Personal video recorders (PVRs) have altered the way users consume television (TV) content by allowing users to record programs and watch them at their convenience, overcoming the constraints of live broadcasting. How...Personal video recorders (PVRs) have altered the way users consume television (TV) content by allowing users to record programs and watch them at their convenience, overcoming the constraints of live broadcasting. However, standalone PVRs are limited by their individual storage capacities, restricting the number of programs they can store. While online catch-up TV services such as Hulu and Netflix mitigate this limitation by offering on-demand access to broadcast programs shortly after their initial broadcast, they require substantial storage and network resources, leading to significant infrastructural costs for service providers. To address these challenges, we propose a collaborative TV content recording system that leverages distributed PVRs, combining their storage into a virtual shared pool without additional costs. Our system aims to support all concurrent playback requests without service interruption while ensuring program availability comparable to that of local devices. The main contributions of our proposed system are fourfold. First, by sharing storage and upload bandwidth among PVRs, our system significantly expands the overall recording capacity and enables simultaneous recording of multiple programs without the physical constraints of standalone devices. Second, by utilizing erasure coding efficiently, our system reduces the storage space required for each program, allowing more programs to be recorded compared to traditional replication. Third, we propose an adaptive redundancy scheme to control the degree of redundancy of each program based on its evolving playback demand, ensuring high-quality playback by providing sufficient bandwidth for popular programs. Finally, we introduce a contribution-based incentive policy that encourages PVRs to actively participate by contributing resources, while discouraging excessive consumption of the combined storage pool. Through extensive experiments, we demonstrate the effectiveness of our proposed collaborative TV program recording system in terms of storage efficiency and performance.展开更多
A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines （A） and 5 restorer lines （R） along with their F1 （A × R） and F2 populations. The unconditional and conditio...A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines （A） and 5 restorer lines （R） along with their F1 （A × R） and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content （PC） and the appearance quality traits of indica rice （Oryza sativa L.）. The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness （BRT）. Only the genetic covariance between PC and the brown rice width （BRW） was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice （WBR） or the amylose content （AC） could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length （BRL）, BRW, or BRT through the geuotype x environmental （GE） interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width （RLW） or the ratio of brown rice length to thickness （RLT）. The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW.展开更多
A vision-based color analysis system was developed for rapid estimation of copper content in the secondary copper smelting process. Firstly, cross section images of secondary copper samples were captured by the design...A vision-based color analysis system was developed for rapid estimation of copper content in the secondary copper smelting process. Firstly, cross section images of secondary copper samples were captured by the designed vision system. After the preprocessing and segmenting procedures, the images were selected according to their grayscale standard deviations of pixels and percentages of edge pixels in the luminance component. The selected images were then used to extract the information of the improved color vector angles, from which the copper content estimation model was developed based on the least squares support vector regression (LSSVR) method. For comparison, three additional LSSVR models, namely, only with sample selection, only with improved color vector angle, without sample selection or improved color vector angle, were developed. In addition, two exponential models, namely, with sample selection, without sample selection, were developed. Experimental results indicate that the proposed method is more effective for improving the copper content estimation accuracy, particularly when the sample size is small.展开更多
By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechan...By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechanism of M. sieversii to changes of relative soil water content. According to the results, with the decrease of relative soil water content, MDA content in M. sieversii leaves increased by mem- brane lipid peroxidation. Cells resist water stress-induced membrane lipid peroxidation and clear the increased reactive oxygen species by improving soluble protein content and SOD, POD, CAT and APX activities. However, various enzymes were involved in the response to water stress under different moisture conditions. In addition, the results indicated that M. sieversii had a good adaptability to higher relative soil water contents.展开更多
OBJECTIVE:To evaluate evidence for the efficacy of Traditional Chinese Medicine(TCM) in systematic reviews.METHODS:Chinese(TCM Periodical Literature Database,Chinese Biological Medicine database,Chinese Medical Curren...OBJECTIVE:To evaluate evidence for the efficacy of Traditional Chinese Medicine(TCM) in systematic reviews.METHODS:Chinese(TCM Periodical Literature Database,Chinese Biological Medicine database,Chinese Medical Current Contents,China Hospital Knowledge Database journal fulltext database,Virtual Machining and Inspection System,and Wanfang) and English(Cochrane Database of Systematic Reviews,PubMed and Embase) databases were searched.RESULTS:Three thousand,nine hundred and fifty-five articles were initially identified,606 of which met the inclusion criteria,including 251 in English(83 from the Cochrane Database) and 355 in Chinese.The number of articles published each year increased between 1989 and 2009.Cardiocerebrovascular disease was the most studied target disease.Intervention measures included TCM preparations(177 articles),acupuncture(133 articles) and combinations of TCM and Western Medicine(38 articles).Control measures included positive medical(177 articles),basic treatment(100 articles),placebo(219 articles),and blank and mutual(107 articles).All articles included at least one reference;the greatest number was 268.Six of 10 articles with high quality references demonstrated curative effectsagainst target diseases including upper respiratory tract infection,dementia and depression.Interventions that were not recommended were tripterygium for rheumatoid arthritis and TCM syndrome differentiation for pediatric nocturia.In 10.4% of the studies,the authors concluded that the intervention had a curative effect.The assessors agreed with the authors' conclusions in 88.32% of cases,but rejected 8.94%(54 articles).CONCLUSION:1) Training in systematic review methods,including topic selection,study design,methods and technology,should be improved.2) Upper respiratory tract infection,dementia and depression may become the predominant diseases treated by TCM,and the corresponding interventions could be developed into practical applications.3) Use of non-recommended interventions should be controlled,and there should be more research on side effects.展开更多
The aim of this study was to compare the quality characteristics and mineral content of the fiber from male and female cashmere goats raised under different management systems. Male and female Raeini cashmere goats （...The aim of this study was to compare the quality characteristics and mineral content of the fiber from male and female cashmere goats raised under different management systems. Male and female Raeini cashmere goats （〈1.5 years of age, n=48） were selected from flocks raised at a government breeding station or raised commercially under either rural or nomadic conditions. The staple length, cashmere fiber diameter, coefficient of variation for fiber diameter, percentage of cashmere in a fleece, percentage of guard hair in a fleece and cashmere tenacity averaged 4.6 ±0.1 cm, 18.0 ±0.1 um, 20.9±0.4%, 66.1 ± 1.5%, 33.8± 1.5% and 1.8±0.2 gf/tex, respectively. The sulfur, copper and zinc content of the cashmere averaged 2.8 ± 0.1%, 0.00065 ± 0.00002% and 0.01276 ± 0.00025%, respectively. Rearing method significantly affected staple length, coefficient of variation of fiber diameter, cashmere tenacity and copper content. Males had a higher coefficient of variation of fiber diameter and cashmere tenacity than females （P 〈 0.05）.展开更多
Objective:This study aims to provide the material basis for the molecular mechanism of Yuxingcao(Houttuynia cordata Thunb,HCT)through the method of evidence-based study to summarize the natural constituents isolated f...Objective:This study aims to provide the material basis for the molecular mechanism of Yuxingcao(Houttuynia cordata Thunb,HCT)through the method of evidence-based study to summarize the natural constituents isolated from HCT.Methods:We searched CNKI,Wanfang,VIP,Pubmed and relevant conference compilations.The keywords were'Yuxingcao or Houttuynia cordata Thunb'and'components'or'ingredients'or'constituent'or'volatile oil'or'flavonoids'or'terpene'or'content',both in Chinese and English.According to the inclusion and exclusion criteria,the reported compositions and contents have been summarized,and SPSS software was used to draw the boxplot of contents.Results:A total of 603 natural compounds in 11 categories were obtained from pooled articles.In the diverse components,the number of aliphatic compounds(n=259)and terpenoids(n=158)are more than those of flavonoids(n=26),alkaloids(n=42)and aromatics(n=42).While,in the part of volatile oils of HCT,the largest components are aliphatic compounds(mainly distributed on the ground)and terpenoids(mainly distributed in the underground).Although,methyl n-nonylketone is distributed in the whole herb plant,a large proportion is present in the underground parts.As for non-volatiles,the flavonoid content(mainly distributed on the ground)was the highest,among which quercetin and its glycosyl derivatives were the prominent.Conclusion:The results of this study provide a more comprehensive material basis for the further study of HCT.It is also helpful to explain the mechanisms of anti-oxidant,anti-inflammatory,anti-bacterial,anti-viral and anti-cancer effects from the molecular target and molecular network levels.展开更多
In order to improve the cyclic stability of La-Mg-Ni system （Ce2Ni7-type） alloy electrode, small amount of Co was added in La0.75Mg0.25Ni3.5 alloy. The effect of Co on electrochemical performance and microstructure ...In order to improve the cyclic stability of La-Mg-Ni system （Ce2Ni7-type） alloy electrode, small amount of Co was added in La0.75Mg0.25Ni3.5 alloy. The effect of Co on electrochemical performance and microstructure of the alloys were investigated in detail. XRD results showed that the alloys had multiphase structure composed of （La, Mg）2Ni7, LaNi5 and small amount of LaNi2 phases. The discharge capacity of the alloys first increased and then decreased with increasing Co content. At a discharge current density of 900 mA/g, the HRD of the alloy electrodes increased from 81.3% （x=0） to 89.2 % （x=0.2）, and then reduced to 87.8 % （x=0.6）. After 60 charge/discharge cycles, the capacity retention rate of the alloys enhanced from 52.67% to 61.32%, and the capacity decay rate of the alloys decreased from 2.60 to 2.05 mAh/g per cycle with increasing Co content. The obtained results by XPS and XRD showed that the fundamental reasons for the capacity decay of the La-Mg-Ni system （Ce2Ni7-type） alloy electrodes were corrosion and oxidation as well as passivation of Mg and Lain alkaline solution.展开更多
Benggang erosion is caused by a special type of gully erosion in southern China that seriously endangers the local ecology and environment.In this study,typical Benggang collapsing-wall soils were used as the study ar...Benggang erosion is caused by a special type of gully erosion in southern China that seriously endangers the local ecology and environment.In this study,typical Benggang collapsing-wall soils were used as the study area to investigate the effects of different initial moisture contents and dicranopteris linearis root weight densities,as well as their interactions on disintegration in orthogonal test method.The results showed that the rate of soil disintegration decreased as a linear function of the initial moisture content.The soil disintegration rate tended to rise and then fall as the root weight density increased,reflecting an optimum root weight density of 0.75-1.00 g/100 cm3.The incorporation of dicranopteris linearis roots was most effective for soil consolidation in the shallow layers of soil.In addition,the disintegration rate of the collapsing-wall soils increases as the soil layer deepened.The dicranopteris linearis root system and initial moisture content had an interactive effect that was more pronounced in deeper soils.However,the combined effect of these processes was always dominated by the initial moisture content.Moderate initial soil moisture content(0.20-0.24 g/g)and the addition of a high root density in dicranopteris linearis(0.75-1.00 g/100 cm3)were the optimal combinations that reduced the disintegration rate.In conclusion,maintaining a suitable natural moisture content in collapsing-wall soils and taking measures that use plants to consolidate soil can effectively prevent and control the occurrence of Benggang erosion.The results of this study provided further insight into the factors that influence soil disintegration and offered a scientific basis for soil erosion management in the southern China.展开更多
This paper proposes a content addres sable storage optimization method, VDeskCAS, for desktop virtualization storage based disaster backup storage system. The method implements a blocklevel storage optimization, by em...This paper proposes a content addres sable storage optimization method, VDeskCAS, for desktop virtualization storage based disaster backup storage system. The method implements a blocklevel storage optimization, by employing the algorithms of chunking image file into blocks, the blockffmger calculation and the block dedup li cation. A File system in Use Space （FUSE） based storage process for VDeskCAS is also introduced which optimizes current direct storage to suit our content addressable storage. An interface level modification makes our system easy to extend. Experiments on virtual desktop image files and normal files verify the effectiveness of our method and above 60% storage volume decrease is a chieved for Red Hat Enterprise Linux image files. Key words： disaster backup; desktop virtualization; storage optimization; content addressable storage展开更多
The ice water content(IWC) distribution in a mixed-phase cloud system was investigated using Cloud-Sat data,aircraft measurements,and the Weather Research and Forecasting(WRF) model.Simulated precipitation and IWC wer...The ice water content(IWC) distribution in a mixed-phase cloud system was investigated using Cloud-Sat data,aircraft measurements,and the Weather Research and Forecasting(WRF) model.Simulated precipitation and IWC were in general agreement with rain gauge,sat-ellite,and aircraft observations.The cloud case was char-acterized by a predominant cold layer and high IWC throughout the cloud-development and precipitation stages.The CloudSat-retrieved products suggested that the IWC was distributed from 4.0 to 8.0 km,with the maximum values(up to 0.5 g m-3) at 5.0-6.0 km at the earlymature stage of cloud development.High IWC(up to 0.8 g m-3) was also detected by airborne probes at 4.2 and 3.6 km at the late-mature stage.The WRF model simulation re-vealed that the predominant riming facilitated rapid ac-cumulation of high IWC at 3.0-6.0 km.展开更多
Nurses are at the forefront of providing healthcare services to individuals of all age groups and with varying medical conditions.Aside from the critical knowledge and technical skills from nursing science,advancement...Nurses are at the forefront of providing healthcare services to individuals of all age groups and with varying medical conditions.Aside from the critical knowledge and technical skills from nursing science,advancement in technology has assisted nurses in delivering quality nursing care by streamlining workflow processes and ensuring that data can easily be retrieved or modified.Electronic health records dramatically changed the landscape of the healthcare practice by providing an electronic means to store data and for healthcare professionals to retrieve and manipulate health information in a secured and collaborative environment.But with the nature of data being stored in the electronic health records,nurses still need to organize and process these data into relevant information,knowledge or wisdom so they can provide better holistic care to patients.This discussion paper details the role of content management systems in addressing nursing workflow by providing a mechanism for nurses to be developers themselves,and not just users or consumers of health innovative technologies.By using content management systems as platform for application development,nurses or other healthcare professionals,may be able to address problems with internal workflow without having to incur huge amounts in software development,or having to extensively learn programming languages.展开更多
This study used Ecopath model of the Jiaozhou Bay as an example to evaluate the effect of stomach sample size of three fish species on the projection of this model. The derived ecosystem indices were classified into t...This study used Ecopath model of the Jiaozhou Bay as an example to evaluate the effect of stomach sample size of three fish species on the projection of this model. The derived ecosystem indices were classified into three categories:(1) direct indices, like the trophic level of species, influenced by stomach sample size directly;(2)indirect indices, like ecology efficiency(EE) of invertebrates, influenced by the multiple prey-predator relationships;and(3) systemic indices, like total system throughout(TST), describing the status of the whole ecosystem. The influences of different stomach sample sizes on these indices were evaluated. The results suggest that systemic indices of the ecosystem model were robust to stomach sample sizes, whereas specific indices related to species were indicated to be with low accuracy and precision when stomach samples were insufficient.The indices became more uncertain when the stomach sample sizes varied for more species. This study enhances the understanding of how the quality of diet composition data influences ecosystem modeling outputs. The results can also guide the design of stomach content analysis for developing ecosystem models.展开更多
Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A goo...Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A good understanding of the relative permeability and capillary pressure characteristics is crucial to predict the process of acid gas injection and migration.The prediction of injection and redistribution of acid gas is important to determine storage capacity,formation pressure,plume extent,shape,and leakage potential.Herein,the existing experimental data and theoretical models were reviewed to gain a better understanding of the issue how the H_(2)S content affects gas density,gas viscosity,interfacial tension,wettability,relative permeability and capillary pressure characteristics of acid gas/brine/rock systems.The densities and viscosities of the acid gas with different H_(2)S mole fractions are both temperature-and pressure-dependent,which vary among the gas,liquid and supercritical phases.Water/acid gas interfacial tension decreases strongly with increasing H_(2)S content.For mica and clean quartz,water contact angle increases with increasing H_(2)S mole fraction.In particular,wettability reversal of mica to a H_(2)S-wet behavior occurs in the presence of dense H_(2)S.The capillary pressure increases with decreasing contact angle.At a given saturation,the relative permeability of a fluid is higher when the fluid is nonwetting.The capillary pressure decreases with decreasing interfacial tension at a given saturation.However,the existing datasets do not show a consistent link between capillary number and relative permeability.The capillary pressure decreases with increasing H_(2)S mole fraction.However,there is no consensus on the effect of the H_(2)S content on the relative permeability curves.This may be due to the limited availability of the relative permeability and capillary pressure data for acid gas/brine/rock systems;thus,more experimental measurements are required.展开更多
Background: Although coronary heart disease (CHD) is the most common cause of death worldwide the literature shows a wide variation in the arrangement of cardiac rehabilitation and achieved lifestyle changes. Aim: The...Background: Although coronary heart disease (CHD) is the most common cause of death worldwide the literature shows a wide variation in the arrangement of cardiac rehabilitation and achieved lifestyle changes. Aim: The purpose of this study was to evaluate the effects of intensity (number of patient follow-ups), duration (length of intervention) and content in cardiac rehabilitation programs (CRP) regarding lifestyle changes in patients with CHD. Method: A systematic literature review of articles published in the databases PubMed and CINAHL between 1990 and 2007 was conducted. This resulted in 1120 hits of which 25 articles finally met the set criteria for inclusion. Results: The majority of significant positive results on lifestyle factors were shown among the studies describing high intensity and long duration. Included studies showed a wide variation in content, but four different interventions (informative content, educational content, practical content, behavioral and self care-oriented content) emerged. The group of studies which contained all four interventions focused on most lifestyle factors and achieved the most significant positive results. Conclusion: This systematic literature review shows that CRP should include high intensity, long duration and an intervention content covering information, knowledge, practical training, self care-activity and behavior changes in order to achieve effect on all four lifestyle factors of diet, physical activity and exercise, smoking and stress. Lifestyle changes can be reached in less lifestyle factors, with a longer duration and a variation of intensity of contacts but in combining with an informative and educational content with an additional content of a practical nature or self activity.展开更多
Content-based filtering E-commerce recommender system was discussed fully in this paper. Users＇ unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products ...Content-based filtering E-commerce recommender system was discussed fully in this paper. Users＇ unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products informa tion, the recommender lists were obtained. Since the system can adapt to the users＇ feedback automatically, its performance were enhanced comprehensively. Finally the evaluation of the system and the experimental results were presented.展开更多
In emulsion system, micro-organisms survive in water phase, thus concentration of preservative in water phase directly reflects to anti-fungi efficacy. As preservative easily migrates into oil phase, it reduces preser...In emulsion system, micro-organisms survive in water phase, thus concentration of preservative in water phase directly reflects to anti-fungi efficacy. As preservative easily migrates into oil phase, it reduces preservative efficacy. A common solution is to increase preservative amount in the whole system. However this way always brings safety issues as preservative is a major allergen. Another effective but safety way is to prohibit preservative migrating into oil phase. In cosmetic research area, phenoxyethanol （PE） and p-Hydroxyacetophenone （p-HAP） pair gradually emerges to be a popular preservative candidate. Thus this new preservative system has been focused as the research object in this work. The relative contents （C） of both PE （CPE） and p-HAP （Cp-HAP） in water phase has been carefully determined. Eight commonly used oils have been further employed to check CPE and Cp-HAP in different oil-water system. The other infuence parameters such as polyols, processing parameters are also investigated. Results shows squalane, petrolatum, silicone oil and hydrogenated polyisobutene might be good oil phase candidates for formulation when using PE and p-HAP preservative system. In these oil systems, PE and p-HAP are mainly located in water phase. Besides, increasing percentage of 1, 3-butylene glycol, shortening homogenization time or adding preservatives at the end of processing under lower temperature could effectively increase effective content preservatives in water phase, either.展开更多
In recent years, the file-sharing applications of peer-to-peer （P2P） systems, such as Napster, Bit-Torrent （BT）, Gnutella, have become very popular, with BT offering particularly high sealability and efficiency se...In recent years, the file-sharing applications of peer-to-peer （P2P） systems, such as Napster, Bit-Torrent （BT）, Gnutella, have become very popular, with BT offering particularly high sealability and efficiency service to transmit files. But BT does not enforce the access control process, so a lot of unauthorized files are freely shared. In this paper, we proposed a digital rights management （DRM） system for BT environment to solve the serious piracy issue by using lightweight encryption methods in order to he adopted by small mobile devices in wireless environment.展开更多
Engineers often need to look for the right pieces of information by sifting through long engineering documents, It is a very tiring and time-consuming job. To address this issue, researchers are increasingly devoting ...Engineers often need to look for the right pieces of information by sifting through long engineering documents, It is a very tiring and time-consuming job. To address this issue, researchers are increasingly devoting their attention to new ways to help information users, including engineers, to access and retrieve document content. The research reported in this paper explores how to use the key technologies of document decomposition （study of document structure）, document mark-up （with EXtensible Mark- up Language （XML）, HyperText Mark-up Language （HTML）, and Scalable Vector Graphics （SVG））, and a facetted classification mechanism. Document content extraction is implemented via computer programming （with Java）. An Engineering Document Content Management System （EDCMS） developed in this research demonstrates that as information providers we can make document content in a more accessible manner for information users including engineers.The main features of the EDCMS system are： 1） EDCMS is a system that enables users, especially engineers, to access and retrieve information at content rather than document level. In other words, it provides the right pieces of information that answer specific questions so that engineers don＇t need to waste time sifting through the whole document to obtain the required piece of information. 2） Users can use the EDCMS via both the data and metadata of a document to access engineering document content. 3） Users can use the EDCMS to access and retrieve content objects, i.e. text, images and graphics （including engineering drawings） via multiple views and at different granularities based on decomposition schemes. Experiments with the EDCMS have been conducted on semi-structured documents, a textbook of CADCAM, and a set of project posters in the Engineering Design domain. Experimental results show that the system provides information users with a powerful solution to access document content.展开更多
For lack of effective resource adjustment method, the supply-demand relationship of each resource in P2P content delivery system are often unbalanced. Especially after a popular content releasing, a burst of downloade...For lack of effective resource adjustment method, the supply-demand relationship of each resource in P2P content delivery system are often unbalanced. Especially after a popular content releasing, a burst of downloaders often can＇t find sufficient uploaders and their request may starve the upload capacity of server. Therefore the overall system QoS may be degraded. To tackle such issue, this paper proposes a download rate accelerate mechanism, called motivate mechanism. With it, the system can quickly find out the files becoming insufficient by monitoring the operating status of the files hourly, Then it promptly increase the number of copies of those files by using free rider nodes so that the whole system QoS is maintained and the system performance is improved. The experiment results on the practical operating system of Tencent demonstrated that the proposed mechanism increases the download rate, saves the traffic on the server and optimizes the system performance.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.2019R1A2C1002221 and RS-2023-00252186)Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(Nos.2021-0-00590,RS-2021-II210590Decentralized High Performance Consensus for Large-Scale Blockchains).
文摘Personal video recorders (PVRs) have altered the way users consume television (TV) content by allowing users to record programs and watch them at their convenience, overcoming the constraints of live broadcasting. However, standalone PVRs are limited by their individual storage capacities, restricting the number of programs they can store. While online catch-up TV services such as Hulu and Netflix mitigate this limitation by offering on-demand access to broadcast programs shortly after their initial broadcast, they require substantial storage and network resources, leading to significant infrastructural costs for service providers. To address these challenges, we propose a collaborative TV content recording system that leverages distributed PVRs, combining their storage into a virtual shared pool without additional costs. Our system aims to support all concurrent playback requests without service interruption while ensuring program availability comparable to that of local devices. The main contributions of our proposed system are fourfold. First, by sharing storage and upload bandwidth among PVRs, our system significantly expands the overall recording capacity and enables simultaneous recording of multiple programs without the physical constraints of standalone devices. Second, by utilizing erasure coding efficiently, our system reduces the storage space required for each program, allowing more programs to be recorded compared to traditional replication. Third, we propose an adaptive redundancy scheme to control the degree of redundancy of each program based on its evolving playback demand, ensuring high-quality playback by providing sufficient bandwidth for popular programs. Finally, we introduce a contribution-based incentive policy that encourages PVRs to actively participate by contributing resources, while discouraging excessive consumption of the combined storage pool. Through extensive experiments, we demonstrate the effectiveness of our proposed collaborative TV program recording system in terms of storage efficiency and performance.
基金This work was supported by National Natural Science Foundation of China (No. 30571198) and the Science and Technology Office of Zhejiang Province (No. 2004C2020-2 and No. 011102471).
文摘A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines （A） and 5 restorer lines （R） along with their F1 （A × R） and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content （PC） and the appearance quality traits of indica rice （Oryza sativa L.）. The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness （BRT）. Only the genetic covariance between PC and the brown rice width （BRW） was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice （WBR） or the amylose content （AC） could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length （BRL）, BRW, or BRT through the geuotype x environmental （GE） interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width （RLW） or the ratio of brown rice length to thickness （RLT）. The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW.
基金Project(2011BAE23B05)supported by National Key Technology R&D Program of ChinaProject(61004134)supported by the National Natural Science Foundation of ChinaProject(LQ13F030007)supported by Zhejiang Provincial Natural Science Foundation of China
文摘A vision-based color analysis system was developed for rapid estimation of copper content in the secondary copper smelting process. Firstly, cross section images of secondary copper samples were captured by the designed vision system. After the preprocessing and segmenting procedures, the images were selected according to their grayscale standard deviations of pixels and percentages of edge pixels in the luminance component. The selected images were then used to extract the information of the improved color vector angles, from which the copper content estimation model was developed based on the least squares support vector regression (LSSVR) method. For comparison, three additional LSSVR models, namely, only with sample selection, only with improved color vector angle, without sample selection or improved color vector angle, were developed. In addition, two exponential models, namely, with sample selection, without sample selection, were developed. Experimental results indicate that the proposed method is more effective for improving the copper content estimation accuracy, particularly when the sample size is small.
基金Supported by Science and Technology Innovation Project of Ji'nan City "Identification of Stress-resistant Malus sieversii Germplasm Resources and Screening of Stressresistance Functional Genes"(201401125)~~
文摘By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechanism of M. sieversii to changes of relative soil water content. According to the results, with the decrease of relative soil water content, MDA content in M. sieversii leaves increased by mem- brane lipid peroxidation. Cells resist water stress-induced membrane lipid peroxidation and clear the increased reactive oxygen species by improving soluble protein content and SOD, POD, CAT and APX activities. However, various enzymes were involved in the response to water stress under different moisture conditions. In addition, the results indicated that M. sieversii had a good adaptability to higher relative soil water contents.
文摘OBJECTIVE:To evaluate evidence for the efficacy of Traditional Chinese Medicine(TCM) in systematic reviews.METHODS:Chinese(TCM Periodical Literature Database,Chinese Biological Medicine database,Chinese Medical Current Contents,China Hospital Knowledge Database journal fulltext database,Virtual Machining and Inspection System,and Wanfang) and English(Cochrane Database of Systematic Reviews,PubMed and Embase) databases were searched.RESULTS:Three thousand,nine hundred and fifty-five articles were initially identified,606 of which met the inclusion criteria,including 251 in English(83 from the Cochrane Database) and 355 in Chinese.The number of articles published each year increased between 1989 and 2009.Cardiocerebrovascular disease was the most studied target disease.Intervention measures included TCM preparations(177 articles),acupuncture(133 articles) and combinations of TCM and Western Medicine(38 articles).Control measures included positive medical(177 articles),basic treatment(100 articles),placebo(219 articles),and blank and mutual(107 articles).All articles included at least one reference;the greatest number was 268.Six of 10 articles with high quality references demonstrated curative effectsagainst target diseases including upper respiratory tract infection,dementia and depression.Interventions that were not recommended were tripterygium for rheumatoid arthritis and TCM syndrome differentiation for pediatric nocturia.In 10.4% of the studies,the authors concluded that the intervention had a curative effect.The assessors agreed with the authors' conclusions in 88.32% of cases,but rejected 8.94%(54 articles).CONCLUSION:1) Training in systematic review methods,including topic selection,study design,methods and technology,should be improved.2) Upper respiratory tract infection,dementia and depression may become the predominant diseases treated by TCM,and the corresponding interventions could be developed into practical applications.3) Use of non-recommended interventions should be controlled,and there should be more research on side effects.
基金the Agricultural Research Center of Kerman for their financial support
文摘The aim of this study was to compare the quality characteristics and mineral content of the fiber from male and female cashmere goats raised under different management systems. Male and female Raeini cashmere goats （〈1.5 years of age, n=48） were selected from flocks raised at a government breeding station or raised commercially under either rural or nomadic conditions. The staple length, cashmere fiber diameter, coefficient of variation for fiber diameter, percentage of cashmere in a fleece, percentage of guard hair in a fleece and cashmere tenacity averaged 4.6 ±0.1 cm, 18.0 ±0.1 um, 20.9±0.4%, 66.1 ± 1.5%, 33.8± 1.5% and 1.8±0.2 gf/tex, respectively. The sulfur, copper and zinc content of the cashmere averaged 2.8 ± 0.1%, 0.00065 ± 0.00002% and 0.01276 ± 0.00025%, respectively. Rearing method significantly affected staple length, coefficient of variation of fiber diameter, cashmere tenacity and copper content. Males had a higher coefficient of variation of fiber diameter and cashmere tenacity than females （P 〈 0.05）.
文摘Objective:This study aims to provide the material basis for the molecular mechanism of Yuxingcao(Houttuynia cordata Thunb,HCT)through the method of evidence-based study to summarize the natural constituents isolated from HCT.Methods:We searched CNKI,Wanfang,VIP,Pubmed and relevant conference compilations.The keywords were'Yuxingcao or Houttuynia cordata Thunb'and'components'or'ingredients'or'constituent'or'volatile oil'or'flavonoids'or'terpene'or'content',both in Chinese and English.According to the inclusion and exclusion criteria,the reported compositions and contents have been summarized,and SPSS software was used to draw the boxplot of contents.Results:A total of 603 natural compounds in 11 categories were obtained from pooled articles.In the diverse components,the number of aliphatic compounds(n=259)and terpenoids(n=158)are more than those of flavonoids(n=26),alkaloids(n=42)and aromatics(n=42).While,in the part of volatile oils of HCT,the largest components are aliphatic compounds(mainly distributed on the ground)and terpenoids(mainly distributed in the underground).Although,methyl n-nonylketone is distributed in the whole herb plant,a large proportion is present in the underground parts.As for non-volatiles,the flavonoid content(mainly distributed on the ground)was the highest,among which quercetin and its glycosyl derivatives were the prominent.Conclusion:The results of this study provide a more comprehensive material basis for the further study of HCT.It is also helpful to explain the mechanisms of anti-oxidant,anti-inflammatory,anti-bacterial,anti-viral and anti-cancer effects from the molecular target and molecular network levels.
基金the National Natural Science Foundation of China (50701011)Natural Science Foundation of Inner Mongolia, China (200711020703)Science and Technology Planned Project of Inner Mongolia, China (20050205)
文摘In order to improve the cyclic stability of La-Mg-Ni system （Ce2Ni7-type） alloy electrode, small amount of Co was added in La0.75Mg0.25Ni3.5 alloy. The effect of Co on electrochemical performance and microstructure of the alloys were investigated in detail. XRD results showed that the alloys had multiphase structure composed of （La, Mg）2Ni7, LaNi5 and small amount of LaNi2 phases. The discharge capacity of the alloys first increased and then decreased with increasing Co content. At a discharge current density of 900 mA/g, the HRD of the alloy electrodes increased from 81.3% （x=0） to 89.2 % （x=0.2）, and then reduced to 87.8 % （x=0.6）. After 60 charge/discharge cycles, the capacity retention rate of the alloys enhanced from 52.67% to 61.32%, and the capacity decay rate of the alloys decreased from 2.60 to 2.05 mAh/g per cycle with increasing Co content. The obtained results by XPS and XRD showed that the fundamental reasons for the capacity decay of the La-Mg-Ni system （Ce2Ni7-type） alloy electrodes were corrosion and oxidation as well as passivation of Mg and Lain alkaline solution.
基金supported by the Special Projects of the Central Government Guiding Local Science and Technology Development in China(Guike.ZY21195022)the National Natural Science Foundation of China(No.42007055 and 42107350)。
文摘Benggang erosion is caused by a special type of gully erosion in southern China that seriously endangers the local ecology and environment.In this study,typical Benggang collapsing-wall soils were used as the study area to investigate the effects of different initial moisture contents and dicranopteris linearis root weight densities,as well as their interactions on disintegration in orthogonal test method.The results showed that the rate of soil disintegration decreased as a linear function of the initial moisture content.The soil disintegration rate tended to rise and then fall as the root weight density increased,reflecting an optimum root weight density of 0.75-1.00 g/100 cm3.The incorporation of dicranopteris linearis roots was most effective for soil consolidation in the shallow layers of soil.In addition,the disintegration rate of the collapsing-wall soils increases as the soil layer deepened.The dicranopteris linearis root system and initial moisture content had an interactive effect that was more pronounced in deeper soils.However,the combined effect of these processes was always dominated by the initial moisture content.Moderate initial soil moisture content(0.20-0.24 g/g)and the addition of a high root density in dicranopteris linearis(0.75-1.00 g/100 cm3)were the optimal combinations that reduced the disintegration rate.In conclusion,maintaining a suitable natural moisture content in collapsing-wall soils and taking measures that use plants to consolidate soil can effectively prevent and control the occurrence of Benggang erosion.The results of this study provided further insight into the factors that influence soil disintegration and offered a scientific basis for soil erosion management in the southern China.
基金the Hi-tech Research and Development Program of China，the National Natural Science Foundation of China，the Beijing Natural Science Foundation，the Fundamental Research Funds for the Central Universities，the Fund of the State Key Laboratory of Software Development Environment
文摘This paper proposes a content addres sable storage optimization method, VDeskCAS, for desktop virtualization storage based disaster backup storage system. The method implements a blocklevel storage optimization, by employing the algorithms of chunking image file into blocks, the blockffmger calculation and the block dedup li cation. A File system in Use Space （FUSE） based storage process for VDeskCAS is also introduced which optimizes current direct storage to suit our content addressable storage. An interface level modification makes our system easy to extend. Experiments on virtual desktop image files and normal files verify the effectiveness of our method and above 60% storage volume decrease is a chieved for Red Hat Enterprise Linux image files. Key words： disaster backup; desktop virtualization; storage optimization; content addressable storage
基金supported by the National Basic Research Program of China (973 Program,Grant No.2013CB430105)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KZCX2-EW-203)the National Natural Science Foundation of China (Grant No.41105095)
文摘The ice water content(IWC) distribution in a mixed-phase cloud system was investigated using Cloud-Sat data,aircraft measurements,and the Weather Research and Forecasting(WRF) model.Simulated precipitation and IWC were in general agreement with rain gauge,sat-ellite,and aircraft observations.The cloud case was char-acterized by a predominant cold layer and high IWC throughout the cloud-development and precipitation stages.The CloudSat-retrieved products suggested that the IWC was distributed from 4.0 to 8.0 km,with the maximum values(up to 0.5 g m-3) at 5.0-6.0 km at the earlymature stage of cloud development.High IWC(up to 0.8 g m-3) was also detected by airborne probes at 4.2 and 3.6 km at the late-mature stage.The WRF model simulation re-vealed that the predominant riming facilitated rapid ac-cumulation of high IWC at 3.0-6.0 km.
文摘Nurses are at the forefront of providing healthcare services to individuals of all age groups and with varying medical conditions.Aside from the critical knowledge and technical skills from nursing science,advancement in technology has assisted nurses in delivering quality nursing care by streamlining workflow processes and ensuring that data can easily be retrieved or modified.Electronic health records dramatically changed the landscape of the healthcare practice by providing an electronic means to store data and for healthcare professionals to retrieve and manipulate health information in a secured and collaborative environment.But with the nature of data being stored in the electronic health records,nurses still need to organize and process these data into relevant information,knowledge or wisdom so they can provide better holistic care to patients.This discussion paper details the role of content management systems in addressing nursing workflow by providing a mechanism for nurses to be developers themselves,and not just users or consumers of health innovative technologies.By using content management systems as platform for application development,nurses or other healthcare professionals,may be able to address problems with internal workflow without having to incur huge amounts in software development,or having to extensively learn programming languages.
基金The National Natural Science Foundation of China under contract No.31772852the Fundamental Research Funds for the Central Universities under contract No.201612004。
文摘This study used Ecopath model of the Jiaozhou Bay as an example to evaluate the effect of stomach sample size of three fish species on the projection of this model. The derived ecosystem indices were classified into three categories:(1) direct indices, like the trophic level of species, influenced by stomach sample size directly;(2)indirect indices, like ecology efficiency(EE) of invertebrates, influenced by the multiple prey-predator relationships;and(3) systemic indices, like total system throughout(TST), describing the status of the whole ecosystem. The influences of different stomach sample sizes on these indices were evaluated. The results suggest that systemic indices of the ecosystem model were robust to stomach sample sizes, whereas specific indices related to species were indicated to be with low accuracy and precision when stomach samples were insufficient.The indices became more uncertain when the stomach sample sizes varied for more species. This study enhances the understanding of how the quality of diet composition data influences ecosystem modeling outputs. The results can also guide the design of stomach content analysis for developing ecosystem models.
基金the National Natural Science Foundation of China(Grant Nos.41872210 and 41274111)the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering(Grant No.Z018002)。
文摘Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A good understanding of the relative permeability and capillary pressure characteristics is crucial to predict the process of acid gas injection and migration.The prediction of injection and redistribution of acid gas is important to determine storage capacity,formation pressure,plume extent,shape,and leakage potential.Herein,the existing experimental data and theoretical models were reviewed to gain a better understanding of the issue how the H_(2)S content affects gas density,gas viscosity,interfacial tension,wettability,relative permeability and capillary pressure characteristics of acid gas/brine/rock systems.The densities and viscosities of the acid gas with different H_(2)S mole fractions are both temperature-and pressure-dependent,which vary among the gas,liquid and supercritical phases.Water/acid gas interfacial tension decreases strongly with increasing H_(2)S content.For mica and clean quartz,water contact angle increases with increasing H_(2)S mole fraction.In particular,wettability reversal of mica to a H_(2)S-wet behavior occurs in the presence of dense H_(2)S.The capillary pressure increases with decreasing contact angle.At a given saturation,the relative permeability of a fluid is higher when the fluid is nonwetting.The capillary pressure decreases with decreasing interfacial tension at a given saturation.However,the existing datasets do not show a consistent link between capillary number and relative permeability.The capillary pressure decreases with increasing H_(2)S mole fraction.However,there is no consensus on the effect of the H_(2)S content on the relative permeability curves.This may be due to the limited availability of the relative permeability and capillary pressure data for acid gas/brine/rock systems;thus,more experimental measurements are required.
文摘Background: Although coronary heart disease (CHD) is the most common cause of death worldwide the literature shows a wide variation in the arrangement of cardiac rehabilitation and achieved lifestyle changes. Aim: The purpose of this study was to evaluate the effects of intensity (number of patient follow-ups), duration (length of intervention) and content in cardiac rehabilitation programs (CRP) regarding lifestyle changes in patients with CHD. Method: A systematic literature review of articles published in the databases PubMed and CINAHL between 1990 and 2007 was conducted. This resulted in 1120 hits of which 25 articles finally met the set criteria for inclusion. Results: The majority of significant positive results on lifestyle factors were shown among the studies describing high intensity and long duration. Included studies showed a wide variation in content, but four different interventions (informative content, educational content, practical content, behavioral and self care-oriented content) emerged. The group of studies which contained all four interventions focused on most lifestyle factors and achieved the most significant positive results. Conclusion: This systematic literature review shows that CRP should include high intensity, long duration and an intervention content covering information, knowledge, practical training, self care-activity and behavior changes in order to achieve effect on all four lifestyle factors of diet, physical activity and exercise, smoking and stress. Lifestyle changes can be reached in less lifestyle factors, with a longer duration and a variation of intensity of contacts but in combining with an informative and educational content with an additional content of a practical nature or self activity.
基金Supported bythe Hunan Teaching Reformand Re-search Project of Colleges and Universities (2003-B72) the HunanBoard of Review on Philosophic and Social Scientific Pay-off Project(0406035) the Hunan Soft Science Research Project(04ZH6005)
文摘Content-based filtering E-commerce recommender system was discussed fully in this paper. Users＇ unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products informa tion, the recommender lists were obtained. Since the system can adapt to the users＇ feedback automatically, its performance were enhanced comprehensively. Finally the evaluation of the system and the experimental results were presented.
文摘In emulsion system, micro-organisms survive in water phase, thus concentration of preservative in water phase directly reflects to anti-fungi efficacy. As preservative easily migrates into oil phase, it reduces preservative efficacy. A common solution is to increase preservative amount in the whole system. However this way always brings safety issues as preservative is a major allergen. Another effective but safety way is to prohibit preservative migrating into oil phase. In cosmetic research area, phenoxyethanol （PE） and p-Hydroxyacetophenone （p-HAP） pair gradually emerges to be a popular preservative candidate. Thus this new preservative system has been focused as the research object in this work. The relative contents （C） of both PE （CPE） and p-HAP （Cp-HAP） in water phase has been carefully determined. Eight commonly used oils have been further employed to check CPE and Cp-HAP in different oil-water system. The other infuence parameters such as polyols, processing parameters are also investigated. Results shows squalane, petrolatum, silicone oil and hydrogenated polyisobutene might be good oil phase candidates for formulation when using PE and p-HAP preservative system. In these oil systems, PE and p-HAP are mainly located in water phase. Besides, increasing percentage of 1, 3-butylene glycol, shortening homogenization time or adding preservatives at the end of processing under lower temperature could effectively increase effective content preservatives in water phase, either.
基金supported by the National Science Council under Grant No. NSC100-2221-E-005-067
文摘In recent years, the file-sharing applications of peer-to-peer （P2P） systems, such as Napster, Bit-Torrent （BT）, Gnutella, have become very popular, with BT offering particularly high sealability and efficiency service to transmit files. But BT does not enforce the access control process, so a lot of unauthorized files are freely shared. In this paper, we proposed a digital rights management （DRM） system for BT environment to solve the serious piracy issue by using lightweight encryption methods in order to he adopted by small mobile devices in wireless environment.
基金This work was supported by the UK Engineering and Physical Sciences Research Council(EPSRC)(No.GR/R67507/01).
文摘Engineers often need to look for the right pieces of information by sifting through long engineering documents, It is a very tiring and time-consuming job. To address this issue, researchers are increasingly devoting their attention to new ways to help information users, including engineers, to access and retrieve document content. The research reported in this paper explores how to use the key technologies of document decomposition （study of document structure）, document mark-up （with EXtensible Mark- up Language （XML）, HyperText Mark-up Language （HTML）, and Scalable Vector Graphics （SVG））, and a facetted classification mechanism. Document content extraction is implemented via computer programming （with Java）. An Engineering Document Content Management System （EDCMS） developed in this research demonstrates that as information providers we can make document content in a more accessible manner for information users including engineers.The main features of the EDCMS system are： 1） EDCMS is a system that enables users, especially engineers, to access and retrieve information at content rather than document level. In other words, it provides the right pieces of information that answer specific questions so that engineers don＇t need to waste time sifting through the whole document to obtain the required piece of information. 2） Users can use the EDCMS via both the data and metadata of a document to access engineering document content. 3） Users can use the EDCMS to access and retrieve content objects, i.e. text, images and graphics （including engineering drawings） via multiple views and at different granularities based on decomposition schemes. Experiments with the EDCMS have been conducted on semi-structured documents, a textbook of CADCAM, and a set of project posters in the Engineering Design domain. Experimental results show that the system provides information users with a powerful solution to access document content.
基金National Science Foundation Project of P.R.China，China Postdoctoral Science Foundation，the Fundamental Research Funds for the Central Universities
文摘For lack of effective resource adjustment method, the supply-demand relationship of each resource in P2P content delivery system are often unbalanced. Especially after a popular content releasing, a burst of downloaders often can＇t find sufficient uploaders and their request may starve the upload capacity of server. Therefore the overall system QoS may be degraded. To tackle such issue, this paper proposes a download rate accelerate mechanism, called motivate mechanism. With it, the system can quickly find out the files becoming insufficient by monitoring the operating status of the files hourly, Then it promptly increase the number of copies of those files by using free rider nodes so that the whole system QoS is maintained and the system performance is improved. The experiment results on the practical operating system of Tencent demonstrated that the proposed mechanism increases the download rate, saves the traffic on the server and optimizes the system performance.
