Generally speaking, being an efficient information hiding scheme, what we want to achieve is high embedding capacity of the cover image and high visual quality of the stego image, high visual quality is also called em...Generally speaking, being an efficient information hiding scheme, what we want to achieve is high embedding capacity of the cover image and high visual quality of the stego image, high visual quality is also called embedding efficiency. This paper mainly studies on the information hiding technology based on gray-scale digital images and especially considers the improvement of embedding capacity and embedding efficiency. For the purpose of that, two algorithms for information hiding were proposed, one is called high capacity of information hiding algorithm (HCIH for short), which achieves high embedding rate, and the other is called high quality of information hiding algorithm (HQIH for short), which realizes high embedding efficiency. The simulation experiments show that our proposed algorithms achieve better performance.展开更多
Relative carrying capacity of resources is an index to measure sustainable development through carrying capacity. Case studies of eleven cities in Zhejiang (Hangzhou, Ningbo, Wenzhou, Jiaxing, Huzhou, Shaoxing, Jinhua...Relative carrying capacity of resources is an index to measure sustainable development through carrying capacity. Case studies of eleven cities in Zhejiang (Hangzhou, Ningbo, Wenzhou, Jiaxing, Huzhou, Shaoxing, Jinhua, Quzhou, Zhoushan, Taizhou and Lishui) illustrated regional sustainable development approach. In this study, to provide insight into spatial and dynamic analysis of region sustainable development, we calculated the relative carrying capacity of land resources and economical resources and synthetical carrying capacity of resources in different cities in Zhejiang, and geographic information system was carried out. The results showed that all cities but Hangzhou and Ningbo were ecologically sustainable, and relative carrying capacity of land resources in northern and eastern Zhejiang was larger than those in southern and western Zhejiang. The sampling years of Wenzhou, Hangzhou and Ningbo contribution rates of land resource to synthetic carrying capacity were grouped into three stages, and there were two milestones trends and changes in 1996 and 2004, respectively. This study demonstrated that geographic information system and relative carrying capacity of resources are effective for assessment of region sustainable development, and provide policy guidelines for decision-making.展开更多
Ambient light display presents peripheral information unobtrusively,and it can be context aware and aesthetically enhance specific environment.However,since the abstract characteristic of light,people should attentive...Ambient light display presents peripheral information unobtrusively,and it can be context aware and aesthetically enhance specific environment.However,since the abstract characteristic of light,people should attentively keep agood balance between unobtrusiveness and effectiveness,when designing an ambient light display.Especially,in the condition of high information capacity,ambient light display need a mechanism to portray information effectively.In this paper,a framework with an overlay mechanism is evaluated for high information capacity.Based on the framework,two ambient light displays are designed to support the evaluation work.The evaluation questions are related with three aspects including information understanding,transition and encoding,special output channel.From the perception level,interpretation level and experience level,the process of evaluation is implemented.The results indicate that the framework with the overlay mechanism can effectively support varied and specific communicating information.The transitions and information encoding benefit from the proper mapping of states and notification levels in the framework.展开更多
In past years,growing efforts have been made to the rapid interpretation of magnetic field data acquired by a sparse synthetic or real magnetic sensor array.An appealing requirement on such sparse array arranged withi...In past years,growing efforts have been made to the rapid interpretation of magnetic field data acquired by a sparse synthetic or real magnetic sensor array.An appealing requirement on such sparse array arranged within a specified survey region is that to make the number of sensor elements as small as possible,meanwhile without deteriorating imaging quality.For this end,we propose a novel methodology of arranging sensors in an optimal manner,exploring the concept of information capacity developed originally in the communication society.The proposed scheme reduces mathematically the design of a sparse sensor array into solving a combinatorial optimization problem,which can be resolved efficiently using widely adopted Simultaneous Perturbation and Statistical Algorithm(SPSA).Three sets of numerical examples of designing optimal sensor array are provided to demonstrate the performance of proposed methodology.展开更多
Recent experimental and theoretical studies show that energy efficiency, which measures the amount of infor- mation processed by a neuron with per unit of energy consumption, plays an important role in the evolution o...Recent experimental and theoretical studies show that energy efficiency, which measures the amount of infor- mation processed by a neuron with per unit of energy consumption, plays an important role in the evolution of neural systems. Here we calculate the information rates and energy efficieneies of the Hodgkin-Huxley (HH) neuron model at different temperatures in a noisy environment. It is found that both the information rate and energy efficiency are maximized by certain temperatures. Though the information rate and energy efficiency cannot be maximized simultaneously, the neuron holds a high information processing capacity at the tempera- ture corresponding to the maximal energy efficiency. Our results support the idea that the energy efficiency is a selective pressure that influences the evolution of nervous systems.展开更多
Wireless statistic division multiplexing (WSDM) is a multiplexing scheme that transmits multiple signals simultaneously in the same frequency band over wireless channels. Based on the Shannon capacity of band-limited ...Wireless statistic division multiplexing (WSDM) is a multiplexing scheme that transmits multiple signals simultaneously in the same frequency band over wireless channels. Based on the Shannon capacity of band-limited waveform AWGN channel with input power constraint, we obtain channel capacity of WSDM. Compared to time division multiplexing (TDM), frequency division multiplexing (FDM), and code division multiplexing (CDM), WSDM is more effective in raising spectrum efficiency. What’s more, we propose information optimization method to separate time-frequency mixed signals. Computer simulations also verify that the proposed method is feasible and performs better than traditional algorithms.展开更多
Beyond-5G(B5G)aims to meet the growing demands of mobile traffic and expand the communication space.Considering that intelligent applications to B5G wireless communications will involve security issues regarding user ...Beyond-5G(B5G)aims to meet the growing demands of mobile traffic and expand the communication space.Considering that intelligent applications to B5G wireless communications will involve security issues regarding user data and operational data,this paper analyzes the maximum capacity of the multi-watermarking method for multimedia signal hiding as a means of alleviating the information security problem of B5G.The multiwatermarking process employs spread transform dither modulation.During the watermarking procedure,Gram-Schmidt orthogonalization is used to obtain the multiple spreading vectors.Consequently,multiple watermarks can be simultaneously embedded into the same position of a multimedia signal.Moreover,the multiple watermarks can be extracted without affecting one another during the extraction process.We analyze the effect of the size of the spreading vector on the unit maximum capacity,and consequently derive the theoretical relationship between the size of the spreading vector and the unit maximum capacity.A number of experiments are conducted to determine the optimal parameter values for maximum robustness on the premise of high capacity and good imperceptibility.展开更多
In order to investigate the impact of channel model parameters on the channel capacity of a multipleinput multiple-output (MIMO) system, a novel method is proposed to explore the channel capacity under Rayleigh fiat...In order to investigate the impact of channel model parameters on the channel capacity of a multipleinput multiple-output (MIMO) system, a novel method is proposed to explore the channel capacity under Rayleigh fiat fading with correlated transmit and receive antennas. The optimal transmitting direction which can achieve maximum channel capacity is derived using random matrices theory. In addition, the closed-form expression for the channel capacity of MIMO systems is given by utilizing the properties of Wishart distribution when SNR is high. Computer simulation results show that the channel capacity is maximized when the antenna spacing increases to a certain point, and furthermore, the larger the scattering angle is, the more quickly the channel capacity converges to its maximum. At high SNR (〉12 dB), the estimation of capacity is close to its true wlue. And, when the same array configuration is adopted both at the transmitter and the receiver, the UCA yields higher channel capacity than ULA.展开更多
In the governing thought, I find an equivalence between the classical information in a quantum system and the integral of that system’s energy and time, specifically , in natural units. I solve this relationship in f...In the governing thought, I find an equivalence between the classical information in a quantum system and the integral of that system’s energy and time, specifically , in natural units. I solve this relationship in four ways: the first approach starts with the Schrodinger Equation and applies the Minkowski transformation;the second uses the Canonical commutation relation;the third through Gabor’s analysis of the time-frequency plane and Heisenberg’s uncertainty principle;and lastly by quantizing Brownian motion within the Bernoulli process and applying the Gaussian channel capacity. In support I give two examples of quantum systems that follow the governing thought: namely the Gaussian wave packet and the electron spin. I conclude with comments on the discretization of space and the information content of a degree of freedom.展开更多
This paper reports on investigations into capacity of ad hoc network whose nodes are equipped with multiple element antennas (MEAs). The investigation of this multi-user Multiple Input Multiple Output (MIMO) system ta...This paper reports on investigations into capacity of ad hoc network whose nodes are equipped with multiple element antennas (MEAs). The investigation of this multi-user Multiple Input Multiple Output (MIMO) system takes into account mutual coupling (MC) in addition to spatial correlation that is present in array antennas. A closed-form expression for an upper bound of mutual information (capacity) of MIMO ad hoc network is derived. An optimal signal transmission scheme is proposed to maximize the MIMO ad hoc network capacity. Simulation results for capacity of non-optimized and optimized cases of signal transmission are presented.展开更多
An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast populat...An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast population growth and continuous development in constructions such as residential complexes, hotels, bridges and shopping malls. Soil investigation data for An-Najaf Province (An-Najaf and Kufa cities) from 464 boreholes drilled by the Na-tional Centre for Construction Laboratories & Researches (NCCLR)/Babylon laboratory were used in this research. The data were analysed and possessed using Excel program then represented on the Geographical Information System (GIS) program by Inverse Distance Weighted (IDW) tool to create an allowable bearing capacity map for the soil at depths 0 - 2 meters. The allowable bearing capacity is one of the most important soil characteristics to be considered when making a database for An-Najaf city soil. Geographical Information System GIS program enables to create reliable database for any characteristic and it is one of the best programs to produce an accurate map and allow ease in dealing with it. Those maps cover all the studied areas and by using contour lines, approximate values for no-data areas can be obtained. The results show that the allowable bearing capacity range is 5 - 20 Ton/m2 for both An-Najaf and Kufa cities. Kufa city has the range 5 - 9 Ton/m2. An-Najaf city has the range 7 - 18 at the center, 8 - 10 Ton/m2 at the north eastern part, 7 - 14 Ton/m2 for the north western part, 6 - 12 Ton/m2 at the south eastern and 12 - 19 Ton/m2 at the south western.展开更多
We investigate the sum capacity of Block Diagonalization precoding Multiple Input Mul-tiple Output Broadcast Channels(BD MIMO BC) with imperfect Channel State Information(CSI) at the base station.Since it is difficult...We investigate the sum capacity of Block Diagonalization precoding Multiple Input Mul-tiple Output Broadcast Channels(BD MIMO BC) with imperfect Channel State Information(CSI) at the base station.Since it is difficult to obtain the exact expression,a lower and an upper bounds of the sum capacity under Gaussian channel estimation errors are drived instead.Analyses show that the gap between two bounds is considerably tight at all Signal to Noise Ratio(SNR) region.From the lower bound of the sum capacity,we can see that the multiplexing gain tends to be zero at high SNR region,which indicates that the BD MIMO BC system with channel estimation errors is interference-limited at high SNR.展开更多
This study addresses the pressing need to assess foundation bearing capacity in Opolo,Yenagoa,Bayelsa State,Nigeria.The significance lies in the dearth of comprehensive geotechnical data for construction planning in t...This study addresses the pressing need to assess foundation bearing capacity in Opolo,Yenagoa,Bayelsa State,Nigeria.The significance lies in the dearth of comprehensive geotechnical data for construction planning in the region.Past research is limited and this study contributes valuable insights by integrating Geographic Information System(GIS)with the Generalized Reciprocal Method(GRM).To collect data,near-surface seismic refraction surveys were conducted along three designated lines,utilizing ABEM Terraloc Mark 6 equipment,Easy Refract,and ArcGIS 10.4.1 software.This methodology allowed for the determination of key geotechnical parameters essential for soil characterization at potential foundation sites.The results revealed three distinct geoseismic layers.The uppermost layer,within a depth of 0.89 to 1.50 meters,exhibited inadequate compressional and shear wave velocities and low values for oedometric modulus,shear modulus,N-value,ultimate bearing capacity,and allowable bearing capacity.This indicates the presence of unsuitable,soft,and weak alluvial deposits for substantial structural loads.In contrast,the second layer(1.52 to 3.84 m depth)displayed favorable geotechnical parameters,making it suitable for various construction loads.The third layer(15.00 to 26.05 m depth)exhibited varying characteristics.The GIS analysis highlighted the unsuitability of the uppermost layer for construction,while the second and third layers were found to be fairly competent and suitable for shallow footing and foundation design.In summary,this study highlights the importance of geotechnical surveys in Opolo’s construction planning.It offers vital information for informed choices,addresses issues in the initial layer,and suggests secure,sustainable construction options.展开更多
In this paper,we explore the capacity during the process of a firm's information system adoption and implementation from knowledge management perspective,based on a firm's level construct. According to the dim...In this paper,we explore the capacity during the process of a firm's information system adoption and implementation from knowledge management perspective,based on a firm's level construct. According to the dimensions of absorptive capacity proposed by Zahra and George,we point out that the concept of IS absorptive capacity,analyze and summarize the elements of potential absorptive capacity and realized absorptive capacity. We use data from two manufacturing organizations,analyze two firm's realities of IS absorptive capacity. The study indicates differing antecedents may have differing effects on potential absorptive capacity and realized absorptive capacity.展开更多
In order to examine the problem of how to improve the use of information technology (IT) in enterprises, this paper makes an exploration from the perspective of organizational absorptive capacity. We propose the con...In order to examine the problem of how to improve the use of information technology (IT) in enterprises, this paper makes an exploration from the perspective of organizational absorptive capacity. We propose the concept of IT absorptive capacity from an organizational level. A dynamic process model is developed to further analyze IT absorption. IT absorptive capacity of this process is embodied as six forms: identification, adoption, adaptation, acceptance, infusion, and knowledge management. By means of questionnaire surveys of 76 Chinese enterprises, the main factors that favor or disable the capacity of each stage are discovered. Using the method of system dynamics, a conceptual model of IT absorptive capacity is developed to analyze the action mechanism of the factors in detail. The model indicates that the critical factors are embodied in the aspect of management. Furthermore, it demonstrates that IT absorption is a spiral process, during which IT absorptive capacity evolves dynamically and, consequently, promotes IT use.展开更多
Today businesses are facing radical transformations through digitalization of services and products.Accordingly,their ability to innovate is increasingly linked to the capacity to innovate through information and comm...Today businesses are facing radical transformations through digitalization of services and products.Accordingly,their ability to innovate is increasingly linked to the capacity to innovate through information and communication technologies(ICTs).This article investigates the role of information systems(IS)as a key factor for innovation capacity.To this end,the article discusses an interpretive framework for understanding the degree of capacity of innovation through information systems(IS)reached by a given company and the contradictions that bound its evolution.An interpretive study is also presented,where the framework has been applied to seven French companies from various industries.Consistently with the framework,the interviews address process areas and practices related to three core categories:management,innovation engineering and support.The study reveals seven fundamental contradictions that can explain the main tendencies observed across the companies.展开更多
This paper studies the important problem of how to coordinate the capacity procurement model with asymmetric demand information.Under the model,the supplier has to secure necessary capacity before receiving a firm ord...This paper studies the important problem of how to coordinate the capacity procurement model with asymmetric demand information.Under the model,the supplier has to secure necessary capacity before receiving a firm order from the manufacturer who possesses private demand information for her product.Optimal supply chain performance requires the manufacturer to share her forecast truthfully and the supplier to build enough capacity.In the literature,some elaborate contracts are designed to solve the problem.However,the authors prove that two simple conventional contracts(linear capacity reservation contract and payback agreement)can coordinate the supply chain and guarantee credible information sharing.Besides,the authors propose a new mechanism in which punishment is imposed in the payment function to bind the parties.To avoid punishment,the firms will choose the best decision for the entire supply chain.The contracts in this paper are all simple and easy to implement.The authors believe this work provides some insights to design coordination contracts in theory or in practice.展开更多
The fight against the COVID−19 epidemic is a war against an“invisible enemy”.Access to accurate information and appropriate allocation of medical resources are key to containing the spread of the virus as soon as po...The fight against the COVID−19 epidemic is a war against an“invisible enemy”.Access to accurate information and appropriate allocation of medical resources are key to containing the spread of the virus as soon as possible.The Chinese government has great power to collect information from individuals and basic-level organizations.It also has strong ability to pool and allocate medical resources.The fight against COVID−19 can be deemed as a quasi-natural experiment and based on this,we examine how government information capacity and medical resource allocation influence epidemic prevention and control in 286 Chinese cities(prefecture level and above).The fi ndings are as follows:(1)Government information capacities improve the effectiveness of prevention and control policies.At city level,for every 0.1 point of increase in government information capacity score,the number of confi rmed cases will reduce by 66.5,and the number of deaths per 10000 people will be down by 0.008.(2)The quantity of medical resources available has no direct influence on the effectiveness of epidemic prevention and control,but higher allocation efficiency does bring higher effectiveness.(3)The government can,on the one hand,allocate public resources based on information,and on the other hand guide the flow of social resources by releasing relevant information.Both can improve the allocation efficiency of medical resources.These fi ndings have some policy implications for improving global emergency management.展开更多
文摘Generally speaking, being an efficient information hiding scheme, what we want to achieve is high embedding capacity of the cover image and high visual quality of the stego image, high visual quality is also called embedding efficiency. This paper mainly studies on the information hiding technology based on gray-scale digital images and especially considers the improvement of embedding capacity and embedding efficiency. For the purpose of that, two algorithms for information hiding were proposed, one is called high capacity of information hiding algorithm (HCIH for short), which achieves high embedding rate, and the other is called high quality of information hiding algorithm (HQIH for short), which realizes high embedding efficiency. The simulation experiments show that our proposed algorithms achieve better performance.
文摘Relative carrying capacity of resources is an index to measure sustainable development through carrying capacity. Case studies of eleven cities in Zhejiang (Hangzhou, Ningbo, Wenzhou, Jiaxing, Huzhou, Shaoxing, Jinhua, Quzhou, Zhoushan, Taizhou and Lishui) illustrated regional sustainable development approach. In this study, to provide insight into spatial and dynamic analysis of region sustainable development, we calculated the relative carrying capacity of land resources and economical resources and synthetical carrying capacity of resources in different cities in Zhejiang, and geographic information system was carried out. The results showed that all cities but Hangzhou and Ningbo were ecologically sustainable, and relative carrying capacity of land resources in northern and eastern Zhejiang was larger than those in southern and western Zhejiang. The sampling years of Wenzhou, Hangzhou and Ningbo contribution rates of land resource to synthetic carrying capacity were grouped into three stages, and there were two milestones trends and changes in 1996 and 2004, respectively. This study demonstrated that geographic information system and relative carrying capacity of resources are effective for assessment of region sustainable development, and provide policy guidelines for decision-making.
基金Supported by the Foundation Program of Education Department of Jiangsu Province for Young Teachers and Principals
文摘Ambient light display presents peripheral information unobtrusively,and it can be context aware and aesthetically enhance specific environment.However,since the abstract characteristic of light,people should attentively keep agood balance between unobtrusiveness and effectiveness,when designing an ambient light display.Especially,in the condition of high information capacity,ambient light display need a mechanism to portray information effectively.In this paper,a framework with an overlay mechanism is evaluated for high information capacity.Based on the framework,two ambient light displays are designed to support the evaluation work.The evaluation questions are related with three aspects including information understanding,transition and encoding,special output channel.From the perception level,interpretation level and experience level,the process of evaluation is implemented.The results indicate that the framework with the overlay mechanism can effectively support varied and specific communicating information.The transitions and information encoding benefit from the proper mapping of states and notification levels in the framework.
文摘In past years,growing efforts have been made to the rapid interpretation of magnetic field data acquired by a sparse synthetic or real magnetic sensor array.An appealing requirement on such sparse array arranged within a specified survey region is that to make the number of sensor elements as small as possible,meanwhile without deteriorating imaging quality.For this end,we propose a novel methodology of arranging sensors in an optimal manner,exploring the concept of information capacity developed originally in the communication society.The proposed scheme reduces mathematically the design of a sparse sensor array into solving a combinatorial optimization problem,which can be resolved efficiently using widely adopted Simultaneous Perturbation and Statistical Algorithm(SPSA).Three sets of numerical examples of designing optimal sensor array are provided to demonstrate the performance of proposed methodology.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11105062,11275003,11265014 and 11275084the Fundamental Research Funds for the Central Universities under Grant No LZUJBKY-2015-119
文摘Recent experimental and theoretical studies show that energy efficiency, which measures the amount of infor- mation processed by a neuron with per unit of energy consumption, plays an important role in the evolution of neural systems. Here we calculate the information rates and energy efficieneies of the Hodgkin-Huxley (HH) neuron model at different temperatures in a noisy environment. It is found that both the information rate and energy efficiency are maximized by certain temperatures. Though the information rate and energy efficiency cannot be maximized simultaneously, the neuron holds a high information processing capacity at the tempera- ture corresponding to the maximal energy efficiency. Our results support the idea that the energy efficiency is a selective pressure that influences the evolution of nervous systems.
文摘Wireless statistic division multiplexing (WSDM) is a multiplexing scheme that transmits multiple signals simultaneously in the same frequency band over wireless channels. Based on the Shannon capacity of band-limited waveform AWGN channel with input power constraint, we obtain channel capacity of WSDM. Compared to time division multiplexing (TDM), frequency division multiplexing (FDM), and code division multiplexing (CDM), WSDM is more effective in raising spectrum efficiency. What’s more, we propose information optimization method to separate time-frequency mixed signals. Computer simulations also verify that the proposed method is feasible and performs better than traditional algorithms.
基金funded by The National Natural Science Foundation of China under Grant(No.62273108,62306081)The Youth Project of Guangdong Artificial Intelligence and Digital Economy Laboratory(Guangzhou)(PZL2022KF0006)+3 种基金The National Key Research and Development Program of China(2022YFB3604502)Special Fund Project of GuangzhouScience and Technology Innovation Development(202201011307)Guangdong Province Industrial Internet Identity Analysis and Construction Guidance Fund Secondary Node Project(1746312)Special Projects in Key Fields of General Colleges and Universities in Guangdong Province(2021ZDZX1016).
文摘Beyond-5G(B5G)aims to meet the growing demands of mobile traffic and expand the communication space.Considering that intelligent applications to B5G wireless communications will involve security issues regarding user data and operational data,this paper analyzes the maximum capacity of the multi-watermarking method for multimedia signal hiding as a means of alleviating the information security problem of B5G.The multiwatermarking process employs spread transform dither modulation.During the watermarking procedure,Gram-Schmidt orthogonalization is used to obtain the multiple spreading vectors.Consequently,multiple watermarks can be simultaneously embedded into the same position of a multimedia signal.Moreover,the multiple watermarks can be extracted without affecting one another during the extraction process.We analyze the effect of the size of the spreading vector on the unit maximum capacity,and consequently derive the theoretical relationship between the size of the spreading vector and the unit maximum capacity.A number of experiments are conducted to determine the optimal parameter values for maximum robustness on the premise of high capacity and good imperceptibility.
基金the National Natural Science Foundation of China (60372055) and the National DoctoralFoundation of China (2003698027).
文摘In order to investigate the impact of channel model parameters on the channel capacity of a multipleinput multiple-output (MIMO) system, a novel method is proposed to explore the channel capacity under Rayleigh fiat fading with correlated transmit and receive antennas. The optimal transmitting direction which can achieve maximum channel capacity is derived using random matrices theory. In addition, the closed-form expression for the channel capacity of MIMO systems is given by utilizing the properties of Wishart distribution when SNR is high. Computer simulation results show that the channel capacity is maximized when the antenna spacing increases to a certain point, and furthermore, the larger the scattering angle is, the more quickly the channel capacity converges to its maximum. At high SNR (〉12 dB), the estimation of capacity is close to its true wlue. And, when the same array configuration is adopted both at the transmitter and the receiver, the UCA yields higher channel capacity than ULA.
文摘In the governing thought, I find an equivalence between the classical information in a quantum system and the integral of that system’s energy and time, specifically , in natural units. I solve this relationship in four ways: the first approach starts with the Schrodinger Equation and applies the Minkowski transformation;the second uses the Canonical commutation relation;the third through Gabor’s analysis of the time-frequency plane and Heisenberg’s uncertainty principle;and lastly by quantizing Brownian motion within the Bernoulli process and applying the Gaussian channel capacity. In support I give two examples of quantum systems that follow the governing thought: namely the Gaussian wave packet and the electron spin. I conclude with comments on the discretization of space and the information content of a degree of freedom.
文摘This paper reports on investigations into capacity of ad hoc network whose nodes are equipped with multiple element antennas (MEAs). The investigation of this multi-user Multiple Input Multiple Output (MIMO) system takes into account mutual coupling (MC) in addition to spatial correlation that is present in array antennas. A closed-form expression for an upper bound of mutual information (capacity) of MIMO ad hoc network is derived. An optimal signal transmission scheme is proposed to maximize the MIMO ad hoc network capacity. Simulation results for capacity of non-optimized and optimized cases of signal transmission are presented.
文摘An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast population growth and continuous development in constructions such as residential complexes, hotels, bridges and shopping malls. Soil investigation data for An-Najaf Province (An-Najaf and Kufa cities) from 464 boreholes drilled by the Na-tional Centre for Construction Laboratories & Researches (NCCLR)/Babylon laboratory were used in this research. The data were analysed and possessed using Excel program then represented on the Geographical Information System (GIS) program by Inverse Distance Weighted (IDW) tool to create an allowable bearing capacity map for the soil at depths 0 - 2 meters. The allowable bearing capacity is one of the most important soil characteristics to be considered when making a database for An-Najaf city soil. Geographical Information System GIS program enables to create reliable database for any characteristic and it is one of the best programs to produce an accurate map and allow ease in dealing with it. Those maps cover all the studied areas and by using contour lines, approximate values for no-data areas can be obtained. The results show that the allowable bearing capacity range is 5 - 20 Ton/m2 for both An-Najaf and Kufa cities. Kufa city has the range 5 - 9 Ton/m2. An-Najaf city has the range 7 - 18 at the center, 8 - 10 Ton/m2 at the north eastern part, 7 - 14 Ton/m2 for the north western part, 6 - 12 Ton/m2 at the south eastern and 12 - 19 Ton/m2 at the south western.
基金Supported by Chinese 863 Program (2006AA01Z268)the National Natural Science Foundation of China (No. 60496311)
文摘We investigate the sum capacity of Block Diagonalization precoding Multiple Input Mul-tiple Output Broadcast Channels(BD MIMO BC) with imperfect Channel State Information(CSI) at the base station.Since it is difficult to obtain the exact expression,a lower and an upper bounds of the sum capacity under Gaussian channel estimation errors are drived instead.Analyses show that the gap between two bounds is considerably tight at all Signal to Noise Ratio(SNR) region.From the lower bound of the sum capacity,we can see that the multiplexing gain tends to be zero at high SNR region,which indicates that the BD MIMO BC system with channel estimation errors is interference-limited at high SNR.
文摘This study addresses the pressing need to assess foundation bearing capacity in Opolo,Yenagoa,Bayelsa State,Nigeria.The significance lies in the dearth of comprehensive geotechnical data for construction planning in the region.Past research is limited and this study contributes valuable insights by integrating Geographic Information System(GIS)with the Generalized Reciprocal Method(GRM).To collect data,near-surface seismic refraction surveys were conducted along three designated lines,utilizing ABEM Terraloc Mark 6 equipment,Easy Refract,and ArcGIS 10.4.1 software.This methodology allowed for the determination of key geotechnical parameters essential for soil characterization at potential foundation sites.The results revealed three distinct geoseismic layers.The uppermost layer,within a depth of 0.89 to 1.50 meters,exhibited inadequate compressional and shear wave velocities and low values for oedometric modulus,shear modulus,N-value,ultimate bearing capacity,and allowable bearing capacity.This indicates the presence of unsuitable,soft,and weak alluvial deposits for substantial structural loads.In contrast,the second layer(1.52 to 3.84 m depth)displayed favorable geotechnical parameters,making it suitable for various construction loads.The third layer(15.00 to 26.05 m depth)exhibited varying characteristics.The GIS analysis highlighted the unsuitability of the uppermost layer for construction,while the second and third layers were found to be fairly competent and suitable for shallow footing and foundation design.In summary,this study highlights the importance of geotechnical surveys in Opolo’s construction planning.It offers vital information for informed choices,addresses issues in the initial layer,and suggests secure,sustainable construction options.
文摘In this paper,we explore the capacity during the process of a firm's information system adoption and implementation from knowledge management perspective,based on a firm's level construct. According to the dimensions of absorptive capacity proposed by Zahra and George,we point out that the concept of IS absorptive capacity,analyze and summarize the elements of potential absorptive capacity and realized absorptive capacity. We use data from two manufacturing organizations,analyze two firm's realities of IS absorptive capacity. The study indicates differing antecedents may have differing effects on potential absorptive capacity and realized absorptive capacity.
基金Supported by the National Natural Science Foundation of China (No. 70471014)
文摘In order to examine the problem of how to improve the use of information technology (IT) in enterprises, this paper makes an exploration from the perspective of organizational absorptive capacity. We propose the concept of IT absorptive capacity from an organizational level. A dynamic process model is developed to further analyze IT absorption. IT absorptive capacity of this process is embodied as six forms: identification, adoption, adaptation, acceptance, infusion, and knowledge management. By means of questionnaire surveys of 76 Chinese enterprises, the main factors that favor or disable the capacity of each stage are discovered. Using the method of system dynamics, a conceptual model of IT absorptive capacity is developed to analyze the action mechanism of the factors in detail. The model indicates that the critical factors are embodied in the aspect of management. Furthermore, it demonstrates that IT absorption is a spiral process, during which IT absorptive capacity evolves dynamically and, consequently, promotes IT use.
文摘Today businesses are facing radical transformations through digitalization of services and products.Accordingly,their ability to innovate is increasingly linked to the capacity to innovate through information and communication technologies(ICTs).This article investigates the role of information systems(IS)as a key factor for innovation capacity.To this end,the article discusses an interpretive framework for understanding the degree of capacity of innovation through information systems(IS)reached by a given company and the contradictions that bound its evolution.An interpretive study is also presented,where the framework has been applied to seven French companies from various industries.Consistently with the framework,the interviews address process areas and practices related to three core categories:management,innovation engineering and support.The study reveals seven fundamental contradictions that can explain the main tendencies observed across the companies.
基金supported by the National Natural Science Foundation of China under Grant No.72071198。
文摘This paper studies the important problem of how to coordinate the capacity procurement model with asymmetric demand information.Under the model,the supplier has to secure necessary capacity before receiving a firm order from the manufacturer who possesses private demand information for her product.Optimal supply chain performance requires the manufacturer to share her forecast truthfully and the supplier to build enough capacity.In the literature,some elaborate contracts are designed to solve the problem.However,the authors prove that two simple conventional contracts(linear capacity reservation contract and payback agreement)can coordinate the supply chain and guarantee credible information sharing.Besides,the authors propose a new mechanism in which punishment is imposed in the payment function to bind the parties.To avoid punishment,the firms will choose the best decision for the entire supply chain.The contracts in this paper are all simple and easy to implement.The authors believe this work provides some insights to design coordination contracts in theory or in practice.
文摘The fight against the COVID−19 epidemic is a war against an“invisible enemy”.Access to accurate information and appropriate allocation of medical resources are key to containing the spread of the virus as soon as possible.The Chinese government has great power to collect information from individuals and basic-level organizations.It also has strong ability to pool and allocate medical resources.The fight against COVID−19 can be deemed as a quasi-natural experiment and based on this,we examine how government information capacity and medical resource allocation influence epidemic prevention and control in 286 Chinese cities(prefecture level and above).The fi ndings are as follows:(1)Government information capacities improve the effectiveness of prevention and control policies.At city level,for every 0.1 point of increase in government information capacity score,the number of confi rmed cases will reduce by 66.5,and the number of deaths per 10000 people will be down by 0.008.(2)The quantity of medical resources available has no direct influence on the effectiveness of epidemic prevention and control,but higher allocation efficiency does bring higher effectiveness.(3)The government can,on the one hand,allocate public resources based on information,and on the other hand guide the flow of social resources by releasing relevant information.Both can improve the allocation efficiency of medical resources.These fi ndings have some policy implications for improving global emergency management.