DEC 中恒近日推出了一款完全自主研发的产品——街舞 M450R,这款产品外形超级可爱,极大地满足了用户对时尚、个性的追求,非常适合精灵小巧的可爱 MM 使用。功能丰富而强大的 M450R 同样继承街舞惯有的精美音质,富有质感的金属色外壳,方...DEC 中恒近日推出了一款完全自主研发的产品——街舞 M450R,这款产品外形超级可爱,极大地满足了用户对时尚、个性的追求,非常适合精灵小巧的可爱 MM 使用。功能丰富而强大的 M450R 同样继承街舞惯有的精美音质,富有质感的金属色外壳,方便好用的 USB 接口,合理而多能的产品设计,街舞 M450R 为喜欢音乐,喜欢 MP3的人士提供了一件很好的随身装备。街舞 M450R 提供了五种音效表现模式,分别为标准模式、爵士乐模式、古典模式、流行音效模式和摇滚乐模式。各频段声音非常清晰且有层次感,音效的表现相当丰富,让您真正享受到歌曲的优美与韵味满足你的各种收听需求。收听 FM 最新流行新动向、音乐排行榜是现代人生活的重要一环,M450R 的收音效果非常清晰,没有太多的噪音和频率漂移现象。通过 MENU键打开 FM 功能,可使用快进及快退键进行 FM 频道自动搜索,为方便频繁使用,M450R 还为我们准备了 FM 预设模式及简单 FM 模式。通过预设模式,可自行保存已经搜索出来的频道,可记忆保存多达30个电台。另外特别值得一提的是街舞 M450R 还支持 ID3 Tag 的显示与编辑。在嘈杂、拥挤的马路上,在缓缓开动的公车里,在你疾速行走的脚步中,MP3中放出的音乐可以让你拥有一个自己的世界,强劲、舒缓、优美、快乐、悲伤,随心所欲调换自己的心情频道。可爱时尚的 MM 准备好街舞 M450R,随心舞动自己快乐的心情了吗?展开更多
Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accide...Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accidents leading to production shrinkage.The potential failure would negatively affect the profitability of the company,including production shut down,cost of spare parts,cost of labor,damage of reputation,risk of injury to people and the environment.In recent years,condition-based maintenance( CBM) and prognostic and health management( PHM) are developed and formed a strong connection among science,engineering,computer,reliability,communication,management,etc.Computerized maintenance management systems( CMMS) store a lot of data regarding the fault diagnosis and life prediction of the machinery equipment.It's too necessary to uncover useful knowledge from the huge amount of data.It's vital to find the ways to obtain useful and concise information from these data.This information can be of great influence in the decision making of managers.This article is a review of intelligent approaches in machinery faults diagnosis and prediction based on PHM and CBM.展开更多
A fast intra mode decision algorithm is proposed in this paper to reduce the complexity of H. 264 encoder. The proposed algorithm adopted the pre-processing method based on edge feature in pictures to filter out some ...A fast intra mode decision algorithm is proposed in this paper to reduce the complexity of H. 264 encoder. The proposed algorithm adopted the pre-processing method based on edge feature in pictures to filter out some impossible prediction modes. Context information and pre-computed threshold are used to determine whether it is necessary to check the DC mode. This method is able to get rid of most of candidate modes so that only 66--150 modes are left for the final mode decision, instead of 592 modes in the case of full search （FS） method of H. 264. Simulation results demonstrate that the coding time of the proposed algorithm falls down 71.7% compared with FS method, while the performance loss is trivial compared with FS mode decision scheme.展开更多
Wind and solar energy are projected to be major sources of the world's power in the coming decades.In this study,we first introduce satellite observations for surface solar irradiance and wind,and then discuss usi...Wind and solar energy are projected to be major sources of the world's power in the coming decades.In this study,we first introduce satellite observations for surface solar irradiance and wind,and then discuss using the data for prediction and assessment of energy distribution.Using the current NCEP global forecast model (GFS),the global mean and standard deviation of solar power at the surface for the 5-d forecast are about 212 and 124 W/m2,respectively.For a 24-h forecast of a 3-h mean,the relative error is about 30%,and for a prediction of the daily mean,it is about 15%.The relative error of wind power forecasts for a 24-h forecast of a 3-h mean and a daily mean is 70% and 35%,respectively.The reanalysis results based on satellite observations and numerical weather prediction model are also used to study the distribution of solar and wind energy and the variation of the distribution related to climate change.No significant trend in downward solar radiation is found at the surface in the reanalysis data sets.Surface wind power however exhibits a significant positive trend as the global temperature is warming up.A comparison of a decadal mean wind energy between two decades (from 1949 to 1958 vs.from 1999 to 2008) shows that most of Asia had experienced a decrease in surface wind energy.Therefore,decisions about renewable energy developments need to consider such climate change scenarios.展开更多
Control invariant sets play a key role in model predictive control.Using Lyapunov function,a technique is proposed to design control invariant sets of planar systems in a precise form.First,itis designed for a linear ...Control invariant sets play a key role in model predictive control.Using Lyapunov function,a technique is proposed to design control invariant sets of planar systems in a precise form.First,itis designed for a linear system in Brunovsky canonical form.Then,the result is extended to generallinear systems.Finally,the nonlinear control systems are considered,and some sufficient conditionsand design techniques are also obtained.Numerical examples are presented to illustrate the proposeddesign methods.展开更多
文摘DEC 中恒近日推出了一款完全自主研发的产品——街舞 M450R,这款产品外形超级可爱,极大地满足了用户对时尚、个性的追求,非常适合精灵小巧的可爱 MM 使用。功能丰富而强大的 M450R 同样继承街舞惯有的精美音质,富有质感的金属色外壳,方便好用的 USB 接口,合理而多能的产品设计,街舞 M450R 为喜欢音乐,喜欢 MP3的人士提供了一件很好的随身装备。街舞 M450R 提供了五种音效表现模式,分别为标准模式、爵士乐模式、古典模式、流行音效模式和摇滚乐模式。各频段声音非常清晰且有层次感,音效的表现相当丰富,让您真正享受到歌曲的优美与韵味满足你的各种收听需求。收听 FM 最新流行新动向、音乐排行榜是现代人生活的重要一环,M450R 的收音效果非常清晰,没有太多的噪音和频率漂移现象。通过 MENU键打开 FM 功能,可使用快进及快退键进行 FM 频道自动搜索,为方便频繁使用,M450R 还为我们准备了 FM 预设模式及简单 FM 模式。通过预设模式,可自行保存已经搜索出来的频道,可记忆保存多达30个电台。另外特别值得一提的是街舞 M450R 还支持 ID3 Tag 的显示与编辑。在嘈杂、拥挤的马路上,在缓缓开动的公车里,在你疾速行走的脚步中,MP3中放出的音乐可以让你拥有一个自己的世界,强劲、舒缓、优美、快乐、悲伤,随心所欲调换自己的心情频道。可爱时尚的 MM 准备好街舞 M450R,随心舞动自己快乐的心情了吗?
基金Fundamental Research Funds for the Central Universities,China(No.DUT17GF214)
文摘Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accidents leading to production shrinkage.The potential failure would negatively affect the profitability of the company,including production shut down,cost of spare parts,cost of labor,damage of reputation,risk of injury to people and the environment.In recent years,condition-based maintenance( CBM) and prognostic and health management( PHM) are developed and formed a strong connection among science,engineering,computer,reliability,communication,management,etc.Computerized maintenance management systems( CMMS) store a lot of data regarding the fault diagnosis and life prediction of the machinery equipment.It's too necessary to uncover useful knowledge from the huge amount of data.It's vital to find the ways to obtain useful and concise information from these data.This information can be of great influence in the decision making of managers.This article is a review of intelligent approaches in machinery faults diagnosis and prediction based on PHM and CBM.
文摘A fast intra mode decision algorithm is proposed in this paper to reduce the complexity of H. 264 encoder. The proposed algorithm adopted the pre-processing method based on edge feature in pictures to filter out some impossible prediction modes. Context information and pre-computed threshold are used to determine whether it is necessary to check the DC mode. This method is able to get rid of most of candidate modes so that only 66--150 modes are left for the final mode decision, instead of 592 modes in the case of full search （FS） method of H. 264. Simulation results demonstrate that the coding time of the proposed algorithm falls down 71.7% compared with FS method, while the performance loss is trivial compared with FS mode decision scheme.
基金supported by National Basic Research Program of China (Grant No. 2010CB951600)NOAA Center for Satellite Applications and Research
文摘Wind and solar energy are projected to be major sources of the world's power in the coming decades.In this study,we first introduce satellite observations for surface solar irradiance and wind,and then discuss using the data for prediction and assessment of energy distribution.Using the current NCEP global forecast model (GFS),the global mean and standard deviation of solar power at the surface for the 5-d forecast are about 212 and 124 W/m2,respectively.For a 24-h forecast of a 3-h mean,the relative error is about 30%,and for a prediction of the daily mean,it is about 15%.The relative error of wind power forecasts for a 24-h forecast of a 3-h mean and a daily mean is 70% and 35%,respectively.The reanalysis results based on satellite observations and numerical weather prediction model are also used to study the distribution of solar and wind energy and the variation of the distribution related to climate change.No significant trend in downward solar radiation is found at the surface in the reanalysis data sets.Surface wind power however exhibits a significant positive trend as the global temperature is warming up.A comparison of a decadal mean wind energy between two decades (from 1949 to 1958 vs.from 1999 to 2008) shows that most of Asia had experienced a decrease in surface wind energy.Therefore,decisions about renewable energy developments need to consider such climate change scenarios.
基金supported by the National Natural Science Foundation of China under Grant Nos. 60674022, 60736022 and 60821091
文摘Control invariant sets play a key role in model predictive control.Using Lyapunov function,a technique is proposed to design control invariant sets of planar systems in a precise form.First,itis designed for a linear system in Brunovsky canonical form.Then,the result is extended to generallinear systems.Finally,the nonlinear control systems are considered,and some sufficient conditionsand design techniques are also obtained.Numerical examples are presented to illustrate the proposeddesign methods.
