With the rapid development of urban rail transit,the traditional operation and maintenance methods mainly rely on manpower,and the pressure on equipment operation and maintenance is increasing,and the low work efficie...With the rapid development of urban rail transit,the traditional operation and maintenance methods mainly rely on manpower,and the pressure on equipment operation and maintenance is increasing,and the low work efficiency,high intensity and high operating costs have always been the main problems at this stage.Through BIM visualization technology can effectively solve those problems,the operation and maintenance mode of urban rail signal equipment at this stage is discussed,the integration and visualization of BIM technology are used to make the judgments and early warnings on the maintenance of urban rail signal equipment,and play a positive and important role in operation and maintenance work,this research result can provide ideas and references for urban rail transit operation and maintenance in the new era.展开更多
Purpose-The aim of this work is to research and design an expert diagnosis system for rail vehicle driven by data mechanism models.Design/methodology/approach-The expert diagnosis system utilizes statistical and deep ...Purpose-The aim of this work is to research and design an expert diagnosis system for rail vehicle driven by data mechanism models.Design/methodology/approach-The expert diagnosis system utilizes statistical and deep learning methods to model the real-time status and historical data features of rail vehicle.Based on data mechanism models,it predicts the lifespan of key components,evaluates the health status of the vehicle and achieves intelligent monitoring and diagnosis of rail vehicle.Findings-The actual operation effect of this system shows that it has improved the intelligent level of the rail vehicle monitoring system,which helps operators to monitor the operation of vehicle online,predict potential risks and faults of vehicle and ensure the smooth and safe operation of vehicle.Originality/value-This system improves the efficiency of rail vehicle operation,scheduling and maintenance through intelligent monitoring and diagnosis of rail vehicle.展开更多
We present an overview of some recent developments in the area of mathematical modeling of maintenance decisions for multi-unit systems. The emphasis is on three main groups of multicomponent maintenance optimization ...We present an overview of some recent developments in the area of mathematical modeling of maintenance decisions for multi-unit systems. The emphasis is on three main groups of multicomponent maintenance optimization models: the block replacement models, group maintenance models, and opportunistic maintenance models. Moreover, an example of a two-unit system maintenance process is provided in order to compare various maintenance policies.展开更多
Defined as total productive maintenance carried out by all cooperators in Supply Chain, Total Operational Maintenance (TOM) focuses on adapting to collaborative business environment in virtue of Internet & Intrane...Defined as total productive maintenance carried out by all cooperators in Supply Chain, Total Operational Maintenance (TOM) focuses on adapting to collaborative business environment in virtue of Internet & Intranet. It focuses on the managerial ideology of embedded with Quick Response (QR),Total Productive Maintenance (TPM) and Supply Chain. And the theoretical architecture and implementation is also described. It offers emphatically that it is necessary to exceed competitive advantage of the enterprises by optimizing reliability, empowerment and Overall Facilities Effectiveness (OFE) applying TOM together into the strategic improvement plan.展开更多
Semarang urban coastal areas are experiencing tidal flood. In addition, land subsidence of 5 to 10 centimetres per year is taking place. The climate change phenomenon provokes land areas that are lower than sea water ...Semarang urban coastal areas are experiencing tidal flood. In addition, land subsidence of 5 to 10 centimetres per year is taking place. The climate change phenomenon provokes land areas that are lower than sea water level from time to time. This makes the situation with respect to flooding increasingly risky. Semarang Old City (heritage) as part of principal Semarang area is suffering also from regular flooding and pollution that hamper the revitalisation of the old city. These areas used to be productive lands, but flooding make the existing public infrastructure does no longer function, and residential areas have changed into unhealthy slams. To overcome these problems, the Government of Semarang chooses a polder drainage system to address the flooding in Semarang. In the framework of the cooperation between Indonesia and the Netherlands, these activities consist of research and workshops on Urban Heritage. The scope consists basically of five components: experiences with urban drainage and flood protection in Semarang with a focus on Semarang Old City, field visit to relevant places with respect to urban drainage and flood protection of Semarang Old City, lectures on the relevant aspects of urban drainage and flood protection, exercises to get an insight in the processes that can take place under normal and extreme conditions, formulation of a preliminary plan to improve the situation with respect to urban drainage and flood protection of Semarang Old City. In this paper, the various relevant points are described, such as scenarios analysis as well as the findings and recommendations for improvement of the urban drainage system and flood protection of Semarang Heritage City.展开更多
In this article, the authors give an overview of different logistics concepts for operation and maintenance of OWPP (offshore wind power plants). These can be generally classified into onshore based and offshore bas...In this article, the authors give an overview of different logistics concepts for operation and maintenance of OWPP (offshore wind power plants). These can be generally classified into onshore based and offshore based concepts. The operation of OWPPs can still be improved as research has shown that the availability of OWPPs is low compared to onshore wind power plants. There are a few tools to calculate operating costs and to evaluate the different concepts. However, most tools have a weak focus on logistics although logistics account for a big share of the costs. The tool the authors are introducing in this article focuses on the logistics processes. It is first explained and then tested with an OWPP scenarin展开更多
Safety is essential when building a strong transportation system.As a key development direction in the global railway system,the intelligent railway has safety at its core,making safety a top priority while pursuing t...Safety is essential when building a strong transportation system.As a key development direction in the global railway system,the intelligent railway has safety at its core,making safety a top priority while pursuing the goals of efficiency,convenience,economy,and environmental friendliness.This paper describes the state of the art and proposes a system architecture for intelligent railway systems.It also focuses on the development of railway safety technology at home and abroad,and proposes the active safety method and technology system based on advanced theoretical methods such as the in-depth integration of cyber–physical systems(CPS),data-driven models,and intelligent computing.Finally,several typical applications are demonstrated to verify the advancement and feasibility of active safety technology in intelligent railway systems.展开更多
Cable fire is one of the most important events for operation and maintenance(O&M)safety in underground utility tunnels(UUTs).Since there are limited studies about cable fire risk assessment,a comprehensive assessm...Cable fire is one of the most important events for operation and maintenance(O&M)safety in underground utility tunnels(UUTs).Since there are limited studies about cable fire risk assessment,a comprehensive assessment model is proposed to evaluate the cable fire risk in different UUT sections and improve O&M efficiency.Considering the uncertainties in the risk assessment,an evidential reasoning(ER)approach is used to combine quantitative sensor data and qualitative expert judgments.Meanwhile,a data transformation technique is contributed to transform continuous data into a five-grade distributed assessment.Then,a case study demonstrates how the model and the ER approach are established.The results show that in Shenzhen,China,the cable fire risk in District 8,B Road is the lowest,while more resources should be paid in District 3,C Road and District 25,C Road,which are selected as comparative roads.Based on the model,a data-driven O&M process is proposed to improve the O&M effectiveness,compared with traditional methods.This study contributes an effective ER-based cable fire evaluation model to improve the O&M efficiency of cable fire in UUTs.展开更多
Purpose–The purpose of this paper is to summarize the status and characteristics of rail technology of high-speed railway in China,and point out the development direction of rail technology of high-speed railway.Desi...Purpose–The purpose of this paper is to summarize the status and characteristics of rail technology of high-speed railway in China,and point out the development direction of rail technology of high-speed railway.Design/methodology/approach–This study reviews the evolution of high-speed rail standards in China,comparing their chemical composition,mechanical attributes and geometric specifications with EN standards.It delves into the status of rail production technology,shifts in key performance indicators and the quality characteristics of rails.The analysis further examines the interplay between wheels and rails,the implementation of grinding technology and the techniques for inspecting rail service conditions.It encapsulates the salient features of rail operation and maintenance within the high-speed railway ecosystem.The paper concludes with an insightful prognosis of high-speed railway technology development in China.Findings–The rail standards of high-speed railway in China are scientific and advanced,highly operational and in line with international standards.The quality and performance of rail in China have reached the world’s advanced level.The 60N profile guarantees the operation quality of wheel–rail interaction effectively.The rail grinding technology system scientifically guarantees the long-term good service performance of the rail.The rail service state detection technology is scientific and efficient.The rail technology will take“more intelligent”and“higher speed”as the development direction to meet the future needs of high-speed railway in China.Originality/value–The development direction of rail technology for high-speed railway in China is defined,which will promote the continuous innovation and breakthrough of rail technology.展开更多
Today we are in a technologically explosive information society. The cross-</span></span><span style="white-space:normal;"><span style="font-family:""> </span&g...Today we are in a technologically explosive information society. The cross-</span></span><span style="white-space:normal;"><span style="font-family:""> </span></span><span style="white-space:normal;"><span style="font-family:"">border integration of manufacturing and construction is prefabricated buildings. The cross-border integration of construction and IT is BIM technology, and the emergence of BIM technology provides new ideas for prefabricated building, and the integration of prefabricated building and BIM technology realizes the construction industrialization. This paper studies the application of BIM technology in prefabricated buildings, including the design phase, construction and assembly phase, operation and maintenance phase, and application analysis of related software, so as to improve the high efficiency, high quality and high precision development of prefabricated projects, and promote domestic green environmental protection. The development of the construction industry provides reference value for the application of BIM technology in prefabricated buildings.展开更多
OAM (Operations, Administration and Maintenance) system is a very impo rtant component of 3G cellular network. In order to acquire overall managemen t, fast response and steady operation, an SCTP (Stream Control Trans...OAM (Operations, Administration and Maintenance) system is a very impo rtant component of 3G cellular network. In order to acquire overall managemen t, fast response and steady operation, an SCTP (Stream Control Transmission Prot ocol) based OAM, i.e., SOAM system was proposed. SOAM implements new characters of SCTP such as multi-stream, enforced SACK and heartbeat mechanism on its tran sport layer. These characters help SOAM decrease the message transmission delay and accelerate the link failure detection. Besides, a new component named SOAM agent was introduced to improve the operation efficiency of SOAM. The experim ental results prove the proposed SOAM system achieves better performance on sign aling transmission compared with conventional TCP based OAM system.展开更多
This paper provides analytical diagnosis of mechanical conditions of medical waste incinerators used for healthcare waste (HCW) treatment in Tanzania. The main features assessed were types of incinerators, features of...This paper provides analytical diagnosis of mechanical conditions of medical waste incinerators used for healthcare waste (HCW) treatment in Tanzania. The main features assessed were types of incinerators, features of incinerators and incinerator house. The assessment was conducted in three levels of health care facilities (HCFs), that is, Regional, district hospitals and health centers, existed in 26 regions of Tanzania. Questionnaires, interview and checklists were used as tools for data collection. It was observed that High-Tech incinerators are mainly used in regional hospitals, while district hospital and health center use both High-Tech and De-Montfort incinerators. About 60% of the incinerators have defective doors. More than 55% of incinerators are corroded in regional and district hospitals. The chimney, top plates and grate which are good condition are 55.6% and 60% in regional hospitals and health centers, respectively. The situation is below 50% in district hospitals. The leakage of the roof and loose structures were observed in district hospitals and health center to be more than 50% of the incinerator houses. On other hand, the performance of burners and incinerator housing cleanliness are generally good. It was concluded that the incinerators in the HCFs are in bad conditions, necessitating maintenance.展开更多
Kabul New City is a new capital development and a modern city development of Afghanistan covering total area of 740 km<sup>2</sup>. In 2009 Afghan cabinet approved developing New Capital to fulfill the req...Kabul New City is a new capital development and a modern city development of Afghanistan covering total area of 740 km<sup>2</sup>. In 2009 Afghan cabinet approved developing New Capital to fulfill the requirement of growing population. For sustainable development, it has been planned to have a green belt and central park about 1298 hectares within the city. It is having positive impact on human health along with the economic, social and environmental benefits. Hence, for sustaining the urban parks, their proper maintenance is a foremost problem. The solid waste management is duly considered in planning stage of development, otherwise, it would encounter major challenges during operation and maintenance of Park. The projected waste generation in KNC park area is required to be assessed, therefore, surveys of Bagh-e-Babur in existing Kabul are carried out for the visitors’ projection and solid waste generation. The highest visitors and waste were estimated in declining order of summer, spring, fall, and winter. Kabul New City Central Park results speculate that the total visitors’ projection is going to be 6,745,313 per year generating about 337 metric tons wastes/year (0.05 kg/visitor/day). 10 Vehicles of capacity 8 m<sup>3</sup> are required to collect waste from central park towards the Transfer Station while 4 vehicles of 23 m<sup>3</sup> are required for collection of waste from TS to Landfill. Moreover, 700 containers of 240 liters are required in the park. Furthermore, different sites were indicated in map for composting area where after the development it would be considered.展开更多
In order to promote the stability of centrifugal pump units and maximize the role of centrifugal pumps, this paper analyzes the composition and basic working principle of centrifugal pumps, presents the main concerns ...In order to promote the stability of centrifugal pump units and maximize the role of centrifugal pumps, this paper analyzes the composition and basic working principle of centrifugal pumps, presents the main concerns of centrifugal pump maintenance, and finally investigates the common faults and maintenance methods of centrifugal pumps for reference.展开更多
In order to recover the value of short texts in the operation and maintenance of power equipment,a short text mining framework with specific design is proposed.First,the process of the short text mining framework is s...In order to recover the value of short texts in the operation and maintenance of power equipment,a short text mining framework with specific design is proposed.First,the process of the short text mining framework is summarized,in which the functions of all the processing modules are introduced.Then,according to the characteristics of short texts in the operation and maintenance of power equipment,the specific design for each module is proposed,which adapts the short text mining framework to a practical application.Finally,based on the framework with the specific designed modules,two examples in terms of defect texts are given to illustrate the application of short text mining in the operation and maintenance of power equipment.The results of the examples show that the short text mining framework is suitable for operation and maintenance tasks for power equipment,and the specific design for each module is beneficial for the improvement of the application effect.展开更多
The bogie is a crucial component of urban rail vehicles,and its performance plays a decisive role in the safe operation of vehicles.Aiming at the intelligent operation and maintenance requirements of rail transit equi...The bogie is a crucial component of urban rail vehicles,and its performance plays a decisive role in the safe operation of vehicles.Aiming at the intelligent operation and maintenance requirements of rail transit equipment,in this paper,it takes several key parts of the urban rail vehicle bogie system as research objects,such as motor bearings,frames,fasteners,etc.,and proposes a three-dimensional(3D)visual collaborative maintenance method.Firstly,a multi-sensor urban rail vehicle bogie running simulation experiment analysis platform was constructed,thereby establishing a database of running state and performance characteristics of the bogie in the whole life cycle.Then,the health status of key components of bogie was predicted by the state interval prediction model.Finally,the three-dimensional visual collaborative maintenance model proposed in this paper was integrated to realize the early warning of the bogie operation faults,3D precise guidance of automatic location and maintenance operation information,and collaborative sharing of visual information among multiple users.展开更多
As a key application of smart grid technologies,the smart distribution network(SDN)is expected to have a high diversity of equipment and complexity of operation patterns.Situational awareness(SA),which aims to provide...As a key application of smart grid technologies,the smart distribution network(SDN)is expected to have a high diversity of equipment and complexity of operation patterns.Situational awareness(SA),which aims to provide a critical visibility of the SDN,will enable a significant assurance for stable SDN operations.However,the lack of systematic evaluation through the three stages of perception,comprehensive,and prediction may prevent the SA technique from effectively achieving the performance necessary to monitor and respond to events in SDN.To analyze the feasibility and effectiveness of the SA technique for the SDN,a comprehensive evaluation framework with specific performance indicators and systematic weighting methods is proposed in this paper.Besides,to implement the indicator framework while addressing the key issues of human expert scoring ambiguity and the lack of data in specific SDN areas,an improved interval-based analytic hierarchy process-based subjective weighting and a multi-objective programming method-based objective weighting are developed to evaluate the SDN SA performance.In addition,a case study in a real distribution network of Tianjin,China is conducted whose outcomes verify the practicality and effectiveness of the proposed SA technique for SDN operating security.展开更多
Prolonged power outages debilitate the economy and threaten public health. Existing research is generally limitedin its scope to a single event, an outage cause, or a region. Here, we provide one of the most comprehen...Prolonged power outages debilitate the economy and threaten public health. Existing research is generally limitedin its scope to a single event, an outage cause, or a region. Here, we provide one of the most comprehensiveanalyses of large-scale power outages in the U.S. from 2002 to 2019. This analysis is based on the outage datacollected under U.S. federal mandates that concern large blackouts, typically of transmission systems and excludemuch more common but smaller blackouts, typically, of distribution systems. We categorized the data into fouroutage causes and computed reliability metrics, which are commonly used for distribution-level small outagesonly but useful for analyzing large blackouts. Our spatiotemporal analysis reveals six of the most resilient U.S.states since 2010, improvement of power resilience against natural hazards in the south and northeast regions,and a disproportionately large number of human attacks for its population in the Western Electricity CoordinatingCouncil region. Our regression analysis identifies several statistically significant predictors and hypotheses forU.S. resilience to large blackouts. Furthermore, we propose a novel framework for analyzing outage data usingdifferential weighting and influential points to better understand power resilience. We share curated data andcode as Supplementary Materials.展开更多
文摘With the rapid development of urban rail transit,the traditional operation and maintenance methods mainly rely on manpower,and the pressure on equipment operation and maintenance is increasing,and the low work efficiency,high intensity and high operating costs have always been the main problems at this stage.Through BIM visualization technology can effectively solve those problems,the operation and maintenance mode of urban rail signal equipment at this stage is discussed,the integration and visualization of BIM technology are used to make the judgments and early warnings on the maintenance of urban rail signal equipment,and play a positive and important role in operation and maintenance work,this research result can provide ideas and references for urban rail transit operation and maintenance in the new era.
基金supported by Hunan Province Enterprise Technology Innovation and Entrepreneurship Team Support Program Project,Hunan Province Science and Technology Innovation Leading Talent Project[2023RC1088]Hunan Province Science and Technology Talent Support Project[2023TJ-Z10].
文摘Purpose-The aim of this work is to research and design an expert diagnosis system for rail vehicle driven by data mechanism models.Design/methodology/approach-The expert diagnosis system utilizes statistical and deep learning methods to model the real-time status and historical data features of rail vehicle.Based on data mechanism models,it predicts the lifespan of key components,evaluates the health status of the vehicle and achieves intelligent monitoring and diagnosis of rail vehicle.Findings-The actual operation effect of this system shows that it has improved the intelligent level of the rail vehicle monitoring system,which helps operators to monitor the operation of vehicle online,predict potential risks and faults of vehicle and ensure the smooth and safe operation of vehicle.Originality/value-This system improves the efficiency of rail vehicle operation,scheduling and maintenance through intelligent monitoring and diagnosis of rail vehicle.
文摘We present an overview of some recent developments in the area of mathematical modeling of maintenance decisions for multi-unit systems. The emphasis is on three main groups of multicomponent maintenance optimization models: the block replacement models, group maintenance models, and opportunistic maintenance models. Moreover, an example of a two-unit system maintenance process is provided in order to compare various maintenance policies.
文摘Defined as total productive maintenance carried out by all cooperators in Supply Chain, Total Operational Maintenance (TOM) focuses on adapting to collaborative business environment in virtue of Internet & Intranet. It focuses on the managerial ideology of embedded with Quick Response (QR),Total Productive Maintenance (TPM) and Supply Chain. And the theoretical architecture and implementation is also described. It offers emphatically that it is necessary to exceed competitive advantage of the enterprises by optimizing reliability, empowerment and Overall Facilities Effectiveness (OFE) applying TOM together into the strategic improvement plan.
文摘Semarang urban coastal areas are experiencing tidal flood. In addition, land subsidence of 5 to 10 centimetres per year is taking place. The climate change phenomenon provokes land areas that are lower than sea water level from time to time. This makes the situation with respect to flooding increasingly risky. Semarang Old City (heritage) as part of principal Semarang area is suffering also from regular flooding and pollution that hamper the revitalisation of the old city. These areas used to be productive lands, but flooding make the existing public infrastructure does no longer function, and residential areas have changed into unhealthy slams. To overcome these problems, the Government of Semarang chooses a polder drainage system to address the flooding in Semarang. In the framework of the cooperation between Indonesia and the Netherlands, these activities consist of research and workshops on Urban Heritage. The scope consists basically of five components: experiences with urban drainage and flood protection in Semarang with a focus on Semarang Old City, field visit to relevant places with respect to urban drainage and flood protection of Semarang Old City, lectures on the relevant aspects of urban drainage and flood protection, exercises to get an insight in the processes that can take place under normal and extreme conditions, formulation of a preliminary plan to improve the situation with respect to urban drainage and flood protection of Semarang Old City. In this paper, the various relevant points are described, such as scenarios analysis as well as the findings and recommendations for improvement of the urban drainage system and flood protection of Semarang Heritage City.
文摘In this article, the authors give an overview of different logistics concepts for operation and maintenance of OWPP (offshore wind power plants). These can be generally classified into onshore based and offshore based concepts. The operation of OWPPs can still be improved as research has shown that the availability of OWPPs is low compared to onshore wind power plants. There are a few tools to calculate operating costs and to evaluate the different concepts. However, most tools have a weak focus on logistics although logistics account for a big share of the costs. The tool the authors are introducing in this article focuses on the logistics processes. It is first explained and then tested with an OWPP scenarin
基金supported by the 2021 Chinese Academy of Engineering(CAE)International Top-level Forum on Engineering Science and Technology,“Safety and Governance of the High-Speed Railway”。
文摘Safety is essential when building a strong transportation system.As a key development direction in the global railway system,the intelligent railway has safety at its core,making safety a top priority while pursuing the goals of efficiency,convenience,economy,and environmental friendliness.This paper describes the state of the art and proposes a system architecture for intelligent railway systems.It also focuses on the development of railway safety technology at home and abroad,and proposes the active safety method and technology system based on advanced theoretical methods such as the in-depth integration of cyber–physical systems(CPS),data-driven models,and intelligent computing.Finally,several typical applications are demonstrated to verify the advancement and feasibility of active safety technology in intelligent railway systems.
基金Airport New City Utility Tunnel PhaseⅡProject,China。
文摘Cable fire is one of the most important events for operation and maintenance(O&M)safety in underground utility tunnels(UUTs).Since there are limited studies about cable fire risk assessment,a comprehensive assessment model is proposed to evaluate the cable fire risk in different UUT sections and improve O&M efficiency.Considering the uncertainties in the risk assessment,an evidential reasoning(ER)approach is used to combine quantitative sensor data and qualitative expert judgments.Meanwhile,a data transformation technique is contributed to transform continuous data into a five-grade distributed assessment.Then,a case study demonstrates how the model and the ER approach are established.The results show that in Shenzhen,China,the cable fire risk in District 8,B Road is the lowest,while more resources should be paid in District 3,C Road and District 25,C Road,which are selected as comparative roads.Based on the model,a data-driven O&M process is proposed to improve the O&M effectiveness,compared with traditional methods.This study contributes an effective ER-based cable fire evaluation model to improve the O&M efficiency of cable fire in UUTs.
基金supported by the National Key R&D Program of China[Grant No.2022YFB2603402]the Task of Science and Technology R&D Program of China Railway Corporation[Grant No.K2023G013]the R&D Fund Project of China Academy of Railway Science Corporation Limited[Grant No.2022YJ165].
文摘Purpose–The purpose of this paper is to summarize the status and characteristics of rail technology of high-speed railway in China,and point out the development direction of rail technology of high-speed railway.Design/methodology/approach–This study reviews the evolution of high-speed rail standards in China,comparing their chemical composition,mechanical attributes and geometric specifications with EN standards.It delves into the status of rail production technology,shifts in key performance indicators and the quality characteristics of rails.The analysis further examines the interplay between wheels and rails,the implementation of grinding technology and the techniques for inspecting rail service conditions.It encapsulates the salient features of rail operation and maintenance within the high-speed railway ecosystem.The paper concludes with an insightful prognosis of high-speed railway technology development in China.Findings–The rail standards of high-speed railway in China are scientific and advanced,highly operational and in line with international standards.The quality and performance of rail in China have reached the world’s advanced level.The 60N profile guarantees the operation quality of wheel–rail interaction effectively.The rail grinding technology system scientifically guarantees the long-term good service performance of the rail.The rail service state detection technology is scientific and efficient.The rail technology will take“more intelligent”and“higher speed”as the development direction to meet the future needs of high-speed railway in China.Originality/value–The development direction of rail technology for high-speed railway in China is defined,which will promote the continuous innovation and breakthrough of rail technology.
文摘Today we are in a technologically explosive information society. The cross-</span></span><span style="white-space:normal;"><span style="font-family:""> </span></span><span style="white-space:normal;"><span style="font-family:"">border integration of manufacturing and construction is prefabricated buildings. The cross-border integration of construction and IT is BIM technology, and the emergence of BIM technology provides new ideas for prefabricated building, and the integration of prefabricated building and BIM technology realizes the construction industrialization. This paper studies the application of BIM technology in prefabricated buildings, including the design phase, construction and assembly phase, operation and maintenance phase, and application analysis of related software, so as to improve the high efficiency, high quality and high precision development of prefabricated projects, and promote domestic green environmental protection. The development of the construction industry provides reference value for the application of BIM technology in prefabricated buildings.
基金High-Tech Research and DevelopmentProgram of China (No. 2003AA123310)
文摘OAM (Operations, Administration and Maintenance) system is a very impo rtant component of 3G cellular network. In order to acquire overall managemen t, fast response and steady operation, an SCTP (Stream Control Transmission Prot ocol) based OAM, i.e., SOAM system was proposed. SOAM implements new characters of SCTP such as multi-stream, enforced SACK and heartbeat mechanism on its tran sport layer. These characters help SOAM decrease the message transmission delay and accelerate the link failure detection. Besides, a new component named SOAM agent was introduced to improve the operation efficiency of SOAM. The experim ental results prove the proposed SOAM system achieves better performance on sign aling transmission compared with conventional TCP based OAM system.
文摘This paper provides analytical diagnosis of mechanical conditions of medical waste incinerators used for healthcare waste (HCW) treatment in Tanzania. The main features assessed were types of incinerators, features of incinerators and incinerator house. The assessment was conducted in three levels of health care facilities (HCFs), that is, Regional, district hospitals and health centers, existed in 26 regions of Tanzania. Questionnaires, interview and checklists were used as tools for data collection. It was observed that High-Tech incinerators are mainly used in regional hospitals, while district hospital and health center use both High-Tech and De-Montfort incinerators. About 60% of the incinerators have defective doors. More than 55% of incinerators are corroded in regional and district hospitals. The chimney, top plates and grate which are good condition are 55.6% and 60% in regional hospitals and health centers, respectively. The situation is below 50% in district hospitals. The leakage of the roof and loose structures were observed in district hospitals and health center to be more than 50% of the incinerator houses. On other hand, the performance of burners and incinerator housing cleanliness are generally good. It was concluded that the incinerators in the HCFs are in bad conditions, necessitating maintenance.
文摘Kabul New City is a new capital development and a modern city development of Afghanistan covering total area of 740 km<sup>2</sup>. In 2009 Afghan cabinet approved developing New Capital to fulfill the requirement of growing population. For sustainable development, it has been planned to have a green belt and central park about 1298 hectares within the city. It is having positive impact on human health along with the economic, social and environmental benefits. Hence, for sustaining the urban parks, their proper maintenance is a foremost problem. The solid waste management is duly considered in planning stage of development, otherwise, it would encounter major challenges during operation and maintenance of Park. The projected waste generation in KNC park area is required to be assessed, therefore, surveys of Bagh-e-Babur in existing Kabul are carried out for the visitors’ projection and solid waste generation. The highest visitors and waste were estimated in declining order of summer, spring, fall, and winter. Kabul New City Central Park results speculate that the total visitors’ projection is going to be 6,745,313 per year generating about 337 metric tons wastes/year (0.05 kg/visitor/day). 10 Vehicles of capacity 8 m<sup>3</sup> are required to collect waste from central park towards the Transfer Station while 4 vehicles of 23 m<sup>3</sup> are required for collection of waste from TS to Landfill. Moreover, 700 containers of 240 liters are required in the park. Furthermore, different sites were indicated in map for composting area where after the development it would be considered.
文摘In order to promote the stability of centrifugal pump units and maximize the role of centrifugal pumps, this paper analyzes the composition and basic working principle of centrifugal pumps, presents the main concerns of centrifugal pump maintenance, and finally investigates the common faults and maintenance methods of centrifugal pumps for reference.
文摘In order to recover the value of short texts in the operation and maintenance of power equipment,a short text mining framework with specific design is proposed.First,the process of the short text mining framework is summarized,in which the functions of all the processing modules are introduced.Then,according to the characteristics of short texts in the operation and maintenance of power equipment,the specific design for each module is proposed,which adapts the short text mining framework to a practical application.Finally,based on the framework with the specific designed modules,two examples in terms of defect texts are given to illustrate the application of short text mining in the operation and maintenance of power equipment.The results of the examples show that the short text mining framework is suitable for operation and maintenance tasks for power equipment,and the specific design for each module is beneficial for the improvement of the application effect.
基金the Key Project of Research and Development Plan of HunanProvince under Grant 2018GK2044in part by the Natural Science Foundation of Hunan Provinceunder Grant 2018JJ4084+1 种基金in part by the National Natural Science Youth Fund Project under Grant51805168in part by the Science and Technology Talent Project of Hunan Province – HuxiangYouth Talent under Grant 2019RS2062.
文摘The bogie is a crucial component of urban rail vehicles,and its performance plays a decisive role in the safe operation of vehicles.Aiming at the intelligent operation and maintenance requirements of rail transit equipment,in this paper,it takes several key parts of the urban rail vehicle bogie system as research objects,such as motor bearings,frames,fasteners,etc.,and proposes a three-dimensional(3D)visual collaborative maintenance method.Firstly,a multi-sensor urban rail vehicle bogie running simulation experiment analysis platform was constructed,thereby establishing a database of running state and performance characteristics of the bogie in the whole life cycle.Then,the health status of key components of bogie was predicted by the state interval prediction model.Finally,the three-dimensional visual collaborative maintenance model proposed in this paper was integrated to realize the early warning of the bogie operation faults,3D precise guidance of automatic location and maintenance operation information,and collaborative sharing of visual information among multiple users.
基金This paper was supported by the National Natural Science Foundation of China(Grant No.51807134).
文摘As a key application of smart grid technologies,the smart distribution network(SDN)is expected to have a high diversity of equipment and complexity of operation patterns.Situational awareness(SA),which aims to provide a critical visibility of the SDN,will enable a significant assurance for stable SDN operations.However,the lack of systematic evaluation through the three stages of perception,comprehensive,and prediction may prevent the SA technique from effectively achieving the performance necessary to monitor and respond to events in SDN.To analyze the feasibility and effectiveness of the SA technique for the SDN,a comprehensive evaluation framework with specific performance indicators and systematic weighting methods is proposed in this paper.Besides,to implement the indicator framework while addressing the key issues of human expert scoring ambiguity and the lack of data in specific SDN areas,an improved interval-based analytic hierarchy process-based subjective weighting and a multi-objective programming method-based objective weighting are developed to evaluate the SDN SA performance.In addition,a case study in a real distribution network of Tianjin,China is conducted whose outcomes verify the practicality and effectiveness of the proposed SA technique for SDN operating security.
基金the National Science Foundation(NSF grant CMMI-1824681)。
文摘Prolonged power outages debilitate the economy and threaten public health. Existing research is generally limitedin its scope to a single event, an outage cause, or a region. Here, we provide one of the most comprehensiveanalyses of large-scale power outages in the U.S. from 2002 to 2019. This analysis is based on the outage datacollected under U.S. federal mandates that concern large blackouts, typically of transmission systems and excludemuch more common but smaller blackouts, typically, of distribution systems. We categorized the data into fouroutage causes and computed reliability metrics, which are commonly used for distribution-level small outagesonly but useful for analyzing large blackouts. Our spatiotemporal analysis reveals six of the most resilient U.S.states since 2010, improvement of power resilience against natural hazards in the south and northeast regions,and a disproportionately large number of human attacks for its population in the Western Electricity CoordinatingCouncil region. Our regression analysis identifies several statistically significant predictors and hypotheses forU.S. resilience to large blackouts. Furthermore, we propose a novel framework for analyzing outage data usingdifferential weighting and influential points to better understand power resilience. We share curated data andcode as Supplementary Materials.