Independent Functionalities Research Articles

Reinforcement learning in autonomous defense systems: Strategic applications and challenges

Reinforcement learning (RL) is one of the most progressive ways to improve the efficiency of drones and robotic systems in the context of the defense and security industries. In Anomaly Detection (AD) systems, this paper discusses the potential of RL as a Model Selection Criteria (MSC) method and its associated issues. RL algorithms enable such systems to adapt to and learn from interactions with their environment, optimizing their response to complex and dynamic threats. This way, new states may be introduced with better decision-making processes, improving the effectiveness of the operations and enabling Reinforcement learning -powered systems to learn new scenarios as well as perform detailed defensive actions in a real-time context. The importance of RL in national defense can therefore be said to lie in its capacities for changing how threats are identified, how threats are responded to, and even what strategies of defense are thought of. Self-governing systems that incorporate Reinforcement learning are capable of functioning in an unpredictable environment, evaluating threats correctly, and carrying out defensive measures with the help of people practically at all. This versatility is critical in modern warfare because a preferred option is the right response to threats that were unknown a few years ago. However, incorporating RL into autonomous defense systems is not without big challenges. Some important problem areas are improved stability and accuracy of RL algorithms in various and critical situations, the legal and practical consequences of autonomous decision-making and possible threats that can arise due to adversarial manipulation of learning algorithms. In addition, such systems have to be developed and put into practice under national and international standards to meet certain requirements and build confidence in such applications. This paper explores these strategic uses and issues and presents a detailed overview of how RL can improve independent defense functionalities, as well as the significant problems relating to this approach. Thus, by providing case studies and theoretical analysis, it aims to demonstrate that RL has the potential to define the technological development of defense and benefit national security systems in the context of a growing threat.

Quantitative Chemical Imaging of Organelles.

ConspectusDNA nanodevices are nanoscale assemblies, formed from a collection of synthetic DNA strands, that may perform artificial functions. The pioneering developments of a DNA cube by Nadrian Seeman in 1991 and a DNA nanomachine by Turberfield and Yurke in 2000 spawned an entire generation of DNA nanodevices ranging from minimalist to rococo architectures. Since our first demonstration in 2009 that a DNA nanodevice can function autonomously inside a living cell, it became clear that this molecular scaffold was well-placed to probe living systems. Its water solubility, biocompatibility, and engineerability to yield molecularly identical assemblies predisposed it to probe and program biology.Since DNA is a modular scaffold, one can integrate independent or interdependent functionalities onto a single assembly. Work from our group has established a new class of organelle-targeted, DNA-based fluorescent reporters. These reporters comprise three to four oligonucleotides that each display a specific motif or module with a specific function. Given the 1:1 stoichiometry of Watson-Crick-Franklin base pairing, all modules are present in a fixed ratio in every DNA nanodevice. These modules include an ion-sensitive dye or a detection module and a normalizing dye for ratiometry that along with detection module forms a "measuring module". The third module is an organelle-targeting module that engages a cognate protein so that the whole assembly is trafficked to the lumen of a target organelle. Together, these modules allow us to measure free ion concentrations with accuracies that were previously unattainable, in subcellular locations that were previously inaccessible, and at single organelle resolution. By revealing that organelles exist in different chemical states, DNA nanodevices are providing new insights into organelle biology. Further, the ability to deliver molecules with cell-type and organelle level precision in animal models is leading to biomedical applications.This Account outlines the development of DNA nanodevices as fluorescent reporters for chemically mapping or modulating organelle function in real time in living systems. We discuss the technical challenges of measuring ions within endomembrane organelles and show how the unique properties of DNA nanodevices enable organelle targeting and chemical mapping. Starting from the pioneering finding that an autonomous DNA nanodevice could map endolysosomal pH in cells, we chart the development of strategies to target organelles beyond the endolysosomal pathway and expanding chemical maps to include all the major ions in physiology, reactive species, enzyme activity, and voltage. We present a series of vignettes highlighting the new biology unlocked with each development, from the discovery of chemical heterogeneity in lysosomes to identifying the first protein importer of Ca2+ into lysosomes. Finally, we discuss the broader applicability of targeting DNA nanodevices organelle-specifically beyond just reporting ions, namely using DNA nanodevices to modulate organelle state, and thereby cell state, with potential therapeutic applications.

Extended Metasurface Spin Functionalities from Rotation of Elements

AbstractMetasurfaces are a class of planar optical components that are engineered to manipulate electromagnetic waves, including their spin states in terms of circular polarizations. For example, the Pancharatnam–Berry (PB) phase has been exploited in metasurfaces for various spin functionalities, but these spin functionalities, exhibit conjugate relations for spin states. Recent advances combining the PB phase and propagation phase have implemented completely independent spin functionalities for spin states. However, the spin functionalities are fixed once the metasurfaces are designed. Here, this work proposes and demonstrates that the spin functionalities designed from the PB phase and propagation phase can be further extended by simply rotating the elements in a metasurface. This extension is based on a relationship between phase profiles of spin states that are acquired before and after the rotation. Proof‐of‐concept demonstrations are performed for the extended spin functionalities, including the conversion from spin angular momentum to orbital angular momentum, and spin‐dependent holograms. This extension may find use in relevant applications such as polarized display and dual‐polarized holography.

Conditional Generative Adversarial Networks for Inverse Design of Multifunctional Metasurfaces

Electromagnetic (EM) metasurfaces can present a versatile platform for realization of multiple diverse EM functionalities with incident wave frequency, polarization, or propagation direction through appropriate choice of unit cells structures. However, the inverse design of multifunctional metasurfaces relies on massive full‐wave EM numerical simulations to obtain an optimized solution. Herein, a step‐by‐step procedure based on conditional generative adversarial networks (cGANs) integrated with Gramian angular fields (GAFs) to reduce the computational time required for the EM simulations in the inverse design of multifunctional microwave metasurfaces is proposed. The proposed procedure initially implements GAFs to encode the desired multiobjective scattering parameters (SPs) to images and then passes them through the cGAN model to map them to three‐layer metasurfaces. The present study uses a robust dataset, including 54 000 metasurface structures and corresponding SPs to train and validate the cGAN model. This article also presents two case study examples using two multifunctional metasurfaces with different independent functionalities and full‐space coverage to justify the performance of the proposed procedure in the inverse design of multifunctional microwave metasurfaces. The case studies demonstrate that, despite the random nature of the training data samples, the cGAN reliably predicts the corresponding metasurfaces of the desired multiobjective SPs.

Quad-channel independent wavefront encoding with dual-band multitasking metasurface.

Achieving multiple electromagnetic (EM) functionalities on a shared aperture in dual frequency bands is crucial for many applications; however, existing dual-band metasurfaces are affected by limited channels or narrow bandwidths. Herein, we propose a reflective coding metasurface that empowers four independent EM functionalities in quad-polarization channels in two wide frequency bands. By integrating quasi-I-shaped and cross-shaped metastructures, the meta-atom can feature independent phase modulation for two orthogonally linear and two decoupled circular polarizations at low and high frequencies, respectively. To validate the proposed metasurface, a multifunctional metadevice is designed that integrates beam deflection, diffuse scattering, and vortex beam generation. Both experimental and simulation results indicate distinct wavefront tailoring in each channel. The proposed multi-functional metasurface with low cross-talk and independent phase modulation depending on frequencies and polarizations may unlock the metasurfaces' potentials for complete wavefront control in EM function integration, multiple channel communication, polarization optics, etc.

Anisotropic metasurface with high-efficiency reflection and transmission for dual-polarization

Recently, accelerating advances in coding metasurfaces linking metamaterial and digital codes have enabled unexampled route for electromagnetic (EM) waves manipulation, including perfect reflection and transmission. In this paper, an anisotropic coding metasurface with a semi-discontinuous metallic ground sheet are proposed, which realizes dual independent functionalities by changing the polarization of incident waves. The ultrathin metasurface is composed of eight coding elements based on a simple rectangle metal patch and the reflective phases of these elements fully cover 360°. Both numerical and measured results show that our design is able to near-perfectly reflect the normally incident y-polarized wave to desired reflection angle and transmit the y-polarized plane wave with high efficiency. In addition, considering the simple structure, easy fabrication process and decent control ability on EM waves, the proposed coding metasurface may be exploited for more complex functionalities.

Polarization and direction-controlled asymmetric multifunctional metadevice for focusing, vortex and Bessel beam generation.

Integrating multiple independent functionalities into one single photonic device has been an important part in optoelectronic system. In this paper, we here propose a kind of asymmetric multifunctional metadevice operating at 1550 nm (in optical communication band), which can manipulate the light with four different functions, depending on the polarization and illumination direction of incident light. As a proof of our concept, we design this metadevice composed of the upper metasurface layer, middle grating layer and lower metasurface layer. For x-polarized incident light, the metadevice under forward illumination works as transmissive focusing lens and vortex beam generator of y-polarized light, while under backward illumination it acts as a reflective vortex beam generator. In contrast, for y-polarized incident light, the metadevice under forward illumination behaves as a reflective Bessel beam generator, while a combination of transmissive vortex beam generator and focusing lens of x-polarized light under backward illumination. Our findings may motivate the realization of high-performance multifunctional metadevices and extend the application in complex integrated optical system.

High-Efficiency Metalenses with Switchable Functionalities in Microwave Region.

Regarding miniaturized and integrated systems, a single flat device that possesses diversified functionalities is highly desirable in optical to microwave regimes. With this perspective, bifunctional metalenses constructed by meta-atoms with integrated response to propagation phase and geometric phase are proposed for independent manipulation of right-handed and left-handed circularly polarized waves. The derived general criterion is verified in the microwave region from three bifunctional metalenses operating in transmission manner. The proof-of-concept measurements show that all these metalenses exhibit two independent functionalities that can be switched by flipping the helicity of the incident illumination. Very high efficiencies of around 80%, with peak value of 91%, are achieved by the ultrathin metasurfaces of thickness 0.15λ0. The proposed metasurfaces provide a promising route for the realization of reconfigurable lenses and antennas in wireless communication systems.

A meta-analysis of catalytic literature data reveals property-performance correlations for the OCM reaction

Decades of catalysis research have created vast amounts of experimental data. Within these data, new insights into property-performance correlations are hidden. However, the incomplete nature and undefined structure of the data has so far prevented comprehensive knowledge extraction. We propose a meta-analysis method that identifies correlations between a catalyst’s physico-chemical properties and its performance in a particular reaction. The method unites literature data with textbook knowledge and statistical tools. Starting from a researcher’s chemical intuition, a hypothesis is formulated and tested against the data for statistical significance. Iterative hypothesis refinement yields simple, robust and interpretable chemical models. The derived insights can guide new fundamental research and the discovery of improved catalysts. We demonstrate and validate the method for the oxidative coupling of methane (OCM). The final model indicates that only well-performing catalysts provide under reaction conditions two independent functionalities, i.e. a thermodynamically stable carbonate and a thermally stable oxide support.

Transmission‐Reflection‐Integrated Multifunctional Coding Metasurface for Full‐Space Controls of Electromagnetic Waves

AbstractDigital coding metasurfaces are aimed at simplifying the design and optimization procedures, and manipulating electromagnetic waves in digital manner. In this paper, a multilayered anisotropic coding metasurface is designed to realize multiple independent functionalities by changing the polarization and direction of incident waves. As a proof of concept, the beam deflection, diffuse scattering, and vortex beam generation are realized by using only a single transmission‐reflection‐integrated (TRI) coding metasurface. This design can achieve three different functionalities and simultaneous controls of transmitted and reflected wavefronts on a shared aperture with the TRI coding scheme. Both numerical and measured results verify the excellent performance of the multifunctional digital coding metasurface, which provides a simple way to extend the functionality of high‐efficiency metadevices.

Amorphous transdisciplinary service systems

Amorphous transdisciplinary system is the application of backend object-oriented service providers - local/remote objects - having independent limited computational functionalities - provider services - that dynamically actualise frontend service-oriented microservices and macroservices. A microservice binds to a single provider and executes a single provider service. A macroservice by contrast is a compound service request comprising of microservices and other macroservices with service fidelities and metafidelities. Macroservices express dynamic collaborations of large number of provider services (applications, tools, and utilities) with emergent multifidelity management. This type of agile service aggregation is often referred to as a system of systems. A metafidelity - fidelity of fidelities - is used by a fidelity management system to morph a macroservice for evolving collaboration of provider services at runtime. The presented amorphous transdisciplinary approach provides service-oriented modelling or programming, or both (mogramming) with a corresponding service-oriented operating system. The operating system runs amorphous frontend macroservices and dynamically manages its service processor - corresponding collaborations of backend service providers.

Power Quality Improvement in Autonomous Microgrids Using Multi-functional Voltage Source Inverters: A Comprehensive Review

Multi-functional voltage source inverters (VSIs) have attracted increasing attention in recent years for their advantageous auxiliary services for power quality enhancement in autonomous microgrids. These types of VSIs can not only achieve a proper control scheme in autonomous mode but also cope with the prescribed power quality and stability requirements. These functionalities are integrated within the same device, thereby significantly improving the cost-effectiveness of microgrids while decreasing the investment and bulk compared with those of multiple devices with independent functionalities. Control strategies for power quality enhancement in autonomous microgrids using multi-functional VSIs are comprehensively reviewed in this paper. In addition, such VSIs are discussed in detail, and comparisons of which are also provided. Lastly, a number of future research directions for multi-functional VSIs are recommended.

Multimedia Streaming Using Cloud-Based P2P Systems

Abstract The past one and a half decades have seen great strides in the field of commercially available distributed computing implementations. The two most popular architectures in the modern world are Peer-to-Peer Systems and Cloud Systems. Peer-to-Peer Systems (P2P) have become very popular in recent times, mainly being used to facilitate file sharing among disparate systems. Another recent trend in modern computing has been the wide scale utilization of Cloud Computing architectures. These systems are used to allow multiple systems to pool their resources and allow other tertiary systems to use these shared resources in bulk for tasks such as data storage, complex calculations, and file sharing. This entails the conceptual outsourcing of various data processing tasks to an external cloud system. Given the two nearly independent functionalities of P2P and Cloud architectures, it is interesting to consider the possibility of fusing these two concepts and researching the applications of the resultant amalgamation. In this research paper, we discuss the theory and application of Cloud Based Peer-to-Peer Systems and their potential application in multimedia streaming services. While the value of P2P Systems and Cloud Computing Systems have been extolled individually, the hybrid of both concepts shows great promise. In this paper we provide an introduction to Cloud Computing Systems, P2P Systems, and the advantages as well as the limitations of both configurations. We then describe the concept of a Cloud-Based P2P System, its basic architecture, and its possible implementations. We also describe the possible application of a Cloud-Based P2P System as a platform for a multimedia streaming service. A proposed algorithm to facilitate streaming in such an application is also described, along with a proposed system model and its advantages.

Engineering interlocking DNA rings with weak physical interactions.

Catenanes are intriguing molecular assemblies for engineering unique molecular devices. The resident rings of a catenane are expected to execute unhindered rotation around each other, and to do so, they must have weak physical interactions with each other. Due to sequence programmability, DNA has become a popular material for nanoscale object engineering. However, current DNA catenanes, particularly in the single-stranded (ss) form, are synthesized through the formation of a linking duplex, which makes them less ideal as mobile elements for molecular machines. Herein we adopt a random library approach to engineer ssDNA [2] catenanes (two interlocked DNA rings) without a linking duplex. Results from DNA hybridization, double-stranded catenane synthesis and rolling circle amplification experiments signify that representative catenanes have weak physical interactions and are capable of operating as independent units. Our findings lay the foundation for exploring free-functioning interlocked DNA rings for the design of elaborate nanoscale machines based on DNA.

Software Development: Agile vs. Traditional

Organizations face the need to adapt themselves to a complex business environment, in continuous change and transformation. Under these circumstances, organization agility is a key element in gaining strategic advantages and market success. Achieving and maintaining agility requires agile architectures, techniques, methods and tools, able to react in real time to change requirements. This paper proposes an incursion in the software development, from traditional to agile.Keywords: Software Development, Traditional Models, Agile Models, Agile Architectures, Agile Techniques, Agile InstrumentsIntroductionIncreased agility is a magnet to all organizations, especially for those in private sector. It will allow a rapid and efficient adaptation to market changes and gaining a strategic advantage. Moreover, increased agility contributes to decreasing the development time for new processes and increasing flexibility for existing processes, where modification and implementation is required. All that leads to decreased time for solving client demands, more clients gained, lower adaptation costs and finally increased revenue.In a complex and permanently changing environment, organization agility is no longer a necessity but a condition to access or remain on the market. An agile enterprise adapts fast to client demands and market opportunities, gaining competitive advantages on the market. This can be achieved only if the stakeholders clearly understand the working ways of the organization.From informational systems point of view, there are several ways to achieve agility, among which: Business Process Management (BPM) for orchestrating independent functionalities, Service Oriented Architecture (SOA) for designing and developing such functionalities and Decision Management (DM) for management of organization decisions.2 Software Development Life CycleDevelopment models are various processes or methodologies, selected to develop the project according to its purpose and objectives. Software developments models help improve the software quality as well as the development process in general.There are several models for the software development life-cycle, each developed for certain objectives. Software Development Life Cycle (SDLC) is an environment that describes activities performed in each stage of the software development process. SDLC consists of a detailed plan that describes how the development, maintenance and replacement of specific software is conducted. This is also known as software development process. [1]The international standard for SDLC is ISO/IEC 12207. It aims to define all activities required to develop and maintain software. Figure 1 depicts the various stages of a typical SDLC.Stage 1: Requirements analysis and planning Analysis of requirements is the most important stage in SDLC. It is performed by senior members of the team, using inputs from the clients, sales department, market research and industry experts. This information is then used for a basic project plan and feasibility study from economic, operational and technical points of view. Also, in this stage the team plans the quality insurance requirements and identifies project risks. The result of technical feasibility study consists of definition of carious technical approaches that can be used to implement the project with minimal risks.Stage 2: Definition of requirementsAfter the requirements are analyzed, product requirements are clearly defined and documented. They must be approved by the client or by the market analysts through SRS (Software Requirement Specification). The SRS document lists all product requirements that must be designed and developed throughout the project life-cycle.Stage 3: Product architecture designSRS is the basic reference from which the architects set out to create the best architecture for the product. Usually, at least one product architecture approach is proposed, and it is documented in a DDS (Design Document Specification). …

Gold-mediated bifunctional modification of oligosaccharidesvia a three-component coupling reaction

An efficient modular approach for single-site incorporation of two independent functionalities (amines and alkynes) into aldehyde-containing oligosaccharides concurrently by using a one-pot gold-mediated three-component coupling reaction in aqueous medium under mild conditions has been developed.

Transaction Management in Service-Oriented Systems: Requirements and a Proposal

Service-Oriented Computing (SOC) is becoming the mainstream development paradigm of applications over the Internet, taking advantage of remote independent functionalities. The cornerstone of SOC's success lies in the potential advantage of composing services on the fly. When the control over the communication and the elements of the information system is low, developing solid systems is challenging. In particular, developing reliable web service compositions usually requires the integration of both composition languages, such as the Business Process Execution Language (BPEL), and of coordination protocols, such as WS-AtomicTransaction and WS-BusinessActivity. Unfortunately, the composition and coordination of web services currently have separate languages and specifications. The goal of this paper is twofold. First, we identify the major requirements of transaction management in Service-oriented systems and survey the relevant standards. Second, we propose a semiautomatic approach to integrate BPEL specifications and web service coordination protocols, that is, implementing transaction management within service composition processes, and thus overcoming the limitations of current technologies.

Evaluation of a degradable shape-memory polymer network as matrix for controlled drug release

Degradable shape-memory polymers are multifunctional materials with broad applicability for medical devices. They are designed to acquire their therapeutically relevant shape and mechanical properties after implantation. In this study, the potential of a completely amorphous shape-memory polymer matrix for controlled drug release was comprehensively characterized according to a four step general strategy which provides concepts for validating multifunctional materials for pharmaceutical applications. Independent functionalities are thereby crucial for fully exploiting the potential of the materials. The copolyester urethane network was synthesized by crosslinking star-shaped tetrahydroxy telechelics of oligo[( rac-lactide)- co-glycolide] with an aliphatic diisocyanate. In step 1 of the four step characterization procedure, this material showed the thermal and mechanical properties, which are required for the shape-memory effect under physiological conditions. Shape recovery could be realized by a one-step or a multi-step methodology. In step 2, feasibility of drug loading of pre-formed shape-memory networks has been demonstrated with drugs of different hydrophobicities. The presence of drugs did not disturb the material's functionalities directly after loading (step 3) and under release conditions (step 4). A predictable release of about 90% of the payload in 80 days was observed. Overall, the synthesized amorphous polymer network showed three independent functionalities, i.e., a shape-memory effect combined with biodegradability and controlled drug release.