Delay Analysis Research Articles

Link‐delay and spectrum‐availability aware routing in cognitive sensor networks

This study designs and presents routing protocols multi-channel, multi-hop cognitive radio sensor network (CRSN), which are based on spectrum sensing, spectrum-availability analysis and per-hop delay analysis. In order to cope with the spectrum dynamics in the CRSNs, a framework is proposed to estimate the remaining duration of spectrum availability which is based on the expected idle length of channels, sensing period and communication history on the channel. Such methodology allows cognitive users to mitigate communication interruptions caused by arrivals of primary users, thus to improve the transmission performance over each hop. In particular, in combination with the per-hop delay analysis, the routing paths from sources to the sink can be established such as they provide the shortest delay opportunistically or shorter delay but reliable communication along the selected paths. Extensive simulation results show that the proposed routing algorithms potentially improve the network performances in terms of throughput, delay and energy consumption.

A Parallel Approach to Perform Threshold Value and Propagation Delay Analyses of Genetic Logic Circuit Models.

Experiments with synthetic genetic logic circuits can be time-consuming and expensive. Accordingly, advances in the field of computer-aided design and simulation of genetic circuits have reduced the cost and time required for experimentation. D-VASim is the first genetic circuit simulation tool that allows users to interact with the model during run-time. In contrast to electronic circuits, genetic circuits have different threshold values for different circuits, which need to be estimated prior to simulation. D-VASim allows the user to perform threshold concentration and propagation delay analysis before simulating the circuit. The algorithm currently used in D-VASim has considerable scope for improvements. Thus, we propose a parallel implementation of the algorithm, significantly faster by up to 16 times. In adddition, we improve the algorithm for consistent runtimes across multiple simulation runs under the same parameter settings, reducing the worst-case standard deviation in runtime from 6.637 to 1.841. Our algorithm also estimates the threshold value more accurately, as evident from experimentation for long runtimes. With these modifications, the utility of D-VASim as a virtual laboratory environment has been significantly enhanced.

Understanding how chemical structure affects ignition-delay-time ϕ-sensitivity

Abstract ϕ -sensitivity is the change in ignition delay time (IDT) with respect to the fuel-to-air equivalence ratio ( ϕ ). High ϕ -sensitivity is a desirable fuel property for applications in advanced compression ignition and multi-mode engine designs. Understanding how ϕ -sensitivity depends on chemical structure is essential for selecting promising biofuels from the ever-growing list of proposed candidates. In this study, we investigate the effect of chemical structure on ϕ -sensitivity with experiment, simulation, and theory. Experimental Advanced Fuel Ignition Delay Analyzer (AFIDA) measurements for 2,4-dimethylpentane and diisopropyl ether provide evidence that branching and functional groups strongly impact ϕ -sensitivity. Further insights into this dependence are obtained with 0-D kinetic simulations with existing mechanisms for n-pentane, diethyl ether, 3-pentanone, n-heptane, 2-methylhexane, 2,4-dimethylpentane, and 2,2,3-trimethylbutane. Quantum mechanical (QM) G4 calculations of low-temperature reactions help explain the observed experimental and simulation trends. Specifically, these QM calculations provide theoretical estimates of the ketohydroperoxide (KHP) dissociation rates, the HO 2 formation rates from peroxy radical (ROO), and the “cross-over” temperatures, i.e., the temperature at which ROO dissociation is favored compared to hydroperoxyl radical (QOOH) formation. Each of these reaction rates is compared to the n-alkane reference point to determine the impact of branching and different functional groups. Although kinetic mechanisms typically assume that KHP dissociation rates are invariant of chemical environment, our QM results suggest that this rate can span a range of roughly two orders of magnitude. We also discuss the importance of including the peroxy-hydroperoxy (OO-OOH) hydrogen transfer reaction for branched ethers. Finally, the insights gained assist in proposing a highly ϕ -sensitive compound, namely, isopropyl propyl ether.

Analysis of backlog and delay in downlink power-domain non-orthogonal multiple access wireless networks

As important quality-of-service (QoS) performance indicators, backlog and delay in wireless networks must be in compliance with the requirement of low-latency and high-reliability scenarios. Non-orthogonal multiple access (NOMA) is a novel and key wireless technology for the next generation of mobile communications. Its potential impacts on backlog and delay deserve to be specially studied. Meanwhile, the stochastic network calculus is an effective tool for analyzing network performances such as backlog and delay. In this paper, for both orthogonal multiple access (OMA) scheme and NOMA scheme, we utilize the stochastic network calculus to characterize respectively cumulative service processes of channels in a downlink network. Based on moment generating functions, the closed-form expressions of the upper bounds on backlog and delay are derived through the definite integral and special function. Simulation results validate reasonableness and effectiveness of the proposed approach. We show that in terms of backlog and delay, performances cannot be always improved by substituting NOMA scheme for OMA scheme, except when the channel gain gap between users is significantly big. Moreover, the sensitivity to the same factor such as arrival rate, transmission power and power allocation, differs from user to user in NOMA. By simulations, it is further demonstrated that the performance loss due to a finite buffer in practical scenarios is acceptable and sometimes negligible, as long as the buffer size is set to be just moderate.

Analysis of Throughput and Delay for an Underwater Multi-DATA Train Protocol with Multi-RTS Reception and Block ACK.

We propose an underwater multi-DATA train protocol with multi-RTS reception and block ACK (BACK) for underwater acoustic sensor networks. Due to long underwater acoustic propagation delay, some RTS frames may not overlap at a sink node, even if the RTS frames were sent to the sink node simultaneously by different sensor nodes. We consider that our underwater sink node can recover these nonoverlapping RTS frames. Since our RTS frame contains ID of the RTS sending node and a timestamp, the sink node calculates the propagation delay between the RTS sending node and the sink node, then broadcasts a CTS frame. Since our CTS frame contains when each RTS sending node can transmit a DATA frame to the sink node, multiple DATA frames transmitted by different sensor nodes can be formed as a train at the sink node. We also propose an underwater BACK protocol which is analogous to our proposed underwater multi-DATA train protocol. We analyze normalized throughput and mean access delay of our proposed protocols and the conventional protocols. The analytical and simulation results show that our analysis is accurate and our proposed protocols outperform the conventional protocols. Our proposed protocol can shorten the delay and increase the throughput via the multi-DATA train, multi-RTS reception, and BACK.

Real-time quintic Hermite interpolation for robot trajectory execution.

This paper presents a real-time joint trajectory interpolation system for the purpose of frequency scaling the low cycle time of a robot controller, allowing a Python application to real-time control the robot at a moderate cycle time. Interpolation is based on quintic Hermite piece-wise splines. The splines are calculated in real-time, in a piecewise manner between the high-level, long cycle time trajectory points, while sampling of these splines at an appropriate, shorter cycle time for the real-time requirement of the lower-level system. The principle is usable in general, and the specific implementation presented is for control of the Panda robot from Franka Emika. Tracking delay analysis is presented based on a cosine trajectory. A simple test application has been implemented, demonstrating real-time feeding of a pre-calculated trajectory for cutting with a knife. Estimated forces on the robot wrist are recorded during cutting and presented in the paper.

The graph-based analysis of structural delays in distributed multiprogram systems of information processing

The paper discusses the issues related to the fault-tolerant computing systems design in terms of the structure and redundancy. It is shown that usage of prospective reservation methods significantly increases a complexity of the system design procedure. This is caused by the growth of the system configuration cases number because of the system redundancy and the need to test as many configurations as possible under the conditions of failures. To reduce the single configuration analysis complexity, an approach based on graphs with multiple edges such as vector allowing combining several edges of different types is proposed. Simultaneously, models based on such graphs allow representing the computer system structure, taking into account multiprogram data processing mode, and significantly reducing the calculation time of basic characteristics.

Developing Framework to Optimize the Preparation of (EOT) Claims Using Integration of (LPS) and (BIM) Techniques in Construction Projects

Construction projects face delays and disturbances that could be caused by one of the contracting parties, both of them, or beyond their control. Proving the delay needs a significant effort to introduce all details, documents, and records which explain the causes of the delays. The contractor needs to submit a claim, whether it is extension of time (EOT) claim or any claim with an adequate definition, causation, liabilities, analysis of delays to get an extension of time-related to the risk event. Claims preparation processes need to be collected and documented daily throughout the project phases, especially during construction phases. Lean Construction, with its common technique, the last planner system (LPS), and building information modeling (BIM) have significant synergies and can bring benefits when implemented together to support the preparation of the extension of time (EOT) claim. Building information modeling used as a digital platform to facilitate communication between the project team, improve project performance, and implement the last planner system (LPS) phases effectively. (LPS) is enhancing the coordination within the project team. The primary purpose of the research is to develop Framework to Optimize the preparation of extension of time (EOT) Claims Using Integration of the last planner system (LPS) and building information modeling (BIM) Techniques in Construction Projects. The integration will represent in implementation of the appropriate (BIM) functionalities along with the five phases of the last planner system (LPS). As a result of the integration, the inputs and outputs well documented, which considered as the primary support to the processes preparation of the extension of time (EOT) claim. Also, The framework supported by process flowchart to clarify outputs, inputs, and the project team's responsibility, Which will contribute to optimizing the preparation of the extension of time (EOT) claims.

Survival analysis of a stochastic delay single-species system in polluted environment with psychological effect and pulse toxicant input

We propose and study a stochastic delay single-species population system in polluted environment with psychological effect and pulse toxicant input. We establish sufficient conditions for the extinction, nonpersistence in the mean, weak persistence, and strong persistence of the single-species population and obtain the threshold value between extinction and weak persistence. Finally, we confirm the efficiency of the main results by numerical simulations.

Hierarchical Security Paradigm for IoT Multiaccess Edge Computing

The rise in embedded and IoT device usage comes with an increase in LTE usage as well. About 70% of an estimated 18 billion IoT devices will be using cellular LTE networks for efficient connections. This introduces several challenges, such as security, latency, scalability, and quality of service, for which reason edge computing or fog computing has been introduced. The edge is capable of offloading resources to the edge to reduce workload at the cloud. Several security challenges come with multiaccess edge computing (MEC), such as location-based attacks, the man- in-the-middle attacks, and sniffing. This article proposes a software-defined perimeter (SDP) framework to supplement MEC and provide added security. The SDP is capable of protecting the cloud from the edge by only authorizing authenticated users at the edge to access services in the cloud. The SDP is implemented within a mobile-edge LTE network. Delay analysis of the implementation is performed, followed by a Denial-of-Service (DoS) attack to demonstrate the resilience of the proposed SDP. Further analyses, such as CPU usage and port scanning were performed to verify the efficiency of the proposed SDP. This analysis is followed by concluding remarks with insight into the future of the SDP in MEC.

Delay Analysis of Highway Construction Using Primavera

Delay being developed industry is an overall marvel, especially in interstate endeavors, and there is no unique case. It is extensively recognized that an errand is productive when it is done on time and cost. Tragically, the colossal number of advancement adventures fails to follow the organized schedule due to various reasons and thus conceded. In any improvement undertaking, arranging and concede assessment transforms into an essential to restrict delays — the utilization of an advancement plan to envision the endeavor fulfillment time. Delay in the zenith of the undertaking can assemble the expense of the endeavor. Errand Management is an essential fundamental capacity in the advancement of the business. Little exercises will be managed capability truly; while immense enterprises aren't likewise, gigantic errands will be better dealt with by utilizing PCs. various combinations of programming packs are offered with the assistance of that adventure. The heads will be done basically. In street advancement, inside and out, different resources are required for execution, and besides, the peril is extra during this kind of adventure. Hence, genuine masterminding and booking are required in massive errands to ensure that an improvement adventure is done on time and within the budgetary arrangement. In our errand, an undertaking is made in arranging and defers assessment of vacillated practices stressed in turnpike advancement in Thanjavur area, Tamilnadu, by using primavera programming. The length of the interstate is 47.835 Kms. Four-way arrangement of versatile black-top includes improving channels, minor expansions, huge frameworks, Flyover, VIPs, PUPs, etc. It wanted to 730 days. The improvement unit's primary goal is to complete the work as an express on time with the proper use of the apparent considerable number of advantages like work, materials, cash, and equipment. To achieve the above goal is to execute the endeavor most financially better, similar to money and time. This examination's guideline focuses on inspecting the delays being the developed of the expressway and controlling the time and cost of the endeavor.

Delay analysis of a discrete-time single-server queue with an occasional extra server

In this work we look at the delay analysis of a customer in a discrete-time queueing system with one permanent server and one occasional extra server. The arrival process is assumed to be general independent, the buffer size infinite and the service times deterministically equal to one slot. The system is assumed to be in one of two different states; during the UP-state 2 servers are available and during the DOWN-state 1 server is available. State changes can only occur at slot boundaries and mark the beginnings and ends of UP-periods and DOWN-periods. The lengths of the UP-periods, expressed in their number of slots, are assumed to follow a geometric distribution, while the lengths of the DOWN-periods follow a general distribution with rational probability generating function. We provide a method to compute the tail characteristics of the delay of an arbitrary customer based on the theory of the dominant singularity. We illustrate the developed method with several numerical examples.

The Analysis of Traffic Delay and Queue due to the Shunting Activities of Pertamina Trains of Tegal City

A crossing is a meeting point between roads and railways, where this often causes delays and traffic queues, as happened at the crossing on Jl. Abimanyu, Tegal City. This study aimed to analyze the volume, delay and queue length of traffic on each road which occured due to the closing of the railroad crossing. Apart from that, this research was also intended to provide reasonable alternative input for both the management of Pertamina and the road users. This research used the analysis method of v/c ratio, queue and delay with reference to the Manual for Indonesian Road Capacity. Results of the analysis show, the highest queue occurred on the Abimanyu road, which was of 70.5 pcu with the delay of 581.5 seconds/pcu. On the segment of Jl. Menteri Supeno I, the traffic queue was reported to have reached 47.8 pcu with the delay time of 441 seconds/pcu; on the segment of Jl. Semeru, the queue was reported to reach 17 pcu with the delay of 395.6 seconds/pcu, and the last one was the queue at the segment of Jl. Menteri Supeno II which was of 10.8 pcu, with the delay time of 368.5 seconds/pcu. Ones of the keys to overcome problems of traffic queues and delay were by dividing the shunting time into 2 phases according to the results of alternative analysis II where the traffic queue became smaller of 35.3 pcu with the delay time of 290 seconds/pcu and by changing the shunting schedule at off peak time.

Delay and Reliability Analysis of p-Persistent Carrier Sense Multiple Access for Multi-Event Industrial Wireless Sensor Networks

In industrial environments various events can concurrently occur and may require different quality of service (QoS) provision based on different priority levels. To reduce the chances of collision and to improve efficiency in multi-event occurrence, Carrier Sense Multiple Access (CSMA) is a preferable choice for Medium Access Control (MAC) protocols. However, it also increases the overall delay. In this paper, a Priority MAC protocol for Multi-Event industrial wireless sensor networks (PMME) is proposed. In PMME, use of different p values/sequences is proposed to enable multi-priority operation, which can be optimized to suit different operational classes within industrial applications including emergency, regulatory control, supervisory control, open-loop control, alerting and monitoring systems. In this work, novel mathematical model as well as simulations are presented to validate the accuracy and performance of the proposed protocol. Mathematical analysis shows that the proposed PMME can prioritize data packets effectively while ensuring ultra-reliable and low latency communications for high priority nodes. Simulations in Castalia verify that PMME with different p values/sequences notably reduces packet delay for all four priority classes. The PMME also returns a high packet success rate compared to other two well-known priority enabled MAC protocols, QoS aware energy-efficient (QAEE) and multi-priority based QoS (MPQ), in multi-event industrial wireless sensor networks.

Information flow perception modeling and optimization of Internet of Things for cloud services

IoT (Internet of Things) information flow perception is the foundation of the IoT architecture and plays an important role. Providing cloud services on demand is one of the key issues and core features of cloud services in the IoT information flow perception. Firstly, we study the mixed logic dynamics (MLD) modeling method of IoT information flow awareness, and use IoT sensor nodes, controlled nodes, and coordination nodes to describe system application scenarios, and use automata for internal information transmission. Secondly, an open queuing method based on large-scale information flow perception modeling and network delay analysis method is proposed. By analyzing the end-to-end delay of the node path and the average delay analysis of the whole queuing network, the open queuing is obtained. Aiming at the characteristics of distributed data of information flow perception in the IoT, a priority-based queuing network is proposed to model and analyze the aggregation nodes based on embedded multi-core SoC(System on Chip), which greatly improves the performance of embedded multi-core SoC.

An analysis of emergency care delays experienced by traumatic brain injury patients presenting to a regional referral hospital in a low-income country.

Trauma is a leading cause of death and disability worldwide. In low- and middle-income countries (LMICs), trauma patients have a higher risk of experiencing delays to care due to limited hospital resources and difficulties in reaching a health facility. Reducing delays to care is an effective method for improving trauma outcomes. However, few studies have investigated the variety of care delays experienced by trauma patients in LMICs. The objective of this study was to describe the prevalence of pre- and in-hospital delays to care, and their association with poor outcomes among trauma patients in a low-income setting. We used a prospective traumatic brain injury (TBI) registry from Kilimanjaro Christian Medical Center in Moshi, Tanzania to model nine unique delays to care. Multiple regression was used to identify delays significantly associated with poor in-hospital outcomes. Our analysis included 3209 TBI patients. The most common delay from injury occurrence to hospital arrival was 1.1 to 4.0 hours (31.9%). Most patients were evaluated by a physician within 15.0 minutes of arrival (69.2%). Nearly all severely injured patients needed and did not receive a brain computed tomography scan (95.0%). A majority of severely injured patients needed and did not receive oxygen (80.8%). Predictors of a poor outcome included delays to lab tests, fluids, oxygen, and non-TBI surgery. Time to care data is informative, easy to collect, and available in any setting. Our time to care data revealed significant constraints to non-personnel related hospital resources. Severely injured patients with the greatest need for care lacked access to medical imaging, oxygen, and surgery. Insights from our study and future studies will help optimize resource allocation in low-income hospitals thereby reducing delays to care and improving trauma outcomes in LMICs.

Delay analysis in the discrete‐time multi‐server queue with batch arrivals of packets having deterministic length

This work considers a discrete-time multi-server queue with batch arrivals of packets having a deterministic length. By a novel analysis, the packet delay distribution is computed with a very light computational workload.

Energy-Efficient Dual-Hop Internet of Things Communications Network With Delay-Outage Constraints

This article considers a dual-hop Internet of Things communications network where sensor nodes transmit data to a gateway either directly or via other nodes using dual-hop communications. Each node employs separate transmission buffers to store its own sensing data and data received from other nodes. End-to-end delay quality-of-service constraints in terms of the maximum acceptable delay-outage probabilities are imposed. We investigate energy-efficient adaptive resource allocation problems (i.e., joint link scheduling, rate, and power allocation) to support minimum data rates of the nodes. A novel approach is proposed exploiting asymptotic delay analysis to first determine the achieved delay exponents of the queue length tail distributions to satisfy the delay-outage constraints. Next, the relation between the delay exponents and resource allocation variables are derived. Last, the solutions to the resulting constrained optimization problems are obtained using the Lagrangian approach and convex optimization. Illustrative examples demonstrate the effects of the rate requirements and delay constraint stringency on the power consumption and routing configuration.

Integrated Probabilistic Delay Analysis Method to Estimate Expected Outcome of Construction Delay Disputes

AbstractDelays are almost inevitable in construction projects. They can have a devastating effects on the project. Therefore, proper analysis of delays and apportionment of liability is of utmost i...

Truncated Multiplier with Delay-Minimized Exact Radix-8 Booth Recoder Using Carry Resist Adder

The delay owing to the generation of odd multiples $$(\pm \,3)$$ in Radix-8 Booth recoding is minimized in this paper using carry resist adder (CRA). CRA is intentionally developed for performing the exact addition of $$\pm \,1$$ and $$\pm \,2$$ without carry propagation. The theoretical delay analysis proves that the 8-bit CRA reduces 86.26% of delay when compared to the conventional Carry Propagate Addition (CPA) methods. Subsequently, the relative comparisons of CRA with various approximation-based recoding show that the CRA consumes fewer area, power and critical path delay. Further, the $$8\times 8$$ and $$16\times 16$$ signed binary multiplication using CRA-based Radix-8 Booth recoder is developed and synthesized on TSMC 65nm CMOS standard cell library. Also, the trade-off between area, power, delay and accuracy is verified for the proposed design using truncation. Finally, the CRA-based truncated Radix-8 Booth $$8\times 8$$ multiplier is applied to the color space conversion for quantifying its amicability in imaging. The PSNR and MSE are used to evaluate the quality of the resultant image and show better performance than other existing approximated as well as truncated Radix-8 Booth multipliers.