The article presents an analysis of the impact of bending optical fibers with tilted Bragg gratings on their spectral parameters. This article proves that it is possible to a choose TFBG cladding mode and the optical spectrum range related to it that allows the best metrological properties to be obtained when measuring bend. The results contained in the paper explain why the minima in the spectral characteristics, corresponding only to some cladding modes, change their shape during TFBG bending, which is important for application of Bragg gratings as bending sensors. It has been presented that in the case of TFBG we are able to aggregate the knowledge obtained during experiment to the form of a physical model of the fiber bending sensor.

In order to guarantee the accuracy of turntable angle measurement, a real-time compensation method for turntable positioning precision based on harmonic analysis is proposed in this paper. Firstly, the principle and feasibility of the real-time compensation method are analysed, and a detailed description of harmonic compensation is provided herein. Secondly, we analyse the relationships between the surface number of the polygon with the compensation order of the harmonic function and its corresponding compensation accuracy. The effects of the iterations number and the data width on calculation accuracy in the coordinate rotation digital computer (CORDIC) algorithm are analysed and the quantization models of the approximation error and rounding error of the CORDIC algorithm are established. Then, the calculation of the harmonic error function and real-time compensation processes are implemented on a field programmable gate array (FPGA) chip. The resource occupation and time delay of the phase angle calculation and the harmonic component calculation are discussed separately. Finally, the validity of the harmonic compensation method is proven through comparing the compensation effect with that of linear interpolation and the polynomial compensation method. The influences of the compensation order, the iterations number and the data width on the compensation results are demonstrated by simulation. A test platform with a laboratory-made FPGA circuit is built to evaluate the effect of real-time compensation with the harmonic function and the positioning error compensation can be performed within 760 ns. The results confirmed the effectiveness of the harmonic compensation method, revealing an improvement of the positioning precision from 54.21″ to 1.63″, equivalent to 96.99% reduction in positioning error.

In modern clinical practice in various areas of dentistry, there is a need to virtualize and determine the diagnostic parameters of the stomatognathic system (SS). The aim of this article is to provide an evaluation of correct SS structures based on a comparison of mappings in pantomography, lateral cephalometry, and volumetric tomography using bone and tooth anthropometric points. The digital measurements performed determine the applicability of the analyzed imaging techniques for clinical diagnostics by indicating discrepancies and errors in the evaluation of geometric parameters. They should verify the location of characteristic points, lines, angles, and planes in relation to spatial objects mapped on the 1:1 scale. The analyses performed confirm the appearance of bone and dental structure asymmetry in healthy patients.

This paper proposes data-based fault detection methods for an electromechanical actuator (EMA) with a brushed DC motor. The jam and winding short faults are considered in the study as the most prominent EMA faults. The fault detection is based on evaluating the properties of the motor current, considering the basic electromechanical parameters of EMAs. The main advantages are a non-intrusive approach utilising a commonly accessible motor current measurement, simple configurability, and the ability to detect faults under varying operation modes of EMA, including changes of speed, load, or movement profiles. The proposed methods have been evaluated with a custom testing system, and the results have proven the performance of the proposed approach to detect faults under varying operating conditions in industrial applications.

Current vision-based roughness measurement methods are classified into two main types: index design and deep learning. Among them, the computation procedure for constructing a roughness correlation index based on image data is relatively difficult, and the imaging environment criteria are stringent and not universally applicable. The roughness measurement method based on deep learning takes a long time to train the model, which is not conducive to achieving rapid online roughness measurement. To tackle with the problems mentioned above, a visual measurement method for surface roughness of milling workpieces based on broad learning system was proposed in this paper. The process began by capturing photos of the milling workpiece using a CCD camera in a normal lighting setting. Then, the train set was augmented with additional data to lower the quantity of data required by the model. Finally, the broad learning system was utilized to achieve the classification prediction of roughness. The experimental results showed that the roughness measurement method in this paper not only had a training speed incomparable to deep learning models, but also could automatically extract features and exhibited high recognition accuracy.

The current research work presents an investigation into use of the fitting coefficients resulting from the cubic curve fitting of the torque transducer calibration results in one direction to calculate the actual torque in the other torque direction with two methods: one is direct substitution with the nominal torque which gives a propagated linear relative interpolation error and the other is changing the sign of the second coefficient in the cubic function when using in the other torque direction. This proposed modification improves the absolute relative interpolation error by 5 to 16 times in the clockwise and counterclockwise directions based on the torque transducer’s classification.

Ultrasonic Non-Destructive Testing (NDT) is a powerful tool used for testing, verification, and inspection of material, especially for quality control and assurance. The key applications are the identification of flaws, cracks, irregularities, defects, and estimation of material thickness. The standard documents available for ultrasonic NDT are used as a guideline for the specifications and certification of the calibration reference standard block (RSB). The method for metrological characterization of the testing blocks is not specifically addressed in standard documents and is left to the wisdom of metrologists working in the ultrasonic calibration laboratories to adopt the suitable one. The ultrasonic flaw detector (UFD) is used most widely in ultrasonic NDT. The International Institute of Welding (IIW) V1 RSB standard is used as a reference to ascertain the functionalities of UFDs. In this article, we have proposed a new methodology for calibration of RSB and evaluation of associated measurement uncertainty along with influencing parameters. The proposed method conforms to the international standard ISO 2400:2012 and Indian standard IS 4904:2006 for validation purposes. According to these standards, the clauses for RSB e.g., dimension and quality of material have been examined. The expanded measurement uncertainty in thickness, ultrasonic longitudinal velocity, ultrasonic attenuation, parallelism and perpendicularity is ±0.068 mm, ±6.70 m/s, ±0.22 dB, and ±0.066 mm, respectively. The measurement uncertainty of these parameters is well within as per clauses stipulated in the standard documents except the ultrasonic longitudinal velocity for the IS standards.

This article presents selected physical diagnostic methods used in otorhinolaryngology and results of their application. In addition to the applications of methods using the capabilities of selective sensors, selected methods of hybrid diagnostics were also presented – for assessment of parameters of respiratory processes, with polysomnography as an example of using both typical diagnostic methods dedicated to otolaryngology, as well as standard EEG and ECG methods. It has been shown that in some special cases of respiratory disorders, measurements of the air flow in the respiratory tract can be supplemented with pressure measurements in selected positions within the airways. The presented optical methods and diagnostic systems are very often used in the diagnosis of diseases not specific for otolaryngology occurring in the area of the head and neck. The presented material is the second part of the study discussing both standard and widely used diagnostic methods. All presented methods are dedicated to otolaryngology. This text is a continuation of the material published in No 4 of 2021 [1].

The manufacturing and characterization of polymer nanocomposites is an active research trend nowadays. Nonetheless, statistical studies of polymer nanocomposites are not an easy task since they require several factors to consider, such as: large amount of samples manufactured from a standardized procedure and specialized equipment to address characterization tests in a repeatable fashion. In this manuscript, the experimental characterization of sensitivity, hysteresis error and drift error was carried out at multiple input voltages (����) for the following commercial brands of FSRs ( force sensing resistors): Interlink FSR402 and Peratech SP200-10 sensors. The quotient between the mean and the standard deviation was used to determine dispersion in the aforementioned metrics. It was found that a low mean value in an error metric is typically accompanied by a comparatively larger dispersion, and similarly, a large mean value for a given metric resulted in lower dispersion; this observation was held for both sensor brands under the entire range of input voltages. In regard to sensitivity, both sensors showed similar dispersion in sensitivity for the whole range of input voltages. Sensors’ characterization was carried out in a tailored test bench capable of handling up to 16 sensors simultaneously; this let us speed up the characterization process.

International standards from IEC and IEEE regulate power grid parameters such as theRMSvalue, frequency, harmonic and interharmonic distortion, unbalance or the presence of transients, that are important to assure the quality of distributed power. Standard IEC 61000-4-30 suggests the zero crossing algorithm for the measurement of the power grid frequency, but also states that different algorithms can be used. This paper proposes a new algorithm, the Fractional Interpolated Discrete Fourier Transform, FracIpDFT, to estimate the power grid frequency, suitable for implementation in resource limited embedded measurement systems. It is based on the non-integer Goertzel algorithm followed by interpolation at non-integer multiples of the DFT frequency resolution. The proposed algorithm is validated and its performance compared with other algorithms through numerical simulations. Implementation details of the FracIpDFT in an ARM Cortex M4 processor are presented along with frequency measurement results performed with the proposed algorithm in the developed system.

As the spherical hinge in the bridge swivel structure bears huge vertical pressure, the material and its structural load-bearing capacity are therefore highly-required. In the latest research, the ultrahigh performance concrete material is applied to the spherical hinge structure and the author of this article has conducted a detailed study on the mechanical properties and failure mechanism of this structure; however, there is still no real bridge application at present. In order to ensure the stability of the structure, based on an actual project, this research proposes a monitoring method for the stability of the UHPC spherical hinge horizontal rotation system, i.e., using theoretical calculations and numerical analysis methods. Besides, the mechanical characteristics of the bridge during the process of rotation are predicted, and the monitoring data of the stress of the UHPC spherical hinge, the bending moment of the pier bottom, as well as the acceleration time history of the cantilever beam end are made a comparison to judge whether the rotating posture of the structure is stable. The results show that UHPC spherical hinge features high strength and will not cause axial damage; also, the horizontal rotation system will not cause the unstability due to wind-induced vibration and structural self-excited vibration. Briefly concluded, the theoretical model is basically consistent with the measured data, i.e., the mechanical properties of the structure can be accurately predicted.

The paste content in the self-compacting concrete is about 40% in unit volume. The rheological properties of paste directly determine the properties of self-compacting concrete. In this paper, the effect of silica fume (2, 3, 4, and 5%), limestone powder (5, 10 and 15%), and the viscosity modified admixture (2, 3, 4, 5, 6, and 7%) on the rheological properties were investigated. The effect of admixtures on shear thickening response was discussed based on the modified Bingham model. The results indicate that yield stress and plastic viscosity increased with increased silica fume and viscosity modified admixture replacement. The paste’s yield stress increases and then decreases with limestone powder replacement. The critical shear stress and minimum plastic viscosity are improved by silica fume and viscosity modifying admixture. The critical shear stress first increases and decreases as the limestone powder replacement increases. A reduction in the shear thickening response of paste was observed with silica fume and viscosity modified admixture replacement increase.

Diverse strategies for identifying and finding the damages in structures have been continuously engaging to originators within the field. Due to the direct connection between the firmness, characteristic frequency, and mode shapes within the structure, the modular parameters may well be utilized for recognizing and finding the damages in structures. In current consider, a modern damage marker named Damage Localization Index (DLI) is applied, utilizing the mode shapes and their derivative. A finite element model of a frame with twenty and thirty components has been utilized, separately. The numerical model is confirmed based on experimental information. The indicator has been explored for the damaged components of a frame with one bay. The results have been compared with those of the well-known index CDF. To demonstrate the capability and exactness of the proposed method, the damages with low seriousness at different areas of the structures are explored. The results are investigated in noisy condition, considering 3% and 5% noise on modal data. The outcomes show the high level of accuracy of the proposed method for identifying the location of the damaged elements in frames.

It is often spoken and written about the use and benefits of BIM in the design, build, and exploitation phases. Based on an extensive analysis of scientific articles and practice, it has been noticed that, however, there is no comprehensive solution for the use of BIM at the stage of preparation for construction. And there is no relevant approach to the organization of construction though various software offers availability to calculate separate processes that are important for the organization of it. For example, based on the BIM model, determine the optimal place for the tower crane. But the problem is that such a local solution does not represent a comprehensive approach and does not represent apprehensive construction planning. It means, currently there is no method of planning, which will answer the questions: whether to choose a tower crane or a truck crane, where is the optimal place for unloading construction materials, considering the location of the crane, etc. Therefore, this article presents the vision and strategy of BIM development at the construction stage. The problem that should be solved now is the creation the strategy that will allow to improve the efficiency of construction works, adjusting them to the current situation in an optimal way. Therefore, the aim of the article is to combine separate ideas of BIM using in construction management as a whole and call scientists to discuss and supplement the topics of using BIM in construction management.

The study analysed a bisymmetric closely-spaced built-up member, pin-supported at both ends. Itwas bipolarly pre-stressed with a displacement (BPCSBM), and loaded with an axial compressive force. Maximum internal gap between the chords was assumed in the section, in which during the stability failure in a classic closely-spaced member, the largest lateral displacements between nodes would potentially occur. As regards the BPCSBM chosen for analysis, the issues of the buckling resistance in the presence of compressive axial load were solved using the energy method, in which the functional minimisation was performed in accordance with the Rayleigh–Ritz algorithm. The problem of BPCSBM stability was also solved using FEM. A spatial shell model was developed. The stability analysis was performed. The analysis resulted in obtaining the buckling load and the member buckling modes. A general conclusion was formulated based on the results obtained: bipolar pre-stressing leads to an increase in buckling resistance of closely-spaced members.

One of the common defects of flexible road pavement is the loss of bonding between two layers of asphalt concrete: the base course and the binder course. The occurrence of this phenomenon has a major impact on the observed state of deflection and deformation of the pavement. This effect affects the results of non-destructive tests which are used to calculate material parameters and then are used in the diagnostics of the pavement condition or design of structural strengthening. This paper discusses the influence of the various level of bonding on the result of backcalculation and the obtained elastic moduli. For the obtained values of moduli, calculations of key deformations and pavement durability were performed. Improper assumptions about the interaction between the layers affects the observed results. Additionally paper discusses the effect of pavement displacement discontinuity on the observed deflection basin and compares the results with those for a model with continuity. Numerical calculations were carried out using Simulia Abaqus software, the computational model was verified using analytical solution.

All the available modes of travel and their respective travel parameters must be known to the commuters before their trip. Otherwise they may either spend more money or more time for the trip. In addition to this, recent pandemic, rapidly spreading novel corona virus is demanding a smart solution for contactless commuting. This paper suggests a practical solution to make both the above possible and it emphasizes the applicability of two developed android applications, one for travel data collection and another to predict travel time for a multimodal trip within the study area. If the whole trip is by a single mode, the user can get the corresponding travel time estimate from “Google maps”. But, if the trip is by multiple modes, it is not possible to get the total travel time estimate for the whole trip at a time from “Google maps”. A separate travel mode for “auto” is unavailable in “Google maps” alongside drive, two-wheeler, train or bus and walk alternatives. It is also observed that the travel time estimate of “Google maps” for the city buses is inaccurate. Hence, the two modes (Buses and Autos) were chosen for the study. Unless and until the travel times and stopping times of the two modes are known, it is not possible to predict their trip times. Hence, the mobility analysis was performed for the two modes in the study area to find their respective average travel rate at peak hours, across 15 corridors and the results were presented.

It is well known that if plastic wastes are not well managed, it has a negative impact on the environment as well as on human health. In this study, recycling plastic waste in form of strips for stabilizing weak subgrade soil is proposed. For this purpose, a weak clay soil sample was mixed with 0.2%, 0.3%, and 0.4% of plastic strips by weight of soil, and the experimental results were compared to the control soil sample with 0% plastic. Laboratory tests on the Standard compaction test, Unconfined compression test (UCS), and California bearing ratio (CBR) were conducted according to the American Society for Testing and Materials (ASTM). The results of the study reveal that there are significant improvements in the strength of weak soil stabilized with plastic waste strips. Accordingly, the Standard Proctor test shows that there is a small increment in the maximum dry density of the soil when it is mixed with plastic strips. The result from the CBR test shows that there is a significant increment of CBR value with the plastic strip content. The unconfined compressive strength test also shows that increasing the percentage of plastic strips from 0 to 0.4% resulted in increased strength of soil by 138% with 2 cm length plastic strips. Therefore, this study recommends the application of plastic strips for improvement of the strength of soft clay for subgrade construction in civil engineering practice as an alternative weak soil stabilization method.

Periodic inventory and check surveys of the surfaces in engineering structures using terrestrial laser scanning require performing scans from many locations. The survey should be planned so as to obtain full coverage of the measured surface with a point cloud of appropriate density. Due to a variety of terrain obstacles in the close vicinity of the surveyed structure, structural and technical elements, as well as machinery and construction equipment (whose removal is impossible e.g. because of their role in the building and protection of the structure), it is often necessary to combine scans acquired from locations having different measurement geometry of the scene and performed in different lighting conditions. This makes it necessary to fill in blank spots with data of different spectral and geometric quality. This paper presents selected aspects of data harmonization in terrestrial laser scanning. The laser beam incidence angle and the scanning distance are assumed as parameters affecting the quality of the data. Based on the assumed minimum parameters for spectral data, an example of a harmonizing function for the concrete surface of a slurry wall was determined, and the methodology for determining its parameters was described. The presented solution for spectral data harmonization is based on the selection of reference fields representative of a given surface, and their classification with respect to selected geometric parameters of the registered point cloud. For geometric data, possible solutions to the harmonization problem have been analyzed, and criteria for point cloud reduction have been defined in order to obtain qualitatively consistent data. The presented results show that harmonization of point clouds obtained from different stations is necessary before their registration, in order to increase the reliability of analyses performed on the basis of check survey results in the assessment of the technical condition of a surface, its deformation, cracks and scratches.

In this investigation, the confinement effects of micro synthetic fibers on lightweight foamed concrete (LFC) were examined. The parameters evaluated were porosity, water absorption, shrinkage, compressive strength, flexural strength and tensile strength. Three densities were cast which were 600 kg/m3, 1100 kg/m3, and 1600 kg/m3. Besides, the number of layers (1 to 3 layers) of micro synthetic fibers was also being examined. Based on the result obtained, the porosity improved by 8.0% to 16.3%, 13.8% to 25.6%, and 9.3% to 24.5% for the LFC with densities of 600 kg/m3, 1100 kg/m3, and 1600 kg/m3 confined with 1 layer, 2 layers, and 3 layers of micro synthetic fibers, respectively. Besides, for the water absorption test, the enhancements were 6.9% to 15.6%, 20.0 to 27.1%, and 12.2 to 29.6% for the respective densities and number of layers of micro synthetic fibers employed, while the drying shrinkage improved by 48.5% to 76.8%, 57.4% to 72.1%, and 43.2 % to 68.2% for the respective densities and number of layers of micro synthetic fibers employed. For the strength properties, a confinement with 3 layers of micro synthetic fibers showed significant results, where enhancements of 153% (600 kg/m3), 97% (1100 kg/m3), and 102% (1600 kg/m3) were obtained for the compression strength; 372% (600 kg/m3), 258% (1100 kg/m3), and 332% (1600 kg/m3) for the bending strength; and 507% (600 kg/m3), 343% (1100 kg/m3), and 332% (1600 kg/m3) for the splitting tensile strength, respectively, compared to the control LFC.

In the developing countries, to build earthquake resistance construction along with seismic retrofit technology, the focus towards global warming problems along with sustainable society, production utilizing natural material, Bamboo lower-cost faster-growing and broad distribution of growth is promoted crucially. To get knowledge about the Bamboo Reinforced Concrete’s (BRC) mechanical behavior along with to verify the variations of structural properties betwixt Steel Reinforced Concrete (SRC) and BRC, researches have been made by several authors. BRC beams are simple, effective, along with cost-effective for rural construction and for which the trials are made in these studies. There is a huge concern over the lifespan of bamboo as it is employed as a substitute for steel; thus, it is enhanced by undergoing certain mechanical along with chemical treatments. The parametric study displays that regarding the robustness along with stability, bamboo is utilized in Reinforced Concrete (RC). Here, the Bamboo Reinforcement’s (BR) performance together with its durability is illustrated by assessing the laboratory determinations as of the available literature.

Steel-wood-steel connection is widely seen in many applications, such as timber structures. The stiffness of steel-wood-steel connection loaded parallel to grain for softwoods originated from Malaysia was investigated in this study. Numerical models have been developed in ABAQUS to study the stiffness connection. Softwoods of Damar Minyak and Podo have been selected in this analysis. The comprehensive study focused on the effect of bolt configurations on stiffness. Numerical analysis is carried out and the developed model has been validated with the previous study. Further investigations have been made by using the validated model. From this model, numerical analysis of the stiffness values have been made for various bolt configurations, including bolt diameter, end distance, bolt spacing, number of rows and bolts and edge distance. The result shows that the stiffness of bolted timber connections for softwood depends on the bolt diameter, number of rows and bolts, end distance and edge distance. Based on the result, stiffness increased as the diameter of the bolt, end distance, number of rows and bolts and edge distance increased. It is also discovered that the stiffness equation in Eurocode 5 (EC5) is inadequate as the equation only considered parameters which are wood density and bolt diameter. Other connection parameters such as geometry are not considered in the EC5 equation.

This paper presents a numerical investigation into the high strength steel (HSS) welded Isection overall buckling performance with respect to the major axis under combined axial compression and bending. The validation of FE models compared with the existing test data to verify the appropriateness of the element division and boundary condition was firstly conducted. In line with the FE arrangement verified, separate 890 numerical models, covering a broader range of eight steel grades (460 MPa, 500 MPa, 550 MPa, 620 MPa, 690 MPa, 800 MPa, 890 MPa and 960 MPa), different overall slenderness and various eccentricities were designated. Subsequently, the comparison of the resistance prediction codified design rules in EN1993-1-1, ANSI/AISC 360-10 and GB50017-2017 was preferentially operated, by the instrumentality of the normalized axial compression-bending moment curves. The results graphically revealed that, the provision given in ANSI/AISC 360-10 concerned in the present work was the most loose, whereas, the corresponding content set out in EN1993-1-1 and GB50017-2017 was relatively on the safe side. Taking account of the FE results, the conservative shortcomings of the considered rules in EN1993-1-1 and GB50017-2017 were further highlighted. Especially, the disparity of EN1993-1-1 and numerical results was higher to 27%, from the perspective of a definition given in the present work. In contrast, the provision in ANSI/AISC 360-10 yielded a relatively accurate prediction, on average. Based on the numerical program, an alternative formula for the HSS welded I-section beam-columns with a general expression form was sought, which intimately reflected the effect of overall slenderness.

In recent years significant progress has been made in structural application of glass elements in building industry. However, the issues related to computer modelling of glass panes, as well as analytical procedures allowing for taking into account the bonding action of PVB foil are not widely known in the engineering environment. In this paper results of numerical study of laminated glass plates are presented. The scope of the research covers over 40 cases of panes. Narrow (characterized by edge length ���� >2) and square (��/�� = 1) panes made of two or three layer laminated glass have been taken into account. The paper deals mainly with point supported glass. However, selected results for linearly supported plates have been included as well for comparison. For each considered case an advanced computational model have been developed within the environment of Abaqus software. Pointwise supports have been modelled using methods of various complexity. The obtained results have been compared with the results of standard calculations using Wölfel–Bennison and Galuppi– Royer–Carfagni hypotheses. The analytical procedures proposed by CEN have been applied as well. As a result, recommendations for static calculations of laminated glass panes have been formulated. The computational procedure based on the hypothesis presented by L. Galuppi and G. Royer-Carfagni should be considered the most universal. The remaining methods may be applied only in limited scope. In order to estimate maximum principal stress in the support zone an advanced computer model has to be used. The support may be modelled in an exact or simplified manner.