Actual Equipment Research Articles

Source free unsupervised domain adaptation for electro-mechanical actuator fault diagnosis

A common necessity for prior unsupervised domain adaptation methods that can improve the domain adaptation in unlabeled target domain dataset is access to source domain dataset and target domain dataset simultaneously. However, data privacy makes it not always possible to access source domain dataset and target domain dataset in actual industrial equipment simultaneously, especially for aviation component like Electro-Mechanical Actuator (EMA) whose dataset are often not shareable due to the data copyright and confidentiality. To address this problem, this paper proposes a source free unsupervised domain adaptation framework for EMA fault diagnosis. The proposed framework is a combination of feature network and classifier. Firstly, source domain datasets are only applied to train a source model. Secondly, the well-trained source model is transferred to target domain and classifier is frozen based on source domain hypothesis. Thirdly, nearest centroid filtering is introduced to filter the reliable pseudo labels for unlabeled target domain dataset, and finally, supervised learning and pseudo label clustering are applied to fine-tune the transferred model. In comparison with several traditional unsupervised domain adaptation methods, case studies based on low- and high-frequency monitoring signals on EMA indicate the effectiveness of the proposed method.

An Operator Training Simulator to Enable Responses to Chemical Accidents through Mutual Cooperation between the Participants

Research in the training simulation sector to improve the realism and immersive experience of operator training simulators (OTSs) entails combining cutting-edge technologies such as virtual reality (VR) and augmented reality (AR). Although most of the existing studies has been about troubleshooting training, research into the response to chemical accidents through mutual cooperation between the participants has been insufficient. Therefore, we developed an immersive OTS that can facilitate mutual cooperation. Training processes to educate trainees in general chemical facilities were selected, while changes that can occur in facilities during an accident and the corresponding responses in various scenarios were used as the training content. A communication system that relays information between the worksite and the control room was implemented using a distributed control system (DCS) and AR technology. We installed a pilot plant and developed a DCS, thereby establishing an infrastructure that allows the boardman and field operator to cooperate during accident scenarios. Furthermore, we developed an OTS that allowed trainees to learn prompt and accurate responses to chemical accidents through operation of the actual equipment. The training effect of the OTS was found to be approximately 4.5 times better than traditional training methods. It is, therefore, anticipated that the developed OTS will minimize losses or damage caused by chemical accidents.

AIUM Official Statement: Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers and Equipment Between Patients as Well as Safe Handling and Use of Ultrasound Coupling Gel.

AIUM Official Statement: Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers and Equipment Between Patients as Well as Safe Handling and Use of Ultrasound Coupling Gel.

Simplified Approach to Characterize the Cooling Crystallization in a Modular Mini-Plant

The characterization of new process equipment often includes tedious experiments, particularly for (cooling) crystallization. This can be cost-intensive and time-consuming when the actual equipment has to be continuously operated to gain new insights. For multi-purpose plants that frequently change the process substance system, this can be especially laborious. In order to accelerate the generation of characterization data for the quasi-continuous filter belt crystallizer (QCFBC), a Peltier-element-driven, simplified experimental benchtop setup is validated in this work using a sucrose/water model substance system. It was shown that the operation conditions during the cooling crystallization on the continuously operated plant can be appropriately emulated; therefore, an actual operation of the entire mini-plant for characterization experiments is no longer necessary.

Cone Beam Computed Tomography in Implant Dentistry- An update

In the more than 20 years that cone beam computed tomography (CBCT) has been available in dentistry, a lot has changed. The image quality has been greatly improved by better detectors and extraction algorithms. Moreover, the grading dose has been reduced by using pulsed beams, the possibility to select smaller fields of view and by the optimization of the reconstruction algorithms [1]. Most modern devices have many setting options, unlike the first generations of devices (Figure 1a and 1b). The field of view can be limited to 4x4cm or similar and the milliamperage, the number of basic projections, the spatial resolution, are all adjustable, so that the image quality and dose can be easily influenced. Something that is also required by the applicable guidelines. The devices have also become a lot more affordable over time. Actual equipment can be used for 2D and/or 3D images.

Development and application of magnesium alloy parts for automotive OEMs: A review

China is currently vigorously implementing the “energy conservation and emission reduction” and “dual carbon” strategies. As the most resource-advantaged light metal material in China, Magnesium (Mg) alloy is progressively expanding its application in automobile, rail transportation, aerospace, medical, and electronic products. Chongqing University, Shanghai Jiaotong University, and Australian National University have conducted extensive research on the preparation, properties, and processes of Mg alloys. In the past 20 years, the proportion of Mg alloy in the automotive industry has gradually expanded, whereas currently the design and development of Mg alloy parts for automobiles has rarely been reported. Thus, the application models and typical parts cases of Mg alloy are summarized mainly from the four systems of the whole vehicle (body system, chassis system, powertrain system, interior, and exterior system). Subsequently, two actual original equipment manufacturers (OEM) cases are used to introduce the development logic of reliable die-cast Mg alloy, including forward design, formability analysis, process design analysis, structural redesign, manufacturing, and testing, aiming to share the methods, processes, and focus of attention of automotive OEMs for developing Mg alloy parts to enhance the confidence and motivation of applying Mg alloy in automotive field. Eventually, the multiple challenges faced by Mg alloy materials are sorted out and how to face these challenges are discussed. National policies and regulations, environmental protection and energy saving, and consumer demand will continue to promote the application of Mg.

Aspen plus Simulation and Analysis of Methanol Synthesis Process

According to the actual situation of methanol production process, Aspen Plus software is used to build the methanol synthesis process flow model. The main and side reaction system is built in the model, which is realized by connecting the main and side reactors in series and setting the conversion rate of side reaction. Considering the model validation and process integrity, the methanol rectification system is connected in series on the basis of the methanol synthesis model, and the steady state simulation of the whole process is carried out. The methanol purity simulated is 99.74%, which shows that the model is reasonable. Through sensitivity analysis, the influence of feed flow change on the flow and purity of crude methanol and the influence of converter temperature change on the flow and purity of crude methanol were investigated. The relationship between the change of control parameters and the actual yield and equipment safety was preliminarily analyzed in order to provide reference and guidance for the development of methanol synthesis process.

A review on dryout and Post-dryout heat transfer inside tubes and tube bundles

• Detailed review on dryout mechanism and dryout and post-dryout heat transfer. • Summarizing the dryout criterions and models of dryout and post-dryout heat transfer. • Elaborating the methods of dryout and post-dryout heat transfer enhancement. • Proposing further research suggestions of dryout and post-dryout heat transfer. The working medium changes from subcooled liquid through flow boiling to superheated vapor in actual once-through thermal equipment (such as once-through steam generators, once-through boilers). Dryout heat transfer deterioration inevitably occur in this vapor-liquid two-phase flow and heat transfer process. After dryout occurs completely, vapor almost completely covers the wall, resulting in a rapid deteriorating heat transfer performance and a sharp rising wall temperature, which puts forward higher requirements on the design, manufacture, and operation of the equipment. The mechanism of dryout is elaborated, and the dryout criterion is summarized in this paper. The three methods that are used to describe the mathematical model of dryout and post-dryout heat transfer are arranged, and the dryout and post-dryout heat transfer in the straight channel is introduced. Furthermore, the methods of enhancing dryout and post-dryout heat transfer are introduced such as changing the geometric structure (including changing the shape of the flow channel and processing the surface of the flow channel) and injecting liquid droplets, etc.

Adjustable Sound Absorber of Multiple Parallel-Connection Helmholtz Resonators with Tunable Apertures Prepared by Low-Force Stereolithography of Photopolymer Resin.

The variable noise spectrum for many actual application scenarios requires a sound absorber to adapt to this variation. An adjustable sound absorber of multiple parallel-connection Helmholtz resonators with tunable apertures (TA-MPCHRs) is prepared by the low-force stereolithography of photopolymer resin, which aims to improve the applicability of the proposed sound absorber for noise with various frequency ranges. The proposed TA-MPCHR metamaterial contains five metamaterial cells. Each metamaterial cell contains nine single Helmholtz resonators. It is treated as a basic structural unit for an array arrangement. The tunable aperture is realized by utilizing four segments of extendable cylindrical chambers with length l0, which indicates that the length of the aperture l is in the range of [l0, 4l0], and that it is tunable. With a certain group of specific parameters for the proposed TA-MPCHR, the influence of the tunable aperture with a variable length is investigated by acoustic finite element simulation with a two-dimensional rotational symmetric model. For the given noise spectrum of certain actual equipment with four operating modes, the TA-MPCHR sample with a limited total thickness of 40 mm is optimized, which is made of photopolymer resin by the low-force stereolithography, and its actual average sound absorption coefficients for the frequency ranges of 500-800 Hz, 550-900 Hz, 600-1000 Hz and 700-1150 Hz reach 0.9203, 0.9202, 0.9436 and 0.9561, respectively. Relative to common non-adjustable metamaterials, the TA-MPCHR made of photopolymer resin can reduce occupied space and improve absorption efficiency, which is favorable in promoting its practical applications in the noise pollution prevention.

A Strategy for Determining the Decommissioning Life of Energy Equipment Based on Economic Factors and Operational Stability

LCC and EL models have been widely used in recent years to determine the decommissioning life of equipment in energy companies, with LCC (life-cycle cost) being the total “lifetime” cost of the equipment from the time it is put into operation until the end of its decommissioning and disposal; the average annual cost of the equipment can be calculated based on the LCC. The overall LCC can be calculated as the average annual LCC, while the EL is the age of the equipment at which its average annual LCC is the lowest. It is believed that the decommissioning of the equipment in the EL year will result in the lowest annual average equipment turnover, thus maximizing the economic benefits of the equipment. Recently, LCC and EL research has been gradually introduced to the energy field, but there remains a lack of research depth. In current practice, energy equipment LCCs are mainly determined by selecting a portion of inventoried equipment to serve as a sample record for all costs incurred. The intent is to derive the economic life of the equipment-year by directly seeking its average annual cost, but this method tends to downplay maintenance, overhaul, and other cost events as “random small probability events”. This method is also incomplete for evaluating the decommissioning life of equipment whose average annual cost strictly decreases year-by-year. In this study, we analyzed the use of 75,220 KV transformers that were put into service by an energy company in 1986 as a case study (costs for this type of equipment were first recorded strictly in terms of LCC in 1986), used Isolated Forest (IF) to screen the outliers of various types of data costs, and then probability-corrected the corrected dataset with a Welbull distribution (Welbull). Then, we employed a stochastic simulation (MC) to calculate the LCC of the equipment and determined its economic lifetime (EL) and compared the results of the stochastic simulation method with those of the traditional method to provide a more reasonable explanation for the “small probability” of cost occurrences. Next, we predicted the average cost of the equipment given a use-period of 38-41-years using AHA, Bi-LSTM, and other comparative algorithms, compared the MAE, MAPE, and RMES indexes, selected the most suitable prediction model, and produced a predicted cost under the chosen method to obtain the economic life of the equipment. Finally, we compared our results with the design life of the equipment (design life being the technical life expectancy of a product based on the expectations of the manufacturer), and determined its best retirement age by comprehensively studying and judging the economic and technical benefits. The retirement age analysis was guided by by a comprehensive study of economic and technical benefits. We refer to our decommissioning life determination model as Monte Carlo -artificial hummingbird algorithm–BiLSTM–lifecycle cost model (MC-AHABi-LCC). We found that the decommissioning life obtained by MC-AHABi-LCC is closer to the actual equipment decommissioning life than that given by standard LCC and EL analysis and that our model is more accurate and scientific.

Study on the Selection of Processing Process and Parameters of Platycodon grandiflorum Seeds Assisted by Machine Vision Technology

Seed processing is an important means of improving seed quality. However, the traditional seed processing process and parameter adjustment are highly empirically dependent. In this study, machine vision technology was used to develop a seed processing method based on the rapid extraction of seeds’ material characteristics. Combined with the results of clarity analysis and the single seed germination test, the seed processing process and parameters were determined through data analysis. The results showed that several phenotypic features were significantly or highly significantly correlated with clarity, but fewer phenotypic features were correlated with viability. According to the probability density distribution of pure seeds and impurities in the features that were significantly correlated with seed clarity, the sorting parameters of length, width, R, G, and B were determined. When the combination of width (≥0.8 mm) + G (<75) was used for sorting, the recall of pure seeds was higher than 91%, and the precision was increased to 98.6%. Combined with the specific production reality, the preliminary determination of the Platycodon grandiflorum seed processing process was air separation—screen (round hole sieve)—color sorting. Then, four commercialized Platycodon grandiflorum seed lots were sorted by this process using corresponding parameters in the actual processing equipment. Subsequently, the seed clarity and germination percentage were significantly improved, and the seed quality qualification rate was increased from 25% to 75%. In summary, by using machine vision technology to quickly extract the material characteristics of the seeds, combined with correlation analysis, probability density distribution plots, single feature selection, and combination sorting comparisons, the appropriate processing process and corresponding sorting parameters for a specific seed lot can be determined, thus maximizing the seed quality.

Research on Training Effectiveness of Professional Maintenance Personnel Based on Virtual Reality and Augmented Reality Technology

The maintenance training method based on Virtual Reality (VR) and Augmented Reality (AR) technology has the characteristics of safety, no space limitation, and good reusability. Compared with the traditional training method, it can reduce the training cost, shorten the training period, and improve training effectiveness. Therefore, more and more maintenance training use VR and AR to replace training based on actual equipment to improve training effectiveness. However, in the context of multi-level tasks, there is still no clear research conclusion on how to choose training methods, maximize the advantages of each training method, and achieve higher training effectiveness. In response to this problem, this study constructed three training platforms based on VR, AR, and actual equipment, designed three maintenance tasks at different levels, and created a comparative analysis of the training effects of 60 male trainees under the three tasks and three training platforms. The results show that for single-level maintenance tasks, the training effect of the traditional group was significantly better than that of the AR group and the VR group. For multi-level maintenance tasks, the training effect of AR group was significantly better than that of the VR group. With the increasing difficulty of maintenance tasks, the training efficiency of the AR group was more than 10% higher than that of the VR group and traditional group and the AR group had less cognitive load. The conclusions of this study can provide a theoretical basis for the selection of training methods and evaluation design and help to formulate training strategies, thereby shortening the training period of professional maintenance personnel.

Partial discharge location method in GIS coaxial bus structure based on multi-normal photoelectric array

Partial discharge is an important reason for the failure of GIS equipment, and its detection can determine the type and position of the defect in GIS. In the discharge inspection, accurate positioning of defects can provide an important reference for maintenance. In response to this, this paper proposes a discharge optical location method based on multi-normal photoelectric array. Based on the SiPM sensor, a multi-normal array is designed and built into the coaxial structure of GIS equipment. Measuring the responses of each unit in the array to get the response ratio of each element and calculate the direction of the discharge light in space. This paper firstly introduces the array structure, and proposes a solution algorithm in space, which uses the proportional relationship of multi-normal elements to solve the discharge direction. Secondly, the feasibility and error source of this method are verified in the simulation software. Finally, the application effect of this method in actual power equipment is verified by actual measurement, and the results show that this method can accurately locate the partial discharge in GIS.

Monitoring the Conditions of Hydraulic Oil with Integrated Oil Sensors in Construction Equipment

Maintenance and reliability are crucial aspects for operating construction equipment in harsh environmental conditions. One of the methods used to improve the maintenance and reliability of construction equipment is oil diagnosis. In this study, monitoring of conditions was performed through the use of an integrated oil sensor for hydraulic oil in construction equipment. Hydraulic oil in construction equipment is polluted by various materials such as moisture and dust. Therefore, the present work investigated the change in the state of hydraulic oil caused by the presence of major pollutants in construction equipment. The degree of contamination of the hydraulic oil was evaluated using an integrated oil sensor that could measure absolute viscosity, density, temperature and dielectric constant. It is difficult to determine the influence of each pollutant source on hydraulic oil. Therefore, a simple experimental device and diagnostic program were constructed to effectively measure variations in the properties of hydraulic oil caused by each contaminant source. In particular, the focus was on the dielectric constant and examination of its usefulness. In addition to testing various contaminant conditions in the laboratory, varnish-contaminated lubricants used in actual construction equipment were verified. The results showed little change in the dielectric constant when introducing dust and improper lubricants. However, the dielectric constant was affected by the incorporation of water and the generation of varnish, which led to evident variations. In particular, a direct correlation was found between varnish contamination and the dielectric constant measured by the oil sensor, and the cause was explained based on the results of elemental component analysis. Therefore, measuring absolute viscosity, density, and temperature when monitoring the condition of hydraulic oil in construction equipment can provide useful information regarding lubricant and machine condition; however, the dielectric constant is most useful in detecting moisture incorporation and varnish contamination caused by oil deterioration.

Research on Semi-physical Simulation of Direct Drive Fan Based on ADPSS

A high proportion of new energy equipment brings problems such as increased power source uncertainty and weaker moment of inertia to the power grid. Through large-scale grid simulation with refined models of new energy equipment, potential grid risks can be discovered and grid security can be effectively improved. The modeling accuracy of the new energy equipment model affects the simulation accuracy of the large power grid. In order to solve the accuracy problem of the new energy equipment model, a semi-physical simulation platform close to the actual equipment is used to carry out simulations of different working conditions. Based on ADPSS, a semi-physical simulation electromagnetic model of a dual-motor dual-power unit two-level direct-drive fan was built, and simulation data of different working conditions were obtained. The direct frequency control method is adopted to optimize the motor model, which reduces the steady-state fluctuation of the semi-physical simulation and improves the simulation accuracy.

Assessing the Equipment Level of Technical Service Enterprises in the Agricultural Sector of the Volga Federal District

Introduction. The level of technological equipment and quality of equipment placement at the technical service enterprises have a significant impact on the size of work areas and the efficiency of travel paths for moving items of agricultural machinery under repair. The purpose of research is to assess the actual equipment level and the quality of equipment placement at the specific work areas of technical service enterprises. Material and Methods. The quality of the equipment placement at technical service enterprises is determined by comparing the actual and standard values of the coefficient that takes into account the size of work areas and travel paths for moving items of agricultural machinery under repair in particular work areas. There has been proposed a method for determining the level of equipment on the basis of the equipment deterioration and the coefficient of the equipment placement density. Results. Eighty percent of the work areas do not comply with the basic standards of technological design. The actual value of the equipment placement density coefficient at the work areas under research was 1.1‒42.8. The average value of the coefficient was 12.5 for enterprises with a fleet of less than 25 tractors, 10.2 for enterprises with a fleet of 25 to 50 tractors and 8.6 for enterprises with a fleet of more than 50 tractors. The share of the work areas with high density of equipment placement was 13.3%, with average density 40.0% and with low density 46.7%. The coefficients closest to the standard values were found in the work areas for repairing the hydraulic systems and oil equipment, restoring machinery parts with polymer composites, and for painting and drying. The values of the coefficient of equipment placement density at such basic work areas as for bench-working and assembling, forging works, welding, fusing, and etc. in some times differ from the standard values. Discussion and Conclusion. The conducted research showed that most of work areas of technical service enterprises in the Volga Federal District have a low level of equipment. The results of the study will allow optimizing the size of the work areas and ensuring the efficiency of travel paths for moving items of agricultural machinery under repair within the buildings.

Secure Chaos of 5G Wireless Communication System Based on IOT Applications

This research is aimed at planning the manner in which the secure 5G communication can be controlled based on traffic floods. To accomplish excellent administration execution of organization observing and 5G directing calculation is inescapable, dynamic steering in actual organization equipment isn't reasonable for practical plans of action. Accordingly, to bring down functional and capital consumption, we propose a strategy called versatile steering made do with the help of 5G (Quality of Service and MANET (Mobile specially appointed Network). A practical 5G steering model which will help with fulfilling the needs of the customers and simultaneously gives huge investment funds in item cost and convenience was presented in this paper. To perform versatile 5G steering, we planned geography in a virtualized climate. We customized CHAOS for network traffic flood the board which goes about as a consistent northward API in 5G directing. Network traffic is infused dynamically from 1MB up to 10MB (connect b/w) in a progressive way for similar organization traffic with 10 organization occurrences. In conclusion, we performed versatile 5G steering applying the control hypothetical method with the assistance of CHAOS and MANET calculations. By looking at two directing situations, we noticed a prominent distinction in throughput for controlling organization traffic application in MANETs. Network traffic flood data is refreshed after clockwork.

What you see may not be what you get! Simulate towards effective planning of pediatric intensive care unit.

Aims and objectivesThis study aimed to describe the application of low-cost inter-professional simulation over 4 phases in identifying structural and design issues, latent safety threats as well as test systems, processes, including facilitated team training during the design of a new pediatric intensive care unit (PICU).Materials and methodsThe four-phase inter-professional simulation sessions involving clinical and non-clinical teams were conducted over a 3-month period in a corporate hospital during the designing of a new PICU. Low-cost resources, such as floor tapes, low-tech manikins, reused sterilized consumables, and actual patient beds and equipment, were used for the in situ simulation sessions. A plus-delta method of debriefing was done, and changes agreed on consensus were implemented after each simulated session.ResultsThere were 10 simulation sessions conducted over 4 phases during the 3-month period of designing the PICU. The participants included 10 doctors from PICU and adult critical care, 25 critical care nurses, 12 members from the project team, and 2 hospital administrators in various combinations. The first phase led to the re-design of workspace and clinical areas for better space utilization. The second phase required further revision to facilitate better mobility and facilities. In the third phase, the number of beds was reduced to 6 beds following the simulated drills involving the actual placement of patient cots and equipment. The fourth phase had thematic 5 simulated exercises involving the newly recruited clinical teams that enabled the identification of systems and process issues. Cognitive aids and video orientation of the setup, team training, and human factors training were addressed, and the unit was open for patient care in a week.ConclusionA phased inter-professional simulation exercise with low-cost resources can enable the identification of structural challenges, design issues, latent safety threats, test systems, processes, patient flow, and facilitated team training during the design of a new PICU. Further studies are needed to understand the generalization of the study findings into designing PICU.

전투기 레이다 개발을 위한 Software-in-Loop Simulation 시스템 구현

Herein, we implement a software-in-loop simulation (SILS) system for fighter radar systems. The implemented SILS system simulates fighter radar environments and hardware by mathematical modeling, generates radar-simulated digital signals, and stores/analyzes simulation results. It includes a personal computer (PC)-based virtual radar processing unit, which can be used to develop radar control and process algorithms and codes and can also examine the functions and performance of the software and code of actual radar processing equipment by connecting actual equipment. Because antenna and transceiver models are included, the performance of the initial hardware designs at the system level can be examined in the simulation environment, thereby increasing the hardware design and development speed. We demonstrate the validity and usefulness of the SILS system, implemented using the radar environment and hardware mathematical models obtained from the development of fighter radars for numerous years, through SILS-based test results.

Roulette: A Diverse Family of Feasible Fault Attacks on Masked Kyber

At Indocrypt 2021, Hermelink, Pessl, and Pöppelmann presented a fault attack against Kyber in which a system of linear inequalities over the private key is generated and solved. The attack requires a laser and is, understandably, demonstrated with simulations—not actual equipment. We facilitate and diversify the attack in four ways, thereby admitting cheaper and more forgiving fault-injection setups. Firstly, the attack surface is enlarged: originally, the two input operands of the ciphertext comparison are covered, and we additionally cover re-encryption modules such as binomial sampling and butterflies in the last layer of the inverse numbertheoretic transform (INTT). This extra surface also allows an attacker to bypass the custom countermeasure that was proposed in the Indocrypt paper. Secondly, the fault model is relaxed: originally, precise bit flips are required, and we additionally support set-to-0 faults, random faults, arbitrary bit flips, and instruction skips. Thirdly, masking and blinding methods that randomize intermediate variables kindly help our attack, whereas the IndoCrypt attack is like most other fault attacks either hindered or unaltered by countermeasures against passive side-channel analysis (SCA). Randomization helps because we randomly fault intermediate prime-field elements until a desired set of values is hit. If these prime-field elements are represented on a circle, which is a common visualization, our attack is analogous to spinning a roulette wheel until the ball lands in a desired set of pockets. Hence, the nickname. Fourthly, we accelerate and improve the error tolerance of solving the system of linear inequalities: run times of roughly 100 minutes are reduced to roughly one minute, and inequality error rates of roughly 1% are relaxed to roughly 25%. Benefiting from the four advances above, we use a reasonably priced ChipWhisperer® board to break a masked implementation of Kyber running on an ARM Cortex-M4 through clock glitching.