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1.
Reperfusion is the key strategy in acute ST-segment elevation myocardial infarction(STEMI) care,and it is time-dependent.Shortening the time from symptom to reperfusion and choosing the optimal reperfusion strategy for STEMI patients are great challenges in practice.We need to improve upon the problems of low reperfusion rate,non-standardized treatment,and economic burden in STEMI care.This article briefly reviews the current status of reperfusion strategy in STEMI care,and also introduces what we will do to bridge the gap between the guidelines and implementation in the clinical setting through the upcoming China STEMI early reperfusion program.  相似文献   

2.
Family foster care placement decision-making has a weak scientific underpinning. Mostly a ‘variable-oriented approach’ is taken, which requires a lot of information that is not always available. The identification of clusters of foster children with similar characteristics may be a more viable decision strategy. In this study we investigated if foster children could indeed be clustered, which problems were identified at the time of placement, and the influence of placement history. It proved possible to group foster children into two clusters: (1) young children with familial problems and few behavioral problems, and (2) older children with prominent child problems and behavioral problems. For foster children with and without placement history, problems associated with placement proved identical. Considering that a foster care placement did not result in fundamental change in the problems present at time of placement, the importance is stressed of approaching foster care assessment as part of a decision making process which looks back as well as forward. Placement decisions should be based on an appraisal of the appropriateness of foster placement as a solution for the child. In conjunction with this appraisal a decision is required on how parents can be supported toward reunification. Or – if this is not an option – whether long term foster care is the best option for the child and if so, what conditions need to be met.  相似文献   

3.
Objective: To determine the effects of albumin administration on lung injury and apoptosis in traumatic/hemorrhagic shock (T/HS) rats. Methods: Studies were performed on an in vivo model of spontaneously breathing rats with induced T/HS; the rats were subjected to femur fracture, ischemia for 30 min, and reperfusion for 20 min with Ringer’s lactate solution (RS) or 5% (w/v) albumin (ALB), and the left lower lobes of the lungs were resected. Results: Albumin administered during reperfusion markedly attenuate...  相似文献   

4.
目的:探讨后适应对接受直接经皮冠状动脉介入(PCI)治疗的急性ST段抬高性心肌梗死(STEMI)患者心血管不良事件的影响。创新点:进一步明确后适应处理对STEMI患者临床预后的影响。方法:对符合入选标准的随机对照临床试验进行meta分析。结论:缺血后适应显著降低ST段抬高性心肌梗死患者心衰风险。  相似文献   

5.
This paper presents a novel strategy for the response enhancement of olfactory sensory neurons (OSNs)-based bio-sensors by monitoring the enhancive responses of OSNs to odorants. An OSNs-based biosensor was developed on the basis of the light addressable potentiometric sensor (LAPS), in which rat OSNs were cultured on the surface of LAPS chip and served as sensing elements. LY294002, the specific inhibitor ofphosphatidylinositol 3-kinase (PI3K), was used to enhance the responses of OSNs to odorants. The responses of OSNs to odorants with and without the treatment of LY294002 were recorded by LAPS. The results show that the enhancive effect of LY294002 was recorded efficiently by LAPS and the responses of this OSNs-LAPS hybrid biosensor were enhanced by LY294002 by about 1.5-fold. We conclude that this method can enhance the responses of OSNs-LAPS hybrid biosensors, which may provide a novel strategy for the bioelectrical signal monitor of OSNs in biosensors. It is also suggested that this strategy may be applicable to other kinds of OSNs-based biosensors for cellular activity detection, such as microelectrode array (MEA) and field effect transistor (FET).  相似文献   

6.
1 Introduction Support vector machine (SVM) is a powerful ma-chine learning tool capable of representing non-linearrelationships and producing models that generalizeswell to unseen data .SVMhave been applied widelyinmany fields[1]such as hand-written character recogni-tion ,text categorization,computer vision,speechrec-ognition and gene classification,etc. Despite this , using an SVM requires a certainamount of model selection,i.e.,selection of the ac-tual kernel and its parameters .In rec…  相似文献   

7.
y Control Based on Genetic Algorithm and Its ApplicationsTX1IntroductionMembershipfunctionisthebasisforfuzzylogictheorytoappli...  相似文献   

8.
To prevent the oxygen starvation and improve the system output performance, an adaptive inverse control (AIC) strategy is developed to regulate the air supply flow of a proton exchange membrane fuel cell (PEMFC) system in this paper.The PEMFC stack and the air supply system including a compressor and a supply manifold are modeled for the purpose of performance analysis and controller design. A recurrent fuzzy neural network (RFNN) is utilized to identify the inverse model of the controlled system and generates a suitable control input during the abrupt step change of external disturbances. Compared with the PI controller, numerical simulations are performed to validate the effectiveness and advantages of the proposed AIC strategy.  相似文献   

9.
With the increase of gray scale and flat panel display (FPD) size, subspace bitwise scanning strategy can be replaced traditional scanning method to cut down frame frequency. However, the direct searching strategy (DSS) becomes unfeasible to obtain corresponding high gray scale scanning matrix. Thus, particle swarm optimization (PSO) is introduced to accelerate searching for high gray scale weights scanning matrix (WSM) with its parallelism and global optimization feature. Finally a WSM of 256 gray scales i...  相似文献   

10.
This paper makes an approach to the approximate optimum in structural design, which combines the global response surface (GRS) based multivariate adaptive regression splines (MARS) with Move-Limit strategy (MLS). MARS is an adaptive regression process, which fits in with the multidimensional problems. It adopts a modified recursive partitioning strategy to simplify high-dimensional problems into smaller highly accurate models. MLS for moving and resizing the search sub-regions is employed in the space of design variables. The quality of the approximation functions and the convergence history of the optimization process are reflected in MLS. The disadvantages of the conventional response surface method (RSM) have been avoided, specifically, highly nonlinear high-dimensional problems. The GRS/MARS with MLS is applied to a high-dimensional test function and an engineering problem to demonstrate its feasibility and convergence, and compared with quadratic response surface (QRS) models in terms of computational efficiency and accuracy.  相似文献   

11.
采用知识工程语言CLIPS研究、开发的电工学智能教学专家系统是基于互联网的新型专家系统。该系统包括学生模型、教师模型、教学模块、诊断模块、测试模块和知识库建设、方法库、试题库、策略库等部分,以最适合学生特点的方式组织教案和教学手段,诊断、纠正学习过程中出现的错误,实现个性化的电工学课程教学。  相似文献   

12.
It is propsed that double level programming technique may be adopted in synthesis strategy ,Optimi-zation of heat exchanger network sturctural configuration (the master problem )may be solved at the upper level ,leaving the rest operaing conditions (the slave problem)being optimized at the lower level ,With the uniqueness in mind,an HEN synthesis expert system may be employed to address both the logical constraints and the global operation parameters‘ optimization using enhanced sequential number optimization theory,Case studies demonstrate that the synthesis strategy proposed can effectively simplify both the problem-solving and the synthesis process,The validity of the strategy recommended is evidenced by case studies‘ results compared.  相似文献   

13.
Control design is important for proton exchange membrane fuel cell (PEMFC) generator. This work researched the anode system ofa 60-kW PEMFC generator. Both anode pressure and humidity must be maintained at ideal levels during steady operation. In view of characteristics and requirements of the system, a hybrid intelligent PID controller is designed specifically based on dynamic simulation. A single neuron PI controller is used for anode humidity by adjusting the water injection to the hydrogen cell. Another incremental PID controller, based on the diagonal recurrent neural network (DRNN) dynamic identification, is used to control anode pressure to be more stable and exact by adjusting the hydrogen flow rate. This control strategy can avoid the coupling problem of the PEMFC and achieve a more adaptive ability. Simulation results showed that the control strategy can maintain both anode humidity and pressure at ideal levels regardless of variable load, nonlinear dynamic and coupling characteristics of the system. This work will give some guides for further control design and applications of the total PEMFC generator.  相似文献   

14.
Voltage source converter high-voltage direct current (VSC-HVDC) is a new power transmission technology pref- erable in small or medium power transmission. In this paper we discuss a new control system based on space vector modulation (SVM) without any voltage line sensors. Using direct power control (DPC) SVM and a new double synchronous reference frame phase-locked loop (DSRF-PLL) approach, the control system is resistant to the majority of line voltage disturbances. Also, the system response has accelerated by using a feed forward power decoupled loop. The operation of this control strategy was verified in a SIMULINK/MATLAB simulation environment. To validate this control system, a 5 kV.A prototype system was constructed. Compared to the original controllers, the current total harmonic distortion (THD), the active and reactive deviations and the DC voltage overshoot were lowered by 2.5%, 6.2% and 8%, respectively. The rectifier power factor in the worst condition was 0.93 and the DC voltage settling time was 0.2 s.  相似文献   

15.
为提高并网直驱永磁风电机组低电压穿越运行能力,提出一种适用于双PWM变换器并网的永磁直驱风电机组低电压穿越运行的电机侧及电网侧变换器协调控制策略。电网电压跌落时,根据输入电网的电磁功率的变化控制电机侧变换器来限制发电机的电磁功率以平衡输入直流侧电容的功率,稳定直流侧电压;根据电网电压跌落深度控制电网侧变换器,提供一定的无功电流,有利于电网电压稳定与恢复,提高风电机组的低电压穿越能力。仿真结果表明,所提控制方案无需硬件装置,能有效实现永磁直驱风电机组的低电压穿越运行。  相似文献   

16.
A new stationary-frame AC current control strategy that can eliminate steady-state errors is discussed and appliedto the control of transverse flux permanent-magnet machine (TFPM). Based on the principle of modulation and demodulation,this AC controller can achieve the same frequency response characteristic as the equivalent DC controller. Validity of the TFPMcontrol system using this current control strategy is confirmed with simulation results.  相似文献   

17.
混合动力客车的控制策略决定整车的性能。分析某混联式混合动力客车的组成结构和基于逻辑控制的控制策略,建立相应的混联式混合动力客车仿真模型及其控制器,通过AVL/CRUISE和MATLAB/Simulink联合仿真分析,获得该车在中国典型城市公交工况下的动力性和百公里油耗。仿真结果表明,各主要部件能按照控制规则实现状态的合理切换,基于逻辑控制的控制策略能满足整车性能指标要求。  相似文献   

18.
This paper investigates the interference cancellation (IC) scheme for uplink cognitive radio systems, using the spectrum underlay strategy where the primary users (PUs) and the secondary users (SUs) coexist and operate in the same spectrum. Joint MMSE-based parallel interference cancellation (PIC) and Turbo decoding scheme is proposed to reduce the interference to the PUs, as well as to the SUs, in which the minimum mean square estimation (MMSE) filter is only employed in the first iteration, regarded as the “weakest link” of the whole detection process, to improve the quality of the preliminary detections results before they are fed to the Turbo decoder. Simulation results show that the proposed scheme can efficiently eliminate the interference to the PUs, as well as to the SUs.  相似文献   

19.
INTRODUCTION The particle swarm optimization (PSO) method is a member of the broad category of swarm intelli- gence techniques for finding optimized solutions. The PSO algorithm is based on the social behavior of animals such as flocking of birds and schooling of fish, etc. PSO has its origin in simulation for visual- izing the synchronized choreography of bird flock by incorporating concepts such as nearest-neighbor ve- locity matching and acceleration by distance (Par- sopoulos and V…  相似文献   

20.
通过分析直接能量平衡在供热机组中的实际应用效果,指出了某300MW机组煤量波动大与协调控制系统调节品质低下的原因;提出了相应的优化策略,并应用于该300MW机组的协调控制系统中,有效根除了优化之前的不良现象,协调控制系统的调节控制品质显著提高,而且使得供热机组的AGC功能正常长期投运.  相似文献   

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