Timeout Threshold Research Articles

Session-Based Time-Window Identification in Virtual Learning Environments

Students organize and manage their own learning time, choosing when, what, and how to study due to the flexibility of online learning. Each person has unique learning habits that define their behaviours and distinguish them from others. To investigate the temporal behaviour of students in online learning environments, we seek to identify suitable time-windows that could be used to investigate their temporal behaviour. First, we present a novel perspective for identifying different types of sessions based on individual needs. The majority of previous works address this issue by establishing an arbitrary session timeout threshold. In this paper, we propose an algorithm for determining the optimal threshold for a given session. Second, we use data-driven methods to support investigators in determining time-windows based on the identified sessions. To this end, we developed a visual tool that assists data scientists and researchers to determine the optimal settings for session identification and locating suitable time-windows.

Energy-saving service management technology of internet of things using edge computing and deep learning

The purpose is to solve the problems of high transmission rate and low delay in the deployment of mobile edge computing network, ensure the security and effectiveness of the Internet of things (IoT), and save resources. Dynamic power management is adopted to control the working state transition of Edge Data Center (EDC) servers. A load prediction model based on long-short term memory (LSTM) is creatively proposed. The innovation of the model is to shut down the server in idle state or low utilization in EDC, consider user mobility and EDC location information, learn the global optimal dynamic timeout threshold strategy and N-policy through trial and error reinforcement learning method, reasonably control the working state switching of the server, and realize load prediction and analysis. The results show that the performance of AdaGrad optimization solver is the best when the feature dimension is 3, the number of LSTM network layers is 6, the time series length is 30–45, the batch size is 128, the training time is 788 s, the number of units is 250, and the number of times is 350. Compared with the traditional methods, the proposed load prediction model and power management mechanism improve the prediction accuracy by 4.21%. Compared with autoregressive integrated moving average (ARIMA) load prediction, the dynamic power management method of LSTM load prediction can reduce energy consumption by 12.5% and realize the balance between EDC system performance and energy consumption. The system can effectively meet the requirements of multi-access edge computing (MEC) for low delay, high bandwidth and high reliability, reduce unnecessary energy consumption and waste, and reduce the cost of MEC service providers in actual operation. This exploration has important reference value for promoting the energy-saving development of Internet-related industries.

Single-Vehicle Transportation Security System of Radioactive Materials Based on Group Relationship to Prevent Loss and Theft

For loss and theft in the transport of radioactive materials by a single vehicle, this article summarizes the characteristics of “illegal movement” and establishes a security system that senses its inter-relationship and responds though the group network relationship. The security system reminds the vehicle crew through on-site response and linkage response. A failure detection method for on-site response is proposed, that is, the push model is used first, and when the measurement results are suspected, the pull model is used to further confirm the failure. The failure detection for linkage response adopts the push model. According to the different security requirements of the basic and enhanced transportation, the principle of setting the timeout threshold in the failure detection algorithm is proposed. In the enhanced type, the value is smaller, otherwise the value is larger. A specific timeout threshold quantification scheme is proposed. Experiments show that the method proposed in this article is effective.

Optimizing Computer-Brain Interface Parameters for Non-invasive Brain-to-Brain Interface.

A non-invasive, brain-to-brain interface (BBI) requires precision neuromodulation and high temporal resolution as well as portability to increase accessibility. A BBI is a combination of the brain–computer interface (BCI) and the computer–brain interface (CBI). The optimization of BCI parameters has been extensively researched, but CBI has not. Parameters taken from the BCI and CBI literature were used to simulate a two-class medical monitoring BBI system under a wide range of conditions. BBI function was assessed using the information transfer rate (ITR), measured in bits per trial and bits per minute. The BBI ITR was a function of classifier accuracy, window update rate, system latency, stimulation failure rate (SFR), and timeout threshold. The BCI parameters, including window length, update rate, and classifier accuracy, were kept constant to investigate the effects of varying the CBI parameters, including system latency, SFR, and timeout threshold. Based on passively monitoring BCI parameters, a base ITR of 1 bit/trial was used. The optimal latency was found to be 100 ms or less, with a threshold no more than twice its value. With the optimal latency and timeout parameters, the system was able to maintain near-maximum efficiency, even with a 25% SFR. When the CBI and BCI parameters are compared, the CBI’s system latency and timeout threshold should be reflected in the BCI’s update rate. This would maximize the number of trials, even at a high SFR. These findings suggested that a higher number of trials per minute optimizes the ITR of a non-invasive BBI. The delays innate to each BCI protocol and CBI stimulation method must also be accounted for. The high latencies in each are the primary constraints of non-invasive BBI for the foreseeable future.

Burst Assembly Framework for High Speed Optical Network

Optical Burst Switching (OBS) is promising technique to support requirements of high speed optical networks. OBS network ingress node assembles packets into bursts. Burst assembly criteria have to be optimally chosen based on network requirements. In this paper, burst assembly framework is presented which can support optimal time/size value selection during burst formation. It is observed that, network with high timeout supports high Transmission Control Protocol (TCP) throughput for a range of burst size. For lower burst timeout values, throughput performance degrades only for small size bursts and further reduction in timeout threshold degrades throughput for range of burst size.

A Framework for Packet Delay Analysis of Point-to-Multipoint Underlay Cognitive Radio Networks

This paper presents a queueing analytical framework for the performance evaluation of the secondary user (SU) packet transmission with service differentiation in a point-to-multipoint underlay cognitive radio network. The transmit power of the SU transmitter is subject to the joint outage constraint imposed by the primary user receivers (PU-Rxs) and the SU maximum transmit power limit. The analysis considers a queueing model for secondary traffic with multiple classes, and different types of arrival and service processes under a non-preemptive priority service discipline. The SU quality of service (QoS) is characterized by a packet timeout threshold and target bit error rate. Given these settings, analytical expressions of the packet timeout probability and average transmission time are derived for opportunistic and multicast scheduling. Moreover, expressions of the average packet waiting time in the queue and the total time in the system for each class of traffic are obtained. Numerical examples are provided to illustrate the secondary network performance with respect to various parameters such as number of PU-Rxs and SU receivers, SU packet arrival process, QoS requirements, and the impact of interference from the primary network to the secondary network.

Empirical observations on the session timeout threshold

The World Wide Web is a popular “tool” for companies. It can be used as a method of communication between companies and their customers; it also allows organizations to setup virtual storefronts that can be accessed by customers from all over the world. The ability to understand customers’ behavior is extremely important as companies strive to increase the usability and profitability of their web service. The concept of a session is a popular unit of measurement used to analyze recorded information. However, this concept is currently rather abstract and lacks definition. How we measure a session is a fundamental question for web services utilizing this concept. Currently, this question has no real answer. This paper presents a session timeout threshold model based on empirical observations as an initial answer to this question. The model seeks to provide accurate session data with respect to individual web services.

An approximation for multi-server queues with deterministic reneging times

This work was motivated by the timeout mechanism used in managing application servers in transaction processing environments. In such systems, a customer who stays in the queue longer than the timeout period is lost. We modeled a server node with a timeout threshold as a multi-server queue with Poisson arrivals, general service time distribution and deterministic reneging times. We proposed a scaling approach, and a fast and accurate approximation for the expected waiting time in the queue.

Reconfigurable Hardware Architectures for Sequential and Hybrid Decoding

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A novel reconfigurable sequential decoder architecture based on the Fano algorithm is presented in which the constraint length, the threshold spacing, and the time-out threshold are all run time reconfigurable. To maximize decoding performance, a maximum possible backward depth (of a whole frame) is performed. This is achieved by using shift registers combined with memory to store the information of an entire visited path. A field-programmable gate array) prototype of the decoder is built and actual hardware decoding performances in terms of decoding speeds, bit error rates (BERs), and buffer overflow rates, are obtained and comparisons made. To overcome the decoding delay that is inherent in sequential decoders, a hybrid scheme, including simple block codes and cyclic redundancy check is proposed to limit the number of backward search operations that the sequential decoder has to execute. As a result, a significant reduction in decoding delay and buffer overflow rate is achieved while maintaining comparative decoding performance in terms of BER. </para>

Statistical analysis of factors influencing the performance of the timeout-based testing model

Time-out collaboration protocol is a mechanism to maximize system performance, with a service discipline (or a dispatching rule) collaborated, by disabling the access of a job to the resource when the job keeps the resource idle for too long and then by giving one of the other waiting jobs the access to the resource. This paper formally defines a generic testing model with a single tester shared by multiple types of jobs and with the repair process. This research performs statistical analysis of the timeout collaboration protocol by considering several factors simultaneously and identifies two key factors that affect the performance of different timeout thresholds in the testing model. It is shown that two extreme timeout threshold values ( T 0 = 0 and X ) outperform intermediate values (0 < T 0 <; X ) with respect to overall mean flow time. This research provides insights into applying the timeout mechanism that originated from communication problems to production systems.

Analysis of a time-out protocol and its applications in a single server environment

The use of time-out protocols can improve distributed system performance by utilizing equipment and resource-time that otherwise would be wasted. In time-out protocols for traditional computer communication networks, set-up time reduction is a major issue. An interesting area of development in networked production and test systems is the inclusion of costs other than set-up time in the evaluation, such as scrap rates and rework, or the effect on neighbouring or upstream client work-centres. The applications of time-out protocols in single, shared server production environments, such as automatic guided vehicle systems (AGVs) and shared testers in assembly processes, are described in this article. Analytical models have provided some insight into the application of time-out protocols but are cumbersome. The focus of this investigation has been in the context of networked task administration, including: (1) quantitative guidelines to evaluate time-out protocols in the context of task administration protocols, and (2) a new model for numerical evaluation, identifying the recommended time-out threshold and the regions where time-out protocols are, or are not, useful. Discrete event simulation models and empirical data from recent research on task administration protocols are described.

Time-out protocol for task allocation in multi-agent systems

In multi-agent system, the implementation of a time-out protocol can improve workflow coherence and reduce the communication congestion due to the coordination process among agents. This approach is part of effective CIM workflow planning and control for agent-based operations emerging in assembly, manufacturing, service, and logistics. The case study illustrated in this article concerns industrial testing and rework services provided by a shared resource. Results of analyses have been verified by simulation to illustrate how performance improves or deteriorates when different time-out protocols are applied. A general model is introduced for numerical evaluation, identifying the recommended time-out threshold, and the regions where time-out protocols are, or are not useful for better workflow. Measures of workflow coordination performance, including time-oriented and viability-oriented measures are discussed.

Performance of an edge-to-edge protocol in a simulated X.25/X.75 packet network

Roundtrip message response time was measured on a simulated packet network subjected to message traffic from interactive users. The links had impairments of errors and propagation delay. Each virtual circuit had its own edge-to-edge protocol. With no link-level protocol in place, the edge-to-edge protocol yielded good performance, provided that the edge-to-edge timeout threshold accounted for network delays due to packet queuing. A link-level protocol with too small a window (such as three) caused excessive network congestion and was worse than no link-level protocol at all. With a sufficient window, the link protocol offered an improvement under high-error conditions with light loads, but the improvement lessened as the load increased.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Timeout thresholds for dialing machines

We consider the problem of determining an optimal timeout threshold for calls to be used by dialing machines. We derive the rate of completed calls as a simple function of the timeout threshold and show a condition for the existence of a unique optimal timeout threshold. The results can be used in determining the staff or equipment required.