Nowadays desalination is one of the main resources to obtain water in many areas. The most advanced method for water filtration is reverse osmosis. In this system, water is injected into semi-membranes by using power ...Nowadays desalination is one of the main resources to obtain water in many areas. The most advanced method for water filtration is reverse osmosis. In this system, water is injected into semi-membranes by using power pumping, and its salt water is taken away from the solution. This paper has tried to offer guidelines to use the pressure created?in situ?of harvesting water, instead of utilizing power pump, which produces the necessary pressure for the reverse osmosis. These guidelines have been divided into 2 main groups: Using the created natural pressure, and the other way is using the pressures that are caused by the constructions built for harvesting water.展开更多
Dual-image reversible data hiding(RDH)is a technique for hiding important messages.This technology can be used to safely deliver secret mes-sages to the recipient through dual images in an open network without being e...Dual-image reversible data hiding(RDH)is a technique for hiding important messages.This technology can be used to safely deliver secret mes-sages to the recipient through dual images in an open network without being easily noticed.The recipient of the image must receive the two stego-images before the secret message can be completely retrieved.Imperceptibility is one of the main advantages of data hiding technology;to increase the imperceptibility,the quality requirements of the stego-images are relatively important.A dual ste-ganographic image RDH method,called a DS-CF scheme that can achieve a bet-ter steganographic image quality using the center folding(CF)strategy.In this paper,we developed a translocation and switching strategy(TaS)to shorten the distances between the stego-pixel coordinates and the cover pixel coordinates after information being hidden.Compared with the DS-CF scheme,our proposed DS-TaS scheme can effectively improve the quality of the steganographic images at the same level of embedding capability.The experimental results show that the PSNR of our DS-TaS scheme at k=1 was 55.66 dB,which is an increase of 1.5 dB,and is 51.43 dB for k=2,46.66 dB for k=3,and 40.91 dB for k=4.In addition,the PSNR values of the stego images was increased by 1.5,0.29,0.29,and 0.19 dB,respectively.This shows that our proposed dual-image RDH method can optimize the visual quality of the stego-images and is better than many other dual-image RDH techniques.展开更多
The exploration of China's community education development practice is well-aligned progressing,community education for improving the quality of the whole people and promoting social development is of great signif...The exploration of China's community education development practice is well-aligned progressing,community education for improving the quality of the whole people and promoting social development is of great significance.Reverse socialization plays an important role in alleviating intergenerational estrangement,providing new development direction and promoting balanced development of community education.To Promote the development of community education under the effect of reverse socialization,"the younger generations should influence the elder"so as to improve the cognition of community education;Optimize the policy,"new insights transforming the old concepts"so as to act well in community education publicity;At the mean time,the construction of characteristic community education work should be done as well.展开更多
The actual circumstances of daily life are crucial for the purchasing and pricing strategies of supermarkets.Developing strategies based on these circumstances can assist businesses in ensuring profits and fostering w...The actual circumstances of daily life are crucial for the purchasing and pricing strategies of supermarkets.Developing strategies based on these circumstances can assist businesses in ensuring profits and fostering win-win cooperation.This paper explores methods to maximize profit through purchasing and sales strategies.Initially,the relevant data for various categories of vegetables is integrated.Through histograms,their sales patterns are directly understood,highlighting the most popular vegetables.Upon analyzing each vegetable category,it becomes evident that their sales data do not conform to normal distributions.Therefore,Spearman correlation coefficients are calculated,revealing strong correlations between certain categories,such as aquatic roots and edible fungi.A line chart depicting the top ten selling vegetables indicates a noticeable periodicity.Traditional fitting methods struggle to adequately model the sales of each vegetable category and their relationship with cost-plus pricing.To address this,additional factors such as holidays,weeks,and months are incorporated using techniques like random forest regression.This approach yields cost-plus pricing dependence curves that better capture the relationship,while effectively managing noise.Regarding sales volume prediction,the original data displays significant volatility,necessitating the handling of outliers using the threshold method.For missing data,linear interpolation is employed to mitigate the impact of continuous missing values on prediction accuracy.Subsequently,Adam-optimized long short-term memory(LSTM)networks are utilized to forecast incoming quantities for the next seven days.By extrapolating from normal sales volume,market capacity is estimated,allowing for additional sales through discount strategies.This framework has the potential to increase original income by 1.1 times.展开更多
AIM: To offer an up-to-date review of all availabletreatment strategies for patients with synchronous colorectal liver metastases(CLM).METHODS: A comprehensive literature search was performed to identify articles rela...AIM: To offer an up-to-date review of all availabletreatment strategies for patients with synchronous colorectal liver metastases(CLM).METHODS: A comprehensive literature search was performed to identify articles related to the management of patients with synchronous CLM. A search of the electronic databases PubMed, MEDLINE, and Google Scholar was conducted in September 2014.The following search terms were used: synchronous colorectal liver metastases, surgery, stage Ⅳ colorectal cancer, liver-first approach, and up-front hepatectomy.These terms were employed in various combinations to maximize the search. Only articles written in English were included. Particular attention was devoted to studies and review articles that were published within the last six years(2009-2014). Additional searches of the cited references from primary articles were performed to further improve the review. The full texts of all relevant articles were accessed by two independent reviewers.RESULTS: Poor long-term outcomes of patients with synchronous CLM managed by a traditional treatment strategy have led to questions about the timing and sequence of possible therapeutic interventions. Thus,alternative paradigms called reverse strategies have been proposed. Presently, there are four treatment strategies available:(1) primary first approach(or traditional approach) comprises resection of the primary colorectal tumor followed by chemotherapy;subsequent liver resection is performed 3-6 mo after colorectal resection(provided that CLM are still resectable);(2) simultaneous resection of the primary colorectal tumor and CLM during a single operation presents intriguing options for a highly select group of patients, which can be associated with significant postoperative morbidity;(3) liver-first(or chemotherapy-first) approach comprises preoperative chemotherapy(3-6 cycles) followed by liver resection,adjuvant chemotherapy, and resection of the primary colorectal tumor(it is best suited for patients withasymptomatic primary tumors and initially unresectable or marginally resectable CLM); and(4) up-front hepatectomy(or "true" liver-first approach) includes liver resection followed by adjuvant chemotherapy,colorectal resection, and adjuvant chemotherapy(strategy can be offered to patients with asymptomatic primary tumors and initially resectable CLM).CONCLUSION: None of the aforementioned strategies appears inferior. It is necessary to establish individual treatment plans in multidisciplinary team meetings through careful appraisal of all strategies.展开更多
Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave propagation.To obtain high-resolution imaging results,these negative effects must be considered during reverse time migration(...Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave propagation.To obtain high-resolution imaging results,these negative effects must be considered during reverse time migration(RTM).We can easily implement attenuation-compensated RTM using the constant Q viscoacoustic wave equation with decoupled amplitude attenuation and phase dispersion terms.However,the nonphysical amplitude-compensation process will inevitably amplify the high-frequency noise in the wavefield in an exponential form,causing the numerical simulation to become unstable.This is due to the fact that the amplitude of the compensation grows exponentially with frequency.In order to achieve stable attenuation-compensated RTM,we modify the analytic expression of the attenuation compensation extrapolation operator and make it only compensate for amplitude loss within the effective frequency band.Based on this modified analytic formula,we then derive an explicit time-space domain attenuation compensation extrapolation operator.Finally,the implementation procedure of stable attenuation-compensated RTM is presented.In addition to being simple to implement,the newly proposed attenuation-compensated extrapolation operator is superior to the conventional low-pass filter in suppressing random noise,which will further improve the imaging resolution.We use two synthetic and one land seismic datasets to verify the stability and effectiveness of the proposed attenuationcompensated RTM in improving imaging resolution in viscous media.展开更多
Two Gaussian air quality dispersion models, the industrial source complex short-term model (ISCST3) with and without modification have been used to simulate the pollutant concentration distribution in urban areas base...Two Gaussian air quality dispersion models, the industrial source complex short-term model (ISCST3) with and without modification have been used to simulate the pollutant concentration distribution in urban areas based on the meteorological data and the emissions distribution of sulfur dioxide. The verified data show that the modified model is more accurate in the urban area of Shijiazhuang. Using the modified model predictions, the control strategies of sulfur dioxide in the urban area have been studied, and the result show that the second long-term (to 2010) strategy can mitigate air pollution significantly and maintain pollution levels within permissible limits.展开更多
针对传统最大似然波达方向(maximum likelihood direction of arrival,ML-DOA)估计存在计算量大、估计精度差等问题,本文提出一种采用改进帝王蝶优化算法(improved monarch butterfly optimization algorithm,IMBO)的ML-DOA估计方法。I...针对传统最大似然波达方向(maximum likelihood direction of arrival,ML-DOA)估计存在计算量大、估计精度差等问题,本文提出一种采用改进帝王蝶优化算法(improved monarch butterfly optimization algorithm,IMBO)的ML-DOA估计方法。IMBO算法通过精英反向学习策略对初始帝王蝶种群进行优化,得到适应度值较优的初始帝王蝶个体,进而能够改善帝王蝶种群的多样性;引入差分进化算法启发的变异操作以及自适应策略对帝王蝶个体的寻优方式进行改进,扩大了算法的搜索空间;引入了高斯-柯西变异算子,自适应调整变异步长,避免算法陷入局部最优。将IMBO应用于ML-DOA,实验表明,与传统的DOA估计算法相比,在不同信源数目、信噪比以及种群数量下,本文提出的算法收敛性能更好,均方根误差更低,运算量更小。展开更多
文摘Nowadays desalination is one of the main resources to obtain water in many areas. The most advanced method for water filtration is reverse osmosis. In this system, water is injected into semi-membranes by using power pumping, and its salt water is taken away from the solution. This paper has tried to offer guidelines to use the pressure created?in situ?of harvesting water, instead of utilizing power pump, which produces the necessary pressure for the reverse osmosis. These guidelines have been divided into 2 main groups: Using the created natural pressure, and the other way is using the pressures that are caused by the constructions built for harvesting water.
文摘Dual-image reversible data hiding(RDH)is a technique for hiding important messages.This technology can be used to safely deliver secret mes-sages to the recipient through dual images in an open network without being easily noticed.The recipient of the image must receive the two stego-images before the secret message can be completely retrieved.Imperceptibility is one of the main advantages of data hiding technology;to increase the imperceptibility,the quality requirements of the stego-images are relatively important.A dual ste-ganographic image RDH method,called a DS-CF scheme that can achieve a bet-ter steganographic image quality using the center folding(CF)strategy.In this paper,we developed a translocation and switching strategy(TaS)to shorten the distances between the stego-pixel coordinates and the cover pixel coordinates after information being hidden.Compared with the DS-CF scheme,our proposed DS-TaS scheme can effectively improve the quality of the steganographic images at the same level of embedding capability.The experimental results show that the PSNR of our DS-TaS scheme at k=1 was 55.66 dB,which is an increase of 1.5 dB,and is 51.43 dB for k=2,46.66 dB for k=3,and 40.91 dB for k=4.In addition,the PSNR values of the stego images was increased by 1.5,0.29,0.29,and 0.19 dB,respectively.This shows that our proposed dual-image RDH method can optimize the visual quality of the stego-images and is better than many other dual-image RDH techniques.
基金The general subject of the 2020 Guangxi University Students'Ideological and Political Education Theory and Practice Research Project"Research on Psychological Stress Adjustment Strategies for College Students in Southwest Guangxi"(Project No.2020LSZ071)。
文摘The exploration of China's community education development practice is well-aligned progressing,community education for improving the quality of the whole people and promoting social development is of great significance.Reverse socialization plays an important role in alleviating intergenerational estrangement,providing new development direction and promoting balanced development of community education.To Promote the development of community education under the effect of reverse socialization,"the younger generations should influence the elder"so as to improve the cognition of community education;Optimize the policy,"new insights transforming the old concepts"so as to act well in community education publicity;At the mean time,the construction of characteristic community education work should be done as well.
文摘The actual circumstances of daily life are crucial for the purchasing and pricing strategies of supermarkets.Developing strategies based on these circumstances can assist businesses in ensuring profits and fostering win-win cooperation.This paper explores methods to maximize profit through purchasing and sales strategies.Initially,the relevant data for various categories of vegetables is integrated.Through histograms,their sales patterns are directly understood,highlighting the most popular vegetables.Upon analyzing each vegetable category,it becomes evident that their sales data do not conform to normal distributions.Therefore,Spearman correlation coefficients are calculated,revealing strong correlations between certain categories,such as aquatic roots and edible fungi.A line chart depicting the top ten selling vegetables indicates a noticeable periodicity.Traditional fitting methods struggle to adequately model the sales of each vegetable category and their relationship with cost-plus pricing.To address this,additional factors such as holidays,weeks,and months are incorporated using techniques like random forest regression.This approach yields cost-plus pricing dependence curves that better capture the relationship,while effectively managing noise.Regarding sales volume prediction,the original data displays significant volatility,necessitating the handling of outliers using the threshold method.For missing data,linear interpolation is employed to mitigate the impact of continuous missing values on prediction accuracy.Subsequently,Adam-optimized long short-term memory(LSTM)networks are utilized to forecast incoming quantities for the next seven days.By extrapolating from normal sales volume,market capacity is estimated,allowing for additional sales through discount strategies.This framework has the potential to increase original income by 1.1 times.
文摘AIM: To offer an up-to-date review of all availabletreatment strategies for patients with synchronous colorectal liver metastases(CLM).METHODS: A comprehensive literature search was performed to identify articles related to the management of patients with synchronous CLM. A search of the electronic databases PubMed, MEDLINE, and Google Scholar was conducted in September 2014.The following search terms were used: synchronous colorectal liver metastases, surgery, stage Ⅳ colorectal cancer, liver-first approach, and up-front hepatectomy.These terms were employed in various combinations to maximize the search. Only articles written in English were included. Particular attention was devoted to studies and review articles that were published within the last six years(2009-2014). Additional searches of the cited references from primary articles were performed to further improve the review. The full texts of all relevant articles were accessed by two independent reviewers.RESULTS: Poor long-term outcomes of patients with synchronous CLM managed by a traditional treatment strategy have led to questions about the timing and sequence of possible therapeutic interventions. Thus,alternative paradigms called reverse strategies have been proposed. Presently, there are four treatment strategies available:(1) primary first approach(or traditional approach) comprises resection of the primary colorectal tumor followed by chemotherapy;subsequent liver resection is performed 3-6 mo after colorectal resection(provided that CLM are still resectable);(2) simultaneous resection of the primary colorectal tumor and CLM during a single operation presents intriguing options for a highly select group of patients, which can be associated with significant postoperative morbidity;(3) liver-first(or chemotherapy-first) approach comprises preoperative chemotherapy(3-6 cycles) followed by liver resection,adjuvant chemotherapy, and resection of the primary colorectal tumor(it is best suited for patients withasymptomatic primary tumors and initially unresectable or marginally resectable CLM); and(4) up-front hepatectomy(or "true" liver-first approach) includes liver resection followed by adjuvant chemotherapy,colorectal resection, and adjuvant chemotherapy(strategy can be offered to patients with asymptomatic primary tumors and initially resectable CLM).CONCLUSION: None of the aforementioned strategies appears inferior. It is necessary to establish individual treatment plans in multidisciplinary team meetings through careful appraisal of all strategies.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2021QNLM020001)the Major Scientific and Technological Projects of Shandong Energy Group(No.SNKJ2022A06-R23)the Major Scientific and Technological Projects of CNPC(No.ZD2019-183-003).
文摘Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave propagation.To obtain high-resolution imaging results,these negative effects must be considered during reverse time migration(RTM).We can easily implement attenuation-compensated RTM using the constant Q viscoacoustic wave equation with decoupled amplitude attenuation and phase dispersion terms.However,the nonphysical amplitude-compensation process will inevitably amplify the high-frequency noise in the wavefield in an exponential form,causing the numerical simulation to become unstable.This is due to the fact that the amplitude of the compensation grows exponentially with frequency.In order to achieve stable attenuation-compensated RTM,we modify the analytic expression of the attenuation compensation extrapolation operator and make it only compensate for amplitude loss within the effective frequency band.Based on this modified analytic formula,we then derive an explicit time-space domain attenuation compensation extrapolation operator.Finally,the implementation procedure of stable attenuation-compensated RTM is presented.In addition to being simple to implement,the newly proposed attenuation-compensated extrapolation operator is superior to the conventional low-pass filter in suppressing random noise,which will further improve the imaging resolution.We use two synthetic and one land seismic datasets to verify the stability and effectiveness of the proposed attenuationcompensated RTM in improving imaging resolution in viscous media.
文摘Two Gaussian air quality dispersion models, the industrial source complex short-term model (ISCST3) with and without modification have been used to simulate the pollutant concentration distribution in urban areas based on the meteorological data and the emissions distribution of sulfur dioxide. The verified data show that the modified model is more accurate in the urban area of Shijiazhuang. Using the modified model predictions, the control strategies of sulfur dioxide in the urban area have been studied, and the result show that the second long-term (to 2010) strategy can mitigate air pollution significantly and maintain pollution levels within permissible limits.
文摘针对传统最大似然波达方向(maximum likelihood direction of arrival,ML-DOA)估计存在计算量大、估计精度差等问题,本文提出一种采用改进帝王蝶优化算法(improved monarch butterfly optimization algorithm,IMBO)的ML-DOA估计方法。IMBO算法通过精英反向学习策略对初始帝王蝶种群进行优化,得到适应度值较优的初始帝王蝶个体,进而能够改善帝王蝶种群的多样性;引入差分进化算法启发的变异操作以及自适应策略对帝王蝶个体的寻优方式进行改进,扩大了算法的搜索空间;引入了高斯-柯西变异算子,自适应调整变异步长,避免算法陷入局部最优。将IMBO应用于ML-DOA,实验表明,与传统的DOA估计算法相比,在不同信源数目、信噪比以及种群数量下,本文提出的算法收敛性能更好,均方根误差更低,运算量更小。