This study develops an Enhanced Threshold Based Energy Detection approach(ETBED)for spectrum sensing in a cognitive radio network.The threshold identification method is implemented in the received signal at the second...This study develops an Enhanced Threshold Based Energy Detection approach(ETBED)for spectrum sensing in a cognitive radio network.The threshold identification method is implemented in the received signal at the secondary user based on the square law.The proposed method is implemented with the signal transmission of multiple outputs-orthogonal frequency division multiplexing.Additionally,the proposed method is considered the dynamic detection threshold adjustments and energy identification spectrum sensing technique in cognitive radio systems.In the dynamic threshold,the signal ratio-based threshold is fixed.The threshold is computed by considering the Modified Black Widow Optimization Algorithm(MBWO).So,the proposed methodology is a combination of dynamic threshold detection and MBWO.The general threshold-based detection technique has different limitations such as the inability optimal signal threshold for determining the presence of the primary user signal.These limitations undermine the sensing accuracy of the energy identification technique.Hence,the ETBED technique is developed to enhance the energy efficiency of cognitive radio networks.The projected approach is executed and analyzed with performance and comparison analysis.The proposed method is contrasted with the conventional techniques of theWhale Optimization Algorithm(WOA)and GreyWolf Optimization(GWO).It indicated superior results,achieving a high average throughput of 2.2 Mbps and an energy efficiency of 3.8,outperforming conventional techniques.展开更多
The optimizationfield has grown tremendously,and new optimization techniques are developed based on statistics and evolutionary procedures.There-fore,it is necessary to identify a suitable optimization technique for a...The optimizationfield has grown tremendously,and new optimization techniques are developed based on statistics and evolutionary procedures.There-fore,it is necessary to identify a suitable optimization technique for a particular application.In this work,Black Widow Optimization(BWO)algorithm is intro-duced to minimize the cost functions in order to optimize the Multi-Area Economic Dispatch(MAED).The BWO is implemented for two different-scale test systems,comprising 16 and 40 units with three and four areas.The performance of BWO is compared with the available optimization techniques in the literature to demonstrate the strategy’s efficacy.Results show that the optimized cost for four areas with 16 units is found to be 7336.76$/h,whereas it is 121,589$/h for four areas with 40 units using BWO.It is also noted that optimization algo-rithms other than BWO require higher cost value.The best-optimized solution for emission is achieved at 9.2784e+06 tones/h,and it is observed that there is a considerable difference between the worst and the best values.Also,the suggested technique is implemented for large-scale test systems successfully with high precision,and rapid convergence occurs in MAED.展开更多
Chinese poetry has exerted a great influence on American modernist poets,especially on William Carlos Williams(1883-1963).William Carlos Williams’The Widow’s Lament in Springtime shares some connections with Chinese...Chinese poetry has exerted a great influence on American modernist poets,especially on William Carlos Williams(1883-1963).William Carlos Williams’The Widow’s Lament in Springtime shares some connections with Chinese Boudoir poems in theme,image,and technique.This paper tends to discuss the influence of Chinese Boudoir poems on William Carlos Williams based on his creating of The Widow’s Lament in Springtime,which provides a new perspective for studying the communication of Chinese and American poetry.展开更多
A distributed generation network could be a hybrid power system that includes wind-diesel power generation based on induction generators(IGs)and synchronous generators(SGs).The main advantage of these systems is the p...A distributed generation network could be a hybrid power system that includes wind-diesel power generation based on induction generators(IGs)and synchronous generators(SGs).The main advantage of these systems is the possibility of using renewable energy in their structures.The most important challenge is to design the voltage-control loop with the frequency-control loop to obtain optimal responses for voltage and frequency deviations.In this work,the voltage-control loop is designed by an automatic voltage regulator.A linear model of the hybrid system has also been developed with coordinated voltage and frequency control.Dynamic frequency response and voltage deviations are compared for different load disturbances and different reactive loads.The gains of the SG and the static volt-ampere reactive compensator(SVC)controllers in the IG terminal are calculated using the Black Widow Optimization(BWO)algorithm to insure low frequency and voltage deviations.The BWO optimization algorithm is one of the newest and most powerful optimization methods to have been introduced so far.The results showed that the BWO algorithm has a good speed in solving the proposed objective function.A 22%improvement in time adjustment was observed in the use of an optimal SVC.Also,an 18%improvement was observed in the transitory values.展开更多
IN 1983, Zhang Jiawang, a farmer in Jingbian County, Shaanxi Province, contracted 10,000 mu of sandy wasteland. He and his family were determined to turn this barren landscape into an oasis of grass and trees. But Zha...IN 1983, Zhang Jiawang, a farmer in Jingbian County, Shaanxi Province, contracted 10,000 mu of sandy wasteland. He and his family were determined to turn this barren landscape into an oasis of grass and trees. But Zhang would never realize this dream; he died of bone cancer four years later. Zhang’s widow, Niu Yuqin, an ordinary country woman, remained determined to carry on with her husband’s work. She named this wasteland "Jiayu Tree Farm," taking the "jia" from her husband’s name and "yu" from her own. With展开更多
文章虽短,文采斐然。标题就新颖,其中的50 Bites就相当于for biting asmany as 50 people.接着,文章的主题句真值得玩昧一番。其中的counting hisdays和本文第四段末尾的to be put to sleep堪称异曲同工。不过后者是专门用 于动物的,put...文章虽短,文采斐然。标题就新颖,其中的50 Bites就相当于for biting asmany as 50 people.接着,文章的主题句真值得玩昧一番。其中的counting hisdays和本文第四段末尾的to be put to sleep堪称异曲同工。不过后者是专门用 于动物的,put to sleep的含义是:(使动物)无痛死亡;人道毁灭。展开更多
文摘This study develops an Enhanced Threshold Based Energy Detection approach(ETBED)for spectrum sensing in a cognitive radio network.The threshold identification method is implemented in the received signal at the secondary user based on the square law.The proposed method is implemented with the signal transmission of multiple outputs-orthogonal frequency division multiplexing.Additionally,the proposed method is considered the dynamic detection threshold adjustments and energy identification spectrum sensing technique in cognitive radio systems.In the dynamic threshold,the signal ratio-based threshold is fixed.The threshold is computed by considering the Modified Black Widow Optimization Algorithm(MBWO).So,the proposed methodology is a combination of dynamic threshold detection and MBWO.The general threshold-based detection technique has different limitations such as the inability optimal signal threshold for determining the presence of the primary user signal.These limitations undermine the sensing accuracy of the energy identification technique.Hence,the ETBED technique is developed to enhance the energy efficiency of cognitive radio networks.The projected approach is executed and analyzed with performance and comparison analysis.The proposed method is contrasted with the conventional techniques of theWhale Optimization Algorithm(WOA)and GreyWolf Optimization(GWO).It indicated superior results,achieving a high average throughput of 2.2 Mbps and an energy efficiency of 3.8,outperforming conventional techniques.
文摘The optimizationfield has grown tremendously,and new optimization techniques are developed based on statistics and evolutionary procedures.There-fore,it is necessary to identify a suitable optimization technique for a particular application.In this work,Black Widow Optimization(BWO)algorithm is intro-duced to minimize the cost functions in order to optimize the Multi-Area Economic Dispatch(MAED).The BWO is implemented for two different-scale test systems,comprising 16 and 40 units with three and four areas.The performance of BWO is compared with the available optimization techniques in the literature to demonstrate the strategy’s efficacy.Results show that the optimized cost for four areas with 16 units is found to be 7336.76$/h,whereas it is 121,589$/h for four areas with 40 units using BWO.It is also noted that optimization algo-rithms other than BWO require higher cost value.The best-optimized solution for emission is achieved at 9.2784e+06 tones/h,and it is observed that there is a considerable difference between the worst and the best values.Also,the suggested technique is implemented for large-scale test systems successfully with high precision,and rapid convergence occurs in MAED.
文摘Chinese poetry has exerted a great influence on American modernist poets,especially on William Carlos Williams(1883-1963).William Carlos Williams’The Widow’s Lament in Springtime shares some connections with Chinese Boudoir poems in theme,image,and technique.This paper tends to discuss the influence of Chinese Boudoir poems on William Carlos Williams based on his creating of The Widow’s Lament in Springtime,which provides a new perspective for studying the communication of Chinese and American poetry.
文摘A distributed generation network could be a hybrid power system that includes wind-diesel power generation based on induction generators(IGs)and synchronous generators(SGs).The main advantage of these systems is the possibility of using renewable energy in their structures.The most important challenge is to design the voltage-control loop with the frequency-control loop to obtain optimal responses for voltage and frequency deviations.In this work,the voltage-control loop is designed by an automatic voltage regulator.A linear model of the hybrid system has also been developed with coordinated voltage and frequency control.Dynamic frequency response and voltage deviations are compared for different load disturbances and different reactive loads.The gains of the SG and the static volt-ampere reactive compensator(SVC)controllers in the IG terminal are calculated using the Black Widow Optimization(BWO)algorithm to insure low frequency and voltage deviations.The BWO optimization algorithm is one of the newest and most powerful optimization methods to have been introduced so far.The results showed that the BWO algorithm has a good speed in solving the proposed objective function.A 22%improvement in time adjustment was observed in the use of an optimal SVC.Also,an 18%improvement was observed in the transitory values.
文摘IN 1983, Zhang Jiawang, a farmer in Jingbian County, Shaanxi Province, contracted 10,000 mu of sandy wasteland. He and his family were determined to turn this barren landscape into an oasis of grass and trees. But Zhang would never realize this dream; he died of bone cancer four years later. Zhang’s widow, Niu Yuqin, an ordinary country woman, remained determined to carry on with her husband’s work. She named this wasteland "Jiayu Tree Farm," taking the "jia" from her husband’s name and "yu" from her own. With
文摘文章虽短,文采斐然。标题就新颖,其中的50 Bites就相当于for biting asmany as 50 people.接着,文章的主题句真值得玩昧一番。其中的counting hisdays和本文第四段末尾的to be put to sleep堪称异曲同工。不过后者是专门用 于动物的,put to sleep的含义是:(使动物)无痛死亡;人道毁灭。
