Recently,electric vehicles(EVs)have been widely used under the call of green travel and environmental protection,and diverse requirements for charging are also increasing gradually.In order to ensure the authenticity ...Recently,electric vehicles(EVs)have been widely used under the call of green travel and environmental protection,and diverse requirements for charging are also increasing gradually.In order to ensure the authenticity and privacy of charging information interaction,blockchain technology is proposed and applied in charging station billing systems.However,there are some issues in blockchain itself,including lower computing efficiency of the nodes and higher energy consumption in the consensus process.To handle the above issues,in this paper,combining blockchain and mobile edge computing(MEC),we develop a reliable billing data transmission scheme to improve the computing capacity of nodes and reduce the energy consumption of the consensus process.By jointly optimizing the primary and replica nodes offloading decisions,block size and block interval,the transaction throughput of the blockchain system is maximized,as well as the latency and energy consumption of the system are minimized.Moreover,we formulate the joint optimization problem as a Markov decision process(MDP).To tackle the dynamic and continuity of the system state,the reinforcement learning(RL)is introduced to solve the MDP problem.Finally,simulation results demonstrate that the performance improvement of the proposed scheme through comparison with other existing schemes.展开更多
The rapid pace of technological change has seen information and communication technologies become the digital backbone of developed nations’ economies and a pre-requisite for global trade. Some enterprise systems are...The rapid pace of technological change has seen information and communication technologies become the digital backbone of developed nations’ economies and a pre-requisite for global trade. Some enterprise systems are however more than mere facilitators, they provide the bedrock without which organizations could not function;we term these mandatory systems “non-volitional”(NVS). With hyper-growth in demand for connectivity, telecommunications are typical of sectors where NVS shape the fiercely competitive landscape. Among them, Billing & Revenue Management Systems (BRMS) are a form of credit, providers deliver a service and subscribers later pay for that service. As such, they are “business critical”, meaning failures may affect an organization’s ability to conduct its core business. Failures also impact user satisfaction, a key measure of information systems success. However, relatively few studies empirically test this notion;fewer still evaluate it at organizational (rather than individual) level, while there is a dearth of literature investigating non-volitional systems and, to the best of our knowledge, none whatsoever consider ways of predicting user satisfaction for BRMS. According to a renowned and widely cited conceptual model, user satisfaction is influenced by information, system, and service quality respectively. To test this theory for telecoms BRMS, we applied structural equation modelling to investigate which of these dimensions has the most effect. The results indicate that information quality, system quality, service quality, and user satisfaction are all valid measures of BRMS success. Hypothesized relationships between the four success dimensions were significantly substantiated. The study also identified five measures of information quality, four measures of system quality, four measures of service quality, and four measures of user satisfaction. Once the proposed model had been successfully validated, we tested the level of significance among user satisfaction and the three quality dimensions. Findings showed that service quality had the strongest influence on user satisfaction, with information quality second. This is quite different from other applications considered in our literature review which mostly have information quality as having the strongest impact (knowledge management systems apart).展开更多
IP billing is not only a basic functionality to operate IP sen＇ices, but also it is fundamental to offer customers with a stable and QoS-enabled network environment. As IP-based network has been widely agreed to be t...IP billing is not only a basic functionality to operate IP sen＇ices, but also it is fundamental to offer customers with a stable and QoS-enabled network environment. As IP-based network has been widely agreed to be the core network of NGN, and existing IP billing system is too simple to fulfill the emerging requirements, the next generation IP billing has become an interesting topic in recent years. Policy-based management brings flexibility and scalability to systems by describing management logic and functions through policies, and thus reduces the complexity of the management of large-scale systems. Working on existing efforts, this paper proposed an improved IETF policy framework based upon which a policy-based billing management architecture for the next generation IP-based network was presented. Then a prototype with some basic functionalities was developed. The results of the experiment validated the expected improvements specified in this paper.展开更多
In order to adopt Billings Method for fertility regulation during the period of breast feeding, cervical mucus was observed and monitored in 61 breast feeding mothers.Urine estrogen and /or pregnanediol ...In order to adopt Billings Method for fertility regulation during the period of breast feeding, cervical mucus was observed and monitored in 61 breast feeding mothers.Urine estrogen and /or pregnanediol were/was measured in 15 breast feeding mothers. Observations on cervical mucus during 244 months were collected. The type of dry or no mucus was observed in 75.27% fully breast feeding mothers. Constant unchanging mucus was observed in 69.39% partially breast feeding mothers. Developmental changing mucus was observed in 79.25% of mothers bottle feeding their infants. According to the record on cervical mucus within 6 months postpartum, 97.14% of the cervical mucus was consistent with normal menstrual cycles. Urine estrogen and /or pregnanediol were/was measured in 15 breast feeding mothers. The level of estrogen in urine averaged 0.08 μmol/24 h in fully breast feeding mothers and 0.14 μmol/24 h in partially breast feeding mothers.The peak level averaged 0.21 μmol/24 h in bottle feeding mothers.The pregnanediol level was determined to confirm ovulation in bottle feeding mothers. The average levels of cut off and the period of ovulation in 6 bottle feeding mother were 7 μmol/24 h and 9 μmol/24 h respectively.Measurement of urine estrogen and pregnanediol level all matched with cervical mucus appearances. Conclusion: Billings Method is a simple, scientific method for contraception without side effects during breast feeding period.展开更多
Objective The effectiveness and acceptability of Billings Ovulation Method (BOM) during breastfeeding were studied. At the same time, the monitoring indexes of fertility return were studied.Methods It was a clinical c...Objective The effectiveness and acceptability of Billings Ovulation Method (BOM) during breastfeeding were studied. At the same time, the monitoring indexes of fertility return were studied.Methods It was a clinical comparative study of BOM and IUD containing copper (200mm 2). The annual rate of pregnancy, discontinuation rate and continuation rate in the two groups was determined. The serum prolactin and estradiol in 90 breastfeeding mothers and urine estrogen and pregnanediol in different feeding mothers were measured.Results There were 219 subjects in the BOM group and 200 in the IUD group. The pregnancy rate in this two groups was 1. 43% and 1. 54% respectively. The rates of discontinuation and continuation in the IUD group were:8. 87% and 91. 35% as well as in the BOM group were 8. 53% and 90. 17% respectively. Neither result was statistically significant (P>0. 05). The experimtal research showed that menses return was well estimated by 0. 35 ratio of serum prolactin vs. estrodiol. Sensitivity and specificity was 94. 61% and 84. 61% respectively. It also indicated that (1) the levels of urine hormone were closely related to the patterns of cervical mucus and (2) the incidence of ovulating before the second return of menses in partially breastfeeding mothers was much lower than that of bottle-feeding mothers (47. 05% vs. 94. 20%). Conclusion BOM is a simple, reliable and well accepted contraceptive method of during breastfeeding. If it can be combined with the measurement of serum prolactin/ estradiol, the date of menses return will be determined more easily. Encouraging mothers to breast-feed will be beneficial to the health of both babies and mothers and delay the fertility return of mothers.展开更多
ZTE Corporation (ZTE) announced that its participation in the 8th Annual Asia-Pacific Billing & Revenue Assurance Conference in Singapore from May 12th till 15th 2008 delivered a keynote on its latest ZSmart opera...ZTE Corporation (ZTE) announced that its participation in the 8th Annual Asia-Pacific Billing & Revenue Assurance Conference in Singapore from May 12th till 15th 2008 delivered a keynote on its latest ZSmart operations and business support solutions and shared the latest BSS/OSS technology with key industry players.展开更多
Extending the lifetime of the wireless sensor networks (WSNs), where recharging sensors is not always possible, has been a major concern for researchers for the past decade. In this paper, we study the cooperation bet...Extending the lifetime of the wireless sensor networks (WSNs), where recharging sensors is not always possible, has been a major concern for researchers for the past decade. In this paper, we study the cooperation between nodes in wireless sensor networks in forwarding packets to others, and we propose a new collaboration technique which stimulates intermediate nodes to forward packets toward their destination. Some nodes show selfish behavior by denying the forwarding packets to other nodes in commercial networks in an effort to preserve their own energy. This paper applies a technique which is used to prolong the network lifetime, based on a node’s energy and trust value, and additionally incorporates fuzzy logic, which stimulates nodes to forward packets by rewarding cooperation. According to simulation results, the proposed approach surpasses the Nuglets (virtual currency) approach and the Reputation approach in network energy and thus prolongs the network lifetime. Additionally, our proposed approach demonstrates better results in the number of dropped packets, PDR and forwarded packets to neighboring nodes.展开更多
Road safety is still an important issue with road accidents among the leading causes of death accounting for more than 1.2 million fatalities and 50 million injuries globally per year. Of these casualties, speeding is...Road safety is still an important issue with road accidents among the leading causes of death accounting for more than 1.2 million fatalities and 50 million injuries globally per year. Of these casualties, speeding is a substantial contributing factor. Nowadays, speed reduction is mainly achieved through speed law enforcement measures. The review is aimed at examining the different enforcement approaches used to control and monitor excessive speeds on highways at large and particularly in Cameroon. A systematic search was performed in Science Direct, Elsevier, google scholar, scientific research, and Springer, ResearchGate, Scopus, and PubMed databases. Furthermore, references of selected articles were reviewed to maximize the rate of articles found. The details of the research articles were generated using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flow chart. The results show that of 658 retried articles, duplicates of 458 were excluded and 200 were screened. A total of 61 and 40 articles were screened from abstract and full pdf text respectively. Finally, 15 relevant studies were included in the study. The review revealed that the included articles on speed enforcement on the highway were limited to sanctioning defaulters for fine payments.展开更多
Customer requirements analysis is the key step for product variety design of mass customiza-tion(MC). Quality function deployment (QFD) is a widely used management technique for understanding the voice of the customer...Customer requirements analysis is the key step for product variety design of mass customiza-tion(MC). Quality function deployment (QFD) is a widely used management technique for understanding the voice of the customer (VOC), however, QFD depends heavily on human subject judgment during extracting customer requirements and determination of the importance weights of customer requirements. QFD pro-cess and related problems are so complicated that it is not easily used. In this paper, based on a general data structure of product family, generic bill of material (GBOM), association rules analysis was introduced to construct the classification mechanism between customer requirements and product architecture. The new method can map customer requirements to the items of product family architecture respectively, accomplish the mapping process from customer domain to physical domain directly, and decrease mutual process between customer and designer, improve the product design quality, and thus furthest satisfy customer needs. Finally, an example of customer requirements mapping of the elevator cabin was used to illustrate the proposed method.展开更多
In hot arid countries with severe weather, the summer air conditioning systems consume much electrical power at peak period. Shifting the loads peak to off-peak period with thermal storage is recommended. Model A of r...In hot arid countries with severe weather, the summer air conditioning systems consume much electrical power at peak period. Shifting the loads peak to off-peak period with thermal storage is recommended. Model A of residential buildings and Model B of schools and hospitals were used to estimate the daily cooling load profile in Makkah, Saudi Arabia at latitude of 21.42°N and longitude of 39.83°E. Model A was constructed from common materials, but Model B as Model A with 5 - 8 cm thermal insulation and double layers glass windows. The average data of Makkah weather through 2010, 2011 and 2012 were used to calculate the cooling load profile and performance of air conditioning systems. The maximum cooling load was calculated at 15:00 o’clock for a main floor building to a 40-floor of residential building and to 5 floors of schools. A district cooling plant of 180,000 Refrigeration Ton was suggested to serve the Gabal Al Sharashf area in the central zone of Makkah. A thermal storage system to store the excess cooling capacity was used. Air cooled condensers were used in the analysis of chiller refrigeration cycle. The operating cost was mainly a function of electrical energy consumption. Fixed electricity tariff was 0.04 $/kWh for electromechanical counter, and 0.027, 0.04, 0.069 $/kWh for shifting loads peak for the smart digital counter. The results showed that the daily savings in consumed power are 8.27% in spring, 6.86% in summer, 8.81% in autumn, and 14.55% in winter. Also, the daily savings in electricity bills are 12.26% in spring, 16.66% in summer, 12.84% in autumn, and 14.55% in winter. The obtained maximum saving in consumed power is 14.5% and the daily saving in electricity bills is 43% in summer when the loads peak is completely shifted to off-peak period.展开更多
基金in part by the National Natural Science Foundation of China under Grant 61901011in part by the Foundation of Beijing Municipal Commission of Education under Grant KM202110005021 and KM202010005017.
文摘Recently,electric vehicles(EVs)have been widely used under the call of green travel and environmental protection,and diverse requirements for charging are also increasing gradually.In order to ensure the authenticity and privacy of charging information interaction,blockchain technology is proposed and applied in charging station billing systems.However,there are some issues in blockchain itself,including lower computing efficiency of the nodes and higher energy consumption in the consensus process.To handle the above issues,in this paper,combining blockchain and mobile edge computing(MEC),we develop a reliable billing data transmission scheme to improve the computing capacity of nodes and reduce the energy consumption of the consensus process.By jointly optimizing the primary and replica nodes offloading decisions,block size and block interval,the transaction throughput of the blockchain system is maximized,as well as the latency and energy consumption of the system are minimized.Moreover,we formulate the joint optimization problem as a Markov decision process(MDP).To tackle the dynamic and continuity of the system state,the reinforcement learning(RL)is introduced to solve the MDP problem.Finally,simulation results demonstrate that the performance improvement of the proposed scheme through comparison with other existing schemes.
文摘The rapid pace of technological change has seen information and communication technologies become the digital backbone of developed nations’ economies and a pre-requisite for global trade. Some enterprise systems are however more than mere facilitators, they provide the bedrock without which organizations could not function;we term these mandatory systems “non-volitional”(NVS). With hyper-growth in demand for connectivity, telecommunications are typical of sectors where NVS shape the fiercely competitive landscape. Among them, Billing & Revenue Management Systems (BRMS) are a form of credit, providers deliver a service and subscribers later pay for that service. As such, they are “business critical”, meaning failures may affect an organization’s ability to conduct its core business. Failures also impact user satisfaction, a key measure of information systems success. However, relatively few studies empirically test this notion;fewer still evaluate it at organizational (rather than individual) level, while there is a dearth of literature investigating non-volitional systems and, to the best of our knowledge, none whatsoever consider ways of predicting user satisfaction for BRMS. According to a renowned and widely cited conceptual model, user satisfaction is influenced by information, system, and service quality respectively. To test this theory for telecoms BRMS, we applied structural equation modelling to investigate which of these dimensions has the most effect. The results indicate that information quality, system quality, service quality, and user satisfaction are all valid measures of BRMS success. Hypothesized relationships between the four success dimensions were significantly substantiated. The study also identified five measures of information quality, four measures of system quality, four measures of service quality, and four measures of user satisfaction. Once the proposed model had been successfully validated, we tested the level of significance among user satisfaction and the three quality dimensions. Findings showed that service quality had the strongest influence on user satisfaction, with information quality second. This is quite different from other applications considered in our literature review which mostly have information quality as having the strongest impact (knowledge management systems apart).
基金Supported by the High Technology Reseearch and Development Plogranune of China （No. 2002AA121062） and the National Natural Science Foundation of China （ No. 90204002 ）.
文摘IP billing is not only a basic functionality to operate IP sen＇ices, but also it is fundamental to offer customers with a stable and QoS-enabled network environment. As IP-based network has been widely agreed to be the core network of NGN, and existing IP billing system is too simple to fulfill the emerging requirements, the next generation IP billing has become an interesting topic in recent years. Policy-based management brings flexibility and scalability to systems by describing management logic and functions through policies, and thus reduces the complexity of the management of large-scale systems. Working on existing efforts, this paper proposed an improved IETF policy framework based upon which a policy-based billing management architecture for the next generation IP-based network was presented. Then a prototype with some basic functionalities was developed. The results of the experiment validated the expected improvements specified in this paper.
文摘In order to adopt Billings Method for fertility regulation during the period of breast feeding, cervical mucus was observed and monitored in 61 breast feeding mothers.Urine estrogen and /or pregnanediol were/was measured in 15 breast feeding mothers. Observations on cervical mucus during 244 months were collected. The type of dry or no mucus was observed in 75.27% fully breast feeding mothers. Constant unchanging mucus was observed in 69.39% partially breast feeding mothers. Developmental changing mucus was observed in 79.25% of mothers bottle feeding their infants. According to the record on cervical mucus within 6 months postpartum, 97.14% of the cervical mucus was consistent with normal menstrual cycles. Urine estrogen and /or pregnanediol were/was measured in 15 breast feeding mothers. The level of estrogen in urine averaged 0.08 μmol/24 h in fully breast feeding mothers and 0.14 μmol/24 h in partially breast feeding mothers.The peak level averaged 0.21 μmol/24 h in bottle feeding mothers.The pregnanediol level was determined to confirm ovulation in bottle feeding mothers. The average levels of cut off and the period of ovulation in 6 bottle feeding mother were 7 μmol/24 h and 9 μmol/24 h respectively.Measurement of urine estrogen and pregnanediol level all matched with cervical mucus appearances. Conclusion: Billings Method is a simple, scientific method for contraception without side effects during breast feeding period.
基金The project was funded by Shanghai Municipal Science & Technology Commission
文摘Objective The effectiveness and acceptability of Billings Ovulation Method (BOM) during breastfeeding were studied. At the same time, the monitoring indexes of fertility return were studied.Methods It was a clinical comparative study of BOM and IUD containing copper (200mm 2). The annual rate of pregnancy, discontinuation rate and continuation rate in the two groups was determined. The serum prolactin and estradiol in 90 breastfeeding mothers and urine estrogen and pregnanediol in different feeding mothers were measured.Results There were 219 subjects in the BOM group and 200 in the IUD group. The pregnancy rate in this two groups was 1. 43% and 1. 54% respectively. The rates of discontinuation and continuation in the IUD group were:8. 87% and 91. 35% as well as in the BOM group were 8. 53% and 90. 17% respectively. Neither result was statistically significant (P>0. 05). The experimtal research showed that menses return was well estimated by 0. 35 ratio of serum prolactin vs. estrodiol. Sensitivity and specificity was 94. 61% and 84. 61% respectively. It also indicated that (1) the levels of urine hormone were closely related to the patterns of cervical mucus and (2) the incidence of ovulating before the second return of menses in partially breastfeeding mothers was much lower than that of bottle-feeding mothers (47. 05% vs. 94. 20%). Conclusion BOM is a simple, reliable and well accepted contraceptive method of during breastfeeding. If it can be combined with the measurement of serum prolactin/ estradiol, the date of menses return will be determined more easily. Encouraging mothers to breast-feed will be beneficial to the health of both babies and mothers and delay the fertility return of mothers.
文摘ZTE Corporation (ZTE) announced that its participation in the 8th Annual Asia-Pacific Billing & Revenue Assurance Conference in Singapore from May 12th till 15th 2008 delivered a keynote on its latest ZSmart operations and business support solutions and shared the latest BSS/OSS technology with key industry players.
文摘Extending the lifetime of the wireless sensor networks (WSNs), where recharging sensors is not always possible, has been a major concern for researchers for the past decade. In this paper, we study the cooperation between nodes in wireless sensor networks in forwarding packets to others, and we propose a new collaboration technique which stimulates intermediate nodes to forward packets toward their destination. Some nodes show selfish behavior by denying the forwarding packets to other nodes in commercial networks in an effort to preserve their own energy. This paper applies a technique which is used to prolong the network lifetime, based on a node’s energy and trust value, and additionally incorporates fuzzy logic, which stimulates nodes to forward packets by rewarding cooperation. According to simulation results, the proposed approach surpasses the Nuglets (virtual currency) approach and the Reputation approach in network energy and thus prolongs the network lifetime. Additionally, our proposed approach demonstrates better results in the number of dropped packets, PDR and forwarded packets to neighboring nodes.
文摘Road safety is still an important issue with road accidents among the leading causes of death accounting for more than 1.2 million fatalities and 50 million injuries globally per year. Of these casualties, speeding is a substantial contributing factor. Nowadays, speed reduction is mainly achieved through speed law enforcement measures. The review is aimed at examining the different enforcement approaches used to control and monitor excessive speeds on highways at large and particularly in Cameroon. A systematic search was performed in Science Direct, Elsevier, google scholar, scientific research, and Springer, ResearchGate, Scopus, and PubMed databases. Furthermore, references of selected articles were reviewed to maximize the rate of articles found. The details of the research articles were generated using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flow chart. The results show that of 658 retried articles, duplicates of 458 were excluded and 200 were screened. A total of 61 and 40 articles were screened from abstract and full pdf text respectively. Finally, 15 relevant studies were included in the study. The review revealed that the included articles on speed enforcement on the highway were limited to sanctioning defaulters for fine payments.
基金the National Natural Science Founda-tion of China (No. 70471022)the NSFC / Hong KongResearch Grant Council (No. 70418013)
文摘Customer requirements analysis is the key step for product variety design of mass customiza-tion(MC). Quality function deployment (QFD) is a widely used management technique for understanding the voice of the customer (VOC), however, QFD depends heavily on human subject judgment during extracting customer requirements and determination of the importance weights of customer requirements. QFD pro-cess and related problems are so complicated that it is not easily used. In this paper, based on a general data structure of product family, generic bill of material (GBOM), association rules analysis was introduced to construct the classification mechanism between customer requirements and product architecture. The new method can map customer requirements to the items of product family architecture respectively, accomplish the mapping process from customer domain to physical domain directly, and decrease mutual process between customer and designer, improve the product design quality, and thus furthest satisfy customer needs. Finally, an example of customer requirements mapping of the elevator cabin was used to illustrate the proposed method.
文摘In hot arid countries with severe weather, the summer air conditioning systems consume much electrical power at peak period. Shifting the loads peak to off-peak period with thermal storage is recommended. Model A of residential buildings and Model B of schools and hospitals were used to estimate the daily cooling load profile in Makkah, Saudi Arabia at latitude of 21.42°N and longitude of 39.83°E. Model A was constructed from common materials, but Model B as Model A with 5 - 8 cm thermal insulation and double layers glass windows. The average data of Makkah weather through 2010, 2011 and 2012 were used to calculate the cooling load profile and performance of air conditioning systems. The maximum cooling load was calculated at 15:00 o’clock for a main floor building to a 40-floor of residential building and to 5 floors of schools. A district cooling plant of 180,000 Refrigeration Ton was suggested to serve the Gabal Al Sharashf area in the central zone of Makkah. A thermal storage system to store the excess cooling capacity was used. Air cooled condensers were used in the analysis of chiller refrigeration cycle. The operating cost was mainly a function of electrical energy consumption. Fixed electricity tariff was 0.04 $/kWh for electromechanical counter, and 0.027, 0.04, 0.069 $/kWh for shifting loads peak for the smart digital counter. The results showed that the daily savings in consumed power are 8.27% in spring, 6.86% in summer, 8.81% in autumn, and 14.55% in winter. Also, the daily savings in electricity bills are 12.26% in spring, 16.66% in summer, 12.84% in autumn, and 14.55% in winter. The obtained maximum saving in consumed power is 14.5% and the daily saving in electricity bills is 43% in summer when the loads peak is completely shifted to off-peak period.
