AIM:To evaluate residents’perceptions and attitudes toward the various aspects of a comprehensive ophthalmic examination,and to determine if these factors correlate with their choices for fellowship and future career...AIM:To evaluate residents’perceptions and attitudes toward the various aspects of a comprehensive ophthalmic examination,and to determine if these factors correlate with their choices for fellowship and future career plans.METHODS:This is a cross-sectional study.A questionnaire on the perception of the ophthalmic exam was sent via SurveyMonkey to ophthalmology residents throughout Israel.Eighty of them(one-half of all ophthalmology residents in 2019)completed it.The first part related to how they perceived each component of the ophthalmic evaluation.The second part related to their future fellowship plans.The Chi-squared test was used to compare categorical variables and Student’s t-test and One-way ANOVA were used to compare continuous variables.Multivariate logistic regression analysis was applied as needed to detect interactions between variables and to exclude confounder effects.RESULTS:Slit-lamp examination of the anterior and posterior segments ranked as the most likeable aspects,whereas gonioscopy,ocular motility examination and visual acuity assessment were least likeable.Anterior segment and retina subspecialties were the ones most sought after.Forty-nine respondents(61.3%)noted a direct correlation between their preferred parts of comprehensive ophthalmic evaluations and their choice of subspecialty.Perceptions of selected components of those evaluations were significantly associated with responders’intentions to pursue anterior segment,retina,or oculoplastic fellowships(P<0.05).CONCLUSION:Perspectives of residents toward the ophthalmic examination,and most specifically its individual components,play an important role in their choice of subspecialty training.展开更多
The Dutch Standardization Institute(NEN) has initiated the establishment of a European technical committee(CEN/TC 474) that will develop European Standards across the CCUS(carbon capture, utilization and storage) valu...The Dutch Standardization Institute(NEN) has initiated the establishment of a European technical committee(CEN/TC 474) that will develop European Standards across the CCUS(carbon capture, utilization and storage) value chain. With broad participation from CEN Members and European organizations, the committee kicked off in Brussels and finalized its scope and first work programme.展开更多
In light of the rapid expansion of China s economy,there has been a notable shift in the consumption patterns of urban and rural residents.This is evident in the increased consumption of agricultural products,with fru...In light of the rapid expansion of China s economy,there has been a notable shift in the consumption patterns of urban and rural residents.This is evident in the increased consumption of agricultural products,with fruit consumption representing a particularly pronounced trend.The 2023 Beijing Consumption Statistics indicate that demand for fruit is increasing,accompanied by heightened competition for quality and brands.The paper is based on research that examines the current situation of fruit consumption among urban and rural residents in Beijing.The results indicate that when urban and rural residents in Beijing purchase fruits,price is the most significant factor influencing fruit consumption.Taste,appearance,and variety are also considered to be important influencing factors,while the influence of factors such as fruit type,consumption pattern,and fruit brand is relatively minor.展开更多
The rapid development of the digital economy has provided a new impetus for rural residents to extend their working hours.Based on the data collected by the China Labor-force Dynamics Survey(CLDS)in 2014,2016,and 2018...The rapid development of the digital economy has provided a new impetus for rural residents to extend their working hours.Based on the data collected by the China Labor-force Dynamics Survey(CLDS)in 2014,2016,and 2018,this paper measured the development level of the digital economy in China from the perspectives of internet development and digital financial inclusion,and tested the mechanisms of how the digital economy affected rural residents’working hours.The results showed that the digital economy extended rural residents’working hours by expanding information channels and enhancing human capital,and this mechanism was affected by heterogeneity in rural residents’educational background,age,and social capital.Building on these findings,this paper holds that to increase rural residents’income by extending their working hours and achieving common prosperity for all,it is necessary to expand the opportunities for rural residents to participate in skills training and promote their accumulation of human capital.展开更多
Background: Transgender healthcare is not a formal learning requirement in Internal Medicine residency or fellowship. The National LGBTQ Task Force appealed to urgently train clinicians on the effective care of transg...Background: Transgender healthcare is not a formal learning requirement in Internal Medicine residency or fellowship. The National LGBTQ Task Force appealed to urgently train clinicians on the effective care of transgender patients. Few studies address the successful implementation of transgender healthcare teaching and education in graduate medical education. Purpose: The purpose was to design an online asynchronous curriculum to address the need for improved transgender healthcare education in graduate medical education and assess change in knowledge and comfort in transgender healthcare for residents and fellow learners. Methods: A 6-module curriculum was developed using established guidelines and ACGME competencies as a framework for content. To assess curriculum effectiveness, participants received anonymous pre- and post-curriculum surveys which included a multiple-choice knowledge assessment, Likert scale comfort questions focusing on healthcare skills, and open-ended feedback questions. Results: Twenty-six internal medicine residents and fellows participated in the curriculum (2022-2023). There was a 69% post-survey response rate. Participants improved their gender-affirming knowledge after completing the curriculum (p Conclusion: This online curriculum was successful in increasing knowledge and comfort in transgender care for IM residents and fellows. It provides a promising framework to address this gap in curricular content.展开更多
The time-varying difference-in-difference model is used to identify the impact of payment technology on residents’consumption,and the moderation effect analysis method is used to identify its mechanism.It is found th...The time-varying difference-in-difference model is used to identify the impact of payment technology on residents’consumption,and the moderation effect analysis method is used to identify its mechanism.It is found that payment technology promotes consumption capacity expansion and quality improvement(CEQI)through three pathways of alleviating liquidity constraints,reducing transaction costs and weakening the payment of pain.The parallel and serial mechanisms of the three are further explored.The effect of payment technology on the CEQI of residents’consumption shows obvious heterogeneity due to differences in urban and rural household registration and financial literacy.Based on the empirical research results and the national conditions of China,targeted policy recommendations are proposed from the demand side,the supply side and the technological side.展开更多
The consumer price index (CPI) measures the relative number of changes in the price level of consumer goods and services over time, reflecting the trend and degree of changes in the price level of goods and services p...The consumer price index (CPI) measures the relative number of changes in the price level of consumer goods and services over time, reflecting the trend and degree of changes in the price level of goods and services purchased by residents. This article uses the ARMA model to analyze the fluctuation trend of the CPI (taking Chongqing as an example) and make short-term predictions. To test the predictive performance of the model, the observation values from January to December 2023 were retained as the reference object for evaluating the predictive accuracy of the model. Finally, through trial predictions of the data from May to August 2023, it was found that the constructed model had good fitting performance.展开更多
Organizations regardless of size can take advantage of the market dynamics brought about by globalization.Supply chain management is crucial for large organizations,especially with regard to the costs,complexity,and r...Organizations regardless of size can take advantage of the market dynamics brought about by globalization.Supply chain management is crucial for large organizations,especially with regard to the costs,complexity,and risks of its large,often global,supply chains.From technology to risk management,learning what it takes to navigate transportation and logistics business management in today’s volatile world is critical.Human migration has accelerated in light of globalization and rapid advances in transportation(particularly aviation)technology.This study investigated the connection between logistics and supply chain management in the age of globalization;reviewed the migration,settlement,and naturalization of Taiwan residents immigrants along the West Coast of the United States;and theoretically analyzed the forces that have led to the construction of the Taiwan residents immigrant community.Taiwan residents immigrants and their settlement are affected by global forces,and factors such as their cross-cultural trade,the characteristics of diasporic communities,and their national identity can provide scholarly and pedagogical insights.展开更多
The Decision of the Central Committee of the Communist Party of China and the State Council on Winning the Battle of Poverty Alleviation points out that by 2020,rural poor people will have stable access to food and cl...The Decision of the Central Committee of the Communist Party of China and the State Council on Winning the Battle of Poverty Alleviation points out that by 2020,rural poor people will have stable access to food and clothing,and compulsory education,basic medical care,and housing security will be guaranteed.The growth rate of per capita disposable income of farmers in poverty-stricken areas is higher than the national average,and the main indicators of basic public services are close to the national average.According to the requirements,the poverty alleviation work team stationed in the village has tailored measures to local conditions and carried out targeted poverty alleviation.Faced with difficulties such as increasing the importance of education among villagers,solving the problem of children going to school,and increasing income for villagers,under the guidance of the assistance unit,the poverty alleviation work team adopts the method of setting an example to ensure education,introducing education to increase knowledge,and expanding knowledge through education going global,in order to change the current situation from point to surface.After unremitting efforts,the villagers began to change their mindset,and the enrollment and enrollment rates of village students were significantly increased.The children enter the classroom,the elderly work at home,and the young and strong labor force actively goes out to work.The villagers have motivation to work,and life has a bright future.The village sees hope.展开更多
Objective:To analyze the importance of general practitioner residents using the combined teaching method(BOPPPS+mind maps).Methods:From September 2023 to August 2024,a study was conducted with 6 control group particip...Objective:To analyze the importance of general practitioner residents using the combined teaching method(BOPPPS+mind maps).Methods:From September 2023 to August 2024,a study was conducted with 6 control group participants receiving traditional teaching and 6 observation group participants receiving the combined teaching method(BOPPPS+mind maps).The study analyzed various indicators between the two groups(including mind map scores and assessment results).Results:Compared with the control group,the assessment scores of the observation group were significantly higher(P<0.05).Conclusion:The application of the combined teaching method(BOPPPS+mind maps)by general practitioner residents can significantly improve their comprehensive abilities.展开更多
In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice re...In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice residents(commonly referred to as general resident training)is an unavoidable trend in the teaching field.Based on the actual situation of our unit at The First Affiliated Hospital of Xi’an Medical University,this paper emphasizes the necessity of incorporating ideological and political education into the general resident training curriculum,despite the absence of pertinent practical experience in how to effectively incorporate such courses into comprehensive residential training.In our hospital,we must assess the ideological and political education in the curriculum of general resident training,proposing a scientific,reasonable ideological and political education concept system for general practice courses,integrating ideological and political education with general practice resident training,and strengthening the team of ideological and political education physicians to teach them to carry out such education,this would foster enthusiasm and initiative.Strengthening admission education and training for general practice resident training,as well as regularly hosting symposiums to share ideas and understand the mission of doctors can provide effective experience for ideological and political education in general resident training courses.展开更多
Change trend of Chinese urban residents' per capita food-nitrogen annual consumption from 1981 to 2007 was analyzed and predicted by using ARIMA time-series model in order to reveal the change of urban food-nitrogen ...Change trend of Chinese urban residents' per capita food-nitrogen annual consumption from 1981 to 2007 was analyzed and predicted by using ARIMA time-series model in order to reveal the change of urban food-nitrogen consumption during the China's urbanization process.Results showed that after 1980s,the annual consumption of Chinese urban residents' food-nitrogen had a change trend of " increase-decrease-increase" and generally presented as a slight increasing trend;With the acceleration of rapid economic development and urbanization process,Chinese urban residents' food-nitrogen consumption will still keep a rising trend in future,and also has a large rising space.展开更多
Traditional village protection has been a hot topic recently. And traditional villages are far from meeting residents' demands in infrastructure as economic and social advances. Besides, local residents are not fully...Traditional village protection has been a hot topic recently. And traditional villages are far from meeting residents' demands in infrastructure as economic and social advances. Besides, local residents are not fully aware of cultural protection or inheritance, so that many traditional buildings long fallen into disrepair, have been replaced by new ones. In the meantime, the population of migrant workers is in- creasing, making cultural inheritance more difficult and causing decreasing of tradi- tional villages. Now, it is an important and tough job to release the conflict between increasing material needs of the people and historical cultural inheritance. In the re- search, field investigation was made on Dongkeng Village, Le'an county to seek the optimal strategy for traditional village sustainable development from the perspective of importance on traditional village protection.展开更多
On the premise that the goal and nature of work remain the same,in order to desalt the regional culture of Europe,it took the internationalism road of pervasive value,thus the International Committee for the Organizat...On the premise that the goal and nature of work remain the same,in order to desalt the regional culture of Europe,it took the internationalism road of pervasive value,thus the International Committee for the Organization of the Pierre de Coubertin Fair Play Awards was renamed as International Fair Play Committee.展开更多
The International Fair Play Committee(CFIP) is committed to promote the social communication and development of the spirit of fair play and strive for the creation of a peaceful and beautiful word.This paper discusses...The International Fair Play Committee(CFIP) is committed to promote the social communication and development of the spirit of fair play and strive for the creation of a peaceful and beautiful word.This paper discusses the CIFP's disregard of Fair Starting so as to lay foundation for further understanding of CIFP and its nature of work by taking the historical motivation and legality of CIFP as the cut-in point from the critical perspective.It suggests that CIFP should tamp the ideal of fair play,re-establish the fair play value system,and conduct effective reform of organization and cause correspondingly instead of becoming agent of European centralism and American hegemonism.展开更多
In consultative committee for space data systems(CCSDS) file delivery protocol(CFDP) recommendation of reliable transmission,there are no detail transmission procedure and delay calculation of prompted negative ac...In consultative committee for space data systems(CCSDS) file delivery protocol(CFDP) recommendation of reliable transmission,there are no detail transmission procedure and delay calculation of prompted negative acknowledge and asynchronous negative acknowledge models.CFDP is designed to provide data and storage management,story and forward,custody transfer and reliable end-to-end delivery over deep space characterized by huge latency,intermittent link,asymmetric bandwidth and big bit error rate(BER).Four reliable transmission models are analyzed and an expected file-delivery time is calculated with different trans-mission rates,numbers and sizes of packet data units,BERs and frequencies of external events,etc.By comparison of four CFDP models,the requirement of BER for typical missions in deep space is obtained and rules of choosing CFDP models under different uplink state informations are given,which provides references for protocol models selection,utilization and modification.展开更多
文摘AIM:To evaluate residents’perceptions and attitudes toward the various aspects of a comprehensive ophthalmic examination,and to determine if these factors correlate with their choices for fellowship and future career plans.METHODS:This is a cross-sectional study.A questionnaire on the perception of the ophthalmic exam was sent via SurveyMonkey to ophthalmology residents throughout Israel.Eighty of them(one-half of all ophthalmology residents in 2019)completed it.The first part related to how they perceived each component of the ophthalmic evaluation.The second part related to their future fellowship plans.The Chi-squared test was used to compare categorical variables and Student’s t-test and One-way ANOVA were used to compare continuous variables.Multivariate logistic regression analysis was applied as needed to detect interactions between variables and to exclude confounder effects.RESULTS:Slit-lamp examination of the anterior and posterior segments ranked as the most likeable aspects,whereas gonioscopy,ocular motility examination and visual acuity assessment were least likeable.Anterior segment and retina subspecialties were the ones most sought after.Forty-nine respondents(61.3%)noted a direct correlation between their preferred parts of comprehensive ophthalmic evaluations and their choice of subspecialty.Perceptions of selected components of those evaluations were significantly associated with responders’intentions to pursue anterior segment,retina,or oculoplastic fellowships(P<0.05).CONCLUSION:Perspectives of residents toward the ophthalmic examination,and most specifically its individual components,play an important role in their choice of subspecialty training.
文摘The Dutch Standardization Institute(NEN) has initiated the establishment of a European technical committee(CEN/TC 474) that will develop European Standards across the CCUS(carbon capture, utilization and storage) value chain. With broad participation from CEN Members and European organizations, the committee kicked off in Brussels and finalized its scope and first work programme.
文摘In light of the rapid expansion of China s economy,there has been a notable shift in the consumption patterns of urban and rural residents.This is evident in the increased consumption of agricultural products,with fruit consumption representing a particularly pronounced trend.The 2023 Beijing Consumption Statistics indicate that demand for fruit is increasing,accompanied by heightened competition for quality and brands.The paper is based on research that examines the current situation of fruit consumption among urban and rural residents in Beijing.The results indicate that when urban and rural residents in Beijing purchase fruits,price is the most significant factor influencing fruit consumption.Taste,appearance,and variety are also considered to be important influencing factors,while the influence of factors such as fruit type,consumption pattern,and fruit brand is relatively minor.
基金This paper is part of the Youth Program of Science and Technology Research of Chongqing Municipal Education Commission(KJQN202300545)Youth Program of National Social Science Fund of China(21CJY001)Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202300567).
文摘The rapid development of the digital economy has provided a new impetus for rural residents to extend their working hours.Based on the data collected by the China Labor-force Dynamics Survey(CLDS)in 2014,2016,and 2018,this paper measured the development level of the digital economy in China from the perspectives of internet development and digital financial inclusion,and tested the mechanisms of how the digital economy affected rural residents’working hours.The results showed that the digital economy extended rural residents’working hours by expanding information channels and enhancing human capital,and this mechanism was affected by heterogeneity in rural residents’educational background,age,and social capital.Building on these findings,this paper holds that to increase rural residents’income by extending their working hours and achieving common prosperity for all,it is necessary to expand the opportunities for rural residents to participate in skills training and promote their accumulation of human capital.
文摘Background: Transgender healthcare is not a formal learning requirement in Internal Medicine residency or fellowship. The National LGBTQ Task Force appealed to urgently train clinicians on the effective care of transgender patients. Few studies address the successful implementation of transgender healthcare teaching and education in graduate medical education. Purpose: The purpose was to design an online asynchronous curriculum to address the need for improved transgender healthcare education in graduate medical education and assess change in knowledge and comfort in transgender healthcare for residents and fellow learners. Methods: A 6-module curriculum was developed using established guidelines and ACGME competencies as a framework for content. To assess curriculum effectiveness, participants received anonymous pre- and post-curriculum surveys which included a multiple-choice knowledge assessment, Likert scale comfort questions focusing on healthcare skills, and open-ended feedback questions. Results: Twenty-six internal medicine residents and fellows participated in the curriculum (2022-2023). There was a 69% post-survey response rate. Participants improved their gender-affirming knowledge after completing the curriculum (p Conclusion: This online curriculum was successful in increasing knowledge and comfort in transgender care for IM residents and fellows. It provides a promising framework to address this gap in curricular content.
基金Foundation items:National Natural Science Foundation of China(No.71874027)Ministry of Education Humanities and Social Sciences Research Youth Fund Project(No.23YJC760028)。
文摘The time-varying difference-in-difference model is used to identify the impact of payment technology on residents’consumption,and the moderation effect analysis method is used to identify its mechanism.It is found that payment technology promotes consumption capacity expansion and quality improvement(CEQI)through three pathways of alleviating liquidity constraints,reducing transaction costs and weakening the payment of pain.The parallel and serial mechanisms of the three are further explored.The effect of payment technology on the CEQI of residents’consumption shows obvious heterogeneity due to differences in urban and rural household registration and financial literacy.Based on the empirical research results and the national conditions of China,targeted policy recommendations are proposed from the demand side,the supply side and the technological side.
文摘The consumer price index (CPI) measures the relative number of changes in the price level of consumer goods and services over time, reflecting the trend and degree of changes in the price level of goods and services purchased by residents. This article uses the ARMA model to analyze the fluctuation trend of the CPI (taking Chongqing as an example) and make short-term predictions. To test the predictive performance of the model, the observation values from January to December 2023 were retained as the reference object for evaluating the predictive accuracy of the model. Finally, through trial predictions of the data from May to August 2023, it was found that the constructed model had good fitting performance.
文摘Organizations regardless of size can take advantage of the market dynamics brought about by globalization.Supply chain management is crucial for large organizations,especially with regard to the costs,complexity,and risks of its large,often global,supply chains.From technology to risk management,learning what it takes to navigate transportation and logistics business management in today’s volatile world is critical.Human migration has accelerated in light of globalization and rapid advances in transportation(particularly aviation)technology.This study investigated the connection between logistics and supply chain management in the age of globalization;reviewed the migration,settlement,and naturalization of Taiwan residents immigrants along the West Coast of the United States;and theoretically analyzed the forces that have led to the construction of the Taiwan residents immigrant community.Taiwan residents immigrants and their settlement are affected by global forces,and factors such as their cross-cultural trade,the characteristics of diasporic communities,and their national identity can provide scholarly and pedagogical insights.
基金Research on Education Leading and Promoting Industrial Development under the Background of the“Double First Class”Construction of the Discipline Development Research Fund of China University of Geosciences(Beijing):A Case Study of Zhihai Mai Village,Hualong County,Qinghai Province,2024XK225.
文摘The Decision of the Central Committee of the Communist Party of China and the State Council on Winning the Battle of Poverty Alleviation points out that by 2020,rural poor people will have stable access to food and clothing,and compulsory education,basic medical care,and housing security will be guaranteed.The growth rate of per capita disposable income of farmers in poverty-stricken areas is higher than the national average,and the main indicators of basic public services are close to the national average.According to the requirements,the poverty alleviation work team stationed in the village has tailored measures to local conditions and carried out targeted poverty alleviation.Faced with difficulties such as increasing the importance of education among villagers,solving the problem of children going to school,and increasing income for villagers,under the guidance of the assistance unit,the poverty alleviation work team adopts the method of setting an example to ensure education,introducing education to increase knowledge,and expanding knowledge through education going global,in order to change the current situation from point to surface.After unremitting efforts,the villagers began to change their mindset,and the enrollment and enrollment rates of village students were significantly increased.The children enter the classroom,the elderly work at home,and the young and strong labor force actively goes out to work.The villagers have motivation to work,and life has a bright future.The village sees hope.
文摘Objective:To analyze the importance of general practitioner residents using the combined teaching method(BOPPPS+mind maps).Methods:From September 2023 to August 2024,a study was conducted with 6 control group participants receiving traditional teaching and 6 observation group participants receiving the combined teaching method(BOPPPS+mind maps).The study analyzed various indicators between the two groups(including mind map scores and assessment results).Results:Compared with the control group,the assessment scores of the observation group were significantly higher(P<0.05).Conclusion:The application of the combined teaching method(BOPPPS+mind maps)by general practitioner residents can significantly improve their comprehensive abilities.
文摘In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice residents(commonly referred to as general resident training)is an unavoidable trend in the teaching field.Based on the actual situation of our unit at The First Affiliated Hospital of Xi’an Medical University,this paper emphasizes the necessity of incorporating ideological and political education into the general resident training curriculum,despite the absence of pertinent practical experience in how to effectively incorporate such courses into comprehensive residential training.In our hospital,we must assess the ideological and political education in the curriculum of general resident training,proposing a scientific,reasonable ideological and political education concept system for general practice courses,integrating ideological and political education with general practice resident training,and strengthening the team of ideological and political education physicians to teach them to carry out such education,this would foster enthusiasm and initiative.Strengthening admission education and training for general practice resident training,as well as regularly hosting symposiums to share ideas and understand the mission of doctors can provide effective experience for ideological and political education in general resident training courses.
基金Supported by State Council Special Fund for Pollution Sources Survey (WPXC2007C200)~~
文摘Change trend of Chinese urban residents' per capita food-nitrogen annual consumption from 1981 to 2007 was analyzed and predicted by using ARIMA time-series model in order to reveal the change of urban food-nitrogen consumption during the China's urbanization process.Results showed that after 1980s,the annual consumption of Chinese urban residents' food-nitrogen had a change trend of " increase-decrease-increase" and generally presented as a slight increasing trend;With the acceleration of rapid economic development and urbanization process,Chinese urban residents' food-nitrogen consumption will still keep a rising trend in future,and also has a large rising space.
文摘Traditional village protection has been a hot topic recently. And traditional villages are far from meeting residents' demands in infrastructure as economic and social advances. Besides, local residents are not fully aware of cultural protection or inheritance, so that many traditional buildings long fallen into disrepair, have been replaced by new ones. In the meantime, the population of migrant workers is in- creasing, making cultural inheritance more difficult and causing decreasing of tradi- tional villages. Now, it is an important and tough job to release the conflict between increasing material needs of the people and historical cultural inheritance. In the re- search, field investigation was made on Dongkeng Village, Le'an county to seek the optimal strategy for traditional village sustainable development from the perspective of importance on traditional village protection.
文摘On the premise that the goal and nature of work remain the same,in order to desalt the regional culture of Europe,it took the internationalism road of pervasive value,thus the International Committee for the Organization of the Pierre de Coubertin Fair Play Awards was renamed as International Fair Play Committee.
文摘The International Fair Play Committee(CFIP) is committed to promote the social communication and development of the spirit of fair play and strive for the creation of a peaceful and beautiful word.This paper discusses the CIFP's disregard of Fair Starting so as to lay foundation for further understanding of CIFP and its nature of work by taking the historical motivation and legality of CIFP as the cut-in point from the critical perspective.It suggests that CIFP should tamp the ideal of fair play,re-establish the fair play value system,and conduct effective reform of organization and cause correspondingly instead of becoming agent of European centralism and American hegemonism.
基金supported by the National Natural Science Fandation of China (6067208960772075)
文摘In consultative committee for space data systems(CCSDS) file delivery protocol(CFDP) recommendation of reliable transmission,there are no detail transmission procedure and delay calculation of prompted negative acknowledge and asynchronous negative acknowledge models.CFDP is designed to provide data and storage management,story and forward,custody transfer and reliable end-to-end delivery over deep space characterized by huge latency,intermittent link,asymmetric bandwidth and big bit error rate(BER).Four reliable transmission models are analyzed and an expected file-delivery time is calculated with different trans-mission rates,numbers and sizes of packet data units,BERs and frequencies of external events,etc.By comparison of four CFDP models,the requirement of BER for typical missions in deep space is obtained and rules of choosing CFDP models under different uplink state informations are given,which provides references for protocol models selection,utilization and modification.