Air pollution has ever become a global major public health problem.Previous studies showed that air pollution is associated with excessive mortality and morbidity of respiratory disease[1-2].The extreme weather temper...Air pollution has ever become a global major public health problem.Previous studies showed that air pollution is associated with excessive mortality and morbidity of respiratory disease[1-2].The extreme weather temperature can impact human health and the thermal stresses can lead not only to direct deaths and illnesses,but also to aggravation of respiratory disease[3-4].Though the independent展开更多
Question-Answer systems are now very popular and crucial to support human in automatically responding frequent questions in manyfields.However,these systems depend on learning methods and training data.Therefore,it is ...Question-Answer systems are now very popular and crucial to support human in automatically responding frequent questions in manyfields.However,these systems depend on learning methods and training data.Therefore,it is necessary to prepare such a good dataset,but it is not an easy job.An ontol-ogy-based domain knowledge base is able to help to reason semantic information and make effective answers given user questions.This study proposes a novel chatbot model involving ontology to generate efficient responses automatically.A case study of admissions advising at the International University–VNU HCMC is taken into account in the proposed chatbot.A domain ontology is designed and built based on the domain knowledge of university admissions using Protégé.The Web user interface of the proposed chatbot system is developed as a prototype using NetBeans.It includes a search engine reasoning the ontology and generat-ing answers to users’questions.Two experiments are carried out to test how the system reacts to different questions.Thefirst experiment examines questions made from some templates,and the second one examines normal questions taken from frequent questions.Experimental results have shown that the ontology-based chatbot can release meaningful and long answers.The results are analysed to prove the proposed chatbot is usable and promising.展开更多
BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU ad...BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU admissions are associated with increased morbidity and mortality and are an indicator of trauma service quality.Two different types of unplanned ICU admissions include upgrades(patients admitted to the floor then moved to the ICU)and bounce backs(patients admitted to the ICU,discharged to the floor,and then readmitted to the ICU).Previous studies have shown that geriatric trauma patients are at higher risk for unfavorable outcomes.AIM To analyze the characteristics,management and outcomes of trauma patients who had an unplanned ICU admission during their hospitalization.METHODS This institutional review board approved,retrospective cohort study examined 203 adult trauma patients with unplanned ICU admission at an urban level 1 trauma center over a six-year period(2017-2023).This included 134 upgrades and 69 bounce backs.Analyzed variables included:(1)Age;(2)Sex;(3)Comorbidities;(4)Mechanism of injury(MOI);(5)Injury severity score(ISS);(6)Glasgow Coma Scale(GCS);(7)Type of injury;(8)Transfusions;(9)Consultations;(10)Timing and reason for unplanned admission;(11)Intubations;(12)Surgical interventions;(13)ICU and hospital lengths of stay;and(14)Mortality.RESULTS Unplanned ICU admissions comprised 4.2%of total ICU admissions.Main MOI was falls.Mean age was 70.7 years,ISS was 12.8 and GCS was 13.9.Main injuries were traumatic brain injury(37.4%)and thoracic injury(21.7%),and main reason for unplanned ICU admission was respiratory complication(39.4%).The 47.3%underwent a surgical procedure and 46.8%were intubated.Average timing for unplanned ICU admission was 2.9 days.Bounce backs occurred half as often as upgrades,however had higher rates of transfusions(63.8%vs 40.3%,P=0.002),consultations(4.8 vs 3.0,P<0.001),intubations(63.8%vs 38.1%%,P=0.001),longer ICU lengths of stay(13.2 days vs 6.4 days,P<0.001)and hospital lengths of stay(26.7 days vs 13.0 days,P<0.001).Mortality was 25.6%among unplanned ICU admissions,31.9%among geriatric unplanned ICU admissions and 11.9%among all trauma ICU patients.CONCLUSION Unplanned ICU admissions constituted 4.2%of total ICU admissions.Respiratory complications were the main cause of unplanned ICU admissions.Bounce backs occurred half as often as upgrades,but were associated with worse outcomes.展开更多
The robust admissibility analysis of a class of uncertain discrete-time switched linear singular（SLS） systems for arbitrary switching laws is addressed. The parameter uncertainty is assumed to be norm-bounded. First...The robust admissibility analysis of a class of uncertain discrete-time switched linear singular（SLS） systems for arbitrary switching laws is addressed. The parameter uncertainty is assumed to be norm-bounded. First, by using the switched Lyapunov function approach, some new sufficient conditions ensuring the nominal discrete-time SLS system to be regular, casual and asymptotically stable for arbitrary switching laws are derived in terms of linear matrix inequalities. Then, the robust admissibility condition for the uncertain discrete-time SLS systems is presented. The obtained results can be viewed as an extension of previous works on the switched Lyapunov function approach from the regular switched linear systems to the switched linear singular cases. Numerical examples show the reduced conservatism and effectiveness of the proposed conditions.展开更多
In this paper, a novel admission scheme is proposed which provides high degrees of quality of service (QoS) guarantees for multimedia traffic carried in mobile networks. The proposed scheme combines the admission cont...In this paper, a novel admission scheme is proposed which provides high degrees of quality of service (QoS) guarantees for multimedia traffic carried in mobile networks. The proposed scheme combines the admission control and bandwidth reservation to guarantee QoS requirements. It considers both local information and remote information to determine whether to accept or reject a connection. In order to embody the characteristics of the algorithms proposed in the article, two traditional algorithms of admission control are used for comparison. In the end of the paper the simulation analyses are given and the results show that the proposed algorithm can adjust the bandwidth according to the current status of networks and decrease the probability of connections forcibly dropped. The most important thing is that the algorithm is based on the multimedia communications and can guarantee the QoS of real time connections through decreasing the bandwidth of non real time connections.展开更多
Objective To investigate the association between ambient air pollution and hospital emergency admissions in Beijing. Methods In this study, a semi-parametric generalized additive model （GAM） was used to evaluate the...Objective To investigate the association between ambient air pollution and hospital emergency admissions in Beijing. Methods In this study, a semi-parametric generalized additive model （GAM） was used to evaluate the specific influences of air pollutants （PM10, SO2, and NO2） on hospital emergency admissions with different lag structures from 2009 to 2011, the sex and age specific influences of air pollution and the modifying effect of seasons on air pollution to analyze the possible interaction. Results It was found that a 10μg/m3 increase in concentration of PMlo at lag 03 day, SO2 and NO2 at lag 0 day were associated with an increase of 0.88%, 0.76%, and 1.82% respectively in overall emergency admissions. A 10 lag/m3 increase in concentration of PM10, SO2 and NO2 at lag 5 day were associated with an increase of 1.39%, 1.56%, and 1.18% respectively in cardiovascular disease emergency admissions. For lag 02, a 10 μg/m3 increase in concentration of PM10, SO2 and NO2 were associated with 1.72%, 1.34%, and 2.57% increases respectively in respiratory disease emergency admissions. Conclusion This study further confirmed that short-term exposure to ambient air pollution was associated with increased risk of hospital emergency admissions in Beijing.展开更多
In this paper, delay-dependent stability analysis and robust stabilization for uncertain singular time-delay systems are addressed. By using Jensen integral inequality, an improved delay-dependent criterion of admissi...In this paper, delay-dependent stability analysis and robust stabilization for uncertain singular time-delay systems are addressed. By using Jensen integral inequality, an improved delay-dependent criterion of admissibility for singular time-delay systems is proposed in terms of linear matrix inequality （LMI）. Our new proposed criterion is less conservative and the numerical complexity is smaller than the existing ones. Based on this criterion, a state feedback controller is designed to ensure that the uncertain singular time-delay system is admissible. Finally, three numerical examples are employed to illustrate the effectiveness of the proposed method.展开更多
This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict...This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict linear matrix inequalities(LMIs). Then, a static output feedback controller is designed for the uncertain closed-loop system to be admissible. Numerical examples are given to illustrate the proposed methods.展开更多
The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new ...The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new sufficient conditions under which the SLS system is admissible for arbitrary switching laws are derived in terms of linear matrix inequalities （LMIs）. Based on the admissibility results, control synthesis is then to design switched state feedback and static output feedback controllers, guaranteeing that the resulting closed-loop system is admissible. The presented results can be viewed as the extensions of previous works on switched Lyapunov function approach from the regular switched systems to singular switched cases. Examples are provided to demonstrate the reduced conservatism and effectiveness of the proposed conditions.展开更多
By means of matrix decomposition method a criterion is presented for the admissibility of T-S fuzzy descriptor system. Then, the problem of passivity control is studied for a kind of T-S fuzzy descriptor system with u...By means of matrix decomposition method a criterion is presented for the admissibility of T-S fuzzy descriptor system. Then, the problem of passivity control is studied for a kind of T-S fuzzy descriptor system with uncertain parameters, and sufficient conditions which make the closed-loop system admissible and strictly passive are obtained based on linear matrix inequality (LMI). The nonstrict LMIs restricted conditions which characterize the descriptor system are transformed into strict ones, so testing admissibility and passivity of the system can be finished simultaneously. The design scheme of state feedback controller is also obtained. Finally, a numerical example is given to show the validity and feasibility of the proposed approach.展开更多
In this article, we mainly investigate the behavior of systems of complex differential equations when we add some condition to the quality of the solutions, and obtain an interesting result, which extends Gaekstatter ...In this article, we mainly investigate the behavior of systems of complex differential equations when we add some condition to the quality of the solutions, and obtain an interesting result, which extends Gaekstatter and Laine＇s result concerning complex differential equations to the systems of algebraic differential equations.展开更多
This paper proposes and evaluates two improved Petri net （PN）-based hybrid search strategies and their applications to flexible manufacturing system （FMS） scheduling. The algorithms proposed in some previous paper...This paper proposes and evaluates two improved Petri net （PN）-based hybrid search strategies and their applications to flexible manufacturing system （FMS） scheduling. The algorithms proposed in some previous papers, which combine PN simulation capabilities with A＊ heuristic search within the PN reachability graph,may not find an optimum solution even with an admissible heuristic function. To remedy the defects an improved heuristic search strategy is proposed, which adopts a different method for selecting the promising markings and reserves the admissibility of the algorithm. To speed up the search process, another algorithm is also proposed which invokes faster termination conditions and still guarantees that the solution found is optimum. The scheduling results are compared through a simple FMS between our algorithms and the previous methods. They are also applied and evaluated in a set of randomly-generated FMSs with such characteristics as multiple resources and alternative routes.展开更多
The proliferation of streaming service system in various application areas gains increasing importance and also poses more challenges in the research of streaming service system. In this paper, we propose a novel dyna...The proliferation of streaming service system in various application areas gains increasing importance and also poses more challenges in the research of streaming service system. In this paper, we propose a novel dynamic model composed of a set of differential equations to describe the evolution of streaming service systems. And in the model, we focus on how the policies for admission control and peer selection influence on the system. We first introduce a flexible abstraction of streaming service systems. The abstraction is generally enough to capture the essences of streaming service systems with different structures, physical characteristics,software protocols and client behaviors. Then, by analyzing the state which is defined as the number of requests, a novel dynamic model is developed in microscopic scale to characterize the behaviors of streaming service systems. The model proposed in this paper demonstrates the interactions between clients and servers and also between different servers. The interactions are primarily influenced by the admission control policy and peer selection policy. Finally, some experiments are designed to verify the validation and reasonability of the model.展开更多
Propose a new degradation call admission control（DCAC）scheme, which can be used in wideband code division multiple access communication system. So-called degradation is that non-real time call has the characteristic...Propose a new degradation call admission control（DCAC）scheme, which can be used in wideband code division multiple access communication system. So-called degradation is that non-real time call has the characteristic of variable bit rate, so decreasing its bit rate can reduce the load of the system, consequently the system can admit new call which should be blocked when the system is close to full load, therefore new call＇s access probability increases. This paper brings forward design project and does system simulation, simulation proves that DCAC can effectively decrease calls＇ blocking probability and increase the total number of the on-line users.展开更多
BACKGROUND Alcoholic liver disease(ALD)is a major cause of chronic liver disease worldwide.AIM To describe the epidemiological profile and mortality rates of patients with ALD admitted to public hospitals in different...BACKGROUND Alcoholic liver disease(ALD)is a major cause of chronic liver disease worldwide.AIM To describe the epidemiological profile and mortality rates of patients with ALD admitted to public hospitals in different regions of Brazil from 2006 to 2015.METHODS This is a descriptive study that evaluated aggregate data from the five Brazilian geographic regions.RESULTS A total of 160093 public hospitalizations for ALD were registered.There was a 34.07%increase in the total number of admissions over 10 years,from 12879 in 2006 to 17267 in 2015.The region with the highest proportion(49.01%)of ALD hospitalizations was Southeast(n=78463).The North region had the lowest absolute number of patients throughout the study period,corresponding to 3.9%of the total(n=6242).There was a 24.72%increase in the total number of ALD deaths between 2006 and 2015.We found that the age group between 50 and 59 years had the highest proportion of both hospitalizations and deaths:28.94%(n=46329)of total hospital admissions and 29.43%(n=28864)of all deaths.Men were more frequently hospitalized than women and had the highest proportions of deaths in all regions.Mortality coefficient rates increased over the years,and simple linear regression analysis indicated a statistically significant upward trend in this mortality(R^2=0.744).CONCLUSION Our study provides a landscape of the epidemiological profile of public hospital admissions due to ALD in Brazil.We detected an increase in the total number of admissions and deaths due to ALD over 10 years.展开更多
<strong>Introduction:</strong> Interdialytic weight-gain (IDWG) has been linked to various complications in hemodialysis (HD) patients. <strong>Method:</strong> Prospective clinical-observation...<strong>Introduction:</strong> Interdialytic weight-gain (IDWG) has been linked to various complications in hemodialysis (HD) patients. <strong>Method:</strong> Prospective clinical-observational study to evaluate the effect of IDWG in HD patients on the rate of hospital admissions over a 12-month period, and the impact of high IDWG on the frequency of IDH. <strong>Results:</strong> Of the 240 patients, those who had IDWG ≥ 4%, 81% had at least one hospital admission due to volume-overload or the need for extra HD-session(s). On the other hand, only 19% of those having IDWG < 4% had been admitted or got extra HD sessions (p < 0.001). Of those who were admitted (over 12 months) due to volume overload;74.1% had IDWG ≥ 4%, while 25.9% had IDWG < 4% (p < 0.001). Regarding IDH, 87% of patients having IDWG ≥ 4% had at least one episode of IDH/week. On the other hand, only 22.5% of those with IDWG < 4% had one episode of IDH/week (p < 0.001). When analyzing those who had at least one IDH episode/week;72.9% of them had IDWG ≥ 4%, while only 27.1% had IDWG < 4% (p < 0.001). <strong>Conclusion:</strong> In HD patients, the frequency of hospital admission due to volume-overload and the need for extra HD-sessions is strongly related to the amount of IDWG (>4% in our patients), the same stands for the frequency of IDH. Thus, control of IDWG in HD patients is of great importance, keeping in mind the importance of the nutrition status of HD patients that may also impact IDWG.展开更多
In recent years the role of HF in the outcomes, cost of treatment in cardiology is raising. Concomitantly a number of studies were published demonstrating connections of many cardiac events with Space Weather Activity...In recent years the role of HF in the outcomes, cost of treatment in cardiology is raising. Concomitantly a number of studies were published demonstrating connections of many cardiac events with Space Weather Activity-Solar, Geomagnetic, Cosmic Ray (Neutron) activity levels. The aim of this study was to study links of timing of hospital admissions for HF with season and space weather components. Patients and Methods: monthly admissions of male and female patients for HF in two hospitals of Rabin Medical Center for years 2000-2012 were the subject of the study. 76,601 patient were included, 42,293 men, 34,308 woman. The cosmophysical data from USA, Russia and Finland were used. Results: Monthly average number of admissions for HF: 491.0 ± 82.4, 271.1 ± 46.75 for men and 219.9 ± 39.8 for woman. Gender admissions strongly correlated. Monthly admission for HF number differed by 2.2 - 2.5 times. Minimal admissions were in August, September;maximal—in January, February, December and March (according to numbers). It was a significant inverse correlation of monthly HF admissions with monthly solar activity and GMA indices and correlation with CRA (neutron) activity. Conclusion: Monthly admissions number for HF is fluctuated by season of the year, depending on gender and related to monthly solar and Cosmic Ray (Neutron) activity level. Gender differences in HF exacerbation may be a component explaining gender differences in longevity.展开更多
BACKGROUND Coronavirus disease 2019(COVID-19)caused by the severe acute respiratory syndrome coronavirus 2 virus most commonly presents with respiratory symptoms.While gastrointestinal(GI)manifestations either at pres...BACKGROUND Coronavirus disease 2019(COVID-19)caused by the severe acute respiratory syndrome coronavirus 2 virus most commonly presents with respiratory symptoms.While gastrointestinal(GI)manifestations either at presentation or during hospitalization are also common,their impact on clinical outcomes is controversial.Some studies have described worse outcomes in COVID-19 patients with GI symptoms,while others have shown either no association or a protective effect.There is a need for consistent standards to describe GI symptoms in COVID-19 patients and to assess their effect on clinical outcomes,including mortality and disease severity.AIM To investigate the prevalence of GI symptoms in hospitalized COVID-19 patients and their correlation with disease severity and clinical outcomes.METHODS We retrospectively reviewed 601 consecutive adult COVID-19 patients requiring hospitalization between May 1-15,2020.GI symptoms were recorded at admission and during hospitalization.Demographic,clinical,laboratory,and treatment data were retrieved.Clinical outcomes included all-cause mortality,disease severity at presentation,need for intensive care unit(ICU)admission,development of acute respiratory distress syndrome,and need for mechanical ventilation.Multivariate logistic regression model was used to identify independent predictors of the adverse outcomes.RESULTS The prevalence of any GI symptom at admission was 27.1%and during hospitalization was 19.8%.The most common symptoms were nausea(98 patients),diarrhea(76 patients),vomiting(73 patients),and epigastric pain or discomfort(69 patients).There was no difference in the mortality between the two groups(6.21%vs 5.5%,P=0.7).Patients with GI symptoms were more likely to have severe disease at presentation(33.13%vs 22.5%,P<0.001)and prolonged hospital stay(15 d vs 14 d,P=0.04).There was no difference in other clinical outcomes,including ICU admission,development of acute respiratory distress syndrome,or need for mechanical ventilation.Drugs associated with the development of GI symptoms during hospitalization were ribavirin(diarrhea 26.37%P<0.001,anorexia 17.58%,P=0.02),hydroxychloroquine(vomiting 28.52%,P=0.009)and lopinavir/ritonavir(nausea 32.65%P=0.049,vomiting 31.47%P=0.004,and epigastric pain 12.65%P=0.048).In the multivariate regression analysis,age>65 years was associated with increased mortality risk[odds ratio(OR)7.53,confidence interval(CI):3.09-18.29,P<0.001],ICU admission(OR:1.79,CI:1.13-2.83,P=0.012),and need for mechanical ventilation(OR:1.89,CI:1.94-2.99,P=0.007).Hypertension was an independent risk factor for ICU admission(OR:1.82,CI:1.17-2.84,P=0.008)and need for mechanical ventilation(OR:1.66,CI:1.05-2.62,P=0.028).CONCLUSION Patients with GI symptoms are more likely to have severe disease at presentation;however,mortality and disease progression is not different between the two groups.展开更多
As the radio spectrum is a very scarce resource,the Call Admission Control (CAC) is one of the most important parts in radio resource management. The Code Division Multiple Access (CDMA) based next generation wireless...As the radio spectrum is a very scarce resource,the Call Admission Control (CAC) is one of the most important parts in radio resource management. The Code Division Multiple Access (CDMA) based next generation wireless communications systems will support the transmission of multimedia traffic,such as voice,video and data,thus the CAC,which can support the multimedia traffic and guarantee the Quality of Service (QoS) of different traffic,has gained broad attention. In this paper,a novel multimedia traffic modeling method and a corresponding dynamic QoS based CAC are proposed. The analysis and simulation results show that the proposed CAC scheme can guarantee the QoS to different traffic demand,and improve the system performance significantly.展开更多
Admission control in high-speed train communication system is quite different from admission control in traditional cellular networks. Conventional admission control strategies cannot be directly applied to this speci...Admission control in high-speed train communication system is quite different from admission control in traditional cellular networks. Conventional admission control strategies cannot be directly applied to this special communication scenario. In this paper, the problem of admission control for handover service is investigated in high-speed train communication environment. An admission control scheme considering bit error rate(BER)and bandwidth borrowing strategy is proposed. On the basis of admission control decision rule taking BER into account, a part of bandwidth obtained by compressing variable rate service in the networks is provided for handover services. The admission control scheme can admit handover services as more as possible while it guarantees the lowest data rate of different services in the networks. Simulation results show that the proposed admission control scheme has a better performance than existing admission control schemes.展开更多
基金supported by the Gong-Yi Program of China Meteorological Administration(GYHY201106034)National Natural Science Foundation of China(41075103)
文摘Air pollution has ever become a global major public health problem.Previous studies showed that air pollution is associated with excessive mortality and morbidity of respiratory disease[1-2].The extreme weather temperature can impact human health and the thermal stresses can lead not only to direct deaths and illnesses,but also to aggravation of respiratory disease[3-4].Though the independent
基金funded by International University,VNU-HCM under Grant Number T2020-03-IT.
文摘Question-Answer systems are now very popular and crucial to support human in automatically responding frequent questions in manyfields.However,these systems depend on learning methods and training data.Therefore,it is necessary to prepare such a good dataset,but it is not an easy job.An ontol-ogy-based domain knowledge base is able to help to reason semantic information and make effective answers given user questions.This study proposes a novel chatbot model involving ontology to generate efficient responses automatically.A case study of admissions advising at the International University–VNU HCMC is taken into account in the proposed chatbot.A domain ontology is designed and built based on the domain knowledge of university admissions using Protégé.The Web user interface of the proposed chatbot system is developed as a prototype using NetBeans.It includes a search engine reasoning the ontology and generat-ing answers to users’questions.Two experiments are carried out to test how the system reacts to different questions.Thefirst experiment examines questions made from some templates,and the second one examines normal questions taken from frequent questions.Experimental results have shown that the ontology-based chatbot can release meaningful and long answers.The results are analysed to prove the proposed chatbot is usable and promising.
文摘BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU admissions are associated with increased morbidity and mortality and are an indicator of trauma service quality.Two different types of unplanned ICU admissions include upgrades(patients admitted to the floor then moved to the ICU)and bounce backs(patients admitted to the ICU,discharged to the floor,and then readmitted to the ICU).Previous studies have shown that geriatric trauma patients are at higher risk for unfavorable outcomes.AIM To analyze the characteristics,management and outcomes of trauma patients who had an unplanned ICU admission during their hospitalization.METHODS This institutional review board approved,retrospective cohort study examined 203 adult trauma patients with unplanned ICU admission at an urban level 1 trauma center over a six-year period(2017-2023).This included 134 upgrades and 69 bounce backs.Analyzed variables included:(1)Age;(2)Sex;(3)Comorbidities;(4)Mechanism of injury(MOI);(5)Injury severity score(ISS);(6)Glasgow Coma Scale(GCS);(7)Type of injury;(8)Transfusions;(9)Consultations;(10)Timing and reason for unplanned admission;(11)Intubations;(12)Surgical interventions;(13)ICU and hospital lengths of stay;and(14)Mortality.RESULTS Unplanned ICU admissions comprised 4.2%of total ICU admissions.Main MOI was falls.Mean age was 70.7 years,ISS was 12.8 and GCS was 13.9.Main injuries were traumatic brain injury(37.4%)and thoracic injury(21.7%),and main reason for unplanned ICU admission was respiratory complication(39.4%).The 47.3%underwent a surgical procedure and 46.8%were intubated.Average timing for unplanned ICU admission was 2.9 days.Bounce backs occurred half as often as upgrades,however had higher rates of transfusions(63.8%vs 40.3%,P=0.002),consultations(4.8 vs 3.0,P<0.001),intubations(63.8%vs 38.1%%,P=0.001),longer ICU lengths of stay(13.2 days vs 6.4 days,P<0.001)and hospital lengths of stay(26.7 days vs 13.0 days,P<0.001).Mortality was 25.6%among unplanned ICU admissions,31.9%among geriatric unplanned ICU admissions and 11.9%among all trauma ICU patients.CONCLUSION Unplanned ICU admissions constituted 4.2%of total ICU admissions.Respiratory complications were the main cause of unplanned ICU admissions.Bounce backs occurred half as often as upgrades,but were associated with worse outcomes.
基金The National Natural Science Foundation of China(No.60835001)the Key Project of Ministry of Education of China (No.108060)
文摘The robust admissibility analysis of a class of uncertain discrete-time switched linear singular（SLS） systems for arbitrary switching laws is addressed. The parameter uncertainty is assumed to be norm-bounded. First, by using the switched Lyapunov function approach, some new sufficient conditions ensuring the nominal discrete-time SLS system to be regular, casual and asymptotically stable for arbitrary switching laws are derived in terms of linear matrix inequalities. Then, the robust admissibility condition for the uncertain discrete-time SLS systems is presented. The obtained results can be viewed as an extension of previous works on the switched Lyapunov function approach from the regular switched linear systems to the switched linear singular cases. Numerical examples show the reduced conservatism and effectiveness of the proposed conditions.
文摘In this paper, a novel admission scheme is proposed which provides high degrees of quality of service (QoS) guarantees for multimedia traffic carried in mobile networks. The proposed scheme combines the admission control and bandwidth reservation to guarantee QoS requirements. It considers both local information and remote information to determine whether to accept or reject a connection. In order to embody the characteristics of the algorithms proposed in the article, two traditional algorithms of admission control are used for comparison. In the end of the paper the simulation analyses are given and the results show that the proposed algorithm can adjust the bandwidth according to the current status of networks and decrease the probability of connections forcibly dropped. The most important thing is that the algorithm is based on the multimedia communications and can guarantee the QoS of real time connections through decreasing the bandwidth of non real time connections.
基金supported by the Gong-Yi Program of China Meteorological Administration(GYHY201106034)the Fundamental Research Funds for the Central Universities(lzuibky-2013-m03)+2 种基金National Natural Science Foundation of China(41075103)National Natural Science Foundation of China(41075102)National Natural Science Foundation of China(41305105)
文摘Objective To investigate the association between ambient air pollution and hospital emergency admissions in Beijing. Methods In this study, a semi-parametric generalized additive model （GAM） was used to evaluate the specific influences of air pollutants （PM10, SO2, and NO2） on hospital emergency admissions with different lag structures from 2009 to 2011, the sex and age specific influences of air pollution and the modifying effect of seasons on air pollution to analyze the possible interaction. Results It was found that a 10μg/m3 increase in concentration of PMlo at lag 03 day, SO2 and NO2 at lag 0 day were associated with an increase of 0.88%, 0.76%, and 1.82% respectively in overall emergency admissions. A 10 lag/m3 increase in concentration of PM10, SO2 and NO2 at lag 5 day were associated with an increase of 1.39%, 1.56%, and 1.18% respectively in cardiovascular disease emergency admissions. For lag 02, a 10 μg/m3 increase in concentration of PM10, SO2 and NO2 were associated with 1.72%, 1.34%, and 2.57% increases respectively in respiratory disease emergency admissions. Conclusion This study further confirmed that short-term exposure to ambient air pollution was associated with increased risk of hospital emergency admissions in Beijing.
基金supported by National Natural Science Foundation of China (No.60904009,No.60974004)
文摘In this paper, delay-dependent stability analysis and robust stabilization for uncertain singular time-delay systems are addressed. By using Jensen integral inequality, an improved delay-dependent criterion of admissibility for singular time-delay systems is proposed in terms of linear matrix inequality （LMI）. Our new proposed criterion is less conservative and the numerical complexity is smaller than the existing ones. Based on this criterion, a state feedback controller is designed to ensure that the uncertain singular time-delay system is admissible. Finally, three numerical examples are employed to illustrate the effectiveness of the proposed method.
文摘This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict linear matrix inequalities(LMIs). Then, a static output feedback controller is designed for the uncertain closed-loop system to be admissible. Numerical examples are given to illustrate the proposed methods.
基金supported partly by the National Natural Science Foundation of China(6057400660835001)+1 种基金the Key Project of Chinese Ministry of Education(108060)the Jiangsu Planned Projects for Postdoctoral Research Funds(0802010c).
文摘The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new sufficient conditions under which the SLS system is admissible for arbitrary switching laws are derived in terms of linear matrix inequalities （LMIs）. Based on the admissibility results, control synthesis is then to design switched state feedback and static output feedback controllers, guaranteeing that the resulting closed-loop system is admissible. The presented results can be viewed as the extensions of previous works on switched Lyapunov function approach from the regular switched systems to singular switched cases. Examples are provided to demonstrate the reduced conservatism and effectiveness of the proposed conditions.
基金Supported by National Natural Science Foundation of P. R, China (60574011)the Distinguished Teacher Funds of Liaoning Universities (124210)the Key Laboratory Funds of Liaoning Universities of Intelligent Control Theory and Applications
文摘By means of matrix decomposition method a criterion is presented for the admissibility of T-S fuzzy descriptor system. Then, the problem of passivity control is studied for a kind of T-S fuzzy descriptor system with uncertain parameters, and sufficient conditions which make the closed-loop system admissible and strictly passive are obtained based on linear matrix inequality (LMI). The nonstrict LMIs restricted conditions which characterize the descriptor system are transformed into strict ones, so testing admissibility and passivity of the system can be finished simultaneously. The design scheme of state feedback controller is also obtained. Finally, a numerical example is given to show the validity and feasibility of the proposed approach.
基金Project Supported by the Natural Science Foundation of China(10471065)the Natural Science Foundation of Guangdong Province(04010474)
文摘In this article, we mainly investigate the behavior of systems of complex differential equations when we add some condition to the quality of the solutions, and obtain an interesting result, which extends Gaekstatter and Laine＇s result concerning complex differential equations to the systems of algebraic differential equations.
文摘This paper proposes and evaluates two improved Petri net （PN）-based hybrid search strategies and their applications to flexible manufacturing system （FMS） scheduling. The algorithms proposed in some previous papers, which combine PN simulation capabilities with A＊ heuristic search within the PN reachability graph,may not find an optimum solution even with an admissible heuristic function. To remedy the defects an improved heuristic search strategy is proposed, which adopts a different method for selecting the promising markings and reserves the admissibility of the algorithm. To speed up the search process, another algorithm is also proposed which invokes faster termination conditions and still guarantees that the solution found is optimum. The scheduling results are compared through a simple FMS between our algorithms and the previous methods. They are also applied and evaluated in a set of randomly-generated FMSs with such characteristics as multiple resources and alternative routes.
基金supported by National Natural Science Foundationof China(Nos.61174124 and 61233003)Research Fund for DoctoralProgram of Higher Education of China(No.20123402110029)Natural Science Research Program of the Anhui High Education Bureau of China(No.KJ2012A286)
文摘The proliferation of streaming service system in various application areas gains increasing importance and also poses more challenges in the research of streaming service system. In this paper, we propose a novel dynamic model composed of a set of differential equations to describe the evolution of streaming service systems. And in the model, we focus on how the policies for admission control and peer selection influence on the system. We first introduce a flexible abstraction of streaming service systems. The abstraction is generally enough to capture the essences of streaming service systems with different structures, physical characteristics,software protocols and client behaviors. Then, by analyzing the state which is defined as the number of requests, a novel dynamic model is developed in microscopic scale to characterize the behaviors of streaming service systems. The model proposed in this paper demonstrates the interactions between clients and servers and also between different servers. The interactions are primarily influenced by the admission control policy and peer selection policy. Finally, some experiments are designed to verify the validation and reasonability of the model.
文摘Propose a new degradation call admission control（DCAC）scheme, which can be used in wideband code division multiple access communication system. So-called degradation is that non-real time call has the characteristic of variable bit rate, so decreasing its bit rate can reduce the load of the system, consequently the system can admit new call which should be blocked when the system is close to full load, therefore new call＇s access probability increases. This paper brings forward design project and does system simulation, simulation proves that DCAC can effectively decrease calls＇ blocking probability and increase the total number of the on-line users.
文摘BACKGROUND Alcoholic liver disease(ALD)is a major cause of chronic liver disease worldwide.AIM To describe the epidemiological profile and mortality rates of patients with ALD admitted to public hospitals in different regions of Brazil from 2006 to 2015.METHODS This is a descriptive study that evaluated aggregate data from the five Brazilian geographic regions.RESULTS A total of 160093 public hospitalizations for ALD were registered.There was a 34.07%increase in the total number of admissions over 10 years,from 12879 in 2006 to 17267 in 2015.The region with the highest proportion(49.01%)of ALD hospitalizations was Southeast(n=78463).The North region had the lowest absolute number of patients throughout the study period,corresponding to 3.9%of the total(n=6242).There was a 24.72%increase in the total number of ALD deaths between 2006 and 2015.We found that the age group between 50 and 59 years had the highest proportion of both hospitalizations and deaths:28.94%(n=46329)of total hospital admissions and 29.43%(n=28864)of all deaths.Men were more frequently hospitalized than women and had the highest proportions of deaths in all regions.Mortality coefficient rates increased over the years,and simple linear regression analysis indicated a statistically significant upward trend in this mortality(R^2=0.744).CONCLUSION Our study provides a landscape of the epidemiological profile of public hospital admissions due to ALD in Brazil.We detected an increase in the total number of admissions and deaths due to ALD over 10 years.
文摘<strong>Introduction:</strong> Interdialytic weight-gain (IDWG) has been linked to various complications in hemodialysis (HD) patients. <strong>Method:</strong> Prospective clinical-observational study to evaluate the effect of IDWG in HD patients on the rate of hospital admissions over a 12-month period, and the impact of high IDWG on the frequency of IDH. <strong>Results:</strong> Of the 240 patients, those who had IDWG ≥ 4%, 81% had at least one hospital admission due to volume-overload or the need for extra HD-session(s). On the other hand, only 19% of those having IDWG < 4% had been admitted or got extra HD sessions (p < 0.001). Of those who were admitted (over 12 months) due to volume overload;74.1% had IDWG ≥ 4%, while 25.9% had IDWG < 4% (p < 0.001). Regarding IDH, 87% of patients having IDWG ≥ 4% had at least one episode of IDH/week. On the other hand, only 22.5% of those with IDWG < 4% had one episode of IDH/week (p < 0.001). When analyzing those who had at least one IDH episode/week;72.9% of them had IDWG ≥ 4%, while only 27.1% had IDWG < 4% (p < 0.001). <strong>Conclusion:</strong> In HD patients, the frequency of hospital admission due to volume-overload and the need for extra HD-sessions is strongly related to the amount of IDWG (>4% in our patients), the same stands for the frequency of IDH. Thus, control of IDWG in HD patients is of great importance, keeping in mind the importance of the nutrition status of HD patients that may also impact IDWG.
文摘In recent years the role of HF in the outcomes, cost of treatment in cardiology is raising. Concomitantly a number of studies were published demonstrating connections of many cardiac events with Space Weather Activity-Solar, Geomagnetic, Cosmic Ray (Neutron) activity levels. The aim of this study was to study links of timing of hospital admissions for HF with season and space weather components. Patients and Methods: monthly admissions of male and female patients for HF in two hospitals of Rabin Medical Center for years 2000-2012 were the subject of the study. 76,601 patient were included, 42,293 men, 34,308 woman. The cosmophysical data from USA, Russia and Finland were used. Results: Monthly average number of admissions for HF: 491.0 ± 82.4, 271.1 ± 46.75 for men and 219.9 ± 39.8 for woman. Gender admissions strongly correlated. Monthly admission for HF number differed by 2.2 - 2.5 times. Minimal admissions were in August, September;maximal—in January, February, December and March (according to numbers). It was a significant inverse correlation of monthly HF admissions with monthly solar activity and GMA indices and correlation with CRA (neutron) activity. Conclusion: Monthly admissions number for HF is fluctuated by season of the year, depending on gender and related to monthly solar and Cosmic Ray (Neutron) activity level. Gender differences in HF exacerbation may be a component explaining gender differences in longevity.
文摘BACKGROUND Coronavirus disease 2019(COVID-19)caused by the severe acute respiratory syndrome coronavirus 2 virus most commonly presents with respiratory symptoms.While gastrointestinal(GI)manifestations either at presentation or during hospitalization are also common,their impact on clinical outcomes is controversial.Some studies have described worse outcomes in COVID-19 patients with GI symptoms,while others have shown either no association or a protective effect.There is a need for consistent standards to describe GI symptoms in COVID-19 patients and to assess their effect on clinical outcomes,including mortality and disease severity.AIM To investigate the prevalence of GI symptoms in hospitalized COVID-19 patients and their correlation with disease severity and clinical outcomes.METHODS We retrospectively reviewed 601 consecutive adult COVID-19 patients requiring hospitalization between May 1-15,2020.GI symptoms were recorded at admission and during hospitalization.Demographic,clinical,laboratory,and treatment data were retrieved.Clinical outcomes included all-cause mortality,disease severity at presentation,need for intensive care unit(ICU)admission,development of acute respiratory distress syndrome,and need for mechanical ventilation.Multivariate logistic regression model was used to identify independent predictors of the adverse outcomes.RESULTS The prevalence of any GI symptom at admission was 27.1%and during hospitalization was 19.8%.The most common symptoms were nausea(98 patients),diarrhea(76 patients),vomiting(73 patients),and epigastric pain or discomfort(69 patients).There was no difference in the mortality between the two groups(6.21%vs 5.5%,P=0.7).Patients with GI symptoms were more likely to have severe disease at presentation(33.13%vs 22.5%,P<0.001)and prolonged hospital stay(15 d vs 14 d,P=0.04).There was no difference in other clinical outcomes,including ICU admission,development of acute respiratory distress syndrome,or need for mechanical ventilation.Drugs associated with the development of GI symptoms during hospitalization were ribavirin(diarrhea 26.37%P<0.001,anorexia 17.58%,P=0.02),hydroxychloroquine(vomiting 28.52%,P=0.009)and lopinavir/ritonavir(nausea 32.65%P=0.049,vomiting 31.47%P=0.004,and epigastric pain 12.65%P=0.048).In the multivariate regression analysis,age>65 years was associated with increased mortality risk[odds ratio(OR)7.53,confidence interval(CI):3.09-18.29,P<0.001],ICU admission(OR:1.79,CI:1.13-2.83,P=0.012),and need for mechanical ventilation(OR:1.89,CI:1.94-2.99,P=0.007).Hypertension was an independent risk factor for ICU admission(OR:1.82,CI:1.17-2.84,P=0.008)and need for mechanical ventilation(OR:1.66,CI:1.05-2.62,P=0.028).CONCLUSION Patients with GI symptoms are more likely to have severe disease at presentation;however,mortality and disease progression is not different between the two groups.
基金Supported in part by the SWJTU Funding under Grant 2003B006.
文摘As the radio spectrum is a very scarce resource,the Call Admission Control (CAC) is one of the most important parts in radio resource management. The Code Division Multiple Access (CDMA) based next generation wireless communications systems will support the transmission of multimedia traffic,such as voice,video and data,thus the CAC,which can support the multimedia traffic and guarantee the Quality of Service (QoS) of different traffic,has gained broad attention. In this paper,a novel multimedia traffic modeling method and a corresponding dynamic QoS based CAC are proposed. The analysis and simulation results show that the proposed CAC scheme can guarantee the QoS to different traffic demand,and improve the system performance significantly.
基金the National Natural Science Foundation of China(Nos.61302080 and 61271182)the Scientific Research Starting Foundation of Fuzhou University(No.022572)
文摘Admission control in high-speed train communication system is quite different from admission control in traditional cellular networks. Conventional admission control strategies cannot be directly applied to this special communication scenario. In this paper, the problem of admission control for handover service is investigated in high-speed train communication environment. An admission control scheme considering bit error rate(BER)and bandwidth borrowing strategy is proposed. On the basis of admission control decision rule taking BER into account, a part of bandwidth obtained by compressing variable rate service in the networks is provided for handover services. The admission control scheme can admit handover services as more as possible while it guarantees the lowest data rate of different services in the networks. Simulation results show that the proposed admission control scheme has a better performance than existing admission control schemes.
