User-defined Applications Research Articles

Delineating redox cooperativity in water-soluble and membrane multiheme cytochromes through protein design.

Nature has evolved diverse electron transport proteins and multiprotein assemblies essential to the generation and transduction of biological energy. However, substantially modifying or adapting these proteins for user-defined applications or to gain fundamental mechanistic insight can be hindered by their inherent complexity. De novo protein design offers an attractive route to stripping away this confounding complexity, enabling us to probe the fundamental workings of these bioenergetic proteins and systems, while providing robust, modular platforms for constructing completely artificial electron-conducting circuitry. Here, we use a set of de novo designed mono-heme and di-heme soluble and membrane proteins to delineate the contributions of electrostatic micro-environments and dielectric properties of the surrounding protein medium on the inter-heme redox cooperativity that we have previously reported. Experimentally, we find that the two heme sites in both the water-soluble and membrane constructs have broadly equivalent redox potentials in isolation, in agreement with Poisson-Boltzmann Continuum Electrostatics calculations. BioDC, a Python program for the estimation of electron transfer energetics and kinetics within multiheme cytochromes, also predicts equivalent heme sites, and reports that burial within the low dielectric environment of the membrane strengthens heme-heme electrostatic coupling. We conclude that redox cooperativity in our diheme cytochromes is largely driven by heme electrostatic coupling and confirm that this effect is greatly strengthened by burial in the membrane. These results demonstrate that while our de novo proteins present minimalist, new-to-nature constructs, they enable the dissection and microscopic examination of processes fundamental to the function of vital, yet complex, bioenergetic assemblies.

AutoML in heavily constrained applications

Optimizing a machine learning pipeline for a task at hand requires careful configuration of various hyperparameters, typically supported by an AutoML system that optimizes the hyperparameters for the given training dataset. Yet, depending on the AutoML system’s own second-order meta-configuration, the performance of the AutoML process can vary significantly. Current AutoML systems cannot automatically adapt their own configuration to a specific use case. Further, they cannot compile user-defined application constraints on the effectiveness and efficiency of the pipeline and its generation. In this paper, we propose Caml, which uses meta-learning to automatically adapt its own AutoML parameters, such as the search strategy, the validation strategy, and the search space, for a task at hand. The dynamic AutoML strategy of Caml takes user-defined constraints into account and obtains constraint-satisfying pipelines with high predictive performance.

A Flexible Heuristic to Schedule Distributed Analytic Applications in Compute Clusters

This work addresses the problem of scheduling user-defined analytic applications, which we define as high-level compositions of frameworks, their components, and the logic necessary to carry out work. The key idea in our application definition, is to distinguish classes of components, including core and elastic types: the first being required for an application to make progress, the latter contributing to reduced execution times. We show that the problem of scheduling such applications poses new challenges, which existing approaches address inefficiently.

Highly time-resolved 4D MR angiography using golden-angle radial sparse parallel (GRASP) MRI

Current dynamic MRA techniques are limited by temporal resolution and signal-to-noise penalties. GRASP, a fast and flexible MRI technique combining compressed-sensing, parallel imaging, and golden-angle radial sampling, acquires volumetric data continuously and can be reconstructed post hoc for user-defined applications. We describe a custom pipeline to retrospectively reconstruct ultrahigh temporal resolution, dynamic MRA from GRASP imaging obtained in the course of routine practice. GRASP scans were reconstructed using a custom implementation of the GRASP algorithm and post-processed with MeVisLab (MeVis Medical Solutions AG, Germany). Twenty consecutive examinations were scored by three neuroradiologists for angiographic quality of specific vascular segments and imaging artifacts using a 4-point scale. Unsubtracted images, baseline-subtracted images, and a temporal gradient dataset were available in 2D and 3D reconstructions. Distinct arterial and capillary phases were identified in all reconstructions, with a median of 2 frames (IQR1-3 and 2–3, respectively). Median rating for vascular segments was 3 (excellent) in all reconstructions and for nearly all segments, with excellent intraclass correlation (range 0.91–1.00). No cases were degraded by artifacts. GRASP-MRI obtained in routine practice can be seamlessly repurposed to produce high quality 4D MRA with 1–2-s resolved isotropic cerebrovascular angiography. Further exploration into diagnostic accuracy in disease-specific applications is warranted.

Conducting Interface for Efficient Growth of Vertically Aligned Carbon Nanotubes: Towards Nano-Engineered Carbon Composite.

Vertically aligned carbon nanotubes (VACNT) are manufactured nanomaterials with excellent properties and great potential for numerous applications. Recently, research has intensified toward achieving VACNT synthesis on different planar and non-planar substrates of various natures, mainly dependent on the user-defined application. Indeed, VACNT growth has to be adjusted and optimized according to the substrate nature and shape to reach the requirements for the application envisaged. To date, different substrates have been decorated with VACNT, involving the use of diffusion barrier layers (DBLs) that are often insulating, such as SiO2 or Al2O3. These commonly used DBLs limit the conducting and other vital physico-chemical properties of the final nanomaterial composite. One interesting route to improve the contact resistance of VACNT on a substrate surface and the deficient composite properties is the development of semi-/conducting interlayers. The present review summarizes different methods and techniques for the deposition of suitable conducting interfaces and controlled growth of VACNT on diverse flat and 3-D fibrous substrates. Apart from exhibiting a catalytic efficiency, the DBL can generate a conducting and adhesive interface involving performance enhancements in VACNT composites. The abilities of different conducting interlayers are compared for VACNT growth and subsequent composite properties. A conducting interface is also emphasized for the synthesis of VACNT on carbonaceous substrates in order to produce cost-effective and high-performance nano-engineered carbon composites.

Guest Editorial: Managing Next-Generation Networks for Intelligent Services and Applications

Next-generation networks (NGNs) integrate the functionalities of a plethora of established and emerging technologies such as 5G, artificial intelligence (AI), edge intelligence, network softwarization, and data plane programmability. NGNs promise to achieve ultra-fast data rates and minimal latency in wireless communication and networking. They enable smart and autonomous services and applications through AI and machine learning (ML). Coupled with advances in end-user devices, NGNs enable a plethora of smart services and user-defined applications. Given the rise in system complexity and the exponential increase in the amount of data exchanged through networks, new state-of-the-art NGN management solutions are needed. By adapting cooperative and distributed management solutions, more reliable and efficient services and applications are conveyed to end users. Moreover, with distributed learning solutions, NGNs could be optimized to support the dynamic nature of network configuration and enable end-to-end system automation. For instance, the integration of federated learning (FL), deep reinforcement learning (DRL), and blockchain to NGNs can support scalable, secure, and diversified services and applications. Furthermore, through data plane programmability, network intelligence could be implemented directly on programmable devices in the network core. An intelligent forwarding plane would enable faster reaction to network events without depending on time-consuming exchange between the data and control planes.

A Labeled Architecture for Low-Entropy Clouds: Theory, Practice, and Lessons

Resource efficiency and quality of service (QoS) are both long-pursuit goals for cloud providers over the last decade. However, hardly any cloud platform can exactly achieve them perfectly even until today. Improving resource efficiency or resource utilization often could cause complicated resource contention between colocated cloud applications on different resources, spanning from the underlying hardware to the software stack, leading to unexpected performance degradation. The low-entropy cloud proposes a new software-hardware codesigned technology stack to holistically curb performance interference from the bottom up and obtain both high resource efficiency and high quality of application performance. In this paper, we introduce a new computer architecture for the low-entropy cloud stack, called labeled von Neumann architecture (LvNA), which incorporates a set of label-powered control mechanisms to enable shared components and resources on chip to differentiate, isolate, and prioritize user-defined application requests when competing for hardware resource. With the power of these mechanisms, LvNA was able to protect the performance of certain applications, such as latency-critical applications, from disorderly resource contention while improving resource utilization. We further build and tapeout Beihai, a 1.2 GHz 8-core RISC-V processor based on the LvNA architecture. The evaluation results show that Beihai could drastically reduce the performance degradation caused by memory bandwidth contention from 82.8% to 0.4%. When improving the CPU utilization over 70%, Beihai could reduce the 99th tail latency of Redis from 115 ms to 18.1 ms. Furthermore, Beihai can realize hardware virtualization, which boots up two unmodified virtual machines concurrently without the intervention of any software hypervisor.

Smart E-Textile Systems: A Review for Healthcare Applications

E-textiles is a new hybrid field developed with the help of the integration of electronic components into our daily usage of textile products. These wearable e-textiles provide user-defined applications as well as normal textile clothing. The medical field is one of the major leading areas where these new hybrid products are being implemented, and relatively mature products can be observed in the laboratory as well as in commercial markets. These products are developed for continuous patient monitoring in large-scale hospital centers as well as for customized patient requirements. Meanwhile, these products are also being used for complex medical treatments and the replacement of conventional methods. This review manuscript contains a basic overview of e-textile systems, their components, applications, and usages in the field of medical innovations. E-textile systems, integrated into customized products for medical needs, are discussed with their proposed properties and limitations. Finally, some recommendations to enhance the e-textile system’s integration into the medical field are argued.

Standards for Major Internet Disruptors: Blockchain, Intents, and Related Paradigms

The six articles in this special section address major issues concerned with evolving standardization processes and underlying technologies in the context of Blockchain for different application domains, showing how distributed ledger technologies can be so disruptive that they can change the Internet as we know it. Software is envisioned to play an unprecedented dominant role in future communication paradigms, with user-defined applications capable of not only communicating with, but also controlling some features of the underlying communication infrastructure in a secure and trustworthy manner. This (r)evolutionary trend toward virtualized and “softwarized” networks enable Internet-based service users and providers, as well as the related stakeholders, to take advantage of resource abstractions and to adopt a programmatic approach to service deployment. In a “game-changing” scenario, a user’s needs can be decoupled and expressed independently of the specific underlying implementable technology, but yet the requested service must meet the expected mutual trustiness and security levels. This trend opens a number of disruptive solutions that can change the Internet as we know it.

Synchro-Measurement Application Development Framework: An IEEE Standard C37.118.2-2011 Supported MATLAB Library

Electrical power system monitoring, protection, operation, and control schemes are undergoing significant changes toward the next generation fully automated, resilient, and self-healing grids. At present, there still exists a lack of available user-friendly tools for the synchronized measurement technology supported application design. This paper presents a synchro-measurement application development framework (SADF) to promote a simplified design and thorough validation of synchro-measurement (IEEE Standard C37.118.2-2011) supported user-defined applications under realistic conditions. The proposed SADF supports online receiving of a phasor measurement unit (PMU) or phasor data concentrator (PDC) provided data stream and enables simultaneous use of processed machine-readable synchro-measurements in advanced user-defined applications. This paper fills the scientific gap between the IEEE Standard C37.118.2-2011 specifications and its implementation by proposing a novel robust communication technique and efficient synchro-measurement data parsing methodology. As a proof of concept, the proposed SADF is implemented as a novel open-source MATLAB library. Combining this library with MATLAB’s signal processing and visualization functions allows mastering the design and validation of complex wide-area monitoring, protection, and control applications, as well as PMU/PDC performance and compliance verification. Finally, this paper verifies the proposed library against the standard specifications, assesses its interoperability and performance via a cyber-physical simulation platform, and presents online voltage magnitude monitoring as an example application.

A Model-driven Ontology Approach for Developing Service System Applications

This paper aims to survey the new methodology and tools for user-defined applications development, based on Service-Oriented Computing (SOC) and Model-Driven Approach (MDA), when all computing units, both hardware and software, can be treated as services and domain ontology acts as a meta-model basis to generate a conceptual model for specific information systems.

Using Algorithms on Smart Transducer: An IEEE Standard Perspective

This paper describes the role of algorithm development in the IEEE standard 21451.001. The purpose is to promote and enhance the computational capabilities of smart transducers and facilitate the flow from sensor raw data processing to sensor knowledge fusion. A case study on real-time segmentation and labeling is conducted to demonstrate the feasibility of the first layer algorithm. The key role of the IEEE 21451.001 standard is to standardize the data structure for user-defined application code and pattern learning algorithms and regulate the protocols for data sharing and exchange. The considerations for the standard development are illustrated and discussed. The foreseeable impact of the standard for algorithms is highlighted as well.

An integrated ocean circulation, wave, atmosphere, and marine ecosystem prediction system for the South Atlantic Bight and Gulf of Mexico

An integrated nowcast/forecast modelling system covering the South Atlantic Bight and Gulf of Mexico (SABGOM) is in operation, utilizing sophisticated model coupling and parallel computing techniques. This three-dimensional, high-resolution, regional nowcast/forecast system provides a nowcast and an 84 h forecast of marine weather, ocean waves and circulation, and basic marine ecosystem conditions to the public via a Google Map interface. The SABGOM system runs automatically daily and supports a series of user-defined online applications. Extensive model validations were performed online against in situ and satellite-observed ocean conditions. The SABGOM system exhibits a reliable capability of providing valuable forecasts.

A General Method Towards Efficient Synthesis and Fluorescence Tuning of Carbon Black-Derived Carbon Dots via Controlled Liquid Oxidization

Efficient synthesis and controlled modification of carbon dots (CDs) with tuneable properties on the basis of facile technical routes are of great significance for user-defined applications as well as more insightful understanding of the unique fluorescence from carbon nanomaterials. In this work, we report an improved nitric acid oxidization method towards low-cost and rapid preparation of fluorescent CDs. This is achieved by using industrial carbon black specimens as the precursor and implementing a reduced pressure distillation for the purpose of eliminating excessive acids. Unexpectedly, the product exhibits an interesting dual luminescence behaviour with tuneable characteristics that differs from all previously reported CDs. The strongest emissions at fixed or varied excitations can be simultaneously tuned from blue to green or yellow by simply prolonging the time of acid oxidization. These emissions show distinct stabilities in acid and alkaline environments, thereby making the resultant CDs very promising candidates for pH probes. It is further revealed that this simple synthesis and fluorescence tuning strategy is also applicable to CDs from other carbon blacks.

Building a Low-Cost Eye-Tracking System

This paper presents the developing of a low-cost eye-tracking system by modifying the commercial-over-the-shelf camera to integrate with the proper-tuned open source drivers and the user-defined application programs. The system configuration is proposed and the gaze-tracking approximated by the least square polynomial mapping is described. Comparisons between other low-cost systems as well as commercial system are provided. Our system obtained the highest image capturing rate of 180 frames per second, and the ISO 9241-Part 9 test performance favored our system, in terms of Response time and Correct response rate. Currently, we are developing gaze-tracking accuracy application. The real time gaze-tracking and the Head Movement Estimation are the issues in future work.

Spatial Analysis and Modeling Tool (SAMT): 2. Applications

The Spatial Analysis and Modeling Tool (SAMT) is a GIS-based analytical software for land use study. This paper demonstrates the capabilities of SAMT as applied in studies of land use and landscape change in the catchment area of the River Quillow, North-East Germany. Neural network and fuzzy models are important features that were incorporated in SAMT. The region of study for this application is a catchment area of about 170 km 2 and is subdivided into 54,000 grid cells for spatial simulations. Three different applications of SAMT are discussed in this article. The first application involves assessment of the potential soil erosion risk on arable land. This user-defined application combines an economic model (LP model), a temperature-driven crop coverage model and a soil erosion risk model (Universal Soil Loss Equation) using data from tables and map information. The second and third applications are winter wheat yield estimates using, respectively, the fuzzy toolbox SAMT_FUZZY in conjunction with expert knowledge, and using the neural network toolbox SAMT_NN based on observations.

Diagnosing the cause of operational faults in machine tools with an open architecture CNC

The conventional computerized numerical controller (CNC) of machine tools has been increasingly replaced by a PC-based open architecture CNC (OAC) that is independent of a CNC vendor. The OAC and machine tools with an OAC have led to a convenient environment in which user-defined applications can be efficiently implemented within a CNC. This paper proposes a method of diagnosing the cause of operational faults. The method is based on the status of a programmable logic controller in machine tools with an OAC. An operational fault is defined as a disability that occurs during the normal operation of machine tools. Operational faults constitute more than 70 percent of all faults and are also unpredictable because most of them occur without any warning. To quickly and correctly diagnose the cause of an operational fault, two diagnostic models are proposed: the switching function and the step switching function. The cause of the fault is logically diagnosed through a fault diagnosis system using diagnostic models. A suitable interface environment between a CNC and developed application modules is constructed to implement the diagnostic functions in the CNC domain. The results of the diagnosis were displayed on a CNC monitor for machine operators and transmitted to a remote site through a Web browser. The proposed diagnostic method and its results were useful to unskilled machine operators and reduced the machine downtime.

CNC-implemented fault diagnosis and web-based remote services

Recently, the conventional controller of machine-tool has been increasingly replaced by the PC-based open architecture controller, which is independent of the CNC vendor and on which it is possible to implement user-defined application programs. This paper proposes CNC-implemented fault diagnosis and web-based remote services for machine-tool with open architecture CNC. The faults of CNC machine-tool are defined as the operational faults occupied by over 70% of all faults. The operational faults are unpredictable as they occur without any warning. Two diagnostic models, the switching function and the step switching function, were proposed in order to diagnose faults efficiently. The faults were automatically diagnosed through the fault diagnosis system using the two diagnostic models. A suitable interface environment between CNC and developed application modules was constructed for the internal function of CNC. In addition, a suitable web environment was constructed for remote services. The web service functions, such as remote monitoring and remote control, were implemented, and their operability was tested through the web. The results obtained through this research could be a model of fault diagnosis and remote servicing for machine-tool with open architecture CNC.

Modeling complex multi-component reactive-transport systems: towards a simulation environment based on the concept of a Knowledge Base

A modelling framework within which transport processes in the hydrosphere can be described and interfaced with relevant biogeochemical reactions is presented. Three key elements of this simulation environment are discussed: (1) a numerical engine for solving sets of coupled non-linear process equations; (2) an automated procedure for model code generation (`Automatic Code Generator'); (3) a Web-distributed Knowledge Base (KB) of processes. The Automatic Code Generator translates the information selected in the KB into computer algorithms using the principles defined in the numerical engine. The code CONTRASTE is a first attempt at developing such a modelling framework. It allows one to easily select, adapt and combine a specific set of biogeochemical processes relevant to a user-defined application. The workings of CONTRASTE are described by means of examples which demonstrate how the various components of the simulation environment are coupled and automated. Prospects for future developments towards a fully automated model generation procedure are discussed.

Modeling buffer layer IGBTs for circuit simulation

The dynamic behavior of commercially available buffer layer insulated gate bipolar transistors (IGBTs) is described. It is shown that buffer layer IGBTs become much faster at high voltages than nonbuffer layer IGBTs with similar low voltage characteristics. Because the fall times specified in manufacturers' data sheets do not reflect the voltage dependence of switching speed, a new method of selecting devices for different circuit applications is suggested. A buffer layer IGBT model is developed and implemented into the Saber circuit simulator, and a procedure is developed to extract the model parameters for buffer layer IGBTs. It is shown that the new buffer layer IGBT model can be used to describe the dynamic behavior and power dissipation of buffer layer IGBTs in user-defined application circuits. The results of the buffer layer IGBT model are verified using commercially available IGBTs. >