Design Codes Research Articles

Using Therapeutic Play to Increase the Oral Administration Adherence Rate of Preschool Pediatric Inpatients

Oral administration is the most common mode of medical treatment for pediatric patients. Although over 98% of the patients in the targeted pediatric unit require oral medication, the oral administration adherence rate in 2022 was 43.9%. The reasons for this low rate were identified as: (1) no relevant oral administration educational materials, (2) no relevant continued nursing education provided, and (3) lack of assistive tools and feeding aids to help administer oral medication to young children. This project was developed to increase the adherence rate of oral administration of preschool pediatric inpatients in our hospital. The improvement strategies included the design of patient-centered oral medication care guidance leaflets and QR code (quick response code) video links, the development of therapeutic play aids, adding cartoon characters to medicine feeders, and the creation of a "Rescue the Forest" picture book and video and reward stickers. The oral medication adherence rate increased from 43.9% pretest to 91.9% posttest. This project and its positive effect on the rate of oral medication adherence may be referenced by other pediatric units.

Combined Loading Effects on the Buckling Strength of Q690 Steel Tubes: An Experimental and Numerical Study

Abstract: This study investigates the stability and buckling behavior of Q690 high-strength steel cylindrical tubes subjected to combined axial compression and bending loads. Experimental testing on 27 specimens, combined with finite element analysis using ABAQUS, revealed critical insights into load-bearing capacity, deformation patterns, and failure modes. The study found that geometric imperfections, such as initial out-of-roundness and local dents, and residual stresses significantly influenced the buckling strength of the tubes, particularly those with high diameter-to-thickness ratios. Finite Element Analysis (FEA) effectively modeled the complex behavior, with deviations from experimental results ranging from 5.6% to 7.9%. Based on these findings, design recommendations, including optimized D/t and slenderness ratios, are proposed to enhance structural safety and efficiency. These results contribute to a better understanding of Q690 steel behavior and can inform the development of improved design codes for critical infrastructure applications

Ray tracing simulation and experimental validation for millimeter-wave massive MIMO systems

Abstract Accurate channel characterization is extremely helpful in channel estimation, channel coding, and many other parts of communication system design and can effectively reduce overhead. Ray tracing (RT) shows accurate channel reconstruction for specific maps, but the multipath propagation in indoor scenes is far more complex than in outdoor scenes leading to a challenge for RT. This work presents and validates an RT tool for a massive multiple-input multiple-output (MIMO) system in the millimeter-wave frequency bands with the associated channel beamforming algorithm and provides ideas for channel estimation algorithm in subsequent MIMO systems. The impact of the order of interactions, e.g. reflections and diffractions on the channel impulse response reconstruction are analyzed in the RT simulation. The comparison between RT simulated and measured results shows a reasonable level of agreement. The presented RT tool that can provide complete and accurate channel information is of high value for the design of reliable communication systems.

Symbolic regression for strength prediction of eccentrically loaded concrete-filled steel tubular columns

Concrete-filled steel tube (CFST) columns are widely employed in high-rise buildings, long-span bridges, and seismic-resistant structures due to their superior load-bearing capacity, structural efficiency, and resilience under extreme loading conditions. This study uses symbolic regression with structural design code provisions to predict the eccentric strength of concrete filled-steel tubular columns with circular shape (CCFST) and rectangular shape (RCFST). Previous studies have used two distinct approaches for estimating eccentric strength: explainable models based on theoretical derivations and black-box models derived from machine learning (ML) methods. This study proposes a hybrid model derived from the design code standards, with performance enhanced by the symbolic regression technique. This model is based on a comprehensive experimental database of 464 tests for CCFST columns and 313 tests for RCFST columns under eccentric loading from various research papers. The developed code-based symbolic regression (C-SR) displays both robust and interpretable, demonstrating high prediction accuracy with mean values of the prediction-to-actual ratios of 1.006 and 0.997 and coefficient of variation (CoV) values of 0.117 and 0.098 for CCFSTs and RCFSTs, respectively, while providing explainable mathematical expressions that align with the mechanical principles of code provisions. The developed C-SR model is benchmarked against EC4 and AISC360 standards and evaluated against the various ML techniques, demonstrating acceptable performance. The results highlight the C-SR model’s effectiveness in providing reliable predictions and valuable insights for practical engineering applications.

Longitudinal joint in decked bulb‐tee beams for accelerated bridge construction with ribbed GFRP bars: Ultimate load and fatigue evaluation

AbstractAccelerated bridge construction (ABC) techniques have gained prominence due to their potential to minimize construction time and traffic disruptions while enhancing sustainability. This study investigates the use of ultra‐high‐performance concrete (UHPC) and glass fiber‐reinforced polymer (GFRP) bars to address critical challenges in bridge durability and longevity. A novel UHPC‐filled precast deck joint was developed for a decked bulb‐tee (DBT) girder system, utilizing GFRP bars to eliminate corrosion‐related issues typical of steel reinforcement. Two actual‐size, GFRP‐reinforced, precast concrete deck slabs were erected to perform fatigue tests using the footprint of the Canadian Highway Bridge Design Code (CHBDC) truck wheel loading to verify the design. Each slab had 200 mm thickness, 2500 mm width, and 3500 mm length in the direction of traffic and rest over braced twin steel girders. The closure strip between connected precast slabs has a width of 125 mm with a vertical shear key. GFRP bars in the precast slab projected into the closure strip with a headed end to provide a 100 mm embedment length. Two types of fatigue tests were performed (i) accelerated variable amplitude cyclic loading and (ii) constant amplitude cyclic loading, followed by loading the slab monotonically to failure. Results demonstrated the system's superior fatigue performance and high ultimate load capacity, making it a promising solution for durable, efficient bridge construction.

CADAIT: a code for automatic design and AI training of microbeam systems

CADAIT: a code for automatic design and AI training of microbeam systems

Effect of the 5E model enriched with coding and digital game design activities on gifted students' academic achievement and problem-solving skills

Effect of the 5E model enriched with coding and digital game design activities on gifted students' academic achievement and problem-solving skills

Diwall: A Lightweight Host Intrusion Detection System Against Jamming and Packet Injection Attacks

The rapid growth of Internet of Things (IoTs) applications in various sectors has led to a significant increase in the number of IoT devices. This has led to the deployment of numerous IoT protocols to provide greater connectivity. However, this extensive adoption has also left them vulnerable to attack. In particular, attacks targeting wireless communication capabilities represent a significant threat. Such attacks exploit various vulnerabilities in the wireless connectivity unit, compromising its security. To counter this threat, this paper proposes a Host Intrusion Detection System (HIDS) for detecting wireless attacks. Its components are customized to support IoT end-devices using low-GHz and sub-GHz data rate protocols. The HIDS deploys a hardware tracer to monitor microarchitecture and network metrics using hardware performance counters (HPCs). It performs monitoring of network and microarchitecture metrics for a 32-bit RISC-V based wireless connectivity unit. The HIDS uses analysis and classification of monitored data for detecting memory corruption and jamming attacks. We evaluate the effectiveness of the HIDS in detecting packet injection and jamming attacks. Our FPGA implementation of HIDS has a logic overhead of about \(14.30\% \) and \(22.89\% \) of flip flops (FFs) and lookup tables (LUTs), respectively, compared to the CV32E40P baseline on an Arty A7 100T board. The design frequency and code size penalties are less than \(1\% \) for a RISC-V processor with a LoRaWAN protocol stack.

A Simplified Analysis Model for Predicting the Crack Width and Deflection of Reinforced UHPC Shallow T-Shaped Beams Under Four-Point Bending

To predict the mid-span deflection and crack width of reinforced ultra-high-performance concrete (R-UHPC) shallow T-shaped beams, a simplified analysis model comprising a bilinear curve with several characterization points is proposed in this paper. The proposed model is distinguished from existing deflection and crack width prediction methods by its consideration of several significant factors, including the tensile stiffening effect, tension contribution of UHPC post-cracking, nonconstant bond behavior of the interface, and shrinkage and creep effect. To obtain closed-form solutions, the proposed simplified analysis model directly incorporates the bond properties from bond tests, thereby eliminating the reliance on constant bond stress simplification and the subsequent necessity for member calibration, which is commonly required in existing design codes for UHPC-based structures. To validate the proposed model, six reinforced UHPC shallow T-shaped specimens with dimensions of 3.7 m × 0.7 m × 0.22 m, varying reinforcement ratios and fiber types within UHPC, are utilized and tested statically under four-point bending conditions. The experimental values obtained from these tests are then compared with the theoretical calculations derived from the simplified analysis model. The ratios of mid-span deflections and crack widths at reinforcement yielding, calculated using the simplified analysis model, to the counterparts from experimental values are found to be within a range of 0.9 and 0.95, respectively. The average percentage of differences between experimental and predicted values for the deflections and crack widths at reinforcement yielding are 4.2% and 5.8%, respectively. These findings demonstrate that the simplified analysis model proposed is accessible and accurate for predicting the deflection and crack width of reinforced UHPC shallow T-shaped beams, which has the potential to be a valuable reference for the design and calculation of such beams.

Structural reliability assessment of a historical reinforced concrete building using numerical analysis and NDT techniques

AbstractThis paper presents a case study of a methodology for assessing the structural reliability of an early reinforced concrete structure using a combination of primarily non‐destructive diagnostic and advanced numerical analysis methods. The case study examines the historical Csíky Gergely Theater in Kaposvár, Hungary, built in 1911. At that time, the design methodology and construction process were carried out using a relatively rudimentary standard framework. This study demonstrates that a multi‐phase assessment procedure integrating numerical analysis and primarily non‐destructive testing techniques can significantly reduce structural analysis uncertainty. This approach allows for an optimal selection of the reliability index (βtarget), even when deviating from design standards. Based on this modified reliability index and considering the diagnostic and material test results, the partial factors used for the assessment can be optimally adjusted, and in most cases reduced, compared to those in design codes for new structures. Consequently, the extent of structural interventions needed to increase the load‐bearing capacity can be minimized.

Novel Visualization of Building Earthquake Response Recorded by a Dense Network of Sensors.

The strong motion records collected in full-scale structures provide the ultimate evidence of how real structures, in situ, respond to earthquakes. This paper presents a novel method for visualization, in three dimensions (3D), of the collective motion recorded by a dense array of sensors in a building. The method is based on one- and two-dimensional biharmonic spline interpolation of the motion recorded by multiple sensors on the same or multiple floors. It is demonstrated on novel data that have been recorded recently in a 50-story skyscraper, uniquely instrumented with multiple triaxial accelerometers per floor, approximately at every five floors above ground and at two basement levels, and with rotational seismometers and two borehole arrays measuring the motion of the soil very near the building foundation. The method is computationally efficient and suitable for real-time application and rapid assessment of structural health. The animations provide invaluable insight into the 3D structural response of the building as a whole, including wave propagation through the structure and the interplay between translations and rotations, which will be useful for testing existing and developing new methods for structural health monitoring of buildings and for the further development of building design codes. Animations of selected earthquakes can be found on YouTube at @TPYC-seismic.

Shear performance of RC slab-wall connections considering out-of-plane offsets reinforced with various types of shear reinforcement details

Out-of-plane offsets causing wall discontinuities in piloti buildings can generate significant shear forces in the transfer slabs, potentially leading to brittle shear failure and slab collapse during earthquakes. To address this issue, this study investigates the effectiveness of practical shear reinforcement details for reinforcing concrete slabs in critical regions influenced by out-of-plane offsets. An experimental program was conducted on ten specimens representing slab-wall connections in piloti buildings. The main test parameters included the shear span-to-depth ratio (a/d) and the configuration of the shear reinforcement. The experimental results found that all the proposed practical shear reinforcement details exhibited favorable performance in strengthening the RC slab-wall connections for a given range of a/d ratios. Notably, these practical details outperformed conventional reinforcement configurations, particularly for slabs with a small a/d ratio of 1.5. Moreover, shear reinforcement details employing T-type units demonstrated comparable performance in reducing crack propagation compared to their U-type- and Z-type counterparts, despite having a smaller effective shear reinforcement area within the shear span. Finally, the shear strengths of the slab-wall connections were evaluated and discussed using current design codes and theoretical models.

Effects of Post-Fire Rehydration on the Mechanical Properties of Slag-Modified Concrete

Although previous research has examined the mechanical properties of concrete exposed to high temperatures, further investigation is needed into the effects of post-fire curing on the recovery of strength and stiffness of sustainable concretes produced with slag-modified cement. This study conducted an experimental analysis of the residual compressive strength and modulus of elasticity of different types of concrete (20 MPa or 30 MPa) exposed to varying maximum temperature levels (200 °C, 400 °C, 600 °C, 800 °C) and post-fire treatments (with or without rehydration). The concrete specimens were produced using Portland cement CP II-E-32. The rehydration method involved one day of water curing, followed by 14 days of air curing. Statistical analyses revealed potential improvements in the mechanical properties of concretes produced with slag-modified cement due to rehydration processes after exposure to different temperatures levels. The highest values of the relative residual strength factor (Φc) were observed in specimens exposed to a maximum temperature of 600 °C, ranging from 0.862 to 0.905. The highest values of the relative residual elastic modulus factor (ψc) were verified for a maximum temperature of 200 °C, ranging from 0.720 to 0.778. The experimental results were compared with strength and stiffness predictions of design codes. The inclusion of slag in concrete reduced microcracking during the rehydration process due to the reduced amount of calcium hydroxide in the cementitious matrix, increasing the concrete’s relative residual strength and stiffness after post-fire curing.

Family of Mutually Uncorrelated Codes for DNA Storage Address Design

Family of Mutually Uncorrelated Codes for DNA Storage Address Design

Optimization design for low-density parity-check codes in NAND flash memory systems

Optimization design for low-density parity-check codes in NAND flash memory systems

Transportation and production collaborative scheduling optimization with multi-layer coding genetic algorithm for non-pipelined wells.

The marginal wells in low-permeability oil fields are characterized by small storage size, scattered distribution, intermittent production, etc. The construction of large-scale gathering pipelines has large investment. So the current production mode is featured by single well tank oil storage, oil tank truck transportation and manual tank truck scheduling. At present, oil well production and crude oil transportation scheduling mainly rely on manual formulation, which has poor coordination and seriously restricts the release of oil well production capacity and the reduction of transportation cost. A mixed-integer linear programming (MILP) model representation was proposed in our previous work. The scale of the built model variables is huge, and the model solution time is long. In this paper, a genetic algorithm based on multi-layer coding is proposed. The first layer of the design code is the driving path of the oil tanker, and the second layer is the crude oil loading and unloading amount and the cumulative time. The algorithm expands the search domain by flipping, exchanging and shifting the code. In the case analysis part, the exact algorithm and the genetic algorithm designed in this paper are used to solve cases of different scales (5, 10, 30 and 200 oil wells) respectively, and the correctness and effectiveness of the algorithm are verified. The results show that, compared with the exact algorithm, the genetic algorithm designed in this paper can quickly solve a feasible scheduling scheme under different oil well scales, especially in the case of large-scale (200 wells) oil well groups. The optimal one-time result in the calculation example (200 wells) takes 1062.3s to run, and the total driving distance of all tank trucks in the obtained feasible scheme is 11280km. This study can guide oilfields to quickly formulate dispatching plans and minimize travel distances in non-pipeline well tanker dispatching.

Ducted Fan Design for VTOL Aircraft Flight Mission Based on Bayesian Optimization

Vertical takeoff and landing (VTOL) aircraft have great potential in both military and civil applications. Due to the high power and energy requirements of VTOL and its potential widespread use in the future, it is important to improve the overall efficiency of VTOL aircraft, where one promising way is using the ducted fan concept because of the potentially higher aerodynamic performance and noise shielding effects. The goal of this paper is to adopt an approach that can efficiently include both continuous and discrete ducted fan design variables and further to design and to optimize the ducted fan for conceptual VTOL aircraft design study. Firstly, the open-source Ducted Fan Design Code (DFDC) tool is employed for fast and efficient ducted fan analysis. Then, we formulate the ducted fan design and optimization problem as mixed integer nonlinear programming to include both class-shape-transformation-based parameters and intuitive ducted fan parameters. The performance of the ducted fan was optimized for hovering, cruising, and the overall flight mission based on the Bayesian optimization approach. The results showed that optimization considering only hovering or cruising can enhance the performance of the ducted fan at the corresponding phase, but the overall aircraft performance might not be improved. As such, the whole aircraft flight mission performance was set as the design objective while carrying out the ducted fan optimization, which in the end led to the reduction of fuel consumption from the original 828.41 kg to 713.46 kg, i.e., about 15.9% fuel saving for the selected flight mission.

Joint 5G NR Polar Code-Convolutional Code design for Massive MIMO-UFMC system

Joint 5G NR Polar Code-Convolutional Code design for Massive MIMO-UFMC system

An alternative recommendation for design eccentricity by consideration of uncoupled frequency ratio

Civil structures are prone to dynamic loadings such as strong winds or ground excitations where torsion becomes an ongoing issue. This arises from a lack of coincidence of the center of mass (CM) and rigidity (CR), known as eccentricity. Seismic design codes often introduce two types of eccentricity: inherent (geometric) and accidental. To account for structural or ground motion uncertainties, an assumption-based solution is provided by many code provisions, which considers the accidental eccentricity as a percentage (5% or 10%) of the building length perpendicular to the direction of exposed ground motion. In this study, as an alternative way to the code design parameters, a new design eccentricity formula that considers the frequency ratio (torsional frequency/translation frequency) and an effective radius of gyration to account for torsional irregularity is considered. For the extended validation of the proposed method, eighteen model buildings with six different floor plans were chosen, representing low, medium-height, and high-rise buildings. Each floor plan had model buildings with three, seven, and twelve stories. The buildings were subjected to selected bidirectional earthquake ground motions and had time history analyses performed. The results of the proposed method were compared to code provision methods, obtained using equivalent lateral force procedures, and also to those obtained utilizing the time history analysis results. It was shown that the proposed method was more effective in estimating the impact of torsional eccentricity and provided a better understanding of its impact on structural dynamic characteristics.

Enhancing the seismic stability of buckling-restrained steel braced frames in subduction interface seismic regions using viscoelastic dampers

This article proposes a stability-enhanced alternative to traditional buckling-restrained steel braced frames (BRBFs) for application in tall-rise steel buildings located in high seismic regions. The viscoelastic (VE)-BRBF is a BRBF featuring V or inverted-V bracing configurations and integrates vertically aligned VE dampers at beam–brace intersections on each story. The incorporation of VE dampers addresses two significant drawbacks of traditional BRBFs. First, it enhances the post-elastic lateral story shear stiffness, crucial for mitigating P-delta-induced inelastic drift concentrations and global instability, particularly under subduction interface events. Second, it augments inherent damping, a parameter typically low in conventional steel buildings. These improvements alleviate the need for the stability-related stringent height limitations imposed by design codes, such as the 40 m limit for SC4 buildings in Canada. Utilizing nonlinear response history analysis, the seismic stability performance of the proposed system is assessed against traditional BRBFs designed with classical strength amplification through an inelastic stability coefficient. The assessment is conducted on 10- and 20-story steel buildings in Vancouver, BC, considering seismic excitations involving the subduction interface. The results demonstrate that traditional BRBF designed overlooking height limitations failed to meet design code acceptance criteria, with several stability cases exhibiting global instability and excessive drifting. In contrast, the incorporation of VE dampers in the VE-BRBF demonstrated responses that met the design code acceptance criteria, with uniform drift distributions and mitigated P-delta effects and with residual post-earthquake drifts within repair limits, regardless of building height or seismic excitation type.