期刊文献+
共找到6,950篇文章
< 1 2 250 >
每页显示 20 50 100
Rock mass quality prediction on tunnel faces with incomplete multi-source dataset via tree-augmented naive Bayesian network 被引量:1
1
作者 Hongwei Huang Chen Wu +3 位作者 Mingliang Zhou Jiayao Chen Tianze Han Le Zhang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第3期323-337,共15页
Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel faces.In tunneling practice,the rock mass quality is often assessed via a combination of qualitative and quantita... Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel faces.In tunneling practice,the rock mass quality is often assessed via a combination of qualitative and quantitative parameters.However,due to the harsh on-site construction conditions,it is rather difficult to obtain some of the evaluation parameters which are essential for the rock mass quality prediction.In this study,a novel improved Swin Transformer is proposed to detect,segment,and quantify rock mass characteristic parameters such as water leakage,fractures,weak interlayers.The site experiment results demonstrate that the improved Swin Transformer achieves optimal segmentation results and achieving accuracies of 92%,81%,and 86%for water leakage,fractures,and weak interlayers,respectively.A multisource rock tunnel face characteristic(RTFC)dataset includes 11 parameters for predicting rock mass quality is established.Considering the limitations in predictive performance of incomplete evaluation parameters exist in this dataset,a novel tree-augmented naive Bayesian network(BN)is proposed to address the challenge of the incomplete dataset and achieved a prediction accuracy of 88%.In comparison with other commonly used Machine Learning models the proposed BN-based approach proved an improved performance on predicting the rock mass quality with the incomplete dataset.By utilizing the established BN,a further sensitivity analysis is conducted to quantitatively evaluate the importance of the various parameters,results indicate that the rock strength and fractures parameter exert the most significant influence on rock mass quality. 展开更多
关键词 Rock mass quality Tunnel faces Incomplete multi-source dataset Improved Swin Transformer Bayesian networks
下载PDF
A multi-source information fusion layer counting method for penetration fuze based on TCN-LSTM
2
作者 Yili Wang Changsheng Li Xiaofeng Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期463-474,共12页
When employing penetration ammunition to strike multi-story buildings,the detection methods using acceleration sensors suffer from signal aliasing,while magnetic detection methods are susceptible to interference from ... When employing penetration ammunition to strike multi-story buildings,the detection methods using acceleration sensors suffer from signal aliasing,while magnetic detection methods are susceptible to interference from ferromagnetic materials,thereby posing challenges in accurately determining the number of layers.To address this issue,this research proposes a layer counting method for penetration fuze that incorporates multi-source information fusion,utilizing both the temporal convolutional network(TCN)and the long short-term memory(LSTM)recurrent network.By leveraging the strengths of these two network structures,the method extracts temporal and high-dimensional features from the multi-source physical field during the penetration process,establishing a relationship between the multi-source physical field and the distance between the fuze and the target plate.A simulation model is developed to simulate the overload and magnetic field of a projectile penetrating multiple layers of target plates,capturing the multi-source physical field signals and their patterns during the penetration process.The analysis reveals that the proposed multi-source fusion layer counting method reduces errors by 60% and 50% compared to single overload layer counting and single magnetic anomaly signal layer counting,respectively.The model's predictive performance is evaluated under various operating conditions,including different ratios of added noise to random sample positions,penetration speeds,and spacing between target plates.The maximum errors in fuze penetration time predicted by the three modes are 0.08 ms,0.12 ms,and 0.16 ms,respectively,confirming the robustness of the proposed model.Moreover,the model's predictions indicate that the fitting degree for large interlayer spacings is superior to that for small interlayer spacings due to the influence of stress waves. 展开更多
关键词 Penetration fuze Temporal convolutional network(TCN) Long short-term memory(LSTM) Layer counting multi-source fusion
下载PDF
Multi-source heterogeneous data access management framework and key technologies for electric power Internet of Things
3
作者 Pengtian Guo Kai Xiao +1 位作者 Xiaohui Wang Daoxing Li 《Global Energy Interconnection》 EI CSCD 2024年第1期94-105,共12页
The power Internet of Things(IoT)is a significant trend in technology and a requirement for national strategic development.With the deepening digital transformation of the power grid,China’s power system has initiall... The power Internet of Things(IoT)is a significant trend in technology and a requirement for national strategic development.With the deepening digital transformation of the power grid,China’s power system has initially built a power IoT architecture comprising a perception,network,and platform application layer.However,owing to the structural complexity of the power system,the construction of the power IoT continues to face problems such as complex access management of massive heterogeneous equipment,diverse IoT protocol access methods,high concurrency of network communications,and weak data security protection.To address these issues,this study optimizes the existing architecture of the power IoT and designs an integrated management framework for the access of multi-source heterogeneous data in the power IoT,comprising cloud,pipe,edge,and terminal parts.It further reviews and analyzes the key technologies involved in the power IoT,such as the unified management of the physical model,high concurrent access,multi-protocol access,multi-source heterogeneous data storage management,and data security control,to provide a more flexible,efficient,secure,and easy-to-use solution for multi-source heterogeneous data access in the power IoT. 展开更多
关键词 Power Internet of Things Object model High concurrency access Zero trust mechanism multi-source heterogeneous data
下载PDF
Runout prediction of potential landslides based on the multi-source data collaboration analysis on historical cases
4
作者 Jun Sun Yu Zhuang Ai-guo Xing 《China Geology》 CAS CSCD 2024年第2期264-276,共13页
Long runout landslides involve a massive amount of energy and can be extremely hazardous owing to their long movement distance,high mobility and strong destructive power.Numerical methods have been widely used to pred... Long runout landslides involve a massive amount of energy and can be extremely hazardous owing to their long movement distance,high mobility and strong destructive power.Numerical methods have been widely used to predict the landslide runout but a fundamental problem remained is how to determine the reliable numerical parameters.This study proposes a framework to predict the runout of potential landslides through multi-source data collaboration and numerical analysis of historical landslide events.Specifically,for the historical landslide cases,the landslide-induced seismic signal,geophysical surveys,and possible in-situ drone/phone videos(multi-source data collaboration)can validate the numerical results in terms of landslide dynamics and deposit features and help calibrate the numerical(rheological)parameters.Subsequently,the calibrated numerical parameters can be used to numerically predict the runout of potential landslides in the region with a similar geological setting to the recorded events.Application of the runout prediction approach to the 2020 Jiashanying landslide in Guizhou,China gives reasonable results in comparison to the field observations.The numerical parameters are determined from the multi-source data collaboration analysis of a historical case in the region(2019 Shuicheng landslide).The proposed framework for landslide runout prediction can be of great utility for landslide risk assessment and disaster reduction in mountainous regions worldwide. 展开更多
关键词 Landslide runout prediction Drone survey multi-source data collaboration DAN3D numerical modeling Jianshanying landslide Guizhou Province Geological hazards survey engineering
下载PDF
An Assessment of Procurement Risks Management Systems in the Public Sector
5
作者 Atoapem Frimpong Barimah Joyce-Jael Amoafoa Mensah 《Chinese Business Review》 2024年第2期76-86,共11页
Risk management in public procurement is a critical aspect that needs to be addressed in the public sector.Several studies have been conducted to understand the challenges and factors influencing risk management in pu... Risk management in public procurement is a critical aspect that needs to be addressed in the public sector.Several studies have been conducted to understand the challenges and factors influencing risk management in public procurement.These studies have explored the importance of risk management principles,the role of political influence,and the need for effective risk assessment and anticipation.The research has also highlighted the need for specific risk management mechanisms and tools to be implemented in public procurement processes.Risk management reforms in the public sector are essential but often circumvented due to assorted reasons,such as political influence and the emergence of new risks.The research investigation employs a quantitative research design.A total of 380 questionnaires were recovered from respondents.The study showed that the public sector has a procurement risk management system that is effective,but there may be some areas for improvement in the prequalification process,onboarding process,and support provided to newly onboarded suppliers.Additionally,the public sector used some strategies to mitigate and control contract risks during the procurement process,but there were some areas for improvement in the review and lessons learned process,risk mitigation measures,contract monitoring and performance evaluation mechanisms,and communication and documentation process.Finally,the results suggest that there were constraints placed on the risk management strategies currently utilized by professionals working in the public sector.These constraints include insufficient support and buy-in from senior management and stakeholders,bureaucratic or administrative hurdles,inadequate policies and regulations,insufficient training and skill development opportunities,and insufficient resources.The study highlights the significance of tackling risk management in the realm of public procurement and offers valuable perspectives on avenues for enhancement,obstacles encountered by practitioners,and the necessity of thorough evaluation and revisions.Through the adoption of the suggestions originating from this study,governmental entities can improve their procurement risk management frameworks and guarantee improved adherence to risk management principles. 展开更多
关键词 public sector public procurement SUPPLIERS risk management STRATEGIES
下载PDF
A Web-Based Approach for the Efficient Management of Massive Multi-source 3D Models
6
作者 ZHAO Qiansheng TANG Ruibing +1 位作者 PENG Mingjun GUO Mingwu 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第3期24-41,共18页
Effectively managing extensive,multi-source,and multi-level real-scene 3D models for responsive retrieval scheduling and rapid visualization in the Web environment is a significant challenge in the current development... Effectively managing extensive,multi-source,and multi-level real-scene 3D models for responsive retrieval scheduling and rapid visualization in the Web environment is a significant challenge in the current development of real-scene 3D applications in China.In this paper,we address this challenge by reorganizing spatial and temporal information into a 3D geospatial grid.It introduces the Global 3D Geocoding System(G_(3)DGS),leveraging neighborhood similarity and uniqueness for efficient storage,retrieval,updating,and scheduling of these models.A combination of G_(3)DGS and non-relational databases is implemented,enhancing data storage scalability and flexibility.Additionally,a model detail management scheduling strategy(TLOD)based on G_(3)DGS and an importance factor T is designed.Compared with mainstream commercial and open-source platforms,this method significantly enhances the loadable capacity of massive multi-source real-scene 3D models in the Web environment by 33%,improves browsing efficiency by 48%,and accelerates invocation speed by 40%. 展开更多
关键词 massive multi-source real-scene 3D model non-relational database global 3D geocoding system importance factor massive model management
下载PDF
Critical care specialists,the missing link in organ procurement for transplantation
7
作者 Francisca Del Rocio Gonzalez Cohens Fernando M Gonzalez 《World Journal of Critical Care Medicine》 2024年第2期1-6,共6页
The procurement process for organ donation begins with the identification of potential organ donors in emergency or critical care units(CCU),followed by their clinical evaluation,diagnostic procedures,and therapeutic ... The procurement process for organ donation begins with the identification of potential organ donors in emergency or critical care units(CCU),followed by their clinical evaluation,diagnostic procedures,and therapeutic interventions,mostly conducted in CCUs.It concludes with the request for organ donation and,if accepted,the retrieval of organs.Despite most interventions occurring in detection units,there has been a neglect of the strategic role played by critical care specialists(CCS)in managing and caring for brain-dead or near-brain-death patients.Questions arise:Are they willing to undertake this responsibility?Do they fully comprehend the nature of organ procurement?Are they aware of the specific interventions required to maintain possible organ donors in optimal physiological condition?Our objective is to examine the role of CCS in organ procurement and propose ways to enhance it,ultimately aiming to increase and enhance organ donation rates. 展开更多
关键词 Organ procurement TRANSPLANTATION Brain death Cardiac death Organ donation
下载PDF
Research on the Status Quo and Optimization of Centralized Procurement of Coronary Stents
8
作者 Zhang Yuting Liu Xiaoxi 《Asian Journal of Social Pharmacy》 2024年第1期20-28,共9页
Objective To study the impact of the first national centralized procurement of coronary stents on patients’psychology,the economy of medical institutions,and the survival and development of the coronary stents indust... Objective To study the impact of the first national centralized procurement of coronary stents on patients’psychology,the economy of medical institutions,and the survival and development of the coronary stents industry,and to provide suggestions on perfecting procedures to better carry out the centralized procurement of coronary stents.Methods Literature analysis was used to investigate the results of the procurement of coronary stent in a province and a hospital.Results and Conclusion The centralized procurement of coronary stents has alleviated the economic pressure of patients,but it has many problems.Therefore,this paper proposes some suggestions,such as promoting the orderly development of the coronary stent industry,improving the evaluation link of the centralized procurement of coronary stents,adopting the accurate reporting model to ensure the quality of coronary stents and improving the standardization of clinical services. 展开更多
关键词 volume procurement coronary stent medical resource
下载PDF
Research on Procurement Cost Control Based on Supply Chain Management
9
作者 Lixia Liu Wenting Shao 《Proceedings of Business and Economic Studies》 2024年第5期106-111,共6页
In modern enterprise management,strengthening the control and management of procurement processes can effectively reduce operational costs.However,with the continuous reform and improvement of China’s market economy ... In modern enterprise management,strengthening the control and management of procurement processes can effectively reduce operational costs.However,with the continuous reform and improvement of China’s market economy system,competition among supply chain enterprises has intensified.The traditional procurement management model is no longer able to meet the needs of enterprise development in the current era.As a result,procurement management based on supply chain management has emerged,offering significant improvements in the scientific management of procurement processes.It has become an important means of promoting the long-term development of enterprises.This paper primarily analyzes and studies procurement cost control based on supply chain management,providing insights for reference. 展开更多
关键词 Supply chain management procurement cost CONTROL
下载PDF
Multi-Source Data Privacy Protection Method Based on Homomorphic Encryption and Blockchain 被引量:3
10
作者 Ze Xu Sanxing Cao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期861-881,共21页
Multi-Source data plays an important role in the evolution of media convergence.Its fusion processing enables the further mining of data and utilization of data value and broadens the path for the sharing and dissemin... Multi-Source data plays an important role in the evolution of media convergence.Its fusion processing enables the further mining of data and utilization of data value and broadens the path for the sharing and dissemination of media data.However,it also faces serious problems in terms of protecting user and data privacy.Many privacy protectionmethods have been proposed to solve the problemof privacy leakage during the process of data sharing,but they suffer fromtwo flaws:1)the lack of algorithmic frameworks for specific scenarios such as dynamic datasets in the media domain;2)the inability to solve the problem of the high computational complexity of ciphertext in multi-source data privacy protection,resulting in long encryption and decryption times.In this paper,we propose a multi-source data privacy protection method based on homomorphic encryption and blockchain technology,which solves the privacy protection problem ofmulti-source heterogeneous data in the dissemination ofmedia and reduces ciphertext processing time.We deployed the proposedmethod on theHyperledger platformfor testing and compared it with the privacy protection schemes based on k-anonymity and differential privacy.The experimental results showthat the key generation,encryption,and decryption times of the proposedmethod are lower than those in data privacy protection methods based on k-anonymity technology and differential privacy technology.This significantly reduces the processing time ofmulti-source data,which gives it potential for use in many applications. 展开更多
关键词 Homomorphic encryption blockchain technology multi-source data data privacy protection privacy data processing
下载PDF
Recent trends of machine learning applied to multi-source data of medicinal plants 被引量:2
11
作者 Yanying Zhang Yuanzhong Wang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2023年第12期1388-1407,共20页
In traditional medicine and ethnomedicine,medicinal plants have long been recognized as the basis for materials in therapeutic applications worldwide.In particular,the remarkable curative effect of traditional Chinese... In traditional medicine and ethnomedicine,medicinal plants have long been recognized as the basis for materials in therapeutic applications worldwide.In particular,the remarkable curative effect of traditional Chinese medicine during corona virus disease 2019(COVID-19)pandemic has attracted extensive attention globally.Medicinal plants have,therefore,become increasingly popular among the public.However,with increasing demand for and profit with medicinal plants,commercial fraudulent events such as adulteration or counterfeits sometimes occur,which poses a serious threat to the clinical outcomes and interests of consumers.With rapid advances in artificial intelligence,machine learning can be used to mine information on various medicinal plants to establish an ideal resource database.We herein present a review that mainly introduces common machine learning algorithms and discusses their application in multi-source data analysis of medicinal plants.The combination of machine learning algorithms and multi-source data analysis facilitates a comprehensive analysis and aids in the effective evaluation of the quality of medicinal plants.The findings of this review provide new possibilities for promoting the development and utilization of medicinal plants. 展开更多
关键词 Machine learning Medicinal plant multi-source data Data fusion Application
下载PDF
Multi-source Data-driven Identification of Urban Functional Areas:A Case of Shenyang,China 被引量:3
12
作者 XUE Bing XIAO Xiao +2 位作者 LI Jingzhong ZHAO Bingyu FU Bo 《Chinese Geographical Science》 SCIE CSCD 2023年第1期21-35,共15页
Urban functional area(UFA)is a core scientific issue affecting urban sustainability.The current knowledge gap is mainly reflected in the lack of multi-scale quantitative interpretation methods from the perspective of ... Urban functional area(UFA)is a core scientific issue affecting urban sustainability.The current knowledge gap is mainly reflected in the lack of multi-scale quantitative interpretation methods from the perspective of human-land interaction.In this paper,based on multi-source big data include 250 m×250 m resolution cell phone data,1.81×105 Points of Interest(POI)data and administrative boundary data,we built a UFA identification method and demonstrated empirically in Shenyang City,China.We argue that the method we built can effectively identify multi-scale multi-type UFAs based on human activity and further reveal the spatial correlation between urban facilities and human activity.The empirical study suggests that the employment functional zones in Shenyang City are more concentrated in central cities than other single functional zones.There are more mix functional areas in the central city areas,while the planned industrial new cities need to develop comprehensive functions in Shenyang.UFAs have scale effects and human-land interaction patterns.We suggest that city decision makers should apply multi-sources big data to measure urban functional service in a more refined manner from a supply-demand perspective. 展开更多
关键词 human-land relationship multi-source big data urban functional area identification method Shenyang City
下载PDF
Threat Modeling and Application Research Based on Multi-Source Attack and Defense Knowledge
13
作者 Shuqin Zhang Xinyu Su +2 位作者 Peiyu Shi Tianhui Du Yunfei Han 《Computers, Materials & Continua》 SCIE EI 2023年第10期349-377,共29页
Cyber Threat Intelligence(CTI)is a valuable resource for cybersecurity defense,but it also poses challenges due to its multi-source and heterogeneous nature.Security personnel may be unable to use CTI effectively to u... Cyber Threat Intelligence(CTI)is a valuable resource for cybersecurity defense,but it also poses challenges due to its multi-source and heterogeneous nature.Security personnel may be unable to use CTI effectively to understand the condition and trend of a cyberattack and respond promptly.To address these challenges,we propose a novel approach that consists of three steps.First,we construct the attack and defense analysis of the cybersecurity ontology(ADACO)model by integrating multiple cybersecurity databases.Second,we develop the threat evolution prediction algorithm(TEPA),which can automatically detect threats at device nodes,correlate and map multisource threat information,and dynamically infer the threat evolution process.TEPA leverages knowledge graphs to represent comprehensive threat scenarios and achieves better performance in simulated experiments by combining structural and textual features of entities.Third,we design the intelligent defense decision algorithm(IDDA),which can provide intelligent recommendations for security personnel regarding the most suitable defense techniques.IDDA outperforms the baseline methods in the comparative experiment. 展开更多
关键词 multi-source data fusion threat modeling threat propagation path knowledge graph intelligent defense decision-making
下载PDF
Risk Analysis Using Multi-Source Data for Distribution Networks Facing Extreme Natural Disasters
14
作者 Jun Yang Nannan Wang +1 位作者 Jiang Wang Yashuai Luo 《Energy Engineering》 EI 2023年第9期2079-2096,共18页
Distribution networks denote important public infrastructure necessary for people’s livelihoods.However,extreme natural disasters,such as earthquakes,typhoons,and mudslides,severely threaten the safe and stable opera... Distribution networks denote important public infrastructure necessary for people’s livelihoods.However,extreme natural disasters,such as earthquakes,typhoons,and mudslides,severely threaten the safe and stable operation of distribution networks and power supplies needed for daily life.Therefore,considering the requirements for distribution network disaster prevention and mitigation,there is an urgent need for in-depth research on risk assessment methods of distribution networks under extreme natural disaster conditions.This paper accessesmultisource data,presents the data quality improvement methods of distribution networks,and conducts data-driven active fault diagnosis and disaster damage analysis and evaluation using data-driven theory.Furthermore,the paper realizes real-time,accurate access to distribution network disaster information.The proposed approach performs an accurate and rapid assessment of cross-sectional risk through case study.The minimal average annual outage time can be reduced to 3 h/a in the ring network through case study.The approach proposed in this paper can provide technical support to the further improvement of the ability of distribution networks to cope with extreme natural disasters. 展开更多
关键词 Distribution network disaster damage analysis fault judgment multi-source data
下载PDF
Evaluation and Improvement Strategies for Slow Traffic Systems Based on Multi-source Big Data:A Case Study of Shijingshan District of Beijing City
15
作者 LI Yiwen 《Journal of Landscape Research》 2023年第4期62-64,68,共4页
The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic syst... The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic system.Shijingshan District of Beijing City is taken as a research object.By analyzing and processing population distribution data,POI data,and shared bicycle data,the shortcomings and deficiencies of the current slow traffic system in Shijingshan District are explored,and corresponding solutions are proposed,in order to provide new ideas and methods for future urban planning from the perspective of data. 展开更多
关键词 multi-source data Slow traffic system Shijingshan District
下载PDF
Classification of Beijing Line 10 Subway Living Circle Based on Multi-source Big Data
16
作者 SUN Shuai LI Ziying 《Journal of Landscape Research》 2023年第3期53-58,共6页
In the first-tier cities,subway has become an important carrier and life focus of people’s daily travel activities.By studying the distribution of POIs of public service facilities around Metro Line 10,using GIS to q... In the first-tier cities,subway has become an important carrier and life focus of people’s daily travel activities.By studying the distribution of POIs of public service facilities around Metro Line 10,using GIS to quantitatively analyze the surrounding formats of subway stations,discussing the functional attributes of subway stations,and discussing the distribution of urban functions from a new perspective,this paper provided guidance and advice for the construction of service facilities. 展开更多
关键词 multi-source big data Subway living circle BEIJING GIS
下载PDF
Renal allograft procurement from living unrelated donors in Iran: What falls under the eclipse
17
作者 Saeed Taheri 《World Journal of Transplantation》 2023年第5期250-253,共4页
Renal transplantation is the treatment of choice for end stage kidney disease.However,despite all the efforts to expand the donor pool,the shortage of donors is increasing and as a consequence,there has been a signifi... Renal transplantation is the treatment of choice for end stage kidney disease.However,despite all the efforts to expand the donor pool,the shortage of donors is increasing and as a consequence,there has been a significant increase in the number of patients on transplant waiting lists globally.Societies worldwide have employed different methods to address this,each with specific ethical concerns surrounding them.Over three decades ago,a governmentally regulated program of kidney transplantation from living unrelated donors was introduced in Iran and since practiced which has been the subject of hot debate in the literature.Nevertheless,despite all these extensive discussions and publications,several key aspects of the program have still not been properly elucidated and addressed.In this article,the author aims to illuminate some dark corners related to this issue that have largely escaped the notice of ethicists. 展开更多
关键词 Allograft procurement Renal transplantation Living unrelated donor Organ market Iran
下载PDF
Research on choice of emergency procurement vendors 被引量:2
18
作者 江孝感 冯勤超 陈丰琳 《Journal of Southeast University(English Edition)》 EI CAS 2007年第S1期124-127,共4页
In order to make the supply chain select the best emergency procurement suppliers in case the procurement system encounters unexpected risks,six indices which can reflect the comprehensive abilities of alternative sup... In order to make the supply chain select the best emergency procurement suppliers in case the procurement system encounters unexpected risks,six indices which can reflect the comprehensive abilities of alternative suppliers are selected,i.e.,the product yield,the toll standard,the on-time-delivery rate,the rate of turnover industry experience and customer satisfaction.Then standardized processing of evaluation is performed.For quantitative indices,vector normalization is adopted to perform standardized processing,and qualitative fuzziness indices are quantified through assignment.Finally,each index can be transformed into a standardized mark which has dimensionless 1 and the same magnitude.And an expert method is used to determine the index weights and then the linear weighted sum method is used to calculate the alternative supplier's comprehensive ability score and by comparing these scores,the optimal emergency procurement supplier is selected. 展开更多
关键词 emergency procurement supply chain VENDOR evaluation index
下载PDF
Separation method for multi-source blended seismic data
19
作者 王汉闯 陈生昌 +1 位作者 张博 佘德平 《Applied Geophysics》 SCIE CSCD 2013年第3期251-264,357,共15页
Multi-source seismic technology is an efficient seismic acquisition method that requires a group of blended seismic data to be separated into single-source seismic data for subsequent processing. The separation of ble... Multi-source seismic technology is an efficient seismic acquisition method that requires a group of blended seismic data to be separated into single-source seismic data for subsequent processing. The separation of blended seismic data is a linear inverse problem. According to the relationship between the shooting number and the simultaneous source number of the acquisition system, this separation of blended seismic data is divided into an easily determined or overdetermined linear inverse problem and an underdetermined linear inverse problem that is difficult to solve. For the latter, this paper presents an optimization method that imposes the sparsity constraint on wavefields to construct the object function of inversion, and the problem is solved by using the iterative thresholding method. For the most extremely underdetermined separation problem with single-shooting and multiple sources, this paper presents a method of pseudo-deblending with random noise filtering. In this method, approximate common shot gathers are received through the pseudo-deblending process, and the random noises that appear when the approximate common shot gathers are sorted into common receiver gathers are eliminated through filtering methods. The separation methods proposed in this paper are applied to three types of numerical simulation data, including pure data without noise, data with random noise, and data with linear regular noise to obtain satisfactory results. The noise suppression effects of these methods are sufficient, particularly with single-shooting blended seismic data, which verifies the effectiveness of the proposed methods. 展开更多
关键词 multi-source data separation linear inverse problem sparsest constraint pseudo-deblending filtering
下载PDF
Issues and Challenges in Implementing China’sGreen Public Procurement Program 被引量:2
20
作者 Yuhua Qiao Conghu Wang 《Journal of Environmental Protection》 2011年第8期1034-1045,共12页
Sustainable development and environmental protection are the themes of the day. One popular policy tool that government uses to promote sustainable development and to protect the environment is green public procuremen... Sustainable development and environmental protection are the themes of the day. One popular policy tool that government uses to promote sustainable development and to protect the environment is green public procurement. Chinese government established its public procurement system in the late 1990s. It has moved to implement green procurement since 2004. In this paper, the authors will first trace the development of Chinese green public procurement program. The authors will then examine the issues involved in its implementation and make suggestions as to how to make green public procurement program more effective. This is one of the first papers examining China’s green public procurement program. 展开更多
关键词 China Green procurement LAWS China Green procurement PROGRAM IMPLEMENTATION ISSUES
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部