Miracle-dz/UniFAR-FTUs huggingface dataset:
Large-area piezoceramic coating with IDT electrodes for ultrasonic sensing applications

In the present paper, the ultrasonic strain sensing performance of large-area piezoceramic coating with Inter Digital Transducer (IDT) electrodes is studied. The piezoceramic coating is prepared using slurry coating technique and the piezoelectric phase is achieved by poling under DC field. To study the sensing performance of the piezoceramic coating with IDT electrodes for strain induced by the guided waves, the piezoceramic coating is fabricated on the surface of a beam specimen at one end and the ultrasonic guided waves are launched with a piezoelectric wafer bonded on another end. Often a wider frequency band of operation is needed for the effective implementation of the sensors in the Structural Health Monitoring (SHM) of various structures, for different types of damages. A wider frequency band of operation is achieved in the present study by considering the variation in the number of IDT electrodes in the contribution of voltage for the induced dynamic strain. In the present work, the fabricated piezoceramic coatings with IDT electrodes have been characterized for dynamic strain sensing applications using guided wave technique at various different frequencies. Strain levels of the launched guided wave are varied by varying the magnitude of the input voltage sent to the actuator. Sensitivity variation with the variation in the strain levels of guided wave is studied for the combination of different number of IDT electrodes. Piezoelectric coefficient 11 e is determined at different frequencies and at different strain levels using the guided wave technique.
10 kV power semiconductors - breakthrough for 6.9 kV medium voltage drives

Requirements on semiconductor ratings and characteristics are established based on demands of voltage and current source inverters. Fundamental parameters such as blocking characteristics and safe operating area have been measured on 10 kV pin diodes and IGBTs and IGCTs for 4 kV DC link voltage to estimate the potential of these devices in the application.
Identyfikacja i strukturalizacja cech otoczenia przedsiębiorstwa

The paper puts domestic and international conclusions of research results on structuralization of company environment regarding its dimensions or features in order. The author describes the process of identification and structuralization of company external environment regarding occurring limitations. The paper focuses on presentation and analysis of synthetic dimensions of company external environment applied not only in theoretical formulations, but mainly in empirical formulations. The aim of the paper is organizing research results on structuralization and typologies of company external environment.
Study on effect of rectangular DMS and DGS on 4 and 8 elements rectangular microstrip linear array antenna

In this experimental study a novel design has been developed to improve the antenna parameters in terms of impedance bandwidth and radiation properties. A 4-element rectangular array antenna (refereed as antenna 1) operating in the range of 10 to 16 GHz with multi bands is used as a reference antenna. The impedance bandwidth and other radiation properties have been enhanced by using defected microstrip structure (DMS) and defected ground structure (DGS). This study is further extended to 8-element array. The design consideration and experimental results of the proposed antennas are presented and discussed.
Controle do veículo subaquático tatuí utilizando estrutura variável

Designing control laws for unmanned underwater vehicles presents extra difficulties, mostly associated with differences between the nominal dynamic model and the physical plant. These differences exist mainly because of the existence of non-modeled dynamics and also the model parameters difficult to be identified. Therefore, it is essential that the control law, designed to be deployed in practice, has characteristics of strength enabling him to maintain the performance and stability. In this sense, control the structure variable is known suitable for systems with parametric uncertainties. This paper describes the kinematic and dynamic model of underwater vehicles. It also presents the development of an automatic controller position. This control is necessary in a position where you want to take the vehicle to a certain position and keep it there while performing some task. After the theoretical development, simulations are presented with the ROV (Tatui), where it was found that the surface integral variable structure showed the best behavior.
Financial Management: Principles and Practice

Offering a unique balance of industry and academic experience, this unique author team presents the latest in financial theory while maintaining a strong real-world connection. Aiming to engage rather than intimidate, they offer a book that is reader-focused yet does not water down content. Their consistent approach focuses on value: what creates value, what destroys it, how value is measured, and how value and risk are related. Offers web-based Interactive Modules that provide extensions of the material presented in the book, such as Excel spreadsheets and Internet links. Bundles with the book Prentice Hall's Mastering Finance CD" that includes video clips and other material to illustrate concepts. Features an earlier presentation of the cost of capital (to Chapter 9 from Chapter 12), preceding capital budgeting and cash flow estimation chapters. Provides all-new material on business valuation techniques. Perfect for the financial analyst, marketing manager, or information technology manager who wants an updated reference on financial topics.
A comprehensive acceptance model for smart home services

Smart home services (SHSs) afford users an effective lifestyle management system, which provides human-oriented networking of smart devices and applications that enable users to control their homes from anywhere at any time. Despite the benefits of SHSs, however, their acceptance is very low. There remains a gap in the literature in terms of a comprehensive model that addresses users’ intention to use SHSs. To address this gap, the present study explored the factors that influence SHS acceptance among users based on well-established theoretical frameworks, such as the technology acceptance model, innovation diffusion theory, and the theory of planned behavior. To this end, the study integrated four additional factors, namely, perceived convenience, perceived connectedness, perceived cost, and perceived privacy risk, into the exploration and carried out structural equation modeling to quantitatively determine the effects of these factors. Questionnaires were administered to 750 users. The findings indicated that perceived compatibility, perceived convenience, perceived connectedness, perceived cost, perceived behavioral control with perceived usefulness, and perceived ease of use directly and indirectly exerted a significant influence on users’ intention to use SHSs.
Practical health indicator construction methodology for bearing ensemble remaining useful life prediction with ISOMAP-DE and ELM-WPHM

To improve the accuracy of our previous bearing ensemble remaining useful life (RUL) prediction model using the genetic algorithm (GA), support vector regression, and the Weibull proportional hazard model (WPHM) (see Qiu et al (2020 Measurement 150 107097)), we proposed a more practical health indicator (HI) construction methodology for bearing ensemble RUL prediction. A weighted coefficient determination method for four prognostic metrics-monotonicity, robustness, trendability, and consistency-was proposed to select sensitive health features accurately using the analytic hierarchy process. The selected sensitive health features were fused through isometric feature mapping (ISOMAP), and differential evolution (DE) was employed to replace GA for computing the optimal weight coefficients of each input fused feature. One-dimensional HI was constructed by multiplying each input fused feature with the corresponding optimal weight coefficient, and RUL prediction was implemented through an extreme learning machine (ELM) and WPHM. The accuracy and effectiveness of the proposed method were validated by a bearing experiment. The results show that HI construction with ISOMAP-DE has achieved the best performance, and the proposed ELM-WPHM model is compared with BP-WPHM, SVM-WPHM, LSTM-WPHM, and DLSTM-WPHM in terms of RMSE criteria. The minimum error and training time appear in ELM-WPHM, indicating the superiority of the proposed bearing ensemble RUL prediction model.
Measuring Agility- A Validity Study on Tools Measuring The Agility Level of Software Development Teams

Context: In the past two decades, an increasing number of software development teams have been transitioning to agile. As a result, a need has emerged for measuring how agile these teams are. To satisfy this need, many researchers have created their own agile measurement tools. However, none of the tools managed to provide a substantial solution. Objective: Many tools have been created for measuring the agility of software development teams, thus creating a saturation in the field. Three tools were selected in order to validate whether they will yield similar results. These tools were the Perceptive Agile Measurement (PAM), the Team Agility Assessment (TAA) and the Objectives Principles Strategies (OPS). Method: The surveys for the three tools were given to the four software development teams of Company A. The survey questions were grouped into agile practices which were checked for correlation in order to establish convergent validity. In addition, we checked whether the questions identified to be the same among the tools would would be given the same replies by the respondents. Moreover, the coverage of agile practices was analysed by checking which tool covers more agile practices. The results were used to see whether the three tools yield similar results. Results: The correlations of the data gathered were very few and very low. As a result, convergent validity could not be established. In addition, the questions which were identified as the same among the tools did not have the same answers from the respondents. Moreover, Objectives Principles Strategies (OPS) was the tool covering the most agile practices. All the above provide evidence that the three tools do not yield similar results. Conclusion: We conclude that the area of measuring agility is still fertile and more work needs to be done. Based on the various agile practices covered by each tool, we believe that not all tools are applicable to every team but they should be selected on the basis of how a team has transitioned to agile. This study has set a milestone in the area and pinpoints the need for a better way to measure agility.
Higher dietary diversity as a protective factor against depression among older adults in China: a cross-sectional study.

BACKGROUND Evidence suggests that poor mental health (MH) is a risk factor for the health of older adults. Dietary diversity is considered to be related to healthy aging. However, the relationship between diet and MH is still unclear. Therefore, the purpose of this study was to investigate the relationship between dietary diversity score (DDS) and anxiety and depression among centenarians and their offspring and spouses. METHODS Evidence suggests that poor mental health (MH) is a risk factor for the health of older adults. Dietary diversity is considered to be related to healthy aging. However, the relationship between diet and MH is still unclear. Therefore, the purpose of this study was to investigate the relationship between dietary diversity score (DDS) and anxiety and depression among centenarians and their offspring and spouses. RESULTS Among the 288 older adults, 12.8% reported symptoms of depression, and 8.7% reported anxiety. People with a lower dietary diversity had higher rates of anxiety and depression. After controlling for age, place of residence, economic status, alcohol drinking, and physical activity, a lower DDS was found to be a risk factor for depressive symptoms [odds ratio (OR): 2.237; 95% confidence interval (CI): 1.009-4.959; P=0.048]. DDS was negatively correlated with depression score in older adults (r=-0.224; P<0.001), especially offspring and their spouses (r=-0.275; P<0.001). However, no significant relationship was observed between DDS and anxiety. In addition, eating legumes (OR: 0.415; 95% CI: 0.188-0.920; P=0.030) and nuts (OR: 0.255; 95% CI: 0.116-0.561; P=0.001) at least once a week can act as protective factors for depression. Eating nuts (OR: 0.405; 95% CI: 0.168-0.978; P=0.044) and meat (OR: 0.396, 95% CI: 0.161-0.975; P=0.044) at least once a week can act as protective factors for anxiety. CONCLUSIONS These results suggest an association between low dietary diversity and a higher incidence of mental disorders. Further, the possibility of reverse causality cannot be ruled out. It is necessary to conduct further prospective studies.
Cellular and Synaptic Diversity of Layer 2-3 Pyramidal Neurons in Human Individuals

Understanding the functional principles of the human brain requires deep insight into the neuronal and network physiology. To what extent such principles of cellular physiology and synaptic interactions are common across different human individuals is unknown. We characterized the physiology of ~1200 pyramidal neurons and ~1400 monosynaptic connections using advanced multineuron patch-clamp recordings in slices from human temporal cortex. To disentangle within and between individual sources of heterogeneity, we recorded up to 100 neurons per single subject. We found that neuronal, but not synaptic physiology varied with laminar depth. Connection probability was ~15% throughout layer 2-3. Synaptic amplitudes exhibited heavy-tailed distributions with an inverse power law relationship to short term plasticity. Neurons could be classified into four functional subtypes. These general principles of microcircuit physiology were common across individuals. Our study advances the understanding of human neuron and synaptic diversity from an individual and phenotypic perspective.
Tracing platform for infrared laser atmospheric communication between warships

The "infrared laser atmospheric communication between warships" mainly solves the problems of secrecy and real-time communication in modern warfare condition. Concerning infrared laser atmospheric communication, the primary problem we should solve is how to acquire, point, and trace an object (shorted for APT) using the optical systems on warships. Therefore, a suitable platform is necessary. The platform is proposed in this paper, which includes the platform's general design framework and principle, the acquisition and tracing algorithm of optical signals, and technical targets. The algorithm is simple and practical. The design of the platform is practically significant for more research in infrared laser atmospheric communication system.
Development of Floating Offshore Wind Turbine and the Mooring System

The offshore wind turbine, especially the floating offshore wind turbine in the deep sea is a perspective technology in the context of increasing energy demands. Mooring system, as an important unit of the floating offshore wind turbine is emphasized. The methods of in-situ test and the laboratory experimental tests are reviewed. Some new testing methods are discussed. The most commonly used anchor systems are explored. The paper aims to present some future research work that is important for the development of the floating offshore wind turbine technology.
Development of Ultrathin Niobium Nitride and Niobium Titanium Nitride Films for THz Hot-Electron Bolometers

The main focus of this work is the development of ultrathin NbN and NbTiN films. A reproducible and reliable deposition process for ultrathin NbN and NbTiN films for the use in phonon-cooled HEB devices was established. The ultrathin films were deposited on silicon (Si) substrates and on 2µm Si3N4 membranes by DC reactive magnetron sputtering. A method for the precise control of the nitrogen partial pressure by monitoring the target voltage has been introduced to deposit high quality, ultrathin NbN (3-4nm, Tc=8.5 K) and NbTiN (4-5nm, Tc=8K) films. Substrate heating of at least 600°C during the deposition is essential for the fabrication of ultrathin NbN and NbTiN films on Si substrates and Si3N4 membranes. The fabrication process required for HEB devices to be used in a quasi-optical mixer was developed. The ultrathin film was patterned by electron beam lithography (EBL), resulting in bolometer devices that measure areas of about 0.4 µm x 4 µm. The nature of the contact determines the interface transparency between the bolometer and the contact structure. Different cleaning processes have been performed and the influence on the contact resistance has been instigated. A better interface transparency gives less RF losses and could improve the HEB sensitivity and local oscillator (LO) requirement. A better control of the interface transparency also leads to a better reproducibility in values of the normal state resistance of the HEB devices. Heterodyne measurements were performed at 0.8 THz and 1.6 THz. For the NbTiN HEB devices, the double sideband (DSB) receiver noise temperature at 0.8 THz was found to be 2500 K for at 1.2 GHz IF. The main problem with HEB mixers is the limitation in the IF bandwidth. The measured noise bandwidth was about 1.5 GHz. The DSB receiver noise temperature at 1.6 THz LO frequency measured at Chalmers University, Sweden, was found to be 1600 K at 1.5 GHz IF. This result shows that the noise of these NbTiN HEB devices is comparable with the NbN HEB mixers fabricated at the Chalmers University. For the NbN HEB devices the DSB receiver noise temperature Trec was 1344 K at 0.8 THz with an absorbed LO power of 55 nW, estimated using the isothermal method. This receiver noise temperature is higher than the state-of-the-art receiver noise temperature at this frequency. This is possibly due to the losses in the optics. It was not possible to determine the noise bandwidth of this device, because the noise temperature did not increase by the factor of two in the bandwidth of the isolator. But the noise bandwidth is estimated to be about than 1.8 GHz. Although the true bandwidth of the NbTiN and NbN HEB devices could only be measured with an appropriate IF system, the combination of these results show that NbTiN is possibly inferior in bandwidth to NbN used for the HEB fabrication.
Global Snow Depth Retrieval From Passive Microwave Brightness Temperature With Machine Learning Approach

Current global snow retrieval algorithms based on spaceborne microwave measurements inherit noticeable biases and uncertainties regarding spatial distribution and temporal variations. In this article, we present an improved spatiotemporally dynamic global snow depth retrieval algorithm to account for the heterogeneity of snowpacks in different seasons worldwide. The proposed model adopts nonlinear machine learning to retrieve snow depths from passive microwave measurements and other auxiliary information. We indirectly characterized the variation in snow grain size using the daily profiles of the temperature gradient within the snowpack. In addition, a zoning and multitemporal modeling strategy was employed to reduce the bias and uncertainty caused by snow heterogeneity across different ecoregions and seasons. The proposed model was implemented to retrieve the global daily snow depth from 2001 to 2010. The results were validated by <italic>in situ</italic> observations and compared with the NASA Advanced Microwave Scanning Radiometer for EOS (AMSR-E) snow water equivalent product (AE_DySno). Satisfactory accuracy was achieved for different ecoregions with regard to daily, monthly, and yearly validations (the root-mean-square error (RMSE) varied from ~7.5 to ~12 cm; the Pearson correlation coefficient <inline-formula> <tex-math notation="LaTeX">$R$ </tex-math></inline-formula> ranged from 0.75 to 0.85). The results of ten trials indicated the promising stability of the proposed model in different ecoregions with small variations in RMSE and <inline-formula> <tex-math notation="LaTeX">$R$ </tex-math></inline-formula> values. Compared with the AE_DySno products, the estimation results did not exhibit the overestimation problem and provided snow depth patterns with greater spatial heterogeneity, showing RMSEs ~5 cm lower and <inline-formula> <tex-math notation="LaTeX">$R$ </tex-math></inline-formula> values ~0.3 higher than those of the AE_DySno products.
The Effectiveness of a Virtual Role-play Environment as a Preparation Activity for Story Writing

Improvisational dramatic role-play activities are used in classrooms to encourage children to explore the feelings of the characters in a story. Roleplay exercises can give a story personal significance to each child, and an insight and understanding of the characters which is reflected in stories written afterwards. The thesis describes the development of a virtual environment designed for similar dramatic role-play exercises. The thesis then investigates its effectiveness as a preparation activity for writing stories. It examines the effects the virtual role-play environment has on the characterisation in children’s imaginative writing. It also investigates the social interactions which children engage in and the moral decisions they make during the role-play; and the motivational effects of the virtual roleplay environment. The virtual role-play environment is based on a commercial computer game. Two children and one role-play leader interact with each other in a perceptually realistic virtual world. Each role-player controls an avatar in order to move around this graphical world, and improvise by sending and receiving typed messages. The high quality graphics, sounds and music contribute to the users’ feelings of perceptual presence while the communication between role-players promotes feelings of social presence. The role-players’ emotional engagement with the other characters and the conflict within the adventure encourages them to experience self presence. The virtual role-play environment was evaluated in a field study with sixty children aged between ten and twelve years. The characterisation in stories written after using the virtual role-play environment was compared to the characterisation in stories written under normal classroom circumstances. The stories were compared using a new, fine-grained analysis scheme for assessing children’s writing. The main result is that the stories written after the virtual role-play contained more dialogue and more indications of relationships between the characters than normal classroom stories. Analysis of the typed communication exchanged between the role-players during the game shows that the role-players formed relationships with the other characters. They also made judgements about the characters’ personalities and to a lesser extent expressed emotional involvement during the game. They made moral decisions and could back up their decisions with reasons. Expert evaluation supports the view that the virtual role-play environment is particularly beneficial to children with low literacy standards. Finally, it also benefits children with low literacy motivation and little interest in school work.