Miracle-dz/UniFAR-FTUs huggingface dataset:
A Study of Oscillator Jitter Due to Supply and Substrate Noise

This paper investigates the timing jitter of single-ended and differential CMOS ring oscillators due to supply and substrate noise. We calculate the jitter resulting from supply and substrate noise, show that the concept of frequency modulation can be applied, and derive relationships that express different types of jitter in terms of the sensitivity of the oscillation frequency to the supply or substrate voltage. Using examples based on measured results, we show that thermal jitter is typically negligible compared to supply- and substrate-induced jitter in high-speed digital systems. We also discuss the dependence of the jitter of differential CMOS ring oscillators on transistor gate width, power consumption, and the number of stages
Wireless sensor network for underwater communication

Although, attenuation in Electromagnetic (EM) wave propagation underwater is high at high frequencies, the theory predicts that propagation is possible at some useful distance in the lower Industrial, Scientific and Medical (ISM) band. The aim of this paper is to study the feasibility of using radio transceivers underwater for developing a Wireless Sensor Network (WSN) that could be used in various applications. Experiments with low cost wireless sensor transceivers operating at a frequency of 2.4GHz ISM band were carried out and data was successfully wirelessly collected underwater. Wireless Sensor Networks is proposed for increasing communication range. Furthermore, antennas experiments shown that monopole outperformed and will be selected for further stage in underwater communication systems. (6 pages)
Optimal coordination of directional overcurrent relays in interconnected power systems

The authors present a new methodology based upon the principles of optimization theory, to treat the problem of optimal coordination of directional overcurrent relays in interconnected power systems. With the application of the proposed technique, this coordination problem is stated as a parameter optimization problem, which in general, is of a large dimension, especially when many different system configurations and perturbations are to be considered. Several optimization procedures, including direct methods and decomposition techniques, for solving this large scale coordination problem are described, and results of optimally coordinating directional overcurrent relays in power systems with up to 30 buses are presented. >
Simulator for the reproduction of "Low Sonic Boom"-signatures

Supersonic aircraft produce a sonic boom when flying faster than the speed of sound. In order to rule out detrimental effects for inhabitants of overflown areas, civil supersonic flights (like the Concorde) were allowed over water only. Due to progress in aircraft design, the super sonic boom may be reduced considerably in the future. Such “Low Sonic Boom”-signatures will be considerably quieter and sound completely different compared to conventional sonic booms [1]. Although a lot of research was carried out to better understand the effects of classical sonic boom on humans, the sensation and subjective response of humans to future “Low Sonic Boom”-signatures is currently under investigation [2, 3]. A level of acceptability is not available at the moment and it is the question how to define it such that the effects on humans are reflected [1, 4]. For an assessment of human responses to “Low Sonic Boom “-signatures, a Sonic-Boom simulator has been built at the University of Oldenburg in the framework of the EU-project RUMBLE [5]. Another simulator, which is used for a sleep study in the RUMBLE project, has been built by the Institute Jean Le Rond d’Alembert at the Sorbonne University in Paris [6].
Near fields evaluated with the wave concept iterative procedure method for an E‐polarisation plane wave scattered by cylindrical strips

The wave concept iterative procedure (WCIP), already improved for planar circuits, is developed in this paper for cylindrical structures. The WCIP method has been applied with success to the scattering of an E‐polarisation plane wave on cylindrical strips. The results are in good agreement with previous works in the literature, and the calculation time involved is quite reasonable. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 403–406, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11074
Determining Fan Performance Using FANS: An Investigation of Performance Impacts

Emission rates of gaseous pollutants from intensive livestock housing are obtained as the product of gas concentration and the ventilation rate. Much effort has been expended developing methods to measure gas and particle concentrations; however accurate in-situ air flow measurements have always been particularly problematic. A Fan Assessment Numeration System (FANS) can be used in the livestock houses to obtain an in-situ calibration of each fan in its exact configuration including shutters, louvers, and discharge cones. An evaluation of the typical mode of use of the FANS to determine the fan performance characteristic for fans between 450- and 1290-mm diameter is reported. The FANS is placed directly in front of the fan to be tested, sealed to minimize air leakage and a single measurement taken at each static pressure is reported. The determination of fan airflow with FANS is very repeatable (within 0.26% of nominal reading), indicating that replicated tests are not required. There was no 'penalty' associated with the FANS when testing fans with diameters of 915 mm or less, or 1220-mm diameter fans with capacities of less than 34,000 m3 h-1. Based on limited testing, a significant 'penalty' could exist for fans with diameters larger than 1220 mm or with higher performance characteristics. When using a FANS to determine the performance characteristic of a fan with a diameter greater than 1220 mm, the 'penalty' should be determined by evaluation in a fan test facility. For fans significantly smaller than the FANS unit, test results suggest that no transition is needed.
Market trading model before the distribution network under the participation of multi-interest parties at the early stage of marketization

Along with the promotion of the electricity sales side market reform, load-side resources, including new energy sources, gradually participate in the distribution network electricity sales market. At the early stage of marketization, in order to give full participation rights to all parties involved in the market and to take into account the responsibility of distribution network operators to ensure the safety and quality of power supply, we propose a distribution network day-ahead market transaction model with the participation of multiple interests at the early stage of marketization. Firstly, a tripartite interest model including distribution network operators, distributed power supply operators and load aggregators is established in the distribution network, and all three parties take time-of-use tariff as the game strategy; secondly, a Pay as Bid (PAB) model is combined with the tripartite interest model to establish a market settlement model, and the three parties can modify their own offers according to the available information in the market settlement process. Finally, the Nash-Q method is used to solve the model. The results show that, compared with the traditional constant/time-sharing tariff, the model can ensure the safe and reliable power supply to customers while stimulating the active participation of new energy and other market players in the market, and can also increase the contribution of new energy to the power balance and reduce the risk of new energy consumption in the distribution network.
Mitigating the irreversible deformation with pressure in silicon/porous silicon composite membranes

Due to the low Young's Modulus of porous silicon (PS), Si/PS composite membranes - where the silicon membrane is converted into PS to a certain depth - deform more than silicon membranes and hence MEMS pressure sensors with composite membranes have higher sensitivity. But the Si/PS composite membranes exhibit a smaller range of linear response with applied pressure than silicon membranes with the linear range being less for Si/microPS as compared to Si/macroPS composite membranes. In addition, while the composite membrane deformation saturates at high pressures like silicon membranes, the deformation is irreversible unlike that seen with silicon membranes within reasonable limits. With the possibility that the irreversible deformation could be due to stiction force between the collapsed pore walls at high pressure, we investigate the effect of formation of self-assembled monolayer (SAM) antistiction coating on the performance of Si/PS composite membranes.
Determination of the steady state of an oscillator by a combined time-frequency method

A novel method for the computation of the steady state of nonlinear oscillators including distributed elements is presented which exploits advantages of both time-domain and frequency-domain simulation. The oscillator network is divided into a linear subnetwork described by a hybrid matrix in the frequency domain and a nonlinear differential equation solved in the time domain. The periodic steady state of the oscillator is shown to be equivalent to the solution of a boundary value problem, where the boundary conditions are given at a set of points along the time axis. For the solution of the boundary value problem the multiple shooting algorithm is applied. It is shown that the bandwidth in the nonlinear subnetwork can be chosen arbitrarily high regardless of the number of harmonics at the ports connecting the subnetworks. In order to demonstrate the feasibility of the method and to discuss the error mechanisms it is applied to two examples: a Clapp oscillator including a piecewise-linear characteristic and an integrated GaAs MESFET oscillator at 10.7 GHz. >
Improvement of output voltage control performance for low speed operation of matrix converter

The matrix converter (MxC) is an ac-to-ac conversion device that can generate variable frequency, variable voltage output. Nine bidirectional switches of MxC allow PWM control of input currents and output voltages. PWM switching needs "switch commutations" from one switch to another. During the switch commutations, however, unwanted voltage error occurs like a dead time effect in voltage source inverter (VSI). When PWM pulse widths are narrower than the time for completing a commutation sequence, voltage error rapidly increases. In the low speed range, PWM pulses become narrower and voltage distortions become larger due to incomplete commutations. Moreover these errors are critical in the low speed operation because system is sensitive to even a small voltage error. In this paper, a new PWM strategy is proposed for improving voltage control performance in the low speed range. Based on the input and output voltage information, PWM pulse widths are controlled to avoid incomplete commutation. The feasibility of the proposed method is proved through simulation and experimental results.
Heterogeneity of Students’ Mathematical Critical Thinking Ability Re-viewed from Education Levels: A Meta-Analysis

Study of meta-analysis by selecting the random effect model was employed to investigate and examine students’ education level predicted as one of the causative factors of the heterogeneity of mathematical critical thinking ability (MCTA) through problem-based learning (PBL). Search engines such as Google Scholar and Semantic Scholar were used to find thirty journal or proceeding articles published in 2011 – 2021 and indexed by Scopus, Sinta, and Web of Science. The Z and Q Cochrane test were used to analyze the data. The results revealed that education level was one of the significant factors causing the heterogeneity of students’ MCTA through PBL. Therefore, mathematics teachers or lecturers should minimize the gap by improving the learning quality through PBL in education level in which students’ MCTA was still low.
Experimental performance of a partially-glazed Modified Trombe Wall

SYNOPSIS The paper investigates the performance of a new configuration of Modified Trombe Wall named the Partially-Glazed Modified Trombe Wall (PG-MTW), which aims to decrease heat accumulation, induce higher natural ventilation and provide daylight for housing. The PG-MTW is composed of a masonry wall which includes transparent material, air gap, and a combination of aluminum-foiled gypsum board and acrylic panel. Two PG-MTW units were built: the first uses commercial glass block whereas the other uses double glazing block. The surface area of each unit was about 2 m2. They were integrated into the south-facing wall of a small house of volume about 25 m3. The performance of PG-MTW units were compared experimentally to a conventional Modified Trombe Wall (MTW) of the same surface area installed close to the two PG-MTW units. To this end, the room was divided into three compartments corresponding to each wall configuration using plywood panels. The results of the study showed that the PG-MTW with glass block of 0.36 m2 surface area (3 rows) induced the highest air flow rate and daylight, about 60–80 m3 h−1 and 350–550 lux respectively. Such airflow rate is about 30% higher than that induced by the MTW. The increase in room temperature of the PG-MTW compartment was not significant and did not exceed 1°C when compared to the MTW compartment. The indoor temperature is 3–4°C below ambient which is extremely interesting. In conclusion, a one row glazed PG-MTW which provides sufficient daylight and ventilation rate is most economically viable for integration into building design.
A Deep Convolutional Neural Network-Based Multi-Class Image Classification for Automatic Wafer Map Failure Recognition in Semiconductor Manufacturing

Wafer maps provide engineers with important information about the root causes of failures during the semiconductor manufacturing process. Through the efficient recognition of the wafer map failure pattern type, the semiconductor manufacturing process and its product performance can be improved, as well as reducing the product cost. Therefore, this paper proposes an accurate model for the automatic recognition of wafer map failure types using a deep learning-based convolutional neural network (DCNN). For this experiment, we use WM811K, which is an open-source real-time wafer map dataset containing wafer map images of nine failure classes. Our research contents can be briefly summarized as follows. First, we use random sampling to extract 500 images from each class of the original image dataset. Then we propose a deep convolutional neural network model to generate a multi-class classification model. Lastly, we evaluate the performance of the proposed prediction model and compare it with three other popular machine learning-based models—logistic regression, random forest, and gradient boosted decision trees—and several well-known deep learning models—VGGNet, ResNet, and EfficientNet. Consequently, the comprehensive analysis showed that the performance of the proposed DCNN model outperformed those of other popular machine learning and deep learning-based prediction models.
THE EFFECT OF A COMMON COACHING CUE ON BODY KINEMATICS IN THE TENNIS SERVE

The objective of this study was to quantify the kinematic changes promoted by instructing players to implement a common coaching constraint, an arabesque finish position, in the tennis serve. A 10 camera 500 Hz 3D VICON MX motion analysis system recorded the service action of 8 elite junior players as they performed 3 normal serves and 3 serves with an arabesque finish. The arabesque finish promoted greater frontal plane trunk range of motion and angular velocity (shoulder over shoulder rotation) as well as increased leg drive; variables established as important in the development of serve speed. Instructing players to finish in an arabesque position can therefore be considered an effective way to elicit the desired kinematic change, and is consequently an effective instructional cue.
EventSKG: a Framework for Public Safety Event Knowledge Graph Construction using Social Network Data

The social network data contain a great deal of unstructured knowledge which is useful to understand public safety incidents. The structure of social network data, such as news, statistical statements, social network messages, government reports and so on, is complicated. So, it is di ﬃ cult to obtain knowledge from social network data because social network data are multi-source heterogeneous. Knowledge graph is one of the e ﬀ ective tools for processing such multi-source heterogeneous data. However, the previous works didn ’ t notice the particularity of entities in public safety incidents and the linguistic characteristics of Chinese. Moreover, previous works on event knowledge graph mainly focus on single data source which make it is di ﬃ cult to process multi-source social network data. Thus, the construction of a public safety incident knowledge graph using complex social network data in the Chinese environment is still a di ﬃ cult problem. In this paper, a framework for public safety event knowledge graph construction towards Chinese social network data, namely EventSKG, is proposed. EventSKG contains a direct mapping module for knowledge extraction from structured data, an Event-Speciﬁc FLAT model for entity extraction from unstructured data, a manual template for relation extraction from unstructured data, and an integration surgery to connect the triples obtained from di ﬀ erent data source. An event knowledge graph related to the ﬂood disaster in 2020 in China is constructed via EventSKG framework, which contains 14397 entities and 43168 relations. The event knowledge graph will form associations around network data from various sources for the same event, not only enabling humans to better understand the event, but also providing basic knowledge base for future intelligent understanding of events
Seismic Site Classification from HVSR Data using the Rayleigh wave ellipticity inversion: A case study in Singapore

Shear wave velocity (Vs) profile is one of the critical geotechnical measurements of soil layers for seismic hazard assessment and liquefaction potential evaluation. Enhancing the effectiveness of in-situ Vs profiling by reducing time and cost is of great interest. For that reason, this study aims at assessing Vs profile generation from a single-station three-component geophone with additional borehole log data for constraining parameter space. Based on multichannel analysis of surface waves (MASW), and microtremor array Measurements (MAM) conducted previously at seven sites located in Bukit Timah Granite, Singapore, this study utilized HVSR signals for Rayleigh wave ellipticity (ellipticity curve) inversion with additional inversion constraint using borehole log data. The resulting Vs profiles and reference Vs profiles from MASW and MAM were quantitatively compared using average Vs of 30 m (Vs30). The profiles generated from ellipticity curve inversion revealed a good agreement with Vs reference profiles. Vs30 based site classification results also indicated a good fit of two test results. Therefore, HVSR measurements for further ellipticity curve inversion, with already available borehole log data for constraint, is considered as a promising cost and time-effective site classification approach.
Tetralin hydrogenation over supported nickel catalysts

An investigation was carried out to study the feasibility of using 5% nickel/alumina catalysts synthesized with different methods and metal precursors for the hydrogenation of tetralin. The catalysts were characterized using atomic absorption spectroscopy, thermogravimetric analysis, X-ray powder diffraction, X-ray photoelectron spectroscopy (XPS), hydrogen chemisorption, and surface area and pore volume analyses. The catalysts were tested in a continuous-flow, fixed-bed, reactor using solvent-free tetralin feed under the conditions of 5 barg hydrogen, 210 °C, a weight hourly space velocity of 5 h–1, and a H2/HC ratio of 7.5 (gas hourly space velocity, 4220 h–1). These reaction conditions were much milder than the ones reported in literature but showed considerably higher catalytic activity even with low metal loadings. The study indicated that the product’s isomer ratio was governed by kinetics. Indeed, a remarkable difference was observed in the selectivity for the catalysts synthesized with different metal precursors in relation to cis/trans decalin ratios, where catalysts derived from nickel carbonate showed higher selectivity to cis-decalin compared to catalysts prepared from nickel nitrate. It was speculated that the dispersion and particle size played an important role in this variance, as suggested by XPS and hydrogen chemisorption. It was also found that this change in selectivity was not related to conversion. Similarly, different deactivation patterns were observed over these catalysts.
Evaluation of Variability of Watershed Hydrological Partitioning: The Case of Mormora River, South Eastern Ethiopia

Water resources management in a watershed requires the quantification of the water potential. This is usually achieved by the estimation of the hydrological and meteorological characteristics of the watershed using observed data to carry out statistical estimates. Hydrological and meteorological data for the Mormora watershed were collected to analyze the hydrologic partitioning behavior of the watershed. The available data include a daily record of stream flow data from 1990 to 2007, a thirty years (1983-2012) monthly average precipitation at meteorological stations with in or near the watershed, and a 31 years (1981-2011) maximum and minimum temperature data at the same meteorological stations. The missed data of stream flow was in filled by simple regression method, and an outlier test, F-test, and T-test was computed for the data to check its quality. Necessary information about the geography of the area was obtained from LuLc, Soil, River, DEM, and climate map of Ethiopia, using ArcGIS software. Daily stream flow was converted to monthly scale and was partitioned to base flow and direct runoff using WHAT software. The maximum and minimum temperature data were used to estimate the potential evapotranspiration of the watershed using the 1985 Hargreaves equation. Average areal rainfall was estimated by Thiessen polygon method using ArcGIS software. Following these, the annual water balance of the watershed was analyzed using ‎water ‎balance ‎theory. The inter-annual variability of the water balance, and hydrologic indices were analyzed. The relationship between climate and landscape is also studied. The result shows that the Horton Index and Humidity Index of the watershed are relatively constant with a coefficient‎ of‎ variation, ‎Cv≤0.127. ‎Finally‎conclusions‎are‎drawn,‎and‎the‎difficulties‎in‎ making hydrological and meteorological estimates in a watershed with little or no data are highlighted.