One-shot Experiment Research Articles

FRIT-based integral action state feedback controller tuning using PSO for a liquid slosh suppression system

This paper presents a model-free approach of controller tuning to a liquid slosh suppression system. The sloshing is the usual occurrence happening to the liquid in a moving container. An integral action state feedback controller was proposed as the selected control structure. A fictitious reference signal was formulated using the recorded input-output data generated from a one-shot experiment and later be used to design the appropriate performance index. The minimization of the performance index of the controlled system was achieved by employing the PSO algorithm. Numerical analyses using MATLAB software have been conducted to evaluate the effectiveness of the proposed model-free approach. The results manifested that the tuned controller had exhibited good transient response performance regarding the trajectory tracking of the cart motion and reduction of slosh level motion.

Cardinal, a metric-based Active learning framework

<h2>Abstract</h2> In Active learning, a trained model is used to select samples to label to maximize its performance. Choosing the best sample selection strategy for a one-shot experiment is hard, but metrics have been proven to help by detecting strategies performing worse than random or detecting and avoiding noisy samples. Cardinal is a python framework that assists the practitioner in selecting a strategy using metrics and the researcher in developing those metrics. Cardinal caches experiments to compute insights costlessly, keeps track of logged metrics, and proposes extensive documentation. It also interfaces with other packages to use state-of-the-art strategies.

Estimated Response Iterative Tuning with signal projection

This paper discusses about a data-driven control method which is called Estimated Response Iterative Tuning (ERIT). ERIT focuses on a two-degree of freedom control system, and updates the feedforward controller from one-shot experiment. The main contribution of this paper is to propose a pre-processing for ERIT to improve robustness against noise. In particular, this paper proposes to project the measured output onto a subspace, and regard the projected signal as a noise-free output. How to design this subspace is also proposed in this paper. A practical experiment with flexible link system is shown to demonstrate the effectiveness of the proposed method.

Indirect Reciprocity for Mitigating Intergroup Hostility: A Vignette Experiment and an Agent-based Model on Intergroup Relations between Mainland Chinese and Taiwanese

Social scientists have proposed myriad solutions for mitigating intergroup conflicts. While the literature, such as studies on intergroup contact theory, focuses on intergroup relations, we argue that it is important not to ignore intragroup relations that may benefit or undermine the improvement of intergroup relations at the same time. In this paper, we investigate a typology of eight mechanisms for the behavior of intergroup and intragroup relations. Specifically, we focused on interactions in a triad consisting of an actor paired up with two alters—one ingroup and one outgroup. The triadic network enabled us to theorize and test how intergroup and intragroup relations coevolve. We conducted a vignette experiment to test the intergroup relationship between mainland Chinese and Taiwanese. We found strong evidence for one mechanism for improving intergroup hostility: indirect reciprocity—people rewarded the outgroup for behaving friendly to their ingroup peers. Using agent-based simulation, we predicted that the triadic effect found in the one-shot experiment can continuously improve and stabilize intergroup relations over time.

Helping under a combination of team and tournament incentives

We study how help can be fostered by means of a team bonus in the presence of rank-order tournaments. In a simple model we combine elements of relative rewards and a team bonus and study their effect on effort, help and sabotage. Quite intuitively the theoretical analysis suggests that team members help less as relative rewards increase. This problem is mitigated by a team bonus that is proportional to the output of the whole team. We compare different parameter constellations of the theoretical benchmark with behavior observed in a one-shot experiment.

Helping Under a Combination of Team and Tournament Incentives

We study how help can be fostered by means of a team bonus in the presence of rank-order tournaments. In a simple model we combine elements of relative rewards and a team bonus and study their effect on effort, help and sabotage. Quite intuitively the theoretical analysis suggests that team members help less as relative rewards increase. This problem is mitigated by a team bonus that is proportional to the output of the whole team. We compare different parameter constellations of the theoretical benchmark with behavior observed in a one-shot experiment.

A methodology for football players selection problem based on multi-measurements criteria analysis

Football is one of the most popular sports in the world. Professional football has become a significant contributor to global economics and business. The game attracts considerable funds, which motivate participants of the sporting process (players, coaches, club owners, administration, etc.) to strive for better athletic results. However, such a motivation simultaneously promotes internal and external rivalry. The increasing number of players, the teams’ desire to attract better team members, and the improved athletes’ performance boost the use of assessment and rating processes. The most popular and widely used player rating systems are based on performance statistics, which reflect situational factors of the game. Most specialists believe that such systems lack objectivity. Thus, this paper presents a new methodology to assess and rank football players based on multi-criteria decision making (MCDM). A hands-on study is conducted for the assessment. A sample of 24 players is grouped into four separate groups consisting of six players for each group. The age of U17 is examined by 12 tests distributed as follows: three anthropometrics, five fitness, and four skills tests. Players are ranked on the basis of a set of measurement metric outcomesusing the technique for order performance by similarity to ideal solution (TOPSIS) method to select the appropriate player using a one-shot experiment. Then, this study utilizes the mean and standard deviation to ensure that the four groups of players undergo systematic ranking, respectively. Findings are as follows: (1) systematic: TOPSIS is an effective tool used to solve player selection problems, and (2) statistics: group number one is the best group among the four groups, identical to the results of the system.

FIB-tomographic studies on chemical vapor deposition grown SnO2 nanowire arrays on TiO2 (001)

Tin oxide nanowire arrays on titania (001) have been successfully fabricated by chemical vapor deposition of Sn(OtBu)4 precursor. The morphologies and structures of ordered SnO2 nanowires (NWs) were analyzed by cross-sectional SEM, HR-TEM and AFM. An FIB-tomography technique was applied in order to reconstruct a 3D presentation of ordered SnO2 nanowires. The achieved 3D analysis showed the spatial orientation and angles of ordered SnO2 NWs can be obtained in a one-shot experiment, and the distribution of Au catalysts showed the competition between 1D and 2D growth. The SnO2 nanowire arrays can be potentially used as a diameter- and surface-dependent sensing unit for the detection of gas- and bio-molecules.

FRIT of Internal Model Controllers for Poorly Damped Linear Time Invariant Systems: Kautz Expansion Approach

[abstFig src='/00280005/18.jpg' width='300' text='Data-driven approach to internal model controller with tunable parameters' ] This paper addresses the tuning of data-driven controllers for poorly damped linear time-invariant systems in the internal model control (IMC) architecture. In this study, fictitious reference iterative tuning (FRIT), which is one of the controller parameter tuning methods with the data obtained from a one-shot experiment, is used for tuning the controller. The Kautz expansion method in which the coefficients are tunable parameters is introduced to approximate the dynamics of linear time-invariant systems, which have poor damping characteristics. Such an approximated model with tunable parameters is implemented in the IMC architecture. A model and a controller can be realized simultaneously with a one-shot experiment by tuning the IMC with the parameterized Kautz expansion model and by using FRIT. The validity of the proposed method is examined with a numerical example.

Virtual Reference Feedback Tuning for Cascade Control Systems

[abstFig src='/00280005/17.jpg' width='300' text='Data-driven approach to cascade control systems' ] Virtual Reference Feedback Tuning (VRFT), proposed by Campi et al., is an effective data-driven tuning method used in feedback controllers because the desired parameters implemented in the controller are obtained by using only one-shot experiment data. In this paper, we apply VRFT to cascade control systems. We also discuss the meaning of the cost function to be minimized. A numerical example is demonstrated to show an effectiveness and validity of our proposed method.

Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes

Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ∼400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

Probing internal gradients dependence in sandstones with multi-dimensional NMR

Multi-dimensional NMR experiments at two magnetic field strengths (2 and 23MHz) are presented in this paper to study the dependence of effective internal gradients in water-saturated sandstone plugs. Special pulse sequence is designed to encode longitudinal relaxation time T1, internal gradient Gin and transverse relaxation time T2 in respective windows. Experimental three-dimensional data are processed with a fast 3D inversion algorithm. Within this one-shot experiment, the three-dimensional distribution function T1-Gin-T2 and projected one- and two-dimensional distributions monitor internal gradients through diffusion in pores and reveal how effective internal gradients scale with magnetic field. Contrasts in behavior of pore size components between the two field strengths, such as T1/T2 ratio increase in T2–T1 maps and signal up-shift in T1-Gin and T2-Gin maps, are associated with variations in effective internal gradients in porous media, so potentially indicating the physical dependence of internal gradients on static field strengths and on heterogeneity of the sandstone matrix.

Data-Driven Controller Tuning: FRIT approach

Abstract In this tutorial paper, we give a basic concept of FRIT (fictitious reference iterative tuning) as one of the data-driven controller tuning methods. We explain how FRIT can achieve a desired property with only one-shot experiment. In addition, some new results on this tuning method are also presented. We also give comparisons between FRIT and the other data-driven controller tuning methods which yield the desired parameter with only one-shot experiment. Finally, as one of the applications of FRIT, we introduce the data-driven approach to simultaneous attainment of model and controller in the IMC architecture.

Fictitious Reference Iterative Tuning of Internal Model Controllers for Non-Minimum Phase Systems: A Laguerre Expansion Approach

Fictitious reference iterative tuning (FRIT) is one of the effective data-driven tuning methods for parameters of a controller with only one-shot experiment. This paper applies FRIT to internal mod...

Voting on Thresholds for Public Goods: Experimental Evidence

Introducing a threshold in the sense of a minimal project size transforms a public-good game with an inefficient equilibrium into a coordination game with a set of Pareto-superior equilibria. Thresholds may therefore improve efficiency in the voluntary provision of public goods. In our one-shot experiment, we find that coordination often fails and exogenously imposed thresholds are ineffective at best and often counterproductive. This holds over a range of threshold levels and refund rates. We test whether thresholds perform better if they are endogenously chosen, i.e., whether a threshold is approved in a referendum, because voting may facilitate coordination due to signaling and commitment effects. We find that voting does have signaling and commitment effects, but they are not strong enough to significantly improve the efficiency of thresholds.

Voting on Thresholds for Public Goods: Experimental Evidence

Introducing a threshold in the sense of a minimal project size transforms a public goods game with an inefficient equilibrium into a coordination game with a set of Pareto-superior equilibria. Thresholds may therefore improve efficiency in the voluntary provision of public goods. In our one-shot experiment, we find that coordination often fails and exogenously imposed thresholds are ineffective at best and often counter-productive. This holds under a range of threshold levels and refund rates. We test if thresholds perform better if they are endogenously chosen, i.e. if a threshold is approved in a referendum, because voting may facilitate coordination due to signaling and commitment effects. We find that voting does have signaling and commitment effects but they are not strong enough to significantly improve the efficiency of thresholds.

Voting on Thresholds for Public Goods: Experimental Evidence

Introducing a threshold in the sense of a minimal project size transforms a public goods game with an inefficient equilibrium into a coordination game with a set of Pareto-superior equilibria. Thresholds may therefore improve efficiency in the voluntary provision of public goods. In our one-shot experiment, we find that coordination often fails and exogenously imposed thresholds are ineffective at best and often counter-productive. This holds under a range of threshold levels and refund rates. We test if thresholds perform better if they are endogenously chosen, i.e. if a threshold is approved in a referendum, because voting may facilitate coordination due to signaling and commitment effects. We find that voting does have signaling and commitment effects but they are not strong enough to significantly improve the efficiency of thresholds.

1H NMR spectroscopy of ascitic fluid: discrimination between malignant and benign ascites and comparison of the results with conventional methods

It is often difficult to distinguish benign ascites from malignant ascites by conventional examination of ascitic fluid. Therefore, (1)H NMR spectroscopy of ascitic fluid specimens was explored as a one-shot experiment to identify potentially interesting metabolic indices that might help to differentiate between the two. Seventy ascitic fluid specimens (15 cytologically positive for malignant cells, eight cytologically negative for malignant cells but remaining suspicious for malignant ascites, and 47 due to liver cirrhosis) were subjected to (1)H NMR spectroscopy for quantitative estimation of 14 metabolites. Mean concentrations of the metabolites were compared with the Mann-Whitney U test. Multivariate discriminant function analysis was performed to determine important descriptors in the discrimination process. The sensitivity and specificity of the proposed model were compared with conventional methods using ascitic fluid protein and serum ascitic albumin gradient. Then, probable predictions for the doubtful cases were made using the proposed model. Patients with malignant ascites had significantly higher mean concentrations (microM) of beta-hydroxybutyrate (594 vs 61), lactate (5384 vs 2104), acetone (136 vs 69), and acetoacetate (122 vs 48) than patients with cirrhotic ascites, and significantly lower concentrations of glutamine (359 vs 615), citrate (62 vs 118), glucose (4933 vs 8411), tyrosine (44 vs 124), and phenylalanine (51 vs 93) (P < 0.05 for all). In the discriminant function analysis model, the best discrimination (P < 0.001) was achieved when beta-hydroxybutyrate, lactate, citrate and tyrosine were considered together as markers. Sensitivity and specificity of the proposed model, ascitic fluid protein and serum ascitic albumin gradient were found to be 100% and 97.9%, 53.3% and 76.6%, and 60% and 87.2%, respectively. The proposed model put five of the eight doubtful cases in the malignant group. This is encouraging and may provide useful information for clinical purposes.

１自由度系に対するＦｉｃｔｉｔｉｏｕｓ Ｒｅｆｅｒｅｎｃｅ Ｉｔｅｒａｔｉｖｅ Ｔｕｎｉｎｇに基づく同定手法の提案とエレベータドア開閉速度動特性の同定への応用

In this paper, we present a new identification method based on the fictitious reference iterative tuning (which is abbreviated to as FRIT in the following). FRIT is one of the parameter tuning methods for controllers based on the direct use of the experimental data without mathematical models, particularly, this method enables one to obtain the optimal parameter with only one-shot experiment. Motivated by such practical advantages, we expand this method to a facile and fast-track identification by using only one-shot experiment data of the closed loop implemented with the existing controller in the one-degree of freedom control system. As one of the real systems in which it is effective for such an identification method to be applied, we consider the identification of the opening-and-closing speed dynamics of an elevator door. For this system, it is important to obtain the actual state of an elevator door for retaining a safety and quick motion. Thus, an identification of this dynamics is one of the most important factors for an effective maintenance. However, it is difficult to obtain the actual parameter because of the fact that there are many cases in which an experiment for the identification spends much time and it is undesirable to use sufficiently excited signals for the identification. We apply our identification method to solve these practical problems. Finally, in order to show the validity of our result in this paper, we also give an experimental result on the identification of the opening-and-closing speed dynamics of the door of an elevator.

ＦＲＩＴを用いた閉ループ特性と目標応答特性の向上のための２自由度制御器のパラメータ調整

In [13], some of the authors of this paper proposed the fictitious reference iterative tuning (which is abbreviated as FRIT in the following) as one of the useful and powerful methods of parameter tuning of an implemented controller in the sense that we require only one-shot experiment for the parameter tuning in order to achieve the minimization of the squared error between the real output and the desired one. However, feedback properties like sensitivity or noise reductionability those are also required for a control system to be more practical have not been addressed yet. On the other hand, it is well known that the two-degree of freedom of control scheme is one of the effective ways those enable us to deal both of tracking property and feedback ones simultaneously. From this reason, in this paper, we expand FRIT into the two-degree of freedom control scheme in order to tune parameters of impelmented controllers in this structure for the sake of the acheivement of given specifications on not only tracking property but also feedback properties. We consider the correspondence of the minimization between desired cost function and the fictitious ones. We then provide effective procedures of FRIT in the two-degree of freedom of control scheme with two-shot experiments. Finally, we also give illustrative examples in order to show the validity of our proposed methods.