Types Of Elements Research Articles

Elements of a Timber Lamella Structure: Analysis and Systematization of Joints

The subject of this paper is the elements of a timber lamella structure: the lamellae and their joints. The lamella structure is usually in a diamond pattern, so it relies on additional elements to achieve stability. The analysis of the elements precedes the design of a prototype of a timber lamella vault. The characteristic diamond pattern can be kept for the design of rigid or semi-rigid joints. The design of the joints is challenging, so this paper focused on the analysis and systematization of joints designed for timber lamella structures. The existing timber lamella joints were classified and analyzed based on five parameters: eccentricity, load capacity, the number of elements, easiness of assembly, and adaptability to the circular cylindrical surface, to systemize the existing joints and propose a new one. A design for a new joint was proposed based on the presented joints. The systematization and discussion gave a comparison of all joints, their advantages, and limitations. The conclusion was that the geometry of a circular cylinder and the type of elements for the prototype confirmed all the benefits of the historical lamella structures: uniformity of elements, easy assembly, and economical design.

The new generation of the FASBs Conceptual Framework

Purpose: The article presents and comments on the main structures, key approaches, and content of the new conceptual framework promulgated by the Financial Accounting Standards Board (FASB) in December 2021.Methodology/approach: Descriptive-analytical and content analysis.Findings: After presenting the modernization of FASBs conceptual approach towards financial reporting, the article presents the results of this modernization. It shows how the primary users have been redefined and it also describes the quality and constitutive elements of financial statements, how the components of these elements are measured, and the principles for shaping general purpose financial reporting. The article points out important differences between the FASB Framework 2021 and the IFRS/IASB Framework 2018 regarding the definition of a reporting entity, the types of financial statements, the number and type of elements of the financial statements, the definition of assets, and the quality of financial information in the notes to the financial statements.Practical implications: FASB modernized approach verifies and develops the conceptual frameworks as a financial reporting theory. It confirms their role as the basis for the standard-setting function, and interpreting standards and financial statements. In this way, the general level of distrust towards financial reporting relevancy and reliability may be reduced, increasing the opportunities to use the new FASB framework for a broadened and deepened interpretation of Polish financial reporting and auditing regulations and practice. As a result, it allows them to be better shaped and taught, and it provides a more informed direction for research.Originality/value: This paper is probably the first public presentation in Polish of the ideas of the new FASB conceptual framework for financial reporting.

A localized stress field approach for calculating the critical stress intensity factor for an isotropic solid at atomistic scale

Crack growth initiation in brittle materials is generally studied using the stress intensity factor (SIF) since linear elasticity is assumed to be valid in the crack-tip region. The critical SIF is the SIF just before the onset of crack growth. In atomistic simulations, the “local” critical SIF is usually found indirectly by relating it to the “global” energetically calculated critical energy release rate. Since the crack growth happens at the crack tip, a method for calculating critical SIF (at a state just before crack growth initiation) directly by near-tip stress field has been implemented. The implementation of this methodology for amorphous isotropic solids is not trivial due to the random arrangement of atoms. Further, the presence of two types of elements in amorphous solids (silica is considered here) complicates the process since the volume occupied by each atom will be different (making the use of virial stress extremely complicated). In the present work, it has first been shown that the amorphous solid is indeed linear elastic isotropic by conducting various tests for finding elastic constants and showing that only two of them are independent. Then, a near-tip stress field is calculated by averaging the analytically calculated stress. The near-tip stresses in amorphous silica, validates the presence of linear elasticity beyond a small region from the crack tip. Even with the truly amorphous nature of silica, the minimum reported R2 for the inverse square-root fit (K-dominance) is around 80% at the critical state just before the onset of crack growth. The value of critical SIF calculated directly from the near-tip stresses in the present work comes out to be very close to those predicted by other indirect methods (experiments and atomistic simulations). The proposed method in the present work has a general applicability to measure the critical SIF directly using the near-tip stress field for any amorphous isotropic solid at the atomistic scale irrespective of the number of type of constituent elements.

Natural Frequency Analysis of Monopile Supported Offshore Wind Turbines Using Unified Beam-Column Element Model

Assessment of the natural frequency of the offshore wind turbine (OWT) system is a critical task in design to avoid resonance. The natural frequency of the monopile supported OWT may change during operation and needs to be calculated regularly. Conventional numerical methods separately model different components of the OWT system using various element types, which require tedious data manipulations and are inefficient to assess the changing natural frequency of the monopile supported OWTs. This paper develops a unified beam-column element by directly integrating the soil-pile interactions in element formulation. The proposed method is applicable for different components of the OWT system, including the rotor, the tower, the transition piece, and the monopile foundation, which enables an integrated and efficient OWT analysis by using only one type of element. The pile-soil interactions are directly considered in the element formulation. The tedious soil spring elements are avoided. Definitions and formulations of the proposed element are provided and the numerical solution procedure for the natural frequency analysis of OWTs is illustrated. The accuracy of the proposed element is validated against several closed-form solutions and the distributed spring model. The proposed method is also applied to analyze the natural frequencies of six OWTs in practice. The calculated results are consistent with the field measured data.

Component-Oriented Modeling Method for Real-Time Simulation of Power Systems

This paper proposes a component-oriented modeling method for power system simulation, which optimizes the modeling process of the FPGA-based real-time digital simulator (FRTDS) to enhance its computational efficiency. In this paper, a component modeling method for various types of elements in the power system is presented, which makes the modeling process in FRTDS more user-friendly and highly scalable. By applying the concepts of combination and reconstruction of components to electrical components, the component-oriented modeling method becomes better suited for combined elements with fixed connection modes and elements that require online model replacement in the power system. Utilizing the characteristics of component-oriented modeling, the variable declaration structure and node elimination strategy in the simulation script are optimized, enabling the simulation script to fit better with the hardware structure of FRTDS. Additionally, a substation is simulated in FRTDS with a simulation step size of 50 µs, thus verifying the correctness of the component-oriented modeling method and its ability to improve the computational power of FRTDS.

Construction of high-precision DEMs for urban plots

ABSTRACT High-precision digital elevation models (DEMs) are the basic data for constructing digital cities. With the acceleration of urbanization, the topography of urban plots is constantly transformed by human activities, so that surface morphology shows the characteristics of diversification and discontinuity. Existing modelling methods focus on the expression of continuous terrain. Constructing high-precision DEM in urban plots is still challenging. A block-based modelling method that considers the morphological characteristics of urban plot elements was proposed. The Jinzhai County urban area was selected as the research area. The elements of urban plots were classified into six types, in which the boundaries and elevation information were extracted with real sense 3D models, Digital Orthophoto Maps (DOMs) and dense matching point cloud data. The DEMs of the 6 types of elements were generated separately with different methods, that are fused to complete the DEM of urban plots. The DEM obtained using the method in this manuscript was consistent with the reality in terms of topographic relief within each element and clarified the boundary of each element. The accuracy assessment showed that the RMSE results of roads, slopes, other terrains and natural terrains are approximately 0.05 m, which meets the elevation accuracy requirements of the 1:1000 large-scale mapping.

Theoretical and experimental study of damaged reinforced concrete shear walls strengthened with FRP composites

The present paper presents the results of a theoretical and experimental program developed to study the seismic performance of precast reinforced concrete wall panels, strengthened with composite materials. These type of elements, also known nowadays as lightly reinforced shear walls with medium ductility (DCM), were widely used between 1955 and 1990 in different European countries (Serbia, Bulgaria, Polonia, Romania etc) being designed at that time without using the principle of shear force associated to the bending resisting moment. The current results refer to the investigation made on five specimens, one “as-built” solid wall, two walls with initial opening and two walls with cut-out opening. Usually, the cut-out procedure is applied cutting the concrete and reinforcements in order to create a new opening or enlarging an existing one. This intervention is widely requested by owners of apartments when they reconfigure the architecture of flats, but this procedure could influence the seismic behaviour by weakening the initial performance of the wall, especially due to the reduction of stiffness. In order to investigate the specimens’ seismic behaviour, in-plane reversed cyclic lateral loadings were applied together with axial vertical loads. The specimens were monitored through the experimental tests using strain gauges, pressure and displacement transducers. Based on the experimental investigations performed on the reference undamaged walls, the specimens were repaired, then after were strengthened with the aim to reestablish the initial capacity of the elements without an important influence to the stiffness. The strengthening strategy proposed had used externally bonded FRP composite reinforcement (EBR-CFRP) and near-surface mounted FRP composite reinforcement (NSM-CFRP). The strengthened elements were tested again to study the behaviour of elements and the effectiveness of the proposed solutions. A numerical analysis was performed in order to check on the accuracy of using simple numerical models to predict the behaviour of strengthened shear walls.

Generation of three-dimensional polarization-controlled tunable multiplex focused optical vortex and vector vortex beams via liquid crystal geometric phase

Optical vortex beams carrying the orbital angular momentum (OAM), especially vector vortex beams, play essential roles in many fields such as optical communication and optical manipulation. In recent years, focusing and multiplexing optical vortex beams have attracted significant interest and become important research topics. In this study, a new type of liquid crystal geometric phase optical element is demonstrated to achieve multiplex focused optical vortex (FOV) beams. The 3D coordinates and the topological charges of each FOV in arrays can be customized on demand. Meanwhile, the distribution of arrays can be switched by the polarization of the incident light. Furthermore, the liquid crystal element is modified to generate multiplex focused vector vortex beams (FVVBs) based on the superposition of multiple OAM states. Similarly, the positions, the Pancharatnam topological charges, and the polarization orders of FVVBs can be preset as required. Besides, the polarization direction of incidence controls the polarization states of the generated FVVBs. This research achieves customized polarization-controlled multiplex FOVs and FVVBs with both multichannel and focusing properties, providing more flexibility for applications.

Analysis of Pleated Discrete Pore Non Woven Layer Type Filter Element for Naval Applications

In naval applications generally, the pleated discrete pore non-woven layer filter element is used. Filters used for such applications require maximized filtration rate, lower pressure drop, higher permeability, effective pore size distribution and good filtration efficiency. In other most common wire mesh filter element types, the geometric parameters are well defined and can easily be modelled. In the case of non-woven layer filter elements the pores are arranged in a randomly distributed manner and the modelling becomes difficult. In this present study a new approach was contemplated for modelling the same. The fluid flow through the filter element is by percolation phenomenon. Using Darcy’s law approach, the pressure drop across the filter element for different flow rates, were found analytically by considering the flow resistance in axial, radial and circumferential directions. The theoretical prediction made by CFD analysis is correlated with actual model behaviour and a good degree of correlation is obtained which shows the efficacy of this method for wider use in similar application. 
 

Syntactical method for reconstructing highly fragmented OOXML files

A common task in computer forensics is to recover files that lack file system metadata. In the case of searching for file fragments in unallocated space, file carving is the most often used method, which is ideal for unfragmented data. However, such methods and the tools based on them are ineffective for recovering OOXML files with a high fragmentation level. These methods do not provide reliable determination of the correct order of fragments. Techniques for reconstructing documents based on the analysis of words and phrases are also ineffective in fragmented OOXML documents. The main reason is that OOXML files are ZIP archives and, as a result, store data on disk space in a compressed form. This paper proposes a syntactical method for reconstructing OOXML documents based on knowledge about the internal structure of this file type, regardless of their content. The details of the implementation of the reconstruction algorithm and the peculiarities of restoring certain types of local elements of the document were considered. The efficiency of the algorithm was tested on the Govdocs1 and NapierOne datasets. The proposed method was applied to 4096-byte data blocks, which correspond to the standard cluster size in different file systems. The experimental results confirmed the method's suitability for practical use with 82.97 % of recovered files, including 34.38 % reconstructed completely, 0.43 % excluding the last 21 bytes at most, and another 48.16 % excluding embeddings that require other approaches. In the latter case, obtaining a fully working document without displaying graphic images and other contents of different embeddings is possible. The presence in OOXML files of CRC-32 hashes of the uncompressed data stream of each local element allows us to confirm the correctness of information recovery and its integrity unambiguously. Simultaneously, the method's effectiveness depends mainly on data verification methods during the reconstruction of local elements that occupy at least three clusters in the file. Therefore, this method is supposed to be improved by developing new mechanisms for verifying XML elements.

Comparative analysis of the working bodies of the vibrating mixer of bulk feed

BACKGROUND: The paper is devoted to the preparation of highly homogeneous bulk feed mixtures. It is known that the efficiency of the mixing process increases significantly when vibra-tion is applied, while reducing the time to achieve maximum uniformity of the mixture and reduc-ing the energy costs of mixing. In some cases, vibration can only intensify the main process, and in others it can cause specific vibration effects that are used for mixing.
 AIMS: Increasing the homogeneity of the mixture due to vibration effects.
 METHODS: A laboratory-experimental vibrating mixer of continuous bulk feed has been de-veloped for conducting research. Its general structure and principle of operation are considered, the influence of design features of replaceable working bodies on the quality of the mixing pro-cess is analyzed.
 RESULTS: Comparative analysis has shown that mixing elements with complex vibration con-tact surfaces provide a sufficiently high quality of the resulting mixture, but the mixer perfor-mance is relatively low. To increase productivity while maintaining consistently high quality, flat working bodies with holes in the form of isosceles triangles are proposed. During the studies of their work, a decrease in the uniformity of the resulting mixture was revealed, therefore, it is pro-posed to install concave or curved triangular plates under the holes. This technical solution allows us to obtain the quality of the feed mixture that meets the requirements without reducing produc-tivity.
 An additional way to intensify the mixing process, regardless of the type of working bodies, is the hinge fastening of the mixing elements. In addition, using a special mechanism, it is possi-ble to change the speed of mass movement inside the vibrating trough and, accordingly, the per-formance of the entire installation as a whole and the mixing intensity.
 CONCLUSIONS: All types of mixing elements have been successfully tested. The laboratory-experimental vibrating mixer has passed the production test as part of a small-sized feed unit.
 The article describes the history of the development and creation of the first domestic neutralizers of exhaust gases of internal combustion engines, which began with testing and research of foreign neutralizers. Sequential stages of design, study and testing of domestic converters for gasoline and diesel engines are considered. There are described the following processes: the process of developing methods for testing engines for toxicity and the process of creating estimated indicators and developing normative and technical documents in the field of toxicity of engines and vehicles.

Experimental and numerical study of structural damping in a beam with bolted splice connection

The objective of this research is to develop a numerical model of one widely used bolted beam splice connection that dissipates energy through structural damping. The reference experimental setup is carefully designed to obtain the highly nonlinear dynamic response due to the suddenly released load. The fact that the monolithic beam with welded connection has a linear response is utilized for the initial calibration of the numerical and experimental models. Then, the numerical model of bolted beam splice connection is verified and adopted through an iterative process. The influences of time and spatial integration, bolt load application, element type, contact formulation, bulk viscosity, and mass scaling are discussed. A special attention is given to the load application and load release functions. After the verification, the Abaqus/Explicit numerical model is validated through the comparison with experimental data, where an appropriate friction coefficient is adopted. It is demonstrated that the nonlinear structural damping occurs due to the complex micro slip behavior at the contact interface.

Enhancing the trade-off between ride comfort and active actuation requirements via an inerter-based passive-active-combined automotive suspension

Ride comfort is an important indicator to evaluate the dynamic performance of automotive vehicles. One method for improving ride comfort is to incorporate an active actuator into the passive suspension. However, the improvement is closely linked with the required actuation power and force. Increased actuation requirements may lead to higher energy consumption and a larger actuator size. To enhance the trade-off between ride comfort and active actuation requirements, a new design approach for searching for the optimal passive-active-combined suspension across many different mechanical component layouts incorporating an inerter is proposed in this paper. Compared with traditional designs where the suspension is limited to a few special layouts, via this approach the optimal passive part among all network possibilities with pre-determined numbers of each element type (springs, dampers and inerters), and optimal controller parameters of the parallel active actuator can be identified. Considering a quarter-car model, with a benchmark combined active-passive suspension in which the passive part is a spring-damper, the optimal inerter-based suspension can reduce the active force by more than 48% and regenerate 6 W more average power in the active part while achieving the same ride comfort. Note that in this case, two constraints are always considered: the road-holding ability (as indicated by the dynamic tyre load) and suspension travel of the identified suspension will not be worse than those of the benchmark suspension. The optimal trade-off obtained with this approach serves as a powerful tool in the automotive suspension design as it provides guidance on the following three aspects: the optimal ride comfort, the minimum power consumption and the feasibility of specific actuation requirements, where the second point is obtained in conjunction with the power conservation theorem proposed in this paper which proves that the total power consumed by the passive and active parts will not vary with changes in the passive part and active controller parameters.

SenseNet: A Physics-Informed Deep Learning Model for Shape Sensing

Shape sensing is an emerging technique for the reconstruction of deformed shapes using data from a discrete network of strain sensors. The prominence is due to its suitability in promising applications such as structural health monitoring in multiple engineering fields and shape capturing in the medical field. In this work, a physics-informed deep learning model, named SenseNet, was developed for shape sensing applications. Unlike existing neural network approaches for shape sensing, SenseNet incorporates the knowledge of the physics of the problem, so its performance does not rely on the choices of the training data. Compared with numerical physics-based approaches, SenseNet is a mesh-free method, and therefore it offers convenience to problems with complex geometries. SenseNet is composed of two parts: a neural network to predict displacements at the given input coordinates, and a physics part to compute the loss using a function incorporated with physics information. The prior knowledge considered in the loss function includes the boundary conditions and physics relations such as the strain–displacement relation, material constitutive equation, and the governing equation obtained from the law of balance of linear momentum. SenseNet was validated with finite-element solutions for cases with nonlinear displacement fields and stress fields using bending and fixed tension tests, respectively, in both two and three dimensions. A study of the sensor density effects illustrated the fact that the accuracy of the model can be improved using a larger amount of strain data. Because general three dimensional governing equations are incorporated in the model, it was found that SenseNet is capable of reconstructing deformations in volumes with reasonable accuracy using just the surface strain data. Hence, unlike most existing models, SenseNet is not specialized for certain types of elements, and can be extended universally for even thick-body applications.

Development of a simple enzyme-linked hybrid-sandwich assay for sensitive detection of cardiac troponin I

This work reports a simple enzyme-linked hybrid-sandwich assay (ELHSA) for one vital cardiac biomarker, cardiac troponin I (cTnl). Aimed at expanding the “antibody-antigen” immunoassay, a distinct “capture antibody-target-detection aptamer” configuration was designed, in which two types of recognition elements were involved. Through systematical study, optimal antibody-aptamer combination and amount ratio between streptavidin-horseradish peroxidase conjugate and biotin-modified aptamer were obtained, and a beneficial interaction mode between cTnI and the two recognition elements was disclosed, namely, cTnI protein binding to the aptamer could be well recognized by antibody, but not vice versa. Moreover, it was first found that, apart from as a blocking agent, bovine serum albumin could be introduced in the detection probe solution as an enhancer, leading to high sensitivity and reproducibility. The BSA-assisted ELHSA can detect as low as 0.24 ng/mL cTnI and is a new, simple and effective strategy to apparently improve ELHSA for cTnI detection. Meanwhile, prominent selectivity derived from dual specific recognition elements and good applicability indicate that the developed ELHSA for cTnI is anticipated to substitute classical ELISA for diagnosis of cardiovascular diseases in the future.

Low-Scattering X-Band Planar Phased Vivaldi Array Antenna

A low-scattering X-band planar phased Vivaldi array antenna is proposed in this communication. To reduce the scattering cross section (SCS) of the antenna, two types of Vivaldi elements with the defected ground structures (DGSs) are designed, as well as an embedded absorbing array. Under the normal co-polarized (co-pol) incident waves, the reflections of the two Vivaldi elements are close in magnitude but out of phase. Hence, the scattering of the two elements cancels out in the normal direction. Besides, the problem of obvious bistatic SCS peaks, which always arise when utilizing the phase cancellation method to achieve SCS reduction (SCSR), is solved by the interlacing arrangement of the two elements. Under the cross-polarized (cr-pol) incident waves, the incident power is mostly received and absorbed by the absorbing array, which is composed of the dipole elements in the array center and the slot elements on two edges. According to the measured results, the proposed phased Vivaldi array antenna achieves notable cr-pol SCSR over 6–18 GHz, and the average in-band co-pol SCSR reaches 20 dB simultaneously, without any deterioration on the radiation and scanning performances compared to a referenced one.

Using multimodal language learning histories to understand learning experiences and beliefs of second language learners in Japan

AbstractThis study explores the possibilities of using digitally produced multimodal language learning histories (MLLHs) to understand the experiences of learning a second language (L2) of a group of university students in Japan (N = 21). The study observes that learners’ MLLHs are texts in which the visual elements of language, place, person, learning resource, and self‐analysis of learning process are represented visually. It also identifies 4 patterns in the ways the MLLHs are constructed by focusing on a certain type of visual element. Person‐oriented MLLHs focus on L2 learning as emotional experience. In resource‐oriented MLLHs, learning is perceived to occur because of engaging with language via favorite media. In analysis‐oriented MLLHs, learning is regarded as a matter of going up and down the scale of linguistic measures. Place‐oriented MLLHs emphasize being on site at an L2‐speaking region as being the key in the era of globalization and mobility. These patterns reflect learners’ beliefs on L2 learning as viewed from a contextual perspective. This study further argues that a multimodal approach can have a significant influence on making visible learners’ subjective perspectives and beliefs as lenses through which they frame their learning experiences, as well as visualizing the dynamics and individualities of learning.

Information Complexity Ranking: A New Method of Ranking Images by Algorithmic Complexity.

Predicting how an individual will perceive the visual complexity of a piece of information is still a relatively unexplored domain, although it can be useful in many contexts such as for the design of human-computer interfaces. We propose here a new method, called Information Complexity Ranking (ICR) to rank objects from the simplest to the most complex. It takes into account both their intrinsic complexity (in the algorithmic sense) with the Kolmogorov complexity and their similarity to other objects using the work of Cilibrasi and Vitanyi on the normalized compression distance (NCD). We first validated the properties of our ranking method on a reference experiment composed of 7200 randomly generated images divided into 3 types of pictorial elements (text, digits, and colored dots). In the second step, we tested our complexity calculation on a reference dataset composed of 1400 images divided into 7 categories. We compared our results to the ground-truth values of five state-of-the-art complexity algorithms. The results show that our method achieved the best performance for some categories and outperformed the majority of the state-of-the-art algorithms for other categories. For images with many semantic elements, our method was not as efficient as some of the state-of-the-art algorithms.

Aeromonas spp. from hospital sewage act as a reservoir of genes resistant to last-line antibiotics.

Aeromonas species are opportunistic pathogens distributed widely in the ecosystem. They are known to be capable of acquiring antibiotic resistance genes, including those encoding proteins against last-line antibiotics, such as the tmexCD-toprJ, mcr and carbapenemase genes. We investigated the genomic and phenotypic characteristics of tmexCD-toprJ-positive Aeromonas strains collected from human, animals, and water samples, particularly those from hospital wastewater in China. Samples were collected from living animals, meat, water and human. Aeromonas strains in these samples were isolated in selective media. Antimicrobial resistance profiles of all Aeromonas strains were tested by the broth microdilution method. The presence of tmexCD-toprJ was verified by polymerase chain reaction (PCR). All tmexCD-toprJ-positive (n=36) and selected tmexCD-toprJ-negative (n=18) Aeromonas strains were subjected to whole genome sequencing. Carriage of antimicrobial resistance genes, the genetic environment of tmexCD-toprJ and genetic diversity of tmexCD-toprJ-positive Aeromonas strains were determined by bioinformatics analysis. Phylogenetic tree of the Aeromonas strains was built by using the Harvest Suite. Among the 636 Aeromonas strains isolated from different sources, 36 were positive for tmexCD-toprJ, with the highest prevalence of tmexCD-toprJ being found in fishes (8.8%, 95 CI% 3.6-17.2%), followed by hospital wastewater (6.5%, 95 CI% 4.3-9.3%), river water (2.0%, 0.1-10.9) and duck (1.2%, 95 CI% 3.6-17.2%). All tmexCD-toprJ-positive Aeromonas strains carried multiple antimicrobial resistance genes and exhibited resistance to different classes of antibiotics. Co-existence of tmexCD-toprJ, mcr and blaKPC-2 were identified in 21 strains. The tmexCD-toprJ-positive Aeromonas strains were genetically diverse and found to belong to four different species that could be clustered into three major lineages. The tmexCD-toprJ gene clusters were predominantly located in the chromosome (35/36) of Aeromonas spp., with only one strain carrying the plasmid-borne tmexCD-toprJ cluster. The tmexCD-toprJ genes were associated with seven different types of genetic environments, each of which carried distinct types of mobile elements that may be responsible for mediating transmission of this gene cluster.

An Analysis of The Types of As-If Elements and Narratives in Pretend Play

The purpose of this study was to analyze the types of asif elements and narratives that appear in pretend play. A total of 29 children participated in this study. These included ten 3yearold children (7 boys and 3 girls), nine 4yearold children (5 boys and 4 girls), and ten 5yearold children (6 boys and 4 girls). Five undergraduates majoring in early childhood care and education were trained to observe and record the asif elements and narratives in the pretend play. The children were divided into 6 groups of 5 children each, and one group of four. The children participated in three pretend play sessions. The first session’s theme was ‘my house and my family’, the second session’s theme was ‘our town’, and the third session’s theme was ‘the castle’. The duration of each play session was 30 minutes. To facilitate the pretend play, 3 observers read fairy tales based on each session’s theme to the children for 10 minutes as an introductory activity and the pretend play session had a duration of 20 minutes. In addition, to activate the pretend play, toys related to each pretend play session and dramatic costumes (for example, prince and princess costumes) were provided. The researcher and five research assistants observed and recorded all play conversations and behaviors. In addition, two video camcorders were used to record all the play sessions. The mean and standard deviations of the asif elements were calculated. The results were as follows: First, the types of pretend play were ‘theatrical pretend play’, ‘doll dramatic pretend play’, and a ‘mix of theatrical and doll dramatic pretend play’. The objects of pretending were ‘pretending to play a role’, ‘pretending play with an object’, and ‘pretending a situation (pretending a time, pretending a space)’. The ways of pretending were the ‘selfsubjective pretend play’ and ‘projective pretend play’. Second, among the types of pretend play, ‘doll dramatic pretend play’ appeared most frequently, followed by ‘theatrical pretend play’, and the ‘mix of theatrical and doll dramatic pretend play’. In the ‘doll dramatic pretend play’, ‘pretending play with an object’ appeared most frequently, followed by ‘pretending to play a role’, and ‘pretending a situation’.