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A Generative Model Approach for Geo-Social Group Recommendation

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Journal of Computer Science & Technology 2018年第4期33卷 727-738页

作者： Peng-Peng Zhao Hai-Feng Zhu Yanchi Liu Zi-Ting Zhou Zhi-Xu Li Jia-Jie Xu Lei Zhao victor S. Sheng School of Computer Science and Technology Soochow University Suzhou 215006 China Department of Management Science and Information Systems Rutgers University Piscataway NJ 08854 U.S.A. Department of Computer Science University of Central Arkansas Conway 72035 U.S.A.

With the development and prevalence of online social networks, there is an obvious tendency that people are willing to attend and share group activities with friends or acquaintances. This motivates the study on group recommendation, which aims to meet the needs of a group of users, instead of only individual users. However, how to aggregate different preferences of different group members is still a challenging problem： 1） the choice of a member in a group is influenced by various factors, e.g., personal preference, group topic, and social relationship; 2） users have different influences when in diffe- rent groups. In this paper, we propose a generative geo-social group recommendation model （GSGR） to recommend points of interest （POIs） for groups. Specifically, GSGR well models the personal preference impacted by geographical information, group topics, and social influence for recommendation. Moreover, when making recommendations, GSGR aggregates the preferences of group members with different weights to estimate the preference score of a group to a POI. Experimental results on two datasets show that GSGR is effective in group recommendation and outperforms the state-of-the-art methods.

关键词： group recommendation topic model social network

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赋范空间中一个二次方程解的个数（英文）

黑龙江大学自然科学学报 2016年第1期33卷 1-5,141页

作者： ALEXANDROV victor 俄罗斯索伯列夫数学研究所新西伯利亚630090 俄罗斯新西伯利亚国立大学物理系新西伯利亚630090

研究方程Q(u)=g,其中Q是映射一个赋范空间到另一个的连续二次算子。显然,若u是该方程的一个解,则-u也是一个解。给出没有其它解的条件,并应用其研究偏微方程uΔu=g的Dirichlet边值问题。

关键词：二次算子二次泛函方程向量空间

术前β受体阻滞剂对肝移植术中循环管理及术后短期心肌损伤和脑卒中的影响:一项倾向评分匹配研究

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第三军医大学学报 2019年第23期41卷 2355-2360页

作者：傅洪 victor W.Xia 重庆市急救医疗中心麻醉科重庆400021 加州大学洛杉矶分校罗纳德里根医学中心麻醉与围术期医学科美国加利福尼亚州90095-1778

目的采用倾向评分匹配研究方法,回顾性分析术前使用β受体阻滞剂对肝移植患者术中输血量、升压药使用、再灌注后综合征以及术后30 d内心肌损伤、脑卒中发生率的影响。方法选取加州大学洛杉矶分校罗纳德里根医学中心2005年10月至2014年9... 详细信息

目的采用倾向评分匹配研究方法,回顾性分析术前使用β受体阻滞剂对肝移植患者术中输血量、升压药使用、再灌注后综合征以及术后30 d内心肌损伤、脑卒中发生率的影响。方法选取加州大学洛杉矶分校罗纳德里根医学中心2005年10月至2014年9月期间接受肝移植手术的患者,按照术前是否使用β受体阻滞剂分为:β受体阻滞剂组(术前持续使用β受体阻滞剂≥7 d)643例和非β受体阻滞剂组809例。两组术前变量的差异采用单因素分析,选取Pu,P=0.155]、升压药使用情况(77.4%vs 79.0%,P=0.569)、再灌注后综合征发生率(14.7%vs 14.9%,P=0.901)以及术后第30天心肌损伤(3.8%vs 4.3%,P=0.761)和脑卒中(0.7%vs 2.0%,P=0.143)的发生率方面,差异均无统计学意义。结论肝移植术前使用β受体阻滞剂≥7 d不会增加术中输血量、升压药的使用以及再灌注后综合征的发生率,对术后第30天心肌损伤或缺血性脑卒中的发生率没有影响。终末期肝病患者在接受肝移植前可以继续使用β受体阻滞剂。

关键词： β受体阻滞剂肝移植围术期管理输血升压药再灌注后综合征心肌损伤脑卒中

Efficient cold atom source from a single-layer atom chip

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Chinese Optics Letters 2024年第6期22卷 103-108页

作者： Petr Skakunenko Darya Bykova Anton Afanasiev Alexey Kalmykov Roman Kirtaev victor Balykin Institute of Spectroscopy Russian Academy of Sciences Moscow 108840Russia Moscow Institute of Physics and Technology Moscow 141700Russia Skolkovo Institute of Science and Technology Moscow 121205Russia National Research university Higher School of Economics Moscow 101000Russia Present affiliation:Emerging Technologies Research Center XPANCEODubaiUnited Arab Emirates

We developed a new single-layer atom chip with an additional u-shaped current-carrying *** new u-shaped microwire creates optimized magnetic field distribution,which increases the trapping volume of a magneto-optical trap(MOT) near the *** approach allows one to localize more atoms,while a setup remains relatively simple (single-layer approach) and consumes low current (up to 10 A). The total number of trapped^(87)Rb atoms in our setup is 5×10^(7).

关键词： atom chip cold atoms laser cooling magneto-optical trap u-MOT

The transition from backarc extension to Andean growth:Insights from geochronologic,sedimentologic,and structural studies of Mesozoic and Cenozoic sedimentary and volcanic rocks in south-central Chile(36°S)

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Geoscience Frontiers 2024年第5期15卷 93-117页

作者： Alfonso Encinas Nicolás Henríquez Daniel Castro Darío Orts Diego Kietzmann Franco Iovino Paulo Vásquez Andrés Folguera victor Valencia Facundo Fuentes Departamento de Ciencias de la Tierra Facultad de Ciencias QuímicasUniversidad de ConcepciónVíctor Lamas 1290Concepción 4030000Chile universidad Nacional de Río Negro.Instituto de Investigación en Paleobiología y Geología.General Roca Río NegroArgentina Instituto de Investigación en Paleobiología y Geología(IIPG).CONICET.Av.J.A.Roca 1242 8332 General RocaRío NegroArgentina universidad de Buenos Aires Facultad de Ciencias Exactas y NaturalesDepartamento de Ciencias GeológicasCiudad UniversitariaPabellón ⅡIntendente Güiraldes 2160C1428EHA Ciudad Autónoma de Buenos AiresArgentina CONICET-universidad de Buenos Aires Instituto de Geociencias BásicasAmbientales y Aplicadas de Buenos Aires(IGeBA)Ciudad UniversitariaPabellón ⅡIntendente Güiraldes 2160C1428EHA Ciudad Autónoma de Buenos AiresArgentina Instituto de Estudios Andinos“Don Pablo Groeber”(IDEAN) CONICET-Universidad de Buenos AiresBuenos AiresArgentina Facultad de Ciencias Exactas y Naturales Universidad de Buenos AiresBuenos AiresArgentina Washington State university School of the EnvironmentPullmanUSA Yacimientos Petrolíferos Fiscales(YPF)S.A. Buenos AiresArgentina

Many studies propose a significant shift in the tectonic and paleogeographic evolution of the Andes in south-central Chile and Argentina during the Late *** has been proposed that the preceding Jurassic-Early Cretaceous extensional regime that resulted in a low-relief volcanic arc and the backarc Neuquén basin came to an end,giving way to shortening and Andean growth from the Late Cretaceous ***,there are disagreements regarding the timing and nature of this transition to Andean *** address these issues,we conducted geochronologic(u-Pb and^(40)Ar/&(39)Ar),sedimentologic,and structural studies on Mesozoic-Cenozoic sedimentary and volcanic rocks in the Río Maule area(Principal Cordillera,Chile,36°S).From our findings and prior analyses,we propose the following tectono-stratigraphic evolution of the region.(1)Marine deposition of the Tithonian-Hauterivian Baños del Flaco Formation took place in an extensional backarc basin.(2)After a~40 Myr hiatus,fluvial deposits of the Colimapu Formation and volcanic rocks of the Plan de los Yeuques Formation accumulated during the *** the Colimapu Formation displays evidence of syndepositional shortening,the Plan de los Yeuques Formation exhibits synextensional growth *** to other studies,our results suggest that the Chilean part of the Principal Cordillera was largely a zone of active deposition rather than an elevated fold-thrust belt during the Late *** propose that sedimentation occurred within a series of relatively stable intermontane subbasins generated by shortening,followed by extension.(3)After a~20 Myr hiatus,middle Eocene to early Miocene(Lutetian-Aquitanian)accumulation of a thick succession of andesitic lavas and minor clastic sediments of the Abanico Formation occurred in an intraarc extensional basin.(4)Finally,major shortening and uplift of previously deposited Mesozoic-Cenozoic rocks took place throughout the *** phase constitu

关键词： Andes South-central Chile Backarc basin Foreland basin Fold-thrust belt

Evaluation of Energy-Efficiency Standards for Room Air Conditioners in the uS

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Open Journal of Energy Efficiency 2012年第2期1卷 9-20页

作者： Alex Lekov victor Franco Steve Meyers Environmental Energy Technologies Division Lawrence Berkeley National Laboratory Berkeley

This article describes an analysis of the energy and economic impacts of possible energy efficiency standards for room air conditioners on both u.S. consumers and the nation as a whole. We used two metrics to determine the effect of standards on a representative sample of u.S. consumers: life-cycle cost change and payback period. For the national impact analysis, we evaluated national energy savings attributable to each potential standard, the monetary value of the energy savings to consumers of room air conditioners, the increased total installed costs because of standards, and the net present value of the difference between the value of energy savings and increased total installed costs. Our analysis indicates that standards for room air conditioners at efficiency level 3, which is 17% more efficient than today’s typical unit in the case of room air conditioners less than 6000 Btu/h with louvers and 12% more efficient in the case of room air conditioners 8000 - 13,999 Btu/h with louvers, would save close to one quad of energy over 30 years and have a net present value of consumer benefit of between ?$0.14 billion and $1.82 billion, depending on the discount rate. In addition, such standards would reduce carbon dioxide emissions and NOx emissions.

关键词： Energy Efficiency Standards Room Air Conditioners Consumer Benefit Energy Savings Life-Cycle Cost Payback Period Emissions Reductions

Fault activation and induced seismicity in geological carbon storage--Lessons learned from recent modeling studies

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第6期8卷 789-804页

作者： Jonny Rutqvist Antonio P. Rinaldi Frederic Cappa Pierre Jeanne Alberto Mazzoldi Luca urpi Yves Guglielmi victor Vilarrasa Energy Geosciences Division Lawrence Berkeley National Laboratory (LBNL) Berkeley USA Swiss Seismological Service Swiss Federal Institute of Technology (ETHZ) Zürich Switzerland GeoAzur University of Nice Sophia-Antipolis Cote Azur Observatory Nice France uMSNH-IIM Instituto de Investigaciones en Ciencias de la Tierra Morelia Mexico Institute of Environmental Assessment and Water Research (IDAEA) Spanish Council for Scientific Research (CSIC) Barcelona Spain

In the light of current concerns related to induced seismicity associated with geological carbon sequestration(GCS),this paper summarizes lessons learned from recent modeling studies on fault activation,induced seismicity,and potential for leakage associated with deep underground carbon dioxide(CO2) *** simulations demonstrate that seismic events large enough to be felt by humans require brittle fault properties and continuous fault permeability allowing pressure to be distributed over a large fault patch to be ruptured at *** fault properties,which are commonly encountered in faults intersecting multilayered shale/sandstone sequences,effectively reduce the likelihood of inducing felt seismicity and also effectively impede upward CO2leakage.A number of simulations show that even a sizable seismic event that could be felt may not be capable of opening a new flow path across the entire thickness of an overlying caprock and it is very unlikely to cross a system of multiple overlying caprock ***-specific model simulations of the In Salah CO2storage demonstration site showed that deep fractured zone responses and associated microseismicity occurred in the brittle fractured sandstone reservoir,but at a very substantial reservoir overpressure close to the magnitude of the least principal *** conclude by emphasizing the importance of site investigation to characterize rock properties and if at all possible to avoid brittle rock such as proximity of crystalline basement or sites in hard and brittle sedimentary sequences that are more prone to injection-induced seismicity and permanent damage.

关键词： Carbon dioxide(CO_2) injection Fault rupture Induced seismicity Ground motion Leakage Modeling

H pylori and host interactions that influence pathogenesis

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World Journal of Gastroenterology 2006年第35期12卷 5599-5605页

作者： Ellen J Beswick Giovanni Suarez victor E Reyes Departments of Pediatrics Microbiology and Immunology University of Texas Medical Branch Galveston TX 77555 United States

H py/ori is probably the most prevalent human pathogen worldwide. Since it was initially suggested in 1983 by Marshall and Warren to be implicated in gastritis and peptic ulcer disease, H pylori has also been implicated in gastric carcinoma and was classified as a class I carcinogen. In the last two decades, a noteworthy body of research has revealed the multiple processes that this gram negative bacterium activates to cause gastroduodenal disease in humans. Most infections are acquired early in life and may persist for the life of the individual. While infected individuals mount an inflammatory response that becomes chronic, along with a detectable adaptive immune response, these responses are ineffective in clearing the infection. Hpylori has unique features that allow it to reside within the harsh conditions of the gastric environment, and also to evade the host immune response. In this review, we discuss the various virulence factors expressed by this bacterium and how they interact with the host epithelium to influence pathogenesis.

关键词： H pylori Gastric cancer Immune response Vacuolating cytotoxin

Factorization of Operators in Krein Spaces and Linear-Fractional Relations of Operator Balls

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Advances in Pure Mathematics 2013年第1期3卷 29-33页

作者： victor Anatoly Khatskevich Valery Anatoly Senderov Department of Mathematics ORT Braude Academic College Karmiel Israel Pyatnitskoe Highway 23-2-156 Moscow Russia

We consider plus-operators in Krein spaces and generated operator linear fractional relations of the following form: . We study some special type of factorization for plus-operators T, among them the following one: T = Bu, where B is a lower triangular plus-operator, u is a J-unitary operator. We apply the above factorization to the study of basical properties of relations (1), in particular, convexity and compactness of their images with respect to the weak operator topology. Obtained results we apply to the known Koenigs embedding problem, the Krein-Phillips problem of existing of invariant semidefinite subspaces for some families of plus-operators and to some other fields.

关键词： Krein Space Linear Fractional Relation Plus-Operator Factorization