The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-bas...The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-based BANs is impacted by challenges related to heterogeneous data traffic requirements among nodes, includingcontention during finite backoff periods, association delays, and traffic channel access through clear channelassessment (CCA) algorithms. These challenges lead to increased packet collisions, queuing delays, retransmissions,and the neglect of critical traffic, thereby hindering performance indicators such as throughput, packet deliveryratio, packet drop rate, and packet delay. Therefore, we propose Dynamic Next Backoff Period and Clear ChannelAssessment (DNBP-CCA) schemes to address these issues. The DNBP-CCA schemes leverage a combination ofthe Dynamic Next Backoff Period (DNBP) scheme and the Dynamic Next Clear Channel Assessment (DNCCA)scheme. The DNBP scheme employs a fuzzy Takagi, Sugeno, and Kang (TSK) model’s inference system toquantitatively analyze backoff exponent, channel clearance, collision ratio, and data rate as input parameters. Onthe other hand, the DNCCA scheme dynamically adapts the CCA process based on requested data transmission tothe coordinator, considering input parameters such as buffer status ratio and acknowledgement ratio. As a result,simulations demonstrate that our proposed schemes are better than some existing representative approaches andenhance data transmission, reduce node collisions, improve average throughput, and packet delivery ratio, anddecrease average packet drop rate and packet delay.展开更多
In response to the high cost and difficulty of high-speed development and testing data in offshore oil fields, this paper proposes to use the most easily available production performance data as the basis and use the ...In response to the high cost and difficulty of high-speed development and testing data in offshore oil fields, this paper proposes to use the most easily available production performance data as the basis and use the grey correlation method to calculate the correlation coefficient between oil and water wells to characterize the degree of development of advantageous channels. The consistency between the calculated results of this method and the tracer test results is over 80%. Based on the fitting results, the correlation coefficient exceeds 0.74 to determine the existence of an advantageous channel. According to the research results of grey correlation method, Bohai K oilfield has completed the combined profile control and flooding measures, and the daily oil production has increased by 20 m3</sup>/d. This method is simple, fast, and can achieve quantitative evaluation, which saves time and investment compared to offshore testing. It has strong application and reference value for the development of other offshore water injection oilfields.展开更多
根据现代飞机视情维修模式下机载设备健康评估实时性与可量化的要求,提出了一种基于自动增益控制(Automatic Gain Control,AGC)偏差的机载战术空中导航(Tactical Air Navigation,TACAN)设备接收信道健康评估方法,以解决目前工程实践中机...根据现代飞机视情维修模式下机载设备健康评估实时性与可量化的要求,提出了一种基于自动增益控制(Automatic Gain Control,AGC)偏差的机载战术空中导航(Tactical Air Navigation,TACAN)设备接收信道健康评估方法,以解决目前工程实践中机载TACAN设备机内测试结果无法量化与地面测试开展时机受限的问题。该方法以机载TACAN设备在飞行中记录的设备工作模式、空空或空地测距结果、接收信道AGC衰减值等数据为输入,建立接收信道AGC衰减值偏差、增益损耗与TACAN功能作用距离的计算模型,以及以增益损耗为健康表征参数的接收信道健康度评估模型,并采用实测数据与仿真分析相结合的方式证明了方法的可行性。该方法可用于维护人员在飞行数据离线分析时精准、量化评估机载设备的健康状态,以减少因设备故障导致的停机时间。展开更多
基金Research Supporting Project Number(RSP2024R421),King Saud University,Riyadh,Saudi Arabia。
文摘The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-based BANs is impacted by challenges related to heterogeneous data traffic requirements among nodes, includingcontention during finite backoff periods, association delays, and traffic channel access through clear channelassessment (CCA) algorithms. These challenges lead to increased packet collisions, queuing delays, retransmissions,and the neglect of critical traffic, thereby hindering performance indicators such as throughput, packet deliveryratio, packet drop rate, and packet delay. Therefore, we propose Dynamic Next Backoff Period and Clear ChannelAssessment (DNBP-CCA) schemes to address these issues. The DNBP-CCA schemes leverage a combination ofthe Dynamic Next Backoff Period (DNBP) scheme and the Dynamic Next Clear Channel Assessment (DNCCA)scheme. The DNBP scheme employs a fuzzy Takagi, Sugeno, and Kang (TSK) model’s inference system toquantitatively analyze backoff exponent, channel clearance, collision ratio, and data rate as input parameters. Onthe other hand, the DNCCA scheme dynamically adapts the CCA process based on requested data transmission tothe coordinator, considering input parameters such as buffer status ratio and acknowledgement ratio. As a result,simulations demonstrate that our proposed schemes are better than some existing representative approaches andenhance data transmission, reduce node collisions, improve average throughput, and packet delivery ratio, anddecrease average packet drop rate and packet delay.
文摘In response to the high cost and difficulty of high-speed development and testing data in offshore oil fields, this paper proposes to use the most easily available production performance data as the basis and use the grey correlation method to calculate the correlation coefficient between oil and water wells to characterize the degree of development of advantageous channels. The consistency between the calculated results of this method and the tracer test results is over 80%. Based on the fitting results, the correlation coefficient exceeds 0.74 to determine the existence of an advantageous channel. According to the research results of grey correlation method, Bohai K oilfield has completed the combined profile control and flooding measures, and the daily oil production has increased by 20 m3</sup>/d. This method is simple, fast, and can achieve quantitative evaluation, which saves time and investment compared to offshore testing. It has strong application and reference value for the development of other offshore water injection oilfields.
文摘根据现代飞机视情维修模式下机载设备健康评估实时性与可量化的要求,提出了一种基于自动增益控制(Automatic Gain Control,AGC)偏差的机载战术空中导航(Tactical Air Navigation,TACAN)设备接收信道健康评估方法,以解决目前工程实践中机载TACAN设备机内测试结果无法量化与地面测试开展时机受限的问题。该方法以机载TACAN设备在飞行中记录的设备工作模式、空空或空地测距结果、接收信道AGC衰减值等数据为输入,建立接收信道AGC衰减值偏差、增益损耗与TACAN功能作用距离的计算模型,以及以增益损耗为健康表征参数的接收信道健康度评估模型,并采用实测数据与仿真分析相结合的方式证明了方法的可行性。该方法可用于维护人员在飞行数据离线分析时精准、量化评估机载设备的健康状态,以减少因设备故障导致的停机时间。
