Considerations for sustainable tourism development in developing countries: Perspectives from the South Pacific

Nations of the South Pacific face a number of major challenges with respect to sustainable tourism development. Much of the literature presents overtly pessimistic conceptualisations of South Pacific nations as environmentally vulnerable and economically dependent. This paper argues that the narrative concerning sustainable tourism development in the South Pacific is incomplete and the predominant narrative viewing the South Pacific nations as economically and environmentally vulnerable is too simplistic. Additionally, this paper challenges the narrative that high or mass levels of tourism within the South Pacific cannot be sustainable. Based on experience derived from operational experience and consultancy, this paper provides insights into the challenges and possibilities for sustainable tourism development in the South Pacific

Using Intelligent Prefetching to Reduce the Energy Consumption of a Large-scale Storage System

Many high performance large-scale storage systems will experience significant workload increases as their user base and content availability grow over time. The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) center hosts one such system that has recently undergone a period of rapid growth as its user population grew nearly 400% in just about three years. When administrators of these massive storage systems face the challenge of meeting the demands of an ever increasing number of requests, the easiest solution is to integrate more advanced hardware to existing systems. However, additional investment in hardware may significantly increase the system cost as well as daily power consumption. In this paper, we present evidence that well-selected software level optimization is capable of achieving comparable levels of performance without the cost and power consumption overhead caused by physically expanding the system. Specifically, we develop intelligent prefetching algorithms that are suitable for the unique workloads and user behaviors of the world\u27s largest satellite images distribution system managed by USGS EROS. Our experimental results, derived from real-world traces with over five million requests sent by users around the globe, show that the EROS hybrid storage system could maintain the same performance with over 30% of energy savings by utilizing our proposed prefetching algorithms, compared to the alternative solution of doubling the size of the current FTP server farm

Transcending the self to transcend suffering

Suffering is inevitable in human life. Our perspective paper theorizes on precise mechanisms for how self-transcendence—the state in which an individual looks beyond the self and adopts a larger perspective including concern for others and the world—may help people endure the experience of suffering. From an examination of empirical literature ranging from social psychology to clinical research, we propose that self-transcendence may aid the endurance of suffering along three psychological levels: (1) On the level of affect, the unique profundity and positivity of self-transcendent experiences (e.g., awe, flow, compassion) may supersede and reduce the salience of negative affect arising from suffering (e.g., fear, despair, depressive mood). (2) On the level of cognition, the larger frame of reference provided by self-transcendent thinking may contextualize one’s suffering as something comprehendible, thereby helping to resolve the challenges of making meaning from suffering (e.g., that one’s existing meaning systems are unable to explain the suffering event). (3) On the level of motivation, the drive to fulfill one’s need for self-transcendence may counterbalance the more hedonically-oriented motivations that can promote negative coping strategies in response to suffering (e.g., avoidance, substance abuse). All three mechanisms may also provoke downstream prosocial behaviors that help embed the individual into networks of social support. Altogether, by synthesizing specific mechanisms from affective, cognitive, and motivational self-transcendent processes, our paper establishes a theoretical framework for how self-transcendence may help people endure and transcend suffering, thereby elevating the conditions and experiences of our existence

FEA simulation studies of accelerated aging of power cables in water tanks

IEEE Standard 1407 provides guidance on accelerated insulation aging experiments on multiple medium voltage (MV) power cables using water-filled tanks. An applied cable current increases the temperature within the water tank and thus provides the accelerated aging conditions for the cables. Understanding the precise nature of the temperature distribution within the water tank and within the cable insulation is important to quantify and calculate the effective aging of the cables. This paper presents initial finite element analysis (FEA) simulation studies that evaluate the temperature distribution within a water filled tank and across submerged power cables when multiple cables are supplied with current. Two scenarios are evaluated and compared, namely the temperature profiles of cables when the water in the tank is treated (a) as a solid material, and (b) as a fluid with natural convection. The importance of applying effective water circulation mechanisms are also highlighted

Network coding based wireless broadcast with performance guarantee

Wireless broadcast has been increasingly used to deliver information of common interest to a large number of users. There are two major challenges in wireless broadcast: the unreliable nature of wireless links and the difficulty of acknowledging the correct reception of every broadcast packet by every user when the number of users becomes large. In this paper, by resorting to stochastic geometry analysis, we develop a network coding based broadcast scheme that allows a base station (BS) to broadcast a given number of packets to a large number of users, without user acknowledgment, while being able to provide a performance guarantee on the probability of successful delivery. Further, the BS only has limited statistical information about the environment including the spatial distribution of users (instead of their exact locations and number) and the wireless propagation model. Performance analysis is conducted. On that basis, an upper and a lower bound on the number of packet transmissions required to meet the performance guarantee are obtained. Simulations are conducted to validate the accuracy of the theoretical analysis. The technique and analysis developed in this paper are useful for designing efficient and reliable wireless broadcast strategies

Accurate Group Delay Measurement for Radial Velocity Instruments Using the Dispersed Fixed Delay Interferometer Method

The dispersed fixed-delay Intereferometer (DFDI) method is attractive for its low cost, compact size, and multiobject capability in precision radial-velocity (RV) measurements. The phase shift of fringes of stellar absorption lines is measured and then converted to an RV shift via an important parameter, phase-to-velocity scale (PV scale), determined by the group delay (GD) of a fixed-delay interferometer. Two methods of GD measurement using a DFDI Doppler instrument are presented in this article: (1) GD measurement using white-light combs gen- erated by the fixed-delay interferometer and (2) GD calibration using an RV reference star. These two methods provide adequate precision of GD measurement and calibration, given the current RV precision achieved by a DFDI Doppler instrument. They can potentially be used to measure GD of an fixed-delay interferometer for submeter- precision Doppler measurement with a DFDI instrument. Advantages and limitations of each method are discussed in detail. The two methods can serve as standard procedures of PV-scale calibration for DFDI instruments and cross- checks for each other.Comment: 19 pages, 7 figures, 3 tables, accepted by PAS

The First Hypervelocity Star from the LAMOST Survey

We report the first hypervelocity star (HVS) discovered from the LAMOST spectroscopic survey. It is a B-type star with a heliocentric radial velocity about 620 km/s, which projects to a Galactocentric radial velocity component of ~477 km/s. With a heliocentric distance of ~13 kpc and an apparent magnitude of ~13 mag, it is the nearest bright HVS currently known. With a mass of ~9Msun, it is one of the three most massive HVSs discovered so far. The star is clustered on the sky with many other known HVSs, with the position suggesting a possible connection to Galactic center structures. With the current poorly-determined proper motion, a Galactic center origin of this HVS remains consistent with the data at the 1sigma level, while a disk run-away origin cannot be excluded. We discuss the potential of the LAMOST survey to discover a large statistical sample of HVSs of different types.Comment: 5 pages, 5 figures, accepted for publication in ApJL, updated contour plot for the ejection positions after correcting a mistake in the calculatio