Maintenance is an important technical measure to maintain and restore the performance status of equipment and ensure the safety of the production process in industrial production,and is an indispensable part of predic...Maintenance is an important technical measure to maintain and restore the performance status of equipment and ensure the safety of the production process in industrial production,and is an indispensable part of prediction and health management.However,most of the existing remaining useful life(RUL)prediction methods assume that there is no maintenance or only perfect maintenance during the whole life cycle;thus,the predicted RUL value of the system is obviously lower than its actual operating value.The complex environment of the system further increases the difficulty of maintenance,and its maintenance nodes and maintenance degree are limited by the construction period and working conditions,which increases the difficulty of RUL prediction.An RUL prediction method for a multi-omponent system based on the Wiener process considering maintenance is proposed.The performance degradation model of components is established by a dynamic Bayesian network as the initial model,which solves the uncertainty of insufficient data problems.Based on the experience of experts,the degree of degradation is divided according to Poisson process simulation random failure,and different maintenance strategies are used to estimate a variety of condition maintenance factors.An example of a subsea tree system is given to verify the effectiveness of the proposed method.展开更多
Charles Dickens was the greatest critical realists in English literary.Almost all of his novels display his deep concern for the society and great sympathy for the low-class people.A Christmas Carol was written in 184...Charles Dickens was the greatest critical realists in English literary.Almost all of his novels display his deep concern for the society and great sympathy for the low-class people.A Christmas Carol was written in 1843 when the society was unrest.The author created the gothic atmosphere himself,and put his characters into that situation and combined the gothic writing methods with the critical realism in order that the gothic elements could express a kind of strong convulsion,which could strength his criti cism for the society.At the same time,the Gothicism also helped to deepen his criticism for the society.展开更多
As the two most important festivals in China and western countries, Spring Festival and Christmas Day each exempli?fies some of the core values and cultural differences in these two cultures wit which this paper is ma...As the two most important festivals in China and western countries, Spring Festival and Christmas Day each exempli?fies some of the core values and cultural differences in these two cultures wit which this paper is mainly concerned. By comparing the external manners such as the family reunion, shopping, exchanging New Year greetings, the paper explore the internal cultur?al differences determining those different external manners such as the collectivism, individualism, filial piety, ancestor worship and religion, etc. Through those comparisons, this paper will succeed to achieve its goal if it exhibits, as the title suggests, a glimpse of cultural differences.展开更多
Every December,millions of Christmas cards go through the post offices.There're pictures of stars, snow or Christmas tree on the cards. In these days it's hard to think of a Christmas without cards,yet
The subsea all-electric Christmas tree(XT) is a key equipment in subsea production systems.Once it fails,the marine environment will be seriously polluted.Therefore,strict reliability analysis and measures to improve ...The subsea all-electric Christmas tree(XT) is a key equipment in subsea production systems.Once it fails,the marine environment will be seriously polluted.Therefore,strict reliability analysis and measures to improve reliability must be performed before a subsea all-electric XT is launched;such measures are crucial to subsea safe production.A fault-tolerant control system was developed in this paper to improve the reliability of XT.A dual-factor degradation model for electrical control system components was proposed to improve the evaluation accuracy,and the reliability of the control system was analyzed based on the Markov model.The influences of the common cause failure and the failure rate in key components on the reliability and availability of the control system were studied.The impacts of mean time to repair and incomplete repair strategy on the availability of the control system were also investigated.Research results show the key factors that affect system reliability,and a specific method to improve the reliability and availability of the control system was given.This reliability analysis method for the control system could be applied to general all-electric subsea control systems to guide their safe production.展开更多
The thesis will introduce two festivals,Tibetan New Year and American Christmas,and compare their cultural differences.It tends to find different cultural background of these two festivals reflected,to compare how peo...The thesis will introduce two festivals,Tibetan New Year and American Christmas,and compare their cultural differences.It tends to find different cultural background of these two festivals reflected,to compare how people celebrate them,Including decoration,clothing and activity,and to see their development.The thesis will help people know more about the two typical festivals,which can reflect the different cultures of Tibet and America.展开更多
The tubing hanger is an important component of the subsea Christmas tree, experiencing big temperature difference which will lead to very high thermal stresses. On the basis of API 17D/ISO 13628-4 and ASME VIII-1, and...The tubing hanger is an important component of the subsea Christmas tree, experiencing big temperature difference which will lead to very high thermal stresses. On the basis of API 17D/ISO 13628-4 and ASME VIII-1, and by comprehensively considering the erosion of oil and the gravity load of the tubing, a calculation model is established by regarding design pressure and thermal stress, and the method for designing the tubing hanger of the horizontal Christmas tree under big temperature difference condition is developed from the fourth strength theory. The proposed theory for strength design of the tubing hanger in big temperature difference is verified by numerical results from ABAQUS.展开更多
Thanksgiving and Christmas are two major holidays in the United States. Many people use social media to stay connected with their families and friends, including sharing their holiday experiences. This study utilized ...Thanksgiving and Christmas are two major holidays in the United States. Many people use social media to stay connected with their families and friends, including sharing their holiday experiences. This study utilized a stream of millions of tweets on Twitter to explore how people feel about these two holidays through real-time sentiment analysis. With help of Twitter Streaming API, we discovered the patterns of sentiment changes by hour before and after the two holidays in 2011, thus providing a unique peek into the celebration of these holidays that could not be accomplished with traditional methods. Our analysis suggested that in 2011 people had higher sentiment toward Christmas than Thanksgiving on average. The sentiment reached its maximum on the Thanksgiving Day and on The Christmas Eve and Christmas Day, highlighting stronger zeal for Christmas than Thanksgiving, while remained a stable and lower sentiment before and after the holidays. Typically there was a peak of sentiment toward Thanksgiving and Christmas in the morning of each day around 9:00am (EST). On the Thanksgiving Day the number of tweets on shopping increased rapidly and monotonically to its maximum as time approaching the midnight when people thinking of shopping on the Black Friday, but unexpectedly the sentiment toward shopping dropped quickly and monotonically, displaying the exact opposite trend. We also investigated the shopping distraction on the theme of these two holidays. It was found that there were more people talking about thankfulness than shopping during the Thanksgiving season, but more people talking about shopping than Jesus during the Christmas season.展开更多
How is English Christmas panto community activism？ The structure of pantomime has not changed in a hundred years, but allows for local creativity to work within its framework to be both family entertainment and socia...How is English Christmas panto community activism？ The structure of pantomime has not changed in a hundred years, but allows for local creativity to work within its framework to be both family entertainment and social satire This basic structure is founded on a children＇s story like Puss ＇n ＇boots or Cinderella. The story and character types remain the same; but the community can add their own jokes and commentary to make the play relevant to themselves and their community. What is added by the community says a lot about who they are and what they care about. The company Price-Waterhouse-Coopers produces their pantomime as management training and team building while engaging the community. The Basel Swiss panto raises money for African Charities. The Maplewood, NJ panto raises money for the homeless and the Jaguar Charity panto in Birmingham performs to disadvantaged children and adults. The productions can be extravagant or threadbare, but share the same goal of raising cheer and goodwill to the benefit of the community. What is it, then, about panto that brings a community together in such civic mindedness？展开更多
Another Christmas season means that the streets and alleys in Europe and the United States have changed into their“Christmas costumes”,and people are busy choosing Christmas decorations and gifts.These dazzling Chri...Another Christmas season means that the streets and alleys in Europe and the United States have changed into their“Christmas costumes”,and people are busy choosing Christmas decorations and gifts.These dazzling Christmas goods are often originally produced in Yiwu,China.展开更多
My Wife,Edna,and I were married on December17,1939.A week later,it was almost Christmas,andI’d spent most of my small savings on our weddingand honeymoon.I had no prospect of income anytimesoon because I worked for a...My Wife,Edna,and I were married on December17,1939.A week later,it was almost Christmas,andI’d spent most of my small savings on our weddingand honeymoon.I had no prospect of income anytimesoon because I worked for a lumber company thatwas closed down for the winter.Nevertheless,Edna and I went shopping foreveryone on our list.It was a cold day,but we wereyoung and enthusiastic,scampering in and out ofstores,picking up gifts here and there.I even展开更多
Christmas season is the most festive time of the year in the UnitedStates. Students from grammar school through college have one to two weck svacation, beginning shortly before Christmas and ending soon after NewYear ...Christmas season is the most festive time of the year in the UnitedStates. Students from grammar school through college have one to two weck svacation, beginning shortly before Christmas and ending soon after NewYear s. Many families go away for the holidays, perhaps to ski in展开更多
He entered my life 20 years ago,leaning against the door-jamb of Room 202,where I taught school.He wore sneakersthree sizes too large and checkered pants ripped at theknees.Daniel,as I’ll call him,though that was not...He entered my life 20 years ago,leaning against the door-jamb of Room 202,where I taught school.He wore sneakersthree sizes too large and checkered pants ripped at theknees.Daniel,as I’ll call him,though that was not his real name,made this undistinguished entrance into the school of a quaintlakeside village known for its old money,fashionable展开更多
Cold Rain mixed with snow fell against the kitchen window ofthe house trailer in the U.S.town of Elkins,West Virginia.Melin-da Eichelberger,seven months pregnant,pulled a tray of Christmascookies from the oven.The fri...Cold Rain mixed with snow fell against the kitchen window ofthe house trailer in the U.S.town of Elkins,West Virginia.Melin-da Eichelberger,seven months pregnant,pulled a tray of Christmascookies from the oven.The frigid weather outside made the trailera cozy haven on this night of December 23,1990.展开更多
In England,Christmas is the most important of all the ’Bank Holidays’ in the year.Two important things,apart from itsreligious significance,help to set this holiday apart fromall others:the custom of giving gifts an...In England,Christmas is the most important of all the ’Bank Holidays’ in the year.Two important things,apart from itsreligious significance,help to set this holiday apart fromall others:the custom of giving gifts and the habit ofspending it with family. In the present highly commercialised age we arereminded of Christmas many weeks before the event.展开更多
基金financially supported by the National Key Research and Development Program of China(Grant No.2022YFC3004802)the National Natural Science Foundation of China(Grant Nos.52171287,52325107)+3 种基金High Tech Ship Research Project of Ministry of Industry and Information Technology(Grant Nos.2023GXB01-05-004-03,GXBZH2022-293)the Science Foundation for Distinguished Young Scholars of Shandong Province(Grant No.ZR2022JQ25)the Taishan Scholars Project(Grant No.tsqn201909063)the sub project of the major special project of CNOOC Development Technology,“Research on the Integrated Technology of Intrinsic Safety of Offshore Oil Facilities”(Phase I),“Research on Dynamic Quantitative Analysis and Control Technology of Risks in Offshore Production Equipment”(Grant No.HFKJ-2D2X-AQ-2021-03)。
文摘Maintenance is an important technical measure to maintain and restore the performance status of equipment and ensure the safety of the production process in industrial production,and is an indispensable part of prediction and health management.However,most of the existing remaining useful life(RUL)prediction methods assume that there is no maintenance or only perfect maintenance during the whole life cycle;thus,the predicted RUL value of the system is obviously lower than its actual operating value.The complex environment of the system further increases the difficulty of maintenance,and its maintenance nodes and maintenance degree are limited by the construction period and working conditions,which increases the difficulty of RUL prediction.An RUL prediction method for a multi-omponent system based on the Wiener process considering maintenance is proposed.The performance degradation model of components is established by a dynamic Bayesian network as the initial model,which solves the uncertainty of insufficient data problems.Based on the experience of experts,the degree of degradation is divided according to Poisson process simulation random failure,and different maintenance strategies are used to estimate a variety of condition maintenance factors.An example of a subsea tree system is given to verify the effectiveness of the proposed method.
文摘Charles Dickens was the greatest critical realists in English literary.Almost all of his novels display his deep concern for the society and great sympathy for the low-class people.A Christmas Carol was written in 1843 when the society was unrest.The author created the gothic atmosphere himself,and put his characters into that situation and combined the gothic writing methods with the critical realism in order that the gothic elements could express a kind of strong convulsion,which could strength his criti cism for the society.At the same time,the Gothicism also helped to deepen his criticism for the society.
文摘As the two most important festivals in China and western countries, Spring Festival and Christmas Day each exempli?fies some of the core values and cultural differences in these two cultures wit which this paper is mainly concerned. By comparing the external manners such as the family reunion, shopping, exchanging New Year greetings, the paper explore the internal cultur?al differences determining those different external manners such as the collectivism, individualism, filial piety, ancestor worship and religion, etc. Through those comparisons, this paper will succeed to achieve its goal if it exhibits, as the title suggests, a glimpse of cultural differences.
文摘Every December,millions of Christmas cards go through the post offices.There're pictures of stars, snow or Christmas tree on the cards. In these days it's hard to think of a Christmas without cards,yet
基金supported by the National Natural Science Foundation of China under Grant No.61703224。
文摘The subsea all-electric Christmas tree(XT) is a key equipment in subsea production systems.Once it fails,the marine environment will be seriously polluted.Therefore,strict reliability analysis and measures to improve reliability must be performed before a subsea all-electric XT is launched;such measures are crucial to subsea safe production.A fault-tolerant control system was developed in this paper to improve the reliability of XT.A dual-factor degradation model for electrical control system components was proposed to improve the evaluation accuracy,and the reliability of the control system was analyzed based on the Markov model.The influences of the common cause failure and the failure rate in key components on the reliability and availability of the control system were studied.The impacts of mean time to repair and incomplete repair strategy on the availability of the control system were also investigated.Research results show the key factors that affect system reliability,and a specific method to improve the reliability and availability of the control system was given.This reliability analysis method for the control system could be applied to general all-electric subsea control systems to guide their safe production.
文摘The thesis will introduce two festivals,Tibetan New Year and American Christmas,and compare their cultural differences.It tends to find different cultural background of these two festivals reflected,to compare how people celebrate them,Including decoration,clothing and activity,and to see their development.The thesis will help people know more about the two typical festivals,which can reflect the different cultures of Tibet and America.
基金financially supported by the National Science and Technology Major Project of China(Grant No.2011ZX05026-003-02)the National High Technology Research and Development Program of China(863 Program,Grant No.2012AA09A205)
文摘The tubing hanger is an important component of the subsea Christmas tree, experiencing big temperature difference which will lead to very high thermal stresses. On the basis of API 17D/ISO 13628-4 and ASME VIII-1, and by comprehensively considering the erosion of oil and the gravity load of the tubing, a calculation model is established by regarding design pressure and thermal stress, and the method for designing the tubing hanger of the horizontal Christmas tree under big temperature difference condition is developed from the fourth strength theory. The proposed theory for strength design of the tubing hanger in big temperature difference is verified by numerical results from ABAQUS.
文摘Thanksgiving and Christmas are two major holidays in the United States. Many people use social media to stay connected with their families and friends, including sharing their holiday experiences. This study utilized a stream of millions of tweets on Twitter to explore how people feel about these two holidays through real-time sentiment analysis. With help of Twitter Streaming API, we discovered the patterns of sentiment changes by hour before and after the two holidays in 2011, thus providing a unique peek into the celebration of these holidays that could not be accomplished with traditional methods. Our analysis suggested that in 2011 people had higher sentiment toward Christmas than Thanksgiving on average. The sentiment reached its maximum on the Thanksgiving Day and on The Christmas Eve and Christmas Day, highlighting stronger zeal for Christmas than Thanksgiving, while remained a stable and lower sentiment before and after the holidays. Typically there was a peak of sentiment toward Thanksgiving and Christmas in the morning of each day around 9:00am (EST). On the Thanksgiving Day the number of tweets on shopping increased rapidly and monotonically to its maximum as time approaching the midnight when people thinking of shopping on the Black Friday, but unexpectedly the sentiment toward shopping dropped quickly and monotonically, displaying the exact opposite trend. We also investigated the shopping distraction on the theme of these two holidays. It was found that there were more people talking about thankfulness than shopping during the Thanksgiving season, but more people talking about shopping than Jesus during the Christmas season.
文摘How is English Christmas panto community activism？ The structure of pantomime has not changed in a hundred years, but allows for local creativity to work within its framework to be both family entertainment and social satire This basic structure is founded on a children＇s story like Puss ＇n ＇boots or Cinderella. The story and character types remain the same; but the community can add their own jokes and commentary to make the play relevant to themselves and their community. What is added by the community says a lot about who they are and what they care about. The company Price-Waterhouse-Coopers produces their pantomime as management training and team building while engaging the community. The Basel Swiss panto raises money for African Charities. The Maplewood, NJ panto raises money for the homeless and the Jaguar Charity panto in Birmingham performs to disadvantaged children and adults. The productions can be extravagant or threadbare, but share the same goal of raising cheer and goodwill to the benefit of the community. What is it, then, about panto that brings a community together in such civic mindedness？
文摘Another Christmas season means that the streets and alleys in Europe and the United States have changed into their“Christmas costumes”,and people are busy choosing Christmas decorations and gifts.These dazzling Christmas goods are often originally produced in Yiwu,China.
文摘My Wife,Edna,and I were married on December17,1939.A week later,it was almost Christmas,andI’d spent most of my small savings on our weddingand honeymoon.I had no prospect of income anytimesoon because I worked for a lumber company thatwas closed down for the winter.Nevertheless,Edna and I went shopping foreveryone on our list.It was a cold day,but we wereyoung and enthusiastic,scampering in and out ofstores,picking up gifts here and there.I even
文摘Christmas season is the most festive time of the year in the UnitedStates. Students from grammar school through college have one to two weck svacation, beginning shortly before Christmas and ending soon after NewYear s. Many families go away for the holidays, perhaps to ski in
文摘He entered my life 20 years ago,leaning against the door-jamb of Room 202,where I taught school.He wore sneakersthree sizes too large and checkered pants ripped at theknees.Daniel,as I’ll call him,though that was not his real name,made this undistinguished entrance into the school of a quaintlakeside village known for its old money,fashionable
文摘Cold Rain mixed with snow fell against the kitchen window ofthe house trailer in the U.S.town of Elkins,West Virginia.Melin-da Eichelberger,seven months pregnant,pulled a tray of Christmascookies from the oven.The frigid weather outside made the trailera cozy haven on this night of December 23,1990.
文摘In England,Christmas is the most important of all the ’Bank Holidays’ in the year.Two important things,apart from itsreligious significance,help to set this holiday apart fromall others:the custom of giving gifts and the habit ofspending it with family. In the present highly commercialised age we arereminded of Christmas many weeks before the event.
