Structural Changes In System Research Articles

Transformation of secondary vocational education in the context of technological changes

Introduction. Modern socio-economic realities associated with a new technological transition necessitate serious structural and substantive changes in the system of vocational education and training. In the 21st century, most countries of the world have faced increasing problems of inconsistency of the structure of modern vocational education with the new technological order and changing personnel demands of the economy. The problems are particularly acute in the Russian system of secondary vocational education, which has been in the mode of reform since the mid-90s of the last century and is designed to play a major role in professional self-determination and the formation of youth.Purpose setting. The objectives of the article are to analyze trends and factors that determine the need for status, structural and substantive changes in the Russian system of vocational education and training.Methodology and methods of the study. The theoretical and methodological basis of the study was the theory of continuing professional education (A. M. Novikov), integrative theory of multilevel continuing professional education (A. P. Belyaeva), professionology (E. F. Zeer), skills of the 21st century (A. J. Rotherham, D. Willingham). Methods of comparative and retrospective analysis of statistical data of Russian and international studies, content analysis of websites of secondary vocational education institutions were used in the work.Results. The results of the study are: the analysis of trends and factors determining changes and improving the efficiency of the functioning of vocational education and training systems; identification of factors of synchronization of the Russian system of secondary vocational education, the labor market and the personnel needs of enterprises; substantiation of the need for status and structural changes in the system of Russian secondary vocational education.Conclusions. The practical significance of the research is to demonstrate the possibilities of retrospective, prognostic and comparative analyses in assessing the activities of secondary vocational education and training institutions, their transformation into other educational systems.

Experimental research on damage identification of fully free beams based on modal shapes

Ship damage identification is a new field of ship research, which is of great significance to damage control, life and property safety and strategic decision-making, but there is no effective method for ship damage identification. The structural system changes caused by ship damage are usually represented by the change of system mass, stiffness and energy dissipation characteristics, and then the change of structural dynamic characteristic parameters, which provides a theoretical basis for ship damage identification. In this paper, the ship is simplified as a beam model with fully free boundary conditions. Based on the dynamic characteristic parameter of the modal shape, the damage identification of the ship under six damage conditions is carried out through numerical simulation and experimental verification by using COMAC and the derived indexes of curvature mode and modal flexibility. The results show that the first four orders of curvature mode difference mean index and the curvature index of modal flexibility change rate can accurately locate the damage of hull beam structure; The damage degree of hull beam can be identified by the change of curvature mode difference index, but there are some errors in this method; The curvature index of modal flexibility change rate is positively correlated with the damage degree, which can reflect the damage degree of the structure. The research results of this paper can provide new methods and ideas for hull beam damage identification.

Monitoring cointegration in systems of cointegrating relationships

Monitoring statistics for structural changes in systems of cointegrating relationships are proposed. The approach is based on parameter estimation over a calibration period. In case of homogenous systems and cross-sectional independence the pooled fully modified OLS estimator takes into account the effects of error serial correlation and regressor endogeneity. Cross-sectional dependence is allowed by using the pooled fully modified GLS estimator for homogenous systems and the fully modified SUR estimator for inhomogenous systems. The detectors show decent behaviour under the null hypothesis with controlled rejection probabilities and power against two alternatives for different data generating processes. An empirical application investigates deviations from the arbitrage parity condition for exchange rate triplets including Bitcoin. The procedures detect breakpoints in May to August 2014 and in January to May 2015 indicating an instability in arbitrage parities. Following this, a promising portfolio trading strategy based on the breakdates is constructed.

Benchmark Examples for Structural System Changes: Analytical and Numerical Approaches

Benchmark Examples for Structural System Changes: Analytical and Numerical Approaches

The Role of Vitamin D Metabolite Deficiency in the Development of Structural and Functional Disorders in Coxarthrosis

Summary. At present, there is a need to systematize the data of our own comprehensive research and literature in order to determine the role of active metabolites of vitamin D in the formation of structural and functional disorders (SFD) in osteoarthritis of the hip.
 Objective: on the basis of our own complex researches and data of literature, to determine the role of the insufficiency of vitamin D metabolites in the development of SFD in coxarthrosis.
 Materials and Methods. The basis for determining the role of active metabolites of vitamin D in the development of SFN in coxarthrosis was our own comprehensive studies of 506 patients with osteoarthritis of the hip and data from the literature.
 Results. On the basis of the theory of functional systems, a conceptual model for the development of SFD in coxarthrosis has been developed. The leading factor in the development of SFD in the rapid progression of idiopathic and dysplastic osteoarthritis of the hip is the lack of active metabolites of vitamin D. The presence of undifferentiated connective tissue dysplasia in turn causes a decrease in the absorption of provitamin D in the stomach and intestines. With a slow progression of idiopathic coxarthrosis, the leading factor in the development of these disorders is the excessive load on the hip joint. Factors of violation of biomechanical conditions and injury of the hip joint are factors of the progression of coxarthrosis of dysplastic and post-traumatic genesis. Pathogenic factors lead to functional and structural changes in systems of different levels and their elements with the development of inverted processes in the structures of the hip joint.
 Conclusions. Insufficiency of vitamin D metabolites on the background of undifferentiated connective tissue dysplasia leads to biochemical changes in articular cartilage and serum, affects both osteo- and chondrogenesis, leads to reduced immune status of patients and the development of clinical manifestations of rapid progression of idiopathic and dysplastic coxarthrosis. With a slow progression of idiopathic coxarthrosis, the main factor leading to the development of the above mentioned disorders is the excessive load on the hip joint. Factors of violation of biomechanical conditions and injury of the hip joint determine the development of SFD in coxarthrosis of dysplastic and post-traumatic genesis.

Subspace‐based Mahalanobis damage detection robust to changes in excitation covariance

In the context of detecting changes in structural systems, several vibration-based damage detection methods have been proposed and successfully applied to both mechanical and civil structures over the past years. These methods involve computing data-based features, which are then evaluated in statistical tests to detect damages. While being sensitive to damages, the data-based features are affected by changes in the ambient excitation properties that potentially lead to false alarms in the statistical tests, a characteristic that renders their use impractical for structural monitoring. In this paper, a damage detection method is presented that is robust to changes in the covariance of the ambient excitation. The proposed approach is based on the Mahalanobis distance of output covariance Hankel matrices, which are normalized with respect to possibly changing excitation properties. The statistical properties of the developed damage feature are reported, and used for efficient hypothesis testing. Its robustness towards changes in the excitation covariance is illustrated on numerical simulations and successfully tested on a numerical offshore foundation model.

Laboratory Investigation of the Temperature-Dependent Mechanical Properties of a CRTS-Ⅱ Ballastless Track-Bridge Structural System in Summer

To study the mechanical properties of the China Railway Track System type II (CRTS-II) ballastless slab track structure, a 1/4-scale specimen of a CRTS-II slab ballastless track-32-m standard prefabricated simply supported box girder bridge with three spans and two high-speed railway lines was developed. The mechanical properties of the structure under the action of daily natural temperatures were studied under the natural environmental conditions. The structural strain and relative interlayer displacements were analyzed. The results show that the temperature of the CRTS-II ballastless track-bridge structural system changes periodically every 24 h. The strain of the structural layers of the track system first increases and then decreases sinusoidally, and the internal strain of the track system lags along the vertical depth direction. The relative displacement between the layers of the ballastless track bridge structure system increases with the increase in temperature. The extreme value of the vertical relative displacement appears between the track bed and the bridge at section 1/4 in the span, so it should be paid attention to by the maintenance personnel. Due to the constraint of the shear slots, the structural strain and relative displacement at the fixed end near the shear slots are smaller than those at the sliding end. The mid-span deflection is the largest, and the overall deflection during the cooling phase is more significant than that during the heating phase.

Use of reflexive interactive design to address challenges to New Zealand dairy farming

The New Zealand dairy industry will undergo significant changes over the next decades, so as to meet sustainability challenges (environmentally, economically, socially and ethically). The objective of the current study was to tackle these challenges by attempting a radical re-design of the dairy system. The study took a structured approach called reflexive interactive design. The intention was to address complex trade-offs between competing goals, deliberately targeting structural system changes in the systems. Through a series of interviews and design workshops, two concepts were drafted. These concepts are intended to be used as vehicles to construct shared meanings, in conversation with farmers, policy makers, scientists, the public, and other influential actors. Two findings relevant for consideration in redesigning dairy systems were as follows: first, the sustainability issues the industry is facing are interconnected, so solutions to one issue have implications for the others; second, the boundaries of the system to be designed may need to go beyond the farm gate, to include other parts of the value chain, groups of farms and possibly interconnected land uses.

THREE-SECTOR MODEL OF THE HIGHER EDUCATION OF UKRAINE

Scientific study of the nature and role of education in the socio-economic development of society has made it possible to consider the essence of education from an economic point of view, namely: to investigate the problem of structural changes in the higher education system of Ukraine. There is a need for interaction of education and science with the real economic space and the solution of new market problems - training highly qualified personnel in accordance with the needs of the labor market. Given the considerable number of publications on the outlined issues, the scientific literature does not find comprehensive coverage of issues related to the study of the relationship of higher education with state regulation of education, the needs of employers and opportunities of higher education institutions of Ukraine, filling the GDP of Ukraine depending on the GDP of Ukraine specializing in specialties. The purpose of the article is to conduct a deep, thorough study of the higher education system of Ukraine, the calculation of the integral index of structural changes, the need for measures to strengthen the role of the state in improving the quality of higher education in Ukraine, taking into account the capabilities of higher education institutions (HEA) and the needs of employers in the skilled professionals. The article proposes an integral index of structural changes in the system of training specialists with higher education of higher education bachelor, which is built according to the rules of the golden section. Assessment of structural changes in the sectoral structure of higher education of Ukraine will create a theoretical basis for identifying and assessing the patterns of transformation of the institution of higher education under market relations, increasing integration and globalization of the educational space. Structural changes in the higher education system of Ukraine today are poorly researched and there is a lack of definition of indicators of structural changes assessment in the higher education system of Ukraine. The study of higher education structures in Ukraine and its structural changes revealed that the share of services that is responsible for the training of bachelor's degree specialists is much greater than the required ideal value, and the provision of specialists to provide GDP to the agriculture sector , - insignificant. This indicates that the domestic economy needs to provide the SServ sector with highly qualified specialists capable of producing high quality intellectual product – that is, demand for specialists of certain specialties, and the institute of training such personnel practically does not take into account the future needs of the market, releasing specialists, practically demanding missing in the future. The smallest deviation is demonstrated by the primary sector (SAgr), which is explained by the inertial consequences of the branch structure, and the development of which is ensured by the high scientific and technical potential of Ukraine.

Mechanical Activation of Ti-2B System: XRD Investigation of Structural Features

XRD investigation of Ti-2B system was carried out with the purpose of determining of structural changes in this system during mechanical activation. The size of coherentscattering region (CSR size) and kind II stresses (microstresses) were calculated by diffraction peaks profile analysis. It was determined that initiation of the synthesis reaction directly in mill is taking place at achievement the value of microstresses for titanium approximately equal to its yield point. Spontaneous reaction in a mill indicates that mechanical activation gives essential structural changes in Ti-2B system. So mechanical activation has essential influence on structural condition of Ti-2B system. Titanium diboride synthesized by high-temperature combustion and by mechanosynthesis have approximately equal crystallites size. These results could clarify the processes of materials structural condition after mechanical activation and have a matter for materials science.

A Framework for Accurately Informing Facilitated Regional Industrial Symbioses on Environmental Consequences

SummaryFacilitated regional industrial symbiosis (FRIS) initiatives mainly aim at increasing regional resource‐use efficiency, but should also assess and anticipate other environmental consequences of the intended structural system changes. To successfully embed environmental criteria in an FRIS process, the environmental impacts resulting from induced system changes should comprehensively address all environmental aspects relevant to stakeholders. Normative environmental assessment frameworks used in FRIS, such as life cycle assessment, fail to address the ambiguity surrounding the concept of environment itself and its social foundations. The “environment” is a polysemous (i.e., has multiple meanings), relative and subjective construction and environmental consequences of FRIS initiative should be selected by means of environmental assessment frameworks that enable subjective identification of environmental phenomena of interest. We propose such an environmental assessment framework providing both (1) a logical basis accommodating all FRIS stakeholders’ perceptions of the environment and environmental consequences and (2) a method, embedding that logical basis, for the consideration of environmental consequences in FRIS. The logical basis is built by conceptually structuring independent key elements of the perception of “environment,” that is, the relation between environmental consequences and FRIS stakeholders (object‐subject relation). This generic environmental assessment framework contrasts with the direct use of normative frameworks under which both the phenomena of interest and their indicators are conflated and predefined. The proposed framework is partially illustrated by describing its application to a specific case: the identification of phenomena of interest within an FRIS process aiming to recycle organic residues in Réunion.

Control of the probability distribution of a system state based on its structure indicator

A nonlinear dynamic system with a random jump structure is considered. When the system's structure changes, the plant's nonlinear characteristic changes in a jump and the input random binary signal also changes. The structure change is registered by the structure indicator; however, its indications are error prone. A Bayesian recurrent algorithm for controlling the plant structure and probability distribution of the plant state is developed.

Notes on Contributors

Notes on Contributors

A CAFÉ CHOICE PROBLEM AS AN EXTENDED ARTHUR'S EL FAROL PROBLEM

In this study, a café choice problem, which is an extension of Arthur's El Farol problem, is formulated, and is examined by an agent-based simulation. In the café choice problem, N agents predict a café's "congestion," and determine which café to visit. The N agents prefer less congested cafés because they are more relaxing. The agent is assumed to know the state of congestion of only the café he visits, and he learns to predict the café's congestion. The simulation results can be summarized as follows: (i) the agent is not necessarily acquiring the correct cognition for the café's congestion, even though sufficient time goes by; (ii) the agents are bifurcated into two groups which consist of agents with cognitions that the congestion of the café they do not visit is significantly more congested than the actual congestion; and (iii) the system does not necessarily converge to a Nash equilibrium, which is a theoretical solution, when the system's structure changes.

Conductivity studies in SnO-NaPO3 glasses

Na+ ion conductivity has been studied in SnO·NaPO3 glasses, which have been prepared over a wide range of compositions using a microwave melting technique. D.c. activation barriers seem to reflect the structural changes in system. A.c. conductivity analysis has revealed that while the power law exponent, s, seem to bear correlation to the structural changes, the exponent β of the stretched exponential function describing the dielectric relaxation is largely insensitive to the structure. Possible importance of the correlation of transport property to the variation of available non-bridging oxygen (NBO) atoms in the structure is discussed.

Exact and Accurate Reanalysis of Structures for Geometrical Changes

A reanalysis approach for geometrical changes in structural systems is presented. The solution procedure is based on the combined approximations method, where the binomial series terms are used as basis vectors in reduced basis approximations. The calculations are based on results of a single exact analysis, calculation of derivatives is not required, and each reanalysis involves a small computational effort. The method is easy to implement, and can be used with general finite element programs. Exact solutions are obtained efficiently for low-rank modifications in the geometry. Accurate solutions are achieved in cases where the basis vectors come close to being linearly dependent. Such solutions are also achieved for nearly scaled geometries, when the angle between the two vectors representing the initial design and modified design is small. Numerical examples demonstrate the high accuracy achieved with a small number of basis vectors

Analysis of time-dependent effects in concrete structures using conventional linear computer programs

Analysis of the time-dependent changes in displacements, internal forces, and reactions at the supports in continuous reinforced concrete structures cast, prestressed, and loaded at different stages is frequently needed in design to satisfy the serviceability requirements. The time-dependent parameters considered in the analysis are creep and shrinkage of concrete, relaxation of prestressed steel, sequence of construction, and changes in structural system and support conditions. A procedure of analysis is presented using conventional linear analysis computer programs. The analysis procedure is explained through examples to demonstrate its simplicity and applicability.Key words: analysis, computer program, creep, displacement, frames, precast concrete, prestressed concrete, relaxation, shrinkage, time-dependent.

Medical residents' education about occupational therapy: implications for referral.

The purpose of this study was to assess sources of physician education concerning occupational therapy and to determine whether these sources influence occupational therapy referral rates. One hundred fifteen medical residents from Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, were surveyed. Residents learn about occupational therapy through informal, direct, and interactive types of contacts (touring occupational therapy departments, having personal contact with an occupational therapist, having a family member receive occupational therapy). Perceived knowledge about occupational therapy was not significantly associated with referral rate, but it did influence a resident's desire for further education about occupational therapy. Strategies for increasing medical residents' understanding of occupational therapy and for increasing their referrals to occupational therapy include opportunities for small group role playing, structural system changes within clinical sites, and direct marketing to consumers.

Structural System Changes by Means of Forcedly Applied Restraints

This paper analyzes the effects produced by the forced application of delayed restraints in viscoelastic structures. Such restraints are frequently used for structures whose statical system changes during construction. Assuming a linear creep law, for homogeneous viscoelastic structures with rigid restraints, the problem can be studied by superimposing two basic problems: structural system change and stress relaxation. The results obtained demonstrate that the redundant reactions at the additional restraints undergo a rapid initial drop, and then start to increase only after a certain time interval. This structural behavior is due to the fact that the relaxation phenomenon involves stress decreases that are much more rapid than the stress increases induced by the structural system change. It follows that, after the application of these restraints, the structure undergoes a significant stress redistribution (about 30%). An invariance of the stress state occurs only for the limit case, where the application of additional restrains is realized immediately after loading, that is, when the structure has undergone only elastic deformation.

Erratum: “Homogeneous Structures Subjected to Repeated Structural System Changes” by Lev Khazanovich and Anastasios M. Ioannides; original paper by Luigino Dezi, Giovanni Menditto, and Angelo Marcello Tarantino (May, 1992, Vol. 118, No. 5)

Erratum: “Homogeneous Structures Subjected to Repeated Structural System Changes” by Lev Khazanovich and Anastasios M. Ioannides; original paper by Luigino Dezi, Giovanni Menditto, and Angelo Marcello Tarantino (May, 1992, Vol. 118, No. 5)