A new power estimation method is proposed for base station(BS) in this paper.Based on this method,a software platform for power estimation is developed.The proposed method models power consumption on different abstrac...A new power estimation method is proposed for base station(BS) in this paper.Based on this method,a software platform for power estimation is developed.The proposed method models power consumption on different abstraction levels by splitting a typical base station into several basic components at different levels in the view of embedded system design.In particular,our focus is on baseband IC(Integrate Circuit) due to it's the dominant power consumer in small cells.Baseband power model is based on arithmetic computing costs of selected algorithms.All computing and storage costs are calibrated using algorithm complexity,hardware architecture,activity ratio,silicon technology,and overheads on all hierarchies.Micro architecture and IC technology are considered.The model enables power comparison of different types of base stations configured with different baseband algorithms,micro architectures,and ICs.The model also supports cellular operators in power estimation of different deployment strategies and transmission schemes.The model is verified by comparing power consumption with a real LTE base station.By exposing more configuration freedoms,the platform can be used for power estimation of current and future base stations.展开更多
Drilling operations in polar regions and mountainous areas are complicated by nature of the extreme environment. Yet conventional rotary drilling technologies can be used to drill ice for scientific samples and other ...Drilling operations in polar regions and mountainous areas are complicated by nature of the extreme environment. Yet conventional rotary drilling technologies can be used to drill ice for scientific samples and other research. Due to such reasons as power consumption and weight complications,it is hard to apply a conventional rotary drilling rig for glacial exploration. Use of small,relatively lightweight,portable engine-powered drilling systems in which the drill lifting from the borehole is carried by the winch. It is reasonable enough for near-surface shallow ice-drilling down to 50 m. Such systems can be used for near-surface ablation-stakes installation,also temperature measurements at the bottom of active strata layer,revealing of anthropogenic pollution,etc. The specified used in this research is an auger ice drill powered by a gasoline engine. At this stage,it is crucial to choose effective drilling parameters such as weight on bit( WOB) and drill bit rotation rate. Sensors equipped on the rig have measured the main parameters of the drilling process,such as drill speed,WOB,drill rotation speed,torque and temperature. This paper addresses research on drilling parameters of engine powered auger ice drill and supplies some recommendations for optimization of any ice-core drilling process.展开更多
This paper is divided into two cases to study the communication transmission equipment reliability in the state of the ice storm, according to the huge losses of power system communication caused by the ice storm. For...This paper is divided into two cases to study the communication transmission equipment reliability in the state of the ice storm, according to the huge losses of power system communication caused by the ice storm. For the nodes or links which are not affected by the ice storm, we use the calculation with “the mean time between failures (MTBF)” and “the mean time to repair” (MTTR) to put forward the calculation methods;for the OPGW cable which influenced greater in ice storm, we use the fiber excess length and the elongation of fiber optic cable. It obtains all the paths of the network through improved adjacency matrix method, and then it uses binary decision diagram to obtain the overall reliability of the network. By testing the network nodes and links using “N-1” inspection, the key nodes and key links can be obtained. Finally, considering the importance degree of network transmission business, the reliability evaluation method of power system communication network based on the risk theory in the case of the ice storm has been put forward, and the example to verify that the method can provide the basis for the reliability assessment of the power system communication in the case of the ice storm has been given.展开更多
When one applies the wavelet transform to analyze finite-length time series, discontinuities at the data boundaries will distort its wavelet power spectrum in some regions which are defined as a wavelength-dependent c...When one applies the wavelet transform to analyze finite-length time series, discontinuities at the data boundaries will distort its wavelet power spectrum in some regions which are defined as a wavelength-dependent cone of influence （COI）. In the COI, significance tests are unreliable. At the same time, as many time series are short and noisy, the COI is a serious limitation in wavelet analysis of time series. In this paper, we will give a method to reduce boundary effects and discover significant frequencies in the COI. After that, we will apply our method to analyze Greenland winter temperature and Baltic sea ice. The new method makes use of line removal and odd extension of the time series. This causes the derivative of the series to be continuous （unlike the case for other padding methods）. This will give the most reasonable padding methodology if the time series being analyzed has red noise characteristics.展开更多
基金The finance supporting from National High Technical Research and Development Program of China(863program)2014AA01A705
文摘A new power estimation method is proposed for base station(BS) in this paper.Based on this method,a software platform for power estimation is developed.The proposed method models power consumption on different abstraction levels by splitting a typical base station into several basic components at different levels in the view of embedded system design.In particular,our focus is on baseband IC(Integrate Circuit) due to it's the dominant power consumer in small cells.Baseband power model is based on arithmetic computing costs of selected algorithms.All computing and storage costs are calibrated using algorithm complexity,hardware architecture,activity ratio,silicon technology,and overheads on all hierarchies.Micro architecture and IC technology are considered.The model enables power comparison of different types of base stations configured with different baseband algorithms,micro architectures,and ICs.The model also supports cellular operators in power estimation of different deployment strategies and transmission schemes.The model is verified by comparing power consumption with a real LTE base station.By exposing more configuration freedoms,the platform can be used for power estimation of current and future base stations.
基金Supported by projects of National Science Foundation of China(No.41327804)the Geological Survey of China(No.3R212W324424)
文摘Drilling operations in polar regions and mountainous areas are complicated by nature of the extreme environment. Yet conventional rotary drilling technologies can be used to drill ice for scientific samples and other research. Due to such reasons as power consumption and weight complications,it is hard to apply a conventional rotary drilling rig for glacial exploration. Use of small,relatively lightweight,portable engine-powered drilling systems in which the drill lifting from the borehole is carried by the winch. It is reasonable enough for near-surface shallow ice-drilling down to 50 m. Such systems can be used for near-surface ablation-stakes installation,also temperature measurements at the bottom of active strata layer,revealing of anthropogenic pollution,etc. The specified used in this research is an auger ice drill powered by a gasoline engine. At this stage,it is crucial to choose effective drilling parameters such as weight on bit( WOB) and drill bit rotation rate. Sensors equipped on the rig have measured the main parameters of the drilling process,such as drill speed,WOB,drill rotation speed,torque and temperature. This paper addresses research on drilling parameters of engine powered auger ice drill and supplies some recommendations for optimization of any ice-core drilling process.
文摘This paper is divided into two cases to study the communication transmission equipment reliability in the state of the ice storm, according to the huge losses of power system communication caused by the ice storm. For the nodes or links which are not affected by the ice storm, we use the calculation with “the mean time between failures (MTBF)” and “the mean time to repair” (MTTR) to put forward the calculation methods;for the OPGW cable which influenced greater in ice storm, we use the fiber excess length and the elongation of fiber optic cable. It obtains all the paths of the network through improved adjacency matrix method, and then it uses binary decision diagram to obtain the overall reliability of the network. By testing the network nodes and links using “N-1” inspection, the key nodes and key links can be obtained. Finally, considering the importance degree of network transmission business, the reliability evaluation method of power system communication network based on the risk theory in the case of the ice storm has been put forward, and the example to verify that the method can provide the basis for the reliability assessment of the power system communication in the case of the ice storm has been given.
基金partially supported by the National Key Science Program for Global Change Research (Grant no.2010CB950504)the National High-Technology Research & Development Program of China (863 Program,Grant no.2010AA012305)+2 种基金the National Natural Science Foundation of China(Grant no.41076125)the Fundamental Research Funds for the Central Universities (Key Program)the Polar Climate and Environment Key Laboratory
文摘When one applies the wavelet transform to analyze finite-length time series, discontinuities at the data boundaries will distort its wavelet power spectrum in some regions which are defined as a wavelength-dependent cone of influence （COI）. In the COI, significance tests are unreliable. At the same time, as many time series are short and noisy, the COI is a serious limitation in wavelet analysis of time series. In this paper, we will give a method to reduce boundary effects and discover significant frequencies in the COI. After that, we will apply our method to analyze Greenland winter temperature and Baltic sea ice. The new method makes use of line removal and odd extension of the time series. This causes the derivative of the series to be continuous （unlike the case for other padding methods）. This will give the most reasonable padding methodology if the time series being analyzed has red noise characteristics.
