Miracle-dz/UniFAR-FTUs huggingface dataset:
Effect of current waveforms on metal transfer in pulsed gas metal arc welding

With new types of welding power supply based on higher performance power electronic devices and digital control techniques, advanced pulse waveforms can be produced to offer more characteristics that can be fine tuned to optimize the welding process. In this paper, pulsed current waveforms with four basic parameters and six secondary parameters are used to study the effect of waveform parameters on the mode of metal transfer in pulsed gas metal arc welding (GMAW-P). An experimental system is developed to sense, observe and analyse the images of droplet/wire, and the transient data of welding current and arc voltage. Experiments are conducted to study the influence of the ratio of the pulsing-current time to the droplet-detachment time as well as the droplet-detachment current level on the mode of metal transfer. Appropriate sets of welding conditions including pulse waveform and parameters are obtained to achieve the ideal transfer mode of one-droplet-per-pulse in GMAW-P.
The management Perception toward the concept and challenges facing the traditional food in the hotel sector: A research in Luxor city

Traditional foods are an expression of culture, history, and lifestyle of the local people, traditional foods are also often related to local foods referring to the used of specific local ingredients in local production which highly involve the knowledge and expertise of local people. The aim of this research is to examine the factors affect on the spread of traditional food in the tourism areas at Luxor and identify the benefits and challenges of using traditional foods in Luxor hotels One hundred seventy questionnaires were distributed to food & beverage managers and supervisors in five-star hotels in Luxor, one hundred fifty were fully completed and returned with a response rate of 88.2%. The main findings indicated that the majority of respondent give the right definition of traditional food and the respondents indicated they serve to the guest traditional food like Koushary - Kebab Halla - Moulkhia - Rise Khalta - Tamia - Fool Medamis Weka - Aish Shames - Sheesh Kebab - Besara - Thikhna – Fata The researcher suggests taking into consideration the important contribution of foods and beverages in the tourist activity, incorporation of some of the traditional food items is a good idea for the hospitality industry in Egypt.
Adaptive Beamforming for Noncircular Signals

Many manmade signals have nonzero noncircularity coefficients such as those used in AM, BPSK, and ASK systems. They are called noncircular signals which have coexisted moment and conjugate moment at the second-order. This redundancy is herein exploited to derive a blind scheme for source separation and classification based on the NonCircularity REstoral (NCRE4) filtering. The present blind scheme has three major advantages: 1) involves only the second-order statistics (SOS) and has a faster convergence speed than the traditional high-order statistics (HOS) methods; and 2) does not require any a prioriknowledge about the content and/or direction of the signal-of-interest (SOI).
Analysis and performance of an ironless stator axial flux PM machine

This paper presents the analysis, design and performance of an axial flux permanent magnet (AFPM) machine with an ironless stator. The topology has a large airgap length and zero core losses. A machine model that uses both lumped magnetic circuit and finite element method results is used with a multi-variable optimization algorithm to obtain the optimum machine dimensions. Special attention is given to the magnet interpolar gap to ensure a certain minimum plateau width for brushless DC operation. The large airgap length allows several approximations to be made that simplifies the machine model. A prototype machine is constructed and evaluated. Measured results of the armature reaction effect in the large airgap are given and discussed.
1.3 μm, 50 Gbit/s electroabsorption modulators integrated with DFB laser for beyond 100G parallel LAN applications

A 1.3 µm, 50 Gbit/s electroabsorption modulator integrated with a DFB laser for future parallel LAN, the total data rate of which is over 100 Gbit/s, is developed. Very clear eye openings after 40 km transmission under 50 Gbit/s operation on singlemode fibre are demonstrated for eight wavelengths with discrete packages for the first time.
A Capacitor-Free CMOS Low-Noise, Low-Dropout Regulator for Capacitive Micro-Machined Accelerometer Application

A capacitor-free CMOS low-noise, low-dropout (LDO) regulator for Micro-accelerometer is presented. Noise performance of the regulator is studied from a theoretical point of view and a chopper stabilized error amplifier is designed to minimize output noise. By adopting pole-zero frequency compensation technique, the proposed LDO regulator, which is independent of an off-chip capacitor, provides high closed-loop stability when the load current is switched by micro-accelerometer. The proposed LDO is designed and fabricated on a 2μm CMOS process. From the simulation results, it shows that the line regulation is 3.5mV/V and the load regulation is 0.33mV/mA when the load current changes from 0 to 30 mA. The experimental results show that the output noise of the regulator is less than 180nV/sqrt(Hz) at low frequency
Research on Application of Solar Photovoltaic Grid Power System Research

Research on the conditions of solar photovoltaic grid connected power generation, research the form of converting solar energy into electrical energy generating.This paper introduces the solar photovoltaic system components, advantages and disadvantages as well as the current domestic solar photovoltaic power generation application status, prospect the development of the trend in the future, according to the analysis of the present problems. And relying on Tianjin CNOOC oil development group of Yingkou natural gas terminal 330KW solar photovoltaic power generation demonstration projects are introduced. For the photovoltaic CNOOC Yingkou terminal-station problems presents the feasibility scheme and suggestion.
Comparative Study on the Use of Widal Test to Stool Culture in the Laboratory Diagnosis of Typhoid Fever in Holy Family Hospital Akum, North West Region of Cameroon

Typhoid fever has several diagnostic tests. However, misdiagnosis is common since most health care facilities use only the Widal test without confirmation of results with a second test method. This study aimed at evaluating the performance of Widal test to stool culture in the Laboratory diagnosis of typhoid fever. Recruited in this study were 112 consented patients ≥1 year presenting with symptoms clinically suspected of typhoid fever visiting the Hospital in April, 2018. Blood and stool samples collected from all participants were subjected to Widal and stool culture, respectively. Serotyping was done using Salmonella O, and H antisera. Widal agglutination titre values ≥1:80 were considered as positive for the Salmonella antigen. Isolation of S. typhi from stool culture indicated an infection. Data was analysed using the Statistical Package for Social Sciences (SPSS). Sensitivity, specificity, Negative Predictive Value (NPV) and Positive Predictive Value (PPV) of Widal test were calculated. The sensitivity and specificity of the stool culture were 100% since it was the ideal to which the Widal test was compared. Prevalence of typhoid fever using stool culture was 39.3%, sensitivity and specificity of Widal were 40.9% and 32.4%, respectively. NPV and PPV were 6.44% and 28.13%, respectively. Widal test is not reliable for diagnosis of typhoid fever. Health care personnel should develop a rapid, highly sensitive and cheap diagnostic method that is also capable of differentiating Salmonella infection from other infections.
Quality limiting factors of imaging endoscopes based on optical fiber bundles

Nowadays, imaging endoscopes have a key role in medicine, for diagnostic, treatment and surgical applications. Coherent optical fiber bundles used for medical imaging show flexibility and a high active area, but they entail two main quality-limiting factors: leaky modes and crosstalk or interference between the optical fibers of the bundle. The former provokes a worsening of lateral resolution, while the latter causes a decrease in the contrast of the final image. In this work, both factors are studied in detail. We analyse the main characteristics of these effects, showing the limitations they impose to the endoscopic system. Finally, some solutions are proposed, and a method for determining optical fibers with the appropriate opto-geometrical parameters is presented in order to achieve an optimum design and improve the image quality of the endoscope.
A wireless video monitoring system based on 3G communication technology

With the rapid development of the electronic technology, multimedia technology and mobile communication technology, video monitoring system is going to the embedded, digital and wireless direction. In this paper, a solution of wireless video monitoring system based on WCDMA is proposed. This solution makes full use of the advantages of 3G, which have Extensive coverage network and wide bandwidth. It can capture the video streaming from the chip's video port, real-time encode the image data by the high speed DSP, and have enough bandwidth to transmit the monitoring image through WCDMA wireless network. The experiments demonstrate that the system has the advantages of high stability, good image quality, good transmission performance, and in addition, the system has been widely used, not be restricted by geographical position since it adopts wireless transmission. So, it is suitable used in sparsely populated, harsh environment scenario.
An improvement of cycloconverter output using phase shifting filter

Cycloconverter used as a power conversion device in the speed and torque control system of AC machines has the advantage of a simple control and a large torque at low speed. In addition, because a rectifier, a DC link, and an inverter are not installed, this system is simple and suitable for large power system. If a power conversion device, which is currently used as a propulsion motor of large vessel, is changed into cycloconverter, the system is simplified and then the installation costs can be significantly reduced. However, conventional cycloconverter has the increased harmonics because the power loss is large and the waveform of output voltage is distorted, due to the high-speed switching of power semiconductor devices. In order to improve these shortcomings, this paper describes a phase shifting filter which is composed of two inputs with different phases in the primary side and one output in the secondary one. As the voltage waveforms with two different phases are added and transformed into the secondary side, these outputs are close to sinusoidal waves. Thereby the voltage waveforms, which are applied to the propulsion motors, are improved and total harmonic distortions (THDs) are significantly reduced.
Prediction of 2-D Lift Motions Using Artificial Neural Networks: An Evolutionary Approach

Movement prediction is an important aspect of human simulation, where more efficient and accurate models are needed. Artificial neural networks could potentially serve as a modeling option in this realm. This investigation evaluates the performance of a particular artificial neural network structure in modeling sagittally symmetric two-dimensional lifting and lowering movements. Model performance was evaluated using three training datasets, each consisting of distinct representation levels of the overall dataset. Results are discussed in terms of their practical meaning, and suggestions for future improvements in the modeling scheme are provided. Overall, artificial neural networks show promise as a modeling paradigm for the prediction of human movement.
Three Dimensional Highway Real-Time Visual System Design and Application

With the fast development of the freeway construction in China and the increasing demand of the improvement of the landscape and safety in the highway system, the traditional method of the highway alignment design cannot meet the need mentioned above. A Three dimensional highway real-time visual system (3DHVS) is developed as a basic platform for the highway visual and physics simulate, which had many merit in the highway alignment, landscape and safety design by the means of fly-through, interactive and physics simulation with the virtual scene. By analyzing the disadvantage of the widely used design method, a performance and expansible architecture of 3DHVS is presented. Finally, we show the application of the system.
Networking reconfigurable smart sensors

In this paper, we present our system infrastructure design and a cost function based geographical self-routing algorithm for networking reconfigurable smart sensors. The algorithm allows for the sensors to automatically negotiate in a geographical radial topology relative to a central location, utilizing other sensors as routes or hops for forwarding information to this central location. A number of these sensors are deployed in the field and performance measurements for routing times are analyzed and presented.
An Optimal Preview Acceleration Driver Model with a Correction Factor for Vehicle Directional Control

Parameters of the optimal preview acceleration driver model for vehicle directional control are determined by drivers delay/lag time and parameters of the reference model of the controlled vehicle. A moving vehicle is a time-varying and nonlinear system, so it is difficult to obtain accurate parameters of the reference model. If large modeling errors of the reference model occur, the classic driver model cannot ensure the driver/vehicle closed-loop system have a satisfactory performance. In this paper, an improved optimal preview acceleration model with a correction factor was proposed, which is based on sensitivity analysis and MRAC (the model reference adaptive control). Simulation results show that the improved driver model has more satisfactory adaptability and robustness comparing with the classic driver model.
Interaction between main line standing waves and side branch resonance: stochastic signal attributes

Acoustic standing waves may be established in main gas delivery lines that are caused by resonance in branch lines. Conventional theory predicts branch line resonance frequency from the geometry of the branch and main line diameter. Data are presented that show the branch line standing wave couples with the main line standing wave, and a range of side branch resonance amplitude and frequency values are possible. Further, the resonance amplitude varies over long periods, and data acquisition using a short moving time window is employed to examine the Power Spectral Density (PSD) as a function of time. Peak amplitude values from the moving time window PSDs are identified and displayed in a Probability Density Function (PDF). The combined PSD and PDF information allows repeatable system characterization as a function of operating parameters and geometry, and data of this type are presented from a low-pressure air test facility.
Interactive Rendering and Modification of Massive Aircraft CAD Models in Immersive Environment

ABSTRACTThis paper proposes a new system framework for the interactive rendering and modification of massive aircraft models. Compared with the existing massive model visualization systems, the framework has higher preprocessing efficiency by employing an automatic LOD generation algorithm while retaining the assembly tree information. The hybrid representation of geometry node based on mesh and B-Rep enables direct and intuitive CAD modification on model nodes in VR environment, which brings faster update speed to massive aircraft models data in comparison with utilizing the traditional preprocessing pipeline.
Environmental effects of airport nodes: a methodological approach

Airports are a local source of environmental impacts that should be estimated and evaluated in order to promote the right development of these transport nodes. The aim of this paper is to present a methodological approach to identify the environmental impacts produced by an airport node, particularly atmospheric pollution produced not only by aircraft but also by land vehicles for handling operations and airport connections, given the airport multifunction role as well as its interchange multimodal function. The identifi ed methodology is formed by several steps; the most relevant ones address the estimation of the air transport demand (linked to the number of aircraft movements) and the car mode share to go in and out of the airport. The proposed methodology is useful in order to establish standard procedures to identify the airport environmental impact footprint for a sustainable development of the air transport within the larger transport system. Keywords: air transport demand module, airport catchment area module, airport nodes, carbon footprint, environmental impact assessment, ground movement module, transport function.
Automatic Delineation of Cracks with Sentinel-1 Interferometry for Monitoring Ice Shelf Damages and Calving

Abstract. Monitoring the evolution of ice shelf damage such as crevasses and rifts is important for a better understanding of the mechanisms controlling the breakup of ice shelves and for improving predictions about iceberg calving and ice shelf disintegration. Nowadays, the previously existing observational gap has been reduced by the Copernicus Sentinel-1 Synthetic Aperture Radar (SAR) mission that provides a continuous coverage of the Antarctic margins with a 6 or 12-day repeat period. These unprecedented coverage and temporal sampling enable for the first time a year-round systematic monitoring of ice shelf fracturing and iceberg calving, as well as the detection of precursor signs of calving events. In this paper, a novel method based on SAR interferometry is presented for an automatic detection and delineation of active cracks on ice shelves. Active cracks cause phase discontinuities in an interferogram that are extracted automatically by applying a Canny edge detection procedure to the spatial phase gradient derived from a SAR interferogram. The potential of the proposed method is demonstrated in the case of Brunt Ice Shelf, Antarctica, using a stack of 6-day repeat Sentinel-1 interferograms acquired between September 2020 and March 2021. The full life cycle of the North Rift is monitored, including the rift detection, its propagation at rates varying between 0.35 km d−1 and 1.29 km d−1, and the final calving event that gave birth to the iceberg A74 on 26 February 2021. The automatically delineated cracks agree well with the eventual location of the ice shelf edge after the iceberg broke off. The stress field variations observed in the interferograms are attributed to a rigid-body rotation of the ice about the expanding tip of the North Rift in response to the rifting activity. The extent of the North Rift is captured by SAR interferometry well before it becomes visible in SAR backscatter images, hence highlighting the high sensitivity of SAR interferometry to small variations in the ice shelf stress field and its potential for detecting early signs of natural calving events, as well as ice shelf fracturing and damage development in response to atmospheric and oceanic warming caused by climate change.
Burst detection using hydraulic data from water distribution systems with artificial neural networks

This paper presents research into the application of artificial neural networks (ANNs) for analysis of data from sensors measuring hydraulic parameters (flow and pressure) of the water flow in treated water distribution systems. Two neural architectures (static and time delay) are applied for time series pattern classification from the perspective of detecting leakage. Results are presented using data from an experimental site in a distribution system of a UK water company in which bursts were simulated by hydrant flushing. Field trials have shown how ANNs can be used effectively for a leakage detection task. Both static and time delay ANNs learned patterns of leaks/bursts. The time delay neural network showed improved performance over the static network. It is concluded that the effectiveness of an ANN in discovering relationships within the data is dependent upon two key factors: availability of sufficient exemplars and data quality.
Front to back ratio improvement of a micro strip patch antenna using dual‐band isolated soft surface structures

This article presents a microstrip patch antenna with a novel soft surface structure. The proposed soft surface structure is useful for suppressing surface waves in a dielectric substrate at dual frequency band (Bluetooth and Wimax). By removing the ground plane edges of the patch antenna and forming soft surfaces within the bare substrate, the front‐to‐back ratio of a patch antenna is significantly improved. The proposed new isolated soft surface structure does not share the ground plane of a patch and it consists of two loops with a corner edged via‐hole. When the three different size of isolated unit cells are used, the front‐to‐back ratio of the fabricated patch antenna improved from about −18.5 to −22.47 dB, compared to a conventional patch antenna without cells. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2396–2400, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26265
General Theory and Design of Optimum Quarter-Wave TEM Filters

The exact synthesis and design of a broad class of quarter-wave TEM mode filters is presented in a three-step procedure. The theory is applicable to all microwave filter forms consisting entirely of a cascade of quarter-wave lines, quarter-wave stubs, and coupled quarter-wave lines. The exact design of many conventional filter forms that heretofore could only be designed using approximate methods is possible using the techniques and functions described. General approximating functions that give the "best" transmission response in a Butterworth or Chebyshev sense are derived. The use of a maximum number of available singularities to augment the filter skirt response leads to a minimum element filter termed "optimum multiple. " An optimum multipole design insures the "best" possible response for the minimum element and all corresponding redundant element networks. The designer has the freedom of introducing sufficient redundancy to obtain a design that is practical to construct, but which still realizes the optimum response. Judicious choice of network form often results in improved performance and reduced size in comparison with many conventional filter forms. Design procedures are presented that allow the practical realization of distributed filter networks in the form of quarter-wave lines. A design example and experimental results are given to confirm the theory.
Low-noise 1 THz superconductor–insulator–superconductor mixer incorporating a NbTiN/SiO2/Al tuning circuit

Low-noise heterodyne mixing at 1 THz is demonstrated in a quasioptical mixer incorporating Nb superconductor–insulator–superconductor tunnel junctions and a NbTiN/SiO2/Al tuning circuit. Receiver noise temperatures as low as 250 K at 850 GHz, 315 K at 980 GHz, and 405 K at 1015 GHz are measured—a factor of 2 improvement in sensitivity versus state-of-the-art 1 THz receivers, which incorporate normal metal tuning circuits. An analysis of the receiver sensitivity at 980 GHz demonstrates that NbTiN is low loss up to ∼1 THz.
Detection of terahertz/sub-terahertz radiation by asymmetrically-shaped 2DEG layers

A diode structure to detect THz/subTHz radiation based on an MBE-grown modulation-doped GaAs/Al0.25Ga0. 75As structure is proposed. Devices have an asymmetrically-shaped geometrical form in the plane of the structure and are fabricated as mesas of 2 µm depth by wet etching. The incident terahertz/sub-terahertz radiation induces a voltage signal over the ends of the sample. Detection by non-uniform carrier heating effects under external illumination is explained and the device operation from 10 GHz up to 2.52 THz at room temperature is demonstrated.