Objective cluster structure of experimental variables vs. "Simple Structure"

1961 ◽  
Author(s):  
Robert C. Tryon
Author(s):  
S.V. Dronov ◽  
A.Yu. Shelar

Processing large amounts of data can be greatly simplified if this data is divided into approximately homogeneous groups. Splitting into such groups is the task of cluster analysis. However, the question of constructing an objective, natural partition into clusters remains open. The paper considers a modern approach to the search for such an objective cluster structure by highlighting the indicator of a common essential part from the set of characteristics that define objects (we call them the forming ones). When this indicator is fixed, the remains of the forming characteristics become independent or close to such. The resulting independent residuals are interpreted as a kind of information noise, and the latent cluster variable, the common fixed part that provides such a transformation, can be a reason for the objective integration of objects into clusters. A new algorithm for the formation of a cluster partition based on the proximity or coincidence of the values of a latent cluster variable with the simultaneous quantification of its values is proposed. The algorithm is based on the targeted search of partitions, the transition from the start one to the partition, more close to the objective. The algorithm proposed in the paper can be easily modified to the case of non-numeric categorized characteristics.


Methodology ◽  
2019 ◽  
Vol 15 (Supplement 1) ◽  
pp. 43-60 ◽  
Author(s):  
Florian Scharf ◽  
Steffen Nestler

Abstract. It is challenging to apply exploratory factor analysis (EFA) to event-related potential (ERP) data because such data are characterized by substantial temporal overlap (i.e., large cross-loadings) between the factors, and, because researchers are typically interested in the results of subsequent analyses (e.g., experimental condition effects on the level of the factor scores). In this context, relatively small deviations in the estimated factor solution from the unknown ground truth may result in substantially biased estimates of condition effects (rotation bias). Thus, in order to apply EFA to ERP data researchers need rotation methods that are able to both recover perfect simple structure where it exists and to tolerate substantial cross-loadings between the factors where appropriate. We had two aims in the present paper. First, to extend previous research, we wanted to better understand the behavior of the rotation bias for typical ERP data. To this end, we compared the performance of a variety of factor rotation methods under conditions of varying amounts of temporal overlap between the factors. Second, we wanted to investigate whether the recently proposed component loss rotation is better able to decrease the bias than traditional simple structure rotation. The results showed that no single rotation method was generally superior across all conditions. Component loss rotation showed the best all-round performance across the investigated conditions. We conclude that Component loss rotation is a suitable alternative to simple structure rotation. We discuss this result in the light of recently proposed sparse factor analysis approaches.


2020 ◽  
Vol 84 (10) ◽  
pp. 1179-1182
Author(s):  
M. A. Zhusupov ◽  
R. S. Kabatayeva ◽  
A. S. Kopenbayeva
Keyword(s):  

2018 ◽  
Vol 13 (3-4) ◽  
pp. 182-195 ◽  
Author(s):  
Aleksandr V. Gura

The prenuptial arrangement in the relatively simple structure of the Prekmurje wedding ceremony is presented in a reduced, fragmentary form. The betrothal is poorly integrated into the ritual structure, which may indicate its late inclusion in the wedding rite. It gravitates towards matchmaking or to church announcement, sometimes betrothal is completely absent, but, by the same token, it demonstrates the terminological variety of nomination models that give the most different Slavic correspondences. Also, a set of the wedding name options well-known in other Slavic areas is widely presented here. The resemblance – in structure and ritual composition – of the Prekmurje wedding on the neighboring South Slavic tradition is not as evident as on the West Slavic one, especially Slovak. In this small peripheral area, not only a significant number of linguistic Slavic archaisms is concentrated, but also a surprisingly large number of cultural “splinters” from different Slavic regions, sometimes far from Prekmurje, are present.


2020 ◽  
Author(s):  
Adrian Patrut ◽  
Roxana Patrut ◽  
Laszlo Rakosy ◽  
Karl von Reden

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, which translates into a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.


Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 863 ◽  
Author(s):  
Weiqing Huang ◽  
Mengxin Sun

A piezoelectric actuator using a lever mechanism is designed, fabricated, and tested with the aim of accomplishing long-travel precision linear driving based on the stick-slip principle. The proposed actuator mainly consists of a stator, an adjustment mechanism, a preload mechanism, a base, and a linear guide. The stator design, comprising a piezoelectric stack and a lever mechanism with a long hinge used to increase the displacement of the driving foot, is described. A simplified model of the stator is created. Its design parameters are determined by an analytical model and confirmed using the finite element method. In a series of experiments, a laser displacement sensor is employed to measure the displacement responses of the actuator under the application of different driving signals. The experiment results demonstrate that the velocity of the actuator rises from 0.05 mm/s to 1.8 mm/s with the frequency increasing from 30 Hz to 150 Hz and the voltage increasing from 30 V to 150 V. It is shown that the minimum step distance of the actuator is 0.875 μm. The proposed actuator features large stroke, a simple structure, fast response, and high resolution.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Jianyong Yao ◽  
Guichao Yang ◽  
Dawei Ma

The integration of internal leakage fault detection and tolerant control for single-rod hydraulic actuators is present in this paper. Fault detection is a potential technique to provide efficient condition monitoring and/or preventive maintenance, and fault tolerant control is a critical method to improve the safety and reliability of hydraulic servo systems. Based on quadratic Lyapunov functions, a performance-oriented fault detection method is proposed, which has a simple structure and is prone to implement in practice. The main feature is that, when a prescribed performance index is satisfied (even a slight fault has occurred), there is no fault alarmed; otherwise (i.e., a severe fault has occurred), the fault is detected and then a fault tolerant controller is activated. The proposed tolerant controller, which is based on the parameter adaptive methodology, is also prone to realize, and the learning mechanism is simple since only the internal leakage is considered in parameter adaptation and thus the persistent exciting (PE) condition is easily satisfied. After the activation of the fault tolerant controller, the control performance is gradually recovered. Simulation results on a hydraulic servo system with both abrupt and incipient internal leakage fault demonstrate the effectiveness of the proposed fault detection and tolerant control method.


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