How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation...How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation of group patterns. Centralized systems excel in precise control over individual behavior within a group, ensuring high accuracy and controllability in task execution. Nevertheless, their sensitivity to group size may limit their adaptability to diverse tasks. In contrast, decentralized systems empower individuals with autonomous decision-making, enhancing adaptability and system robustness. Yet, this flexibility comes at the cost of reduced accuracy and efficiency in task execution. In this work, we present a unique method for regulating the centralized dynamic behavior of self-organizing clusters based on environmental interactions. Within this environment-coupled robot system, each robot possesses similar dynamic characteristics, and their internal programs are entirely identical. However, their behaviors can be guided by the centralized control of the environment, facilitating the accomplishment of diverse cluster tasks. This approach aims to balance the accuracy and flexibility of centralized control with the robustness and task adaptability of decentralized control. The proactive regulation of dynamic behavioral characteristics in active matter groups, demonstrated in this work through environmental interactions, holds the potential to introduce a novel technological approach and provide experimental references for studying the dynamic behavior control of large-scale artificial active matter systems.展开更多
Smart grid is an idea of upgradation of the traditional electric grid infrastructure. The efficiency of the existing electrical grid can be automated by integrating with innovative technical equipment such as:?high-te...Smart grid is an idea of upgradation of the traditional electric grid infrastructure. The efficiency of the existing electrical grid can be automated by integrating with innovative technical equipment such as:?high-tech forecasting system, digital sensors, advanced two-way communication and two-way power flow systems. Smart grid establishes an interface between utility and consumer which helps to use energy, based on the preferences of price, eco-friendly and without technical system issues. It empowers the grid to be more secure, reliable and efficient. The peer-reviewed articles and published government reports have been reviewed, based on the analysis of technical characteristics of power generation systems, eco-friendly sources of power generations, cost reduction, functionality and design of traditional grid versus smart grid. Furthermore, the innovative technologies that enable the grid to integrate with decentralized power generation system efficiently have been considered. This paper claims that in this modern era, it is arduous for traditional grid to fulfill the rising demand of electricity, along with sustainable, eco-friendly and stable power supply, as it cannot be efficiently integrated with decentralized and localized power generation systems and renewable energy sources. The result of this paper shows that decentralized and localized power generation systems are located close to end-users which decrease the transmission and supply cost of electricity. Innovative technologies allow the decentralized and localized power generation systems to be integrated with renewable energy sources which help to reduce the cost of utility services and provide clean energy. Moreover, technological advancement played a decisive role in enabling the electrical system to be more efficient. Electrical reliability can be improved,?greenhouse gas emissions can be reduced, renewable energy sources can efficiently be integrated,?and?rising demand for electricity can be met by embedding advanced applications and technological equipment in the electrical grid.展开更多
AIM:To evaluate the efficacy of centralized culture and possible influencing factors.METHODS:From January 2010 to July 2012,66452 patients with suspected Helicobacter pylori(H.pylori) infection from 26 hospitals in Zh...AIM:To evaluate the efficacy of centralized culture and possible influencing factors.METHODS:From January 2010 to July 2012,66452 patients with suspected Helicobacter pylori(H.pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy.Gastric mucosal biopsies were taken from the antrum for culture.These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time:5,24 and 48 h.The culture results were reported after 72 h and the positive culture rates were analyzed by a χ2 test.An additional 5736 biopsies from H.pylori-positive patients(5646 rapid urease test-positive and 90 14C-urease breath test-positive) were also cultured for quality control in the central laboratory setting.RESULTS:The positive culture rate was 31.66%(21036/66452) for the patient samples and 71.72%(4114/5736) for the H.pylori-positive quality control specimens.In the 5 h transport group,the positiveculture rate was 30.99%(3865/12471),and 32.84%(14960/45553) in the 24 h transport group.In contrast,the positive culture rate declined significantly in the 48 h transport group(26.25%; P < 0.001).During transportation,the average natural temperature increased from 4.67 to 29.14℃,while the positive culture rate declined from 36.67%(1462/3987) to 24.12%(1799/7459).When the temperature exceeded 24℃,the positive culture rate decreased significantly,especially in the 48 h transport group(23.17%).CONCLUSION:Transportation of specimens within 24 h and below 24℃ is reasonable and acceptable for centralized culture of multicenter H.pylori samples.展开更多
This study aims to analyze the clinical use of ornidazole injection at the post-marketing stage by centralized hospital monitoring system method,and investigate its widespread use in patients,in order to regulate and ...This study aims to analyze the clinical use of ornidazole injection at the post-marketing stage by centralized hospital monitoring system method,and investigate its widespread use in patients,in order to regulate and guide the rational drug use,improve the drug specificity and provide a basis for drug therapy.The study adopts a prospective,multi-center,large sample size,centralized hospital monitoring system.We selected five leading hospitals in Hubei province,and observed the inpatients who received the ornidazole injection from July 1,2015 to October 31,2015.The basic information of patients was recorded,as well as the drug use and adverse events.The statistical analysis was performed based on these data.A total of 4396 individuals were enrolled in this study,most of them were middle-aged female patients and the ornidazole injection was mainly used as prophylactic prior to surgery to prevent the infections,and surgical treatment of anaerobic infections,abdominal infections and pelvic infections.The irrational drug use existed mainly in the prescribing and administration process,including unreasonable dosing frequency,rapid intravenous drip speed and extended duration of drug use.Eleven cases of adverse reactions were collected during the monitoring,incidence rate of adverse reactions was 2.5‰;adverse drug reactions occurred within 30 min.The study results fully reflected the usage of ornidazole injection in the real world.Based on the study,we calculated the adverse reaction incidence of ornidazole and identified the risk factors which may affect the safety of ornidazole injection.Study results strongly recommend that the manufacturers should publish standards for inpatient use and doctors should prescribe with caution accordingly.展开更多
The coronavirus disease 2019(COVID-19)pandemic increased the burden on many healthcare systems and in the process,exposed the need for medical resources and physical space.While few studies discussed the efficient uti...The coronavirus disease 2019(COVID-19)pandemic increased the burden on many healthcare systems and in the process,exposed the need for medical resources and physical space.While few studies discussed the efficient utilization of medical resources and physical space so far.Therefore,this study aimed to summarize experiences related to facilities used for centralized isolation for medical observation and treatment during the COVID-19 pandemic in China and to provide suggestions to further improve the management of confirmed cases,suspected cases,and close contacts.In China,three types of facilities for centralized isolation(Fangcang shelter hospitals,refitted non-designated hospitals,and quarantine hotels)underwent retrofitting for the treatment and isolation of confirmed and suspected cases.These facilities mitigated the immediate high demand for space.Moreover,in order to minimize infection risks in these facilities,regulators and governmental agencies implemented new designs,management measures,and precautionary measures to minimize infection risk.Other countries and regions could refer to China’s experience in optimally allocating social resources in response to the COVID-19 pandemic.As a conclusion,government should allocate social resources and construct centralized isolation and quarantine facilities for an emergency response,health authorities should issue regulations for centralized isolation facilities and pay strict attention to the daily management of these facilities,a multidisciplinary administration team is required to support the daily operation of a centralized isolation facility,in-depth studies and international collaboration on the centralized isolation policy are encouraged.展开更多
With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality...With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality of data, the message integrity and the endpoint authentication. One core technique of VPN is tunneling, by which clients can access the in- ternal servers traversing VPN. However, the tunneling technique also introduces a concealed security hole. It is possible that if one vicious user can establish tunneling by the VPN server, he can compromise the internal servers behind the VPN server. So this paper presents a novel Application-layer based Centralized Information Access Control (ACIAC) for VPN to solve this problem. To implement an efficient, flexible and multi-decision access control model, we present two key techniques to ACIAC—the centralized management mechanism and the stream-based access control. Firstly, we implement the information center and the constraints/events center for ACIAC. By the two centers, we can provide an abstract access control mechanism, and the material access control can be decided dynamically by the ACIAC’s constraint/event mechanism. Then we logically classify the VPN communication traffic into the access stream and the data stream so that we can tightly couple the features of VPN communication with the access control model. We also provide the design of our ACIAC prototype in this paper.展开更多
Based on the monitoring data of water quality of more than 40 centralized drinking water sources in 40 towns (townships or streets) of Kaixian County in the first and second half of each year during the "Twelfth Fi...Based on the monitoring data of water quality of more than 40 centralized drinking water sources in 40 towns (townships or streets) of Kaixian County in the first and second half of each year during the "Twelfth Five-year Plan" period, the changing rules of the water quality were studied to provide scientific references for the improvement of drinking water safety of urban and rural residents and drinking water quality. The re- sults show that the water quality of centralized drinking water sources in Kaixian County improved year by year during the "Twelfth Five-year Plan" period, and most monitoring sites with water quality exceeding the standard are distributed in reservoirs. Total phosphorus, total nitrogen, chemical oxygen demand, and permanganate index exceeded the standard obviously. Main pollution sources are domestic pollution and non-point source pol- lution caused by excessive discharge of nitrogen, phosphorus and organic pollutants. To improve drinking water quality, it is suggested that some towns can get drinking water from other reservoirs, surface water or underground water with better quality instead of previous reservoirs with water quality exceeding the standard, and the control of non-point source pollution should be enhanced.展开更多
Global renewable energy has maintained a steady growth in recent years, mainly fostered by national policies and increasing demand. Analyzing the experience of renewable energy development in developed countries can b...Global renewable energy has maintained a steady growth in recent years, mainly fostered by national policies and increasing demand. Analyzing the experience of renewable energy development in developed countries can be important to provide reference and guidance for its adoption in other countries. First, we compare and summarize definitions of distributed generation from 18 leading countries and organizations in renewable energy. On this basis, we provide three basic characteristics for successful distributed generation using renewable resources. Then, we empirically analyze the distributed and centralized development of renewable energy in Germany with focus on wind and photovoltaic power. We determined that 95% of the photovoltaic generation and 85% of the wind power generation is distributed in Germany, suggesting that the most suitable generation mode for renewable energy is the distributed approach.展开更多
On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousnes...On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousness, shortage of capital and other factors, the rural residents in Chongqing City mainly live scattered. In addition to opportunities of the expansion and drive of city, rural market development, rural resources development, rural industrial development, and rural ecological migration, the model of urban development promotion, the model of market development drive, the model of land development drive, the model of rural industry construction and the model of resettlement and reconstruction are advocated in order to guide the rural residents to adopt relative centralized residence. The suggestions concerning guiding rural residents' relative centralized residence are put forward as follows: firstly, act according to circumstances and conduct scientific planning and design; secondly, propagate extensively and activate famers' willingness; thirdly, first experiment and exert the exemplary guide; fourthly, perfect policy and guarantee farmers' benefit; fifthly, strengthen leadership and decrease the risk of centralized residence; sixthly, boost gradually and realize moderate centralized residence.展开更多
In Europe Health Organizations are progressively modifying their management models to rationalize expenditure in order to assure better levels of effectiveness and efficiency: many countries are going to centralize th...In Europe Health Organizations are progressively modifying their management models to rationalize expenditure in order to assure better levels of effectiveness and efficiency: many countries are going to centralize the management of goods and services supply. In this paper a specific model of centralized purchasing is proposed;it is particularly suitable in cases of severe economy suffering at regional level (e.g. Campania, Lazio, Calabria in Italy) or at national level (e.g. Greece, Ireland, Italy), that means in all those cases where the scale economies, obtainable by supply centralization, would be partly or totally compromised by the extra charges induced by the missing of contractual commitments. This work aims either to analyse such specific approach for centralized purchasing or to propose a simulation model based on Petri net, which could be useful for designing and managing similar case studies.展开更多
The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In t...The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In this paper, we present Switched-Beam (SB) and Rotatable Equal Sectoring (RES) techniques for CDMA cellular systems in a 2D urban environment. In the SB technique by using a number of fixed, independent, or directional antennas we increase the downlink capacity of the CDMA systems. Also in the RES method, the equal sectors of the base stations are rotating together to decrease the inter-cell and intra-cell interferences. Also in this paper we use centralized power control to overcome the near-far problem. Simulation results indicate that the proposed techniques considerably increase the capacity of the CDMA cellular systems compared to ordinary Equal Sectoring (ES) method.展开更多
The clearing price and bidding price in electricity market are two key indicators to measure whether it is reasonable or not. Based on the grey incidence analysis, this paper studies the correlation coefficient betwee...The clearing price and bidding price in electricity market are two key indicators to measure whether it is reasonable or not. Based on the grey incidence analysis, this paper studies the correlation coefficient between the clearing price and bidding price with the generation cost, the supervision and rules of the market, the supply and demand situation, the behavior of market members over the same period, which is based on the actual data of the trans-provincial centralized trading market of East China Power Grid. The results show that the factors affecting the clearing price and bidding price from largest to smallest are generation cost, supervision and rules of the market, the supply and demand situation, the behavior of market members. The conclusion is that the trans-provincial trading platform of East China Power Grid is a reasonable regional market which can discover the market cost, and regulate the market supply and demand balance, and promote healthy competition.展开更多
An ADS (automated dispensing system) was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI (r...An ADS (automated dispensing system) was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI (return on investment), after seven years of use. ROI was calculated annually (from 2008 to 2015), by deducting the cost of investment (ADS buying and implementation, maintenance, repairs and ADS upgrade) from the cost saving (drugs stock reduction and decrease of pharmacy staff dedicated to global dispensing). In 2015, total costs saving (+$1,141,987) were divided between decreasing drug stock value and reduction of pharmacy staff. Total costs of investment (-$978,656) were acquisition, maintenance, repairs and an unplanned upgrade costs. Finally, the real ROI was +$163,331 after seven years of use. In 2008, projected ROI was +$410,786. The real payback period has been increased by approximately two years (six years of use, instead of four years as expected). Despite their cost, ADSs are a worthwhile investment, leading to a ROI within a few years. These economic considerations should be put into perspective with optimization of drugs stock management, greater efficiency of the global dispensing process, securitization of medication process and redeployment of pharmacy staff.展开更多
In this paper,we derive the Symbol Error Probability(SEP)of cooperative systems with incremental relaying and Distributed Relay Selection(DRS).The relays remain idle when the Signal to Noise Ratio(SNR)between the sour...In this paper,we derive the Symbol Error Probability(SEP)of cooperative systems with incremental relaying and Distributed Relay Selection(DRS).The relays remain idle when the Signal to Noise Ratio(SNR)between the source and destination is larger than T.Otherwise,we activate a relay using DRS.Relay nodes transmit only if their SNR is larger than thresholdβ.If the SNRs of more than two relays is larger thanβ,there is a collision and the destination uses only the received signal from the source.If all relays have SNR less thanβ,no relay is chosen.Thresholdβis optimized to yield the lowest SEP at the destination.Our results are compared to centralized relay selection using opportunistic Amplify and Forward(OAF),Partial and Reactive Relay Selection(PRS and RRS).We compare our results to computer simulations for Rayleigh fading channels.展开更多
Let G be a finite group, H ≤ G and R be a commutative ring with an identity 1R. Let CRG(H)={α ∈ RG|αh = hα for all h ∈ H), which is called the centralizer subalgebra of H in RG. Obviously, if H=G then CRG(H...Let G be a finite group, H ≤ G and R be a commutative ring with an identity 1R. Let CRG(H)={α ∈ RG|αh = hα for all h ∈ H), which is called the centralizer subalgebra of H in RG. Obviously, if H=G then CRG(H) is just the central subalgebra Z(RG) of RG. In this note, we show that the set of all H- conjugacy class sums of G forms an R-basis of CRG(H). Furthermore, let N be a normal subgroup of G and γthe natural epimorphism from G to G to G/N. Then γ induces an epimorphism from RG to RG, also denoted by % We also show that if R is a field of characteristic zero, then γ induces an epimorphism from CRG(H) to CRG(H), that is, 7(CRG(H)) = CRG(H).展开更多
IEEE 802.16 mesh mode defines routing tree for transmitting data in centralized scheduling but it does not define any explicit proposal for combining uplink and downlink subframes. Deploying combined uplink and downli...IEEE 802.16 mesh mode defines routing tree for transmitting data in centralized scheduling but it does not define any explicit proposal for combining uplink and downlink subframes. Deploying combined uplink and downlink subframes on the centralized scheduling scheme can be more flexible and utilization is improved. However, existing interferences among the transmission of neighboring nodes lead to performance reduction of the network. In this paper, an efficient routing tree algorithm is proposed with combined uplink and downlink slot allocation on the centralized scheduling scheme which can abate interferences in the network. This algorithm allows more subscriber stations to transmit concurrently and so improves spatial reuse in the network. Also, the algorithm uses multi-channel and single channel systems and considers relay model, smoothing switching frequently between transmitting and receiving in successive time slots and fairness in the network. Extensive simulation results demonstrate the effectiveness of the proposed method in terms of scheduling length, link concurrency ratio, network throughput and Channel Utilization Ratio (CUR).展开更多
It is significant to research the voltage stability of the wind power centralized system (WPCS) for the effective development of the large scale clustering wind energy resources. A steady state voltage stability analy...It is significant to research the voltage stability of the wind power centralized system (WPCS) for the effective development of the large scale clustering wind energy resources. A steady state voltage stability analysis of the WPCS by employing the PV curve and model analysis is proposed to reveal the voltage stability influence from different aspects. The PV curve is utilized to trace and indicate the voltage collapse point of the WPCS when the small disturbance of wind power is increased gradually. Then the steady state voltage instability modes of the WPCS are analyzed by calculating the bus participation factors of the minimum eigenvalue model at the collapse point. The simulation results of an actual WPCS in North China show that the static state voltage instability mode of the WPCS is closely related to the operating features and control strategies of different reactive power sources. In addition, the implementation of the doubly-fed induction generator wind turbine generator voltage control is beneficial to improve the WPCS voltage stability.展开更多
Before the construction of the Kuching Centralized Wastewater Treatment System Package 1 (KCWTSP1), partially treated blackwater and greywater were discharged directly into natural waterways. The accumulated wastewate...Before the construction of the Kuching Centralized Wastewater Treatment System Package 1 (KCWTSP1), partially treated blackwater and greywater were discharged directly into natural waterways. The accumulated wastewater had polluted Sarawak river, which is regulated and cannot discharge freely into the South China Sea. The polluted Sarawak river has endangered human health, river water quality, and aquatic ecosystems. Hence, the KCWTSP1 commissioned in 2015 serves the purpose of removing pollutants from wastewater before it is discharged into natural waterways. However, the effectiveness of KCWTPP1 is unknown. This paper is aimed to discuss and review the effectiveness of KCWTPP1 in treating wastewater since its inception in 2015. From 2017 to 2020, KCWTPP1 has treated an average of 4,200,000 m<sup>3</sup> of wastewater per year. Generally, most of the discharge effluent met Environmental Quality Act (1974) Standard A criteria, except for the oil and grease parameter. Initially, the plant could not treat suspended solids and total phosphorus, but this was greatly improved in subsequent years. Therefore, some improvements are required to treat oil and grease parameters effectively and efficiently to ensure that only Standard A effluent is discharged into the Sarawak River in the future.展开更多
The establishment of a centralized monitoring system is an effective means to achieve the goal that no or fewer people are on duty. The function of the current 500kV centralized monitoring system is not enough mature ...The establishment of a centralized monitoring system is an effective means to achieve the goal that no or fewer people are on duty. The function of the current 500kV centralized monitoring system is not enough mature to meet the requirement of the large-scale operation and large-scale maintenance model proposed by the State Grid. In order to fully utilizing the function of the centralized monitoring system, an improved design scheme is presented for the current 500kV centralized monitoring of the Jiangxi Power Grid. The improved centralized monitoring system is divided into three layers: monitoring center layer, operating team layer, and substation layer, which not only has the advantages of high security, high reliability, and easy maintenance, but also realizes the management model of regional control. So it can perfectly meet anti-misoperation requirement in the large operation and large maintenance mode, which can provide reference and guidance for the design of the 500kV centralized monitoring system of Jiangxi Power Grid.展开更多
Wireless sensor networks (WSNs) attract considerable amount of research efforts from both industry and academia. With limited power and computational capability available on a sensor node, robustness and efficiency ar...Wireless sensor networks (WSNs) attract considerable amount of research efforts from both industry and academia. With limited power and computational capability available on a sensor node, robustness and efficiency are the main concerns when designing a routing protocol for WSNs with low complexity. There are various existing design approaches, such as data-centric approach, hierarchical approach and location-based approach, which were designed for a particular application with specific requirements. In this paper, we study the design and implementation of a routing protocol for data acquisition in WSNs. The designed routing protocol is named Centralized Sensor Protocol for Information via Negotiation (CSPIN), which essentially combines the advertise-request-transfer process and a routing distribution mechanism. Implementation is realized and demonstrated with the Crossbow MicaZ hardware using nesC/TinyOS. It was our intention to provide a hand-on study of implementation of centralized routing protocol for WSNs.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 12174041)China Postdoctoral Science Foundation (CPSF)(Grant No. 2022M723118)the seed grants from the Wenzhou Institute,University of Chinese Academy of Sciences (Grant No. WIUCASQD2021002)。
文摘How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation of group patterns. Centralized systems excel in precise control over individual behavior within a group, ensuring high accuracy and controllability in task execution. Nevertheless, their sensitivity to group size may limit their adaptability to diverse tasks. In contrast, decentralized systems empower individuals with autonomous decision-making, enhancing adaptability and system robustness. Yet, this flexibility comes at the cost of reduced accuracy and efficiency in task execution. In this work, we present a unique method for regulating the centralized dynamic behavior of self-organizing clusters based on environmental interactions. Within this environment-coupled robot system, each robot possesses similar dynamic characteristics, and their internal programs are entirely identical. However, their behaviors can be guided by the centralized control of the environment, facilitating the accomplishment of diverse cluster tasks. This approach aims to balance the accuracy and flexibility of centralized control with the robustness and task adaptability of decentralized control. The proactive regulation of dynamic behavioral characteristics in active matter groups, demonstrated in this work through environmental interactions, holds the potential to introduce a novel technological approach and provide experimental references for studying the dynamic behavior control of large-scale artificial active matter systems.
文摘Smart grid is an idea of upgradation of the traditional electric grid infrastructure. The efficiency of the existing electrical grid can be automated by integrating with innovative technical equipment such as:?high-tech forecasting system, digital sensors, advanced two-way communication and two-way power flow systems. Smart grid establishes an interface between utility and consumer which helps to use energy, based on the preferences of price, eco-friendly and without technical system issues. It empowers the grid to be more secure, reliable and efficient. The peer-reviewed articles and published government reports have been reviewed, based on the analysis of technical characteristics of power generation systems, eco-friendly sources of power generations, cost reduction, functionality and design of traditional grid versus smart grid. Furthermore, the innovative technologies that enable the grid to integrate with decentralized power generation system efficiently have been considered. This paper claims that in this modern era, it is arduous for traditional grid to fulfill the rising demand of electricity, along with sustainable, eco-friendly and stable power supply, as it cannot be efficiently integrated with decentralized and localized power generation systems and renewable energy sources. The result of this paper shows that decentralized and localized power generation systems are located close to end-users which decrease the transmission and supply cost of electricity. Innovative technologies allow the decentralized and localized power generation systems to be integrated with renewable energy sources which help to reduce the cost of utility services and provide clean energy. Moreover, technological advancement played a decisive role in enabling the electrical system to be more efficient. Electrical reliability can be improved,?greenhouse gas emissions can be reduced, renewable energy sources can efficiently be integrated,?and?rising demand for electricity can be met by embedding advanced applications and technological equipment in the electrical grid.
基金Supported by Grants from the Science and Technology Program of Zhejiang Province China,No.2001C23140National Technology RD Program in the 12th Five-Year Plan of China,No.2012BAI06B02+3 种基金the Major Technology Project as part of"Prevention and Control of Major Infectious Diseases including AIDS and Viral Hepatitis",No.2013ZX10004216-002the National Key Scientific Instrument and Equipment Development Project,No.2012YQ180117the Medical and Health Science and Technology Plan Project of Zhejiang Province,No.2012KYB248the Science and Technology Project of Zhejiang province,No.2011C23140
文摘AIM:To evaluate the efficacy of centralized culture and possible influencing factors.METHODS:From January 2010 to July 2012,66452 patients with suspected Helicobacter pylori(H.pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy.Gastric mucosal biopsies were taken from the antrum for culture.These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time:5,24 and 48 h.The culture results were reported after 72 h and the positive culture rates were analyzed by a χ2 test.An additional 5736 biopsies from H.pylori-positive patients(5646 rapid urease test-positive and 90 14C-urease breath test-positive) were also cultured for quality control in the central laboratory setting.RESULTS:The positive culture rate was 31.66%(21036/66452) for the patient samples and 71.72%(4114/5736) for the H.pylori-positive quality control specimens.In the 5 h transport group,the positiveculture rate was 30.99%(3865/12471),and 32.84%(14960/45553) in the 24 h transport group.In contrast,the positive culture rate declined significantly in the 48 h transport group(26.25%; P < 0.001).During transportation,the average natural temperature increased from 4.67 to 29.14℃,while the positive culture rate declined from 36.67%(1462/3987) to 24.12%(1799/7459).When the temperature exceeded 24℃,the positive culture rate decreased significantly,especially in the 48 h transport group(23.17%).CONCLUSION:Transportation of specimens within 24 h and below 24℃ is reasonable and acceptable for centralized culture of multicenter H.pylori samples.
文摘This study aims to analyze the clinical use of ornidazole injection at the post-marketing stage by centralized hospital monitoring system method,and investigate its widespread use in patients,in order to regulate and guide the rational drug use,improve the drug specificity and provide a basis for drug therapy.The study adopts a prospective,multi-center,large sample size,centralized hospital monitoring system.We selected five leading hospitals in Hubei province,and observed the inpatients who received the ornidazole injection from July 1,2015 to October 31,2015.The basic information of patients was recorded,as well as the drug use and adverse events.The statistical analysis was performed based on these data.A total of 4396 individuals were enrolled in this study,most of them were middle-aged female patients and the ornidazole injection was mainly used as prophylactic prior to surgery to prevent the infections,and surgical treatment of anaerobic infections,abdominal infections and pelvic infections.The irrational drug use existed mainly in the prescribing and administration process,including unreasonable dosing frequency,rapid intravenous drip speed and extended duration of drug use.Eleven cases of adverse reactions were collected during the monitoring,incidence rate of adverse reactions was 2.5‰;adverse drug reactions occurred within 30 min.The study results fully reflected the usage of ornidazole injection in the real world.Based on the study,we calculated the adverse reaction incidence of ornidazole and identified the risk factors which may affect the safety of ornidazole injection.Study results strongly recommend that the manufacturers should publish standards for inpatient use and doctors should prescribe with caution accordingly.
文摘The coronavirus disease 2019(COVID-19)pandemic increased the burden on many healthcare systems and in the process,exposed the need for medical resources and physical space.While few studies discussed the efficient utilization of medical resources and physical space so far.Therefore,this study aimed to summarize experiences related to facilities used for centralized isolation for medical observation and treatment during the COVID-19 pandemic in China and to provide suggestions to further improve the management of confirmed cases,suspected cases,and close contacts.In China,three types of facilities for centralized isolation(Fangcang shelter hospitals,refitted non-designated hospitals,and quarantine hotels)underwent retrofitting for the treatment and isolation of confirmed and suspected cases.These facilities mitigated the immediate high demand for space.Moreover,in order to minimize infection risks in these facilities,regulators and governmental agencies implemented new designs,management measures,and precautionary measures to minimize infection risk.Other countries and regions could refer to China’s experience in optimally allocating social resources in response to the COVID-19 pandemic.As a conclusion,government should allocate social resources and construct centralized isolation and quarantine facilities for an emergency response,health authorities should issue regulations for centralized isolation facilities and pay strict attention to the daily management of these facilities,a multidisciplinary administration team is required to support the daily operation of a centralized isolation facility,in-depth studies and international collaboration on the centralized isolation policy are encouraged.
基金Project (No. 60373088) supported by the National Natural ScienceFoundation of China
文摘With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality of data, the message integrity and the endpoint authentication. One core technique of VPN is tunneling, by which clients can access the in- ternal servers traversing VPN. However, the tunneling technique also introduces a concealed security hole. It is possible that if one vicious user can establish tunneling by the VPN server, he can compromise the internal servers behind the VPN server. So this paper presents a novel Application-layer based Centralized Information Access Control (ACIAC) for VPN to solve this problem. To implement an efficient, flexible and multi-decision access control model, we present two key techniques to ACIAC—the centralized management mechanism and the stream-based access control. Firstly, we implement the information center and the constraints/events center for ACIAC. By the two centers, we can provide an abstract access control mechanism, and the material access control can be decided dynamically by the ACIAC’s constraint/event mechanism. Then we logically classify the VPN communication traffic into the access stream and the data stream so that we can tightly couple the features of VPN communication with the access control model. We also provide the design of our ACIAC prototype in this paper.
文摘Based on the monitoring data of water quality of more than 40 centralized drinking water sources in 40 towns (townships or streets) of Kaixian County in the first and second half of each year during the "Twelfth Five-year Plan" period, the changing rules of the water quality were studied to provide scientific references for the improvement of drinking water safety of urban and rural residents and drinking water quality. The re- sults show that the water quality of centralized drinking water sources in Kaixian County improved year by year during the "Twelfth Five-year Plan" period, and most monitoring sites with water quality exceeding the standard are distributed in reservoirs. Total phosphorus, total nitrogen, chemical oxygen demand, and permanganate index exceeded the standard obviously. Main pollution sources are domestic pollution and non-point source pol- lution caused by excessive discharge of nitrogen, phosphorus and organic pollutants. To improve drinking water quality, it is suggested that some towns can get drinking water from other reservoirs, surface water or underground water with better quality instead of previous reservoirs with water quality exceeding the standard, and the control of non-point source pollution should be enhanced.
基金supported by National Natural Science Foundation of China (No.U1766201)the State Grid Science and Technology Project (Title: Research on China’s New Energy Resources & Development Roadmap)
文摘Global renewable energy has maintained a steady growth in recent years, mainly fostered by national policies and increasing demand. Analyzing the experience of renewable energy development in developed countries can be important to provide reference and guidance for its adoption in other countries. First, we compare and summarize definitions of distributed generation from 18 leading countries and organizations in renewable energy. On this basis, we provide three basic characteristics for successful distributed generation using renewable resources. Then, we empirically analyze the distributed and centralized development of renewable energy in Germany with focus on wind and photovoltaic power. We determined that 95% of the photovoltaic generation and 85% of the wind power generation is distributed in Germany, suggesting that the most suitable generation mode for renewable energy is the distributed approach.
基金Supported by the Research on the Mechanism and System of Guiding Farmers' Relatively Centralized Residence (0106002442003)Research Program of the Comprehensive Matching Reform Subject of Coordinating City and Village in 2009
文摘On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousness, shortage of capital and other factors, the rural residents in Chongqing City mainly live scattered. In addition to opportunities of the expansion and drive of city, rural market development, rural resources development, rural industrial development, and rural ecological migration, the model of urban development promotion, the model of market development drive, the model of land development drive, the model of rural industry construction and the model of resettlement and reconstruction are advocated in order to guide the rural residents to adopt relative centralized residence. The suggestions concerning guiding rural residents' relative centralized residence are put forward as follows: firstly, act according to circumstances and conduct scientific planning and design; secondly, propagate extensively and activate famers' willingness; thirdly, first experiment and exert the exemplary guide; fourthly, perfect policy and guarantee farmers' benefit; fifthly, strengthen leadership and decrease the risk of centralized residence; sixthly, boost gradually and realize moderate centralized residence.
文摘In Europe Health Organizations are progressively modifying their management models to rationalize expenditure in order to assure better levels of effectiveness and efficiency: many countries are going to centralize the management of goods and services supply. In this paper a specific model of centralized purchasing is proposed;it is particularly suitable in cases of severe economy suffering at regional level (e.g. Campania, Lazio, Calabria in Italy) or at national level (e.g. Greece, Ireland, Italy), that means in all those cases where the scale economies, obtainable by supply centralization, would be partly or totally compromised by the extra charges induced by the missing of contractual commitments. This work aims either to analyse such specific approach for centralized purchasing or to propose a simulation model based on Petri net, which could be useful for designing and managing similar case studies.
文摘The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In this paper, we present Switched-Beam (SB) and Rotatable Equal Sectoring (RES) techniques for CDMA cellular systems in a 2D urban environment. In the SB technique by using a number of fixed, independent, or directional antennas we increase the downlink capacity of the CDMA systems. Also in the RES method, the equal sectors of the base stations are rotating together to decrease the inter-cell and intra-cell interferences. Also in this paper we use centralized power control to overcome the near-far problem. Simulation results indicate that the proposed techniques considerably increase the capacity of the CDMA cellular systems compared to ordinary Equal Sectoring (ES) method.
文摘The clearing price and bidding price in electricity market are two key indicators to measure whether it is reasonable or not. Based on the grey incidence analysis, this paper studies the correlation coefficient between the clearing price and bidding price with the generation cost, the supervision and rules of the market, the supply and demand situation, the behavior of market members over the same period, which is based on the actual data of the trans-provincial centralized trading market of East China Power Grid. The results show that the factors affecting the clearing price and bidding price from largest to smallest are generation cost, supervision and rules of the market, the supply and demand situation, the behavior of market members. The conclusion is that the trans-provincial trading platform of East China Power Grid is a reasonable regional market which can discover the market cost, and regulate the market supply and demand balance, and promote healthy competition.
文摘An ADS (automated dispensing system) was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI (return on investment), after seven years of use. ROI was calculated annually (from 2008 to 2015), by deducting the cost of investment (ADS buying and implementation, maintenance, repairs and ADS upgrade) from the cost saving (drugs stock reduction and decrease of pharmacy staff dedicated to global dispensing). In 2015, total costs saving (+$1,141,987) were divided between decreasing drug stock value and reduction of pharmacy staff. Total costs of investment (-$978,656) were acquisition, maintenance, repairs and an unplanned upgrade costs. Finally, the real ROI was +$163,331 after seven years of use. In 2008, projected ROI was +$410,786. The real payback period has been increased by approximately two years (six years of use, instead of four years as expected). Despite their cost, ADSs are a worthwhile investment, leading to a ROI within a few years. These economic considerations should be put into perspective with optimization of drugs stock management, greater efficiency of the global dispensing process, securitization of medication process and redeployment of pharmacy staff.
文摘In this paper,we derive the Symbol Error Probability(SEP)of cooperative systems with incremental relaying and Distributed Relay Selection(DRS).The relays remain idle when the Signal to Noise Ratio(SNR)between the source and destination is larger than T.Otherwise,we activate a relay using DRS.Relay nodes transmit only if their SNR is larger than thresholdβ.If the SNRs of more than two relays is larger thanβ,there is a collision and the destination uses only the received signal from the source.If all relays have SNR less thanβ,no relay is chosen.Thresholdβis optimized to yield the lowest SEP at the destination.Our results are compared to centralized relay selection using opportunistic Amplify and Forward(OAF),Partial and Reactive Relay Selection(PRS and RRS).We compare our results to computer simulations for Rayleigh fading channels.
基金The NSF(11071155) of Chinathe NSF(2008A03) of Shandong Province
文摘Let G be a finite group, H ≤ G and R be a commutative ring with an identity 1R. Let CRG(H)={α ∈ RG|αh = hα for all h ∈ H), which is called the centralizer subalgebra of H in RG. Obviously, if H=G then CRG(H) is just the central subalgebra Z(RG) of RG. In this note, we show that the set of all H- conjugacy class sums of G forms an R-basis of CRG(H). Furthermore, let N be a normal subgroup of G and γthe natural epimorphism from G to G to G/N. Then γ induces an epimorphism from RG to RG, also denoted by % We also show that if R is a field of characteristic zero, then γ induces an epimorphism from CRG(H) to CRG(H), that is, 7(CRG(H)) = CRG(H).
文摘IEEE 802.16 mesh mode defines routing tree for transmitting data in centralized scheduling but it does not define any explicit proposal for combining uplink and downlink subframes. Deploying combined uplink and downlink subframes on the centralized scheduling scheme can be more flexible and utilization is improved. However, existing interferences among the transmission of neighboring nodes lead to performance reduction of the network. In this paper, an efficient routing tree algorithm is proposed with combined uplink and downlink slot allocation on the centralized scheduling scheme which can abate interferences in the network. This algorithm allows more subscriber stations to transmit concurrently and so improves spatial reuse in the network. Also, the algorithm uses multi-channel and single channel systems and considers relay model, smoothing switching frequently between transmitting and receiving in successive time slots and fairness in the network. Extensive simulation results demonstrate the effectiveness of the proposed method in terms of scheduling length, link concurrency ratio, network throughput and Channel Utilization Ratio (CUR).
文摘It is significant to research the voltage stability of the wind power centralized system (WPCS) for the effective development of the large scale clustering wind energy resources. A steady state voltage stability analysis of the WPCS by employing the PV curve and model analysis is proposed to reveal the voltage stability influence from different aspects. The PV curve is utilized to trace and indicate the voltage collapse point of the WPCS when the small disturbance of wind power is increased gradually. Then the steady state voltage instability modes of the WPCS are analyzed by calculating the bus participation factors of the minimum eigenvalue model at the collapse point. The simulation results of an actual WPCS in North China show that the static state voltage instability mode of the WPCS is closely related to the operating features and control strategies of different reactive power sources. In addition, the implementation of the doubly-fed induction generator wind turbine generator voltage control is beneficial to improve the WPCS voltage stability.
文摘Before the construction of the Kuching Centralized Wastewater Treatment System Package 1 (KCWTSP1), partially treated blackwater and greywater were discharged directly into natural waterways. The accumulated wastewater had polluted Sarawak river, which is regulated and cannot discharge freely into the South China Sea. The polluted Sarawak river has endangered human health, river water quality, and aquatic ecosystems. Hence, the KCWTSP1 commissioned in 2015 serves the purpose of removing pollutants from wastewater before it is discharged into natural waterways. However, the effectiveness of KCWTPP1 is unknown. This paper is aimed to discuss and review the effectiveness of KCWTPP1 in treating wastewater since its inception in 2015. From 2017 to 2020, KCWTPP1 has treated an average of 4,200,000 m<sup>3</sup> of wastewater per year. Generally, most of the discharge effluent met Environmental Quality Act (1974) Standard A criteria, except for the oil and grease parameter. Initially, the plant could not treat suspended solids and total phosphorus, but this was greatly improved in subsequent years. Therefore, some improvements are required to treat oil and grease parameters effectively and efficiently to ensure that only Standard A effluent is discharged into the Sarawak River in the future.
文摘The establishment of a centralized monitoring system is an effective means to achieve the goal that no or fewer people are on duty. The function of the current 500kV centralized monitoring system is not enough mature to meet the requirement of the large-scale operation and large-scale maintenance model proposed by the State Grid. In order to fully utilizing the function of the centralized monitoring system, an improved design scheme is presented for the current 500kV centralized monitoring of the Jiangxi Power Grid. The improved centralized monitoring system is divided into three layers: monitoring center layer, operating team layer, and substation layer, which not only has the advantages of high security, high reliability, and easy maintenance, but also realizes the management model of regional control. So it can perfectly meet anti-misoperation requirement in the large operation and large maintenance mode, which can provide reference and guidance for the design of the 500kV centralized monitoring system of Jiangxi Power Grid.
文摘Wireless sensor networks (WSNs) attract considerable amount of research efforts from both industry and academia. With limited power and computational capability available on a sensor node, robustness and efficiency are the main concerns when designing a routing protocol for WSNs with low complexity. There are various existing design approaches, such as data-centric approach, hierarchical approach and location-based approach, which were designed for a particular application with specific requirements. In this paper, we study the design and implementation of a routing protocol for data acquisition in WSNs. The designed routing protocol is named Centralized Sensor Protocol for Information via Negotiation (CSPIN), which essentially combines the advertise-request-transfer process and a routing distribution mechanism. Implementation is realized and demonstrated with the Crossbow MicaZ hardware using nesC/TinyOS. It was our intention to provide a hand-on study of implementation of centralized routing protocol for WSNs.