检索结果-内蒙古大学图书馆

arXiv 2023年

作者： Katsaragakis, Manolis Baloukas, Christos Papadopoulos, Lazaros Kantere, Verena Catthoor, Francky Soudris, Dimitrios Microprocessors and Digital Systems Laboratory ECE National Technical University of Athens Greece Katholieke Universiteit Leuven Kasteelpark Arenberg 10 Heverlee3001 Belgium Knowledge and Database Systems Laboratory ECE National Technical University of Athens Greece IMEC Kapeldreef 75 Heverlee3001 Belgium

The Intel Optane DC Persistent Memory (DCPM) is an attractive novel technology for building storage systems for data intensive HPC applications, as it provides lower cost per byte, low standby power and larger capacities than DRAM, with comparable latency. This work provides an in-depth evaluation of the energy consumption of the Optane DCPM, using well-established indexes specifically designed to address the challenges and constraints of the persistent memories. We study the energy efficiency of the Optane DCPM for several indexing data structures and for the LevelDB key-value store, under different types of YCSB workloads. By integrating an Optane DCPM in a memory system, the energy drops by 71.2% and the throughput increases by 37.3% for the LevelDB experiments, compared to a typical SSD storage solution. © 2023, CC BY-NC-ND.

关键词： Energy utilization

来源：评论

学校读者我要写书评

暂无评论

Energy Consumption Evaluation of Optane DC Persistent Memory for Indexing Data Structures

Energy Consumption Evaluation of Optane DC Persistent Memory...

引用

International Conference on High Performance Computing

作者： Manolis Katsaragakis Christos Baloukas Lazaros Papadopoulos Verena Kantere Francky Catthoor Dimitrios Soudris Microprocessors and Digital Systems Laboratory ECE National Technical University of Athens Greece Katholieke Universiteit Leuven Heverlee Belgium Knowledge and Database Systems Laboratory ECE National Technical University of Athens Greece IMEC Heverlee Belgium

关键词： Performance evaluation Energy consumption Costs High performance computing Memory management Random access memory Data structures

来源：评论

学校读者我要写书评

暂无评论

On processing Top-k spatio-textual preference queries 18

On processing Top-k spatio-textual preference queries

引用

18th International Conference on Extending database Technology, EDBT 2015

作者： Tsatsanifos, George Vlachou, Akrivi Knowledge and Database Systems Laboratory National Technical University of Athens Greece Institute for the Management of Information Systems R.C. Athena Greece

ISBN: (纸本)9783893180677

In this paper we propose a novel query type, termed top-k spatio-textual preference query, that retrieves a set of spatio-textual objects ranked by the goodness of the facilities in their neighborhood. Consider for example, a tourist that looks for "hotels that have nearby a highly rated Italian restaurant that serves pizza". The proposed query type takes into account not only the spatial location and textual description of spatio-textual objects (such as hotels and restaurants), but also additional information such as ratings that describe their quality. Moreover, spatio-textual objects (i.e., hotels) are ranked based on the features of facilities (i.e., restaurants) in their neighborhood. Computing the score of each data object based on the facilities in its neighborhood is costly. To address this limitation, we propose an appropriate indexing technique and develop an efficient algorithm for processing our novel query. Moreover, we extend our algorithm for processing spatio-textual preference queries based on alternative score definitions under a unified framework. Last but not least, we conduct extensive experiments for evaluating the performance of our methods. © 2015, Copyright is with the authors.

关键词： Hotels

来源：评论

学校读者我要写书评

暂无评论

Continuous monitoring of nearest trajectories 14

Continuous monitoring of nearest trajectories

引用

22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information systems, ACM SIGSPATIAL GIS 2014

作者： Sacharidis, Dimitris Skoutas, Dimitrios Skoumas, Georgios Institute for the Management of Information Systems R.C. ATHENA Greece Knowledge and Database Systems Laboratory National Technical University of Athens Greece

ISBN: (纸本)9781450331319

Analyzing tracking data of various types of moving objects is an interesting research problem with numerous real-world applications. Several works have focused on continuously monitoring the nearest neighbors of a moving object, while others have proposed similarity measures for finding similar trajectories in databases containing historical tracking data. In this work, we introduce the problem of continuously monitoring nearest trajectories. In contrast to other similar approaches, we are interested in monitoring moving objects taking into account at each timestamp not only their current positions but their recent trajectory in a defined time window. We first describe a generic baseline algorithm for this problem, which applies for any aggregate function used to compute trajectory distances between objects, and without any restrictions on the movement of the objects. Using this as a framework, we continue to derive an optimized algorithm for the cases where the distance between two moving objects in a time window is determined by their maximum or minimum distance in all contained timestamps. Furthermore, we propose additional optimizations for the case that an upper bound on the velocities of the objects exists. Finally, we evaluate the efficiency of our proposed algorithms by conducting experiments on three real-world datasets. Copyright 2014 ACM.

关键词： Trajectories

来源：评论

学校读者我要写书评

暂无评论

Global, regional, and national sex-specific burden and control of the HIV epidemic, 1990–2019, for 204 countries and territories: the Global Burden of Diseases Study 2019

引用

The Lancet HIV 2021年第10期8卷 e633-e651页

作者： Jahagirdar, Deepa Walters, Magdalene K. Novotney, Amanda Brewer, Edmond D. Frank, Tahvi D. Carter, Austin Biehl, Molly H. Abbastabar, Hedayat Abhilash, E.S. Abu-Gharbieh, Eman Abu-Raddad, Laith Jamal Adekanmbi, Victor Adeyinka, Daniel Adedayo Adnani, Qorinah Estiningtyas Sakilah Afzal, Saira Aghababaei, Soodabeh Ahinkorah, Bright Opoku Ahmad, Sajjad Ahmadi, Keivan Ahmadi, Sepideh Ahmadpour, Ehsan Ahmed, Muktar Beshir Rashid, Tarik Ahmed Salih, Yusra Ahmed Aklilu, Addis Akram, Tayyaba Akunna, Chisom Joyqueenet Al Hamad, Hanadi Alahdab, Fares Alanezi, Fahad Mashhour Aleksandrova, Ekaterina A. Alene, Kefyalew Addis Ali, Liaqat Alipour, Vahid Almustanyir, Sami Alvis-Guzman, Nelson Ameyaw, Edward Kwabena Amu, Hubert Andrei, Catalina Liliana Andrei, Tudorel Anvari, Davood Arabloo, Jalal Aremu, Olatunde Arulappan, Judie Atnafu, Desta Debalkie Quintanilla, Beatriz Paulina Ayala Ayza, Muluken Altaye Azari, Samad Darshan, B.B. Banach, Maciej Bärnighausen, Till Winfried Barra, Fabio Barrow, Amadou Basu, Sanjay Bazargan-Hejazi, Shahrzad Belay, Habtamu Gebrehana Berheto, Tezera Moshago Bezabhe, Woldesellassie Mequanint Bezabih, Yihienew Mequanint Bhagavathula, Akshaya Srikanth Bhardwaj, Nikha Bhardwaj, Pankaj Bhattacharyya, Krittika Bibi, Sadia Bijani, Ali Bisignano, Catherine Bolarinwa, Obasanjo Afolabi Boloor, Archith Boltaev, Azizbek A. Briko, Nikolay Ivanovich Buonsenso, Danilo Burkart, Katrin Butt, Zahid A. Cao, Chao Charan, Jaykaran Chatterjee, Souranshu Chattu, Soosanna Kumary Chattu, Vijay Kumar Choudhari, Sonali Gajanan Chu, Dinh-Toi Couto, Rosa A.S. Cowden, Richard G. Dachew, Berihun Assefa Dadras, Omid Dagnew, Amare Belachew Dahlawi, Saad M.A. Dai, Xiaochen Dandona, Lalit Dandona, Rakhi das Neves, José Degenhardt, Louisa Demeke, Feleke Mekonnen Desta, Abebaw Alemayehu Deuba, Keshab Dhamnetiya, Deepak Dhungana, Govinda Prasad Dianatinasab, Mostafa Diaz, Daniel Djalalinia, Shirin Doan, Linh Phuong Dorostkar, Fariba Edinur, Hisham Atan Effiong, Andem Eftekharzadeh, Sahar El Sayed Zaki, Maysaa Elayedath, Rajesh Elhadi, Institute for Health Metrics and Evaluation University of Washington Seattle WA United States Department of Health Metrics Sciences School of Medicine University of Washington Seattle WA United States Division of Allergy and Infectious Diseases University of Washington Seattle WA United States Department of Global Health University of Washington Seattle WA United States School of Social Work University of Washington Seattle WA United States Department of Medicine University of Washington Seattle WA United States Vagelos College of Physicians and Surgeones Columbia University Medical Center New York NY United States Division of Data Analytics and Delivery for Impact WHO Geneva Switzerland Advanced Diagnostic and Interventional Radiology Research Centre Tehran University of Medical Sciences Tehran Iran Multiple Sclerosis Research Centre Tehran University of Medical Sciences Tehran Iran School of Public Health Tehran University of Medical Sciences Tehran Iran Department of Epidemiology and Biostatistics Tehran University of Medical Sciences Tehran Iran Paediatric Chronic Kidney Disease Research Centre Tehran University of Medical Sciences Tehran Iran Department of Psychiatry Tehran University of Medical Sciences Tehran Iran Metabolomics and Genomics Research Centre Tehran University of Medical Sciences Tehran Iran Sina Trauma and Surgery Research Centre Tehran University of Medical Sciences Tehran Iran Research Centre for Immunodeficiencies Tehran University of Medical Sciences Tehran Iran Non-Communicable Diseases Research Centre Tehran University of Medical Sciences Tehran Iran Department of Botany Sree Narayana Guru College Chelannur Kozhikode India Clinical Sciences Department University of Sharjah Sharjah United Arab Emirates Mass Communication Department University of Sharjah Sharjah United Arab Emirates Department of Health-Care Policy and Research Weill Cornell Medical College in Qatar Doha Qatar Department of Population Medicine Ca

Background: The sustainable development goals (SDGs) aim to end HIV/AIDS as a public health threat by 2030. Understanding the current state of the HIV epidemic and its change over time is essential to this effort. This study assesses the current sex-specific HIV burden in 204 countries and territories and measures progress in the control of the epidemic. Methods: To estimate age-specific and sex-specific trends in 48 of 204 countries, we extended the Estimation and Projection Package Age-Sex Model to also implement the spectrum paediatric model. We used this model in cases where age and sex specific HIV-seroprevalence surveys and antenatal care-clinic sentinel surveillance data were available. For the remaining 156 of 204 locations, we developed a cohort-incidence bias adjustment to derive incidence as a function of cause-of-death data from vital registration systems. The incidence was input to a custom Spectrum model. To assess progress, we measured the percentage change in incident cases and deaths between 2010 and 2019 (threshold >75% decline), the ratio of incident cases to number of people living with HIV (incidence-to-prevalence ratio threshold <0·03), and the ratio of incident cases to deaths (incidence-to-mortality ratio threshold <1·0). Findings: In 2019, there were 36·8 million (95% uncertainty interval [UI] 35·1–38·9) people living with HIV worldwide. There were 0·84 males (95% UI 0·78–0·91) per female living with HIV in 2019, 0·99 male infections (0·91–1·10) for every female infection, and 1·02 male deaths (0·95–1·10) per female death. Global progress in incident cases and deaths between 2010 and 2019 was driven by sub-Saharan Africa (with a 28·52% decrease in incident cases, 95% UI 19·58–35·43, and a 39·66% decrease in deaths, 36·49–42·36). Elsewhere, the incidence remained stable or increased, whereas deaths generally decreased. In 2019, the global incidence-to-prevalence ratio was 0·05 (95% UI 0·05–0·06) and the global incidence-to-mortality ratio was

关键词：

来源：评论

学校读者我要写书评

暂无评论

Efficient identification and approximation of k-nearest moving neighbors 13

Efficient identification and approximation of k-nearest movi...

引用

21st ACM SIGSPATIAL International Conference on Advances in Geographic Information systems, ACM SIGSPATIAL GIS 2013

作者： Skoumas, Georgios Skoutas, Dimitrios Vlachaki, Alexandra Knowledge and Database Systems Laboratory National Technical University of Athens Greece Institute for the Management of Information Systems R.C. Athena Greece

ISBN: (纸本)9781450325219

Nowadays, massive amounts of tracking data for various types of moving objects, including vehicles, humans and animals, are becoming available. Analyzing this type of spatio-temporal data is crucial for discovering movement patterns, understanding and forecasting behaviors, and developing novel applications and services. One problem of particular interest is finding objects that move close together with a certain object during some periods of time. In this paper, we focus on finding the k-nearest moving neighbors for a given query object and time interval. We formulate the problem, using a similarity function that takes into consideration both the proximity and the direction of the trajectories, and we firstly present an exact algorithm. Then, we focus on approximate algorithms in order to reduce the execution time, investigating two directions. The first employs line simplification to approximate the compared trajectories, thus reducing the calculations needed to identify the nearest neighbors. The second relies on estimates of prior probabilities derived from trajectory distributions and attempts to achieve a faster approximation of the k-nearest neighbors. A detailed experimental evaluation of the aforementioned algorithms on three real-world datasets is finally presented in order to verify their efficiency and accuracy. © 2013 ACM.

关键词： Trajectories

来源：评论

学校读者我要写书评

暂无评论

User-contributed relevance and nearest neighbor queries

User-contributed relevance and nearest neighbor queries

引用

13th International Symposium on Spatial and Temporal databases, SSTD 2013

作者： Efstathiades, Christodoulos Pfoser, Dieter Knowledge and Database Systems Laboratory National Technical University of Athens Greece Research Center Athena Maroussi Greece George Mason University Fairfax VA United States

ISBN: (纸本)9783642402340

Novel Web technologies and resulting applications have lead to a participatory data ecosystem that when utilized properly will lead to more rewarding services. In this work, we investigate the case of Location-based Services and specifically of how to improve the typical location-based Point-Of-Interest (POI) request processed as a k-Nearest-Neighbor query. This work introduces Links-of-interest (LOI) between POIs as a means to increase the relevance and overall result quality of such queries. By analyzing user-contributed content in the form of travel blogs, we establish the overall popularity of a LOI, i.e., how frequently the respective POI pair is mentioned in the same context. Our contribution is a query processing method for so-called k-Relevant Nearest Neighbor (k-RNN) queries that considers spatial proximity in combination with LOI information to retrieve close-by and relevant (as judged by the crowd) POIs. Our method is based on intelligently combining indices for spatial data (a spatial grid) and for relevance data (a graph) during query processing. An experimental evaluation using real and synthetic data establishes that our approach efficiently solves the k-RNN problem when compared to existing methods. © 2013 Springer-Verlag.

关键词： Query processing

来源：评论

学校读者我要写书评

暂无评论

On quantifying qualitative geospatial data: A probabilistic approach

On quantifying qualitative geospatial data: A probabilistic ...

引用

2nd ACM SIGSPATIAL International Workshop on Crowdsourced and Volunteered Geographic Information, GEOCROWD 2013

作者： Skoumas, Georgios Pfoser, Dieter Kyrillidis, Anastasios Knowledge and Database Systems Laboratory National Technical University of Athens Greece Dept. of Geography and Geoinformation Science George Mason University United States Laboratory for Information and Inference Systems Ecole Polytechnique Federale de Lausanne Switzerland

ISBN: (纸本)9781450325288

Living in the era of data deluge, we have witnessed a web content explosion, largely due to the massive availability of User-Generated Content (UGC). In this work, we specifically consider the problem of geospatial information extraction and representation, where one can exploit diverse sources of information (such as image and audio data, text data, etc), going beyond traditional volunteered geographic information. Our ambition is to include available narrative information in an effort to better explain geospatial relationships: with spatial reasoning being a basic form of human cognition, narratives expressing such experiences typically contain qualitative spatial data, i.e., spatial objects and spatial relationships. To this end, we formulate a quantitative approach for the representation of qualitative spatial relations extracted from UGC in the form of texts. The proposed method quantifies such relations based on multiple text observations. Such observations provide distance and orientation features which are utilized by a greedy Expectation Maximization-based (EM) algorithm to infer a probability distribution over predefined spatial relationships;the latter represent the quantified relationships under user-defined probabilistic assumptions. We evaluate the applicability and quality of the proposed approach using real UGC data originating from an actual travel blog text corpus. To verify the quality of the result, we generate grid-based "maps" visualizing the spatial extent of the various relations. © 2013 ACM.

关键词： Probability distributions

来源：评论

学校读者我要写书评

暂无评论

SPARQL2XQuery 2.0: Supporting semantic-based queries over XML data

SPARQL2XQuery 2.0: Supporting semantic-based queries over XM...

引用

5th International Workshop on Semantic Media Adaptation and Personalization, SMAP 2010

作者： Stavrakantonakis, Ioannis Tsinaraki, Chrisa Bikakis, Nikos Gioldasis, Nektarios Christodoulakis, Stavros MUSIC TUC Technical University of Crete Greece Department of Information Engineering and Computer Science University of Trento Italy Knowledge and Database Systems Laboratory National Technical University of Athens Greece

ISBN: (纸本)9781424486007

The dominant standards in multimedia content and service description, namely the MPEG-7 and the MPEG-21, have been expressed in XML Schema syntax. In addition, ontologies that capture the semantics of these standards have been developed using the semantic web languages. Since different communities in the industry and the academia work and are familiar with the Semantic Web environment or the XML environment, a Schema mapping framework and a Query mapping framework are needed that will allow querying multimedia content and service descriptions in a uniform way in both the XML and Semantic Web environments. We present in this paper SPARQL2XQuery 2.0, a framework that allows expressing semantic queries on top of XML data through the translation of SPARQL queries in XQuery syntax. SPARQL2XQuery 2.0 may work with both existing ontologies and with automatically produced ones, formed according to our XS2OWL 2.0 transformation model. XS2-OWL 2.0 exploits the OWL 2.0 semantics and supports the new XML constructs introduced by XML Schema 1.1. © 2010 IEEE.

关键词： XML

来源：评论

学校读者我要写书评

暂无评论

SPARQL2XQuery 2.0: Supporting Semantic-based queries over XML data

SPARQL2XQuery 2.0: Supporting Semantic-based queries over XM...

引用

International Workshop on Semantic Media Adaptation and Personalization (SMAP)

作者： Ioannis Stavrakantonakis Chrisa Tsinaraki Nikos Bikakis Nektarios Gioldasis Stavros Christodoulakis MUSIC/TUC Technical University of Crete Greece Department of Information Engineering and Computer Science University of Trento Italy Knowledge and Database Systems Laboratory National and Technical University of Athens Greece

The dominant standards in multimedia content and service description, namely the MPEG-7 and the MPEG-21, have been expressed in XML Schema syntax. In addition, ontologies that capture the semantics of these standards have been developed using the semantic web languages. Since different communities in the industry and the academia work and are familiar with the Semantic Web environment or the XML environment, a Schema mapping framework and a Query mapping framework are needed that will allow querying multimedia content and service descriptions in a uniform way in both the XML and Semantic Web environments. We present in this paper SPARQL2XQuery 2.0, a framework that allows expressing semantic queries on top of XML data through the translation of SPARQL queries in XQuery syntax. SPARQL2XQuery 2.0 may work with both existing ontologies and with automatically produced ones, formed according to our XS2-OWL 2.0 transformation model. XS2-OWL 2.0 exploits the OWL 2.0 semantics and supports the new XML constructs introduced by XML Schema 1.1.

关键词： XML Ontologies OWL Syntactics Semantics Resource description framework

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：