Meaningful Block Research Articles

Determination of meaningful block sizes for rockfall modelling

The determination of the so-called design block is one of the central elements of the Austrian guideline for rockfall protection ONR 24810. It is specified as a certain percentile (P95–P98, depending on the event frequency) of a recorded block size distribution. Block size distributions may be determined from the detachment area (in situ block size distribution) and/or from the deposition area (rockfall block size distribution). Deposition areas, if present, are generally accessible and measurable without technical aids. However, most measuring methods are subjective, uncertain, not verifiable, or inaccurate. Also, rockfall blocks are often fragmented due to the preceding fall process. The in situ block size distribution is (also) required for meaningful rockfall modelling. The statistical method seems to be the most efficient and cost-effective method to determine in situ block size distributions with many blocks within the whole range of block sizes. In the current literature, joint properties are often described by the lognormal and exponential distribution functions. Today, we can model synthetic rock masses on the basis of discrete fracture networks. They statistically describe the geometric properties of the joint sets. This way, we can carry out exact rock mass block surveys and determine in situ block size distributions. We wanted to know whether the in situ block size distributions derived from the synthetic rock mass models can be described by probability distribution functions, and if so, how well. We fitted various distribution functions to three determined in situ block size distributions of different lithologies. We compared their correlations using the Kolmogorov–Smirnov test and the mean-squared error method. We show that the generalized exponential distribution function best describes the in situ block size distributions across various lithologies compared to 78 other distribution functions. This could lead to more certain, accurate, verifiable, holistic, and objective results. Further investigations are required.

Prognostic model of socio-pedagogical assistance to employment of university graduates

The paper presents theoretical and methodological grounds that update the development of a prognostic model of social and pedagogical assistance to the employment of university graduates. Problems and risks have been identified that objectively impede the entry of young people into the labor market and the negative consequences (effects) of the employment of young specialists for themselves, educational organizations of higher education, and in general, the state. On the basis of interdisciplinary analysis of domestic and foreign scientific literature, advanced pedagogical experience, the basic concepts of research were clarified and the block structure of the prognostic model of social and pedagogical assistance to the employment of university graduates was substantiated. The paper describes the interrelated target, methodological, meaningful, organizational and technological, productive blocks of the authors model. A target block of the model is presented, reflecting the target guidelines for providing social and pedagogical assistance to the employment of university graduates on the basis of analyzing the social order of society for productive primary employment of university students, studying regulatory documents in the fields of education, labor, economics, and employment centers. The methodological block of the authors model was characterized, reflecting the conceptual ideas of acmeological and activity scientific approaches, patterns and the general scientific principles arising from them (professional orientation; focus on self-development of key competencies; subjectivity; expediency and conscious perspective; activity polyphonism). A meaningful block of the prognostic model is presented, aimed at the phased implementation of semantic guidelines (subjectivity, facilitation, partnership), strategies (updating the professional and personal potential of young specialists; socio-pedagogical orientation of students to successful self-presentation; activating professional self-determination and granting the right to choose; scaffolding), methods and forms of prognostic orientation of the studied phenomenon. The organizational and technological unit of the authors model describing the set of organizational conditions of the optimal functioning of the model is considered. An effective block of the prognostic model of social and pedagogical assistance to the employment of university graduates is presented, which performs feedback functions and allows, during the justification of the criterion and diagnostic tools, to determine the dynamics and level of formation of the culture of employment of university graduates (as a result of the authors model).

Model of Formation of Teacher's Readiness to Learning on the Base of Interactive Methods as the Conditions of Creation of Students Abilities

In the article considered the psychological-pedagogical conditions of formation of teacher's readiness to learning on the base of interactive methods as a conditions for the development of creative abilities of students. On the base of psychological-pedagogical literature analysis and empirical researches, was developed a model of formation of teacher's readiness for training based on interactive methods as a condition for the development of creative abilities of students. The model of formation of teacher's readiness to the learning based on the interactive methods as a condition for the development of creative abilities of students includes the most essential properties and relationship of this process and consists of motivational-target block, theoretical block, meaningful block, procedural and effective blocks. In motivational-objective block reflects the aim, objectives and motivation of the formation of the required readiness. Theoretical block includes a complex of pedagogical principles: the principle of professional orientation, the principle of motivational supporting of the educational process, the principle of humanistic orientation of the pedagogical process. In the meaningful block of the model is determined the structure and content of the process of formation of teacher's readiness to learning based on the interactive methods as a condition for the development of creative abilities of students. Procedural block includes basic forms and methods of learning, which contributes to the formation of the required readiness. The degree of achieving this aim is reflected in a meaningful block.

Forecasting macroeconomic time series: LASSO-based approaches and their forecast combinations with dynamic factor models

In a data-rich environment, forecasting economic variables amounts to extracting and organizing useful information from a large number of predictors. So far, the dynamic factor model and its variants have been the most successful models for such exercises. In this paper, we investigate a category of LASSO-based approaches and evaluate their predictive abilities for forecasting twenty important macroeconomic variables. These alternative models can handle hundreds of data series simultaneously, and extract useful information for forecasting. We also show, both analytically and empirically, that combing forecasts from LASSO-based models with those from dynamic factor models can reduce the mean square forecast error (MSFE) further. Our three main findings can be summarized as follows. First, for most of the variables under investigation, all of the LASSO-based models outperform dynamic factor models in the out-of-sample forecast evaluations. Second, by extracting information and formulating predictors at economically meaningful block levels, the new methods greatly enhance the interpretability of the models. Third, once forecasts from a LASSO-based approach are combined with those from a dynamic factor model by forecast combination techniques, the combined forecasts are significantly better than either dynamic factor model forecasts or the naïve random walk benchmark.

Forecasting Macroeconomic Time Series: LASSO-Based Approaches and Their Forecast Combinations with Dynamic Factor Models

In a data-rich environment, forecasting economic variables amounts to extracting and organizing useful information out of a large number of predictors. So far dynamic factor model and its variants have been the most successful models for such exercises. In this paper, we investigate a category of LASSO-based approaches and evaluate their predictive abilities in forecasting twenty important macroeconomic variables. These alternative models could handle hundreds of data series simultaneously, and extract useful information for forecasting. We also show analytically and empirically that combing forecasts from LASSO-based models and those from dynamic factor models could further reduce the mean square forecast error (MSFE). Our three main findings can be summarized as follows. First, for most of the variables under investigation, all LASSO-based models outperform dynamic factor models in the out-of-sample forecast evaluations. Second, by extracting information and formulating predictors at the economically meaningful block levels, new methods greatly enhance model interpretabilities. Third, once forecasts from a LASSO-based approach and those from a dynamic factor model are combined by forecasts combination techniques, the combined forecasts are significantly better than dynamic factor model forecasts and the naive random walk benchmark.

An accurate physical knowledge-based model for behavioral modeling and digital predistortion of power amplifiers

The objective of this article is to present an accurate model for behavioral modeling and digital predistortion of power amplifiers (PAs) using physical knowledge. Starting with the physically meaningful block model, we present a novel approach to simplify the block model and propose a simplified physical knowledge-based (SPK) model. The SPK model's performance was experimentally assessed by two types of PAs (a LDMOS Doherty PA and a GaN Doherty PA) and two signals (a single carrier 16QAM signal and a 2-carrier WCDMA signal). All experimental results prove the superiority of the SPK model. Compared with the 1st-dynamic deviation reduction (DDR) approach and the 2nd-simplified DDR approach, the SPK approach achieves average ACPR improvements of 4.4 dB and 2.5 dB, respectively. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 23: 682–689, 2013.

A novel efficient dynamic programming algorithm for haplotype block partitioning

In this paper, a new efficient algorithm is presented for haplotype block partitioning based on haplotype diversity. In this algorithm, finding the largest meaningful block that satisfies the diversity condition is the main goal as an optimization problem. The algorithm can be performed in polynomial time complexity with regard to the number of haplotypes and SNPs. We apply our algorithm on three biological data sets from chromosome 21 in three different population data sets from HapMap data bulk; the obtained results show the efficiency and better performance of our algorithm in comparison with three other well known methods.

Pruning the Volterra Series for Behavioral Modeling of Power Amplifiers Using Physical Knowledge

This paper presents an efficient and effective approach to pruning the Volterra series for behavioral modeling of RF and microwave power amplifiers. Rather than adopting a pure black-box approach, this model pruning technique is derived from a physically meaningful block model, which has a clear linkage to the underlying physical behavior of the device. This allows all essential physical properties of the PA to be retained, but significantly reduces model complexity by removing unnecessary coefficients from the general Volterra series. A reduced-order model of this kind can be easily extracted from standard time/frequency-domain measurements or simulations, and may be simply implemented in system-level simulators. A complete physical analysis and a systematic derivation are presented, together with both computer simulations and experimental validations