Interruption Probability Research Articles

Relay Selection for UAV-Assisted Urban Vehicular Ad Hoc Networks

This letter investigates the relay selection problem for the air-to-ground vehicular ad hoc networks (A2G VANETs). Specifically, we use unmanned aerial vehicle (UAV) to enhance VANETs communications and network performance. For the considered network, we calculate the state transition probability (STP) of communication interruption and the transmission consumption (TC) including energy consumption and delay consumption. Afterward, we formulate the relay selection problem as a multi-objective optimization problem by jointly considering the STP and the TC. For tackling this hard problem, we simplify the primal problem by setting the STP threshold and devise a relay selection algorithm with low complexity through Q-learning. Finally, the simulation results exhibit the performance improvement of our algorithm against other schemes in terms of delivery ratio, delivery latency, and signaling overhead.

Oral therapies for treatment of relapsing\u2013remitting multiple sclerosis in Austria: a 2-year comparison using an inverse probability weighting method

ObjectivesTo compare the efficacies, frequencies and reasons for treatment interruption of fingolimod (FTY), dimethyl fumarate (DMF) or teriflunomide (TERI) in a nationwide observational cohort.Materials and methodsTwo cohorts of patients with relapsing–remitting multiple sclerosis (RRMS) having started treatment with FTY, DMF or TERI documented in the Austrian MS Treatment Registry (AMSTR) since 2014 and either staying on therapy for at least 24 months (24 m cohort) or with at least one follow-up visit after start of treatment (total cohort). The 24 m cohort included 629 RRMS patients: 295 in the FTY, 227 in the DMF and 107 in the TERI group. We used multinomial propensity scores for inverse probability weighting in generalized linear and Cox proportional hazards models to correct for the bias of this non-randomised registry study.ResultsEstimated mean annualized relapse rates (ARR) over 24 months were 0.13 for FTY, 0.09 for DMF and 0.11 for TERI treatment. For TERI in comparison with DMF, we observed higher probability for treatment interruption (p = 0.023) and reduced sustained EDSS regression for 12 (p = 0.016) and 24 weeks (p = 0.031) and, for the comparison of DMF versus FTY, a reduced sustained EDSS progression for 12 weeks (p = 0.02).ConclusionsRelapse rates with treatment with FTY, DMF and TERI were similar. Patients treated with DMF showed less sustained disability progression for 12 weeks than FTY-treated patients. However, FTY and DMF treatment was associated with more likely EDSS regression for 12 and 24 weeks and a lower probability for treatment interruption as compared to TERI-treated patients.

Population Pharmacokinetics and Exposure Response Analysis of Pomalidomide in Subjects With Relapsed or Refractory Multiple Myeloma From the Novel Combination Treatment of Pomalidomide, Bortezomib, and Low-Dose Dexamethasone.

Multiple myeloma is an incurable progressive neoplastic disease that accounts for 10% of all hematologic malignancies. Even though significant progress has been made in the treatment of newly diagnosed multiple myeloma, the disease follows a relapsing course in the majority of patients, and there is a need for more effective therapeutic options for the treatment of relapsed or refractory multiple myeloma. CC-4047-MM-005 and CC-4047-MM-007 were phase 1 and 3 studies to evaluate the novel combination of pomalidomide, bortezomib, and low-dose dexamethasone for the treatment of patients with relapsed or refractory multiple myeloma who have already received lenalidomide-based treatments early. This analysis was performed to characterize the population pharmacokinetics (PK) of pomalidomide from the combination treatment and to examine exposure-response relationships. Our analysis showed that pomalidomide concentration-time profiles from the combination treatment were adequately described with a 1-compartment PK model, with first-order absorption and elimination and pomalidomide exhibiting linear and time-invariant PK with moderate variability from the combination treatment. Except for the body surface area, none of the tested covariates had an effect on pomalidomide PK. Although body surface area was identified as a statistically significant covariate of pomalidomide PK, the impact was not deemed clinically relevant. A flat exposure-response curve was observed, consistent with a near-saturated drug effect at the tested exposure range suggesting an appropriately recommended clinical dose of 4mg of pomalidomide for the combination treatment. Finally, pomalidomide exposure was not associated with higher probabilities of dose interruption during cycle 1 or dose reduction during the treatment period.

A continuum model with traffic interruption probability and electronic throttle opening angle effect under connected vehicle environment

The electronic throttle system is the key component of the intelligent control system of connected and automated vehicles (CAVs). Although CAVs are expected to be commercialized in the near future, in practice the disturbances and interruptions are not uncommon along the road. In this paper, we propose a new continuum model considering the traffic interruption probability and the electronic throttle opening angle effect. Based on the linear stability analysis, the stability condition of the proposed model is obtained. The KdV-Burgers equation of the new continuum model is further obtained in the nonlinear analysis. The density solution obtained by solving the above equation can be used to describe the evolution characteristics of traffic flow near the neutral stability curve. Results show that the traffic interruption probability and the electronic throttle opening angle effect has a considerable impact on the stability of traffic flow.

QoS Provision in a Dynamic Channel Allocation Based<?brk?> on Admission Control Decisions

Cognitive Radio Networks have emerged in the last decades as a solution of two problems: spectrum underutilization and spectrum scarcity. In this work, we propose a dynamic spectrum sharing mechanism, where primary users have strict priority over secondary ones in order to improve the mean spectrum utilization with the objective of providing to secondary users a satisfactory grade of service with a small interruption probability. We study a stochastic model for Cognitive Radio Networks with fluid limits techniques. Our main findings consist in a Gaussian limit theorem in the sub-critical case, and a non-Gaussian limit theorem, under a different scaling scheme, in the critical case. These results provide us practical QoS criteria for sharing policies. We support our analysis with representative simulated examples in both scenarios.

Optimization of Investments in the Resilience of Water Distribution Systems Subject to Interruptions

In this paper, we propose an optimization model to support decisions related to the design of water distribution systems (WDS) that are subjected to interruptions caused by disruptive events, emphasizing their resilience capabilities, namely: absorption, adaptation, and recovery. Considering the exposure of WDS operation to random interruptions, we aim at minimizing the total investment considering the possibility of implementing actions that improve these capabilities, which can be put in place prior or posterior to the occurrence of a disruptive event. An application example is discussed as a way to understand the nature of the problem and to support the formulation of the proposed model. The results demonstrate the need to invest in resilient capacities adequate to each interruption probability associated to the disruptive scenarios, characterizing these considerations as of great importance to support managerial decisions, thus constituting a guideline for the allocation of investments before and/or after the occurrence of the event.

D2D Communication Relay Selection Algorithm Based on Game Theory

Abstract In D2D communication, when the distance between the source node and the destination node is too large, the relay node can be introduced to improve the communication quality, so as to extend the communication coverage and improve the system performance. This paper proposes an algorithm based on game theory for D2D communication relay selection. The algorithm firstly limits the relay location area based on the distance loss, then analyzes the forwarding ability of candidate nodes considering the problem that too low energy will cause communication interruption, and obtains candidate relay set through screening, finally selects the optimal relay node for data transmission by using the game theory source node. The simulation results show that compared with the random selection algorithm and the optimal relay selection algorithm based on channel state information, the proposed algorithm effectively improves the coverage of D2D communication, reduces the interruption probability of the communication link, improves throughput of the system.

The Design of Power Security Defense System Based on Resource Pool Cloud Computing Technology

In order to realize the power system defense security, this article puts forward the idea and method of constructing power dispatching automation systems with a cloud computing architecture and realizes the unified management of distributed resources with server virtualization technology. Real-time online migration of each module of the scheduling system is realized by using the in-memory data transfer technology. The multi-node network heartbeat detection technology is used to realize the complete monitoring of the server cluster. In the form of an independent disk array, the fault node is removed, and the service is restored automatically. The whole disaster reserve of the system is realized by means of remote resource mapping. System analysis results show that compared with traditional architecture, the service interruption probability of the new scheduling automation system is effectively reduced. Fault redundancy capacity in the station is increased from a key module 2 node to multi-node protection of all modules.

Cumulative functions of vertical atmospheric attenuation of millimeter radio waves over Kharkov

For the first time in Ukraine, on the basis of the experimental data of the annual cycle of radiometric observations of the thermal radiation of the atmosphere at a frequency of 39 GHz, micro-climate-based estimates of the probabilities of communication failure on inclined terrestrial-space lines have been made. The cumulative distribution functions of atmospheric attenuation, analyzed in the work, make it possible to give a reasonable quantitative estimate of the probability and duration of interruptions in the operation of EHF communication due to meteorological conditions for the first time for one of the regions of Ukraine. The data obtained can be used in other regions with similar climatic regimes.

A Packet Reception Probability-Based Reliable Routing Protocol for 3D VANET

In three-dimensional (3D) vehicular ad-hoc network (VANET) scenario, dynamic vehicles, complex node distribution and severe path loss increase the probability of link interruption significantly, which deteriorates the packet reception probability sharply. However, reliability is a crucial issue as efficiency to improve the performance of routing protocol in 3D VANET. In this letter, for the dynamic and multi-level shadowing scenario, we propose a packet reception probability-based reliable routing (PPR) protocol to improve the transmission link reliability. Especially, we introduce a packet reception probability model to characterize the link reliability of 3D network, and the unique characteristics of 3D VANETs are integrated into this model. Then, we formulate the routing decision issue as a constrained multi-objective optimization problem, which attempts to find a link with the highest packet reception probability as the relay link. The simulation results demonstrate that PPR outperforms the existing protocols in the aspects of packet delivery ratio, end-to-end delay and throughput.

Bayesian Network-Based Process Downtime Cost Determination of an Industrial Plant

Industrial plants utilize sensitive equipment to produce their products and meet their financial targets. Equipment downtime caused by power quality issues such as voltage sag affects production and entails cost hence poses a threat to their ability to deliver their financial objectives. This research aims to determine the response of industrial equipment to sag events and quantify the downtime cost caused by interruption in the production process. The study used the voltage tolerance curve to determine the individual equipment response to sag events and the Bayesian Network to establish the network structure of the production process. The probability of process interruption and the associated downtime losses was computed using a mathematical software. The research shows a strong relationship between the equipment’s response to voltage sag events and the production downtime cost and highlights the importance of the immunity of equipment to voltage sags.

MAPPS: A stochastic computational tool for multi-path analysis of physical protection systems

We present a new stochastic computational tool, Multi-path Analysis of Physical Protection Systems (MAPPS) useful for Physical Protection System (PPS) effectiveness analysis. MAPPS tool can perform multi-path (adversary paths) analysis using an Adversary Sequence Diagram (ASD) and can determine the Most Vulnerable Path (MVP). The MVP determination by MAPPS uses the concept of Critical Detection Point (CDP). Suitability of MAPSS for PPS design effectiveness analysis is confirmed through an example. A comparison of MAPPS results with the traditional single path analysis (employing the Estimate of Adversary Sequence Interruption-EASI model) shows the advantages of using MAPPS. MAPPS correctly predicts the MVP and the distribution of probability of interruption (PI) values for various adversary strategies including collusion with facility insiders. MAPPS results show that a focusing only on mean of PI value distribution may not be appropriate instead, a analyzing the low probability tail of the PI distribution is important.

A method for the multi-objective optimization of the operation of natural gas pipeline networks considering supply reliability and operation efficiency

Reliable gas supply for minimum risk of supply shortage and minimum power demand for low energy cost are two fundamental objectives of natural gas pipeline networks. In this paper, a multi-objective optimization method is developed to trade-off reliability and power demand in the decision process. In the optimization, the steady state behavior of the natural gas pipeline networks is considered, but the uncertainties of the supply conditions and customer consumptions are accounted for. The multi-objective optimization regards finding operational strategies that minimize power demand and risk of gas supply shortage. To quantify the probability of supply interruption in pipeline networks, a novel limit function is introduced based on the mass conservation equation. Then, the risk of interruption is calculated by combining the probability of interruption and its consequences, measured in utility terms. The multi-objective optimization problem is solved by the NSGA-II algorithm and its effectiveness is tested on two typical pipeline networks, i.e., a tree-topology network and a loop-topology network. The results show that the developed optimization model is able to find solutions which effectively compromise the need of minimizing gas supply shortage risk and reducing power demand. Finally, a sensitivity analysis is conducted to analyze the impact of demand uncertainties on the optimization results.

The security of Internet of drones

In order to study the security of Internet of drones (IoD), convolutional neural network (CNN) algorithm was compared with autonomous IoD. Moreover, wireless communication technology was used to analyze and design a more optimized model for system security performance. The model constructed was simulated, and relevant data were collected to verify its security performance. The results show that the clustering algorithm based on node energy has the best performance in the performance analysis of IoD. When the number of nodes is appropriate, it can avoid wasting bandwidth resources and overloading, and the number of switching between clusters is less than other algorithms. Therefore, EWCA algorithm can be used to improve the lifetime of the whole network and enhances the availability of IoD. When analyzing the security performance based on the system security interruption probability, it is found that the lower the security interruption rate is when the energy acquisition coefficient α is close to 0.5, the longer the IoD is used for information transmission, and the better the security performance is. The greater the signal-to-noise ratio is, the better the network security performance is, and the network performance is the best when the number of nodes tends to be 10. Therefore, through the research, it is found that the model built increases the security of IoD. Although there are some shortcomings in the experimental process, it still provides experimental basis for the later development of IoD.

Designing of stand-alone hybrid PV/wind/battery system using improved crow search algorithm considering reliability index

In this paper, the design of a hybrid renewable energy PV/wind/battery system is proposed for improving the load supply reliability over a study horizon considering the Net Present Cost (NPC) as the objective function to minimize. The NPC includes the costs related to the investment, replacement, operation, and maintenance of the hybrid system. The considered reliability index is the deficit power-hourly interruption probability of the load demand. The decision variables are the number of PV panels, wind turbines and batteries, capacity of transferred power by inverter, angle of PV panels, and wind tower height. To solve the optimization problem, a new algorithm named improved crow search algorithm (ICSA) is proposed. The design of the system is done for Zanjan city, Iran based on real data of solar radiation and wind speed of this area. The performance of the proposed ICSA is compared with crow search algorithm (CSA) and particle swarm optimization methods in different combinations of system. This comparison shows that the proposed ICSA algorithm has better performance than other methods.

Lattice hydrodynamic model-based feedback control method with traffic interruption probability

Connected vehicles are expected to become commercially available by the next decade, while traffic interruption is not uncommon in the real traffic environment. In this paper, we propose a feedback control method for lattice hydrodynamic model considering the traffic interruption probability effect. The stability criterion of the new model is explored through linear stability analysis of transfer function. When the stability conditions are not satisfied, a delay feedback controller is used to control the discharging flow to suppress traffic congestion. The impact of gain coefficient and delay time on the performance is discussed. We verify the effectiveness of the devised delay feedback controller by simulations. Results show that the traffic interruption probability effect has a considerable impact on the stability of traffic flow, while the controller is effective in suppressing traffic congestion.

Temperature effects on atmospheric continuous-variable quantum key distribution**Project supported by the National Natural Science Foundation of China (Grant No. 61505261).

Compared with the fiber channel, the atmospheric channel offers the possibility of a broader geographical coverage and more flexible transmission for continuous-variable quantum key distribution (CVQKD). However, the fluctuation of atmospheric conditions will lead to the loss of performance in atmospheric quantum communication. In this paper, we study how temperature affects atmospheric CVQKD. We mainly consider the temperature effects on the transmittance and interruption probability. From the numerical simulation analysis, it can be shown that the performance of atmospheric CVQKD is improved as temperature increases, with the other factors fixed. Moreover, the results in this work can be used to evaluate the feasibility of the experimental implementation of the atmospheric CVQKD protocols.

Efficacy and safety of dolutegravir-based regimens in advanced HIV-infected naïve patients: results from a multicenter cohort study

The aims were to describe efficacy and tolerability of regimens containing dolutegravir (DTG) in advanced ART-naïve people living with HIV (PLHIV) from the clinical practice.The frequency of Immune Reconstitution Inflammatory Syndrome (IRIS), the estimated time of discontinuation of the first ART regimen and the time to reach virological suppression in a multicenter cohort of AIDS-presenters or late-presenters with CD4 <350/μL were assessed.We included 272 PLHIV: 120 (44%) AIDS-presenters and 152 (56%) late-presenters. The most frequent AIDS-defining event was Pneumocystis jirovecii pneumonia in 41 (34%). One hundred-thirty-two PLHIV (48%) started first-line cART regimens including DTG and 140 PLHIV (52%) were treated with cART regimens without DTG. One-hundred-eighty-two (67%) individuals discontinued their first-line regimen: 109 (60%) for simplification, 32 (18%) for toxicities, 4 (2%) for drug-drug interactions, 37 (20%) for other reasons. DTG was interrupted in 19/132 (14%) PLHIV: 13 (68%) for adverse events (5 intolerance, 4 gastrointestinal disorders and 4 neurological symptoms), 2 (11%) for proactive switch and 4 (21%) for medical/individual choice. IRIS was reported in 13 (5%) AIDS-presenters without differences between arms. During a median observation time of 16 months (IQR 5–24), HIV-1 RNA<50 copies/mL was achieved in 95/132 (72%) individuals on DTG-based regimen and in 92/140 (66%) individuals with other regimens. The 12-month estimated probability of DTG interruption was 14% (95% CI 11–17).The results demonstrated the low risk for IRIS and the high potency, good tolerability and safety of DTG in our population of advanced naïve PLHIV.

PF674 OUTCOME OF PATIENTS WITH MYELOFIBROSIS AFTER RUXOLITINIB DISCONTINUATION: ROLE OF DISEASE STATUS AND TREATMENT STRATEGIES IN 218 PATIENTS

Background:After discontinuation of Ruxolitinib (RUX), the outcome of patients (pts) with myelofibrosis (MF) has been reported to be poor.Aims:Here, we investigated the impact of baseline features, responses, and type of salvage therapy on survival in 218 pts who received and discontinued RUX in routine clinical practice.Methods:A clinical database was created in 20 European Hematology Centers including retrospective data of 521 MF pts treated with RUX from Jan 2011 to October 2018. Spleen/symptoms response to RUX were evaluated according to the 2013 IWG‐MRT/ELN criteria. Overall (OS) was estimated from the date of RUX discontinuation to the date of death or last contact (log‐rank test). Comparisons of continuous or categorical variables between groups were carried out by Wilcoxon‐Mann‐Whitney rank‐sum test or χ2, respectively. Risk factors for RUX discontinuation and prognostic factors for survival were identified using Cox proportional hazards model.Results:After a median follow‐up from RUX start of 37 months, 268 out of 521 (51.2%) pts stopped RUX, with a discontinuation rate of 19.6 per 100 patient‐years. Intermediate‐2/High DIPSS risk score, platelet count &lt;100 x109/l, Charlson Comorbidity Index ≥2 and unfavorable karyotype were significantly associated with a higher probability of drug interruption. Fifty pts (18.7%) died while taking RUX; median survival time of the remaining 218 pts after RUX stop was 13.2 months. Causes of RUX discontinuation in the 218 pts were: lack (22.9%) / loss (11.9%) of response, progression to blast phase (23.4%), toxicity (28.9%; specifically anemia [10.5%], thrombocytopenia [6.9%], infections [9.2%], other adverse events [2.3%]), second solid neoplasia (4.6%), and thrombosis (3.2%). 11 pts (5.1%) stopped RUX while in response and underwent allogeneic stem cell transplantation (alloSCT). Compared to the 256 pts still on treatment at last contact, the 218 pts who discontinued RUX had started the therapy with a significantly more advanced disease in terms of higher DIPSS risk score, larger splenomegaly, and deeper cytopenias. Previous response to RUX did not influence OS. OS was significantly influenced by disease status (chronic vs blast phase) but not by reason of discontinuation (resistance vs intolerance) (Fig. 1a). A total of 167 pts discontinued RUX in chronic phase (CP) and had a median survival after discontinuation of 27.5 mos. In this cohort, hemoglobin&lt;10 g/dl (p = 0.01) and a circulating blasts ≥1% (p = 0.01) at the time of RUX withdrawal correlated with worse survival. 111 CP pts (66.5%) received a salvage therapy that included JAK2‐inhibitors and/or other investigational agents in 31 cases and only conventional medical therapies in 54; 26 pts underwent alloSCT after conventional therapies. Pts treated with novel agents had a significantly better OS (Fig. 1b). 51 (23.4%) pts discontinued RUX in BP, and 28 (54.9%) received salvage treatments including hydroxyurea (n. 14), hypometylating agents (n. 7), chemotherapy (n. 6), alloSCT (n. 5). Median survival time was significantly higher for pts who received therapy after RUX (7.9 mos vs 2.2 in untreated pts, p = 0.005).Summary/Conclusion:A greater burden of disease at RUX start is significantly associated with higher discontinuation rate. After RUX stop, outcome is mostly influenced by disease phase and type of salvage therapies, with CP pts treated with novel agents having the best outcome. Earlier RUX therapy and innovative salvage strategies may improve outcome of MF pts.image

Optimization of Adaptive Handover Algorithm Based on Distributed Antenna in LTE-R

In the high-speed railway, the traditional handover algorithm uses a fixed handover hysteresis threshold, which will result in a lower success rate of the train when the train is traveling at a high speed, and cannot meet the wireless communication needs of the passenger. According to the distribution of antennas in the high-speed railway and the analysis of the handover process and measurement parameters, an adaptive handoff algorithm based on distributed antenna is proposed. For the deployment of antennas in high-speed railways, a distributed approach is adopted, and the RAUs with the best quality are selected to maintain the connection. In the process of switching, the hysteresis threshold value of switching is dynamically adjusted at different positions according to different speeds, and the success rate, interruption probability and average value of switching are simulated and comparedSimulation results show that in the case of distributed antenna deployment, handover threshold is dynamically adjusted according to different speeds to reduce the interruption probability of handover, and the success rate of handover is significantly improved, but the average number of handover will increase correspondingly, which can meet the requirements of passengers for wireless communication system in high-speed railway.