Complexity Analysis of Balloon Drawing for Rooted Trees

In a balloon drawing of a tree, all the children under the same parent are placed on the circumference of the circle centered at their parent, and the radius of the circle centered at each node along any path from the root reflects the number of descendants associated with the node. Among various styles of tree drawings reported in the literature, the balloon drawing enjoys a desirable feature of displaying tree structures in a rather balanced fashion. For each internal node in a balloon drawing, the ray from the node to each of its children divides the wedge accommodating the subtree rooted at the child into two sub-wedges. Depending on whether the two sub-wedge angles are required to be identical or not, a balloon drawing can further be divided into two types: even sub-wedge and uneven sub-wedge types. In the most general case, for any internal node in the tree there are two dimensions of freedom that affect the quality of a balloon drawing: (1) altering the order in which the children of the node appear in the drawing, and (2) for the subtree rooted at each child of the node, flipping the two sub-wedges of the subtree. In this paper, we give a comprehensive complexity analysis for optimizing balloon drawings of rooted trees with respect to angular resolution, aspect ratio and standard deviation of angles under various drawing cases depending on whether the tree is of even or uneven sub-wedge type and whether (1) and (2) above are allowed. It turns out that some are NP-complete while others can be solved in polynomial time. We also derive approximation algorithms for those that are intractable in general

Relationship among Expectation, Motivation, and Intention of Chinese Cruise Travelers

School of Hotel and Tourism ManagementOther conference pape

From Brand Identity to Brand Equity: A Multilevel Analysis of the Organization–Employee Bidirectional Effects in Upscale Hotels

Purpose: This study examines the mechanism of how hotel executive brand identity influences physical facility quality and customer-based brand equity (CBBE) and employee-based brand equity (EBBE). Design: The study introduces a multilevel model and collects 925 executive and 1,978 employee responses from 62 upscale hotels in China. Findings: Executive brand identity positively affects employee brand internalization, which leads to positive EBBE. Meanwhile, executive brand identity positively influences the physical facility quality, which leads to positive CBBE. Practical implications: Once hotel executives have a clear understanding of the brand identity, they will provide the necessary leadership in imparting the brand identity on their employees. Hotel executives must also convince owners of the value of physical facility quality to achieve a desirable CBBE. Originality/Value: This study considers the tangible (physical facilities) and intangible (employees) elements of hotel services to comprehensively investigate the brand equity (BE) formation. By applying multilevel structural equation modeling (SEM), the study examines the bidirectional relationship between organizations and employees in the brand value transformation process

Bandwidth Improvement of MMIC Single-Pole-Double-Throw Passive HEMT Switches with Radial Stubs in Impedance-Transformation Networks

In this paper, we propose a new configuration for improving the isolation bandwidth of MMIC single-pole-double-throw (SPDT) passive high-electron-mobility transistor (HEMT) switches operating at millimeter frequency range. While the conventional configuration adopted open-stub loading for compensation of the off-state capacitance, radial stubs were introduced in our approach to improve the operational bandwidth of the SPDT switch. Implemented in 0.15 m GaAs pHEMT technology, the proposed configuration exhibited a measured insertion loss of less than 2.5 dB with better than 30 dB isolation level over the frequency range from 33 GHz to 44 GHz. In terms of the bandwidth of operation, the proposed configuration achieved a fractional bandwidth of 28.5% compared to that of 12.3% for the conventional approach. Such superior bandwidth performance is mainly attributed to the less frequency dependent nature of the radial stubs

Comparing Motivations and Intentions of Potential Cruise Passengers from Different Demographic Groups: The Case of China

The cruise industry is the fastest growing leisure market in the world. As an essential component, the cruise market in China is growing rapidly over the recent years with the introduction of favorable government policies, new cruise terminals, and increased cruise awareness of customers. Unfortunately, only few studies have investigated the perceptions of Mainland Chinese consumers toward such industry. Hence, by adopting qualitative and quantitative research methods, this study explored how the motivation and intention of potential cruise consumers differed in terms of their demographic background. Travelers from different age, income, and marital status groups demonstrated varying cruise motivations and intentions. The influences of motivation factors on the cruise intention of consumers were also explored. Both the theoretical and practical contributions of the study were put forward accordingly

Estimation of conditional average treatment effects with high-dimensional data

Ministry of Education, Singapore under its Academic Research Funding Tier

High-definition vertically aligned liquid crystal microdisplays using a circularly polarized light

A high-definition vertically aligned liquid crystal (LC) microdisplay exhibits a excellent contrast ratio, but its fringing field effect splits the bright state unevenly and leads to a very slow response time. By utilizing a circularly polarized light instead of conventional linearly polarized light, we have overcome the long-standing problems of poor sharpness, low brightness, and slow response time. Confirming computer simulations agree with the experimental results well. This approach can be applied to both reflective and transmissive LC microdisplays