Satellite-based atmospheric sounding measurements with high spectral resolution or from hyperspectral infrared （IR） sounders are important global observations for improving weather forecasts through assimilating the...Satellite-based atmospheric sounding measurements with high spectral resolution or from hyperspectral infrared （IR） sounders are important global observations for improving weather forecasts through assimilating them into operational numerical weather prediction （NWP） systems.展开更多
为了提高无线携能通信(Simultaneous Wireless nformation and Power Transfer,SWIPT)通信系统的安全性,同时克服系统收发机硬件损伤(Hardware Impairments,HIs)的影响,提出一种硬件损伤下的智能反射面(Intelligent Reflecting Surface,...为了提高无线携能通信(Simultaneous Wireless nformation and Power Transfer,SWIPT)通信系统的安全性,同时克服系统收发机硬件损伤(Hardware Impairments,HIs)的影响,提出一种硬件损伤下的智能反射面(Intelligent Reflecting Surface,IRS)辅助的SWIPT系统安全波束成形设计方法.考虑能量接收设备为潜在的窃听者,在基站最大发射功率、最小接收能量和IRS相移约束下,通过联合优化基站波束赋形矢量、人工噪声矢量和IRS的相移矩阵,构建系统安全速率最大化问题.针对该优化问题是非凸的,且优化变量是耦合的,提出一种基于交替优化和半正定松弛的有效算法来次优地解决该问题.仿真结果表明,本文所提算法能够在保障能量需求的同时,提升系统的安全性和抗硬件损伤能力.展开更多
Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although...Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although the intelligent reflecting surface(IRS)can be adopted to create effective virtual links to address the mmWave blockage problem,the conventional solutions only adopt IRS in the downlink from the Base Station(BS)to the users to enhance the received signal strength.In practice,the reflection of IRS is also applicable to the uplink to improve the spectral efficiency.It is a challenging to jointly optimize IRS beamforming and system resource allocation for wireless energy acquisition and information transmission.In this paper,we first design a Low-Energy Adaptive Clustering Hierarchy(LEACH)clustering protocol for clustering and data collection.Then,the problem of maximizing the minimum system spectral efficiency is constructed by jointly optimizing the transmit power of sensor devices,the uplink and downlink transmission times,the active beamforming at the BS,and the IRS dynamic beamforming.To solve this non-convex optimization problem,we propose an alternating optimization(AO)-based joint solution algorithm.Simulation results show that the use of IRS dynamic beamforming can significantly improve the spectral efficiency of the system,and ensure the reliability of equipment communication and the sustainability of energy supply under NLOS link.展开更多
This letter presents a new discriminative model for Information Retrieval (IR), referred to as Ordinal Regression Model (ORM). ORM is different from most existing models in that it views IR as ordinal regression probl...This letter presents a new discriminative model for Information Retrieval (IR), referred to as Ordinal Regression Model (ORM). ORM is different from most existing models in that it views IR as ordinal regression problem (i.e. ranking problem) instead of binary classification. It is noted that the task of IR is to rank documents according to the user information needed, so IR can be viewed as ordinal regression problem. Two parameter learning algorithms for ORM are presented. One is a perceptron-based algorithm. The other is the ranking Support Vector Machine (SVM). The effec- tiveness of the proposed approach has been evaluated on the task of ad hoc retrieval using three English Text REtrieval Conference (TREC) sets and two Chinese TREC sets. Results show that ORM sig- nificantly outperforms the state-of-the-art language model approaches and OKAPI system in all test sets; and it is more appropriate to view IR as ordinal regression other than binary classification.展开更多
Ontology is the progression of interpreting the conceptions of the information domain for an assembly of handlers.Familiarizing ontology as information retrieval(IR)aids in augmenting the searching effects of user-req...Ontology is the progression of interpreting the conceptions of the information domain for an assembly of handlers.Familiarizing ontology as information retrieval(IR)aids in augmenting the searching effects of user-required relevant information.The crux of conventional keyword matching-related IR utilizes advanced algorithms for recovering facts from the Internet,mapping the connection between keywords and information,and categorizing the retrieval outcomes.The prevailing procedures for IR consume considerable time,and they could not recover information proficiently.In this study,through applying a modified neuro-fuzzy algorithm(MNFA),the IR time is mitigated,and the retrieval accuracy is enhanced for trouncing the above-stated downsides.The proposed method encompasses three phases:i)development of a crop ontology,ii)implementation of the IR system,and iii)processing of user query.In the initial phase,a crop ontology is developed and evaluated by gathering crop information.In the next phase,a hash tree is constructed using closed frequent patterns(CFPs),and MNFA is used to train the database.In the last phase,for a specified user query,CFP is calculated,and similarity assessment results are retrieved using the database.The performance of the proposed system is measured and compared with that of existing techniques.Experimental results demonstrate that the proposed MNFA has an accuracy of 92.77% for simple queries and 91.45% for complex queries.展开更多
Based on the comparison between ontology and thesaurus, and the analysis of an ontology-based Information Retrieval （IR） model, the potential advantages that ontology may contribute to IR are analyzed. Then a genera...Based on the comparison between ontology and thesaurus, and the analysis of an ontology-based Information Retrieval （IR） model, the potential advantages that ontology may contribute to IR are analyzed. Then a general architecture of ontology-based Information Retrieval System （IRS） and the approach of constructing it are presented. Based on the researches, the role of ontology in IR is summarized from four aspects and a typical system called Textpresso is analyzed. Finally, a conclusion is drawn that utilizing ontology is the trend of IR and can really improve the IRS.展开更多
信息检索(IR)是一种通过特定的技术和方法组织、处理信息,以满足用户的信息需求的过程。近年来,基于预训练模型的稠密检索方法取得了巨大的成功;然而,这些方法只利用了文本和词语的向量表征计算查询与文档相关度,忽略了它们短语层面间...信息检索(IR)是一种通过特定的技术和方法组织、处理信息,以满足用户的信息需求的过程。近年来,基于预训练模型的稠密检索方法取得了巨大的成功;然而,这些方法只利用了文本和词语的向量表征计算查询与文档相关度,忽略了它们短语层面间的语义信息。针对该问题,提出一种名为MSIR(Multi-Scale IR)的IR方法。所提方法通过融合查询与文档中多种不同粒度的语义信息提高IR性能。首先,构建查询和文档中词语、短语和文本这3个粒度的语义单元;其次,利用预训练模型对这3个语义单元分别进行编码获得它们的语义表征;最后,利用语义表征计算查询和文档相关度。在Corvid-19、TREC2019和Robust04这3个不同大小的经典数据集上进行了对比实验。与ColBERT(ranking model based on Contextualized late interaction over BERT(Bidirectional Encoder Representation from Transformers))相比,MSIR在Robust04数据集的P@10、P@20、NDCG@10和NDCG@20指标上均实现了约8%的提升,同时在Corvid-19和TREC2019数据集上也取得了一定的改进。实验结果表明,MSIR能够成功融合多种语义粒度,提升检索精度。展开更多
This paper focuses on investor relations （IR） as an element of companies＇ communication with the external environment. It shows the place and role of IR in communication with the general market, and the stock excha...This paper focuses on investor relations （IR） as an element of companies＇ communication with the external environment. It shows the place and role of IR in communication with the general market, and the stock exchange market in particular. The study is illustrated with an example of IR in Poland, a relatively new European Union （EU） member state and an emerging market. As can be seen, IR goes beyond the traditionally understood maintenance of communication with the capital market. It is also shown that the main role of IR ought to be the reduction of investment risk and enhancement of the companies＇ value, which is of particular significance in light of the current globalization of capital markets. It has been found that Polish companies, especially those listed on the Warsaw Securities Exchange （WSE）, commonly rely on IR as a means of communication with the environment. And yet, as the results of the analysis show, the quality of that communication is still far from satisfactory, despite efforts undertaken by various external entities to encourage more focus on the development of IR, or understanding of the company＇s relevant staff of its important role.展开更多
文摘Satellite-based atmospheric sounding measurements with high spectral resolution or from hyperspectral infrared （IR） sounders are important global observations for improving weather forecasts through assimilating them into operational numerical weather prediction （NWP） systems.
文摘为了提高无线携能通信(Simultaneous Wireless nformation and Power Transfer,SWIPT)通信系统的安全性,同时克服系统收发机硬件损伤(Hardware Impairments,HIs)的影响,提出一种硬件损伤下的智能反射面(Intelligent Reflecting Surface,IRS)辅助的SWIPT系统安全波束成形设计方法.考虑能量接收设备为潜在的窃听者,在基站最大发射功率、最小接收能量和IRS相移约束下,通过联合优化基站波束赋形矢量、人工噪声矢量和IRS的相移矩阵,构建系统安全速率最大化问题.针对该优化问题是非凸的,且优化变量是耦合的,提出一种基于交替优化和半正定松弛的有效算法来次优地解决该问题.仿真结果表明,本文所提算法能够在保障能量需求的同时,提升系统的安全性和抗硬件损伤能力.
基金supported by the National Natural Science Foundation of China 62001051.
文摘Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although the intelligent reflecting surface(IRS)can be adopted to create effective virtual links to address the mmWave blockage problem,the conventional solutions only adopt IRS in the downlink from the Base Station(BS)to the users to enhance the received signal strength.In practice,the reflection of IRS is also applicable to the uplink to improve the spectral efficiency.It is a challenging to jointly optimize IRS beamforming and system resource allocation for wireless energy acquisition and information transmission.In this paper,we first design a Low-Energy Adaptive Clustering Hierarchy(LEACH)clustering protocol for clustering and data collection.Then,the problem of maximizing the minimum system spectral efficiency is constructed by jointly optimizing the transmit power of sensor devices,the uplink and downlink transmission times,the active beamforming at the BS,and the IRS dynamic beamforming.To solve this non-convex optimization problem,we propose an alternating optimization(AO)-based joint solution algorithm.Simulation results show that the use of IRS dynamic beamforming can significantly improve the spectral efficiency of the system,and ensure the reliability of equipment communication and the sustainability of energy supply under NLOS link.
基金Supported by the High Technology Research and Devel-opment Program of China (No.2006AA01Z150)the Key Project of the National Natural Science Foundation of China (No.60373101)+1 种基金the Natural Science Foundation of Heilongjiang Province (No.F2007-14)the Project of Heilongjiang Outstanding Young University Teacher (No. 1151G037).
文摘This letter presents a new discriminative model for Information Retrieval (IR), referred to as Ordinal Regression Model (ORM). ORM is different from most existing models in that it views IR as ordinal regression problem (i.e. ranking problem) instead of binary classification. It is noted that the task of IR is to rank documents according to the user information needed, so IR can be viewed as ordinal regression problem. Two parameter learning algorithms for ORM are presented. One is a perceptron-based algorithm. The other is the ranking Support Vector Machine (SVM). The effec- tiveness of the proposed approach has been evaluated on the task of ad hoc retrieval using three English Text REtrieval Conference (TREC) sets and two Chinese TREC sets. Results show that ORM sig- nificantly outperforms the state-of-the-art language model approaches and OKAPI system in all test sets; and it is more appropriate to view IR as ordinal regression other than binary classification.
文摘Ontology is the progression of interpreting the conceptions of the information domain for an assembly of handlers.Familiarizing ontology as information retrieval(IR)aids in augmenting the searching effects of user-required relevant information.The crux of conventional keyword matching-related IR utilizes advanced algorithms for recovering facts from the Internet,mapping the connection between keywords and information,and categorizing the retrieval outcomes.The prevailing procedures for IR consume considerable time,and they could not recover information proficiently.In this study,through applying a modified neuro-fuzzy algorithm(MNFA),the IR time is mitigated,and the retrieval accuracy is enhanced for trouncing the above-stated downsides.The proposed method encompasses three phases:i)development of a crop ontology,ii)implementation of the IR system,and iii)processing of user query.In the initial phase,a crop ontology is developed and evaluated by gathering crop information.In the next phase,a hash tree is constructed using closed frequent patterns(CFPs),and MNFA is used to train the database.In the last phase,for a specified user query,CFP is calculated,and similarity assessment results are retrieved using the database.The performance of the proposed system is measured and compared with that of existing techniques.Experimental results demonstrate that the proposed MNFA has an accuracy of 92.77% for simple queries and 91.45% for complex queries.
文摘Based on the comparison between ontology and thesaurus, and the analysis of an ontology-based Information Retrieval （IR） model, the potential advantages that ontology may contribute to IR are analyzed. Then a general architecture of ontology-based Information Retrieval System （IRS） and the approach of constructing it are presented. Based on the researches, the role of ontology in IR is summarized from four aspects and a typical system called Textpresso is analyzed. Finally, a conclusion is drawn that utilizing ontology is the trend of IR and can really improve the IRS.
文摘信息检索(IR)是一种通过特定的技术和方法组织、处理信息,以满足用户的信息需求的过程。近年来,基于预训练模型的稠密检索方法取得了巨大的成功;然而,这些方法只利用了文本和词语的向量表征计算查询与文档相关度,忽略了它们短语层面间的语义信息。针对该问题,提出一种名为MSIR(Multi-Scale IR)的IR方法。所提方法通过融合查询与文档中多种不同粒度的语义信息提高IR性能。首先,构建查询和文档中词语、短语和文本这3个粒度的语义单元;其次,利用预训练模型对这3个语义单元分别进行编码获得它们的语义表征;最后,利用语义表征计算查询和文档相关度。在Corvid-19、TREC2019和Robust04这3个不同大小的经典数据集上进行了对比实验。与ColBERT(ranking model based on Contextualized late interaction over BERT(Bidirectional Encoder Representation from Transformers))相比,MSIR在Robust04数据集的P@10、P@20、NDCG@10和NDCG@20指标上均实现了约8%的提升,同时在Corvid-19和TREC2019数据集上也取得了一定的改进。实验结果表明,MSIR能够成功融合多种语义粒度,提升检索精度。
文摘This paper focuses on investor relations （IR） as an element of companies＇ communication with the external environment. It shows the place and role of IR in communication with the general market, and the stock exchange market in particular. The study is illustrated with an example of IR in Poland, a relatively new European Union （EU） member state and an emerging market. As can be seen, IR goes beyond the traditionally understood maintenance of communication with the capital market. It is also shown that the main role of IR ought to be the reduction of investment risk and enhancement of the companies＇ value, which is of particular significance in light of the current globalization of capital markets. It has been found that Polish companies, especially those listed on the Warsaw Securities Exchange （WSE）, commonly rely on IR as a means of communication with the environment. And yet, as the results of the analysis show, the quality of that communication is still far from satisfactory, despite efforts undertaken by various external entities to encourage more focus on the development of IR, or understanding of the company＇s relevant staff of its important role.
