Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium最新文献

筛选
英文 中文
Characterization and control of a high-Q MEMS inertial sensor using low-cost hardware 采用低成本硬件的高q MEMS惯性传感器的特性和控制
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236886
J. A. Gregory, J. Cho, K. Najafi
{"title":"Characterization and control of a high-Q MEMS inertial sensor using low-cost hardware","authors":"J. A. Gregory, J. Cho, K. Najafi","doi":"10.1109/PLANS.2012.6236886","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236886","url":null,"abstract":"We propose a high-performance, low-cost system for control and characterization of MEMS rate and rate-integrating gyroscopes and other resonant sensors. MEMS gyroscopes, some accelerometers and clocks utilize mechanical resonators. High-quality factor, low-frequency resonator devices with damping time constants from seconds to several minutes pose special characterization challenges. The proposed system uses the commercial “USRP” software defined radio (SDR) hardware and open source GnuRadio software as a platform for the proposed characterization and control system. For characterization of resonators, we developed software to perform dual channel swept-frequency gain-phase analysis, impulse response real-time spectral analysis, and ring down testing which achieve performance comparable to dedicated commercial hardware. To highlight the capabilities of the characterization tools, we implemented an automatic mode matching algorithm in the software. The same hardware is used for control of gyroscopes in either rate or rate integrating modes. We present here two control schemes; a rate-only control implemented entirely in the FPGA of a USRP1, and a hybrid software/firmware control which is capable of rate and rate-integrating operation. Experimental results of characterization, automatic tuning and rate-mode operation of a rate and rate-integrating MEMS gyroscope are presented to demonstrate the viability of the proposed system.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124281957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
A novel optimal redundant inertial sensor configuration in strapdown Inertial Navigation System 带式惯性导航系统中的新型冗余惯性传感器优化配置
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236887
Li Fu, Xi Yang, LinLin Wang
{"title":"A novel optimal redundant inertial sensor configuration in strapdown Inertial Navigation System","authors":"Li Fu, Xi Yang, LinLin Wang","doi":"10.1109/PLANS.2012.6236887","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236887","url":null,"abstract":"This paper presents a novel optimal redundant inertial sensors configuration in SINS with overall considerations of reliability, navigation accuracy, size and cost of system. The optimal number of redundant sensors is determined by considering the reliability and cost. Based on D-optimality criteria and real code genetic algorithm (RCGA), a novel optimal redundant configuration scheme is established. The experiment results show that the proposed redundant sensors configuration achieves required accuracy with smaller size which is 26.4% of the widely adopted redundant dodecahedron configuration. The optimal experiment method proposed in this paper has been proved to be simple and efficient for designing redundant sensor configuration.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127149336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
An empirical solar radiation pressure model for autonomous GNSS orbit prediction 自主GNSS轨道预测的经验太阳辐射压力模型
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236929
Juha Ala-Luhtala, Mari Seppanen, R. Piché
{"title":"An empirical solar radiation pressure model for autonomous GNSS orbit prediction","authors":"Juha Ala-Luhtala, Mari Seppanen, R. Piché","doi":"10.1109/PLANS.2012.6236929","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236929","url":null,"abstract":"GNSS satellite orbits can be predicted by integrating the satellites' equation of motion. If the prediction is done in a consumer grade positioning device, a simplified version of the equation of motion is required. The forces due to Earth's gravitation, solar gravitation and lunar gravitation should be included, but the models for the smaller non-gravitational forces can be fairly simple. This paper presents a simple empirical two parameter solar radiation pressure model for an orbit prediction application in a navigation device that does not have a network connection. The model is tested by predicting the orbits of GPS and GLONASS satellites up to 5 days into the future, using position and improved velocity from broadcast ephemerides as an initial state. The predicted orbits are compared to the precise orbits from International GNSS Service (IGS).","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126954813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 16
Scenario-based evaluations of high-accuracy personal positioning systems 基于场景的高精度个人定位系统评估
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236871
J. Rantakokko, E. Emilsson, P. Stromback, J. Rydell
{"title":"Scenario-based evaluations of high-accuracy personal positioning systems","authors":"J. Rantakokko, E. Emilsson, P. Stromback, J. Rydell","doi":"10.1109/PLANS.2012.6236871","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236871","url":null,"abstract":"Foot-mounted inertial sensors combined with GPS-receivers, magnetometers, and barometric pressure sensors have shown great potential in providing high-accuracy positioning systems for first responder and military applications. Several factors, including the type of movement, surface, and the shape of the trajectory, can strongly influence the performance of foot-mounted inertial navigation systems. There is a need for realistic scenario-based evaluations as a complement to the controlled environment tests that have been published in the literature. In this work we evaluate the performance of a foot-mounted inertial navigation system using three-axis accelerometers, gyroscopes and magnetometers during realistic scenario-based measurements. The position accuracy is evaluated by using a camera-based reference system which positions itself towards visual markers placed at pre-surveyed positions, using a slightly modified version of the ARToolKitPlus software. Maximum position errors of 2.5 to 5.5 meters were obtained during four separate high-tempo building clearing operations that lasted approximately three and a half minutes each. Further improvements in accuracy, as well as improved robustness towards different movement patterns, can be achieved by implementing an adaptive stand-still detection algorithm.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115179250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 15
A USRP-based GNSS and interference signal generator and playback system 基于usrp的GNSS和干扰信号发生器和回放系统
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236916
Ruihui Di, S. Peng, S. Taylor, Y. Morton
{"title":"A USRP-based GNSS and interference signal generator and playback system","authors":"Ruihui Di, S. Peng, S. Taylor, Y. Morton","doi":"10.1109/PLANS.2012.6236916","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236916","url":null,"abstract":"This paper presents a low cost, portable, and flexible GNSS signal and interference signal generator based on a general purpose software radio front end, the Universal Serial Radio Peripheral (USRP) family of devices. We paired a USRP-N210 mother board with appropriate RFX daughter boards to generate all GNSS signals controlled by a personal computer. The source of the signal can be pre-recorded digital samples obtained from specific RF front end or arbitrary samples generated using MATLAB programs. An adjustable low noise signal amplifier mounted between the USRP output and the transmitting antenna was used to control the transmitted power of the signal. A spectrum analyzer was used to directly monitor the transmitted signal. The NovAtel receiver was used to verify the performance of this signal generator and playback system. The received GNSS data after transmitting via USRP-N210 and the original GNSS data before transmitting are processed by NovAtel receiver and software receiver programs respectively for performance evaluation purposes. Some comparisons had been done to demonstrate the accuracy of the playback system.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116040802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 17
Relative navigation for formation flying spacecrafts using X-ray pulsars 利用x射线脉冲星进行编队飞行航天器的相对导航
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236986
Falin Wu, Xiaohong Sui, Yan Zhao, Yun Zhang
{"title":"Relative navigation for formation flying spacecrafts using X-ray pulsars","authors":"Falin Wu, Xiaohong Sui, Yan Zhao, Yun Zhang","doi":"10.1109/PLANS.2012.6236986","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236986","url":null,"abstract":"Relative navigation for spacecrafts has received a great deal of attention recently because of its importance for space applications, especially for formation flights. One approach of relative navigtion is to use the Global Positioning System (GPS). However, GPS signals are not available for deep space missions. Hence, an alternative solution is needed. A possibility is to use the signals emitted from X-ray celestial sources. One of the most reliable X-ray sources is pulsars. Relative navigation of spacecrafts may be accomplished by observing X-ray sources and indirectly determining the spacecrafts' relative position. This paper investigates the algorithm of relative navigation for formation flying spacecrafts using X-ray pulsars. A novel relative navigation algorithm for multiple-satellite formation using X-ray pulsars measurements is proposed. The problem of relative navigation between formation flights utilizing X-ray pulsars measurements is investigated. The time difference of signal arrival (TDOA) is estimated by signal's cross-correlated processing, which is further used as measurement to achieve the relative navigation. An Extended Kalman filter is employed to estimate the relative positions and velocities between the formation flights. Numerical simulations are performed to assess the proposed navigation algorithm. Furthermore, errors of the navigation are analyzed in order to improve the accuracy of this method.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129496800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Mobile ad-hoc communication in machine swarms for relative positioning based on GNSS-raw data exchange 基于gnss -原始数据交换的机群相对定位移动自组织通信
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236983
J. Schattenberg, T. Lang, S. Batzdorfer, M. Becker, U. Bestmann, P. Hecker
{"title":"Mobile ad-hoc communication in machine swarms for relative positioning based on GNSS-raw data exchange","authors":"J. Schattenberg, T. Lang, S. Batzdorfer, M. Becker, U. Bestmann, P. Hecker","doi":"10.1109/PLANS.2012.6236983","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236983","url":null,"abstract":"The increasing automation of mobile working machines and the progressive use of more than one machine up to machine swarms for cooperative tasks demands information about the relative position between the machines as well as between the machines and their attachments. This is especially necessary and important when carrying out tasks on distributed machines in a formation. Examples for application are parallel harvesting process in agricultural business or the cooperative search for survivors after a snow slide or e.g. an earthquake in urban scenarios. Moreover, it is very important to ensure relative position information in case of partial failure or a poor reception of the GNSS receiver, for example to avoid the collision between the machines. Options to handle this problem are the coupling of Global Navigation Satellite System (GNSS) measurements with measurements of an Inertial Measurement Unit (IMU). A further improvement or stabilization can be done by vision based systems, like 2D- or 3D-camera system using methods of optical flow for motion estimation. Another possibility for improvement for determining the swarm geometry, which will be described in this paper, is the so called swarm positioning method. This method is based on the exchange of the measured GNSS raw data, i.e. range measurements, between each participant in the swarm using a mobile ad-hoc network. Additionally, GNSS raw measurements and inertial measurements are coupled using multiple filters in order to detect degraded GNSS measurements and exclude these from further data processing. The challenge of the mobile ad-hoc network is the time variant network structure and the small available transmission rate in combination with a high demand for quick data exchange. The requirement to respond very flexibly to changes in topology and to compensate the loss of individual network participants as well as to spontaneously integrate further participants forbids the use of a fixed coordinator. Therefore different routing algorithms have to be combined and developed to ensure an information exchange in various scenarios.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128390695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
High-precision GNSS orbit, clock and EOP estimation at the United States Naval Observatory 美国海军天文台的高精度GNSS轨道、时钟和EOP估计
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236940
S. Byram, C. Hackman
{"title":"High-precision GNSS orbit, clock and EOP estimation at the United States Naval Observatory","authors":"S. Byram, C. Hackman","doi":"10.1109/PLANS.2012.6236940","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236940","url":null,"abstract":"The United States Naval Observatory (USNO) produces GPS-based estimates of satellite orbits, satellite- and receiver-clock time corrections, and earth-orientation parameters five times per day: once in a daily “rapid” process, the results of which are available with approximately 16-hour latency, and four times in an every-six-hours “ultra-rapid” process, the results of which are available with 3-hour latency. The rapid products supply 24 hours of post-processed estimates; the ultra-rapid products supply 24 hours of post-processed estimates with 24 hours of predictions. As is, the ultra-rapid products are suited for real-time systems where high-accuracy GPS orbits are required. In addition to providing high precision and low latency, these products are available on an extremely reliable basis. USNO is one of the few DoD providers of these GPS-based estimates and performs duties as an Analysis Center (AC) of the International GNSS Service (IGS). Recently, the USNO has begun testing on incorporating GLONASS observational data into a non-operational “rapids” processing. The resulting solutions from this case study will be compared to a USNO's GPS-based control solution as well as to the combination rapid products produced by the IGS. It is shown that the network stations used in the GLONASS test case have a noticeable improvement in in their position estimate RMS in comparison to the control solution. Performing a 7-parameter Helmert transformation indicates that the Z-direction rotational values appear to have the most improvement from the inclusion of the GLONASS observations.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128708379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
A location-based services system (LBSS) designed for an arboretum 为植物园设计的位置服务系统(LBSS)
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236842
Jidong Huang, P. Uys
{"title":"A location-based services system (LBSS) designed for an arboretum","authors":"Jidong Huang, P. Uys","doi":"10.1109/PLANS.2012.6236842","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236842","url":null,"abstract":"This paper describes the research efforts at California State University, Fullerton (CSUF), for establishing a Location-Based Services System (LBSS) at the Arboretum. An LBSS is a networked, computer-based service which provides location-aware, mobile devices access to context-sensitive information. The LBSS has greater potential to meet the challenges and educational needs of generating enthusiasm, interest and appreciation and of fostering learning in an interactive way. In order to accurately locate the plants and/or facilities in the garden, Differential-GPS (DGPS) with RTK capability is used. For places where GPS's positioning performance is adversely affected by obstacles like tree-cover and buildings, the possibility of using computer visual recognition techniques to aid DGPS for identifying the plants is discussed. Since cameras are readily available in many mobile devices such as in a smart-phone, the use of computer visual aids is preferred, as the initial approach, over the use of inertial navigation measurements. Finally, results from the preliminary design phase, where a laptop computer with Windows operating system was used to access the location-based services, are discussed.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130328678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Towards a robust multi-antenna mass market GNSS receiver 迈向稳健的多天线大众市场GNSS接收机
Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium Pub Date : 2012-04-23 DOI: 10.1109/PLANS.2012.6236894
G. Kappen, Christian Hättich, M. Meurer
{"title":"Towards a robust multi-antenna mass market GNSS receiver","authors":"G. Kappen, Christian Hättich, M. Meurer","doi":"10.1109/PLANS.2012.6236894","DOIUrl":"https://doi.org/10.1109/PLANS.2012.6236894","url":null,"abstract":"An architecture concept for multi-antenna mass market GNSS receivers is presented. The architecture is composed of a central processing unit and attached coprocessors to solve the conflict between continuously increasing computational complexity of receiver algorithms and the demand for maximal receiver mobility (i.e. hardware featuring low cost and low energy consumption). To optimize navigation performance and robustness the presented receiver processing relies on the collected data in space, time, and frequency domain. Multi-antenna algorithms, e.g. interferer suppression, direction of arrival estimation, and tracking are briefly described. The basic hardware building blocks (coprocessors) required to efficiently realize these algorithms are introduced. Examples for the dimensioning of internal word length and block parameters are presented and first coprocessor implementations are shown. To reduce the costs of the overall receiver, synergistic effects should be exploited and the coprocessors should be used in a time multiplexed manner, where possible. Therefore, a first simple scheduling for the coprocessor access is shown. Finally, a platform for a real-time prototype realization of the presented architecture concept, on a state-of-the-art FPGA development board, is introduced. This paper proves that high performance multi-antenna GNSS receivers featuring interferer suppression as well as advanced signal processing and analysis can be realized using state-of-the-art FPGAs and thus shows a first step towards a mass market multi-antenna GNSS receiver.","PeriodicalId":282304,"journal":{"name":"Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130355526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 18
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信