Improved Compact Visibility Representation of Planar Graph via Schnyder's Realizer

Let $G$ be an $n$-node planar graph. In a visibility representation of $G$, each node of $G$ is represented by a horizontal line segment such that the line segments representing any two adjacent nodes of $G$ are vertically visible to each other. In the present paper we give the best known compact visibility representation of $G$. Given a canonical ordering of the triangulated $G$, our algorithm draws the graph incrementally in a greedy manner. We show that one of three canonical orderings obtained from Schnyder's realizer for the triangulated $G$ yields a visibility representation of $G$ no wider than $\frac{22n-40}{15}$. Our easy-to-implement O(n)-time algorithm bypasses the complicated subroutines for four-connected components and four-block trees required by the best previously known algorithm of Kant. Our result provides a negative answer to Kant's open question about whether $\frac{3n-6}{2}$ is a worst-case lower bound on the required width. Also, if $G$ has no degree-three (respectively, degree-five) internal node, then our visibility representation for $G$ is no wider than $\frac{4n-9}{3}$ (respectively, $\frac{4n-7}{3}$). Moreover, if $G$ is four-connected, then our visibility representation for $G$ is no wider than $n-1$, matching the best known result of Kant and He. As a by-product, we obtain a much simpler proof for a corollary of Wagner's Theorem on realizers, due to Bonichon, Sa\"{e}c, and Mosbah.Comment: 11 pages, 6 figures, the preliminary version of this paper is to appear in Proceedings of the 20th Annual Symposium on Theoretical Aspects of Computer Science (STACS), Berlin, Germany, 200

Mourning before death: mother-son relationships in Shakespeare's histories and tragedies

In Mourning Before Death, I discuss the representation of maternal mourning in King John, the Henry VI trilogy, Richard III, Titus Andronicus, and Coriolanus. Primarily, I explore Shakespeare's expansion of maternal roles from his source texts, especially their lamentations anticipating the death of sons in these plays. Shakespeare emphasises the grief experienced by mothers which is largely absent in the historical accounts on which the plays are based. My research addresses Phyllis Rackin's definition of females as 'anti-historians' and examines how mothers in mourning intrude into historical events and confront masculine authority.This study focuses principally on Shakespeare's representation of maternal authority in terms of mother-son relationships. The introduction identifies the importance of'women's time' and physical expressions of maternal distress and the dramatic conflicts these provoke. Chapter 2 examines how Constance's grief affects the reaction of the audience to the power struggle in King John. Chapter 3 is concerned with how Margaret's queenship in Henry VI disrupts the development of English kingship and endangers the existing Lancastrian rule. Chapter 4 discusses the psychological and physical meanings expressed through the use of the sitting posture, a gesture which embodies the mothers' pain. Chapter 5 discusses Shakespeare's exploration of political wildness and barbarism through his representation of Tamora's tragic passion. Chapter 6 discusses Volumnia's maternity and her appropriation of the Roman concept of honour. The conclusion considers the strength of maternal authority and female power in Shakespeare's representations of maternal mourning

Orderly Spanning Trees with Applications

We introduce and study the {\em orderly spanning trees} of plane graphs. This algorithmic tool generalizes {\em canonical orderings}, which exist only for triconnected plane graphs. Although not every plane graph admits an orderly spanning tree, we provide an algorithm to compute an {\em orderly pair} for any connected planar graph $G$, consisting of a plane graph $H$ of $G$, and an orderly spanning tree of $H$. We also present several applications of orderly spanning trees: (1) a new constructive proof for Schnyder's Realizer Theorem, (2) the first area-optimal 2-visibility drawing of $G$, and (3) the best known encodings of $G$ with O(1)-time query support. All algorithms in this paper run in linear time.Comment: 25 pages, 7 figures, A preliminary version appeared in Proceedings of the 12th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2001), Washington D.C., USA, January 7-9, 2001, pp. 506-51

VI-Band Follow-Up Observations of Ultra-Long-Period Cepheid Candidates in M31

The ultra-long period Cepheids (ULPCs) are classical Cepheids with pulsation periods exceeding $\approx 80$ days. The intrinsic brightness of ULPCs are ~1 to ~3 mag brighter than their shorter period counterparts. This makes them attractive in future distance scale work to derive distances beyond the limit set by the shorter period Cepheids. We have initiated a program to search for ULPCs in M31, using the single-band data taken from the Palomar Transient Factory, and identified eight possible candidates. In this work, we presented the VI-band follow-up observations of these eight candidates. Based on our VI-band light curves of these candidates and their locations in the color-magnitude diagram and the Period-Wesenheit diagram, we verify two candidates as being truly ULPCs. The six other candidates are most likely other kinds of long-period variables. With the two confirmed M31 ULPCs, we tested the applicability of ULPCs in distance scale work by deriving the distance modulus of M31. It was found to be $\mu_{M31,ULPC}=24.30\pm0.76$ mag. The large error in the derived distance modulus, together with the large intrinsic dispersion of the Period-Wesenheit (PW) relation and the small number of ULPCs in a given host galaxy, means that the question of the suitability of ULPCs as standard candles is still open. Further work is needed to enlarge the sample of calibrating ULPCs and reduce the intrinsic dispersion of the PW relation before re-considering ULPCs as suitable distance indicators.Comment: 13 pages, with 14 Figures and 4 Tables (one online table). AJ accepte

"An Econometric Analysis of SARS and Avian Flu on International Tourist Arrivals to Asia"

This paper compares the impacts of SARS and human deaths arising from Avian Flu on international tourist arrivals to Asia. The effects of SARS and human deaths from Avian Flu will be compared directly according to human deaths. The nature of the short run and long run relationship is examined empirically by estimating a static line fixed effect model and a difference transformation dynamic model, respectively. Empirical results from the static fixed effect and difference transformation dynamic models are consistent, and indicate that both the short run and long run SARS effect have a more significant impact on international tourist arrivals than does Avian Flu. In addition, the effects of deaths arising from both SARS and Avian Flu suggest that SARS is more important to international tourist arrivals than is Avian Flu. Thus, while Avian Flu is here to stay, its effect is currently not as significant as that of SARS.

A Study of Online Customer Loyalty Based on the Theory of Planned Behavior

The Internet has introduced major changes in the way companies conduct business. Practically, rising numbers of customers are using the Internet for Electronic Commerce (EC). In the respect of customer relationship, Business-to-Consumer (B2C) EC provides ongoing information, service, and support that have changed the approaches of communication and interaction with customers. The nature of online customer behavior in the EC transaction is therefore different from the one in a traditional retailing channel. This research focuses on the online customer behavior through examining the relationship between the behavior intention and the online behavior itself. Based on the Theory of Planned Behavior (TPB), a base model of Online Customer Loyalty is developed. The research also proposes an alternative model in which Satisfaction is adopted as a mediated variable. Four hundred and twenty-three questionnaires are collected for the empirical experiment. The method of Structural Equation Modeling (SEM) is used to evaluate the measurement and structural models. The result indicates that TPB can be used to explain the behavior of Online Customer Loyalty. The structure relationship between Behavior Intention and Online Customer Loyalty is significant. The three constructs influencing Behavior Intention including Attitude toward Behavior, Subjective Norm and Perceived Behavioral Control also have indirectly positive effects on the behavior of Online Customer Loyalty. The two competing models are compared. Both models are acceptable when judged by the criteria of goodness-of-fit measures. However, the alternative model has a higher explained proportion of variance in Online Customer Loyalty

Deep Reinforcement Learning for Resource Management in Network Slicing

Network slicing is born as an emerging business to operators, by allowing them to sell the customized slices to various tenants at different prices. In order to provide better-performing and cost-efficient services, network slicing involves challenging technical issues and urgently looks forward to intelligent innovations to make the resource management consistent with users' activities per slice. In that regard, deep reinforcement learning (DRL), which focuses on how to interact with the environment by trying alternative actions and reinforcing the tendency actions producing more rewarding consequences, is assumed to be a promising solution. In this paper, after briefly reviewing the fundamental concepts of DRL, we investigate the application of DRL in solving some typical resource management for network slicing scenarios, which include radio resource slicing and priority-based core network slicing, and demonstrate the advantage of DRL over several competing schemes through extensive simulations. Finally, we also discuss the possible challenges to apply DRL in network slicing from a general perspective.Comment: The manuscript has been accepted by IEEE Access in Nov. 201

Nanocrystalline diamond microstructures from Ar/H2/CH4-plasma chemical vapour deposition

[[abstract]]The incorporation of H2 into Ar plasma was observed to markedly alter the microstructure of diamond films. The addition of a small percentage of H2 (<1.5%) into the Ar plasma leads to the presence of stacking faults in plate-like diamond grains, the incorporation of 75% H2 induces the formation of the diamond polymorph (8H). Optical emission spectroscopy indicated that addition of H2 into the Ar/CH4 plasma decreased the CH/C2 ratio and increased the proportion of atomic hydrogen. The small proportion of atomic hydrogen in 1.5%H2–Ar plasma can only induce the formation of (111) stacking faults, resulting in scarcely distributed plate-like diamond grains. The large proportion of atomic hydrogen in 75%H2–Ar plasma causes the rapid growth of diamond grains, leading to the formation of polymorphs of diamond lattices. The tuning on the microstructure of the UNCD films by incorporating either small or large amounts of H2 in Ar-plasma can be attributed to the interaction of H-species with the grain boundary hydrocarbons. Such a capability opens up the potential for applications of UNCD films. Despite the complication in granular structure resulted from the CH4/(Ar–H2) plasma chemical vapour deposition, the formation of microstructures can be explained by the same pathway, the competition of the processes (i) formation of a hydrocarbon passivation layer and the re-activation of the hydrocarbon layer and (ii) secondary nucleation and the enlargement of diamond grains.[[incitationindex]]SCI[[booktype]]電子

Usability Evaluation And Correspondence Analysis Of Smartphone Operating Systems

User-centered smartphone interface design is important so that consumers can easily learn about and begin to use newly purchased smartphones. This study first evaluates the effectiveness, efficiency, and user satisfaction of smartphone interfaces in Taiwan in terms of two representational operating systems: Android and iPhone OS. The usability evaluation includes observational experiments, user questionnaires, and the Wilcoxon sign-rank test. This study then conducts the correspondence analysis to summarize positive/ negative evaluations of usage and specification for smartphone OS. In observational experiments, a total of 48 participants with no previous smartphone experience on using smartphone with Android and iPhone OS are asked to perform five common phone tasks. All experiments are recorded and observed. Results and observations are discussed to attain a closer match between user needs and the performance of smartphone OS