Asymptotic Optimality in Byzantine Distributed Quickest Change Detection

Abstract:The Byzantine distributed quickest change detection (BDQCD) is studied, where a fusion center monitors the occurrence of an abrupt event through a bunch of distributed sensors that may be compromised. We first consider the binary hypothesis case where there is only one post-change hypothesis and prove a novel converse to the first-order asymptotic detection delay in the large mean time to a false alarm regime. This converse is tight in that it coincides with the currently best achievability shown by Fellouris et al.; hence, the optimal asymptotic performance of binary BDQCD is characterized. An important implication of this result is that, even with compromised sensors, a 1-bit link between each sensor and the fusion center suffices to achieve asymptotic optimality. To accommodate multiple post-change hypotheses, we then formulate the multi-hypothesis BDQCD problem and again investigate the optimal first-order performance under different bandwidth constraints. A converse is first obtained by extending our converse from binary to multi-hypothesis BDQCD. Two families of stopping rules, namely the simultaneous d-th alarm and the multi-shot d-th alarm, are then proposed. Under sufficient link bandwidth, the simultaneous d-th alarm, with d being set to the number of honest sensors, can achieve the asymptotic performance that coincides with the derived converse bound; hence, the asymptotically optimal performance of multi-hypothesis BDQCD is again characterized. Moreover, although being shown to be asymptotically optimal only for some special cases, the multi-shot d-th alarm is much more bandwidth-efficient and energy-efficient than the simultaneous d-th alarm. Built upon the above success in characterizing the asymptotic optimality of the BDQCD, a corresponding leader-follower Stackelberg game is formulated and its solution is found.View less &nbsp;</p

A LITERATURE REVIEW OF SUSTAINABLE TOURISM (1990-2016): DEVELOPMENT TRAJECTORY AND FRAMEWORK

Purpose of the study—Tourism is one of the largest and fastest growing industries in the world. Just like an enterprise today, sustainability is the long-term objective pursued by tourism industry. However, little effort has been made to systematically provide sufficient information to academicians and practitioners who have great research interests in sustainable tourism. Therefore, this paper aims to figure out the knowledge mapping of sustainable tourism and to indicate its research hot spots and trends for future research. Methodology—This paper surveys the development trajectory of sustainable tourism using a literature review and classification of articles retrieved from 5 online databases with solo keyword “sustainable tourism” from 1900 to 2016. Main findings—Based on the scope of 641 articles, this study reveals that the number of publication on sustainable tourism has significantly increased since 2006. In addition, these articles are scattered across 125 journals and mostly published in 23 academic journals. The majority of targeted countries/regions for sustainable tourism focus on Asia, Europe and America. Limitation—Restricted to limited knowledge, we make a brief literature survey on sustainable tourism from 1990-2016 to explore how sustainable tourism and its applications have developed in this period. Originality/value—In fact, sustainable tourism is a belief and an overall concept in every tourism activities. Though this research has done lots, it still has rooms to make more complete. Finally, we present a conceptual framework integrating 13 classifications criteria derived from our analysis with 3247 keywords. Most interestingly, we further present a conceptual framework with a visual effect to operationalize the coverage of sustainable tourism. Based on our analysis, any researcher can easily find the popular and right journal to get into it, if he/she is in need, he/she also can roughly know its applications so far and completely get a whole picture of sustainable tourism quickly

THE ACUTE EFFECT OF UPPER EXTREMITY PLYOMETRIC TRAINING

The purpose of this study was to probe the acute effect of the performance of upper extremity muscle groups after the plyometric training intervention. The participants were 13 healthy male college students. The force transducers (300kg, 200 Hz) and EMG sensor (1000 Hz) were taken to diagnose the acute effects of strength and muscle activation done by upper extremity pre and post plyometric training (load :24kg, 12 repetiiion times Iset, 3 set), and pair t-test was taken to test the significance(a=.05). The result showed that the strength after the upper extremity plyometric training intervention obviously had decreased 8% (

ELEMENTARY SCHOOL BOYS’ SOCCER KICK SKILL ANALYSIS

The purpose of this study is aimed to analyze elementary school boys’ kicking skills on the perspective of motor skills. The data is collected by Vicon Motion Analysis System (250Hz). The parameters include the compare of the instant joint angles and the time proportion during the process of the kicking toward the different kick performance groups. The participants are 36 elementary boy soccer players (age: 11.7±0.3 yrs; height: 1.42±0.13 m; weight: 37.5±13.0 kg). The subjects were divided to two groups according to the instance kicking ball speed. The result indicated that the high ball speed group players have greater extremity joint angles than the low ball speed group. No difference was found on the time proportion during the process of the kicking. We suggest that the learning of kicking skill can start with the lower speed in the beginner stage