Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In exist...Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In existing technologies,the efficiency of big data applications(BDAs)in distributed systems hinges on the stable-state and low-latency links between worker nodes.However,LMCNs with high-dynamic nodes and long-distance links can not provide the above conditions,which makes the performance of OBDP hard to be intuitively measured.To bridge this gap,a multidimensional simulation platform is indispensable that can simulate the network environment of LMCNs and put BDAs in it for performance testing.Using STK's APIs and parallel computing framework,we achieve real-time simulation for thousands of satellite nodes,which are mapped as application nodes through software defined network(SDN)and container technologies.We elaborate the architecture and mechanism of the simulation platform,and take the Starlink and Hadoop as realistic examples for simulations.The results indicate that LMCNs have dynamic end-to-end latency which fluctuates periodically with the constellation movement.Compared to ground data center networks(GDCNs),LMCNs deteriorate the computing and storage job throughput,which can be alleviated by the utilization of erasure codes and data flow scheduling of worker nodes.展开更多
The root-knot nematode disease(RKN)caused by Meloidogyne incognita is a devastating threat to the production of crops,especially greenhouse vegetables.Fluopyram,a new nematicide,has been widely used by root drenching ...The root-knot nematode disease(RKN)caused by Meloidogyne incognita is a devastating threat to the production of crops,especially greenhouse vegetables.Fluopyram,a new nematicide,has been widely used by root drenching one-by-one plants for the management of RKN.However,as a common non-fumigation nematicide,its distribution in soil was often the key limiting factor that determined the efficacy and efficiency.To optimize the utilization of fluopyram against RKN,the control efficacy of application methods including blending-of-soil,rootirrigation,drip-irrigation,and furrow-irrigation and the correlation between nematicide distribution and efficacy were studied.The toxicities of fluopyram and abamectin to nematodes collected from different sources and backgrounds exhibited limited differences from crop and region.Compared to the control,all nematicide treatments reduced root galling by M.incognita in cucumber and increased the yield of cucumber.Blending-of-soil treatment and root-irrigation treatment were more beneficial for increasing the distribution area of nematicides in soil,then promoting the control efficacy of nematicides against RKN and improving cucumber production.This work showed that the application of fluopyram by blending-of-soil has the same efficacy as by rootirrigation in controlling RKN in cucumber production,moreover is more efficient and can be an alternative option.展开更多
The actively heated fiber-optic(AHFO)technology has emerged as a frontier and hotspot in soil water content measurement,offering advantages such as easy installation,large-scale distributed measurement capability,and ...The actively heated fiber-optic(AHFO)technology has emerged as a frontier and hotspot in soil water content measurement,offering advantages such as easy installation,large-scale distributed measurement capability,and resistance to electromagnetic interference.However,current AHFO water content sensors fail to simultaneously achieve high precision,applicability for deep soil,and automated real-time monitoring,thereby limiting their development and application.Therefore,this study introduces a novel actively heated fiber Bragg grating(AH-FBG)cable.Laboratory tests were conducted to assess the heating uniformity of the AH-FBG cable and to establish the temperature characteristic value(T_(t))-soil water content(θ)calibration formula for water content measurement.Subsequently,AH-FBG cables were deployed for in situ soil water content monitoring in a test pit on the Loess Plateau.Through two-year monitoring data verified the accuracy of the AH-FBG cable and elucidated the spatiotemporal distribution of in situ loess water content.Laboratory results demonstrated superior heating uniformity of AHFBG cable,with a T_(t) standard deviation of approximately 0.3℃.In the field,the AH-FBG cable exhibited excellent performance in soil water content measurement,achieving a high accuracy of 0.023 cm^(3)/cm^(3).Further analysis revealed that the θ fluctuation predominantly occurred within a 10 m depth from the soil surface,with an overall upward trend over the two-year monitoring period;the response of shallow θ to precipitation was significant but exhibited increasing hysteresis with depth;frequent precipitation significantly enhanced water infiltration depth.This study provides technical guidance for highprecision,quasi-distributed,automated and real-time water content measurement of deep soil.展开更多
Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless...Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.展开更多
In this paper, at first the appearance background electricity grid in the rural areas of west China, and its meaning as well as the concept and structure of DG technologies are resented, and a DG technologies mode of ...In this paper, at first the appearance background electricity grid in the rural areas of west China, and its meaning as well as the concept and structure of DG technologies are resented, and a DG technologies mode of development in the rural areas of west China is given. The development ideas and the future development direction of DG in are compared and summarized. At last, the significance of DG in future development of the rural areas of west China is prospected and some problems to be especially considered in the domestic research on DG technologies are put forward.展开更多
In this paper, a Distributed In-Memory Database （DIMDB） system is proposed to improve processing efficiency in mass data applications. The system uses an enhanced language similar to Structured Query Language （SQL...In this paper, a Distributed In-Memory Database （DIMDB） system is proposed to improve processing efficiency in mass data applications. The system uses an enhanced language similar to Structured Query Language （SQL） with a key-value storage schema. The design goals of the DIMDB system is described and its system architecture is discussed. Operation flow and the enhanced SOL-like language are also discussed, and experimental results are used to test the validity of the system.展开更多
IT as a dynamic filed changes very rapidly; efficient management of such systems for the most of the companies requires handling tremendous complex situations in terms of hardware and software setup. Hardware and soft...IT as a dynamic filed changes very rapidly; efficient management of such systems for the most of the companies requires handling tremendous complex situations in terms of hardware and software setup. Hardware and software itself changes quickly with the time and keeping them updated is a difficult problem for the most of the companies; the problem is more emphasized for the companies having large infrastructure of IT facilities such as data centers which are expensive to be maintained. Many applications run on the company premises which require well prepared staff for successfully maintaining them. With the inception of Cloud Computing many companies have transferred their applications and data into cloud computing based platforms in order to have reduced maintaining cost, easier maintenance in terms of hardware and software, reliable and securely accessible services. The benefits of building distributed applications using Google infrastructure are conferred in this paper.展开更多
Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for wa...Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for ways to reduce their drilling costs and be as efficient as possible. A system called the Drilling Comprehensive Information Management and Application System (DCIMAS) is developed and presented here, with an aim at collecting, storing and making full use of the valuable well data and information relating to all drilling activities and operations. The DCIMAS comprises three main parts, including a data collection and transmission system, a data warehouse (DW) management system, and an integrated platform of core applications. With the support of the application platform, the DW management system is introduced, whereby the operation data are captured at well sites and transmitted electronically to a data warehouse via transmission equipment and ETL (extract, transformation and load) tools. With the high quality of the data guaranteed, our central task is to make the best use of the operation data and information for drilling analysis and to provide further information to guide later production stages. Applications have been developed and integrated on a uniform platform to interface directly with different layers of the multi-tier DW. Now, engineers in every department spend less time on data handling and more time on applying technology in their real work with the system.展开更多
The urban thermal distribution characteristics and its variation are dynamically monitored and synthetically analyzed by using GIS technology. The meteorological satellite data serve as main information source, assist...The urban thermal distribution characteristics and its variation are dynamically monitored and synthetically analyzed by using GIS technology. The meteorological satellite data serve as main information source, assisted as auxiliary information sources by the landsat satellite TM data, land use thematic maps and meteorological observed data. A correlated pattern on the ground surface brightness temperatures and air temperatures has been studied and established with good performance of application.展开更多
Increasing zinc(Zn)concentration in wheat grain is important to minimize human dietary Zn deficiency.This study aimed to investigate the effect of foliar Zn and soil nitrogen(N)applications on the accumulation and dis...Increasing zinc(Zn)concentration in wheat grain is important to minimize human dietary Zn deficiency.This study aimed to investigate the effect of foliar Zn and soil nitrogen(N)applications on the accumulation and distribution of N and Zn in grain pearling fractions,N remobilization,and the relationships between nutrient concentration in the vegetative tissues and grain or its fractions in two cropping years in the North China Plain.The results showed a progressive decrease in N and Zn concentrations from the outer to the inner parts of grain,with most of the accumulation in the core endosperm.Foliar Zn application significantly increased N concentration in the pericarp,and soil N application increased N concentration in each grain fraction.Both treatments significantly increased core endosperm Zn concentration.Foliar Zn had no effect on grain N and Zn distribution.Soil N application made N concentrated in the aleurone,promoted Zn translocation to the core endosperm and also increased N remobilization and its efficiency from the shoot to the grain,but no improved contribution to grain was found.N concentration in grain and its fractions were positively correlated with N in vegetative organs at anthesis and maturity,while positive correlations were obtained between N concentration in the pericarp and progressive central area of the endosperm and Zn concentration in the core endosperm.Thus,foliar Zn and soil N applications effectively increased yield and N and Zn concentrations in the wheat grain,particularly in the endosperm,and could be promising strategies to address Zn deficiency.展开更多
Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capabl...Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. In this work, we will examine the effect of the smart grid applications in improving the reliability of the power distribution networks. The test system used in this paper is the IEEE 34 node test feeder, released in 2003 by the Distribution System Analysis Subcommittee of the IEEE Power Engineering Society. The objective is to analyze the feeder for the optimal placement of the automatic switching devices and quantify their proper installation based on the performance of the distribution system. The measures will be the changes in the reliability system indices including SAIDI, SAIFI, and EUE. In addition, the goal is to design and simulate the effect of the installation of the Distributed Generators (DGs) on the utility’s distribution system and measure the potential improvement of its reliability.展开更多
Probe-based confocal laser endomicroscopy(p CLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However,...Probe-based confocal laser endomicroscopy(p CLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. p CLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared with that after 1 min. The presence of fluorescein in the mucosa was observed within a short time after local mucosal application of fluorescein, suggesting that pC LE images similarly to those after intravenous fluorescein administration can be acquired by local mucosal application of fluorescein.展开更多
This paper reveals that the long-period statistic distribution of the characteristic heights of deep-water waves assumes the lognormal distribution. Thereafter, the largest wave-height which may occur in the service l...This paper reveals that the long-period statistic distribution of the characteristic heights of deep-water waves assumes the lognormal distribution. Thereafter, the largest wave-height which may occur in the service life of coastal structures is derived in this paper.展开更多
The effect of fertilizer application on biomass dry weight and element distribution of various organs of maize was investigated from the aspect of microscopic view to disclose the internal mechanism of fertilizer effe...The effect of fertilizer application on biomass dry weight and element distribution of various organs of maize was investigated from the aspect of microscopic view to disclose the internal mechanism of fertilizer effect on crop. Five fertilizer treatments： no fertilizer （CK）, nitrogen phosphorus fertilizer （NP）, nitrogen potassium fertilizer （NK）, phosphorus potassium （PK）, and nitrogen phosphorus potassium fertilizer （NPK） were designed. Field experiment on the response of biomass dry weight and N, P, K, Cu, Zn, Fe, and Mn element distribution of stem, leaf and seed of maize （Zea mays L.） to different fertilizer treatments application was carried out. The results showed that dry weight and element content of various organs of maize were different. N content of various organs followed this order leaf〉 seed 〉 stem; P content of various organs was seed 〉 leaf〉 stem; K content was stem 〉 leaf〉 seed; and Fe content was leaf〉 stem 〉 seed. Fertilizer application reduced the differences of N, P, K, and Fe contents of various organs, and changed the size order of the dry weight and the Cu and Zn contents of leaf, seed and stem. Except for individual treatment, the response direction of N, P and Fe elements to fertilizer application was similar to Cu and Zn. The response of element content of various organs of maize to different fertilizer combinations was also different. The response extent of N, P and K major elements to fertilizer application was larger than microelement of Cu, Zn, Fe, and Mn; the response extent of stem and leaf was larger than seed; the response to NPK fertilizer treatment was bigger than NP, NK and PK. In the whole, response differences of element distribution to various fertilizer treatments were not remarkable. Besides, element distribution of various organs of maize was also influenced by the mutual effect of fertilizer varieties. The response direction and extent of various element distributions to different fertilizer treatments had both similarities and differences. Adjusting fertilizer application could change the biomass dry weight and element distribution of various organs of maize, thus promote the uptake and cycle of nutrient. This investigation could provide useful information for high production.展开更多
The phosphate in the soil-root interface zone under various soil water contents and application rates ofphosphate was still of depletion distribution which could be described by a power function in the form ofC/Co= ax...The phosphate in the soil-root interface zone under various soil water contents and application rates ofphosphate was still of depletion distribution which could be described by a power function in the form ofC/Co= ax￣b(C/Co is the relative content of fertilized phosphate in a distance from the root surface x, a andb are the regression constants). The depletion rate of phosphate in soil near the root surface was higher andthe depletion range was narrower under lower soil moisture. On the contrary, at higher soil water content thedepletion range was wider, generally The application rate of phosphate led to the greater depletion intensityof phosphorus was higher in the heavier texture soils. In general, the depletion intensity in the soils, whichdecreased with increasing clay content or increa.sing buffering power of soil, decreased in the order as loessalsoil and black fou soil> lou soil> yellow cinnamon soil when 50 or 100 mg of phosphorus were applied in theform of KH_2PO_4. This result indicated that the phosphate distribution and its movement in the soil-rootinterface zone closely related with the buffering capacity of soil.展开更多
Complex multi-tier applications deployed in cloud computing environments can experience rapid changes in their workloads. To ensure market readiness of such applications, adequate resources need to be provisioned so t...Complex multi-tier applications deployed in cloud computing environments can experience rapid changes in their workloads. To ensure market readiness of such applications, adequate resources need to be provisioned so that the applications can meet the demands of specified workload levels and at the same time ensure that service level agreements are met. Multi-tier cloud applications can have complex deployment configurations with load balancers, web servers, application servers and database servers. Complex dependencies may exist between servers in various tiers. To support provisioning and capacity planning decisions, performance testing approaches with synthetic workloads are used. Accuracy of a performance testing approach is determined by how closely the generated synthetic workloads mimic the realistic workloads. Since multi-tier applications can have varied deployment configurations and characteristic workloads, there is a need for a generic performance testing methodology that allows accurately modeling the performance of applications. We propose a methodology for performance testing of complex multi-tier applications. The workloads of multi-tier cloud applications are captured in two different models-benchmark application and workload models. An architecture model captures the deployment configurations of multi-tier applications. We propose a rapid deployment prototyping methodology that can help in choosing the best and most cost effective deployments for multi-tier applications that meet the specified performance requirements. We also describe a system bottleneck detection approach based on experimental evaluation of multi-tier applications.展开更多
A general version of the inverted exponential distribution is introduced, studied and analyzed. This generalization depends on the method of Marshall-Olkin to extend a family of distributions. Some statistical and rel...A general version of the inverted exponential distribution is introduced, studied and analyzed. This generalization depends on the method of Marshall-Olkin to extend a family of distributions. Some statistical and reliability properties of this family are studied. In addition, numerical estimation of the maximum likelihood estimate（MLE） parameters are discussed in details. As an application, some real data sets are analyzed and it is observed that the presented family provides a better fit than some other known distributions.展开更多
By analysing the scatter diagrams of characteristic the wave height H and the period T on the basis of instrumental data from various ocean wave stations, we found that the conditional expectation and standard deviati...By analysing the scatter diagrams of characteristic the wave height H and the period T on the basis of instrumental data from various ocean wave stations, we found that the conditional expectation and standard deviation of wave period for a given wave height can be better predicted by using the equations of normal linear regression rather than by those based on the log- normal law. The latter was implied in Ochi' s bivariate log-normal model(Ochi. 1978) for the long-term joint distribution of H and T. With the expectation and standard deviation predicted by the normal linear regression equations and applying proper types of distribution, we have obtained the conditional distribution of T for given H. Then combining this conditional P(T / H) with long-term marginal distribution of the wave height P(H) we establish a new parameterized model for the long-term joint distribution P(H,T). As an example of the application of the new model we give a method for estimating wave period associated with an extreme wave height.展开更多
Surface distribution and seasonal variation of alkalinity and specific alkalinity in Kuroshio area of the East ChinaSea and their application to the water mass tracing are discussed in this paper. Results show a disti...Surface distribution and seasonal variation of alkalinity and specific alkalinity in Kuroshio area of the East ChinaSea and their application to the water mass tracing are discussed in this paper. Results show a distinct seasonal variation of the alkalinity, which is concerned with the process of vertical mixing. Different specific alkalinity in various water masses has been found. On the basis of the difference of the specific alkalinity and the distribution of alkalinity, two water fronts in summer season, located at 27°-30°N and 124°-1 27°E, (Ⅰ), and at the northern waters about one latitude from the Taiwan Island, (Ⅱ); one in winter season at about one longitude from coast of mainland of China and 26°-30°N were found. In summer season, about 1-2 longitudes eastward shift of front (Ⅰ) is found by comparison of data in May and August. And the high alkalinity of the northern East China Sea in summer season may be caused by the Huanghe River runoff flowing southward along with the Huanghai Sea Coastal Current.展开更多
Recently, a novel kind of quantum key distribution called the round-robin differential phase-shift （RRDPS） protocol was proposed, which bounds the amount of leakage without monitoring signal disturbance. The protoco...Recently, a novel kind of quantum key distribution called the round-robin differential phase-shift （RRDPS） protocol was proposed, which bounds the amount of leakage without monitoring signal disturbance. The protocol can be implemented by a weak coherent source. The security of this protocol with a simply characterized source has been proved. The application of a common phase shift can improve the secret key rate of the protocol. In practice, the randomized phase is discrete and the secret key rate is deviated from the continuous case. In this study, we analyze security of the RRDPS protocol with discrete-phase-randomized coherent state source and bound the secret key rate. We fix the length of each packet at 32 and 64, then simulate the secret key rates of the RRDPS protocol with discrete-phase randomization and continuous-phase randomization. Our simulation results show that the performance of the discrete-phase randomization case is close to the continuous counterpart with only a small number of discrete phases. The research is practically valuable for experimental implementation.展开更多
基金supported by National Natural Sciences Foundation of China(No.62271165,62027802,62201307)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030297)+2 种基金the Shenzhen Science and Technology Program ZDSYS20210623091808025Stable Support Plan Program GXWD20231129102638002the Major Key Project of PCL(No.PCL2024A01)。
文摘Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In existing technologies,the efficiency of big data applications(BDAs)in distributed systems hinges on the stable-state and low-latency links between worker nodes.However,LMCNs with high-dynamic nodes and long-distance links can not provide the above conditions,which makes the performance of OBDP hard to be intuitively measured.To bridge this gap,a multidimensional simulation platform is indispensable that can simulate the network environment of LMCNs and put BDAs in it for performance testing.Using STK's APIs and parallel computing framework,we achieve real-time simulation for thousands of satellite nodes,which are mapped as application nodes through software defined network(SDN)and container technologies.We elaborate the architecture and mechanism of the simulation platform,and take the Starlink and Hadoop as realistic examples for simulations.The results indicate that LMCNs have dynamic end-to-end latency which fluctuates periodically with the constellation movement.Compared to ground data center networks(GDCNs),LMCNs deteriorate the computing and storage job throughput,which can be alleviated by the utilization of erasure codes and data flow scheduling of worker nodes.
基金supported by the National Key Research and Development Program of China(2022YFD1700500)the National Natural Science Foundation of China(32272596)the Modern Agricultural Industry Technology System for Vegetables in Shandong Province(SDAIT-05).
文摘The root-knot nematode disease(RKN)caused by Meloidogyne incognita is a devastating threat to the production of crops,especially greenhouse vegetables.Fluopyram,a new nematicide,has been widely used by root drenching one-by-one plants for the management of RKN.However,as a common non-fumigation nematicide,its distribution in soil was often the key limiting factor that determined the efficacy and efficiency.To optimize the utilization of fluopyram against RKN,the control efficacy of application methods including blending-of-soil,rootirrigation,drip-irrigation,and furrow-irrigation and the correlation between nematicide distribution and efficacy were studied.The toxicities of fluopyram and abamectin to nematodes collected from different sources and backgrounds exhibited limited differences from crop and region.Compared to the control,all nematicide treatments reduced root galling by M.incognita in cucumber and increased the yield of cucumber.Blending-of-soil treatment and root-irrigation treatment were more beneficial for increasing the distribution area of nematicides in soil,then promoting the control efficacy of nematicides against RKN and improving cucumber production.This work showed that the application of fluopyram by blending-of-soil has the same efficacy as by rootirrigation in controlling RKN in cucumber production,moreover is more efficient and can be an alternative option.
基金supported by the National Natural Science Foundation of China(Grant Nos.42307189 and 42030701)the China Postdoctoral Science Foundation(Grant No.2023M740974).
文摘The actively heated fiber-optic(AHFO)technology has emerged as a frontier and hotspot in soil water content measurement,offering advantages such as easy installation,large-scale distributed measurement capability,and resistance to electromagnetic interference.However,current AHFO water content sensors fail to simultaneously achieve high precision,applicability for deep soil,and automated real-time monitoring,thereby limiting their development and application.Therefore,this study introduces a novel actively heated fiber Bragg grating(AH-FBG)cable.Laboratory tests were conducted to assess the heating uniformity of the AH-FBG cable and to establish the temperature characteristic value(T_(t))-soil water content(θ)calibration formula for water content measurement.Subsequently,AH-FBG cables were deployed for in situ soil water content monitoring in a test pit on the Loess Plateau.Through two-year monitoring data verified the accuracy of the AH-FBG cable and elucidated the spatiotemporal distribution of in situ loess water content.Laboratory results demonstrated superior heating uniformity of AHFBG cable,with a T_(t) standard deviation of approximately 0.3℃.In the field,the AH-FBG cable exhibited excellent performance in soil water content measurement,achieving a high accuracy of 0.023 cm^(3)/cm^(3).Further analysis revealed that the θ fluctuation predominantly occurred within a 10 m depth from the soil surface,with an overall upward trend over the two-year monitoring period;the response of shallow θ to precipitation was significant but exhibited increasing hysteresis with depth;frequent precipitation significantly enhanced water infiltration depth.This study provides technical guidance for highprecision,quasi-distributed,automated and real-time water content measurement of deep soil.
文摘Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.
文摘In this paper, at first the appearance background electricity grid in the rural areas of west China, and its meaning as well as the concept and structure of DG technologies are resented, and a DG technologies mode of development in the rural areas of west China is given. The development ideas and the future development direction of DG in are compared and summarized. At last, the significance of DG in future development of the rural areas of west China is prospected and some problems to be especially considered in the domestic research on DG technologies are put forward.
文摘In this paper, a Distributed In-Memory Database （DIMDB） system is proposed to improve processing efficiency in mass data applications. The system uses an enhanced language similar to Structured Query Language （SQL） with a key-value storage schema. The design goals of the DIMDB system is described and its system architecture is discussed. Operation flow and the enhanced SOL-like language are also discussed, and experimental results are used to test the validity of the system.
文摘IT as a dynamic filed changes very rapidly; efficient management of such systems for the most of the companies requires handling tremendous complex situations in terms of hardware and software setup. Hardware and software itself changes quickly with the time and keeping them updated is a difficult problem for the most of the companies; the problem is more emphasized for the companies having large infrastructure of IT facilities such as data centers which are expensive to be maintained. Many applications run on the company premises which require well prepared staff for successfully maintaining them. With the inception of Cloud Computing many companies have transferred their applications and data into cloud computing based platforms in order to have reduced maintaining cost, easier maintenance in terms of hardware and software, reliable and securely accessible services. The benefits of building distributed applications using Google infrastructure are conferred in this paper.
文摘Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for ways to reduce their drilling costs and be as efficient as possible. A system called the Drilling Comprehensive Information Management and Application System (DCIMAS) is developed and presented here, with an aim at collecting, storing and making full use of the valuable well data and information relating to all drilling activities and operations. The DCIMAS comprises three main parts, including a data collection and transmission system, a data warehouse (DW) management system, and an integrated platform of core applications. With the support of the application platform, the DW management system is introduced, whereby the operation data are captured at well sites and transmitted electronically to a data warehouse via transmission equipment and ETL (extract, transformation and load) tools. With the high quality of the data guaranteed, our central task is to make the best use of the operation data and information for drilling analysis and to provide further information to guide later production stages. Applications have been developed and integrated on a uniform platform to interface directly with different layers of the multi-tier DW. Now, engineers in every department spend less time on data handling and more time on applying technology in their real work with the system.
基金The Key Project of the Ninth Five-Year Plan Period, No. 96-908-05-06
文摘The urban thermal distribution characteristics and its variation are dynamically monitored and synthetically analyzed by using GIS technology. The meteorological satellite data serve as main information source, assisted as auxiliary information sources by the landsat satellite TM data, land use thematic maps and meteorological observed data. A correlated pattern on the ground surface brightness temperatures and air temperatures has been studied and established with good performance of application.
基金the National Key Research and Development Program of China(2018YFD0300707 and 2016YFD0300400)the Modern Wheat Industrial Technology System of Henan Province,China(S2010-01-G07).
文摘Increasing zinc(Zn)concentration in wheat grain is important to minimize human dietary Zn deficiency.This study aimed to investigate the effect of foliar Zn and soil nitrogen(N)applications on the accumulation and distribution of N and Zn in grain pearling fractions,N remobilization,and the relationships between nutrient concentration in the vegetative tissues and grain or its fractions in two cropping years in the North China Plain.The results showed a progressive decrease in N and Zn concentrations from the outer to the inner parts of grain,with most of the accumulation in the core endosperm.Foliar Zn application significantly increased N concentration in the pericarp,and soil N application increased N concentration in each grain fraction.Both treatments significantly increased core endosperm Zn concentration.Foliar Zn had no effect on grain N and Zn distribution.Soil N application made N concentrated in the aleurone,promoted Zn translocation to the core endosperm and also increased N remobilization and its efficiency from the shoot to the grain,but no improved contribution to grain was found.N concentration in grain and its fractions were positively correlated with N in vegetative organs at anthesis and maturity,while positive correlations were obtained between N concentration in the pericarp and progressive central area of the endosperm and Zn concentration in the core endosperm.Thus,foliar Zn and soil N applications effectively increased yield and N and Zn concentrations in the wheat grain,particularly in the endosperm,and could be promising strategies to address Zn deficiency.
文摘Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. In this work, we will examine the effect of the smart grid applications in improving the reliability of the power distribution networks. The test system used in this paper is the IEEE 34 node test feeder, released in 2003 by the Distribution System Analysis Subcommittee of the IEEE Power Engineering Society. The objective is to analyze the feeder for the optimal placement of the automatic switching devices and quantify their proper installation based on the performance of the distribution system. The measures will be the changes in the reliability system indices including SAIDI, SAIFI, and EUE. In addition, the goal is to design and simulate the effect of the installation of the Distributed Generators (DGs) on the utility’s distribution system and measure the potential improvement of its reliability.
基金Supported by Japanese Foundation for Research and Promotion of Endoscopy
文摘Probe-based confocal laser endomicroscopy(p CLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. p CLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared with that after 1 min. The presence of fluorescein in the mucosa was observed within a short time after local mucosal application of fluorescein, suggesting that pC LE images similarly to those after intravenous fluorescein administration can be acquired by local mucosal application of fluorescein.
文摘This paper reveals that the long-period statistic distribution of the characteristic heights of deep-water waves assumes the lognormal distribution. Thereafter, the largest wave-height which may occur in the service life of coastal structures is derived in this paper.
基金supported by the National Basic ResearchProgram of China (2007CB109300)
文摘The effect of fertilizer application on biomass dry weight and element distribution of various organs of maize was investigated from the aspect of microscopic view to disclose the internal mechanism of fertilizer effect on crop. Five fertilizer treatments： no fertilizer （CK）, nitrogen phosphorus fertilizer （NP）, nitrogen potassium fertilizer （NK）, phosphorus potassium （PK）, and nitrogen phosphorus potassium fertilizer （NPK） were designed. Field experiment on the response of biomass dry weight and N, P, K, Cu, Zn, Fe, and Mn element distribution of stem, leaf and seed of maize （Zea mays L.） to different fertilizer treatments application was carried out. The results showed that dry weight and element content of various organs of maize were different. N content of various organs followed this order leaf〉 seed 〉 stem; P content of various organs was seed 〉 leaf〉 stem; K content was stem 〉 leaf〉 seed; and Fe content was leaf〉 stem 〉 seed. Fertilizer application reduced the differences of N, P, K, and Fe contents of various organs, and changed the size order of the dry weight and the Cu and Zn contents of leaf, seed and stem. Except for individual treatment, the response direction of N, P and Fe elements to fertilizer application was similar to Cu and Zn. The response of element content of various organs of maize to different fertilizer combinations was also different. The response extent of N, P and K major elements to fertilizer application was larger than microelement of Cu, Zn, Fe, and Mn; the response extent of stem and leaf was larger than seed; the response to NPK fertilizer treatment was bigger than NP, NK and PK. In the whole, response differences of element distribution to various fertilizer treatments were not remarkable. Besides, element distribution of various organs of maize was also influenced by the mutual effect of fertilizer varieties. The response direction and extent of various element distributions to different fertilizer treatments had both similarities and differences. Adjusting fertilizer application could change the biomass dry weight and element distribution of various organs of maize, thus promote the uptake and cycle of nutrient. This investigation could provide useful information for high production.
文摘The phosphate in the soil-root interface zone under various soil water contents and application rates ofphosphate was still of depletion distribution which could be described by a power function in the form ofC/Co= ax￣b(C/Co is the relative content of fertilized phosphate in a distance from the root surface x, a andb are the regression constants). The depletion rate of phosphate in soil near the root surface was higher andthe depletion range was narrower under lower soil moisture. On the contrary, at higher soil water content thedepletion range was wider, generally The application rate of phosphate led to the greater depletion intensityof phosphorus was higher in the heavier texture soils. In general, the depletion intensity in the soils, whichdecreased with increasing clay content or increa.sing buffering power of soil, decreased in the order as loessalsoil and black fou soil> lou soil> yellow cinnamon soil when 50 or 100 mg of phosphorus were applied in theform of KH_2PO_4. This result indicated that the phosphate distribution and its movement in the soil-rootinterface zone closely related with the buffering capacity of soil.
文摘Complex multi-tier applications deployed in cloud computing environments can experience rapid changes in their workloads. To ensure market readiness of such applications, adequate resources need to be provisioned so that the applications can meet the demands of specified workload levels and at the same time ensure that service level agreements are met. Multi-tier cloud applications can have complex deployment configurations with load balancers, web servers, application servers and database servers. Complex dependencies may exist between servers in various tiers. To support provisioning and capacity planning decisions, performance testing approaches with synthetic workloads are used. Accuracy of a performance testing approach is determined by how closely the generated synthetic workloads mimic the realistic workloads. Since multi-tier applications can have varied deployment configurations and characteristic workloads, there is a need for a generic performance testing methodology that allows accurately modeling the performance of applications. We propose a methodology for performance testing of complex multi-tier applications. The workloads of multi-tier cloud applications are captured in two different models-benchmark application and workload models. An architecture model captures the deployment configurations of multi-tier applications. We propose a rapid deployment prototyping methodology that can help in choosing the best and most cost effective deployments for multi-tier applications that meet the specified performance requirements. We also describe a system bottleneck detection approach based on experimental evaluation of multi-tier applications.
基金supported by the Research Center of the Female Scientific and Medical Colleges,Deanship of Scientific Research,King Saud University
文摘A general version of the inverted exponential distribution is introduced, studied and analyzed. This generalization depends on the method of Marshall-Olkin to extend a family of distributions. Some statistical and reliability properties of this family are studied. In addition, numerical estimation of the maximum likelihood estimate（MLE） parameters are discussed in details. As an application, some real data sets are analyzed and it is observed that the presented family provides a better fit than some other known distributions.
文摘By analysing the scatter diagrams of characteristic the wave height H and the period T on the basis of instrumental data from various ocean wave stations, we found that the conditional expectation and standard deviation of wave period for a given wave height can be better predicted by using the equations of normal linear regression rather than by those based on the log- normal law. The latter was implied in Ochi' s bivariate log-normal model(Ochi. 1978) for the long-term joint distribution of H and T. With the expectation and standard deviation predicted by the normal linear regression equations and applying proper types of distribution, we have obtained the conditional distribution of T for given H. Then combining this conditional P(T / H) with long-term marginal distribution of the wave height P(H) we establish a new parameterized model for the long-term joint distribution P(H,T). As an example of the application of the new model we give a method for estimating wave period associated with an extreme wave height.
文摘Surface distribution and seasonal variation of alkalinity and specific alkalinity in Kuroshio area of the East ChinaSea and their application to the water mass tracing are discussed in this paper. Results show a distinct seasonal variation of the alkalinity, which is concerned with the process of vertical mixing. Different specific alkalinity in various water masses has been found. On the basis of the difference of the specific alkalinity and the distribution of alkalinity, two water fronts in summer season, located at 27°-30°N and 124°-1 27°E, (Ⅰ), and at the northern waters about one latitude from the Taiwan Island, (Ⅱ); one in winter season at about one longitude from coast of mainland of China and 26°-30°N were found. In summer season, about 1-2 longitudes eastward shift of front (Ⅰ) is found by comparison of data in May and August. And the high alkalinity of the northern East China Sea in summer season may be caused by the Huanghe River runoff flowing southward along with the Huanghai Sea Coastal Current.
基金Supported by the National Basic Research Program of China under Grant No 2013CB338002the National Natural Science Foundation of China under Grant Nos 11304397 and 61505261
文摘Recently, a novel kind of quantum key distribution called the round-robin differential phase-shift （RRDPS） protocol was proposed, which bounds the amount of leakage without monitoring signal disturbance. The protocol can be implemented by a weak coherent source. The security of this protocol with a simply characterized source has been proved. The application of a common phase shift can improve the secret key rate of the protocol. In practice, the randomized phase is discrete and the secret key rate is deviated from the continuous case. In this study, we analyze security of the RRDPS protocol with discrete-phase-randomized coherent state source and bound the secret key rate. We fix the length of each packet at 32 and 64, then simulate the secret key rates of the RRDPS protocol with discrete-phase randomization and continuous-phase randomization. Our simulation results show that the performance of the discrete-phase randomization case is close to the continuous counterpart with only a small number of discrete phases. The research is practically valuable for experimental implementation.
