Overload Control Research Articles

Research on Guidance and Control Method of Hypersonic UAV Capture Segment Based on Overload

With the implementation of China’s high supersonic aircraft science and technology engineering and the key basic scientific problems of near space vehicles major research programs.In this context, China is also vigorously developing high-speed high-mobility, long range and recyclable aircraft. In view of the tracking problem of a hypersonic vehicle when it reaches the capture segment, a mathod based on overload guidance law is proposed. The relationship between force and head-on angle can be deduced from the relationship between overload and head-on angle, thus transforming the overload control problem into the head-on control problem. Inversion controller design method is adopted for its parameter uncertainty rigid body model, and the derivative of virtual control amount is obtained by dynamic surface method to avoid the problem of differential expansion. Based on the secound-order tracking-differential, a nonlinear interference observer is designed to estimate and compensate for model uncertainties. The simulation results show that the controller can achieve stable tracking of the angle and high reference instructions, and has a strong robustness to the uncertainty effect of the model.

SDNShield: NFV-Based Defense Framework Against DDoS Attacks on SDN Control Plane

Software-defined networking (SDN) is increasingly popular in today’s information technology industry, but existing SDN control plane is insufficiently scalable to support on-demand, high-frequency flow requests. Weaknesses along SDN control paths can be exploited by malicious third parties to launch distributed denial-of-service (DDoS) attacks against the SDN control plane. Recently proposed solutions only partially solve the problem, by protecting either the SDN network edges or the centralized controller. We propose SDNShield, a solution based on emerging network function virtualization (NFV) technologies, which enforces more comprehensive defense against potential DDoS attacks on SDN control plane. SDNShield incorporates a three-stage overload control scheme. The first stage statistically identifies legitimate flows with low complexity and performance overhead. The second stage further performs in-depth TCP handshake verification to ensure good flows are eventually served. The third stage intellectually salvages the misclassified legitimate flows that are falsely dropped from the first two stages. Prototype tests and real data-driven simulation results show that SDNShield can achieve high resilience against brute-force attacks, and maintain good flow-level service quality at the same time.

Study on the influence of thermal characteristics of transmission components on overload control of grid-connected lines of wind farms

The rapid growth of the installed capacity of wind power is not coordinated with the planning and development of the power grid, which may lead to transmission line overload when N-1 failure occurs in gridconnection lines of large-scale wind power. However, the existing overload protection and stability control strategies cannot adapt to this short-term power flow overload, so a large number of wind turbines need to be removed, which is brought the accommodation problem of large scale cluster wind power. The grid-connection line of wind farms has significant non-synchronization (thermal inertia) between current-carrying and temperature changes, and the short-term current-carrying potential needs to be tapped. This paper summarizes the thermal balance models of two kinds of transmission components and explores the influence of thermal characteristics of transmission components on the overload control of gridconnected lines of wind farms. The simulation results show that considering the thermal inertia of transmission components in overload control can significantly reduce the cut of wind power, fully tap the overload capacity of grid-connection lines.

DIVINE: Data offloading in vehicular networks with QoS provisioning

In vehicular networks, vehicles may carry various types of data that need to be offloaded to the RoadSide Units (RSUs) through Vehicle-to-Infrastructure (V2I) communications when vehicles come into their coverage. RSUs are not widely deployed everywhere, which causes intermittent connectivity between vehicles and RSUs. In this paper, we propose DIVINE, a Data offloading In VehIcular NEtworks scheme with QoS provisioning, which enables a vehicle to offload its data to RSU directly through V2I communications or using other neighboring vehicles through Vehicle-to-Vehicle (V2V) communications. DIVINE considers the connectivity time of an offloading vehicle with the RSU, with other vehicles heading either on the same or opposite direction, offloading capacity, expected time to reach RSU and contact duration with neighboring vehicles. Additionally, the Quality of Service (QoS) is an important consideration for data offloading in vehicular networks due to the coexistence of urgent data to offload (e.g., accident or emergency data). Therefore, for QoS provisioning, DIVINE uses three QoS functions: traffic classification, overload control and admission control. DIVINE is presented with algorithms and procedures, as well as with illustrative examples. The performance evaluation in network simulator OMNeT++ with Veins and SUMO frameworks shows that DIVINE outperforms other schemes in terms of average offloading delay, maximum offloading delay and running time for a varying number of vehicles, maximum speed values, number of RSUs and RSUs’ capacity. It also best behaves in terms of amount of offloaded important data.

Circulating miRNAs and tissue iron overload in transfusion-dependent β-thalassemia major: novel predictors and follow-up guide.

Tissue iron overload is a life-threatening scenario in children with transfusion-dependent β-thalassemia major, miRNAs that are involved in iron hemostasis could serve as therapeutic targets for control of iron overload. We aimed to find out the association between three iron-related miRNAs "miR-let-7d, miR-122, and miR-200b" and excess iron in tissues, in transfusion-dependent β-thalassemia major patients. Circulating miRNA expressions are measured in peripheral blood (PB) samples using qPCR of transfusion-dependent (TDT) β-thalassemia patients (n = 140) and normalized to non-transfusion-dependent (NTDT) β-thalassemia (n = 45). Results revealed that plasma expression levels of miR-let-7d and miR-200b were significantly downregulated in TDT patients; however, miR-122 was upregulated. In terms of tissue iron load, aberrant expression of miRNAs was significantly associated with increased-iron accumulation in hepatic and cardiac tissues. We concluded that circulating miRNAs are strong candidates that associate iron hemostasis in transfusion-dependent β-thalassemia major patients. And by extension, targeting miR-let-7d, miR-122, and miR-200 might serve as novel sensitive, specific and non-invasive predictor biomarkers for cellular damage under condition of tissue iron excess.

Blood Volume Monitoring: A Clinical Tool to Guide Ultrafiltration in Volume Control and Optimisation of Intradialytic Blood Pressure

The importance of extracellular volume control and avoidance of volume overload has been well documented in relation to the management of patients with chronic haemodialysis. Chronic volume overload results in poorly controlled hypertension, increased cardiovascular events, and increased all-cause mortality. Traditional methods of dry weight assessment have relied on clinical assessment to guide volume status. The challenge of achieving the balance between dry weights and preventing intradialytic complications is a formidable one. In order to achieve this, reproducible and sensitive methods are desirable to aid objective quantification of volume status. One such method is by the use of blood volume monitoring, which is achieved by real-time calculation of changes in relative blood volume via a cuvette placed in the arterial blood-line, which can be used to guide ultrafiltration targets during the haemodialysis session. This review article examines the use of blood volume monitoring as a tool to guide ultrafiltration during dialysis and to examine the current evidence to supports its use in assessing dry weight and in preventing intradialytic hypotension events.

Complication Rates after Endometrial Ablation in Ontario: A Cohort Analysis of 76 446 Patients

Endometrial ablation (EA) is an alternative to hysterectomy for the management of heavy menstrual bleeding; however, EA is not without risk. Our objective was to determine complication rates in women undergoing EA in the province of Ontario over a 15-year time period. The primary outcome was a composite of multiple complications within 30 to 180 days of surgery. The secondary outcomes included mortality, length of hospital stay, hospital readmission, and emergency department visit within 30 days of discharge. Retrospective cohort study using Cochran-Armitage test for trend. Administrative data from the Canadian province of Ontario, assessing patients undergoing surgery in a publicly funded healthcare system. Women in Ontario undergoing a primary EA over a 15-year time period. The intervention was a primary EA. We assessed for genitourinary complication, fistula, gastrointestinal complication, pain, control of bleeding, blood transfusion, infectious complication, venous thromboembolism, fluid overload, thermal injury, and other injuries related to surgery. The secondary outcomes included 1-month and 6-month mortality, length of hospital stay, hospital readmission, and emergency department visit within 30 days of discharge. A total of 76 446 primary EAs were evaluated from 2002 to 2017, with the number of EAs per year increasing over the study period by 47%. Complications were seen in 4.8% of the cohort, with the complication rate being relatively stable over time. Although 6.2% of the cohort re-presented to the emergency department, <1% required readmission, and <0.05% died within 180 days. On multivariable analysis, the risk of complications increased with a preoperative diagnosis of other than bleeding (odds ratio [OR] 2.89; 95% confidence interval [CI], 2.61-3.21; p <.001), previous abdominal surgery (OR 1.42; 95% CI, 1.28-1.56; p <.001), and American Society of Anesthesiologists score 3+ (OR 1.37; 95% CI, 1.27-1.48; p <.001). Primary EA is associated with complications in <5% of the patients, with serious complications infrequent.

Study of drive currents for lifting bridge cranes of metallurgical enterprises for early diagnosis of load excess weight

The article discusses an approach based on the analysis of the drive motor currents to create an additional means of protection against emergency situations during the operation of bridge cranes associated with lifting a load with a mass exceeding the permissible one. A mathematical model of an overhead crane drive is described, as well as the results of computer simulation. It is shown that in the process of lifting up, before the stage of lifting the load, the stator current of the drive electric motor does not depend of the load mass, but when the load is detached, already for several periods of the mains voltage after the rope is pulled, when the mass of the load is exceeded, a measurable excess of the amplitude value of the current is recorded. This pattern has been confirmed for a number of cranes of various lifting capacities used at metallurgical enterprises. The possibility of diagnosing excess weight of the lifted load with a higher speed than existing mechanical methods of overload control is demonstrated, at the same time it is not required to make changes to the structural elements of overhead cranes.

An Efficient Routing Protocol with Overload Control for Group Mobility in Delay-Tolerant Networking

In delay-tolerant networking (DTN), messages are delivered to destination nodes by using opportunistic contacts between contact nodes, even if stable routing paths from source nodes to destination nodes do not exist. In some DTN network environments, such as military networks, nodes movement follows a group movement model, and an efficient DTN routing protocol is required to use the characteristics of group mobility. In this paper, we consider a network environment, where both intra- and intergroup routing are carried out by using DTN protocols. Then, we propose an efficient routing protocol with overload control for group mobility, where delivery predictability for group mobility is defined and proactive overload control is applied. Performance evaluation results show that the proposed protocol had better delivery ratios and overhead ratios than compared protocols, although the delivery latency was increased.

Controle de sobrecarga de equipamentos de transporte de minérios

Overloading of ore transportation equipment is a problem that directly impacts the physical availability and maintenance costs of the equipment, and must be managed and minimized. In this context, the objective of this study is to improve the overload control of trucks used in the transportation of ore from an underground mine by adopting the 10/10/20 payload control policy and to evaluate the impacts on the physical availability of this equipment. Therefore, the methodology consisted basically in defining the problems caused by the overload of transportation equipment, elaboration and implementation of new operational procedures aiming at the application of the 10/10/20 load control policy, generation of management reports, evaluation of physical availability indicators and problem mitigation. The results indicated an increase in average physical availability of 9.21% from the first to the second half of 2019, the latter contemplating the period in which the overload control actions were implemented. In addition, an increase in the number of trips with load suitable to the equipment's capacity was noted.

Ilex paraguariensis (A. St.-Hil.) leaf infusion decreases iron absorption in patients with hereditary hemochromatosis: a randomized controlled crossover study.

This study proposed to investigate the effect of Ilex paraguariensis infusion on the absorption of non-heme iron in hereditary hemochromatosis (HH) patients with the HFE genotype. A two-way randomized, controlled, crossover trial was conducted on patients, aged 29-69 years, undergoing maintenance therapy. Fourteen HFE-HH patients ingested a meal containing 11.4 mg iron and 200 mL either of water (control) or of Ilex paraguariensis leaf infusion. The beverages were offered in random order, at intervals separated by a washout period of 7 days. Active surveillance showed no adverse effects. Blood samples were drawn shortly before and 1, 2, 3, and 4 h after the meal for serum iron measurement. A significant reduction in the postprandial serum iron was observed for HH patients after intake of the Ilex paraguariensis infusion (area under the curve (AUC) expressed as mean ± SEM: 173.3 ± 44.7 μmol h-1 L-1) compared to water (1449.4 ± 241.5 μmol h-1 L-1) (p < 0.001). In summary, intake of Ilex paraguariensis leaf infusion significantly inhibited the absorption of iron in patients with HH and, therefore, should be considered as a potential adjuvant for iron overload control.

Chlortalidone and bumetanide in advanced chronic kidney disease: HEBE-CKD Trial

Abstract Introduction Current treatment for hypertension and volume overload in chronic kidney disease consists of loop diuretics, nevertheless, chronic use leads to adaptive changes at the distal nephron, which in turn decreases their efficacy. The use of thiazide diuretics could be another treatment option in these patients, notwithstanding, there's not enough evidence to justify their use in this population. Purpose To evaluate the efficacy and safety of treatment with bumetanide plus chlorthalidone in in patients with advanced chronic kidney disease. Methods A double-blind randomized controlled trial was conducted at our hospital. Thirty-two patients with hypertension, chronic kidney disease stage IV/V, and chronic loop diuretic use where divided in two groups. The dual treatment group received bumetanide (4 mg QD) plus chlorthalidone (100 mg QD), while the control group was given bumetanide (4 mg QD) plus placebo, both for twenty-eight days. Systemic blood pressure, bioimpedance, and urinary electrolytes were measured at seven and twenty-eight days of treatment. Results There was a significant decrease of systemic blood pressure in the dual treatment group when compared with the control group; systolic blood pressure −26.1±15.3 vs. −10±23.3 mmHg (p=0.028), diastolic blood pressure −13.5±10.7 vs. −3.4±11.9 mmHg (p=0.018), and mean arterial pressure −18.1±8.7 vs. −5.4±14.3 mmHg (p=0.006). There was also a significant decrease of volume overload in the dual treatment group when compared to the control group; total body water −4.36±3.29 vs. +0.075±1.78 litres (p&amp;lt;0.001), extracellular water −2.55±1.1 vs. +0.150±1.2 litres (p&amp;lt;0.001), and extracellular water to total body water ratio −2.92±4.76 vs. −0.24±1.42 (p=0.039). The treatment group increased its fractional excretion of sodium, while the control group demonstrated an increase, though differences were non-significant. As for adverse effects, there was a non-significant increase of urea and creatinine levels in the dual treatment group when compared with controls. Conclusions In advanced chronic kidney disease plus hypertension patients whose treatment with loop diuretics is insufficient, combined use of bumetanide plus chlorthalidone can be useful for systemic blood pressure and volume overload control. Figure 1 Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Hospital General de México

P0809LEFT VENTRICULAR DIASTOLIC DYSFUNCTION IN PATIENTS WITH DIABETIC CHRONIC KIDNEY DISEASE

Abstract Background and Aims Left ventricle diastolic dysfunction (LVDD) is common cardiac changes in diabetic patients without renal insufficiency. LVDD is also frequently occurs in chronic kidney disease (CKD). Diabetic patients with CKD are at increased risk of developing cardiovascular diseases. Therefore, early detection and prevention of risk factors are critical. The aim of this study was to evaluate the impact of type 2 diabetes on left ventricular (LV) diastolic function among CKD stage 3 and 5 patients, and whether markers of fluid balance can predict LVDD. Method A total of 409 patients (age and sex matched non-diabetic CKD stage 3 [nDMCKD3], n = 106; diabetic CKD stage 3 [DMCKD3], n = 106; non-diabetic CKD stage 5 [nDMCKD5], n = 73; diabetic CKD stage 5 [DMCKD5], n = 124) were analyzed. The stage 3 CKD patients were retrospectively reviewed, and stage 5 CKD patients were prospectively analyzed. All cohort patients with stage 5 CKD were hospitalized to plan their first dialysis treatment. The following exclusion criteria were applied: ejection fraction less than 45%, history of coronary artery disease and/or intervention treatment, history of angina or myocardial infarction, abnormalities of cardiac rhythm, moderate or severe valvular heart diseases, systemic immunologic diseases, liver cirrhosis, malignancy, infection, and previous renal transplantation. Coronary artery disease having regional wall motion abnormalities on echocardiographic examination was also ruled out. Clinical and echocardiographic parameters were compared among groups. Echocardiography, bioimpedance spectroscopy, and serum NT-proBNP were analyzed in patients with stage 5 CKD. The LVDD was defined as E/é ratio greater than 15. Extracellular water/total body water (ECW/TBW) and NT-proBNP were used as markers of fluid balance. Results Patients with E/é ratio &amp;gt; 15 presented with more advanced stages of CKD. Prevalence of LVDD in patients with diabetes was higher compared to those without diabetes. Patients in DMCKD5 group demonstrated higher E/é ratios compared to those with nDMCKD5, DMCKD3, and nDMCKD3 (16.63±5.04 vs. 14.12±4.60 vs. 14.69±4.65 vs. 13.07±3.76, p &amp;lt; 0.001). The E/é ratio in patients with DMCKD5 were significantly higher than those with DMCKD3 (16.63±5.04 vs. 14.69±4.65, p = 0.003). In contrast, the E/é ratio was not significantly different between nDMCKD3 and nDMCKD5 patients (13.07±3.76 vs. 14.12±4.60, p = 0.099). The ECW/TBW in patients with DMCKD5 were significantly higher than nDMCKD5 patients (0.51±0.04 vs. 0.48±0.05, p &amp;lt;0.001). In a multiple regression analysis, the presence of diabetes, serum albumin level, NT-proBNP, and ECW/TBW were significantly associated with LVDD in CKD5 patients. Conclusion Our results suggest that an echocardiographic examination and assessment of volume status should routinely be performed in patients with type 2 DMCKD. Early detection of LVDD before clinical symptoms are apparent is important, regardless of the stage of DMCKD. Fluid overload could be one of the aggravating factors of LVDD in DMCKD patients. Early evaluation of volume status and control of fluid overload should be considered important therapeutic approaches for LVDD in DMCKD patients, especially for those in advanced stages.

A Study on Effect and Improvement Plan of Overload Control of Freight Transportation on Transshipment Cargo and Port Hinterland

A Study on Effect and Improvement Plan of Overload Control of Freight Transportation on Transshipment Cargo and Port Hinterland

Evaluation of the efficacy and safety of deferiprone compared with deferasirox in paediatric patients with transfusion-dependent haemoglobinopathies (DEEP-2): a multicentre, randomised, open-label, non-inferiority, phase 3 trial

Transfusion-dependent haemoglobinopathies require lifelong iron chelation therapy with one of the three iron chelators (deferiprone, deferasirox, or deferoxamine). Deferasirox and deferiprone are the only two oral chelators used in adult patients with transfusion-dependent haemoglobinopathies. To our knowledge, there are no randomised clinical trials comparing deferiprone, a less expensive iron chelator, with deferasirox in paediatric patients. We aimed to show the non-inferiority of deferiprone versus deferasirox. DEEP-2 was a phase 3, multicentre, randomised trial in paediatric patients (aged 1 month to 18 years) with transfusion-dependent haemoglobinopathies. The study was done in 21 research hospitals and universities in Italy, Egypt, Greece, Albania, Cyprus, Tunisia, and the UK. Participants were receiving at least 150 mL/kg per year of red blood cells for the past 2 years at the time of enrolment, and were receiving deferoxamine (<100 mg/kg per day) or deferasirox (<40 mg/kg per day; deferasirox is not registered for use in children aged <2 years so only deferoxamine was being used in these patients). Any previous chelation treatment was permitted with a 7-day washout period. Patients were randomly assigned 1:1 to receive orally administered daily deferiprone (75-100 mg/kg per day) or daily deferasirox (20-40 mg/kg per day) administered as dispersible tablets, both with dose adjustment for 12 months, stratified by age (<10 years and ≥10 years) and balanced by country. The primary efficacy endpoint was based on predefined success criteria for changes in serum ferritin concentration (all patients) and cardiac MRI T2-star (T2*; patients aged >10 years) to show non-inferiority of deferiprone versus deferasirox in the per-protocol population, defined as all randomly assigned patients who received the study drugs and had available data for both variables at baseline and after 1 year of treatment, without major protocol violations. Non-inferiority was based on the two-sided 95% CI of the difference in the proportion of patients with treatment success between the two groups and was shown if the lower limit of the two-sided 95% CI was greater than -12·5%. Safety was assessed in all patients who received at least one dose of study drug. This study is registered with EudraCT, 2012-000353-31, and ClinicalTrials.gov, NCT01825512. 435 patients were enrolled between March 17, 2014, and June 16, 2016, 393 of whom were randomly assigned to a treatment group (194 to the deferiprone group; 199 to the deferasirox group). 352 (90%) of 390 patients had β-thalassaemia major, 27 (7%) had sickle cell disease, five (1%) had thalassodrepanocytosis, and six (2%) had other haemoglobinopathies. Median follow-up was 379 days (IQR 294-392) for deferiprone and 381 days (350-392) for deferasirox. Non-inferiority of deferiprone versus deferasirox was established (treatment success in 69 [55·2%] of 125 patients assigned deferiprone with primary composite efficacy endpoint data available at baseline and 1 year vs 80 [54·8%] of 146 assigned deferasirox, difference 0·4%; 95% CI -11·9 to 12·6). No significant difference between the groups was shown in the occurrence of serious and drug-related adverse events. Three (2%) cases of reversible agranulocytosis occurred in the 193 patients in the safety analysis in the deferiprone group and two (1%) cases of reversible renal and urinary disorders (one case of each) occurred in the 197 patients in the deferasirox group. Compliance was similar between treatment groups: 183 (95%) of 193 patients in the deferiprone group versus 192 (97%) of 197 patients in the deferisirox group. In paediatric patients with transfusion-dependent haemoglobinopathies, deferiprone was effective and safe in inducing control of iron overload during 12 months of treatment. Considering the need for availability of more chelation treatments in paediatric populations, deferiprone offers a valuable treatment option for this age group. EU Seventh Framework Programme.

No child with a transfusion-dependent haemoglobinopathy left unchelated: are we there yet?

Haemoglobinopathies such as thalassaemias and sickle cell disease pose substantial clinical and public health challenges across the world. 1 Shah FT Sayani F Trompeter S Drasar E Piga A Challenges of blood transfusions in β-thalassemia. Blood Rev. 2019; 37100588 Crossref PubMed Scopus (33) Google Scholar The Global Burden of Disease Study 2017 2 GBD 2017 Disease and Injury Incidence and Prevalence CollaboratorsGlobal, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet. 2018; 392: 1789-1858 Summary Full Text Full Text PDF PubMed Scopus (3032) Google Scholar estimates a prevalence of 411 000 and incidence of 106 300 new cases per year globally of clinically significant thalassaemias. Because most patients with β-thalassaemia major require regular blood transfusions for the treatment of severe anaemia, often starting within the first 2 years of life, most of these patients have transfusion-associated iron overload with its long-term sequelae. Allogeneic haematopoietic stem-cell transplantation is the only potentially curative therapeutic option; however, this treatment is limited by accessibility issues and its associated morbidity and mortality. Therefore, iron chelation therapy to mitigate the effects of transfusion-associated iron overload has been a standard of care in the treatment of transfusion-dependent haemoglobinopathies. 1 Shah FT Sayani F Trompeter S Drasar E Piga A Challenges of blood transfusions in β-thalassemia. Blood Rev. 2019; 37100588 Crossref PubMed Scopus (33) Google Scholar , 3 Di Maggio R Maggio A The new era of chelation treatments: effectiveness and safety of 10 different regimens for controlling iron overloading in thalassaemia major. Br J Haematol. 2017; 178: 676-688 Crossref PubMed Scopus (16) Google Scholar Iron chelation therapy has been shown to improve outcomes, and the oral iron chelators deferiprone and deferasirox seem to be more effective and lead to greater compliance than the parenteral deferoxamine. 4 Pennell DJ Berdoukas V Karagiorga M et al. Randomized controlled trial of deferiprone or deferoxamine in beta-thalassemia major patients with asymptomatic myocardial siderosis. Blood. 2006; 107: 3738-3744 Crossref PubMed Scopus (388) Google Scholar , 5 Pennell DJ Porter JB Piga A et al. A 1-year randomized controlled trial of deferasirox vs deferoxamine for myocardial iron removal in β-thalassemia major (CORDELIA). Blood. 2014; 123: 1447-1454 Crossref PubMed Scopus (82) Google Scholar , 6 Ladis V Chouliaras G Berdoukas V et al. Survival in a large cohort of Greek patients with transfusion-dependent beta thalassaemia and mortality ratios compared to the general population. Eur J Haematol. 2011; 86: 332-338 Crossref PubMed Scopus (43) Google Scholar Although data for patients as young as 2 years are available for deferasirox, there are few high-quality randomised studies in paediatric patients receiving deferiprone. Evaluation of the efficacy and safety of deferiprone compared with deferasirox in paediatric patients with transfusion-dependent haemoglobinopathies (DEEP-2): a multicentre, randomised, open-label, non-inferiority, phase 3 trialIn paediatric patients with transfusion-dependent haemoglobinopathies, deferiprone was effective and safe in inducing control of iron overload during 12 months of treatment. Considering the need for availability of more chelation treatments in paediatric populations, deferiprone offers a valuable treatment option for this age group. Full-Text PDF

A logical model of the distributed corporate network of an insurance company

In the context of hardware heterogeneity and the use of multi-platform software in insurance companies, it is necessary to develop specific schemes for the implementation of a distributed corporate network. This article proposes a logical model of an information and communications network built in the form of subnetworks of two types: a head office and branches of an insurance company. The proposed recommendations include the application of special adaptive traffic routing and service technologies, overload control through constructing virtual channels and introduction of packet queues optimization policies.

Analysis of the State-Dependent Queueing Model and Its Application to Battery Swapping and Charging Stations

This study analyzes the performance of a queue length-dependent overload control policy using a leaky bucket (LB) scheme. This queueing model is applied to the operation of a battery swapping and charging station for electric vehicles (EVs). In addition to the LB scheme, we propose two congestion control policies based on EV queue length thresholds. With these policies, the model determines both EV-arrival and battery-supply intervals, and these depend on the number of EVs waiting in the queue. The queue length distributions, including those at arbitrary epochs, are derived using embedded Markov chain and supplementary variable methods. Performance measures such as blocking probability and mean waiting time are investigated using numerical examples. We study the characteristics of the system using numerical examples and use a cost analysis to investigate situations in which the application of each congestion control policy is advantageous.

Overload control in SIP signalling networks with redirect servers

Session Initiation Protocol (SIP) is the most popular IP-based application level signalling protocol used for managing multimedia sessions and chat sessions between two or more users. Expeditious growth in usage of smart phones spurred the usage of IP-based multimedia communications. Rapid growth in the usage of Internet Telephony is increasing the load on servers resulting in server overload. Overload control techniques for SIP servers were proposed and standardised; however, existing SIP signalling networks with redirect servers are not well equipped to handle overload conditions. This research work discusses the limitations of existing SIP overload control techniques when employing redirect servers and proposes a solution for controlling overload in downstream SIP servers when employing redirect servers. We propose an algorithm for controlling overload state and formulate the conditions for analysing the overload control parameters, based on queue lengths. Simulation studies revealed that retransmissions in the proposed system are reduced by 63.64% and that of throughput is increased by 27.39%. Call failure rate is reduced by 0.5%.

Overload control in SIP signalling networks with redirect servers

Overload control in SIP signalling networks with redirect servers