Application-specific Functionality Research Articles

Cationic Foldamer-Catalyzed Asymmetric Synthesis of Inherently Chiral Cages.

The stereochemistry of shape-persistent molecular cages, particularly those resembling prisms, exerts significant influence on their application-specific functionalities. Although methods exist for fabricating inherently chiral prism-like cages, strategies for catalytic asymmetric synthesis of these structures in a diversity-oriented fashion remain unexplored. Herein, we introduce an unprecedented organocatalytic desymmetrization approach for the generation of inherently chiral prism-like cages via phosphonium-containing foldamer-catalyzed SNAr reactions. This methodology establishes a topological connection, enabling the facile assembly of a wide range of versatile stereogenic-at-cage building blocks possessing two highly modifiable groups. Furthermore, subsequent stereospecific transformations of the remaining chlorides and/or ethers afford convenient access to numerous functionally relevant chiral-at-cage molecules.

Fibro-porous materials: 3D-printed hybrid porous materials for multifunctional applications

This work demonstrates the additive manufacturing of fibro-porous materials—hybrid materials with a fiber mesh integrated within the open cells of a base porous scaffold. The presented method allows seamless incorporation of fibers, with precise control of the fiber diameter and mesh density, into the scaffold without requiring any additional postprocessing steps. Here, using a gyroid pore architecture as the base scaffold, this study fabricates the fibro-porous materials using an extrusion-based additive technique and investigates their resultant sound absorption, pressure drop, mechanical stiffness, and energy absorption properties. Two-microphone normal incidence impedance tube measurements reveal significant improvements in the sound absorption performance compared to that of denser, fiberless porous material counterparts while maintaining a 33 % lighter weight. Additional tests, including pressure drop and static airflow resistivity measurements, indicate that fiber integration reduces the effective pore size and increases flow resistance, boosting sound absorption at lower frequencies. The mechanical properties are also markedly improved, with stiffness and yield stress increasing by 27 % and 37.85 %, respectively. The fibro-porous samples provide 30 % more energy absorption per unit volume due to their increased resistance to deformation. This research demonstrates that additively manufactured fibro-porous materials provide substantial multifunctional performance gains without significant weight increase. The adaptable manufacturing process is compatible with various extrudable materials and opens a new route to designing complex, customized engineering structures with application-specific functionalities.

Point defect–dislocation interactions in BEOL-compatible Ge-on-Si epitaxy

Reduced thermal budget is required for back-end-of-line (BEOL) integration of application specific functionality into the multilevel metal stack of a processor “substrate.” We report 400 °C BEOL-compatible Ge-on-Si growth (LT Ge) that is epitaxial and single crystalline with a defect density similar to high temperature growth and a small 0.05% tensile strain. Room temperature methanol–iodine passivation is employed pre-growth in lieu of the typical 800 °C oxide removal step. Undoped LT Ge exhibits p-type conductivity initially and n-type conductivity conversion upon annealing. Hall effect measurements following post growth heat treatment between 400 and 600 °C reveal an acceptor removal reaction that follows first-order kinetics with an activation energy of 1.7 ± 0.5 eV and a pre-exponential factor of 2.3×107 s−1 consistent with a point defect, diffusion limited process. We also observe that 90° sessile dislocations identified via transmission electron microscopy are annihilated in the same temperature regime, which is evidence for point defect-mediated climb. Ensuring high-quality epitaxy by characterizing defect reactions in a BEOL-compatible Ge-on-Si process flow is key to enabling vertical integration of optical interconnects.

Dispersal Foraging Strategy With Cuckoo Search Optimization Based Path Planning in Unmanned Aerial Vehicle Networks

Unmanned aerial vehicles (UAVs) are assumed to be a promising model of automatic emergency tasks in dynamic marine ecosystems. But, the real-time communication efficacy betwixt UAVs and base platforms is developing a serious challenge. The compact-sized powerful flying robots can be wirelessly controlled and accomplish end tasks with and without human involvement. UAVs still face severe challenges that limit the dream of completely autonomous unmanned flying machines. The main difficulties contain path planning and hindrance avoidance of such unmanned flying robots, which are mandatory but carry out the application-specific functionality in either indoor or outdoor environments. This study introduces a new Dispersal Foraging Strategy with Cuckoo Search Optimization based Path Planning (DFSCSO-PP) technique for UAV networks. In the presented DFSCSO-PP technique, the identification of optimal paths for data transmission is performed in the UAV network. In addition, the presented DFSCSO-PP technique involves the optimal allocation of resources while finding the optimal paths in the network. Moreover, the DFSCSO technique can be designed by integrating the DFS concept into the CSO method to avoid local optima problems. A widespread simulation analysis is performed to exhibit the enhanced outcome of the DFSCSO-PP approach. A detailed set of comparative studies assured the improved performance of the DFSCSO-PP technique over other approaches.

FabSim3: An automation toolkit for verified simulations using high performance computing

A common feature of computational modelling and simulation research is the need to perform many tasks in complex sequences to achieve a usable result. This will typically involve tasks such as preparing input data, pre-processing, running simulations on a local or remote machine, post-processing, and performing coupling communications, validations and/or optimisations. Tasks like these can involve manual steps which are time and effort intensive, especially when it involves the management of large ensemble runs. Additionally, human errors become more likely and numerous as the research work becomes more complex, increasing the risk of damaging the credibility of simulation results. Automation tools can help ensure the credibility of simulation results by reducing the manual time and effort required to perform these research tasks, by making more rigorous procedures tractable, and by reducing the probability of human error due to a reduced number of manual actions. In addition, efficiency gained through automation can help researchers to perform more research within the budget and effort constraints imposed by their projects.This paper presents the main software release of FabSim3, and explains how our automation toolkit can improve and simplify a range of tasks for researchers and application developers. FabSim3 helps to prepare, submit, execute, retrieve, and analyze simulation workflows. By providing a suitable level of abstraction, FabSim3 reduces the complexity of setting up and managing a large-scale simulation scenario, while still providing transparent access to the underlying layers for effective debugging. The tool also facilitates job submission and management (including staging and curation of files and environments) for a range of different supercomputing environments. Although FabSim3 itself is application-agnostic, it supports a provably extensible plugin system where users automate simulation and analysis workflows for their own application domains. To highlight this, we briefly describe a selection of these plugins and we demonstrate the efficiency of the toolkit in handling large ensemble workflows. Program summaryProgram Title: FabSim3CPC Library link to program files:https://doi.org/10.17632/6nfrwy7ptj.1Licensing provisions: BSD 3-clauseProgramming language: Python 3Nature of problem: Many aspects are crucial for obtaining reproducible and robust simulation results. For instance, we need to curate all the inputs and outputs for later scrutiny, scrutinize the model behaviour under slightly perturbed circumstances, quantify the propagation of key uncertainties from input data and known parameters and analyze the sensitivity for any parameters for which the exact specification eludes us.Solution method: FabSim3 uses a range of methods to provide automation. These primarily include: (i) SSH + Fabric2 to enable remote execution of SSH commands, (ii) an internal parameter state space using primarily Python dict objects that can be customized with machine- plugin- and user-specific modifications, (iii) Python templating to quickly enable the insertion of state space variables into supercomputing scripts, (iv) multiprocessing and/or QCG-PilotJob to enable efficient submission and execution of job arrays and (v) a system of flexibly installable and modifiable Python3 plugins which allows users to create and customize application-specific functionalities without modifying the core code base. In addition to the written code, FabSim3 also relies on a set of user conventions to maintain a separation of concerns (particularly between machine-, user- and application-specific settings).Additional comments including restrictions and unusual features: This paper serves as the definitive reference for FabSim3.

Speed vs Efficiency and Storage Type in Portable Energy Systems

Portable power management systems must optimise power interfacing, storage and routing, to meet application specific functionality requirements. Two key aspects are reliability and efficiency. For reliable operation, it is required that powering on/off the system must occur in a planned manner. For efficient operation, it is desired that the system is powered for an optimal amount of time. maximizing its useful operational outcome per unit of energy consumed. This can be achieved by optimizing energy usage based on the anticipated energy income and power demand of duty-cycled power consumers. Both battery and supercapacitor storage can be employed to meet energy and power density demand, on both sides, and to enable fast transition from cold-starting to active power management. A simplified model is used to calculate the reliability of a simple solar-powered microsystem. The modelling of dynamically configurable interfacing and storage may enable a new generation of power management, providing reliable power from irregular and small energy sources.

DetLogic: A black-box approach for detecting logic vulnerabilities in web applications

Web applications are subject to attacks by malicious users owing to the fact that the applications are implemented by software developers with insufficient knowledge about secure programming. The implementation flaws arising due to insecure coding practices allow attackers to exploit the application in order to perform adverse actions leading to undesirable consequences. These flaws can be categorized into injection and logic flaws. As large number of tools and solutions are available for addressing injection flaws, the focus of the attackers is shifting towards exploitation of logic flaws. The logic flaws allow attackers to compromise the application-specific functionality against the expectations of the stakeholders, and hence it is important to identify these flaws in order to avoid exploitation. Therefore, a prototype called DetLogic is developed for detecting different types of logic vulnerabilities such as parameter manipulation, access-control, and workflow bypass vulnerabilities in web applications. DetLogic employs black-box approach, and models the intended behavior of the application as an annotated finite state machine, which is subsequently used for deriving constraints related to input parameters, access-control, and workflows. The derived constraints are violated for simulating attack vectors to identify the vulnerabilities. DetLogic is evaluated against benchmark applications and is found to work effectively.

A DSL for modeling application-specific functionalities of business applications

Models have been widely used in the information system development process. Models are not just means for system analysis and documentation. They may be also transformed into system implementation, primarily program code. Generated program code of screen forms and transaction programs mainly implements generic functionalities that can be expressed by simple retrieval, insertion, update, or deletion operations over database records. Besides the program code of generic functionalities, each application usually includes program code for specific business logic that represents application-specific functionalities, which may include complex calculations, as well as a series of database operations. There is a lack of domain-specific and tool-supported techniques for specification of such application-specific functionalities at the level of platform-independent models (PIMs). In this paper, we propose an approach and a domain-specific language (DSL), named IIS⁎CFuncLang, aimed at enabling a complete specification of application-specific functionalities at the PIM level. We have developed algorithms for transformation of IIS⁎CFuncLang specifications into executable program code, such as PL/SQL program code. In order to support specification of application-specific functionalities using IIS⁎CFuncLang, we have also developed appropriate tree-based and textual editors. The language, editors, and the transformations are embedded into a Model-Driven Software Development tool, named Integrated Information Systems CASE (IIS⁎Case). IIS⁎Case supports platform-independent design and automated prototyping of information systems, which allows us to verify and test our approach in practice.

Introduction to the special issue on application-specific processors

Introduction to the Special Issue on Application-Specific Processors Application-specific processors offer performance, energy, and cost benefits compared to their general-purpose counterparts for a wide variety of market segments, ranging from low-cost micro-controllers to high-end supercomputers. The design and usage of application-specific processors are strikingly different from general-purpose comput- ers as the architecture is tuned to accelerate only a specific application or a class of applications. Application-specific architectures are often derived from a high-level specification of an application through a hardware/software co-design process, which can be highly automated; such a process would be inappropriate for general-purpose processor de- sign. Moreover, code compilation targeting application-specific processors is often inter- twined with the co-design process. Lastly, the system software may provide reduced and targeted functionality and interfaces at a much lower cost than a traditional embedded or real-time operating system such as iOS or Android. Historically, application-specific processors have been part of low-cost embedded devices; however, the landscape is rapidly changing. One important factor is the emer- gence of graphics processing units (GPUs) as general-purpose high-performance computing devices, which utilize graphics-specific hardware, but can also provide sig- nificant acceleration boosts for vectorizable applications. Similarly, reconfigurable computing devices, such as FPGAs, provide a flexible hardware fabric that can be used to implement a wide variety of application-specific functionality and as such are increasingly used for code acceleration in different domains. This special issue of ACM Transactions on Embedded Computing Systems is dedi- cated to all aspects of application-specific processors. Part of this special issue presents extended versions of some of the best papers that were presented at the IEEE Sym- posium on Application-Specific Processors (SASP) in 2009 and 2010. Altogether, we received 66 submitted manuscripts for the special issue, 10 of which were accepted for inclusion in this special issue. It is our great honor to introduce the articles. Our first article, “Hardware Architectural Support for Control Systems and Sensor Processing” by Sundhanshu Vyas, Adwait Gupta, Christopher Gill, Ron K. Cytron, Joseph Zambreno and Philip Jones, describes a microcontroller that has been cus- tomized to control thousands of PID controllers concurrently. Most application-specific processors in the past have extended RISCs or VLIWs. This article represents a land- mark effort in the design of customizable application-specific microcontrollers. This special issue features three articles that focus on the architecture of application- specific processors and the design of application-specific accelerators, namely, “Multicore-Based Vector Coprocessor Sharing for Performance and Energy Gains” by Spiridon F. Beldianu and Sotirios G. Ziavras, “A Systematic Approach for Optimized By- pass Configurations for Application-Specific Embedded Processors” by Thorsten Junge- blut, Boris Hubener, Mario Porrmann, and Ulrich R uckert, and “Custom Architecture for Multicore Audio Beamforming Systems” by Dimitris Theodoropoulos and Georgi Kuzmanov. They all represent interesting design points for different application- specific architectural styles. This is a large design space, and these three articles provide excellent insights about how one can customize a hardware platform. c 2013 ACM 1539-9087/2013/09-ART15 $15.00 DOI: http://dx.doi.org/10.1145/2514641.2514642 ACM Transactions on Embedded Computing Systems, Vol. 13, No. 2, Article 15, Publication date: September 2013.

Phase formation and morphology control of niobium oxide nanopillars

Abstract Nanopillar metal oxide thin films offer versatility as ultra high surface area supports and conductors. Metal oxide properties (e.g. stability, conductivity) can be tuned via phase and composition control to achieve desired application-specific functionality. Here we demonstrate phase control of high surface area thin films grown by glancing angle deposition and transformed to desired phases through high temperature annealing in a reducing environment. The post-annealed properties such as stoichiometry, phase, and morphology are shown to be largely dependent on initial film structure and hydrogen forming gas flow rate. Initially amorphous films of approximate stoichiometry Nb 2 O 5 are transformed to NbO 2 or NbN x O 1− x through annealing. Transformation to oxygen-deficient phases is more easily achieved for films of higher initial porosity. Higher forming gas flow rates result in both increased oxygen removal and significantly less physical degradation of nanostructures. A phase map is included as a guide to phase formation and morphology control in annealed nanopillar niobium oxide films.

Modeling a distributed intrusion detection system using collaborative building blocks

Developing complex distributed systems is a non-trivial task. It is even more difficult when the systems need to dynamically reconfigure the distributed functionalities or tasks. Not only do we need to deal with the application-specific functionalities that are intricate, but we also have to handle the complex logic of coordinating the distribution and relocation of tasks. In this paper, we model an intrusion detection system that distributes its analysis units to a number of hosts and assigns fine-grained analysis tasks to these hosts in order to cope with the rapid increase of audit data from today's IT systems. The system is further capable to react to overload situations and to shift tasks to other hosts. To develop this complex system, we apply the model-based engineering method SPACE. In particular, we show that the collaborative specification style of the method can significantly reduce the development effort. Also, the formal semantics of SPACE ensures the correctness of important design properties.

JLab: Integrating a scripting interpreter with Java technology for flexible and efficient scientific computation

The jLab environment extends the potential of Java for scientific computing. It provides a Matlab/Scilab like scripting language that is executed by an interpreter implemented in the Java language. The scripting language supports the basic programming constructs with Matlab like matrix manipulation operators. The jLab “core” provides the general purpose functionality with an extensive set of built in mathematical routines that cover all the basic numerical analysis tasks. Application specific functionality can be dynamically “plugged” in jLab by means of toolboxes. These toolboxes can be easily implemented in Java. They are packaged in .jar files for convenient handling and their corresponding classes can be dynamically integrated to the system. The important advantage of jLab compared to other similar environments is the potentiality to dynamically and automatically integrate Java code to the system in order to obtain both execution speed and to reduce the programming effort. This task is supported both by an easy to use extension Java class wizard and by application specific class wizards that automate the utilization of jLab's scientific libraries. Numerical analysis algorithms can require enormous computation resources and at the same time an expressive programming environment. We demonstrate the potentiality of jLab by describing the implementation of a simple numerical analysis algorithm that detects the zero of a function. Also an additional example concerning the solution of ODEs with the compute intensive Runge–Kutta methods is illustrated. The former task can be facilitated with the external class wizard while the ODE wizard can completely automate the later.

Securing the Next Steps In Signalling (NSIS) protocol suite

The Next Steps In Signalling (NSIS) protocol suite represents an extensible framework for enabling various signalling applications over IP-based networks. The framework consists of two layers that need different types of security protection; the lower layer mainly deals with the discovery of adjacent peers and establishment of channel security to protect the delivery of signalling messages between two peers, while the upper layer provides the signalling application specific functionalities. Different security properties are required at the two layers with stronger authorisation functionality at the signalling application layer. In this paper we examine how various security vulnerabilities can be utilised by an adversary, including eavesdropping, Man-In-The-Middle (MITM) attacks, fraud and Denial of Service (DoS) attacks. Moreover, we describe how to protect against a number of selected security threats and highlight some security challenges that require further research.

Fabrication of multilevel silicon structures by anisotropic deep silicon etching

The process of advanced silicon etching (ASE™) with its possibility to pattern silicon independent from its crystal orientation has opened up a bunch of new applications in various fields such as sensor technology and micro fluidics. At IMM, a method which allows the realisation of patterns with multiple levels of almost arbitrary shapes in silicon has been developed. Using a special combination of masking layers and a dedicated process sequence, various four-level silicon structures have been realised. For example, micro fluidic devices with several regions of different depths and widths were fabricated, enabling application specific functionalities of the individual device areas. Additionally, a special post-treatment has been applied to further reduce surface roughness of sidewalls. The multilevel silicon structures can either be used directly for, e.g. complex fluidic applications, or can serve as a starting point for the Si–LiGA process, allowing the mass production of plastic micro devices.

Software of silicon? the designer's option

Traditionally, the bulk of computer system functionality is implemented in the software medium, as a sequence of instructions for a general-purpose processor. Historically, this has provided the best balance of flexibility, cost, and performance. The new economics of VLSI and continuing advances in VLSI CAD capability open the possibility of application-specific functionality embedded in silicon as a matter of routine. This paper presents several case studies of silicon solutions used in typical software areas, including regular language recognition, Ada program unit replacement, dictionary machines, and string pattern matching. Either software or hardware designers may benefit from a study of such architectures, and Organick's notion of heterosystems designers proficient in both domains is supported.