing Map), dimensionality reduction (Principal Component Analysis) and computational classification (Adam Deep Learning) to overcome the problem. Moreover, for further clarification, a comparative study between various well known approaches and the proposed approach was conducted. The proposed approach was also used in different sizes of social network data sets to verify its superior efficient and feasibility, mainly in the case of Big Data. Overall, the experiments and their analysis suggest that the proposed approach is very promissing.
Challenges to Overcome and Scaffolding to Build on
Authors: Yang Hao , Ma Zhiqiang
Published: July 2019

While current research on the flipped classroom generally focuses on test results and (or) student/teacher perceptions as a measurement of its pedagogical efficacy, students' adaptation to it and the essential conditions for its application are rarely explored. This exploratory case study aims to rectify this by examining how university students adapted to flipped classrooms implemented in a public university in East China. The findings suggest that while the flipped model is impeded by entrenched polarity between students in terms of their learning dispositions and academic competence, students do develop a prototype of theories of learning, a sense of better self through learning from their peers and an awareness of the importance of intrinsic motivation. A gradualist approach is thus proposed for implementing flipped classrooms, which requires longitudinal studies accordingly to understand its long-term effects on learning behavior hitherto left unexplored.
Machine Learning Based Taxonomy and Analysis of English Learners' Translation Errors
Authors: Qin Ying
Published: July 2019

This study extracts the comments from a large scale of Chinese EFL learners' translation corpus to study the taxonomy of translation errors. Two unsupervised machine learning approaches are used to obtain the computational evidences of translation error taxonomy. After manually revision, ten types of English to Chinese (E2C) and eight types Chinese to English (C2E) translation errors are finally confirmed. There probably exists three categories of top-level errors according to the hierarchical clustering results. In addition, three supervised learning methods are applied to automatically recognize the types of errors, among which the highest performance reaches F1 = 0.85 on E2C and F1 = 0.90 on C2E translation. Further comparison to the intuitive or theoretical studies on translation taxonomy shows some phenomenon accompanied by language skill improvement of Chinese learners. Analysis on translation problems based on machine learning provides the objective insight and understanding on the students' translations.
Petri Net Recommender System to Model Metabolic Pathway of Polyhydroxyalkanoates
Authors: Gupta Sakshi , Singh Gajendra Pratap , Kumawat Sunita
Published: July 2019

Due to the complexity of the metabolic pathways, their modeling has been a great challenge for the researchers. Various mathematical models have been developed and are continuing to be developed to model and study metabolic pathways. In this article, the authors have described Petri nets (PNs) as a recommender system to model one of the metabolic pathways of Polyhydroxyalkanoates. Recommender systems have become an integral part of today's world. Their applications lie in the fields of e-commerce, bioinformatics and many more. Petri nets are one of the promising mathematical tools which can be treated as a recommender system to model and analyze the complex metabolic pathways of various organisms because of the representation of these pathways as graphs. The PN toolbox validates the obtained Petri net model. Polyhydroxyalkanoates, commonly known as PHAs, are biodegradable microbial polyesters and have properties quite similar to commonly used non-biodegradable plastics. Due to their biodegradability, biocompatibility, and eco-friendly nature, they are of biological significance and are used in various applications in wide range of sectors like medical sector, drug delivery, tissue engineering, and many more. The obtained PN model of Polyhydroxyalkanoates has been validated using PN toolbox.
Comparative Analysis of Flight Search Representations
Authors: Rextin Aimal Tariq , Iftekhar Fatima , Malik Muhammad Muddasir , Abbas Faheem
Published: July 2019

Visualization has been extensively used in almost all the fields, but unfortunately, there is very little work on the visualization of flight search. The literature discusses only two representations: textual representation and linear representation. In this study, the authors introduce a new form of visualization called circular representation and compare it with the existing visualization techniques. The authors found that each representation has its own merits and demerits. More specifically, they found that users were able to find required flight circular efficiently when using circular representation, while most errors were committed by the user when using textual representation, and users ranked circular representation low in terms of qualitative satisfaction.
Personality Traits as Predictor of M-Payment Systems
Authors: Khan Ali Nawaz , Cao Xiongfei , Pitafi Abdul Hameed
Published: July 2019

Mobile phones have led to a great revolution of modern society, helpful for many businesses to reorient their sales methods towards effective commercial formats. The m-payment, for instance, as an emergent technology to these novel commercial setups, is now undertaking the adoption process. Individual users are known to vary in their tendency to accept new technologies. Not surprisingly, some conceptual models describe how and why individuals use m-payments. Until recently, however, the role of personality in overall, and the big five model of personality, in particular, had remained mostly unexplored. This article aims to ascertain the impact of personality traits on m-payment adoption. Data were collected from 323 m-payment customers and analyzed using a two-step research methodology. SEM was applied to test the hypothesis, and significant antecedents of m-payment were identified. Next significant personality factors were input to a neural network model for ranking. The results showed that conscientious and agreeableness is the two main predictors of m-payment adoption.
Cold Split Kerf-Free Wafering Results for Doped 4H-SiC Boules
Authors: Swoboda Marko , Rieske Ralf , Beyer Christian , Ullrich Albrecht , Gesell Gino , Richter Jan
Published: July 2019

We report on the results of intense third party evaluation of the COLD SPLIT technology. In total nine different SiC manufactures supplied test material. The results confirm the tremendous potential of the technology with total kerf losses per wafer of less than 100μm. Furthermore, our general approach led to comparable results for all vendors. The vendor specific difference like lateral doping level were addressed via control loops in our lasering process. These loops take crystal properties into account and adjust the applied laser energy and the depth of the laser process accordingly. Even the current best case results of sub 80μm split loss per wafer are dominated by systematic effects, which are addressed by continuous improvement efforts.
Tracking of the Growth Interface during PVT-Growth of SiC Boules Using a X-Ray Computed Tomography Setup
Authors: Arzig Matthias , Salamon Michael , Uhlmann Norman , Wellmann Peter J.
Published: July 2019

A crystal comprising various polytype switches was analyzed in detail. A very flat temperature profile together with an on axis seed are used to increase the probability for the nucleation of foreign polytypes during growth. Formation of foreign polytype occurred from thin lamella propagating from the edge of the main facet to the crystal rim as well as from 2D nucleation. The evolution of the crystal surface during the growth time is visualized using in-situ X-Ray computed tomography. Two concurrent growth centers are identified in the beginning of the growth process. Nucleation and lateral growth of foreign polytypes in the main facet area can be traced during the growth process.
Modeling of the PVT Growth Process of Bulk 3C-SiC - Growth Process Development and Challenge of the Right Materials Data Base
Authors: Schöler Michael , Schuh Philipp , Steiner Johannes , Wellmann Peter J.
Published: July 2019

We report on the modeling of the temperature field and supersaturation in front of the SiC crystal growth interface of a physical vapor transport growth configuration. The data are compared with experimental results, like the growth of free standing 3C-SiC wafers with a diameter of 50 mm and a thickness of 870 µm. Special emphases is put on the precise handling of the materials properties which include the temperature dependency of the heat and electrical conductivity of the graphite parts at temperatures above 2000 °C.
Impacts of TaC Coating on SiC PVT Process Control and Crystal Quality
Authors: Fan Wei , Qu Hao , Chang Sung Il , Kozak Brian , Shaffer Gregory , Galyukov Alex , Lee Won Jae
Published: July 2019

Tantalum carbide (TaC) coating, produced in an ultrahigh temperature chemical vapor deposition (CVD) process, exhibited high thermal and chemical stabilities, low emissivity, and high purity. The present research investigated through modeling the TaC emissivity and reactivity impacts on the temperature, C/Si ratio and growth rate in SiC physical vapor transport (PVT) process. The TaC coating effect was further validated by SiC crystal shape and quality through a series of growth experiments. As our study revealed, TaC coating can act as a protection and isolation layer to extend graphite component life, improve radial temperature uniformity, maintain SiC sublimation stoichiometry, suppress impurity migration, and reduce energy consumption. Ultimately a TaC-coated graphite crucible set is expected to improve SiC PVT process control and product quality.
Major Carrier Element Concentrations in SiC Powder and Bulk Crystal
Authors: Hsiao Ta Ching , Tsao S. , Nagalyuk Sergey , Mokhov Evgeniy
Published: July 2019

Boron, aluminum, and nitrogen are major and critical elements in silicon carbide. The concentrations of these elements influence the electrical properties of silicon carbide and also the generation of defects. Purification was executed in the powder manufacturing process. High purity powder was used to grow the crystal, which was then sliced into wafers in this work. Secondary ion mass spectroscopy (SIMS) and glow discharge mass spectrometry (GDMS) were used to measure boron, aluminum, and nitrogen concentrations in wafer and powder to compare the concentration difference. The concentration of the elements varies depending on the element’s physical property. Transfer coefficient is defined as the ratio of element concentration in wafer to powder, which is interesting to realize the element behavior in PVT process and studied in this work.
Electrically Active Levels Generated by Long Oxidation Times in 4H-SiC
Authors: Knoll Lars , Kranz Lukas , Alfieri Giovanni
Published: July 2019

We electrically characterized 4H-SiC n-type epilayers, oxidized in dry ambient in the 1200<T<1300 °C temperature range, for 75-600 min. Consistently with the literature, our results show the reduction of the concentration of the carbon vacancy concentration and of the D-center. Oxidation times equal or longer than 75 min, lead to the formation of two new electrically active levels in the upper part of the band gap and to four new electrically active levels in the lower part.
Minority Carrier Lifetime Measurements on 4H-SiC Epiwafers by Time-Resolved Photoluminescence and Microwave Detected Photoconductivity
Authors: Beyer Jan , Schüler Nadine , Erlekampf Jürgen , Kallinger Birgit , Berwian Patrick , Dornich Kay , Heitmann Johannes
Published: July 2019

Temperature dependent microwave detected photoconductivity MDP and time-resolved photoluminescence TRPL were employed to investigate the carrier lifetime in CVD grown 4H-SiC epilayers of different thickness. The minority carrier lifetime may be found from both theMDP and defect PL decay at room temperature for all epilayers, whereas the near bandedge emission (NBE) decay is much faster for thin epilayers (<17 μm) due to the substrate proximity and only follows the minority carrier lifetime for thicker samples at lower excess carrier concentrations.
Carrier Transport Mechanisms in Ion Implanted and Highly-Doped p-Type 4H-SiC(Al)
Authors: Parisini Antonella , Nipoti Roberta
Published: July 2019

Fundamental aspects of transport in Al ion implanted p-type 4H-SiC are briefly reviewed, in the light of recent literature. Particular attention is paid on (i) the Hall factor and (ii) the role of disorder in the onset of a variable range hopping mechanism (VRH) at high temperatures as doping level increases, up to a 2D-VRH induced by extended defects in the heaviest doped samples. The study allowed to understand the critical balance between implanted impurity density and annealing temperature that leads to the searched doping level, ensuring an efficient electrical activation of implanted impurities, on a side, and, on the other side, avoiding stacking faults that cause anisotropic hopping transport.
4H-SiC p-Type Doping Determination from Secondary Electrons Imaging
Authors: Kayambaki Maria , Makris Nikolaos , Tsagaraki Katerina , Peyré Hervé , Stavrinidis Antonis , Konstantinidis George , Zekentes Konstantinos
Published: July 2019

Secondary electron imaging of SiC epi-structures is commonly used as it allows doping topography i.e. the knowledge of the spatial extension of differently doped layers. Determination of the doping level of the layers was not possible until now. The present work presents how to use this technique for 4H-SiC p-type doping determination. This is indeed, possible for specific experimental data analysis and for doping levels higher than 1017cm-3.
Study on N and B Doping by Closed Sublimation Growth Using Separated Ta Crucible
Authors: Tanaka Daiki , Kurokawa Hiroaki , Kamiyama Satoshi , Takeuchi Tetsuya , Iwaya Motoaki , Akasaki Isamu
Published: July 2019

Boron (B) doping sources and crucible materials for stable, reproducible and high concentration B doping in fluorescent SiC (f-SiC) were investigated. When a Ta crucible was used with BN powder as a B doping source were used, B doping did not occur owing to too low C/Si ratio. On the other hand, when a C crucible and suitable Ta components inside the crucible were used, a high B concentration of 1.58 × 1019 cm-3 was obtained, owing to the high C/Si ratio. The results indicate that a C crucible with optimal Ta components and BN powder are suitable for high concentration B doping.
Recent Advances in the Doping of 4H-SiC by Channeled Ion Implantation
Authors: Hallén Anders , Linnarsson Margareta K. , Vines Lasse
Published: July 2019

The effect of lattice thermal vibrations on the channeling of 100 keV Al ions in 4H-SiC is investigated. By implanting at room temperature in the direction, the depth distribution of the incident ions is shown to be about 7 times deeper than for random implantations. At higher implantation temperatures, the channeling is reduced by the lattice vibrations and, for instance, at 600 °C implantation the distribution is about 3-4 times deeper than for a RT random implantation. The results are of technological interest for further development of implantation technology for 4H-SiC device manufacturing.
High-Concentration, Low-Temperature, and Low-Cost Excimer Laser Doping for 4H-SiC Power Device Fabrication
Authors: Imokawa Kaname , Kikuchi Toshifumi , Okamoto Kento , Nakamura Daisuke , Ikeda Akihiro , Asano Tanemasa , Ikenoue Hiroshi
Published: July 2019

We developed a novel KrF excimer laser doping system for 4H-SiC power devices, and demonstrated laser doping of 4H-SiC with Al thin film deposited on the surface. As seen from the results of the Al depth profile, high concentration implantation (~ 1021 cm-3 at the surface) of Al was achieved by laser ablation of the Al thin film. A high, built-in-potential (~3.5 V) of the pn junction diode was clearly seen in the I-V curve. In addition, the contact resistivity of the deposited Al/Ti electrodes on the surface was 1.9 × 10−4 Ωcm2 by TLM (Transmission Line Model). It was confirmed that a high concentration of Al doping and low contact resistivity were achieved by the KrF excimer laser doping system.
Lateral Straggling of Ion Implantation Distributions in 4H-SiC Investigated by SIMS
Authors: Müting Johanna , Bobal Viktor , Azarov Alexander , Svensson Bengt Gunnar , Grossner Ulrike
Published: July 2019

Ion implantation is a crucial step in the process of SiC device fabrication. Precise and predictable doping distributions are necessary for reduced cell pitches and integrated circuit development. However, straggling due to ion channeling affects this goal. Even though vertical channeling has been investigated successfully, lateral straggling remains unclear. Therefore, two-dimensional SIMS concentration distributions are used to investigate lateral straggling of Al and P implanted in 4H-SiC. Results, for both Al and P, show that there is a significant influence of the crystal orientation showing that some channels lead to a few micrometers more lateral straggling than others. High implantation doses increase the amount of amorphization, which leads to more dechanneling and, thus, less straggling. Even though elevated implantation temperatures increase lattice vibrations and thus act in favor of dechanneling, the implantation distributions show significant lateral straggling as amorphization is suppressed.
Electrical Characterization of MOCVD Grown Single Crystalline AlN Thin Films on 4H-SiC
Authors: Khosa Rabia Y. , Chen J.T. , Pálsson K. , Karhu Robin , Hassan Jawad , Rorsman Niklas , Sveinbjörnsson E.Ö.
Published: July 2019

We report on a very low density of interface traps at the AlN/4H-SiC interface estimated from capacitance-voltage (CV) analysis of metal-insulator-semiconductor (MIS) capacitors. Single crystalline aluminum nitride (AlN) films are grown by metal organic chemical vapor deposition (MOCVD). Current-voltage (IV) analysis shows that the breakdown electric field across the AlN dielectric is 3 MV/cm. By depositing an additional SiO2 layer on top of the AlN layer it is possible to increase the breakdown voltage of the MIS capacitors significantly without having pronounced impact on the quality of the AlN/SiC interface.
Argon Bombardment of 4H Silicon Carbide Substrates for Tailored Schottky Diode Barrier Heights
Authors: Schneider Michael , Stöber Laura , Konrath Jens P. , Patocka Florian , Schmid Ulrich
Published: July 2019

In this paper, the impact of substrate preconditioning by ion bombardment in-situ in a conventional sputter equipment on n-doped 4H-silicon carbide (SiC) Schottky diodes with molybdenum nitride metallization is studied. By variation of the plasma power during argon ion bombardment, the effective barrier height is adjustable in the range from 0.66 to 0.96 eV, as deduced by current / voltage measurements over a wide temperature range. Therefore, this approach offers a straightforward method to tailor the Schottky barrier height over a significant range by introducing an insitu substrate pretreatment step available in most sputter equipment.
Impact of Subsurface Damage on SiC Wafer Shape
Authors: Moeggenborg Kevin , Manning Ian , Searson Jon , Chung Gil Yong
Published: July 2019

The impact of surface stress due to polish and grind processes on wafer bow was studied as a function of abrasive size. Results indicate that sub-surface damage from these processes can introduce significant surface stress. For polishing processes, this stress is proportional to mean abrasive size. The study also investigates stress as a function of depth below the wafer surface and finds that most stress is concentrated near the wafer surface.
The Impact of Non-Ideal Ohmic Contacts on the Performance of High-Voltage SiC MPS Diodes
Authors: Huang Yaren , Buettner Jonas , Lechner Benedikt , Wachutka Gerhard
Published: July 2019

The wide band gap of SiC semiconductor devices constitutes a serious challenge to build good Ohmic contacts on the surface of the p-type material. This is reflected in the numerical analysis of ”realistic” devices, where we have to cope with serious problems, such as a shifting threshold voltage, reduced forward conductivity, and no noticeable conductivity modulation by minority carrier injection from p+-emitters, in matching measured data with simulation results, as a consequence of the significant impact of non-ideal poor Ohmic contacts. In this work, we used a Schottky contact model together with a barrier tunneling model, instead of common ideal Ohmic contact model, to simulate the non-ideal Ohmic contact on SiC MPS diodes. Based on this approach, the I-V characteristics of real Ohmic contacts can be reproduced in high-fidelity simulations, providing us physical insight of the observed operational behavior.
Advanced Electrical Characterisation of High Voltage 4H-SiC PiN Diodes
Authors: Asllani Besar , Planson Dominique , Bevilacqua Pascal , Fonder Jean Baptiste , Choucoutou Beverley , Morel Hervé , Phung Luong Viet
Published: July 2019

This paper reports the design, the processing, the static characterisation, the switching behaviour and the high current stress test of 10 kV aimed 4H-SiC bipolar diodes. The actual breakdown voltage of the selected devices is between 7 kV and 8 kV. The switching characterisations show a good behaviour with a trr of only 90 ns. No degradation was observed after the application of 10 000 high current pulses during the stress tests.
Performance of 4H-SiC Bipolar Diodes as Temperature Sensor at Low Temperatures
Authors: di Benedetto Luigi , Matthus C.D. , Erlbacher Tobias , Bauer Anton J. , Licciardo Gian Domenico , Rubino Alfredo , Frey Lothar
Published: July 2019

In this paper we report on the performance of 4H-SiC bipolar diodes as temperature sensors far beyond 273K. The sensor is measured from 150K to 445K covering a temperature range of 295K. In this operating temperature range, the sensor characteristic VD-T is highly linear and it is dominated by the typical dependence of the p-i-n diode voltage on the temperature. The sensor sensitivity is -4.48mV/K for a diode current of 2nA with a maximum error of 4.3K across the full temperature range. Although 4H-SiC p-i-n are mainly focused on very high temperature applications, our analysis on the performance of bipolar diodes at low temperatures highlights its feasibility as temperature sensor for aerospace and high altitude applications where cryogenic temperatures are achieved.
Experimental Study of High-Temperature Switching Performance of 1.2kV SiC JBSFET in Comparison with 1.2kV SiC MOSFET
Authors: Kanale Ajit , Baliga B. Jayant , Han Ki Jeong , Bhattacharya Subhashish
Published: July 2019

The high-temperature switching performance of a 1.2kV SiC JBSFET is compared with a 1.2kV SiC MOSFET using a clamped inductive load switching circuit representing typical H-bridge inverters. The switching losses of the SiC MOSFET are also evaluated with a SiC JBS Diode connected antiparallel to it. Measurements are made with different high-side and low-side device options across a range of case temperatures. The JBSFET is observed to display a reduction in peak turn-on current – up to 18.9% at 150°C and a significantly lesser turn-on switching loss – up to 46.6% at 150°C, compared to the SiC MOSFET.
SiC Charge-Balanced Devices Offering Breakthrough Performance Surpassing the 1-D Ron versus BV Limit
Authors: Bolotnikov Alexander , Losee Peter A. , Ghandi Reza , Kennerly Stacey , Datta Rajib , She Xu
Published: July 2019

This work presents experimental validation of novel device design, based on charge-balance concept expected to expand SiC utilization space for industrial and transportation power conversion applications. Fabricated 2kV and 3kV SiC CB-JBS diodes have surpassed the 1-D BV versus ROn,sp tradeoff with the highest reported breakdown voltage. Static and dynamic characteristics of these new diodes are reported.
SiC Vertical-Channel n- and p-JFETs Fully Fabricated by Ion Implantation
Authors: Kaneko Mitsuaki , Grossner Ulrike , Kimoto Tsunenobu
Published: July 2019

Silicon carbide (SiC) n-and p-channel junction field effect transistors (JFETs) with vertical channels were fabricated by direct ion implantation into a high-purity semi-insulating 4H-SiC substrate in order to further develop the path towards complementary JFET integrated circuits for applications in harsh environments. Compared with the conventional structure (lateral channel), the proposed structure is suitable for integration and inherently has a high transconductance owing to the double-gate configuration. The threshold voltage (Vth) can be controlled by mask design, while Vth in the conventional structure is solely determined by the ion implantation conditions. We demonstrate the transistor operation of the vertical-channel n-and p-channel JFETs fully fabricated by ion implantation.
An Efficient Simulation Methodology to Quantify the Impact of Parameter Fluctuations on the Electrothermal Behavior of Multichip SiC Power Modules
Authors: Borghese Alessandro , Catalano Antonio Pio , Riccio Michele , Codecasa Lorenzo , Fayyaz Asad , d'Alessandro Vincenzo , Castellazzi Alberto , Maresca Luca , Breglio Giovanni , Irace Andrea
Published: July 2019

Despite their growing adoption in a variety of applications, SiC MOSFETs are generally not available at high current rating. Therefore, there is a high demand for power modules exploiting configurations based on parallel devices. However, these products still need optimization in order to ensure long-term reliability. This paper presents a methodology relying on fast electrothermal simulations aimed at aiding this optimization procedure. The proposed approach is applied to a power module in which the parallel MOSFETs are realistically subject to mismatched parameters.
6.5 kV Si/SiC Hybrid Power Module Technology
Authors: Sharma Yogesh , Mumby-Croft P. , Ngwendson L. , Packwood M. , Coulbeck L. , Birkett M. , Kong C. , Jiang H. , Wang Y. , Deviny I.
Published: July 2019

Substituting Si diodes with SiC Schottky diodes in Si insulated gate bipolar transistor (IGBT) modules is beneficial, as it can reduce power losses in electrical systems significantly. The fast switching nature of the SiC diode will allow Si IGBTs to operate at their full high-switching-speed potential, which at present is not possible because of the Si diodes. In this work, the electrical test results for Si-IGBT/4HSiC-Schottky hybrid substrates (hybrid SiC substrates) are presented. Comparisons of the 6.5 kV Si and hybrid SiC at room temperature and high temperature have shown that the switching losses in hybrid SiC substrates are low as compared to those in Si substrates but necessary steps are required to mitigate the ringing observed in the output waveforms.
Nurses’ perspectives about communication with patients in an intensive care setting using a communication board: A pilot study
Authors: Gropp Martelize , Johnson Ensa , Bornman Juan , Koul Rajinder
Published: July 2019

Background: Communication in the intensive care setting (ICS) is critical for both the patient and the medical staff to provide efficient care and thus alleviate possible patient adverse effects. Persons with complex communication needs are particularly vulnerable in ICSs and therefore require additional communication support.Aim: This study focused on the perspectives of nurses about communication with patients with communication needs in ICSs using paper-based communication boards, namely the translated Vidatak EZ Board, before and after a training session.Setting: A 1650-bed public hospital with a 26-bed ICS in a semi-urban, low socio-economic area in South Africa served as the research setting.Methods: A quasi-experimental pre-test post-test group design with withdrawal and a control group was used. Data were gathered using a custom-designed questionnaire completed by ICS nurse participants recruited from a public hospital.Results: Responses of some nurses did not change in post-test 1, but their responses did change in post-test 2. Some of the nurses’ perspectives changed, as expected from the pre-test to post-test 1. Nurses recommended specific adaptations to the communication board.Conclusions: Most nurses agreed that communication is crucial in ICSs and that a communication board can be implemented; however, limited success was observed implementing the board following a short training. The inter-professional collaboration between nurses and speech-language therapists to provide optimal health care to patients in ICS is emphasised.
Sampling Techniques to Overcome Class Imbalance in a Cyberbullying Context
Authors: Colton David , Hofmann Markus
Published: July 2019

The majority of datasets suffer from class imbalance where samples of a dominant class significantly outnumber the samples available for the minority class that is to be detected. Prediction and classification machine learning models work best when there are roughly equal numbers of each class type. This paper explores sampling techniques that can be used to overcome this class imbalance problem in a cyberbullying context. A newly classified cyberbullying dataset, including detailed descriptions of the criteria used in its classification, was used to examine the feasibility of applying text mining techniques, to automate the detection of cyberbullying text when the dataset shows a significant class imbalance between the positive, cyberbullying, sample and the negative, not cyberbullying, samples. In this paper, we will investigate if oversampling the minority positive class or undersampling the majority negative class affects the performance of a prediction model. A compromise solution where the positive class is partially oversampled, and the negative class is partially undersampled is also examined. Although not strictly a class imbalance solution, sampling using the most frequently observed features was also explored.

 
An Evaluation Of A Linguistically Motivated Conversational Software Agent Framework
Authors: Panesar Kulvinder
Published: July 2019

This paper presents a critical evaluation framework for a linguistically motivated conversational software agent (CSA). The CSA prototype investigates the integration, intersection and interface of the language, knowledge, and speech act constructions (SAC) based on a grammatical object, and the sub-model of belief, desires and intention (BDI) and dialogue management (DM) for natural language processing (NLP). A long-standing issue within NLP CSA systems is refining the accuracy of interpretation to provide realistic dialogue to support human-to-computer communication. This prototype constitutes three phase models: (1) a linguistic model based on a functional linguistic theory – Role and Reference Grammar (RRG), (2) an Agent Cognitive Model with two inner models: (a) a knowledge representation model, (b) a planning model underpinned by BDI concepts, intentionality and rational interaction, and (3) a dialogue model. The evaluation strategy for this Java-based prototype is multi-approach driven by grammatical testing (English language utterances), software engineering and agent practice. A set of evaluation criteria are grouped per phase model, and the testing framework aims to test the interface, intersection and integration of all phase models. The empirical evaluations demonstrate that the CSA is a proof-of-concept, demonstrating RRG’s fitness for purpose for describing, and explaining phenomena, language processing and knowledge, and computational adequacy. Contrastingly, evaluations identify the complexity of lower level computational mappings of NL – agent to ontology with semantic gaps, and further addressed by a lexical bridging solution.
The impact of applying the FonF practice model on developing L2 listening and speaking with a focus on intentional and incidental vocabulary acquisition in CALL context
Authors: Bahari Akbar
Published: July 2019

Drawing on dynamic systems theory, FonF practice model was contextualized with respect to its impact on L2 learners’ incidental and intentional vocabulary acquisition in CALL context. To this end, a mixed methods approach was conducted on a sample of 93 intermediate EFL learners in CALL setting in keeping with the FonF practice model. Comparing incidental and intentional acquisition was the target of the study. The obtained results confirmed the effectiveness of the FonF practice model via form-, meaning-, and communication-oriented strategies to develop listening and speaking proficiency as well as incidental and intentional vocabulary acquisition among the experimental group. The main educational implication of the study is the effectiveness of FonF practice model at recruiting the potential behind CALL affordances towards developing listening-speaking proficiency and developing intentional and incidental vocabulary while catering for nonlinear dynamic motivational factors at individual L2 learner level.

 
Logistic calibrated items (LCI) method: does it solve subjectivity in translation evaluation and assessment?
Authors: Akbari Alireza
Published: July 2019

This research paper introduces a model of translation evaluation called Logistic Calibrated Items method. The aim of LCI method is to maximize a translators’ performance and to identify top competent translators through detecting all parsing items within a source text. Parsing items are extracted by the application of Brat software. The purpose of LCI was to identify parsing items having optimal item difficulty and item discrimination values. LCI method involves six stages: (1) holistic scoring; (2) the application of Brat software to extract all parsing items; (3) the calculation of item difficulty; (4) the calculation of item discrimination; (5) the identification of items with optimal item difficulty and item discrimination values; and (6) the recalculation of scores. 125 translation students and 4 professional translation evaluators took part in this research. The final results showed that LCI method was more consistent when compared to holistic method. Limitations and implications were also discussed.
Dyadic adjustment in couples: How partners' social value within couple and emotional competences predict it
Authors: Delelis Gérald , Heuschen Mathilde
Published: July 2019

Knowing the determinants of couple adjustment is a challenge, both for predicting this adjustment and for helping couples in therapy in the best possible way. We based this study on the Person’s Social Value Theory (Beauvois, J.-L. [1976]. The topic of social conduct evaluation. Connexions, 19, 7-30) which postulates that two dimensions – social utility and social desirability – support self- and other- descriptions. This study aimed to evaluate the way the evaluation of own social value within couple and the evaluation of social value within couple of the partner influence the dyadic adjustment of the spouses. In addition, we took into account the duration of the couples and the emotional competences of the spouses (using the PEC). Participants were the spouses of 152 voluntary heterosexual couples who completed a booklet of questionnaires. The results showed that the two dimensions of person’s social value within couple influence partners' dyadic adjustment but in a different way for men and women and according to the duration of the couples’ relationship. Furthermore, the effect of social value within couple seems to cover partially the classic effect of emotional competences on couple experience and satisfaction. The discussion underlines the relevance and interest of using the social value within the couple in the study of conjugal relationships as well as in counselling couples.
Presumptive spontaneous brain microhemorrhages in geriatric dogs: a comparative retrospective MRI study of dogs with and without evidence of canine cognitive dysfunction
Authors: Dewey Curtis W , Rishniw Mark , Johnson Philippa J , Davies Emma S , Sackman Joseph J , O'Donnell Marissa
Published: July 2019

The objective of this study was to compare specific brain MRI anatomic measurements between three groups of geriatric ( > 8yrs) dogs: 1) neurologically impaired dogs with presumptive spontaneous brain microhemorrhages and no clinical evidence of canine cognitive dysfunction 2) dogs with canine cognitive dysfunction 3) dogs without clinical evidence of cognitive impairment or abnormalities on neurologic examination (control dogs). MR images from 46 geriatric dogs were reviewed and measurements were obtained of interthalamic adhesion height (thickness) and mid-sagittal interthalamic adhesion area for all dogs, in addition to total brain volume. Interthalamic adhesion measurements, either absolute or normalized to total brain volume were compared between groups. Signalment (age, breed, sex), body weight, presence and number of SBMs, as well as other abnormal MRI findings were recorded for all dogs. All interthalamic adhesion measurement parameters were significantly (p<0.05) different between control dogs and affected dogs. Both dogs with cognitive dysfunction (12/13; 92 %) and dogs with isolated brain microhemorrhages had more microhemorrhages than control dogs (3/19; 16%). Affected dogs without cognitive dysfunction had more microhemorrhages than dogs with cognitive dysfunction. In addition to signs of cognitive impairment for the CCD group, main clinical complaints for SBM and CCD dogs were referable to central vestibular dysfunction, recent-onset seizure activity, or both. Geriatric dogs with spontaneous brain microhemorrhages without cognitive dysfunction have similar MRI abnormalities as dogs with cognitive dysfunction but may represent a distinct diseasecategory.
Correlation Analysis of Toxic Metals Distribution and Pollution Indices in Soil, Beans and Maize Samples of Kano State, Nigeria
Authors: Alhassan A. J. , Muhammad I. U. , Sule M. S. , Dangambo M. A. , Gadanya A. M. , Umar Y. , Dangambo Misbahu A. , Mohammed A. , Syed M.
Published: July 2019

Correlational study and evaluation of pollution indices of toxic metals distribution in soil and crops of a population are imperative for assessing the risk of chronic diseases associated with these metals. Correlational analysis for the distribution of; lead (Pb), cadmium (Cd), chromium (Cr) and mercury (Hg) in soil (S), bean (B) and maize (M) was conducted around Bunkure (BKR), Danbatta (DBT), Gwarzo (GRZ), Ungogo (UGG) and Wudil (WDL) as sampling zones around Kano State, Nigeria. The samples were collected from farm harvests in each of the sampling zones. The metal concentration was determined using atomic absorption spectrometry (AAS). Results in mg/kg across the local governments indicate respective ranges for Hg, Pb, Cd, and Cr of; 0.33 - 3.13, 0.14 - 0.84, 0.02 - 0.05 and 0.01- 0.49 in soil, 0.04-4.23, 0.06-0.23, 0.02-0.04 and 0.00-0.10 in maize and 0.20-4.23, 0.16-0.19, 0.03-0.04 and 0.00-0.03 in beans. Although with the exception of mercury, the ranges of the toxic metals are within the tolerable range set by International Standard Tolerable Limits and European Regulatory Standard. Potential hazard may be speculated because the detected levels are on higher tolerable ranges. A higher level of mercury in almost all the samples indicates potential hazards associated with human activities in those areas. A strong positive correlation between soils samples in respect to the level of some of the toxic metal may suggest a common nature of the soil, while the negative correlation may be due to variation in agrochemicals in-use. For the pollution load index, Wudil had the highest soil pollution load index for Hg (3.13 ± 0.16), Cd (1.6×10-2 ± 0.01) and Cr (4.9×10-3 ± 0.01), while Ungogo had the highest pollution load for Pb. Also, all grains within the study zones exhibited a positive transfer factor, except Cr in Bunkure, Danbatta and Gwarzo. It may be concluded that crops grown in those areas may bioaccumulate some of these toxic metals, thereby incorporating them into the food chain, hence potential health risk.
Autogenous Growth of Hierarchical NiFe(OH)x/FeS Nanosheet‐On‐Microsheet Arrays for Synergistically Enhanced High‐Output Water Oxidation
Authors: Niu Shuai , Jiang Wen‐Jie , Tang Tang , Yuan Lu‐Pan , Luo Hao , Hu Jin‐Song
Published: July 2019

Practical electrochemical water splitting requires cost‐effective electrodes capable of steadily working at high output, leading to the challenges for efficient and stable electrodes for the oxygen evolution reaction (OER). Herein, by simply using conductive FeS microsheet arrays vertically pre‐grown on iron foam (FeS/IF) as both substrate and source to in situ form vertically aligned NiFe(OH)x nanosheets arrays, a hierarchical electrode with a nano/micro sheet‐on‐sheet structure (NiFe(OH)x/FeS/IF) can be readily achieved to meet the requirements. Such hierarchical electrode architecture with a superhydrophilic surface also allows for prompt gas release even at high output. As a result, NiFe(OH)x/FeS/IF exhibits superior OER activity with an overpotential of 245 mV at 50 mA cm−2 and can steadily output 1000 mA cm−2 at a low overpotential of 332 mV. The water‐alkali electrolyzer using NiFe(OH)x/FeS/IF as the anode can deliver 10 mA cm−2 at 1.50 V and steadily operate at 300 mA cm−2 with a small cell voltage for 70 h. Furthermore, a solar‐driven electrolyzer using the developed electrode demonstrates an exceptionally high solar‐to‐hydrogen efficiency of 18.6%. Such performance together with low‐cost Fe‐based materials and facile mass production suggest the present strategy may open up opportunities for rationally designing hierarchical electrocatalysts for practical water splitting or diverse applications.
Flexible Quasi‐Solid State Ionogels with Remarkable Seebeck Coefficient and High Thermoelectric Properties
Authors: Cheng Hanlin , He Xu , Fan Zeng , Ouyang Jianyong
Published: July 2019

Thermoelectric materials can be used to harvest low‐grade heat that is otherwise dissipated to the environment. But the conventional thermoelectric materials that are semiconductors or semimetals, usually exhibit a Seebeck coefficient of much less than 1 mV K−1. They are expensive and consist of toxic elements as well. Here, it is demonstrated environmental benign flexible quasi‐solid state ionogels with giant Seebeck coefficient and ultrahigh thermoelectric properties. The ionogels made of ionic liquids and poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) can exhibit a giant Seebeck coefficient up to 26.1 mV K−1, the highest for electronic and ionic conductors. In addition, they have a high ionic conductivity of 6.7 mS cm−1 and a low thermal conductivity of 0.176 W m−1 K−1. Their thermoelectric figure of merit (ZT) is thus 0.75. The giant Seebeck coefficient is related to the ion‐dipole interaction between PVDF‐HFP and ionic liquids. Their application in ionic thermoelectric capacitors is also demonstrated for the conversion of intermittent heat into electricity. They are especially important to harvest the low‐grade thermal energy that is abundant on earth.
Skin‐Inspired Electronics and Its Applications in Advanced Intelligent Systems
Authors: Li Jie-an , Ma Zhong , Wang Hui-ting , Gao Xing-xun , Zhou Zhou , Tao Ruo-wen , Pan Li-jia , Shi Yi
Published: July 2019

Recent interdisciplinary progress in flexible materials, devices, and system designs has brought about an emerging paradigm of skin‐like multifunctional electronic platforms named skin‐inspired electronics. Featured with excellent flexible mechanical properties, thin and conformal devices, and integrated sensing functions similar to those of human skin, skin‐inspired electronics exhibit great potential in the application fields of wearable electronics and human–machine interfaces. Many real‐world implementations of the intelligent system of skin‐inspired electronics in healthcare monitoring, artificial prosthetics via the creation of sensitive skin, and robot tactile perception are demonstrated. Combined with the technologies of wireless data transmission, self‐powered supply modules, and signal‐processing circuits, skin‐inspired electronics are expected to achieve improved portability, multifunctional integration, on‐site analysis, and in‐time feedback. Herein, recent advances in skin‐inspired electronics, its promising solutions to engineering challenges, and opinions on future research directions are discussed.
Error in the estimation of periosteal and endosteal contours from micro‐CT scans for nonadult tibiae and humeri
Authors: Sládek Vladimír , Čerevková Simona , Zikmund Tomáš , Kaiser Jozef
Published: July 2019

Objectives

This article summarized errors obtained by diverse techniques used for the derivation of cross‐sectional contours in nonadult humeri and tibiae.

Materials and Methods

We analyzed cross‐sectional contours in a total sample of 62 humeral and 75 tibial diaphyses in the age between birth and 12 years divided into three age groups. Long bone 35% (humeri) and midshaft (tibiae) cross‐sections were taken on micro‐CT images and analyzed by EPJMacro in FIJI. Properties were extracted from contours derived by manual, automatic, spline, and ellipse techniques. Agreement between techniques was assessed using manually extracted properties such as the true value using percent prediction error (%PE), reduced major axis regression, and ±95% limits of agreement.

Results

The lowest measurement errors were obtained for total areas, moderate errors for cortical areas and section moduli, and the highest errors for medullary areas for both bones. Derivation of humeral nonadult cross‐sectional properties is less sensitive to the technique used for derivation of periosteal and endosteal contours, reaching mean %PEs below 5%. In contrast, tibial nonadult cross‐sectional properties are more sensitive to the technique used and exceed 5% for some combinations.

Discussion

Automatic techniques provide reasonably high agreement with manually extracted contours for nonadult humeri but low agreement for tibiae. Semiautomatic approaches—spline and ellipse techniques—may reduce the error for all studied properties in tibiae, especially when combined with manually traced periosteal contours. The positive effect of the semiautomatic technique on measurement error is low for humeri.