International Journal of Engineering
Volume:35 Issue: 7, Jul 2022

Poor economic growth due to Covid-19 pandemic in the last two years has resulted in a decline in indicators of public welfare. The construction industry sector also experienced a severe decline in productivity; thus, adjustments had to be made to survive the crisis situation. In addition, environmental problems due to development activities also threaten the lives and incomes of people who depend on natural products. These conditions encourage the escalation of interests that affect infrastructure projects in Indonesia. This study aimed to predict the influence of project and affected local community's interests on infrastructure projects social conflicts. Data were obtained by questionnaire from 68 project managers as respondents and analyzed using PLS-SEM. The findings of this study are that the influence of affected community is more dominant than that of project interests on project social conflicts. This shows the important role of communities in the concept of sustainable development with environmental and social perspectives. The results of this study will be useful in drafting the concept of an integrated and standardized environmental and social safeguard framework. To achieve an appropriate framework, further research is needed to examine the framework concept as a moderation of the relationship between interests and project social conflicts.

Aiming at the problem that it is difficult to realize the optimal design due to the fuzzy mapping relationship for the structural stiffness of multiple stepped cantilever beam; a stiffness matching modeling and active stiffness design approach was proposed. Firstly, by deriving out the continuous coordination conditions and the load extrapolation expressions of the cantilever joint, the stiffness analytical model and the recursive model were established for multiple cantilever beam segments, and the stiffness influence coefficient of those composition parameters were obtained by the sensitivity analysis. Then, the active stiffness optimization design process was constructed according to the stiffness design level of the stepped cantilever beam, and those implementation procedures were clearly figured out. Finally, the comparison and verification of the stiffness design of the stepped cantilever beam was carried out through numerical simulations, finite element analysis and bench test. The obtained results showed that the established models and the active stiffness design method are reasonable and effective. The stiffness match parameters are easy to meet the stiffness index requirements, and the safety factor is greater than 1; when the number of steps is not more than 5. The relative error between the match stiffness and the test stiffness is less than 15%, which can be reduced to less than 5% by adding redundancy coefficient (1.05, 1.15).

The purpose of this study is to evaluate the behaviour and the performance of reinforced concrete (RC) exterior Beam-Column Joints (BCJ) experimentally under reverse quasi-static cycle displacement test conducted for ductile and non-ductile detailed reinforcement. Two columns (one upper and one lower) and one beam were used to construct the specimen; the beam end is free, while the other ends are fixed. These specimens were subjected to reverse cyclic quasi-static stress till failure. At each cycle, the hysteresis curve, cracking loads, ultimate loads, deflection of the loaded at the free end of the beam, crack patterns, and failure mechanisms of BCJ were recorded and studied. Additionally, all specimens’ energy dissipation and stiffness deterioration were addressed. The experimental results reveal that the ductile joint (DJ) performance is more satisfactory in all the parameters than the non-ductile joint (NDJ). The ultimate load and energy dissipation of DJ is approximately 20% higher than the NDJ. However, expected beam failure occurred in the ductile joint, and the non-ductile joint underwent undesirable joint failure.

The Jakarta Government Hospital provides cancer services with several available types of equipment, one of which is the Linear accelerator (LINAC) Synergy Platform (SP) machine. The phenomenon of this machine experiencing a low effectiveness value because it is not able to handle the patient queue so it is not able to reduce the severity of cancer. The purpose of this study was to determine the factors causing the low value of Overall Equipment Effectiveness (OEE) and provide suggestions for improvement to increase the OEE value. The new approach of this research is using the Total Productive Maintenance (TPM) approach with OEE analysis as a success parameter because TPM is more identical in the manufacturing industry. Another update is using Failure Mode and Effect Analysis (FMEA) through Focus Group Discussions (FGD) with experts. The results of the study found that the factors that influenced the low OEE value on the LINAC SP machine were caused by breakdown loss of 76.29%, setup loss of 9.59%, idling and minor stop of 8.80%, and a decrease in speed of 5.29%. The continuous and consistent implementation of the TPM Pillar has increased the OEE value of the LINAC SP machine.

Texture image segmentation plays an important role in various computer vision tasks. Active contour models are one of the most efficient and popular methods for identifying the purpose and segmentation of objects in the image. This paper presents a parametric active contour model (PACM) with a robust minimization framework based on image texture energy. First, the texture features of the original image are extracted using gray level co-occurrence matrix (GLCM). Subsequently, based on the GLCM texture features inside and outside the active contour, Jensen-Tsallis divergence of energies is calculated. The Jensen-Tsallis divergence is added to the parametric active contour using the balloon equation. The divergence is maximum at the boundary between the foreground and background of the image, which results in minimizing the active contour equation at the boundary of the target object. This global minimization energy function with texture feature can avoid the existence of local minima in the PACM models. Also, as opposed to previous models, the proposed model only requires the initial contour and is not dependent on the distance of the initial contour from the target object. In terms of segmentation accuracy and efficiency, experiments with synthetic and natural images demonstrate that the proposed approach obtains more satisfactory results than the previous state-of-the-art methods.

To ensure the safe and stable operation of nuclear power plants (NPP), many non-structural components (NSCs) are actively associated with NPP. Generally, floor response spectrum (FRS) is used to design the NSCs. Nevertheless, it is essential to focus on the mounting position and frequency of NSCs which is normally ignored during the conventional design of NSCs. This paper evaluates the effect of mounting location for NSCs over the same floor in a channel-type auxiliary building. The modal parameter estimation is taken into account to capture the dynamic property of the NPP auxiliary building by the shake table test; which leads to the calibration of the finite element model (FEM). The calibration of FEM was conducted through response surface methodology (RSM) and the calibrated model is verified utilizing modal parameters as well as frequency response spectrum function. Finally, the location sensitivity was investigated by time history analysis (THA) under artificially generated design response spectrum compatible earthquakes and sine sweeps. The result showed that the right choice of location for NSCs can be an important measure to reduce the undesirable responses during earthquakes, which can reduce up to 30% horizontal and 70% vertical zero period acceleration (ZPA) responses in channel-type auxiliary buildings.

In the presented paper, the phenomenon of impact response of glass/epoxy laminates of thickness 5, 7, 10 mm subjected to impact energy of 50, 100, 150 J were numerically analyzed using the commercially available finite element software LS-DYNA. To predict the energy absorption capability and damage response, a finite element model was developed. The impact response was assessed in terms of maximum displacement, contact force at the event of an impact and energy absorption. Laminates with higher thickness showed better results in deformation and contact force generation when compared with thin laminates. The numerical results in terms of displacement and contact force are validated with experimental studies in the literature. Moreover, there is a good agreement between numerical results and experimental studies. In this study chang chang failure criteria were considered for predicting the impact response at low-velocity impact. Based on the observed numerical results, the energy absorption capability and the perforation resistance of the laminated composite structure were revealed. These results can be further referred to in the design and modelling of the composite laminated structure subjected to impact loadings. A grid independent study has been performed in this paper, which will be helpful for the researchers to select an optimized element size to reduce the computational time. In addition, the finite element analysis reasonably predicted the impact load–displacement responses and the perforation energies of laminated plates.

A Work Breakdown Structure (WBS) is a key visual project tool functioning as an obligation in managing construction projects, due to playing a crucial role from planning to execution. However, there are still several problems related to the implementation of WBS, such as miscommunication and poor development, where all involved execution parties do not accurately understand the scopes and objectives. This ultimately leads to project losses, based on cost, time, and quality, where standardization is not observed within the WBS preparation and development. Therefore, this study aims to develop a standard stadium WBS, for all involved execution parties to understand and achieve work information consistency. This was performed by mapping the Focus Group Discussions (FGDs) and Bill of Quantities (BQ) data of previous stadium projects with experts in their respective fields. The results showed the development of a standard WBS containing levels 1-6, including design alternatives, implementation requirements, and material specifications. During application, this tool helped to compile the entire scope of results-oriented projects as related guidelines and standards, with each hierarchical level from the top to the lower components. The obtained results also considered the consultants, contractors, and auditors at the planning, implementation, and monitoring stages, respectively.

The effect of frequency of speaker membrane vibration on the grain size of the silica nanoparticles (SNP) was investigated. SNP was synthesized using the alkaline fusion method under the vibration of the membrane speaker. Variations of membrane vibration used in this research were 0, 50, 100, and 200 Hz. The material compositions, crystal structure, and morphology of the synthesized SNP were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), and transmission electron microscopy (TEM), respectively. Meanwhile, its dielectric property was determined using impedance spectroscopy. The results showed that the SNP consisted of 99.35% silica and corresponded to the crystalline structure of quartz silica. The SNP size was decreased with increasing vibration frequencies. The smallest size of SNP (9.04±1.9 nm) was obtained at a frequency of 200 Hz. Moreover, the dielectric constant and dielectric losses were increased with an increase in membrane vibration frequency due to the decrease of SNP size.

Continuous deep beams (CDBs) are the most used members in constructions with highly exposing to different types of dynamic loads. It is well known that; the concrete is a brittle material and has a weak resistance to energy absorption. Using scrapped tire rubber enhances the concrete energy absorption for sustainability purposes. Timoshenko beam theory has been used to solve CDBs subjected to sinusoidal load and has been adopted for verification of numerical results of ANSYS APDL V.15.0. Seven concrete mixes have been simulated with different types and amounts of aggregate – rubber replacements. Several parameters have been studied like replacing type, percentages, shear span of beam to depth ratio (a/h) and load intensity. It was found that Timoshenko beam theory can be used for harmonic loading CDBs. Furthermore, replacement in general provided more ductility due to rubber elasticity property. Gravel replacement by 45% has the larger displacement values among the other types. Also, it has been noted that, the sensitive of concrete deep beams towards a/h ratio stills considerable for harmonic loads, i.e. minimizing the ratio leads to decrementing the deflection wave amplitudes.

In this paper, we discussed the application of a compositional adaptation approach to recommend learning resources to users in the area of software development.  This approach makes use of a domain-specific ontology in this area to find those words, which are used in the technical description of the stored cases. A point peculiar with representing cases in the proposed approach is to take into account the characteristics of included learning resources, which justify the way they support the essential operations in the case of solution. In this way, only those components that comply with user’s request would be considered in the final solution. In the paper, the performance of the proposed approach for recommending learning resources together with the status of user experience in his/ her interaction with the resulted recommending system, have been evaluated. Results demonstrate the fact that the learning resources through this approach are sufficiently beneficial for the users. Although the proposed approach has been applied for recommending learning resources in the area of software development, it can be equally applied to any technological area through developing domain-specific ontology for that area. This is mainly because any technological area has its own specific objects/ entities holding their own semantic similarities that finally lead to forming a domain-specific ontology for that area.

Eddy current distribution is important to the performance of planar eddy current probes. In this paper, the Jensen-Shannon divergences of tangential intersection angle spectrum and radial direction energy spectrum were proposed to evaluate the difference between eddy current distributions generated by circular and fractal Koch excitation coils. By the simulation for the circular and Koch shape excitation coils, it works out that the difference of the eddy current distributions between the two kinds of coils becomes larger and larger with an increase in the values of the two Jensen-Shannon divergences. At the same time, the correlation between the change of Jensen-Shannon divergence and the detectability of the short crack in the special direction was discussed through simulation and experiment results. It is found that, relative to the crack in 0° direction, the detectability of the Koch and circular differential pickup probes to the crack in 90° direction has a correlation with the Jensen-Shannon divergence of tangential intersection angle spectrum. The width of each signal generated by the two probes has a correlation with the Jensen-Shannon divergence of radial direction energy spectrum.

This article presents an optimization-based technique for solving the inverse kinematics (IK) of spatially redundant manipulators in agricultural environments (workspaces). A kinematic configuration of 9 degrees of freedom (DOF) manipulator with eight revolute and one prismatic joint has been modelled to improve the accessibility in complex workspaces. The proposed manipulator has been simulated for harvesting fruits and vegetables. To perform the desired task in the working environment, the IK solution of the robot needs to be determined. The IK problem has been formulated as a constrained optimization problem with the objective of minimizing the positional and orientational errors by avoiding obstacles. A 3D CAD environment with different fruits and vegetable plants has been modelled in Solidworks. A target location in this environment has been chosen to pluck the fruit/vegetables. The trunk, branches, and leaves are considered as obstructions. The collision avoidance technique was implemented using a bounding box approach by including a collision detection algorithm. IK simulations of the spatial redundant manipulator in a cluttered environment were performed and results are reported. The joint trajectories of the robot while reaching desired task-space location has been depicted using Simscape Multibody. The results demonstrate that the end-effector of the robot has been reached desired task location successfully with an accurate IK solution.The approach is adaptable in a wide range of working environments based on the simulation results of the IK solution of robots.

This research study focused on the alliance of blending silicon carbide powder of size 60 µm into dielectric oil (kerosene) with electrode revolution in electrical discharge machining of D3 steel using electrode made of copper. Peak current, pulse on-time, and electrode revolution were picked as machining variables to check their influence on the surface roughness of the workpiece. The full factorial experimentation was performed with 27 experimental runs. The analysis of variance result indicated electrode revolution as the most influential variable with a percentage aid of 32.75%, followed by peak current and pulse on-time, which accounted for 28.98 and 6.09%, respectively. The decrement in surface roughness was recorded at higher electrode rotational speed. The field emission scanning electron microscopy of machined samples was performed and results showed significant improvement on surface characteristics. The surface finish improved from 12.36 µm to 10.32 µm in silicon carbide powder blended rotational electrical discharge machining over traditional electrical discharge machining. The minimum surface roughness achieved was 4.81 µm at optimal conditions.

In order to investigate the effect of fiber volume fraction on the mechanical behavior of ultra-high performance concrete composites (UHPCC), five different volume fractions of macro steel fibers (Vf = 0.5, 1, 1.5, 2 and 2.5%) are used within identical mortar matrix. Ultra-high performance fiber reinforced concrete (UHPFRC) mix was designed to achieve a compressive strength of 155 MPa based on the particle packing method. For 12 series of UHPCC mixes, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity at 28 days are determined. Test results showed a significant improvement in splitting tensile and flexural strengths of UHPFRC with the addition of steel fibers. The maximum values of compressive, splitting tensile and flexural strengths were 155.39, 17.76, and 32.50 MPa, respectively. Stress-strain behavior of fiber-reinforced concrete composites is studied and elastic modulus values evaluated are in the range of 39.52-47.99 GPa. Empirical expressions are developed based on the test results in terms of fiber volume fraction to predict the 28-day strengths of UHPFRC. Comparing the experimental values of earlier researchers to the ones predicted by empirical equations, the average absolute error (AAE) value obtained is within 5%. The proposed model's predictions are in good agreement with the experimental values. Relationship between compressive and flexure strengths of UHPFRC isdeveloped with R2=0.99 and validated.

The rapid growth in the supply chain of electronic devices has led companies to purchase Intellectual Property or Integrated Circuits from unreliable sources. This dispersion in the design to fabrication stages of IP/IC has led to new attacks called hardware Trojans. Hardware Trojans can bargain information, reduce performance, or cause failure. Various methods have been introduced to detect or prevent hardware Trojans. Machine learning methods are one of these. Selecting the type and number of input variables in the learning algorithm has an important role in the performance of the learning model. Some previous hardware Trojan detection studies have used structural gate-level features to create data sets for machine learning models. In this paper, a method based on directed graphs for extracting features is proposed. The proposed method use Graph Centrality Algorithm and structural gate-level features. To examine the importance and the impact of the extracted features with the proposed method, three types of data sets are created as input to the learning model made with XGBoost. The trained learning models based on these three data sets show that extracting graph-based features has improved the F1-score by 10% and the ROC by 22%. The combination of these features with the structural gate-level features improved the F1-score by 17.5% and the ROC by 38.5%.

The effect of nano KCC-1/Ag and nano SiO2 in concrete have been investigated in this study. Nano KCC-1/Ag and nano SiO2 are synthesized and their characterization was investigated by FTIR, SEM, and TEM analysis. After that, these materials use as cement replacement in 1, 2, and 3 percent amounts. SEM images illustrate the denser structure of KCC-1/Ag nanoparticles. Furthermore, in the FTIR  spectra 3640 cm-1 is related to C-S-H, which is sharper and more severe in samples with nano KCC-1/Ag and nano SiO2. The results revealed that nano SiO2 and nano KCC-1/Ag both improved the microstructure of cement paste and increased the concrete compressive and splitting tensile strength. For comparison the performance of nano KCC-1/Ag and nano SiO2, the results indicated that nano KCC-1/Ag improved the microstructure of concrete better than nano SiO2. Hence, it has a better performance in enhancing the strength of concrete. The study showed that the optimal percentage of using nano KCC-1/Ag was 2%.

Vibration of a floating roof in cases of tube and foam seals has been analyzed by ANSYS. Fluid-Structure Interaction (FSI) and sloshing phenomenon have been considered. Modal responses, time waves and frequency spectrums of the roof vibrations in the two sealing cases were evaluated during horizontal seismic excitation of the tank base. Then, the effects of the main mechanical factors of the seal on the roof vibration were investigated. The roof vibration amplitude in the foam sealing case was considerably lower than that in the tube sealing case due to more damping of the foam seal. Also, the foam sealing case had higher natural frequency than the tube sealing case due to more tank-axial (vertical) shear modulus of the foam seal in relative to the tube seal. Regarding this result, the foam seal was vertically added by 50% and the tank base was seismically excited again. It was seen that this improvement in thickness has more contribution to the floating roof vibration mitigation.

High-velocity oxy fuel (HVOF) sprayed coatings can improve the corrosion resistance of bare ASTM SA213-T22 boiler steel. In this report, we have investigated the NiCrMoFeCoAl-30%SiO2 and NiCrMoFeCoAl-30%Cr2O3 composite coatings were deposited on bare ASTM SA213-T22 boiler steel for corrosion protection. High-temperature corrosion studies were conducted in a molten salt (Na2SO4-60%V2O5) environment at 700ºC under thermo-cyclic conditions. The as-sprayed composite coatings are characterized for microstructure and mechanical properties. The thermo-gravimetric method was utilized to understand the kinetics of corrosion. Characterization of the corrosion products was examined by using scanning electron microscope (SEM)/ Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The obtained results suggest both the composite coatings are favorable to corrosion resistance over the bare ASTM SA213-T22 boiler steel. The NiCrMoFeCoAl-30%Cr2O3 composite coating was concluded to present a superior corrosion resistance in the high-temperature corrosion environment because of the uniform distribution of the composite coating matrix and the development of protective protection Cr2O3 in the scale. The molten salt heat-treated chromium oxide containing coating shows good corrosion stability than the silica composite. This could be attributed to the high temperature assisted formation metal chromates, chromites and oxide layers.

The rising cost of asphalt pavements reconstruction, the discussion of non-renewable resources maintenance and reducing the harmful impacts caused by reclaimed asphalt pavement (RAP) disposal have led to reusing RAP material and studying its effects on asphalt mixture performance. In this paper, recycled asphalt mixtures with higher contents of RAP were investigated, and a method was defined for evaluating the rutting behavior of conventional and recycled asphalt mixtures. Rutting is one of the major distresses in flexible pavements, commonly caused by the accumulation of permanent deformation in the asphalt layer of the pavement structure during its service life. For study purpose, conventional and recycled asphalt samples (containing 50% and 80% RAP + rejuvenator agents) were prepared. Then indirect tensile and uniaxial repeated loading tests were conducted to obtain elastic and creep properties of the studied mixtures. The available creep power-law model in ABAQUS finite element program was used to simulate rutting. After developing models, fairly acceptable outputs have been achieved regarding wheel track test results. Moreover, results showed that the addition of 50% and 80% RAP decreased rut depth by 33% and 47%, respectively.

An efficient design of a water supply and wastewater collection system is significantly important to tackle the natural uncertainty of this system and the sustainable development goals in developing countries like Iran. To address the natural uncertainty in the water supply and the challenge of global warming, this design must be robust and this motivates a robust optimization. To consider the sustainability criteria, this design should cover all economic, environmental and social impacts. Hence, this study develops innovative solutions based on recent and traditional metaheuristic algorithms for a robust and sustainable water supply and wastewater collection system. Red deer algorithm (RDA) and Keshtel algorithm (KA) as the recent algorithms, are employed. These recent algorithms are compared with the state-of-the-art methods like genetic algorithm (GA) and particle swarm optimization (PSO). An application of our model and algorithms, is tested on a case study in North Khorasan province. After performing some analyses on the performance of our algorithms and sensitivities on the model, a discussion is provided to conclude managerial insights and findings for practitioners in the applied system.