Miracle-dz/UniFAR-FTUs huggingface dataset:
Determining the relative effectiveness of islanding detection methods using phase criteria and nondetection zones

Islanding of a utility-interactive photovoltaic (UIPV) system occurs if the UIPV system continues to power a section of the utility system after that section has been disconnected from the utility source. Since islanding creates hazards for personnel and equipment, UIPV systems are required to detect and prevent it. It is desirable to have a simplified method of determining which islanding detection methods (IDMs) are most effective. In this paper, a previously described method for finding the nondetection zones (NDZs) of IDMs is experimentally verified. This method is used to determine the NDZs of several common IDMs. These results indicate that, of the IDMs discussed in this paper: (1) Sandia Frequency Shift (SFS) is most effective; and (2) the worst-case loads are low-power loads that are near resonance at the line frequency and have a large capacitance and small inductance (a high value of the quality factor Q).
Design Thinking: Notes on Its Nature and Use

Problems induced by continuing population growth and its pressure on resources and environment have reached a stage where serious concern must be given to the processes of decision making being used by governmental and institutional leaders. Science thinking is frequently unheard or unheeded and design thinking is not engaged at all. Design thinking, as a complement to science thinking, embodies a wide range of creative characteristics as well as a number of other special qualities of distinct value to decision makers. In advisory roles, properly prepared design professionals could make substantial contributions to a process now dominated by political and economic views. This paper examines the nature of design thinking as it differs from other ways of thinking. A model for comparing fi elds is introduced and a number of characteristics of creative individuals in general and designers in particular are presented. Preparing designers for participation in policy planning will be a challenge for design education. Meeting the challenge will require new understanding, an extended range of design tools, and concerted support from the design professions to demonstrate the value of design thinking to decision making at the highest levels.
Point-Cloud-Based Comparison between Construction Schedule and As-Built Progress: Long-Range Three-Dimensional Laser Scanner’s Approach

This research compares the work process at a construction site with the original construction schedule using point-cloud records that were retrieved using a long-range 3D laser scanner. The comparison was used to quantify the differences as a reference for the verification and modification of the original building design. This study compared 4D computer models with 3D clouds of a campus building. The differences could easily be identified from the perspectives and elevations of different views. To determine the degree of progress more precisely, a slice of clouds was defined to show the differences when compared with a cross section of a computer model. The format of the point cloud provided a new way to inspect construction progress.
The Analysis Model of Torsion Behavior for Octopus-Inspired Robotic Arm

Abstract. Octopus can achieve a variety of dexterous movements at any point along its arm, such as elongating, shorting, bending, twisting, or changing the stiffness, which have been considered as an interesting model of inspiration in robotics. Among the complex behaviors, the torsion behavior is important because it provide extra degree of freedom of movement, like twisting. This paper proposed a detailed dynamic model that describes the torsion behavior of octopus arm, based on torsional vibration theory. The initial conditions and boundary conditions that explained the main features of the torsion behaviors of octopus arm are acknowledged. The mode shapes, which describe the torsional vibration frequency and type, were solved as the sum of the time and the distance from the fixed end to where the deformation happened. By comparing the mode shapes results solved by the method proposed in this paper and by FEA Soft ANSYS, the effectiveness of this method has been verified. Further torsional stresses and torsion angles of deformation and vibrations on rod can be expressed as the functions of the mode shapes and the external torque exerted on one end of the rod. This method can be applied to calculate the kinematics results of the torsion behaviors and the appropriate activations related for continuum robotic manipulators inspired by octopus arm.
AC/DC power factor correction using interleaved boost and Cuk converters

The interleaving of modules in AC/DC switch mode power supply designs has been extended to the Cuk converter. The suitability of this topology has been compared with that of a more established boost converter. Simulation results have been used to determine whether the greater complexity of the Cuk converter outweighs its performance advantage over the boost converter. The Cuk converter offers incorporation of isolation without extra active devices and so is attractive for mains operated equipment and reduces overall system complexity in such cases. The inclusion of isolation opens up the possibility of having different input and output interleaving methods. For mains input and low voltage output it is possible to use series interleaving of the input and parallel interleaving of the output.
A Novel Accelerometer Using Silicon Micromachined Cantilever Supported Optical Grid And Pin Protodetector

SUMMARY An optical accelerometer has been designed and fabricated using the conventional KOH etching of silicon wafer. The seismic mass acts as an optical shutter which consists! of evenly spaced vertically etched slots. This shutter is suspended by two cantilever beams and controls the aniount of light from a red LED reaching a PIN photodetector. The accelerometer measured 3x4 mm and its amplified output varies linearly from - 3.6 V to + 3.6 V for static accelerations from - 84 g to + 84 g. The dynamic response of the device shows a flat response up to 700Hz and peaks at a resonant frequency of 3.2 kHz.
Plant-wide predictive control for a thermal power plant based on a physical plant model

A constrained nonlinear, physical model-based, predictive control (NPMPC) strategy is developed for improved plant-wide control of a thermal power plant. The strategy makes use of successive linearisation and recursive state estimation using extended Kalman filtering to obtain a linear state-space model. The linear model and a quadratic programming routine are used to design a constrained long-range predictive controller. One special feature is the careful selection of a specific set of plant model parameters for online estimation, to account for time-varying system characteristics resulting from major system disturbances and ageing. These parameters act as nonstationary stochastic states and help to provide sufficient degrees-of-freedom to obtain unbiased estimates of controlled outputs. A 14th order nonlinear plant model, simulating the dominant characteristics of a 200 MW oil-fired power plant has been used to test the NPMPC algorithm. The results compare favourably to those obtained with the state-space GPC method designed under similar conditions.
The cadaveric study of lumbricals of hand in 100 specimens

This study on the lumbricals was performed on 50 (100 specimens of human hands) embalmed donated cadavers (40 males & 10 females) in the department of Anatomy of K.J. Somaiya Medical College, Sion, Mumbai, India. The dissection of the palm was done meticulously to expose all the tendons of flexor digitorum superficialis and flexor digitorum profundus. The proximal and distal attachments of the lumbricals were seen. The arterial pattern of upper limb was also observed. The photographs of the variations were taken for proper documentation. Out of 100 specimens the variations were observed in 22 specimens. Out of 22 specimens in 7 specimens two bellies of second lumbrical were observed originating from the radial side of the tendon of both flexor digitorum profundus and flexor digitorum superficialis going to the middle finger, in 5 specimens an accessory belly of first lumbrical was observed originating from the radial side of the tendon of the flexor digitorum profundus going to the index finger and in remaining 10 specimens the bipennate second lumbrical originating from the ulnar side of the tendon of the flexor digitorum profundus going to the index finger and radial side of the tendon of the flexor digitorum profundus going to the middle finger was observed. There were no associated neuro vascular variations seen. All the variations were unilateral.
CÁLCULO Y DISEÑO DE LA PALA (EHECAMANI) DE UN AEROGENERADOR TESIS PARA OBTENER EL GRADO DE

V Abstract The following work contains the design of a Horizontal axis wind turbine 3-blade rotor with a diameter of 4 m. It was through the use of the Strip Theory, which is no more than the application of two methods to estimate aircraft propellers. One of these methods is called Rankine-Froude and the other is the Blade element model. Besides the presentation of theoretical results, a numeric simulation is done using CFD software to obtain the aerodynamic forces for different rotor configurations.
Piezoelectric transformer AC-DC converter over a worldwide range of input voltage by combined PWM and PFM control

An AC-DC power converter using a piezoelectric transformer is presented. A new control method of the combination of PVM and PFM control is used. The AC-DC power converter for worldwide range of input voltage implemented on a printed circuit board is experimentally evaluated and as a result, a good controllability is successfully achieved.
Stratospheric gravity waves excited by a propagating Rossby wave train – A DEEPWAVE Case Study

Stratospheric gravity waves observed during the DEEPWAVE research flight RF25 over the Southern Ocean are analyzed and compared with numerical weather prediction (NWP) model results. The quantitative agreement of the NWP model output and the tropospheric and lower stratospheric observations is remarkable. The high-resolution NWP models are even able to reproduce qualitatively the observed upper stratospheric gravity waves detected by an airborne Rayleigh lidar. The usage of high-resolution ERA5 data – partially capturing the long internal gravity waves – enabled a thorough interpretation of the particular event. Here, the observed and modeled gravity waves are excited by the stratospheric flow past a deep tropopause depression belonging to an eastward propagating Rossby wave train. In the reference frame of the propagating Rossby wave, vertically propagating hydrostatic gravity waves appear stationary; in reality, of course, they are transient and propagate horizontally at the phase speed of the Rossby wave. The subsequent refraction of these transient gravity waves into the polar night jet explains their observed and modeled patchy stratospheric occurrence near 60°S. The combination of both unique airborne observations and high-resolution NWP output provides evidence for the one case investigated in this paper. As the excitation of such gravity waves persists during the quasi-linear propagation phase of the Rossby wave’s life cycle, a hypothesis is formulated that parts of the stratospheric gravity wave belt over the Southern Ocean might be generated by such Rossbywaves trains propagating along the mid-latitude wave guide.
Design and fully digital control of parallel active filters for thyristor rectifiers to comply with IEC-1000-3-2 standards

This paper presents the implementation of a digitally controlled parallel active filter for a thyristor rectifier with inductive load. Using a state-of-the-art digital signal processor (DSP) platform (ADSP21020 and ADMC200), a fully digital control of the system, based on the dead-beat control of inverter currents and space vector modulation, is implemented. The intrinsic calculation delay of the dead-beat algorithm is shown to represent a serious hurdle for the achievement of a satisfactory compensation quality. In particular, meeting the IEC 1000-3-2 standards for class A equipment appears to be quite difficult, especially in the high-frequency range. This paper investigates the effects of the input passive filters and power converter design on the system's performance and describes the implementation of the digital control by means of the specified hardware. Experimental results are finally given to evaluate the achieved performance.
Improved Model Predictive Current Control With Series Structure for PMSM Drives

In order to improve the control performance of conventional finite-control-set model predictive control (FCS-MPC) method and keep the balance between the steady-state performance and switching frequency of the system, this article proposes an improved MPC method based on the conventional MPC method. First, the reference voltage vector of the next control instant is predicted to determine the candidate voltage vectors of the next two control instants. Then, an optimal vector selection way is proposed, in which candidate voltage vectors selected by the reference voltage vector and designed cost function structure in series. Moreover, the selection process of optimal voltage vector from the candidate voltage vectors is analyzed. Finally, the comparison experiments between the conventional FCS-MPC method and the proposed MPC method are conducted. And experimental results show the validity of the proposed control strategy.
Modelling distributed generations in three-phase distribution load flow

The mathematical models of distributed generations (DGs) are integrated into three-phase distribution load flow program to analyse and simulate the penetrations of DGs for distribution systems. DGs can utilise the traditional energy sources such as oil and coal or renewable energy sources such as wind, solar and fuel cell and use rotating generators or converters to transfer energy to power grids. According to the characteristics of output power, DGs can be specified as constant power factor model, constant voltage model or variable reactive power model in the load flow analysis. These three models are all derived and integrated into the proposed load flow method. Test results demonstrate the validity and capability of the proposed method.
Development and Validation of the Iranian Body Image Scale (IBIS)

Background: Body dissatisfaction has been known as an important public health concern which can influence physical and psycho-social health of adolescents. Hence, health professionals need a valid and reliable tool to assess this problem and its related factors in youth. This study aims to develop and assess psychometric properties of an indigenous scale for evaluation of body image and to investigate its association with body weight status among Iranian adolescents.Methods: This study conducted on 857 adolescents who completed the Iranian body image scale (IBIS) and self-reported their body weight and height. Face, content and construct validity methods were used to assess validity of the IBIS. Exploratory factor analysis (EFA) was used to assess construct validity. Moreover, internal consistency of the scale was assessed by calculating Cronbach’s alpha coefficient (α), and test-retest reliability was examined using intra-class correlation coefficient (ICC). To compare the IBIS scores across sex and body weight status groups, the Mann–Whitney and Kruskal-Wallis tests were used, respectively.Results: Mean age and body mass index (BMI) of participants were 16.5±1.1 years and 22.4±4.5 kg/m2, respectively. The EFA showed a 10-factor construct which explained 57% of the variance. The Cronbach’s alpha coefficient for overall items of the scale was 0.896 and ranged from 0.42 to 0.92 for subscales. The test retest reliability result was acceptable for the IBIS (ICC= 0.805). The ICC values ranged from 0.753 to 0.990 for IBIS subscales. The IBIS total score was significantly higher in girls compared to boys (median (Q1-Q3): 32.2 (25.5-43.3) vs. 30.3(24.0-38.0); p<0.001). In girls, the IBIS total score was significantly lower in normal weight girls compared to their overweight (p=0.001), and obese (p=0.001) counterparts. This difference was not observed in boys. Conclusion: These findings support reliability and validity of the IBIS for assessment of body image in Iranian adolescents; this scale can be applied as an appropriate tool for assessment of body image in adolescents in related future studies. Current findings highlight considering body image as an important aspect of intervention programs targeting overweight and obesity in adolescents, specifically girls.
A simple broad-band coherence multiplexed optical access network and its scalability

This paper proposes a novel and simply configured broad-band optical access network that uses coherence multiplexing (CM) and half-duplex bidirectional transmission. It allows the on-demand use of broad bandwidth on existing fiber-to-the-home (FTTH) access lines. The design of the proposed CM network considers degradation factors in CM systems. This paper introduces two analyses. The first one is a numerical simulation to optimize the tradeoff between available user number and fiber dispersion degradation, and the second estimates acceptable access-line loss in the network. These analyses show that 16 users/spl times/100 Mb/s (or 12 users/spl times/155 Mb/s) bandwidth Is possible on a standard single-mode fiber access line whose loss and length are under 9 dB and 10 km (and 7 km), respectively. The feasibility and scalability of the proposed network are verified by an experiment in which eight-channel 155-Mb/s half-duplex optical packet transmission is successfully demonstrated on a 7-km standard fiber access line with bit error rates better than 1/spl times/10/sup -9/. This study shows that the capacity of existing FTTH access lines that employ star couplers can be significantly enhanced.
Reduction of spectral distortion in class D amplifiers by an enhanced pulse width modulation sampling process

An enhanced sampling process which can be used to reduce spectral distortion in the output of digital pulse width modulated class D amplifiers is presented. This process arises from a generalisation of the concepts of natural and uniform sampling and can be adjusted such that the spectra produced by the process can take a number of forms for the same signal. Analytical expressions for the spectra produced by the sampling process are derived for both single and double sided modulation. The performance of the process is assessed by case studies on full bandwidth and bass to midrange audio class D amplifiers. It is shown that at carrier frequencies around 88 kHz in a full bandwidth amplifier and 44 kHz in a bass to midrange amplifier the new sampling process will result in significantly lower distortion when compared with either natural or uniform sampling.
Ultra high frequency (UHF) partial discharge detection for power transformers: Sensitivity check on 800 MVA power transformers and first field experience

Partial discharge (PD) activity in power transformers is often measured during factory acceptance testing. The conventional measurement according to IEC 60270 is usually applied but the direction in the technology leads towards the UHF method. The latter records partial discharge activity in the frequency range between 100 MHz and 2 GHz. This frequency range offers the advantage that suppression of external noise can easily be achieved. There is, however, no direct correlation between the conventional measurement according to IEC 60270 and the UHF method as used at present. This may be one of the reasons why the UHF method is not yet very common, neither during factory acceptance tests nor for condition monitoring of power transformers.
The research tree of the innovation ecosystems

Innovative ecosystems continue to expand in the socio-economic sphere. The relevance and timeliness of the topic of ecosystems, insufficient elaboration of theoretical issues, incomplete methodological validity, high practical significance of the problems of management of the development of innovative ecosystems led to the choice of the purpose of this work: the development of a tree of research of innovative ecosystems. On the basis of the Schumpeter approach to innovation as the fundamental conditions of entrepreneurial activity, a hierarchy of scientific developments concerning the understanding of the essence of ecosystems and their models is built. The conceptual foundations of the ecosystem approach, universal ecosystem models and the typology of stakeholder configurations of the considered type of communities are highlighted.
A Meta Study of Transfer of Training

A Meta study of four empirical studies of simulator training was performed. The empirical studies were performed at a battle tank simulator, a combat vehicle simulator, an active sonar anti-submarine warfare simulator, and at a simulated command and control staff exercise of an international naval mine countermeasures mission. The combined number of participants in the Meta study made use of inferential and causal statistics possible. The results showed higher ratings of motivation/fun and effect on reality than fidelity. This suggests that a simulator can provide both motivating and valuable training even if it does not have very high fidelity. The casual analysis with LISREL provided a model showing that the feeling of involvement in the simulation influences the training in the simulator, which in turn has a positive influence on the transfer of training to real world performance. Since the analysis is based on amalgamated data from different studies with partly different conditions, site specific models may be different.
Thermal aspects of burn-in of high power semiconductor devices

Burn-in systems provide a controlled environment to test semiconductor devices at temperature and voltage extremes. These systems typically contain ovens or environmental chambers with test electronics. A number of thermal issues must be appropriately managed to achieve success. These thermal issues grow more complex as the device power increases. An example is provided of a device mounted on a burn-in board that illustrates thermal resistance measurements and calculations. This example is then extended to illustrate the minimum and maximum die temperatures encountered in a typical test application. This wide temperature spread creates the need for individual temperature control for each device. A number of the most recent advances in high-power burn-in address problems created by increased device power. Techniques using individual thermal control with air-cooled and water-cooled devices are described.
Zero-voltage-ripple rectifiers and DC/DC resonant converters

Class E zero-voltage-ripple (ZVR) rectifiers are introduced. The proposed circuits offer a new means of a significant improvement in suppressing the output voltage ripple compared with their predecessors. Therefore, the size of the output filter can be considerably reduced, the rI/sub rms//sup 2/ conduction power loss in the equivalent series resistance of the filter capacitor can be lowered, aluminum or tantalum electrolytic capacitors may be entirely eliminated, filter capacitors with low capacitances and thereby high self-resonant frequencies can be used, and a faster dynamic response becomes achievable. ZVR is accomplished by reducing the AC component of the current at the input of the output filter. Class E/sup 2/ and Class D-E ZVR resonant DC/DC power converters are derived using the Class E ZVR rectifiers. An experimental prototype of a Class E/sup 2/ 30 W/500 kHz DC/DC converter was built and tested. Its output voltage ripple was as much as 20 times lower than that of the corresponding conventional converter. The new converters are suitable for noise-sensitive high-output-current applications. >