Tec-Masters (United States)

Running Title ML prediction of punching shear in FRP slabs Abstract The increasing demand for resilient structures in earthquake-prone and high-impact areas has necessitated the accurate prediction of the punching shear strength of concrete slabs reinforced with FRP (Fiber Reinforced Polymer) and without shear reinforcement. The classical approaches, including physical testing and mathematically derived models, tend to have limitations in terms of both accuracy and speed. The present work carries out the prediction of the punching shear strength of FRP-reinforced concrete slabs by employing various machine learning (ML) techniques like decision tree, random forest, stochastic gradient boosting, and so on. The research conducted involved a thorough study through a dataset comprising experiments on slabs with different design parameters, including thickness, strength of the concrete, type of FRP reinforcement, and ratio of reinforcement, which was then used to train and evaluate the ML-based models. Out of all the models that were put to the test, the GEP (Gene Expression Programming) method attained the utmost R² value equal to 0.86, which is an indication of getting shear strength prediction more accurately than traditional models. Furthermore, the ML models were compared through statistical errors, including RMSE, MAE, and R², with the attained values being within the acceptable range. The analysis of feature importance showed that the parameters slab thickness, concrete strength, and reinforcement ratios were the key players in the determination of the punching shear strength. The present study clearly points to the machine learning potential in reducing the effort and time in punching shear strength prediction, the outcome being better design codes and standards for FRP-reinforced concrete slabs in the future. Keywords Punching shear strength; FRP-reinforced concrete; machine learning; gene expression programming; slab thickness; reinforcement ratio Article Type Research Article Subject Area / Discipline Structural Engineering / Civil Engineering Funding Information None Conflicts of Interest The authors declare no conflicts of interest. Ethics Approval Not applicable. This study does not involve human participants, animals, or sensitive personal data. Data Availability The data supporting the findings of this study are confidential and are therefore not publicly available.

Abstract The digital infrastructure in America is undergoing a change as the country struggles to deal with the increasing crisis of legacy systems. These old systems, which are deeply rooted in such sectors of the economy as health care, finances, and government, are expensive to maintain, may be easily attacked by hackers, and cannot be scaled to meet the needs of contemporary technologies. With the digital world transitioning to more adaptable, agile systems, legacy systems have become an innovation, efficiency, and security bottleneck. The microservices architecture and federated cloud systems have come out as a strong solution to these problems. Microservices provide a modular mechanism in the development of software that can be more scaled, deployed faster and more resilient. Federated cloud architectures provide interoperable data sharing, which is secure, across several cloud environments and disaggregates the silos that exist with traditional, centralized systems. When combined, the technologies will help to transform the U.S. digital infrastructure to modernize it and create more efficient, secure, and nimble systems that will be able to meet the demands of the future. This paper will examine the role of microservices and federated cloud architecture in transforming the digital landscape of America, dealing with the inefficiencies of the old system, and allowing organizations to keep up with the technological landscape that is changing so fast. The article explores the advantages, issues, and opportunities of these transformative technologies through the expert opinions, case studies and real world examples. It eventually provides a guide on how organizations could seek to modernize their digital infrastructure and remain competitive in an increasingly digitalized world.

The article examines the issue of the exemption from liability under Article 79 of the United Nations Convention on Contracts for the International Sale of Goods. This provision is crucial in international trade, as it outlines conditions under which a party may be exempted from liability for non­performance due to «impediments beyond his control». The study is particularly relevant in light of the 2022 Russian invasion of Ukraine, which disrupted many international contracts. The article discusses the multifaceted nature of «impediments» that may qualify for exemption, including natural disasters, political upheavals, and unforeseen legal restrictions. It emphasizes that for an exemption to be valid, the impediment must be beyond the party’s control, unforeseeable, unavoidable, and directly causing the non­performance. Key judicial decisions are reviewed, including the case of Scafom International BV v. Lorraine Tubes S.A.S., where the court defined the notion of «impediment» as changed circumstances that have made a party’s performance a matter of economic hardship or have increased the burden of performance of the contract in a disproportionate manner. Another case, the «Vine Wax» case, highlights the importance of the causal link between the impediment and the failure to perform. The article also addresses the challenges in proving unforeseeability, often assessed using the «reasonable person» standard. This standard considers whether a «reasonable person» from a point of view of the defaulting party could have foreseen the initial or subsequent existence of an impediment. In conclusion, the article suggests that while Article 79 provides a reliable framework for exemption from liability for a party, its application requires careful consideration of contractual obligations, trade practices, and the specific circumstances surrounding the impediment. It advocates for clearer guidelines and consistent judicial interpretations to aid in the uniform application of Article 79 across different legal systems.

Color fading naturally occurs with time under light illumination. It is triggered by the high photon energy of light. The rate of color fading and darkening depends on the substance, lighting condition, and storage conditions. Color fading is only observed after some time has passed. The current color of objects of interest can only be compared with old photographs or the observer’s perception at the time of reference. Color fading and color darkening rates between two or more points in time in the past can only be determined using photographic images from the past. For objective characterization of color difference between two or more different times, quantification of color in either digital or printed photographs is required. A newly developed image analysis and comparison software (PicMan) has been used for color quantification and pixel-by-pixel color difference mapping in this study. Images of two copies of Japanese wood-block prints with and without color fading have been selected for the exemplary study of quantitative characterization of color fading and color darkening. The fading occurred during a long period of exposure to light. Pixel-by-pixel, line-by-line, and area-by-area comparisons of color fading and darkening between two images were very effective in quantifying color change and visualization of the phenomena. RGB, HSV, CIE L*a*b* values between images and their differences of a single pixel to areas of interest in any shape can be quantified. Color fading and darkening analysis results were presented in numerical, graphical, and image formats for completeness. All formats have their own advantages and disadvantages over the other formats in terms of data size, complexity, readability, and communication among parties of interest. This paper demonstrates various display options for color analysis, a summary of color fading, or color difference among images of interest for practical artistic, cultural heritage conservation, and museum applications. Color simulation for various moments in time was proposed and demonstrated by interpolation or extrapolation of color change between images, with and without color fading, using PicMan. The degree of color fading and color darkening over the various moments in time (past and future) can be simulated and visualized for decision-making in public display, storage, and restoration planning.

n-type SiC wafers with localized 4H, 6H, and 15 R polytype grains were photographed and their colors were analyzed to find correlations among polytypes, carrier concentration and apparent color. The SiC wafers were photographed and the color information of different colored regions from the photographs was extracted, both for RGB (red, green, and blue) and HSV (hue, saturation, and value) color space formats using image processing software (PicMan). Polytype and carrier concentration of n-type SiC wafers were identified from Raman spectra for correlation with the color analysis results. The carrier concentration of SiC wafers was estimated to be in the range of 2 × 1017 cm−3 to 1 × 1019 cm−3 from a line-shape analysis of measured Raman spectra. The color analysis revealed that there is very strong correlation between polytype and hue value. The carrier concentration strongly affects saturation and value of apparent color. SiC wafers with lower carrier concentration showed higher clarity (lower saturation (or colorless) and higher value (higher transparency)). As the carrier concentration is increased, the wafer becomes translucent (high saturation or colored) and dark or opaque (low value). The polytype and carrier concentration of SiC wafers can conveniently be estimated from their apparent color.

Photographic images of the Samseong-version (三省本: Korea’s Treasure No. 758-1) and the Gongin-version (空印本: Korea’s Treasure No. 758-2) of Nammyeongcheon Hwasangsong Jeungdoga (南明泉和尙頌證道歌: Nanmingquan Song Zhengdaoge) were compared and analyzed to investigate the differences between the two versions. According to a report in 2012 at the time of the designation of the Gongin-version as Korea’s treasure, both versions were printed from the same woodblocks. The Gongin-version is presumed to be a later print than the Samseong-version. The two versions are very similar in format and shape of border lines and characters. It is difficult to determine the differences with the naked eye, even for experts. In this study, based on the printing characteristics observed from each version through image analysis, useful evidence to determine whether it was printed using the same or different woodblocks and the order of printing was collected. As a result of careful image comparison and analysis, we concluded that the Samseong- and the Gongin-version were printed from different woodblocks, or possibly different typesetting. It was difficult to agree with the content of the report that the Gongin-version was a later print than the Samseong-version. In addition, it was noted that the Gongin-version print has characteristics quite different from the typical characteristics of woodblock printing seen in the Samseong-version. Additional investigations and follow-up studies on the printing technology used for Gongin-version print and the timing of printing are recommended.

The history of printing technology in Korea is studied by investigating existing ancient documents and records and comparing accumulated data and knowledge. Cultural property research requires non-destructive testing and observation with the naked eye or aided by a microscope. Researchers’ experience and knowledge are required even though they cannot guarantee the outcome. For ancient documents and records that are presumed to consist of woodblock printing, wood type printing, metal type printing, or their combinations, each researcher draws various opinions and conclusions. This often causes confusion and divides the opinions of ordinary citizens and field specialists. Among them, the criteria for judging ancient documents or books printed using woodblock and metal movable material are ambiguous. Academic research on the development history of printing technology in ancient Korea has been stagnant, and conflicts among researchers have also erupted. Involvement of national investigative agencies not specialized in cultural properties has exacerbated the situation. In this study, we investigated printing characteristics that are likely to serve as more objective judgment criteria by quantitatively analyzing the experiments of retrieving several sheets of Korean paper (Hanji) using a replicated Hunminjeongeum (訓民正音) woodblock and quantitatively analyzing the images of the printed papers. In addition, the validity and questions for the typical phenomena presented as a method for distinguishing between woodblock and metal print are reviewed. We investigated the possibility of developing new objective judgement criteria through quantitative analysis using image analysis and investigating the printing characteristics of Korean paper through a reproduction experiment of woodblock printing.

The traditional, triangular yield-line method used by most departments of transportation for analyzing concrete traffic barriers and bridge rails has been largely unchanged since 1978. Testing of concrete barriers since this time has indicated that the triangular yield-line method is not qualitatively representative of observed damage patterns and is overconservative. Further, the conversion from NCHRP Report 350 to the crash test criteria from the Manual for Assessing Safety Hardware (MASH) will result in increases to lateral impact loads; therefore, overconservative analysis practices may result in many concrete barriers being unnecessarily deemed inadequate. In this research, alternative analysis methods for concrete barriers were extracted from an extensive literature review of concrete barrier investigations. These methods were applied to a sample of eight concrete barriers to demonstrate and compare their effects on capacity estimates. Alternative methods included trapezoidal yield-line mechanisms, effects of impact heights lower than the top of the barrier, punching shear evaluation, and consideration of expected material strengths. Capacity estimates of the selected barriers were increased by an average of 47 percent when alternative methods were cumulatively applied. Although the traditional method does not consider punching shear, the capacity of one of the eight barriers was controlled by punching shear rather than by yield-line flexure. With the alternative methods applied, seven of the eight barriers were deemed adequate relative to the increased lateral loads corresponding to MASH criteria for Test Levels 2 through 5. By contrast, if analyzed according to the traditional method, three of the eight barriers would have been deemed insufficient considering MASH loads.

ABSTRACTObjectives: Prudent dry needling techniques are commonly practiced with the intent to avoid large neurovascular structures, thereby minimizing potential excessive bleeding and neural injury. Patient position is one factor thought to affect the size of the safe zone during dry needling of some muscles. This study aimed to compare the size of the needle safe zone of the iliacus muscle during two different patient positions using ultrasound imaging.Methods: The distance from the anterior inferior iliac spine (AIIS) to the posterior pole of the femoral nerve was measured in 25 healthy participants (11 male, 14 female, mean age = 40) in both supine and sidelying positions using a Chison Eco1 musculoskeletal ultrasound unit. The average distance was calculated for each position and a two-tailed, paired t-test (α < 0.05) was used to examine the difference between positions.Results: The mean distance from the AIIS to the posterior pole of the femoral nerve was statistically greater with participants in the sidelying position (mean[SD] = 35.7 [6.2] mm) than in the supine position (mean[SD] = 32.1 [7.3] mm, p < .001).Discussion: Although more study is needed, these results suggest that patient positioning is one of several potential variables that should be considered in the optimization of patient safety/relative risk when performing trigger point dry needling.Level of Evidence: Level 4 (Pre-Post Test)