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
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
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
I decided to visit my friends in Stockholm, Sweden in October. Took an overnight flight to Northern Europe from East Africa, and same as the return journey. It saved me two days of accommodation in this way. I can als...I decided to visit my friends in Stockholm, Sweden in October. Took an overnight flight to Northern Europe from East Africa, and same as the return journey. It saved me two days of accommodation in this way. I can also go directly to the scenic spots if I am not tired after getting off the plane.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
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
This paper explores and validates the process of customer value creation in self-service technologies(SSTs)in the context of the tourism industry.As the self-technology has been gradually advanced,its adoption in the ...This paper explores and validates the process of customer value creation in self-service technologies(SSTs)in the context of the tourism industry.As the self-technology has been gradually advanced,its adoption in the tourism industry has brought many changes.A new trend of self-service technologies has helped service firms to save the labor costs and customers’waiting time for transactions.The purpose of this study is to confirm an applicability and a design of the original model of SSTs and explore the connection between SSTs and creation of value perception through a confirmatory factor analysis in the context of the tourism industry.Furthermore,the results of the online survey questionnaire from 234 responses in the United States and South Korea are explained in this study.The results of this study concluded that five statistically important factors are related to customers’motivations to use SSTs and enable customers to interact with SSTs as“SST location and capacity planning”,“SST service quality”,“motivations to use SST”,“SST design”,and“SST encounter”.These factors may imply an important meaning to better understand about customer value during the adoption of SSTs in the tourism industry.Tourism firms may use the results of this study to effectively enhance how customers perceive value about their products and services during the usage of SSTs.This will help tourism firms’efficiencies on the adoption of SSTs for their business plans and help them remain profitable in the competitive market.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.
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I decided to visit my friends in Stockholm, Sweden in October. Took an overnight flight to Northern Europe from East Africa, and same as the return journey. It saved me two days of accommodation in this way. I can also go directly to the scenic spots if I am not tired after getting off the plane.
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This paper explores and validates the process of customer value creation in self-service technologies(SSTs)in the context of the tourism industry.As the self-technology has been gradually advanced,its adoption in the tourism industry has brought many changes.A new trend of self-service technologies has helped service firms to save the labor costs and customers’waiting time for transactions.The purpose of this study is to confirm an applicability and a design of the original model of SSTs and explore the connection between SSTs and creation of value perception through a confirmatory factor analysis in the context of the tourism industry.Furthermore,the results of the online survey questionnaire from 234 responses in the United States and South Korea are explained in this study.The results of this study concluded that five statistically important factors are related to customers’motivations to use SSTs and enable customers to interact with SSTs as“SST location and capacity planning”,“SST service quality”,“motivations to use SST”,“SST design”,and“SST encounter”.These factors may imply an important meaning to better understand about customer value during the adoption of SSTs in the tourism industry.Tourism firms may use the results of this study to effectively enhance how customers perceive value about their products and services during the usage of SSTs.This will help tourism firms’efficiencies on the adoption of SSTs for their business plans and help them remain profitable in the competitive market.