A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2020; you can also visit the original URL.
The file type is
As an important tool for multi-criteria decision making in database systems, the regret minimization query is shown to have the merits of top-k and skyline queries: it controls the output size while does not need users to provide any preferences. Existing researches verify that the regret ratio can be much decreased when interaction is available. In this paper, we study how to enhance current interactive regret minimization query by sorting mechanism. Instead of selecting the most favoritearXiv:2006.10949v1 fatcat:lkhz5d5b3zb77hnmjy5b2rlwqi
more »... most favorite point from the displayed points for each interaction round, users sort the displayed data points and send the results to the system. By introducing sorting mechanism, for each round of interaction the utility space explored will be shrunk to some extent. Further the candidate points selection for following rounds of interaction will be narrowed to smaller data spaces thus the number of interaction rounds will be reduced. We propose two effective sorting-based algorithms namely Sorting-Simplex and Sorting-Random to find the maximum utility point based on Simplex method and randomly selection strategy respectively. Experiments on synthetic and real datasets verify our Sorting-Simplex and Sorting-Random algorithms outperform current state-of-art ones.
Assisting end users to identify desired results from a large dataset is an important problem for multi-criteria decision making. To address this problem, top-k and skyline queries have been widely adopted, but they both have inherent drawbacks, i.e., the user either has to provide a specific utility function or faces many results. The k-regret minimization query is proposed, which integrates the merits of top-k and skyline queries. Due to the NP-hardness of the problem, the k-regretarXiv:2103.11630v1 fatcat:6jglhgvuv5gh5oqiaaobuwdaw4
more »... -regret minimization query is time consuming and the greedy framework is widely adopted. However, formal theoretical analysis of the greedy approaches for the quality of the returned results is still lacking. In this paper, we first fill this gap by conducting a nontrivial theoretical analysis of the approximation ratio of the returned results. To speed up query processing, a sampling-based method, StocPreGreed" is developed to reduce the evaluation cost. In addition, a theoretical analysis of the required sample size is conducted to bound the quality of the returned results. Finally, comprehensive experiments are conducted on both real and synthetic datasets to demonstrate the efficiency and effectiveness of the proposed methods.
To identify potential stars in social networks, the idea of combining member promotion with skyline operator attracts people's attention. Some algorithms have been proposed to deal with this problem so far, such as skyline boundary algorithms in unequal-weighted social networks. We propose an improved member promotion algorithm by presenting ReputationRank based on eigenvectors as well as Influence and Activeness and introduce the concept of skyline distance. Furthermore, we perform skylinedoi:10.1186/s40649-018-0055-9 pmid:30221125 pmcid:PMC6132376 fatcat:746bwu5mxrgzljf2ajnfec3xwm
more »... perform skyline operator over non-skyline set and choose the infra-skyline as our candidate set. The added ReputationRank helps a lot to describe the importance of a member while the skyline distance assists us to obtain the necessary condition for not being dominated so that some meaningless plans can be pruned. Experiments on the DBLP and WikiVote datasets verify the effectiveness and efficiency of our proposed algorithm. Treating the infra-skyline set as candidate set reduces the number of candidates. The pruning strategies based on dominance and promotion cost decrease the searching space.
Lecture Notes in Computer Science
Recovering from malicious attacks in survival database systems is vital in mission-critical information systems. Traditional rollback and reexecute techniques are too time-consuming and can not be applied in survival environments. In this paper, two efficient approaches -transaction dependency based and data dependency based are proposed. Comparing to transaction dependency based approach, data dependency recovery approaches need not undo innocent operations in malicious and affecteddoi:10.1007/978-3-540-72586-2_158 fatcat:6dd3zxkh7ffjrigk3czd5rnvey
more »... affected transactions even some benign blind writes on bad data item speed up recovery process.
Global biodiversity is markedly decreasing in response to climate change and human disturbance. Sanjiang Plain is recognized as a biodiversity hotspot in China due to its high forest and wetland coverage, but species are being lost at an unprecedented rate, induced by anthropogenic activities. Identifying hotspot distributions and conservation gaps of threatened species is of particular significance for enhancing the conservation of biodiversity. Specifically, we integrated the principles anddoi:10.3390/su10010194 fatcat:573ekwfglvh7jbh6hl6slkonn4
more »... he principles and methods of spatial hotspot inspection, geographic information system (GIS) technology and spatial autocorrelation analysis along with fieldwork to determine the spatial distribution patterns and unprotected hotspots of vulnerable and endangered plants in Sanjiang Plain. A gap analysis of the conservation status of vulnerable and endangered plants was conducted. Our results indicate that six nationally-protected plants were not observed in nature reserves or were without any protection, while the protection rates were <10% for 10 other nationally-protected plants. Protected areas (PAs) cover <5% of the distribution areas for 31 threatened plant species, while only five species are covered by national nature reserves (NNRs) within >50% of the distribution areas. We found 30 hotspots with vulnerable and endangered plants in the study area, but the area covered by NNRs is very limited. Most of the hotspots were located in areas with a high-high aggregation of plant species. Therefore, it is necessary to expand the area of existing nature reserves, establish miniature protection plots and create new PAs and ecological corridors to link the existing PAs. Our findings can contribute to the design of a PA network for botanical conservation.
Neddylation is a ubiquitin-like posttranslational modification that conjugates neural precursor cell expressed developmentally downregulated-8 (Nedd8) to specific substrates for regulation of protein activity. In light of current researches, the neddylation pathway is aberrant in the pathogenesis of many diseases. In our review, we summarize the versatile roles of neddylation in chronic liver diseases (CLDs). CLDs are one of the leading causes of chronic disease-associated deaths worldwide.doi:10.3389/fmed.2020.586881 pmid:33195347 pmcid:PMC7604315 fatcat:pnqwg6bwa5ahjggxvvklipk7aq
more »... aths worldwide. There are diverse etiologic agents causing CLDs, mainly including hepatitis B virus (HBV) infection, nonalcoholic fatty liver disease (NAFLD), chronic exposure to alcohol or drugs, and autoimmune causes. So far, however, there remains a paucity of effective therapeutic approach to CLDs. In this review, we summarized the role of the neddylation pathway which runs through the chronic hepatitis B/NAFLD-liver fibrosis-cirrhosis-hepatocellular carcinoma (HCC) axis, a canonical pattern in the process of CLD development and progression. The dysregulation of neddylation may provide a better understanding of CLD pathology and even a novel therapeutic strategy. Correspondingly, inhibiting neddylation via MLN4924, a small molecule compound targeting NEDD8-activating enzyme (NAE), can potently alleviate CLD progression and improve the outcome. On this basis, profiling and characterization of the neddylation pathway can provide new insights into the CLD pathology as well as novel therapeutic strategies, independently of the etiology of CLD.
IET Image Processing
Computational cost-ineffectiveness and ambiguity due to self-occlusion are bottlenecks of vision-based hand gesture recognition. In this study, the authors address these issues by proposing a novel multi-view hand gesture recognition method based on Pareto optimal front. They first present an oriented gradient local binary pattern operator to generate a groupwise gesture feature data set for multi-view hand gesture images. Then they take hand gesture recognition over multi-view hand images as adoi:10.1049/iet-ipr.2019.0924 fatcat:gjof5ejtzrcyzpojsgtfgl5mui
more »... ew hand images as a multi-query image retrieval problem and Pareto optimal front is constructed based on the dissimilarities between the testing images and sample images. The gesture corresponding to the point with the shortest distance to the origin on the Pareto optimal front is the final recognised result. Extensive experiments verify the accuracy and efficiency of their Pareto optimal font-based method.
The skyline query processing problem has been well studied for many years. The literature on skyline algorithms so far mainly considers static query points on static attributes. With the popular usage of mobile devices along with the increasing number of mobile applications and users, continuous skyline query processing on both static and dynamic attributes has become more pressing. Existing efforts on supporting moving query points assume that the query point moves with only one direction anddoi:10.3390/ijgi6030091 fatcat:po45g6vxbzfx7csh7ztbtdvmxq
more »... one direction and constant speed. In this paper, we propose continuous skyline computation over an incremental motion model. The query point moves incrementally in discrete time steps with no restrictions and predictability. Geometric properties over incremental motion denoted by a kinetic data structure are utilized to prune the portion of data points not included in final skyline query results. Various geometric strategies are asymptotically proposed to prune the querying dataset, and event-driven mechanisms are adopted to process continuous skyline queries. Extensive experiments under different data sets and parameters demonstrate that the proposed method is robust and more efficient than multiple snapshots of I/O optimal branch-and-bound skyline (BBS) skyline queries.
Zongyi He and Jiping Liu advised for the method of terrain information content, and did the part of the experimental analysis. ... Chunhua Zheng provided the basic information entropy calculation method in the information theory for this paper, and advised for the method of terrain information content. ...doi:10.3390/e17107021 fatcat:e4q5kns4wjctjbaj4ern3faapq
A centralized grid-connected photovoltaic (PV) station is a widely adopted method of neutral grounding using resistance, which can potentially make pre-existing protection systems invalid and threaten the safety of power grids. Therefore, studying the fault characteristics of grid-connected PV systems and their impact on power-grid protection is of great importance. Based on an analysis of the grid structure of a grid-connected PV system and of the low-voltage ride-through controldoi:10.3390/en10111910 fatcat:canz3syrdzg7pefyagemz5rzx4
more »... ntrol characteristics of a photovoltaic power supply, this paper proposes a short-circuit calculation model and a fault-calculation method for this kind of system. With respect to the change of system parameters, particularly the resistance connected to the neutral point, and the possible impact on protective actions, this paper achieves the general rule of short-circuit current characteristics through a simulation, which provides a reference for devising protection configurations.
Hepatocellular carcinoma remains the sixth most lethal malignancy in the world. While HCC is often diagnosed via current biomarkers at a late stage, early detection of HCC has proven to be very difficult. Recent studies have focused on using exosomal miRNAs in clinical diagnostics and therapeutics, because they have improved stability in exosomes than as free miRNAs themselves. Exosomal miRNAs act through novel mechanisms for inducing cellular responses in a variety of biological circumstances.doi:10.1186/s13045-018-0579-3 pmid:29642941 pmcid:PMC5896112 fatcat:ngrnp77qjnay7bavzcwhcsfgee
more »... ical circumstances. Dysregulated expression of miRNAs in exosomes can also accelerate HCC progression, including cell proliferation and metastasis, via alteration of a network of genes. Growing evidence demonstrates that exosomal miRNAs can affect many aspects of physiological and pathological conditions in HCC and indicates that miRNAs in exosomes can not only serve as sensitive biomarkers for cancer diagnostics and recurrence but can also potentially be used as therapeutics to target HCC progression. In this review, we summarize the latest findings between exosomal miRNAs and HCC, in order to better comprehend the functions and applications in HCC. Moreover, we discuss critical issues to consider when developing anti-tumor exosomal miRNAs as a novel therapeutic strategy for treating HCC in the clinic.
Author Contributions: All authors (Sanli Zhu, Jiping Lu, Zheng Li and Junyi Lin) contributed for bringing the manuscript in its current state. ...doi:10.3390/en10101539 fatcat:4hmywkyrzrhvdfxqbzzsiuiwpu
Copyright © 2021 Zhao, Ying, Wang, Yao, Zhu, Zheng, Chen and Yang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). ...doi:10.3389/fmed.2020.591736 pmid:33644083 pmcid:PMC7904900 fatcat:3qnsupa67fdqximxjplqas6aya
This work elucidates dynamic control equations of the anchoring system and the derivation of displacement equations and corresponding vibration modes. Furthermore, the anchoring system is found to be composed of three different vibration modes: (1) when ω < (k1/ρ1A1)1/2, the vibration mode of the anchoring section is an exponential function; (2) when ω = (k1/ρ1A1)1/2, the vibration mode of the anchoring section is a parabolic function; (3) when ω > (k1/ρ1A1)1/2, the vibration mode of thedoi:10.1155/2021/5560075 fatcat:qeit5rnt35fyfaijdhqf6bwaty
more »... mode of the anchoring section is a trigonometric function, while all the free sections are trigonometric functions. With an increase of frequency, the amplitude of the bolt exhibits multipeak distribution characteristics and an intermittent amplification phenomenon. When the frequency reaches a certain value, the bolt of the free section exhibits only the amplified state. Under dynamic load, the amplitude of the bolt increases from end of bolt to the maximum in the root. On the other hand, when the frequency is low, the peak position of the roof bolt is stable, and the excitation wave component is the main influencing factor of the peak value of axial force at the root of the bolt, independent of frequency. When the frequency is relatively high, the peak value of the axial force is stable at the interface, and the higher the frequency, the greater the peak value of axial force. Axial force of the bolt has responded strongly to the frequency at the interface, and the farther away from the interface, the weaker the response.
« Previous Showing results 1 — 15 out of 342 results