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We present a low-cost terahertz wave plate based on form birefringence fabricated using ordinary paper. Measurements of the transfer function of the wave plate between polarizers closely agree with predictions based on the measured complex indices of refraction of the effective medium. For the design frequency, the dependence on wave plate angle also agrees with theory.

Molecular modeling and the art of computer-aided drug discovery seldom make much use of statistics, despite being fields that can not calculate important properties with great reliability. The 2013 CADD Gordon conference intends to examine what prevents a more effective use of statistics in routine modeling and to raise consciousness as to what is possible. Practical methods will be discussed, deeper issues in applying standard approaches addressed and research on successes and failures in other disciplines presented by invited experts.

Segment-edges for extremely large telescopes are critical for observations requiring high contrast and SNR, e.g. detecting exo-planets. In parallel, industrial requirements for edge-control are emerging in several applications. This paper reports on a new approach, where edges are controlled throughout polishing of the entire surface of a part, which has been pre-machined to its final external dimensions. The method deploys compliant bonnets delivering influence functions of variable diameter, complemented by small pitch tools sized to accommodate aspheric mis-fit. We describe results on witness hexagons in preparation for full size prototype segments for the European Extremely Large Telescope, and comment on wider applications of the technology.

Highlights • Superstructure of integrated biorefinery in pulp and paper industry was developed. • It includes pulping, biochemical production and black liquor utilization sections. • Lignocellulosic biomass extracted from eucalyptus and bagasse are the feedstocks. • Potential of integrated biorefinery process was illustrated in three scenarios. • Integrated succinic acid and lactic acid can improve profitability. Abstract This work aims at developing sustainable processes for pulp and paper industry by integration of the biorefinery concept to an existing pulp and paper process. A systematic methodology employing a superstructure-based process synthesis approach is employed with support from computer-aided tools to determine potential pathways for a long-term sustainable growth objective. A superstructure of the multi-product biorefinery process network for the pulp and paper industry is developed. It is divided into three sub-networks, a chemical pulping section, a biochemical production section and a black liquor utilization section. Superstructure optimization is performed with the objective to maximize profit to determine optimal integrated networks for three scenarios. The obtained results provide useful insights for further development of the optimal networks as sustainable integrated biorefinery combined with pulp and paper mills. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Dental anatomy education for dental technology students should be developed in alignment with digital dental laboratory practices. We hypothesized that a virtually assisted sketching-based dental anatomy teaching module could improve students' acquisition of skills essential for digital restoration design. The second-year dental technology curriculum included a novel virtual technology-assisted sketching-based module for dental anatomy education. Pre- and post-course assessments evaluated students' skill sets and knowledge bases. Computer-aided design (CAD) scores were analyzed after one year to assess how the skills students developed through this module impacted their subsequent CAD performance. Participants who undertook the dental sketching-based teaching module demonstrated significantly improved theoretical knowledge of dental anatomy, dental aesthetic perception, and spatial reasoning skills. A partial least squares structural equation model indicated that the positive effects of this module on subsequent CAD performance were indirectly mediated by dental aesthetic perception, spatial reasoning, and practice time. A virtually assisted sketching-based dental anatomy teaching module significantly improved students' acquisition of skills and knowledge and positively mediated dental technology students' CAD performance., (© 2024 American Association for Anatomy.)

Computer-aided design (CAD) systems have advanced to become a critical tool in product design. Nevertheless, they still primarily rely on the traditional mouse and keyboard interface. This limits the naturalness and intuitiveness of the 3D modeling process. Recently, a multimodal human–computer interface (HCI) has been proposed as the next-generation interaction paradigm. Widening the use of a multimodal HCI provides new opportunities for realizing natural interactions in 3D modeling. In this study, we conducted a literature review of a multimodal HCI for CAD to summarize the state-of-the-art research and establish a solid foundation for future research. We explore and categorize the requirements for natural HCIs and discuss paradigms for their implementation in CAD. Following this, factors to evaluate the system performance and user experience of a natural HCI are summarized and analyzed. We conclude by discussing challenges and key research directions for a natural HCI in product design to inspire future studies.

Aim: Computer-aided drug design (CADD) is a drug design technique for computing ligand-receptor interactions and is involved in various stages of drug development. To better grasp the frontiers and hotspots of CADD, we conducted a review analysis through bibliometrics., Methods: A systematic review of studies published between 2000 and 20 July 2023 was conducted following the PRISMA guidelines. Literature on CADD was selected from the Web of Science Core Collection. General information, publications, output trends, countries/regions, institutions, journals, keywords, and influential authors were visually analyzed using software such as Excel, VOSviewer, RStudio, and CiteSpace., Results: A total of 2031 publications were included. These publications primarily originated from 99 countries or regions led by the U.S. and China. Among the contributors, MacKerell AD had the highest number of articles and the greatest influence. The Journal of Medicinal Chemistry was the most cited journal, whereas the Journal of Chemical Information and Modeling had the highest number of publications., Conclusions: Influential authors in the field were identified. Current research shows active collaboration between countries, institutions, and companies. CADD technologies such as homology modeling, pharmacophore modeling, quantitative conformational relationships, molecular docking, molecular dynamics simulation, binding free energy prediction, and high-throughput virtual screening can effectively improve the efficiency of new drug discovery. Artificial intelligence-assisted drug design and screening based on CADD represent key topics that will influence future development. Furthermore, this paper will be helpful in better understanding the frontiers and hotspots of CADD., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Microtia is a congenital and morphological anomaly of one or both ears, which results from a confluence of genetic and external environmental factors. Up to now, extensive research has explored the potential utilization of computational methodologies in microtia and has obtained promising results. Thus, the authors reviewed the achievements and shortcomings of the research mentioned previously, from the aspects of artificial intelligence, computer-aided design and surgery, computed tomography, medical and biological data mining, and reality-related technology, including virtual reality and augmented reality. Hoping to offer novel concepts and inspire further studies within this field., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Background: The rising demand for improved aesthetics has driven the utilization of recently introduced aesthetic materials for creating custom post and core restorations. However, information regarding the fracture resistance of these materials remains unclear, which limits their practical use as custom post and core restorations in clinical applications. AIM OF THE STUDY: This study aimed to evaluate the fracture resistance of three non-metallic esthetic post and core restorations and their modes of failure., Materials and Methods: Thirty-nine single-rooted human maxillary central incisors were endodontically treated. A standardized post space preparation of 9mm length was performed to all teeth to receive custom-made post and core restorations. The prepared teeth were randomly allocated to receive a post and core restoration made of one of the following materials (n=13): glass fiber-reinforced composite (FRC), polyetheretherketone (PEEK) and polymer-infiltrated ceramic-network (PICN). An intraoral scanner was used to scan all teeth including the post spaces. Computer-aided design and computer-aided manufacturing (CAD-CAM) was used to fabricate post and core restorations. Post and core restorations were cemented using self-adhesive resin cement. All specimens were subjected to fracture resistance testing using a universal testing machine. Failure mode analysis was assessed using a stereomicroscope and SEM. The data was statistically analyzed using One-Way ANOVA test followed by multiple pairwise comparisons using Bonferroni adjusted significance level., Results: Custom PEEK post and core restorations displayed the least fracture load values at 286.16 ± 67.09 N. In contrast, FRC exhibited the highest average fracture load at 452.60 ± 105.90 N, closely followed by PICN at 426.76 ± 77.99 N. In terms of failure modes, 46.2% of specimens with PICN were deemed non-restorable, while for PEEK and FRC, these percentages were 58.8% and 61.5%, respectively., Conclusions: Within the limitation of this study, both FRC and PICN demonstrated good performance regarding fracture resistance, surpassing that of PEEK., (© 2024. The Author(s).)

Due to the increasing size of integrated circuits (ICs), their design and optimization phases (i.e., computer-aided design, CAD) grow increasingly complex. At design time, a large design space needs to be explored to find an implementation that fulfills all specifications and then optimizes metrics like energy, area, delay, reliability, etc. At run time, a large configuration space needs to be searched to find the best set of parameters (e.g., voltage/frequency) to further optimize the system. Both spaces are infeasible for exhaustive search typically leading to heuristic optimization algorithms that find some tradeoff between design quality and computational overhead. Machine learning (ML) can build powerful models that have successfully been employed in related domains. In this survey, we categorize how ML may be used and is used for design-time and run-time optimization and exploration strategies of ICs. A metastudy of published techniques unveils areas in CAD that are well explored and underexplored with ML, as well as trends in the employed ML algorithms. We present a comprehensive categorization and summary of the state of the art on ML for CAD. Finally, we summarize the remaining challenges and promising open research directions. [ABSTRACT FROM AUTHOR]

Plain and simple, a corrugated cardboard material provides the right level of protection for goods in transit, which helps keep shipping costs down. As made mostly from wood material, a fairly renewable resource, corrugated cardboards are easily processed and also recycled into paper products and even new boxes. Moreover, thanks to the material's durability, many corrugated packages can be reused multiple times before hitting the recycle bin, which promotes eco-friendly corrugated packaging needs for the environment with no glues or extra binding chemical included inside the packaging at all. The research in this paper proposes a tentative design testbed for a product model of setter tray, wholly made in corrugated paperboard and seated inside packaging with no additional filling material, which, after all, aids realization of a totally eco-friendly corrugated packaging design. A methodical approach, a systematic functional design framework with design thinking methodologies such as function decomposition (FD), quality function deployment (QFD), and morphological matrix, has been introduced to generate a promising concept continuously refined onto a product model. The validation of mechanical properties of the designed product for its functions as desired has been conducted by using not only a computer-aided engineering (CAE) analysis of the computer-aided design (CAD) model, but also an engineering experiment of the product prototypes made of corrugated paperboard, followed by an in-depth discussion on design contributions and future works as well. [ABSTRACT FROM AUTHOR]

Paper pop-ups are interesting three-dimensional books that fascinate people of all ages. The design and construction of these pop-up books however are done manually and require a lot of time and effort. This has led to computer-assisted or automated tools for designing paper pop-ups. This paper proposes an approach for automatically converting a 3D model into a multi-style paper pop-up. Previous automated approaches have only focused on single-style pop-ups, where each is made of a single type of pop-up mechanisms. In our work, we combine multiple styles in a pop-up, which is more representative of actual artist's creations. Our method abstracts a 3D model using suitable primitive shapes that both facilitate the formation of the considered pop-up mechanisms and closely approximate the input model. Each shape is then abstracted using a set of 2D patches that combine to form a valid pop-up. We define geometric conditions that ensure the validity of the combined pop-up structures. In addition, our method also employs an image-based approach for producing the patches to preserve the textures, finer details and important contours of the input model. Finally, our system produces a printable design layout and decides an assembly order for the construction instructions. The feasibility of our results is verified by constructing the actual paper pop-ups from the designs generated by our system. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to compare the sensitivity of T-Scan digital occlusal analysis system and the occlusal analysis mode of the CEREC Omnicam system, which is mainly used for design/production, using the data recorded at the maximum intercuspal position., Materials and Methods: Occlusal recordings were obtained from healthy 20 females and 20 males aged 18-25 at the maximum intercuspal position. Records were saved as.jpeg format and transferred to Adobe Photoshop CS6 program. Blue, green, and red colors (shown by the same color codes in both systems) representing light, intense, and tight contacts, respectively, were evaluated in terms of the pixel counts. For statistical comparison, the differences between the systems independent sample T test and, between the genders, one sample T test were used (α = 0.05)., Results: The total numbers of pixels of all colors which are evaluated with T-Scan and CEREC Omnicam in females were 31,296.6 and 15,745, respectively, and in males 39,812.3 and 17,462, respectively. In both systems, the blue contact area is the most seen. For all colors tested, T-Scan recorded more contact than those of CEREC Omnicam in both genders and statistically significant difference was found between two systems for all colors. In both systems, recorded contacts are significantly higher in men than in women. Compared with women, 27% more contact area was recorded in men with T-Scan and 11% more with CEREC Omnicam was obtained., Conclusions: While T-Scan was found sensitive even in the diagnosis of light contacts, the CEREC Omnicam was found sensitive only in the diagnosis of tight contacts., Clinical Relevance: Although both T-Scan and CEREC Omnicam are effective in occlusal analysis, T-Scan's sensitivity was found to be higher., Trial Registration: ClinicalTrials.gov identifier: NCT04798729., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This investigation examines the impact of two psychoeducational programs (i.e., computer-assisted versus pencil-and-paper) for the empowerment of visuospatial skills of 7-year-old pupils. At pretest, posttest and at a three-month follow-up, 58 children attending the second grade of Italian primary school completed a battery of tests assessing visuospatial problem solving, speed of processing, spatial comprehension, mental imagery, passive and active verbal working memory, respectively. After the pretest, 19 participants were presented the computer-assisted "Recovery in ... visuo-spatial abilities" training, whereas further 20 pupils were trained with the pencil-and-paper "Recovery in ... visuo-spatial abilities" psychoeducational intervention, respectively. At posttest and follow-up, the positive impact of the computer-assisted training has been documented, whereas the efficacy of the pencil-and-paper intervention has been found only at the posttest. Overall, the computer-based program was particularly effective in favoring the development of spatial comprehension, mental imagery, and processing speed in second graders. [ABSTRACT FROM AUTHOR]

In this paper, an efficient computational framework for the full-wave design by optimization of complex microwave passive devices, such as antennas, filters, and multiplexers, is described. The framework consists of a computational engine, a 3D object modeler, and a graphical user interface. The computational engine, which is based on a finite element method with curvilinear higher-order tetrahedral elements, is coupled with built-in or external gradient-based optimization procedures. For speed, a model order reduction technique is used and the gradient computation is achieved by perturbation with geometry deformation, processed on the level of the individual mesh nodes. To maximize performance, the framework is targeted to multicore CPU architectures and its extended version can also use multiple GPUs. To illustrate the accuracy and high efficiency of the framework, we provide examples of simulations of a dielectric resonator antenna and full-wave design by optimization of two diplexers involving tens of unknowns, and show that the design can be completed within the duration of a few simulations using industry-standard FEM solvers. The accuracy of the design is confirmed by measurements. [ABSTRACT FROM AUTHOR]

Purpose This paper aims to investigate the applicability of 3D-printed molds to be used as a substitute for photolithography in the formation of polymer-based stamps. It proposes leveraging 3D printing as a rapid prototyping tool to be applied to microfluidic fabrication.Design/methodology/approach Different designs are created using computer-aided design (CAD) software and printed via Makerbot 3D printer. The molds serve as negative reliefs for a PDMS stamp. The stamp is used to apply paraffin wax to chromatography paper, creating hydrophobic barriers and hydrophilic channels. The minimum functional channel widths and barrier widths are determined for the method.Findings The method is demonstrated to be effective for bypassing the more cost-prohibitive photolithography approach for rapid paper microdevice fabrication. This approach produces functional channels that can be used for on-chip analytical assays. The minimum functional barrier widths and minimum functional channel widths are in good agreement with other published methods for paper-based microchannel fabrication.Research limitations/implications The approach cannot generate the high-resolution structures possible with photolithography. Therefore, if higher resolutions are needed for a particular application, this approach is not the best.Practical implications The simplicity of the approach introduces an affordable method to create disposable devices that can be used at the point of testing.Originality/value The paper satisfies a need for inexpensive, rapid prototyping of paper-based devices. The method is simple and can be used as a tool for introducing labs to microfluidics research. [ABSTRACT FROM AUTHOR]

A paper sliceform or lattice-style pop-up is a form of papercraft that uses two sets of parallel paper patches slotted together to make a foldable structure. The structure can be folded flat, as well as fully opened (popped-up) to make the two sets of patches orthogonal to each other. Automatic design of paper sliceforms is still not supported by existing computational models and remains a challenge. We propose novel geometric formulations of valid paper sliceform designs that consider the stability, flat-foldability and physical realizability of the designs. Based on a set of sufficient construction conditions, we also present an automatic algorithm for generating valid sliceform designs that closely depict the given 3D solid models. By approximating the input models using a set of generalized cylinders, our method significantly reduces the search space for stable and flat-foldable sliceforms. To ensure the physical realizability of the designs, the algorithm automatically generates slots or slits on the patches such that no two cycles embedded in two different patches are interlocking each other. This guarantees local pairwise assembility between patches, which is empirically shown to lead to global assembility. Our method has been demonstrated on a number of example models, and the output designs have been successfully made into real paper sliceforms. [ABSTRACT FROM PUBLISHER]

Origami is the art of creating a three-dimensional (3D) shape by folding paper. It has drawn much attention from researchers, and the designs that origami has inspired are used in various engineering applications. Most of these designs are based on familiar origami patterns and their known deformations, but origami patterns were originally intended for materials of near-zero thickness, primarily paper. To use the designs in engineering applications, it is necessary to simulate origami in a way that enables designers to explore and understand the designs while taking the thickness of the material to be folded into account. Because origami is primarily a problem in geometric design, this paper develops a geometric simulation for thick origami. The actuation, constraints, and assignment of mountain and valley folds in origami are also incorporated into the geometric formulation. The experimental results show that the proposed method is efficient and accurate. The method can successfully simulate a flat-foldable degree-four vertex, two different action origami, the bistable property of a waterbomb base, and the elasticity of non-rigid origami panels. [ABSTRACT FROM AUTHOR]

3D printing or additive manufacturing process is known as part of the digital manufacturing process, involves gradually adding materials to a geometric representation to manufacture physical objects. A quickly developing technology is 3D printing. The world now uses 3D printing extensively in the many fields such as automotive, locomotive, healthcare, agriculture mass customization, aviation sectors and manufacture of any form of open source designs using 3D printing technology are becoming more common. 3D printing process produce an object directly from a computer-aided design model by depositing material layer by layer. In this world mostly many countries are quickly advancing and heavily investing in 3D printing. The advancement of 3D printing technology in Pakistan will be accelerated by strong government assistance, both in the form of laws that are welcoming to investors and subsidies during the early stages of growth. The use of this technology will bear fruit with a few years. Economy will boost as a result of strong manufacturing base. Pakistan will be able to contribute to the international market with skilled professionals and complex products, thus paving way for a sustainable future. The varieties of 3D printing technologies, the materials utilised in 3D printing, the applications for 3D printing technology, and the difficulties associated with adopting 3D printing technologies in Pakistan are all covered in this article. [ABSTRACT FROM AUTHOR]

Freehand sketch is a natural and intuitive communication channel for idea expression. Lines are drawn one after another to create the outline before additional lines are often drawn over the existing ones to make a sketch clearer. Typically, the sketch is transformed to be a 3D CAD model by a designer for use in subsequent operations. Sketch-based modeling has been researched to support this transformation but mainly for an online sketch on a digital device. For an offline sketch on a paper, commonly found used in practice, sketch-based modeling remains a challenge because a scanned image conceals enriched information on the sketch in a batch of data points. This paper proposes an approach for reconstructing a 3D model from a paper-based overtraced freehand sketch. Two main modules in this approach are single-line drawing identification and 3D reconstruction. The first module where image processing technique is applied is for transforming a paper-based overtraced freehand sketch to be a single-line drawing in order to generate more information about the sketch (i.e., the number of lines and their starting points and endpoints). The second module where progressive reconstruction approach with cubic corner is applied is for reconstructing a 3D model from the obtained single-line drawing. Steps to be taken in both modules have been formalized. The approach has been successfully implemented on LabVIEW, and tested with several samples. [ABSTRACT FROM AUTHOR]