Flexible Client Research Articles

Reproducible and Portable Big Data Analytics in the Cloud

Cloud computing has become a major approach to help reproduce computational experiments. Yet there are still two main difficulties in reproducing batch based big data analytics (including descriptive and predictive analytics) in the cloud. The first is how to automate end-to-end scalable execution of analytics including distributed environment provisioning, analytics pipeline description, parallel execution, and resource termination. The second is that an application developed for one cloud is difficult to be reproduced in another cloud, a.k.a. vendor lock-in problem. To tackle these problems, we leverage serverless computing and containerization techniques for automated scalable execution and reproducibility, and utilize the adapter design pattern to enable application portability and reproducibility across different clouds. We propose and develop an open-source toolkit that supports 1) fully automated end-to-end execution and reproduction via a single command, 2) automated data and configuration storage for each execution, 3) flexible client modes based on user preferences, 4) execution history query, and 5) simple reproduction of existing executions in the same environment or a different environment. We did extensive experiments on both AWS and Azure using four big data analytics applications that run on virtual CPU/GPU clusters. The experiments show our toolkit can achieve good execution performance, scalability, and efficient reproducibility for cloud-based big data analytics.

Spectrum Sensing Utilizing Power Threshold and Artificial Intelligence in Cognitive Radio

The purpose of this paper was to take a preventative approach to predict the transmission status of the primary user (PU) on the white spectrum throughout the duration of the simulation. We intend to reduce the computational simulation budget to eliminate user interference by precise spectrum sensing handoff. We develop PU behaviors to use a time waiting estimate methodology that gives band occupancy time intervals. The proposed strategy may also lessen risks associated with flexible clients and adapt to changing channels. Real-time applications will use ANN range sharing, which reduces transmission delay, while high-throughput applications will use PTHD range sharing. Since noise as well as obscuring effects after each transmission plan, their proximity in the channel can influence range detection. This finding is in line with published investigations. Most range detection systems compare frequency test results with the operating channel's control scope thickness. The paper met design objectives by developing a noise-independent sensing methodology with proactive time estimation. The trial is accomplished with reduced cost and latency.

A hardware and software system for MRI applications requiring external device data.

Numerous MRI applications require data from external devices. Such devices are often independent of the MRI system, so synchronizing these data with the MRI data is often tedious and limited to offline use. In this work, a hardware and software system is proposed for acquiring data from external devices during MR imaging, for use online (in real-time) or offline. The hardware includes a set of external devices-electrocardiography (ECG) devices, respiration sensors, microphone, electronics of the MR system etc.-using various channels for data transmission (analog, digital, optical fibers), all connected to a server through a universal serial bus (USB) hub. The software is based on a flexible client-server architecture, allowing real-time processing pipelines to be configured and executed. Communication protocols and data formats are proposed, in particular for transferring the external device data to an open-source reconstruction software (Gadgetron), for online image reconstruction using external physiological data. The system performance is evaluated in terms of accuracy of the recorded signals and delays involved in the real-time processing tasks. Its flexibility is shown with various applications. The real-time system had low delays and jitters (on the order of 1 ms). Example MRI applications using external devices included: prospectively gated cardiac cine imaging, multi-modal acquisition of the vocal tract (image, sound, and respiration) and online image reconstruction with nonrigid motion correction. The performance of the system and its versatile architecture make it suitable for a wide range of MRI applications requiring online or offline use of external device data.

On the Efficiency of Flexible Ethernet Client Architectures in Optical Transport Networks [Invited

The data-center interconnection (DCI) market has been rising sharply for some time, leading to the development of networking solutions tailored specifically for it. On the side of the transport network, DCI devices are characterized by simple, footprint-efficient designs focused on scalability, but still leverage the benefits of flexible-rate transponders on the line-side, to extract the most from costly optical transport infrastructures. Accompanying this evolution arose the need for a technology that could provide a flexible client layer where aggregation was done outside the transport device, but flows could still be efficiently mapped to flexible-rate transponder modules. In this context, the appearance of Flex Ethernet (FlexE) is targeted at decoupling the rates of interfaces connecting routers to transport boxes, from the actual flows traversing them. Through the introduction of an additional mapping/de-mapping layer, the capacity of multiple Ethernet interfaces can be virtualized in a resource pool for different flows. This paper addresses the application of FlexE to dense wavelength division multiplexing (DWDM) transport scenarios. Specifically, it evaluates how agnostic to FlexE a transport box should be, considering the potential trade-off between its complexity and the ability to efficiently fill lightpaths. Through a network simulation handling the provisioning of Ethernet flows in a DCI scenario, we evaluate the various FlexE use cases envisioned for transport networks, and how they affect the efficiency of router port usage and transport box provisioning, as well as their effect on the capacity of the DWDM layer.

Elastic Optical Networking: Roles and Benefits in Beyond 100-Gb/s Era

Emerging technologies such as spectrally efficient multicarrier higher order modulation and bandwidth variable wavelength selective switches have led to a change in the optical network architecture from rigid and homogeneous to flexible and heterogeneous in terms of the bit rate, center frequency spacing, modulation format, and optical reach. The elastic optical network (EON) is a network architecture toward beyond the 100-Gb/s era. This tutorial paper reviews elastic opticalnetworking technology and presents its roles and benefits in a new era, where major line rates in metro/core optical networks are 100 Gb/s and beyond. The main features of the EON are that it increases the spectral efficiency in a network manner through rate-adaptive superchannels and distance-adaptive modulation, and it provides cost- and energy-efficient traffic grooming in the optical domain. The EON concept has been widely accepted by industry and academia. Significant standardization efforts have yielded great advances evidenced by the flexible grid and the flexible OTUCn frame format recommendations. Hardware virtualization such as a sliceable multiflow transponder in cooperation with emerging flexible clients will be key to achieving more flexible and cost-effective next generation optical networks.

Impact of Client- and Line-Side Flexibility in the Lifecycle of Next-Generation Transport Networks [Invited

Fast developments in the transport network ecosystem are putting into question the foundations on which to base next-generation backbone networks. Flexibility is touted as an essential requirement to cope with traffic increasing in volume and unpredictability. Based on this principle, flexible transmission modules such as the sliceable bandwidth-variable transponder (SBVT) have been proposed to exploit the networking advantages of flexible-grid networks and more advanced modulation formats. Although the network-wide benefits of SBVTs have been the object of many studies, these do not usually consider the type of client architectures supporting them, which is critical in order to account for constraint introduced by specific architectures and emulate an operator's management of its network infrastructure over time in a convincing way. The purpose of this paper is to perform a realistic techno-economic comparison between architectures based on fixed and flexible client- and line-side elements. The relevant parameters regarding cost, traffic, and equipment availability over each planning period are modeled and conveyed to a multi-period optimization framework based on integer linear programming models tailored to cost-effectively dimension the network for each client- and line-side architecture. The simulation examines the impact in each scenario of shifting client traffic patterns (from 10G/100G to 100G/400G) and the gradual introduction of higher-capacity network elements. Its results provide insight on the cost and spectrum utilization impact of deploying fixed transponders or SBVTs, coupled with fixed and flexible client-to-line interconnections, and how each of these alternatives copes with aggregated traffic increases of 400% over several years in national and pan-European backbone network topologies.

Mobile computer vision system for hand-based identification

A mobile computer vision system for real-time biometric hand-based identification is presented in the paper. This system is characterized by a flexible client---server architecture and a simple interface for interaction with the end user. It may be implemented on any mobile device under Android operating system version 4.0 or higher with an integrated camera and Internet access. The designed system was applied for collecting a hand database with further field testing. To solve identification problems, a continuous skeleton approach was used, which showed satisfactory results, and may thus be applicable as a part of a more complex multimodal classification scheme of hands (objects) by people (classes).

Where has all the psychology gone?

Evidence-Based Practice (EBP) represents the gold standard for effective clinical psychological practice. In this review, we examine ways in which EBP tenets are being neglected by correctional psychologists worldwide. We examine three key aspects of EBP currently being neglected: (a) individualized and flexible client focus, (b) the therapeutic alliance, and (c) psychological expertise. We also highlight two highly related issues responsible for correctional psychologists' neglect of EBP. The first relates to policy makers' and correctional psychologists' overreliance on the Risk–Need–Responsivity Model to guide correctional practice. We argue that the narrow focus and implementation of this model has resulted in a severe identity problem for correctional psychologists that has severely exacerbated the dual relationship problem. That is, the tension psychologists experience as a result of engaging in psychological practice while also obliging the risk and security policies of correctional systems. The second issue concerns psychologists' response to the dual relationship problem. In short, psychology, as a discipline appears to have acquiesced to the dual-relationship problem. In our view, this constitutes a ‘crisis’ for the discipline of correctional psychology. We offer several recommendations for injecting EBP back into correctional psychology for the individual, psychology as a discipline, and correctional policy makers.

On the synergy between electrical and photonic switching

This article focuses on the values of electrical switching vs. photonic switching in the context of telecom transport networks. In particular, we show that the requirement of providing agility at the optical layer in the face of traffic forecast uncertainties is served better through photonic switching. On the other hand, some of the network-level functions, such as fast protection, subwavelength aggregation, and flexible client connectivity, require electrical switching. We further argue that additional values are achieved with hybrid photonic and electrical switching, which do not exist when either of these options is used in isolation.

Managerial Openness to Change and the Introduction of GDSS: Explaining Initial Success and Failure in Decision Conferencing

The term Group Decision Support System (GDSS) refers broadly to any application of information technology that supports the work of groups. As more organizations increasingly explore possible applications of GDSS in ways that have the potential to alter managerial routines, the extent of managerial openness to change will be tested at least as much as the new technology. The relation of managerial openness to the successful introduction of GDSS was studied by analyzing a survey of participants in 26 decision conferences hosted by the Decision Techtronics Group of the State University of New York. The perceived benefit of each conference was assessed by a global outcome scale. Eight additional scales were employed to measure group decision process effectiveness, based on the Competing Values Approach to organizational analysis. Results indicated that conferences were evaluated as most beneficial by flexible client organizations that appeared open to the initial use of GDSS. As expected, positive outcomes also were found to be associated with conferences that involved fewer participants and in which participants believed that important decisions had been made. To the extent that the process of GDSS introduction can be managed to avoid failures, the research findings strongly encourage the design of meetings that both efficiently focus on the task (i.e., are highly goal centered) while simultaneously engaging the full involvement of every group member (i.e., are highly participatory). While new technology must be repeatedly modified following adoption to suit the unique demands of each workplace, an organizational unit also must be able to change appropriately its established structures and processes to make accommodation. Such mutual adaptation suggests that the eventual assimilation of new technology will become threatened wherever it is rigidly introduced or wherever management teams are not flexible enough to alter their decision-making routines at the time of initiation.