Free-form optimization of nanophotonic devices: from classical methods to deep learning

Nanophotonic devices have enabled microscopic control of light with an unprecedented spatial resolution by employing subwavelength optical elements that can strongly interact with incident waves. However, to date, most nanophotonic devices have been designed based on fixed-shape optical elements, and a large portion of their design potential has remained unexplored. It is only recently that free-form design schemes have been spotlighted in nanophotonics, offering routes to make a break from conventional design constraints and utilize the full design potential. In this review, we systematically overview the nascent yet rapidly growing field of free-form nanophotonic device design. We attempt to define the term “free-form” in the context of photonic device design, and survey different strategies for free-form optimization of nanophotonic devices spanning from classical methods, adjoint-based methods, to contemporary machine-learning-based approaches.

Computer-aided solid form design

Susan M. Reutzel-Edens introduces the CrystEngComm themed collection on computer-aided solid form design.

RESISTANCE PREDICTION USING ARTIFICIAL NEURAL NETWORKS FOR PRELIMINARY TRI-SWACH DESIGN

Due to the novel hull form design, at present no standard series or full-scale data is publicly available to predict Tri- SWACH resistance during the preliminary ship design process. This work investigates the viability of using an Artificial Neural Network (ANN) to quickly predict total resistance for preliminary Tri-SWACH design. An ANN was trained using total resistance experimental data obtained from model tests, which varied side hull arrangements. The results highlight strong correlation for model resistance prediction. A Tri-SWACH case study was then developed which had side hull geometric properties different to any previously used to train the ANN. The results, validated against CFD predictions, mimicked the resistance pattern generated by other model experimental data, providing confidence in the ANN’s ability to function as a resistance prediction tool. This work demonstrates the viability of ANN to assess Tri-SWACH resistance as part of a preliminary design process. These results suggest that ANNs can be effective tools for assessing performance given relevant training data.

HYDRODYNAMIC HULL FORM DESIGN SPACE EXPLORATION OF LARGE MEDIUM-SPEED CATAMARANS USING FULL-SCALE CFD

Large medium-speed catamarans are a new class of vessel currently under development as fuel-efficient ferries for sustainable fast sea transportation. Appropriate data to derive design guidelines for such vessels are not available and therefore a wide range of demihull slenderness ratios were studied to investigate the design space for fuel-efficient operation. Computational fluid dynamics for viscous free-surface flow simulations were utilised to investigate resistance properties of different catamaran configurations having a similar deadweight at light displacement, but with lengths ranging from 110 m to 190 m. The simulations were conducted at full-scale Reynolds numbers (log(Re) = 8.9 – 9.6) and Froude numbers ranged from Fr = 0.25 to 0.49. Hulls of 130 m and below had high transport efficiency below 26 knots and in light loading conditions while hulls of 150 m and 170 m showed benefits for heavier displacement cases and speeds up to 35 knots. Furthermore, the study concluded that the lowest drag was achieved with demihull slenderness ratios between 11 and 13.

Grey-based Taguchi Method to Optimize the Multi-response Design of Product Form Design

This paper presents a multi-response optimization method that uses the grey-based Taguchi method as the integrative product form design optimization method, and it serves as a tool for product form design to determine the optimal combination of design parameters in Kansei engineering (KE). This method is unique in that it combines the Taguchi method (TM) and grey relational analysis (GRA), allowing it to take advantage of the benefits of both methods. The TM is used to design experiments and generate combinative product form design samples which can be used to improve product quality. The GRA is applied to multi-response optimization problems. Factor effect analysis and analysis of variance (ANOVA) are used to determine which combinations of design parameters will result in the optimal product design. To demonstrate the applicability of the grey-based TM, a case study of a car form design is presented, and a confirmation test is performed to verify the performance of the optimal product design. The results show that the grey-based TM can deal with optimization problems with multiple Kansei responses and determine an optimal car form design that is representative of the consumers' perception in a systematic manner. The confirmation test results also show that the optimal product design generated by the grey-based TM can be used to improve the overall quality of a product form.

The model of eco-friendly packaging center to increase the competitiveness of MSMEs’ local products

Packaging problem is still a weak point for Micro Small Medium Enterprises (MSMEs). This is due to the lack of understanding of MSME about the importance of image, quality, and packaging appearance. This research is a solution to increase the competitiveness of local MSME products in the global market with a focus on the study to identify the internal and external factors that affect eco-friendly packaging for MSMEs, formulate a strategy to develop a packaging center, and create a model for environmentally friendly packaging development center for processed food MSME products. The Model of Eco-Friendly Packaging Center is an effort to increase the competitiveness of local MSMEs that provide services as an information center for packaging activities, a packaging material procurement center, an eco-friendly product packaging service center, a graphic design mediator and packaging form design, and branding.

Chitosan and its Use as a Polymeric Drug Carrier Material in Dosage Form Design- A Critical Review

The prime goal in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. To minimize drug degradation/loss, prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are presently under investigation. Chitosan has been the subject of interest for its use as a polymeric drug carrier material in dosage form design due to its appealing properties such as biocompatibility, biodegradability, low toxicity and relatively low production cost from abundant natural sources. Microspheres are the choice of drug delivery system for the controlled release of drugs, vaccines, antibiotics, and hormones for specific target sites. There are various methods that can be used to encapsulate drugs within chitosan matrixes such as ionotropic gelation, spray drying, emulsification-solvent evaporation, co-acervation, double layer coating and many more. Combinations of these practices are also used in order to obtain micro-particles with specific properties and performances. Double-layer coating method is used to prevent the loss of encapsulated materials in the acidic medium. The microspheres should be coated with another polymer that forms a membrane on the surface. Due to the bilayer properties, the micro carriers additionally protected against acidic conditions of the stomach and drug releases in the intestine in a better controlled manner. This review focused on the techniques applied directly to chitosan micro-particulate systems and their role in novel drug delivery systems