A definition of self-determined priority is used in airfight decision firstly. A scheme of grouping the whole fighters is introduced, and the principle of target assignment and fire control is designed. Based on the ...A definition of self-determined priority is used in airfight decision firstly. A scheme of grouping the whole fighters is introduced, and the principle of target assignment and fire control is designed. Based on the neutral network, the decision algorithm is derived and the whole coordinated decision system is simulated. Secondly an algorithm for missile-attacking area is described and its calculational result is obtained under initial conditions. Then the attacking of missile is realized by the proportion guidance. Finally, a multi-target attack system. The system includes airfight decision, estimation of missile attack area and calculation of missile attack procedure. A digital simulation demonstrates that the airfight decision algorithm is correct. The methods have important reference values for the study of fire control system of the fourth generation fighter.展开更多
In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and reso...In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and resource allocation while establishing a realistic scenario of three-tier heterogeneous network architecture. The scheme consists of two stages: in stage I, a two-level sub-channel allocation algorithm and a power control method based on the logarithmic function are applied to allocate resource for Macrocell and Picocells, guaranteeing the minimum system capacity by considering the power limitation and interference coordination; in stage II, an interference management approach based on K-means clustering is introduced to divide Femtocells into different clusters. Then, a prior sub-channel allocation algorithm is employed for Femtocells in diverse clusters to mitigate the interference and promote system performance. Simulation results show that the proposed scheme contributes to the enhancement of system throughput and spectrum efficiency while ensuring the system energy efficiency.展开更多
Wireless Body Area Networks(WBANs) are expected to achieve high reliable communications among a large number of sensors.The outage probability can be used to measure the reliability of the WBAN.In this paper,we optimi...Wireless Body Area Networks(WBANs) are expected to achieve high reliable communications among a large number of sensors.The outage probability can be used to measure the reliability of the WBAN.In this paper,we optimize the outage probability with the harvested energy as constraints.Firstly,the optimal transmit power of the sensor is obtained while considering a single link between an access point(AP) located on the waist and a sensor attached on the wrist over the Rayleigh fading channel.Secondly,an optimization problem is formed to minimize the outage probability.Finally,we convert the non-convex optimization problem into convex solved by the Lagrange multiplier method.Simulations show that the optimization problem is solvable.The outage probability is optimized by performing power allocation at the sensor.And our proposed algorithm achieves minimizing the outage probability when the sensor uses energy harvesting.We also demonstrate that the average outage probability is reduced with the increase of the harvested energy.展开更多
Some unsafe languages,like C and C++,let programmers maximize performance but are vulnerable to memory errors which can lead to program crashes and unpredictable behavior.Aiming to solve the problem,traditional memory...Some unsafe languages,like C and C++,let programmers maximize performance but are vulnerable to memory errors which can lead to program crashes and unpredictable behavior.Aiming to solve the problem,traditional memory allocating strategy is improved and a new probabilistic memory allocation technology is presented.By combining random memory allocating algorithm and virtual memory,memory errors are avoided in all probability during software executing.By replacing default memory allocator to manage allocation of heap memory,buffer overflows and dangling pointers are prevented.Experiments show it is better than Diehard of the following aspects:memory errors prevention,performance in memory allocation set and ability of controlling working set.So probabilistic memory allocation is a valid memory errors prevention technology and it can tolerate memory errors and provide probabilistic memory safety effectively.展开更多
As a result of the recently increasing demands on high-performance aero-engine,the machining accuracy of blade profile is becoming more stringent. However,in the current profile,precision milling,grinding or near-nets...As a result of the recently increasing demands on high-performance aero-engine,the machining accuracy of blade profile is becoming more stringent. However,in the current profile,precision milling,grinding or near-netshape technology has to undergo a tedious iterative error compensation. Thus,if the profile error area and boundary can be determined automatically and quickly,it will help to improve the efficiency of subsequent re-machining correction process. To this end,an error boundary intersection approach is presented aiming at the error area determination of complex profile,including the phaseⅠof cross sectional non-rigid registration based on the minimum error area and the phaseⅡof boundary identification based on triangular meshes intersection. Some practical cases are given to demonstrate the effectiveness and superiority of the proposed approach.展开更多
Objective Basic science studies demonstrated a general intramyocardial angiogenetic response potentially responsible for the creation of a microvascular neocapillaries network assisting myocardial function. We hypothe...Objective Basic science studies demonstrated a general intramyocardial angiogenetic response potentially responsible for the creation of a microvascular neocapillaries network assisting myocardial function. We hypothesized that the benefit provided by the reperfusion of left anterior descending （LAD） territories and the biological angiogenetic drive triggered by the revascularization could translate in a global improvement in ventricular contractility, not restricted to the grafted area. Methods High-risk patients with multivessel coronary artery disease and preoperative wall motion abnormalities were retrospectively analyzed to compare outcomes and regional ventricular function of those who received optimal medical therapy （OMT） versus those who underwent off-pump coronary artery bypass grafting （OPCABG） and received an incomplete myocardial revascularization using left internal mammary artery （LIMA） on LAD （OPCABG group）. From January 2007 to December 2014, 206 patients （OMT, n = 136, OPCABG, n = 70） were propensity-score matched to have 70 matched pairs. Variables included in propensity score analyses were ejection fraction （EF）, left ventricular end diastolic volume （LVEDVi）, EuroSCORE II. Primary endpoint was the variation in the global wall motion score index （AWMSI） as evaluated by transthoracic echocardiography. Follow up was completed at 3 years from surgery or hospital discharge. Results Regional analysis of ventricular function revealed a regional WMSI improvement in the OPCABG group not only for LAD territories but also for non-LAD regions, associated with a reduction in the negative left ventricular ischemic remodeling, compared to patients discharged in optimal medical therapy. Global AWMSI was negative in OPCABG group （-3.4 ± 2.8%） and positive in the OMT group （5.9 ± 3.1%）, indicating a better wall motion score for OPCAB patients. Surprisingly, regional WMSI improved also in non-grafted territories in the off-pump CABG group with a delta value of -3.7 ± 5.3% for left circumflex artery （LCX） area and -3.5 ± 5.4% for right coronary artery （RCA） area. Conclusions In patients with multivessel coronary artery disease, LIMA-to-LAD grafting is associated with an improvement in the WMSI involving also the surrounding non-LAD ungrafted segments and with the attenuation of negative global and regional ischemic ventricular remodeling.展开更多
When gob-side entry retaining is implemented in deep coal seams threatened by rockburst, the cementbased supporting body beside roadway will bear greater roof pressure and strong impact load. Then the supporting body ...When gob-side entry retaining is implemented in deep coal seams threatened by rockburst, the cementbased supporting body beside roadway will bear greater roof pressure and strong impact load. Then the supporting body may easily deform and fail because of its low strength in the early stage. This paper established the roadside support mechanical model of gob-side entry retaining. Based on this model,we proposed and used the soft–strong supporting body as roadside support in the gob-side entry retaining. In the early stage of roof movement, the soft–strong supporting body has a better compressibility, which can not only relieve roof pressure and strong impact load, but also reduce the supporting resistance and prevent the supporting body from being crushed. In the later stage, with the increase of the strength of the supporting body, it can better support the overlying roof. The numerical simulation results and industrial test show that the soft–strong supporting body as roadside support can be better applied into the gob-side entry retaining in deep coal seams threatened by rockburst.展开更多
The interval graph completion problem of a graph G includes two class problems： the profile problem and the pathwidth problem, denoted as P（G） and PW（G） respectively, where the profile problem is to find an inter...The interval graph completion problem of a graph G includes two class problems： the profile problem and the pathwidth problem, denoted as P（G） and PW（G） respectively, where the profile problem is to find an interval supergraph with the smallest possible number of edges; the pathwidth problem is to find an interval supergraph with the smallest possible cliquesize. These two class problems have important applications to numerical algebra, VLSI- layout and algorithm graph theory respectively; And they are known to be NP-complete for general graphs. Some classes of special graphs have been investigated in the literatures. In this paper the exact solutions of the profile and the pathwidth of the complete multipartite graph Kn1,n2,...nr （r≥ 2） are determined.展开更多
文摘A definition of self-determined priority is used in airfight decision firstly. A scheme of grouping the whole fighters is introduced, and the principle of target assignment and fire control is designed. Based on the neutral network, the decision algorithm is derived and the whole coordinated decision system is simulated. Secondly an algorithm for missile-attacking area is described and its calculational result is obtained under initial conditions. Then the attacking of missile is realized by the proportion guidance. Finally, a multi-target attack system. The system includes airfight decision, estimation of missile attack area and calculation of missile attack procedure. A digital simulation demonstrates that the airfight decision algorithm is correct. The methods have important reference values for the study of fire control system of the fourth generation fighter.
基金partially supported by the Major Project of National Science and Technology of China under Grants No. 2016ZX03002010003 and No. 2015ZX03001033-002
文摘In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and resource allocation while establishing a realistic scenario of three-tier heterogeneous network architecture. The scheme consists of two stages: in stage I, a two-level sub-channel allocation algorithm and a power control method based on the logarithmic function are applied to allocate resource for Macrocell and Picocells, guaranteeing the minimum system capacity by considering the power limitation and interference coordination; in stage II, an interference management approach based on K-means clustering is introduced to divide Femtocells into different clusters. Then, a prior sub-channel allocation algorithm is employed for Femtocells in diverse clusters to mitigate the interference and promote system performance. Simulation results show that the proposed scheme contributes to the enhancement of system throughput and spectrum efficiency while ensuring the system energy efficiency.
文摘Wireless Body Area Networks(WBANs) are expected to achieve high reliable communications among a large number of sensors.The outage probability can be used to measure the reliability of the WBAN.In this paper,we optimize the outage probability with the harvested energy as constraints.Firstly,the optimal transmit power of the sensor is obtained while considering a single link between an access point(AP) located on the waist and a sensor attached on the wrist over the Rayleigh fading channel.Secondly,an optimization problem is formed to minimize the outage probability.Finally,we convert the non-convex optimization problem into convex solved by the Lagrange multiplier method.Simulations show that the optimization problem is solvable.The outage probability is optimized by performing power allocation at the sensor.And our proposed algorithm achieves minimizing the outage probability when the sensor uses energy harvesting.We also demonstrate that the average outage probability is reduced with the increase of the harvested energy.
基金supported by the Natural Science Foundation of China under Grant No.61100205the National High-Tech Research and Development Plan of China under Grant No.2009AA01Z433the Project of the Fundamental Research Funds of Beijing Institute of Technology
文摘Some unsafe languages,like C and C++,let programmers maximize performance but are vulnerable to memory errors which can lead to program crashes and unpredictable behavior.Aiming to solve the problem,traditional memory allocating strategy is improved and a new probabilistic memory allocation technology is presented.By combining random memory allocating algorithm and virtual memory,memory errors are avoided in all probability during software executing.By replacing default memory allocator to manage allocation of heap memory,buffer overflows and dangling pointers are prevented.Experiments show it is better than Diehard of the following aspects:memory errors prevention,performance in memory allocation set and ability of controlling working set.So probabilistic memory allocation is a valid memory errors prevention technology and it can tolerate memory errors and provide probabilistic memory safety effectively.
基金supported by the Aeronautical Science Foundation of China (No.20200016112001)。
文摘As a result of the recently increasing demands on high-performance aero-engine,the machining accuracy of blade profile is becoming more stringent. However,in the current profile,precision milling,grinding or near-netshape technology has to undergo a tedious iterative error compensation. Thus,if the profile error area and boundary can be determined automatically and quickly,it will help to improve the efficiency of subsequent re-machining correction process. To this end,an error boundary intersection approach is presented aiming at the error area determination of complex profile,including the phaseⅠof cross sectional non-rigid registration based on the minimum error area and the phaseⅡof boundary identification based on triangular meshes intersection. Some practical cases are given to demonstrate the effectiveness and superiority of the proposed approach.
文摘Objective Basic science studies demonstrated a general intramyocardial angiogenetic response potentially responsible for the creation of a microvascular neocapillaries network assisting myocardial function. We hypothesized that the benefit provided by the reperfusion of left anterior descending （LAD） territories and the biological angiogenetic drive triggered by the revascularization could translate in a global improvement in ventricular contractility, not restricted to the grafted area. Methods High-risk patients with multivessel coronary artery disease and preoperative wall motion abnormalities were retrospectively analyzed to compare outcomes and regional ventricular function of those who received optimal medical therapy （OMT） versus those who underwent off-pump coronary artery bypass grafting （OPCABG） and received an incomplete myocardial revascularization using left internal mammary artery （LIMA） on LAD （OPCABG group）. From January 2007 to December 2014, 206 patients （OMT, n = 136, OPCABG, n = 70） were propensity-score matched to have 70 matched pairs. Variables included in propensity score analyses were ejection fraction （EF）, left ventricular end diastolic volume （LVEDVi）, EuroSCORE II. Primary endpoint was the variation in the global wall motion score index （AWMSI） as evaluated by transthoracic echocardiography. Follow up was completed at 3 years from surgery or hospital discharge. Results Regional analysis of ventricular function revealed a regional WMSI improvement in the OPCABG group not only for LAD territories but also for non-LAD regions, associated with a reduction in the negative left ventricular ischemic remodeling, compared to patients discharged in optimal medical therapy. Global AWMSI was negative in OPCABG group （-3.4 ± 2.8%） and positive in the OMT group （5.9 ± 3.1%）, indicating a better wall motion score for OPCAB patients. Surprisingly, regional WMSI improved also in non-grafted territories in the off-pump CABG group with a delta value of -3.7 ± 5.3% for left circumflex artery （LCX） area and -3.5 ± 5.4% for right coronary artery （RCA） area. Conclusions In patients with multivessel coronary artery disease, LIMA-to-LAD grafting is associated with an improvement in the WMSI involving also the surrounding non-LAD ungrafted segments and with the attenuation of negative global and regional ischemic ventricular remodeling.
基金supported by the National Basic Research Program of China (No. 2010CB226805)the Taishan Scholar Construction Project of Shandong Province, China+3 种基金the National Natural Science Foundation of China (No. 51344009)the Research Award Fund for Outstanding Young Scientists of Shandong Province (No. BS2012NJ007)the Ground Pressure and Strata Control Innovative Team Fund of SDUST (No. 2010KYTD105)the Natural Science Foundation of Shandong Province (No. ZR2012EEZ002)
文摘When gob-side entry retaining is implemented in deep coal seams threatened by rockburst, the cementbased supporting body beside roadway will bear greater roof pressure and strong impact load. Then the supporting body may easily deform and fail because of its low strength in the early stage. This paper established the roadside support mechanical model of gob-side entry retaining. Based on this model,we proposed and used the soft–strong supporting body as roadside support in the gob-side entry retaining. In the early stage of roof movement, the soft–strong supporting body has a better compressibility, which can not only relieve roof pressure and strong impact load, but also reduce the supporting resistance and prevent the supporting body from being crushed. In the later stage, with the increase of the strength of the supporting body, it can better support the overlying roof. The numerical simulation results and industrial test show that the soft–strong supporting body as roadside support can be better applied into the gob-side entry retaining in deep coal seams threatened by rockburst.
基金Supported by the Natural Science Foundation of Henan Province（082300460190） Sponsored by Program for Science and Technology Innovation Talents in Universities of Henan Province.
文摘The interval graph completion problem of a graph G includes two class problems： the profile problem and the pathwidth problem, denoted as P（G） and PW（G） respectively, where the profile problem is to find an interval supergraph with the smallest possible number of edges; the pathwidth problem is to find an interval supergraph with the smallest possible cliquesize. These two class problems have important applications to numerical algebra, VLSI- layout and algorithm graph theory respectively; And they are known to be NP-complete for general graphs. Some classes of special graphs have been investigated in the literatures. In this paper the exact solutions of the profile and the pathwidth of the complete multipartite graph Kn1,n2,...nr （r≥ 2） are determined.
