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Satellite and high altitude platform-based inter-vehicle communications in vast and desolate areas 被引量:1
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作者 林元乖 王琳 沈连丰 《Journal of Southeast University(English Edition)》 EI CAS 2012年第2期135-139,共5页
In order to solve the problem of inter-vehicle communication (IVC) in vast and desolate areas such as the desert and the Gobi, two vehicle network models are proposed. One is based on satellite communication and the... In order to solve the problem of inter-vehicle communication (IVC) in vast and desolate areas such as the desert and the Gobi, two vehicle network models are proposed. One is based on satellite communication and the other is based on high altitude platform ( HAP ) communication. The system outline and networking modes of the two models are described. In the satellite communication based model, all the vehicles are equipped with vehicle-bone satellite communication on the move terminals and the communication signals between vehicles are forwarded by satellite. In the high altitude platform-based model, the HAPs are equipped with base station facilities to form aerial base stations, and vehicles can communicate with each other via common terrestrial mobile communication devices. Some key parameters such as path loss, link loss and system capacity are also computed. The analysis shows that both the two models can satisfy the requirement of IVC in the descriptive environment. 展开更多
关键词 inter-vehicle communication satellite communication high altitude platform communication terrestrial mobile communication device system capacity
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The Kuroshio Transport East of Taiwan and the Sea Surface Height Anomaly from the Interior Ocean 被引量:4
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作者 LIUWei LIUQinyu JIAYinglai 《Journal of Ocean University of China》 SCIE CAS 2004年第2期135-140,共6页
The relationship between the Kuroshio transport to the east of Taiwan and the SSHA (Sea Surface Height Anomaly) field is studied based on the World Ocean Circulation Experiment (WOCE) PCM-1 moored current meter array ... The relationship between the Kuroshio transport to the east of Taiwan and the SSHA (Sea Surface Height Anomaly) field is studied based on the World Ocean Circulation Experiment (WOCE) PCM-1 moored current meter array observation, the satellite altimeter data from the MSLA (Map of Sea Level Anomaly) products merged with the ERS and TOPEX/POSEIDON (T/P) data sets, and the WOCE satellite-tracked drifting buoy data. It is confirmed that the Kuroshio transport across PCM-1 array highly correlates with the SSHA upstream (22°-24°N, 121.75°-124°E). The SSHA is not locally generated by the developed Kuroshio meandering but is from the interior ocean and is propagating westward or northwestward. During the period from October 1992 to January 1998, two events of the northwestward propagating negative SSHA occurred, during which the SSHA merged into the Kuroshio and caused the remarkable low transport events in contrast to the normal westward propagating negative SSHA. It is also shown that the lower Kuroshio transport event would be generated in different ways. The negative anomaly in the upstream of PCM-1 array can reduce the Kuroshio transport by either offshore or onshore Kuroshio meandering. The positive anomaly, which is strong enough to detour the Kuroshio, can cause an offshore meandering and a low transport event at the PCM-1 array. 展开更多
关键词 KUROSHIO MEANDERING SSHA (Sea Surface Height Anomaly) PCM-1 satellite altimeter
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Mapping and Assessing Typhoon-induced Forest Disturbance in Changbai Mountain National Nature Reserve Using Time Series Landsat Imagery 被引量:5
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作者 GUO Xiao-yi ZHANG Hong-yan +1 位作者 WANG Ye-qiao John Clark 《Journal of Mountain Science》 SCIE CSCD 2015年第2期404-416,共13页
Monitoring forest disturbances is important for understanding changes in ecosystems. The 1986 Typhoon Vera was a serious disturbance that severely impacted the forest ecosystems of Changbai Mountain National Nature Re... Monitoring forest disturbances is important for understanding changes in ecosystems. The 1986 Typhoon Vera was a serious disturbance that severely impacted the forest ecosystems of Changbai Mountain National Nature Reserve. Although the typhoon disturbance occurred more than two decades ago, the effects of the typhoon still remain within the study area. Few studies have focused on mapping and assessing disturbances across broad spatial and temporal scales. For this study, we first generated a map of forest composition prior to the typhoon disturbance, which served as a baseline data for the extraction of disturbed area. Then, the Disturbance Index(DI) method was tested for mapping the extent and magnitude of disturbance in the study area by applying a Tasseled Cap transformation to the Landsat imagery. The Landsatbased DI method estimated that an area of 13,764.78 ha of forest was disturbed by the typhoon. Based on visual assessments, these results correspond closely with the reference map derived from ground surveys. These results also revealed the influence of local topographic features on the distribution of windthrow areas. Windthrow areas were more pronounced inareas with elevations ranging from 1,000 to 2,000 m, slopes of less than 10 degrees, and southwestern to northwestern aspects. In addition, the relatively long(25 years) post-typhoon recovery period assessed by this study provided a more comprehensive analysis of the dynamics of forest recovery processes over time. Windthrow areas did not recover immediately after the typhoon, likely due to forest management practices enacted at the time. So far, forest recovery has proceeded more rapidly at elevations below 1,400 m, particularly on western slopes within the study area. Finally, a time series of DI values within the study period suggests a secondary disturbance may have occurred between 2000 and 2001. 展开更多
关键词 Typhoon Vera Windthrow areas Disturbance Index(DI) Topographic features Forest recovery process
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Hybrid Satellite-Aerial-Terrestrial Networks in Emergency Scenarios:A Survey 被引量:14
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作者 Ying Wang Yichun Xu +1 位作者 Yuan Zhang Ping Zhang 《China Communications》 SCIE CSCD 2017年第7期204-216,共13页
Natural disaster or large-scale unexpected events easily make the terrestrial network overloaded,paralyzed, or totally destroyed. It is highly demanded to build an emergency network which can be deployed rapidly, offe... Natural disaster or large-scale unexpected events easily make the terrestrial network overloaded,paralyzed, or totally destroyed. It is highly demanded to build an emergency network which can be deployed rapidly, offer high data rate and wide coverage. The emergence of aerial platforms especially the low altitude platforms(LAPs) indicates a stable and reliable direction for the development of emergency network. Hybrid satellite-aerial-terrestrial(HSAT) networks have the ability to provide effective services rather than traditional infrastructures during the emergency situation. In this paper, the aerial platforms and the HSAT networks are surveyed and the key technologies are discussed from several aspects. The challenges of the HSAT networks are also outlined finally. 展开更多
关键词 emergency communication aerial platforms hybrid satellite-aerial-terrestrial networks
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緣裻廬遺札(上)
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作者 梁穎 《历史文献》 CSSCI 2014年第1期202-267,7,共68页
致潘祖年八十九通一仲午比部以紅梅兩盆見貽賦謝二律即用前韻送到春消息,先春一日期。喜神原有譜,寒友只宜詩。鶴守開前蕾,鳩營去後枝。花橋老屋去秋祊田來復,非始願所及。未須三月暮,花發報邱遲。聽到山陽笛,淒涼向子期。還山銅井約,... 致潘祖年八十九通一仲午比部以紅梅兩盆見貽賦謝二律即用前韻送到春消息,先春一日期。喜神原有譜,寒友只宜詩。鶴守開前蕾,鳩營去後枝。花橋老屋去秋祊田來復,非始願所及。未須三月暮,花發報邱遲。聽到山陽笛,淒涼向子期。還山銅井約,度隴玉關詩。自隴上歸,僑居香溪。早春,銅井方伯輒約赴山中探梅。追溯舊游,不勝山陽之感。鞠爲新年瑞,松餘老圃枝。皆君家盛事。歲寒開共早,頓覺百花遲。辛亥人日緣裻拜稿。 展开更多
关键词 比部 向子期 香溪 探梅 春消息 星臺 滂喜 士禮 刻安 山陽
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The Road of the “Wonder Kid”
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作者 WANG SONG 《China Today》 2007年第6期44-46,共3页
FORMER snooker world champion Peter Ebdon once said that the rising Chinese star Ding Junhui is destined to become the World Number 1. Ebdon, who has been on the snooker circuit for some time, rates Ding as a more dif... FORMER snooker world champion Peter Ebdon once said that the rising Chinese star Ding Junhui is destined to become the World Number 1. Ebdon, who has been on the snooker circuit for some time, rates Ding as a more difficult opponent than legends like Steve Davis and Stephen Hendry. He reckons Ding will soon become "the Tiger Woods of snooker." 展开更多
关键词 snooker world champion Peter Chinese star snooker Ding Junhui
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Tracking typhoon-generated swell in the western North Pacific Ocean using satellite altimetry 被引量:3
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作者 王璇 陈戈 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第5期1157-1163,共7页
This paper proposes a scheme for detecting the swell decay of a moving typhoon. We considered a typhoon that was neither far from a point source nor had a belt-like homogenous source,as previously studied. We tracked ... This paper proposes a scheme for detecting the swell decay of a moving typhoon. We considered a typhoon that was neither far from a point source nor had a belt-like homogenous source,as previously studied. We tracked the swell close to the source during a typhoon in the western North Pacific Ocean. We used wind speed and significant wave height data derived from the Geophysical Data Record of the Jason-1 altimeter and the best-track information of the typhoon from the China Meteorological Administration tropical cyclone database. We selected three specific cases to reveal the decay characteristics of the swell generated by a moving typhoon. Based on an altimeter-based typhoon swell identification scheme and the dispersion relationship for deep water,we relocated the swell source for each altimeter measurement. The subsequent statistical decay coefficient was comparable to previous studies,and effectively depicted the swell propagation conditions induced by the typhoon. We hope that our results provide a new understanding of the characteristics and wave energy budget of the North Pacific Ocean,and significantly contribute to wave modeling in this region. 展开更多
关键词 swell decay rate ALTIMETER TYPHOON western North Pacific Ocean
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Local Spiral Curves Simulating Based on Hough Transformation and Center Auto-Locating of Developing Typhoon 被引量:1
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作者 王萍 郭传澍 罗颖昕 《Transactions of Tianjin University》 EI CAS 2006年第2期142-146,共5页
In the developing phase of typhoon formation, the spiral belt partly emerges in satellite cloud images. This research starts from images and moves on to graphics and then to representation and recognition. Following t... In the developing phase of typhoon formation, the spiral belt partly emerges in satellite cloud images. This research starts from images and moves on to graphics and then to representation and recognition. Following this route, local spiral cloud belt is segmented from the raw images using image segmentation, the spiral information is extracted using mathematic morphology, and local spiral curves are detected using Hough transformation. The problem of center locating of developing typhoon has finally been solved through a search algorithm of spiral curve. For No. 99082008 cloud image, the result produced by the algorithm in this paper is at 122..3 degree west longitude, 117.5 degree north latitude. The real typhoon center location was at 122.4 degree west longitude, 18 degree north latitude. 展开更多
关键词 Hough transformation spiral curve simulating infrared satellite cloud images center locating of developing typhoon
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BeiDou Integrated Disaster Reduction Application Platform 被引量:3
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作者 Lü Xuefeng LIAO Yongfeng +1 位作者 LI Bo DENG Lan 《China Communications》 SCIE CSCD 2015年第8期169-182,共14页
To better improve the emergency communication and location-based services of disaster information reporting network for serious natural response and relieL disaster emergency the national natural disaster reduction ap... To better improve the emergency communication and location-based services of disaster information reporting network for serious natural response and relieL disaster emergency the national natural disaster reduction application platform based on BeiDou navigation satellite system is constructed. The administrative distributed platform is integrated with BeiDou positioning and multiple communication ways so as to achieve main disaster reduction application services, including disaster information acquisition and monitoring, emergency relief for trapped people, on-site emergency relief command service, relief supplies' transportation monitoring, and disaster information publishing service. By the platform, serious disaster information reporting time may be reduced to one hour and the emergency decision-making information service for serious natural disasters can be effectively improved, and it will be helpful to provide technical references for the industrial application and promotion of BeiDou inte- grated disaster reduction. 展开更多
关键词 beidou navigation satellite sys-tem disaster location service emergencycommunication disaster information manage- ment disaster emergency relief
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Evaluation of the Use of Inertial Platform for the Generation of Cartography
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作者 Luis Antonio de Lima Diogenes Cortijo Costa +1 位作者 Jorge Luiz Alves Trabanco Maria Teresa Francoso 《Journal of Civil Engineering and Architecture》 2014年第9期1204-1210,共7页
This study aims to analyze the quality of positioning orthophoto generated through the technique of direct georeferencing using metric digital camera system coupled to the laser system, and both systems were aided ine... This study aims to analyze the quality of positioning orthophoto generated through the technique of direct georeferencing using metric digital camera system coupled to the laser system, and both systems were aided inertial navigation platform. For this, we compared the coordinates obtained in 16 control points collected in the field with dual-frequency GNSS (global navigation satellite system) receiver with those obtained in the orthophoto, flight conducted in June 2009 on the campus of the State University of Campinas--UNICAMP, using a medium format digital camera and laser system, with which we obtained images with a spatial resolution of 0.15 m. Taking into account the pattern accuracy cartographic used in Brazil, it is concluded that the products produced have a standard accuracy "A" to 1:2,000 scale, which represents the best quality level, both for planimetric as for altimetry, and that the procedure reached results consistent with cartographic products in 1:2,000 scale, representing a reduction of steps in the mapping process, necessary for the preparation of cartographic databases with reduction of time for preparation of design basis large civil engineering projects, such as roads, railways, studies of urban road systems, power plants and other infrastructure systems needed to develop the country. 展开更多
关键词 Orthophotos PHOTOGRAMMETRY GNSS.
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Shifts in water-level variation of Namco in the central Tibetan Plateau from ICESat and Cryo Sat-2 altimetry and station observations 被引量:8
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作者 Chunqiao Song Qinghua Ye Xiao Cheng 《Science Bulletin》 SCIE EI CAS CSCD 2015年第14期1287-1297,共11页
The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining large... The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining largescale and temporally continuous information of lake-level changes. The CryoSat-2 altimetry is expected to solve the current problem that earlier radar altimeters are only practical for monitoring large water bodies, while ICESat laser altimetry is available only for the period 2003-2009. In this study, the comparison of CryoSat-2 altimetry for Namco with in situ water-level data suggests a high cor- relation coefficient of 0.71 (P 〈 0.01), with the mean error of -0.12 m and root-mean-square error of 0.18 m. Further, the combination of ICESat and CryoSat-2 altimetry data and in situ lake-level observations reveals a rapid water- level rise of 0.24 4- 0.04 m/year during 2003-2008 and then a slightly decreasing trend of -0.09 4- 0.04 m/year during 2009-2013. This study suggests that the CryoSat-2 altimetry has the potential of sustaining the fine observa- tions on Tibetan lakes, following the ICESat mission. Besides, the examination of four key climatic variables (temperature, precipitation, potential evapotranspiration, and relative humidity) during 1990-2013 indicates that the wetting climate over Namco Basin stagnated or even reversed around 2006, which may be tightly related to the slowing lake growth. 展开更多
关键词 LAKE Satellite altimetry CryoSat-2ICESat Tibetan Plateau - Climate change
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The global star formation law of galaxies revisited in the radio continuum 被引量:1
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作者 LIU LiJie GAO Yu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第2期347-353,共7页
We study the global star formation law, the relation between the gas and star formation rate (SFR) in a sample of 130 local galaxies with infrared (IR) luminosities spanning over three orders of magnitude (109-10... We study the global star formation law, the relation between the gas and star formation rate (SFR) in a sample of 130 local galaxies with infrared (IR) luminosities spanning over three orders of magnitude (109-1012 Lo), which includes 91 normal spiral galaxies and 39 (ultra)luminous IR galaxies [(U)LIRGs]. We derive their total (atomic and molecular) gas and dense molecular gas masses using newly available HI, CO and HCN data from the literature. The SFR of galaxies is determined from total IR (8-1000 μm) and 1.4 GHz radio continuum (RC) luminosities. The galaxy disk sizes are defined by the de-convolved elliptical Gaussian FWHM of the RC maps. We derive the galaxy disk-averaged SFRs and various gas surface densities, and investigate their relationships. We find that the galaxy disk-averaged surface density of dense molecular gas mass has the tightest correlation with that of SFR (scatter -0.26 dex), and is linear in log-log space (power-law slope of N=1.03±0.02) across the full galaxy sample. The correlation between the total gas and SFR surface densities for the full sample has a somewhat larger scatter (-0.48 dex), and is best fit by a power-law with slope 1.45±0.02. However, the slope changes from -1 when only normal spirals are considered, to -1.5 when more and more (U)LIRGs are included in the fitting. When different CO-to-H2 conversion factors are used to infer molecular gas masses for normal galaxies and (U)LIRGs, the bi-modal relations claimed recently in CO observations of high-redshift galaxies appear to also exist in local populations of star-forming galaxies. 展开更多
关键词 galaxies: evolation galaxies: ISM radio lines: galaxies stars: fromation
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Activity of comet 103P/Hartley 2 from September 30 to November 04, 2010
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作者 SHI JlanChun ZHAO HaiBin MA YueHua 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第8期1515-1518,共4页
The CCD photometric observation of comet 103P/Hartley 2 with broadband optical filters was carried out at Xuyi Station of Purple Mountain Observatory, Chinese Academy of Sciences by use of Near Earth Object Telescope ... The CCD photometric observation of comet 103P/Hartley 2 with broadband optical filters was carried out at Xuyi Station of Purple Mountain Observatory, Chinese Academy of Sciences by use of Near Earth Object Telescope (NEOT). We monitored the comet from September 30 to November 4, 2010 and investigated the variation of activities. The Afp parameter derived from our r broadband data varies from 46.0 to 126.0 cm and increases with time. The dust production rate in terms of Afp was measured and a tentative calculation of the dust (or gas) loss-rate of nucleus was executed under the assumption that the nucleus of comet 103P/l-lartley 2 is spherical. The r-band image and the surface brightness profile taken on September 30, 2010 was measured and the gradient of surface brightness profile of 103P/Hartley 2 showed m 〈 -1.5, 展开更多
关键词 comets 103P/Hartley 2 ACTIVITY
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