An Radio Frequency Impedance Matching Control Benchmark System for Advanced Control Strategies Evaluation

An impedance matching network is mandatory between the source and the load to obtain the maximum power transfer in a system. For example, in the plasma processing technology widely used in semiconductor wafer processing, guaranteeing the maximum transference of power is the main goal. This paper presents the problem definition and guidelines for a radio-frequency (RF) impedance matching benchmark. This benchmark system we developed in public domain is useful in studying and evaluating various impedance patching algorithms fairly. The goal is to match the impedance of the source with its complex conjugate of the load in a minimum time. The reflection coefficient is used as an evaluation metric to measure the reflected power, which has to be zero to guarantee the maximum power transfer. Some impedance matching controllers proposed in the literature are tested as sample applications on this benchmark in a fair manner to check and evaluate its robustness and stability performance against different initial conditions, load conditions and perturbations on the impedance matching network control system. We also suggested a novel Feedforward Control (FF) profile generation method with a primitive sample feedback control strategy (proportional-integral (PI) controller) as a baseline reference for the benchmark.

Halogens in Acetophenones Direct the Hydrogen Bond Docking Preference of Phenol via Stacking Interactions

Phenol is added to acetophenone (methyl phenyl ketone) and to six of its halogenated derivatives in a supersonic jet expansion to determine the hydrogen bonding preference of the cold and isolated 1:1 complexes by linear infrared spectroscopy. Halogenation is found to have a pronounced effect on the docking site in this intermolecular ketone balance experiment. The spectra unambiguously decide between competing variants of phenyl group stacking due to their differences in hydrogen bond strength. Structures where the phenyl group interaction strongly distorts the hydrogen bond are more difficult to quantify in the experiment. For unsubstituted acetophenone, phenol clearly prefers the methyl side despite a predicted sub-kJ/mol advantage that is nearly independent of zero-point vibrational energy, turning this complex into a challenging benchmark system for electronic structure methods, which include long range dispersion interactions in some way.

Halogens in Acetophenones Direct the Hydrogen Bond Docking Preference of Phenol via Stacking Interactions

Phenol is added to acetophenone (methyl phenyl ketone) and to six of its halogenated derivatives in a supersonic jet expansion to determine the hydrogen bonding preference of the cold and isolated 1:1 complexes by linear infrared spectroscopy. Halogenation is found to have a pronounced effect on the docking site in this intermolecular ketone balance experiment. The spectra unambiguously decide between competing variants of phenyl group stacking due to their differences in hydrogen bond strength. Structures where the phenyl group interaction strongly distorts the hydrogen bond are more difficult to quantify in the experiment. For unsubstituted acetophenone, phenol clearly prefers the methyl side despite a predicted sub-kJ/mol advantage which is nearly independent of zero point vibrational energy, turning this complex into a challenging benchmark system for electronic structure methods which include long range dispersion interactions in some way.

A BERT-Based Multi-Criteria Recommender System for Hotel Promotion Management

Numerous reviews are posted every day on travel information sharing platforms and sites. Hotels want to develop a customer recommender system to quickly and effectively identify potential target customers. TripAdvisor, the travel website that provided the data used in this study, allows customers to rate the hotel based on six criteria: Value, Service, Location, Room, Cleanliness, and Sleep Quality. Existing studies classify reviews into positive, negative, and neutral by extracting sentiment terms through simple sentimental analysis. However, this method has limitations in that it does not consider various aspects of hotels well. Therefore, this study performs fine-tuning the BERT (Bidirectional Encoder Representations from Transformers) model using review data with rating labels on the TripAdvisor site. This study suggests a multi-criteria recommender system to recommend a suitable target customers for the hotel. As the rating values of six criteria of TripAdvisor are insufficient, the proposed recommender system uses fine-tuned BERT to predict six criteria ratings. Based on this predicted ratings, a multi-criteria recommender system recommends personalized Top-N customers for each hotel. The performance of the multi-criteria recommender system suggested in this study is better than that of the benchmark system, a single-criteria recommender system using overall ratings.

Time and Costs Optimized Performance Evaluation Tests of Alternative Shaft-Bushing Concepts

The present case-study was aimed at evaluating and comparing the frictional properties (friction and wear) of alternative concepts for a shaft-bushing component in comparison to the actually used benchmark system. Through the use of a specially designed shaft-bushing tribology labor-sized test setup in combination with a high-precision modular tribometer, the overall performance of alternative concepts were evaluated and compared. Benchmark shafts consisted of nitro-carburized and oxidized bearing steel and benchmark bushings were made of sintered steel. The investigated alternative concepts consisted of shafts with a different thermal pre-treatment against benchmark bushings; benchmark shafts against surface modified bushings; and lubricated benchmark bushings (instead of lubricated shafts) with two different lubrication times before testing. For each concept under study, 3 performance tests were performed in order to assess the reproducibility of the results obtained. The most promising alternative component concepts identified through this labor-sized model screen test were then field tested by IMS Gear and the obtained results were in accordance with the labor test results.

Nonlinear analysis and prediction of soybean futures

We use chaotic artificial neural network (CANN) technology to predict the price of the most widely traded agricultural futures – soybean futures. The nonlinear existence test results show that the time series of soybean futures have multifractal dynamics, long-range dependence, self similarity, and chaos characteristics. This also provides a basis for the construction of a CANN model. Compared with the artificial neural network (ANN) structure as our benchmark system, the predictability of CANN is much higher. The ANN is based on Gaussian kernel function and is only suitable for local approximation of nonstationary signals, so it cannot approach the global nonlinear chaotical hidden pattern. Improving the prediction accuracy of soybean futures prices is of great significance for investors, soybean producers, and decision makers.

A receding horizon event-driven control strategy for intelligent traffic management

In this paper, the intelligent traffic management within a smart city environment is addressed by developing an ad-hoc model predictive control strategy based on an event-driven formulation. To this end, a constrained hybrid system description is considered for safety verification purposes and a low-demanding receding horizon controller is then derived by exploiting set-theoretic arguments. Simulations are performed on the train-gate benchmark system to show the effectiveness and benefits of the proposed methodology.

Coordinated fuzzy operation of battery energy storage and resistive brake for mitigation of SSR oscillations

The work presented herein is focusing on mitigating sub-synchronous-resonance (SSR) oscillatory torque and speed responses developed in power network equipped with series capacitor compensation as an outcome of the network perturbations. The mitigation effect of a battery-energy-storage (BES) controlled via a fuzzy-logic-controller (FLC) is explored. It is also explored accompanied by a fuzzy-bases resistor brake controlled via FLC. The IEEE second benchmark system is selected as a test grid under the MATLAB™/Simulink simulation environment. The signal utilized for the propositioned controller is the alternator rotor speed deviation. The key conclusions of this investigation are the employment of a BES in the discharging mode alone might be utilized to alleviate the SSR relative speed, and torque oscillations, the BES employment accompanied with dynamic resistive brake is supplying faster-decaying rates for the SSR oscillations in observation with the BES employment only.