327 research outputs found
Joint Topic-Semantic-aware Social Recommendation for Online Voting
Online voting is an emerging feature in social networks, in which users can
express their attitudes toward various issues and show their unique interest.
Online voting imposes new challenges on recommendation, because the propagation
of votings heavily depends on the structure of social networks as well as the
content of votings. In this paper, we investigate how to utilize these two
factors in a comprehensive manner when doing voting recommendation. First, due
to the fact that existing text mining methods such as topic model and semantic
model cannot well process the content of votings that is typically short and
ambiguous, we propose a novel Topic-Enhanced Word Embedding (TEWE) method to
learn word and document representation by jointly considering their topics and
semantics. Then we propose our Joint Topic-Semantic-aware social Matrix
Factorization (JTS-MF) model for voting recommendation. JTS-MF model calculates
similarity among users and votings by combining their TEWE representation and
structural information of social networks, and preserves this
topic-semantic-social similarity during matrix factorization. To evaluate the
performance of TEWE representation and JTS-MF model, we conduct extensive
experiments on real online voting dataset. The results prove the efficacy of
our approach against several state-of-the-art baselines.Comment: The 26th ACM International Conference on Information and Knowledge
Management (CIKM 2017
Lower Bounds for Achieving Synchronous Early Stopping Consensus with Orderly Crash Failures
In this paper, we discuss the consensus problem for synchronous distributed systems with orderly crash failures. For a synchronous distributed system of n processes with up to t crash failures and f failures actually occur, first, we present a bivalency argument proof to solve the open problem of proving the lower bound, min (t + 1, f + 2) rounds, for early-stopping synchronous consensus with orderly crash failures, where t < n - 1. Then, we extend the system model with orderly crash failures to a new model in which a process is allowed to send multiple messages to the same destination process in a round and the failing processes still respect the order specified by the protocol in sending messages. For this new model, we present a uniform consensus protocol, in which all non-faulty processes always decide and stop immediately by the end of f + 1 rounds. We prove that the lower bound of early stopping protocols for both consensus and uniform consensus are f + 1 rounds under the new model, and our proposed protocol is optimal.Singapore-MIT Alliance (SMA
Life History of Lepidostoma hirtum in an Iberian Stream and its Role in Organic Matter Processing
Abstract The goal of this research was to determine the role of Lepidostoma hirtum Fabricius 1775 in the fragmentation of allochtonous organic material, in a segment of a mountain river in central Portugal. For this purpose, we measured leaf fragmentation and growth rates at four temperatures (9, 12, 15 and 18 C) and four leaf types (alder, Alnus glutinosa L.; oak, Quercus andegavensis Hy; poplar, Populus canadensis Moench; and chestnut, Castanea sativa Mill.). Growth rates ranged from 0.012 to 0.049 mg AFDW day-1 with no significant effect of temperature and leaf type. Fragmentation/consumption rates were significantly higher for alder (1.62 mg animal-1 day-1) than for other leaf types, and significantly lower at 9 C (0.70 mg animal-1 day-1) than at any other temperature (1.12 mg animal-1 day-1). In the studied stream, L. hirtum larvae had a univoltine life history, with an asynchronous development. Secondary production of L. hirtum ranged from 53.95 mg m-2 year-1 (pools) to 63.12 mg m-2 year-1 (riffles). Annual P/B ratios differ between habitats: they were 4.01 year-1 for pools and 4.49 year-1 for riffles. Considering the average density of this species in the study river and their consumption rates, this species has the potential to fragment 8.6 times the mean annual standing stock of organic matter, in the study location
Simple Bivalency Proofs of the Lower Bounds in Synchronous Consensus Problems
A fundamental problem of fault-tolerant distributed computing is for the reliable processes to reach a consensus. For a synchronous distributed system of n processes with up to t crash failures and f failures actually occur, we prove using a straightforward bivalency argument that the lower bound for reaching uniform consensus is (f + 2)-rounds in the case of 0 < f ⤠t â2, and a new lower bound for early-stopping consensus is min (t + 1, f + 2)-rounds where 0 ⤠f ⤠t. Both proofs are simpler and more intuitive than the traditional methods such as backward induction. Our main contribution is that we solve the open problem of proving that bivalency can be applied to show the (f + 2)-rounds lower bound for synchronous uniform consensus.Singapore-MIT Alliance (SMA
Verification of {\Gamma} symmetry assignment for the top valence band of ZnO by magneto-optical studies of the free A exciton state
The circularly-polarized and angular-resolved magneto-photoluminescence
spectroscopy was carried out to study the free A exciton 1S state in wurtzite
ZnO at 5 K.Comment: 4 figures, 16 pages. arXiv admin note: substantial text overlap with
arXiv:0706.396
Evaluation of MiR-181a as a potential therapeutic target in osteoarthritis
Purpose: To investigate microRNA-181 (miR-181) as a potential therapeutic target in osteoarthritis (OA).Methods: MiR-181 expression was evaluated in articular cartilage samples obtained from OA patients undergoing knee arthroplasty and non-OA (control) patients undergoing other orthopedic procedures. Following the isolation of total RNA, miRNA and mRNA expression was determined by real timepolymerase chain reaction (RT-PCR). Luciferase reporter assay and miRNA mimic or inhibitor were then used to establish the molecular target of miR-181 in chondrocytes.Results: miR-181 family members, namely, miR-181a, miR-181c and miR-181d were significantly upregulated in articular cartilage obtained from OA patients compared to non-OA control subjects. However, no significant difference in up-regulation of miR-181b expression. B-cell lymphoma 2 (BCL2), a putative target of the miR-181 family, was significantly down-regulated in OA patients compared to control subjects. Furthermore, luciferase reporter assay confirmed direct interaction between miR-181a and three prime untranslated region The 3’UTR of BCL2 in chondrocytes. Transfection of miR-181 mimic resulted in BCL2 suppression in chondrocytes. On the other hand, transfection of miR-181 inhibitor led to increased BCL2 expression and decreased interleukin 1-beta (IL1-β) induced apoptosis.Conclusion: miR-181 is differentially expressed in articular cartilage of OA patients and leads to downregulation of BCL2, a regulator of apoptosis. Therefore, miR-181 may be a potential therapeutic target in the treatment of OA.Keywords: MicroRNA, Osteoarthritis, Apoptosis, B-cell lymphoma 2, Transfection, Chondrocyte
Energy-efficient active tag searching in large scale RFID systems
Radio Frequency Identification (RFID) has attracted much research attention in recent years. RFID can support automatic information tracing and management during the management process in many fields. A typical field that uses RFID is modern warehouse management, where products are attached with tags and the inventory of products is managed by retrieving tag IDs. Many practical applications require searching a group of tags to determine whether they are in the system or not. The existing studies on tag searching mainly focused on improving the time efficiency but paid little attention to energy efficiency which is extremely important for active tags powered by built-in batteries. To fill in this gap, this paper investigates the tag searching problem from the energy efficiency perspective. We first propose an Energy-efficient tag Searching protocol in Multiple reader RFID systems, namely ESiM, which pushes per tag energy consumption to the limit as each tag needs to exchange only one bit data with the reader. We then develop a time efficiency enhanced version of ESiM, namely TESiM, which can dramatically reduce the execution time while only slightly increasing the transmission overhead. Extensive simulation experiments reveal that, compared to state-of-the-art solution in the current literature, TESiM reduces per tag energy consumption by more than one order of magnitude subject to comparable execution time. In most considered scenarios, TESiM even reduces the execution time by more than 50%.This work is partially supported by the National Science Foundation of China (Grant Nos. 61103203, 61332004, 61402056 and 61420106009), NSFC/RGC Joint Research Scheme (Grant No. N_PolyU519/12), and the EU FP7 CLIMBER project (Grant Agreement No. PIRSES-GA-2012-318939)
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