Adding Logical Operators to Tree Pattern Queries on Graph-Structured Data

As data are increasingly modeled as graphs for expressing complex relationships, the tree pattern query on graph-structured data becomes an important type of queries in real-world applications. Most practical query languages, such as XQuery and SPARQL, support logical expressions using logical-AND/OR/NOT operators to define structural constraints of tree patterns. In this paper, (1) we propose generalized tree pattern queries (GTPQs) over graph-structured data, which fully support propositional logic of structural constraints. (2) We make a thorough study of fundamental problems including satisfiability, containment and minimization, and analyze the computational complexity and the decision procedures of these problems. (3) We propose a compact graph representation of intermediate results and a pruning approach to reduce the size of intermediate results and the number of join operations -- two factors that often impair the efficiency of traditional algorithms for evaluating tree pattern queries. (4) We present an efficient algorithm for evaluating GTPQs using 3-hop as the underlying reachability index. (5) Experiments on both real-life and synthetic data sets demonstrate the effectiveness and efficiency of our algorithm, from several times to orders of magnitude faster than state-of-the-art algorithms in terms of evaluation time, even for traditional tree pattern queries with only conjunctive operations.Comment: 16 page

Optimal synthesis of general multi-qutrit quantum computation

Quantum circuits of a general quantum gate acting on multiple $d$-level quantum systems play a prominent role in multi-valued quantum computation. We first propose a new recursive Cartan decomposition of semi-simple unitary Lie group $U(3^n)$ (arbitrary $n$-qutrit gate). Note that the decomposition completely decomposes an n-qutrit gate into local and non-local operations. We design an explicit quantum circuit for implementing arbitrary two-qutrit gates, and the cost of our construction is 21 generalized controlled X (GCX) and controlled increment (CINC) gates less than the earlier best result of 26 GGXs. Moreover, we extend the program to the $n$-qutrit system, and the quantum circuit of generic $n$-qutrit gates contained $\frac{41}{96}\cdot3^{2n}-4\cdot3^{n-1}-(\frac{n^2}{2}+\frac{n}{4}-\frac{29}{32})$ GGXs and CINCs is presented. Such asymptotically optimal structure is the best known result so far.Comment: 16 pages, 14 figure

(Nitrato-κ2 O,O′)bis­(tryptanthrin-κN)silver(I)

In the crystal structure of the title compound, [Ag(NO3)(C15H8N2O2)2], tryptanthrin (indolo[2,1-b]quinazoline-6,12-dione) and silver nitrate form a 2:1 complex. The silver ion is surrounded by two tryptanthrin ligands, each coordinating through the N atoms, with Ag—N bond lengths of 2.247 (3) and 2.264 (3) Å, and an anionic nitrate ligand coordinating through two O atoms, with Ag—O bond lengths of 2.499 (3) and 2.591 (3) Å. The N—Ag—N plane and the O—Ag—O plane are roughly perpendicular, making a dihedral angle of 81.6 (2)°. In the crystal, C—H⋯O inter­actions between aromatic H atoms and keto and nitrate O atoms as well as π–π inter­actions [centroid-centroid distance = 3.706 (4) Å] give rise to a three-dimensional network

Cognitive Non-Orthogonal Multiple Access with Cooperative Relaying:A New Wireless Frontier for 5G Spectrum Sharing

Two emerging technologies toward 5G wireless networks, namely non-orthogonal multiple access (NOMA) and cognitive radio (CR), will provide more efficient utilization of wireless spectrum in the future. In this article, we investigate the integration of NOMA with CR into a holistic system, namely a cognitive NOMA network, for more intelligent spectrum sharing. Design principles of cognitive NOMA networks are perfectly aligned to functionality requirements of 5G wireless networks, such as high spectrum efficiency, massive connectivity, low latency, and better fairness. Three different cognitive NOMA architectures are presented, including underlay NOMA networks, overlay NOMA networks, and CR-inspired NOMA networks. To address inter-network and intra-network interference, which largely degrade the performance of cognitive NOMA networks, cooperative relaying strategies are proposed. For each cognitive NOMA architecture, our proposed cooperative relaying strategy shows its potential to significantly lower outage probabilities. We discuss open challenges and future research directions on implementation of cognitive NOMA networks

Influencing factors and clinical significance of the metastatic lymph nodes ratio in gastric adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>To investigate influencing factors of the metastatic lymph nodes ratio (MLR) and whether it is related to survival in patients with gastric adenocarcinoma.</p> <p>Methods</p> <p>We retrospectively evaluated the clinical features of 121 patients with gastric adenocarcinoma enrolled in our hospital between 2000 and 2007. The receiver operating characteristic (ROC) curve was used to determine the cutoff of the MLR, and CK20 immunohistochemical staining was used to detect micrometastasis of the lymph nodes.</p> <p>Results</p> <p>The areas under the ROC curve of MLR used to predict the death of 3-year and 5-year postoperative patients were 0.826 ± 0.053 and 0.896 ± 0.046. Thus MLR = 30.95% and MLR = 3.15% were designated as cutoffs. The MLR was then classified into three groups: MLR₁(MLR<3.15%); MLR₂(3.15% ≤ MLR ≤ 30.95%); and MLR₃(MLR>30.95%). We found that patients with a higher MLR demonstrated a much poorer survival period after radical operation than those patients with a lower MLR (P = 0.000). The COX model showed that MLR was an independent prognostic factor (P = 0.000). The MLR could also discriminate between subsets of patients with different 5-year survival periods within the same N stage (P < 0.05). The MLR has been shown to be 34.7% (242/697) by HE staining and 43.5% (303/697) by CK staining (P = 0.001). The clinicopathological characteristics of lymph vessel invasion and the depth of invasion could significantly affect the MLR.</p> <p>Conclusion</p> <p>MLR is an independent prognostic factor in gastric cancer. The combined ROC curve with MLR is an effective strategy to produce a curve to predict the 3-year and 5-year survival rates.</p

Inter-rater and Intra-rater Reliability of the Chinese Version of the Action Research Arm Test in People With Stroke

Purpose: To detect the inter-rater and intra-rater reliability of the Chinese version of the Action Research Arm Test (C-ARAT) in patients recovering from a first stroke.Methods: Fifty-five participants (45 men and 10 women) with a mean age of 58.67 ± 12.45 (range: 22–80) years and a mean post-stroke interval of 6.47 ± 12.00 (0.5–80) months were enrolled in this study. To determine the inter-rater reliability, the C-ARAT was administered to each participant by two raters (A and B) with varying levels of experience within 1 day. To determine intra-rater reliability, rater A re-administered the C-ARAT to 33 of the 55 participants on the second day. Intra-class correlation coefficients (ICCs) and Bland–Altman plots were used to analyse the inter-rater and intra-rater reliability.Results: Regarding inter-rater reliability, the total, grasping, gripping, pinching, and gross movement scores received respective ICCs of 0.998, 0.997, 0.995, 0.997, and 0.960 (all p &lt; 0.001), indicating excellent inter-rater reliability in stroke patients. Regarding intra-rater reliability, the corresponding ICCs were 0.987, 0.980, 0.975, 0.944, and 0.954 (all p &lt; 0.001), again indicating excellent intra-rater reliability. The Bland–Altman plots yielded a mean difference of 0.15 with 95% limits of agreement (95%LOA) ranging from −2.16 to 2.46 for the inter-rater measurements and a mean difference of −1.06 with 95%LOA ranging from −6.43 to 4.31 for the intra-rater measurement. The C-ARAT thus appeared to be a stable scoring method.Conclusions: The C-ARAT yielded excellent intra-rater and inter-rater reliability for evaluating the paretic upper extremities of stroke patients. Therefore, our results supported the use of the C-ARAT in this population

Cooperative Non-Orthogonal Layered Multicast Multiple Access for Heterogeneous Networks

This paper proposes a novel design of cooperative non-orthogonal layered multicast multiple access in a heterogeneous network, where the information is encoded into the messages of high-priority (HP) and low-priority (LP). Two types of multicast users coexist in the network: 1) regular users (RUs), which are located far away from the base-station (BS) and expect to decode only the HP message (due to the weak channels); 2) advanced users (AUs), which are located close to the BS and expect to decode both HP and LP messages. To improve the reliability of layered multicast, we consider that the successful AUs (those AUs who successfully decode the HP and LP messages) serve as potential relays to assist other AUs/RUs. Based on this idea, two novel cooperation strategies are proposed for different cases of channel information availability. For each proposed strategy, we derive closed-form exact outage probabilities of AUs and RUs, and then further analyze their diversity orders. Moreover, considering that the layered multicast is outage-constrained, we theoretically evaluate the energy consumption of both strategies and demonstrate their energy saving gains over the direct non-orthogonal multiple access for layered multicast. Finally, our theoretical analysis is verified by numerical results, and the advantages of the proposed strategies are also demonstrated