Setup Delay Research Articles

Factors Influencing Roll-Out of an m-Health Intervention in India: Results from a Dynamic and Responsive Process Evaluation

Abstract Objectives Implementation research can support iterative program improvement, yet limited examples of such dynamic experiences exist. We conducted a multi-stage and multi-method process evaluation (PE) of a large-scale m-Health intervention in India that currently reaches 581,282 frontline workers (FLWs). The intervention (Common Application Software (CAS)) includes a smartphone application that digitizes FLW service-tracking registers and acts as a job aid and multiple dashboards for real-time monitoring. We examined factors affecting the roll-out of CAS in two Indian states. Methods Program impact pathways were developed with implementers to inform research questions and methods. Data were collected across many time points between 2016 and 2018 to temporally align with program roll-out. In total, we did in-person surveys with FLWs (n = 100), supervisors (n = 55), other staff (n = 18), two phone surveys with FLWs (n = 404), interviews with national and state-level stakeholders (n = 21), and routine meetings with implementers. Short phone surveys were conducted between in-person surveys to give rapid feedback to implementers. Results Impediments to roll-out included state readiness, delays in device procurement and set-up, dashboard readiness, and low data storage space. Over time, FLWs satisfaction with training remained consistent (100–99%), use of CAS (82–100%), and preference to use it (74–80%) increased. Challenges declined over time [e.g., slow internet (79– >58%), battery heating (62– >45%), and network issues (68– >52%). Most FLWs were knowledgeable of CAS but were confused with symbols/colors in certain domains of CAS. Supervisors were satisfied with training, were knowledgeable of CAS, but hardware issues precluded some from using it. Use of the dashboard, a critical feedback mechanism, was limited due to gaps in staff training and version modifications. Conclusions A dynamic and engaged PE implemented with inputs from multiple stakeholders helped provide timely and meaningful feedback to a large-scale program, enabling corrective actions and increasing potential for impact of the program. Implementing a dynamic PE is time and resource intensive and required flexibility in timing and modalities of data collection. Funding Sources Bill & Melinda Gates Foundation, via grants to IFPRI and UCSF.

On value functions for FCFS queues with batch arrivals and general cost structures

We develop a unified framework for analyzing and optimizing costs for systems of FCFS queues with batch arrivals, setup delays and a general nonlinear cost structure that includes costs associated with energy used, setup times and Quality of Service (QoS) measures. We focus on the MX/G/1 and GeoX/G/1 queues with i.i.d. service times, but our results hold also for arbitrary i.i.d. batch structures where service times within a batch may depend on the batch size and have different, possibly dependent, distributions. We use the notion of value functions from the theory of Markov decision processes (MDPs), along with exponential cost functions, to develop the notion of, and simple expressions for, value generating functions. These can be used to find efficient energy control and job dispatching policies.

Delay Aware RSA Algorithm Based on Scheduling of Differentiated Services With Dynamic Virtual Topology Construction

The fast and diversified development of Internet services leads to numerous services with differentiated delay tolerance of optical connections set-up are converging in the optical network. Consequently, the average set-up delay of optical connection is increased, which will inevitably bring pressures to optical networks. To solve this problem, a delay aware routing spectrum assignment (RSA) algorithm based on services scheduling in priority queues with dynamic virtual topology construction (QVT-RSA) is proposed. First, the QVT-RSA algorithm reasonably identifies various different services and arranges them in order according to their priority, waiting time and delay tolerance requirements. Then, software defined networks (SDN) controller with multi-threads technology is adopted to innovatively parallel serve the ordered service requests to reduce the average set-up delay of optical connections, which also offset the induced delay caused by services scheduling. The network resource is accurately shared among multi-threads using the proposed mutual exclusive resource utilization model realized by dynamic virtual topology construction. The continuously coloring and usable virtual topology linkage reconfiguration can provide topology resources for service requests and adapt the dynamic transformation among serving, waiting and new arriving service requests. The shortest-path routing and first fit spectrum assignment (SPFF-RSA) algorithm is used as the baseline algorithm. Furthermore, by combining the SPFF-RSA algorithm and partial strategy of our strategy, the QSPFF-RSA and V-RSA algorithms are proposed as baseline algorithms as described in V-B. The simulation experiment results demonstrate that the average optical connections set-up delay of QVT-RSA algorithm is reduced compared with SPFF-RSA and QSPFF-RSA algorithms, and the blocking probability of QVT-RSA algorithm is reduced compared with SPFF-RSA, QSPFF-RSA and VRSA algorithms. The optical connections set-up success probability within delay tolerance about high, medium and low priority services of QVT-RSA algorithm is higher than that of the SPFF-RSA, QSPFF-RSA and VRSA algorithms.

Self-Forming Multiple Sub-Nets Based Protocol for Tactical Networks Consisting of SDRs

The paper presents a novel approach for tactical networks in which radios form self-regulatory virtual sub-nets on the basis of control messages. The design uses hybrid of frequency division multiple access (FDMA) and time division multiple access (TDMA) approaches with less call setup delays and increases in network throughput. This multiple sub-nets based distributed algorithm exploits available spectrum resources, provides collision-free simultaneous transmissions and autonomous selection of time slots over different frequency sub-bands with self-organizing and self-forming network capabilities. We propose two schemes which provide multi-channel medium access control with autonomous scheduling of time slots for software-defined radios (SDRs). The schemes use request and acknowledgment frames as control messages to devise a distributed solution. These control messages alone help to form virtual sub-nets, preserve frequency channels and schedule transmissions over multiple time slot intervals, depend on the type of data messages. In order to demonstrate the behavior of sub-nets for tactical networks, theoretical findings are exploited with experimental analysis to provide practical implementation of schemes using contention-free time slotted common control channel for nodes coordination and time slotted collision-free multi-channel environment for data transmissions. The results show the effective coexistence of multiple transmissions in a network with increase in network throughput and lower the data latency up-to 76.8%, when compare to conventional MAC protocols. The design is workable for time sensitive, mission critical networks and expected to support multi-hop transmissions in similar manner.

Industry 4.0 and circular economy: Operational excellence for sustainable reverse supply chain performance

The present research proposes a roadmap to the excellence of operations for sustainable reverse supply chain/logistics by the joint implementation of principles of Industry 4.0 (I4.0) and ReSOLVE model of circular economy (CE) approaches. The connection between I4.0 and CE is unveiled by addressing the case-based model affecting the economic and environmental performances imparting two important dimensions: (i) the information sharing with the reverse logistics system is in real-time mode, and (ii) diffusion of green product in the market. The effectiveness of the virtual world in I4.0 environment is explored using simulation of reverse logistics model involving operations such as inventory and production planning policy, family-based dispatching rules of remanufacturing, and additive manufacturing. The remanufacturing model examines the trade-off between set-up delays and the availability of green transportation. For managerial insights, Taguchi experimental design framework has been used for the analysis. Based on the trade-off analysis between environmental and economic performances, the findings of the paper suggest appropriate combinations of information-sharing and family-based dispatching rules. Further, the findings suggest that, given the I4.0 and circular capabilities, it is necessary to focus on the cost of the socially influenced operations involving factors such as collection investment and size of the end-user market that governs the product returns. Therefore, in the present paper, the integration of I4.0 and CE represents a real-time decision model for the sustainable reverse logistics system.

On energy-aware M/G/1-LAS queue with batch arrivals

We analyze an energy-aware MX/G/1 queue under LAS scheduling with a setup delay and an idle timer that controls the delay before the server enters a sleep state. Through a classical busy period analysis, the expression for the mean conditional delay is derived, which generalizes the earlier well-known result for the ordinary M/G/1-LAS queue. We also analyze the performance-energy tradeoff and show that two well-known cost metrics, weighted sum and product of the mean delay and mean power, are minimized by setting the timer equal to zero or infinite, i.e., a finite idle timer is never used.

Model-Driven Joint Optimization of Power and Latency Guarantee in Data center Applications

Cloud data centers try to achieve two primary but competing goals for latency-sensitive services: meeting latency service-level objective (SLO) and reducing energy utilization. In this paper, we perform a joint optimization of both goals, such that given a tail latency constraint and request rate, the number of active servers and their corresponding core frequencies which cause the least energy overhead can be derived. Both the server sleep mode and setup delay are taken into account. Based on the assumption that requests arrive following a Poisson process, we provide a numerical method to compute the optimal number of active servers and a closed-form expression for their corresponding core frequency. We propose how the optimization technique can be used for real, bursty, non-Poisson data center traffic.

Near-optimal dispatching policy for energy-aware server clusters

A server cluster can be modeled as a set of parallel queues, and the dispatcher decides to which queue the arriving jobs are routed. We consider an energy-aware dispatching system in a Markovian setting, where each server, upon becoming empty, enters a sleep mode to save energy, and to activate the server after sleep incurs an additional setup delay cost. We seek to optimize the performance-energy trade-off by applying the so-called Whittle index approach. As our main result, we derive sufficient conditions for the system parameters under which the problem is provably indexable, and also determine the corresponding Whittle index values explicitly. Our numerical experiments demonstrate that the resulting energy-aware Whittle index policy is able to perform very close to the numerically solved optimal policy and outperforms all considered reference policies.

Optimal energy-aware load balancing and base station switch-off control in 5G HetNets

We consider optimal energy-aware load balancing of elastic downlink data traffic inside a macrocell with multiple small cells within its coverage area. The system is modeled as a set of parallel queues. In particular, the model of the small cell includes the setup delay resulting from activating the base station after being placed in a low power off state and the idle timer controlling the amount of time to wait before being switched off. We apply the theory of MDPs to develop state-dependent dynamic policies for controlling both the routing of the arrivals as well as the length of the idle timer that minimizes the weighted sum of energy and performance. In particular, we show that in the optimal policy the idle timer control can be simplified to selecting a value arbitrarily close to zero or infinite. Additionally, by utilizing the first step of the well-known policy iteration method, we develop an explicit near-optimal dynamic policy for routing the arrivals and also for determining the idle timer configuration of the system, based on the expressions for the future marginal costs. The performance of the policy is illustrated through numerical examples.

소프트웨어 정의 무선 메쉬 네트워크에서 마스터 컨트롤러 선택방법

소프트웨어 정의 무선 메쉬 네트워크에서 새로운 패킷에 실시간으로 잘 대응하기 위해선 가장 낮은 지연시간을 갖는 Flow Setup이 필요하다. 본 논문은 서포트 백터 머신(SVM)으로 영구적 링크 끊김을 예측하고 이를 바탕으로 미리 Flow Setup을 준비하여 기존 방법보다 끊김없이 낮은 지연시간을 갖는 마스터 컨트롤러 선택방법 RCM을 제안한다. In Software-Defined Wireless Mesh Network, a Flow Setup with the lowest delay is needed to adequately cope with new incoming packet in real time. Therefore, Master Controller Selection Method RCM that prepares Flow Setup in advance for more seamless and lower Flow Setup delay than existing methods is proposed by using SVM that predicts permanent link failure.

Analyzing enhanced real‐time uplink scheduling algorithm in 3GPP LTE‐advanced networks using multimedia systems

AbstractThird Generation Partnership Project (3GPP) standardizes the Long‐Term Evolution (LTE) to improve the quality of service in modern communication systems using 3GPP LTE‐advanced (LTE‐A) networks. As this technology is converging with modern devices, efficient resource allocation schemes are essential for minimization of the communication delay for the sensitive real‐time devices. To achieve the demands of latest technologies, this paper proposes two novel mechanisms, enhanced real‐time polling system with continuous time–batch Markovian arrival process and proactive resource allocation framework. The objective of the former mechanism is to improvise the service connectivity between the multimedia devices in LTE‐A networks and the latter is to exploit the transmission bits in each user's buffer in addition to the state information of wireless channel. The proposed mechanisms consider the constraints enforced by 3GPP standard in terms of radio resource blocks allocation for LTE‐A networks. In addition, the proposed mechanisms use LTE‐A networks to investigate the Voice over LTE traffic in order to analyze various quality‐of‐service measures, namely, sum throughput, session setup delay, packet delivery ratio, resource utilization ratio, and throughput improvement via real‐time multimedia client‐server systems. The probing results show that the proposed algorithm is superior in comparison to other typical services of IEEE 802.16d/e–based systems as well as LTE‐A system with 7 orthogonal frequency‐division multiplexing symbols over a duration slot 0.5 ms. While the slotted duration is set to 5 ms, the proposed framework effectively utilizes the resource allocation cycle to support the uplink scheduling to outperform at least 38% better throughput performance in comparison with existing mechanisms.

Reliable location aware and Cluster-Tap Root based data collection protocol for large scale wireless sensor networks

Designing a stable and energy efficient routing protocol for mobility based Wireless Sensor Networks (WSNs) is a great challenge, because frequent link changes or failures make the network topology unstable. In this paper, we propose a Cluster-Tap Root based Data Collection (CTRDC) protocol which produces a highly stable and reliable routing path for data transmission. In cluster formation phase, the Cluster Heads (CHs) are elected in a distributed manner in two levels: (i) Tentative CH (TCH) candidate selection based on node's residual energy (ii) a fuzzy logic based final CHs selection which is obtained by using node speed, number of neighbor nodes, and average connection time. This distributed CH selection ensures the two hop distance between the CHs. Besides, we introduce the tap root principle for constructing a route between the CHs and Base Station (BS), in which it uses a minimal number of sensor nodes (i.e., O(n2)), whereas the tree topology utilized O(2n) nodes and n denotes the depth of the tap root. It is observed that it lessens the path setup delay, interference, collision, and also avoids the redundant searching of nodes in the same place. In addition, an effective localization method is proposed, in which all the sensor nodes are equipped with Digital Magnetic Compass (DMC). The DMC is used to measure the moving direction (azimuth) of the mobile node, thus the sensor node finds its location in the sensing area with the help of two anchor nodes. From the simulation results, it is showed that the proposed CTRDC protocol provides better performance in terms of Packet Delivery Ratio (PDR), throughput, Average Energy Consumption (AEC), Average End-to-End Delay (AEED) and control overhead as compared to MBC, OZEEP, and ES-WCA. Additionally, CTRDC adapts to mobility scenario, where the reliability, fault tolerance, scalability, and stability of the networks are enhanced, even if it gets frequent link failures.

Applying Multi-Controller Collaboration in Fine-Grained All-Optical Intra-Datacenter Networks

The exponential growth in emerging applications in datacenters leads to significant increases in traffic and bandwidth consumption in datacenter networks. Finegrained optical switching technology can provide lowlatency end-to-end connection with flexible granularity in intra-datacenter networks. In such a scheme, the centralized network controller will compute an end-to-end path and provide switch state commands for each connection request. However, as network scale and traffic requirements continually increase, the centralized controller will face a significant challenge in low-latency end-to-end connection provisioning under a heavy traffic load. Limited by the controller’s computation and processing performance, the continuously arriving connection requests may block the server's message queue and slow down the controller’s processing rate. In this paper, we propose a multi-controller control scheme for fine-grained all-optical datacenter networks. We take optical time slice switching as an example of fine-grained all-optical switching to illustrate our detailed control scheme. Partitioning rules for the network and controllers’ responsibilities, the routing algorithm, and the signaling process are also discussed. The proposed multi-controller control scheme can greatly reduce each controller’s computation and processing burden and improve network performance. Dynamic datacenter network emulations are launched to verify our proposed scheme. The emulation results indicate that the multi-controller scheme can reduce connection setup delays and request and data failure rates, while the single controller fails to handle all the requests.

S80. Utility of reduced montage EEG in detecting seizures or seizure-like activity

Introduction Standard scalp EEG is used to detect a wide range of cerebral pathologies. However, its utility in emergency and resource-limited settings may be impeded by delays in setup and interpretation. Past studies have investigated reduced channel arrays as screening tools, but inferred a lower utility in detecting epileptiform abnormalities. The current study tested the utility of reduced (8-channel) montage (rm-EEG) covering the lateral hemispheres compared to full (18-channel) montage (fm-EEG) for detection of generalized and hemispheric seizures and seizure-like patterns by neurologists with extensive EEG training, neurology residents with minimal EEG training, and medical students without EEG training. Methods Forty neurologists (7 epileptologists, 13 epilepsy fellows, 20 neurology residents) from 7 institutions and 42 medical students from Stanford University were presented 44 samples of EEG recordings (15-s long) as both fm-EEG and rm-EEG formats in a random order. Samples represented seizures ( n = 8), seizure-like activity (lateralized or generalized periodic discharges or burst suppression, n = 12) or non-rhythmic, non-periodic patterns (normal or slowing, n = 24) as determined by majority agreement among 3 senior epileptologists with >10 years of training (Fleiss’ kappa 0.79). Both physicians and students were asked to determine whether each sample represented seizure activity (yes/no), while epileptologists and residents were also asked to specify any and all pathological activity present in each sample. We calculated the overall accuracy of fm-EEG and rm-EEG, as well as their sensitivity and specificity for seizures and seizure-like activity; differences were assessed using paired t -tests. Results EEG samples were evaluated with almost identical accuracy using fm-EEG (epileptologists: 88%; residents: 75%; students: 57%) and rm-EEG (epileptologists: 84%, p = 0.156; residents: 75%, p = 0.086; students: 57%, p = 0.461). While epileptologists identified hemispheric or generalized seizure activity with high sensitivity using fm-EEG (99%) and rm-EEG (94%, p = 0.172), individuals with minimal or no EEG experience demonstrated lower sensitivity using rm-EEG (residents: 79%; students: 45%) compared to fm-EEG (residents: 91%, p = 0.031; students: 62%, p = 0.048). However, specificity for seizures/seizure-like activity was greater using rm-EEG (epileptologists: 91%; residents: 84%; students: 73%) compared to fm-EEG (epileptologists: 85%, p = 0.015; residents: 77%, p = 0.018; students: 63%, p Conclusion Our study demonstrates that a reduction from 18 to 8 channels does not degrade the sensitivity for generalized and hemispheric seizures, and yet provide more specific information for ruling in such epileptic activity even when read by individuals with minimal or no EEG experience. On the basis of these findings, we suggest that a restricted channel configuration can be used for faster diagnosis of generalized and hemispheric seizures that ought to be detected and treated expeditiously.

Energy efficient link stable routing in internet of things

In future communication networks with Internet of Things (IoT), each of the smart devices will be able to communicate with other smart devices ubiquitously throughout the time clock. These smart devices contain limited amount of energy, memory, and processing power. Additionally, short range radios are very susceptible to noise, multi route distortion, and interference. In this context this paper proposes an energy efficient link stable routing (EELSR) to conserve energy of the smart devices and to account link stability for enhancing the network lifetime. In order to verify the correctness of the proposed routing, first, analytical models for link stability, and residual energy of a route have proposed, second, an optimal route selection algorithm that uses residual energy of a route, link stability of a route, and route distance, has been designed. The performance of the proposed EELSR is evaluated and compared with AODV and REL in the terms of network life time, packet delivery ratio, routing success probability, and route setup delay. EELSR outperforms the state of art routing algorithms.

An intra–inter-cell device-to-device communication scheme to enhance 5G network throughput with delay modeling

As the number of mobile users is growing, so is the demand for more bandwidth. It becomes important that the required bandwidth and spectral resources do not scale with traffic in the next generation of wireless networks [i.e. fifth generation (5G)]. Device-to-device (D2D) communication underlaying cellular networks has been recognized as an essential technique in 5G networks. By applying definite principles and strategies, D2D communication not only increases the spectral and energy efficiency, but also enhances network throughput, network coverage and reduces delay. In this paper, we present an intra–inter-cell D2D communication scheme to enhance throughput of 5G networks. We study call setup delay of two developed communication scenarios and throughput gain comparing three systems. Firstly, we show the enhancements required in current cellular architectures to support inter-cell D2D communication. We develop protocols for two scenarios and demonstrate how architecture entities cooperate for the call setup between D2D users. We measure the overall call setup time for the developed protocols and derive a closed-form delay formula to estimate call setup time probability. Secondly, we perform simulations using a topology similar to that found in realistic urban environments to study throughput gains of the proposed intra–inter-cell D2D communication scheme. We compare three systems in terms of throughput: (1) pure cellular system (with cellular users only), (2) pure cellular system with intra-cell D2D users sharing the same cellular resource, and (3) pure cellular system with intra–inter-cell D2D users sharing the same cellular resource. Simulation results show that the proposed scheme substantially increases the network throughput and spectrum efficiency.

Scalable distributed control plane for On-line social networks support cognitive neural computing in software defined networks

Though most of the current proposed distributed control planes maintain strong consistency among their controllers, this paper argues the strong consistency is not a prerequisite and proposes an Event Coordination System (ECS) that enables an efficient event replaying system and a distributed control plane (DisCon) using this event replaying system to construct eventually consistent global network topologies among its controllers without sacrificing scalability. Our ECS implements a novel request handling procedure that ensures a firstly received write request is firstly multi-casted, notified, and updated, so thus our DisCon can maximally ensure the same time sequence in which topology events get updated at different controllers and the constructed topologies can reflect the real network change in practice. We highlight the major mechanisms used, discuss the major causes of this eventual consistency, estimate the inconsistency window among controllers, and show how this eventual consistency does not make a big difference in supporting network applications. Experiments are conducted to evaluate our ECS and DisCon. The results show our DisCon has a larger event replay throughput and a lower event converging delay than HyperFlow, and larger flow setup rate and lower flow setup delay than most of the current distributed control planes.

Energy-aware SRPT server with batch arrivals: Analysis and optimization

We consider the optimal energy-aware control of a single server with batch arrivals and applying the SRPT scheduling rule. The server is modeled as an MX∕G∕1 queue with a particular control policy that puts the server to a sleep mode to save energy with an additional delay cost, the setup delay, after the server is turned on again. We first consider an ordinary MX∕G∕1-SRPT system that does not go to sleep, and derive the mean response time equation. We then consider the more elaborate energy-aware MX∕G∕1-SRPT system, and show that the mean response time can be decomposed into two parts: the mean response time of an ordinary MX∕G∕1-SRPT, and an additional penalty term for switching the server to a sleep state. Furthermore, we study the energy-performance optimization of the system and prove that, for the Energy Response time Weighted Sum (ERWS) and Energy Response time Product (ERP) cost metrics, the optimal control either puts the server into a sleep state immediately when it becomes idle or keeps it idling until the next job arrives.

Impact of instrument and column parameters on high-throughput liquid chromatography performance

The speed and separation performance of high-throughput liquid chromatography (HT LC) was investigated. We evaluated the contributions of various experimental parameters to the total analysis cycle time, including column length (column void time), gradient delay, flow rate, auto-sampler (A/S) speed, and software related delays. The best case injection-to-injection cycle time of 22s was achieved using 12s gradient time and 2.1×20mm columns packed with 1.7μm C18 particles. The total 22s analytical duty cycle consisted of 2.5s column void time, 1.8s gradient delay, 12s gradient time, and approximately 5.7s for software setup delay time that served as column re-equilibration time. The achieved peak capacity for an alkylphenone sample was approximately 35, giving a peak production rate of 95 peaks per minute. We estimated the impact of LC system dispersion on peak capacity and peak production rate (peak capacity per unit of time). For HT LC scenarios (5–50mm columns and 4.8–120s long gradients) we observed that even a minor amount of system dispersion (2μL2) reduces the achievable peak capacity and peak productivity rate significantly. HT LC–MS analysis using 2.1×5mm guard column with duty cycle of 22s was successfully demonstrated.

Crosstalk-aware routing, spectrum, and core assignment in space-division multiplexing optical networks with multicore fibers

The transmission capacity of existing optical fiber will reach its physical limitation due to increasing network bandwidth. Recently, space-division multiplexing (SDM) technology has been proposed to increase the fiber transmission capacity. Multicore fiber (MCF) is a strong candidate for SDM transmission, but the intercore crosstalk will be a critical issue with MCF transmission. We make a specific analysis of transmission crosstalk in elastic optical networks. Then, the concept of spare spectrum availability is introduced to accommodate connection requests. Based on it, two different crosstalk-aware routing, spectrum, and core assignment algorithms are presented at different network states. Simulation results show that our proposed scheme improves the spectrum resource utilization and reduces blocking, with a cost of additional algorithm complexity and set-up delay.